CN101203034A - Switching method system and equipment for packet switching under downlink dual-carrier/multi-carrier transmission technology - Google Patents

Abstract

The invention discloses a handover method and system for packet switching under the downlink dual-carrier or multi-carrier transmission technology, as well as a base station and a mobile station device, mainly including: the source network device where the mobile station MS is located determines that there is an MS that needs more than one carrier frequency During the handover, the target base station system BSS sends a handover request message for more than one carrier frequency handover; after receiving the handover request message, the target BSS allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a message to the MS after the allocation is completed. The source BSS of the MS returns a response message; after receiving the response message, the source BSS sends a handover command to the current MS, and includes the allocated radio resource information in the handover command; after the current MS receives the handover command, it leaves the data transmission channel The carrier frequency of the source BSS is connected to more than one carrier frequency allocated by the target BSS. The invention simply and reliably realizes PS switching under the downlink dual-carrier or multi-carrier transmission technology.

Description

Switching method system and equipment for packet switching under downlink dual-carrier/multi-carrier transmission technology

technical field

The present invention relates to the technical field of wireless communication, in particular to a packet switching (PS, Packet Switching) switching method and system under the downlink dual-carrier or multi-carrier transmission technology, as well as base station and mobile station equipment.

Background technique

With the rapid development of General Packet Radio Service (GPRS, General Packet Radio Service), users have new requirements for the real-time performance of GPRS services. For this reason, the existing standard proposes a handover processing scheme of the GPRS service, and the handover processing process is shown in Figure 1, corresponding to the following steps:

Step 101, in the packet transfer (Packet transfer) mode, the source base station system (BSS, BaseStation System) sends a handover request message to the target BSS when determining that there is a mobile station (MS, Mobile Station) that needs to be handed over, indicating that there is an MS that needs to be handed over to the target BSS.

Step 102, the target BSS establishes a BSS context for the MS according to the received handover request message, allocates radio resources, and notifies the source BSS through a handover request response message after the establishment and allocation are completed.

Step 103, after receiving the handover request response message, the source BSS sends a handover command including radio parameters to the MS.

Step 104, after obtaining the wireless parameters in the received handover command, the MS leaves the source BSS, and initiates an Access Burst at the target BSS.

Step 105, after receiving the access burst initiated by the MS, the target BSS notifies the MS of the timing advance that should be used in a signaling manner.

Step 106, after receiving the timing advance, the MS performs data transmission according to the timing advance.

Step 107, when the target BSS receives the first correct radio link control or medium access control (RLC/MAC) block sent by the MS, it determines that the current handover is successful.

In above-mentioned handover process, also need the support of equipment such as GPRS business support node (SGSN, ServingGPRS Supporting Node) in the network, GPRS gateway support node (GGSN, Gateway GPRS Supporting Node) in the network.

In the current GPRS system, an MS can only receive downlink data on one carrier frequency, and the working bandwidth is 200KHz, which obviously limits the data transmission rate. For example: based on this data receiving scheme, under the current Global System for Mobile Communications (GSM, Global System for Mobilecommunications) Evolved Enhanced Data Rate Radio Access Network (EGRPS, GSM EDGE Radio Accesss Network) system, even if a carrier frequency is allocated 4 time slots, the actual rate of these 4 time slots is less than 200kbps. With the development of data-type services, the existing rate can no longer meet the needs of users.

In view of the above situation, a number of communication equipment manufacturers have proposed a new data transmission scheme, that is, downlink dual-carrier/multi-carrier transmission. As the name implies, downlink dual-carrier/multi-carrier transmission is to break through the bandwidth limitation that the GSM system has always followed, so that an MS can simultaneously receive downlink data on more than one carrier frequency. Assuming that the number of carriers used to receive downlink data is N, this transmission scheme can change the working bandwidth to 200×N KHz, and the corresponding data transmission rate is also increased proportionally according to the number of carrier frequencies. Still taking the current EGRPS system as an example, the actual rate of 4 time slots assigned to one carrier frequency is 200kbps, and if the MS can simultaneously receive downlink data on 5 carrier frequencies, the rate can be close to 1Mkbps, which can fully meet the needs of 3G systems. speed requirements.

It can be seen from the above description that the introduction of the downlink dual-carrier/multi-carrier transmission scheme can greatly prolong the application time of 2G systems like GSM, and this scheme only needs to be simply upgraded on the basis of the existing system. Increase the downlink data transmission rate. This solution not only saves the operator's investment in equipment, but also satisfies the development of new services, and has broad application prospects in 2G systems.

However, the existing packet-switching (PS) domain switching method can only be applied to the switching between single carrier frequencies, and cannot meet the switching requirements of the PS domain after the introduction of downlink dual-carrier or multi-carrier transmission technology. For example, if the MS is in the downlink dual-carrier or multi-carrier transmission state and receives data on two carrier frequencies, since the existing technology only provides a switching method from one carrier frequency to another carrier frequency, it cannot realize that the MS is in Handover process under two carrier frequencies.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a handover method and system for packet switching under the downlink dual-carrier or multi-carrier transmission technology, as well as base station and mobile station equipment, so as to realize PS handover under the downlink dual-carrier or multi-carrier transmission technology .

Based on the above purpose, the present invention provides a method for handover of packet switching under the downlink dual-carrier or multi-carrier transmission technology, including:

A. When the source network device where the mobile station MS is located determines that there is an MS that requires switching of more than one carrier frequency, it sends a handover request for switching of more than one carrier frequency to the target base station system BSS of the handover;

B. After the target BSS receives the handover request, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and returns a response message to the source BSS of the MS after the allocation is completed;

C. After receiving the response message, the source BSS sends a handover command to the current MS, and includes the allocated radio resource information in the handover command;

D. After the current MS receives the handover command, the data transmission channel leaves the carrier frequency of the source BSS and connects to one or more carrier frequencies allocated by the target BSS.

After step D, the method further includes: the current MS sends an access pulse to the target BSS through the above one carrier frequency;

When the target BSS receives the access pulse on any allocated carrier frequency, it determines that the MS access is successful.

In step D of the method, if the MS fails to access the target BSS, the method further includes: re-connecting the data transmission channel to the source BSS.

In step D of the method, after the current MS leaves, the source BSS still reserves the radio resources of the original carrier frequency for the MS;

If the MS fails to access the target BSS, the data transmission channel is re-connected to the original carrier frequency of the source BSS.

After the current MS reconnects the data transmission channel to the source BSS, the method further includes: the current MS sends an access pulse to the source BSS through more than one carrier frequency that it has accessed;

When the source BSS receives the access pulse on any allocated carrier frequency, it determines that the MS access is successful.

In the method, after the BSS allocates wireless resources for the current MS, it further schedules a user state identifier USF on the allocated carrier frequency;

The current MS monitors the USF on the currently accessed carrier frequency, and sends the access pulse if it detects the USF on any carrier frequency.

In this method, after the BSS receives the access pulse sent by the MS on any carrier frequency allocated to the MS, it further includes: notifying the MS of the timing advance that should be used;

After receiving the timing advance, the MS performs data transmission with the BSS through the allocated carrier frequency according to the timing advance;

When the BSS receives the first correct RLC/MAC block sent by the MS, it determines that the current handover is successful.

The handover request in step A of the method includes indication information that more than one carrier frequency handover is required.

In this method, the MS maintains the downlink transmission state of the above one carrier frequency during the whole handover process.

Based on the above purpose, the present invention also provides a handover system for packet switching under the downlink dual-carrier or multi-carrier transmission technology, including: a base station system BSS and a mobile station MS,

When the BSS is the target BSS for MS handover, after receiving a handover request for more than one carrier frequency handover, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a radio resource to the source BSS of the MS after the allocation is completed. return response message;

When serving as the source BSS for MS handover, after receiving a response message from the target BSS about performing more than one carrier frequency handover, send a handover command to the current MS, and include the allocated radio resource information in the handover command;

After the MS receives a switching command for switching over one or more carrier frequencies, the data transmission channel leaves the carrier frequency of the source BSS and accesses one or more carrier frequencies allocated by the target BSS.

When the BSS in the system is used as the source BSS for the handover of the MS, it is further used to send a handover request for handover of more than one carrier frequency to the target BSS of the handover when it is determined that the MS needs handover of more than one carrier frequency;

Based on the above purpose, the present invention also provides a base station system BSS under the downlink dual-carrier or multi-carrier transmission technology,

When the BSS is the target BSS for MS handover, after receiving a handover request for more than one carrier frequency handover, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a radio resource to the source BSS of the MS after the allocation is completed. return response message;

When serving as the source BSS for MS handover, after receiving a response message from the target BSS about switching over one carrier frequency, it sends a handover command to the current MS, and includes the allocated radio resource information in the handover command.

Finally, based on the above purpose, the present invention also provides a mobile station MS under the downlink dual-carrier or multi-carrier transmission technology, the MS will leave the data transmission channel from the source BSS after receiving a handover command for more than one carrier frequency handover The carrier frequency is connected to more than one carrier frequency allocated by the target BSS.

It can be seen from the above that, in the handover method and system of packet switching under the downlink dual-carrier or multi-carrier transmission technology provided by the present invention, as well as the base station and mobile station equipment, when the source BSS requests handover from the target BSS, it indicates more than one carrier frequency switching, and ensure the smooth execution of the switching of more than one carrier frequency during the switching process, and further ensure a higher data transmission rate by maintaining the transmission status of more than one downlink carrier frequency. In addition, the MS in the present invention returns to the source BSS after the target BSS fails to access, which ensures the data transmission in the handover process.

Description of drawings

Fig. 1 is the handover processing flow schematic diagram of existing GPRS service;

Fig. 2 is a schematic diagram of a handover processing flow in a preferred embodiment of the present invention.

Detailed ways

In order to realize PS handover under the downlink dual-carrier or multi-carrier transmission technology, the main idea of the present invention includes: when the source network device determines that there is an MS that needs double-carrier or multi-carrier handover, it sends more than one carrier frequency to the handover target base station system BSS A handover request message for handover; after receiving the handover request message, the target BSS allocates radio resources corresponding to the number of carrier frequencies for the current MS, and returns a response message to the source BSS of the MS after the allocation is completed; after receiving the response message, the source BSS , sending a handover command to the current MS, and including the allocated radio resource information in the handover command; after the current MS receives the handover command, the data transmission channel leaves the source BSS and connects to the carrier frequency allocated by the target BSS.

Based on this idea, the embodiment of the present invention proposes a handover system for packet switching under the downlink dual-carrier or multi-carrier transmission technology, at least including: BSS and MS, wherein

When the BSS is the target BSS for MS handover, after receiving a handover request for more than one carrier frequency handover, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a radio resource to the source BSS of the MS after the allocation is completed. return response message;

And when it is the source BSS for MS handover, after receiving the response message from the target BSS about switching more than one carrier frequency, it sends a handover command to the current MS, and includes the allocated radio resource information in the handover command.

After the MS receives a switching command for switching over one or more carrier frequencies, the data transmission channel leaves the carrier frequency of the source BSS and accesses one or more carrier frequencies allocated by the target BSS.

In addition, when the BSS serves as the source BSS for MS handover, it can be further used to send a handover request for handover of more than one carrier frequency to the handover target BSS when it is determined that an MS needs more than one carrier frequency handover. Of course, this function can also be realized by the SGSN.

Referring to FIG. 2 , based on the above system, a preferred embodiment of the PS switching method of the present invention will be described in detail below.

The network devices involved in the process of this embodiment include: MS, source BSS, target BSS, and core network devices, such as SGSN. Wherein, the MS, the source BSS and the target BSS all support the downlink dual-carrier or multi-carrier transmission technology.

Assume that the MS is in the transmission state of n downlink carrier frequencies, n≥2, and simultaneously receives data on the n different carrier frequencies.

Step 201, when the source BSS where the current MS is located determines that there is an MS that needs n-carrier handover, it initiates a handover request, that is, sends a handover request message to the target BSS, requiring the target BSS to establish a relevant context for the MS and allocate radio resources, and here The request indicates switching of n carrier frequencies.

Wherein, this process may also be initiated and executed by a core network device, such as an SGSN.

Step 202, after receiving the handover request message, the target BSS judges that the message is a handover request for n carrier frequencies according to the indication information in the message, then establishes a BSS context for the MS, and allocates wireless resources for n carrier frequencies, mainly for The MS allocates n usable carriers in the downlink direction; after the allocation is completed, the target BSS returns to the source BSS through a handover request response message, and schedules the user state flag (USF) on the allocated carrier frequency.

Step 203, the source BSS receives the handover request response message returned by the target BSS, indicating that the resource allocation has been completed, and the source BSS sends a PS handover command (Handover Command) message to the current MS, indicating that the MS initiates PS handover, and the handover command message includes n carrier frequency information allocated by the target BSS.

Step 204, after the current MS receives the handover command message, it leaves the source BSS to connect the downlink data transmission channel to the n carrier frequencies allocated by the target BSS, and transmits the data on the n carrier frequencies according to the radio resource information described in the handover command. Monitor USF on frequency.

At this time, the source BSS may reserve its original carrier frequency resources for the current MS for a period of time or always.

The MS can disconnect the downlink data transmission channel connected to the source BSS one by one, and then access to the newly allocated carrier frequency, and it can also be performed in parallel. Moreover, the MS maintains the transmission state of downlink n-carrier frequency during the handover process, that is, the MS continues to maintain the original temporary data block flow (TBF), and this TBF belongs to n-carrier frequency TBF, and can receive or send on more than one carrier frequency RLC/MAC block.

Step 205, if the current MS receives a USF on any carrier frequency that is newly switched, it initiates an Access Burst to the target BSS.

Step 206: After receiving the Access Burst sent by the MS on any carrier frequency allocated to the current MS, the target BSS notifies the MS of the timing advance that should be used by signaling.

Step 207, after receiving the timing advance, the MS performs data transmission with the target BSS through the newly allocated n carrier frequencies according to the timing advance.

Step 208, when the target BSS receives the first correct RLC/MAC block sent by the current MS, it determines that the current handover is successful.

The MS fails to access the target BSS, for example: within the predetermined time, the MS does not receive the USF; or within the predetermined time, the target BSS does not receive the Access Burst sent by the MS, and the target BSS notifies the MS. Then the MS switches back to the n carrier frequencies of the source BSS again, and the specific process is as follows:

The MS connects the downlink data transmission channel to the n carrier frequencies reserved by the source BSS, and monitors the USF on the n carrier frequencies according to the radio resource information described in the handover command;

If the current MS receives USF on any carrier frequency reserved for it by the source BSS, it initiates an Access Burst to the source BSS;

After receiving the Access Burst sent by the MS on any reserved carrier frequency, the source BSS notifies the MS of the timing advance that should be used by signaling;

After receiving the timing advance, the MS performs data transmission with the source BSS through the newly allocated n carrier frequencies according to the timing advance;

When the source BSS receives the first correct RLC/MAC block sent by the current MS, it determines that the current handover is successful.

Of course, the above process is performed on the premise that the source BSS reserves the original radio resources for the MS. If the source BSS does not reserve the original radio resources for the MS, the source BSS can re-allocate the radio resources for the MS during the above handover process. .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (13)

1. A handover method of packet switching under a downlink dual-carrier or multi-carrier transmission technology, characterized in that, comprising: A. When the source network device where the mobile station MS is located determines that there is an MS that requires switching of more than one carrier frequency, it sends a handover request for switching of more than one carrier frequency to the target base station system BSS of the handover; B. After the target BSS receives the handover request, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and returns a response message to the source BSS of the MS after the allocation is completed; C. After receiving the response message, the source BSS sends a handover command to the current MS, and includes the allocated radio resource information in the handover command; D. After the current MS receives the handover command, the data transmission channel leaves the carrier frequency of the source BSS and connects to one or more carrier frequencies allocated by the target BSS. 2. The method according to claim 1, further comprising: after step D, the current MS sends an access pulse to the target BSS through the above one carrier frequency; When the target BSS receives the access pulse on any allocated carrier frequency, it determines that the MS access is successful. 3. The method according to claim 1, wherein in step D, if the MS fails to access the target BSS, further comprising: re-connecting the data transmission channel to the source BSS. 4. The method according to claim 3, wherein the source BSS in step D still reserves the radio resources of the original carrier frequency for the MS after the current MS leaves; If the MS fails to access the target BSS, the data transmission channel is re-connected to the original carrier frequency of the source BSS. 5. The method according to claim 3, wherein after the current MS re-accesses the data transmission channel to the source BSS, it further comprises: the current MS sends an access link to the source BSS through more than one upload frequency that it has accessed. pulse; When the source BSS receives the access pulse on any allocated carrier frequency, it determines that the MS access is successful. 6. The method according to claim 2 or 5, characterized in that, after the BSS allocates radio resources for the current MS, it further schedules a user state identifier (USF) on the allocated carrier frequency; The current MS monitors the USF on the currently accessed carrier frequency, and sends the access pulse if it detects the USF on any carrier frequency. 7. The method according to claim 2 or 5, characterized in that, after the BSS receives the access burst from the MS on any carrier frequency allocated to the MS, it further includes: notifying the MS of the time it should use advance amount; After receiving the timing advance, the MS performs data transmission with the BSS through the allocated carrier frequency according to the timing advance; When the BSS receives the first correct RLC/MAC block sent by the MS, it determines that the current handover is successful. 8. The method according to claim 1, wherein the handover request in step A includes indication information that more than one carrier frequency handover is required. 9. The method according to claim 1, wherein the MS maintains the downlink transmission state of the more than one carrier frequency during the whole handover process. 10. A switching system for packet switching under a downlink dual-carrier or multi-carrier transmission technology, comprising: a base station system BSS and a mobile station MS, characterized in that, When the BSS is the target BSS for MS handover, after receiving a handover request for more than one carrier frequency handover, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a radio resource to the source BSS of the MS after the allocation is completed. return response message; When serving as the source BSS for MS handover, after receiving a response message from the target BSS about performing more than one carrier frequency handover, send a handover command to the current MS, and include the allocated radio resource information in the handover command; After the MS receives a switching command for switching over one or more carrier frequencies, the data transmission channel leaves the carrier frequency of the source BSS and accesses one or more carrier frequencies allocated by the target BSS. 11. The system according to claim 10, wherein, when the BSS is the source BSS for MS handover, it is further configured to send a message to the handover target BSS when it is determined that an MS needs handover of more than one carrier frequency Carry out more than one handover request for carrier frequency handover; 12. A base station system BSS under the downlink dual-carrier or multi-carrier transmission technology, characterized in that, When the BSS is the target BSS for MS handover, after receiving a handover request for more than one carrier frequency handover, it allocates radio resources corresponding to the number of carrier frequencies for the current MS, and sends a radio resource to the source BSS of the MS after the allocation is completed. return response message; When serving as the source BSS for MS handover, after receiving a response message from the target BSS about switching over one carrier frequency, it sends a handover command to the current MS, and includes the allocated radio resource information in the handover command. 13. A mobile station MS under the downlink dual-carrier or multi-carrier transmission technology, characterized in that, after the MS receives a switching command for switching over one or more carrier frequencies, the data transmission channel is separated from the carrier frequency of the source BSS, Access to more than one carrier frequency allocated by the target BSS.

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