WO2009050210A1

WO2009050210A1 - A method of providing information

Info

Publication number: WO2009050210A1
Application number: PCT/EP2008/063901
Authority: WO
Inventors: Jyri Hamalainen; Antti Sorri; Markku Vainikka; Vinh Van Phan
Original assignee: Nokia Siemens Networks Oy
Priority date: 2007-10-15
Filing date: 2008-10-15
Publication date: 2009-04-23
Also published as: GB0720114D0

Abstract

A method comprising determining in user equipment information (51) relating to at least one neighbouring cell which is in a different network to a network of said user equipment; and sending said information to a base station (52).

Description

A METHOD OF PROVIDING INFORMATION

FIELD OF THE INVENTION

The present invention relates to a method of providing information about neighbouring cells and in particular but not exclusively in an arrangement where the neighbouring cells are provided in a different network. The present invention also relates to a system and to a node, such as user equipment or base station,

BACKGROUND OF THE INVENTION

A communication system is a facility which facilitates communication between two or more entities such as communication devices, network entities and other nodes. A communication system may be provided by one or more interconnect networks. It should be appreciated that although a communication system typically comprises at least one communication network, for example a fixed line network or a wireless or a mobile network, in its simplest form a communication system is provided by two entities communicating which each other. The communication may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text messages, multimedia and so on. The user may communicate by means of an appropriate communication device such as user equipment.

An appropriate access system allows the communication device to access the communication system. An access to the communication system may be provided by means of a fixed line or wireless communication interface, or a combination of these. Examples of wireless access systems include cellular access network, various wireless local area networks (WLANs), wireless personal area networks (WPANs), satellite based communication system and various combinations of these.

A communications system typically operates in accordance with the standard and/or certain specifications and protocols which set out what the various elements of the system are permitted to do and how that should be achieved. For example, it is typically defined if the user, or more precisely a user equipment is provided with a circuit switched bearer or a packet switched bearer or both. Also, the manner in which communication and various aspects thereof should be implemented between the user equipment and the various elements of the communication system and their function and responsibilities are typically defined by a predefined communication protocol.

Reference is made to the following documents: IST-2003-507581 WINNER

D6.1: WINNER Spectrum Aspects: Methods for Efficient Sharing, Flexible Spectrum

Use and Coexistence. This document provides a background to the general concept of flexible spectrum use FSU and spectrum sharing SS in IMT (international mobile telecommunications) - A (advanced) systems.

FSU relates to flexible spectrum use. This refers to the concept of spatially and/or temporarily varying use of the radio spectrum. In other words, in a system comprising more than one operator, each operator does not have an exclusive harmonised spectrum assignment.

Spectrum sharing refers to the situation where different systems or subsystems utilise the same part of the spectrum in a coordinated or uncoordinated manner. A special case is sharing based on flexible spectrum use. Typically, these systems are based on similar technology and offer similar services, for example different apparatus sharing the same spectrum by utilising dynamic channel assignment from a common pool of channels.

IMT-Advanced system refer to radio access system beyond the IMT-2000 system, A global unified wireless architecture is proposed which visualises a hierarchy of interconnected access systems. This system envisages new radio interfaces with mobile class targeting for lOOMbps and nomadic or local area class targeting for IGBPs.

Current existing cellular network systems operate with pre-assigned, fixed, non-overlapping frequency bands. In the current proposal for 3GPP LTE release .08, E-UTRAN (evolved UMTS (universal mobile telecommunications system) terrestrial radio access network) sharing between different operators or multi-core networks is being considered for standardisation. However, no consideration has been given to spectrum usage.

In the current 3GPP LTE Rel.08 E-UTRAN, direct interface between eNBs (E-UTRAN node Bs), referred to as X2, has been specified. The X2 general aspects and principles are described in 3GPP TS 36.420. This allows for distributed control and data forwarding between neighbouring eNBs, e.g., at handover in intra-system E- UTRAN. It should be appreciated that eNB is the terminology used in 3GPP LTE for a base station entity.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a method comprising determining in user equipment information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; and sending said information to a base station.

According to a second aspect of the present invention, there is a method comprising receiving a base station from user equipment information relating to at least one neighbouring cell which are in a different network to a network of said user equipment; requesting connection information for at least one of said neighbouring cells; and sending a request to a neighbouring base station associated with at least one of said neighbouring cells using said connection information.

According to another aspect of the present invention, there is provided a user equipment configured to determining information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; and to send said information to a base station.

According to a further aspect of the present invention, there is provided a base station configured: to receive station from user equipment information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; to request connection information for at least one of said neighbouring cells; and to send a request to a neighbouring base station associated with at least one of said neighbouring cells using said connection information.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the present invention and as to how the same may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which:

Figure 1 illustrates an example of spectrum sharing;

Figure 2 shows an example of a system comprising two operators with which embodiments of the invention may be used;

Figure 3 shows a flow diagram of an embodiment of the invention; Figure 4 shows a single operator network with which embodiments of the present invention may be used; and

Figure 5 schematically shows a user equipment and node b embodying the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Some embodiments of the invention are concerned with efficient FSU and SS between radio access networks of different operators which operate in overlapping spectrum or frequency bands and geographical service area. In such a situation, sufficient interconnectivities and interactions between those networks including their operation support systems may be required. These can be realized on different levels: deeper into the core-network part, e.g., for a more vertical, centralized control approach; or closer to the radio-interface part where actual spectrum usage, in effect, is taking place, e.g., for a more horizontal, distributed control approach.

Both the vertical, centralized control and the horizontal, distributed control may be used in parallel to ensure an overall stable and at the same time efficient network operation. The vertical, centralized control provides somewhat slower but globally reassuring semi-static control of FSU and SS. The horizontal, distributed control allows for faster reaction and adaptation to the dynamic changing of local spectrum usage specific to a certain group of neighbouring cells so as to gain an optimal FSU and SS.

FSU and SS are potential feature candidates for the next release of 3GPP LTE, that is, Rel.09.

Embodiments of the invention relate to the applicability of the UE (user equipment) measurement reporting and X2 interface for the aforementioned horizontal rnterconnectivities and interactions between E-UTRAN systems of different operators hi FSU and SS, hereafter referred to as inter-operator interactions. As mentioned above, this X2 interface is a direct connection between two eNBs. In embodiments of the invention, there is provided an UE-assisted neighbouring cell discovery mechanism to facilitate mter-operator interactions.

Reference is first made to Figure 1 which shows an example of a spectrum sharing situation. In the example shown in Figure 1 , there are two system operators, operator A and operator B. Each operator is responsible for a different network to the other operator. Operator A and operator B operate networks which have a spatially overlapping area. In Figure 1, one cell 10 belongs to operator A and one cell 12 belongs to operator B. In the example shown in Figure 1, the cell of operator A is indicated diagrammatically by reference numeral 10. The cell allocated to the operator B system is indicated diagrammatically by reference numeral 12. In practice, each network will have a plurality of cells. It is also possible that more than two cells may be overlapping.

It should be appreciated that the example shown in Figure 1 is in terms of the spectrum provided in each cell. In the first cell 10, a first part of the spectrum 14 is dedicated to the operator A cell site. Likewise, a part of the spectrum 16 is dedicated to the operator B cell site, that is cell 12, In other words, a part of the spectrum dedicated to the operator A cell site is different to a part of the spectrum dedicated to the operator B cell site. Each of the cells 10 and 12 has access to a part of the spectrum 18. This part of the spectrum is shared between the operator A cell site and the operator B cell site. This shared spectrum allows for a better utilisation of spectrum. This is because the various cells can adapt to changing resource needs of the local cell that may belong to the different operator networks. For example, there may be a greater demand on the operator B cell site than on the operator A cell site. In that situation, more of the shared spectrum would be used by the operator B cell site.

However, there is a potential problem that m the shared spectrum, there is potential contention and local outage may happen in the shared spectrum region. In other words, an insufficient part of the shared spectrum is allocated to a particular cell resulting in a dropped connection, a reduced data rate, a reduction in quality or the like.

Embodiments of the present invention aim to allow inter-operator coordination for the shared spectrum in order to avoid this contention and local outage.

Embodiments of the present invention are particularly applicable to the 3GPP LTE system, for example Release 09 onwards. Additionally, flexible spectrum use and shared spectrum may also be used with an IMT-A band expansion.

Embodiments of the present invention may assist in the provision of the requirements of the proposed LTE systems such as: 1. It is proposed to support a high bit rate of up to lOOMbps in a high mobility environment and lGbps in low mobility environment using flexible spectrum allocation within a provision in total of up to 10 OMHz bandwidth of the IMT-A band.

Preferably, the content delivery is supported over an aggregation of resources including Radio Band Resources (RBR) in the same and different bands, both in uplink and downlink directions as well as in adjacent and non-adjacent channel arrangements. RBR can be regarded as being all the radio spectrum available to an operator. 2. There is a further requirement to support a high density of local area eNB (E UTRAN node B) cells operating as home eNBs with self-reorganised radio access networks.

Embodiments of the present invention provide a mechanism for determining neighbouring cells of different operators' network systems involved in said FSU and SS. This means that inter-operator signalling methods and mechanisms to prevent and resolve local outage due to interference in a certain RBR of a cell operating in overlap with a cell site or adjacent the cell site of a different operator can be supported.

It should be appreciated that embodiments of the present invention are applicable to supporting spectrum sharing between two or more cells. These cells may be at least partially overlapping or simply adjacent.

Reference is now made to Figure 2. The arrangement of Figure 2 shows two operators, operator A and operator B. The domain of operator A is shown as being separated from the domain of operator B diagrammatic ally by line 30. The two networks share a common IP (internet protocol) core 20. The internet protocol core 20 is connected to a network control entity/gateway 28 of the operator A system. This network control entity/gateway 28 is connected to an eNB 22 of the operator A system. The entity may be MME/S-GW or common RRM (Radio Resource Manager) server or the like.

The IP core 20 is also connected to a network control entity/gateway 26 of the operator B system. The network control entity/gateway 26 of the operator B system is connected to an eNB 24. The eNB 24 of the operator B system has a direct connection with the eNB 22 of the operator system. This interface between the two eNBs is sometimes referred to as an X2 interface. It should be appreciated that in some embodiments of the present invention, this direct connection may not be provided. However, when provided, this direct connection allows fast interoperating interactions as regards the shared spectrum. In some embodiments of the invention, the neighbouring cell in another network is discovered. Then it is tried to establish network connectivity to the neighbouring cell including an open X2, if allowed, for possible inter-operator interactions on a local cell level. This is triggered by the UE measurement report and then information may be exchanged between two networks which are new to current cellular operations.

The network control entity/gateway 28 of the operator A system is also connected to the network control entity/gateway 26 of the operator B system.

Reference will now be made to Figure 4 which shows a single operator system. This system may for example be similar to that provided by operator A or that provided by operator B. Additionally, with reference to Figure 4, a brief explanation of the general principals of wireless communications in a system comprising a base station and a communication device such a mobile station will be provided. This explanation may also be applicable to the arrangement of Figure 2.

In the exemplary embodiment of Figure 4, the system shown is a LTE radio system. As such, the term eNB is used for the base station function. A communication device, for example a user device can be used for accessing various services and/or applications provided by a communication system. In wireless or mobile systems, the access is provided via an access interface between a user device 1 and an appropriate wireless access system. The user device can typically access wirelessly the communication system via at least one base station (eNB) 110 and 115. In the example shown, two eNBs are shown. In practice, many more will be provided.

The eNBs 110 and 115 can be connected to another system, for example a data network 112. A gateway function between an eNB and the other network can be provided by means of any appropriate gateway node 114, for example a packet data gateway and/or an access gateway. The eNB is typically controlled by at least one appropriate controller entity 116. The controller entity can be provided for managing of the overall operation of the eNB and communications via the eNB. The controller entity 116 is typically with memory capacity and at least one data processor. Functional entities may be provided in the controller by means of a data processing capability thereof. It should be appreciated that the network control entity/gateway shown in Figure 2 can be regarded as being equivalent to the controller 116 and/or gateway 114,

In the embodiment shown in Figure 4, a single controller is provided.

However, in practice more than one controller may be provided in a system and accordingly different eNBs will be connected to different controllers.

As discussed, embodiments of the present invention can be used in the long term evolution (LTE) radio system. The system provides an evolved radio access system that is connected to a packet data system. Such an access system may be provided, for example, based on architecture that is known from the E-UTRA

(evolved UMTS terrestrial radio access) and based on the use of EUTRAN node Bs

(eNBs). An E-UTRAN comprises of E-UTRAN node Bs which are configured to provide base station and control functionalities.

It should be appreciated that Figures 2 and 4 shows example architectures only to give examples of possible communication systems where the embodiments described may be provided. It should be appreciated that other arrangements and architectures are also possible.

The user device 101 can be used for various tasks such as making and receiving phone calls, for receiving and sending data from and to a data network and for experiencing, for example multimedia or other content. For example, a user device may access data applications provided by a data network. The various applications may be offered m a data network based on the internet protocol (IP) or any other appropriate protocol.

An appropriate user device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile telephone, a mobile station, a portable computer provided with a wireless interface card or other wireless interface facility, a personal data assistant provided with wireless communication capabilities or any combination of these or the like. The term user equipment UE is used to cover all types of user devices. The user device may communicate via an appropriate radio interface arrangement of the mobile device. The interface arrangement may be provided for example by means of a radio part 107 and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device. The mobile device is typically provided with at least data processing entity 103 and at least one memory 104 for use in the tasks that it is designed to perform. The data processing and storage entities can be provided on an appropriate circuit board, in an integrated circuit or in chip set. This is denoted diagrammatically by reference 106.

Reference numeral 109 diagrammatically represents the measurement and reporting functionality which will be described in more detail hereinafter. As will be described in more detail, the user device makes some measurements for example relating to the channel quality and this is then reported back to the relevant eNB. It should be appreciated that the functionality indicated diagrammatically 109 may be formed at least partially by the data processing entity.

The user can control operation of the mobile device by means of a suitable user interface such as a keypad 102, voice command, touch-sensitive screen or pad, combination thereof or the like. A display 105, a speaker and a microphone are also typically provided. Furthermore, the mobile device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories such as hand-free equipment.

In embodiments of the present invention, the user equipment is arranged to carry out measurements and/or calculations based on measurements and to report the result. This will now be described in more detail with reference to the flow diagram of Figure 3.

In the first step Sl, the UE determines a measurement report. This measurement report is arranged to support FSU and/or SS. This measurement report may comprise a detailed list of all detected local cells which can belong to the same or different networks and which may be involved in FSU and SS. The different networks may be operated by the same or different operators. The UE provides one or more of the following for one or more neighbouring cells:

PLMN-ID (public land mobile network -identity) - this identifies the network;

Cell-ID - this identifies the cell; RAT-ID radio access technology identity - this identifies the radio access technology used;

Operating spectrum information -that is the spectrum which is used in the neighbouring cell; and any other information available through the received system broadcast information of each detected cell.

It should be appreciated that UE measurement is often controlled by the network. Thus in step Sl, the UE may determine relevant network rules. For examples, in step S 1 the UE determines measurement reports according to the rules configured by the network. Thus, new rules for UE measurement which are designated for FSU and SS can be also claimed. In a very simple case, the network may announce its support for FSU and SS in the broadcast system information so that the UE can determines whether to generate and send such a measurement report.

The user equipment may be also be able to measure channel quality, the generic state of one or more groups of radio resource blocks and radio band resources, carrier signal strength and so on. It should be appreciated that the cell information which is obtained may m practice be measurements made by the UE of a signal or signals transmitted by a base station or similar entity serving the neighboring cell. The measurement information obtained by the UE may be based on information provided by the base station. For example, the base station may transmit information indicating the traffic volume, interference levels or the like being experienced in the cell associated with the base station. In the alternative or additionally the measurement information obtained may be based on the quality, strength, interference or the like of the received signal at the UE, from the base station.

The UE thus generates the measurement report.. In practice, at this stage the UE just has to listen to broadcast system information of detectable radio systems or cells and then generate suitable report to send back to the selected cell. Thus the actual radio measurements like channel quality, carrier signal, etc. may not be required for the initial discovery stage, However this information is useful and may be discovered as a part of that initial procedure or as a subsequent procedure.

Furthermore, this type of the UE measurement can be controlled by the network; and for that control information (inc. triggering conditions, rules, etc.) can be sent to the UE via broadcast system information or a RRC (radio resource controller) dedicated signalling procedure. Consider a simple example, a cell should at least announce in broadcast system information whether it supports FSU and SS. UE then can decide to report about such a cell or not for FSU and SS.

In step S2, this measurement report is sent by the UE to the controlling eNB. The controlling eNB is the base station with which the UE is in communication. In some alternative embodiments, the UE may be in communication with more than one base station. The UE may in this alternative, but not necessarily, send the measurement report to more than one base station. This measurement report may take the form of a radio-resource-control protocol message (RRC MEASUREMENT REPORT). For example a FSU/SS Support element may be provided a a new IE (information element) in the RRC measure. This IE may include at least part of list as described in step S 1 above. Alternatively or additionally information such as traffic levels or utility indexes of shared resource blocks (in spectrum), interference levels, etc., can also be included as well.

In step S3, the controlling eNB, based upon the neighbouring-cell information provided in the UE measurement report, can decide to send a request to a network control entity.

The control entity may be any suitable network control entity such as a mobility management entity MME in E-UTRAN or any other suitable control entity. Each eNB will be associated with a MME/S-GW. The controlling entity can obtain information directly from the user equipment UE if a non-access-stratum procedure is applied or from the eNB which in turn collects the information based on UE measurement reports. In step S4, the control entity provides interconnectivities with the neighboring cells of other operators, (i.e., those in the reported list belong to other operators). This information may comprise IP (internet protocol) routing information, connection security related information, and other exchangeable information such as the current neighboring cell list relevant to FSU and SS₅ synchronization timing offset information, current status of spectrum allocation and usage, etc. This is sent to the controlling eNB.

In current cellular systems including LTE, connectivities of cells of the same network areconsidered as available by the network planning, i.e., set up manually at deployment. Taking into account plug-and-play eNB requirement, the procedure discussed in relation to two networks can also be used for cells in the same network.

It should be appreciated that the request of step S3 may also trigger a necessary intra-system cell reconfiguration for the initiating eNB cell, in step S5. It should be appreciated that step S5 can take place at the same time as step S4, before or after step S4. This involves recalculation of cell-specific system parameters and system information, and then reconfiguration of a cell or a group. The control entity will recalculate cell specific parameters for the initiating cell (and others in effect). Then, a Cell Reconf. Req. (cell reconfiguration request) is issued. This in general can be used to change any cell-specific parameters including resource allocation and, herein, how to use the shared resources.

It should be appreciated that a controlling eNB will have a current neighboring-cell list stored in the controlling eNB (not that from the UE measurement report) which includes all the neighboring cells of which the relevant relation to the controlling eNB has been established (e.g., being interconnected to the controlling eNB, either directly or via IP transport network, or just co-existing without any interactions). In. step S6, the eNB sends a request towards a different network. This is handled on a proper network^' control level, provided that these two networks are interconnected (e.g., through common IP core network and access gateways). Thus if two networks are interconnected on MME/S-GW level, the actual inter-operator interactions happen on MME/S-GW level. This is first triggered by the request sent by the eNB. This may end with MME/S-GW configuring the eNB under its control with information obtained from the other network. If two networks are connected on eNB level, then the interactions can be carried out on eNB level and so forth.

Figure 2 illustrates an example of possible inter-operator communications.

This network may be operated by a different operator,

In step S7, in cooperative cases, the two networks will exchange necessary information according to the initiated request as mentioned above, and, as a result, the initiating eNB will get requested information of the neighboring cell or cells of the different network.

In step S8, the initiating eNB will then update its neighboring-cell list to include the neighboring cell, as they become interconnected and ready for further interactions. The initiating eNB may also receive updated cell configuration parameters from its centralized network control entity for a reconfiguration if needed.

In non-cooperative cases, the initiating eNB may get no response. This may be because a guarding timer starting right after the eNB having sent the request has expired, a negative indication has been received from the network control entity of the network of the controlling eNB, or not enough information has been provided for the neighboring cell as requested and required for a meaning cooperation, hi the latter case, an example is that the initiating eNB receives only updated cell configuration parameters from its centralized network control entity for a reconfiguration. The initiating eNB then ignores and operates independently from the neighboring cell of a different network.

If the operator networks are not interconnected, the initiating eNB may receive a negative acknowledgement from its own network control entity, if needed, with updated cell configuration parameters for a reconfiguration, or a time-out of the guarding timer as mentioned above. The eNB then ignores and operates independently from its neighbor, in a different network.

In step S9, the initiating eNB will communicate directly via the X2 interface with the eNB of a neighboring cell. Alternatively, the communication between the eNB s can be via at least one other node.

Embodiments of the present invention thus provide a method and system which may permit an optimized fast and dynamic SS between cooperative radio access networks of different operators with possible horizontal, distributed control.

These measurements are then reported back to the controlling eNB. In some embodiments, the user equipment measurement and reporting is controllable by the network to support effective radio transmission, mobility, network self configuration, spectrum sharing or the like.

In Figure 5, the user equipment 32 comprises a processor 50. The processor 50 is connected to a transmitter 52 which is m turn connected to an antenna 54. The antenna 54 is connected to a receiver 56 which is connected to a processor 50.

Based on information received by the receiver 56, via the antenna 54, the processor 50 is able to formulate a measurement report (as discussed m more detail above), which is sent by the transmitter 52 to the antenna 54 for transmission to a node B.

The node B comprises an antenna 61 for receiving radio communication. The antenna 61 is connected to a receiver 60 which is in turn connected to a processor 68. The processor 68 is able to transmit to the user equipment by sending messages to the transmitter 58. The transmitter 58 passes the message for transmission to the antenna 61 for transmission. The processor 68 is also connected to an interface 66 which connected to entity 28. The processor is also connected to the X2 interface 64 which permits the initiating eNB 22 to communicate with the eNB of another cell. The eNB also comprises a memory 70 which can store various information as discussed in more detail here and before. The processor is able to make the various determinations and formulate the various requests for information. Where there is cell configuration carried out by the eNB, this would be under the control of the processor 68.

Where two networks are provided which spectrum share, the networks may be cooperative and interconnected. For example, the networks may be interconnected over the common IP core, as shown in the example of Figure 2. However, it should be appreciated that any suitable method of connecting the networks may alternatively be used.

It should be appreciated that embodiments of the present invention can be applied to a single operator network as well where the neighbouring cells in the network operate in at least partially or fully overlapping allocated resource bands.

Embodiments of the present invention may allow the prevention and/or resolution of possible local outages affecting certain groups of resource blocks or radio band resources which result from intolerable interference from overlapping cells belonging to different operators and operating in overlapping radio band resources. Embodiments of the present invention may provide an efficient adaptive spectrum sharing and network operation in co-sited environments.

Embodiments of the invention have been described in the context of two overlapping networks. In alternative embodiments, there may be more than two networks which overlap. The two or more overlapping networks may be operated each by different operators. Alternatively, at least two of the different networks may be operated by the same operator.

It should be appreciated that aspects of the embodiments of the present invention can be implemented at least partially in software. Accordingly, embodiments of the present invention may be partially implemented by a computer program when executed by a suitable processor or the like.

It should be appreciated that whilst embodiments of the present invention have been described as being particularly relevant to the LTE proposal, embodiments of the present invention can be used with any other suitable wireless network. Thus, whilst embodiments of the present invention have been described in relation to a base station or eNB and user devices such as mobile stations, embodiments of the present invention are applicable to any other type apparatus suitable for wireless communication, particularly where there is some aspect of spectrum sharing.

It is also noted herein that whilst the above-described exemplifying embodiments of the invention have been described, there are several variations or modifications which may be made to the disclosed arrangements without parting from the scope of the present invention.

Claims

1. A method comprising: determining in user equipment information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; and sending said information to a base statioa

2. A method as claimed in claim 1, wherein said determining comprises determining identity information associated with said at least one cell.

3. A method as claimed in claim 2, wherein said identity information comprises at least one of PLMN-ID (public land mobile network -identity); Cell-ID; and RAT- ID (radio access technology identity).

4. A method as claimed in any preceding claim 1, comprising determining if said at least one neighbouring cell supports spectrum sharing.

5. A method as claimed in claim 4, wherein said determining if said at least one neighbouring cell supports spectrum sharing comprises checking for spectrum sharing information broadcast by at least one neighbouring cell.

6. A method as claimed in any preceding claim, wherein said determining comprises determining spectrum information for said at least one neighbouring cell.

7. A method as claimed in any preceding claim, wherein said information comprises at least one of: channel quality, carrier signal information, traffic volume, interference level, and signal strength.

8. A method as claimed in any preceding claim, comprising sending said information in a RRC measurement report message,

9. A method as claimed in any preceding claim, wherein said information relating to at least on neighbouring cell is transmitted by said neighbouring cell.

10. A method comprising: receiving a base station from user equipment information relating to at least one neighbouring cell which are in a different network to a network of said user equipment; requesting connection information for at least one of said neighbouring cells; and sending a request to a neighbouring base station associated with at least one of said neighbouring cells using said connection information.

11. A method as claimed in claim 9 wherein said information comprises information indicating if said at least one neighbouring cell supports spectrum sharing.

12. A method as claimed in claim 10 or 11, comprising sending ^"said request directly to said neighbouring base station,

13. A method as claimed in claim 10, 11 or 12, comprising sending said request to said neighbouring base station via an X2 interface therebetween.

14. A method as claimed in any of claims 10 to 13, comprising updating a list of neighbouring cells to include at least one of said neighbouring cells.

15. A method as claimed in claim in any of claims 10 to 14, comprising performing a cell reconfiguration at said base station.

16. A method as claimed in any of claims 10 to 15, comprising receiving connection information.

17. A method as claimed in claim 16, wherein said connection information comprises at least one of: IP (internet protocol) routing information, connection security related information.

18. A method as claimed in any of claims 10 to 17, comprising receiving at said base station at least one of: current neighboring cell list; synchronization timing offset information; current status of spectrum allocation; and usage of spectrum.

19. A method as claimed in any preceding claim, wherein said different network and said network of the user equipment are controlled by different operators.

20. A method as claimed in any preceding claim, comprising sharing spectrum in a cell of the user equipment with at least one neighbouring cell.

21 User equipment configured to determining information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; and to send said information to a base station.

22. A base station configured: to receive station from user equipment information relating to at least one neighbouring cell which is in a different network to a network of said user equipment; to request connection information for at least one of said neighbouring cells; and to send a request to a neighbouring base station associated with at least one of said neighbouring cells using said connection information.

23. A base station as claimed in claims 22 configured to update a list of neighbouring cells to include at least one of said neighbouring cells.

24. A base station as claimed in claim 22 or 23 configured to perform a cell reconfiguration.