Marine asset security and tracking (mast) system

MARINE ASSET SECURITY AND TRACKING (MAST) SYSTEM

<b>STATEMENT REGARDING RIGHTS TO INventionS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT</b>

This invention was made with U.S. federal support under prime contract number (DE-AC05-00OR22725) awarded to UT-Battelle, LLC by the U.S. Department of Energy. The United States Government has certain rights in this invention.

Embodiments of the present invention relate generally to the field of security and tracking. More specifically, embodiments of the present invention relate to maritime asset security and tracking (MAST).

The global maritime-traffic freight transport infrastructure, known as the Maritime Transport Management System (MTS), is affected by terrorism, obsolete technology, environmental constraints, on-time manufacturing practices, overlapping national/federal/regional jurisdictions, and It is under pressure from a number of issues, including a lack of basic technology infrastructure. Terrorist attacks can focus on economic terrorism to influence the upheaval of the modern world. In order to find a simple, effective and efficient means of large-scale economic damage, it is necessary to look at the open movement of container cargo (RFID Journal, 2003). Disruption or cessation of flow in several important ports can damage the national economy and render the country incapacitated in approximately a few weeks (Flynn, 2003). Consequently, there is a need to develop and deploy tracking and monitoring technologies at the container level to help secure the global supply chain and critical port facilities that provide economic prosperity for home and other countries (Gills and McHugh, 2002; Bonner, 2002; Verton, 2002).

Ports are open to federal officials (e.g., U.S. Customs Service, Coast Guard, DOD, TSA, FBI, etc.), state officials (e.g., Port Authority, state law enforcement, emergency preparedness, etc.) and local officials ( It is an assembly of many facilities, entities, and functions, including, for example, local law enforcement, local fire agencies, port security, and commercial terminal operators, trade unions, etc.). The development of additional facilities to network the critical components of operations at each port to provide port security/management and shipping/cargo security/tracking/management will aid efficient use and security of each port. Consequently, these regional port facilities must be linked to regional centers and/or national centers with potential for international expansion. As a result, geographic information systems (GIS), global satellite communications, Internet and wireless monitoring, in managing/secured the current supply chain, preferably with open systems, to engage multiple public and private entities. You need to adopt techniques like /tracking/security infrastructure.

Contributed $750 billion to U.S. gross domestic product in calendar year 1999, and the volume of shipments via the Maritime Transportation System (MTS), totaling $480 billion of cargo, and the volume of current domestic ocean shipments is expected to double over the next 20 years. (USDOT, 1999). International shipping shipments are expected to triple over the same period (Prince, 2001). Outdated technology, environmental constraints, on-time manufacturing practices, overlapping federal/national/regional jurisdictions, and the underlying technical infrastructure in many port facilities safely and efficiently coordinating container management systems. It is under economic pressure from several of the above-mentioned problems, including a lack of structure. In addition, onshore competition and environmental regulations will constrain the geographic expansion of most current port facilities. Information systems responsible for the management of containers still rely heavily on manual data entry. Consequently, there is a need for automated technical solutions to increase the efficiency and security of port facilities (Gills and McHugh, 2003; Verton, 2002; Gillis, 2002).

In addition to concerns about MTS's economic inefficiency, MTS currently places an unprecedented emphasis on national security. In 2001, 5.7 million containers entered the United States via MTS (Gills and McHugh, 2002). The US Customs Service relies on information on "profile" containers to manually inspect less than 2% of these containers. The Coast Guard and US Customs do not have the manpower or resources to manually inspect each container entering the United States, which would result in a catastrophic disruption to the supply chain (Loy, 2002). Intelligent profiling of cargo and containers is critical to enabling secure and legitimate commerce in global supply chains. Tracking and monitoring will provide better data for building intelligent profiles. Therefore, investment in appropriate tracking and monitoring technology is required as a key to increased security and economic efficiency (Flynn, 2003).

An important concern in container freight transport is the relative ease with which radioactive materials or nuclear fusion devices for "contaminated bombs" can be smuggled into the shipping container's target country. A particular issue important to national security is the potential shipment of radioactive material to the United States in shipping containers for "contaminated bombs." Standard sea shipping containers have become the predominant method of importing and exporting goods worldwide. Since the number of containers entering and leaving US ports every day is very large, only a small fraction is being investigated. Since only a small portion of the containers can be irradiated, some method must be used to "flag" containers for inspection. Positioning sensor portals that each container must pass through at each port facility are considered impractical. Working disability could cost the US economy billions of dollars every day. The use of radiation sensors in, on, or near containers to look for rises in radiation levels would be one way to flag containers.

However, there are problems with existing radiation sensors proposed in shipping containers. First, conventional radiation sensors must use power during a dose integration (active detection) time. Existing actinic radiation sensors will have to use very short integration times, which will weaken their sensitivity or consume available battery power long before the end of the container's service life. Replacing batteries requires personal maintenance time, coordination and logical support between the maintenance schedule and the physical location of the container. Radiation sensors with longer, non-hazardous service life will be needed.

Second, existing active radiation sensors do not produce dose integral data available for uninterrupted monitoring of the security of each container. Reading the dose integral data requires each sensor to be removed and read, or at least individually read, which causes the same problems as expensive personal maintenance time, coordination and logical support between the data collection schedule and the physical location of the container. Intelligent profiling and analysis will require radiation sensors that automatically and remotely generate available dose integral data.

Third, existing active radiation sensors are prone to false alarms. Existing actinic radiation sensors cannot distinguish between different types of radioactivity, from substances used in medical diagnostics, and even bananas that naturally contain concentrations of ionizing radioactive substances (eg potassium). False alarms from benign cargo such as More sophisticated, differential radiation sensors will be needed.

To date, container-level tracking and monitoring requirements by long-lived sensors for automatically, remotely usable critical data for intelligent profiling and analysis have not been met. There will be a need for a universal container security and asset (ship and cargo) tracking system that meets these requirements (preferably both simultaneously).

The following examples of the invention will be needed. Naturally, the present invention is not limited to these embodiments.

According to an embodiment of the present invention, a method comprises transmitting identification data, location data and environmental condition sensor data from a radio frequency tag. According to another embodiment of the present invention, a device comprises a radio frequency tag for transmitting identification data, location data and environmental condition sensor data.

According to another embodiment of the present invention, a method includes transmitting identification data and location data from a radio frequency tag using hybrid spread spectrum modulation. According to another embodiment of the present invention, an apparatus includes a radio frequency tag that transmits both identification data and location data using hybrid spread spectrum modulation.

According to another embodiment of the present invention, a method comprises transmitting dosimetric data from first passively integrated ionizing radiation sensors and from second passively integrated ionizing radiation sensors. a suite) in situ polling of passive integral ionizing radiation sensors, wherein the first passive integral ionizing radiation sensors and the second passive integral ionizing radiation sensor have radiation dosimetry data It is positioned where it is integrated as it is read. According to another embodiment of the present invention, an apparatus comprises: a first passive integral ionizing radiation sensor; a second passively integrated ionizing radiation sensor coupled to the first passively integrated ionizing radiation sensor; and a communication circuit coupled to the first passively integrated ionizing radiation sensor and the second passively integrated ionizing radiation sensor, wherein the first passively integrated ionizing radiation sensor and the second passively integrated ionizing radiation sensor include: and transmits the quantity measurement data to the communication circuit.

According to another embodiment of the present invention, a method comprises the steps of: arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering the alarm condition when the dose level of the ionizing radiation source is calculated to exceed the threshold. According to another embodiment of the present invention, an apparatus comprises a plurality of ionizing radiation sensors arranged in a spatially dispersed array, wherein the relative position of each array of plurality of sensors is determined to define a volume of interest; a data collection circuit coupled to the plurality of ionizing radiation sensors to collect ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and a computer coupled to the data collection circuitry to i) calculate a dose level of the ionizing radiation source and compare the dose level with a threshold, and ii) trigger an alarm when the dose level matches or is greater than the threshold. .

The above and other embodiments of the present invention will be better read and understood by reference to the following detailed description and accompanying drawings. However, while the following detailed description sets forth various embodiments of the invention and numerous specific details thereof, it is to be understood that these are provided by way of illustration and not limitation. Many substitutions, modifications, additions and/or reconstructions may be made within the scope of the present invention without departing from the spirit of the present invention, and embodiments of the present invention cover all such substitutions, modifications, additions and/or reconstructions. or reconstructions.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of this specification, are included to illustrate certain embodiments of the present invention. Embodiments of the present invention, a clearer idea of components combinable with the embodiments, and operation of the systems provided in the embodiments will be more apparent by reference to exemplary and non-limiting embodiments shown in the drawings. will do Embodiments of the present invention may be better understood by reference to one or more of these drawings in connection with the detailed description presented herein. It should be noted that features shown in the drawings are not necessarily drawn to scale.

1 is an overall schematic diagram of a Maritime Asset Security and Tracking (MAST) system representing an embodiment of the present invention;

2 is a radio frequency RF data link operation for use both on board and a terminal having radio frequency identification (RFID) tags capable of communicating simultaneously with shore-based and ship-based receivers, representing an embodiment of the present invention; is a schematic diagram of

3 illustrates an embodiment of the present invention, when tags use RF for local-area communications (eg, for onboard and terminal local area (land-side) operations), land-side and on-board site; It schematically shows communications between RFID tags and a network operations center (NOC) via a site server.

Figure 4 schematically illustrates two-way communications between RFID tags and a Network Operations Center (NOC) when using cellular or satellite communications over road or during rail transport, representing an embodiment of the present invention.

5 is a schematic block diagram of functional elements comprising an RFID tag, representing an embodiment of the present invention.

6 is an overall schematic diagram of readers and RFID tags in the context of containers in a stacked array, representing one embodiment of the present invention.

7 is a flowchart of an RFID tag boot-up sequence including a node discovery sequence mode that may be performed by a computer program, representing an embodiment of the present invention.

8 is a flowchart of an RFID tag start sequence mode that may be performed by a computer program, representing an embodiment of the present invention.

9 is hermetically stacked (at a nominal value of 40 feet) on the deck or within the terminal yard of a vessel having a single RF emitter (indicated as a radiating dot) mounted near the center of the top of a host container, representing one embodiment of the present invention; A schematic top plan view of a group of containers, where arrows indicate RF energy leaking from the ends of the container into adjacent aisles and then reflecting along the aisles, with potential RF receiving locations located at the ends of the aisles. It is indicated by the positioned dots.

10 is a schematic block diagram of a set of sensors polled in situ, representing one embodiment of the present invention, where each sensor has a different filter.

11 is a schematic structural diagram of an in situ polled sensor with integrated temperature compensation, representing an embodiment of the present invention.

Embodiments of the present invention, various features and advantageous details thereof are more fully described with reference to the non-limiting embodiments shown in the accompanying drawings and illustrated in the detailed description which follows. Descriptions of well-known starting materials, processing techniques, components, and equipment are omitted so as not to unnecessarily obscure embodiments of the invention in detail. However, while the detailed description and specific examples represent preferred embodiments of the present invention, it is to be understood that they are provided by way of example only and that the present invention is not limited thereto. Various substitutions, modifications, additions and/or reconstructions that fall within the scope and/or spirit of the inventive concept below will become apparent to those skilled in the art from this disclosure.

The US patents, published PCT applications and US patent applications designating the US, which are hereby incorporated by reference, disclose embodiments useful for the purposes for which they are intended. Herein, the entire contents of U.S. Patent Nos. 6.603.818, 6,606,350, 6,625,229, 6,621,878, 6,556,942 are incorporated herein by reference for all purposes. The entire contents of published PCT applications WO 02/27992, WO 02/19550, WO 02/19293, and WO 02/23754 are incorporated herein by reference for all purposes. U.S. Patent Application Nos. 09,671,636 (filed September 27, 2000), 09,653,788 (filed September 1, 2000), 09/942.308 (filed August 29, 2001), 09/ 660,743 (filed September 13, 2000), 10/726,446 (filed December 3, 2003), 10/726,475 (filed December 3, 2003), and 10/817,759 The entire contents of the issue (filed December 31, 2003) are incorporated herein by reference for all purposes. This application also includes disclosures that are also incorporated in a currently pending, co-pending US patent application filed on May 6, 2004 (Attorney Docket No. UBAT1570), which in its entirety is incorporated herein by reference in its entirety. It is incorporated herein by reference for all purposes.

One embodiment of the present invention may include a method and/or apparatus for monitoring the status and tracking of shipping containers at a terminal on board, and during transport by road (truck and rail). Accordingly, the present invention may include a truly "inter-modal" tracking and monitoring system. The method and/or apparatus may utilize hybrid spread spectrum (HSS) communications for robust two-way data transmission to and from containers on board and at shipping terminals. The phrase "hybrid spread spectrum (HSS)," as used herein, is as described, for example, by US Patent Application Serial No. 10/817,759, filed December 31, 2003 and/or published PCT Application WO 02/27292. Direct sequence spread spectrum (DSSS), such as code division multiple access (CDMA), and frequency hopping, time hopping, time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM) and/or space division multiplexing It is defined as a combination of at least one of access (SDMA). Fast HSS is a particularly preferred embodiment, where spreading and hopping occur during one bit time (ie, each bit is spread and hoped individually). The present invention may utilize cellular and/or satellite data transmissions for communications during on-road transportation. Sensors that monitor container cargo status and conditions may be included in the system. The location of the container can be determined during transportation on the road by using a universal positioning system (GPS) and by using more local radiolocation techniques that use RF signals of HSS communication. The location and status of containers may be relayed to a national operations center, which combines this data with manifests in a geographic information system database for monitoring, tracking, management and display of container information.

One embodiment of the present invention provides maritime asset security and tracking linking robust long-range RFID technology and GIS-based tracking infrastructure over a universal satellite network to create a truly universal asset management and cargo tracking/visualization system using an open systems architecture. (MAST) system. The MAST system is incorporated to provide real-time ship/road/rail container and freight tracking in an environment of open systems architecture for port and supply chain security needs. This tracking technology is used in a number of commercial applications including national security, supply chain management, port automation, insurance applications and potential recovery/rescue of nuisance cargo lost in the commercial market to finance the expansion and adoption of the system. will create opportunities. The MAST system initiative will also facilitate the development of new standards and "best practices" practices for tracking and security monitoring of containerized cargo and assets.

The present invention can be designed to provide real-time asset, container and cargo tracking for port security/management needs while increasing the safety of life and property across intermodal transport networks. The ability to track containers in real-time on a universal basis, along with internal condition monitoring, is essential to the security of supply chains and port systems. Preferred HSS, two-way low power wireless communications will work well in the environment of ship and/or terminal communication distances (eg, in the range of 300 to 500 meters) at a power of approximately 10 mW.

RF propagation issues within and around hermetically stacked steel shipping containers are addressed by very robust data-communication techniques (eg, to successfully transmit telemetry signals from each container RF tags to ship receivers (readers)). for example, improved spread spread modulation and diversity receiving systems). The purpose of very accurate radiolocation of these containers, especially in large, hermetically packed stacks of ships' docks, is that many receivers (readers) across the yard facilities, across each ship's decks and docks. It will not be achieved if it is not dispersed. If some loss of positioning is tolerable in normal operation, in most cases carefully manufactured container RF tags, adapted for their deployment to special environments (ie yards or ships). and the use of infrastructure components allows for effective remote access of container ID and status data (eg door security, temperature) and fairly accurate container location information (ie information within a stack location) in most special environment cases. Measurements shall be provided.

A preferred MAST system implementation may use the 2450 to 2483.5 MHz ISM band in accordance with international regulations, particularly for ships loaded in foreign ports. Moreover, foreign port facilities will undoubtedly eventually use some form of RF telemetry for tracking containers. If the MAST system is suitable for the international allocation of the 2.4 GHz ISM band, it will be adopted worldwide to track shipping containers (first in ports, and consequently in other places such as railways, airplanes and trucks). ). For narrowband system warning signals, beacons, etc., other ISM band possibilities include 13.56 and 433 MHz slots, while the 868 MHz (Europe) and 915 MHz (North America) bands are somewhat wider for high-speed and spread-out use. to provide. The data protocol of commercial embodiments of the present invention has very wide bandwidths (&gt;1 MHz), long code lengths (eg 63) for better process gain, jamming resistance, and lower collision statistics. ) can be a hybrid or direct-sequence spread spectrum signal with

To deploy a MAST system in a maritime (yard/ship) environment, several areas of functionality must be coupled into the system. The first functional group includes the basic architecture of a marine-based system, which includes (1) communication links, (2) antennas, (3) electronics, (4) container-based power sources, (5) Ship-to-shore system interface, e.g. satellite link, (6) container telemetry system integration, (7) container position detection [GPS, optionally augmented by local RF triangulation], (8) sensors, ( 9) system central monitoring units, and (10) container database interfaces. The second functional group includes the port container-yard system, which is very identical in setup and functionality on board except that additional system logic is needed to manage the tracking system handoff between the vessel and yard systems.

<b>One. summary</b>

1 , one or more radio frequency identification tags 101 coupled to containers 105 are in two-way radio frequency communication with a reader 107 on a vessel 110 . The vessel 110 also includes a site server (not shown in FIG. 1 ), but is in two-way radio frequency communication with a low earth orbit satellite 120 . The low orbit satellite 120 is in two-way radio frequency communication with the ground station 125 .

Simultaneously, another radio frequency identification tag 102 (carried by the chassis of the truck) and an associated transport container 106 are also in contact with the low orbit satellite 120 . It should be noted that the radio frequency identification tag 102 may also (alternatively and/or concurrently) communicate with the cell tower 130 . Although the radio frequency identification tag 102 is shown in direct communication with the low orbit satellite 120 and/or the cell tower 130, the radio frequency identification tag 102 communicates with a reader and/or site server located on the undercarriage of the truck. It should be noted that it can be relayed through

The network operations center 140 is in bidirectional communication with the ground station 125 and the cell tower 130 . The Network Operations Center (NOC) also downloads the data to multiple recipients, including, in this embodiment, Customs, the Department of Defense, the National Transportation Security Administration, the National Security Council, the US Coast Guard, the FBI, and commercial officials.

The Maritime Asset Security and Tracking (MAST) system shown in FIG. 1 is a maritime industry-standard 20 ft and 40 ft shipping container during loading, unloading, and hauling operations at port-side wharf facilities, and during offshore transportation of containers on board. It is a radio (RF)-based communication and sensing/telemetry system for tracking and monitoring devices. This system utilizes both local-terminal communication systems and other wide area commercial communication systems (including satellite and/or cellular/PCS) on ships, railroads, aircraft, on-road trucks, and their associated It can provide a true intermodal tracking and monitoring system that can operate within terminal facilities. This RFID tag system includes RFID tags attached to each shipping container, local site readers located throughout the vessel and at shipping terminals, a central site server on each vessel or at each terminal, and a network operations center (NOC). - where all data is collected, combined, stored, analyzed, and disseminated). Shipping containers can be both refrigeration-freight shipping containers (refrigeration vessels) and dry-freight shipping containers (dry-boxes). In addition to identifying and tracking the location of containers or other equipment adapted to one of the RFID tags, each tag may be equipped with a (eg IEEE 1451) sensor interface and optionally additional serial interfaces. , this allows a wide range of sensors to be connected to RFID tags to monitor the status of containerized cargo or other tagged equipment. Sensors that may be coupled to an RFID tag include, but are not limited to, temperature, pressure, relative humidity, accelerometer, radiation, and Global Positioning System (GPS). Additional sensors may be included to monitor the condition of a machine, such as refrigeration compressors, or to read from a diagnostic data port on some refrigerated cargo containers.

The MAST system includes three main modes of operation, first when the RFID tag is on the ship, second when the RFID tag is on the terminal, and third when the RFID tag is transported by road or rail (which is (including all cases where the RFID tag is not on the ship or in the terminal). A terminal may be thought of as any local area served by an RF communication system. The RFID tag system comprises a) a Network Operations Center (NOC) - where the Network Operations Center may contain status and data regarding all RFID tags and associated cargo containers (or other assets) and provides this information to users. provides - with; b) Local site servers (there is one per ship or terminal) - where local site servers manage local-area communications (ie each ship or terminal) and can relay RFID tag data to a central system server there is - with; c) RFID tag readers, wherein the RFID tag readers receive communication from local area RFID tags and relay it to the local site receiver; and d) RFID tags.

2, the shore and/or vessel communication flexibility of the present invention is illustrated. A first radio frequency identification tag 201 coupled to a first container 211 is communicatively coupled to a plurality of radio frequency identification tag readers 221 , 222 , 223 and 224 positioned on the vessel 230 . . A plurality of radio frequency identification tag readers 221 , 222 , 223 and 224 are communicatively coupled to a site server 235 on the vessel 230 . The site server 235 is communicatively coupled to a satellite (in FIG. 2, not shown), but is also communicatively coupled to a network operations center.

A second radio frequency identification tag 202 coupled to the second container 212 is communicatively coupled to the plurality of radio frequency identification tag readers 221 , 222 , 223 and 224 , and is also simultaneously located within or around the terminal. communicatively coupled to a plurality of site radio frequency identification tag readers 241 and 242 located on light poles or towers. A plurality of site radio frequency identification tag readers 241 and 242 are communicatively coupled to a site server 250 associated with the terminal. The site server 250 is communicatively coupled to the network operations center via a satellite data link or other communication circuit (eg, a hardwire Internet connection).

A third radio frequency identification tag 203 coupled to the third container 213 is communicatively coupled to the plurality of site radio frequency identification tag readers 241 and 242 . The third radio frequency identification tag 203 is not shown in communication with the plurality of radio frequency identification tag readers 221 , 222 , 223 and 2240 , but if the third container 213 is physically near the vessel 230 , It should be noted that it can be communicated when moving to .

Still referring to FIG. 2 , ship or terminal communication RFID tags may use RF communications to communicate with RFID tag readers. Preferred RF communications are hybrid spread spectrum (HSS) RF data links operating in the 2.45 GHz band. Radiolocation or triangulation of the RF signal from each tag can be used to determine the location of each RFID tag.

Referring to FIG. 3 , a network operations center 310 is bidirectionally coupled to a land-side site server 320 via an Ethernet or satellite data link. At the same time, the network operations center 310 is bidirectionally connected to the on-board site server 330 via a satellite data link.

The landside site server 320 is bidirectionally coupled to a first radio frequency identification tag reader 340 , a second radio frequency identification tag reader 350 and a third radio frequency identification tag reader 360 . It should be noted that, in this embodiment, the communication coupling between the site server 320 and the three tag readers 340, 350 and 360 may be one or more of a radio frequency wireless, power line, Ethernet or optical data link. A plurality of radio frequency identification tags located on terminal 345 are bidirectionally communicatively coupled to at least one of three tag readers 340 , 350 and 360 .

An onboard site server 330 is bidirectionally communicatively coupled to a fourth radio frequency identification tag reader 370 , a fifth radio frequency identification tag reader 380 and a sixth radio frequency identification tag reader 390 . It should be noted that the onboard site server 330 is coupled to the three tag readers 370 , 380 and 390 via one or more of a power line, radio frequency wireless or Ethernet data link. A plurality of radio frequency identification tags located on the vessel 375 are in bidirectional communication with at least one of the three tag readers 370 , 380 and 390 .

As shown in Figure 3, RFID tag communications are picked up by RFID tag readers in several possible ways: (a) an RF data link; b) Ethernet; c) powerline data link; d) light; and/or e) other methods) to the local site server. Once the tag data is relayed to the local site server, the data may be uploaded to the NOC by a satellite-based data link or other Internet service provider link (eg, Ethernet). Local site servers may also generate reports for use by local personnel, such as engineers on the ship. The NOC may in turn communicate tag commands, verifications and/or queries. The data for any particular container may be made available to any user around the world with Internet access and adequate security validity.

Referring to FIG. 4 , a network operations center 410 is coupled to a first cellular or satellite system 420 , a second cellular or satellite system 430 and a third cellular or satellite system. The two-way communication couplings between the network operations center 410 and the systems 420, 430 and 440 may be through a telephone line or base station connection. Each of the three systems 420 , 430 and 440 is associated with a subset of a plurality of radio frequency identification tags outside the local area (RF coverage) zone 450 . The two-way communication coupling between the three systems 420 , 430 and 440 with each subset of RFID tags outside the local-area zone 450 may be via a cellular or satellite data link.

For on-road and rail communications as shown in FIG. 4, RFID tags may be communicated to the NOC by cellular or satellite data links. A preferred method is direct satellite communications, since cellular does not provide worldwide coverage. The satellite or cellular system may relay the RFID tag data to the NOC via a base station (satellite) coupled to the NOC or via a modem bank (cellular) coupled to the NOC. Operation on the road may include all operations when the RFID tag is not on the ship or at the terminal (any local area served by the RF communication system). Each tag's GPS receiver can be used to track the container's movement and location while being transported on the road. It is preferred that the containers are not stacked during on-road operation. As is possible on some rail cars, if a tagged container is stacked on top of another container, the satellite or cellular modem data links and GPS system may not function. Other tagged containers in the stack may act as repeaters or repeaters (expanders) to the first container. More specifically, the first container may use HSS RF communications when other methods fail. The second container receives these communications with its HSS RF receiver, which can then relay them to the NOC using a satellite or cellular modem data link.

<b>2. RFID tag description</b>

Each RFID tag has four main functional blocks; (1) microprocessor control subsystem; (2) the sensor subsystem; (3) communication subsystem; and (4) a power supply subsystem. 5 shows a block diagram of an RFID tag.

Referring to FIG. 5 , the radio frequency identification tag 500 includes a microprocessor control subsystem 510 , a power subsystem 520 , a sensor subsystem 530 , and a communication subsystem 540 . Microprocessor control subsystem 510 includes input/output interface circuitry 511 . Microprocessor circuitry 512 is coupled to input/output interface circuitry 511 . A flash memory circuit 513 is coupled to the microprocessor circuit 512 . Random access memory circuitry 514 is also coupled to microprocessor circuitry 512 . The microprocessor circuit 512 is coupled to the power subsystem 520 via a power line 515 .

Power subsystem 520 includes power management module circuitry 521 . An AC to DC power circuit 522 is coupled to the power management module 521 . A battery 523 (eg, lithium ion) is coupled to the power management module 521 . An alternative power source 524 is coupled to the power management module 521 . Power subsystem 520 provides power to sensor subsystem 530 via a set of power lines 525 . Power subsystem 520 provides power to communication subsystem 540 via a set of power lines 526 .

Sensor subsystem 530 includes a serial interface 531 coupled to input/output interface circuitry 511 of microprocessor control subsystem 510 via line 532 . A temperature sensor 533 is coupled to the serial interface 531 . A relative humidity sensor 534 is coupled to the serial interface 531 . A door ajar sensor 535 is coupled to the serial interface 531 . Other sensors 536 (eg, ionizing radiation sensors) are coupled to the serial interface 531 . The sensor subsystem 530 includes a GPS module 537 coupled to the input/output interface circuit 511 of the microprocessor control subsystem 510 . The sensor subsystem 530 includes a refrigeration unit data port 538 coupled to an input/output interface circuit 511 of the microprocessor control subsystem 510 via an interface converter circuit 539 .

Communication subsystem 540 includes local/serial communication circuitry 541 , cellular modem module 542 , hybrid spread spectrum radio frequency module 543 , and satellite module 544 , all of which are line 545 . is coupled to the input/output interface circuit 511 of the microprocessor control subsystem 510 via One or more antennas 546 are coupled to the cellular modem module 542 , the hybrid spread spectrum radio frequency module 543 and/or the phase module 544 .

Microprocessor Control Subsystem: The microprocessor control subsystem may operate as a controller for the RFID tag. It can interface with the communication module, the sensor module, and the power modules. The microprocessor may use both non-volatile and volatile memory to store system software, system instructions, and sensor data.

Sensor Subsystem: The sensor subsystem may use IEEE 1451-compliant protocols to communicate with one or more sensor modules. This allows the addition of arbitrary sensors in the future as long as they are compliant with the 1451 protocol. Some basic sensors, such as GPS and refrigeration ship data port readers, can use serial communication ports on the microprocessor. Sensor types that may be part of RFID tags may include temperature, relative humidity, radiation, biological, chemical, accelerometer, door switch, intrusion, and the like.

Communication Subsystem: The communication subsystem allows a plurality of different types of communication links to be included in the tag platform. They may be connected, for example, via a serial port or an Ethernet port.

The basic communication modes are as follows.

RF CommunicationRF communication may take the form of any number of available wireless communication protocols. However, the preferred method is a hybrid spread spectrum protocol. This protocol provides higher reliability, lower power, and robust communications than other wireless technologies. RF communications may be intended for use when tags are primarily located on a ship or in a terminal (local-area communications).

Cellular/PCS CommunicationsStandard commercial cellular analog or digital modems such as CDMA or GSM may be used by the tag for on-road (truck or rail transport) communications. However, there is no standard cellular infrastructure installed worldwide. Thus, each tag requires several different protocols to operate over a limited market area. In addition to this, tags can travel through areas that do not have cellular coverage.

Satellite Communications - Uses satellite-based communications networks to provide an on-road communications link that can function anywhere in the world. This provides a simpler, more robust and more secure communication system as an alternative to or in addition to a cellular system. A preferred embodiment may use a low orbit (LEO) satellite network system.

Local communications - each tag developed. It may have a serial port used for troubleshooting and/or initial setup. The serial port can take the form of, for example, RS232, USB or IrDA (infrared).

Power Subsystem: The power subsystem can provide power to all other subsystems. Power sources that may be used include batteries, AC power (eg, from refrigeration power sources on refrigeration ships) and photovoltaic cells, vibration converters, electrostatic rechargeable batteries, radio frequency power rectifiers, thermo-electric generators and/or radioisotope decay energy recovery. other power scavenging and/or generating devices such as devices. For RFID tags located on assets other than containers, DC power from the asset electrical system may also be used. The power subsystem may convert the power supply voltage to a voltage required for each subsystem. It may also perform power management functions to monitor battery health and power availability.

<b>3. RFID tag reader</b>

RFID tag readers relay communication of RFID tags to (and from) the site server. RFID tag readers may be similar to RFID tags, but with different communication modules, optionally without sensors. RFID tag readers may communicate with RFID tags via a local RF communication module (preferably using HSS protocol). RFID tag readers may use one of several possible techniques: wireless RF communications (preferably HSS communications at a different frequency than RFID tag communications, such as eg 5.8 GHz), (powerline communications, such as Ethernet or serial) ) wireless communications, and/or optical communications (such as fiber optic or transceiver straight line laser communications).

Referring to FIG. 6 , a plurality of intermodal shipping containers 610 are stacked in a two tier height array. Each of the articulated shipping containers 610 includes a radio frequency identification tag 620 . A plurality of tag readers 630 are located at the ends of the open passageways defined by the two tire height arrays.

Another optional feature of the MAST system is the use of "hand-held (portable) readers" to read RFID tag data and cargo inventory directly from the container. The hand-held reader may be used by customs, coast guard, shippers or other authorized groups to verify the contents of the container and the status of the cargo (sensor data, movement history, etc.). A hand-held reader is located near the container and can then be operated. An appropriate identification code (or possibly barcode) may be entered into the hand-held reader, after which RF communications are used for the hand-held reader to communicate with the RFID tags. RF communications may preferably utilize HSS communications used for local terminal and ship communications. The RFID tag then downloads the container list (stored in the RFID tag or downloaded from the NOC via an uplinked request from the RFID tag) and the trip log of the container sensor(s) to the hand-held reader. something to do. This travel log may include historical reports of all sensors, any sensor alerts (including container intrusions, temperature excursions, etc.), and container specific geographic routes.

Hand-held readers can also be used to upload a container's cargo inventory (this can also be done by using the portal). When the container is loaded, barcodes or other types of packaging-type RFID tags can be read by a hand-held reader. From a hand-held reader (or other type of RFID reader), the cargo identifiers are loaded into a container inventory on the container's RFID tag, which can then be uploaded to the NOC.

An alternative approach is to use the IrDA (infrared) data port on the container. Thereafter, the hand-held reader will point to the IrDA port, and communication will be established. Thereafter, data download will be unified with the above.

<b>4. site server</b>

Site servers may receive RFID tags data from RFID tag readers. Site servers may send RFID tag data to the NOC. The site server also performs local analysis of the RFID tags data and can manage the multi-access aspect of the present invention with tens of thousands of tags at a terminal or on a ship. Site servers have three main subsystems: (1) computer-based servers and system controllers; (2) an RFID tag reader communication subsystem comprising the same communication modules as the RFID tag readers to communicate with the RFID tag readers [i.e. they communicate with wireless RF communications (preferably different from RFID tag communications, such as 5.8 Ghz) HSS communications in frequency), wired communications (such as powerline communications, Ethernet or serial), or optical communications (such as fiber optic or transceiver straight line laser communications); and (3) a NOC communications subsystem that may utilize hardwired, cellular, optical or satellite communications modules.

<b>5. Network Operations Center</b>

The Network Operations Center (NOC) can be the clearinghouse for global maritime transport control systems. All RFID tag data from all RFID tags located anywhere in the world may be relayed to the NOC by a local site server or via direct cellular or satellite communications. The NOC collects, stores, and disseminates RFID tag data, including location, sensor data, and RFID tag status.

The present invention provides a global positioning system, a radio frequency identification (RFID) based tracking system for assets and cargo containers; globally available commercial satellite and Internet communication systems; geographic information systems (GIS) and real-time logical analysis capabilities; A hardened continuous data flow is provided to private sector asset and cargo owners, relevant state and federal entities (such as Coast Guard, TSA, Customs, NTSB, and DoD), and local first responders (law enforcement, Fault-tolerant systems provided to fire departments, local governments); and the incorporation of technologies in a central operations center architecture that includes commercial programs and existing federal systems for asset and cargo tracking.

The use of a geographic information system (GIS) in the NOC will allow analysis and presentation of asset locations in a variety of formats, from simple web-browser based latitude/longitude reports to map-based city/state/zip code/country information. . The system may provide the ability to monitor and profile assets in real time based on specified conditions, including geographic patterns. This approach also provides for the incorporation of real-time logical analysis of the movement of assets. The long-term goal of GIS development is to intelligently profile containers containing geographic patterns, while creating an information infrastructure that can analyze the movement of goods and assets across the supply chain.

RFID tag data can be integrated into a central GIS-based tracking infrastructure via a global satellite communications network to create a MAST system. A preferred embodiment of the MAST system invention utilizes one or more global satellite networks.

Satellite networks provide global, real-time tracking and monitoring of assets with the ability to efficiently centralize all information in one location. This provides advantages for security, fault tolerance, data backup/archiving, and maintenance. NOC may integrate geographic information systems (GIS) technology, satellite communications, global positioning systems, RFID (electronic seals, etc.), and the Internet in an open systems architecture to create a real-time tracking and asset management system. NOC provides global management of mobile assets using a web-based tracking system that allows individuals or entities to manage assets over the Internet in real time with stringent data protection protocols (eg, login and/or encryption). Only one location can be provided for real-time logic support for Information is distributed to interested parties through secure transactions in a need-to-know manner, thus precluding the use of systems aimed at theft of assets.

The NOC is one or more of the following resulting operational capabilities: 1) real-time, global vessel location tracking with detailed historical history; 2) tracking container locations with tampering notifications and internal environmental radioactivity status; 3) Early warning/threat notification of the arrival of ships and containers in US territorial waters and ports with an audit trail that identifies potential threats, risks and responsibilities; 4) detecting and monitoring suspicious shipping activities (such as unplanned port calls) and identifying long-term patterns of activity at both the ship and container level; 5) To (and/or from) the Department of Defense, US Coast Guard, US Customs, National Security Commission, as well as local "first response" law enforcement agencies for national security, port security, smuggling, and theft concerns data security; 6) security of data to (and/or from) consignors and ports for planning and management of cargo arrival and dispersal as needed; 7) Systems for "fast tracking" for customs inspection and comprehensive port, vessel, and container management; 8) Real-time monitoring performance for frozen, hazardous and HAZMAT cargo; 9) remote control tower(s) for the maritime industry to maximize efficiency and contact center for critical information (eg, protocols, regulations, weather forecasts, notifications to sailors, etc.); and 10) can have the integration of intermodal warehouse management, port, ship, road, and rail supply chain management and insurance applications on a global scale.

<b>6. multi-access</b>

The multiple access approach described herein is distributed to a terminal or vessel located in an environment that may include more than 90,000 additional RFID tags (potential interferers) located in/on the vicinity of the terminals or vessels. It may enable a multiple access network capable of operatively housing approximately 10,000 RFID tags. Such multiple-access designs may use one or more of CDMA, FDMA, TDMA, and/or SDMA (Space Division Multiple Access) to achieve these requirements. Each of the RFID tags may report electronic identification codes, sensor data, and location information to an array of RFID tag readers that form a grid around or across the perimeter of the terminal or vessel. RFID tag reader locations may utilize the existing infrastructure of lighting towers currently in yards. These RFID tag readers can report all useful data to a nearby site server while coordinating data from the tags. Thereafter, the site server can relay important events and sensor data to the NOC. A discussion of terminal/ship area communications with focus on RFID tag to RFID tag reader links will follow.

<b>overall strategy</b>

The following describes the elements of a desirable overall communication strategy. One embodiment of the present invention is a combination of code division multiple access (CDMA), time division multiple access (TDMA) and space division multiple access (SDMA) using both direct sequence bandspreading (DSSS) and frequency-hopping bandspreading (FHSS). , which may be used for tag-to-reader links. One embodiment of the present invention may include a reader-to-server link using a different frequency band (eg, 5 GHz). An embodiment of the present invention may include two-way communications such that power control may be used to optimize CDMA and SDMA methods. Embodiments of the present invention may include independent terminals (yards) provided adjacent to identifiable groups of spreading codes from adjacent neighboring yards. Embodiments of the present invention may include the option of subdividing the yard into micro cells.

The following describes the key performance parameters of the above-described preferred overall communication strategy. The site server may receive updates from 10,000 neighbor tags at a time at least every 100 seconds with a 99.99% success probability. A network including a site server may have the capability to "ignore" up to 90,000 semi-adjacent tags. The high priority message(s) from the tag(s) can be sent with a delay of 1 second.

<b>avatar</b>

The following implementation analysis includes the following assumptions. One thousand bits are used from each node every 100 seconds. Offset-quadrature phase modulation keying (QQPSK) modulation with a 5 MHz bandwidth and nearly constant envelope signals is used. 16 or more hop frequencies with managed overlap. Length-63 spreading codes for the direct sequence are used.

Based on the above explicit assumptions, 1000 bit (125 bytes) packets can be transmitted once every 100 seconds from each of 10,000 nodes at a bit rate of 80 kbps with a chipping length of 63. Accordingly, an embodiment of the present invention has a chipping rate of approximately 2.5 Mbps, which translates to a spatial bandwidth of approximately 5 MHz with QQPSK modulation. It is assumed that RFID tag readers need to communicate with each RFID tag at a time, approximately every 100 seconds. Thus, 10,000 RFID tags are converted to an average of 20,000 packets every 100 seconds. These 2000 packets have 4000 time slots (25 ms long) and 32 CDMA users (assuming maximum concurrent users are approximately the product of the square root of the chip length and the square root of the number of hops - a combination of 63 length codes and 16 hops) ) can be multiplexed.

Perimeter RFID tag readers may use directional antennas aimed between rows of containers for RFID tag communications. Directional antennas operating in another frequency band (eg, 5 GHz) (or alternatively, powerline communications) may be used for tower-to-tower/server communications. Depending on yard size and other environmental parameters, towers may also be required to provide relayed communications.

The main functions of RFID tag readers may be to capture information from all RFID tags and then relay this information to a site server. They can coordinate with each other in a way that optimizes multiple access schemes for tags over 10K, or they can just communicate directly to the site server. For example, where multiple readers are capturing data from one RFID tag, the readers can cooperatively determine the lowest power level at which at least one reader can reliably communicate with the RFID tag.

<b>power control</b>

As discussed above, power control may be used to optimize network communications. Naturally, it is desirable to use DS-CDMA to a large extent for power control. This multiple access approach may include protocols for network discovery, power back-off, and interface mitigation techniques, all of which involve control of power transmitted from the RFID tag.

<b>re-send </b><b>redundancy</b>

The above analysis assumes that the system needs to listen from all RFID tags at a rate of once every 100 seconds, and that approximately 1000 bit messages are sufficient. This includes a conservative estimate of the packet guard interval of 100% packet length. In the example above, the packets will be approximately 12.5 ms, and the average guard time will also be approximately 12.5 ms. This guard time is very tight and can possibly be reduced by more than 90%, thus enabling almost another doubling of throughput or redundancy. A small fraction of the guard time is used for "emergency" events in a CSMA fashion. Moreover, most applications will not require 100 second update rates, so consecutive time slots for a subsequent 100 second cycle can be used to re-transmit bad packets. For example, update rates of once per hour, once per second, or even once every three hours may be sufficient for most applications.

In order to perform power control as described above, and to perform the typical duties of channel allocation and network optimization, a strict control flow must be established for the start-sequence of all nodes. The following description in conjunction with Figures 7 and 8 (flow charts) presents an example of a design of this process.

<b>discovery process</b>

As shown in Figure 7, the nodes will start on the system control (default) RF channel. Nodes will cycle over a small set of "pilot" channels until they establish a link with one of the RFID tag readers. This loop is necessarily an infinite loop until or if successful communication with the reader (or another tag, if an alternative tag-to-tag approach is used in a given system) is established. Embodiments of the present invention may include power enhancement and/or such procedures.

Referring to FIG. 7 , an exemplary tag start sequence may begin with a tag turn on step 710 . In step 720, the tag sets a default receiver code. In step 730, the tag listens for a pilot transmission signal from the tower. At step 740 , if a signal from the tower is identified, the tag proceeds to transport-to-network communications 750 . If the tower is not identified, the tag determines whether a timeout period has elapsed (step 760). If the timeout period has not elapsed, the tag continues attempting to identify the tower. If the time-out period has elapsed, the tag proceeds to step 770, which includes setting alternative receiver frequency codes. After setting the alternative receiver frequency code, the tag proceeds to step 730, again listening for a pilot transmission from the tower.

During the discovery process, it may be desirable to minimize the number of tags transmitted at any given time. This can be done by letting the reader node control the discovery process. The reader will send an ID request prompting all tags within range to transmit in a given order (see Network ID Transmission Order below) for a given temporary code. Afterwards, the reader will start receiving and processing messages from the tags. After the first cycle of node identification is complete, the reader will send a message to the tags confirming receipt as well as specifying both the network ID and time slot assignment for the tag. This cycle will repeat with the condition that all tags with network ID assignments (associated with this reader ID) have not acknowledged the ID request message. The present invention may include protocols for resolving conflicts and the like.

<b>Network ID Transmission Order</b>

The reader may require all tags capable of deciphering the ID request (and not previously logged by this reader) to send a 5-ms message x times 10 ms after receipt of the request, where x is the tags UUID are the three least significant digits of (eg, a tag with a UUID of 2345678 may wait 6,780 ms before sending to the reader). In addition to this, the tag may select a combination of FH and DS codes using the subsequent two upper digits (45 in this example). So the reader must be able to handle 100,000 clearly.

Once the RFID tag and the RFID tag reader have established a link, the reader will assign the RFID tag a code and frequency combination that makes the tag part of an optimized network. This process is illustrated in FIG. 8 .

Referring to FIG. 8 , under transmission 810 from communication discovery, the tag obtains or adopts a default transmission frequency code in step 820 . In step 830, the tag sends a default transmit frequency code to the tower. In step 840 , if the tower ascertains the default transmit frequency code, the site server will assign a code frequency and time slot to the tag in step 850 . If the tower does not check in step 840, the tag proceeds to step 860, where it determines whether a timeout period has elapsed. If the timeout period has not elapsed, the tag returns to step 840 and will continue to wait for confirmation from the tower. If the time-out period has elapsed in step 860, the tag proceeds to step 870, where an alternative transmit frequency code will be obtained or adopted. Thereafter, the tag will proceed to step 830 .

<b>packet structure</b>

This section focuses on packet parts dedicated to ensuring robust communication, such as preamble and error correction/detection coding. The payload of the packet can be any useful payload (eg, identification, location, radiation dose, etc.).

Because the preferred waveform uses direct sequence spread as well as frequency hopping, the preamble can have two parts: a 64-bit constant frequency DSSS part followed by a 63-bit hybrid FH/DSSS part. A receiver correlator may search the beginning of the transmitted waveform for autocorrelation peaks on a known frequency. Once the receiver derives the (timely) position of the "bit" edges, it can start hopping of the carrier frequency. The transmitted waveform may start hopping at the beginning of a second portion of the preamble that may act as a data delimiter word. The receiver may re-establish synchronization with the hopping sequence at the beginning of this second (63 bits) sequence. This causes the receiver to miss sequences of more than 5 bits and still successfully discover the start of the data payload. A CRC word of 32 bits (length) will complete the packet and may be used to ensure the integrity of the actual data payload.

<b>direct</b><b></b><b>sequence</b><b> spread spectrum</b>

DSSS assignments may be selected from the Kasami code generator which generates approximately 520 codes of length 63. Only approximately 32 codes can be used within a given cell, within a given time slot. However, the use of such a large set of codes makes code allocation processes manageable.

<b>frequency </b><b>hopping</b><b> spread spectrum</b>

During any given packet slot, some of the channel orthogonality may be achieved through frequency hopping assignments. Since the assumed RF tag spectrum is approximately 5 MHz and the industrial, scientific and medical (ISM) band of 2.45 GHz is 80 MHz, only 16 hopping center frequencies will be used in this example. While hybrid spreading is primarily desirable for improving the robustness of individual links exposed to a hash multipath environment, DSSS spreading can be used independently to distinguish multiple concurrent users.

<b>7. Maritime system observations and analyzes</b>

The size of the ship terminal facility will greatly affect the configuration (ie, number and distribution of receivers) of the shore-side RF system required to track containers throughout this facility space. The terminal's light poles are preferred locations for facility receivers and transmitters (or transceivers).

The RF container-monitoring receiver(s) on the ship may be located on the mast at the bow end of the ship. It should be noted that the containers are not always stacked on the deck at a uniform height or with a very uniform distribution. There may be essentially little to no in or out of covered holds (steel hatches), therefore it is necessary to provide RF system receiver(s) in the holds to facilitate monitoring of containers therein. do.

In a loaded vessel, containers are often stacked above the deck to the edges of the hull. Bridge wings and masts may be used to mount the RF infrastructure components for the MAST system. Gaps between each row and stack of containers allow the RF signal of the appropriate wavelength to bounce back and forth before finally reaching the edge of the vessel. In order to achieve uniform coverage of all containers above the deck, at each end of this space, it may be desirable to position the system antenna along the perimeter of the vessel.

Containers are typically hermetically stacked in a hold. Containers slide down vertical retaining rails attached to the ship structure. The metal bulkheads effectively partition the areas around the ends of the containers and additionally interfere with RF propagation from the containers in the hold. Once the hatch is positioned over the hold, a pretty good Faraday cage is formed, with very little RF going in or out. Thus, where near real-time (eg daily) telemetry is required from containers stacked on docks, some in-hold RF infrastructure (ie receivers and relevant data to a central monitoring station on the vessel bridge) links) may be required. The container lock mechanism ensures gaps of 2-3 inches between the tops and bottoms of the stacked containers. A spacing of approximately 2-3 inches between the tops and bottoms of the containers should be sufficient to provide an RF path (at suitable frequencies) between the containers. The corresponding spacing between the sides of the containers varies from 0.5 inches to approximately 2 inches. This configuration can create ohmic (lossy) and/or capacitor connections at radio frequencies between containers, which can somewhat impair signal propagation from the stack.

Referring to FIG. 9 , a plurality of intershipping vessel containers 910 are arranged in an orthogonal array. A radio frequency identification tag 920 is shown on top of one of the articulated vessel containers 910 . A plurality of readers 930 are located at the ends of the passageways formed by the plurality of articulated vessel containers 910 .

9 shows a top view of a group of hermetically stacked containers (nominal 40 feet), which may be arranged on the deck of a ship or on the ground in a terminal yard. One RF emitter (indicated by the radiating red dot in the figure) may be mounted near the top center of the container. Because the container's substructures and upper side rails tend to send a signal longitudinally, most of the RF energy will leak from the two ends of the container to adjacent passageways in both directions (up and down in the figure). These signals will bound between the ends of the containers, bounding the passageway until they appear at the edges of the array, which will result in moderate losses and significant waveform distortion. Very wide band (ie, several MHz) spread spectrum signals with high immunity to dispersion and multipath-type distortions can be best received. Naturally, the present invention is not limited to any particular environmental configuration.

Potential RF receive and/or transmit locations are indicated by dots at the ends of the passageways in FIG. 9 . Although each dot may represent a separate antenna, a more practical, robust construction may utilize short pieces of "leaky coaxial" cables to augment the passageways and standard low-loss coaxial sections between them. For better physical protection, the "leaking" cable can be housed in heavy-walled PVC pipe sections, where the PVC pipe provides relatively low losses up to several GHz frequencies. Standard cables can run in PVC or even metal conduit, since traditional coaxial is fully shielded. These receive and/or transmit location systems may be (semi)permanently mounted on the perimeter of the vessel, or near deck levels, perhaps even on balustrades or other convenient structures. There is typically a staff passage between rows of containers on each side of the cargo holds. It is possible to position the RF system antennas for the container telemetry links on appropriate locations on the aisle assemblies.

The exact locations and mode(s) for the mounting of these antenna components are highly dependent on the specific characteristics of the individual vessel structure. In the case of containers in one of the ship's holds, a leak-coaxial cable can be installed along the sidewall, in approximately the same vertical plane as the container guide rails. In both cases, the orientation of the leaky-coaxial cable should be maintained to provide the most efficient energy in terms of polarization and orientation of the antennas on the containers. For example, for horizontal container RF launchers, the cable is also approximately horizontal to maintain relatively low coupling losses in the container-to-local receiver RF links (assuming horizontally polarized container antennas). should proceed

Another major system design consideration lies in the selection of appropriate RF operating frequencies. Legal and licensing restrictions apply to the current industrial, scientific, and medical (ISM) bands of 13.56, 27.55, 433, 902-928, 2450-2483.5 and 5725-5825 MHz and the United States and the rest of North America [and/or Similar allocations in other parts of the world] encourage the use of unallocated bands, such as the so-called Unlicensed National Information Infrastructure (U-NII) bands of 5150-5250 and 5250-5350 MHz. The first three parts are narrow (well below 1 MHz), and the latter five are for various forms of spread spectrum signaling.

Although narrowbands can support very low rates of data transmission, their performance over radiolocation and very robust links is severely limited. On the other hand, spread bands allow for significantly higher RF power levels and will support much more flexible modulation schemes. Overall, the 902-928 MHz band will provide the greatest coverage, but 2450-2483.5 MHz is essentially universal and (at least in part) available worldwide. There are several emerging RF standards in the general fields of wireless facial expression and telemetry. The HSS protocol is already explicitly permitted in the ISM and U-NII bands by current Federal Communications Commission rules.

Although the penalties in tag cost, power efficiency and complexity can be quite significant, the flexibility of multi-band and/or multi-protocol devices for container tracking may also be exploited by the present invention. The present invention can utilize highly integrated multi-band RF devices (including transmitter and receiver electronics, filter structures, and antennas) desirable for worldwide versions of the MAST system idea.

An additional consideration is the specific type of RF system architecture required to achieve the desired level of functionality. Bidirectional data-telemetry system provides accurate RF-signal power control, remote reprogrammability; individual tag (addressable) queries; multi-tag relay capabilities; ad-hoc dynamic tag-to-tag data routing to overcome RF path obstacles and nodes with low power battery conditions; And it will allow for a more sophisticated set of tag-device properties, including networking tasks such as rolling security codes, remote software changes/updates over the network, and node-state queries. Whole node power efficiency and energy utilization are also typically optimal with a bidirectional protocol, which results in the longest possible battery lifes and the most timely node-alarm reporting and diagnostics capabilities. Naturally, the penalty for such an RFID tag node is increased complexity and increased cost due to the presence of an on-board RF receiver, but the additional acquisition cost will more than be compensated for by the increased battery life, and thus the ship's crew or Reduce maintenance interventions by other maintenance/service personnel.

In contrast, a basic unidirectional network generally includes autonomous tags operating in a "dumb chirper" mode, where the tags simply burst out data to the system infrastructure receiver(s) at predetermined intervals. do. These transmission intervals may be regular, randomized, slot randomized or even changed by the characteristics of the tag data. For example, a highly preferred embodiment is a "smart" tag that simply omits transmissions of extra data, and instead only sends new, modified reads. Minor modifications to these protocols are made to repeat the true data values (in case the change is inadvertently missed), as well as pass some basic state information to ensure that the node is still operating properly, several at selectable intervals. will include the direct insertion of additional transmissions of

A third type of telemetry system architecture will support the strategic (or even accidental) combination of bidirectional and unidirectional tags as dictated by the specific implementation scenario. Although there is some cost in overall RF system performance and an overall reduction in tag battery life, this format allows for considerable flexibility in the selection of tag types. Although the preceding descriptions are nominally based on single-band network setups, more flexibility and higher performance could be obtained in a multi-band system, despite a significant cost penalty (mainly in the total price of all tags). can In all such cases, the use of the HSS technique is not limited to bit-error rates, loss of packets, collision rates, RF power efficiencies, and superficial to other facility RF systems (especially those sharing the same universal bands). It enables advantages in interference levels. One embodiment of the present invention may include a combination of two-way relay tags and "dumb chopper" tags in one system.

A refrigerated container ("reefer") typically includes a three-phase power cable that plugs into the deck outlet fed from the ship's power distribution system. In general, refrigerator-monitoring applications are particularly important because of the high values of chilled cargoes (eg, pharmaceuticals, perishables, and medical supplies). Current practice is for ship personnel to manually monitor and record a single internal temperature periodically (ie with a pencil and clipboard) during the voyage, any deviations being reported to the ship's engineer. In addition to the internal temperature (possibly in multiple locations), additional data such as relative humidity, compressor pressures, coolant flows, supply voltage/current, and container integrity (door breakage) can be monitored via automatic monitoring and alarm telemetry. can be obtained. This information can add great economic value to embodiments of the present invention by providing early warnings of refrigeration failures and thus avoiding costly cargo damage while facilitating rapid repairs. This telemetry can be handled via RF techniques as described above, or via robust data transmission via the ship's ac power system. More advanced methods, such as electrical signal interpretation methods, more accurately evaluate the conditions of operating compressors, fans, pumps, valves, and other motor-driven and solenoid-driven loads, providing high-level real-time Provides state-monitoring capabilities.

<b>8. Analysis of RFID tag system communication requirements</b>

Perhaps the foremost technical issue in the deployment of an operable RF-based tag system protocol is the creation of highly reliable, robust, low-power RF communication links between, in particular, sensor/ID tags mounted on containers and a facility or ship receiver infrastructure. it is a need Hybrid (direct sequence/frequency-hopping) band-spread to significantly improve RF tag performance (with respect to data and location accuracies) while reducing RF interference generation and sensitivity to other tags and facility RF systems A telemetry approach using As noted above, the phrase "hybrid band-spreading (HSS)," as used herein, refers to, for example, US Patent Application Serial No. 10/817,759, filed December 31, 2003 and published PCT Application WO 02/27992. Direct sequence band-spreading (DSSS) as described, e.g. code division multiple access (CDMA), and frequency hopping, time hopping, time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM) and/or space division It is defined as a combination of at least one of multiple access (SDMA). Another advantage of the present technology lies in the area of power usage - the HSS protocol limits the number of RF transmissions from each tag while dynamically minimizing collisions with other tags, thus allowing tag data messages (e.g., for example, features that facilitate power reduction by reducing (absolute) requirements for retransmission(s)) to a minimum. Another important system operation issue is internal power management for the tag subsystem (ie, logic, RF circuitry and sensors).

To maintain useful battery-charge intervals, both the command-receive and data-transmit functions of RFID tags can be performed on a very small duty-cycle basis, which means that receive-system power consumption levels are often significantly higher than those of transmitters. because it is not low. In addition to this, all data from the smart-tag sensors can be processed to remove extra transmissions together. Finally, low-battery alerts can preferably be sent to the facility receiver(s) to ensure proper tag operability (ie, data access and tag location) at all times when needed. Alternative tag-energy options may include local passive-style powering through an interrogator wand, onboard photocells, or other energy sources. While some of the system protocol described above assumes bidirectional transfer to container tags, it is feasible to consider unidirectional "dumb-chuffer" tags for some system implementations that do not require on-demand query capabilities.

Relevant port (coast side) facility-system design issues include the use of RF repeaters to provide adequate and uniform spatial RF coverage throughout the facility, internal infrastructure signaling options, and deployment of distributed transceiver/radiolocation units. . The basic infrastructure may use twisted pair wires, coaxial cables, powerline RF transmission technologies, or wireless RF transceivers for data transmission between facility transceivers and a central container monitoring and control point. Yard RF transceivers may be mounted on existing structures, but such configuration will depend heavily on the specific setup of the terminal. The corresponding onboard RF infrastructure will be further constrained by the vessel's layout and limited opportunities to selectively deploy RF equipment for best coverage. Since the fixed RF device will need to be operated from the ship's power and will need to be mounted in locations that do not interfere with normal ship operations and maintenance activities, numerous compromises can be accommodated. For this, it is highly desirable to handle RF infrastructure data communication via the ship's AC distribution system. This would provide a physically protected route and eliminate the need to perform additional cabling throughout the vessel when installing a system embodiment of the present invention on the vessel.

<b>9. container </b><b>monitoring</b><b> and requirements for sensors</b>

Container locating may require different solutions for ship transportation versus rail and truck transportation. On a ship, GPS-based tags may not exist on their own unless combined with triangulation. More specifically, GPS is a direct-to-receive positioning system in which the receiver must be able to see three or more satellite sources. Containers embedded in deck stacks or in a ship's hold will not be able to obtain the transmit and receive direct-line signals required to use GPS satellite sources. The addition of a local GPS repeater on board will not solve this problem. Even when GPS signals of adequate strength are received and repeated, high levels of local RF multipath reflections in the stacks can cause major uncertainties in location accuracies, and results are generally unacceptable. Moreover, the requirements for very low tag operating powers will almost certainly preclude individual GPS receivers even where adequate satellite reception is possible. A preferred onboard solution involves the use of a local triangulation system. The use of a local triangulation system adapted to the local onboard environment may allow for the best possible container-location performance. Due to severe multipath reflections and limited (power-constrained) number of tag transmissions, this system cannot provide accurate container position in all cases, but possibly ±1 container up/down, front/rear. and an approximate location within port/starboard. In most cases, this level of accuracy should be quite reasonable.

For linear triangulation, multiple receivers may be required. The lack of direct transmission and reception from a given container to a fixed central receiver will require a set of receivers to localize the container transmission location for deck-stacked containers. In addition to this, it would be difficult to localize containers in holds beyond identifying the holds in which they are located. Because of the overwhelming levels of multipath and interference to RF signal paths, each hold has one receiver and per-container antenna mounted on the bulkhead near the end of each container to accurately localize the container location within the hold. You can request up to This possibly exceeds the number acceptable for cost-effective solutions with current technology. Moreover, the incremental value of knowing the exact location of each container in the hold is not great, since there is no practical way to access most containers once they are stacked in the hold. In any event, the priority of finding a particular container within a hold is clearly lower than accurately tracking the container through loading and unloading (due to time), which has a strong economic effect on the entire cargo loading and transport process (due to time).

The solution to this problem is to deploy smart antenna structures (ie a plurality of interconnected, horizontally polarized wire-type dipole antennas are mounted on the walls of the docks, all with a remotely controlled RF PIN-diode switch. coupled to common cables). This setup effectively implements a group of scanning antenna arrays for a hold, where the antenna arrays can identify the container being loaded into the hold and provide its location when being loaded. The positioning function for a particular dock may be triggered by a local container-tag RF interrogation signal (ie, a burst of coded RF energy at 13.56 or other convenient frequency), where the interrogation signal is a "warning" or "wake up" signal. will be detected manually or semi-manually by container tags. Then, each of these interrogated containers whose codes (last few digits of the container serial ID number) match the alert signal will respond with an HSS burst signal in a pseudo-random-timely manner. The dock receiving subsystem will acquire these signals and relay the results to the main onboard system for correlation with the full serial numbers of the vessel's container inventory database.

Another key part of the MAST system is tracking the location of containers at the loading dock or container yard. Assuming huge volumes of containers move in and out of these facilities, a tracking system that can tell facility operators where a particular container is located can be a significant time-saver. Within the yard, a local band-spread RF triangulation system can be used to track the container position. Four or more strategic locations around the yard (more locations for very large installations) will provide dynamic tracking of container locations. Additional receiving units may be located generally at the exits and entries of the terminal, where their data may be used to record the entry and departure of containers from the facility. Typical direct transmit/receive straight line communication distances in open yards should be approximately 300m to approximately 500m for tag RF transmit power levels of 10mW, which easily extends to approximately 1km for 100mW tags. Radiolocation accuracies can be good within 1m for typical (short) tag-read average times. In addition to this, when longer average times are used, greater position resolution can be obtained. A set of radio positioning receivers equipped with adaptive beam-steering antennas are placed on each loading crane to obtain complete telemetry and position data about each container, typically over a short range as the container is moved to or from the vessel. will be installed This data set may be the most reliable validation for a tracking database system, where a particular container actually moved from the yard to the ship or vice versa. An optional feature that may be included in container-location monitoring software is movement detection. That is, whenever the container position changes by more than an incidental amount (i.e. greater than the system position-uncertainty specification), a security routine that tracks the movement of the container as its ID is compared against active vessel lists. can be activated. If a container is moved a significant distance (more than the normal yards that delamination/restack operations typically involve) but does not plan to move, yard personnel will automatically be alerted to a potential misplacement or theft attempt.

In general, GPS container positioning is theoretically possible for containers with clear direct-to-receive lines to GPS satellites, but for the reasons outlined previously for on-board containers (i.e., sufficient direct-to-receive reception of in terms of) may not be feasible in the terminal yard, particularly in stacks. The same logic applies to containers transported by rail or truck.

The present invention also provides an option for monitoring and sensing container cargo conditions, including a wide range of sensor devices capable of detecting interference with container cargo, container temperature, mechanical shock, radiation, stowage, or chemical/biological factors. techniques may be included. Some of these sensors (eg temperature sensors, door switches, accelerometers, bead-type impact sensors) are essentially off-the-shelf requiring little technical effort to be included in a container monitoring system. ) devices.

Door integrity monitoring will use sensors to indicate if container doors have been opened or removed. This sensor may be a mechanical or magnetic switch, but other means may also be used, such as optical, capacitor, or reluctance-measuring devices. All of these items are off-the-shelf and should be easily deployed at low cost.

Radiation monitoring may be performed using sensors that record the interaction of radiation with matter, such as standard thermoluminescent dosimetry (TLD) of the type used for general staff dosimetric monitoring. Analysis of radiation-induced changes in a material over several days can detect very low levels of radiation. The sensor does not require continuous battery power, only battery power that measures changes in the sensing medium intermittently. Although TLDs are off-the-shelf, and reasonably cheap automated reader units are commercially available, container applications may dictate reasonable optimization-technological efforts. A number of methods are available at a reasonable cost, depending on whether alpha, beta, gamma, X-ray, and/or neutron radiation is desired and the sensitivity levels to provide continuous, in-container radiation sensing. For large scale applications, the present invention may include inexpensive multilayer detector materials capable of responding to small radiation fluxes with low-level photocurrents readable by a low-power CMOS electrometer circuit (similar to cheap home smoke detectors). have. Radiation monitoring can also be performed using passive integral ionizing radiation sensors described below.

An alternative strategy for rapid, wide-scale radiation screening of containers would be best performed via a sensitive multi-detector array scanning system mounted on a loading crane or within an offshore facility. However, due to the extreme economic time pressures in loading/unloading operations, these container scandals may occur either offline or on-the-fly prior to (or immediately after) crane-transport operations so as not to affect overall container throughput rates. on-the-fly).

Monitoring of stowaways in containers can be performed with several types of sensors. The present invention may include the use of a heartbeat detector known as an Enclosed-Space Detection System. This sensor system, including a vibration probe (eg accelerometer) and detection and recognition electronics, periodically records microvibrations of the container, and a wavelet for time/frequency signal signatures of human (or animal) heartbeats. - Analyze them through transformation methods. This system is most efficient for monitoring single, isolated containers (eg, in a wharf-yard), but can even be adapted for onboard use. Another potential way to detect stowaways or other unauthorized items inserted into containers is a device that generates a special electromagnetic pulse inside (or in the container) the container. Thereafter, field levels at two or more locations are detected, telemetered, and recorded. Periodic retransmission of the electromagnetic field pulse and comparison of the new and original responses will reveal any significant changes in field patterns determined by the dispersion of the material within the container. It would also indicate movement of material within the container due to cargo movement or the presence of humans (or animals). Although the technology is commercially available, more traditional (and possibly less expensive) approaches to this problem include simpler but less sensitive steady-state or pulsed ultrasound and / or RF (microwave) systems. The latter techniques are essentially off-the-shelf, but can be blocked or screened by cargo stacked in front of the sensor.

Chemical/biological factors are difficult and expensive to detect, mainly because extremely small quantities of these factors have to be detected with high accuracy (low incorrect negatives and incorrect positives). The present invention may include chemical or biological "lab-on-a-chip" detectors. A less expensive chemical/biological detection system for containers could mount the detector on or near a mobile crane, where the container could be passed through a "sniffer tunnel" for rapid online investigation. . In addition, individual chemical/biological detector(s) may be mounted to and/or on the container(s).

Shock and/or acceleration sensing for sensitive cargo can be achieved with MEMS/electronic devices (similar to automotive airbag sensors), glass beads or granules (for shock or tilt-limited sensing), piezoelectric devices may be performed with any one of several techniques including devices (eg, classic accelerometers), microcantilevers and inductive sensors (eg, geophones). . A major constraint is generally available power. Most of these devices require so much power that they cannot be easily handled by a small battery for a significant amount of time (eg, a month). However, the use of a continuously time-sampled acceleration profile is valuable in determining cases of excessively rough handling of containers during transport and tracking of fragile cargoes. Most of these types of sensors are commercially available today, and proper packaging and interfacing of them into a container telemetry system will be quick and easy.

Refrigerated container systems, particularly compressor and refrigeration system components, would ideally be monitored using the techniques described above with respect to refrigerators. This compressor and refrigeration system technology, including electrical signal analysis components, is readily commercially available and will be simple to implement for transportation environments.

Preferably, a typical container tag (whether simply a long-range ID device or a more sophisticated data acquisition/telemetry device for container security and detailed monitoring of internal conditions (ie temperature, humidity, shock)) is battery- power is supplied Thus, careful unit and system design that assures wide acceptance by the marine industry by ensuring proper member operation for long intervals is also desirable. Preferably, the tags should have maintenance-free usage periods of at least approximately one year. Most shipping companies will want intervals of 3 to 5 years that approximate the lightly loaded life of a camera-style lithium battery, which is the best energy-density format currently available in readily available commercial products. Because the shelf life of lithium-ion batteries is typically on the order of 10 years, sealed container tags stored in an unpowered state for several years prior to use should still indicate a normal operating life target of 3-5 years. Suggested tag lookup intervals in most planned scenarios range from 1 to 4 times per day, depending on the container type; the relative destructibility or sensitivity of the cargo; And depend on other factors such as security, cargo value, theft potential, and traumatic event (eg, container going under water). Some of the latter factors may also influence the deployment of emergency transmitters or beacons on containers to facilitate immediate crew response to these emergency situations. Assuming typical battery performance of 1400 mAH (3-V AA size), one routine lookup per hour (consuming an average of 10 mA for 10 seconds) would result in a useful operating battery life of just over 5 years. If charging is performed, this interval can easily exceed 20 years, possibly close to the life expectancy of the electronics package. Although solar charging is the preferred charging mechanism used, micro fuel cells, kinetic generators (e.g., micro-pendulum or MEMS types), thermocouples (temperature-differential), and even RF energy scavenging ( Other power mechanisms including scavenging are possible.

Embodiments of the present invention may include embedding an RFID tag into a container structure. Embodiments of the present invention may include providing a plurality of RFID tags on a container for redundancy or as (non)functional decoy(s).

<b>Empty Charge Dosimetry for Extremely Low Voltage Measurements of Ship Containers</b>

Electron dosimetry devices can measure the dose of a container, but they must be powered (active) during integration times. Therefore, they must integrate for short periods of time to conserve battery power (thus reducing sensitivity). The use of large size or large quantities of batteries is not economically feasible and does not replace batteries during the life of the container (a typical ship container life is 5 to 7 years).

There is a need for a simple, robust, low-cost, low-power device that can be installed in any ship container to manually integrate the radiation dose. During transportation, this device can integrate the radiation dose over very long periods to obtain a very sensitive measurement of the presence of radiation in the container. Even a well shielded radioactive material will result in a slight increase in the background radiation levels of the container. There is also a need for a device capable of reducing the occurrence of inaccurate positives.

Space charge dosimeters (SCD) can manually integrate the radiation dose continuously, requiring only power for reading or charging the device. These devices work by charging or generating an initial potential between the anode and cathode. A dielectric medium is positioned between the cathode and the anode. This potential creates an electric field across the dielectric medium. As radiation passes through the dielectric material, it causes ionization of the dielectric. The electric field then sweeps away the ions or charge carriers from the dielectric, thus reducing the potential between the anode and cathode. The measurement of the depleted charge during the exposure period is a measurement of the ionization integrated during the measurement period. The charge (or some physical aspect of the device controlled by the charge) is read before and after exposure to obtain a dose rate.

By using various materials as filters around the SCD, the type of radiation to be sensed is determined, or the energy range of the radiation is determined. A set of (plural) such low cost sensors in each container with a different filter around each SCD can provide an indication of increased background radiation as well as an indication of the type of radiation and energy levels. This can help identify the potential type of radioactive material in the container, which for example identifies whether the increased radiation levels in the container are due to bananas (potassium-40) and not from cobalt-60 in the lead shielded box. can do.

Embodiments of the present invention can solve the problem of how to measure radiation in a ship container, where the radiation sensor is low cost, and the battery is powered but still has a battery life of many years. Embodiments of the present invention provide very low cost space charge radiation dosimeters (SCDs) such as Electret Ion Chambers, field effect transistors such as IGFETs (Insulated Gate Field Effect Transistors) to manually integrate the radiation dose. FETs, MOSFETs (oxide semiconductor field effect transistors) and/or micro-cantilevers may be used. In such devices, radiation (air chamber for EIC or dielectric layers for FETs and micro-cantilevers) passing through the sensitive volume of the radiation meter ionizes the gas or dielectric (ie, creates charge pairs). These radiation induced charges then cause a change in the potential or electric field of the device. This change in potential or electric field is proportional to the received radiation dose.

Embodiments of the present invention may include an actinic radiation detection volume of material that is an electrical insulator. When radiation collides with this volume, an electric charge is created that is trapped within the volume. This trapped charge changes the electric field distribution within the volume. Embodiments of the present invention can then sense this change in electric field by placing electrodes on opposite sides of the volume. It should be noted that these electrodes will respond to this electric field. If these electrodes are, for example, the gate and body of an IGFET transistor, an embodiment of the present invention can indirectly measure the change in electric field by monitoring the channel conductance of the transistor without dissipating the trapped charge. can Alternatively, if an embodiment of the present invention includes a detection volume (eg, such as a microcantilever) moving in the direction of the insulated electrode, where the generated change includes a reading of the cantilever deflection, the same results can be achieved.

An intermittent reading of the voltage or potential of the SCD dosimeter provides a reading proportional to the radiation dose received by the device. One or more SCDs may optionally be mounted to a shipping container in a radio frequency identification tag environment. During container transport (such as by ship or rail), SCDs integrate the received radiation dose. After a time interval, such as every 24 hours, the voltage potential of each SCD can be read. The potential change from reading to reading is proportional to the radiation dose.

Multiple SCDs with various types of filters can be used to distinguish between radiation types (eg, gamma, x-ray, neutron or beta) as well as between energy levels of these particles or photons. An SCD located outside the container or well shielded inside the container can be used to eliminate ambient or background radiation.

The data from these radiation sensors can then be relayed to the RFID tag on the container. This RFID tag collects data from radiation sensors, other sensors (eg, temperature, acoustic, etc.) and location information (eg, from GPS or triangulation), all of which are wirelessly to a receiver coupled to a central database by communications (eg, HSS). In the central database, the radiation dose readings can be analyzed to find indications that the container has a higher than normal radiation field. Radiation fields above normal radiation levels may indicate that a hazardous (radioactive) cargo is in a container and, therefore, a particular container needs to be flagged for more detailed investigation.

Embodiments of the present invention may include systems using space charge radiation dosimeters (SCDs). SCDs include semiconductor devices such as charged film ionization chambers (EICs), insulated gate field effect transistors (IGFETs) and/or microcantilevers. SCDs can be used to continuously monitor radiation levels in shipping containers. These radiation sensors can be combined with communications and tracking systems located on each container, thereby allowing real-time worldwide monitoring of the container's location as well as the container's radiation level. Radiation levels higher than unexplained or expected radiation levels in the container may be used to flag the container for more detailed investigation at an American open port (or preferably before a vessel enters a US port).

As noted above, the basic principle of operation of SCDs is that ionizing radiation interacts with a material (such as air or dielectric) to create pairs of charges (ionization). Afterwards, these charge pairs move through the material due to the presence of an electric field. Thereafter, the movement and collection of charge carriers causes a decrease in the voltage potential across the device. Once the SCD is charged, ionization in the active region reduces the potential. Charging the device takes a very small amount of power. Once charged, the device continuously integrates the received dose, which is measured as a drop in potential. Thus, reading of this potential before and after exposure provides an indication of the received dose. Importantly, the SCD does not require any power during the dose integration period. The only time power is required is when charging the device or reading the potential. As also noted, the three possible SCDs for which the dose can be manually integrated are the charged film ionizing chamber (EIC) dosimeter, the insulated gate field effect transistor (IGFET) dosimeter, and the microcantilever dosimeter.

A preferred operating method of the radiation sensors of the present invention is as follows. The container is adapted to one or more radiation sensors and an RFID communication system, and the container is then loaded into the cargo. The container is then transported to a shipping terminal. Thereafter, the container is loaded onto the vessel for shipment to the United States or other importing country. During sea voyages, a signal is sent to the RFID system to activate the radiation sensor (read the sensor to get a baseline reading, or get a baseline reading after charging the sensor). Thereafter, the radiation sensor manually integrates the received radiation dose, which is done until the RFID system instructs the sensor for another reading or until a predetermined amount of time has elapsed. Thereafter, the radiation sensor is powered up, reads the voltage level, and transmits the reading to the RFID system. This reading is then relayed to the surrounding RFID system for collection and analysis at one or more central locations. The dose integration time (interval) can be from several minutes to several days. Since a sea voyage can last for several days, it can allow several days of dose integration for very sensitive measurements.

The central RFID system may send a message to each container to obtain a baseline reading when the vessel leaves port. The central system can then instruct the RFID tags to read the radiation sensors at regular intervals (eg, every 12 or 24 hours) during the voyage. The sensor readings may be communicated to the RFID central system by RFID tags, tag readers, site servers, etc., where the received doses are collected and analyzed. As the vessel passes through the ocean (ie, during voyage), any radiation dose readings above expected background levels will be flagged and the appropriate authorities notified. This will stop the vessel before it reaches the US port (or other importing country) and allow the container to be inspected.

<b>filling membrane</b><b> loot (</b><b>EIC</b><b>) dosimeters</b>

The EIC consists of an electrically charged polymer (eg, Teflon) filament or disk called an electret, placed inside an electrically conductive plastic chamber with a known volume of air. The electret serves as a high voltage (anode) source for the chamber to operate as an ion chamber. It also serves as a sensor for ionization measurements in chamber air. Negative ions generated inside the sensitive volume of the chamber by radiation-induced ionization of air are collected by the electret, causing charge depletion. The measurement of the depleted charge during the exposure period is a measurement of the ionization integrated during the measurement period. The electret charge can be read before and after exposure, or on a known schedule using a non-contact electret voltage reader.

In a preferred embodiment of the present invention, the electret charge reading voltmeter is a very small, low cost electronic circuit, or possibly an ASIC chip, which not only reads the electret charge but also charges the electret as needed. This circuit or chip may also include data sufficient to convert the measured voltage to a radiation dose, and transmit this data via a (eg IEEE 1451 compliant) sensor bus.

A further optional feature of the present invention is that it is possible to surround the EICs, such that each EIC is sensitive to different radiation types (eg, neutron, gamma or x-ray) or energies (hard x-ray, soft x-ray, etc.). radiation filtering materials or converters. Measurement of the presence and amount of increased radiation levels, as well as some qualitative characteristics of radiation, will help to distinguish hazardous radioactive cargo from normal safe cargoes (usually bananas, some pottery, etc.) that normally have higher radiation levels. can Additionally, one EIC sensor can be mounted and shielded to measure background radiation to remove background from sensor measurements inside the container.

EIC devices are shock sensitive and can partially discharge when shaken or dropped. To prevent inaccurate positive radiation measurements due to severe handling experienced by shipping containers, the present invention may include active and passive preventive measures. First, the ability to communicate to each sensor via an RFID tag on each container allows the radiation sensors to integrate doses, which are then read during known low-impact potential times, such as during sea shipping. Readings begin when the vessel leaves port and may be taken during the voyage time period. Second, an accelerometer can be positioned with the sensors to identify shock events of sufficient magnitude to cause the EIC to discharge. After these events, the EIC is read and the dose integration time can be restarted.

<b>electric field</b><b> effect transistor dosimeters</b>

FET dosimeter operation is based on the generation of electron-hole pairs in the oxide (or other insulator material with very low hole mobility) of the (eg, IGFET) structure (gate oxide) due to ionizing radiation. The energy to generate one electron-hole (eh) pair in silicon oxide is approximately 18 eV. Electron mobility is that (assuming an n-channel device) electrons are collected on the gate of the transistor, but the hole mobility is much smaller. Thus, the holes are effectively fixed in the oxide between the gate and the body. This causes a change in the electric field between the channel and gate of the transistor, which alters the current-carrying performance of the channel. Thereafter, these changes can be read at any time without affecting the dosimetry-modified electric field. Thus, the gate bias voltage is a direct measure of the absorbed radiation dose. This technique can be applied to both field-oxide FETs (parasitic FETs, IGFETs) or to FETs intentionally fabricated in a given CMOS process. The latter case will display more sensitivity due to thicker oxides.

<b>micro cantilever</b><b> radiation dosimeters</b>

Microcantilever dosimeters are created by making the microcantilever an electrode separated from ground by an insulator. An electric charge is applied to the microcantilever. This charge does not change until radiation creates electron-hole pairs in the insulator. Thus, the absorbed radiation dose is continuously and manually integrated. To read the radiation dose, the change in the voltage potential of the microcantilever is measured. This potential or change in potential is determined by measuring the deflection of the microcantilever.

<b>Radiation types or energy </b><b>between the levels</b><b> Filters and Converters for Differentiation</b>

The present invention may include the use of different types and thicknesses of materials to create radiation sensors that are sensitive to specific types of radiation or to different energy levels. The present invention may include the use of a plurality (eg, an array) of low cost detectors in a shipping container, each having a different filter. Since the types of SCD radiation detectors described above can be produced in large quantities very cheaply, an array of detectors can be located throughout the container. Filters of variable density metals such as lead, tin, and aluminum can be used to roughly determine the energy of the impinging gamma or x-rays. Radiation converters such as boron or lithium-6 can be used to create devices sensitive to thermal neutrons. Teflon or high hydrogen-containing plastics can be used to increase sensitivity to medium-energy neutrons. By using an array of detectors, each using a different filter and converter, located inside the container, any radiation detected in the container can be measured in energy bands (eg, low, medium, and high) and radiation type (beta, x-ray, gamma).

<b>RFID communication system</b>

The present invention may combine radiation sensors with a communication and tracking system that relays sensor data and container location to a central database, where the radiation data from all containers is analyzed to flag containers requiring further scrutiny. can be The entire RFID system may be referred to as a "Maritime Asset Security and Tracking (MAST) System". The MAST system is preferably radio (RF)-based for tracking and monitoring of maritime industry-standard shipping containers both at port-side wharf facilities as well as during onboard loading, unloading, and transport operations during overseas transport of containers. It is a communication and sensing/telemetry system. The system also provides a true linkage tracking and monitoring system that can operate within ships, railroads, on-road trucks and associated terminal facilities, including local-terminal including satellite and/or cellular/PCS. communication systems and other wide area commercial communication systems. This RFID tag system consists of RFID tags attached to each shipping container, local site readers located throughout the vessel and at shipping terminals, one central site server on each vessel or at each terminal, and all data is collected, It may include a National Operations Center (NOC) that is integrated, stored, analyzed, and disseminated. Shipping containers can be both refrigeration-freight shipping containers (refrigeration vessels) and dry-freight shipping containers (dry-boxes). In addition to identifying and tracking the location of containers or other equipment adapted to one of the RFID tags, each tag also allows the connection of a wide range of sensors to the RFID tag to monitor the status of container cargo or other tagged equipment. For example, an IEEE 1451 sensor interface and redundant serial interfaces are equipped. Other sensors that may be coupled to RFID tags include, but are not limited to, temperature, pressure, relative humidity, accelerometer, radiation, door seals, and GPS (Global Positioning System). Additional sensors may also be included to monitor the condition of machinery such as refrigeration compressors and read a diagnostic data port for some refrigerated cargo containers.

The present invention may include the implementation of a radiation sensor system for MAST system RFID tags. The MAST system provides a solution to the problem of combining data from a container facility with a full monitoring, tracking or communication system, and the problem of not using power during the dose integration time is addressed by using a set of passively integrating radiation sensors. . An embodiment of the present invention continuously, manually integrates the radiation dose, and transmits this data to an RFID tag on the container through the IEEE 1451 sensor interface, and then transmits this data and other sensor data with location to the MAST system national operation It includes a class of radiation dosimeters that transmit to a center (NOC). In the NOC, all sensor data, a list of containers, routes traveled by the container and other information are analyzed and can be used to identify containers for detailed investigation at Ports of Entry.

The present invention may involve manually integrating the radiation dose over long periods of time while using power only to read the received dose. The present invention may include coupling a radiation sensor and an RFID system, wherein the RFID system will communicate sensor data to a central database in near real-time to identify and flag containers with abnormal radiation readings. Analysis of sensor data may be performed.

The present invention may include in situ polling a set of passively integrated ionizing radiation sensors comprising reading dosimetry data from a first passively integrated ionizing radiation sensor and a second passively integrated ionizing radiation sensor, wherein , the first passively integrating ionizing radiation sensor and the second passively integrating ionizing radiation sensor are positioned where the dosimetric data is integrated while reading the dosimetric data, and the first passively integrating radiation sensor and the second passive integral The type radiation sensor is coupled to readout circuits presenting a very high impedance during passive integration mode and during active readout mode, which without destroying the integrated dosimetry data, the first passively integrating ionizing radiation sensor and the second 2 Passive integration allows continuous integration of ionizing radiation with the maximum range of the ionizing radiation sensor. Upon detection of reaching the maximum integration limits, the readout circuits reset the passively integrating radiation sensors and can accumulate the number of sensor reset cycles in a non-volatile manner.

The present invention relates to a first passive integral ionizing radiation sensor; a second passive integral ionizing radiation sensor; a readout circuit coupled to both the first passive integrating ionizing radiation sensor and the second passively integrating ionizing radiation sensor, wherein the readout circuit generates a first very high impedance both while in the passive integration mode and while in the active readout mode. present in both the passive integral ionizing radiation sensor and the second passive integral ionizing radiation sensor; and communication circuitry coupled to the reading circuitry, wherein the reading of the dosimetry data from both the first passively integrated radiation sensor and the second passively integrated radiation sensor is presented to the communication circuitry.

One or both of the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor may comprise a thick oxide insulated gate field effect transistor space charge dosimeter. The read circuits are approximately 10<sp>11</sp> ohms to about 10<sp>15</sp> ohms, preferably about 10<sp>12</sp> to about 10<sp>14</sp> of ohms, most preferably about 10<sp>13</sp> You can give the impedance in ohms.

As noted above, the present invention may include a thick oxide dosimeter (TOD). In such a TOD, the FETs may be arranged such that the gates are connected to two or more levels of metal or polysilicon. This is because SiO can interact with ionizing radiation.<sb>2</sb>will increase the active volume of These devices have the significant selective advantage of temperature and process compensation by reading the voltage across the drains, assuming the sources are connected to a common electrical potential. The gates and drains for a given IGFET may be connected together.

This technique can be extended by simply adding FETs to the limitations of the semiconductor fabrication process used, as well as stacking metal layers on top of them. The advantage is that the active volume of the oxide used for detection increases, but the electric field created by the charge trapped between any two plates is reduced by increasing the distance between the plates. As many plates as the manufacturing process allows can be used to obtain the largest electric field for a given ionizing radiation event to ensure the highest probability of detection.

10 and 11 show two IGBT examples of the present invention. In the description of the elements shown in these figures, the use of the terms "first, second and third" is merely for distinguishing between similar elements, and the designation of these terms is arbitrary.

Referring to FIG. 10 , a set of passively integrated ionizing radiation sources includes a first sensor 1010 that is shielded by a first filter 1011 . This set of passively integrated ionizing radiation sensors also includes a second sensor 1020 that is shielded by a second filter 1021 . Both the first sensor 1010 and the second sensor 1020 are coupled to the communication circuit 1030 . A temperature compensation circuit 1040 is coupled to the communication circuit 1030 . Calibration circuitry 1050 is also coupled to communication circuitry 1030 . Each of the sensors 1020 and 1030 is based on a pair of insulated gate field effect transistors.

The present invention may include an apparatus comprising a thick oxide dosimeter and a readout circuit coupled to the thick oxide dosimeter, wherein the thick oxide dosimeter and the readout circuitry are on one high impedance and low leakage substrate. is composed in The thick oxide dosimeter may comprise a thick oxide insulated gate field effect transistor space charge dosimeter. One high impedance and low leakage substrate may include a construction of silicon on sapphire, silicon on insulator and/or strained high resistivity silicon. The board is about 10<sp>11</sp> ohms to about 10<sp>15</sp> ohms, preferably about 10<sp>12</sp> to about 10<sp>14</sp> of ohms, most preferably about 10<sp>13</sp> It can have an impedance of ohms.

Referring to FIG. 11 , the passively integrated ionizing radiation sensor 1100 includes a first active region (region) 1110 and a second active region (region) 1120 . The first active region 1110 is sandwiched by the common conductor 1130 and the first active region conductor 1140 . The second active region 1120 is sandwiched by the common conductor 1130 and the second active region conductor 1150 . A first active region conductor 1140 couples to the gate of a first insulated gate field effect transistor 1160 . A second active region conductor 1150 couples to the gate of a second insulated gate field effect transistor 1170 . The sources of both the first insulated gate field effect transistor 1160 and the second insulated gate field effect transistor 1170 are coupled together and coupled to a common conductor 1130 . A third insulated gate field effect transistor 1180 provides integrated temperature compensation functionality.

During the passive-mode dosimetry operation of the examples shown in FIG. 11, ionizing radiation passes through the active region, generating a net charge that is trapped in the oxide. This charge creates an electric field between adjacent conductors, thus creating a net change in resistance seen between the gate and source of the FET where the active region strikes. The net radiation dose is proportional to the change in resistance. Temperature compensation is applied by tracking changes in the third IGFET, which has much less radiation sensitivity than others.

The present invention provides a first insulated gate field effect transistor comprising a first source, a first drain and a first insulated gate; a second insulated gate field effect transistor comprising a second source, a second drain and a second insulated gate, wherein the second source is coupled to the first source; a first conductor coupled to the second gate; a first active region coupled to the first conductor; the first active region accumulates dosimetry data from incident ionizing radiation; a second conductor connected to the first active region; a second active region coupled to the second conductor, wherein the second active region accumulates dosimetry data from incident ionizing radiation; and a third conductor coupled between the second active region and the first gate, wherein the second conductor couples to both the first source and the second source. The third insulated gate field effect transistor may provide temperature compensation data.

The present invention may include arranging a plurality of sensors in a spatially distributed (eg, array) configuration, and setting an alarm condition based on readings of the plurality of sensors.

The present invention may include pattern recognition. For example, the method may include arranging a plurality of passively integrating ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of a plurality of passively integrating ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of passively integrated ionizing radiation sensors; and triggering an alert condition when the ionizing radiation data collected from the subset of the plurality of passively integrated ionizing radiation sensors meets a predetermined spatial pattern criterion. A given spatial pattern reference may include a plurality of alternative patterns. The predetermined spatial pattern reference may comprise a dosimetry data pattern defined by a function comprising the cube root of a radius from the approximate location of the ionizing radiation source.

Embodiments of the present invention are cost effective and may be advantageous for at least the following reasons. Embodiments of the present invention may provide world-wide asset and/or cargo tracking, monitoring and security. Embodiments of the present invention may include integration of RFID tag data in GIS-based systems for asset tracking, management and visualization. An embodiment of the present invention may include RFID tag communications using hybrid spread-spread signaling. Embodiments of the present invention may include multiple-access techniques that allow communication with more than 10,000 RFID tags, but ignore up to 90,000 tags in the same RFID tag reader zone. Embodiments of the present invention improve quality and/or reduce cost compared to conventional approaches.

As used herein, the phrase "hybrid band-spreading (HSS)" refers to direct sequence band-spreading (DSSS) (eg, code division multiple access (CDMA)), and frequency hopping, time hopping, time division multiple access (TDMA), ), orthogonal frequency division multiplexing (OFDM) and/or spatial division multiple access (SDMA). As used herein, the singular expression includes the plural expression. A plural expression as used herein is defined to include at least two or more. As used herein, the terms "comprises, comprises", "comprises, consists open to including unspecified process(s), structure(s) and/or component(s) in quantities). As used herein, the terms "consisting of (consisting of, comprising)" and/or "comprising Closes a disclosed method, apparatus, or configuration for inclusion of other processes, structure(s) and/or component(s). The recitation of the term "essentially" in conjunction with the terms "consisting of" or "comprising" refers to an unspecified process(s) in which the disclosed method, apparatus and/or composition does not materially affect the basic novel properties of the composition; be open only to the inclusion of structure(s) and/or component(s). As used herein, the term "coupled" is defined as "connected", although not necessarily directly and not necessarily mechanically. As used herein, the term "any" is defined as the set of all applicable members or at least a subset of the set of all applicable members. As used herein, the term "approximately" is defined as at least close to a predetermined value (eg, preferably within 10%, more preferably within 1%, and most preferably within 0.1%). As used herein, the term "substantially" is defined broadly but not necessarily in its entirety. As used herein, the term "in general" is defined as approaching at least a certain state. As used herein, the term "deployed" is defined as designing, building, shipping, installing and/or operating. As used herein, the term "means" is defined as hardware, firmware and/or software for achieving a result. As used herein, the term "program" or the phrase "computer program" is defined as a sequence of instructions designed for execution on a computer system. A program or computer program is a subroutine, function, process, object method, object implementation, executable application, applet, servlet, source code, object code, shared library/dynamic load library designed for execution on a computer or computer system. and/or other instruction sequences. As used herein, the term "proximate" is defined as close, nearly adjacent and/or coincident, and includes spatial situations in which certain functions and/or results can be performed and/or achieved. As used herein, the phrase "radio frequency" is defined as including infrared as well as frequencies below approximately 300 GHz.

All embodiments of the invention disclosed herein may be formed and used without undue experimentation in light of this disclosure. The embodiments of the present invention are not limited to the theoretical statements set forth herein. Although the best mode for carrying out the embodiments of the invention contemplated by the inventor(s) has been disclosed, the practice of the embodiments of the invention is not limited thereto. Accordingly, it will be understood by those skilled in the art that embodiments of the present invention may be practiced otherwise than as specifically disclosed herein.

It will be apparent that various substitutions, modifications, additions and/or reconstructions of features of the embodiments of the present invention may be made without departing from the spirit and/or scope of the inventive concept below. The spirit and/or scope of the inventive concept below, as defined by the appended claims and their equivalents, is intended to cover all such substitutions, modifications, additions and/or reconstructions.

All disclosed elements and features of each disclosed embodiment may be combined with or substituted for the disclosed elements and features of each other disclosed embodiment, except where such elements or features are mutually exclusive. Changes may be made in the steps or sequence of steps defining the methods described herein.

Although the sensor(s) with or without filters described herein may be a separate module, it will be apparent that the sensor(s) may be integrated into an associated system. Individual components need not be formed in the disclosed shapes or combined in the disclosed configurations, but may be provided in all shapes and/or combined in all configurations. The individual components need not be made from the disclosed materials, but may be made from any suitable materials.

The appended claims are not to be construed as including means-plus-function limitations (provided that the use of the phrase(s) "means for" and/or "steps for" except where such limitations are expressly stated in the claims). Subgeneric embodiments of the invention are illustrated by the appended independent claims and their equivalents. Certain embodiments of the invention are differentiated by the appended dependent claims and their equivalents.