Method to establish and maintain an aircraft ad-hoc communication network

(54) Title: METHOD OF COMMUNICATING A MESSAGE IN A SPECIFIC DIRECT COMMUNICATION NETWORK TO AN AIRCRAFT (30) Unionist Priority: 19/10/2007 usn / 875.660 (73) Owner (s): Honeywell International INC.

(72) Inventor (s): Donald C. Kauffman, Eric N. Foster (57) Summary: method of communicating a message on a SPECIFIC DIRECT COMMUNICATION NETWORK FOR AN AIRCRAFT. A specific direct communication network including at least two vehicles such as at least two aircraft. Each vehicle includes recognition equipment, a recognition transmitter, a communication management function (CMF), a communication transmitter, and a communication receiver. The reconnaissance equipment is configured to generate at least position information and ID information. The recognition transmitter is configured to transmit at least position information and ID information. The reconnaissance receiver is configured to receive at least position information and ID information from other vehicles. The communication management function (CMF) is configured to determine a communication network topology based on the received at least position information and ID information and to determine a route for a communication signal based on the determined communication network topology and the communication transmitter is configured to transmit communication signals to a communication receiver selected in accordance with the given route.

<img file="BRPI0805213A2_D0001.tif" />

AIRCRAFT 1 .1

<img file="BRPI0805213A2_D0002.tif" />

PI0805213-1

METHOD OF COMMUNICATING A MESSAGE IN

SPECIFIC DIRECT FOR AN AIRCRAFT

Foundations

Currently in the aeronautical data link environment, the data link service of an aircraft is limited to communications links provided by data link service providers. Large airlines spend more than $ 10 million a year on data link services. Data link costs could be significantly reduced if the aircraft had a means to communicate with the airline's operations center without using data link service providers. Given the large number of aircraft operating at any given time, a feasible approach is to form an aircraft-specific direct communication network where messages are relayed to the final destination. The establishment of a specific direct communication network is based on two basic techniques: discovery of the neighbor and discovery of the topology. The purpose of discovering the neighbor is to determine which nodes are contained in the range of direct communication. In specific direct mobile communications networks, neighborhood relationships change frequently. The discovery of the neighbor is typically accomplished using a greeting protocol over the network of

A COMMUNICATION NETWORK communication. To respond to the continuous changes in the topology of the communication network, the nodes broadcast greeting messages periodically. Based on the greeting messages received, each node is able to certify its neighboring nodes. Before a routing decision can be made, a node must also determine a complete path to the destination. The discovery of the topology is performed to determine all communication routes that are available on the communication network.

During topology discovery, neighbor information is distributed to the entire communication network using topology control messages. Topology control messages are periodically distributed to the entire communication network using methods such as message flooding. The broadcasting of greeting messages and the distribution of topology information induces a significant amount of additional cost to the communication network. Due to the additional cost associated with discovering the neighbor and discovering the topology, the establishment of specific direct communication network routes and the determination that an aircraft (node) on the route is no longer available, can induce considerable additional cost on a network of communication as well as delays in routing a message, or result in drops, 25 of messages that cannot be delivered.

For the reasons set out above and for other reasons set out below it will become evident to those usually skilled in the art when reading and understanding this specification, that there is a need for a communication system in a specific direct air-to-air communication network that is efficient , reliable and relatively inexpensive to operate.

Summary of the Invention

The above mentioned problems of the systems in use today are treated by the modalities of the present invention and will be understood by reading and studying the specification presented below. The summary presented below is done by way of example and not by way of limitation. It is simply provided to assist the reader in understanding some aspects of the invention.

In one embodiment, a specific direct communication network is provided. The communication network includes at least two vehicles such as at least two aircraft.

Each vehicle includes recognition equipment, a recognition transmitter, a communication management function (CMF), a communication transmitter, and a communication receiver. The reconnaissance equipment is configured to generate at least position information and ID information. The recognition transmitter is configured to transmit at least position information and ID information. 0 reconnaissance receiver is configured to receive at least position information and ID information from other vehicles.

The communication management function (CMF) is configured to determine a communication network topology based on the received at least position information and ID information and to determine a route for a communication signal based on the determined communication network topology and the communication transmitter is configured to transmit communication signals to a communication receiver selected in accordance with the given route.

Brief Description of Drawings

The present invention can be more easily understood and its advantages and additional uses more easily evident, when considered in view of the detailed description and the following Figures in which:

Figure 1 is an illustration of a communication network of an embodiment of the present invention;

Figure 2 is a block diagram of an aircraft on a communication network of the present invention; and

<td>20 The Figure</td><td>3 is</td><td>a flow chart of</td><td>a method</td><td>in</td>

<td>communication in a</td><td>network</td><td>communication of a</td><td>modality</td><td>gives</td>

<td>present invention.</td><td></td><td></td><td></td><td></td>

<td>According</td><td>with</td><td>common practice,</td><td colspan="2">the various</td>

features described are not drawn to scale but are designed to emphasize specific features relevant to the present invention. Reference characters denote similar elements throughout the text and figures.

Detailed Description

In the detailed description, presented below, reference is made to the accompanying drawings, which form part of it, and in which specific modalities in which the invention can be practiced are shown only as illustrations. These modalities are described in sufficient detail to allow those usually skilled in the art to practice the invention, and it is to be understood that other modalities can be used and that logical, mechanical and electrical changes can be made without departing from the spirit and scope of the present invention. . The detailed description presented below is therefore not to be taken in a limiting sense, and the scope of the present invention is defined only by its claims and equivalents.

The modalities of the present invention provide a specific direct air-to-air communication network that is efficient and reliable by using existing knowledge of the communication network topology without the need to distribute this information over a communication link. The modalities use recognition data that is transmitted between the aircraft and also from the ground stations to the aircraft to obtain the existing knowledge of the topology of the communication network. This recognition data not only provides more reliable notifications of aircraft positions and flight paths than those produced by monitoring communications alone, but also avoids the additional additional cost of transmitting position and flight path information over flight links. communications.

Referring to Figure 1, an example of a communication network 100 including aircraft 102, 104 and 106 and a ground terminal 108 is illustrated. In this example, an aircraft, such as aircraft 102, wishes to communicate a message to the destination of message 108, but aircraft 102 is beyond the range of communication with the ground terminal

108. Communications between the aircraft are made with very high frequency (VHF) communications that have a relatively short range of visual communication line.

Therefore, aircraft 102 needs to find a communication path between aircraft 106 and 104 for the message to reach land terminal 108. As discussed above, the modalities use reconnaissance data from the reconnaissance equipment on the aircraft to discover the topology of the aircraft. communication network of the aircraft and ground terminals.

Referring to Figure 2, block diagrams of a communication network 200 constituted by aircraft 202, 204 and 206, are shown. It will be understood that the block diagrams show only parts of the .202, 204 and 206 aircraft that are relevant to the present invention. In this example, the first aircraft 202 wants to send a message via communication network 200. The first aircraft 202 is illustrated as having reconnaissance equipment.

201, a communications management function (CMF) 210, a recognition transceiver 212, a recognition antenna 216, a communication transceiver 214 and a communication antenna 218. The second aircraft 204 is also illustrated as having recognition equipment 203 , a CMF 221, a recognition transceiver 220, recognition antenna 224, communication transceiver 222 and communication antenna 226.

Likewise, the third aircraft 206 is illustrated as including recognition equipment 205, CMF 242, recognition transceiver 228, recognition antenna

230, communication transceiver 244 and communication antenna 240. The reconnaissance equipment 201, 203 and 205 is used by the respective aircraft 202, 204 and 206 to periodically broadcast at least their position and ID to other aircraft and systems on the ground . An example of a type of 201 recognition equipment is Automatic Dependent Recognition Broadcasting (ADS-B). The primary purpose of ADS-B is to create notification of situational traffic for both pilots and air traffic controllers. Another example of recognition equipment is the Consultative and Traffic Conflict Systems (TCAS). A TCAS system provides positional data from one aircraft in response to a query by another aircraft with a TCAS interrogator. Yet another example of a planned recognition system is an Automatic Dependent Recognition Broadcast (ADS-R). An ADS-R transmits positional and flight intent data to an aircraft from multiple data sources, originating from an airborne reconnaissance source, land based reconnaissance source, or both. Modalities of the present invention use data from the reconnaissance equipment to discover the topology.

In the communication network 200 example of Figure 2, the recognition equipment 205 of the third aircraft 206 provides information such as its ID and its position to the recognition transmitter 228. The recognition transmitter 228 sends a message 230 through the recognition antenna 230 regarding information.

This message is received by the reconnaissance receiver 212 through the reconnaissance antenna 216 of the first aircraft 202. Also illustrated, it is the reconnaissance equipment 203 on the second aircraft 204 that provides at least position information and ID information to its reconnaissance transmitter. 220. 0 reconnaissance transmitter 220 transmits message 232 which includes at least position information and ID information via reconnaissance antenna 224 to reconnaissance transceiver 212 on the first aircraft 202 by reconnaissance antenna 216. Therefore, in this example, the first aircraft 202 has position information from both the second and third aircraft 204 and 206. The CMF 210 of the first aircraft takes position information 234 from the second and third aircraft 204 and 206 and creates a topology of the 200 communication network. The CMF 210 uses the discovered topology to determine where to send its 240 communication signal. Figure 2, the CMF 210 determined the second aircraft 204 provided the best route for its communication signal 240 based on the discovered topology.

The first aircraft 202 uses its communication transceiver 214 to transmit communication signal 240 to the second aircraft 204 through communication antenna 218. The second aircraft 204 receives communication signal 240 through its communication antenna 226 and its transceiver 222. The second aircraft 204 will then discover the topology of its communication network as the first aircraft 202 did, to determine where to next send the communication signal on its route to its destination. If the reconnaissance equipment on the aircraft is capable of providing complete topology information (for example, an ADS-B or ADS ^ R system where onshore systems redefine reconnaissance data), nodes in the vicinity (aircraft) and the entire topology of the communication network are determined using the acknowledgment data without the need for exchanging greeting messages or topology information. This modality avoids any additional costs associated with discovering a neighbor. Although this modality is less preferred, it still provides a significant additional cost reduction.

In reference to recognition transceivers

212, 220 and 228 and communication transceivers 214, 222 and

244, the term transceiver is meant as a generic term that describes a combination unit with both transmitter and receiver functionality. However, as those usually skilled in the art will understand, the invention could work equally well if the transceiver function were physically represented in two separate units, one being a transmitter and the other being a receiver. Therefore, the present invention is not limited to transceivers.

Figure 3 illustrates a communication flowchart according to a modality. In this example, an aircraft has a message to send to a destination node (302). The destination node can be another aircraft, a ground station or the like. It is then determined whether the destination node is within the radio communication range of the aircraft (301).

If the destination node is within the communication range, the message is sent to the destination node (303).

However, if the destination node is not within the communication range, a specific direct communication network is used to deliver the message. The specific direct communication network takes advantage of the continuous transmission of recognition information by the aircraft or other sources. As illustrated, in Figure 3, the source aircraft monitors the reconnaissance information (304). The recognition information is communicated to the CMF (306). The current topology of the communication network is determined by the CMF based on the recognition information (308). Then the current topology is stored in a database (309).

This monitoring and storage, as illustrated, is continuously recycled through a selected frequency rate. As also illustrated in the communication flowchart 300 of Figure 3, when the communication network is necessary to deliver a message, the CMF of the node that sends the message determines the most efficient and reliable route in the communication network based on the then current stored topology (310). The reliability and longevity of the communication network route for future traffic messages to the same destination on land can be further improved by taking into account the intended trajectory of the other aircraft. This can be achieved by using positioning data, aircraft intention data, and communication link properties, to predict when existing links will break, when new links will become available, and to assess aircraft-aircraft link reliability based on in the vicinity of the aircraft. For example, if another aircraft is flying on a trajectory towards the ground station, this may be a preferable choice than choosing another aircraft in the same relative position but transiting away from the intended ground station. The choice of the authoring aircraft may increase the likelihood that the same aircraft can be used for future traffic messages between the same two end points.

Once the most efficient and reliable route (310) is determined, the communication message is transmitted to the next selected node (312). Once the communication message is received at the next node (314), the next one determines whether it is within the communication range of the destination node (301). The process continues until the message is received by the destination node (303).

The methods and techniques used by CMU as described above in discovering the topology can be implemented in electrical circuits of digital electronics, or with a programmable processor (for example, a special purpose processor or a general purpose processor such as a computer), firmware, software, or combinations thereof. Equipment that materializes these techniques may include appropriate input and output devices, a programmable processor, and a means of

I storage that tangibly materializes the program instructions for execution by the programmable processor. A process that materializes these techniques can be performed by a programmable processor that executes an instruction program to perform desired ones by operating on the input data and generating the appropriate output data. The techniques can be advantageously implemented in one or more programs that are executable in a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, by at least one input device., and at least one output device. In general, a processor will receive instructions and data from a read-only memory and / or a random access memory.

Storage devices suitable for tangibly materializing computer program instructions and data include all forms of non-volatile memory, including, for example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard drives and removable disks; magnetic-optical disks; and DVD discs.

Any of those mentioned can be supplemented, or incorporated, into specially designed application-specific integrated circuits (ASICs).

Although the specific modalities have been illustrated and described here, it will be noted by those usually skilled in the art that any provisions, which are calculated to achieve the same purpose, can be a substitute for the specific modalities presented. For example, non-aeronautical vehicles employing similar reconnaissance equipment can implement modalities of the present invention. This application is intended to cover any such adaptations or variations. Therefore, it is clearly intended that this information is limited only by the claims and their equivalents.