System providing land mobile radio content using a cellular data network

The present invention relates to terrestrial mobile radio, and more specifically to a system that provides terrestrial mobile radio content using a cellular data network.

The land mobile radio (LMR) can be used to communicate (transmit) between different mobile units, such as the land mobile radio. Land mobile radio band communications, such as public safety radio communications (eg, police, fire departments, etc.), are generally available within the VHF, UHF, 700 MHz and 800 MHz frequency bands. Some of these frequency bands are allocated by the Federal Communications Commission (FCC) for public security communications services and are also referred to as public security frequency bands. These communications can also be provided using the Private Land Mobile Radio Service (PLMRS).

Cellular nets also provide communication between different mobile users, such as mobile phones. These cellular networks continue to be strengthened, enabling continuous growth of applications to make them available to users. For example, these cellular networks offer push-to-talk (PTT), which provides the ability to connect directly. This allows the mobile phone user to request a direct connection communication link with another mobile phone user in two-way wireless or "walkie-talkie" communication. As another example, these cellular networks include, for example, General Packet Radio Service (GPRS), Enhanced Data Rate for GMS Evolution (EDGE), Evolution Data Optimization (EV-DO) and UMTS Mobile Phone Services ( Provides high-speed data services such as UMTS).

Known systems that provide enhanced calls or features, such as enhanced calls or voice features that can be used, for example for mission critical wireless networks, for public safety applications, etc., to augment or replace conventional LMS systems. Use commercial cellular services such as PTT services. These known systems allow some interaction between cellular and LMR systems capable of PTT by translating or translating data or voice communications communicated between networks, such as from LMR networks to cellular networks. Provided using special gateway equipment that enables capabilities.

New technologies will also be offered in the land mobile radio (LMR) industry, including the use of digital communications as an alternative to analog communications. In addition, today, LMR systems use packet switching instead of circuit switching, using, for example, Internet Protocol (IP) and voice over IP over the Internet, for highly scalable and low cost LMR networks. Can be configured.

Traditionally, LMR networks have been used to provide mission-critical applications such as public security communications. In addition to providing a very high level of system availability, LMR networks are primarily designed to support PTT services such as dispatch mode of operations. In LMR networks, PTT services are often configured to operate while connected to a given workgroup. Workgroups can be further organized into talkgroups for communication purposes. During operation, wireless users and dispatchers are willing to use PTT on talk groups. The LMR network is configured so that all members of a workgroup receive communications broadcast in a particular talkgroup.

In addition to PTT services, LMR networks can also have features that support a variety of mission-critical applications. For example, in public security applications, LMR networks provide a number of emergency services, for example, allowing a user in need to issue an emergency alert with the push of a button. The LMR network also offers a variety of priority and preemptive services. These services provide system access to the most important communications when the capacity or resources to handle all simultaneous PTT calls are inadequate.

<p> These LMR systems use a special LMR airlink protocol that wirelessly communicates between the LMR radio and the LMR infrastructure. A known system for providing LMR communication, such as PTT, on a public network, such as a public cellular network, uses VoIP to translate or translate data or communication, for example, on a terminal / wireless device. As a result, these systems complicate the entire system and increase costs by requiring additional controls and equipment to perform interconnectivity.</p>

<p> The solution is provided by a method of transmitting (communication) terrestrial mobile radio (LMR) content. The method comprises the steps of transmitting LMR content via at least one LMR network and a cellular data network. The method further comprises the step of encapsulating the LMR content using a packet switching protocol when transmitting the LMR content over the cellular data network.</p><p> The solution is also provided by a radio communication system having a packet-switched land mobile radio (LMR) infrastructure configured to communicate with multiple LMR units via at least one LMR network and a cellular data network. The communication system further has an interface configured to process received LMR content encapsulated in a packet switching protocol.</p><p> The solution is also contained in a carrier wave and is provided by a digital signal having a land mobile radio (LMR) data unit and a packet switching protocol encapsulation unit.</p>

Hereinafter, the present invention will be described with reference to the accompanying drawings.

Various embodiments of the present invention include a system for providing LMR content, such as a land mobile radio (LMR) service using a cellular data network. The LMR content has an LMR application layer, but instead of using the LMR frequency band with the LMR transport protocol, the LMR content is transmitted using the cellular frequency band over the cellular packet switched data network.

When referring to LMR content herein, LMR content generally refers to any type or type of LMR audio / data content, which may define specific LMR services, behaviors, controls, etc. Please note. For example, LMR content includes voice data, emergency signal data, control data related to the selection of a specific talk group, LMR data for movement between wireless units and servers, reprogramming data (eg, software upgrade data). ) Etc., but not limited to these.

In particular, as shown in FIG. 1, a wireless communication system, particularly an LMR communication system 20 configured according to various embodiments of the present invention, provides communication between a plurality of LMR units 22, i.e., LMR terminals. Communication between the LMR units 22 is provided via the LMR network 24 or the cellular data network 26. Each LMR unit 22 is configured to use one of the LMR network 24 and the cellular data network 26 to provide communication with, for example, the other LMR unit 22. In particular, each LMR unit 22 is configured to switch between the LMR network 24 and the cellular data network 26 based on, for example, the available network, available bandwidth, service area, communication signal strength, and the like. There is. Optionally, in another embodiment, switching between one of the LMR network 24 and the cellular data network 26 is based on the type of communication or content. Thus, in addition to providing communication over the LMR network 24, the wireless data service of the cellular data network 26 may be used to support communication and / or transport of the LMR application layer protocol.

In various embodiments, the inter-terminal LMR service can be located at the top of the cellular data network 26, so that it is possible to implement a core LMR system within the service area of these cellular data networks 26, for example. To provide this functionality and communication of LMR content using the cellular data network 26, each LMR unit 22 such as an LMR radio has a service between the LMR unit 22 and the packet-switched LMR infrastructure and an inter-terminal LMR. A cellular wireless modem device is provided so that the application layer protocol can be operated.

In particular, as shown in FIG. 2, the LMR unit 22 has a plurality of modules or components configured to communicate via the LMR network 24 or the cellular data network 26. Specifically, the LMR unit 22 has an LMR application module 30. Application module 30 communicates over LMR network 24 (with one or more LMR base stations 46) using LMR transmitter / receiver 34, which may be provided as a separate unit or as a single transceiver. It is connected to the LMR transfer module 32 that constitutes one or both of the voice and data for the operation. The LMR application module 30, the LMR transfer module 32, and the LMR transmitter / receiver 34 generally define the LMR communication unit 40 of the LMR unit 22. The LMR unit 22 further includes an LMR encapsulation module 36 that encapsulates one or both of voice and data for communication over the cellular data network 26 using the cellular wireless modem 38. The LMR application module 30, the LMR encapsulation module 36, and the cellular wireless modem 38 generally define the cellular data network communication unit 42 of the LMR unit 22.

The LMR unit 22 may have additional components such as antennas (not shown) used for transmitting and receiving signals, as is known, for example. Further, for example, the LMR unit 22 may have a filter (not shown) such as a reception filter and a transmission filter for filtering the signals received and transmitted by the LMR unit 22, respectively. The LMR unit 22 may also have, for example, a switch or other controller (not shown) for switching between the LMR communication unit 40 and the cellular data network communication unit 42.

In operation, the LMR system 20 may communicate over the LMR network 24 using a different known protocol, such as the LMR airlink protocol. For example, these LMR Airlink protocols include Project 25 (TIA102) and the ETSI TETRA standard. These LMR airlink protocols identify formats and procedures for exchanging information between the LMR unit 22 and the LMR network 24, and in particular the LMR base station 46. If base station 46 is part of a larger system, base station 46 reciprocally (not shown) a switching device (not shown) that sends audio and data between different parts of the system to other LMR base stations, dispatch controllers, etc. Note that it will be connected.

As is known, the LMR base station 46 is of voice, data and control received on an airlink into another format suitable for communicating within the LMR network 24, for example to transfer to a switching device. Process, eg, manipulate information. For example, the received discontinuous voice, data and control transmissions are known as the resulting IP packet being transmitted (communicated) between the LMR base station 46 and the switching device on the IP network. May be encapsulated in TCP / IP or UDP / IP packets.

LMR Unit 22 also includes, for example, General Packet Radio Service (GPRS), Enhanced Data Rate for GMS Evolution (EDGE), Evolution Data Optimization (EV-DO) and UMTS Mobile Phone Service (UMTS) and 802.16 standards. Etc. may be used to communicate over the cellular data network 26 using different known protocols such as. These cellular protocols identify formats and procedures for exchanging information between the LMR unit 22, in particular the cellular wireless modem 38, and the cellular data network 26.

For example, a cellular tower (not shown) with a base station (not shown) receives a signal from the LMR unit 22 and processes it, eg, receives voice, data and control information within the cellular data network 26. It may be provided to operate in another format suitable for communication with, for example, to transfer to routers and servers (not shown) based on the IP address for received data packets. For example, the received encapsulated signal is decapsulated and appropriately sent within the cellular data network 26.

Therefore, the data from the LMR network 24 or the cellular data network 26 is transmitted to the packet-switched LMR board 41. Note that LMR content and LMR networks may be configured based on different airlink protocols. To communicate over the LMR network 24 or the cellular data network 26 using the LMR unit 22, the communication protocol stack for communicating with each of these networks is partitioned as shown in FIG. In particular, with respect to communicating with the LMR unit 22 using the LMR network 24, the LMR protocol stack 60 is a plurality of two-layer protocol stacks having the LMR application layer 62 and the LMR transport layer 64 in one typical embodiment. It is divided into layers. The application layer 62 and the LMR transfer layer 64 can be provided, for example, by the LMR application module 30 and the LMR transfer module 32 (both of which are shown in FIG. 2), respectively. The LMR application layer 62 is configured to provide translation and processing of voice, data and control information. In addition, the LMR transport layer 64 is configured to deliver voice, data and control information on the transmission medium. As described herein, the LMR Airlink Protocol defines both the LMR application layer 62 and the LMR transport layer 64.

In this two-layer protocol stack model, the switching equipment in the LMR base station 46 (see FIG. 2) and the LMR network 24 (see FIG. 2) receives the content from the LMR communication unit 40 and the LMR application layer 62 in between. Communicate content with different transport layers. In particular, as shown in FIG. 3, the content of application layer 62 is encapsulated at LMR base station 46 (see FIG. 2) using LMR content encapsulation 66 as is known. In one typical embodiment, the discontinuous transmission unit is encapsulated within the transport datagram, particularly within the packet-switched transport datagram 68 that is communicated using the transport protocol. Upon receiving the encapsulated datagram, the application layer content is then recovered, especially uncapsulated.

In addition, this two-tier protocol stack model allows, for example, the cellular data network communications section 42 (see Figure 2) to deliver LMR application layer services over non-LMR wireless networks. Specifically, the cellular data network communication unit 42 is configured to provide the LMR application layer 62, and instead of using the LMR transport layer 64, the transport service of the wireless cellular data network 26 (see FIG. 2) is used. .. In particular, since the LMR encapsulation layer 70 is used with packet-switched transport datagrams 68, the wireless cellular data network 26 communicates with the switching equipment using a suitable transport protocol. As a result, the same LMR application layer service as the LMR communication unit 40 is distributed. Specifically, the packet-switched LMR infrastructure 41 (see Figure 2) uses the LMR application layer switching 72 in combination with the packet-switched transport datagram 68 to convey LMR application services.

Note that the various embodiments are not limited to the two-layer protocol stack and may include additional layers in the multi-layer protocol stack if desired. For example, different session layers such as a mass encryption layer may be provided. Further, for example, an RTP layer may be provided.

Various embodiments of the present invention use an LMR network, and in particular a non-LMR wireless network, which is a wireless cellular data network, to control the communication of LMR content within an LMR communication system. In particular, method 100 for controlling the communication of LMR content is shown in FIG. 4 and includes step 102 of determining the network used to transmit the LMR content. In one typical embodiment, a decision is made as to whether LMR content is transmitted using an LMR network or cellular data network. This decision may be based on manual selection, for example based on user input of the choice of which network to use. This selection may be made, for example, using the buttons or switches on the LMR unit 22 (see FIG. 2). Alternatively, optionally, the decision of which network to use may be made automatically. For example, the choice of network to convey LMR content is the amount of data traffic on a particular network or available bandwidth, the level of transmission priority, the type of communication or content (eg, voice or emergency broadcast signal, emergency communication or It may be based on PTT requirements), signal strength for the LMR unit, geographic location of the LMR unit, user choice, etc.

After the network used to transmit the LMR content is determined in step 102, the communication method is selected in step 104 based on the network determined to be used. For example, the communication speed or baud rate may be selected (manually or automatically) from the range of communication data rates. In addition, you may choose the preparatory steps to establish and connect to the determined network. For example, when an LMR network is used, a preparatory routine for LMR network communication may be executed to establish a communication link between the LMR unit and the LMR network via the LMR transmitter / receiver in the LMR unit. If a cellular data network is used, a preparatory routine for cellular data network communication may be performed to establish a communication link between the LMR unit and the cellular data network via the LMR unit's cellular wireless modem. This preparatory routine may include any suitable processing, as is known for establishing wireless communication links.

Then, in step 106, the LMR content is configured to be propagated based on the selected network and the selected communication method. For example, if LMR content is propagated using an LMR network, a particular LMR standard that configures or formats the LMR content is selected. In particular, the LMR standard that constitutes the payload of one or both of the audio and data that define the LMR content is selected. This may include, for example, selecting either Project 25 (TIA102) for communication methods or the ETSI TETRA standard. Further, for example, a proprietary format such as an open sky Maycom proprietary format, network first, or an EDACS system proprietary format may be selected.

Further, for example, when LMR content is transmitted using a cellular data network, a specific wireless cellular data network standard that configures or formats the LMR content is selected. In particular, the radio cellular standard that constitutes the payload of one or both of the audio and data that define the LMR content is selected. This includes, for example, General Packet Radio Service (GPRS), Enhanced Data Rate for GMS Evolution (EDGE), Evolution Data Optimization (EV-DO) and UMTS Mobile Phone Service (UMTS) and 802.11 system standards. It may include selecting one of the above.

Additionally, a specific protocol stack may be used based on the network used to convey the LMR content, as described in detail with respect to FIG. In addition, when LMR content is propagated using the LMR network, LMR protocol headers are added to the LMR data payload. Packet switch protocol headers are added when LMR content is propagated using a cellular data network. As described in detail below, when using a cellular data network to convey LMR content, the LMR content is encapsulated, for example, before communication to or to the cellular data network, the Internet Protocol ( IP) IP encapsulated with a wrapper. The method of encapsulating the data is described in detail below with reference to FIG.

Returning to FIG. 4, after the LMR content is configured in step 106, the configured LMR content is transmitted in step 108. For example, if the LMR network is configured to carry LMR content, LMR transmitters and receivers may be used to carry the LMR content. If the cellular data network is configured to propagate LMR content, a cellular wireless modem may be used to propagate the LMR content. Note that the cellular wireless modem may be configured to operate in a single mode of operation or in multiple modes. In another embodiment, two or more cellular wireless modems may be provided. Each cellular wireless modem may be configured to operate in a single mode of operation or may be configured to operate in multiple modes of operation.

For example, after the LMR content is transmitted and received by a network base station, the LMR content is processed in step 110 to determine an action. For example, this process may be a decision to convey voice data, a decision to issue an emergency signal, or a decision to issue a PTT request to a talk group. For example, if LMR content is propagated using a cellular data network, the IP destination address of the encapsulated datagram is determined first, and then to that location for processing using the network's routers. It may be transmitted.

In another embodiment, a packet-switched protocol interface 120 may be provided in connection with the cellular data network 26 (see FIG. 2), as shown in FIG. The packet-switched protocol interface 120 may be, for example, a separate unit (eg, a stand-alone module), a card for connecting to a server within a cellular data network, software for downloading to a server within a cellular data network, or the like. You may make it as. The packet-switched protocol interface 120 includes a processor 122 for processing packet-switched encapsulated LMR content received, eg, to propagate to a packet-switched LMR infrastructure 41 (see FIG. 2). In particular, as detailed in connection with FIGS. 4 and 5, the processor may receive LMR content formatted as shown in FIG. LMR content generally has an LMR data section and a packet switching protocol encapsulation section. Specifically, the LMR content 130 may include LMR data 136 such as packet switch protocol header 132, LMR protocol header 134, and LMR data payload.

The LMR content 130 is basically encapsulated, for example with an IP wrapper. Processor 122 may uncapsule the LMR content 130, for example by removing the packet switch protocol header 132, and store the encapsulated LMR content 130 in memory 124. The LMR content 130 is then further processed by the processor 122 to determine the action to be performed or the address within the packet-switched LMR infrastructure to which the LMR content 130 is transmitted. Basically, the LMR content 130 is configured to propagate within a packet-switched LMR infrastructure or LMR network once it is uncapsulated. The transmission of the LMR content 130 is controlled by the controller 126. The controller 126 may have, for example, a router 128 for sending LMR content 130 to a destination in the LMR network. Note that the LMR content may be re-encapsulated for transmission within the LMR network or within the cellular data network.

Next, with reference to FIG. 5, the LMR content processing method 150 is disclosed, and in step 152, a decision is made as to whether the LMR content is transmitted using the LMR network. If it is determined in step 152 that the LMR content is propagated using the LMR network, then in step 154 the LMR content is propagated to the LMR network. This may include the step of transmitting the LMR content to the base station of the LMR network based on the LMR protocol header provided in connection with the LMR content. The LMR content is then encapsulated in step 156, eg, encapsulated in a wrapper defined by the Airlink protocol as described herein and sent in step 158. For example, encapsulated LMR content, which may be configured as a datagram, may be sent within a packet-switched LMR infrastructure.

At the destination of the LMR content, the LMR content is processed in step 160, eg, uncapsulated, and then the action is determined in step 162 based on the processed data. For example, in step 162, a decision is made that an emergency signal is transmitted, or that LMR content is further sent to another base station. Then, in step 164, the corresponding action is performed, for example, within the packet-switched LMR infrastructure.

If it is determined in step 152 not to propagate the LMR content using the LMR network, then the LMR content is encapsulated for transmission (communication) in step 166. For example, in one typical embodiment, the LMR encapsulation module 36 (see FIG. 2) performs the LMR encapsulation layer 70 (see FIG. 3) and encapsulates the LMR content in a wrapper, such as an IP wrapper. The encapsulated LMR content is then propagated in step 168 using a cellular data network. This may include in step 170 the step of sending encapsulated LMR content within the cellular data network. The LMR content is transmitted to the packet-switched substrate in step 172, for example, based on the IP address from the IP wrapper.

The LMR content is then processed at the destination. This process may include uncapsulating the LMR content and determining the action in step 162. For example, an emergency signal may be transmitted, or a decision may be made to further send LMR content to another base station. The corresponding action is then performed in step 164, for example, within the packet-switched LMR infrastructure.

As such, various embodiments of the invention are provided to convey LMR content using LMR networks, or, for example, non-LMR networks, which are cellular data networks. When LMR content is propagated using a cellular data network, the LMR content is encapsulated in a packet switching protocol prior to transmission. For example, as shown in FIG. 9, the LNR communication system 200 generally has a plurality of cellular data network base stations 202 and a plurality of LMR network base stations 204. The plurality of cellular data network base stations 202 and the plurality of LMR network base stations 204 have corresponding cellular data network communication service areas 206 and LMR network communication service areas 208, respectively. The cellular data network communication service area 206 and the LMR network communication service area 208 may overlap at several positions. In various embodiments of the invention described herein, for example, a mobile unit or an LMR unit 210 that is an LMR radio in an automobile depends, for example, on the location of the LMR unit 210 and the corresponding available service area. Allows communication via a cellular data network or LMR network. In particular, a communication tower (not shown) corresponding to each of the plurality of cellular data network base stations 202 and each of the plurality of LMR network base stations 204 enables wireless communication as described herein.

Further, as shown in FIG. 9, the controller 212 in the packet-switched substrate 41 communicates from the plurality of cellular data network base stations 202 and the plurality of LMR network base stations 204 as described herein. May be configured to control. As described herein, the controller processes multiple data packets received from the LMR network 24 or cellular data network 26 to determine the appropriate action or delivery procedure for a particular data packet. May be good.

Various embodiments or components, such as the LMR communication system 20 or controller, may be implemented as part of one or more computer systems that are separate from or integrated with the LMR communication system 20. .. The computer system may have a computer, an input device, a display unit, and an interface for, for example, internet access. The computer may have a microprocessor. The microprocessor may be connected to the communication bus. The computer may have memory. The memory may include random access memory (RAM) and read-only memory (ROM). The computer system may further have a storage device which is a separable storage drive such as a hard disk drive or a flexible disk drive, an optical disk drive or the like. The storage device may also be another similar means for loading a computer program or other directive into the computer system.

As used herein, the term "computer" refers to a system using a microcontroller, RISC, ASIC, logic circuit, any other circuit, or a processor capable of performing the functions described in the present invention. It may have any processor-based or microprocessor-based system, including. The above examples are typical and are not intended to limit the definition or meaning of "computer".

The computer system executes a set of instructions stored in one or more storage elements to process the input data. The storage element may also store data or other information if desired. The storage element may be in the form of a source of information or may be a physical memory element within the processing device.

The set of instructions may have various instructions that command the computer as a processing device that performs a particular operation, such as the methods and processes of the various embodiments of the invention. The instruction set may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a separate collection of programs, a program module within a large program, or a portion of a program module. The software may also have modular programming in the form of object-oriented programming. The processing of the input data by the processing device may respond to a user command, a result of the previous processing, or a request of another processing device.

As used herein, the terms "software" and "farmware" are interchangeable and include RAM memory, ROM memory, EPROM memory, EEPROM memory, non-volatile RAM (NVRAM) in a computer. It may include any computer program stored in memory for execution. The types of memory are examples only and do not limit the types of memory that can be used to store computer programs.

It should be noted that the various embodiments of the present invention may also be provided with different functionality, additional functionality. For example, end-to-end encryption may be performed, thereby eliminating the use of intervening cryptographic equipment and the security risks encountered by having access to cryptographic keys and having such intervening equipment. .. In addition, various embodiments of the invention can provide digital audio coding between terminations, which can be encountered in the use of intervening code conversion equipment and when the digital audio format is converted to another format. Eliminate the loss of fidelity.

Further, various embodiments of the present invention may provide key functions such as PTT, scanning, priority call with preemptive rights, emergency alert, attention, content scanning and tracking, navigation, dispatch and GPS positioning. .. Core functions can be performed in different core applications, including but not limited to the public security, utility and public transport industries.

<figref num="1">FIG. 6 is a block diagram showing a land mobile radio (LMR) communication system configured according to a typical embodiment of the present invention.</figref><figref num="2">FIG. 5 is a block diagram showing an LMR unit of the LMR communication system of FIG. 1 configured according to a typical embodiment of the present invention.</figref><figref num="3">It is a block diagram which shows the protocol stack according to one typical embodiment of this invention.</figref><figref num="4">It is a flowchart of the method of controlling the communication of LMR contents in the LMR communication system according to one typical embodiment of this invention.</figref><figref num="5">It is a flowchart of the method of processing the LMR content according to one typical embodiment of this invention.</figref><figref num="6">FIG. 6 is a block diagram showing a packet-switched protocol interface configured according to a typical embodiment of the present invention.</figref><figref num="7">FIG. 6 is a block diagram showing formatted LMR content according to a typical embodiment of the present invention.</figref><figref num="8">It is a block diagram which shows the LMR communication system which was configured according to one typical Embodiment of this invention which shows a communication service area.</figref><figref num="9">FIG. 6 is a block diagram showing an LMR communication system configured according to a typical embodiment of the present invention showing data flow.</figref>

Code description

22 LMR unit 24 LMR network 26 Cellular data network 41 LMR platform 60 Multi-tier protocol stack 62 LMR application layer 64 LMR transport layer 120 interface 130 LMR content 132 Packet switching protocol encapsulation section 136 LMR data section 206 Cellular data network communication service area 208 LMR Network Communication Service Area