US 8045493 B2
A network controller operates in an unlicensed wireless communication system including a first radio access network. The network controller includes a Up interface for communicating with a mobile station and an IP network interface. The network controller includes a network interface for connecting the network controller to a UMTS core network that is accessible to a second radio access network that includes a UTRAN. The network interface includes an Iu-CS interface to communicate with a MSC in the UMTS core network. The network interface supports signaling protocols for circuit-switched services while inter-working with the UMTS core network via the Iu-CS interface using a layered protocol that includes a RANAP layer over a SCCP layer and several Iu-CS control plane lower layers. The network controller includes modules for generating and/or processing messages transmitted over the network interface. The network controller appears to the UMTS core network as a UTRAN RNC.
1. A network controller to operate in an unlicensed wireless communication system comprising a first radio access network, the network controller comprising:
a first network interface comprising an Internet Protocol (IP) network interface;
a second network interface comprising a Up interface for communicating with a mobile station (MS) via an access point communicatively coupled between the network controller and the MS, the Up interface including a plurality of protocol layers implemented over the IP network interface;
a third network interface for connecting the network controller to a Universal Mobile Telecommunications System (UMTS) core network that is accessible to a second radio access network comprising a UMTS Terrestrial Radio Access Network (UTRAN), the third network interface comprising an Iu-CS (circuit-switched) interface to communicate with a Mobile Switching Center (MSC) in the UMTS core network, the third network interface supporting signaling protocols for circuit-switched services while inter-working with the UMTS core network via the Iu-CS interface using a layered protocol that includes a Radio Access Node Application Part (RANAP) layer over a Signaling Connection Control Part (SCCP) layer and a plurality of Iu-CS control plane lower layers; and
one or more modules for generating and/or processing a plurality of messages transmitted over the third network interface between the network controller and the UMTS core network, wherein the network controller appears to the UMTS core network as a UTRAN Radio Network Controller (RNC).
2. The network controller of
3. The network controller of
4. The network controller of
a first network interface for connecting the SGW to the first radio access network;
a second network interface for connecting the SGW to the UMTS core network.
5. The network controller of
6. The network controller of
7. The network controller of
8. The network controller of
9. A mobile station operable to communicate with a Universal Model Telecommunications System (UMTS) telecommunications network using a licensed wireless communication channel serviced by a UMTS Terrestrial Radio Access Network (UTRAN) and an unlicensed wireless communication channel in an unlicensed wireless access area,
wherein the mobile station is associated with a licensed wireless network identifier and a licensed wireless location identifier for use when the mobile station is in a licensed wireless access area, and associated with an unlicensed wireless network identifier and an unlicensed wireless location identifier when the mobile station is in the unlicensed wireless access area,
wherein the mobile station employs a plurality of protocol layers to access an unlicensed wireless service and a UMTS core network, the protocol layers being used to support communication with an unlicensed wireless network controller over a Up interface and the UMTS core network via an Iu-PS interface,
wherein the mobile station supports signaling protocols for packet-switched services while inter-working with the UMTS core network via the Iu-PS interface using a layered protocol, the layered protocol including a General Packet Radio Service (GPRS) Mobility Management/Session Management/Short Message Service (GMM/SM/SMS) layer, an unlicensed wireless communication radio resource (RR) layer, and a transmission control protocol (TCP) layer, and
wherein the layered protocol further includes a remote IP layer, a security layer, a transport IP layer, and a plurality of unlicensed lower layers.
10. The mobile station of
11. The mobile station of
12. The mobile station of
13. The mobile station of
14. The mobile station of
15. The mobile station of
16. The mobile station of
17. The mobile station of
18. The mobile station of
This application is a continuation application of U.S. patent application Ser. No. 11/200,736, entitled “MECHANISMS TO EXTEND UMA OR GAN TO INTER-WORK WITH UMTS CORE NETWORK,” filed Aug. 10, 2005, which has issued as U.S. Pat. No. 7,843,900. U.S. patent application Ser. No. 11/200,736 and U.S. Pat. No. 7,843,900 are incorporated herein by reference.
This application is related to commonly-owned U.S. applications: Ser. No. 11/096,800, entitled, “A Method and System for Determining the location of an Unlicensed Mobile Access Subscriber,” filed Mar. 31, 2005, now issued as U.S. Pat. No. 7,369,859; Ser. No. 11/129,134, entitled, “Messaging in an Unlicensed Mobile Access Telecommunications System,” filed May 12, 2005, now issued as U.S. Pat. No. 7,953,423; Ser. No. 11/129,424, entitled “Handover Messaging in an Unlicensed Mobile Access Telecommunications System,” filed May 12, 2005, now issued as U.S. Pat. No. 7,565,145; Ser. No. 11/129,131, entitled, “Registration Messaging in an Unlicensed Mobile Access Telecommunications System,” filed May 12, 2005, now issued as U.S. Pat. No. 7,349,698; Ser. No. 11/128,615, entitled, “Channel Activation Messaging in an Unlicensed Mobile Access Telecommunications System,” filed May 12, 2005, now issued as U.S. Pat. No. 7,471,655; and Ser. No. 11/128,461, entitled, “Apparatus and Messages for Interworking Between Unlicensed Access Network and GPRS Network for Data Services,” filed May 12, 2005, now issued as U.S. Pat. No. 7,606,190, the contents of each of which are hereby incorporated by reference.
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 Universal Mobile Telecommunication System (UMTS) core network.
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 have 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. unlicensed wireless networks and for directing them to an appropriate network controller.
In accordance with aspects of the present invention, mechanisms to extend UMA (Unlicensed Mobile Access) or GAN (General Access Network) to inter-work with a UMTS (Universal Mobile Telecommunications System) core network are disclosed. A UMA network controller (UNC) is provided to interface between a UMA/GAN network and a UMTS core network using the standard Iu-CS and Iu-PS interfaces. From the viewpoint of the UMTS core network, the UNC appears as another Radio Network Controller (RNC). Protocol layer schemes are disclosed for mobile stations, UNCs, SGSNs and MSCs to support signaling and data messaging in both the packet-switched and circuit-switched domains. The mobile stations provide dual-mode operation, such that they are able to access the UMTS core network via unlicensed service when in a UMA/GAN access area, and to access the UMTS core network via licensed service when outside of a UMA/GAN access area and in a UTRAN service area.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified:
In the following description, numerous specific details are set forth to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
In the present description the unlicensed wireless system may be a short-range wireless system, which may be described as an “indoor” solution. However, it will be understood through the application that the unlicensed wireless system includes unlicensed wireless systems that cover not only a portion of a building but also local outdoor regions, such as outdoor portions of a corporate campus serviced by an unlicensed wireless system. The mobile station may, for example, be a wireless phone, smart phone, personal digital assistant, or mobile computer. The “mobile station” may also, for example, be a fixed wireless device providing a set of terminal adapter functions for connecting Integrated Services Digital Network (ISDN) or Plain Old Telephone Service (POTS) terminals to the wireless system. Application of the present invention to this type of device enables the wireless service provider to offer so-called landline replacement service to users, even for user locations not sufficiently covered by the licensed wireless system. The present description is in the context of the UMA (Unlicensed Mobile Access) standardized architecture as promulgated by the UMA consortium. However, the invention is not so limited.
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 specific to this application is included in Appendix I.
UMA architecture 100 enables a user of a mobile station 102 to access a UMTS core network 104 via either a licensed wireless communications session 106, or an unlicensed wireless communication session 108. The UMTS core network 104 is depicted to include a Mobile services Switching Center (MSC) 110, which provides access to a voice network 112, and a Serving GPRS (General Packet Radio Service) Support Node (SGSN) 114, which provides access to a data network 116. In addition, the UMTS core network may include various other components typically implemented in UMTS networks, as are well-known in the art.
In further detail, the licensed wireless communication session is facilitated by infrastructure provided by a licensed wireless network 118 that includes UMTS core network 104. In the illustrated embodiment, licensed wireless network 118 depicts components common to a UMTS-based cellular network that includes multiple Radio Base Stations (RBS) 120 (of which only one is shown for simplicity) that facilitate wireless communication services for various mobile stations 102 via respective licensed radio links 122 (e.g., radio links employing radio frequencies within a licensed bandwidth). Under UMTS, a Radio Base Station is commonly referred to as “Node B.” Typically, the multiple RBSs 120 are configured in a cellular configuration (one per each cell) that covers a wide service area. The various RBSs 120 for a given area or region are managed by a Radio Network Controller (RNC) 124, with each RBS 120 communicatively-coupled to its RNC 124 via a private trunk 125. In general, a large licensed wireless network, such as that provided by a regional or nationwide mobile services provider, will include multiple RNCs 124. The RBSs 120 and RNCs 124 collectively comprise a UMTS Terrestrial Radio Access Network (UTRAN).
The UMTS core network is divided into circuit-switched and packet-switched domains. Some of the circuit-switched elements include MSC 110, Visitor Location Register (VLR) and Gateway MSC (latter two both not shown). Packet-switched elements include SGSN 114 and Gateway GPRS Support Node (GGSN) (not shown). Some network elements, such as EIR, HLR, VLR and AUC (all not shown) are shared by both domains.
The architecture of the UMTS core network may change when new services and features are introduced. Number Portability DataBase (NPDB) will be used to enable user to change the network while keeping their existing phone number. Gateway Location Register (GLR) may be used to optimize the subscriber handling between network boundaries.
Each RNC 124 communicates with UMTS core network 104 through a standard RNC interface 126. For example, a RNC 124 may communicate with MSC 110 via the Iu-CS (circuit-switched) interface for circuit switched voice services and with SGSN 114 via the Iu-PS (packet-switched) interface for packet data services. The UMTS core network 104 includes protocols to permit seamless handoffs from one serving RNC 124 to another RNC (not shown) to provide mobile access across cells.
An unlicensed communication session 108 is facilitated via an (wireless) access point (AP) 128 comprising an indoor base station 130. (As used herein, an AP and indoor base station are one in the same. However, the separate terminology is provided to identify that AP's need not be indoor.) Typically, AP 128 will be located in a fixed structure, such as a home 132 or an office building 134. The service area of indoor base station 130 generally includes an indoor portion of such a home or building, although it will be understood that the service area of an indoor base station may include an outdoor portion of a building or campus. As indicated by the arrow representing unlicensed communication session 108, the mobile station 102 may be connected to UMTS core network 104 via a second data path that includes an unlicensed wireless channel 136, access point 128, an access network 138, and an unlicensed mobile access network controller (UNC) 140. The UNC 140 communicates with UMTS core network 104 using a RNC interface 126B that is similar to or the same as RNC interface 126A, and includes an Iu-CS interface and an Iu-PS interface. AP 128 may include software entities stored in memory and executing on one or more microprocessors (not shown in
The unlicensed wireless channel 136 is facilitated by a radio link employing a wavelength (or wavelength range) in an unlicensed, free spectrum (e.g., spectrum around 2.4 GHz, 5 GHz, 11-66 GHz). An unlicensed wireless service hosting unlicensed wireless channel 136 may have an associated communication protocol. As examples, the unlicensed wireless service may be a Bluetooth™ compatible wireless service supporting a Bluetooth personal local area network (PLAN), or a wireless local area network (LAN)(WiFi) service (e.g., the IEEE 802.11a, b, or g wireless standard). This provides the user with potentially improved quality of service in the service regions of the unlicensed wireless service (i.e., within the service range of a corresponding AP). Thus, when a subscriber is within range of the unlicensed AP, the subscriber may enjoy low cost, high speed, and high quality voice and data services. In addition, the subscriber enjoys extended service range since the handset can receive services deep within a building at locations that otherwise may not be reliably serviced by a licensed wireless system. At the same time, the subscriber can roam outside the range of the unlicensed AP without dropping communications. Instead, roaming outside the range of the unlicensed AP results in a seamless handoff (also referred to as a handover) wherein communication services are automatically provided by the licensed wireless system, as described in more detail in U.S. patent application Ser. No. 10/115,833, the contents of which are hereby incorporated by reference.
Mobile station 102 may include a microprocessor and memory (not shown) that stores computer program instructions for executing wireless protocols for managing communication sessions. (Further details of aspects mobile station operation are described below with reference to
The mobile station may also include an unlicensed wireless service physical layer 152 (i.e., a physical layer for unlicensed wireless service such as Bluetooth, WiFi, or other unlicensed wireless channel (e.g., WiMAX)). The mobile station also includes an unlicensed wireless service level 2 link layer 154, and an unlicensed wireless service radio resource sublayer(s) 156 and networking layers 158. An access mode switch 160 is included for the mobility management 148 and call management layers 150 to access the unlicensed wireless service radio resource sublayer 156 and unlicensed wireless service link layer 154 when the mobile station 102 is within range of an unlicensed AP 128 and to support switching between licensed RR sublayer 146 and unlicensed wireless service RR sublayer 156.
The unlicensed radio resource sublayer 156 and unlicensed link layer 154 may include protocols specific to the unlicensed wireless service utilized in addition to protocols selected to facilitate seamless handoff between licensed and unlicensed wireless systems. Consequently, the unlicensed radio resource sublayer 156 and unlicensed link layer 154 need to be converted into a format compatible with a conventional RNC interface protocol 126 recognized by UMTS core network interfaces such as MSC 110 and SGSN 114.
When operating in the UMTS access context, UNC 140 appears to UMTS core network as an RNC network element and is managed and operated as such. In this architecture the principle elements of transaction control (e.g., call processing) are provided by higher network elements; namely the MSC 110 VLR and SGSN 114. Authorized mobile stations are allowed access to the UMTS core network either directly through the UTRAN if they are outside of the service area of an AP 128 or via the UMA network system if they are within the service area of an AP.
Since a communication session hosted by the UMA architecture 100 is transparent to a voice network 112 or data network 116, the unlicensed wireless service may support all user services that are typically offered by a wireless service provider. In the UMTS case, this typically includes the following basic services: Telephony; Emergency call (e.g., E911 calling in North America); Short message, mobile-terminated point-to-point (MT/PP); Short message, mobile-originated point-to-point (MO/PP); UMTS bearer services; and Handover (outdoor-to-indoor, indoor-to-outdoor, voice, data, SMS, SS). Additionally, the UMTS core network may also support, various supplementary services that are well-known in the art.
When the mobile station is operating in an UMA mode, the UMA-RR entity 212 is the current “serving” RR entity providing service to the mobility management (MM) sublayer via the designated service access point (RR-SAP). The corresponding UMTS lower layer entity is detached from the MM sublayer in this mode. The UMA-RR entity 212 provides a new set of functions, and is responsible for several tasks. First the UMA-RR entity is responsible for discovery of UMA coverage and UMA registration. Second, the UMA-RR entity is responsible for emulation of the UMTS RR layer to provide the expected services to the MM layer; i.e., create, maintain and tear down RR connections. The plug-in of UMA-RR entity 212 is made transparent to the upper layer protocols in this way. Third, a UMA-RR entity 212 is responsible for coordination with the UMTS lower layers to manage access mode switching and handover.
Under architecture 300, CS signaling messages are transported between MS 102 and UNC+ 140 using the enhanced UMA-RR+ protocol, which supports the UMA “layer 3” signaling functions via UMA-RR+ layers 212 provided by each of the mobile station 102 and UNC+ 140. The UMA-RR+ (URR+) protocol comprises a modified version of the URR protocol that supports UMTS-specific information and procedures. The UNC+ 140, functioning like an RNC, terminates UMA-RR+ protocol messages and is responsible for the interworking between these messages and the analogous Iu-CS-interface messages. The CS signaling messages are relayed between UNC 140 and MSC 110 over the RANAP layer 306 as per the standard Iu-CS interface.
The layers below the UMA-RR+ layer 212 in each of mobile station 104 and UNC+ 140 include a TCP layer 312, and a remote IP IpSec (IP security)/UDP layer 314. As an option, a standard Secure Socket Layer (SSL) protocol running over TCP/IP (not shown) may be deployed in place of IPSec.
Lower-level IP connectivity between mobile station 102 and UNC+ 140 is supported by appropriate layers hosted by an intervening access point 128 and broadband IP network 138 (i.e., the access network 138 shown in
At the lowest layers (i.e., the physical and data link layers), mobile station 104 and AP 128 are depicted as providing unlicensed lower layers 318, while each of AP 128, IP network 138, and UNC 140 provide appropriate access layers 320. Typically, access layers 320 will include conventional Ethernet PHY and MAC layers (IEEE 802.3), although this is not limiting.
As shown in
In addition to the like-named and referenced components common to the architectures of
To facilitate communication over the Iu-PS interface, architecture 350 employs Iu-PS user plane lower layers 352 at each of UNC+ 140 and SGSN 110. These layers comprise well-known conventional Iu-PS layers, further details of which are shown in
Additional layers are provided at MS 102, SGSN 110, and GGSN 115. The Gn interface is employed for communication between SGSN 110 and GGSN 115, and may be viewed as the downlink interface of a GGSN. The Gn interface uses the GPRS tunneling protocol (GTP), which is supported by GTP-U (user) layer 352. User data packets (typically IP packets) are tunneled over GTP, which employs UDP layer 354 over IP layer 356. Each of SGSN 110 and GGSN 115 further employ GSN lower layers 358 to support communication over the Gn interface. Another IP layer 360 supports communication between MS 102 and GGSN 115. PS service over the Iu-PS interface between UNC+ 140 and SGSN 110 is facilitated, in part, by Iu-PS user plane lower layers 362, further details of which are shown in
Under architecture 350, the transport of data messages is optimized compared to both UMA/GAN and 3GPP transport mechanisms. GTP tunnels for user data transport are extended to the MS to make the transport more efficient; consequently, the data packets are relayed between the MS and SGSN directly by the SGW effectively bypassing the INC (see
As noted above, the mobile station may be, for example, a wireless phone, smart phone, personal digital assistant, or mobile computer. The mobile station may also be, for example, a fixed wireless device providing a set of terminal adapter functions for connecting Integrated Services Digital Network (ISDN) or Plain Old Telephone Service (POTS) terminals to the wireless system.
Other terminal adapter types than those listed above may be employed with embodiments of the present invention. For example: (1) a terminal adapter that supports cordless telephones rather than POTS phones; (2) a terminal adapter that supports standard Session Initiation Protocol (SIP) telephones; and (3) a terminal adapter that also integrates a corded handset and user interface, such as one would find on a desk phone. In each case, the invention described herein describes how these terminal adapter functions can be connected to the wireless system via the unlicensed network.
The use of other standard Bluetooth capabilities together with embodiments of the present invention is possible. For example, there is a Bluetooth standard capability called “SIM Access Profile” that allows one Bluetooth device (e.g., an embedded cell phone subsystem in a car) to access the SIM that is in another Bluetooth device (e.g., the user's normal cell phone), allowing the first device to take on the “personality” associated with the SIM (i.e., that of the user's normal cell phone). The embodiments described above could make use of this standard capability to give the terminal adapter-attached devices (e.g., a POTS phone) the personality of the user's cell phone.
The UNC+ 140 provides functions equivalent to that of a UMTS RNC, and as such controls one or more (virtual) UMA cells. In one embodiment, there may be a single UMA cell per UNC, in another embodiment there may be a single UMA cell per UTRAN registration area and, in an alternative embodiment, there may be one UMA cell per access point connected to a UNC. The latter embodiment may be less desirable due to the large number of APs expected to be used, so the UMA architecture permits flexible groupings of APs into UMA cells. Each UMA cell may be mapped to a physical boundary by associating it with specific UTRAN registration areas served by the MSC. Note that UMA cells may use the same registration area identifiers as existing UMTS cells, or a new registration area identifier may be used for UMA cells. The latter is useful in reducing paging in UMTS cells when a mobile station is known to be registered via an UNC+.
Customer premise equipment (CPE) may include the mobile station and the access point (AP) through which the mobile station may access the UNC for UMA service. UMA CPE addressing parameters may include the parameters described below.
The UMA CPE addressing includes the international mobile subscriber identity
(IMSI) associated with the SIM in the mobile equipment as a parameter. The IMSI is provided by the UMA mobile station to the UNC when it requests UMA service via the Up interface to the UNC. Unlike the UMTS RNC, the UNC manages a context for each mobile station that is operating in UMA mode. Therefore, the UNC maintains a record for each served mobile station. For example, IMSI may be used by the UNC to find the appropriate mobile station record when the UNC receives a RANAP mobile terminated call notification.
The UMA CPE addressing includes the address associated with the unlicensed interface in the mobile equipment (e.g., 802.11 MAC address) as a parameter. This identifier may be provided by the UMA mobile station to the UNC when it requests UMA service via the Up interface. The UNC may use this address as an alternative to the IMSI to limit the transfer of the IMSI over the Up interface and to assist in the routing of messages.
The UMA CPE addressing also includes the temporary logical link identifier (TLLI) assigned to the mobile station by the serving GPRS support node (SGSN) as a parameter. This identifier may be provided via standard Iu-PS interface procedures. The UNC may track this address for each served mobile station to support UMTS Iu-PS interface procedures (e.g., so that downlink GPRS packets may be routed to the correct mobile station).
The UMA CPE addressing also includes the access point ID (AP-ID) as a parameter. The AP-ID may be the MAC address of the unlicensed mode access point through which the mobile station is accessing UMA service. This identifier may be provided by the UMA mobile station to the UNC when it requests UMA service via the Up interface. The AP-ID may be used by the UNC to support location services (e.g., enhanced 911 service) to the user based on the AP from which the service is being accessed. The AP-ID may also be used by the service provider to restrict UMA service access only to authorized APs.
Other CPE addressing parameters that may be used depend on the security requirements of the Up interface (e.g., the need to manage UMA mobile station IP addresses for message routing via tunneled IPSec connections, or the need to manage local credentials assigned to the mobile station by the UNC).
In order to facilitate the mobility management functions in UMTS, the coverage area may be split into logical registration areas. Mobile stations may be required to register with the network each time the serving registration area changes. One or more registration areas identifiers may be associated with each visited location register (VLR) in a carrier's network. Likewise, one or more registration area identifiers may be controlled by a single SGSN. In one embodiment, a UMTS cell is identified within the registration area by adding a cell identity (CI) to the registration area identification.
One example of a UMA cell identification approach is described below. In this embodiment, a single UNC provides service for one or more UMA registration areas, and each UMA registration area is distinct from, or the same as, the registration area of the overlapping UMTS cell. A UMA cell is identified within the UMA registration area by adding a cell identity (CI) to the registration area identification. The UMA cell global identification (UMA-CGI) is the concatenation of the registration area identification and the cell identity. In one embodiment, a UMA cell may be a pre-defined partition of the overall UMA coverage area identified by a UMA-CGI value. Note that cell identification, like UMA information, may be transparent to the AP, such that the AP is not aware of its associated UMA-CGI value. The UMA components (e.g., mobile station and UNC) may support the ability to partition the overall UMA coverage area.
A partitioning method may include implementing a one-to-one or a many-to-one correspondence between UMTS cell identity and UMA cell identity. Given the identification of a preferred UMTS cell in a particular area, it may be possible to determine the corresponding UMA cell identity based, for example, on UNC provisioning. An example of a one-to-one relationship is mapping a UMTS cell to a UMA cell. An example of a many-to-one relationship is mapping a UMTS registration area (and associated UMTS cells) to a UMA cell.
When a UMA mobile station connects to the UNC for UMA service, it sends the identity of the current UMTS camping cell, as well as the neighbor cells, to the UNC. The UNC maps the UMTS camping cell's identity to a corresponding UMA cell's identity based on mapping logic provisioned in the UNC. This may be a one-to-one mapping (e.g., if there is one UMA cell per UMTS cell) or a many-to-one mapping (e.g., if there is one UMA cell per UMTS registration area). If no UMTS coverage is available in the UMA service area, the UNC may assign the mobile station to a default “no licensed coverage” UMA cell. A single UNC may serve one MSC. This does not preclude UNC embodiments that combine multiple UNC “instances,” as defined above, in a single device (for example, a UNC that servers multiple MSCs). Each UNC may also be assigned a unique “UMA-Handover-CGI” value used for UMTS-to-UMA handover purposes. For example, this may be the value provisioned in the UTRAN RNC's cell-to-RNC tables and in the MSCs (e.g., to point to the UNC).
In one embodiment, as described above, a UMA registration process does not employ signaling to the PLMN infrastructure and is contained within the UMA system (i.e., the mobile station sends a UMA registration request message to the UNC and the UNC responds with registration accept and provide certain operating parameters to the MS). The UMA registration process may serve at least two purposes. It may inform the UNC that a mobile station is connected through a particular AP and is available at a particular IP address. The UNC may keep track of this information, for example, for mobile-terminated calling. The registration process may also provide the mobile station with the operating parameters associated with the UMA service on the AP. This may be analogous to the use of the UMTS broadcast control channel (BCCH) to transmit system parameters to mobile stations in UMTS cells. UMTS system information message content that is applicable in UMA mode may be delivered to the mobile station during the UMA registration process.
Similarly, a UMA deregistration process may allow the mobile station to explicitly inform the UNC that it is leaving UMA mode, allowing the UNC to free resources that it may have assigned to the mobile station. The UNC may also support implicit UMA deregistration, wherein a secure channel to the mobile station is abruptly terminated.
In one embodiment, as described above, when a UMA mobile station connects to the UNC for UMA service, it may send a cell identity value and a signal quality measurement of the current UMTS camping cell, as well as the neighbor cells, to the UNC. Using this information, as well as internal database information, the UNC may be able to determine if it is the correct serving UNC for the mobile station, and if it is not the correct serving UNC, to redirect the mobile station to the correct UNC. The correct serving UNC may be the UNC whose UMA service area overlaps the mobile station's umbrella UMTS coverage. In one embodiment, the correct serving UNC might be attached to the same MSC as the UMTS RNC to which the umbrella UMTS cell belongs. In an alternative embodiment, the correct serving UNC might be attached to a different MSC that may hand-over to the MSC that provides umbrella UMTS coverage to the mobile station, allowing the UNC to handover calls to and from UMTS. It may also enable certain location-based services (e.g., E911 Phase 1) that can be tied to the location of the UMTS cell. An internal database used by the UNC may map UMTS registration areas to serving UNCs and conserve the amount of data that needs to be managed. This database may only need to change when a new UNC or a new UMTS registration area is added.
If no UMTS coverage is available when a mobile station connects to the UNC for UMA service, then, under some instances, the UNC may not reliably determine the location of the mobile station for the purposes of assigning the mobile station to the correct serving UNC (e.g., to enable handover and location-based services). The UNC may permit the operator to determine the service policy in this case (e.g., the operator may provide service to the user with certain limitations, possibly with a user interface indication on the mobile station).
As described above, a UMA device may encounter different radio environments, such as illustrated in
At power on, and when the mobile station is idle and there is no coverage of any type, the mobile station may scan for both UMTS and UMA radio coverage. If UMTS coverage is detected, then the normal UMTS mobility management procedure may be initiated. This condition may apply when no UMA coverage has been detected by the mobile station when UMTS coverage is detected, or prior to the completion of the UMA registration process. If UMA coverage is detected, then the UMA mobile station establishes an unlicensed wireless link (e.g., WLAN link) to the AP and monitors signal quality. When the received signal level at the mobile station passes a predefined threshold, the mobile station performs the UMA registration procedure. Based upon the information returned, the mobile station may determine if a full network registration is required, and if so, what type (e.g., UMTS). This procedure may apply when no UMTS coverage exists or when UMA coverage is detected prior to detecting UMTS coverage.
When the mobile station is idle in UMTS coverage, and there is no UMA coverage, the mobile station may periodically scan for UMA coverage. If UMA coverage is detected, the mobile station may initiate the UMA registration procedure described above.
When the mobile station is idle in UMA coverage and there is no UMTS coverage, the mobile station may continue to perform normal UMTS PLMN search procedures. If UMTS coverage is detected, the mobile station may send the UMTS cell information to the UNC for possible UMA redirection purposes as described above. Alternatively, the mobile station may disable normal UMTS PLMN search procedures to conserve power.
When the mobile station is idle in UMA coverage, and there is UMTS coverage, the mobile station may continue to perform normal UMTS cell reselection procedures and may store the identification of the selected UMTS cell to speed the transition to UMTS mode, if required. Alternatively, the mobile station may disable normal UMTS cell reselection procedures to conserve power.
At power off in UMA coverage, a detach indication may be sent by the mobile station to the PLMN via the UMAN (e.g., if required by the PLMN network or normally sent by the mobile station at power off). This indication may be encoded per the current UMTS mode of operation.
The UMA environment may be an IEEE 802.11 environment. In this case, the mobile station periodically performs an active scan for available 802.11 APs. When an AP is discovered, it may be matched against a stored profile of user preferences and security credentials, in which case the mobile station may automatically associate with the AP. The mobile station may enter low-power sleep mode, waking up periodically to measure signal quality for determining when to trigger UMA registration.
The UMA environment may be a Bluetooth environment. In this case, the mobile station previously paired with the Bluetooth AP through which it will access UMA service. Periodically, the mobile station may enter a page scan receive mode, and respond to an AP transmit page to establish a link-level connection. Once a link-level control channel is established, and if the mobile station is not otherwise active, it may enter a low-power Bluetooth state (e.g., park mode) to conserve power. Periodically, the AP may poll the mobile station to allow it to re-enter active-power mode. This periodic traffic may also be used by the mobile station to measure signal quality to determine when to perform the UMA registration procedure.
A UMA device engaged in a voice call, a data transaction or a simultaneous voice/data transaction may encounter a transition from UMTS coverage to UMA coverage or a transition from UMA coverage to UMTS coverage. In one embodiment, when the coverage transitions from UMTS to UMA coverage, calls may be handed over transparently between the UTRAN and the UMAN. In the case of voice, the handover may be accomplished by a handover function. In the case of data, session management controls may provide a common end-user experience to that provided in GPRS. Normal registration actions may occur upon a return to the idle state, if appropriate. When the coverage transitions from UMA to UMTS coverage, calls may be handed over transparently between the UMAN and the UTRAN. In the case of voice, the handover may be accomplished by a handover function. In the case of data, session management controls may provide a common end-user experience to that provided in GPRS.
A block diagram illustrating a high-level architecture corresponding to one embodiment of a UNC+ is shown in
In general, the UNC+ may provide one or more communication ports to support communications between mobile stations and the UNC+ (e.g., via an AP 128 and broadband IP network 138 as shown in
The SGW server 602 performs security and authentication services. It may be an integrated unit (as shown), or may be a separate (physical) unit connected to the UNC+ via an appropriate communication link.
The INC 600 includes resources to support (i.e., generate and process) the UP+ interface messages described herein. These resources are depicted as UP+ Interface (I/F) logic 612. Similarly, INC 600 includes Iu-PS/SGSN interface logic 614 to support communications with SGSN 114 via an IP (or ATM) port 616 using the Iu-PS interface, and IuCS/MSC interface logic 618 to support communication with MSC 110 via an IP (or ATM) port 620 using the Iu-CS interface.
Meanwhile, SGW server 602 includes Iu-PS/SGSN interface logic 622 to support communication with SGSN 114 via an IP port 624 using the Iu-PS interface and Iu-CS/MSC interface logic 626 to support communication with MSC 110 via a port 628 using the Iu-CS interface. SGW server 602 also is able to communicate directly with voice network 112 via an IP port 630 and an AAA (authentication, authorization, and accounting) server 632. AAA server 632 employs an IP security mechanism for authentication/authorization, such as the Remote Authentication Dial-In User Service (RADIUS) or the Diameter protocol.
Each of UP interface logic 612, Iu-PS/SGSN interface logic 614 and 622, and Iu-CS/MSC interface logic 618 and 626 may be implemented via execution of software, built-in programmed hardware, or a combination of the two. For example, UP interface logic 612 may be facilitated by executing one or more software modules on a processor, wherein the software modules are coded to generate and/or process URR+ and URLC+ messages.
In general, a UNC may be implemented by a single server, multiple distributed servers, and multiple clustered servers. For example, a single server 634 may be employed for running various software applications to provide the various functions shown in the block diagram of the UNC+architecture of
Licensed RAN antenna sub-system 704 and licensed RAN interface logic 708 are employed to facilitate conventional licensed RAN operations. For example, in one embodiment the licensed RAN comprises a UMTS network, and thus these components facilitate normal UMTS network operations typically employed by UMTS-based cellular devices and the like, which are well-known in the cellular communication art. Meanwhile, the unlicensed RAN antenna system 606 and WLAN interface logic 610 are used to support an unlicensed wireless channel (i.e., link) 136 with an access point 128 via which UMAN services may be accessed. In general, these blocks represent conventional components and logic employed to support communications over an unlicensed WLAN link. For example, these components are illustrative of components that may be employed to implement the Bluetooth lower layers shown in
Up interface logic 712 is used to provide the MS-side Up interface functions and operations described herein. This includes generating and processing various URR messages, as well as providing the various UP interface layers depicted in FIGS. 3A and 3D-F.
The controller may also be coupled to one or more other I/O (Input/Output) devices 810. Typical I/O devices include a synchronization port, an accessory port, a wired network interface, a docking port, and a port replicator that permits further external devices to be attached or an interface to a base station. If the MS is adapted for use as a component of a larger computer system, then the display, input, microphone or speaker may be removed in favor of a bus interface. The bus interface may comprise a PC cardbus, PCI (Peripheral Component Interconnect) bus, a USB (Universal Serial Bus), IDE (Integrated Device Electronics), ATA (Advanced Technology Attachment) or other type of bus. The bus interface may be combined with a display 802, such as status LEDs (Light Emitting Diodes) and a speaker 808.
The controller 800 is further coupled to one or more storage devices 812 such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, a disk drive and an optical drive. The storage may be used to store operating instructions, applications, and data that is communicated with an enterprise and public domains. The controller is also coupled to a host DSP (Digital Signal Processor) 814. The host DSP communicates data with the controller that is to be carried by the radios. The data may represent voice, text, graphics, applications, etc. The host DSP 814 controls the flow of the data to and from the radio and controls the radios themselves through an RF controller 816. The RF controller controls timing, frequencies, and other aspects of the radios.
The MS of
The radios 822, 824, controlled by RF controller 816, may contain amplifiers, frequency converters, multiplexers, demultiplexers, equalizers, analog and digital converters, encoders and decoders, splitters and combiners, spreaders, despreaders and other elements. The radios are operatively coupled to voice and data codecs 826, 826 which are, in turn, coupled to the host DSP. Data or voice received from the antenna propagates through the duplexer to the appropriate radio, through the codec, to the host DSP and then to the controller for display, output, play or storage. Data or voice to be transmitted follows the opposite path from the controller through the DSP to the appropriate codecs and radio, through the duplexer and the antenna. The particular type of radio and transmission and reception chain may be adapted to suit different applications. More or less components than those shown in
The means for facilitating various message generation and processing operations, as well as various aspects of the Up, Iu-CS, and Iu-PS interfaces may include execution of software/firmware instructions on an appropriate processing element, such as, but not limited to, a processor, multiple processors, a multi-core processor, a DSP, a microcontroller, etc. Thus, embodiments of this invention may be used as or to support instructions executed upon some form of processing core or otherwise implemented or realized upon or within a machine-readable medium. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium can include a read only memory (ROM); a random access memory (RAM); a magnetic disk storage media; an optical storage media; and a flash memory device, etc. In addition, a machine-readable medium can include propagated signals such as electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). For example, in one contemplated implementation, instructions embodied as software upgrades for facilitating UMA messaging may be downloaded to a mobile device via a wireless link, such as a UMAN or UMTS link.
The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the drawings. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.