Abstract:
The present invention is related to a method of activating multiple bearer services in a long term evolution (LTE) wireless communication system including multiple bearers. At least one of the multiple bearers is activated during initial attach procedures which combine an attach procedure with activate packet data protocol (PDP) context activation procedures. In one embodiment, LTE attach procedures are implemented for multi-bearer services activation that establishes an LTE direct general packet radio service (GPRS) tunneling protocol (GTP) tunnel or normal GTP two-tunnels operation. In another embodiment, the initial attach procedures are used to activate a default PDP context to be followed by modified PDP context activation procedures for multi-bearer services activation. These procedures can be used to establish a modified LTE direct GTP tunnel or a normal GTP two-tunnels operation.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/830,194 filed Jul. 12, 2006, which is incorporated by reference as if fully set forth. 
     
     FIELD OF INVENTION 
       [0002]    The present invention is related to a wireless communication system. More particularly, the present invention is related to the simultaneous activation of multiple bearer services upon attachment based on pre-configuration data stored in the WTRU in a long term evolution (LTE) general packet radio service (GPRS) tunneling protocol (GTP)-based system. 
       BACKGROUND 
       [0003]      FIG. 1  shows a conventional GPRS/third generation (3G) wireless communication system architecture  100  that shows various interfaces/protocols as well as user data transfer interfaces between various network entities. The wireless communication system  100  includes at least one serving GPRS support node (SGSN)  105  and at least one gateway GPRS support node (GGSN)  110 . The wireless communication system  100  further comprises a universal terrestrial radio access network (UTRAN)  115  which includes one or more radio access networks (RANs), base station systems (BSSs) and radio network controllers (RNCs), (not shown). The system  100  also comprises a plurality of wireless transmit/receive units (WTRUs)  120 , each including a terminal equipment (TE)  125  coupled to a mobile terminal (MT)  130 . The mobility in the wireless communication system  100  is facilitated by anchoring an Internet Protocol (IP) session at the GGSN  110  and allowing for multi-level mobility by supporting mobility management (MM) protocols for IP and non-IP traffic/services provided by the SGSN  105 . 
         [0004]      FIG. 2A  shows how dual tunnels are established in the conventional wireless communication system  100  of  FIG. 1  to provide IP connectivity for user plane traffic. As shown in  FIG. 2A , a GPRS tunnelling protocol (GTP) user plane (GTP-U) tunnel  220  is established between a GGSN  205  and an SGSN  210 , and a second user plane tunnel  225  is established between the SGSN  210  and a radio network controller (RNC)  215 . Both tunnels are dedicated to the same user. The GTP tunnel  220  has a user plane and a control plane. The user tunnel  225  is an IP tunnel having a user plane and a RAN application part (RANAP) control plane used for control messaging. 
         [0005]      FIG. 3  shows the system architecture evolution (SAE) of a long term evolution (LTE)-based network with various interfaces/protocols as well as user data transfer interfaces between various network entities. The wireless communication system  300  includes an evolved packet core  305  comprising at least one mobility management entity (MME)/user plane entity (UPE)  310  and at least one inter-access system (AS) anchor  315 , also called an access gateway (AGW). An evolved radio access network  320  includes at least one evolved Node-B (eNodeB). The wireless communication system  300  further comprises a GPRS core  325  as described above with reference to  FIG. 1 , which includes at least one universal terrestrial radio access network (UTRAN)  330 , and at least one GPRS enhanced data rates for global system for mobile communications (GSM) evolution (EDGE) radio access network (GERAN)  335 . Mobility of WTRUs (not shown) in the wireless communication system  300  is facilitated by anchoring Internet Protocol (IP) sessions at the AGW  315  and allowing for multi-level mobility by supporting MM protocols for IP traffic/services provided by the AGW  315 . 
         [0006]    LTE based networks are the evolution toward all IP Networks (AIPNs). IP traffic generated from the network operator, such as instant messaging, and non third generation partnership project (3GPP) IP traffic, (i.e., wireless local area network (WLAN) traffic), is anchored and routed through the AGW  315 . 
         [0007]    One objective in LTE is to facilitate mobility and reducing development cost by anchoring IP sessions at the AGW and allowing for multi-level mobility and supporting existing GPRS/3G MM protocols. In LTE, most of the services and applications are migrating toward IP-based platforms. This migration requires IP connectivity and the traffic generated does not have be terminated at a mobility management entity (MME)/user plane entity (UPE), as it is the case in GPRS. 
         [0008]    The current packet data protocol (PDP) context activation performed in GPRS and universal mobile telecommunications system (UMTS) 3GPP systems is dedicated to single bearer services. 
         [0009]    Primary PDP context activation performs IP configuration and the selection of access point name (APN) associated with session initiation protocol (SIP) signaling. A secondary PDP context activation is needed for each additional bearer service. This means that the three-way handshake process will be repeated over and over for each additional service to be activated, (e.g., email, streaming, web browsing, and the like). There is a need to simplify this method by reducing the number of PDP (primary and secondary) activations signaled and increase the setup time to perform any of the above mentioned services. 
       SUMMARY 
       [0010]    The present invention is related to a method of activating multiple bearer services in an LTE wireless communication system including multiple bearers. At least one of the multiple bearers is activated during the initial attach procedures combining the attach procedure with activate PDP context activation procedures. In one embodiment, LTE attach procedures are implemented for multi-bearer services activation that establishes an LTE direct GTP tunnel or normal GPRS GTP two-tunnels operation. In another embodiment, the initial attach procedures are used to activate a default PDP context to be followed by modified PDP context activation procedures for multi-bearer services activation. These procedures can be used to establish a modified LTE direct GTP tunnel or a normal GTP two-tunnels operation. 
         [0011]    The present invention changes existing GPRS procedures by performing a single step of activation of multiple bearers during the initial attached procedures, or using the initial attached procedures to activate a default bearer, followed by modify procedures that activate the remaining multiple bearers in a single step. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    A more detailed understanding of the invention may be had from the following description of a preferred embodiment, given by way of example and to be understood in conjunction with the accompanying drawings wherein: 
           [0013]      FIG. 1  shows a conventional GPRS/3G wireless communication system architecture; 
           [0014]      FIG. 2A  shows establishment of a conventional GTP user plane tunnel; 
           [0015]      FIG. 2B  shows establishment of a single GTP tunnel in accordance with the present invention; 
           [0016]      FIG. 3  shows the system architecture evolution (SAE) of an LTE-based wireless communication system; 
           [0017]      FIG. 4  shows a conventional tunnel protocol stack; 
           [0018]      FIG. 5  shows an LTE GTP protocol stack in accordance with the present invention; 
           [0019]      FIG. 6  is a signal flow diagram of a conventional tunnel establishment procedure; 
           [0020]      FIG. 7  is a signal flow diagram of LTE attach procedures for a multi-bearer services activation for establishing an LTE single GTP tunnel; and 
           [0021]      FIG. 8  is a signal flow diagram of modified PDP context activation procedures for multi-bearer services activation for establishing an LTE single GTP tunnel. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    When referred to hereafter, the terminology “wireless transmit/receive unit (WTRU)” includes but is not limited to a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, or any other type of user device capable of operating in a wireless environment. When referred to hereafter, the terminology “base station” includes but is not limited to an eNodeB, a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment. 
         [0023]    The features of the present invention may be incorporated into an integrated circuit (IC) or be configured in a circuit comprising a multitude of interconnecting components. 
         [0024]    In accordance with the present invention, the mobility in GPRS, (3G or beyond), systems is facilitated by anchoring the IP session at the home GGSN and allowing for multi-level mobility, and by supporting existing MM protocols for non-IP traffic/services provided by the SGSN. 
         [0025]      FIG. 2B  shows a single user-plane tunnel approach in accordance with the present invention. A single user plane tunnel  260  is used to reduce the delay and processing power of an MME/UPE  255 . In the two-tunnel approach shown in  FIG. 2A , the SGSN  210  terminates both the GTP tunnel  220  and a user plane tunnel  225  to the RNC  215 , which means that the SGSN  210  decodes the packets traveling in both directions and translates them into the different protocol formats of the two tunnels  220  and  225 . In a single tunnel approach shown in  FIG. 2B , the MME/UPE  255  only establishes a tunnel between the AGW  265  and the eNodeB  250  via two separate interfaces/protocols, (RANAP-C and GTP-C). In the single tunnel approach, the MME/UPE  255  is not involved in the user plane traffic. Thus, the user traffic passes through the MME/UPE  255  unchanged, (i.e., unaltered), in both directions. Only the eNodeB  250  and the AGW  265  are allowed to perform/act on the user plane traffic. The MME/UPE  255  only manages the control traffic, including MM, routing area update (RAU), and the like, associated with the user and its IP based traffic. The MME/UPE  255  connects an eNodeB  250  and an AGW  265  using a GTP control plane to communicate with the AGW  265  and a RANAP control plane to communicate with the eNodeB  250 . When a handoff occurs between eNodeBs, the MME/UPE  255  is responsible for providing the AGW  265  with the new eNodeB tunnel endpoint identity (TEID) information and the establishment of the single tunnel  260 . 
         [0026]      FIG. 4  shows a prior art tunnel protocol stack according to existing GPRS protocol. A GTP-U tunnel transfers, (i.e., tunnels), user data between a UTRAN (which includes RANs, BSSs and RNCs) and a 3G-SGSN, and between the 3G-SGSN and a 3G-GGSN. 
         [0027]      FIG. 5  shows tunnel protocol stack in accordance with the present invention, in which the user plane tunnel is established between an eNodeB and an AGW. The IP Tunnel shown in  FIG. 5  can be GTP-based or any generic IP-Tunnel. In a preferred embodiment, the GTP-U tunnel is used as an IP tunnel. 
         [0028]      FIG. 6  is a conventional signaling diagram of a process for single tunnel establishment. The single tunnel functionality reduces the delay and processing power at the SGSN by reducing the need for protocol translation between the RNC and GGSN interfaces, and by enabling direct user plane tunnel between the RAN/RNC and the GGSN within the packet switched (PS) domain. However, the single tunnel approach will not eliminate the need for the SGSN to manage control traffic for IP-based traffic. The SGSN is still needed for the control plane signalling, MM and call/session management, and the SGSN makes a decision as to whether to establish a single tunnel or establish dual tunnels. 
         [0029]    In the case of a single tunnel, the SGSN should connect the RAN/RNC TEID and the GGSN TEID for user plane by informing each end point of the tunnel of the corresponding TEID of the other end point, (i.e., informing the GGSN of the RNC TEID and informing the RNC of the GGSN TEID). In the case of a handoff between RNCs, the SGSN is responsible for updating and providing the GGSN with new RNC TEID information and the establishment of the single tunnel. 
         [0030]    In a preferred embodiment of the invention, the activation of multiple bearers for multiple services during the primary PDP context activation are performed while the WTRU initiates packet switched (PS)-attach procedures. The WTRU preferably includes a list of services that need to be activated and the associated network service access point identifier (NSAPI) in the attach request. 
         [0031]    The SGSN then preferably selects the APN, (e.g., a GGSN or an AGW) that performs these services. In the preferred embodiment, an MME/UPE is used as the SGSN. The SGSN (MME/UPE) preferably establishes the multi bearers in the radio network controller (RNC)/eNodeB. The RNC/eNodeB preferably establishes the multi-bearers with the WTRU and confirms back to the SGSN. The SGSN (MME/UPE) preferably establishes the tunneling required between the GGSN/AGW and the RNC/eNodeB whether it is a single tunnel (LTE/single tunnel GPRS) or two tunnels (GPRS). The SGSN then preferably allocates the IP and confirms the allocation of bearers and their associated NSAPI. 
         [0032]      FIG. 7  shows an LTE single GTP tunnel establishment (LTE attach) procedure  700  for activating multi-bearer services, which is implemented in a wireless communication system including a WTRU  705 , an eNodeB  710 , an MME/UPE  715  and an AGW  720  in accordance with a first embodiment of the present invention. The WTRU  705  sends an LTE attach request message to the eNodeB  710  and the MME/UPE  715  that includes one or more information elements (IEs) (step  725 ). The IEs may include one or more of the following: PDP type, PDP address, service list, APNs, a NSAPI list and quality of service (QoS) associated with each service. The NSAPI list is used to map specific services to specific end points at the WTRU  705  and the Core Network. The MME of the MME/UPE  715  validates the LTE attach request, selects an APN, maps the selected APN to the AGW  720  and determines the GTP TEIDs and the NAPSI list (step  730 ). The MME of the MME/UPE  715  forwards the NSAPI list to the AGW  720  to identify the user service end points. The MME of the MME/UPE  715  validates the service list against the subscriber profile in the home subscriber server (HSS). The selection of APN is based on many variables including the service identification. The MME/UPE  715  determines if a single tunnel is supported and/or requested, and notes the existence of the GTP TEIDs and NSAPI list (step  730 ). The admission control point where the MME performs service validation against the user profile selects the appropriate APN for each service. The MME then contacts the gateway(s) to establish the PD context for each service identified in the list and according to the respective QoS profile. 
         [0033]    The MME/UPE  715  creates a PDP context request that includes information regarding at least one of the following: PDP Type, PDP Address, service list, NSAPI list, APNs list, eNodeB TEID and QoS (step  735 ). The AGW  720  creates a PDP context response that preferably includes information regarding at least one of the following: PDP Type, PDP Address, APN, an indicator that the establishment of the GTP tunnel is granted, AGW TEID and QoS (step  740 ). The WTRU  705  and the eNodeB  710  setup a plurality of radio access bearers (RABs) that include APNs, a service list and a NSAPI list (step  745 ). In this step, the eNodeB  810  establishes a radio bearer for each service and uses the NSAPI list to mark each service. In step  750 , the MME/UPE  715  and the eNodeB  710  exchange tunnel setup signaling that includes a mobile station international subscriber directory number (MSISDN), a PDP address, APNs, a NSAPI list and an AGW TEID, and the MME/UPE  715  sends tunnel establishment information to the eNodeB  710  after receiving an indication of acceptance from the AGW  720  to establish the tunnel. In step  755 , the MME/UPE  715  sends an invoke trace message to the eNodeB  710 . The MME/UPE  715  sends an update PDP context request to the AGW  720  (step  760 ) to establish the new tunnel by informing the AGW  720  of the AGW TEID associated with the request, and the AGW  720  sends an update PDP context response to the MME/UPE  715  (step  765 ) confirming or rejecting the establishment of the tunnel and the associated attributes, (RNC TEID, PDP type, PDP address, user ID, and the like). The MME/UPE  715  inserts the AGW address in its PDP context, sends the PDP address received from the AGW  720  (step  770 ) and prepares for the response to be sent down to the WTRU  705 . Thus, if necessary, the MME/UPE  715  updates the PDP context in the AGW  720  to reflect any changes in the QoS attributes resulting from the RAB setup of step  745 . Tunnel establishing signaling is exchanged between the eNodeB  710  and the AGW  720  including the MSISDN, PDP address, eNodeB TEID, AGW TEID and NSAPI list (step  775 . The MME/UPE  715  sends an activate PDP context accept signal to the WTRU  705  that indicates the presence of a single tunnel (step  780 ). The activate PDP context accept signal preferably includes PDF information, a service list, APNs and a NSAPI list. The PDP information includes the IP address and IP version, (e.g., v4 or v6). 
         [0034]      FIG. 8  shows an LTE single GTP tunnel establishment (PDF context modification) procedure  800  for activating multi-bearer services, which is implemented in a wireless communication system including a WTRU  805 , an eNodeB  810 , an MME/UPE  815  and an AGW  820  in accordance with a second embodiment of the present invention. The WTRU  805  sends an modify PDF context request message to the eNodeB  810  and the MME/UPE  815  that includes one or more IEs (step  825 ). The IEs may include one or more of the following: PDP type, PDP address, service list, APNs, a NSAPI list and QoS associated with each service (step  825 ). The NAPSI list is used to map specific services to specific end points at the WTRU  805  and the Core Network. The MME of the MME/UPE  815  validates the modify PDP context request, selects an APN, maps the selected APN to the AGW  820  and determines the GTP TEIDs and the NAPSI list (step  830 ). The MME of the MME/UPE  815  determines if a single tunnel is supported and/or requested, and notes the existence of the GTP TEIDs and NSAPI list (step  830 ). 
         [0035]    The MME/UPE  815  creates a modify PDP context request that includes information regarding at least one of the following: PDP Type, PDP Address, service list, NSAPI list, APNs list, eNodeB TEID and QoS (step  835 ). The AGW  820  creates a PDP context response that preferably includes information regarding at least one of the following: PDP Type, PDP Address, APN, an indicator that the establishment of the GTP tunnel is granted, AGW TEID and QoS (step  840 ). The WTRU  805  and the eNodeB  810  setup a plurality of RABs that include APNs, a service list and a NSAPI list (step  845 ). In step  850 , the MME/UPE  815  and the eNodeB  810  exchange tunnel setup signaling that includes a mobile station international subscriber directory number (MSISDN), a PDP address, APNs, a NSAPI list and an AGW TEID, and the MME/UPE  815  sends tunnel establishment information to the eNodeB  810  after receiving an indication of acceptance from the AGW  820  to establish the tunnel. In step  855 , the MME/UPE  815  sends an invoke trace message to the eNodeB  810 . The MME/UPE  815  sends an update PDP context request to the AGW  820  (step  860 ) to establish the new tunnel by informing the AGW  820  of the AGW TEID associated with the request, and the AGW  820  sends an update PDP context response to the MME/UPE  815  (step  865 ) confirming or rejecting the establishment of the tunnel and the associated attributes, (RNC TEID, PDP type, PDP address, user ID, and the like). The MME/UPE  815  inserts the AGW address in its PDP context, sends the PDP address received from the AGW  820  (step  870 ) and prepares for the response to be sent down to the WTRU  805 . Thus, if necessary, the MME/UPE  815  updates the PDP context in the AGW  820  to reflect any changes in the QoS attributes resulting from the RAB setup of step  845 . A modified tunnel establishing signaling is exchanged between the eNodeB  810  and the AGW  820  including the MSISDN, PDP address, eNodeB TEID, AGW TEID and NSAPI list (step  875 ). The MME/UPE  815  sends a modify PDP context accept signal to the WTRU  805  that indicates the presence of a single modified tunnel (step  880 ). The activate PDP context accept signal preferably includes PDF information, a service list, APNs and a NSAPI list. 
         [0036]    The above preferred methods are preferably implemented, by way of example, as software or middleware, at the WTRU and the eNodeB or similar base station. The implementation is applicable to various communication layers, including by not limited to the network layer, the session layer and the presentation layer. 
         [0037]    Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention. The methods or flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). 
         [0038]    Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine. 
         [0039]    A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any wireless local area network (WLAN) module.