AU2013201462A1 - Method and apparatus for reporting WLAN capabilities of a dual mode GPRS/WLAN or UMTS/WLAN WTRU - Google Patents

Abstract

Method and apparatus for enabling a wireless terminal to communication the dual-mode capabilities and reporting the interworking capabilities of the two 5 networks with which the wireless terminal have the added capability of obtaining services from either one of the interworking networks.

Description

1 METHOD AND APPARATUS FOR REPORTING WLAN CAPABILITIES OFA DUAL MODE GPRS/WLAN OR UMTS/WLAN WTRU FIELD OF THE INVENTION 5 The present invention relates to WTRUs having dual-mode capabilities and more particularly to method and apparatus for reporting dual mode capabilities and for reporting availability of network interworking. BACKGROUND TO THE INVENTION The current developments of wireless local area networks (WLANs) 10 interworking with general packet radio service/universal mobile telecommunications system/third generation (GPRS/UMTS/3G) networks has resulted in products that include two radio units in a common enclosure (e.g., cards supporting 802.11b + GPRS air interfaces and 802.11b +UMTS air interfaces). The units may be separate cards or may be integrated onto one 15 common card. Hereafter a wireless transmit/receive unit (WTRU) includes but is not limited to a user equipment, mobile station, fixed or mobile subscriber unit, pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, a base station (BS) includes but is not limited to a Node-B, 20 site controller, access point or any other type of interfacing device in a wireless environment. Currently the network may not be aware of the dual-mode capabilities of the terminal. In addition, the offered services may change dramatically based on the terminal capabilities in terms of processing power, memory availability, 25 screen size, bit rate, etc. For example, a dual mode 802+GPRS personal digital assistant (PDA) may be able to receive short message service (SMS) or multimedia message service (MMS) messages over a GPRS or an 802 network, however, several variations of these services may be provided in accordance with allotted memory space of the wireless terminal. Rich multimedia services may 30 require larger memory size than that available in the PDA. Therefore, the same multimedia services may be provided via black and white or a reduced set of colors depending on terminal capabilities. Also, the possibility of network assisted handoff can be provided to those terminals that indicate dual mode 2 (WLAN/GPRS or WLAN/3G) capabilities. A mechanism is needed to indicate these capabilities to the existing GPRS/UMTS networks. In addition, in network interworking, there is no capability of informing a wireless terminal having dual-mode radio capabilities and relying upon one of the 5 networks with which it communicates to be advised of the interworking capability to enable the wireless terminal to have the increased ability of communicating with either of the two networks. Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be 10 taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the priority date of the claims herein. SUMMARY OF THE INVENTION In accordance with a first aspect of the present invention there is provided 15 a method for use in a dual-mode wireless transmit/receive unit (WTRU), the method including: generating an association request message indicating a request to associate with a network node of a first radio access technology and including a capability indicator indicating whether the WTRU is capable of communicating 20 via a second radio access technology that is a packet-switched technology; communicating the association request message to the network node; and receiving services based on the capability indicator. In accordance with a further aspect of the present invention there is provided a wireless transmit/receive unit (WTRU) including: 25 a processor configured to generate an association request message, the association request message indicating a request to associate with a network node of a first radio access technology and including a capability indicator indicating whether the WTRU is capable of communicating via a second radio access technology that is a packet-switched technology; 30 a transmitter configured to transmit the association request rnessage to the network node; and a receiver configured to receive services based on the capability indicator.

3 "Comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 5 BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood from a consideration of the figures in which like elements are designated by like numerals and, wherein: Figure 1 is a simplified schematic diagram of the network having integrated universal mobile telephone service (UMTS) and wireless local area network 10 (WLAN) networks.

3a Figure 2 is a simplified schematic diagram showing an attach procedure and embodying the capabilities of the present invention. Figure 3 shows a WTRU network capability information element (IE). Figures 4 and 5 respectively show the existing and modified network 5 capability and radio access (RA) capability information element (IE). Figure 4A shows the modified network capabilities IE of Figure 4 in greater detail. Figures 5A1-5A2 and 5B show the modified RA capability IE of Figure 5 in greater detail and Figure 5A shows the manner in which Figures 5A1 and 5A2 are 10 arranged. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The problem solved by this invention is the mechanism by which a terminal that supports both GPRS and WLAN, or 3G and WLAN can report its WLAN capabilities to the supporting GPRS/UMTS networks. Also, the invention 15 identifies the mechanism by which a 3G network can indicate that 3G or packet switched domain services over WLAN are available. Figure 1 shows a simplified block diagram of a network in which a UMTS and a WLAN are integrated. The WTRUs 12, 14 and 16 communicate with the 20 4 network over respective radio links (RL-1 RL-2 and RL-3). More particularly, WTRU 12 communicates with a GSM radio access network (RAN); WTRU 14 communicates with a 2.5/3G RAN and WTRU 16 communicates with a WLAN access point (AP). WTRUs 12 and 14 may be cellular telephones while WTRU 5 16 may be a laptop, personal digital assistant (PDA) or other like device having an appropriate card enabling communication with the WLAN AP. The GSM RAN communicates with a mobile switching center (MSC) which, as is known in the art, has the capability of interworking with location data bases. The MSC communicates with the visitor location register (VLR) to identify, 10 authenticate, etc. the WTRU 12. The MSC also communicates with the short message service-gateway mobile switching center/interworking-mobile switching center (SMS-GMSC/IW-MSC) which provides the services such as short message service (SMS) data. The home location register (HLR) is a data base within the home public land mobile network (HPLMN) providing routing 15 information for mobile terminated calls and SMS data and is also responsible for maintenance of user subscription information distributed to the relevant VLR (note the VLR in Figure 1) or GSN (GPRS support node) through the attached process and mobility management procedures such as location area and routing area updates. 20 The WLAN AP communicates with a packet data gateway/WLAN access gateway (PDG/WAG). Capability information is exchanged between the GSN and the PDG/WAG. Services such as SMS data services are communicated to the PDG/WAG and hence to the WTRU 16 by way of the PDG/WAG and WLAN AP. Based on the capability of the WTRU 16, SMS data may be delivered 25 thereto. The WTRUs 12 and 14 when respectively communicating with the network through their associated RAN, provide information regarding their capability which, in accordance with the present invention, includes WLAN compatibility. Figure 2 shows an attach procedure combined with a WLAN capability 30 update. In the procedure shown in Figure 2, a UMTS dual mode WTRU, at step SI, powers up for a signaling connection to perform the ATTACH procedure. At step S2, a radio resource control (RRC) connection request message is conveyed to the radio network controller (RNC). Admission control and availability of 5 resources is performed by the RNC, at step S3, which then conveys an RRC connection setup message to the dual mode WTRU, at step S4. The WTRU, at step S5, provides an RRC connection set up complete message providing the WTRU radio access (RA) compatibility and, at step S6, provides the initial direct 5 transfer message, which includes the attach request and the point-to-multipoint system information (PtM SI), instant messaging system information (IM SI), network (NW) capability and radio access (RA) capability. The RNC, at step S7, provides an initial WTRU Message: attach request including the network and radio access capabilities. In addition to the UMTS capabilities, the message 10 further contains WLAN capability. At step S8, authentication and ciphering request and security mode commands are performed and the WTRU is authenticated, at step S9. Thereafter, the SGSN provides to the SGSN a WTRU capability update to the WAG-PDG, at step S10, and provides an attach-accept message to the RNC, at step S11, which is then conveyed, at S12, to the WTRU. 15 The update of the WTRU capability sent to WAG-PDG, at step S10, causes the SGSN to update the WAG, which may then decide if the service request can be terminated. The purpose of a mobile station WTRU network capability information element is to provide the network with information concerning aspects of the 20 WTRU related to the GPRS. The contents of the information element can affect the manner in which the network handles the operation of the WTRU. WTRU network capability information indicates general WTRU characteristics and, except for fields explicitly indicated, is independent of the frequency band of the sending channel. 25 WTRU network capability is a type 4 information element (lE) having a maximum length of ten octets. The value part of the WTRU network capability IE is coded, as shown in Figure 3. Figure 4 is a comparison of the existing network capability IE with the 30 network capability information element of the present invention and Figure 5 shows a comparison of the radio access capability information element (RAC IE) with the RAG IE of the present invention.

6 The purpose of the mobile station (MS) network capability IE is to provide the network with information concerning aspects of the mobile station (ie., WTRU) related to GPRS. The contents can affect the manner in which the network handles the operation of the mobile station. The MS network capability 5 information indicates general mobile station characteristics and except for fields explicitly indicated, is independent of the frequency band of the channel it is sent on. The MS network capability is a type 4 information element with a maximum of ten octets length. The value part of a MS network capability information element is coded as shown in Figure 3. 10 Making reference to Figure 4, which shows the network capability IE in amplified fashion, item (1) of both the existing and new IE, namely the system management capabilities by way of dedicated channels, are the same. Item (2) listed in the existing and new IE, the system management capabilities by way of GPRS channels are the same. Item (3) in the existing IE, and item (6) in the new 15 information element, the Universal Multiple - Octet Coded Character Set (UCS), USC2 16 bit coding support, are the same. Item (4) in the existing IE and item (7) in the new IE, i.e. the supplementary service (SS) screening indicator, are the same. The support of localized service area (SoLSA) capability, item (5) of the existing IE and item (8) of the new IE, are 20 the same. Item (6) in the existing IE, the revision level indicator, is the same as item (9) in the new IE. Items (4) and (5) in the new IE, namely, the system management capability by way of the WLAN and the short message system (SMS) item which identifies text only, text and animation, the instant message 25 service and the multimedia service as well as others are provided to the WTRU, are not provided in the existing IF. Items (7) through (10) of the existing IF are omitted from the new IF and will not be discussed herein for simplicity. Figure 4A shows the network capability IF in greater detail. For example, as shown in Figure 4A, the location service (LCS) value added (VA) location 30 request notification bit, (in binary format) is "0,, when not supported and is "1", when supported. WLAN capability is supported when its binary bit is "1", and is not supported when in the "0" state. The bit or bits identifying each capability are assigned predetermined locations with the IF. This is also the case for the PA 7 capabilities. Also note that the GPRS encryption algorithm (GEA) capability bit is "0" when not supported and "1" when supported. The purpose of the mobile station radio access (MS RA) capability information element (IE) is to provide the radio part of the network with 5 information concerning radio aspects of the mobile station (i.e., the WTRU). The contents can affect the manner in which the network handles the operation of the mobile station. The MS RA capability is a type 4 information element, with a maximum length of 52 octets. The value part of a MS RA capability information element is coded as shown in Figures 5A and 5B. 10 Figure 5 compares the existing and new radio access capability lEs. Items (1) through (4) of the existing IE, namely the access technology type, access capabilities, UMTS FDD RA technology capability and UMTS 3.84 Mcps TDD RA technology capability, are identical to the items (1) through(4) in the new IE. Items (5) and (6) in the existing IE are omitted from the new IE and hence 15 will not be discussed herein for purposes of simplicity. Item (5) of the new IE does not appear in the existing IE and provides WLAN radio access capability which identifies the type of remote terminal, (such as PDA, laptop, phone, etc.), memory size, screen size, processing power, technology version (such as 802.11, 802.15, 802.16 and so forth), service profile, (such as SMS text only or 20 text and animation), MMS, IMS, location, MBMS, and the like. Figures 5A1-5A2/5B show the MS RA capability IE in greater detail. In Figures 5A1-5A2, the Access Technology type of four binary bits, represents the technology type used for access. Gaussian minimum shift keying (GMSK) is a form of frequency shift keying providing good spectral efficiency. 8PSK is a 25 modulation technique where the carrier exists in one of eight states. Figure SB shows the fields and binary bits for identifying some of the capabilities. For example, a three bit field is used to identify WLAN 802 PA Technology wherein the technology supported is identified by a particular combination of binary bits. Note that no support of WLAN 802.xx technology is represented by "000,," support 30 for WLAN 802.11b technology represented by "001,, and so forth. As another example, the ODMA 2000 PA Technology capability is "0,, when not supported and "1" when supported.

8 A dual mode WTRU provides a WLAN capability report over its UMTS (or GPRS) network depending on whether the dual mode WTRU has WLAN/UMTS or WLAN/GPRS capability. As shown in Figure 2, when the WTRU is powered up, it first 5 communicates by way of the UMTS channels and performs a non-access stratum (NAS) "ATTACH" procedure whereupon the UMTS/WLAN capability is exchanged with the network, as shown in Figure 2. Depending on implementation, the user may chose to continue communicating with the UMTS network, manually switch over to WLAN channels 10 or perform an automatic handover to the WLAN network, if available. The present invention thus introduces two new lEs to existing GPRS/UMTS capability messages between WTRU and network and network and WTRU. The radio access capability information element (RAC IE) is modified to inform the network about the dual-mode capabilities of the WTRU/card, i.e., 15 GPRS + WLAN or UMTS/WLAN. The radio access capability (RAC), carries all aspects of the WLAN capabilities including terminal type, (such as PDA, laptop, cell phone), memory size, screen size, processing power, technology version (such as 802.11, 802.15, 802.16 and so forth), service profile (such as SMS text only or text and animation), SMS, MMS, IMS, location, multicast broadcast media 20 service (MBMS) and so forth. The WLAN capability update procedures are achieved without modification of the existing "ATTACH" procedure. The network capability is modified to inform dual mode WTRUs regarding the existence of WLAN interworking capabilities and the different types of services that can be provided over a WLAN network. 25

Claims (16)

1. A method for use in a dual-mode wireless transmit/receive unit (WTRU), the method including: generating an association request message indicating a request to associate with a network node of a first radio access technology and including a capability indicator indicating whether the WTRU is capable of communicating via a second radio access technology that is a packet-switched technology; communicating the association request message to the network node; and receiving services based on the capability indicator.

2. The method of claim 1, wherein the second radio access technology is an IEEE 802.11-based technology.

3. The method of claim 1, wherein the second radio access technology is general packet radio service (GPRS).

4. The method of claim 1, wherein the second radio access technology is IEEE 802.16.

5. The method of claim 1, wherein the capability indicator is a radio access capability information element or a MS network capability information element.

6. The method of claim 2, further including: receiving Short Message Service (SMS) messages via the IEEE 802.11 based technology.

7. The method of claim 1, further including: receiving an acknowledgement of the association request message from the network node. 10

8. A wireless transmit/receive unit (WTRU) including: a processor configured to generate an association request message, the association request message indicating a request to associate with a network node of a first radio access technology and including a capability indicator indicating whether the WTRU is capable of communicating via a second radio access technology that is a packet-switched technology; a transmitter configured to transmit the association request message to the network node; and a receiver configured to receive services based on the capability indicator.

9. The WTRU of claim 8, wherein the second radio access technology is an IEEE 802.11-based technology.

10. The WTRU of claim 8, wherein the second radio access technology is general packet radio service (GPRS).

11. The WTRU of claim 8, wherein the second radio access technology is IEEE 802.16.

12. The WTRU of claim 8, wherein the WTRU capability indicator is a radio access capability information element or a MS network capability information element.

13. The WTRU of claim 9 wherein the receiver is further configured to receive Short Message Service (SMS) via the IEEE 802.11-based technology.

14. The WTRU of claim 8, wherein the receiver is further configured to receive an acknowledgement of the association request message from the network.

15. The method of claims and substantially as hereinbefore described with reference to the accompanying figures. 11

16. The WTRU of claim 8 and substantially as hereinbefore described with reference to the accompanying figures. InterDigital Technology Corporation WATERMARK PATENT & TRADE MARK ATTORNEYS P26573AU02