CN1887020A - Intersystem handover between wireless communication networks of different radio access technologies - Google Patents

Abstract

Various schemes for performing inter-system handoff, e.g., from a UTRAN to a cdma2000 Radio Access Network , are disclosed. For a MAHHO scheme, the UTRAN uses measurements obtained by a multi-RAT device to determine the cdma2000 cells suitable for handover. The measurement values are obtained through an alternative frequency search procedure and the handover is completed through a handover execution procedure. For an MDHHO scheme, the UTRAN relies on the location information of the multi-RAT device to select a cdma2000 cell suitable for handover. For a CRHHO scheme, a new call is established over the cdma2000RAN and the pending call over the UTRAN is released in a manner that makes the handover appear seamless to the multi-RAT device. The multi-RAT device includes two modem processors that perform processing for the UTRAN and cdma2000RAN and an application processor that controls the modem processors.

Description

Intersystem handover between wireless communication networks of different radio access technologies

Related Application Cross Reference

This application claims the benefit of Provisional US Application No. 60/508,452, filed October 2, 2003, and entitled "Inter-System Handoff Procedures."

technical field

The present disclosure relates generally to communications, and more particularly to techniques for intersystem handoff of a wireless device between two wireless communication networks that are different radio access technologies.

Background technique

Wireless communication systems are widely used to provide various communication services such as voice, packet data, and the like. These systems may be multiple access systems capable of supporting multiple users by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, and Frequency Division Multiple Access (FDMA) systems. A CDMA system may implement a Radio Access Technology (RAT) such as Wideband-CDMA (W-CDMA), cdma2000, or others. RAT refers to a technology used for radio communication. A TDMA system may implement a RAT such as Global System for Mobile Communications (GSM). W-CDMA and GSM are described in a set of documents from a consortium called the "3rd Generation Partnership Project" (3GPP). cdma2000 is described in a set of documents from a consortium named "3rd Generation Partnership Project 2" (3GPP2). 3GPP and 3GPP2 documents are publicly available.

W-CDMA and cdma2000 are third generation (3G) RATs that can provide enhanced services and capabilities (eg, higher data transfer rates, parallel voice and data calls, etc.). W-CDMA and cdma2000 utilize different signal processing and control. Thus, a CDMA system implements W-CDMA or cdma2000, if at all.

A wireless multi-RAT device, such as a dual-mode cellular phone, may have the capability to communicate with both W-CDMA and cdma2000 systems. This may thereby enable a user/subscriber to obtain service from both W-CDMA and cdma2000 systems and to extend the coverage of the same device. For example, a multi-RAT device may first establish communication with a W-CDMA system and thereafter move out of the coverage area of the W-CDMA system and into the coverage area of a cdma2000 system. In such a situation, it would be desirable to hand off (or transfer) the multi-RAT device from the W-CDMA system to the cdma2000 system in a manner that minimizes interruption of pending communications. Regrettably, 3GPP and 3GPP2 have not elaborated the terms for implementing handover from W-CDMA system to cdma2000 system yet.

Accordingly, there is a need in the art to provide techniques for implementing inter-system handover (eg, from a W-CDMA system to a cdma2000 system) for a multi-RAT device.

Contents of the invention

Techniques for implementing inter-system handoff using various schemes are set forth herein. These schemes include a measurement-assisted hard handoff (MAHHO) scheme, a measurement-directed hard handoff (MDHHO) scheme, and a call reestablishment hard handoff (CRHHO) scheme. These schemes can be implemented for a multi-RAT device having, for example: (1) a first modem processor, which is a first ("serving") wireless network (with which it currently has a pending call ) performs processing, (2) a second second modem processor that performs processing on a second ("target") wireless network to which the device is to be handed off, and (3) an application processor that performs processing on a second ("target") wireless network to which the device is to be handed off Controlling the first and second modem processors. The first and second wireless networks may be, for example, a UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network (UTRAN) and a cdma2000 Radio Access Network (RAN) respectively.

For the MAHHO scheme, the UTRAN uses measurements obtained by the multi-RAT device to determine a cdma2000 cell suitable for handover of the device to. The measurements are obtained by performing an alternate frequency search procedure, and handover is accomplished by performing a handover execution procedure. For the MDHHO scheme, the UTRAN relies on the location information of the multi-RAT device to select the most suitable cdma cell for handover to. For the CRHHO scheme, a new call is established on the target wireless network and the pending call on the serving wireless network is released. The new call may be originated or terminated by the multi-RAT device. The call setup and call release may also be implemented to make the handover appear seamless to the multi-RAT device with minimal disruption to communications. Exemplary signal flows for all three intersystem handover schemes are described below.

In an embodiment of the CRHHO scheme, the first modem processor processes a call pending with the first wireless network (eg, UTRAN), receives a first message (such as a Handover from UTRAN Command (from UTRAN handover command)) to implement handover to the second wireless network (such as a cdma2000 RAN), and provide notification of the handover. The application processor receives the notification from the first modem processor and instructs the second modem processor to establish a new call with the second wireless network. In response thereto, the second demodulator processor establishes a traffic channel with the second wireless network and performs processing for the new call. The first wireless network releases the pending call and the application processor switches the data path from the first wireless network to the second wireless network (eg, from UTRAN to a cdma2000 vocoder).

Various aspects and embodiments of the present invention will be further described in detail below.

Description of drawings

Read above-mentioned detailed description in conjunction with accompanying drawing, will understand the feature and property of the present invention more easily, in all accompanying drawings, identical reference symbol all represents identical meaning, in accompanying drawing:

Figure 1 shows a deployment comprising a UTRAN and a cdma200 RAN;

Figure 2 shows a multi-RAT device with two modem processors;

Figure 3 shows another view of the multi-RAT device;

4A and 4B show two procedures for transferring the capabilities of a multi-RAT device to UTRAN;

Figure 5 shows the layer 3 processing status of IS-2000;

Figure 6 shows an alternative frequency search procedure for MAHHO;

Figure 7 shows a handover execution procedure of MAHHO;

Figure 8 shows a MAHHO procedure without previous synchronization information;

Figure 9 shows a MAHHO procedure with previous synchronization information;

Figures 10A and 10B show a CRHHO procedure in the case of call reestablishment by Mobile Termination (MT); and

11A and 11B show a CRHHO procedure in case of mobile originated (MO) call re-establishment.

Detailed ways

As used herein, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any implementation or design termed "example" herein is not necessarily to be construed as better or advantageous over other implementations or designs.

The inter-system handover technology described herein can be used in various wireless communication systems and networks. A network usually refers to a system deployment, although the two terms are often used interchangeably. Handover and handover, which are also generic terms, refer to the transfer or handover of a wireless device from one network controller to another. For clarity, these techniques are specifically illustrated for handover from a UTRAN to a cdma2000 RAN. In the following description, UMTS generically refers to the technology described by 3GPP, and cdma2000 generically refers to the technology described by 3GPP2.

Figure 1 shows a deployment including a UTRAN 110 and a cdma2000 RAN 120. UTRAN 110 may support W-CDMA in frequency division duplex (FDD) mode and/or GSM in time division duplex (TDD) mode. The W-CDMA standard is the part related to W-CDMA in the 3GPP specification.

UTRAN 110 includes: (1) Node Bs 112, which provide communication for wireless devices within the UTRAN coverage area, and (2) a radio network controller (RNC) 114, which provide coordination and control for Node Bs. The RNC 114 is further connected to a core network (CN), and the core network (CN) implements switching and routing for user services and provides network management functions. The core network includes various network entities such as UMTS Mobile Switching Center (MSC) 116 . UMTS MSC 116 provides circuit-switched communications (eg, for voice calls) and further supports GSM Mobile Application Part (GSM-MAP) - a mobile network protocol that enables roaming and advanced services.

Likewise, the cdma2000 RAN 120 includes: (1) a base transceiver system (BTS) 122 that provides communication for wireless devices within the coverage area of the cdma2000 RAN and (2) a base station controller (BSC) 124 that provides coordination for the BTS and control. The cdma2000 RAN 120 may implement IS-2000, IS-856, IS-95 and/or other standards based on documents promulgated by 3GPP2. BSC 124 further interfaces with other network entities such as IS-41 MSC 126. IS-41 MSC 126 provides circuit-switched communications and further supports ANSI-41 - another mobile network protocol that enables roaming and advanced services. The IS-41 MSC 126 communicates with the UMTS MSC 116 through an interworking function (IWF) 130 that provides an interface between the UTRAN and the cdma2000 RAN. IWF 130 may implement the IS-41 Handover Application Part (HAP) which is an extension of GSM-MAP.

Node B and BTS are base stations in UTRAN and cdma2000 RAN respectively. Each base station provides communication coverage for a specific geographic area. A base station and/or its coverage area is generally referred to as a "cell," depending on the context in which the term is used.

A wireless multi-RAT device 150 (such as a dual-mode cellular phone) has the capability to communicate with UTRAN 110 and cdma2000RAN 120. This capability enables a user/subscriber to obtain services from both networks through the same device. The multi-RAT device 150 may be both fixed and mobile and is referred to as a user equipment (UE) in 3GPP terminology and a mobile station (MS) in 3GPP2 terminology. Multi-RAT device 150 may communicate with one or more base stations on the downlink and/or uplink at any given moment. The downlink (or forward link) refers to the communication link from the base station to the device, and the uplink (or reverse link) refers to the communication link from the device to the base station.

FIG. 2 shows an embodiment of a multi-RAT device 150 including two modem processors 210a and 210b. Modem processor 210a performs processing for UMTS downlink and uplink transmissions as described in 3GPP TS 25-321, TS 25-308, TS 25-212, and other 3GPP documents. As described in the publicly available 3GPP2C.S0002-C titled "Physical Layer Standard forcdma2000 Spread Spectrum Systems, Release C (Physical Layer Standard forcdma2000 Spread Spectrum Systems, Release C)", the modem processor 210b is based on the 3GPP2 document The downlink and uplink transmissions of one of the CDMA standards such as IS-2000 are processed. Modem processors 210a and 210b are also referred to herein as UMTS Mobile Station Modem (UMTS MSM) and cdma2000 MSM, respectively.

Within the modem processor 210a, UMTS uplink signaling and data are processed (e.g., formatted, encoded, and interleaved) by a transmit (TX) data processor 212a and further processed by a modulator (MOD) 214a (e.g., channelization/spreading, scrambling and modulation) to obtain a stream of data chips. A transmit unit (TMTR) 232a then conditions (eg, converts to analog form, amplifies, filters, and frequency upconverts) the stream of chips to generate an uplink signal. The uplink signal is routed through a diplexer/duplexer 234 and transmitted through an antenna 236 to the Node B 112 in the UTRAN.

On the UMTS downlink, downlink signals from Node B 112 in the UTRAN are received by antenna 236, routed through diplexer/duplexer 234 and provided to a receive unit (RCVR) 238a. Receive unit 238a conditions (eg, filters, amplifies, and downconverts) the received signal and digitizes the conditioned signal to obtain samples. Within modem processor 210a, a demodulator (DEMOD) 216a receives and processes (eg, descrambles, channelizes/despreads, and demodulates) the samples to obtain symbols. As is known in the art, demodulator 216a may implement a rake receiver that can process multiple signal instances (or multipath components) in the received signal. A receive (RX) data processor 218a then processes (eg, deinterleaves and decodes) the symbols, examines received data blocks and provides decoded data.

For the embodiment shown in FIG. 2, modem processors 210a and 210b may perform separate processing for UTRAN and cdma2000 RAN, respectively. For example, each modem processor 210 may perform encoding and decoding for its network. Modem processors 220a and 220b control the processing units within modem processors 210a and 210b, respectively, and further maintain protocol stacks and states for UMTS and cdma2000, respectively. The dual modem processor design simplifies the implementation of multi-RAT devices because (1) the modem processor 210a can be built with a modem processor for single-mode UMTS devices (with little or no hardware and software changes) and (2) The modem processor 210b can be constructed by a modem processor for a single mode cdma2000 device (again with little or no change).

The dual-modem design shown in Figure 2 can be built in different ways. For example, each modem processor 210 may be implemented within one or more application specific integrated circuits (ASICs). The applications processor 240 can be implemented in a separate integrated circuit (IC) or incorporated into one of the modem processor's ASICs. Likewise, the host controller 250 can be built into a separate IC or incorporated into a modem's ASIC. As another example, the two modem processors 210a and 210b, the application processor 240, and the main controller 250 may be built within a single ASIC.

Figure 2 also shows separate transmit units 222a and 222b and separate receive units 238a and 238b for UMTS and cdma2000. This transceiver design enables multi-RAT devices to communicate with UTRAN and cdma2000 RAN simultaneously using separate transmit/receive paths. The two wireless networks may also share transmitter and receiver circuitry. For example, a single power amplifier may amplify both UMTS and cdma2000 uplink signals if the signals are on two different frequency bands and the power amplifier is a broadband amplifier.

An application processor 240 controls the operation of modem processors 210a and 210b and supports upper layer applications that require the services of these modem processors (eg, for voice and packet data). A main controller 250 controls the operation of various processing units in the multi-RAT device. Memories 242 and 252 store data and codes used by controllers 240 and 250, respectively.

FIG. 3 shows another view of the multi-RAT device 150 from an application point of view. The UMTS MSM 210a and the cdma2000 MSM 210b perform processing on the UTRAN and the cdma2000 RAN separately. The application processor 240 sends 'commands' to instruct the operation of UMTS MSMs and cdma2000 MSMs and receives 'events' of information/conditions from these MSMs.

The UTRAN may be made aware of the dual-mode capabilities of multi-RAT devices so that UTRAN can distinguish multi-RAT devices from single-mode (eg, UMTS-only) wireless devices. This distinction is required to facilitate intersystem handover between UTRAN and cdma2000 RAN. Several techniques for communicating device capabilities to UTRAN are described below.

FIG. 4A shows a radio resource control (RRC) connection establishment completion procedure for establishing a connection (or call) for a multi-RAT device and transferring device capabilities to UTRAN. RRC is part of layer 3 in the UMTS protocol stack, which provides information transfer services to a non-access stratum (NAS) and controls the configuration of layers 1 and 2 in the protocol stack. NAS is a functional layer that supports traffic and signaling messages between wireless devices and the core network interfacing with UTRAN.

The multi-RAT device (or more specifically the UMTS MSM) initiates the RRC connection establishment completion procedure by sending an RRC Connection Request (RRC connection request) message (step 412). This message contains an "Establishment Cause" value set to initiate or terminate a call. Then, UTRAN sends an RRC connection establishment message with related information to establish the call (step 414). This message contains a "Capability Update Requirement" information element (IE) with a "System Specific Capability Update Requirement" set to (for example) 'IS-2000' field. Release 99 of 3GPP TS 25-331 specifies a single enumeration (or value) 'GSM' for the "System Specific Capabilities Update Requirements" field. A new enumeration 'IS-2000' may be specified for this field.

The multi-RAT device performs connection establishment according to the information included in the RRC connection establishment message. After the establishment is completed, the multi-RAT device sends an RRC connection establishment complete message to the UTRAN (step 416). This message contains an "Inter-RATUE Radio Access Capability" information element encapsulating multiple cdma2000 (eg IS-2000) messages. For example, the IE may contain three instances of an IS-2000 status message (StatusMessage), each message instance containing a different information record. Different relevant information can be sent to UTRAN, such as, for example, device information (such as slot cycle index (SLOT_CYCLE_INDEX), station class designation, mobile device manufacture code, and model), a country of origin and network for identifying the device 15-digit International Mobile Subscriber Identity (IMSI) code, and an Electronic Serial Number (ESN) of the device. An ESN is a unique identification number embedded or engraved on a device's microchip by the manufacturer, which is used to authenticate the device and prevent counterfeiting.

Figure 4B shows a procedure used by a multi-RAT device to autonomously communicate its capabilities to UTRAN. After successfully establishing an RRC connection, the UMTS MSM autonomously sends a UE Capability Information (UE Capability Information) message (step 452). As mentioned above, this message contains an "Inter-RATUE Radio Access Capability" information element, which encapsulates multiple cdma2000 messages with different related information. The UTRAN replies with a UECapability Information Confirm message to confirm receipt of the message sent by the multi-RAT device (step 454). UMTS messages and information elements are described in 3GPP TS 25-331.

As mentioned above, UMTS MSM and cdma2000 MSM maintain the protocol stacks of UTRAN and cdma2000 RAN respectively. UMTS MSM and cdma2000 MSM also maintain the state machine of layer 3 and other functions (call control) of their respective networks. For clarity, the IS-2000 Layer 3 state machine will be described below.

FIG. 5 shows a state diagram 500 of the Layer 3 processing state of IS-2000. After power up, the cdma2000 MSM transitions to a mobile initialization state 510. The cdma2000 MSM remains in state 510 when idle and acquires the cdma2000 RAN upon receipt of an appropriate command from the application processor. The cdma2000 MSM transitions to a mobile station idle state 520 after acquiring the cdma2000 system timing. In state 520, the cdma2000 MSM can receive or initiate a call, perform registration, receive or initiate a message transmission, and perform other operations. Generally, after starting any one of these operations, the cdma2000 MSM transitions to a System Access (SystemAccess) state 530 to access the cdma2000 RAN. In state 530, the cdma2000 MSM exchanges signaling with the cdma2000 RAN on forward and reverse shared channels and is directed to a dedicated traffic channel. If an IS-2000 call is active, the cdma2000 MSM proceeds from state 530 to state 540 where a Mobile Station Controls on the Traffic Channel and communicates with the cdma2000 RAN in state 540. After ending the call, the cdma2000 MSM returns to state 510.

Figure 5 also shows the substates of state 540 where the mobile station exercises control over the traffic channel. In a Traffic Channel initialization (Traffic Channel) substate 542, the cdma2000 MSM verifies that it can receive a forward traffic channel and begins transmission on a reverse traffic channel. In a Traffic Channel substate 544, the cdma2000MSM exchanges data with the cdma2000 RAN according to a service configuration. In a Release substate 546, the cdma2000 MSM disconnects the IS-2000 call and releases the traffic channel.

Figure 5 further shows a call control state machine 550 maintained by the cdma2000 MSM for voice calls. In a Waiting for Order substate 552, the cdma2000 MSM waits for a message from the cdma2000 RAN indicating how and when to ring the phone. In a waiting for Mobile Station Answer (Waitingfor Mobile Station Answer) substate 554, the cdma2000 MSM waits for the user to respond to the call. The cdma2000 MSM changes to a Conversation substate 556 after receiving the user response and communicates with the cdma2000 RAN through the assigned traffic channel according to the service configuration. The cdma2000 MSM changes to a call release (Call Release) substate 588 after receiving a command to release the call from the user or the cdma RAN, confirms that the call is disconnected, and returns to the mobile station initialization state 510.

IS-2000 is described in 3GPP2C.S0005-C named "UpperLayer (Layer 3) Signaling Standard for cdma2000 Spread Spectrum Systems, Release C)" state and substates. 3GPP also describes the state diagram for UMTS calls in 3GPP TS 25-331.

As shown in Figure 1, a multi-RAT device may be mobile and move around within the coverage areas of UTRAN and cdma2000 RAN. A multi-RAT device can communicate with one network (eg, UTRAN) and can move out of the coverage area of that network and into the coverage area of another network (eg, cdma2000 RAN). When this happens, the multi-RAT device needs to be handed over from the serving network to a more suitable (eg, better signal quality) target network.

In this paper, several inter-system handover schemes for handover of multi-RAT devices from UTRAN to cdma2000 RAN are described. These handoff schemes include: (1) with measurement aided hard handoff (MAHHO) scheme, (2) with measurement directed hard handoff (MDHHO) scheme, and (3) call reestablishment hard handoff ( CRHHO) program. These schemes may be implemented in accordance with the dual modem processor shown in FIG. 2 for a multi-RAT device. The signal flow described below for the inter-system handover scheme can also be used as a flowchart of procedures to be implemented by multi-RAT devices and network entities.

A. Measurement Assisted Hard Handoff (MAHHO)

MAHHO is an intersystem handover technique in which the UTRAN uses measurements obtained by multi-RAT devices to determine cdma2000 cells suitable for handover of the devices to. For example, UTRAN may use MAHHO to trigger handover of a multi-RAT device to a target cell whose signal quality has been measured and reported by the device while in a call state on the serving network. MAHHO increases the probability of successful handover, especially when the base stations of the source cell and the target cell are not co-located. MAHHO can be implemented by means of two procedures - an alternative frequency search procedure and a handover execution procedure.

FIG. 6 shows an exemplary alternative frequency search procedure 600 for MAHHO. When a multi-RAT device is in the coverage area of a border UMTS cell, which is a cell located at the border of UTRAN, UTRAN enables the device to report cdma2000 measurements periodically or on an event basis. This is achieved by sending a Handover from UTRAN Command to the device (step 612). This command contains an "Inter-RAT System Message (Inter-RAT System Message)" IE encapsulated with, for example, an IS-2000 Candidate Frequency Search Request Message (CFSRM). CFSRM carries search configuration (such as an alternative frequency search list, which is a list of frequencies used to search for cdma2000 cells) and reporting standard information (such as specifying which measurements to report to UTRAN and under what conditions such measurements should be reported ). The UTRAN can determine the candidate frequency search list based on cdma2000 cells that are known in advance to cover border UMTS cells.

The UMTS MSM receives the handover command from UTRAN from UTRAN, extracts the CFSRM from the received command, and forwards the extracted message to the application processor (step 614). The application processor then initiates or opens the cdma2000 MSM and provides it with search commands and information from the CFSRM (step 616).

The cdma2000 MSM turns on the cdma2000 receiver (receive unit 238b in FIG. 2) and waits a predetermined amount of time for the receiver circuitry to warm up (block 620). After the cdma2000 receiver finishes warming up, the cdma2000 MSM starts to perform pilot signal acquisition for each target frequency in the candidate frequency search list (block 622). Each UMTS and cdma2000 cell transmits a pilot signal that can be processed by wireless devices in its coverage area to obtain system timing, frequency and other information for that cell. If a cdma2000 pilot signal is found (which may be a frequency not in the candidate frequency search list), the cdma2000 MSM acquires synchronization with the cdma2000 cell that transmitted the pilot signal and adjusts its timing to that cell (block 624 ). Synchronization acquisition may be performed based on a synchronization message sent by the cdma2000 cell. The cdma2000 MSM does not need to obtain system information from the cdma2000 cell and is not registered in the cdma2000 RAN. The cdma2000 MSM then performs an alternate frequency search and reports the search results according to the criteria sent in the CFSRM (block 626).

Since the multi-RAT device has established a connection with UTRAN, the cdma2000 MSM sends search results over this connection. The cdma2000 MSM sends the search results to the UMTS MSM through the application processor (step 632). The cdma2000 MSM remains active while measurement reporting is active and is forced offline whenever measurement reporting is deactivated. Then, the UMTS MSM sends a measurement report (Measurement Report) message containing the search results from the cdma2000 MSM (step 634). 3GPP does not specify in TS 25-331 Release 99 an extended form of the Measurement Report message for carrying search results from a cdma2000 MSM.

The UTRAN obtains the search results from the multi-RAT device and determines whether there is a cdma2000 cell with better quality than the UMTS serving cell. If the handover condition is determined to be satisfied according to the measurement report from the multi-RAT device, the UTRAN initiates a handover execution procedure to handover the multi-RAT device from the UMTS serving cell to a better cdma2000 cell.

FIG. 7 shows an exemplary handover execution procedure 700 for MAHHO. The UTRAN initiates the handover by sending a Relocation Required message to the "source" UMTSMSC, which is the UMTS MSC currently handling the pending UMTS call for the multi-RAT device (step 712). This message enables the serving UTRAN RNC - which is the RNC that currently has a signaling connection with the multi-RAT device - to request that the multi-RAT device be relocated to another RAN's RNC or BSC. This message carries information about (1) the identity, capabilities, and location of the multi-RAT device (which can be obtained through one of the capability reporting procedures described in Figures 4A and 4B) and (2) alternate frequencies Search results (which can be obtained by the alternative frequency search procedure shown in Figure 6). The source UMTS MSC forwards the relocation required message to the IWF, which converts the message to a Facility Instruction 2 (FACDIR2) message and sends the new message to a target IS-41 MSC (step 714). The target IS-41 MSC is the MSC that interfaces with the cdma2000 RAN to which the multi-RAT device is to be handed over.

The target IS-41 MSC receives the FACDIR2 message, and in response thereto, sends a handoff request (HandoffRequest) message to the cdma2000 BSC of the cdma2000 target cell, to start the hard handoff of the multi-RAT device (step 722). Then, the cdma2000 RAN sends a handoff request confirmation (Ack) (Handoff RequestAcknowledgment) message to the target IS-41 MSC (step 724) and sends signaling to the multi-RAT device on the forward fundamental channel (F-FCH) ( Step 726). The target IS-41 MSC also sends a facdir2 message to the source UMTS MSC via the IWF (step 732). Then, the source UMTS MSC sends a relocation command (RelocationCommand) to the UTRAN (step 734). This message contains information normally carried in an IS-2000 Extended (or Universal) Handoff Direction Message (EHDM) for the cdma2000 target cell to be handed over. Then, the UTRAN sends a handover command from UTRAN to the multi-RAT device to instruct the device to perform handover (step 742). This command contains an "Inter-RAT System Message" IE encapsulated with EHDM, which in turn contains cdma2000 target cell information.

The UMTS MSM receives the handover command from UTRAN, extracts the EHDM from the received command, and forwards the extracted EHDM to the application processor (step 744). Then, the application processor starts the cdma2000MSM and gives it a handoff command (step 746). The cdma2000 MSM then enters a traffic channel initialization substate to establish and synchronize traffic channels for the downlink and uplink of the cdma target cell (block 752). cdma2000 MSM is implemented based on signaling received on the F-FCH (step 726) and signaling sent on a reverse link fundamental channel (R-FCH), such as a traffic channel header (TCH header) Traffic channel setup (step 762). F-FCH and R-FCH are traffic channels in cdma2000. The cdma2000 MSM bypasses the system access state for intersystem handoff (see Figure 5), because the cdma2000 MSM is directed to a dedicated traffic channel for hard handoff and the cdma2000 MSM does not need to enter this state to perform a hard handoff in the forward direction. and exchange signaling on the reverse shared channel to establish a traffic channel.

Once the traffic channel is established, the application processor switches the data path from the UMTS MSM to the cdma2000 MSM and begins processing data from the cdma2000 MSM (block 754). For example, for a voice call, the application processor switches from a UMTS vocoder to a cdma2000 vocoder. Transmitter and receiver cells are also switched appropriately in multi-RAT devices.

After passing a message from the handover command from UTRAN to the application processor, the UMTS MSM can release the pending UMTS call and deactivate itself either autonomously or according to a command from the application processor.

After the traffic channel is established, the cdma2000 MSM sends a Handoff Completion message (HCM) to the cdma2000 RAN to indicate that the handoff is successfully completed (step 764). Then, cdma2000 RAN sends a handoff complete (Handoff Complete) message to the target IS-41 MSC to notify it of handoff success (step 766). Then, the target IS-41 MSC sends a mobile station on channel (Mobile Station on Channel, MSONCH) message to the source UMTS MSC through the IWF (step 768). The source UMTS MSC then sends a Release Command to the UTRAN on an Iu interface to terminate the pending UMTS call on the UTRAN side (step 772). Then, UTRAN sends a release complete (Release Complete) message to the source UMTS MSC through the Iu interface to indicate that the UMTS call has been released (step 774). Implement steps 722 to 732 and Steps 762 to 774. TIA/EIA/IS-2001.3-B also describes the messages between the MSC and the cdma2000 BSC interface for handover between two BSCs that may or may not belong to the same MSC.

FIG. 7 shows a simple handover scenario when a radio bearer is established and the multi-RAT device is in the talk substate shown in FIG. 5 . The concepts set forth in FIG. 7 can be extended to situations where a multi-RAT device is in the Waiting Order substate or the Waiting for Mobile Station Acknowledgment substate.

B. Measurement Directed Hard Handoff (MDHHO)

MDHHO is a semi-blind inter-system handover technique in which the source UTRAN relies on the location information of the multi-RAT device to select the best cdma2000 target cell for the device. The location information may be derived from the currently active set of the multi-RAT device, round trip delay (RTD) measurements at the base station, and the like. The active set contains the cells with which the device communicates. MDHHO performance can be degraded if (1) the base station locations of the source and target cells are not close to each other and/or (2) the layout of the source and target cells - which depends on the orientation of the base station antennas - is different. The presence of repeaters also complicates the selection of the target cell because the additional delay introduced by the repeaters distorts the RTD estimate, making the RTD estimate a biased indicator of the location of the multi-RAT device. MDHHO performance is improved if the target network supports hard handoff to soft handoff to enable the device to communicate with multiple cells after hard handoff. MDHHO is usually easier to implement than MAHHO.

There are two situations in MDHHO. The first scenario assumes that the cdma2000 MSM has not acquired the timing of the cdma2000 RAN when the multi-RAT device receives a handover command from the UTRAN. The second scenario assumes that the cdma2000 MSM has acquired cdma2000 timing when it receives the handoff command.

FIG. 8 shows an example procedure 800 for MAHHO without previous synchronization information. The UTRAN initiates the handover by sending a handover command from UTRAN to the multi-RAT device and instructs the device to perform the handover (step 812). This command carries an "Inter-RAT System Message" IE that contains information for handover of the cdma2000 target cell. The UTRAN determines the cdma2000 target cell based on the location information available to the multi-RAT device. For example, UTRAN can query a local database of cdma2000 cells using the UMTS serving cell as the key.

The UMTS MSM receives the handover command from UTRAN, extracts the target cell information from the received command and forwards the extracted information to the application processor (step 814). After transmitting the extracted information up, the UMTS MSM can disable itself autonomously or according to a command from the application processor. Then, the application processor starts the cdma2000 MSM and gives it a handoff command (step 816). The cdma2000 MSM turns on the cdma2000 receiver and waits for the receiver circuitry to warm up (block 820). After warming up, the cdma2000 MSM starts to acquire pilot signals for each cdma2000 target cell (step 822). For each cdma2000 pilot signal found, the cdma2000 MSM acquires synchronization with the cdma2000 cell and adjusts its timing to that cell (block 824). Then, the cdma2000 MSM enters the traffic channel initialization (Traffic Channel Initialization) substate to set up the traffic channel of the cdma2000 target cell (block 826). The cdma2000 MSM bypasses the System Access state because it is directed directly to a dedicated traffic channel. The application processor then switches the data path from the UMTS MSM to the cdma2000 MSM (eg, switches the voice call vocoder) and begins processing data from the cdma2000 MSM (block 828). After the traffic channel is established, the cdma2000 MSM sends a handover complete message to the cdma2000 RAN to indicate that the handover was successfully completed (step 832).

The MAHHO procedure on the UTRAN and core network side without previous synchronization information is shown in FIG. 7 .

For the MAHHO procedure shown in FIG. 8, after receiving the handover command from UTRAN, the multi-RAT device performs both synchronization acquisition and handover execution. When the cdma2000 timing information is not known, the amount of time required to perform handover becomes longer. In order to speed up the handover, the timing of cdma2000 can be obtained in advance, that is, before starting the handover.

When (1) the UMTS MSM is in idle mode and camps on a UMTS cell broadcasting System Information Type 13 (SystemInformation Type 13, SIB13) information, or (2) the UMTS MSM is in a connected mode and its active set includes A multi-RAT device may acquire cdma2000 timing when a UMTS cell broadcasts SIB 13 information. A UMTS MSM is in (1) idle mode - if it is registered in UTRAN but has no activity and (2) connected mode - if it has data to transmit and/or receive. The idle and connected modes are described in 3GPP TS 25.331. The SIB 13 information includes system information (such as identity, number of channels, and frequency band class) of a cdma2000 neighbor cell that is an overlapping UMTS serving cell or a cdma2000 cell that is a neighbor of the UMTS serving cell. A cdma2000 MSM can use SIB13 information to search for cdma2000 neighbor cells when communicating with or camping on a UMTS cell. If the UMTS MSM is in connected mode, it decodes the Broadcast Control Channel (BCCH) from the UMTS serving cell or a UMTS neighbor cell to obtain both Management Information Base (MIS) and SIB 13 information, and then uses the two or to obtain a System Frame Number (SFN) identifying the framing and timing of the UMTS cell.

FIG. 9 shows an example procedure 900 for MAHHO with previous synchronization information. The procedure 900 includes a synchronization acquisition procedure 910 and a handover execution procedure 930 . When the UMTS MSM is in idle or connected mode, the multi-RAT device implements a synchronization acquisition procedure 910 to acquire the timing of the cdma2000 cell for faster handover if and when instructed by the UTRAN. When the UTRAN commands the handover, the multi-TAT device implements the handover execution procedure 930 . The handover execution procedure 930 is similar to the MAHHO procedure shown in FIG. 8 , but does not include the synchronization acquisition in block 824 .

For the synchronization acquisition procedure 910, the UMTS MSM receives the SIB 13 information broadcast by a UMTS cell (step 912) and forwards this information to the application processor (step 914). Then, the application processor starts the cdma2000 MSM and gives it a search command (step 916). The cdma2000 MSM turns on the cdma2000 receiver (block 920), starts to implement pilot signal acquisition (block 922) for each cdma2000 neighboring cell, and uses the obtained pilot signal to obtain the synchronization and timing of each cdma2000 cell (block 924) . Steps 920, 922, and 924 may be implemented as described above in FIG. 6 for steps 620, 622, and 624, respectively. The cdma2000 MSM does not enter the system access state, does not decode the paging channel (PCH), and does not register on the cdma2000 RAN. After acquiring the timing of cdma2000 neighbor cells, the cdma2000 MSM goes into a sleep state and only wakes up periodically to take measurements on these cells (block 926).

For the handover execution procedure 930, the UMTS MSM receives a handover command from the UTRAN from the UTRAN (step 932), extracts the target cell information from the received command, and forwards the information to the application processor (step 932) 934). The application processor then starts the cdma2000 MSM (step 936). The cdma2000 MSM waits for the receiver circuit to warm up (block 940), performs pilot signal reacquisition for each cdma2000 target cell whose timing information is already known to obtain updated cell timing (block 942), and for each of its timing information A search is performed for still unknown cdma2000 target cells (block 942). Then, the cdma2000 MSM enters the traffic channel initialization substate to establish the traffic channel of the cdma2000 target cell (block 944). cdma2000 MSM bypasses the system access state. The application processor then switches the data path (eg, vocoder) from the UMTS MSM to the cdma2000 MSM and begins processing data from the cdma2000 MSM (block 946). After the traffic channel has been established, the cdma2000 MSM sends a Handover Complete message to the cdma2000 RAN to indicate that the handover was successful (step 952).

The procedures of the handover execution procedure 930 on the UTRAN and core network side are shown in FIG. 7 .

C. Call Reestablishment Hard Handoff (CRHHO)

CRHHO is an intersystem handover technique in which a new call is reestablished on a target network and the pending call on the serving network is released. Call setup and call release may be implemented to make handover seamless from the perspective of multi-RAT devices and to minimize communication disruption.

CRHHO can be performed using several procedures - a mobile terminated (MT) call setup procedure and a mobile originated (MO) call setup procedure. For these two procedures, UTRAN can trigger CRHHO to target cdma2000 RAN according to different criteria. For example, CRHHO may be triggered based on (1) obtained measurements of multi-RAT devices, (2) location information of the devices, and/or (3) some other information or mechanism. The measurements can be used for quality metrics such as pilot signal energy-to-interference ratio per chip (Ec/Io), block error rate (BLER), traffic channel transmit power, and the like. The measurements may be used to detect when a multi-RAT device is located in a fringe UMTS coverage area. The location information may include the currently active set of the multi-RAT device, RTD measurements, etc., and is used to detect when the multi-RAT device is located near the edge of the UMTS coverage area.

FIG. 10A shows the first part of an example procedure 1000 for CRHHO terminating call reestablishment by a mobile device. First, the multi-RAT device is active when making a call with UTRAN. In order to reduce handover delay for CRHHO, the cdma2000 MSM is enabled when the UMTS MSM establishes a UMTS call, remains in the mobile station idle state, but does not register with the cdma2000 RAN while in this state (block 1010).

The UTRAN initiates a handover by sending a Handover from UTRAN command to the multi-RAT device (step 1012). This command carries an "Inter-RAT System Message" IE, which contains information (such as frequency and band class) for cdma2000 target cell handover. The UTRAN MSM receives the handover command from the UTRAN, extracts the target cell information from the received command and forwards the extracted information to the application processor (step 1014). Then, the application processor starts the cdma2000 MSM and gives it a wakeup/handover command (step 1016).

The UTRAN also sends a Relocation Required message to the source UMTS MSC to request relocation of the multi-RAT device (step 1022). This message carries (1) information about the identity, capabilities and location of the multi-RAT device, (2) slot cycle information, and (3) the identity of the cdma2000 target cell. Then, the source UMTS MSC sends a FACDIR2 message (or an equivalent information) carrying cdma2000 related information and the target cell identifier to the target IS-41 MSC through the IWF (step 1024). Then, the target IS-41 MSC sends a paging request (Paging Request) message to the cdma2000BSC of the cdma2000 target cell to initiate a call setup procedure terminated by the mobile device to the multi-RAT device (step 1026). This message instructs the multi-RAT device to bypass the alert (eg, not ring) because there is currently a pending UMTS call on the device. Then, the cdma2000BTS corresponding to the target cell pages the multi-RAT device by sending an IS-2000 General Page Message (GPM) on the paging channel with the address of the multi-RAT device. This GPM commands the multi-RAT device to bypass the alert.

After receiving the wake-up command, the cdma2000 MSM turns on and warms up the cdma2000 receiver (block 1030), performs pilot signal reacquisition (step 1032) for each cdma2000 target cell whose timing is already known and A cell search is performed for unknown cdma2000 target cells (again, block 1032). The cdma2000 MSM then receives the IS-2000 General Page Message from each cdma2000 cell whose timing has been acquired (step 1028) and updates the overhead information for each cdma2000 cell with a received GPM (block 1034). The cdma2000 MSM enters the system access state for each cdma2000 cell with the updated overhead information and sends access probes on the reverse link through an access channel for accessing the cdma2000 RAN (block 1036). After receiving the GPM, the cdma2000 MSM sends an IS-2000 paging response message (Page Response Message, PRM) to the cdma2000 RAN to confirm the paging (step 1038).

FIG. 10B shows the second part of the CRHHO procedure 1000 . After receiving the PRM from the multi-RAT device, the cdma2000 RAN (1) implements a call setup procedure 1040 to establish a new call with the multi-RAT device, and (2) initiates a call release procedure 1060 to terminate the connection between the device and the UTRAN current call between Procedure 1040 may be performed concurrently with procedure 1060 and may be timed to minimize interruption of communication of multi-RAT devices.

For the call setup procedure 1040, the cdma2000 RAN sends a base station confirmation order (BS Ack Order) to the cdma2000 MSM to confirm receipt of the PRM (step 1042). Then, the cdma2000 RAN sends (1) an IS-2000 extended channel assignment message (Extended Channel AssignmentMessage, ECAM) to the cdma2000 MSM to initiate the establishment of a traffic channel (step 1044), and (2) a specified new cdma2000 call The IS-2000 service connection (Service Connect Message, SCM) message of service configuration (step 1046). The cdma2000 MSM sends an IS-2000 service connection complete message (Service Connect Complete Message) to the cdma2000 RAN to confirm receipt of the SCM (step 1048). Then, the cdma2000 MSM starts to process the communication from the cdma2000 RAN according to the specified service configuration.

After completing the service configuration, the cdma2000 MSM notifies the AP that the service to the cdma2000 RAN has been connected (step 1052). The application processor then instructs the UMTS MSM to terminate the current UMTS call (step 1054), switches the data path from the UMTS MSM to the cdma2000 MSM (e.g. switching the voice call vocoder) and begins processing data from the cdma2000 MSM (block 1056) .

For call release procedure 1060, the cdma2000 RAN sends an IS-2000 Page Response message to the target IS-41 MSC to acknowledge the Page Request message (step 1062). Then, the target IS-41 MSC sends a mobile station on channel (MSONCH) message to the source UMTMSC through the IWF to notify the UMTS MSC that the call is controlled by the IS-41 MSC at this time (step 1064). An inter-MSC trunk is connected and the data flow of the multi-RAT device is rerouted therefrom towards the target IS-41 MSC (instead of the UMTS MSC) (block 1070). For voice calls, pulse code modulation (PCM) is used to encode analog voice into 64Kbps digital data, and the PCM stream of the multi-RAT device is rerouted towards the target IS-41 MSC. The source UMTS MSC then sends a release command to the UTRAN over the Iu interface (step 1072). After receiving this command, the UTRAN implements multi-RAT devices by sending an RRC Connection Release (RRC Connection Release) message to the UMTS MSM (step 1074) and receiving a RRC Connection Release Complete (RRC Connection Release Complete) message from the UMTS MSM. An RRC connection release procedure (step 1076). Then, UTRAN sends a release complete (ReleaseComplete) message to the source UMTS MSC through the Iu interface to indicate that the UMTS call has been released (step 1078). After releasing the UMTS call, the UMTSMSM goes offline (block 1080).

FIG. 11A shows the first part of an example procedure 1100 for CRHHO when call re-establishment is initiated by the mobile device. Initially, the multi-RAT device is active while making a call with UTRAN, the UMTS MSM is in connected mode (block 1108), and the cdma2000 MSM is offline (block 1110).

UTRAN initiates a handover by sending a Handover from UTRAN command to the multi-RAT device carrying an "Inter-RAT System Message" IE with cdma2000 target cell information (step 1112). The UMTS MSM receives the handover command from UTRAN and extracts the target cell information and provides it to the application processor (step 1114). Then, the application processor starts the cdma2000 MSM and gives it a wakeup/handover command (step 1116). The UTRAN also sends a Relocation Required message to the IWF through the source UMTS MSC to request relocation of the multi-RAT device (step 1118).

After receiving the handover command, the cdma2000 MSM turns on and warms up the cdma2000 receiver (block 1120), implements pilot signal acquisition (block 1122) for each cdma2000 target cell, and acquires each cdma2000 with the acquired pilot signal Synchronization and timing of cells (block 1124), update system information of each cdma2000 cell with acquired synchronization and timing (block 1126), and enter system access state and attempt to access each cdma2000 cell with updated system information Cell (block 1128).

FIG. 11B shows the second part of the CRHHO procedure 1100 , which includes a call setup procedure 1130 and a call release procedure 1160 . For the call setup program 1130, after successfully completing the system access, the cdma2000 MSM sends to the cdma2000 RAN an IS-2000 initial message (Origination Message) that includes a predefined feature code string associated with call reestablishment (step 1132). Then, the cdma2000 RAN sends a service request (Service Request) message including a feature code string to the target IS-41 MSC (step 1134). The target IS-41 MSC responds by sending an Assignment Request message containing information used by the cdma2000 RAN to establish a connection with the cdma2000 MSM (step 1136). Then, the cdma2000RAN sends (1) an Extended Channel Assignment Message (Extended Channel Assignment Message) to direct the multi-RAT device to a traffic channel (step 1138) and (2) an IS- 2000 Service Connect Message (Service Connect Message) (step 1142). The cdma2000 MSM responds with an IS-2000 Service Connect Complete message (step 1144).

Thereafter, the cdma2000 MSM starts to process communications from the cdma2000 RAN according to the specified service configuration. The cdma2000 MSM also notifies the application processor that services to the cdma2000 RAN are connected (step 1152). The application processor then commands the UMTS MSM to terminate the current UMTS call (step 1154), switches the data path from the UMTS MSM to the cdma2000 MSM (e.g., switches the voice call vocoder), and begins processing data from the cdma2000 MSM (block 1156 ).

For the call release program 1160, after receiving the service connection completion message, the cdma2000 RAN sends an Assignment Complete message to the target IS-41 MSC (step 1162). The target IS-41 MSC then sends to the source UMTS MSC a signaling message containing (1) information equivalent to that carried in an IS-41 mobile station on-channel message and (2) The identity of the cdma2000 target cell (step 1164). The IWF combines the indication received from the IS-41 MSC with the pending call re-establishment instance (step 1066). At this point the inter-MSC trunk is connected and the multi-RAT device data (e.g. PCM) stream is thereafter rerouted towards the target IS-41 MSC (block 1170). Then, in steps 1172 to 1176 (which correspond to steps 1072 to 1076 in FIG. 10B ), the UMTS call is released by signaling.

For CRHHO from UMTS to cdma2000, the UMTS MSM appears as if it is releasing a pending call, while the cdma2000 MSM appears as if it is establishing a new call. In general, CRHHO can be implemented using existing network entities and does not require any changes to the UMTS and cdma2000 protocol stacks. CRHHO does not require new functionality, such as no modification to call control for (1) releasing calls in UMTS and (2) originating calls in cdma2000. A new message (new extension) may only be needed for CRHHO. Additionally, CRHHO can be implemented with no or minimal interruption of service.

The inter-system handover techniques described herein enable a multi-RAT device to be handed over from one network to another in a seamless manner. Different handover techniques have different requirements and advantages.

handover technology.

Table 1 lists the requirements for these handover techniques.

Table 1 Require advantage (a) MAHHO RRC and RANAP need to be expanded. IS-41 HAP is required at the source MSC. The cdma2000 MSM needs to build a modified protocol state machine. The UMTS MSM needs to process two new messages. Since the two MSMs do not need to be transmitted simultaneously, only one power amplifier is required. The selection of the target cell is reliable and the handover delay is shortened. No need to make any changes to the cdma2000 core network and BSC. (b) MDHHO (no previous synchronization information) RANAP needs to be expanded. IS-41 HAP is required at the source MSC. The cdma2000 MSM requires the construction of a modified L3 state machine. Since the two MSMs do not need to be transmitted simultaneously, only one power amplifier is required. RRC needs to be extended. Less impact on UMTS MSMR. (c) MDHHO (with previous synchronization information) RANAP needs to be expanded. IS-41HAP is required at the source MSC. The cdma2000 MSM needs to build a modified protocol state machine. UMTS MSM needs to read SIB 13. Since the two MSMs do not need to be transmitted simultaneously, only one power amplifier is required. The handover delay is shorter than (b). Easier to build at a multi-RAT device than (a) but more complex than (b). (d) CRHHO RRC and RANAP require new procedures and protocol changes. The handover delay becomes longer. Since these two MSMs need to be transmitted simultaneously, two power amplifiers are required. Minimal development cost at build time. No changes to UTRAN are required.

RANAP (Radio Access Network Application Part) is the interface between the core network and UTRAN RNC, and is equivalent to the A1 interface in IS-41.

Intersystem handover techniques can be constructed in various ways. For example, these techniques may be implemented in hardware, software, or a combination thereof. For hardware implementations, the processing units for implementing intersystem handoff at wireless devices (e.g., UMTS MSM 210a, cdma2000 MSM 210b, and application processor 240 in FIG. 2) can be implemented in one or more ASICs, digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), Processors, Controllers, Microcontrollers, Microprocessors, and others designed to An electronic unit, or a combination thereof, that performs the functions described herein. Likewise, processing units for supporting inter-system handoff on the network side may be built in one or more ASICs, DSPs, and the like.

For a software construction solution, the inter-system handover technology can be constructed by means of modules (eg, procedures, functions, and so on) that can implement the functions described herein. The software codes may be stored in a storage unit (eg, memory 242 in FIG. 2 ) and executed by a processor (eg, application processor 240 ). The memory unit can be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor by various means as is known in the art.

The above description of the disclosed embodiments is intended to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is not intended herein to limit the present invention to the embodiments shown herein but to give it the widest scope consistent with the principles and novel features disclosed herein.

Claims (29)

1, a kind of wireless device that communicates with first and second cordless communication network that moves with different radio access technologies, it comprises:

One first modem processor, its operation is to carry out processing to one with the unsettled calling of described first wireless network, receive one first message with the handover of execution from described first wireless network, and the notice of described handover is provided to described second wireless network; And

One second modem processor, its operation is newly called out to set up one with described second wireless network to exchange one second message with described the two or two wireless network, carry out one with the call setup procedure of described second wireless network setting up described new calling, and handle carrying out with the described new calling of described second wireless network.

2, wireless device as claimed in claim 1, it further comprises:

One application processor, it moves to receive described notice from described first modem processor, instructs described second modem processor to set up described new calling, and instructs described first modem processor to discharge described unsettled calling.

3, wireless device as claimed in claim 2, wherein said application processor operation is to instruct described first modem processor to discharge described unsettled calling at once so that service disruption is reduced to bottom line in described new call setup or after described new calling has been set up.

4, wireless device as claimed in claim 1, wherein said first wireless network implement Wideband Code Division Multiple Access (WCDMA) (W-CDMA) and described second wireless network is implemented IS-2000.

5, wireless device as claimed in claim 4, the operation of wherein said second modem processor to be carrying out a call setup procedure by mobile device termination (MT) by the IS-2000 defined, and wherein said second message is a general page messages that is sent by described second wireless network.

6, wireless device as claimed in claim 4, the operation of wherein said second modem processor with carry out one by the IS-2000 defined initiate the call setup procedure of (MO) by mobile device, and wherein said second message is one to be sent to the initiation message of described second wireless network.

7, wireless device as claimed in claim 1, wherein said unsettled and new calling is voice call.

8. wireless device as claimed in claim 1, the operation of wherein said first modem processor is to keep one to be used for first protocol stack that communicates with described first wireless network and the operation of described second modem processor to keep one to be used for second protocol stack that communicates with described second wireless network.

9, wireless device as claimed in claim 1, wherein said second modem processor operation is obtained and Cell searching again optionally to carry out pilot signal, the system information of acquisition through upgrading, and the system that carries out described second wireless network inserts to set up described new calling.

10, wireless device as claimed in claim 1, it can move to communicate with described first and second wireless network simultaneously.

11, wireless device as claimed in claim 1, wherein said handover are to be triggered according to the measured value that described wireless device obtained by described first wireless network.

12, wireless device as claimed in claim 1, wherein said handover are to be triggered by the positional information of described first wireless network according to described wireless device.

13, a kind of method that is used between first and second cordless communication network of different radio access technologies, carrying out a handover, it comprises:

The unsettled calling of processing one and described first wireless network;

Receive one first message to carry out a handover to described second wireless network from described first wireless network;

Exchanging one second message with described second wireless network newly calls out to set up one with described second wireless network;

The call setup procedure of execution one and described second wireless network is to set up described new calling; And

The described new calling of processing and described second wireless network, and

Wherein said processing one unsettled calling and described reception one first message are to be carried out by one first modem processor, and wherein said exchange one second message, carry out a call setup procedure, and to handle described new calling be to be carried out by a second modem processor.

14, method as claimed in claim 13, wherein said first wireless network implement Wideband Code Division Multiple Access (WCDMA) (W-CDMA) and described second wireless network is implemented IS-2000.

15, a kind of operation between first and second cordless communication network of different radio access technologies, to carry out the equipment of a handover, it comprises:

Be used to handle one with the device of the unsettled calling of described first wireless network;

Be used for receiving one first message to carry out one to the described second wireless network zone-skipping device for switching from described first wireless network;

Be used for exchanging one second message to set up a new device of calling out with described second wireless network with described second wireless network;

Be used to carry out one with the call setup procedure of described second wireless network to set up the device of described new calling; And

Be used to handle the device with the described new calling of described second wireless network, and

The described device that wherein is used to handle the described device of a unsettled calling and is used to receive one first message is independent of the described device that is used to exchange one second message, the described device that is used to carry out the described device of a call setup procedure and is used to handle described new calling.

16, equipment as claimed in claim 15, wherein said first wireless network implement Wideband Code Division Multiple Access (WCDMA) (W-CDMA) and described second wireless network is implemented IS-2000.

17, a kind of UMTS (Universal Mobile Telecommunications System) terrestrial radio access network (UTRAN), it comprises:

Be used to handle the device of the unsettled calling of one and one wireless device;

Be used for one first message is sent to described wireless device to carry out a device to cdma2000 radio access network (RAN) handover;

Be used for one second message is sent to the device that a UMTS mobile switching centre (MSC) is repositioned to described wireless device with request described another MSC of cdma2000 RAN;

Be used to receive a indication about and a new calling described cdma2000 RAN that set up for described wireless device; And

Device with the described unsettled calling of described wireless device is used to terminate.

18, a kind of wireless device that communicates with first and second cordless communication network that moves with different radio access technologies, it comprises:

One first modem processor, its operation is to carry out processing to one with the unsettled calling of described first wireless network, receive one first message carrying out a handover to described second wireless network from described first wireless network, and the notice of described handover is provided;

One second modem processor, its operation with set up one's own business affair channel and carry out with the new calling of described second wireless network and to handle of described second establishing wireless network; And

One application processor, it moves to receive described notice from described first modem processor and to instruct described second modem processor to set up the described new calling of described Traffic Channel and processing and described second wireless network.

19, wireless device as claimed in claim 18, wherein said first wireless network implement Wideband Code Division Multiple Access (WCDMA) (W-CDMA) and described second wireless network is implemented IS-2000.

20, wireless device as claimed in claim 18,

Wherein said first modem processor further operation carries second message that is used at the list of frequency of the described second wireless network search cell to receive one from described first wireless network, and send the 3rd message that carries the Search Results of described list of frequency to described first wireless network, and

Wherein said second modem processor further operation described list of frequency is carried out pilot signal is obtained and Cell searching and described Search Results is provided.

21, wireless device as claimed in claim 18 wherein comprises the information of one or more Target cells in described second wireless network that described wireless device is handed off to from described first message of described first wireless network.

22, wireless device as claimed in claim 21, wherein said one or more Target cells are determined from the Search Results to a list of frequency in described second wireless network of described second modem processor by described first wireless network basis.

23, wireless device as claimed in claim 18, wherein said second modem processor further operation complete successfully with the described handover of indication to described second wireless network so that one second message is sent to described second wireless network.

24, wireless device as claimed in claim 18, the operation of wherein said first modem processor is with the described unsettled calling of termination and described first wireless network independently after the described notice of described handover is provided.

25, wireless device as claimed in claim 18, wherein said application processor further operation to instruct the described unsettled calling of described first modem processor termination and described first wireless network.

26, wireless device as claimed in claim 18, wherein said first wireless network is according to the described unsettled calling that terminates of the signaling between described first and second wireless network.

27, a kind of method of between first and second cordless communication network of different radio access technologies, carrying out a handover, it comprises:

The unsettled calling of processing one and described first wireless network;

Receive one first message from described first wireless network, to carry out a handover to described second wireless network;

With described second establishing wireless network affair channel of setting up one's own business; And

The new calling of processing one and described second wireless network, and

Wherein said processing one unsettled calling and described reception one first message are to be carried out by one first modem processor, and wherein saidly set up Traffic Channel and described processing one new the calling is to be carried out by a second modem processor.

28, method as claimed in claim 27, wherein said first wireless network implement bandwidth code division multiple access (W-CDMA) and described second wireless network is implemented IS-2000.

29, a kind of operation between first and second cordless communication network of different radio access technologies, to carry out the equipment of a handover, it comprises:

Be used to handle one with the device of the unsettled calling of described first wireless network;

Be used for receiving one first message to carry out a device to the handover of described second wireless network from described first wireless network;

Be used for and the set up one's own business device of affair channel of described second establishing wireless network; And

Be used to handle one with the device of the new calling of described second wireless network, and

The described device that wherein is used to handle the described device of a unsettled calling and is used to receive one first message is independent of and is used to set up the described device of Traffic Channel and is used to handle a new described device of calling out.

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