Title:

Generic Access to the Iu Interface

Document Type and Number:

United States Patent Application 20080043669

Kind Code:

Abstract:

Some embodiments provide a method of activating a packet transport channel (PTC) in a communication system that includes a first licensed wireless communication system and a second generic access network (GAN) that has a generic access network controller (GANC). The GANC is communicatively coupled to the first communication system through a universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN) Iu interface. The method sends a GA-PSR activate PTC request message from the GANC to a user equipment (UE). The message comprises a terminal endpoint identifier (TEID) that the GANC assigns to the UE. The message also receives a GA-PSR activate PTC acknowledge message from the UE at the GANC.

Inventors:

Gallagher, Michael D. (San Jose, CA, US)
Markovle, Milan (Pleasanton, CA, US)
Tao, Patrick (San Jose, CA, US)
Khetawat, Amit (San Jose, CA, US)

Plaque It!

CLAIM OF BENEFIT TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application 60/807,470, entitled “E-UMA Technology,” filed Jul. 14, 2006; U.S. Provisional Application 60/823,092, entitled “Generic Access to the Iu Interface,” filed Aug. 21, 2006; U.S. Provisional Application 60/862,564, entitled “E-UMA—Generic Access to the Iu Interface,” filed Oct. 23, 2006, and U.S. Provisional Application 60/949,826, entitled “Generic Access to the Iu Interface,” filed Jul. 13, 2007. The contents of each of these four provisional applications are hereby incorporated by reference.

FIELD OF THE INVENTION

The field of invention relates generally to telecommunications. More particularly, this invention relates to a mechanism for extending Unlicensed Mobile Access (UMA) or Generic Access Network (GAN) to inter-work with a GSM core network using the Universal Mobile Telecommunication System (UMTS) Iu interface.

BACKGROUND OF THE INVENTION

Licensed wireless systems provide mobile wireless communications to individuals using wireless transceivers. Licensed wireless systems refer to public cellular telephone systems and/or Personal Communication Services (PCS) telephone systems. Wireless transceivers include cellular telephones, PCS telephones, wireless-enabled personal digital assistants, wireless modems, and the like.

Licensed wireless systems utilize wireless signal frequencies that are licensed from governments. Large fees are paid for access to these frequencies. Expensive base station (BS) equipment is used to support communications on licensed frequencies. Base stations are typically installed approximately a mile apart from one another (e.g., cellular towers in a cellular network). The wireless transport mechanisms and frequencies employed by typical licensed wireless systems limit both data transfer rates and range. As a result, the quality of service (voice quality and speed of data transfer) in licensed wireless systems is considerably inferior to the quality of service afforded by landline (wired) connections. Thus, the user of a licensed wireless system pays relatively high fees for relatively low quality service.

Landline (wired) connections are extensively deployed and generally perform at a lower cost with higher quality voice and higher speed data services. The problem with landline connections is that they constrain the mobility of a user. Traditionally, a physical connection to the landline was required.

In the past few years, the use of unlicensed wireless communication systems to facilitate mobile access to landline-based networks has seen rapid growth. For example, such unlicensed wireless systems may support wireless communication based on the IEEE 802.11a, b or g standards (WiFi), or the Bluetooth® standard. The mobility range associated with such systems is typically on the order of 100 meters or less. A typical unlicensed wireless communication system includes a base station comprising a wireless access point (AP) with a physical connection (e.g., coaxial, twisted pair, or optical cable) to a landline-based network. The AP has a RF transceiver to facilitate communication with a wireless handset that is operative within a modest distance of the AP, wherein the data transport rates supported by the WiFi and Bluetooth® standards are much higher than those supported by the aforementioned licensed wireless systems. Thus, this option provides higher quality services at a lower cost, but the services only extend a modest distance from the base station.

Currently, technology is being developed to integrate the use of licensed and unlicensed wireless systems in a seamless fashion, thus enabling a user to access, via a single handset, an unlicensed wireless system when within the range of such a system, while accessing a licensed wireless system when out of range of the unlicensed wireless system.

SUMMARY OF THE INVENTION

Some embodiments provide a method of registering a user equipment (UE) in a communication system that includes a licensed wireless communication system and a generic access network (GAN) that has a generic access network controller (GANC). The method sends a register request message from the UE to the GANC that indicates a GAN mode capability of A/Gb only for the UE. When the GANC has a GAN mode capability of A/Gb, the GANC registers the UE with the GAN. When the GANC has a GAN mode capability of Iu only, the GANC rejects the register request message. When the GANC has a GAN mode capability of both A/Gb and Iu, the GANC registers the UE based on a set of GANC mode selection rules that the GANC applies for registering UEs with the GAN.

Some embodiments provide a communication system that includes a first licensed wireless communication system, a second generic access network (GAN) that includes a generic access network controller (GANC). The GANC is communicatively coupled to the first communication system through a universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN) Iu interface. The communication system also includes a user equipment (UE). The GANC includes a UDP protocol layer and a GTP-U protocol layer over the UDP protocol layer of the GANC. The UE includes a UDP protocol layer and a GTP-U protocol layer over said UDP protocol layer of the UE. The UDP protocol layer of the GANC is communicatively coupled to the UDP protocol layer of the UE. The GTP-U protocol layer of the GANC is communicatively coupled to the GTP-U protocol layer of the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth in the appended claims. However, for purpose of explanation, several embodiments of the invention are set forth in the following figures.

FIG. 1 illustrates an integrated communication system (ICS) of some embodiments.

FIG. 2 illustrates several applications of an ICS in some embodiments.

FIG. 3 illustrates the overall A/Gb-mode GAN functional architecture of some embodiments.

FIG. 4 illustrates the overall Iu-mode GAN functional architecture of some embodiments.

FIG. 5 illustrates the basic elements of a Femtocell system architecture with Asynchronous Transfer Mode based Iu interfaces towards the core network in some embodiments.

FIG. 6 illustrates the basic elements of a Femtocell system architecture with an IP based Iu interface towards the core network in some embodiments.

FIG. 7 illustrates the CS domain control plane architecture of some embodiments.

FIG. 8 illustrates the CS domain control plane architecture of some embodiments.

FIG. 9 illustrates the CS domain control plane architecture of some embodiments.

FIG. 10 illustrates the UE CS domain control plane architecture of some embodiments.

FIG. 11 illustrates CS domain user plane protocol architecture of some embodiments.

FIG. 12 illustrates CS domain user plane protocol architecture of some embodiments.

FIG. 13 illustrates the UE CS domain user plane architecture of some embodiments.

FIG. 14 illustrates PS domain control plane architecture of some embodiments.

FIG. 15 illustrates PS domain control plane architecture of some embodiments.

FIG. 16 illustrates the UE PS domain control architecture of some embodiments.

FIG. 17 illustrates PS domain user plane protocol architecture of some embodiments.

FIG. 18 illustrates PS domain user plane protocol architecture of some embodiments.

FIG. 19 illustrates PS domain user plane protocol architecture of some embodiments.

FIG. 20 illustrates the UE PS domain user plane architecture of some embodiments.

FIG. 21 illustrates state diagram for generic access in the UE of some embodiments.

FIG. 22 illustrates GAN security mechanisms of some embodiments.

FIG. 23 illustrates discovery procedure of some embodiments.

FIG. 24 illustrates registration procedure of some embodiments.

FIG. 25 illustrates De-Registration initiated by the UE in some embodiments.

FIG. 26 illustrates De-Registration initiated by the GANC in some embodiments.

FIG. 27 illustrates registration Update Uplink of some embodiments.

FIG. 28 illustrates Registration Update Downlink of some embodiments.

FIG. 29 illustrates Keep Alive procedure of some embodiments.

FIG. 30 illustrates Cell Broadcast Information in some embodiments.

FIG. 31 illustrates GA-CSR Connection Establishment of some embodiments.

FIG. 32 illustrates GA-CSR Connection Release in some embodiments.

FIG. 33 illustrates Security Mode Control in some embodiments.

FIG. 34 illustrates core network to UE NAS signaling in some embodiments.

FIG. 35 illustrates UE to core network NAS signaling in some embodiments.

FIG. 36 illustrates Mobile Originated CS Call in some embodiments.

FIG. 37 illustrates Mobile Originated CS Call in some embodiments.

FIG. 38 illustrates Mobile Terminated CS Call in some embodiments.

FIG. 39 illustrates UE initiated CS Call clearing in some embodiments.

FIG. 40 illustrates CS Handover from GERAN to GAN in some embodiments.

FIG. 41 illustrates an alternative procedure performed during GERAN to GAN in some embodiments.

FIG. 42 illustrates CS Handover from UTRAN to GAN in some embodiments.

FIG. 43 illustrates an alternative procedure performed during UTRAN to GAN in these embodiments.

FIG. 44 illustrates CS Handover from GAN to GERAN in some embodiments.

FIG. 45 illustrates CS Handover from GAN to UTRAN in some embodiments.

FIG. 46 illustrates GA-PSR Connection Establishment of some embodiments.

FIG. 47 illustrates GA-PSR Connection Release in some embodiments.

FIG. 48 illustrates the message flow for PS security mode control in some embodiments.

FIG. 49 illustrates core network to user equipment PS NAS signaling in some embodiments.

FIG. 50 illustrates user equipment to core network NAS signaling in some embodiments.

FIG. 51 illustrates PTC initial activation in some embodiments.

FIG. 52 illustrates PTC Data Transfer in some embodiments.

FIG. 53 illustrates UE initiated PTC deactivation in some embodiments.

FIG. 54 illustrates UE initiated PTC re-activation in some embodiments.

FIG. 55 illustrates Network initiated PTC de-activation in some embodiments.

FIG. 56 illustrates Network initiated PTC re-activation in some embodiments.

FIG. 57 illustrates Implicit PTC deactivation in some embodiments.

FIG. 58 illustrates PDP Context Activation in some embodiments.

FIG. 59 illustrates Network Requested PDP Context Activation in some embodiments.

FIG. 60 illustrates UTRAN to GAN SRNS Relocation Preparation Phase in some embodiments.

FIG. 61 illustrates UTRAN to GAN SRNS Relocation Execution Phase in some embodiments.

FIG. 62 illustrates GAN to UTRAN SRNS Relocation Preparation Phase in some embodiments.

FIG. 63 illustrates GAN to UTRAN SRNS Relocation Execution Phase in some embodiments.

FIG. 64 illustrates the GAN architecture in support of the CS Domain control plane in some embodiments.

FIG. 65 illustrates the GAN protocol architecture in support of the CS domain user plane in some embodiments.

FIG. 66 illustrates the GAN architecture in support of the PS Domain Control Plane in some embodiments.

FIG. 67 illustrates the GAN architecture for the PS Domain User Plane in some embodiments.

FIG. 68 illustrates the GA-RC sublayer in the UE in some embodiments.

FIG. 69 illustrates successful (and unsuccessful) establishment of the GA-RRC Connection when initiated by the UE in some embodiments.

FIG. 70 illustrates successful establishment of the GA-RRC Connection when initiated by the network in some embodiments.

FIG. 71 shows release of the logical GA-RRC connection between the UE and the GANC in some embodiments.

FIG. 72 illustrates the message flow for security mode control in some embodiments.

FIG. 73 illustrates core network to UE NAS signaling of some embodiments.

FIG. 74 illustrates the UE to core network NAS signaling of some embodiments.

FIG. 75 illustrates mobile originated CS call procedure in some embodiments.

FIG. 76 illustrates an alternative procedure performed during a mobile originated CS call in some embodiments.

FIG. 77 illustrates mobile terminated CS call procedure in some embodiments.

FIG. 78 illustrates call clearing initiated by the UE in some embodiments.

FIG. 79 illustrates the CS Handover from GERAN to GAN procedure in some embodiments.

FIG. 80 illustrates an alternative procedure for CS handover from GERAN to GAN in some embodiments.

FIG. 81 illustrates the CS Handover from UTRAN to GAN procedure in some embodiments.

FIG. 82 illustrates an alternative procedure for CS handover from UTRAN to GAN using RRC protocol in some embodiments.

FIG. 83 illustrates the CS handover from GAN to GERAN procedure in some embodiments.

FIG. 84 illustrates the CS handover from GAN to UTRAN procedure in some embodiments.

FIG. 85 illustrates the Packet Transport Channel initial activation procedure of some embodiments.

FIG. 86 illustrates the transfer of GPRS user data packets via the GAN Packet Transport Channel in some embodiments.

FIG. 87 illustrates the scenario when the user equipment deactivates the Packet Transport Channel after the PTC Timer expires in some embodiments.

FIG. 88 illustrates the scenario when the user equipment initiates re-activation of the Packet Transport Channel in some embodiments.

FIG. 89 illustrates the scenario when the network initiates de-activation of the Packet Transport Channel in some embodiments.

FIG. 90 illustrates the scenario when the network initiates re-activation of the Packet Transport Channel in some embodiments.

FIG. 91 illustrates the successful user equipment initiated PDP Context Activation procedure in some embodiments.

FIG. 92 illustrates the successful Network-Requested PDP Context Activation procedure in some embodiments.

FIG. 93 illustrates the successful UE-initiated PDP Context Activation procedure in some embodiments.

FIG. 94 illustrates SRNS relocation procedure from UTRAN to GAN for a UE that is in PMM Connected state in some embodiments.

FIG. 95 conceptually illustrates a computer system with which some embodiments of the invention are implemented.

FIG. 96 illustrates the procedure for implicit PTC de-activation in some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, numerous details, examples, and embodiments of the invention are set forth and described. However, it will be clear and apparent to one skilled in the art that the invention is not limited to the embodiments set forth and that the invention may be practiced without some of the specific details and examples discussed.

Throughout the following description, acronyms commonly used in the telecommunications industry for wireless services are utilized along with acronyms specific to the present invention. A table of acronyms used in this application is included in Section IX.

Several more detailed embodiments of the invention are described in sections below. Specifically, Section I describes the overall integrated communication system in which some embodiments are incorporated. The discussion in Section I is followed by a discussion of the functional entities of some embodiments in Section II. Next, Section III describes the control and user plane architecture of some embodiments. Section IV then describes the generic access network (GAN) security mechanism of some embodiments.

Next, Section V describes high level procedures such as discovery, registration, authentication, handover, etc. of some embodiments. Section VI then describes the configuration information of some embodiments. Next, identifiers used in GAN are presented in Section VII. An alternative embodiment that utilizes the same protocol for both voice and data services is disclosed in Section VIII. The discussion is followed by Section IX description of a computer system with which some embodiments of the invention are implemented. Finally, Section X lists the abbreviations used.

I. OVERALL SYSTEM

A. Integrated Communication Systems (ICS)

FIG. 1 illustrates an integrated communication system (ICS) architecture 100 in accordance with some embodiments of the present invention. ICS architecture 100 enables user equipment (UE) 102 to access a voice and data network 165 via either a licensed air interface 106 or an ICS interface 110 through which components of a mobile core network 165 are alternatively accessed. In some embodiments, a communication session includes voice services, data services, or both.

The mobile core network 165 includes one or more Home Location Registers (HLRs) 150 and databases 145 for subscriber authentication and authorization. Once authorized, the UE 102 may access the voice and data services of the mobile core network 165 . In order to provide such services, the mobile core network 165 includes a mobile switching center (MSC) 160 for providing access to the voice services. Data services are provided for through a Serving GPRS (General Packet Radio Service) Support Node (SGSN) 155 in conjunction with a gateway such as the Gateway GPRS Support Node (GGSN) 157 .

The SGSN 155 is typically responsible for delivering data packets from and to the GGSN 157 and the user equipment within the geographical service area of the SGSN 155 . Additionally, the SGSN 155 may perform functionality such as mobility management, storing user profiles, and storing location information. However, the actual interface from the mobile core network 165 to various external data packet services networks (e.g., public Internet) is facilitated by the GGSN 157 . As the data packets originating from the user equipment typically are not structured in the format with which to access the external data networks, it is the role of the GGSN 157 to act as the gateway into such packet services networks. In this manner, the GGSN 157 provides addressing for data packets passing to and from the UE 102 and the external packet services networks (not shown). Moreover, as the user equipment of a licensed wireless network traverses multiple service regions and thus multiple SGSNs, it is the role of the GGSN 157 to provide a static gateway into the external data networks.

In the illustrated embodiment, components common to a UMTS Terrestrial Radio Access Network (UTRAN) based cellular network 185 are depicted that include multiple base stations referred to as Node Bs 180 (of which only one is shown for simplicity) that facilitate wireless communication services for various user equipment 102 via respective licensed radio links 106 (e.g., radio links employing radio frequencies within a licensed bandwidth). However, one of ordinary skill in the art will recognize that in some embodiments, the licensed wireless network may include other licensed wireless networks such as the GSM/EDGE Radio Access Network (GERAN). An example of a system using A and Gb interfaces to access GERAN is shown in FIG. 3 below.

The licensed wireless channel 106 may comprise any licensed wireless service having a defined UTRAN or GERAN interface protocol (e.g., Iu-cs and Iu-ps interfaces for UTRAN or A and Gb interfaces for GERAN) for a voice/data network. The UTRAN 185 typically includes at least one Node B 180 and a Radio Network Controller (RNC) 175 for managing the set of Node Bs 180 . Typically, the multiple Node Bs 180 are configured in a cellular configuration (one per each cell) that covers a wide service area.

Each RNC 175 communicates with components of the core network 165 through a standard radio network controller interface such as the Iu-cs and Iu-ps interfaces depicted in FIG. 1. For example, a RNC 175 communicates with MSC 160 via the UTRAN Iu-cs interface for circuit switched voice services. Additionally, the RNC 175 communicates with SGSN 155 via the UTRAN Iu-ps interface for packet data services through GGSN 157 . Moreover, one of ordinary skill in the art will recognize that in some embodiments, other networks with other standard interfaces may apply. For example, the RNC 175 in a GERAN network is replaced with a Base Station Controller (BSC) that communicates voice to the MSC 160 via an A interface and the BSC communicates data to the SGSN via a Gb interface of the GERAN network.

In some embodiments of the ICS architecture, the user equipment 102 use the services of the mobile core network (CN) 165 via a second communication network facilitated by the ICS access interface 110 and a Generic Access Network Controller (GANC) 120 (also referred to as a Universal Network Controller or UNC).

In some embodiments, the voice and data services over the ICS access interface 110 are facilitated via an access point 114 communicatively coupled to a broadband IP network 116 . In some embodiments, the access point 114 is a generic wireless access point that connects the user equipment 102 to the ICS network through an unlicensed wireless network 118 created by the access point 114 .

The signaling from the UE 102 is passed over the ICS access interface 110 to the GANC 120 . After the GANC 120 performs authentication and authorization of the subscriber, the GANC 120 communicates with components of the mobile core network 165 using a radio network controller interface that is the same or similar to the radio network controller interface of the UTRAN described above, and includes a UTRAN Iu-cs interface for circuit switched voice services and a UTRAN Iu-ps interface for packet data services (e.g., GPRS). In this manner, the GANC 120 uses the same or similar interface to the mobile core network as a UTRAN Radio Network Subsystem (e.g., the Node B 180 and RNC 175 ).

In some embodiments, the GANC 120 communicates with other system components of the ICS system through one or more of several other interfaces, which are (1) “Up”, (2) “Wm”, (3) “D′/Gr′”, (4) “Gn′”, and (5) “S1”. The “Up” interface is the interface between the UE 102 and the GANC 120 . The “Wm” interface is a standardized interface between the GANC 120 and an Authorization, Authentication, and Accounting (AAA) Server 170 for authentication and authorization of the UE 102 into the ICS. The “D′/Gr′” interface is the standard interface between the AAA server 170 and the HLR 160 . Optionally, some embodiments use the “Gn′” interface which is a modified interface for direct communications with the data services gateway (e.g., GGSN) of the core licensed network. Some embodiments optionally include the “S1” interface. In these embodiments, the “S1” interface provides an authorization and authentication interface from the GANC 120 to an AAA 140 server. In some embodiments, the AAA server 140 that supports the S1 interface and the AAA server 170 that supports Wm interface may be the same. More details of the S1 interface are described in U.S. application Ser. No. 11/349,025, entitled “Service Access Control Interface for an Unlicensed Wireless Communication System”, filed Feb. 6, 2006.

In some embodiments, the UE 102 must register with the GANC 120 prior to accessing ICS services. Registration information of some embodiments includes a subscriber's International Mobile Subscriber Identity (IMSI), a Media Access Control (MAC) address, and a Service Set Identifier (SSID) of the serving access point as well as the cell identity from the GSM or UTRAN cell upon which the UE 102 is already camped. In some embodiments, the GANC 120 may pass this information to the AAA server 140 to authenticate the subscriber and determine the services (e.g., voice and data) available to the subscriber. If approved by the AAA 140 for access, the GANC 120 will permit the UE 102 to access voice and data services of the ICS system.

These voice and data services are seamlessly provided by the ICS to the UE 102 through the various interfaces described above. In some embodiments, when data services are requested by the UE 102 , the ICS uses the optional Gn′ interface for directly communicating with a GGSN 157 . The Gn′ interface allows the GANC 120 to avoid the overhead and latency associated with communicating with the SGSN 155 over the Iu-ps interface of the UTRAN or the Gb interface of the GSM core networks prior to reaching the GGSN 157 .

In some other embodiments, the access point 114 is a Femtocell access point (FAP). The FAP facilitates short-range licensed wireless communication sessions 118 that operate independent of the licensed communication session 106 . In case of the Femtocell, the user equipment 102 connects to the ICS network through the short-range licensed wireless network 118 created by the FAP 114 . Signals from the FAP are then transmitted over the broadband IP network 116 .

B. Applications of ICS

An ICS provides scalable and secure interfaces into the core service network of mobile communication systems. FIG. 2 illustrates several applications of an ICS in some embodiments. As shown, homes, offices, hot spots, hotels, and other public and private places 205 are connected to one or more network controllers 210 (such as the GANC 120 shown in FIG. 1) through the Internet 215 . The network controllers in turn connect to the mobile core network 220 (such as the core network 165 shown in FIG. 1).

FIG. 2 also shows several user equipments. These user equipments are just examples of user equipments that can be used for each application. Although in most examples only one of each type of user equipments is shown, one of ordinary skill in the art would realize that other type of user equipments can be used in these examples without deviating from the teachings of the invention. Also, although only of each type of access points, user equipment, or network controllers are shown, many such access points, user equipments, or network controllers may be employed in FIG. 2. For instance, an access point may be connected to several user equipment, a network controller may be connected to several access points, and several network controllers may be connected to the core network. The following sub-sections provide several examples of services that can be provided by an ICS.

1. Wi-Fi

A Wi-Fi access point 230 enables a dual-mode cellular/Wi-Fi UEs 260 - 265 to receive high-performance, low-cost mobile services when in range of a home, office, or public Wi-Fi network. With dual-mode UEs, subscribers can roam and handover between licensed wireless communication system and Wi-Fi access and receive a consistent set of services as they transition between networks.

2. Femtocells

A Femtocell enables user equipments, such as standard mobile stations 270 and wireless enabled computers 275 shown, to receive low cost services using a short-range licensed wireless communication sessions through a FAP 235 .

3. Terminal Adaptors

Terminal adaptors 240 allow incorporating fixed-terminal devices such as telephones 245 , Faxes 250 , and other equipments that are not wireless enabled within the ICS. As long as the subscriber is concerned, the service behaves as a standard analog fixed telephone line. The service is delivered in a manner similar to other fixed line VoIP services, where a UE is connected to the subscriber's existing broadband (e.g., Internet) service.

4. WiMAX

Some licensed wireless communication system operators are investigating deployment of WiMAX networks in parallel with their existing cellular networks. A dual mode cellular/WiMAX UE 290 enables a subscriber to seamlessly transition between a cellular network and such a WiMAX network.

5. SoftMobiles

Connecting laptops 280 to broadband access at hotels and Wi-Fi hot spots has become popular, particularly for international business travelers. In addition, many travelers are beginning to utilize their laptops and broadband connections for the purpose of voice communications. Rather than using mobile phones to make calls and pay significant roaming fees, they utilize SoftMobiles (or SoftPhones) and VoIP services when making long distance calls.

To use a SoftMobile service, a subscriber would place a USB memory stick 285 with an embedded SIM into a USB port of their laptop 280 . A SoftMobile client would automatically launch and connect over IP to the mobile service provider. From that point on, the subscriber would be able to make and receive mobile calls as if she was in her home calling area.

Several examples of Integrated Communication Systems (ICS) are given in the following sub-sections. A person of ordinary skill in the art would realize that the teachings in these examples can be readily combined. For instance, an ICS can be an IP based system and have an A/Gb interface towards the core network while another ICS can have a similar IP based system with an Iu interface towards the core network.

C. Integrated Systems with A/GB and/or Iu Interfaces Towards the Core Network

FIG. 3 illustrates the A/Gb-mode Generic Access Network (GAN) functional architecture of some embodiments. The GAN includes one or more Generic Access Network Controllers (GANC) 310 and one or more generic IP access networks 315 . One or more UEs 305 (one is shown for simplicity) can connect to a GANC 310 through a generic IP access network 315 . The GANC 310 has the capability to appear to the core network 325 as a GSM/EDGE Radio Access Network (GERAN) Base Station Controller (BSC). The GANC 310 includes a Security Gateway (SEGW) 320 that terminates secure remote access tunnels from the UE 305 , providing mutual authentication, encryption and data integrity for signaling, voice and data traffic.

The generic IP access network 315 provides connectivity between the UE 305 and the GANC 310 . The IP transport connection extends from the GANC 310 to the UE 305 . A single interface, the Up interface, is defined between the GANC 310 and the UE 305 .

The GAN co-exists with the GERAN and maintains the interconnections with the Core Network (CN) 325 via the standardized interfaces defined for GERAN. These standardized interfaces include the A interface to Mobile Switching Center (MSC) 330 for circuit switched services, Gb interface to Serving GPRS Support Node (SGSN) 335 for packet switched services, Lb interface to Serving Mobile Location Center (SMLC) 350 for supporting location services, and an interface to Cell Broadcast Center (CBC) 355 for supporting cell broadcast services. The transaction control (e.g. Connection Management, CC, and Session Management, SM) and user services are provided by the core network (e.g. MSC/VLR and the SGSN/GGSN).

As shown, the SEGW 320 is connected to a AAA server 340 over the Wm interface. The AAA server 340 is used to authenticate the UE 305 when it sets up a secure tunnel. Some embodiments require only a subset of the Wm functionalities for the GAN application. In these embodiments, as a minimum the GANC-SEGW shall support the Wm authentication procedures.

FIG. 4 illustrates the Iu-mode Generic Access Network (GAN) functional architecture of some embodiments. The GAN includes one or more Generic Access Network Controllers (GANC) 410 and one or more generic IP access networks 415 . One or more UEs 405 (one is shown for simplicity) can be connected to a GANC 410 through a generic IP access network 415 . In comparison with the GANC 310 , the GANC 410 has the capability to appear to the core network 425 as a UMTS Terrestrial Radio Access Network (UTRAN) Radio Network Controller (RNC). In some embodiments, the GANC has the expanded capability of supporting both the Iu and A/Gb interfaces to concurrently support both Iu-mode and A/Gb-mode UEs. Similar to the GANC 310 , the GANC 410 includes a Security Gateway (SEGW) 420 that terminates secure remote access tunnels from the UE 405 , providing mutual authentication, encryption and data integrity for signaling, voice and data traffic.

The generic IP access network 415 provides connectivity between the UE 405 and the GANC 410 . The IP transport connection extends from the GANC 410 to the UE 405 . A single interface, the Up interface, is defined between the GANC 410 and the UE 405 . Functionality is added to this interface, over the UP interface shown in FIG. 3 to support the Iu-mode GAN service.

The GAN co-exists with the UTRAN and maintains the interconnections with the Core Network (CN) 425 and via the standardized interfaces defined for UTRAN. These standardized interfaces include the Iu-cs interface to Mobile Switching Center (MSC) 430 for circuit switched services, Iu-ps interface to Serving GPRS Support Node (SGSN) 435 for packet switched services, Iu-pc interface to Serving Mobile Location Center (SMLC) 450 for supporting location services, and Iu-bc interface to Cell Broadcast Center (CBC) 455 for supporting cell broadcast services. The transaction control (e.g. Connection Management, CC, and Session Management, SM) and user services are provided by the core network (e.g. MSC/VLR and the SGSN/GGSN).

As shown, the SEGW 420 is connected to a AAA server 440 over the Wm interface. The AAA server 440 is used to authenticate the UE 405 when it sets up a secure tunnel. Some embodiments require only a subset of the Wm functionalities for the Iu mode GAN application. In these embodiments, as a minimum the GANC-SEGW shall support the Wm authentication procedures.

D. ATM and IP Based Architectures

In some embodiments, the system uses Asynchronous Transfer Mode (ATM) based Iu (Iu-cs and Iu-ps) interfaces towards the CN. In some embodiments, the system architecture can also support an IP based Iu (Iu-cs and Iu-ps) interface towards the CN. The following two sub-sections describe examples of these architectures for Femtocell.

A person of ordinary skill in the art would realize that the same examples can be readily applied to other types of ICS. For instance, these examples can be used when the ICS access interface 110 (shown in FIG. 1) uses unlicensed frequencies (instead of Femtocell's licensed frequencies), the access point 114 is a generic WiFi access point (instead of a FAP), etc. Also, a person of ordinary skill in the art would realize that the same examples can be readily implemented using A/Gb interfaces (described above) instead of Iu interfaces.

FIG. 5 illustrates the basic elements of a Femtocell system architecture with Asynchronous Transfer Mode (ATM) based Iu (Iu-cs and Iu-ps) interfaces towards the CN in some embodiments. These elements include the user equipment (UE) 505 , the FAP 510 , and the Generic Access Network Controller (GANC) 515 , and the Access Point Management SYSTEM (AMS) 570 .

For simplicity, only one UE and one FAP are shown. However, each GANC can support multiple FAPs and each FAP in turn can support multiple UEs. As shown, the GANC 515 includes an IP Network Controller (INC) 525 , a GANC Security Gateway (SeGW) 530 , a GANC Signaling Gateway 535 , a GANC Media Gateway (MGW) 540 , an ATM Gateway ( 545 ). Elements of the Femtocell are described further below.

FIG. 6 illustrates the basic elements of a Femtocell system architecture with an IP based Iu (Iu-cs and Iu-ps) interface towards the CN in some embodiments. For simplicity, only one UE and one FAP are shown. However, each GANC can support multiple FAPs and each FAP in turn can support multiple UEs. This option eliminates the need for the GANC Signaling gateway 535 and also the ATM gateway 545 . Optionally for IP based Iu interface, the GANC Media Gateway 540 can also be eliminated if the R4 MGW 605 in the CN can support termination of voice data i.e. RTP frames as defined in “IETF RFC 3267—Real-Time Transport Protocol (RTP) Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs”, “RFC 3267”.

Also shown in FIGS. 5 and 6 are components of the licensed wireless communication systems. These components are 3G MSC 550 , 3G SGSN 555 , and other Core Network System (shown together) 565 . The 3G MSC 550 provides a standard Iu-cs interface towards the GANC. Another alternative for the MSC is shown in FIG. 6. As shown, the MSC 650 is split up into a MSS (MSC Server) 675 for Iu-cs based signaling and MGW 680 for the bearer path. R4 MSC 650 is a release 4 version of a 3G MSC with a different architecture i.e. R4 MSC is split into MSS for control traffic and a MGW for handling the bearer. A similar MSC can be used for the ATM architecture of FIG. 5. Both architectures shown in FIGS. 5 and 6 are also adaptable to use any future versions of the MSC.

The 3G SGSN 555 provides packet services (PS) via the standard Iu-ps interface. The SGSN connects to the INC 525 for signaling and to the SeGW 530 for PS data. The AAA server 560 communicates with the SeGW 530 and supports the EAP-AKA and EAP-SIM procedures used in IKEv2 over the Wm interface and includes a MAP interface to the HLR/AuC. In some embodiments, this system also supports the enhanced service access control functions over the S1 interface.

II. FUNCTIONAL ENTITIES

A. User Equipment

The UE 405 contains the functions that are required to access the Iu-mode GAN. In some embodiments, the UE additionally contains that are required to access the A/Gb-mode GAN. In some embodiments, the User Equipment (UE) 305 is a dual mode (e.g., GSM and unlicensed radios) handset device with capability to switch between the two modes. The user equipment can support either Bluetooth® or IEEE 802.11 protocols. In some embodiments, the UE supports an IP interface to the access point. In these embodiments, the IP connection from the GANC extends all the way to the UE. In some other embodiments, the User Equipment (UE) 305 is a standard 3G handset device operating over licensed spectrum of the provider.

In some embodiments, the user equipment includes a cellular telephone, smart phone, personal digital assistant, or computer equipped with a subscriber identity mobile (SIM) card for communicating over the licensed or unlicensed wireless networks. Moreover, in some embodiments the computer equipped with the SIM card communicates through a wired communication network.

Alternatively, in some embodiments the user equipment includes a fixed wireless device providing a set of terminal adapter functions for connecting Integrated Services Digital Network (ISDN), Session Initiation Protocol (SIP), or Plain Old Telephone Service (POTS) terminals to the ICS. Application of the present invention to this type of device enables the wireless service provider to offer the so-called landline replacement service to users, even for user locations not sufficiently covered by the licensed wireless network. Moreover, some embodiments of the terminal adapters are fixed wired devices for connecting ISDN, SIP, or POTS terminals to a different communication network (e.g., IP network) though alternate embodiments of the terminal adapters provide wireless equivalent functionality for connecting through unlicensed or licensed wireless networks.

B. Generic Access Network Controller (GANC)

The core network 425 interacts with the GANC 410 as though it was an RNC. The generic IP access network 415 provides connectivity between the GANC 410 and the UE 405 . The GANC 410 entity inter-works between the Iu interfaces and a generic IP access network, using the control plane and user plane functionalities. The control plane functionality is utilized for call control signaling and the user plane functionality is utilized for information transfer (e.g., voice or data). In some embodiments, the GANC has the extended capability to also inter-work with GERAN A/Gb interfaces.

Some embodiments of the above mentioned devices, such as the user equipment, FAP, or GANC, include electronic components, such as microprocessors and memory (not shown), that store computer program instructions for executing wireless protocols for managing voice and data services in a machine-readable or computer-readable medium as further described below in the section labeled “Computer System”. Examples of machine-readable media or computer-readable media include, but are not limited to magnetic media such as hard disks, memory modules, magnetic tape, optical media such as CD-ROMS and holographic devices, magneto-optical media such as optical disks, and hardware devices that are specially configured to store and execute program code, such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), ROM, and RAM devices. Examples of computer programs or computer code include machine code, such as produced by a compiler, and files containing higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter.

III. CONTROL AND USER PLANE ARCHITECTURE

In some embodiments, the Iu interface includes support for both Asynchronous Transfer Mode (ATM) and IP-based signaling and user data transport mechanisms. The following sections describe the control and user plane architectures for the Circuit Switched (CS) domain and Packet Switched (PS) domain of some embodiments.

A. Circuit Switched (CS) Domain

1. CS Domain—Control Plane

FIG. 7 illustrates the GAN architecture in support of the CS Domain control plane in some embodiments. The figure shows different protocol layers for the UE 705 , Generic IP Network 710 , GANC 715 , and MSC 720 . FIG. 7 also shows the two interfaces Up 725 and Iu-cs 730 . The main features of the GAN CS domain control plane architecture are as follows. The underlying Access Layers 735 and Transport IP layer 740 provide the generic IP connectivity between the UE 705 and the GANC 715 . The IPSec layer 745 provides encryption and data integrity between the UE 705 and GANC 715 . The Remote IP layer 750 is the ‘inner’ IP layer for IPSec tunnel mode and is used by the UE 705 to be addressed by the GANC 715 . The Remote IP layer 750 is configured during the IPSec connection establishment.

In some embodiments, a single TCP connection is used to provide reliable transport for both the GA-RC and GA-CSR signaling between the UE 705 and GANC 715 . The TCP connection is managed by GA-RC and is transported using the Remote IP layer. Non-Access Stratum (NAS) protocols, such as MM 760 and above, are carried transparently between the UE 705 and MSC 720 . The Generic Access Resource Control (GA-RC) protocol manages the Up session, including the GAN discovery and registration procedures. The GA-RC protocol (described in clause 8.1.4 of “Generic access to the A/Gb interface; Stage 2”, 3GPP TS 43.318 standard) is extended to include support for the selection of either A/Gb mode or Iu mode GAN.

The Generic Access Circuit Switched Resource (GA-CSR) protocol supports UMTS-specific requirements as well as GERAN-specific requirements. The GANC 715 terminates the GA-CSR protocol and inter-works it to the RANAP 755 protocol over the Iu-cs 730 interface. In some embodiments, the Iu-cs signaling transport layers 765 are per “UTRAN Iu interface signalling transport”, 3GPP TS 25.412 standard, hereinafter “3GPP TS 25.412”.

a) Alternative Architectures for Cs Domain—Control Plane

The embodiment shown in FIG. 7 is just one alternative for implementing the CS domain control plane architecture in which a UE 705 and a Generic IP Network 710 are used to connect a subscriber using the UE to the MSC 720 through the GANC 715 . A person of ordinary skill in the art would realize that the teachings of the invention can be applied for other user equipment and access points (such as the ones described in FIG. 2).

For instance, FIG. 8 illustrates the CS domain control plane architecture of some embodiments. As shown, the GANC and MSC in FIG. 8 are similar to the GANC and MSC shown in FIG. 7. In FIG. 8, the local node in which the subscriber is located is represented as a black box (referred to as Local Node 805 ). Different embodiments utilize different equipments in order to connect a subscriber located in the Local Node 805 with the MSC 720 through the GANC 715 . For instance, in the embodiment shown in FIG. 7, a UE 705 and a Generic IP Network are used 710 . FIG. 9 illustrates another embodiment in which a UE 905 , a Femtocell access point (FAP) 910 , and a Generic IP Network 915 are used to connect the Local Node 805 with the MSC 720 through the GANC 715 .

As shown, the protocol layers of the GANC 880 - 885 are communicatively coupled (shown with arrows 845 - 850 respectively) with their corresponding layers in the Generic IP Network 915 . Similarly, the GANC layers 855 - 875 are communicatively coupled (shown with arrows 820 - 840 respectively) with their corresponding layers in the FAP 910 . Also the MM layer 890 and CC/CS/SMS layers 895 of the MSC 720 are transparently connected (shown with arrows 810 - 815 respectively) to their corresponding layers in the UE 905 . Using this technique, the FAP similar to the FAP 235 shown in FIG. 2 can be utilized to connect a UE (such as UEs 270 - 275 ) to the wireless core network 220 through a network controller 210 . A person of ordinary skill in the art would be able to apply the technique shown in FIGS. 8 and 9 to communicatively couple any user equipment, access points, terminal adaptors, SoftMobiles, etc. (such as the ones shown in FIG. 2) to an integrated communication system (ICS) that uses a multi-layer CS domain control architecture as shown in FIG. 7.

b) CS Domain—Control Plane—UE Architecture

FIG. 10 illustrates the UE architecture for the CS domain control plane. As shown, the architecture includes support for GERAN, UTRAN, and both A/Gb mode GAN and Iu mode GAN. The main features of the UE CS Domain Control Plane architecture shown in FIG. 10 are as follows. The GERAN RR-SAP interface 1015 to the GSM-MM layer 1005 is preserved identically for both GERAN and A/Gb-mode GAN access. Likewise, the UTRAN RR-SAP interface 1020 to the GSM-MM layer 1005 is preserved identically for both UTRAN and Iu-mode GAN access. An access mode switch 1010 is provided to switch between GERAN/UTRAN, A/GB-mode GAN and Iu-mode GAN modes. GA-CSR/GA-RC 1025 peers directly with the UTRAN RRC 1030 and GERAN RRC 1035 layers to provide coordination for roving and handover. As shown in FIG. 10, GA-CSR/GA-RC 1025 , UTRAN RRC 1030 , and GERAN RRC 1035 interface through a set of service access interfaces (SAPs) 1040 .

2. CS Domain—User Plane

FIG. 11 illustrates the GAN protocol architecture in support of the CS domain user plane in some embodiments. The figure shows different protocol layers for the UE 1105 , Generic IP Network 1110 , GANC 1115 , and MSC 1120 . FIG. 11 also shows the two interfaces Up 1125 and Iu-cs 1130 . The main features of the GAN CS domain user plane architecture are as follows. The underlying Access Layers 1135 and Transport IP layer 1140 provide the generic connectivity between the UE 1105 and the GANC 1115 . The IPSec layer 1145 provides encryption and data integrity. The CS user plane data transport over the Up interface 1125 is the same as the CS user plane for A/Gb-mode GAN (i.e., using the Real Time Protocol, RTP, per IETF RFC 3267. The GANC 1115 interworks the CS domain user plane between RTP/UDP and the Iu User Plane (Iu-UP) protocol on the Iu-cs interface 1130 . In some embodiments, the Iu-cs Data transport layers 1165 are per 3GPP TS 25.414 standard.

A person of ordinary skill in the art would realize that other user equipments, access point, terminal adaptor, SoftMobiles, etc. can be connected to the core network through a GANC. For instance, FIG. 12 illustrates the CS domain, user plane protocol architecture of a UE 1205 , a Femtocell access point (FAP) 1210 , and Generic IP Network 1215 . Using the technique described in conjunction with FIGS. 8 and 9, a person of ordinary skill in the art would be able to replace the UE 1105 and Generic IP Network 1110 shown in FIG. 11 with the UE 1205 , FAP 1210 , and Generic IP Network 1215 to connect the Femtocell UE 1205 to the core network through the GANC. Similarly, other types of UE, access points, terminal adaptors, SoftMobiles, etc. can be connected to the core network through the GANC.

b) CS Domain—User Plane—UE Architecture

FIG. 13 illustrates the UE architecture for the CS domain user plane in some embodiments. As shown, the architecture includes support for both A/Gb mode and Iu mode GAN 1305 , as well as GERAN 1310 , and UTRAN 1315 . The RFC 3267 AMR Processing layer 1320 is utilized for connecting the GAN RTP/UDP/IP layers 1325 to the AMR Audio Processing layer 1330 through the CS User Plane Routing Service layer 1335 , which routes CS user plane data to and from the selected access network; i.e., GERAN, UTRAN, or GAN. The RFC 3267 AMR Processing layer 1320 is not used when connecting to the CS Data Processing layer 1340 ; i.e., in the case of circuit switched data, as opposed to circuit switched voice.

B. Packet Switched (PS) Domain

1. PS Domain—Control Plane

FIG. 14 illustrates the GAN architecture in support of the PS Domain Control plane. The figure shows different protocol layers for the UE 1405 , Generic IP Network 1410 , GANC 1415 , SGSN 1420 . FIG. 14 also shows the two interfaces Up 1425 and Iu-ps 1430 . The main features of the GAN PS domain control plane architecture shown in FIG. 14 are as follows. The underlying Access Layers 1435 and Transport IP layer 1440 provide the generic connectivity between the UE 1405 and the GANC 1415 . The IPSec layer 1445 provides encryption and data integrity. TCP 1450 provides reliable transport for the GA-PSR between UE 1405 and GANC 1415 . The GA-RC manages the IP connection, including the GAN registration procedures. The Generic Access Packet Switched Resource (GA-PSR) protocol supports UMTS-specific requirements.

The GANC 1415 terminates the GA-PSR protocol and inter-works it to the RANAP protocol 1455 over the Iu-ps interface 1430 . NAS protocols 1460 , such as for GMM, SM and SMS, are carried transparently between the UE 1405 and SGSN 1420 . In some embodiments, the Iu-ps signaling transport layers 1465 are per 3GPP TS 25.412.

A person of ordinary skill in the art would realize that other user equipments, access point, terminal adaptor, SoftMobiles, etc. can be connected to the core network through a GANC. For instance, FIG. 15 illustrates the PS domain, control plane protocol architecture of a UE 1505 , a Femtocell access point (FAP) 1510 , and Generic IP Network 1515 . Using the technique described in conjunction with FIGS. 8 and 9, a person of ordinary skill in the art would be able to replace the UE 1405 and Generic IP Network 1410 shown in FIG. 11 with the UE 1505 , FAP 1510 , and Generic IP Network 1515 to connect the Femtocell UE 1505 to the core network through the GANC. Similarly, other types of UE, access points, terminal adaptors, SoftMobiles, etc. can be connected to the core network through the GANC.

c) PS Domain—Control Plane—UE Architecture

FIG. 16 illustrates the UE architecture for the PS domain control plane in some embodiments. As shown, the architecture includes support for both A/Gb mode and Iu mode GAN, as well as GERAN and UTRAN. The main features of the UE PS Domain Control Plane architecture shown in FIG. 16 are as follows. The GERAN GRR-SAP interface 1615 and GERAN GMMRR-SAP interface 1617 to the GMM layer 1605 is preserved identically for both GERAN and A/Gb-mode GAN access. Likewise, the UTRAN RABMAS-SAP interface 1620 and UTRAN GMMAS-SAP interface 1622 to the GMM layer 1605 is preserved identically for both UTRAN and Iu-mode GAN access. An access mode switch 1610 is provided to switch between GERAN/UTRAN, A/GB-mode GAN and Iu-mode GAN modes. GA-PSR/GA-RC 1625 peers directly with the UTRAN RRC 1630 and GERAN RRC 1635 layers to provide coordination for roving and handover. As shown in FIG. 16, GA-PSR/GA-RC 1625 , UTRAN RRC 1630 , and GERAN RRC 1635 interface through a set of service access interfaces (SAPs) 1640 .

2. PS Domain—User Plane

FIG. 17 illustrates the GAN architecture for the PS Domain User Plane in some embodiments. The figure shows different protocol layers for the UE 1705 , Generic IP Network 1710 , GANC 1715 , SGSN 1720 . FIG. 17 also shows the two interfaces Up 1725 and Iu-ps 1730 . The main features of the GAN PS domain user plane architecture shown in FIG. 17 are as follows. The underlying Access Layers 1735 and Transport IP layer 1740 provide the generic connectivity between the UE 1705 and the GANC 1715 . The IPSec layer 1745 provides encryption and data integrity.

GA-PSR is extended to include support for the GTP-U G-PDU message format to transport PS User Data (e.g., IP packets), rather than LLC PDUs as in A/Gb mode GAN. As shown in FIG. 17, user data in GTP-U G-PDU messages may be carried transparently between the UE 1705 and core network through the SGSN to the GGSN. In some embodiments, the Iu-ps data transport lower layers 1765 are per 3GPP TS 25.414 standard.

FIG. 18 illustrates an alternative GAN PS domain user plane configuration which is supported by the Up interface procedures of some embodiments. In this configuration, the GANC 1815 terminates the Up interface GTP-U tunnel with the UE 1805 and also terminates the separate Iu-ps GTP-U tunnel to the SGSN 1820 . The GANC 1815 relays the PS user data between the Up interface GTP-U tunnel and the associated Iu-ps interface GTP-U tunnel to allow the PS user data to flow between the UE and the SGSN.

This configuration minimizes the number of active GTP-U “paths” presented to the core network; i.e., the SGSN may be limited in the number of RNCs with which it can concurrently exchange PS user data (e.g., today, there can be no more than 4096 RNCs in a given PLMN). It may not be able to support-without a software upgrade, for example—concurrent communication with hundreds of thousands of UEs as would be required if the GTP-U tunnels were from UE to SGSN. Terminating the Iu-ps GTP-U tunnels on the GANC avoids this potential SGSN limitation. In some embodiments, the Iu-ps data transport lower layers 1865 are per 3GPP TS 25.414 standard.

A person of ordinary skill in the art would realize that other user equipments, access point, terminal adaptor, SoftMobiles, etc. can be connected to the core network through a GANC. For instance, FIG. 19 illustrates the PS domain, user plane protocol architecture of a UE 1905 , a Femtocell access point (FAP) 1910 , and Generic IP Network 1915 . Using the technique described in conjunction with FIGS. 8 and 9, a person of ordinary skill in the art would be able to replace the UE 1805 and Generic IP Network 1810 shown in FIG. 11 with the UE 1905 , FAP 1910 , and Generic IP Network 1915 to connect the Femtocell UE 1905 to the core network through the GANC. Similarly, other types of UE, access points, terminal adaptors, SoftMobiles, etc. can be connected to the core network through the GANC.

a) PS Domain—User Plane—UE Architecture

FIG. 20 illustrates the UE architecture for the PS domain user plane in some embodiments. As shown, the architecture includes support for both A/Gb mode and Iu mode GAN 2005 , as well as GERAN 2010 , and UTRAN 2015 . An access mode switch 2020 is provided to switch between GERAN/UTRAN, A/GB-mode GAN and Iu-mode GAN modes.

C. GA-RC (Generic Access Resource Control)

The GA-RC protocol provides a resource management layer, with the following functions. Discovery and registration with GANC, registration update with GANC, application level keep-alive with GANC; and support for identification of the AP being used for GAN access.

1. States of the GA-RC Sub-Layer

FIG. 21 illustrates the state diagram for generic access in the UE in some embodiments. As shown, the GA-RC sub-layer in the UE can be in one of two states: GA-RC-DEREGISTERED 2105 or GA-RC-REGISTERED 2110 . The following outcomes are possible when switching (shown by arrow 2112 ) the serving RR to Iu-mode GAN: (1) Transition to GA-CSR-IDLE 2115 and GA-PSR-IDLE 2120 (i.e., if the UE is idle during the transition), (2) Transition to GA-CSR-CONNECTED 2125 and GA-PSR-IDLE 2130 (i.e., due to CS handover or relocation), (3) Transition to GA-CSR-IDLE 2115 and GA-PSR-CONNECTED 2130 (i.e., due to PS handover or relocation), (4) Transition to GA-CSR-CONNECTED 2125 and GA-PSR-CONNECTED 2130 (i.e., due to dual transfer mode handover or CS+PS relocation). The switch of the serving RR from GAN to GERAN/UTRAN RRC (shown by arrow 2135 ) may occur when the UE is in any combination of the GA-CSR and GA-PSR states.

In the GA-RC-DEREGISTERED state 2105 , the UE may be in a GAN coverage area; however, the UE has not registered successfully with the GANC. The UE may initiate the GAN Registration procedure when in the GA-RC-DEREGISTERED state 2105 . The UE returns to GA-RC-DEREGISTERED state 2105 on loss of TCP or IPSec connection or on execution of the GAN De-registration procedure.

In the GA-RC-REGISTERED state 2110 , the UE is registered with the Serving GANC. The UE has an IPSec tunnel and a TCP connection established to the Serving GANC through which the UE may exchange GA-RC, GA-CSR, and GA-PSR signaling messages with the GANC.

While the UE remains in the GA-RC-REGISTERED state 2110 it performs application level keep-alive with the GANC. In the GA-RC-REGISTERED state 2110 , the UE may be in either UTRAN/GERAN mode or GAN mode. The UE may either (1) be camped on GERAN or UTRAN and idle, (2) be active in GERAN or UTRAN (e.g., a GSM RR or a UTRAN RRC connection may be established), (3) have “roved in” to GAN mode, or (4) have recently “roved out” of GAN mode (e.g., due to handover from GAN).

D. GA-CSR (Generic Access Circuit Switched Resources)

The GA-CSR protocol provides a circuit switched services resource management layer which supports the following functions: (1) setup of transport channels for CS traffic between the UE and GANC, (2) CS handover support between UTRAN/GERAN and GAN, (3) direct transfer of NAS messages between the UE and the core network, and (4) other functions such as CS paging and security configuration.

1. States of the GA-CSR Sub-Layer

The GA-CSR sub-layer in the UE can be in two states, GA-CSR-IDLE or GA-CSR-CONNECTED as illustrated in FIG. 21. The UE enters the GA-CSR-IDLE state 2115 when the UE switches the serving RR entity to GAN. This switch may occur only when the GA-RC is in the GA-RC-REGISTERED state 2110 .

The UE moves from the GA-CSR-IDLE state 2115 to the GA-CSR-CONNECTED state 2125 when the GA-CSR connection is established and returns to GA-CSR-IDLE state 2115 when the GA-CSR connection is released. Upon GA-CSR connection release, an indication that no dedicated CS resources exist is passed to the upper layers. The UE may also enter the GA-CSR-CONNECTED state 2125 while in the GA-RC-REGISTERED state 2110 in GERAN/UTRAN mode when Handover to GAN is being performed. In the same way, the UE enters the GA-RC-REGISTERED state 2110 in GERAN/UTRAN mode from the GA-CSR-CONNECTED state 2125 when Handover from GAN is successfully executed.

E. GA-PSR (Generic Access Packet Switched Resources)

The GA-PSR protocol provides a packet switched services resource management layer which supports the following functions: (1) setup of transport channels for PS traffic between the UE and network, (2) PS relocation/handover support between UTRAN/GERAN and GAN, (3) direct transfer of NAS messages between the UE and the PS core network, (4) transfer of GPRS user plane data, and (5) other functions such as PS paging and security configuration.

1. States of the GA-PSR Sub-Layer

The GA-PSR sub-layer in the UE can be in two states, GA-PSR-IDLE or GA-PSR-CONNECTED as illustrated in FIG. 21. The UE enters the GA-PSR-IDLE state 2120 when the UE switches the serving RR entity to GAN. This switch may occur only when the GA-RC is in the GA-RC-REGISTERED state 2110 . The UE moves from the GA-PSR-IDLE state 2120 to the GA-PSR-CONNECTED state 2130 when the GA-PSR connection is established and returns to GA-PSR-IDLE state 2120 when the GA-PSR connection is released. Upon GA-PSR connection release, an indication that no dedicated resources exist is passed to the upper layers.

The UE may also enter the GA-PSR-CONNECTED state 2130 while in the GA-RC-REGISTERED state 2110 in GERAN/UTRAN mode when Handover to GAN is being performed. In the same way, the UE enters the GA-RC-REGISTERED state 2110 in GERAN/UTRAN mode from the GA-PSR-CONNECTED state 2130 when Handover from GAN is successfully executed. The GA-PSR Packet Transport Channel (GA-PSR PTC) provides the association between the UE and GANC for the transport of GPRS user data over the Up interface. It is described in PS NAS Signaling Procedures in sub-section V.P, below.

IV. GAN SECURITY MECHANISMS

GAN supports security mechanisms at different levels and interfaces as depicted in FIG. 22. The security mechanisms 2205 over the Up interface protect control plane and user plane traffic flows between the UE 2210 and the GANC 2215 from unauthorized use, data manipulation and eavesdropping; i.e., authentication, encryption and data integrity mechanisms are supported.

Network access security 2220 includes the mechanisms defined in “3G Security; Security Architecture”, 3GPP TS 33.102 standard. Mutual authentication of the subscriber and the core network (CN) 2225 occurs between the MSC/VLR or SGSN and the UE and is transparent to the GANC. However, there is a cryptographic binding between the UE-CN authentication and the UE-GANC authentication to prevent man-in-the-middle attacks.

Additional application level security mechanisms 2230 may be employed in the PS domain to secure the end-to-end communication between the UE 2210 and the application server 2235 . For example, in some embodiments the UE 2210 may run the HTTP protocol over an SSL session for secure web access.

All control plane and user plane traffic sent between the UE 2210 and the GANC 2215 over the Up interface is protected by an IPSec tunnel between the UE 2210 and GANC-SEGW, that provides mutual authentication (using USIM credentials), encryption and data integrity using the same mechanisms as specified in “3G security; Wireless Local Area Network (WLAN) interworking security”, 3GPP TS 33.234.

As described above (in relation to FIGS. 9, 12, 15 , and 19 ), some embodiments utilize a Femtocell access point (FAP) to communicatively couple a user equipment UE to the GANC via a Generic IP Network. As shown in FIG. 9, the FAP architecture for the CS control plane has an IPSec layer 920 . Similarly the FAP architectures for the CS user plane, PS control plane, and PS user plane architectures also include IPSec (or IPSec ESP) layers ( 1220 , 1520 , and 1920 respectively). As shown in FIGS. 9, 12, 15 , and 19 , these IPSec layers are over the transport IP layer and Remote IP layers of the GANC and are communicatively coupled to their corresponding GANC IPSec layers, thereby providing a secured link between the GANC and the FAP.

V. HIGH-LEVEL PROCEDURES

A. Mode Selection in Multi-Mode Terminals

A Generic Access capable UE can support any IP access technology in addition to the UTRAN and possibly GERAN radio interfaces. The UE can be either in the GERAN/UTRAN mode or in GAN mode of operation. The UE can be configured to operate in one of the two modes (i.e., GERAN/UTRAN or GAN) at any given time. There may be a preferred mode of operation that can be configured by the subscriber or by the service provider through various mechanisms, e.g. device management.

On power up, the UE always starts in GERAN/UTRAN mode and executes the normal power-up sequence. The UE in some embodiments executes the power-up sequence as specified in “Non-Access-Stratum functions related to Mobile Station (MS) in idle mode”, 3GPP TS 23.122 standard. Following this, the UE may switch into GAN mode based on mode selection preference determined by user preferences or operator configuration.

The various preferences for the UE that are possible are as follows: GERAN/UTRAN-only, GERAN/UTRAN-preferred, GAN-preferred, and GAN-only. In GERAN/UTRAN-only, the UE RR entity remains in GERAN/UTRAN mode and does not switch to GAN mode. In GERAN/UTRAN-preferred, the UE RR entity is in GERAN/UTRAN mode as long as there is a PLMN available and not forbidden through GERAN/UTRAN. If no allowable PLMN is available through GERAN/UTRAN, and UE has successfully registered with a GAN over the generic IP access network, then the UE switches to GAN mode. When a PLMN becomes available over GERAN/UTRAN and the PLMN is not forbidden, or the UE has de-registered or lost connectivity with the GAN over the generic IP access network, the UE returns to GERAN/UTRAN mode.

In GAN-preferred, when the UE has successfully registered with the GAN over the generic IP access network, the UE switches to GAN mode and stays in this mode as long as the GAN is available. When the UE deregisters, or otherwise loses connectivity with the GAN over the generic IP access network, the UE switches to GERAN/UTRAN mode.

In GAN-only, the UE switches to GAN mode (after initial power up sequence in GERAN/UTRAN mode to obtain cellular network information, but excluding MM and GMM procedures with GERAN/UTRAN core network) and does not switch to GERAN/UTRAN mode. During the initial power up sequence in GERAN/UTRAN mode the UE shall ignore all paging messages received through the GERAN/UTRAN network.

B. PLMN Selection

In some embodiments, there are no changes from the PLMN selection procedures in the NAS layers (MM and above) in the UE, with the exception that in GAN mode the “in VPLMN background scan” is disabled. A GANC can only be connected to one PLMN. The PLMN selection in the NAS layers does not lead to a change of mode between GERAN/UTRAN mode and GAN mode. For a specific instance of PLMN selection, only PLMNs available via GAN or only PLMNs available via GERAN/UTRAN are provided to the NAS layer (i.e., no combination of the PLMNs available via GERAN/UTRAN and GAN).

In the case of a GAN capable UE, some embodiments require a GANC selection process as part of the process of establishing the connectivity between the UE and the GANC. This takes place when, during GAN registration, a GAN capable UE may have a choice among two or more GANC-PLMN pairs indicated by the Default GANC (i.e., in the GA-RC REGISTER REDIRECT message). The GANC selection process takes place while the UE is still in GERAN/UTRAN mode, and before the UE roves into GAN mode. If the current selected PLMN is available via GAN, it shall be selected. If not, the selection of GANC is implementation specific.

If the UE does not have any stored information related to the Serving GANC for the cell or AP to which the UE is currently connected, the UE attempts to register with the Default GANC (always located in the HPLMN) stored in UE. The UE includes an indication, identifying the GANC as the Default GANC in the GA-RC REGISTER REQUEST message.

When a UE attempts to register on the Default GANC including an indication that it is in automatic PLMN selection mode one of the followings happens. If the Default GANC decides to serve the UE, the Default GANC responds with a GA-RC REGISTER ACCEPT message. When the Default GANC decides to redirect the UE to another GANC within the HPLMN, the Default GANC responds with a GA-RC REGISTER REDIRECT message, not including a list of PLMN identities.

When the Default GANC decides to redirect the UE to a PLMN that is not the HPLMN, the Default GANC responds with a GA-RC REGISTER REDIRECT message and includes a list of PLMNs that may provide GAN service to the UE in its current location. The list contains one or more PLMN identities along with the identities of their associated GANC and SEGW nodes (either in IP address or FQDN format). Following the GANC selection process, the GA-RC entity in the UE attempts to register on the associated GANC.

If at any time the user wishes to perform manual PLMN selection or a “User reselection” irrespective of whether the UE is in manual or automatic PLMN selection mode, the UE sends a GA-RC REGISTER REQUEST message to the Default GANC, including an indication that it is in manual PLMN selection mode. The Default GANC is not allowed to accept the registration and responds with a GA-RC REGISTER REDIRECT message and includes a list of PLMNs that may provide GAN service to the UE in its current location.

When the UE includes the identity of the current serving GSM network in the GA-RC REGISTER REQUEST message, the Default GANC uses this to identify the list of PLMNs to send to the UE in the response message.

After successful registration with a serving GANC, the UE does not store the PLMN list. The UE does not use the PLMN list, provided to the UE during the registration procedure, for background scanning. A UE cannot use GA in a VPLMN unless the HPLMN supports and authorizes GA.

C. Re-selection between GERAN/UTRAN and GAN Modes

1. Rove-In (from GERAN/UTRAN Mode to GAN Mode)

This procedure is applicable only when GAN service is available, a UE is not in NC2 mode (applicable if the UE is in GERAN mode and as defined in “Radio subsystem link control”, 3GPP TS 45.008 standard) and has a UE preference for GAN-only, GAN-preferred or, if no allowable PLMN is available through GERAN/UTRAN, for GERAN/UTRAN-preferred.

Following successful GAN registration, the access mode in the UE is switched to GAN mode. The GA-CSR entity in the UE provides the NAS-related system information received in the GAN Registration Procedure to the NAS layers. The NAS considers the GANC-allocated cell identity as the current serving cell.

While in GAN mode, GERAN-RR and UTRAN RRC entities are detached from the RR-SAP in the UE. As a result the entities do not: (1) inform NAS about any GERAN/UTRAN cell re-selection and/or the change of system information of the current camping cell, (2) inform NAS about any newly found PLMN over GERAN or UTRAN, and (3) act on any paging request message received over GERAN or UTRAN.

2. Rove-Out (from GAN Mode to GERAN/UTRAN Mode)

This procedure is applicable when the UE detaches from the generic IP access network, and its mode selection is GAN-preferred or GERAN/UTRAN-preferred. When the UE detaches from the generic IP access network, depending on prevailing circumstances the UE may be able to deregister first with the GANC.

For the GAN-preferred and GERAN/UTRAN-preferred mode selections, the UE detaches the GA-CSR entity from the RR-SAP and re-attaches the GERAN-RR or UTRAN RRC entity to the RR-SAP and restores normal GERAN-RR or UTRAN RRC functionality. For the GAN-only mode selection, GA-CSR remains attached to the NAS and the UE stays in GAN mode (i.e., in “No Service” condition).

D. GAN Registration Related Procedures

1. Discovery and Registration for Generic Access

The Discovery and Registration procedures are applicable only if the UE preference is operating in GAN-only, GAN-preferred or, if no allowable PLMN is available through GERAN/UTRAN, in GERAN/UTRAN-preferred mode.

Once the UE has established a connection to the generic IP access network, the UE determines the appropriate GANC-SEGW to connect to, by completing the Discovery Procedure to the Provisioning GANC in the HPLMN of the UE. The Provisioning GANC provides the address of the Default GANC in the HPLMN of the UE, to which the UE can register.

The UE attempts to register on the Default GANC provided by the Provisioning GANC during the Discovery procedure, by completing the Registration Procedure. The Default GANC may accept the Registration; redirect the UE to another GANC; or reject the Registration.

a) Security Gateway Identification

The USIM of the UE contains the FQDN (or IP address) of the Provisioning GANC and the associated SEGW or the UE derives this information based on information in the USIM. When the UE does not have any information about other GANCs and associated SEGW stored, then the UE completes the Discovery procedure towards the Provisioning GANC. As part of the Registration Procedure, the Default GANC can indicate whether this GANC and SEGW address or the address of a GANC that the UE is being redirected to, may be stored by the UE.

The UE can also store Serving GANC information for Serving GANCs with which the UE was able to complete a successful registration procedure. The default GANC is in control of whether the UE is allowed to store Serving GANC information. When there is no GERAN/UTRAN coverage in the AP location, the stored Serving GANC information is associated with the AP-ID. When there is GERAN/UTRAN coverage in the AP location, the stored Serving GANC information is associated with the GSM CGI or LAI or UTRAN CI. The stored Serving GANC information is: (1) serving SEGW FQDN or IP address following successful registration, (2) serving GANC FQDN or IP address following successful registration, and (3) optionally, Serving GANC TCP port following successful registration and if returned from the network. Different embodiments store different number of such entries in the UE is implementation specific. Only the last successfully registered GANC association is stored when the Default GANC indicates that the UE is allowed to store these addresses. A UE may preferentially join a generic IP access network point of attachment whose association with a Serving GANC has been stored in memory.

On connecting to the generic IP access network, when the UE has a stored Serving GANC for the AP-ID or the GERAN/UTRAN cell, the UE attempts to register with the associated Serving GANC in its memory. The GANC may still reject the UE for any reason even though it may have served the UE before. The UE deletes from its stored list the address of the Serving GANC on receiving a registration reject or if the registration fails for any other reason (e.g., not receiving any response).

If the UE does not receive a response to the Registration Request sent to the Serving GANC (and which is not the Default GANC), the UE re-attempt to register with the Default GANC. If the UE does not receive a response to the registration request sent to the Default GANC, it attempts the discovery procedure with the Provisioning GANC to obtain a new Default GANC.

In the case when a UE is attempting to register or discover a GANC after failing to register on a GANC, the UE provides in the Registration or Discovery procedure an indication that the UE has attempted to register on another GANC, the failure reason, and the GANC and SEGW addresses of the failed registration. When the UE connects to a generic IP access network, for which the UE does not have a stored Serving GANC in it's memory, the UE attempt to register with the Default GANC.

b) GANC Capabilities

GANC specific information is transferred to the UE on successful registration.

c) UE Capabilities

GAN specific capabilities of the UE are transferred to the GANC during registration.

d) Required GAN Services

The UE may request which GAN services it requires from the GANC as part of the Registration procedures.

e) GAN Mode Selection

The UE (i.e., with Iu-mode GAN support) transfers its GAN Mode Support information to the GANC during Discovery and Registration procedures; i.e., in the GAN Classmark IE. GAN Mode Support options are A/Gb mode supported, Iu mode supported, or both modes supported. When no GAN Mode Support information is received, the GANC assumes that the UE supports A/Gb mode operation only.

The provisioning GANC may use the received GAN Mode Support information to assign the UE to an appropriate default GANC (e.g., if separate A/Gb mode and Iu-mode GANCs are deployed in the network) or to an appropriate TCP port on the default GANC (e.g., if separate TCP ports are used for A/Gb mode and Iu-mode GAN service). The Iu-mode capable GANC also indicates the GAN mode to use for the current session in the GAN Mode Indicator IE; this allows the UE to determine the Iu-mode capability of the Home PLMN.

Table 1 enumerates the discovery handling for the various combinations of UE and Home PLMN GAN mode capabilities.

TABLE 1


GAN Mode Selection procedures associated with GAN Discovery
UE GAN Mode	Home PLMN GAN Mode Capabilities
Capabilities	A/Gb only	Iu only	Both

A/Gb only	GANC: Handle as	GANC: No GAN	GANC: No GAN
	normal A/Gb mode	Mode Support	Mode Support
	discovery	information provided	information provided
	UE: Proceed with	or A/Gb mode (only)	or A/Gb mode (only)
	A/Gb mode	indicated by UE,	indicated by UE,
	registration	therefore Reject	therefore handle as
		(Unspecified)	normal A/Gb mode
		UE: Retry on next	discovery. Assign UE
		power-on	to A/Gb-capable
			GANC.
			UE: Proceed with
			A/Gb mode
			registration
Iu only	GANC: Handle as	GANC: Iu Mode	GANC: Iu Mode
	normal A/Gb mode	Support (only)	Support (only)
	discovery	indicated by UE,	indicated by UE,
	UE: No GAN Mode	therefore accept and	therefore accept and
	Selection provided by	send GAN Mode	send GAN Mode
	GANC, therefore abort	Indicator = Iu	Indicator = Iu. Assign
	GAN operation and	UE: Proceed with Iu	UE to Iu-capable
	retry on next power-on	mode registration	GANC.
			UE: Proceed with Iu
			mode registration
Both	GANC: Handle as	GANC: Support for	GANC: Support for
	normal A/Gb	both modes indicated	both modes indicated
	discovery	by UE, therefore	by UE, therefore
	UE: No GAN Mode	accept and send GAN	accept and send GAN
	Selection provided by	Mode Indicator = Iu	Mode Indicator = Iu.
	GANC, therefore	UE: Proceed with Iu	Assign UE to Iu-
	proceed with Iu mode	mode registration	capable GANC.
	registration (Note 1)		UE: Proceed with Iu
			mode registration

Note:
As described in Table 2 below, the result of Iu mode registration of a A/Gb-capable UE on a A/Gb-capable GANC is that the UE is placed in A/Gb mode.

In some embodiments, the default or serving GANC uses the received GAN Mode Support information to redirect the UE to a different GANC or a different TCP port on the current GANC. The Iu-mode capable GANC also indicates the GAN mode to use for the current session in the GAN Mode Indicator IE.

Table 2 enumerates the registration handling for the various combinations of UE and Home PLMN GAN mode capabilities.

TABLE 2


GAN Mode Selection procedures associated with GAN Registration
UE GAN Mode	Default/Serving GANC GAN Mode Capabilities
Capabilities	A/Gb only	Iu only	Both

A/Gb only	GANC: Handle as	GANC: No GAN	GANC: No GAN
	normal A/Gb mode	Mode Support	Mode Support
	registration	information provided	information provided
	UE: Proceed per A/Gb	or A/Gb mode (only)	or A/Gb mode (only)
	mode GAN procedures	indicated by UE,	indicated by UE,
		therefore Reject	therefore handle as
		(Invalid GANC)	normal A/Gb mode
		UE: Attempt	registration. If
		registration with	required, redirect UE
		Default GANC or re-	to A/Gb-capable
		discovery (per A/Gb	GANC.
		mode GAN	UE: Proceed per A/Gb
		procedures)	mode GAN procedures
Iu only	GANC: Handle as	GANC: Iu Mode	GANC: Iu Mode
	normal A/Gb mode	Support (only)	Support (only)
	registration	indicated by UE,	indicated by UE,
	UE: No GAN Mode	therefore accept and	therefore accept and
	Selection provided by	send GAN Mode	send GAN Mode
	GANC, therefore	Indicator = Iu	Indicator = Iu.
	Deregister and treat as	UE: Proceed per Iu	UE: Proceed per Iu
	register reject (Invalid	mode GAN procedures	mode GAN procedures
	GANC)
Both	GANC: Handle as	GANC: Support for	GANC: Support for
	normal A/Gb	both modes indicated	both modes indicated
	registration	by UE, therefore	by UE, therefore
	UE: No GAN Mode	accept and send GAN	accept and send GAN
	Selection provided by	Mode Indicator = Iu	Mode Indicator = Iu or
	GANC, therefore	UE: Proceed per Iu	A/Gb (see Note 1
	proceed per A/Gb	mode GAN procedures	below). If required,
	mode GAN procedures		redirect UE to Iu or
			A/Gb-capable GANC.
			UE: Proceed per Iu or
			A/Gb mode GAN
			procedures

Note 1:
The GANC's choice of Iu-mode versus A/Gb-mode may be based on other information received in the GAN registration message from the UE, information stored in the GANC, and on operator (i.e., service provider) policy; e.g., if the GSM RR/UTRAN RRC State IE indicates that the UE is in GERAN Dedicated mode, the UE location is an area without UTRAN coverage and the operator wants to minimize inter-RAT handovers, the GANC may direct the UE to use A/Gb mode.

f) Discovery Procedure

When a UE supporting GAN first attempts to connect to a GAN, the UE needs to identify the Default GANC. Each GAN capable UE can be configured with the FQDN (or IP address) of the Provisioning GANC and the associated SEGW or the UE can derive this FQDN based on information in the USIM (see “Numbering, addressing and identification”, 3GPP TS 23.003 standard). The UE first connects to a Provisioning GANC-SEGW and GANC in the HPLMN of the UE, by establishing a secure IPSec tunnel and a TCP connection using the provisioned or derived addresses. The UE obtains the FQDN or IP address of the Default GANC in the HPLMN and the associated SEGW, through the Discovery procedure.

If no GERAN/UTRAN coverage is available when a UE connects to the GANC for GAN service, then the GANC cannot necessarily determine the location of the UE for the purposes of assigning the UE to the correct serving GANC (e.g., to enable handover and location-based services). The GANC permits the operator to determine the service policy in this case; e.g., the operator could provide service to the user with certain limitations (possibly with a user interface indication on the UE). When the UE initiates the Discovery/Registration procedures and no GERAN/UTRAN coverage is available, the GANC may have insufficient information to correctly route subsequent emergency calls.

FIG. 23 illustrates the Discovery procedure in some embodiments. The figure shows different messages exchanges between the UE 2305 , DNS 2310 , the provisioning GANC 2315 , the security gateway SEGW 2320 associated with the provisioning GANC 2315 , and the DNS server 2325 associated with the provisioning GANC 2315 . In the description below it is assumed that the UE 2305 has a mode selection of GAN-only or GAN-preferred or GERAN/UTRAN-preferred and that the UE has already connected to the generic IP access network. Different embodiments deem different signal levels as sufficient for triggering the GAN Discovery and Registration procedures. The following steps are taken during Discovery procedure in some embodiments.

As shown in FIG. 23, when the UE 2305 has a provisioned or derived FQDN of the Provisioning SEGW, the UE performs (in Step 1 ) a DNS query (via the generic IP access network interface) to resolve the FQDN to an IP address. When the UE has a provisioned IP address for the Provisioning SEGW, the DNS step is omitted. Next, the DNS Server 2310 returns (in Step 2 ) a response including the IP Address of the Provisioning SEGW 2320 .

As shown, the UE 2305 establishes (in Step 3 ) a secure tunnel to the Provisioning SEGW 2320 . When the UE 2305 has a provisioned or derived FQDN of the Provisioning GANC 2315 , the UE 2305 performs (in Step 4 ) a DNS query (via the secure tunnel) to the DNS server 2325 associated with the provisioning GANC 2315 to resolve the FQDN to an IP address. When the UE 2305 has a provisioned IP address for the Provisioning GANC, the DNS step will be omitted. The DNS Server 2325 returns (in Step 5 ) a response including the IP Address of the Provisioning GANC 2315 .

The UE 2305 sets up a TCP connection to a well-defined port on the Provisioning GANC 2315 . It then queries (in Step 6 ) the Provisioning GANC 2315 for the Default GANC, using GA-RC DISCOVERY REQUEST. The message contains: (1) Cell Info: Either current camping UTRAN/GERAN cell ID or the last LAI where the UE successfully registered, along with an indicator stating which one it is, (2) Generic IP access network attachment point information: AP-ID, as defined in Identifiers in GAN, sub-section VII, below, (3) UE Identity: IMSI, and (4) GAN Classmark: Including indications of A/Gb Mode supported and Iu Mode supported.

Next, the Provisioning GANC 2315 returns (in Step 7 ) the GA-RC DISCOVERY ACCEPT message, using the information provided by the UE (e.g. the cell ID), to provide the FQDN or IP address of the Default GANC and its associated Default SEGW. This is done so the UE is directed to a “local” Default GANC in the HPLMN to optimize network performance. The GANC Port that the UE must use for registration may be included. The GAN Mode Indicator may be included as described in GAN Mode Section, sub-section above.

When the Provisioning GANC 2315 cannot accept the GA-RC DISCOVERY REQUEST message, it returns (in Step 8 ) a GA-RC DISCOVERY REJECT message indicating the reject cause. The secure IPSec tunnel to the Provisioning SEGW 2320 is released (in Step 9 ). It is possible to reuse the same IPSec tunnel for GAN Registration procedures. In this case the IPSec tunnel is not released.

g) Registration Procedure—Normal Case

Following the Discovery procedure the UE establishes a secure tunnel with the security gateway of the Default GANC, provided by the Provisioning GANC in the Discovery procedure, and attempts to register with the Default GANC. The Default GANC may become the Serving GANC for that connection by accepting the registration, or the Default GANC may redirect a UE performing registration to a different Serving GANC.

GANC redirection may be based on information provided by the UE during the Registration procedure, operator chosen policy or network load balancing. The GAN Registration procedure serves the following functions: (1) Ensures the UE is registered to the appropriate GANC entity; i.e., with use of the redirection process, (2) Informs the GANC that the UE is now connected through a generic IP access network and is available at a particular IP address. The GANC maintains the registration context for the purposes of (for example) mobile-terminated calling, (3) Provides the UE with the operating parameters associated with the GAN service. The “System Information” message content that is applicable to the GAN cell is delivered to the UE during the GAN registration process. This enables the UE to switch to GAN mode, and following the Registration procedure trigger NAS procedures with the core network (such as Location/Routing Area Update, mobile originated calls, mobile terminated calls, etc.), and (4) Enables the UE to request which GAN services are required.

FIG. 24 illustrates Registration procedure in some embodiments. The figure shows different messages exchanges between the UE 2405 , DNS 2410 , the provisioning GANC 2415 , the security gateway SEGW 2420 associated with the provisioning GANC 2415 , and the DNS server 2425 associated with the provisioning GANC 2415 . The following steps are done during Registration procedure.

As shown in FIG. 24, when the UE 2405 was provided the FQDN of the Default or Serving SEGW, the UE performs (in Step 1 ) a DNS query (via the generic IP access network interface) to resolve the FQDN to an IP address. When the UE has a provisioned IP address for the SEGW, the DNS step is omitted. The DNS Server 2410 returns (in Step 2 ) a response.

As shown, the UE 2405 sets up (in Step 3 ) a secure IPSec tunnel to the SEGW 2420 . This step may be omitted if an IPSec tunnel is being reused from an earlier Discovery or Registration. When the UE 2405 was provided the FQDN of the Default or Serving GANC, the UE then performs (in Step 4 ) a DNS query (via the secure tunnel) to resolve the FQDN to an IP address. When the UE has an IP address for the GANC, the DNS step is omitted. Next, the DNS Server 2425 returns (in Step 5 ) a response.

The UE 2405 then sets up a TCP connection to a TCP port on the GANC. The TCP port can either be a well-known port or one that has been earlier received from the network during Discovery or Registration. The UE 2405 attempts (in Step 6 ) to register on the GANC by transmitting the GA-RC REGISTER REQUEST. The message includes: (1) Cell Info: Either current camping UTRAN/GERAN cell ID, or last LAI where the UE successfully registered, along with an indicator stating which one it is, (2) Generic IP access network attachment point information: AP-ID, as defined in Identifier in GAN, Section VII, below, (3) UE Identity: IMSI, (4) UE Capability Information, (5) GAN Services Required, (6) GAN Classmark: Including indications of A/Gb Mode supported, Iu Mode supported.

When the GANC 2415 accepts the registration attempt, the GANC 2415 responds (in Step 7 ) with a GA-RC REGISTER ACCEPT. In this case the TCP connection and the secure IPSec tunnel are not released and are maintained as long as the UE is registered to this GANC.

The GA-RC REGISTER ACCEPT message includes (1) GAN Capability Information and (2) GAN specific system information which includes (a) GAN Mode Indicator: A/Gb Mode GAN or Iu Mode GAN, (b) Cell description of the GAN cell, (c) Location-area identification comprising the mobile country code, mobile network code, and location area code corresponding to the GAN cell, (d) Cell identity identifying the cell within the location area corresponding to the GAN cell, and (e) Applicable system timer values (e.g., for the application-level keep alive message transmission interval, see Keep Alive sub-section, below)

Alternatively, the GANC 2415 may reject the request. In this case, the GANC 2415 responds (in Step 8 ) with a GA-RC REGISTER REJECT indicating the reject cause. The TCP connection and the secure IPSec tunnel are then released.

Alternatively, if the GANC 2415 decides to redirect the UE to (another) Serving GANC, the GANC 2415 responds (in Step 9 ) with a GA-RC REGISTER REDIRECT providing the FQDN or IP address of the target Serving GANC and the associated SEGW, and the GAN Mode Indicator if the GANC requires that a particular mode be used with the Serving GANC (e.g., if the GANC knows that the Serving GANC supports only A/Gb mode GAN). In this case the TCP connection is released and the secure IPSec tunnel is optionally released (in Step 10 ) depending on if the network indicates that the same IPSec tunnel can be reused for the next registration. The GA-RC REGISTER REDIRECT message may contain: (1) a single Serving SEGW and GANC address or (2) a list of PLMN identities and associated Serving SEGW and GANC addresses. The message also may contain an Indication of whether GANC address(es) can be stored in the UE for future use.

a) Registration Procedure—Abnormal Cases

When the Serving GANC rejects the Register request and does not provide redirection to another Serving GANC, the UE re-attempts Registration to the Default GANC including a cause that indicates the failed registration attempt and the Serving GANC and SEGW with which the Register request failed. The UE also deletes all stored information about this Serving GANC.

When the Default GANC rejects a Registration Request and is unable to provide redirection to suitable Serving GANC, the UE may re-attempt the Discovery procedure to the Provisioning GANC (including a cause indicating the failed registration attempt and the Default GANC provided in the last Discovery procedure). The UE also deletes all stored information about the Default GANC.

2. De-Registration

FIG. 25 illustrates De-Registration initiated by the UE 2505 in some embodiments. The GA-RC De-Registration procedure allows the UE 2505 to explicitly inform the GANC 2510 that it is leaving GAN mode (e.g., when it detaches from the generic IP access network), by sending (in Step 1 ) a GA-RC DEREGISTER message to the GANC 2510 , allowing the GANC 2510 to free resources that it assigned to the UE 2505 . The GANC 2510 also supports “implicit GAN de-registration”, when the TCP connection to the UE is abruptly lost.

FIG. 26 illustrates De-Registration initiated by the GANC 2610 in some embodiments. As shown, the GANC 2610 can autonomously release the UE registration context, and send (in Step 1 ) a GA-RC DEREGISTER message to the UE 2605 . Alternatively, the GANC 2610 can implicitly deregister the UE 2605 by closing the TCP connection with the UE. At power-down the GA-RC sublayer of the UE ensures that the UE explicitly detaches from the network, where possible, before completing the GA-RC De-Registration procedure.

3. Registration Update

FIG. 27 illustrates Registration Update in some embodiments. The GA-RC Registration Update procedure allows the UE 2705 to update information in the GANC 2710 regarding changes to the identity of the overlapping GERAN cell or changes to the generic IP access network point of attachment. As shown, the UE 2705 sends (in Step 1 ) a GA-RC REGISTER UPDATE UPLINK message to the GANC 2710 carrying the updated information. This may result in the UE 2705 being redirected to another serving GANC, or being denied service; e.g., due to operator policy.

When the UE 2705 detects UTRAN/GERAN coverage after reporting no coverage during GAN registration, the UE sends the GA-RC REGISTER UPDATE UPLINK to the GANC with the updated information. Whenever the generic IP access network point of attachment changes, the UE sends a GA-RC REGISTER UPDATE UPLINK to the GANC with the updated generic IP access network point of attachment information. When the UE requires to update the GANC with a new list of GAN Services required, then the UE sends GA-RC REGISTER UPDATE UPLINK message to the GANC including the new GAN Services Required list.

The GANC 2710 may optionally send (in Step 2 ) the GA-RC REGISTER REDIRECT when it decides to redirect the UE based on updated information. The GANC 2710 may also optionally deregister the UE 2705 on receiving an update by sending (in Step 3 ) GA-RC DEREGISTER to the UE.

FIG. 28 illustrates Registration Update Downlink procedure in some embodiments. The GAN Registration Update procedure also allows the GANC 2810 to update the GAN system information in the UE 2805 , if needed, by sending (in Step 1 ) a GA-RC REGISTER UPDATE DOWNLINK message to the UE carrying the updated information.

4. Keep Alive

FIG. 29 illustrates the Keep Alive process in some embodiments. The Keep Alive process is a mechanism between the peer GA-RC entities to indicate that the UE is still registered to the GANC. Using periodic transmissions (in Step 1 ) of the GA-RC KEEP ALIVE message the UE 2805 in turn determines that the GANC 2810 is still available using the currently established lower layer connection.

5. Cell Broadcast Information

FIG. 30 illustrates the Cell Broadcast Information mechanism of some embodiments. The Cell Broadcast Information is a mechanism between the peer GA-RC entities, allowing the GANC to pass the UE information relating to the Cell Broadcast Services. The UE 3005 includes GAN Service Required information in the GA-RC REGISTER REQUEST and GA-RC REGISTER UPDATE UPLINK messages passed to the GANC, indicating that the UE requires the Cell Broadcast Service. The GANC 3010 then passes (in Step 1 ) the required information to the UE 1105 in the GA-RC CELL BROADCAST INFO message.

E. Authentication

The Up interface supports the ability to authenticate the UE with the GANC (for the purposes of establishing the secure tunnel) using GSM or UMTS credentials. Authentication between UE and GANC is performed using EAP-SIM or EAP-AKA within IKEv2.

F. Encryption and Integrity Protection

All control and user plane traffic over the Up interface is sent through the pair of IPSec ESP tunnel mode security associations (one for each direction) that are established during the establishment of the IKEv2 security association. Encryption and integrity protection are via the negotiated cryptographic algorithms, based on core network policy, enforced by the GANC-SEGW.

G. GA-CSR Connection handling

The Iu-mode GAN GA-CSR connection is a logical connection between the UE and the GANC for the CS domain. A GA-CSR connection is established when the upper layers in the UE request the establishment of a CS domain signaling connection and the UE is in GA-CSR-IDLE state; i.e., no GA-CSR connection exists. When a successful response is received from the network, GA-CSR replies to the upper layer that the CS domain signaling connection is established and the UE has entered the equivalent of the RRC connected mode (i.e., the GA-CSR-CONNECTED state).

1. GA-CSR Connection Establishment

FIG. 31 illustrates successful and unsuccessful establishment of the GA-CSR Connection in some embodiments. As shown, the UE 3105 initiates GA-CSR connection establishment by sending (in Step 1 ) the GA-CSR REQUEST message to the GANC 3110 . This message contains the Establishment Cause indicating the reason for GA-CSR connection establishment.

When GANC determines that the connection request can be accepted, the GANC 3110 signals the acceptance of the connection request to the UE 3105 by sending (in Step 2 ) the GA-CSR REQUEST ACCEPT and the UE enters the GA-CSR-CONNECTED state. On the other hand, when the GANC determines that the GA-CSR connection request has to be rejected, the GANC 3110 sends (in Step 3 ) a GA-CSR REQUEST REJECT to the UE 3105 indicating the reject cause, completing the procedure.

2. GA-CSR Connection Release

FIG. 32 illustrates release of the logical GA-CSR connection between the UE and the GANC in some embodiments. As shown, the MSC 3215 indicates to the GANC 3210 to release the CS resources allocated to the UE, by sending (in Step 1 ) the RANAP Iu Release Command message to the GANC 3210 .

Next, the GANC 3210 </