CN1756419A - CDMA system terminal switching method - Google Patents

Abstract

The invention relates to the field of data communication, and discloses a switching method for a terminal in an active state of a data service to solve the problem that a terminal in an active state cannot switch to an EVDO system autonomously. The method includes the following steps: the base station controller (BSC) judges according to the measurement message reported by the terminal in the service active state that it enters the mixed coverage area of the CDMA 1X system and the CDMA EVDO system from the pure CDMA 1X system coverage area, if it is a dual-mode terminal , interrupt the current service of the terminal and release the air interface of the terminal; the terminal re-establishes the connection in the CDMA EVDO system, and continues the current service. Furthermore, the air interface can be directly released without making a judgment on the dual-mode terminal. If the terminal does not support the CDMA EVDO system, the terminal will reconnect in the CDMA 1X system without causing service interruption.

Description

A terminal switching method in code division multiple access system

technical field

The present invention relates to handover technology in the field of data communication, in particular to CDMA 1X (CodeDevision Multiple Access 1X, code division multiple access single carrier system) data service active state terminal, from pure CDMA 1X system coverage area to CDMA 1X system and CDMA EVDO (CDMAEVolution To packet Data Optimized, code division multiple access data system) system mixed coverage area, how to switch to the method of CDMA EVDO system.

Background technique

In the mobile communication network adopting CDMA (Code Devision Multiple Access, Code Division Multiple Access) standard, CDMA EVDO is a pure data communication system. In the field of wireless communication, the cost per megabit of data transmitted by CDMA EVDO is much lower than that of CDMA 1X system. At present, the CDMA EVDO system is positioned as a superimposed network of CDMA 1X, that is, the superimposed coverage of CDMA EVDO and CDMA 1X is used in hotspot areas, and CDMA 1X is used to complete wide coverage in marginal areas, so as to realize a seamless wireless data network. Switch between dual networks. Due to the low cost of CDMA EVDO, data services should be run on the CDMA EVDO system as much as possible to improve the spectrum utilization of the system and reduce user investment. This is also taken as a principle and implemented in the design of dual-mode terminals.

However, the dual-mode terminal can successfully complete the switching between CDMA EVDO and CDMA 1X in the dormant state, and when the CDMA EVDO is activated, the mixed coverage area of CDMA EVDO and CDMA 1X enters the pure CDMA 1X coverage area (that is, in the CDMA 1X coverage area When the CDMA EVDO system does not cover the area), the switch from the CDMA EVDO system to the CDMA 1X system, but when the user enters the CDMA 1X and CDMA EVDO mixed coverage area from the pure CDMA 1X coverage area, due to the active dual-mode terminal cannot search CDMA EVDO frequency point, so it cannot automatically switch to the CDMA EVDO system, and can only continue to perform data transmission on CDMA 1X, wasting precious spectrum resources.

The existing technology cannot realize the switching from the active state of CDMA 1X to CDMA EVDO. Therefore, in the mixed coverage area of CDMA 1X and CDMA EVDO, the terminal continues to work in the CDMA 1X mode, which prevents users from enjoying high-speed wireless communication and wastes precious CDMA 1X carrier frequency resources.

Contents of the invention

The present invention aims to solve the problem that the terminal cannot be switched to the CDMA EVDO system when it enters the mixed coverage area of CDMA 1X and CDMA EVDO from the pure CDMA 1X coverage area when it is activated by CDMA 1X, and provides two switching methods, which are realized by the following steps .

A code division multiple access system terminal switching method, when BSC (Base Station Controller, base station controller) receives the measurement message of the data service active state terminal, carry out the following steps: confirm that the terminal enters the CDMA 1X from the pure CDMA 1X system coverage area The mixed coverage area of the system and the CDMA EVDO system; confirm that the terminal is a dual-mode terminal, and the dual-mode terminal supports the CDMA 1X system and the CDMA EVDO system at the same time; interrupt the current service of the terminal and release the air interface of the terminal, so that the terminal searches CDMA EVDO system frequency and establish a connection to continue the current business.

Another CDMA system terminal switching method, when the BSC receives the measurement message of the terminal in the active state of the data service, the following steps are performed: confirm that the terminal enters the mixed CDMA 1X system and CDMA EVDO system from the coverage area of the pure CDMA 1X system coverage area; interrupt the current service of the terminal and release the terminal air interface, make the terminal re-initiate the initialization request, and choose to perform the following operations: a, if the terminal only supports the CDMA 1X system, then the terminal calls the CDMA 1X system and Re-establish the connection and continue the current business; b. If the terminal supports both the CDMA1X system and the CDMA EVDO system, then the terminal registers with the CDMA EVDO system and establishes a connection to continue the current business.

The difference between the above two methods lies in whether the BSC firstly judges the terminal mode after receiving the measurement message of the active terminal, and then performs related switching. The method can pre-set the following lists according to needs: dual-mode terminal list, pure CDMA 1X system coverage area edge list and handover area list, to facilitate BSC inquiry.

In order to ensure the handover effect, the handover area list can be further set. The handover area is an area where the CDMA EVDO pilot signal is higher than a set threshold value in the mixed coverage area of the CDMA 1X system and the CDMA EVDO system. When the terminal Switch when entering the switching area.

When setting different area lists, the identifier of each area is the pilot sequence code or the identifier of the sector in each area, and the BSC judges the different areas where the terminal is located and the location change according to the pilot signal reported by the terminal measurement.

By applying the method of the present invention, the switching from the CDMA 1X data service active state terminal to the CDMA EVDO is realized, and the utilization rate of the CDMA EVDO data service is improved.

Description of drawings

FIG. 1 is a schematic diagram of a switching process.

Detailed ways

The CDMA 1X network coverage is larger than the CDMA EVDO network. The CDMA EVDO system is controlled by the BSC of the CDMA EVDO. The location of the BTS of the CDMA EVDO determines its coverage area. The BSC and BTS can be built in one, or they can be built with different equipment.

The main reason why the terminal cannot switch is that when CDMA 1X is in the activated state, when the user enters the mixed coverage area from the pure CDMA 1X coverage area, the terminal cannot search for CDMA EVDO frequency points at the same time, and cannot switch to the CDMA EVDO system. The information reported by it, such as the pilot frequency strength, makes the user in the active state enter the dormant state for a short time, and the terminal will search for the CDMA EVDO carrier frequency again, so as to transfer the data service to the CDMA EVDO system.

As shown in Figure 1, it is a schematic diagram of the switching process, and the specific switching steps are as follows:

1. When the BSC receives the measurement message reported by the terminal in the active state, according to the measurement message, it judges that the terminal enters the handover area from the coverage area of the pure CDMA 1X network system, and further queries the list of dual-mode terminals to confirm whether the terminal is a dual-mode terminal. If it is a dual-mode terminal, start the next step immediately to switch it to the CDMA EVDO system; if not, keep the state of the terminal.

When the wireless environment changes and each terminal needs to add or delete soft handoff branches, it will report a measurement report. If the branch required to be deleted is a pure CDMA 1X coverage area pilot, at the same time, all active set pilots are CDMA 1X and CDMA When piloting in EVDO hybrid coverage area, it means that the terminal enters the mixed coverage area from the pure CDMA 1X coverage area. If the terminal is in the active data service state, the terminal needs to be handed over to the CDMA EVDO system in order to optimize resource allocation.

When the BSC judges the location change of the terminal, the most convenient method is to set the area edge list. The mark of each area is the pilot sequence code or the identifier of the sector in each area. The position of the terminal and its change can be determined by querying the edge list. The edge area list is implemented inside the BSC and can be set during system planning. Based on the edge area list, an auxiliary switching area can be further set to avoid frequent switching. For example, the auxiliary handover area is located in an area with relatively good CDMA EVDO coverage, rather than a real coverage edge area. The pilot signal in this area is higher than a set threshold value, so that when handing over, the terminal being handed over is not located in the coverage area. Instead, it is located in the middle of the mixed-coverage cells at the edge or, when performing interruption, all soft-handover cells in the active set of the terminal are required to be cells in the mixed-coverage area. In this way, a hysteresis is introduced when handover is actually performed, which avoids the occurrence of ping-pong handover and ensures the quality of service.

A dual-mode terminal is a terminal that can work in CDMA 1X and CDMA EVDO systems at the same time. BSC confirms the identity of the dual-mode terminal through the dual-mode terminal list. The dual-mode terminal list is actually provided by the operator at the same time. The users of the service are distinguished from different dual-mode terminals by their IMSI (International Mobile Subscriber Identity, International Mobile Subscriber Identity).

2. The BSC interrupts the ongoing data service of the terminal and releases the air interface of the terminal.

3. Since the air interface is released, the terminal immediately initiates an initialization procedure. Firstly, the CDMA1X system is searched, and no operation is performed because it has already been registered, and then the CDMA EVDO system is found, and the registration process is carried out.

4. Since there is still data to be transmitted, according to the characteristics of the terminal, when CDMA 1X and CDMA EVDO systems exist at the same time, the connection establishment process is performed on the CDMA EVDO system.

5. The terminal performs data transmission on the CDMA EVDO system and completes the handover.

This is a method implemented on CDMA 1X. The execution of the above method depends on the realization of the following list: dual-mode terminal list and edge area list, pure CDMA 1X system coverage area and CDMA 1X system and CDMA EVDO system mixed coverage area edge list (or auxiliary handover area list). The area edge list is the boundary definition of the pure CDMA 1X boundary and the mixed coverage area. The sector identifier can be used as the boundary mark, which can be determined during system setup, and all sector identifiers can be made into a list form for easy query, or can be Divide all cells into two types, pure CDMA 1X cells and mixed coverage cells, so that if the terminal is gradually switched from pure CDMA 1X cells in the activation set to all mixed coverage cells, it can also be regarded as entering the mixed coverage area from the 1X coverage area. The BSC can judge the location change of the terminal according to the pilot signal reported by the terminal.

In this way, on the BSC side of CDMA 1X, the dual-mode terminal list and the pure CDMA 1X coverage area and mixed coverage area edge list or auxiliary handover area list are reserved. When the BSC confirms that a dual-mode terminal has entered the mixed area or auxiliary handover area according to the list , the BSC initiates the release of the air interface, and the dual-mode terminal will re-search the frequency point. After finding the CDMA EVDO frequency point, it will switch over the core network and transfer the data service to the CDMA EVDO to continue, thus completing the activation of CDMA1X. state to CDMA EVDO handover.

However, the list of dual-mode terminals is not necessary, and the list of dual-mode terminals requires the support of 3GPP2 or operators due to reasons related to operators and terminal manufacturers. Even if there is no such list, this method can also be used, but after the pure CDMA 1X terminal data service is briefly interrupted, it initiates a call on the CDMA 1X system, continues the data service, and performs data transmission. If it is a dual-mode terminal, based on the characteristics of the terminal, the terminal initiates a registration request after searching for the frequency point of the CDMA EVDO system. The CDMA EVDO system responds to the registration request and establishes a data connection for it, and continues the previous data service. The switching of the dual-mode terminal, and after the switching, the transmission rate of the data service is improved.

Although the above two methods may cause short-term data service interruption during execution, the method is feasible in practice based on the fact that data services are not sensitive to interruption. And if the dual-mode terminal list is included in the specification, this method can also change the dual-system waiting paging of CDMA 1X and CDMAEVDO into single-system waiting, which improves the standby time of the terminal.

Claims (11)

1, a kind of CDMA system terminal switching method is characterized in that, when code division multiple access single-carrier system base station controller is received the measurement message of data service activated state terminal, carries out the following step:

The affirmation terminal divides multiple access single-carrier system overlay area to enter code division multiple access single-carrier system and CDMA data system mixing overlay area from pure code;

Confirm that this terminal is a dual-mode terminal, described dual-mode terminal is supported code division multiple access single-carrier system and CDMA data system simultaneously;

Interrupt the current business of this terminal and discharge the air interface of this terminal, make this terminal searching CDMA data system frequency and connect, proceed described current business.

2, the method for claim 1 is characterized in that: also be included in the step that the dual-mode terminal tabulation is set in the base station controller, described dual-mode terminal is for supporting the terminal of code division multiple access single-carrier system and CDMA data system simultaneously.

3, the method for claim 1 is characterized in that: also be included in the step that pure code divides multiple access single-carrier system overlay area tabulation and code division multiple access single-carrier system and CDMA data system mixing overlay area to tabulate is set in the base station controller.

4, method as claimed in claim 3, it is characterized in that: also be included in the step that Zone switched tabulation is set in the base station controller, described Zone switched be the code division multiple access single-carrier system with CDMA data system mixing overlay area in, the pilot signal of CDMA data system is higher than the zone of setting threshold value, switches when Zone switched when terminal enters this again.

5, as claim 3 or 4 described methods, it is characterized in that: in the edges of regions tabulation, distinguish zones of different with the identifier of pilot frequency sequence sign indicating number in each zone or sector.

6, method as claimed in claim 5 is characterized in that: base station controller is judged the residing zones of different of terminal according to the pilot signal in the measurement message of terminal to report.

7, a kind of CDMA system terminal switching method is characterized in that, when code division multiple access single-carrier system base station controller is received the measurement message of data service activated state terminal, carries out the following step:

Confirm that this terminal divides multiple access single-carrier system overlay area to enter code division multiple access single-carrier system and CDMA data system mixing overlay area from pure code;

Interrupt the current business of described terminal and discharge this terminal air interface, make this terminal initiate initialization request again, and select to carry out following operation:

If this terminal of a is only supported the code division multiple access single-carrier system, then this terminal call code division multiple access single-carrier system and rebulid connection is proceeded described current business;

If this terminal of b is supported code division multiple access single-carrier system and CDMA data system simultaneously, then this terminal is proceeded described current business in CDMA data system registration and connect.

8, method as claimed in claim 7 is characterized in that: also comprise being listed in down the step that pure code divides the tabulation of edge, multiple access single-carrier system overlay area and code division multiple access single-carrier system and CDMA data system mixing overlay area to tabulate is set in the base station controller.

9, method as claimed in claim 8, it is characterized in that: also be included in the step that Zone switched tabulation is set in the base station controller, described Zone switched be the code division multiple access single-carrier system with CDMA data system mixing overlay area in, code division multiple access data pilot signal is higher than the zone of setting threshold value, switches when Zone switched when terminal enters this again.

10, method as claimed in claim 9 is characterized in that: in the edges of regions tabulation, distinguish zones of different with the identifier of pilot frequency sequence sign indicating number in each zone or sector.

11, method as claimed in claim 10 is characterized in that: base station controller is judged the residing zones of different of terminal according to the pilot signal in the measurement message of terminal to report.

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