Title of Invention	METHOD OF ESTABLISHING A HRPD SIGNAL LINK
Abstract	A method (10) of establishing an alternate HRPD signaling link between an HRPD access network and an access terminal over a non-HRPD access is disclosed. It includes: providing (12) a signal forwarding function (SFF) (22) between an access terminal (AT) (24) and a high rate packet data (HRPD) access network (AN) (26); establishing (14) a data tunnel (28) between the access terminal (24) and the SFF (22); exchanging (16) HRPD signaling messages and HRPD data via the data tunnel (28); identifying (18) the HRPD access network (26) and the access terminal (24) over non-HRPD access by the SFF (22), by reading a header with certain identifiers and mapping the header to an address of the access terminal or network; and forwarding (20) the HRPD signaling messages and the HRPD data that arrive at the SFF (22) from the access terminal (24) and the HRPD access network (26) to the HRPD access network (26) and the access terminal (24), respectively. The method (10) performs an initiation and session establishment procedure, minimizes the time, disruption and packet loss during handoff to a HRPD access network and enables seamless mobility.

Title of Invention

METHOD OF ESTABLISHING A HRPD SIGNAL LINK

Abstract

A method (10) of establishing an alternate HRPD signaling link between an HRPD access network and an access terminal over a non-HRPD access is disclosed. It includes: providing (12) a signal forwarding function (SFF) (22) between an access terminal (AT) (24) and a high rate packet data (HRPD) access network (AN) (26); establishing (14) a data tunnel (28) between the access terminal (24) and the SFF (22); exchanging (16) HRPD signaling messages and HRPD data via the data tunnel (28); identifying (18) the HRPD access network (26) and the access terminal (24) over non-HRPD access by the SFF (22), by reading a header with certain identifiers and mapping the header to an address of the access terminal or network; and forwarding (20) the HRPD signaling messages and the HRPD data that arrive at the SFF (22) from the access terminal (24) and the HRPD access network (26) to the HRPD access network (26) and the access terminal (24), respectively. The method (10) performs an initiation and session establishment procedure, minimizes the time, disruption and packet loss during handoff to a HRPD access network and enables seamless mobility.

Full Text	METHOD OF ESTABLISHING A HRPD SIGNAL LINK BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of establishing an HRPD signal link, and more particularly to a method of establishing an alternate HRPD signaling link between the access terminal and the access network over a non-HRPD access and the pre-establishment of HRPD sessions over the alternate signaling link. 2. Description of the Related Art There is interest in developing multi-mode devices, capable of seamlessly transferring data, voice and video services from one radio technology to another one, without adversely affecting the user-experience. One such device is 3GPP2-EVDO interoperating with other wireless standards, such as 3GPP Long Term Evolution (LTE), WLAN, WiMax, etc. This type of inter-technology handoffs is gaining special attention, as there is keen interest in integrating different air-interface technologies. Also as major cellular operators migrate to 4G and newer operators in broadband space emerge, multi-mode radio devices will be needed for both intra-operator as well as inter operator roaming for the foreseeable future as 4G technologies mature. A real-time data-session, for example, a VoIP call, that is initiated on one technology, such as LTE, may move or roam into an area where only HRPD is available. It becomes necessary to transfer the VoIP call from LTE to HRPD seamlessly and without a long delay. However, the HRPD requires that a session is established, before it is allowed to make/receive any type of calls. The initialization and session establishment of HRPD includes the following steps, which requires signaling exchanges between a mobile device and the HRPD network: 1. Unicast Access Terminal Identifier (UATI) assignment procedure, 2. HRPD session establishment procedure, 3. Access Authentication, 4. Point-to-point protocol (PPP) set-up, and 5. IP-setup as a preparation for a future handoff to HRPD. However, the complexity and cost constraints limit the mobile device to have typically, one transmitter antenna, which is standard industry practice today. In the example detailed above, this would require that there is an additional transmitter available for signaling exchanges for initialization and session establishment, while the device is actively transmitting and receiving on the other radio-interface. This invention proposes a method and solution to perform the initialization and session-establishment procedure of HRPD, from a mobile active on a non-HRPD network or other air-interface, such as LTE, WLAN, WiMax, etc., so as to minimize the disruption and packet loss during handoff or transfer to HRPD network, free of having to use two transmitter antennas. Thus, there is a need to perform the initialization and session-establishment procedure of HRPD, from a mobile active on a non-HRPD air-interface (by way of example, this term includes LTE, WLAN, WiMax and the like), so as to minimize the disruption and packet loss during handoff or transfer to the HRPD air-interface, which is cost effective, quick or user friendly and free from requiring use of two transmitter antennas, for example. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the inventive aspects of this disclosure will be best understood with reference to the following detailed description, when read in conjunction with the accompanying drawings, in which: FIG. 1 is a simplified illustration of HRPD signaling on a non-HRPD access, in accordance with the invention. FIG. 2 is a block diagram for a method of establishing an HRPD signal link over a non-HRPD access, in accordance with the invention. FIG. 3 illustrates a HRPD 10S Architecture, as defined in the HRPDIOS standard for 3GPP2, A.S0008 in phantom, including a Signal Forwarding Function and a new interface (Axx), in accordance with the invention. FIG. 4 is a flow diagram for establishing an HRPD signal link over a non- HRPD access over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access Network-AAA (AN-AAA) and times a-h, illustrating how a link is opened or established, in accordance with the invention. FIG. 5 is a flow diagram for closing (or turning off) an HRPD signal link over a non-HRPD access over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access Network-AAA (AN-AAA) and times a-f, illustrating how a link is turned off or terminated, in accordance with the invention. FIG. 6 is a flow diagram showing HRPD signaling exchanges over a non- HRPD access using TCP/IP over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN). Access Network-AAA (AN-AAA) and times a-c, in accordance with the invention. FIG. 7 is an illustration of a Protocol Structure as defined by HRPD Standard IS856, illustrating a default signaling path and a default data path, as detailed herein. FIG. 8 is an environmental illustration showing the Protocol Structure as defined by HRPD Standard IS856, in Fig. 7, including a Signaling Adaptation Protocol (SAP) and signaling path in an opened (operational) position, in accordance with the invention. FIG. 9 is an embodiment of the Signaling Adaptation Protocol in Fig. 8 and exemplary signaling path in an opened state (operational), in accordance with the invention. FIG. 10 is an alternate second embodiment of the Signaling Adaptation Protocol in Fig. 8 and exemplary signaling path in an opened state (operational), in accordance with the invention. FIG. 11 is an alternate third embodiment of the Signaling Adaptation Protocol in Fig. 8 and exemplary signaling path in an opened state (operational), in accordance with the invention. FIG. 12 shows an Access Terminal State Machine of the Signaling Adaptation Protocol, in Fig. 8 including a Closed State, Setup State and Open State, illustrating how an alternate link is opened and closed, in accordance with the invention. FIG. 13 shows an Access Network State Machine of the Signaling Adaptation Protocol, in Fig. 8 including a Closed State, Setup State and Open State, illustrating how an alternate link is opened and closed, in accordance with the invention. FIG. 14 is a flow diagram for establishing an HRPD signal link over a non- HRPD air-interface over time, the diagram includes columns for each of the Alternate Link, Signaling Network Protocol (SNP), Signaling Adaptation Protocol (SAP). Access Network (AN), and times a-1, in accordance with the invention. FIG. 15 is a block diagram of an embodiment of a signaling adaptation method for converting HRPD messages and HRPD data on to a generic container that can be transported over a non-HRPD access, in accordance with the invention. DETAILED DESCRIPTION Referring to Figs. 1 and 2, a method 10 of establishing an alternate HRPD signaling link between an HRPD access network and an access terminal over a non- HRPD access, is shown. The method 10 generally includes a providing step 12, an establishing step 14, an exchanging step 16, an identifying step 18 and a forwarding step 20. In more detail, the method 10 includes: providing 12 a signal forwarding function (SFF) 22 between an access terminal (AT) 24 and a high rate packet data (HRPD) access network (AN) 26; establishing 14 a data tunnel 28 between the access terminal 24 and the SFF 22; exchanging 16 HRPD signaling messages and HRPD data via the data tunnel 28; identifying 18 the HRPD access network 26 and the access terminal 24 over non-HRPD access by the SFF 22, by reading a header comprising HRPD sector identification, access terminal identification and stream identification and mapping the header to an address of one of the access terminal and the access network; and forwarding 20 the HRPD signaling messages and the HRPD data that arrive at the SFF 22 from the access terminal 24 and the HRPD access network 26 to the HRPD access network 26 and the access terminal 24, respectively. Advantageously, the method 10 performs an initiation and session establishment procedure, minimizes the time, disruption and packet loss during handoff to a HRPD access network and enables seamless mobility. In more detail, the method 10 performs the initiation and session establishment procedure for HRPD. For example, in use an AT 24, such as a mobile, would by active on a non-HRPD access (such as 3GPP Long Term Evolution (LTE), wireless local area network (WLAN), and WIMax). The method 10 is adapted to minimize the time, disruption and packet loss during handoff to a HRPD access network and maximize user's experiences. In one embodiment, the HRPD signaling messages are over a TCP/IP link, with a newly defined header to uniquely identify the HRPD Access Network. In addition, the method 10 is particularly adapted for use in multi- mode devices or access terminals, with HRPD as one of the access technologies. Stated another way, the method 10 provides seamless mobility between HRPD and non-HRPD air-interface technologies. Detailed below and throughout this application are brief definitions of the terms and acronyms used. All such terms and acronyms have their common ordinary meanings, unless explicitly stated to the contrary. The definitions herein arc an attempt at clarity. 1. Evolution-Data Optimized or Evolution-Data are abbreviated as EV-DO or EVDO or 1xEV. 2. High Data Rate (HDR) and High Rate Packet Data (HRPD) generically refer to telecommunications standards for the wireless transmission of data through radio signals. HRPD can provide for broadband Internet access and various data services including real time data services like Voice Over Internet Protocol (VoIP). 3. EVDO employs multiplexing techniques such as CDMA (Code division multiple access) as well as Frequency division duplex (FDD) to maximize the amount of data transmitted. It is standardized by the 3rd Generation Partnership Project 2 (3GPP2), as part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world, and particularly those previously employing CDMA networks. A more detailed description of the CDMA2000 High Rate Packet Data (HRPD) EVDO (Evolution Data Optimized) is provided in 3GPP2 C.S0024-A, entitled "cdma2000 High Rate Packet Data Air Interface Specification", September 2006, and in TIA-IS-856 (also known as IS856). 4. An HRPD session refers to a shared state between an access terminal (AT) and the access network (AN). Other than to open a session, the AT cannot communicate with the AN without having an open session. 5. A connection or dedicated radio connection, refers to a particular state of an air-link in which the AT is assigned a forward traffic channel, a reverse traffic channel and associated medium access control channels. 6. As used herein, the HRPD acronym generically refers to and includes, by way of example, HDR, EV-DO, EVDO, 1 x EV, CDMA, CDMA2000 Evolution Data Optimized (EVDO), standards TIA-IS-856, 3GPP2 HRPD interoperability specification A.S0008, cdma2000 wireless IP network based standard TIA-IS-835 and the like. 7. 3G refers to Third Generation Cellular Technology 8. 3GPP refers to Third Generation Partnership Project, a standardization group that develops GSM standards and its evolution 9. 3GPP2 refers to a Third Generation Partnership Project 2, a standardization group that develops cdma2000 development 10. 4G refers to Fourth Generation broadband wireless technology 11. WiMAX means Worldwide Interoperability for Microwave Access 12. TCP means Transmission Control Protocol (a part of TCP/IP) 13. IP is Internet Protocol (a part of TCP/IP) In one embodiment, the method 20 includes pre-establishing an HRPD session over a non-HRPD access prior to establishing a traffic channel on an HRPD air- interface. In order to perform a handoff between non-HRPD access and HRPD access, it is required that an HRPD session be established before the handoff (at a suitable radio-frequency). A problem in real time services like Voice over IP (VoIP) is that the HRPD session establishment takes a period of time, in the order of seconds, which can introduce an unacceptable break in communication. In order to support low- latency (low set up time) active session handoffs between non-HRPD and HRPD access, the method 20 provides a solution and effective procedures, to pre-establish the HRPD session, while on the non-HRPD access, before the radio frequency antenna switches from non-HRPD access to HRPD access. The term HRPD access as used herein, includes at least one of HRPD air- interface, HRPD access network, wherein access network includes a radio network controller, base station(s) and the like and HRPD core-network, wherein the core- network includes Packet Data Service Network (PDSN), Mobile IP Home agent. Mobile IP foreign agent and the like and the term non-HRPD access as used herein, includes at least one of non-HRPD air-interface, non-HRPD access network and non- HRPD core-network. In one embodiment, the method 20 includes authenticating and pre- establishing an HRPD session from a HRPD multi-mode access terminal, (wherein the HRPD multi-mode access terminal is a mobile device, which implements one or more than one access technology in addition to HRPD access technology) active on a non-HRPD access, prior to establishing a traffic channel on an HRPD air-interface. Preferably, this includes obtaining UATI assignment, protocol subtype negotiation and protocol configuration parameters negotiation of all protocol layers of HRPD, prior to establishing a traffic channel. In order to perform an active session handoff between non-HRPD and HRPD, it may be required that access terminal obtain UATI from the access network by means of UATI assignment, negotiate the protocol subtypes and protocol configuration parameters between the HRPD access network and the access terminal. However, these procedures can take an unacceptable period of time (negative user experience) and can cause an unacceptable break in communication, in known real time services like VoIP. As used above, active session means the access terminal is sending and receiving user data on a dedicated radio connection. Advantageously, in order to support low latency (break in communication reduced to a minimum) active session handoff between non-HRPD and HRPD access, the method includes establishing effective procedures to obtain the HRPD UATI, HRPD protocol subtypes and configuration parameters while on the non-HRPD access, before the radio frequency antenna switches from non-HRPD access to the HRPD access In one embodiment, the data tunnel in FIG. 1, is secure in order to minimize the possibility of a security attack on the access network as well as to protect the privacy of the access terminal. In another embodiment, the method includes the step of allowing HRPD access channel messaging from and to a non-HRPD air-interface access terminal. This feature can reduce the time it takes to perform a handoff from a non-HRPD network to a HRPD network, for example. In this embodiment, it is desirable that the access procedures that are required on HRPD to obtain HRPD traffic channel be bypassed, thus advantageously improving the user experience during handoff. As should be understood by those skilled in the art, an access network can include a base station controller, radio network controller, a plurality of the preceding and the like. It is understood that, a base station provides a Radio Frequency (RF) interface between an access terminal and an access network via one or more transceivers. An access network exchanges the signaling messages with a HRPD access terminal in order to establish the session, maintenance of session and so on. In yet another embodiment, the method can include: providing an interface between the access terminal and SFF; and providing an interface between the SFF and access network. In this embodiment, the SFF can be defined as a stand alone module or feature, in order to ease the access network implementation and the scalability based on access network loading and operator network layout. Advantageously, the interface between the Access Terminal and SFF, can support interoperability between different access terminal vendors and SFF vendors. Likewise, the interface defined as being between the SFF and HRPD access network provides and supports interoperability between different HRPD access network vendors and SFF vendors. In a preferred embodiment, the method includes: mapping of the HRPD access terminal identification to the IP address assigned by the non-HRPD network. In order to keep the non-HRPD network free of having to process the HRPD specific information, it is important to use a generic transport mechanism over the data tunnel established between the access terminal and the SFF, and TCP/IP provides such an option. It is necessary that the identification used for identifying the access terminal in the HRPD access be mapped to the TCP/IP domain, where IP addresses are used. This feature enables this function. Also in a preferred embodiment, the method includes routing encapsulated messages by SFF over IP by mapping SectorID to the 1P address of the HRPD access network. The HRPD signaling messages that arrive at the SFF, from the access terminal need to be forwarded to the HRPD access network, and the HRPD signaling messages that arrive at the SFF from the access network need to be forwarded to the access terminal. However, having one SFF for every HRPD access network is impractical. It is desirable to have one SFF serve many HRPD access networks. This feature maps the Identity of the HRPD network, which is identified by the SectorlD uniquely to an IP address of the HRPD network that is reachable within the access network. Referring to FIG. 3, this figure illustrates a HRPD IOS Architecture, as defined in the HRPDIOS standard for 3GPP2, A.S0008 in phantom, which is incorporated herein by reference. Fig. 3 also includes a Signal Forwarding Function. Advantageously, the SFF in the context of this figure and application provides quick and reliable handoffs between HRPD and non-HRPD, as well as a cost effective solution. In more detail, in order to pre-establish a HRPD session (by exchanging the HRPD signaling messages and data over a non-HRPD access), it is necessary that an alternate path is defined. The method and SFF provide: an alternate path such that the non-HRPD access does not have to process the HRPD specific information and the TCP/IP on a data tunnel over non-HRPD; HRPD signaling messages that are sent on TCP/IP over a non-HRPD, be routed to the right access network and access terminal; and translation from a TCP/IP domain to HRPD domain; and security to protect the access network from attack. FIG. 4 is a flow diagram for establishing an HRPD signal link over a non- HRPD air-interface over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access Network-AAA (AN-AAA) and times a-h, illustrating how a link is opened. In more detail, items a through h provide a detailed flow over time and in sequence. At time a, the AT establishes an IP connection. The IP connection is established over a non-EVDO air interface. At time b, the AT sends AlternateLinkOpenReq message over the IP bearer to Signal Forwarding Function. The AlternateLinkOpenReq message contains the identity of the mobile station. At time c, the Signal Forwarding Function, upon getting the AltemateLinkOpenReq message obtains the Access Terminal credentials from the AN-AAA. At time d, the Signal Forwarding Function, triggers authentication of the mobile, in order to establish a secure data tunnel between Access Terminal and the Signal Forwarding Function. At time e, a secure data tunnel is created between the Signal Forwarding Function and the Access Terminal. At time f, a Signal Forwarding Function, sends the Axx-AlternateLinkOpenReq message to Access Network. At time g, the Access Network responds back to Signal Forwarding Function, with an Axx- AlternateLinkOpenResp message. At item h, the Signal Forwarding Function forwards an AlternateLinkOpenResp message to the Access Terminal. Advantages, This procedure advantageously provides an effective way of establishing an alternate signaling link, and preferably it can include means for a network to conduct authentication and establish a secure tunnel. In addition, it can include a mechanism provides an effective way of discovering if the access network supports the HRPD signaling over an alternate link, without having to inform the access network capability by explicit means, which could be time consuming and expensive. As used herein, Access Network-AAA (AN-AAA) means Access Network - Authentication, Authorization & Accounting: Authentication refers to the confirmation that a user who is requesting services is a valid user of the network services requested. Authentication is accomplished via the presentation of an identity and credentials. Examples of types of credentials are passwords, one-time tokens, digital certificates, and phone numbers (calling/called). Authorization refers to the granting of specific types of service (including "no service") to a user, based on their authentication, what services they are requesting. and the current system state. Authorization may be based on restrictions, for example time-of-day restrictions, or physical location restrictions, or restrictions against multiple logins by the same user. Authorization determines the nature of the service which is granted to a user. Examples of types of service include, but are not limited to: IP address filtering, address assignment, route assignment, QoS/differential services, bandwidth control/traffic management, compulsory tunneling to a specific endpoint and encryption. Accounting refers to the tracking of the consumption of network resources by users. This information may be used for management, planning, billing, or other purposes. Real-time accounting refers to accounting information that is delivered concurrently with the consumption of the resources. Batch accounting refers to accounting information that is saved until it is delivered at a later time. Typical information that is gathered in accounting is the identity of the user, the nature of the service delivered, when the service began and when it ended. FIG. 5 is a flow diagram for closing (or turning off) an HRPD signal link over a non-HRPD air-interface over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN). Access Network-AAA (AN-AAA) and times a-f, illustrating how a link is turned off. accordance with the invention. In a preferred embodiment and in more detail, at time a, the AT has already established a secure data tunnel between an Access Terminal and the Signal Forwarding Function (SFF). At time b, the AT sends AlternateLinkCloseReq messages to SFF, over the IP bearer. At time c, the Signal Forwarding Function, upon receiving the AlternateLinkCloseReq initiates a procedure to close the alternate link connection between the access terminal and the access network, and sends an Axx- AlternateLinkCloseReq message to the access network. At time d, the access network, responds back with Axx-AlternateLinkCloseResp message. At time e, the SFF completes the procedure to close the alternate link and sends AltemateLinkCloseResp to the access terminal. And, at time f, a secure data tunnel is closed between the access terminal and the SFF. As used herein, IP bearer refers to a data transport using TCP/IP as the mechanism for end-to-end transport protocol. This provides a reliable procedure for closing or turning off the alternate signaling link between the HRPD access network and the access terminal over non- HRPD air-interfaces, ensuring the synchronization of a Signaling Adaptation state machine running on access terminal and the access network, in one embodiment. FIG. 6 is a flow diagram showing HRPD signaling exchanges over a non- HRPD air-interface using TCP/IP over time, the diagram includes columns for each of the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access Network-AAA (AN-AAA) and times a-c, accordance with the invention. In more detail and in a preferred embodiment, at time a, the AT has already established a secure data tunnel between Access Terminal and the Signal Forwarding Function (SFF). At time b, the AT sends AltemateLinkMessage messages to the SFF, over the IP bearer. The AltemateLinkMessage has an encapsulated HRPD signaling message, with the header information for the SFF to determine which Access Network this message should be forwarded to. And, at time c, the SFF, upon receiving the AltemateLinkMessage forwards the message to the appropriate access network. This provides a mechanism for exchanging the HRPD signaling messages and HRPD data transparently over non-HRPD access, without requiring the non-HRPD network to interpret and process the HRPD specific information Referring to Fig. 15, an alternate embodiment of a signaling adaptation method 50 for converting HRPD messages and HRPD data on to a generic container that can be transported over a non-HRPD access, is shown. The method 50, comprises the steps of: providing 52 a HRPD protocol including a Signal Adaptation Protocol (SAP) including an open state, set up state and a default closed state; requesting 54 an alternate HRPD signaling link over a non-HRPD access to be opened; activating 56 the alternate HRPD signaling link upon entering the open state; adapting 58 (and encapsulating) the HRPD signaling messages and HRPD Radio Link Protocol (RLP) data on to a non-HRPD access; exchanging 60 HRPD signaling messages and HRPD data between the access terminal and the HRPD access network via the alternate HRPD signaling link, free of establishing an HRPD traffic channel; and identifying 62 the HRPD access network and the access terminal over non-HRPD access by inserting a header comprising sector identification, stream identification and access terminal identification. The method performs an initiation and session establishment procedure, minimizes the time, disruption and packet loss during handoff to a HRPD access network and enables seamless mobility. Advantageously, the method provides a mechanism or process for exchanging HRPD signaling messages and HRPD data over the dedicated radio connection of non-HRPD technology which reduces the cost of development of a multimode access terminal capable of performing active session handoff between non-HRPD wireless technology and HRPD cellular technology. To provide context, to send or receive HRPD signaling messages according to known methods, such as in 3GPP2 C.S0024A, entitled "cdma2000 High Rate Packet Data Air Interface Specification", September 2006, a dedicated radio connection needs to be established. The dedicated radio connection is defined as a particular state of the air-link in which the AT is assigned a forward traffic channel, a reverse traffic channel and associated medium access control channels. In a multimode mobile device, wherein a HRPD wireless technology and a non-HRPD wireless technology is implemented, and when a non-HRPD is on a dedicated radio connection, it is expensive and redundant to have the HRPD technology also be on a dedicated radio connection simultaneously. In order for a multimode access terminal with one technology such as HRPD to perform active session handoff (where in active session means, the access terminal is sending and receiving user data on a dedicated radio connection) from non-HRPD wireless technology to HRPD wireless technology, it is required per 3GPP2 C.S0024A, that an HRPD session be established, which includes HRPD signaling messages and HRPD data is exchanged on a dedicated radio connection between an access terminal and HRPD access network. However, having two dedicated radio connections would be expensive in implementation and technologically complicated. This method 50 provides a cost effective method and mechanism for exchanging HRPD signaling messages and HRPD data over a dedicated non-HRPD radio connection, which reduces the cost of development of a multimode access terminal capable of performing active session handoff between non-HRPD wireless technology and HRPD technology. In a preferred embodiment, the method 50 can further include providing pre- establishment of an HRPD session, HRPD point-to-point (PPP) and HRPD internet protocol (IP) session over a non-HRPD access, free of establishing an HRPD traffic channel. In order for a multimode access terminal with one technology such as HRPD to perform active session handoff from non-HRPD wireless technology to HRPD wireless technology, it is required under 3GPP2 C.S0024A, that an HRPD session, PPP session and an IP session be established, which includes HRPD signaling messages and HRPD data be exchanged on a dedicated radio connection between an access terminal and a HRPD access network. In a multimode mobile device, wherein HRPD wireless technology and a non-HRPD wireless technology is implemented and when a non-HRPD is on a dedicated radio connection, it would be costly and technologically redundant and use valuable air time to have the HRPD technology also be on the dedicated radio connection simultaneously. This pre-establishing feature allows a multimode access terminal the capability of performing active session handoff between non-HRPD wireless technology and HRPD cellular technology. In yet another preferred embodiment, the method 50 includes performing traffic establishment free of a HRPD access channel procedure. This advantageously provides a means of transmitting HRPD access channel messages over the alternate link on a non-HRPD network, thus bypassing access channel procedures of HRPD to obtain a traffic channel. As context, current implementations, such as the HRPD 3GPP2 C.S0024A standard, requires access channel procedures, such as exchanging access channel messages, which introduce additional time in the active session handoff from non- HRPD to HRPD. Generally, access channel messages are sent in order to obtain a traffic channel assignment for a dedicated radio connection between a HRPD access network and an access terminal. To reduce the time it takes to perform active session handoff from a non- HRPD network to a HRPD network, in a preferred embodiment, the access channel messages are sent free of performing access procedures, thus effectively bypassing such procedures. This provides an effective handoff and an improvement to the user experience during handoff. In yet another embodiment, the method 50 can include providing an alternate link open request message including an identity of the access terminal and the connection is an IP connection, as shown in FIGs. 12-14. This feature provides an beneficial procedure where an identity of the access terminal is sent in an Alternate Link Open Request message, such that the access network can validate the credentials of the access terminal and optionally perform authentication and validation procedures in order to ensure a secure communication link between the access terminal and the access network over a non HRPD network. FIG. 7 is an illustration of a Protocol Structure as defined by HRPD Standard IS856, which is hereby incorporated herein by reference. It also shows a default signaling path, as detailed herein. The figure shows an HRPD layered architecture with a modular design that allows partial updates to protocols, software and independent protocol negotiation. Detailed below is a general discussion of the protocol stack layers shown in FIG. 7. Starting at the bottom right and moving up, the Physical Layer provides the channel structure, frequency, power output, modulation, and encoding specifications for the Forward and Reverse link channels and provides protocols to support the procedure. The Medium Access Control (MAC) layer defines the protocol to support procedures that are used to receive and transmit over the Physical Layer. The Security Layer provides protocols to support authentication and encryption services. The Connection Layer provides protocols to support air link connection establishment and maintenance services. The Session Layer provides protocols to support protocol negotiation, protocol configuration, and session state maintenance services. The Stream Layer provides protocols to support multiplexing of distinct application streams. The Application Layer provides application protocols to support the Default Signaling Application for transporting HRPD protocol messages and the Default Packet Application for transporting user data. For more detail, refer to the HRPD Standard IS856. FIG. 8 is an environmental illustration showing the Protocol Structure as defined by HRPD Standard IS856, in Fig. 7, including a Signaling Adaptation Protocol (SAP) and signaling path in an opened (operational) position, in accordance with the invention. The SAP provides FIGs. 9, 10 and 11 show three embodiments of the Signaling Adaptation Protocol in Fig. 8 and exemplary signaling paths in an opened (operational) state. In one embodiment, the SNP protocol messages and the RLP packets are forwarded to the SAP, shown in the solid line signaling paths in FIG. 9. In order perform HRPD session establishment, free of establishing the dedicated radio communication between HRPD access network and a multimode access terminal, for example, this method advantageously provides a procedure for forwarding the signaling messages generated by all of the seven layers of the HRPD protocol stack to the Signaling Adaptation Protocol through the Signaling Network Protocol (SNP). Thus, by forwarding: 1.) the HRPD signaling messages generated by all the layers of HRPD to the Signaling Adaptation Protocol from the SNP (left solid line signal path in FIG. 9); and 2.) the HRPD data that is generated or passed through by the Radio Link Protocol (RLP) to the Signaling Adaptation Protocol ( through the right signaling path in FIG. 9), this minimizes the technical impact on known implementations, such as the IS-56A HRPD standard. In addition, In FIGs. 9 and 10, a SAP state controlling a switch is shown, as a double-pole like switch, which provides two software connected switches, to allow a signal to follow the default path (in phantom, closed state) or operational state following the solid line signaling paths. In a second embodiment, as shown in FIG. 10, the Signaling Link Protocol-D (SLP-D) protocol messages and the RLP packets are forwarded to the SAP. In order perform HRPD session establishment, free of establishing the dedicated radio communication between HRPD access network and a multimode access terminal, this method advantageously provides a procedure for forwarding the signaling messages generated by all of the seven layers of the HRPD protocol stack to the Signaling Adaptation Protocol through the Signaling Network Protocol (SNP) and Signaling Link Protocol (SLP-D). By forwarding the HRPD signaling messages generated by all the layers of HRPD to the Signaling Adaptation Protocol, by the SLP, this frees the SAP to perform sequencing and retransmission of the signaling messages, and hence simplifies the Signaling Adaptation Protocol procedures. In addition, HRPD data that is generated or passed through by the Radio Link Protocol (RLP) is forwarded to the Signaling Adaptation Protocol. In a third embodiment, as shown in FIG. 11, packets of stream protocol arc forwarded to the SAP. In order to perform HRPD session establishment, free of establishing the dedicated radio communication between HRPD access network and a multimode access terminal, this method advantageously provides a procedure for forwarding the signaling messages generated by all of the seven layers of the HRPD protocol stack to the Signaling Adaptation Protocol through the Signaling Network Protocol (SNP) and Signaling Link Protocol (SLP-D) and the steam protocol. By forwarding the HRPD signaling messages generated by all the layers of HRPD to the Signaling Adaptation Protocol, by the stream protocol, frees the SAP to perform sequencing and retransmission of the signaling messages as well as the inclusion and interpretation of stream identifier, which further simplifies the Signaling Adaptation Protocol procedures. In addition, HRPD data that is generated or passed through by the Radio Link Protocol (RLP) is forwarded to the Signaling Adaptation Protocol through the stream protocol further simplifies the development of Signaling Adaptation Protocol. FIGs. 12 and 13 show Access Terminal and Access Network State Machines of the Signaling Adaptation Protocol, in Fig. 9 including a Closed State, Setup State and Open State, illustrating how an alternate link is opened. The method advantageously provides a procedure to effectively transition from a non-HRPD alternate link to a default HRPD signaling link and vice versa. The state transition and the messages defined in this method ensure an effective way of synchronizing a HRPD network and a multimode access terminal. In addition, another benefit of this feature is it provides a mechanism to determine the support of Signaling Adaptation Protocol or the Alternate Link Support by the access network, free of explicit signaling, which reduces the usage of radio frequency resources of the HRPD and non-HRPD wireless system. FIG. 14 is a flow diagram for establishing an HRPD signal link over a non- HRPD air-interface over time, the diagram includes columns for each of the Alternate Link, Signaling Network Protocol (SNP), Signaling Adaptation Protocol (SAP). Access Network (AN), and times a-1, in accordance with the invention. In a preferred embodiment, the method 50 further includes providing a message sequence for requesting and activating the alternate link by the SAP. This feature advantageously provides a means to establish and adapt the HRPD signaling messages free of establishing a dedicated HRPD radio connection, in a cost effective manner. This method can also provide backward compatibility with HRPD access networks and mobile devices that are already implemented and deployed, such as under the 3GPP2-C.S0024A standard. In more detail, the flow diagram depicts the dynamic behavior of Signaling Adaptation Protocol in the context of other protocols already defined in the HRPD standard, C.S0024A. At time a, a mobile device powers up, At time b, a Signaling Network Protocol Activates the Signaling Adaptation Protocol. At time c, Signaling Adaptation Protocol initializes its local variables and enters a closed state. At time d. when a dedicated channel is available on an alternate link, SNP is informed about it. At time e, the SNP sets the availability on an alternate link to true. At time f, the SNP detects the need to send signaling messages to a network. It activates the signaling over Alternate Link by sending, SAP.AlternateLinkActivate. At time g, the SAP sends AlternateLinkOpenReq message to the network. At time h, the SAP enters a setup state and updates the appropriate variables. At time i, the Network sends an AlternateLinkOpenResp message, after it sets-up the signaling link over the alternate link. This can involve secure data-tunnel setup, etc. At time j, the SAP enters an open state and sets appropriate variables. At time k, the SAP sends SAP.AlternateLinkOpenlnd indication to the SNP. And at time 1, the SNP sets AlternateLinkOpen status to true. It should be understood that the inventive concepts disclosed herein are capable of many modifications. To the extent such modifications fall within the scope of the appended claims and their equivalents, they are intended to be covered by this patent application. CLAIMS We claim: 1. A method of establishing an alternate HRPD signaling link between an HRPD access network and an access terminal over a non-HRPD access, comprising: providing a signal forwarding function (SFF) between an access terminal and a high rate packet data (HRPD) access network; establishing a data tunnel between the access terminal and the SFF ; exchanging HRPD signaling messages and HRPD data via the data tunnel; identifying the HRPD access network and the access terminal over non- HRPD access by the SFF, by reading a header comprising HRPD sector identification, access terminal identification and stream identification and mapping the header to an address of one of the access terminal and the access network; and forwarding the HRPD signaling messages and the HRPD data that arrive at the SFF from the access terminal and the HRPD access network to the HRPD access network and the access terminal respectively. 2. The method of claim 1, further comprising the step of pre-establishing an HRPD session over a non-HRPD access defined as at least one of a non-HRPD air interface, a non-HRPD access network and a non-HRPD core network, prior to establishing a traffic channel on an HRPD air-interface. 3. The method of claim 1, further comprising the step of authenticating and pre- establishing an HRPD session from a non-HRPD access, prior to establishing a traffic channel on an HRPD air-interface. 4. The method of claim 1, wherein the data tunnel is secure. 5. The method of claim 1, further comprising the step of allowing HRPD access channel messaging transaction between the access terminal and the HRPD access network over a non-HRPD access. 6. The method of claim 1, wherein the access network includes at least one of a base station controller and radio network controller. 7. The method of claim 1, further comprising closing the data tunnel between the access terminal and SFF. 8. The method of claim 1, further comprising at least one of: providing an interface between the access network and SFF; providing an interface between the SFF and access network; mapping of the HRPD access terminal identification to an IP address assigned by the non-HRPD network; and routing encapsulated messages by SFF over IP by mapping SectorID to an IP address of the HRPD access network. 9. A signaling adaptation method for converting HRPD messages and HRPD data on to a generic container that can be transported over a non-HRPD access, comprising: providing a HRPD protocol including a Signal Adaptation Protocol (SAP) including an open state, set up state and a default closed state; requesting an alternate HRPD signaling link over a non-HRPD access to be opened; activating the alternate HRPD signaling link upon entering the open state; adapting (encapsulating) the HRPD signaling messages and HRPD Radio Link Protocol (RLP) data on to a non-HRPD access; exchanging HRPD signaling messages and HRPD data between the access terminal and the HRPD access network via the alternate HRPD signaling link, free of establishing an HRPD traffic channel; and identifying the HRPD access network and the access terminal over non- HRPD access by inserting a header comprising sector identification, stream identification and access terminal identification. 10. The method of claim 9, wherein the alternate link is a data tunnel and the non- HRPD access is defined as at least one of a non-HRPD air interface, a non-HRPD access network and a non-HRPD core network. 11. The method of claim 11, further comprising at least one of: forwarding SNP protocol messages and RLP packets to the SAP; forwarding SLP-D protocol messages and RLP packets to the SAP; and forwarding packets of stream protocol to the SAP 12. The method of claim 9, further comprising providing state machines for at least one of the access terminal and access network. 13. The method of claim 9, further comprising providing a message sequence for requesting and activating the alternate HRPD signaling link by the SAP. 14. The method of claim 9, further comprising pre-establishing an HRPD session. HRPD point-to-point (PPP) and HRPD internet protocol (IP) session over non-HRPD access, free of establishing an HRPD traffic channel, the non-HRPD access being defined as at least one of a non-HRPD air interface, a non-HRPD access network and a non-HRPD core network. 15. The method of claim 9, further comprising performing traffic establishment free of HRPD access channel procedure. 16. The method of claim 9, further comprising providing an alternate link open request message including an identity of the access terminal and the connection is an IP connection. 17. A signaling adaptation method for converting HRPD messages and HRPD data on to a generic container that can be transported over a non-HRPD access, comprising: providing a HRPD protocol including a Signal Adaptation Protocol (SAP) including an open state, set up state and a default closed state; requesting an alternate HRPD signaling link over a non-HRPD access to be opened; activating the alternate HRPD signaling link upon entering the open state; adapting or encapsulating the HRPD signaling messages and HRPD Radio Link Protocol (RLP) data on to a non-HRPD access, the non-HRPD access being defined as at least one of a non-HRPD air interface, a non-HRPD access network and a non-HRPD core network; exchanging HRPD signaling messages and HRPD data between the access terminal and the HRPD access network via the alternate HRPD signaling link, free of establishing an HRPD traffic channel; identifying the HRPD access network and the access terminal over non- HRPD access by inserting a header comprising sector identification, stream identification and access terminal identification; providing at least one state machine for the access terminal and access network; and providing a message sequence for requesting and activating the alternate HRPD signaling link by the SAP. 18. The method of claim 17, further comprising forwarding SNP protocol messages and RLP packets to the SAP. 19. The method of claim 17, further comprising at least one of: forwarding SNP protocol messages and RLP packets to the SAP; forwarding the SLP-D protocol messages and the RLP packets to the SAP; and forwarding packets of stream protocol to the SAP. 20. The method of claim 17, further comprising pre-establishing an HRPD session, HRPD point-to-point (PPP) and HRPD internet protocol (IP) session over non-HRPD access, free of establishing an HRPD traffic channel. A method (10) of establishing an alternate HRPD signaling link between an HRPD access network and an access terminal over a non-HRPD access is disclosed. It includes: providing (12) a signal forwarding function (SFF) (22) between an access terminal (AT) (24) and a high rate packet data (HRPD) access network (AN) (26); establishing (14) a data tunnel (28) between the access terminal (24) and the SFF (22); exchanging (16) HRPD signaling messages and HRPD data via the data tunnel (28); identifying (18) the HRPD access network (26) and the access terminal (24) over non-HRPD access by the SFF (22), by reading a header with certain identifiers and mapping the header to an address of the access terminal or network; and forwarding (20) the HRPD signaling messages and the HRPD data that arrive at the SFF (22) from the access terminal (24) and the HRPD access network (26) to the HRPD access network (26) and the access terminal (24), respectively. The method (10) performs an initiation and session establishment procedure, minimizes the time, disruption and packet loss during handoff to a HRPD access network and enables seamless mobility.

Full Text

METHOD OF ESTABLISHING A HRPD SIGNAL LINK
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of establishing an HRPD signal link,
and more particularly to a method of establishing an alternate HRPD signaling link
between the access terminal and the access network over a non-HRPD access and the
pre-establishment of HRPD sessions over the alternate signaling link.
2. Description of the Related Art
There is interest in developing multi-mode devices, capable of seamlessly
transferring data, voice and video services from one radio technology to another one,
without adversely affecting the user-experience.
One such device is 3GPP2-EVDO interoperating with other wireless
standards, such as 3GPP Long Term Evolution (LTE), WLAN, WiMax, etc. This type
of inter-technology handoffs is gaining special attention, as there is keen interest in
integrating different air-interface technologies. Also as major cellular operators
migrate to 4G and newer operators in broadband space emerge, multi-mode radio
devices will be needed for both intra-operator as well as inter operator roaming for
the foreseeable future as 4G technologies mature.
A real-time data-session, for example, a VoIP call, that is initiated on one
technology, such as LTE, may move or roam into an area where only HRPD is
available. It becomes necessary to transfer the VoIP call from LTE to HRPD
seamlessly and without a long delay.
However, the HRPD requires that a session is established, before it is allowed
to make/receive any type of calls. The initialization and session establishment of
HRPD includes the following steps, which requires signaling exchanges between a
mobile device and the HRPD network: 1. Unicast Access Terminal Identifier (UATI)

assignment procedure, 2. HRPD session establishment procedure, 3. Access
Authentication, 4. Point-to-point protocol (PPP) set-up, and 5. IP-setup as a
preparation for a future handoff to HRPD. However, the complexity and cost
constraints limit the mobile device to have typically, one transmitter antenna, which is
standard industry practice today.
In the example detailed above, this would require that there is an additional
transmitter available for signaling exchanges for initialization and session
establishment, while the device is actively transmitting and receiving on the other
radio-interface.
This invention proposes a method and solution to perform the initialization
and session-establishment procedure of HRPD, from a mobile active on a non-HRPD
network or other air-interface, such as LTE, WLAN, WiMax, etc., so as to minimize
the disruption and packet loss during handoff or transfer to HRPD network, free of
having to use two transmitter antennas.
Thus, there is a need to perform the initialization and session-establishment
procedure of HRPD, from a mobile active on a non-HRPD air-interface (by way of
example, this term includes LTE, WLAN, WiMax and the like), so as to minimize the
disruption and packet loss during handoff or transfer to the HRPD air-interface, which
is cost effective, quick or user friendly and free from requiring use of two transmitter
antennas, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the inventive aspects of this disclosure will be best
understood with reference to the following detailed description, when read in
conjunction with the accompanying drawings, in which:
FIG. 1 is a simplified illustration of HRPD signaling on a non-HRPD access,
in accordance with the invention.
FIG. 2 is a block diagram for a method of establishing an HRPD signal link
over a non-HRPD access, in accordance with the invention.

FIG. 3 illustrates a HRPD 10S Architecture, as defined in the HRPDIOS
standard for 3GPP2, A.S0008 in phantom, including a Signal Forwarding Function
and a new interface (Axx), in accordance with the invention.
FIG. 4 is a flow diagram for establishing an HRPD signal link over a non-
HRPD access over time, the diagram includes columns for each of the Access
Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access
Network-AAA (AN-AAA) and times a-h, illustrating how a link is opened or
established, in accordance with the invention.
FIG. 5 is a flow diagram for closing (or turning off) an HRPD signal link over
a non-HRPD access over time, the diagram includes columns for each of the Access
Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access
Network-AAA (AN-AAA) and times a-f, illustrating how a link is turned off or
terminated, in accordance with the invention.
FIG. 6 is a flow diagram showing HRPD signaling exchanges over a non-
HRPD access using TCP/IP over time, the diagram includes columns for each of the
Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN).
Access Network-AAA (AN-AAA) and times a-c, in accordance with the invention.
FIG. 7 is an illustration of a Protocol Structure as defined by HRPD Standard
IS856, illustrating a default signaling path and a default data path, as detailed herein.
FIG. 8 is an environmental illustration showing the Protocol Structure as
defined by HRPD Standard IS856, in Fig. 7, including a Signaling Adaptation
Protocol (SAP) and signaling path in an opened (operational) position, in accordance
with the invention.
FIG. 9 is an embodiment of the Signaling Adaptation Protocol in Fig. 8 and
exemplary signaling path in an opened state (operational), in accordance with the
invention.
FIG. 10 is an alternate second embodiment of the Signaling Adaptation
Protocol in Fig. 8 and exemplary signaling path in an opened state (operational), in
accordance with the invention.
FIG. 11 is an alternate third embodiment of the Signaling Adaptation Protocol
in Fig. 8 and exemplary signaling path in an opened state (operational), in accordance
with the invention.

FIG. 12 shows an Access Terminal State Machine of the Signaling Adaptation
Protocol, in Fig. 8 including a Closed State, Setup State and Open State, illustrating
how an alternate link is opened and closed, in accordance with the invention.
FIG. 13 shows an Access Network State Machine of the Signaling Adaptation
Protocol, in Fig. 8 including a Closed State, Setup State and Open State, illustrating
how an alternate link is opened and closed, in accordance with the invention.
FIG. 14 is a flow diagram for establishing an HRPD signal link over a non-
HRPD air-interface over time, the diagram includes columns for each of the Alternate
Link, Signaling Network Protocol (SNP), Signaling Adaptation Protocol (SAP).
Access Network (AN), and times a-1, in accordance with the invention.
FIG. 15 is a block diagram of an embodiment of a signaling adaptation method
for converting HRPD messages and HRPD data on to a generic container that can be
transported over a non-HRPD access, in accordance with the invention.
DETAILED DESCRIPTION
Referring to Figs. 1 and 2, a method 10 of establishing an alternate HRPD
signaling link between an HRPD access network and an access terminal over a non-
HRPD access, is shown. The method 10 generally includes a providing step 12, an
establishing step 14, an exchanging step 16, an identifying step 18 and a forwarding
step 20. In more detail, the method 10 includes: providing 12 a signal forwarding
function (SFF) 22 between an access terminal (AT) 24 and a high rate packet data
(HRPD) access network (AN) 26; establishing 14 a data tunnel 28 between the access
terminal 24 and the SFF 22; exchanging 16 HRPD signaling messages and HRPD
data via the data tunnel 28; identifying 18 the HRPD access network 26 and the
access terminal 24 over non-HRPD access by the SFF 22, by reading a header
comprising HRPD sector identification, access terminal identification and stream
identification and mapping the header to an address of one of the access terminal and
the access network; and forwarding 20 the HRPD signaling messages and the HRPD
data that arrive at the SFF 22 from the access terminal 24 and the HRPD access
network 26 to the HRPD access network 26 and the access terminal 24, respectively.
Advantageously, the method 10 performs an initiation and session establishment

procedure, minimizes the time, disruption and packet loss during handoff to a HRPD
access network and enables seamless mobility.
In more detail, the method 10 performs the initiation and session establishment
procedure for HRPD. For example, in use an AT 24, such as a mobile, would by
active on a non-HRPD access (such as 3GPP Long Term Evolution (LTE), wireless
local area network (WLAN), and WIMax). The method 10 is adapted to minimize the
time, disruption and packet loss during handoff to a HRPD access network and
maximize user's experiences. In one embodiment, the HRPD signaling messages are
over a TCP/IP link, with a newly defined header to uniquely identify the HRPD
Access Network. In addition, the method 10 is particularly adapted for use in multi-
mode devices or access terminals, with HRPD as one of the access technologies.
Stated another way, the method 10 provides seamless mobility between HRPD and
non-HRPD air-interface technologies.
Detailed below and throughout this application are brief definitions of the
terms and acronyms used. All such terms and acronyms have their common ordinary
meanings, unless explicitly stated to the contrary. The definitions herein arc an
attempt at clarity.
1. Evolution-Data Optimized or Evolution-Data are abbreviated as EV-DO or
EVDO or 1xEV.
2. High Data Rate (HDR) and High Rate Packet Data (HRPD) generically refer
to telecommunications standards for the wireless transmission of data through
radio signals. HRPD can provide for broadband Internet access and various
data services including real time data services like Voice Over Internet
Protocol (VoIP).
3. EVDO employs multiplexing techniques such as CDMA (Code division
multiple access) as well as Frequency division duplex (FDD) to maximize the
amount of data transmitted. It is standardized by the 3rd Generation
Partnership Project 2 (3GPP2), as part of the CDMA2000 family of standards
and has been adopted by many mobile phone service providers around the
world, and particularly those previously employing CDMA networks. A more
detailed description of the CDMA2000 High Rate Packet Data (HRPD)
EVDO (Evolution Data Optimized) is provided in 3GPP2 C.S0024-A, entitled

"cdma2000 High Rate Packet Data Air Interface Specification", September
2006, and in TIA-IS-856 (also known as IS856).
4. An HRPD session refers to a shared state between an access terminal (AT) and
the access network (AN). Other than to open a session, the AT cannot
communicate with the AN without having an open session.
5. A connection or dedicated radio connection, refers to a particular state of an
air-link in which the AT is assigned a forward traffic channel, a reverse traffic
channel and associated medium access control channels.
6. As used herein, the HRPD acronym generically refers to and includes, by way
of example, HDR, EV-DO, EVDO, 1 x EV, CDMA, CDMA2000 Evolution
Data Optimized (EVDO), standards TIA-IS-856, 3GPP2 HRPD
interoperability specification A.S0008, cdma2000 wireless IP network based
standard TIA-IS-835 and the like.
7. 3G refers to Third Generation Cellular Technology
8. 3GPP refers to Third Generation Partnership Project, a standardization group
that develops GSM standards and its evolution
9. 3GPP2 refers to a Third Generation Partnership Project 2, a standardization
group that develops cdma2000 development
10. 4G refers to Fourth Generation broadband wireless technology
11. WiMAX means Worldwide Interoperability for Microwave Access
12. TCP means Transmission Control Protocol (a part of TCP/IP)
13. IP is Internet Protocol (a part of TCP/IP)
In one embodiment, the method 20 includes pre-establishing an HRPD session
over a non-HRPD access prior to establishing a traffic channel on an HRPD air-
interface. In order to perform a handoff between non-HRPD access and HRPD access,
it is required that an HRPD session be established before the handoff (at a suitable
radio-frequency). A problem in real time services like Voice over IP (VoIP) is that
the HRPD session establishment takes a period of time, in the order of seconds, which
can introduce an unacceptable break in communication. In order to support low-
latency (low set up time) active session handoffs between non-HRPD and HRPD
access, the method 20 provides a solution and effective procedures, to pre-establish

the HRPD session, while on the non-HRPD access, before the radio frequency
antenna switches from non-HRPD access to HRPD access.
The term HRPD access as used herein, includes at least one of HRPD air-
interface, HRPD access network, wherein access network includes a radio network
controller, base station(s) and the like and HRPD core-network, wherein the core-
network includes Packet Data Service Network (PDSN), Mobile IP Home agent.
Mobile IP foreign agent and the like and the term non-HRPD access as used herein,
includes at least one of non-HRPD air-interface, non-HRPD access network and non-
HRPD core-network.
In one embodiment, the method 20 includes authenticating and pre-
establishing an HRPD session from a HRPD multi-mode access terminal, (wherein
the HRPD multi-mode access terminal is a mobile device, which implements one or
more than one access technology in addition to HRPD access technology) active on a
non-HRPD access, prior to establishing a traffic channel on an HRPD air-interface.
Preferably, this includes obtaining UATI assignment, protocol subtype negotiation
and protocol configuration parameters negotiation of all protocol layers of HRPD,
prior to establishing a traffic channel. In order to perform an active session handoff
between non-HRPD and HRPD, it may be required that access terminal obtain UATI
from the access network by means of UATI assignment, negotiate the protocol
subtypes and protocol configuration parameters between the HRPD access network
and the access terminal. However, these procedures can take an unacceptable period
of time (negative user experience) and can cause an unacceptable break in
communication, in known real time services like VoIP. As used above, active session
means the access terminal is sending and receiving user data on a dedicated radio
connection.
Advantageously, in order to support low latency (break in communication
reduced to a minimum) active session handoff between non-HRPD and HRPD access,
the method includes establishing effective procedures to obtain the HRPD UATI,
HRPD protocol subtypes and configuration parameters while on the non-HRPD
access, before the radio frequency antenna switches from non-HRPD access to the
HRPD access

In one embodiment, the data tunnel in FIG. 1, is secure in order to minimize
the possibility of a security attack on the access network as well as to protect the
privacy of the access terminal.
In another embodiment, the method includes the step of allowing HRPD
access channel messaging from and to a non-HRPD air-interface access terminal. This
feature can reduce the time it takes to perform a handoff from a non-HRPD network
to a HRPD network, for example. In this embodiment, it is desirable that the access
procedures that are required on HRPD to obtain HRPD traffic channel be bypassed,
thus advantageously improving the user experience during handoff.
As should be understood by those skilled in the art, an access network can
include a base station controller, radio network controller, a plurality of the preceding
and the like. It is understood that, a base station provides a Radio Frequency (RF)
interface between an access terminal and an access network via one or more
transceivers. An access network exchanges the signaling messages with a HRPD
access terminal in order to establish the session, maintenance of session and so on.
In yet another embodiment, the method can include: providing an interface
between the access terminal and SFF; and providing an interface between the SFF and
access network. In this embodiment, the SFF can be defined as a stand alone module
or feature, in order to ease the access network implementation and the scalability
based on access network loading and operator network layout. Advantageously, the
interface between the Access Terminal and SFF, can support interoperability between
different access terminal vendors and SFF vendors. Likewise, the interface defined as
being between the SFF and HRPD access network provides and supports
interoperability between different HRPD access network vendors and SFF vendors.
In a preferred embodiment, the method includes: mapping of the HRPD access
terminal identification to the IP address assigned by the non-HRPD network. In order
to keep the non-HRPD network free of having to process the HRPD specific
information, it is important to use a generic transport mechanism over the data tunnel
established between the access terminal and the SFF, and TCP/IP provides such an
option. It is necessary that the identification used for identifying the access terminal in
the HRPD access be mapped to the TCP/IP domain, where IP addresses are used. This
feature enables this function.

Also in a preferred embodiment, the method includes routing encapsulated
messages by SFF over IP by mapping SectorID to the 1P address of the HRPD access
network. The HRPD signaling messages that arrive at the SFF, from the access
terminal need to be forwarded to the HRPD access network, and the HRPD signaling
messages that arrive at the SFF from the access network need to be forwarded to the
access terminal. However, having one SFF for every HRPD access network is
impractical. It is desirable to have one SFF serve many HRPD access networks. This
feature maps the Identity of the HRPD network, which is identified by the SectorlD
uniquely to an IP address of the HRPD network that is reachable within the access
network.
Referring to FIG. 3, this figure illustrates a HRPD IOS Architecture, as
defined in the HRPDIOS standard for 3GPP2, A.S0008 in phantom, which is
incorporated herein by reference. Fig. 3 also includes a Signal Forwarding Function.
Advantageously, the SFF in the context of this figure and application provides quick
and reliable handoffs between HRPD and non-HRPD, as well as a cost effective
solution. In more detail, in order to pre-establish a HRPD session (by exchanging the
HRPD signaling messages and data over a non-HRPD access), it is necessary that an
alternate path is defined. The method and SFF provide: an alternate path such that the
non-HRPD access does not have to process the HRPD specific information and the
TCP/IP on a data tunnel over non-HRPD; HRPD signaling messages that are sent on
TCP/IP over a non-HRPD, be routed to the right access network and access terminal;
and translation from a TCP/IP domain to HRPD domain; and security to protect the
access network from attack.
FIG. 4 is a flow diagram for establishing an HRPD signal link over a non-
HRPD air-interface over time, the diagram includes columns for each of the Access
Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN), Access
Network-AAA (AN-AAA) and times a-h, illustrating how a link is opened.
In more detail, items a through h provide a detailed flow over time and in
sequence. At time a, the AT establishes an IP connection. The IP connection is
established over a non-EVDO air interface. At time b, the AT sends
AlternateLinkOpenReq message over the IP bearer to Signal Forwarding Function.
The AlternateLinkOpenReq message contains the identity of the mobile station. At

time c, the Signal Forwarding Function, upon getting the AltemateLinkOpenReq
message obtains the Access Terminal credentials from the AN-AAA. At time d, the
Signal Forwarding Function, triggers authentication of the mobile, in order to
establish a secure data tunnel between Access Terminal and the Signal Forwarding
Function. At time e, a secure data tunnel is created between the Signal Forwarding
Function and the Access Terminal. At time f, a Signal Forwarding Function, sends the
Axx-AlternateLinkOpenReq message to Access Network. At time g, the Access
Network responds back to Signal Forwarding Function, with an Axx-
AlternateLinkOpenResp message. At item h, the Signal Forwarding Function
forwards an AlternateLinkOpenResp message to the Access Terminal. Advantages,
This procedure advantageously provides an effective way of establishing an
alternate signaling link, and preferably it can include means for a network to conduct
authentication and establish a secure tunnel. In addition, it can include a mechanism
provides an effective way of discovering if the access network supports the HRPD
signaling over an alternate link, without having to inform the access network
capability by explicit means, which could be time consuming and expensive.
As used herein, Access Network-AAA (AN-AAA) means Access Network -
Authentication, Authorization & Accounting:
Authentication refers to the confirmation that a user who is requesting services
is a valid user of the network services requested. Authentication is accomplished via
the presentation of an identity and credentials. Examples of types of credentials are
passwords, one-time tokens, digital certificates, and phone numbers (calling/called).
Authorization refers to the granting of specific types of service (including "no
service") to a user, based on their authentication, what services they are requesting.
and the current system state. Authorization may be based on restrictions, for example
time-of-day restrictions, or physical location restrictions, or restrictions against
multiple logins by the same user. Authorization determines the nature of the service
which is granted to a user. Examples of types of service include, but are not limited
to: IP address filtering, address assignment, route assignment, QoS/differential
services, bandwidth control/traffic management, compulsory tunneling to a specific
endpoint and encryption.

Accounting refers to the tracking of the consumption of network resources by
users. This information may be used for management, planning, billing, or other
purposes. Real-time accounting refers to accounting information that is delivered
concurrently with the consumption of the resources. Batch accounting refers to
accounting information that is saved until it is delivered at a later time. Typical
information that is gathered in accounting is the identity of the user, the nature of the
service delivered, when the service began and when it ended.
FIG. 5 is a flow diagram for closing (or turning off) an HRPD signal link over
a non-HRPD air-interface over time, the diagram includes columns for each of the
Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN).
Access Network-AAA (AN-AAA) and times a-f, illustrating how a link is turned off.
accordance with the invention.
In a preferred embodiment and in more detail, at time a, the AT has already
established a secure data tunnel between an Access Terminal and the Signal
Forwarding Function (SFF). At time b, the AT sends AlternateLinkCloseReq
messages to SFF, over the IP bearer. At time c, the Signal Forwarding Function, upon
receiving the AlternateLinkCloseReq initiates a procedure to close the alternate link
connection between the access terminal and the access network, and sends an Axx-
AlternateLinkCloseReq message to the access network. At time d, the access network,
responds back with Axx-AlternateLinkCloseResp message. At time e, the SFF
completes the procedure to close the alternate link and sends AltemateLinkCloseResp
to the access terminal. And, at time f, a secure data tunnel is closed between the
access terminal and the SFF. As used herein, IP bearer refers to a data transport using
TCP/IP as the mechanism for end-to-end transport protocol.
This provides a reliable procedure for closing or turning off the alternate
signaling link between the HRPD access network and the access terminal over non-
HRPD air-interfaces, ensuring the synchronization of a Signaling Adaptation state
machine running on access terminal and the access network, in one embodiment.
FIG. 6 is a flow diagram showing HRPD signaling exchanges over a non-
HRPD air-interface using TCP/IP over time, the diagram includes columns for each of
the Access Terminal (AT), Signal Forwarding Function (SFF), Access Network (AN),
Access Network-AAA (AN-AAA) and times a-c, accordance with the invention.

In more detail and in a preferred embodiment, at time a, the AT has already
established a secure data tunnel between Access Terminal and the Signal Forwarding
Function (SFF). At time b, the AT sends AltemateLinkMessage messages to the SFF,
over the IP bearer. The AltemateLinkMessage has an encapsulated HRPD signaling
message, with the header information for the SFF to determine which Access
Network this message should be forwarded to. And, at time c, the SFF, upon receiving
the AltemateLinkMessage forwards the message to the appropriate access network.
This provides a mechanism for exchanging the HRPD signaling messages and HRPD
data transparently over non-HRPD access, without requiring the non-HRPD network
to interpret and process the HRPD specific information
Referring to Fig. 15, an alternate embodiment of a signaling adaptation
method 50 for converting HRPD messages and HRPD data on to a generic container
that can be transported over a non-HRPD access, is shown. The method 50, comprises
the steps of: providing 52 a HRPD protocol including a Signal Adaptation Protocol
(SAP) including an open state, set up state and a default closed state; requesting 54 an
alternate HRPD signaling link over a non-HRPD access to be opened; activating 56
the alternate HRPD signaling link upon entering the open state; adapting 58 (and
encapsulating) the HRPD signaling messages and HRPD Radio Link Protocol (RLP)
data on to a non-HRPD access; exchanging 60 HRPD signaling messages and HRPD
data between the access terminal and the HRPD access network via the alternate
HRPD signaling link, free of establishing an HRPD traffic channel; and identifying 62
the HRPD access network and the access terminal over non-HRPD access by inserting
a header comprising sector identification, stream identification and access terminal
identification. The method performs an initiation and session establishment
procedure, minimizes the time, disruption and packet loss during handoff to a HRPD
access network and enables seamless mobility.
Advantageously, the method provides a mechanism or process for exchanging
HRPD signaling messages and HRPD data over the dedicated radio connection of
non-HRPD technology which reduces the cost of development of a multimode access
terminal capable of performing active session handoff between non-HRPD wireless
technology and HRPD cellular technology.

To provide context, to send or receive HRPD signaling messages according to
known methods, such as in 3GPP2 C.S0024A, entitled "cdma2000 High Rate Packet
Data Air Interface Specification", September 2006, a dedicated radio connection
needs to be established. The dedicated radio connection is defined as a particular state
of the air-link in which the AT is assigned a forward traffic channel, a reverse traffic
channel and associated medium access control channels. In a multimode mobile
device, wherein a HRPD wireless technology and a non-HRPD wireless technology is
implemented, and when a non-HRPD is on a dedicated radio connection, it is
expensive and redundant to have the HRPD technology also be on a dedicated radio
connection simultaneously.
In order for a multimode access terminal with one technology such as HRPD
to perform active session handoff (where in active session means, the access terminal
is sending and receiving user data on a dedicated radio connection) from non-HRPD
wireless technology to HRPD wireless technology, it is required per 3GPP2
C.S0024A, that an HRPD session be established, which includes HRPD signaling
messages and HRPD data is exchanged on a dedicated radio connection between an
access terminal and HRPD access network. However, having two dedicated radio
connections would be expensive in implementation and technologically complicated.
This method 50 provides a cost effective method and mechanism for
exchanging HRPD signaling messages and HRPD data over a dedicated non-HRPD
radio connection, which reduces the cost of development of a multimode access
terminal capable of performing active session handoff between non-HRPD wireless
technology and HRPD technology.
In a preferred embodiment, the method 50 can further include providing pre-
establishment of an HRPD session, HRPD point-to-point (PPP) and HRPD internet
protocol (IP) session over a non-HRPD access, free of establishing an HRPD traffic
channel. In order for a multimode access terminal with one technology such as HRPD
to perform active session handoff from non-HRPD wireless technology to HRPD
wireless technology, it is required under 3GPP2 C.S0024A, that an HRPD session,
PPP session and an IP session be established, which includes HRPD signaling
messages and HRPD data be exchanged on a dedicated radio connection between an
access terminal and a HRPD access network. In a multimode mobile device, wherein

HRPD wireless technology and a non-HRPD wireless technology is implemented and
when a non-HRPD is on a dedicated radio connection, it would be costly and
technologically redundant and use valuable air time to have the HRPD technology
also be on the dedicated radio connection simultaneously. This pre-establishing
feature allows a multimode access terminal the capability of performing active session
handoff between non-HRPD wireless technology and HRPD cellular technology.
In yet another preferred embodiment, the method 50 includes performing
traffic establishment free of a HRPD access channel procedure. This advantageously
provides a means of transmitting HRPD access channel messages over the alternate
link on a non-HRPD network, thus bypassing access channel procedures of HRPD to
obtain a traffic channel.
As context, current implementations, such as the HRPD 3GPP2 C.S0024A
standard, requires access channel procedures, such as exchanging access channel
messages, which introduce additional time in the active session handoff from non-
HRPD to HRPD. Generally, access channel messages are sent in order to obtain a
traffic channel assignment for a dedicated radio connection between a HRPD access
network and an access terminal.
To reduce the time it takes to perform active session handoff from a non-
HRPD network to a HRPD network, in a preferred embodiment, the access channel
messages are sent free of performing access procedures, thus effectively bypassing
such procedures. This provides an effective handoff and an improvement to the user
experience during handoff.
In yet another embodiment, the method 50 can include providing an alternate
link open request message including an identity of the access terminal and the
connection is an IP connection, as shown in FIGs. 12-14. This feature provides an
beneficial procedure where an identity of the access terminal is sent in an Alternate
Link Open Request message, such that the access network can validate the credentials
of the access terminal and optionally perform authentication and validation
procedures in order to ensure a secure communication link between the access
terminal and the access network over a non HRPD network.
FIG. 7 is an illustration of a Protocol Structure as defined by HRPD Standard
IS856, which is hereby incorporated herein by reference. It also shows a default

signaling path, as detailed herein. The figure shows an HRPD layered architecture
with a modular design that allows partial updates to protocols, software and
independent protocol negotiation.
Detailed below is a general discussion of the protocol stack layers shown in
FIG. 7. Starting at the bottom right and moving up, the Physical Layer provides the
channel structure, frequency, power output, modulation, and encoding specifications
for the Forward and Reverse link channels and provides protocols to support the
procedure. The Medium Access Control (MAC) layer defines the protocol to support
procedures that are used to receive and transmit over the Physical Layer. The Security
Layer provides protocols to support authentication and encryption services. The
Connection Layer provides protocols to support air link connection establishment and
maintenance services. The Session Layer provides protocols to support protocol
negotiation, protocol configuration, and session state maintenance services. The
Stream Layer provides protocols to support multiplexing of distinct application
streams. The Application Layer provides application protocols to support the Default
Signaling Application for transporting HRPD protocol messages and the Default
Packet Application for transporting user data. For more detail, refer to the HRPD
Standard IS856.
FIG. 8 is an environmental illustration showing the Protocol Structure as
defined by HRPD Standard IS856, in Fig. 7, including a Signaling Adaptation
Protocol (SAP) and signaling path in an opened (operational) position, in accordance
with the invention. The SAP provides
FIGs. 9, 10 and 11 show three embodiments of the Signaling Adaptation
Protocol in Fig. 8 and exemplary signaling paths in an opened (operational) state.
In one embodiment, the SNP protocol messages and the RLP packets are
forwarded to the SAP, shown in the solid line signaling paths in FIG. 9.
In order perform HRPD session establishment, free of establishing the
dedicated radio communication between HRPD access network and a multimode
access terminal, for example, this method advantageously provides a procedure for
forwarding the signaling messages generated by all of the seven layers of the HRPD
protocol stack to the Signaling Adaptation Protocol through the Signaling Network
Protocol (SNP). Thus, by forwarding: 1.) the HRPD signaling messages generated by

all the layers of HRPD to the Signaling Adaptation Protocol from the SNP (left solid
line signal path in FIG. 9); and 2.) the HRPD data that is generated or passed through
by the Radio Link Protocol (RLP) to the Signaling Adaptation Protocol ( through the
right signaling path in FIG. 9), this minimizes the technical impact on known
implementations, such as the IS-56A HRPD standard. In addition,
In FIGs. 9 and 10, a SAP state controlling a switch is shown, as a double-pole
like switch, which provides two software connected switches, to allow a signal to
follow the default path (in phantom, closed state) or operational state following the
solid line signaling paths.
In a second embodiment, as shown in FIG. 10, the Signaling Link Protocol-D
(SLP-D) protocol messages and the RLP packets are forwarded to the SAP. In order
perform HRPD session establishment, free of establishing the dedicated radio
communication between HRPD access network and a multimode access terminal, this
method advantageously provides a procedure for forwarding the signaling messages
generated by all of the seven layers of the HRPD protocol stack to the Signaling
Adaptation Protocol through the Signaling Network Protocol (SNP) and Signaling
Link Protocol (SLP-D). By forwarding the HRPD signaling messages generated by
all the layers of HRPD to the Signaling Adaptation Protocol, by the SLP, this frees the
SAP to perform sequencing and retransmission of the signaling messages, and hence
simplifies the Signaling Adaptation Protocol procedures. In addition, HRPD data that
is generated or passed through by the Radio Link Protocol (RLP) is forwarded to the
Signaling Adaptation Protocol.
In a third embodiment, as shown in FIG. 11, packets of stream protocol arc
forwarded to the SAP. In order to perform HRPD session establishment, free of
establishing the dedicated radio communication between HRPD access network and a
multimode access terminal, this method advantageously provides a procedure for
forwarding the signaling messages generated by all of the seven layers of the HRPD
protocol stack to the Signaling Adaptation Protocol through the Signaling Network
Protocol (SNP) and Signaling Link Protocol (SLP-D) and the steam protocol. By
forwarding the HRPD signaling messages generated by all the layers of HRPD to the
Signaling Adaptation Protocol, by the stream protocol, frees the SAP to perform
sequencing and retransmission of the signaling messages as well as the inclusion and

interpretation of stream identifier, which further simplifies the Signaling Adaptation
Protocol procedures. In addition, HRPD data that is generated or passed through by
the Radio Link Protocol (RLP) is forwarded to the Signaling Adaptation Protocol
through the stream protocol further simplifies the development of Signaling
Adaptation Protocol.
FIGs. 12 and 13 show Access Terminal and Access Network State Machines
of the Signaling Adaptation Protocol, in Fig. 9 including a Closed State, Setup State
and Open State, illustrating how an alternate link is opened. The method
advantageously provides a procedure to effectively transition from a non-HRPD
alternate link to a default HRPD signaling link and vice versa. The state transition and
the messages defined in this method ensure an effective way of synchronizing a
HRPD network and a multimode access terminal. In addition, another benefit of this
feature is it provides a mechanism to determine the support of Signaling Adaptation
Protocol or the Alternate Link Support by the access network, free of explicit
signaling, which reduces the usage of radio frequency resources of the HRPD and
non-HRPD wireless system.
FIG. 14 is a flow diagram for establishing an HRPD signal link over a non-
HRPD air-interface over time, the diagram includes columns for each of the Alternate
Link, Signaling Network Protocol (SNP), Signaling Adaptation Protocol (SAP).
Access Network (AN), and times a-1, in accordance with the invention. In a
preferred embodiment, the method 50 further includes providing a message sequence
for requesting and activating the alternate link by the SAP. This feature
advantageously provides a means to establish and adapt the HRPD signaling
messages free of establishing a dedicated HRPD radio connection, in a cost effective
manner. This method can also provide backward compatibility with HRPD access
networks and mobile devices that are already implemented and deployed, such as
under the 3GPP2-C.S0024A standard.
In more detail, the flow diagram depicts the dynamic behavior of Signaling
Adaptation Protocol in the context of other protocols already defined in the HRPD
standard, C.S0024A. At time a, a mobile device powers up, At time b, a Signaling
Network Protocol Activates the Signaling Adaptation Protocol. At time c, Signaling
Adaptation Protocol initializes its local variables and enters a closed state. At time d.

when a dedicated channel is available on an alternate link, SNP is informed about it.
At time e, the SNP sets the availability on an alternate link to true. At time f, the SNP
detects the need to send signaling messages to a network. It activates the signaling
over Alternate Link by sending, SAP.AlternateLinkActivate. At time g, the SAP
sends AlternateLinkOpenReq message to the network. At time h, the SAP enters a
setup state and updates the appropriate variables. At time i, the Network sends an
AlternateLinkOpenResp message, after it sets-up the signaling link over the alternate
link. This can involve secure data-tunnel setup, etc. At time j, the SAP enters an open
state and sets appropriate variables. At time k, the SAP sends
SAP.AlternateLinkOpenlnd indication to the SNP. And at time 1, the SNP sets
AlternateLinkOpen status to true.
It should be understood that the inventive concepts disclosed herein are
capable of many modifications. To the extent such modifications fall within the scope
of the appended claims and their equivalents, they are intended to be covered by this
patent application.

CLAIMS
We claim:
1. A method of establishing an alternate HRPD signaling link between an
HRPD access network and an access terminal over a non-HRPD access, comprising:
providing a signal forwarding function (SFF) between an access terminal
and a high rate packet data (HRPD) access network;
establishing a data tunnel between the access terminal and the SFF ;
exchanging HRPD signaling messages and HRPD data via the data tunnel;
identifying the HRPD access network and the access terminal over non-
HRPD access by the SFF, by reading a header comprising HRPD
sector identification, access terminal identification and stream
identification and mapping the header to an address of one of the
access terminal and the access network; and
forwarding the HRPD signaling messages and the HRPD data that arrive at
the SFF from the access terminal and the HRPD access network to the
HRPD access network and the access terminal respectively.
2. The method of claim 1, further comprising the step of pre-establishing an
HRPD session over a non-HRPD access defined as at least one of a non-HRPD air
interface, a non-HRPD access network and a non-HRPD core network, prior to
establishing a traffic channel on an HRPD air-interface.
3. The method of claim 1, further comprising the step of authenticating and pre-
establishing an HRPD session from a non-HRPD access, prior to establishing a traffic
channel on an HRPD air-interface.
4. The method of claim 1, wherein the data tunnel is secure.
5. The method of claim 1, further comprising the step of allowing HRPD access
channel messaging transaction between the access terminal and the HRPD access
network over a non-HRPD access.

6. The method of claim 1, wherein the access network includes at least one of a
base station controller and radio network controller.
7. The method of claim 1, further comprising closing the data tunnel between the
access terminal and SFF.
8. The method of claim 1, further comprising at least one of: providing an
interface between the access network and SFF; providing an interface between the
SFF and access network; mapping of the HRPD access terminal identification to an IP
address assigned by the non-HRPD network; and routing encapsulated messages by
SFF over IP by mapping SectorID to an IP address of the HRPD access network.
9. A signaling adaptation method for converting HRPD messages and HRPD
data on to a generic container that can be transported over a non-HRPD access,
comprising:
providing a HRPD protocol including a Signal Adaptation Protocol (SAP)
including an open state, set up state and a default closed state;
requesting an alternate HRPD signaling link over a non-HRPD access to
be opened;
activating the alternate HRPD signaling link upon entering the open state;
adapting (encapsulating) the HRPD signaling messages and HRPD Radio
Link Protocol (RLP) data on to a non-HRPD access;
exchanging HRPD signaling messages and HRPD data between the access
terminal and the HRPD access network via the alternate HRPD
signaling link, free of establishing an HRPD traffic channel; and
identifying the HRPD access network and the access terminal over non-
HRPD access by inserting a header comprising sector identification,
stream identification and access terminal identification.
10. The method of claim 9, wherein the alternate link is a data tunnel and the non-
HRPD access is defined as at least one of a non-HRPD air interface, a non-HRPD
access network and a non-HRPD core network.

11. The method of claim 11, further comprising at least one of: forwarding SNP
protocol messages and RLP packets to the SAP; forwarding SLP-D protocol messages
and RLP packets to the SAP; and forwarding packets of stream protocol to the SAP
12. The method of claim 9, further comprising providing state machines for at
least one of the access terminal and access network.
13. The method of claim 9, further comprising providing a message sequence for
requesting and activating the alternate HRPD signaling link by the SAP.
14. The method of claim 9, further comprising pre-establishing an HRPD session.
HRPD point-to-point (PPP) and HRPD internet protocol (IP) session over non-HRPD
access, free of establishing an HRPD traffic channel, the non-HRPD access being
defined as at least one of a non-HRPD air interface, a non-HRPD access network and
a non-HRPD core network.
15. The method of claim 9, further comprising performing traffic establishment
free of HRPD access channel procedure.
16. The method of claim 9, further comprising providing an alternate link open
request message including an identity of the access terminal and the connection is an
IP connection.
17. A signaling adaptation method for converting HRPD messages and HRPD
data on to a generic container that can be transported over a non-HRPD access,
comprising:
providing a HRPD protocol including a Signal Adaptation Protocol (SAP)
including an open state, set up state and a default closed state;
requesting an alternate HRPD signaling link over a non-HRPD access to
be opened;
activating the alternate HRPD signaling link upon entering the open state;
adapting or encapsulating the HRPD signaling messages and HRPD Radio
Link Protocol (RLP) data on to a non-HRPD access, the non-HRPD

access being defined as at least one of a non-HRPD air interface, a
non-HRPD access network and a non-HRPD core network;
exchanging HRPD signaling messages and HRPD data between the access
terminal and the HRPD access network via the alternate HRPD
signaling link, free of establishing an HRPD traffic channel;
identifying the HRPD access network and the access terminal over non-
HRPD access by inserting a header comprising sector identification,
stream identification and access terminal identification;
providing at least one state machine for the access terminal and access
network; and
providing a message sequence for requesting and activating the alternate
HRPD signaling link by the SAP.
18. The method of claim 17, further comprising forwarding SNP protocol
messages and RLP packets to the SAP.
19. The method of claim 17, further comprising at least one of: forwarding SNP
protocol messages and RLP packets to the SAP; forwarding the SLP-D protocol
messages and the RLP packets to the SAP; and forwarding packets of stream protocol
to the SAP.
20. The method of claim 17, further comprising pre-establishing an HRPD
session, HRPD point-to-point (PPP) and HRPD internet protocol (IP) session over
non-HRPD access, free of establishing an HRPD traffic channel.

A method (10) of establishing an alternate
HRPD signaling link between an HRPD access network
and an access terminal over a non-HRPD access is
disclosed. It includes: providing (12) a signal forwarding
function (SFF) (22) between an access terminal (AT)
(24) and a high rate packet data (HRPD) access network
(AN) (26); establishing (14) a data tunnel (28) between
the access terminal (24) and the SFF (22); exchanging
(16) HRPD signaling messages and HRPD data via
the data tunnel (28); identifying (18) the HRPD access
network (26) and the access terminal (24) over non-HRPD
access by the SFF (22), by reading a header with certain
identifiers and mapping the header to an address of
the access terminal or network; and forwarding (20)
the HRPD signaling messages and the HRPD data that
arrive at the SFF (22) from the access terminal (24)
and the HRPD access network (26) to the HRPD access
network (26) and the access terminal (24), respectively.
The method (10) performs an initiation and session
establishment procedure, minimizes the time, disruption
and packet loss during handoff to a HRPD access network
and enables seamless mobility.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=R6+L6umTUW/jufgKohtdsA==&loc=wDBSZCsAt7zoiVrqcFJsRw==

« Previous Patent

Next Patent »

Patent Number

272705

Indian Patent Application Number

4418/KOLNP/2009

PG Journal Number

17/2016

Publication Date

22-Apr-2016

Grant Date

21-Apr-2016

Date of Filing

21-Dec-2009

Name of Patentee

MOTOROLA, INC.

Applicant Address

1303 EAST ALGONQUIN ROAD, SCHAUMBURG, ILLINOIS 60196 UNITED STATES OF AMERICA

Inventors:

#	Inventor's Name	Inventor's Address
1	LALWANEY, POORNIMA A.	13235 CAPSTONE DRIVE, SAN DIEGO, CALIFORNIA 92130 UNITED STATES OF AMERICA
2	CHERIAN, GEORGE	10955 AVENIDA DE LOS LOBOS, SAN DIEGO, CALIFORNIA 92127 UNITED STATES OF AMERICA

PCT International Classification Number

H04L12/56; H04W36/14; H04L12/56

PCT International Application Number

PCT/US2008/069911

PCT International Filing date

2008-07-14

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	11/778,746	2007-07-17	U.S.A.