WO2014013187A1

WO2014013187A1 - Method for aerial-terrestrial communication, program, terminals and installation

Info

Publication number: WO2014013187A1
Application number: PCT/FR2013/051708
Authority: WO
Inventors: Laurent Reynaud; Karina GOMEZ CHAVEZ; Tinku Mohamed-Rasheed
Original assignee: Orange
Priority date: 2012-07-17
Filing date: 2013-07-16
Publication date: 2014-01-23
Also published as: FR2993736A1

Abstract

The invention relates to a method for communication between the nodes of a hybrid terrestrial and aerial network, the nodes of said network comprising a plurality of first terminals (UT) pertaining to a first terrestrial or aerial network and at least one second other aerial or terrestrial terminal other than that of the first network. According to the invention, at least one of the first terminals (UT) emits, to at least one other first terminal (UT3), at least one signalling message (BEAC-UT) containing at least one parameter, representating the quality of the communication channel between at least one of the first terminals (UT) and the second terminal, said second terminal being associated with the first emitter terminal by a direction communication channel.

Description

Air-to-air communication method, program, terminals, installation

The invention relates to a communication method between the nodes of a hybrid network, terrestrial and aerial, the nodes of which comprise a plurality of first terminals belonging to a first network of the terrestrial or air type and at least a second other terminal of the aerial type. or terrestrial other than that of the first network.

One field of application of the invention is notably the implementation of communication networks in the event of emergency situations, for example in the case of an earthquake or more generally of any disaster situation or any situation. affecting existing communication infrastructures.

Indeed, in these situations, backup communications must be provided, since the existing telecommunication infrastructure can be damaged at least in part and can become largely inoperative. Rapid deployment of flexible emergency telecommunication systems is required.

Given their ability to access disaster-affected geographical areas that would otherwise be difficult to reach, air platforms, and particularly low-altitude platforms, may provide a solution for emergency communications. Depending on multiple factors, including the type of aerial platforms, antenna and radio technology choices, available payload power, and planned rescue missions, a low altitude platform can be used at altitudes between a few tens and a few thousand meters. In addition, given their payload flexibility, relatively fast deployment times, and short propagation times, it is envisaged that such platforms will be able to rapidly restore communications in the affected areas as a complement to existing terrestrial infrastructures.

The most common scenario for this type of aerial and terrestrial hybrid communication network is a network scenario with several thousand terrestrial user terminals connected to multiple air platforms, one or more of which are interconnected with one or more ground stations to provide different services.

Such hybrid networks are for example known from the document entitled "Energy efficient cooperative strategies in hybrid aerial-terrestrial networks for emergencies" by S. Kandeepan, K. Gomez, T. Rasheed and L. Reynaud, 2011 IEEE 22 ^nd International Symposium on personal, indoor and mobile radiocommunications. This document describes an example in which a user terminal acts as a relay for another user terminal to communicate with an aerial platform in particular cases. However, no criteria are defined for choosing a path in terrestrial and air networks. In addition, for this type of network, an interconnection of the air network can be provided with another communication network, through one or more ground stations. Only a few air platforms are connected in point-to-point mode to these ground stations. An air platform that is not directly connected to a ground station then contacts one of these other airplanes arbitrarily.

One of the aims of the invention is to remedy the shortcomings / disadvantages of the state of the art and / or to make improvements thereto.

For this purpose, the subject of the invention is a method of communication between terminals in a hybrid terrestrial and overhead communication network, said network comprising a plurality of first terminals belonging to a first terrestrial or aerial type network and at least one second other terminal of the air or land type other than that of the first network,

characterized in that

at least one of the first terminals sends to at least one other first terminal at least one signaling message containing at least one parameter, which is representative of the quality of the communication channel between the first transmitting terminal and a second terminal, said second terminal being associated with the first transmitting terminal by a direct communication channel.

Thus, the first terminals of the first terrestrial or air network inform each other of the quality of the link they have to a second terminal respectively air or ground.

This parameter can then be used to decide which path to take in the hybrid network useful data to be sent from one of the terminals. The use of this parameter makes it possible to take a decision optimizing the energy resources in the hybrid network.

In particular, this parameter makes it possible to decide whether one goes through an intermediate terminal or by several intermediate terminals or by the second terminal to route the data of a terminal to a destination terminal.

Embodiments are described below.

The various embodiments or features mentioned below may be added independently or in combination with each other, to the steps of the communication method as defined above.

According to one embodiment of the invention, the parameter is calculated based at least on the quality of the reception by the first transmitting terminal of at least one other previous message sent directly by the second associated terminal.

According to one embodiment of the invention, the second terrestrial type associated terminal transmits to at least one of the first aerial-type terminals at least one signaling message containing said representative parameter. According to one embodiment of the invention, a communication from a terminal directly to another terminal is called a hop, one of the first terminals of terrestrial type, said source terminal, having data to be sent to a destination terminal by the terminal. intermediary of the air network chooses an indirect transmission mode by a path formed of a first communication channel from the source terminal to another first terminal, said intermediate terminal, and a second communication channel from the intermediate terminal to a second terminal associated with said intermediate terminal, on the basis of said at least one parameter representative of the quality of the second communication channel.

When data can not be routed over the terrestrial network by a path of no more than two jumps, the decision is made to route the data through the air network. This makes it possible to avoid the implementation of a complex routing in the terrestrial network and thus limits the consumption of energy.

In order to route the data via the air network, a first choice is made between a direct transmission mode and an indirect transmission mode on the basis of the parameters representative of the qualities of the links from the terrestrial network to the air network. This optimizes the energy resources in the network.

According to one embodiment of the invention, the source terminal selects at least one intermediate terminal on the basis of at least said parameter representing the quality of the second communication channel and transmits a resource reservation request for the transmission of the data. .

The transmission of a resource reservation request makes it possible to ensure that the link between the intermediate terminal and the associated second terminal in the air network makes it possible to route the data to be sent. This then makes it possible to choose between different intermediate terminals.

According to one embodiment of the invention, when none of the intermediate terminals has the resources requested, the direct transmission mode is chosen.

The fallback to the direct transmission mode thus ensures a routing of data to the air network.

According to one embodiment of the invention, wherein an intermediate terminal, no longer having the resources requested when receiving a resource reservation confirmation, indicates to the source terminal the remaining available resources.

The data can thus be transmitted via several intermediate terminals to the air network.

According to one embodiment of the invention, in which one of the first terminals, of aerial type, said source terminal, having data to be sent respectively to a destination terminal, located in another communication network, selects a second terminal of type terrestrial network, allowing access to the other communication network, depending on at least said parameter representative of the quality of the communication channel between another of the first terminals to which the second terminal is associated and the second terminal.

For a first air terminal not associated with a second terminal, this makes it possible to select a second gateway terminal with the other communication network among several second terminals while preserving the energy resources of the hybrid network.

Another object of the invention is a computer program comprising instructions for implementing the communication method as described above, when this program is executed by a processor.

Another object of the invention is a recording medium readable by a terminal on which is recorded the program as described above.

Another object of the invention is a terminal of the terrestrial or aerial type, belonging to a first network, comprising a first communication interface having a determined communication range intended for at least one other terminal of identical type and a second interface. communication device having a defined communication range to at least one second terminal of the air or land type other than that of the first network by a communication channel,

characterized in that it comprises means for transmitting by the first communication interface at least one signaling message containing at least one parameter, which is representative of the quality of said communication channel between said terminal and the second terminal.

Another object of the invention is a communication installation of a hybrid communication network, terrestrial and air, comprising a plurality of first terminals belonging to a first network of the terrestrial or air type and at least a second other terminal type aerial or terrestrial other than that of the first network,

characterized in that

at least one of the first terminals comprises means for transmitting, to at least one other first terminal, at least one signaling message containing a parameter, which is representative of the quality of the direct communication channel between at least one of the first terminals and the second terminal, said second terminal being associated with the first transmitting terminal by a direct communication channel.

According to one embodiment of the invention, the communication installation further comprises at least a second other terrestrial terminal, said terrestrial terminal comprising a first air communication interface having a determined communication range intended for at least one other aerial terminal and a second communication interface with at least one other communication network, and further comprising means for transmitting by the first overhead communication interface at least one signaling message containing a parameter, which is representative of the quality of the direct communication channel between the air terminal and the land terminal.

The invention will be better understood on reading the description which follows, given solely by way of non-limiting example with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of an example of hybrid network, aerial and terrestrial according to the invention;

Figure 2 is a schematic view of the contents of a beacon message of a first type according to the invention;

FIG. 3 is a schematic view of the exchange of beacon messages of FIG. 2; Figure 4 is a schematic view of the contents of a table of a user terminal according to the invention;

Figure 5 is a schematic view showing a data transmission between two user terminals;

FIG. 6 is a schematic view of data transmission between two user terminals in another case;

Fig. 7 is a schematic view of transmission of different messages between a user terminal and an associated coverage terminal in one case;

Fig. 8 is a schematic view of data transmission between a user terminal and a coverage terminal through another user terminal;

Figure 9 is a schematic view of the contents of a message that can be used following the beacon message of Figure 2;

Figure 10 is a schematic view of the contents of a message that can be used following the message of Figure 2;

FIG. 11 is a schematic view of the contents of a table of a user terminal; Figure 12 is a schematic view of the contents of a message that may appear following the message of Figure 2;

FIG. 13 is a schematic view of data exchanges in another case following the message of FIG. 2;

FIG. 14 is a schematic view of a table of a gateway terminal;

Fig. 15 is a schematic view of the contents of a beacon message of a second type;

Fig. 16 is a schematic view of a table of a coverage terminal;

Fig. 17 is a schematic view of message exchanges between a gateway terminal and coverage terminals;

Figure 18 is a schematic view of the contents of a message that may appear following the message of Figure 15; Figure 19 is a schematic view of the contents of a message that may appear following the message of Figure 15;

Fig. 20 is a schematic view of a table of a gateway terminal;

FIG. 21 is a schematic view of message exchanges between several gateway terminals and several coverage terminals in one case;

Fig. 22 is a schematic view of exchanges of a third type beacon message between coverage terminals;

Fig. 23 is a schematic view of the contents of the beacon message of the third type; Fig. 24 is a schematic view of the contents of a table of a coverage terminal; FIG. 25 is a schematic view of messages between several coverage terminals and a gateway terminal;

Fig. 26 is a schematic view of the contents of a table of a coverage terminal; Fig. 27 is a schematic view of exchanges of a fourth type beacon message between coverage terminals and a gateway terminal;

FIG. 28 is a schematic view of the beacon message of the fourth type of FIG.

27.

In the figures, the communication network comprises nodes comprising user terminals UT, UT1, UT2, UT3 and others (reference signs starting with UT), at least one AS terminal, AS1 covering (reference signs starting with AS ) respectively embedded on at least one AP, API and at least one GS terminal of a land station (reference signs starting with GS), able to be connected to another network, such as for example an external network or a wide area network (WAN), such as for example the Internet or other. The communication network is therefore hybrid, both terrestrial and aerial.

Each AS terminal is an air terminal and can be replaced everywhere by

'Air terminal' means the term 'terminal' and the reference signs beginning with AS. Each UT terminal is a terrestrial terminal and it will therefore be possible to replace everywhere by "terrestrial terminal" the term "user terminal" and the reference signs starting with UT. Each land terminal can be a fixed or mobile terminal. Each gateway GS terminal is a terrestrial terminal and therefore we can replace everywhere by "land terminal" the term "gateway terminal" and the reference signs starting with GS.

For example, at least two AS1 and AS2 coverage terminals are provided on at least two separate API and AP2 air platforms. The AS terminals for example form an air network between them.

In FIG. 1, the UT terminals are represented by way of example by radio coverage cells, but this is in no way limiting. The UT terminals form a terrestrial network between them. The identifiers and addresses of the terminals UT, AS and GS are given for example by an address resolution protocol (ARP) which guarantees a single identifier and a single address for each terminal in the network (for example by IPV4 or IPV6). Of course, any other algorithm, protocol or mechanism that guarantees unique addressing and a unique identifier can be used.

The user terminals UT each comprise a first terrestrial wireless communication interface INT1 having a determined range of communication between these user terminals UT and a second wireless communication interface INT2 with the associated coverage terminal AS. an aerial platform. For example, in FIG. 1, the coverage terminal AS1 is associated with (or covers) a plurality of user terminals UT, UT1, UT2, UT3, called associated terminals, situated in a terrestrial area covered by a third interface INT3. wireless communication terminal of this AS1 coverage terminal and allowing the AS1 coverage terminal to communicate with these associated terminals UT, UT1, UT2, UT3. The respective coverage areas of the coverage terminals may partially overlap.

Each AS terminal covering the AP air platform comprises a fourth interface INT4, for example wireless air communication, allowing it to communicate with a terminal GS terminal of a land station. The gateway GS terminal comprises a fifth communication interface INT5, for example overhead wireless, with the associated cover terminal AS1 of the aircraft API and a seventh communication interface INT7, which can be wireless or wired, with the other network. Each associated AP terminal terminal of the aircraft AP comprises a sixth interface INT6 enabling it to communicate with at least one other on-board coverage terminal AS2 on at least one other AP, AP2 aircraft located in the atmosphere.

An aerial platform AP may for example be formed by a captive balloon or not or more generally any air vehicle.

One of the objectives of the invention is to find an optimized communication path in the hybrid communication network. This path is optimized according to the energy consumption in the system and optionally one or more different criteria, such as, for example, the availability of energy in the AS coverage terminals and in the UT user terminals. , the throughput in the system and the delays in the system.

The INT4 and INT5 communication interfaces between each GS terminal and each overhead AS terminal are, for example, of the IEEE 802.11a type with directional antennas (eg point-to-point link). The air communication interfaces INT6 between the AS coverage terminals are for example of the IEEE 802.11 type. The communication interfaces INT2 and INT3 between the user terminals UT and the coverage terminals AS are for example 3GPP type LTE / LTE-A (for "3rd Generation Partnership"). Project- Long Term Evolution "). The communication interfaces INT1 between the user terminals UT are for example of the IEEE 802.11 type. In general, the messages indicated are radio signals, for example wireless. The invention provides a method of communication between terminals.

A first embodiment of the invention is described below for the communication of data from a user terminal UT to another user terminal UT.

In general, the CQI, CQI1, CQI2 parameters are metrics based on channel conditions such as a signal-to-noise ratio, a bit rate, a link quality that quantifies the quality of the communication channel.

In FIGS. 2 and 3, during a first step E1, at least one, several or each UT terminal, called the first terminal UT, transmits, for example at first determined time intervals a1, a2 which may be of the order for example, several milliseconds, on its first interface INT1 a beacon or signaling message BEAC-UT containing:

at least one first field containing an identifier ID of this first terminal UT,

and / or at least one second NEIGH field containing at least one identifier NEIGH, ID (1), ID (2), ID (n) of at least one other second neighboring user terminal NEIGH, UT2,

and / or at least a third field containing at least a first parameter BATT of remaining power supply of the first terminal UT,

and / or at least a fourth CQI2 field containing a second parameter CQI2 = CQI

(UT-AS1) quality of the direct communication channel between the first terminal UT and the associated cover terminal AS1,

and / or at least one fifth delay parameter DD field for the link between the terminal UT and the associated coverage terminal AS 1.

Of course, only one, several or all of these fields can be provided.

These terminals UT play the role of first terminals, in this case terrestrial. These first UT terminals form a first terrestrial network.

The second quality parameter CQI2 = CQI (UT-AS1) has, for example, been calculated by the first terminal UT, when it has received a previous message directly from the associated cover terminal AS1. The second parameter CQI2 = CQI (UT-AS1) is representative of the quality of the direct communication channel between the terminal AS1 and the terminal UT. The second parameter CQI2 = CQI (UT-AS1) is calculated by UT in particular according to at least the power reception level of a previous message sent from AS1 to UT. More specifically, the terminal UT determines for the associated AS terminal a power level of the received signal, updated when receiving a packet from AS. The parameter CQI2 = CQI (UT-AS) is then determined according to at least the power level and / or depending, if necessary, other statistics, such as modulations and coding schemes, flow rates, obtained from the layer MAC (for "Medium Access Control"), representative of the quality of the communication channel from UT to AS. As an illustrative example, the power level corresponds to the RSSI parameter (for "Received Signal Strength Indication"). The second user terminal NEIGH, UT2 is determined to be close to the first terminal UT when the first terminal UT has received by its first interface INT1 a previous message directly from the second terminal NEIGH, UT2.

The delay corresponds for example to a measurement of a round trip time of a message on the link UT-AS 1.

The BEAC-UT message is of the broadcast type to several other UT terminals (in English).

"broadcast") and does not have a mandatory response message. Each communication by an interface of any terminal directly to another terminal is called jump. Therefore, the NEIGH field contains the identifiers ID (1), ID (2), ID (n) of the UT2 terminals of active users located in the direct vicinity of the user terminal UT, that is to say remote of a jump with respect to this terminal UT.

FIG. 3 shows a terminal UT1 sending for example to another terminal UT3 the first BEAC-UT message at regular intervals, al / UT1 and a2 / UT3, by their first terrestrial interface INT1.

During a second step E2, in FIG. 4, each terminal UT maintains a first table T1 or neighbor table with the information received from the BEAC-UT message. Each terminal UT3 receiving the beacon message BEAC-UT stores in at least its own first table Tl the identifier ID of the terminal, called active terminal ID, contained in the first field of the beacon message BEAC-UT received during the last of second determined time intervals bl, in association with the first parameter BATT of remaining power supply contained in the third field of this beacon BEAC-UT message received and / or the second parameter CQI2, CQI (UT-AS1) of quality the communication channel contained in the fourth CQI2 field of this BEAC-UT received beacon message and / or a third quality parameter CQI1, CQI (UT3-UT) of the direct communication channel between the UT3 and UT terminals, and / or the delay parameter DD contained in the fifth field of this BEAC-UT received beacon message, and / or the at least one NEIGH, UT2 identifier of the at least one neighboring NEIGH, UT2 terminal contained in the second NEIGH field of this BEAC message -UT e tag received. The third parameter CQI1 = CQI (UT3-UT) is representative of the quality of the direct communication channel between the terminal UT and the terminal UT3. The third parameter CQI1 = CQI (UT3-UT) is calculated by UT3 in particular according to at least the power reception level of the BEAC-UT message sent from UT to UT3. More specifically, the terminal UT3 determines for each terminal UT a power level of the received signal, updated when receiving a packet from UT. The parameter CQI1 = CQI (UT3-UT) is then determined according to at least the power level and / or depending, if necessary, other statistics, such as modulations and coding schemes, rates, obtained from the MAC layer, representative of the quality of the communication channel UT3 to UT. As an illustrative example, the power level corresponds to the RSSI parameter. This first table T1 is updated at second time intervals b2 in order to keep in the table T1 only the information concerning the active user terminals. The lifetime of each user terminal in the table T1 is determined by a TTL time counter. Active terminals are terminals that update their neighbor NEIGH with their own information by the BEAC-UT message before the end of the TTL time slot. Inactive or expired terminals are terminals that have not updated their NEIGH neighbor with their own information by the BEAC-UT message before the end of the TTL time interval. In order to determine the terminals of active or expired users, each user terminal maintains a register with the last moment when the information of the members of the table has been updated. Whenever a terminal UT3 receives a BEAC-UT message from a neighbor terminal UT, the terminal UT3 evaluates the quality of this particular link and updates the table by CQI1 = CQI (UT3-UT). The NEIGH identifier of the neighboring user terminals is included in the Tl table only if this NEIGH terminal is not a direct neighbor of the UT3 terminal, UT being a direct neighbor of UT3, the NEIGH terminal being the neighbor's neighbor. of UT3.

In step E3, in FIG. 5, each user terminal UT4 which has data to be sent to another recipient user terminal UT5 checks from the identifier of the destination terminal UT5 if the destination terminal UT5 is a terminal active in its first table Tl, for, if so, send to the destination terminal UT5 by the first interface INT1 a TRANS data transmission message containing the data and the UT5 identifier of the destination terminal UT5,

- in the negative, select at least one next hop from this terminal UT4 and arriving at at least one intermediate terminal UT6 other than the destination terminal UT5 and send the selected intermediate terminal UT6 the data transmission message TRANS containing the data and the UT5 identifier of the destination terminal UT5. This step of selecting a next hop is described later.

Thus, if the destination terminal UT5 is in the direct vicinity, that is to say at a distance jump, of the terminal UT4, the latter sends the data TRANS by the first interface INT1 directly to the destination terminal UT5.

All the figures illustrate, for the sake of simplicity, the sending of a single TRANS message. The TRANS message can be a stream. It can therefore be provided several TRANS messages, for example successive. For example, it can be expected that FUT source, when the path is established, sends a TRANS message or several TRANS messages. All of these TRANS messages represent the TRANS data flow. Examples of data flow or message TRANS can be: sending a text, a message, a video or any other type of data, etc. A TRANS flow or message can also be bidirectional. This may be for example a telephone conversation over IP (VoIP), an instant messaging conversation. There is therefore generally at least one TRANS message.

In general, the data transmission TRANS message comprises at least a first field containing the data to be sent, at least a second field containing the identifier UT4 of the terminal sending this message TRANS and at least a third field containing the UT5 identifier of the destination terminal UT5. The data is for example useful data, such as user data.

The intermediate terminal may be for example a user terminal UT6 or a cover terminal AS1 associated with the terminal UT4, as described below.

FIG. 5 represents the case where the intermediate terminal is a user terminal UT6. Below is described how the intermediate terminal is selected in this case. If the destination terminal UT5 is in the neighborhood of a neighbor (two distance jumps of UT4), that is, if UT5 = NEIGH in the Tl table of UT4, the terminal UT4, also called source terminal, determines the best path according to the parameters stored in the table T1 to establish the communication with the destination terminal UT5, for example via the user terminal UT6, and the terminal UT4 sends the data TRANS by the first interface INT1 to the destination of the destination terminal UT5.

The user terminal UT6 receiving the message TRANS checks whether the UT5 identifier of the destination terminal UT5 contained in this data transmission TRANS message is an identifier of an active terminal in its own first table Tl, for in the affirmative to send by its first interface INT1 this TRANS data transmission message to the destination terminal UT5. The TRANS data transmission message is thus sent in two jumps from UT4 to UT6, then from UT6 to UT5, since UT5 is a neighbor of UT6, itself UT4 neighbor, as shown in FIG. the negative, that is to say when the identifier of UT5 is not in the table T1, in one embodiment (FIG. 6), the user terminal UT6 sends an acknowledgment NACK message negative by its first interface INT1 to the user terminal UT4. In the case where the source terminal UT4 receives a NACK message, the terminal UT4 looks for a new path for the message TRANS. The choice to implement the NACK message depends on the capabilities of the default routing protocol support of the user terminals, i.e., the features for detecting interrupted paths.

During step E3, if no two jump paths have been found in the terrestrial network, the communication to the destination terminal UT5 will be routed via the overhead network. In this case, an associated cover terminal AS1 plays the role of the intermediate user terminal (FIGS. 7 and 8). The terminal UT4 selects on the basis of the parameter CQI2 and optionally one or more of the parameters stored in the table T1, that is a direct jump by the second interface INT2 of the terminal UT4 to transmit the data transmission TRANS message to the associated cover terminal AS1 (first direct link case, shown in FIG. 7, called the direct transmission mode), or chooses to go through at least one other intermediate user terminal UT6 for sending the data transmission TRANS message, then this terminal UT6 to the associated cover terminal AS1 (second indirect link case, shown in FIG. 8, called the transmission mode). indirect).

It is emphasized here that in this illustrative example, the two user terminals UT4, UT6 are associated with the same ASl coverage terminal. No limitation is attached to this illustrative example. The two user terminals UT4, UT6 can in particular be each associated with a separate coverage terminal.

This selection by the terminal UT4 is made on the basis of the parameter representative of the quality, in particular for the communication channel from UT4 to the AS1 coverage terminal (direct link) (quality parameter CQI (UT-AS1)) and for one indirect path consisting of a communication channel from UT4 to UT6 and a communication channel from UT6 to AS1, based on quality CQI (UT4-UT6) and CQI (UT6-AS1) parameters. It is recalled here that in general, the power consumption for transmitting data decreases when the quality of a communication channel increases. In a particular embodiment, the parameter BATT of the remaining power supply of the terminals UT4, UT6, the delay parameters D (UT4-AS1), D (UT6-AS1) are also taken into account during this step of selection. These parameters CQI1, CQI2, BATT, D are notably stored in the table Tl.

Figure 7 illustrates the case of choice of the direct link UT4 to AS1. The terminal UT4 sends a resource request message QUES2 from the interface INT2 from UT4 to AS1, which responds to UT4 by sending a response message (not shown in FIG. 7) containing information X, indicating the resources available. . This message QUES2 includes a communication resource request REQ REQ concerning the TRANS transmission message of data to be transmitted, such as for example the size and / or the bit rate, etc. The terminal UT4 then sends a confirmation message CONF2 to AS1 to reserve the resource X from UT4 to AS1, and the message TRANS of data transmission by its second air interface INT2 from UT4 to AS1.

The case of the choice of the indirect link UT4 to UT6 and then UT6 to AS1 is explained below with reference to FIG.

The terminal UT4 implements the steps described above in connection with FIG. 7 to obtain the information X indicating the resources available for sending the data transmission TRANS message. The terminal UT4 updates a second table T2 (FIG. 11) comprising the identifier ID-UT4 of UT4 in association with the information X indicating the communication resources available on the second interface INT2 of UT4 for establishing a communication with the terminal. cover AS 1, in a first field. In step E4, the terminal UT4 determines one or more neighboring terminals UT6 as user terminals of next hop. More specifically, the terminal UT4 the or selects on the basis of the CQI parameter (UT-ASl) stored in the table T1. As an illustrative example, the terminal UT4 selects as identifier NH-ID, or those of terminals for which the quality of the corresponding indirect path is the best. The quality of the indirect path is determined from the quality parameter of the direct communication channel between itself UT4 and this neighbor UT6 CQI (UT4-UT6) and the quality parameter of the communication channel between this neighbor UT6 and the communication terminal. AS1 cover associated. In a particular embodiment, the BATT parameters of the remaining power supply of the terminals UT4, UT6, the delay parameters D (UT4-AS1), D (UT6-AS1) are also taken into account during this step of determination. The identifier (s) of the neighbors and these parameters CQI (UT-UT), CQI (UT-AS), BATT, D (UT-AS) are stored in the table T1. Then, the terminal UT4 sends a second message next-hop beacon tag (FIG. 9) comprising in a first field an NH-ID identifier of the next hop user terminals or possible relays, that is to say the UT terminals situated at a jump of terminal UT4 and in a second field a communication resource request REQ information concerning the transmission TRANS message message to be transmitted, such as for example the size and / or the rate, etc. The message NH-BEAC further comprises in another third field the identifier ID-UT4 of the fourth terminal UT4.

The NH-BEAC message makes it possible to ask the UT6 user terminals of the next hop which are their available resources for the TRANS data transmission message to be transmitted.

The terminal UT4 waits for an ACK-NH-BEAC response message, returned by the terminal UT6. If the user terminal UT4 does not receive at least one ACK-NH-BEAC response, as shown for the NH-BEAC message crossed by a cross in FIG. 8, the terminal UT4 sends again the message NH- BEAC. In the case where the message NH-BEAC is returned a maximum number of n times without obtaining an ACK-NH-BEAC response message, the terminal UT4 then uses the direct link to send the message TRANS by the second air interface INT2 directly to the associated AS1 cover terminal, as previously described in connection with FIG. 7.

In step E5, when the next hop terminal UT6 receives the message NH-BEAC, the terminal UT6 checks whether it is the recipient of this message, that is to say if its identifier corresponds to one of the identifiers NH-ID contained in the NH-BEAC message for:

- if not, ignore this message NH-BEAC;

- if so, the UT6 terminal uses the REQ information contained in the message

NH-BEAC and check by its second air interface INT2 what are the resources available for the transmission of the message TRANS by sending to the terminal AS1 a message QUES, including the REQ information. The terminal AS1 responds to UT6 by sending another response message not shown in FIG. 8 containing information IREQ indicating its available resources Y, Z. The terminal UT6, which is then a terminal of the next hop, then responds to the terminal UT4 by the ACK-NH-BEAC response message, which contains in a first field IREQ information on the resources available for the transmission of UT6 to the associated coverage terminal AS1, in a second field the identifier ID-UT6 of this terminal UT6 and in a third field the ID-UT4 UT4 terminal, as shown in Figure 10. The ACK-NH-BEAC message is sent by UT6 to UT4 by the first terrestrial interface INT1 UT6. When the next hop terminal UT6 sends the ACK-NH-BEAC message, the terminal UT6 starts a counter up to a prescribed time interval L to wait for a CONF confirmation message from the terminal UT4. The ACK-NH-BEAC message is for example transmitted in point-to-point mode.

In step E6, when the terminal UT4 receives the ACK-NH-BEAC message, the terminal UT4 updates the second table T2 (FIG. 11) with the NH-IDs of the next-hop user terminals in association with the available IREQ communication resource information of the second INT2 interface of these NH-ID terminals with an associated coverage terminal AS, received in the ACK-NH-BEAC message.

At the expiration of the time interval k, the terminal UT4 compares the available resource X with each of the available resources IREQ of the next hop terminals NH-ID of its table T2, to choose the appropriate link that best meets the demand. TRANS message resource.

In step E7, in the case where the resource X from UT4 to AS1 is greater than each of the IREQ resources of the next hop terminals NH-ID to AS1 in the table T2, the terminal UT4 chooses the direct link through the second interface INT2 from UT4 to AS1 and sends the CONF2 confirmation message to AS1 to reserve the resource X from UT4 to AS1 (FIG. 7). The terminal UT4 then sends the data transmission TRANS message by its second air interface INT2 from UT4 to AS1, as shown in FIG. 7.

In step E7, in the case where the terminal UT4 has determined on the basis of this comparison that its resource X to AS1 is less than one or more resources IREQ of the NH-ID terminals of next hop in its table T2 , the terminal UT4 selects one or more of these next hop NH-ID terminals. The terminal UT4 then sends the confirmation CONF message to at least one selected next hop terminal NH-ID, in order to confirm to this NH-ID terminal its role of next hop user terminal, and sets a TTL time slot. in order to start sending the TRANS data transmission message.

If the terminal UT4 does not receive a negation message DEN and if the time TTL is not passed, the terminal UT4 releases on its second interface INT2 the reserved resources reserved from UT4 to AS1 by sending the message REL of release of these resources (Figure 8) and Terminal UT4 establishes the connection by the first interface INT1 with the next-hop user NH-ID terminal to reach the destination user terminal UT5.

In step E8, when the next hop terminal UT6 receives a confirmation CONF message, the next hop terminal UT6 checks whether this message is intended for it.

If so, the next hop terminal UT6 confirms the available IREQ resources reserved on its second air interface INT2 with AS1 for the data coming from the user terminal UT4 and then sends the CONF3 message confirming the reservation of these resources. UT6 to AS1 by the second INT2 interface of UT6.

The data transmission TRANS message is then sent from the terminal UT4 by the first interface INT1 from UT4 to UT6, then from the second air interface INT2 of UT6 to the associated coverage terminal AS1, as shown in FIG. 8.

In the negative, that is to say that the message CONF is not intended for him, this terminal UT6 can for example:

- either immediately release the IREQ resources initially reserved from UT6 to AS1, - or keep the reservation of resources towards AS1 until the expiry of a time interval L.

In one embodiment, in the case where the time interval L has expired and the next hop user terminal UT6 has not received the confirmation CONF message, the next hop user terminal UT6 releases the resources reserved for AS1.

In one embodiment, in the case where the next hop user terminal UT6 has received the confirmation CONF message after the expiration of the prescribed time interval L, this terminal UT6 decides to confirm the resources reserved to AS1. depending on the availability of these IREQ resources to AS 1. In the case where the UT6 terminal can not satisfy the REQ request, the next hop UT6 terminal sends the negation DEN message to the UT4 terminal (in point-to-point mode). -point) (Figure 12). If the next-hop user UT6 terminal has IREQ available resources, it includes in this negation DEN message the maximum value of IREQMAX available resources from UT6 to AS1. The UT4 terminal is thus informed by UT6 that IREQ resources from UT6 to AS1 are no longer available. The UT4 terminal obtains the information indicating the maximum resources IREQMAX, which are available at this time.

In one embodiment, in the case where the next hop user terminal UT6 having received the confirmation CONF message does not receive the data transmission TRANS message before the time interval L expires, the terminal Next hop user UT6 releases the reserved IREQ resources reserved on its second interface INT2 to AS1, as shown in FIG. 13, by sending an IREQ resource release REL message to AS1. In step E9, when the user terminal UT4 receives a deny DEN message, the terminal UT4 sends a confirmation CONF message to another next hop user terminal, other than the terminal UT6.

The process is therefore restarted with this other next-hop ID-NH terminal thus selected, instead of the terminal UT6 in the foregoing.

When one or more next hop NH-ID user terminals are selected until the TTL time slot is passed, the user terminal UT4 checks for each selected next hop terminal NH-ID the resources IREQMAX maximums available to AS1 for:

- or choose multiple paths (multi-path case) to satisfy the initial request

REQ of resources and choose the best NH-ID terminals for a multi-path communication solution from UT4 to multiple NH-ID terminals by one jump, then these NH-ID terminals to their associated AS coverage terminals, the message TRANS data transmission is then divided into several parts sent separately from UT4 to several next-hop NH-ID terminals, and then from these to their associated AS coverage terminals by their second interface INT2,

or the terminal UT4 confirms with the message CONF2 the available resources X reserved by its second interface INT2 to AS1 and this terminal T4 sends the message TRANS of data transmission by its interface INT2 directly to the associated terminal AS1, for sending to recipient user terminal UT5 (single-path solution).

The terminal UT4 chooses the single-path or multi-path solution to satisfy the initial resource REQ request and makes this determination on the basis of the quality parameter CQI (UT-AS), and optionally other parameters, stored in the table T1 for each path. The division of the data in the multipath case is performed according to the available resources IREQMAX of each user terminal of next hop NH-ID. The multi-path solution is optional in the routing algorithm and will only be selected if all other options have been eliminated and network performance allows.

In step E10, the next hop user terminal UT6 performs the following operations.

If the next hop user terminal UT6, after receiving a confirmation CONF message, does not receive any data transmission TRANS messages until a prescribed time interval x has expired, the terminal UT6 releases by the message REL releasing the available IREQ resources reserved by its second INT2 interface.

If the next hop user terminal UT6, after sending a deny DEN message, does not receive from the user terminal UT4 any TRANS data transmission message until a prescribed time interval t expires, it releases the available IREQ resources reserved by its second interface INT2 by the REL message. If the next hop user terminal UT6, after sending a deny DEN message, receives the data transmission TRANS message from the terminal UT4 before the prescribed time interval t expires, the user terminal UT6 of next hop confirms the available IREQ resources, reserved on its second interface INT2 for the data contained in the message TRANS (confirmation message CONF3 from UT6 to AS1 in FIG. 8). The TRANS data transmission message is then sent from UT6 to AS1 by the second air interface INT2 of UT6 (FIG. 8).

In the case where the cover terminal AS 1 has received the data transmission TRANS message containing the UT5 identifier of the destination terminal UT5, the coverage terminal AS1 sends this data transmission TRANS message to the destination terminal UT5, and this is directly by the third interface INT3 of AS1 by a hop when the destination terminal UT5 is an associated terminal (covered by) at the terminal AS1 coverage, or through at least one other terminal (AS2 or other) coverage by the sixth interface INT6 of AS1 when the destination terminal UT5 is an associated terminal (covered by) the cover terminal AS1, until the message TRANS is transmitted to the associated intermediate coverage terminal AS (covering) to the destination terminal UT5. This associated intermediary AS cover terminal (covering) at the destination terminal UT5 then sends this TRANS data transmission message (received from AS1 or another AS) to the destination terminal UT5 directly by the third interface INT3 of AS by a hop. It is emphasized here that in order to be able to carry data, a coverage terminal AS has means for obtaining information relating to terrestrial UT terminals located in its coverage area, for example a routing table.

Embodiments of the invention are described below for the data communication of an AS terminal for coverage to an external terminal via a GS gateway terminal, and vice versa. In a particular embodiment, the destination terminal is a gateway GS terminal.

In step El i, in FIGS. 14 to 17, each gateway terminal GS transmits a beacon or signaling message BEAC-GS containing (FIG. 15) at first intervals of time on its fifth INT5 interface:

at least one first field indicating an identifier ID of this terminal GS,

optionally, at least one second AS-INF field indicating at least one AS-ID of at least one coverage ASl terminal associated with the GS coverage terminal and a second channel quality CQI2 = CQI parameter (GS-AS1) direct communication between the associated ASl coverage terminal and the GS gateway terminal. The BEAC-GS message also includes a MID message identifier in another field. The BEAC-GS message is for example sent to several other AS terminals coverage (for example of the type "broadcast" in English).

Each terminal GS comprises a third table T3 (FIG. 14) in which the identifier ID of this terminal GS is registered in association with one or more parameters CQI2 = CQI (GS-AS1), in association with the identifier AS-ID of the associated cover ASl terminal and / or in association with another quality parameter CQI1 = CQI (AS1-GS) quality of the direct communication channel between the AS terminal and the GS terminal, and in association with the MID identifier of the message BEAC-GS issued.

For example, the second quality parameter CQI2 = CQI (GS-AS1) has been calculated based at least on the quality of the reception, by the terminal GS, of at least one other previous message sent directly by the terminal AS1. The second parameter CQI2 = CQI (GS-AS1) is representative of the quality of the direct communication channel between the AS1 terminal and the GS terminal. The second parameter CQI2 = CQI (GS-AS1) is calculated by GS as described later as a function of at least the power reception level of the previous message sent from AS1 to GS.

The third parameter CQI 1 = CQI (AS1 -GS) is representative of the quality of the direct communication channel between the terminal GS and the terminal AS1. The third parameter CQI1 = CQI (AS1-GS) is calculated by AS1 as described later as a function of at least the power reception level of the BEAC-GS message sent from GS to AS1.

A CQI1 and / or a CQI2 is provided for each association between the gateway GS terminal and a coverage AS terminal. Several CQI1 and / or several CQI2s can be provided when the GS terminal is associated with several AS coverage terminals, as shown in FIGS. 15 and 21.

If the GS terminal has no associated ASl terminal, the BEAC-GS message does not include a second AS-INF field.

Each gateway GS terminal determines for each AS terminal a power level of the received signal, updated when receiving a packet from AS. The parameter CQI2 = CQI (GS-AS1) is then determined according to at least the power level and / or according to the parameter CQI1 = CQI (AS1-GS) received in an ACK-BEAC-GS message (which is described later ) and / or depending, if necessary, other statistics, such as modulations and coding schemes, rates, obtained from the MAC layer, representative of the quality of the communication channel from GS to AS. It can thus be seen that the parameter CQI2, quality of the communication channel evaluated by the terminal AS, depends on the quality of the communication channel evaluated by the terminal AS. The use of this CQI2 metric makes it possible to avoid selecting asymmetrical links later. In step E12, each cover terminal AS1, which receives the beacon message BEAC-GS, records in at least a fourth table T4 (FIG. 16) of this terminal AS1 the identifier ID of the terminal GS terminal, called terminal. active ID, contained in the first field of beacon message BEAC-GS received during the last of second determined time intervals blO, in association with:

- the content of the second field of this beacon BEAC-GS received message (second parameter CQI2 = CQI (GS-AS1) communication channel quality), and / or a third quality parameter CQI1 = CQI (AS1-GS) communication channel, this third CQI parameter (AS1-GS) being calculated by the third terminal AS1 and in association with the MID identifier.

The table T4 also contains, in association with the identifier ID of the terminal GS, a parameter D of distance equal to one jump (direct link).

The AS1 terminal having received the BEAC-GS message sends an acknowledgment message ACK-BEAC-GS by its fourth interface INT4, to reply to the received BEAC-GS message and to send to the GS terminal the parameter CQI1 = CQI (AS1-GS ) calculated by AS1. The gateway GS terminal is then a terminal associated with the coverage terminal AS1. The table T4 of AS1 is updated at time intervals y10 to keep in the table T4 only the information on the active GS. The life period of the GS in the T4 table is determined by a TTL (GS) timer.

The ASl coverage terminal determines a received signal power level, updated upon receipt of a packet from GS. The parameter CQI1 = CQI (AS1-GS) is then determined according to at least the power level and / or depending, if necessary, other statistics, such as modulations and coding schemes, rates obtained from the MAC layer , representative of the quality of the communication channel from ASl to GS.

In FIG. 18, the acknowledgment message ACK-BEAC-GS comprises a first field containing the AS-ID of the covering ASl terminal sending it, in association with the parameter CQI1 = CQI (AS1-GS) in a second field. This message is for example point-to-point.

The AS1 terminal having received the BEAC-GS message sends a signaling SGS message via its sixth INT6 interface in order to send the information concerning the GS terminal to one, several or all the other AS coverage terminals. These terminals AS, AS1 act as first terminals, in this case aerial. These first terminals AS, AS1 form a first air network.

In FIG. 19, the signaling message SGS comprises a message identifier MID2 in a first field, a distance information D in a second field and / or, in a third field GS-INF, the parameter CQI2 = CQI (GS-1). AS1), for example in association with the identifier ID of the terminal GS corresponding to this parameter CQI2, which was present in the BEAC-GS message received by the terminal AS1. The distance D is expressed for example in number of jumps from the GS terminal to AS1 increased by one jump, that is to say that for example D is equal to two jumps for the transmission of the SGS message from AS1 to another AS2 coverage terminal. The SGS message is sent at a time interval a30 and sent to several other AS terminals of coverage (for example of the "broadcast" type in English). There can also be several GS terminals which are associated with the same terminal AS 1 directly (Figure 21). In this case, the SMS message comprises in the third GS-INF field the identifier or identifiers ID-GS (2), ID-GS (n) in association with the respective parameters CQI2 = CQI (GS-AS1) (2), CQI2 = CQI (GS-AS1) (n) relative to this other gateway GS terminal or these other gateway GS terminals.

In the step E13, when the terminal GS receives the message ACK-BEAC-GS, the table T3 of this terminal GS is updated at the determined time intervals blO in order to keep in the table T3 the identifier AS-ID of the associated coverage AS1 terminal, contained in this ACK-BEAC-GS message and the parameter CQI1 = CQI (AS1-GS) contained in this ACK-BEAC-GS message. The lifetime of a GS terminal in the T5 table is determined by a TTL10 timer.

In step E14, in FIG. 20, when another cover terminal AS2 receives a message

SGS, this terminal AS2 updates a fifth table T5 with the information concerning the GS terminal (s) contained in the SMS message. Each covering AS2 terminal receiving the SGS signaling message, keeps stored in its own fifth table T5, the third GS-INF field of the SGS signaling message received during the last of said determined time intervals b 10, that is, say the identifier ID of the terminal GS, called the active terminal ID, in association with the second parameter CQI2 = CQI (GS-AS1), the identifier MID2 of the message SGS and the distance D2 equal to the distance D contained in the message SGS to which is added a jump. The GS gateway terminal is then a gateway terminal referenced for the AS2 coverage terminal.

The terminal AS2 checks whether the MID2 message identifier contained in the SGS message it receives is not already contained in its table T5, for:

in the negative, retransmitting from AS2 by its sixth interface INT6 the message SGS in which the distance D2 has been increased by one jump; in this case, AS2 received this SGS message for the first time;

if so, the terminal AS2 checks whether the distance D present in the message SGS received by AS2 is smaller than the distance D2 recorded in the table T5 of AS2 or if the message SGS registered in the table T5 has expired for, in if so, update the T5 table with this received SMS message and, if not, ignore the received SMS message (because the information contained in the received SMS message is no longer useful as a better information is already stored in table T5). In Figure 21 is shown an example, where two separate gateway terminals GS1 and GS2 are associated with the same ASl terminal by a direct jump. The gateway terminal GS1 is also associated by a direct jump to an AS2 coverage terminal. In this case, GS1 sends the beacon message BEAC-GS 1, as indicated above, and the GS2 terminal sends the beacon message BEAC-GS2, as indicated above. The AS1 terminal receiving BEAC-GS 1 and BEAC-GS2 sends the message SGS = SGS1 + GS2 containing the information on BEAC-GS 1 and BEAC-GS2 to AS2, as indicated above. The AS2 coverage terminal receiving BEAC-GS 1 retransmits the message SGS 1 containing the information of the message BEAC-GS 1 received by AS2. The SGS1 + GS2 message received from AS1 is also retransmitted by the AS2 coverage terminal as indicated above.

More than one gateway GS terminal, two gateway GS1, GS2 terminals, or more than two gateway GS terminals can be provided, which are associated with a direct jump to the gate AS1 terminal.

In step E15, each covering terminal AS, in FIG. 22, transmits, at determined time intervals b20, b21, on its sixth interface INT6, a beacon message BEAC-AS containing (FIG. 26):

at least one first field indicating an identifier ID of this coverage terminal AS,

and / or at least a second field BATT indicating at least a first parameter BATT of remaining power supply of the terminal AS of coverage,

and / or a third field indicating an identifier ID-GS of the referenced gateway GS terminal (for example having been registered in the T5 table of AS),

and / or a fourth field indicating the distance D in hop count of this gateway GS terminal corresponding to this ID-GS identifier to this coverage AS terminal.

This BEAC-AS message is broadcast to several other AS terminals of coverage (for example of the "broadcast" type in English).

In step E16, in FIG. 24, each coverage terminal AS3, which receives the beacon message BEAC-AS, stores in at least one sixth table T6 of this coverage terminal AS3 the identifier ID of the coverage terminal AS. called active coverage terminal ID, contained in the first field of the beacon message BEAC-AS received during the last of predetermined time intervals b22, in association with:

the first parameter BATT of remaining power of power contained in the second field of this beacon message BEAC-AS received, and / or

the gateway terminal identifier ID-GS contained in the beacon BEAC-AS message received, and / or

the distance information D contained in the beacon message BEAC-AS received, and / or

a third reception channel quality parameter CQI1 = CQI (AS3-AS) of this BEAC-AS beacon message received by AS3, and / or a TTL lifetime of the identifier ID of the terminal AS in the table T6. If the current time is less than this TTL duration, the AS terminal corresponding to the identifier ID in the T6 table is active. Otherwise, the identifier ID of the terminal AS in the table T6 is not active and is expired.

In order to determine active or expired AS terminals, each AS3 terminal maintains a register comprising the last time when the information on the AS terminals of the T6 table has been updated. Whenever the AS3 terminal receives a beacon message BEAC-AS, this terminal AS3 calculates the quality CQI1 of this particular link and updates the table T6 with this parameter CQI1 = CQI (AS3-AS).

The parameter CQI1 = CQI (AS3-AS) is representative of the quality of the direct communication channel between the AS terminal and the AS3 terminal. The parameter CQI1 = CQI (AS3-AS) is calculated by AS3 as a function of at least the power reception level of the BEAC-AS message sent from AS to AS3. More specifically, the AS3 terminal determines for each AS terminal a power level of the received signal, updated when receiving a packet from AS. The parameter CQI1 = CQI (AS3-AS) is then determined according to at least the power level and / or depending, if necessary, other statistics, such as modulations and coding schemes, flow rates, obtained from the layer MAC, representative of the quality of the communication channel from AS3 to AS.

In step El 7, in FIG. 25, each terminal AS4 (or AS1 or AS 3 in the foregoing) of coverage, having data to be sent to another terminal located in the other communication network via of a gateway GS terminal, checks whether it is associated with a gateway terminal neighbor of a jump in the table T6 of this fourth terminal AS4.

If so, the terminal AS4 sends directly to the associated gateway GS terminal by the fourth interface INT4 a second transmission TRANS message containing the data and the identifier ID-GS of the gateway terminal GS,

If not, the AS4 terminal initially selects a referenced gateway GS terminal, based on at least the quality parameters of the communication channels between the referenced gateway GS terminals and the AS, CQI ( GS-AS) and the quality parameters of the communication channels between the AS terminals CQI1 = CQI (ASx-ASy). In a particular embodiment, the BATT parameters and the distance parameters are also taken into account in this selection step. These different parameters are stored in its own table T6. In a second step, the terminal AS4 selects at least one next hop starting from this terminal AS4 and arriving at at least one intermediate coverage terminal AS6 other than the selected gateway GS terminal, on the basis of at least the CQI parameters ( GS-AS) of its own table T6, and sends, through the sixth interface INT6 to the selected intermediate terminal AS6, the second transmission TRANS message containing the data and the identifier ID-GS of the selected gateway GS terminal. In a particular embodiment, one of the parameters BATT, CQI1 = CQI (AS4-AS6), D is also taken into account in this selection step.

The AS4 terminal stores, in the table T6 of AS4, in addition to the parameter BATT of the neighbors of AS4 in the table T6 (from BEAC-AS), its own parameter BATT of the remaining power supply of AS4, which is used to maximize the life of AS4.

The neighbor BATT parameter in table T6 (from BEAC-AS), i.e. AS4 neighbors, represents the amount of power remaining from neighbors of AS4 and is used to maximize their lifetime in the network.

The CQI parameter (AS4-AS6) in the T6 table of AS4 is an indicator of the quality of the channel between AS4 and AS4 terminals near AS4 and is used to maximize the throughput in the network and minimize power consumption. in the system, especially that of AS4.

The CQI parameter (GS-ASl) is an indicator of the quality of the direct communication channel between the gateway GS terminal and the associated AS1 coverage terminal and is used to maximize the throughput in the network and minimize the power consumption of the gateway. network.

The distance D from the GS gateway terminal is used to minimize the communication delay.

In general, in the various cases mentioned above, several or all the parameters can be used in addition to the CQI parameter (GS-AS) jointly or the priority orders of the parameters can be set. For example, the order of priority can be as follows: first, the BATT energy of the neighboring terminals, then, if two neighboring terminals have the same BATT parameter or a BATT parameter located in the same range, they are then separated for example on the basis of the distance D, then on the basis of the parameter CQI (AS4-AS6) (or CQI (UT4-UT6)). For example, an energy cost is calculated based on one or more of these parameters and the solution with the lowest energy cost is selected.

For example, if the BATT parameter is very low, we try to maximize the lifetime and minimize the power consumption. Consequently, the terminal AS4 selects the intermediate terminal AS6 having the best parameter CQI (AS4-AS6), in order to use less energy in the communication, even if this intermediate terminal AS6 does not have the smallest distance D in number of hops relative to the associated GS terminal, which can increase the delay.

In step El 8, when the intermediate coverage terminal AS6 receives the message

Data transmission trans to be sent to the selected gateway GS terminal, this intermediate terminal AS6 selects, based on at least the CQI parameter (GS-AS7), at least one AS7 intermediate terminal of next hop in view of reach this selected GS gateway terminal. In a particular embodiment, the BATT parameters of the terminals of the AS7 terminals neighboring AS6 in the T6 table of AS6, the CQI parameters (AS6-AS7), the distance D in number of hops to the GS terminal are also taken into account. . Therefore, at this step El 8, the terminal AS6 executes on the basis of its tables T5 and T6 recorded in AS6 the same process as AS4 in the previous step E17.

If AS6 is associated with a direct jump with the selected gateway GS terminal and if, based on at least the CQI (GS-AS) parameter, the AS6-GS hop is the best option to communicate with the GS terminal of gateway selected, the AS6 terminal sends the TRANS message to the GS terminal selected by the fourth interface INT4 of AS6.

If the terminal AS6 is not associated by a direct jump with the selected GS terminal, the terminal AS6 sends the selected intermediate terminal AS7 the TRANS message, this being the case shown in FIG. 25. In this figure, the terminal AS7 (or AS1) associated with GS then sends the TRANS message directly to GS.

In order to avoid that the next AS7 terminal selected by AS6 is the AS4 terminal, the AS6 terminal excludes AS4 from the T6 table of AS6, before AS6 begins its selection of AS7.

In step E19, in one embodiment, when the gateway terminal GS receives the TRANS message including its own identifier, the GS terminal creates or updates a T7 table by recording the route R to the AS coverage terminal. having the identifier ID indicated in this message TRANS and also recorded in association with the information R in the table T7 (Figure 26). This makes it possible to keep in the table T7 only information concerning the active route to a specific coverage terminal AS. The lifetime of this information in the T7 table is determined by a TTL timer (AS-R). Thus, optionally, the gateway GS terminal can use the R route registered in the T7 table to communicate with the coverage AS terminal registered association by its identifier ID in this table T7. The choice to use the R route of the T7 table depends on the default routing protocol media capabilities of each coverage AS terminal (i.e., to maintain bidirectional routes). The TRANS message is then routed by the gateway GS terminal to the destination terminal located in the other communication network.

In step E20, in FIG. 27, an optional procedure is provided for updating in a table of the GS gateway terminal or terminals information concerning the AS coverage terminals. For this purpose, each covering AS terminal transmits an AS-GS-BEAC beacon message at determined time intervals c on its sixth INT7 interface, this AS-GS-BEAC beacon message containing:

at least one first field indicating an identifier ID of this terminal AS,

at least one third field indicating at least a first parameter BATT of remaining power supply of this terminal AS,

and / or the NH-ID identifier of the next intermediate AS6 terminal of coverage,

and / or the distance D in number of jumps with respect to the terminal GS,

and / or the ID-GS identifier of the terminal GS, possibly associated with the terminal AS,

possibly the longitude LON and / or latitude LAT of the terminal AS. The terminal AS selects, based on the parameter CQI (GS-AS) and optionally at least one of the parameters D, BATT, and CQI (AS-AS), recorded in its table or tables, a terminal cover intermediate AS6 to reach the destination GS terminal, as described above, in order to transport by this AS6 intermediate terminal the AS-GS-BEAC beacon message. The role of the beacon AS-GS-BEAC message is to send information to the gateway GS terminal, this information being used by this gateway GS terminal in order to implement network management strategies, maintain a trace AS terminals and have an active route between this GS terminal and AS terminals (Figures 30 and 31).

The time intervals mentioned above are for example periodic.

In a particular embodiment, the BEAC-GS message broadcast by a gateway GS terminal does not include the second AS-INF field. The SMS message sent by the terminal AS then comprises in the third field GS-INF the identifier or identifiers ID-GS (2), ID-GS (n) in association with the respective parameters CQI1 = CQI (AS1-GS) (2). ), CQI1 = CQI (AS1-GS) (n) relative to this other GS gateway terminal or these other gateway GS terminals.

In another embodiment, for a data communication from the user terminal UT to another user terminal external to the hybrid network, the user terminal UT implements the steps of the communication method as described above in relation to the first user terminal. embodiment, from the terminal UT to a terminal AS of coverage, directly or indirectly, then the steps of the communication method as described above, from the terminal AS of coverage to the other external terminal, via a terminal GS Gateway.

The communication method thus enables the UT terminals to communicate with each other and to join any other terminal, while optimizing the energy consumption in the hybrid network.

The above-mentioned CQI, CQI1, CQI2, D, DD, D2 parameter (s) are calculated on the basis of measurements made, each user terminal UT, each covering terminal AS and each gateway terminal GS having at least one device for measuring at least one physical quantity (which may be the one (s) indicated above, such as, for example, the power of the signal or message received, measured by a measurement circuit measuring the signal received on the corresponding interface), from which a computing device calculates this or these parameters.

Each user terminal UT, each covering terminal AS and each gateway terminal GS also comprises a device for implementing the communication method described above, and in particular a control device for controlling its interfaces, a device for calculation of the CQI, CQI1, CQI2, D, DD, D2 parameter (s) from measurements provided by his measuring device (s), a device for shaping the one or more messages to be sent, a storage device for storing the tables, these devices may comprise one or more computers or electronic and / or computer programmed means.

The invention thus provides a device for implementing the communication method, comprising means for performing the operations indicated above.

In a particular embodiment, the control, calculation, formatting and storage devices are arranged to implement the previously described method. These are preferably software modules comprising software instructions for executing the steps of the method described above, implemented by a terminal. The invention therefore also relates to:

a computer program for a terminal, comprising program code instructions intended to control the execution of the steps of the method described above, when said program is executed by this terminal;

a recording medium readable by a terminal on which the terminal program is recorded.

The software devices may be stored in or transmitted by a data carrier. This may be a hardware storage medium, for example a CD-ROM, a magnetic diskette or a hard disk, or a transmission medium such as an electrical signal, optical or radio, or a telecommunications network.

The invention also relates to a communication installation of a hybrid network, terrestrial and air, comprising a plurality of first terminals belonging to a first network of the terrestrial or air type and at least a second other terminal of the aerial or terrestrial type other than that of the first network, as previously described.

Claims

A method of communication between terminals in a hybrid communication network, terrestrial and overhead, said network comprising a plurality of first terminals (UT, AS) belonging to a first terrestrial or aerial type network and each having an interface (INT1, INT6) of communication having a defined communication range to at least one other terminal of identical type, and at least a second other terminal (AS1, GS) of the aerial or terrestrial type other than that of the first network,

characterized in that

at least one of the first terminals (UT, AS) sends via its interface (INT1, INT6) communication with said at least one other first terminal (UT3, AS2), to said at least one other first terminal (UT3, AS2) of type identical, at least one signaling message (BEAC-UT, SGS) containing at least one parameter (CQI2 = CQI (UT-AS1), CQI2 = CQI (GS-AS1)), which is representative of the quality of the communication channel between the first transmitting terminal (UT, AS) and said second terminal (AS1, GS), said second terminal being associated with the first transmitting terminal by a direct communication channel.

2. The communication method according to claim 1, wherein said parameter is computed according to at least the quality of the reception by the first transmitting terminal (UT, AS1) of at least one other previous message sent directly by the second terminal. associate (ASl, GS).

3. The communication method according to claim 1, wherein the second terrestrial associated terminal (GS) transmits at least one of the first aerial-type terminals (AS1) at least one signaling message (BEAC-GS). containing said representative parameter (CQI2 = CQI (GS-AS1)).

4. The communication method according to claim 1, wherein a communication from a terminal directly to another terminal is called a hop,

one of the first terminals (UT4), of terrestrial type, said source terminal, having data to be sent to a destination terminal via the air network chooses an indirect transmission mode by a path formed by a first communication channel of the source terminal to another first terminal, said intermediate terminal, and a second communication channel of the intermediate terminal to a second terminal associated with said intermediate terminal, on the basis of said at least one parameter representative of the quality of the second communication channel.

The communication method according to claim 4, wherein the source terminal selects at least one intermediate terminal on the basis of at least said parameter representative of the quality of the second communication channel and transmits a resource reservation request for the data transmission.

The communication method according to claim 5, wherein when none of the intermediate terminals has the requested resources, the direct transmission mode is chosen.

7. The communication method according to claim 5, wherein an intermediate terminal, no longer having the resources requested when receiving a resource reservation confirmation, indicates to the source terminal the remaining available resources.

8. The communication method as claimed in claim 1, in which one of the first terminals (AS1), of the aerial type, called the source terminal, having data to be sent respectively to a destination terminal, located in another communication network, selects a second terrestrial type terminal, allowing access to the other communication network, according to at least said parameter representative of the quality of the communication channel between another of the first terminals to which the second terminal is associated and the second terminal.

9. Computer program comprising instructions for implementing the communication method according to any one of claims 1 to 8, when the program is executed by a processor.

10. Recording medium readable by a terminal on which the program according to claim 9 is recorded.

11. Terminal (UT, AS) of the terrestrial or aerial type, belonging to a first network, comprising a first communication interface (INT1, INT6) having a determined communication range to at least one other terminal of identical type and a second communication interface (INT2, INT4) having a determined communication range intended for at least one second terminal (AS, GS) of the aerial or terrestrial type other than that of the first network by a communication channel,

characterized in that it comprises means for transmitting by the first communication interface at least one signaling message (BEAC-UT, SGS) containing at least one parameter (CQI2 = CQI (UT-ASl)), which is representative of the quality of said communication channel between said terminal and the second terminal.

12. Communication installation, of a hybrid communication network, terrestrial and aerial, comprising a plurality of first terminals (UT, AS) belonging to a first network of terrestrial or aerial type and each having an interface (INT1, INT6) of communication having a defined communication range to at least one other terminal of identical type, and at least one second terminal (AS 1, GS) of the aerial or terrestrial type other than that of the first network,

characterized in that

at least one of the first terminals (UT, AS1) comprises transmitting means for sending via its interface (INT1, INT6) communication with said at least one other first terminal (UT3, AS2), to said at least one other first terminal (UT3, AS2) of identical type, at least one signaling message (BEAC-UT, SGS) containing a parameter (CQI2 = CQI (UT-AS1), CQI2 = CQI (GS-AS1)), which is representative of the quality of the direct communication channel between at least one first terminals (UT, AS) and the second terminal (AS1, GS), said second terminal being associated with the first transmitting terminal by a direct communication channel.

The communication installation according to claim 12, further comprising at least a second other terrestrial terminal (GS), said second other terrestrial terminal (GS) having a first air communication interface (INT5) having a determined communication range at destination. at least one other air terminal (AS1) and a second interface (INT7) communicating with at least one other communication network, and further comprising transmission means by the first air communication interface (INT5) of at least one signaling message (BEAC-GS) containing a parameter (CQI2 = CQI (GS-ASl)), which is representative of the quality of the direct communication channel between the air terminal (AS1) and the second other terrestrial terminal ( GS).