OPERATORS

BACKGROUND

Field

[0001] The present disclosure relates generally to communication systems, and more particularly, to enabling multiple high rate packet data (HRPD) operators to share a long term evolution (LTE) radio access network (RAN).

Background

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of an emerging telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using, for example, OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple- output (MEVIO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

[0004] In an aspect of the disclosure, a method, a computer program product, and an apparatus are provided. The apparatus receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet, distinguishes the first code from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator, and determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first code.

[0005] In a further aspect, the apparatus receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet; receives a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator, the second code associated with a second HRPD subnet, wherein a first code value is the same as a second code value; transmits a session transfer request upon receiving a third code associated with a third HRPD subnet, the third code having a value different from the first code value or the second code value; receives a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code; and receives a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code.

[0006] In another aspect, the apparatus receives a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet; distinguishes the first HRPD subnet identifier from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator; and determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first HRPD subnet identifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a diagram illustrating an example of a network architecture.

[0008] FIG. 2 is a diagram illustrating an example of an access network.

[0009] FIG. 3 is a diagram illustrating an example of a base station and user equipment in an access network.

[0010] FIG. 4 is a diagram illustrating an interface between an evolved universal terrestrial radio access network (E-UTRAN)/evolved packet core (EPC) system and a 3GPP2 core network.

[0011] FIG. 5 is a flow chart of a method of wireless communication.

[0012] FIG. 6 is a flow chart of a method of wireless communication.

[0013] FIG. 7 is a flow chart of a method of wireless communication.

[0014] FIG. 8 is a flow chart of a method of wireless communication.

[0015] FIG. 9 is a flow chart of a method of wireless communication.

[0016] FIG. 10 is a flow chart of a method of wireless communication.

[0017] FIG. 11 is a conceptual data flow diagram illustrating the data flow between different modules/means/components in an exemplary apparatus.

[0018] FIG. 12 is a conceptual data flow diagram illustrating the data flow between different modules/means/components in an exemplary apparatus.

[0019] FIG. 13 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0020] FIG. 14 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

[0021] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0022] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0023] By way of example, an element, or any portion of an element, or any combination of elements may be implemented with a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0024] Accordingly, in one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer- readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer- readable media.

[0025] FIG. 1 is a diagram illustrating an LTE network architecture 100. The LTE network architecture 100 may be referred to as an Evolved Packet System (EPS) 100. The EPS 100 may include one or more user equipment (UE) 102, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) 104, an Evolved Packet Core (EPC) 110, a Home Subscriber Server (HSS) 120, and an Operator's IP Services 122. The EPS can interconnect with other access networks, but for simplicity those entities/interfaces are not shown. As shown, the EPS provides packet- switched services, however, as those skilled in the art will readily appreciate, the various concepts presented throughout this disclosure may be extended to networks providing circuit- switched services.

[0026] The E-UTRAN includes the evolved Node B (eNB) 106 and other eNBs 108.

The eNB 106 provides user and control planes protocol terminations toward the UE 102. The eNB 106 may be connected to the other eNBs 108 via a backhaul (e.g., an X2 interface). The eNB 106 may also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The eNB 106 provides an access point to the EPC 110 for a UE 102. Examples of UEs 102 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The UE 102 may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0027] The eNB 106 is connected by an SI interface to the EPC 110. The EPC 110 includes a Mobility Management Entity (MME) 112, other MMEs 114, a Serving Gateway 116, and a Packet Data Network (PDN) Gateway 118. The MME 112 is the control node that processes the signaling between the UE 102 and the EPC 110. Generally, the MME 112 provides bearer and connection management. All user IP packets are transferred through the Serving Gateway 116, which itself is connected to the PDN Gateway 118. The PDN Gateway 118 provides UE IP address allocation as well as other functions. The PDN Gateway 118 is connected to the Operator's IP Services 122. The Operator's IP Services 122 may include the Internet, the Intranet, an IP Multimedia Subsystem (IMS), and a PS Streaming Service (PSS).

[0028] FIG. 2 is a diagram illustrating an example of an access network 200 in an LTE network architecture. In this example, the access network 200 is divided into a number of cellular regions (cells) 202. One or more lower power class eNBs 208 may have cellular regions 210 that overlap with one or more of the cells 202. The lower power class eNB 208 may be a femto cell (e.g., home eNB (HeNB)), pico cell, micro cell, or remote radio head (RRH). The macro eNBs 204 are each assigned to a respective cell 202 and are configured to provide an access point to the EPC 110 for all the UEs 206 in the cells 202. There is no centralized controller in this example of an access network 200, but a centralized controller may be used in alternative configurations. The eNBs 204 are responsible for all radio related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway 116.

[0029] The modulation and multiple access scheme employed by the access network

200 may vary depending on the particular telecommunications standard being deployed. In LTE applications, OFDM is used on the DL and SC-FDMA is used on the UL to support both frequency division duplexing (FDD) and time division duplexing (TDD). As those skilled in the art will readily appreciate from the detailed description to follow, the various concepts presented herein are well suited for LTE applications. However, these concepts may be readily extended to other telecommunication standards employing other modulation and multiple access techniques. By way of example, these concepts may be extended to Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. These concepts may also be extended to Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W- CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDM A. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

[0030] The eNBs 204 may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the eNBs 204 to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data steams may be transmitted to a single UE 206 to increase the data rate or to multiple UEs 206 to increase the overall system capacity. This is achieved by spatially precoding each data stream (i.e., applying a scaling of an amplitude and a phase) and then transmitting each spatially precoded stream through multiple transmit antennas on the DL. The spatially precoded data streams arrive at the UE(s) 206 with different spatial signatures, which enables each of the UE(s) 206 to recover the one or more data streams destined for that UE 206. On the UL, each UE 206 transmits a spatially precoded data stream, which enables the eNB 204 to identify the source of each spatially precoded data stream.

[0031] Spatial multiplexing is generally used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions. This may be achieved by spatially precoding the data for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity.

[0032] In the detailed description that follows, various aspects of an access network will be described with reference to a MIMO system supporting OFDM on the DL. OFDM is a spread- spectrum technique that modulates data over a number of subcarriers within an OFDM symbol. The subcarriers are spaced apart at precise frequencies. The spacing provides "orthogonality" that enables a receiver to recover the data from the subcarriers. In the time domain, a guard interval (e.g., cyclic prefix) may be added to each OFDM symbol to combat inter-OFDM-symbol interference. The UL may use SC-FDMA in the form of a DFT-spread OFDM signal to compensate for high peak- to-average power ratio (PAPR).

[0033] FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, upper layer packets from the core network are provided to a controller/processor 375. The controller/processor 375 implements the functionality of the L2 layer. In the DL, the controller/processor 375 provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE 350 based on various priority metrics. The controller/processor 375 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE 350.

[0034] The transmit (TX) processor 316 implements various signal processing functions for the LI layer (i.e., physical layer). The signal processing functions includes coding and interleaving to facilitate forward error correction (FEC) at the UE 350 and mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase- shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then split into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream is then provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX modulates an RF carrier with a respective spatial stream for transmission.

[0035] At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The RX processor 356 implements various signal processing functions of the LI layer. The RX processor 356 performs spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, is recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359.

[0036] The controller/processor 359 implements the L2 layer. The controller/processor can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the core network. The upper layer packets are then provided to a data sink 362, which represents all the protocol layers above the L2 layer. Various control signals may also be provided to the data sink 362 for L3 processing. The controller/processor 359 is also responsible for error detection using an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support HARQ operations.

[0037] In the UL, a data source 367 is used to provide upper layer packets to the controller/processor 359. The data source 367 represents all protocol layers above the L2 layer. Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 implements the L2 layer for the user plane and the control plane by providing header compression, ciphering, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations by the base station 310. The controller/processor 359 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the base station 310.

[0038] Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 are provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX modulates an RF carrier with a respective spatial stream for transmission.

[0039] The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370. The RX processor 370 may implement the LI layer.

[0040] The controller/processor 375 implements the L2 layer. The controller/processor

375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the control/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the UE 350. Upper layer packets from the controller/processor 375 may be provided to the core network. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

[0041] FIG. 4 is a diagram 400 illustrating an interface between an evolved universal terrestrial radio access network (E-UTRAN)/evolved packet core (EPC) system and a 3GPP2 core network. In one example, the UE 410 may have radio access to a high rate packet data serving gateway (HSGW) 440 and an enhanced high rate packet data access network (eAN)/packet control function (PCF) 430 via a high rate packet data (HRPD) base transceiver station (BTS) 420. The UE 410 may also have radio access to an E-UTRAN 450. As such, FIG. 4 illustrates how the UE 410 accesses the EPC from an LTE radio access technology and an enhanced high rate packet data (eHRPD) radio access technology.

[0042] The EPC is a common core network for an LTE or eHRPD wireless communication system. The common core network serves as a common backbone infrastructure for a wireless communication system. The EPC may include any one of the following entities: mobility management entity (MME) 460, serving gateway (SGW) 470, packet data network (PDN) gateway 480, home subscriber server (HSS) 490, authentication authorization and accounting entity (AAA), access network discovery and selection function (ANDSF), evolved packet data gateway (ePDG), etc. An LTE network may be shared by more than one high rate packet data (HRPD) network operator. The LTE network may advertise a parameter indicating a footprint of an HRPD network. The parameter may be referred to as a preregistration zone ID or HRPD color code, for example. When the UE moves from one HRPD subnet to another HRPD subnet, the UE may perform a session transfer operation for transferring a session from the one HRPD subnet to the other HRPD subnet. The UE may request the session transfer by sending a unicast access terminal identifier (UATI) assignment request message to the LTE network.

The UE monitors the LTE network, but may not monitor an HRPD network. Therefore, a mechanism is needed for indicating to the UE when to perform an HRPD session setup or session transfer operation even though the UE does not directly monitor the HRPD network. To setup a session transfer operation, the UE may establish a tunnel with the HRPD network through the LTE network and perform the session transfer operation. While the UE is in an idle mode, no tunnel is established and the UE does not monitor the HRPD network. The preregistration zone ID (or HRPD color code) may be transmitted as a broadcast message so that idle UEs may informed of when to initiate a session transfer operation as the UE moves from one HRPD footprint to another HRPD footprint.

The HRPD color code may be a 24 bit-value, which is a reduced value of an actual parameter indicating an HRPD subnet, i.e., a subnet ID. The subnet ID may be a 128-bit value. To save air interface resources, the 24-bit color code is transmitted by the LTE network instead of the 128-bit subnet ID to indicate an HRPD subnet.

The 24-bit color code may be unique to a particular location (e.g., area or region). Accordingly, when the UE moves from one area to another area, because the 24-bit value may be unique to an area, the UE may immediately detect whether an HRPD color code has changed, and hence detect whether an HRPD subnet has changed, and perform a session transfer operation to a new HRPD subnet having a new 128- bit subnet ID. The UE may correlate the new 24-bit value (new color code value) with the new 128-bit subnet ID.

Therefore, to quickly detect whether an HRPD subnet has changed, the UE assesses a newly received color code. If the received color code has changed from a previously received color code, the UE initiates a session transfer operation to obtain a new 128-bit subnet ID value. The UE may then associate the new 128-bit subnet ID value with the new color code received.

[0048] In an aspect, when two HRPD networks are overlaid on the same LTE network, two HRPD footprints exist. Accordingly, the LTE network should be able to indicate to the UE whether an HRPD color code transmission (HRPD preregistration zone ID transmission) is related to a first HRPD footprint or a second HRPD footprint. This prevents the UE connected to the first HRPD operator from potentially performing a false session transfer operation when the footprint of the second HRPD operator has changed.

[0049] Because the first and second HRPD operators are not coordinated, the HRPD color code (preregistration zone ID) of the first HRPD operator may be the same as the HRPD color code of the second HRPD operator. For example, a UE A is connected to HRPD operator A with subnet ID A matched to color code X. Moreover, a UE B is connected to HRPD operator B with subnet ID B, which is also matched to color code X. Thus, both color codes having the same value are transmitted (advertised) by the LTE network. When the color codes are received by the UE A connected to HRPD operator A, the UE A may realize at some point that the color code X changes to a color code Y. However, the UE A does not know for which HRPD operator (A or B) the color code change applies to. That is, the UE A does not know whether the subnet A or the subnet B has changed, and therefore may inappropriately perform a session transfer operation based on the color code change even if the subnet (HRPD subnet A) it is currently connected to has not changed.

[0050] The 24-bit HRPD color code value may be independently managed by an HRPD operator. Thus, different HRPD operators may choose to use the same value. The 24-bit value may be used in conjunction with a unique 128-bit HRPD subnet ID value. Accordingly, what is needed is a mechanism for distinguishing between a first HRPD operator and a second HRPD operator sharing the same LTE network when a transmitted HRPD color code (preregistration zone ID) of the first HRPD operator has the same value as a transmitted HRPD color code (preregistration zone ID) of the second HRPD operator.

[0051] In an aspect, a new format for the HRPD color code may be defined. Here, the

LTE network may demand from HRPD operators that a color code of a respective HRPD operator have a unique identifier. The unique identifier allows the UE to distinguish one HRPD operator from other HRPD operators. The LTE operator may work with the HRPD operators to make sure that the color codes do not overlap or have the same value.

[0052] For example, when two HRPD operators sharing the same LTE network exist, one bit of the 24-bit color code may be reserved for uniquely identifying an HRPD operator. As such, the first HRPD operator may be identified by "0" and the second HRPD operator may be identified by "1" using the reserved bit. Additional bits may be reserved to accommodate the identification of more than two HRPD operators. Hence, a unique identifier may include X most significant bits embedded in the 24- bit color code, where X is an integer (e.g., 2). Alternatively, a standard format may be defined for uniquely identifying an HRPD operator using the 24-bit color code. For example, a portion of the 24-bit color code may be reserved for embedding a 12- bit mobile network code (MNC) identifying an HRPD operator.

[0053] The color code used by an HRPD session matches a preregistration zone ID.

Hence, within an operator network, the operator specifies a new coding format for the color code. The new coding format may be used in both the eHRPD network and in the LTE network. By using the above-described mechanism, the color codes (preregistration zone IDs) for different HRPD operators transmitted by the LTE network are guaranteed to be different in a location (area or region).

[0054] In another aspect, the UE may receive color codes associated with different

HRPD operators having the same value. However, the color codes may not include a unique identifier for distinguishing between the different HRPD operators. Accordingly, when the UE receives a new color code different from the previously received color codes, the UE will assume that an HRPD subnet currently connected to the UE has changed. This will cause the UE to send a session transfer request (e.g., UATI assignment request message) to the LTE network for transferring a session to the HRPD subnet the UE believes is a new HRPD subnet. Accordingly, an enhanced high rate packet data access network (eAN) will respond to the UE with a session transfer response (e.g., UATI assignment response message) even if the HRPD color code (preregistration zone ID), and hence the HRPD subnet, has not changed.

[0055] In a further aspect, the parameter used by the LTE network for advertising a footprint of an HRPD network is the subnet ID. As stated above, the subnet ID is 128-bit value indicating an HRPD subnet. The subnet ID is unique to the HRPD operator and may be used to avoid potential overlap between multiple HRPD operators, as may be the case when using an HRPD color code (preregistration zone ID). Hence, when the UE receives two or more HRPD subnet IDs from the LTE network, the UE is able to distinguish one HRPD operator from other HRPD operators. Accordingly, the when the UE moves from one HRPD subnet to another HRPD subnet, the UE may easily determine to perform a session transfer operation for transferring a session from the one HRPD subnet to the other HRPD subnet based on the unique subnet ID.

[0056] FIG. 5 is a flow chart 500 of a method of wireless communication. The method may be performed by a UE. At step 502, the UE receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet. At step 504, the UE distinguishes the first code from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator.

[0057] At step 506, the UE determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first code. In particular, the UE determines if a value of the distinguished first code is different from a code value associated with a current HRPD subnet. If so, at step 508, the UE performs the session transfer operation to the first HRPD subnet.

[0058] In an aspect, the code may be an HRPD color code, or preregistration zone ID, indicating a footprint of an HRPD network. The first code may include an identifier for distinguishing the first code from the second code. Moreover, the first code may be an 8-bit code and the identifier may be X most significant bits unique to the first HRPD operator embedded in the 8-bit code, where X is a set of bits less than 8 bits. Alternatively, X may be a hash of a 12-bit mobile network code (MNC) embedded in the 8 -bit code. In an alternate aspect, the identifier X may be a new field (different from the preregistration zone ID) that is associated with the preregistration zone ID, and is set to a public land mobile network (PLMN) identifier of the corresponding preregistration zone ID. The association may be derived based on the order of inclusion of the preregistration zone ID with respect to X.

[0059] FIG. 6 is a flow chart 600 of a method of wireless communication. The method may be performed by an eNB. At step 602, the eNB transmits a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet. The first code is distinguishable from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. At step 604, the eNB receives at least one request to transfer a session to the first HRPD subnet based on the first code. A value of the distinguished first code may be different from a code value associated with a current HRPD subnet.

[0060] In an aspect, the code may be an HRPD color code, or preregistration zone ID, indicating a footprint of an HRPD network. The first code may include an identifier for distinguishing the first code from the second code. Moreover, the first code may be an 8-bit code and the identifier may be X most significant bits unique to the first HRPD operator embedded in the 8-bit code, where X is a set of bits less than 8 bits. Alternatively, the identifier may be a hash of a 12-bit mobile network code (MNC) embedded in the 8-bit code.

[0061] FIG. 7 is a flow chart 700 of a method of wireless communication. The method may be performed by a UE. At step 702, the UE receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet. At step 704, the UE receives a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator. The second code is associated with a second HRPD subnet. Moreover, a first code value is the same as a second code value.

[0062] At step 706, the UE transmits a session transfer request upon receiving a third code associated with a third HRPD subnet. The third code has a value different from the first code value or the second code value. At step 708, the UE receives a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code. At step 710, the UE receives a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code.

[0063] FIG. 8 is a flow chart 800 of a method of wireless communication. The method may be performed by an eNB. At step 802, the eNB transmits a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet. At step 804, the eNB transmits a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator. The second code is associated with a second HRPD subnet. A first code value is the same as a second code value.

[0064] At step 806, the eNB receives a session transfer request upon transmitting a third code associated with a third HRPD subnet. The third code has a value different from the first code value or the second code value. At step 808, the eNB transmits a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code. At step 810, the UE transmits a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code.

[0065] FIG. 9 is a flow chart 900 of a method of wireless communication. The method may be performed by a UE. At step 902, the UE receives a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet. At step 904, the UE distinguishes the first HRPD subnet identifier from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator.

[0066] At step 906, the UE determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first HRPD subnet identifier. In particular, the UE determines if the distinguished first HRPD subnet identifier is different from an HRPD subnet identifier associated with a current HRPD subnet. If so, at step 908, the UE performs the session transfer operation to the first HRPD subnet.

[0067] FIG. 10 is a flow chart 1000 of a method of wireless communication. The method may be performed by an eNB. At step 1002, the eNB transmits a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet. The first HRPD subnet identifier is distinguishable from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. At step 1004, the eNB receives at least one request to transfer a session to the first HRPD subnet based on the first HRPD subnet identifier. The first HRPD subnet identifier may be different from an HRPD subnet identifier associated with a current HRPD subnet. FIG. 11 is a conceptual data flow diagram 1100 illustrating the data flow between different modules/means/components in an exemplary apparatus 1102. The apparatus may be a UE. The apparatus includes a receiving module 1104, a code distinguishing module 1106, a session transfer module 1108, a subnet ID distinguishing module 1110, and transmission module 1112.

The receiving module 1104 receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet from an eNB 1150. The code distinguishing module 1106 distinguishes the first code from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. The session transfer module 1108 determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first code. In particular, the session transfer module 1108 determines if a value of the distinguished first code is different from a code value associated with a current HRPD subnet. If so, the session transfer module 1108 performs the session transfer operation to the first HRPD subnet via the transmission module 1112.

In an aspect, the code may be an HRPD color code, or preregistration zone ID, indicating a footprint of an HRPD network. The first code may include an identifier for distinguishing the first code from the second code. Moreover, the first code may be a 24-bit code and the identifier may be X most significant bits unique to the first HRPD operator embedded in the 24-bit code, where X is an integer. Alternatively, the identifier may be a 12-bit mobile network code (MNC) embedded in the 24-bit code.

In a further aspect, the receiving module 1104 receives a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet and a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator. The second code is associated with a second HRPD subnet. Moreover, a first code value is the same as a second code value.

The session transfer module 1108 transmits a session transfer request via the transmission module 1112 upon receiving a third code associated with a third HRPD subnet. The third code has a value different from the first code value or the second code value. The session transfer module 1108 receives a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code. The session transfer module 1108 may also receive a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code.

[0073] In another aspect, the receiving module 1104 receives a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet. The subnet ID distinguishing module 1110 distinguishes the first HRPD subnet identifier from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. The session transfer module 1108 determines whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first HRPD subnet identifier. In particular, the session transfer module 1108 determines if the distinguished first HRPD subnet identifier is different from an HRPD subnet identifier associated with a current HRPD subnet. If so, the session transfer module 1108 performs the session transfer operation to the first HRPD subnet via the transmission module 1112.

[0074] The apparatus may include additional modules that perform each of the steps of the algorithm in the aforementioned flow charts of FIGs. 5, 7, and 9. As such, each step in the aforementioned flow charts of FIGs. 5, 7, and 9 may be performed by a module and the apparatus may include one or more of those modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

[0075] FIG. 12 is a conceptual data flow diagram 1200 illustrating the data flow between different modules/means/components in an exemplary apparatus 1202. The apparatus may be an eNB. The apparatus includes a receiving module 1204, a code generating module 1206, a session transfer module 1208, a subnet ID generating module 1210, and transmission module 1212.

[0076] The transmission module 1212 transmits to the UE 1250 a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet. The first code may be generated by the code generating module 1206. The first code is distinguishable from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. The session transfer module 1208 receives, via the receiving module 1204, at least one request to transfer a session to the first HRPD subnet based on the first code. A value of the distinguished first code may be different from a code value associated with a current HRPD subnet.

[0077] In an aspect, the code may be an HRPD color code, or preregistration zone ID, indicating a footprint of an HRPD network. The first code may include an identifier for distinguishing the first code from the second code. Moreover, the first code may be a 24-bit code and the identifier may be X most significant bits unique to the first HRPD operator embedded in the 24-bit code, where X is an integer. Alternatively, the identifier may be a 12-bit mobile network code (MNC) embedded in the 24-bit code.

[0078] In a further aspect, the transmission module 1212 transmits a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet, and a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator. The second code is associated with a second HRPD subnet. A first code value may be the same as a second code value.

[0079] The session transfer module 1208 receives a session transfer request upon a third code associated with a third HRPD subnet being transmitted. The third code has a value different from the first code value or the second code value. The session transfer module 1208 transmits a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code. The session transfer module 1208 may also transmit a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code.

[0080] In another aspect, the transmission module 1212 transmits a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet. The first HRPD subnet identifier may be generated by the subnet ID generating module 1210. The first HRPD subnet identifier is distinguishable from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator. The session transfer module 1208 receives at least one request to transfer a session to the first HRPD subnet based on the first HRPD subnet identifier. The first HRPD subnet identifier may be different from an HRPD subnet identifier associated with a current HRPD subnet.

[0081] The apparatus may include additional modules that perform each of the steps of the algorithm in the aforementioned flow charts of FIGs. 6, 8, and 10. As such, each step in the aforementioned flow charts of FIGs. 6, 8, and 10 may be performed by a module and the apparatus may include one or more of those modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

[0082] FIG. 13 is a diagram 1300 illustrating an example of a hardware implementation for an apparatus 1102' employing a processing system 1314. The processing system 1314 may be implemented with a bus architecture, represented generally by the bus 1324. The bus 1324 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1314 and the overall design constraints. The bus 1324 links together various circuits including one or more processors and/or hardware modules, represented by the processor 1304, the modules 1104, 1106, 1108, 1110, 1112 and the computer-readable medium 1306. The bus 1324 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

[0083] The processing system 1314 may be coupled to a transceiver 1310. The transceiver 1310 is coupled to one or more antennas 1320. The transceiver 1310 provides a means for communicating with various other apparatus over a transmission medium. The processing system 1314 includes a processor 1304 coupled to a computer-readable medium 1306. The processor 1304 is responsible for general processing, including the execution of software stored on the computer- readable medium 1306. The software, when executed by the processor 1304, causes the processing system 1314 to perform the various functions described supra for any particular apparatus. The computer-readable medium 1306 may also be used for storing data that is manipulated by the processor 1304 when executing software. The processing system further includes at least one of the modules 1104, 1106, 1108, 1110, and 1112. The modules may be software modules running in the processor 1304, resident/stored in the computer readable medium 1306, one or more hardware modules coupled to the processor 1304, or some combination thereof. The processing system 1314 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359.

In one configuration, the apparatus 1102/1102' for wireless communication includes means for receiving a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet; means for distinguishing the first code from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator; means for determining whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first code; means for performing the session transfer operation to the first HRPD subnet when a value of the distinguished first code is different from a code value associated with a current HRPD subnet; means for receiving a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet; means for receiving a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator, the second code associated with a second HRPD subnet, wherein a first code value is the same as a second code value; means for transmitting a session transfer request upon receiving a third code associated with a third HRPD subnet, the third code having a value different from the first code value or the second code value; means for receiving a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code; means for receiving a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code; means for receiving a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet; means for distinguishing the first HRPD subnet identifier from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator; means for determining whether to perform a session transfer operation to the first HRPD subnet based on the distinguished first HRPD subnet identifier; and means for performing the session transfer operation to the first HRPD subnet when the first HRPD subnet identifier is different from an HRPD subnet identifier associated with a current HRPD subnet.

[0085] The aforementioned means may be one or more of the aforementioned modules of the apparatus 1102 and/or the processing system 1314 of the apparatus 1102' configured to perform the functions recited by the aforementioned means. As described supra, the processing system 1314 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

[0086] FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for an apparatus 1202' employing a processing system 1414. The processing system 1414 may be implemented with a bus architecture, represented generally by the bus 1424. The bus 1424 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1414 and the overall design constraints. The bus 1424 links together various circuits including one or more processors and/or hardware modules, represented by the processor 1404, the modules 1204, 1206, 1208, 1210, 1212 and the computer-readable medium 1406. The bus 1424 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

[0087] The processing system 1414 may be coupled to a transceiver 1410. The transceiver 1410 is coupled to one or more antennas 1420. The transceiver 1410 provides a means for communicating with various other apparatus over a transmission medium. The processing system 1414 includes a processor 1404 coupled to a computer-readable medium 1406. The processor 1404 is responsible for general processing, including the execution of software stored on the computer- readable medium 1406. The software, when executed by the processor 1404, causes the processing system 1414 to perform the various functions described supra for any particular apparatus. The computer-readable medium 1406 may also be used for storing data that is manipulated by the processor 1404 when executing software. The processing system further includes at least one of the modules 1204, 1206, 1208, 1210, and 1212. The modules may be software modules running in the processor 1404, resident/stored in the computer readable medium 1406, one or more hardware modules coupled to the processor 1404, or some combination thereof. The processing system 1414 may be a component of the eNB 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

In one configuration, the apparatus 1202/1202' for wireless communication includes means for transmitting a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet, the first code distinguishable from a second code associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator; means for receiving at least one request to transfer a session to the first HRPD subnet based on the first code; means for transmitting a first code associated with a first high rate packet data (HRPD) operator and a first HRPD subnet; means for transmitting a second code associated with a second high rate packet data (HRPD) operator sharing a long term evolution (LTE) network with the first HRPD operator, the second code associated with a second HRPD subnet, wherein a first code value is the same as a second code value; means for receiving a session transfer request upon transmitting a third code associated with a third HRPD subnet, the third code having a value different from the first code value or the second code value; means for transmitting a first session transfer response associated with one of the first HRPD operator and the second HRPD operator for transferring a session from a current HRPD subnet to the third HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has changed to the third code; means for transmitting a second session transfer response associated with one of the first HRPD operator and the second HRPD operator for maintaining a session in the current HRPD subnet when the code associated with one of the first HRPD operator and the second HRPD operator has not changed to the third code; means for transmitting a first high rate packet data (HRPD) subnet identifier associated with a first HRPD operator and a first HRPD subnet, the first HRPD subnet identifier distinguishable from a second HRPD subnet identifier associated with a second HRPD operator sharing a long term evolution (LTE) network with the first HRPD operator; and means for receiving at least one request to transfer a session to the first HRPD subnet based on the first HRPD subnet identifier.

[0089] The aforementioned means may be one or more of the aforementioned modules of the apparatus 1202 and/or the processing system 1414 of the apparatus 1202' configured to perform the functions recited by the aforementioned means. As described supra, the processing system 1414 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

[0090] It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Further, some steps may be combined or omitted. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0091] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless specifically stated otherwise, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase "means for."