WO2006070375A1

WO2006070375A1 - A communication system and a communication method

Info

Publication number: WO2006070375A1
Application number: PCT/IL2006/000004
Authority: WO
Inventors: Rafael Tuval
Original assignee: Elta Systems Ltd.
Priority date: 2004-12-30
Filing date: 2006-01-01
Publication date: 2006-07-06
Also published as: IL166050A0

Abstract

The present invention provides for a communication system and a method thereof. According to one embodiment of the invention the communication system comprises one or more end user communication units (EU) and one or more airborne base stations (BS). Each BS being associated with on or more EUs defining together a local wireless communication network with a topology permitting one or two-way communication between the local network members.

Description

A Communication System and a communication Method

FIELD OF THE INVENTION

This invention relates to communication system. More specifically, the present invention relates to a communication system for fast deployment, e.g. in a hostile territory, e.g. in a combat zone, in disaster areas, etc., permitting communication between different end users and between them and a remote communication center.

BACKGROUND OF THE INVENTION

There are situations where a need exists to rapidly deploy a communication network for voice and data applications in areas without appropriate infrastructure. Such a need may arise, for example in the case of a military activity in a hostile territory, in a disaster area where the normal communication network has been damaged, etc.

Existing solutions that can be considered for these problems include deployment of a cellular network or the use of satellite communication. A combat or a military action scenario is a specific case in point.

Deployment of a cellular communication system in a hostile territory requires a good measure of control of the territory. Furthermore, it imposes technical and operational limitations. The communication between the cellular communication links and a remote command and control post may also present an issue. Satellite communication requires expensive and at times relatively bulky end user units, typically having limited capabilities. Furthermore this requires also continuously retain unused communication modules in the satellite which is a very expensive proposition SUMMARY OF THE INVENTION

It is the object of the invention to provide a versatile wireless communication system that can be rapidly deployed in an area and maintain provide one-way and two-way communication links between end user units in the area.

The present invention provides a communication system comprising one or more end user communication units (EU) and one or more airborne base stations (BS); each BS being associated with one or more EUs defining together a local wireless communication network with a topology permitting one or two- way communication to the local network members.

The communication system of the invention preferably comprises also a remote communication center (RCC). The term "remote communication center" refers to a communication center that is at distance from the area in which the communication system is deployed, such that without a suitable communication relay system, is too distanced to allow good quality communication link with some or all of the EUs. In such a communication system, each EU is in a two- way wireless communication link with said BS that provides a gateway for oneway or two-way wireless communication link between the EUs and the RCC. A communication system of the invention that is not linked to an RCC, typically comprises also a local command and control center.

The present invention further provides an airborne base station (BS) for a wireless communication system that comprises one or more EUs and one or more BSs. The BS is configured so that once deployed it can associate with one or more EUs to define together a local wireless communication network with a topology permitting one or two-way communication between network members. A BS for a communication system of the invention that comprises also an RCC, is configured also to permit it to establish a two-way wireless communication link with said RCC to provide a gateway for one-way or two-way communication between the EUs and the RCC. The airborne BS is typically mounted on an unmanned airborne vehicle (UAV). UAVs are typically small planes steered from a remote control center by an operator. The UAV may, however also be automatically steered according to a predefined flight plan. Such an automatic flight plan may, for example, dictate that the UAV will circulate at certain defined altitude over an area in which it is to serve as a base station. Additionally, the airborne BS may also be mounted in a payload of a balloon.

The airborne BSs are a key factor in the communications system's high versatility and rapid deployment purposes. The communication system can in fact be established at the moment the airborne BSs are in place over the specific area. In the typical case where the BSs are mounted in an UAV, the time to establish the communication system may be as rapid as the time it takes the UAV to fly from its launching site to the respective area.

Typically, the communication system of the invention comprises one or more airborne BSs, each of which has its associated EUs, defining corresponding one or more local network. In case of a communication system formed with one or more local network, each with its BS and EUs, the different local networks are typically in different geographical areas although this is not always necessarily so. There may at times, be an overlap in the geographical coverage area of each of the local networks, with EUs in overlapping regions becoming associated with one or another according to some predefined system rules. It is also clear that by virtue of the fact the coverage area of each BS may occasionally change as it moves. The communication system may at times also deployed with a certain degree of redundancy, with more BSs that are actually needed with a considerable degree of overlap between them so as to ensure uninterrupted service.

A local network in a communication system of the invention is in fact a virtual association between the BS and the network subscribers, i.e. the EUs. It is thus clear that the association between BSs and EUs is defined ad hoc and may change as the dynamics of the system may require. The association of BSs to a specific EU may be a priori defined; the association may be according to a set of predefined rules or policy and geared to accommodate changes in requirement that may arise out of the operational dynamics; or a certain combination of the two. In a dynamic system the association between a BS and EUs may switch occasionally, e.g. in a manner similar to that in which a mobile cellular communication devices switch from one cell to another in a cellular telephone system. Rules that define and police these dynamics, defining association of EUs and BSs and the switch of EUs from a one BS-defined local network to another, may be based on physical distance, on the specific terrain, on line of sight, quality of service, temporary or ongoing bandwidth required, available communication channels, and others.

The EUs may be manned or unmanned ground devices as well as airborne systems. Ground devices may include personal or vehicle-mounted mobile communication devices for voice and/or data communication; on-ground stationary devices, e.g. a local relay station; a remote-operated unmanned sensing unit, e.g. a surveillance camera, a remote chemicals detector, etc.; a local command and control center; remote-operated weapon systems, e.g. artillery guns or launchers; a remote operated vehicle; and many others. Airborne systems that are EUs in the communication system of the invention may be surveillance UAVs; sensing systems mounted in a balloon payload, and others.

A specific, albeit non-limiting, embodiment of the invention is a communication system for military use for rapid deployment in combat or in any other military operation needing communication support. Other embodiments are such systems for civil use, for example: for deployment in disaster areas; for deployment to support rescue operations in remote regions; etc. The invention will be described, at times, with reference to its military use, it being understood that the invention is not limited thereto. The different BSs may be all identical or similar or may be different.

Different BSs may be deployed at different altitudes. Communication between the BSs and the RCC may also be through a mediating communication platform, which may be an airborne or ground vehicle (e.g. via line-of-site communication) or a communication satellite.

The local network can typically operate a different communication channels at different wavelengths and bandwidth. Typically, the local network has a certain frequency range on which all EUs and the BS can communicate, and typically establish a point-to-multi point communication with one another(in other words, a shared communication channel is established). This communication channel typically serves as a command control and access channel (CCA) that operates in a network protocol that permits communication between the different EUs, between them and the BS and through the BS with the RCC (e.g. using TDMA or polling network control schemes). The CCA also serves as a control channel through which EUs engage into the network (register) or disengage therefrom, etc. The CCA is typically a relatively narrow bandwidth channel

The BS allocates different frequency ranges (different channels) to specific EUs, upon demand, thereby providing a specific EU with uplink and/or downlink communication, as required for a specific need (e.g. transmitting and/or receiving of high-volume data). In other words, each EU is a participant of the shared communication channel and upon demand is allocated with an uplink and/or downlink communication channel.

The RCC may, by some embodiments of the invention, be a member of the remote communication network. This permits at times for EUs to link, through the RCC₅ with other members of the remote network. This may permit the EUs, for example, to make direct use of the remote network resources. BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, some specific embodiments will now be described, by way of non- limiting example only, with reference to the accompanying drawings, in which: Fig. 1 is a schematic representation of a communication system according to an embodiment of the invention.

Figs. 2 and 3 are schematic block diagrams illustrating some features of the network topology according to embodiments of the invention.

Fig. 4 is a schematic block diagram illustrating some functionalities of the airborne BSs and the EUs.

Fig. 5 is a block illustration of a deployed communication system in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description the invention will be illustrated with reference to specific embodiments of a communication system in accordance with the invention for military use that can be rapidly deployed and that has versatility to meet the needs of the modem battle field. It may be appreciated, the invention is not limited to such use and the illustrated embodiment is illustrative to the full scope of the invention as described and claimed herein. Reference is first made to Fig. 1 illustrating a communication system, generally designated 100 deployed so as to support a military operation. The illustrated communication system includes two local wireless communication networks 102 and 104. While only two such networks are illustrated in Fig. 1, it is clear that a communication system of the invention may equally include more local communication networks and so provide wireless communication solution to a large area. Furthermore, the embodiment illustrated herein is shown in supporting a wireless communication for a ground operation. It is clear that a communication system of the invention may also provide communication in other combat situations, for example, for wireless communication in a sea operation, in an air attack, etc.

Local wireless network 102 has a base station (BS) 106 mounted on a UAV 108, that may be remotely steered from a remote flight control station (not shown). UAVs are generally known in the art and in generally any kind of a UAV that can carry BS 106 may be used in accordance with the invention, a UAV is the preferred platform for the BS but others may not be excluded. For example, a BS may also be carried in the payload of an airborne balloon, as illustrated in the case of local wireless network 104 that has a BS 110, which is mounted on the payload of an airborne balloon 112.

Local network 102 includes a plurality of associated EUs, of which five 114, 116, 118, 120 and 122, which are respectively a remotely operated surveillance camera, a low level tactical support unmanned plane, an armored personnel carrier, a control and command vehicle and a hand-held personal communication device. All these EUs are in a two-way communication link with the BS 106 and with one another. Similarly, local network 104 has a plurality of associated EUs 124, 126 ... n, illustrated by way of blocks.

The BSs 106 and 110 as well as any others of the system may communicate with a central command and control unit (CCU) 132, e.g. by means of a line-of-site communication, satellite communication (not shown in fig. 1) or via the a remote flight control station/s operating the BSs. The remote communication center unit 132 define in turn an airborne network 130 that permits two-way communication between the different BSs and also between the BSs and the CCU 132. The BSs are configured to establish a network with a topology that permits to engage (register) or disengage EUs., to manage the communication of the different EUs and also to provide a gateway for direct one- or two-way communication link between the EUs and the CCU 132. It should be noted that the local wireless networks are virtual in that members of the networks can engage with the network or disengage therefrom and engage into a different local wireless network. For example, armored personnel carrier 118, once it moved to a different area, can become associated with a different local network. Similarly, the BS 106 can change its location and associate with different EUs to define a different local network, its place then as a BS for the EU with which it was associated beforehand being taken by a different airborne, unmanned plane- mounted BS.

A simplified diagram of a network topology is illustrated in Fig. 2. The communication system illustrated in Fig.2 includes a BS 140, a plurality of EUs 142 and a CCU 144. Each of the EUs 142 is in a two-way communication link with the BS 140, illustrated by bi-directional arrows 146 through one communication channel that is typically of a narrow bandwidth and serves as a command control and access channel (CCA). The CCA permits regular communication between the different EUs and between them, through a BS- enabled gateway, with the CCU over the two-way broad band communication link illustrated by arrow 148. At times, specific EUs may have increased communication demands and the BS 140 may then allocate an ad hoc or permanent broad bandwidth communication channel for a specific EU, e.g. a broad bandwidth uplink illustrated by arrow 150.

A simplified diagram of a network topology of another embodiment is illustrated in Fig. 3. Like components to those of Fig. 2 were given like reference numerals and the reader is referred to the description above for their explanation. In this embodiment the two-way communication between the BS 140 and CCU 144, is mediated through additional system component, which in this case includes two mediating platforms - an airborne mediating communication platform (AMCP) 152 and a ground mediating communication platform (GMCP) 154, the latter being linked to a CCU through a line network 156. AMCP 152 may, for example, be mounted on a high altitude plane, which may be manned or unmanned. The communication between the BS 140 and the mediating platforms may employ line-of-site communication and/or satellite communication (via satellite 158). Thus, EUs 142, in addition to being able to communicate with CCU 144, can also establish a communication link with other subscribes of network 156 and make use of network resources.

Reference is made to Fig. 4 which is a schematic block diagram that illustrates components of the system in accordance with an embodiment of the invention. Depicted are two representative BSs, indicated as BS-A and BS-B and two respective representative associated EUs, indicated as ETJ-A and EU-B. Each of the EUs has a CPU 170, a transmission module (Tx) 172 and a receiving module (Rx) 174, both linked to antenna module 176. Each of the BSs has a main CPU, a CCA (Tx/Rx) module 182, a plurality of broad bandwidth Tx/Rx modules 184, with the Tx/Rx modules being linked to an antenna unit 186. Regular two-way communication on a CCA channel between the BSs and their associated EUs, represented by bi-directional arrow 190, is through by the Tx/Rx module in the BS and the Tx and Rx modules in the EUs. Upon need, the BS can allocate an ad hoc or a permanent broad bandwidth channel, through one of the Tx/Rx units 184, for high capacity uplink and/or downlink communication, illustrated by bi-directional arrow 192. The BSs may have further Tx/Rx modules. The different BSs define together an airborne network and are thus in two-way communication link with one another, as represented by bi-directional arrow 194, through dedicated Tx/Rx modules via a dedicated channel. A UAV, which is typically the platform for carrying the BS, is linked through a Tx/Rx module 196, via a dedicated communication channel 198, to a control unit (not shown). In some embodiments of the invention this channel, typically with increased bandwidth, may be used for linking the local network components, the EUs and the BS with the CCU. Reference is made to Fig. 5 which is a block illustration of a deployed communication system in accordance with an embodiment of the invention, illustrating an architecture of the system. A local wireless network includes a plurality of EUs, five being illustrated (EUl - EU5), which include some on the ground (EUl, EU2 and EU4, in this illustration) and some airborne at different altitudes (EU3 at 1000 feet, and EU5 at 2000 feet) in this illustration. A plurality of BSs, four in this illustration, are deployed at different altitudes, whereby some, such as BSl and BS2 in this illustration are at relatively low altitudes (e.g. 10000 feet) and are associated with EUs to jointly define a local communication network, while others are deployed at relatively high altitudes (e.g. 30000 feet). It should be noted that the role of a specific device (EU1-EU5, BS1-BS4) is dynamically defined with respect to the other devices which participate in the same local wireless network at a given time. Any device may participate in more that one wireless network at the same time, and may have different role in each network. This is illustrated by BSl, which serves as a BS (as explained with reference Fig. 2) to in a local network in which ETJ4 and EU5 participate. At the same time, BSl participate in a network in which BS4 serves as the BS.

Those skilled in the art will readily appreciated that various modifications and alterations can be applied to the present invention as hereinbeforedescribed without departing from its scope defined in and by the appended claims.

Claims

CLAIMS:

1. A communication system comprising one or more end user communication units (EU) and one or more airborne base stations (BS); each BS being associated with on or more EUs defining together a local wireless communication network with a topology permitting one or two-way communication between the local network members.

2. A communication system according to Claim 1, comprising one or more end user communication units (EU), one or more airborne base stations (BS) and a remote communication center unit (CCU); said BS being in a two-way wireless communication link with said RCC and providing a gateway for one-way or two- way communication link between the EUs and the RCC.

3. A communication system according to Claim 1 or 2, comprising two or more BSs₅ each of which having associated EUs, each of said airborne BSs and its associated EUs defining together a local communication network, the two or more BSs being members of an airborne communication network in which network members are in or can establish a two-way communication with one another.

4. A communication system according to Claim 3, wherein the airborne communication network permits the establishment of a communication link between EUs of different local communication networks.

5. A communication system according to Claim 3 or 4, wherein the association is dynamic, such that each EU can switch its association from one BS to another thereby switching its membership from one local network to another.

6. A communication system according to Claim 5, wherein the association between EUs and a BS is maintained according to a pre-defined system policy.

7. A communication system according to Claim 5, wherein policy criteria include one or more of distance, terrain, line of sight, quality of service, EU- required bandwidth.

8. A communication system according to any one of the preceding claims, wherein at least one of the airborne BSs is mounted on an unmanned airborne vehicle (UAV).

9. A communication system according to any one of the preceding claims, wherein the communication link between the BS and associated EUs can be through different communication channels including at least one narrow bandwidth and at least one broad bandwidth channel.

10. A communication system according to any one of the preceding claims, wherein the local network members are on a common command control and access channel (CCA) under a network protocol that permits communication between different EUs of the local network and the associated BS.

11. A communication system according to Claim 10, wherein the CCA serves for low bandwidth two-way communication between the EUs and between the EUs and the BS.

12. A communication system according to Claim 10 or 11, wherein the CCA operates in a network protocol channel permitting control of the EUs by the BS, engagement and disengagement of EUs from the local network and for allocating a broad bandwidth uplink or downlink communication channel to EUs.

13. A communication system according to any one of the preceding claims, wherein the communication between the BS and the CC is through one or more mediating communication platforms.

14. A communication system according to Claim 13, wherein the mediating communication platform is carried on an airborne vehicle or a satellite.

15. A communication system according to any one of the preceding claims, wherein the CCU is part of a remote communication network, whereby one or more EUs can communicate with members of the remote communication network.

16. An airborne base station (BS) for a communication system that comprises one or more end user communication units (EU), said BS being configured such so as to permit it to associate with one or more EUs to define together a wireless communication network with a topology permitting one or two-way communication between network members.

17. A BS according to Claim 16, for a communication system that comprises one or more end user communication units (EU), one or more BSs and a remote communication center unit (CCU); said BS being configured such so as to permit it to associate with one or more EUs to define together a wireless communication network with a topology permitting one or two-way communication between network members, and to permit it to establish a two-way wireless communication link with said CCU and provide a gateway for one-way or two- way communication between the EUs and the CC.

18. A BS according to Claim 17, comprising a communication module permitting two-way communication with other BSs.

19. A BS according to any one of Claims 16-18, mounted on an unmanned airborne vehicle (UAV).

20. A BS according to any one of Claims 16-19, capable of establishing a communication link with other BSs and associated EUs in different communication channels including at least one narrow bandwidth and at least one broad bandwidth channel.

21. A BS according to any one of Claims 16-20, comprising one or more communication modules for communication with other EUs on a command control and access channel (CCA).

22. A BS according to any one of claims 16-21, for use in a communication system according to any one of claims 1-15.