WO2008155290A1

WO2008155290A1 - Method, user equipment, network element, software product and system for user equipment handling in redirection

Info

Publication number: WO2008155290A1
Application number: PCT/EP2008/057448
Authority: WO
Inventors: Jarkko T. Koskela; Benoist Sebire
Original assignee: Nokia Siemens Networks Oy
Priority date: 2007-06-18
Filing date: 2008-06-13
Publication date: 2008-12-24

Abstract

A method, user equipment, network device, and software product enable a user equipment to seek a connection to a network via a base station, receive system information, and determine in response to the system information a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

Description

Title:

METHOD, USER EQUIPMENT, NETWORK ELEMENT, SOFTWARE PRODUCT AND SYSTEM FOR USER EQUIPMENT HANDLING IN REDIRECTION

Field of the Invention

The invention relates to the field of wireless telecommunications. More particularly, the present invention pertains to redirection.

Background of the Invention

The telecommunications industry is in the process of developing a new generation of flexible and affordable communications that includes high-speed access while also supporting broadband services. Many features of the third generation (3G) mobile telecommunications system have already been established, but many other features have yet to be perfected. The Third Generation Partnership Project (3GPP) has been pivotal in these developments.

One of the systems within the third generation of mobile communications is the Universal Mobile Telecommunications System (UMTS) which delivers voice, data, multimedia, and wideband information to stationary as well as mobile customers. UMTS is designed to accommodate increased system capacity and data capability. Efficient use of the electromagnetic spectrum is vital in UMTS. It is known that spectrum efficiency can be attained using frequency division duplex (FDD) or using time division duplex (TDD) schemes. Space division duplex (SDD) is a third duplex transmission method used for wireless telecommunications.

As can be seen in FIG. 1, the UMTS architecture consists of user equipment 102 (UE), the UMTS Terrestrial Radio Access Network 104 (UTRAN), and the Core Network 126 (CN). The air interface between the UTRAN and the UE is called Uu, and the interface between the UTRAN and the Core Network is called Iu.

High-Speed Downlink Packet Access (HSDPA) and High-Speed Uplink Packet Access (HSUPA) are further 3G mobile telephony protocols in the High-Speed Packet Access (HSPA) family. They provide a smooth evolutionary path for UMTS-based networks allowing for higher data transfer speeds.

Evolved UTRAN (EUTRAN) is a more recent project than HSPA, and is meant to take 3G even farther into the future. EUTRAN is designed to improve the UMTS mobile phone standard in order to cope with various anticipated requirements. EUTRAN is frequently indicated by the term Long Term Evolution (LTE), and is also associated with terms like System Architecture Evolution (SAE). One target of EUTRAN is to enable all internet protocol (IP) systems to efficiently transmit IP data. The system will only use a PS (packet switched) domain for voice and data calls, i.e. the system will contain Voice Over Internet Protocol (VoIP). Information about LTE can be found in 3GPP TS 36.300 (V8.0.0, March 2007),

Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN) - Overall description; Stage 2 (Release 8), which is incorporated herein by reference in its entirety. UTRAN and EUTRAN will now be described in some further detail, although it is to be understood that especially E-UTRAN is evolving over time.

The UTRAN consists of a set of Radio Network Subsystems 128 (RNS), each of which has geographic coverage of a number of cells 110 (C), as can be seen in FIG. 1. The interface between the subsystems is called lur. Each Radio Network Subsystem 128 (RNS) includes a Radio Network Controller 112 (RNC) and at least one Node B 114, each Node B having geographic coverage of at least one cell 110. As can be seen from Figure 1, the interface between an RNC 112 and a Node B 114 is called Iub, and the Iub is hard-wired rather than being an air interface. For any Node B 114 there is only one RNC 112. A Node B 114 is responsible for radio transmission and reception to and from the UE 102 (Node B antennas can typically be seen atop towers or preferably at less visible locations). The RNC 112 has overall control of the logical resources of each Node B 114 within the RNS 128, and the RNC 112 is also responsible for handover decisions which entail switching a call from one cell to another or between radio channels in the same cell. In UMTS radio networks, a UE can support multiple applications of different qualities of service running simultaneously. In the MAC layer, multiple logical channels can be multiplexed to a single transport channel. The transport channel can define how traffic from logical channels is processed and sent to the physical layer. The basic data unit exchanged between MAC and physical layer is called the Transport Block (TB). It is composed of an RLC PDU and a MAC header. During a period of time called the transmission time interval (TTI), several transport blocks and some other parameters are delivered to the physical layer. Generally speaking, a prefix of the letter "E" in upper or lower case signifies the Long Term Evolution (LTE). The E-UTRAN consists of eNBs (E-UTRAN Node B), providing the E-UTRA user plane (RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE. The eNBs interface to the EPC (evolved packet core) via the Sl, and are inter-connected via the X2.

An example of the E-UTRAN architecture is illustrated in FIG. 2. This example of E-UTRAN consists of eNBs, providing the E-UTRA user plane (RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE. The eNBs are connected by means of the Sl interface to the EPC (evolved packet core), which includes, for example,

Mobility Management Entities (MMEs). The Sl interface supports a many-to-many relation between MMEs and eNBs. Packet Data Convergence Protocol (PDCP) is located in an eNB.

In this example there exists an X2 interface between the eNBs that need to communicate with each other. For exceptional cases (e.g. inter-PLMN handover), LTE_ACTIVE inter-eNB mobility is supported by means of MME relocation via the Sl interface.

The eNB may host functions such as radio resource management (radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to UEs in both uplink and downlink), selection of a mobility management entity (MME) at UE attachment, scheduling and transmission of paging messages (originated from the MME), scheduling and transmission of broadcast information (originated from the MME or O&M), and measurement and measurement reporting configuration for mobility and scheduling. The MME may host functions such as the following: distribution of paging messages to the eNBs, security control; termination of U-plane packets for paging reasons; switching of U-plane for support of UE mobility, idle state mobility control, System Architecture Evolution (SAE) bearer control, and ciphering and integrity protection of NAS signaling.

Redirection is used in cellular networks in order to redirect a user terminal to a target system or to a carrier frequency. The purpose of such redirection is an efficient usage of network capacity (load reasons) and also improvement or retention of call quality in acceptable levels (service reasons). For example, a voice call in UMTS may be redirected to Global System for Mobile Communications (GSM) so that enough UMTS load is available for other connections demanding more resources from the network. Another example: a video stream initiated in General Packet Radio System (GPRS) can be redirected to UMTS in order to provide better user experience.

For the specific case of service based redirection during connection setup in E- UTRAN, several advantages have been found. For example, service based redirection during connection setup avoids inter-RAT/Inter-frequency measurements during dedicated mode which has less impact on the terminal's battery consumption, and also signaling procedures required by handovers are avoided. Additionally, if used together with load control mechanism, the service redirection during connection setup can be used to add more intelligent decision for handling congestion. Furthermore, in the case of a voice call, voice based redirection is a good complement for voice call continuity from packet switching (LTE) to circuit switching (2G/3G).

A requisite for service based redirection during connection setup is network awareness of the service type being requested. This can be handled by the UE being able to report the service requested in an "establishment cause" field of the RRC: Connection request message. For mobile-terminated call (MTC) attempts, it may be required that the EPC includes when possible the service type information on the paging request sent to the eNodeB. Note that the term "base station" is used broadly in this application, and may refer to a Node B or an eNodeB. During a 3GPP meeting in Kobe, Japan in May of 2007 (called "RAN2#58"), there was discussion about the handling of UE capabilities in case of redirection, and it became apparent that there is a desire to handle redirection without establishment of Sl. One possible reason for Sl establishment is that UE capabilities are stored in a central node of the E-UTRAN system when the UE is in idle, and when the UE starts accessing the eNB the eNB does not know UE capabilities. In order to avoid Sl -establishment, there needs to be some mechanism to allow the eNB get those capabilities of the UE before establishing the Sl connection. A drawback of requiring Sl establishment is that such establishment delays connection setup in case of redirection, and additionally much Sl establishment signalling needs to be done. It would be advantageous to avoid all of this.

Summary of the Invention

Although the present invention is applicable in the context of the E-UTRAN (LTE or 3.9G), its principles are not limited to such an environment, and instead may also be applicable to various other current and future wireless telecommunications systems and access technologies. The present invention concerns redirection, and how the eNB obtains knowledge about UE capabilities.

One possible way of solving the above-described problems would be for the UE to disclose its inter-frequency/radio access technology (RAT) capabilities in a radio resource control (RRC) connection request. However, that approach would increase the message size of the RRC_CONNECTION_REQUEST, and it may be that this RRC connection request feature is not even used in some network configurations. Increased size has the disadvantage that it may cause additional delay for connection establishment. A further drawback of this possible way of solving the problem is that in most cases redirection might not be supported/required, and additional elements would be needed in the RRC_CONNECTION_REQUEST. This could delay normal connection establishment procedures.

In the system information of the present invention, there is a new piece of information telling the UEs in a cell whether to disclose their inter-frequency/RAT capabilities in an RRC_CONNECTION_REQUEST, or instead require the UEs to wait for Sl establishment. According to this method, each network deployment can use an optimal RRC connection establishment message.

It is also possible to control the RRC_CONNECTION_REQUEST message size so that it does not become too large. The size of UE capabilities may conceivably become very large, and UE capability size can be optimized somewhat. The UE can indicate capabilities of only those frequencies/RATs that are indicated in system information to be available in the area (e.g. in the neighbour cell lists). This capability indication can be just a bitmap pointing to system information. Additionally, if it is required for the UE to do some measurements in case of redirection, then the UE can omit indication of such RATs that it does not hear well enough to be redirected to them. There may be no real need to send a measurement report, and instead the UE can merely indicate what RAT/frequencies the UE hears well enough.

Brief Description of the Drawings Figure 1 shows a UTRAN network.

Figure 2 shows an LTE architecture.

Figure 3 is a flow chart showing and embodiment of a method according to the present invention.

Figure 4 is a block diagram of a system according to an embodiment of the present invention. Detailed Description of the Invention

A preferred embodiment of the present invention will now be described. This is merely to illustrate one way of implementing the invention, without limiting the scope or coverage of what is described elsewhere in this application.

If the system information contains a new piece of information telling the UEs in a cell whether to disclose their inter-frequency/RAT capabilities, or instead require the UEs to wait for Sl establishment. Then this embodiment of the present invention can be implemented by just a bit or two (or a few bits) in system information indicating which method to apply in this cell when starting any procedures leading to possible redirection. For example, the bit informs whether UE needs to indicate UE capabilities in the RRC-CONNECTION-REQUEST. This optimizes message size for all network deployments.

Whether or not system information contains this new piece of information, the disclosure of UE capabilities can still be kept to a manageable size. In normal network deployments, the network provides information in neighbour cell lists, or in any similar information element, what other RATs (and possible bands/carriers) and frequencies of current RAT may be heard in the cell. This information can be used to optimize contents of UE capability that is sent by the UE to the network for determining which system to redirect the UE.

For example, suppose the network provides the following in system information: UTRAN band 1&3, GSM EDGE radio access network (GERAN) band 2 and E-UTRAN band 4 are heard in the vicinity. The UE supports UTRAN band 1 and GERAN band 5 and also E-UTRAN band 4. Consequently, the UE only reports capability of those bands/RATs that are indicated by the network to be available (e.g. in the neighbour cell list). In this example, that means that UE only reports capability of UTRAN band 1 and E-UTRAN band 4. Here is this same example in tabular form:

This embodiment of the invention can be further optimized, e.g. to utilize the order in which the network describes other RATs/frequencies in the system information. For instance, there could be just one bit field (in this example 8 bits), such that the first bit indicates UTRAN band 1 support, the second bit indicates UTRAN band 3 support, the third bit indicates GERAN band 2 support, and the fourth bit indicates E_UTRAN band 4 support. Thus, the UE would indicate the following bit field to the network: 1001 0000. Of course, all of these band numbers are merely exemplary.

Additionally, if the UE is required to measure some RATs/frequencies before being redirected, the UE may omit any capability indications that the UE did not hear well enough to be redirected to. In the above-mentioned example, if the UE is not hearing UTRAN band 1, then the UE would only indicate its capability of E-UTRAN band 4, and in the optimization case (bit field) the UE would simply indicate the following bit field: 0001 0000.

By thus limiting the UE report about its capabilities, the UE can always report its capabilities in RRC_CONNECTION REQUEST in a way that optimizes the size of the UE capability information needed for redirection. And even if the UE only reports its capabilities if the system information contains a new piece of information telling the UEs in a cell to do so, still in such cases the size of the UE capability information can be reduced. Reducing the size of RRC CONNECTION REQUEST may mean faster connection establishment. It is also possible to incorporate measurements into the UE capability indication.

FIG. 3 shows a basic method 300 according to an embodiment of the invention. A UE starts 307 to seek a connection from the UE to a base station (BS) such as an eNodeB. The UE receives 315 broadcasted system information (SI) from the BS. The UE uses 325 the SI to determine set of UE capabilities, if any, that should be disclosed to the BS for purposes of being redirected by the BS. Then the UE goes ahead and discloses 335 those capabilities, if any, to the BS. And, the UE is then redirected 370 by the BS. FIG. 4 shows a system 400 according to an embodiment of the present invention, including user equipment 405 and a network element 492, each including a transceiver 411 and 454 respectively. The network element broadcasts system information which may indicate whether the UE should disclose any capabilities at all, since the network element could alternatively obtain the capabilities from the access gateway 470. Assuming that the broadcasted system information indicates that the US should make a disclosure of capabilities, the system information may indicate what available frequency or radio access technology those capabilities should be associated with. The SI is passed along in the UE to an SI processing module 413, which then enables a determination module 404 to determine what capabilities (if any) should be disclosed. The disclosure module 409 then makes that disclosure via the transmitter 411. This disclosure allows the redirection module 463 to redirect the UE.

The invention includes a variety of concepts, which can be briefly described as follows, without in any way limiting what will be claimed in this application. It is to be understood that these concepts can be further combined with each other in any multiple dependent manner.

The invention includes a first concept which is a method comprising: starting to seek a connection from a user equipment to a network via a base station; receiving system information; and, determining, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

The invention includes a second concept which is the method of the first concept, further comprising disclosing said user equipment capabilities, if any, to the base station; and, being redirected by the base station.

The invention includes a third concept which is the method of the first concept, wherein the system information includes an indication of whether user equipments in a cell should disclose said capabilities, or instead should allow the base station to obtain said capabilities from a network. The invention includes a fourth concept which is the method of the first concept, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes a fifth concept, which is the method of the third concept, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that user equipments in the cell should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology. The invention includes a sixth concept, which is the method of the first concept, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment omits at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability. The invention includes a seventh concept which is an apparatus comprising: means for starting to seek a connection from a user equipment to a network via a base station; means for receiving system information; and, means for determining, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

The invention includes a eighth concept which is the apparatus of the seventh concept, further comprising means for disclosing said user equipment capabilities, if any, to the base station; and, means for being redirected by the base station.

The invention includes an ninth concept which is the apparatus of the seventh concept, wherein the system information includes an indication of whether user equipments in a cell should disclose said capabilities, or instead should allow the base station to obtain said capabilities from a network. The invention includes a tenth concept which is the apparatus of the seventh concept, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes a eleventh concept, which is the apparatus of the ninth concept, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that user equipments in the cell should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology. The invention includes a twelfth concept, which is the apparatus of the seventh concept, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment is configured to omit at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability.

The invention includes a thirteenth concept which is user equipment comprising: a transceiver configured to start seeking a connection from a user equipment to a network via a base station; a system information processing module configured to receive system information; and, a determination module configured to determine, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

The invention includes a fourteenth concept which is the user equipment of the thirteenth concept, further comprising a disclosure module configured to disclose said user equipment capabilities, if any, to the base station; and, a redirection module configured to comply with redirection by the base station.

The invention includes a fifteenth concept which is the user equipment of the thirteenth concept, wherein the system information includes an indication of whether user equipments in a cell should disclose said capabilities, or instead should allow the base station to obtain said capabilities from a network.

The invention includes a sixteenth concept which is the user equipment of the thirteenth concept, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes a seventeenth concept, which is the user equipment of the fifteenth concept, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that user equipments in the cell should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes an eighteenth concept, which is the user equipment of the thirteenth concept, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment is configured to omit at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability. The invention includes a nineteenth concept which is a computer program product, the computer program product comprising a computer readable medium having executable code stored therein; the code, when executed by a processor, being adapted to carry out the functions of: starting to seek a connection from a user equipment to a network via a base station; receiving system information; and, determining, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

The invention includes a twentieth concept which is the computer program product of the nineteenth concept, wherein the functions further comprise disclosing said user equipment capabilities, if any, to the base station; and, being redirected by the base station.

The invention includes a twenty-first concept which is the computer program product of the nineteenth concept, wherein the system information includes an indication of whether user equipments in a cell should disclose said capabilities, or instead should allow the base station to obtain said capabilities from a network. The invention includes a twenty-second concept which is the computer program product of the nineteenth concept, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology. The invention includes a twenty-third concept, which is the computer program product of the twenty-first concept, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that user equipments in the cell should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes a twenty-fourth concept which is a system comprising: a base station; and, user equipment configured to start seeking a connection to a network via the base station; wherein the base station is further configured to broadcast system information to the user equipment; and, wherein the user equipment is further configured to determine, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for purposes of being redirected by the base station.

The invention includes a twenty-fifth concept which is the system of the twenty- fourth concept, wherein the user equipment is further configured to disclose said user equipment capabilities, if any, to the base station; and, wherein the base station is further configured to redirect the user equipment in response to the capabilities.

The invention includes a twenty-sixth concept which is a network element comprising: a transceiver configured to broadcast system information relevant to determining a set of user equipment capabilities, if any, to provide to the network element for purposes of being redirected by the network element; and, a redirection module configured to redirect the user.

The invention includes a twenty- seventh concept which is the network element of the twenty-sixth concept, wherein the system information includes an indication of whether user equipments in a cell should disclose said capabilities, or instead should allow the network element to obtain said capabilities from elsewhere in the network.

The invention includes a twenty-eighth concept which is the network element of the twenty- sixth concept, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

The invention includes a twenty-ninth concept, which is the network element of the twenty- seventh concept, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that user equipments in the cell should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology. Each of the embodiments described above can be implemented using a general purpose or specific-use computer system, with standard operating system software conforming to the method described herein. The software is designed to drive the operation of the particular hardware of the system, and will be compatible with other system components and I/O controllers. The computer system of this embodiment includes a CPU processor, comprising a single processing unit, multiple processing units capable of parallel operation, or the CPU can be distributed across one or more processing units in one or more locations, e.g., on a client and server. A memory may comprise any known type of data storage and/or transmission media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), a data cache, a data object, etc. Moreover, similar to the CPU, the memory may reside at a single physical location, comprising one or more types of data storage, or be distributed across a plurality of physical systems in various forms.

It is to be understood that the present figures, and the accompanying narrative discussions of best mode embodiments, do not purport to be completely rigorous treatments of the method, system, mobile device, network element, and software product under consideration. A person skilled in the art will understand that the steps and signals of the present application represent general cause-and-effect relationships that do not exclude intermediate interactions of various types, and will further understand that the various steps and structures described in this application can be implemented by a variety of different sequences and configurations, using various different combinations of hardware and software which need not be further detailed herein.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: receiving system information; and determining, in response to the system information, a set of user equipment capabilities, if any, to disclose for redirecting said user equipment.

2. The method of claim 1, further comprising disclosing said set of user equipment capabilities to a base station, wherein said redirecting is by the base station in response to said set of user equipment capabilities, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency.

3. The method of claim 1, wherein the system information includes an indication of whether said user equipment should disclose said set of user equipment capabilities to a base station, or instead should allow the base station to obtain said set of user equipment capabilities from a network.

4. The method of claim 1, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

5. The method of claim 3, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that said user equipment should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

6. The method of claim 1, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment omits at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability.

7. An apparatus comprising: means for receiving system information; and, means for determining, in response to the system information, a set of user equipment capabilities, if any, to disclose for redirecting said user equipment.

8. The apparatus of claim 7, further comprising: means for disclosing said set of user equipment capabilities to a base station, wherein said redirecting is by the base station in response to said set of user equipment capabilities, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency.

9. The apparatus of claim 7, wherein the system information includes an indication of whether said user equipment should disclose said set of user equipment capabilities to a base station, or instead should allow the base station to obtain said set of user equipment capabilities from a network.

10. The apparatus of claim 7, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

11. The apparatus of claim 9, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that said user equipment should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

12. The apparatus of claim 7, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment is configured to omit at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability.

13. User equipment comprising: a system information processing module configured to receive system information; and, a determination module configured to determine, in response to the system information, a set of user equipment capabilities, if any, to disclose for redirecting said user equipment.

14. The user equipment of claim 13, further comprising a disclosure module configured to disclose said user equipment capabilities to a base station; wherein said redirecting is by the base station in response to said set of user equipment capabilities, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency.

15. The user equipment of claim 13, wherein the system information includes an indication of whether said user equipment should disclose said capabilities to a base station, or instead should allow the base station to obtain said capabilities from a network.

16. The user equipment of claim 13, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

17. The user equipment of claim 15, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that said user equipment should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

18. The user equipment of claim 13, wherein said system information includes an indication of whether the user equipment is required to perform a measurement before being redirected, and wherein the user equipment is configured to omit at least one capability from said set of user equipment capabilities if the user equipment is unable to hear or adequately measure a quantity associated with said at least one capability.

19. A computer program product, the computer program product comprising a computer readable medium having executable code stored therein; the code, when executed by a processor, being adapted to carry out the functions of: receiving system information; and, determining, in response to the system information, a set of capabilities, if any, to disclose for redirecting said user equipment.

20. The computer program product of claim 19, wherein the functions further comprise: disclosing said user equipment capabilities to a base station, wherein said redirecting is by the base station in response to said set of user equipment capabilities, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency.

21. The computer program product of claim 19, wherein the system information includes an indication of whether said user equipment should disclose said capabilities to a base station, or instead should allow the base station to obtain said capabilities from a network.

22. The computer program product of claim 19, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

23. The computer program product of claim 21, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that said user equipment should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

24. A system comprising: a base station; and, user equipment configured to communicate with the base station; wherein the base station is configured to broadcast system information to the user equipment; and, wherein the user equipment is further configured to determine, in response to the system information, a set of user equipment capabilities, if any, to disclose to the base station for redirecting said user equipment.

25. The system of claim 24, wherein the user equipment is further configured to disclose said user equipment capabilities to the base station, wherein said redirecting is by the base station in response to said set of user equipment capabilities, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency.

26. A network element comprising: a transceiver configured to broadcast system information relevant to a user equipment determining a set of user equipment capabilities to disclose to the network element; and, a redirection module configured to redirect the user, in response to receiving information about said capabilities.

27. The network element of claim 26, wherein the system information includes an indication of whether said user equipment should disclose said capabilities to the network element, or instead should allow the network element to obtain said capabilities from elsewhere in the network, and wherein said redirecting redirects said user equipment to a target system or to a carrier frequency

28. The network element of claim 26, wherein said system information includes an indication of at least one available frequency or radio access technology, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.

29. The network element of claim 27, wherein said system information also includes an indication of at least one available frequency or radio access technology if the system information indicates that said user equipment should disclose said capabilities, and wherein said set of user equipment capabilities only includes capabilities for said at least one available frequency or radio access technology.