WO2006111075A1

WO2006111075A1 - A method for implementing user roaming limit

Info

Publication number: WO2006111075A1
Application number: PCT/CN2006/000700
Authority: WO
Inventors: Zongyan Li
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-04-21
Filing date: 2006-04-17
Publication date: 2006-10-26
Also published as: CN100417281C; CN1688175A

Abstract

A method for implementing user roaming limit in the communication field. When CDMA WLL user switches in a session process, the method takes the cells that related to the signal quality possibly meeting the requirement of the session as the roaming limit authorization cells and binds the CDMAWLL user to these cells, which may be cells centralizing activated devices in soft switch or those before or after the device switch in hard switch. Those at un-binding state for a long time are bound to the cell where this time of session is made.

Description

Method for realizing user roaming restrictions

TECHNICAL FIELD The present invention relates to the field of wireless communications, and in particular, to a method for implementing user roaming restriction in a Code Division Multiple Access (CDMA) system. Background technique

CDMA is a technology used in wireless communication, which allows all users to use the entire frequency band at the same time, and treats the signals sent by other users as noise, regardless of the collision problem. In general, the advantages of CDMA include: The voice coding technology provided in CDMA, the call quality is better than the Global System for Mobile Communication (GSM), and the user can talk to the surrounding environment. The noise is reduced, making the call clearer. CDMA utilizes spread spectrum communication technology, which can reduce interference between mobile phones, and can increase the capacity of users, and the power of mobile phones can be relatively low, which can not only make the use time longer, but more importantly, can reduce electromagnetic waves. Radiation damage to people. The bandwidth of CDMA can be expanded to a large extent, and images can also be transmitted. This is the reason why CDMA is selected for the third generation communication system. In terms of security performance, CDMA not only has a good authentication system, but also has the ability to prevent people from being intercepted by using code division and multiplex.

Wireless Local Loop ("WLL") technology refers to wireless transmission in all or part of the access network between the end user and the switching office to provide users with fixed or mobile access services. technology. As an effective supplement to the wired access network, it has the characteristics of large system capacity, voice quality and cable coverage, wide coverage, convenient system planning, convenient expansion, password encryption or CDMA enhanced confidentiality. The problem of information transmission in difficult-to-wire areas is one of the fastest growing access networks. At present, wireless access technology has been widely used in rural areas and towns, and has also been applied to a certain extent in specialized networks such as water conservancy and electric power, industrial and mining.

There are many ways to access wireless, such as microwave transmission technology (including one-point multiple access microwave), satellite communication technology, cellular mobile communication technology, personal handyphone system (Personal Handyphone System, "PHS"), cluster communication technology, wireless local area network (Wireless Local Area Network, referred to as "WLAN").

WLL uses wireless means to connect fixed users to the fixed telephone network, that is, to replace the traditional wired user access by wireless, and to provide terminal service services for users. Among them, CDMAWLL is a wireless local loop solution based on CDMA technology specifications.

Deployers of CDMAWLL are generally fixed-line operators. Due to policy constraints, mobile license issues, and differentiated competition of fixed-line mobile networks, operators have the need for roaming restrictions, that is, users who do not want CDMAWLL systems have roaming. Features, limited mobility, if the users are all fixed-station users, the operator wants the user's range of movement to be as small as possible, for example, the service can be used only in a certain cell.

In response to this situation, the currently feasible roaming restriction scheme is first through CDMA.

The OTAPA (Over the Air Parameter Administration) function controls the Preferred Roaming List ("PRL") stored in the terminal. Among them, OTAPA refers to the function of effective communication and authentication for mobile workstations in wireless communication, thereby realizing the management of them and providing services to them. PRL is a combination of System ID ("SID") / Network ID (Network ID, "NID"). The NID of the CDMAWLL system can be configured to the cell level, that is, a base transceiver station (Base Transceiver Station, referred to as Each cell under "BTS" can correspond to a unique NID. The CDMA WLL can modify the SID/NID group in the terminal PRL through the OTAPA process, so that the SID/NID stored in the terminal is only the same as the SID/NID corresponding to a certain cell.

After the terminal is powered on, the system first performs the system detection. The search terminal sets the pilot signal of each cell in the frequency point, and after capturing a certain pilot signal on the frequency point, the terminal starts to receive the synchronization channel message sent by the cell. The message carries the SID/NID; if the SID/NID is the same as a pair of SID/NIDs stored by the terminal, the terminal locks the network, in which case the terminal can see that there is a signal; if the synchronization channel is under If the SID/NID of the current cell is not in the SID/NID group of the terminal, the terminal will not lock the cell and behave as no signal.

However, since the CDMA system is a shared power system, after the system capacity is changed or the network is optimized, the original non-cell boundary users may become the cell border users. For these cell boundary users, once the roaming restriction is bound to a certain cell, Since the signal of the neighboring cell is not searched, the success rate of the service access is low, or the voice cannot be supported after the access, since the voice cannot be supported. low quality. The operators maintain and optimize this situation, and the operators have insufficient control means. In summary, the above roaming restriction scheme has a defect that the roaming restriction control means for the cell border user is insufficient. In this case, a solution is proposed. First, when the voice shield is poor or no signal, the user of the CDMA WLL makes a complaint call to the operator, and the operator of the operator consults by telephone or obtains the actual location of the user in the business hall, and according to the network topology. Or the neighboring area data table obtains the SID/NID corresponding to the cell adjacent to the current roaming restriction binding cell of the user, and thereafter, manually sets the neighboring SID/NID group on the network side. Then, the operator manually triggers the OTAPA process to validate the SID/NID group settings manually set on the network side to the terminal. After the terminal's PRL is updated, neighboring cells can be detected, and neighbor cell signals can be used for service access, and handover can be supported during the call.

In practical applications, the above solutions have the following problems: It is neither convenient nor reliable.

The main reason for this situation is that, first of all, the CDMA LL network side needs to configure the neighbor relationship table, which is a large amount of maintenance work, especially after capacity expansion and network optimization. Second, relying on manual query and setting SID NID is not convenient. In addition, it is not accurate enough because it is subject to the operator's subjective judgment of the signal's good neighborhood. In this case, the business access success rate is low and the voice quality is poor, resulting in more customer complaints.

Summary of the invention

In view of this, the main object of the present invention is to provide a method for realizing user roaming restriction, so that the network side operator is no longer required to perform manual operation with subjective judgment, which can more conveniently and more reliably ensure better call quality.

To achieve the above object, the present invention provides a method for implementing user roaming restriction, including: A setting a user equipment to an unbound state;

If the user equipment switches during the call, the cell involved in the handover and having the signal quality likely to meet the call requirement is obtained as the roaming restriction authorized cell when the handover is completed;

C binds the user equipment to the roaming restriction 4 authorized cell.

Preferably, in the step B, when the handover is a soft handover, the cell in which the signal quality involved in the handover is likely to satisfy the call requirement is a cell in the user equipment activation set. Preferably, in the step B, when the handover is a hard handover, the cell in which the signal quality involved in the handover is likely to satisfy the call requirement is a cell before and after the handover.

Preferably, the step A includes:

When the signal is not good, the user equipment is set as a cell border user on the network side; or when the account is opened, the user equipment is set as a cell border user according to network planning conditions.

Preferably, before the step B, the method further includes:

The network side determines whether the user equipment is a cell border user according to the international mobile station identification number reported by the user equipment that initiates the call. If yes, the process proceeds to step B, otherwise, the general call processing is performed.

Preferably, the method further comprises:

After the user equipment is bound, the user equipment is set as a normal user.

Preferably, the method further comprises:

When the user equipment ends the call, if the user equipment is in the unbound state for more than the predetermined threshold, the user equipment is bound to the d area where the current call is made.

Preferably, when applied to a code division multiple access wireless local loop, the step B includes:

The B1 radio access controller-virtual core network sends an extended assignment request message to the radio access controller-base station controller, and the message is added on the basis of the standard assignment request message to indicate whether handover of the current call needs to be performed. An information element for performing a roaming restriction authorization cell decision;

B2. The radio access controller-base station controller responds to the extended assignment request message, establishes a traffic channel, and performs a call;

During the B3 call, the radio access controller-base station controller performs signal quality measurement between the user equipment and the cell equipment, and performs cell handover when the signal quality is poor;

After the B4 handover is completed, the radio access controller-base station controller notifies the radio access controller-virtual core network of the cell involved in the handover, and the signal quality is likely to satisfy the call requirement, as the roaming restriction authorization. Community.

Preferably, in the step B4, when the handover is a hard handover, the radio access controller-base station controller notifies the radio access controller-virtual core network by using an extended "Handoff Complete" message. , the message is added to the standard "Handoff Complete" message. The selected "cell identity list" information element is used to report the roaming restriction authorized cell list, wherein the "cell identity list" information element is a "ΑΓ" interface standard information element, and the cell type adopts "CELL ID 7".

Preferably, in the step B4, when the handover is a soft handover, the radio access controller-base station controller notifies the radio access controller-virtual core network through a standard "Handoff Performed" message. The cell listed in the "Cell Identity List" information element in the message acts as the roaming restriction authorized cell.

Preferably, when applied to a code division multiple access full mobile network, the step B includes:

The B1 core network sends an extended assignment request message to the base station controller, and the message adds an information element for indicating whether a roaming restriction authorized cell decision needs to be performed on the handover of the current call, based on the standard assignment request message;

B2, the base station controller, in response to the extended assignment request message, establishes a traffic channel, and performs a call;

During the B3 call, the base station controller and the user equipment perform signal shield measurement, and when the signal quality is not good, perform cell handover;

After the B4 handover is completed, the base station controller notifies the core network of the cell involved in the handover, and the signal quality is likely to satisfy the call requirement, as the roaming restriction authorized cell.

By comparison, it can be found that the main difference between the technical solution of the present invention and the prior art is that when the CDMA user performs handover during the call, the cell whose signal quality involved in the handover is likely to meet the call requirement is used as the roaming restriction. Authorize the cell and bind the CDMA user to these authorized cells. .

In addition, the authorized cells may be the cells in the user equipment activation set in the soft handover, or may be the cells before and after the user equipment handover in the hard handover. And, for a user who is in the bound state for a long time, bind it to the cell where the call is made.

The difference in this technical solution has brought about a more obvious beneficial effect, that is, simplified

It is more convenient to maintain and operate the roaming restriction of the user boundary of the CDMA cell; and effectively avoid the unreliable problem caused by the subjective judgment of the call quality, improve the service access success rate, and ensure a good voice. quality. Can alleviate the phenomenon of more customer complaints. DRAWINGS 1 is a schematic diagram of a process for automatically binding a cell boundary user roaming restriction according to a first embodiment of the present invention;

2 is a schematic diagram of a TLV format of a standard A1 interface according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail with reference to the accompanying drawings.

The principles of the invention are first explained. In the method for implementing the user roaming restriction, the user equipment (User Equipment, referred to as "UE") is first set to an unbound state, that is, the user in this state is preset to belong to the cell border user. The initial setting can be set at the time of account opening or when the user complaint signal is not good. When the UE sends a call, the network side > the International Mobile Subscriber Identity (IMSI) reported by the user. If it is a cell border user, if the UE is a cell border user, it needs to be processed according to the subsequent steps of the present invention. If not, it indicates that the cell signal of the UE is good, and no soft handover or hard handover is encountered. In the case of the general call processing. Those skilled in the art will recognize that IMSI is unique worldwide and is assigned to every user in a mobile communication system; its composition includes three mobile country code numbers, two to three mobile network codes, and multiple mobile users. Identification code; IMSI can only contain 0 to 9 numeric characters, all digits cannot exceed 15 digits, so IMSI can easily determine a specific user and implement some special functions.

Next, if it is determined that the UE belongs to the cell border user, and the UE has switched during the call, the cell with the signal quality involved in the handover may be satisfied as the roaming restriction authorized cell when the handover is completed. The roaming restriction authorized cell is a cell in the UE active set when the UE encounters the soft handover, and is a cell before and after the handover when the hard handover is encountered, so that the roaming restriction of the UE can be reflected, otherwise the UE and the ordinary mobile phone Users are completely similar and can roam freely. At the same time, because it is a technical solution for implementing cell border user roaming restriction based on the handover algorithm, it can effectively avoid the unreliable problem caused by the subjective judgment of the call quality, improve the service access success rate, and ensure better voice quality.

Finally, the UE is bound to the roaming restriction authorized cell, and the UE is set as a normal user. That is, the roaming restriction cell binding is performed by the Over the Air Parameter Administration (OTAPA) process, and the UE can improve by soft handover or hard handover when the signal encounters a bad place in the vicinity of several cells. The call effect ensures good wireless access, but it can not roam freely to other cells according to the needs of fixed network operators.

In addition, for a UE that does not switch for a long time, that is, a cell signal in which the UE is located is better, when the UE ends the call, it is determined whether the UE's duration in the unbound state exceeds a predetermined threshold, and if so, The UE is bound to the cell in which the call is made. In this way, the UE can be distinguished from other ordinary mobile phone users, and the roaming restriction feature is realized.

The first embodiment of the present invention will be described in detail below with reference to Fig. 1. In the first embodiment, the principles of the present invention are applied to a CDMA WLL.

1 shows a mobile station (Mobile Station, referred to as "MS"), a base station subsystem ("BSS"), and a radio access controller-base station controller (Radio Access Controller-Base Station Controller). "RAC-BSC"), Radio Access Controller-Virtual Core Network ("RAC-VCN") and Local Exchanger ("LE") are five functional entities. It should be noted that, in this embodiment, the UE and the MS actually refer to the same device.

First, the UE is set to the unbound state. When the signal is not good, the UE is set as the cell border user on the network side. Specifically, when the user opens the account, the UE is set as the cell border user according to the network planning situation; or when the account is opened, the user is first set to the ordinary user, and when the user reflects the signal is not good, the user is changed to the cell border user.

When the user makes a call, the calling party initiates the call through the air interface's initial call message and the called party through the paging response message. The air interface access process and the V5 interface establishment process in this embodiment are exactly the same as those of the ordinary user. As is known to those skilled in the art, various functional entities in a wireless access system are connected to each other through a series of interfaces. The two most important interfaces in the wireless access system, one is the wireless between the base station and the fixed terminating device. The interface is called the air interface, and the other is the interface between the controller and the switch. The V5 interface is one of them. Next, the network side determines whether the UE is a cell border user according to the IMSI reported by the user, and if yes, proceeds to the subsequent step, otherwise, according to the general call processing. Specifically, the RAC-VCN determines, according to the IMSI reported by the user, whether the user is a border user in the saved user data. It is the border user who wants to restrict roaming, and further processing is performed below. If not, it is processed as a normal user.

The following describes a series of steps that need to be performed when the UE is a border user who needs to restrict roaming, and the handover occurs during the call due to poor quality of the location signal.

First, the RAC-VCN sends an extended assignment request message to the RAC-BSC, where the message adds an information element for indicating whether a roaming restriction authorized cell decision needs to be made for the handover of the current call based on the standard assignment request message; In other words, the RAC-VCN notifies the RAC-BSC through the extended CDMA A1 interface message, that is, the Assignment request message (ASSIGN REQ), to perform measurement reporting of the roaming restriction authorized cell.

Next, the RAC-BSC responds to the extended assignment request message, establishes a traffic channel, and conducts a call. That is, the service channel establishment process is performed between the RAC-BSC and the MS.

On the other hand, the RAC-BSC feeds back the Assignment complete message to the RAC-VCN.

( ASSIGN COMPLETE ), the terminal access process is completed.

Then, after the LE makes the called connection, the calling user and the called user enter the call process. During the call, the RAC-BSC performs signal quality measurement with the UE, and when the signal quality is poor, the cell handover is performed. It should be noted that, regardless of the location signal of the UE, during the call, the RAC-BSC and the UE must perform measurements to determine the signal quality during the call. For a specific cell in which the UE is located, the neighboring cell may be an intra-frequency cell or an inter-frequency cell. During the call, the UE continuously measures and reports the pilot strength of the neighboring cell in order to assist the base station in making the handover decision. For the same-frequency measurement, the RAC-BSC configures the intra-frequency neighbor relationship table of the base station, and updates the neighboring set of the UE by the neighbor list update message. The UE continuously measures the pilot strength of the active set and the adjacent set. When the pilot strength meets the predetermined threshold (T__ADD, T_DROP), the UE reports a pilot strength measurement message to the RAC-BSC, and the assistant RAC-BSC performs a soft handover decision. For the inter-frequency measurement, the RAC-BSC configures the inter-frequency neighbor relation table of the base station, and updates the candidate freq neighbor set of the UE by using the candidate frequency request message. The UE continuously measures the pilot strength of the adjacent set of candidate frequencies. Pilot intensity In conjunction with the predetermined threshold (CF_T_ADD), the UE reports a candidate frequency search report message to the RAC-BSC, and assists the RAC-BSC in performing a hard handover decision.

Then, if the UE is in a bad signal position, as described above, handover will occur, and when the handover is completed, the cell involved in the handover and whose signal quality is likely to satisfy the call requirement is acquired as the roaming restriction authorized cell. Specifically, in this embodiment, the handover can be divided into two cases. The first one is a soft handover. In this case, the cell involved in the handover may have a cell that meets the call requirement and is a cell in the active set. The second type is hard handover. In this case, the cell involved in the handover may have a cell that meets the call requirement is a cell before and after handover.

It should be noted that, in this embodiment, the RAC-BSC handover algorithm is used to complete the acquisition process of the roaming restriction authorized cell. There are several cases here. In the first case, there is a high possibility that the UE at the boundary of the cell is switched. Based on the measurement information, the RAC-BSC decides to initiate a soft handover or a hard handover by using a handover decision algorithm. If the RAC-BSC initiates a hard handover, the information of the handover to the new cell can be obtained, that is, the new roaming restriction authorized cell with the good signal is obtained; if the RAC-BSC initiates the soft handover, the active set information of the current UE can be obtained, and the current UE is obtained. The activation set is used as the roaming restriction authorization cell; in the second case, if the MS is at the edge of the cell 1 and the cell 2, and the cell 1 and the cell 2 belong to the inter-frequency neighbor relationship, this may result in frequent changes with the wireless signal. A hard switch occurs. After the MS switches from cell 1 to cell 2, the RAC-BSC passes the roaming restriction authorization cell decision, and reports the cell 2 as the roaming restriction authorized cell to the RAC-VCN, but still needs the MS to return to the cell 1, that is, the cell 1 remains It is his roaming restriction authorized community. In the RAC-VCN roaming restriction authorized cell list, the cell 1 needs to be included, that is, the cell that is initially accessed should also be reserved as the roaming restriction grant cell of the cell border user.

After the handover is completed, the RAC-BSC notifies the RAC-VCN of the roaming restriction authorized cell. Specifically, the handover is completed. If it is a soft handover, the standard Handoff Performed message (HO PERFORMED) of the A1 interface is used. If it is a hard handover, the extended CRC-VCN is notified by the extended Handoff Complete message (HO COMPLETE). Restrict the authorized cell. The extended Handoff Complete message adds an optional cell identifier list information element to the standard Handoff Complete message for reporting the flood The cell restricts the authorized cell list, where the cell identity list information element is an A1 interface standard information element, and the cell type adopts a CELL ID 7. The cell listed in the cell identification list information element in the standard Handoff Performed message acts as a roaming restriction authorized cell.

After the handover is completed, the UE needs to be bound to the roaming restriction authorized cell. Moreover, in this embodiment, after the UE is bound, the UE is set as a normal user.

Specifically, the RAC-VCN authorizes the cell information according to the obtained roaming restriction, and performs mapping conversion of the system identity ij/network identity. And determining the binding of the roaming restriction binding, and determining the triggering timing of the roaming restriction binding of the boundary user of the cell. If the RAC-VCN does not receive the roaming restriction authorized cell, it indicates that the terminal does not have a handover, which may be that the signal quality of the cell in the cell is good, or may not be at the cell boundary, or the condition for switching to the neighboring cell is not met, then RAC-VCN The binding process of roaming restricted cells is not triggered. When the latter user calls again, the same processing will be performed until the neighboring cell that has passed the handover algorithm decision is triggered to trigger the binding process.

Finally, the OTAPA process between the RAC-VCN and the MS performs roaming restriction cell binding. The SID/NID group in the terminal priority roaming list is modified by the OTAPA process, so that the SID/NID stored in the terminal is only the same as the SID/NID corresponding to a certain cell. As is well known to those skilled in the art, for example, the SID/NID group of the MS is (2, 3), (2, 0), (3, 1), and the SID/NID group of the base station in the coverage area is (2, 3). ), since (2, 3) is in the MS's attribution table, the MS is a non-roamer, if entering the neighboring base station coverage area, and its SID/NID pair is (2, 0) or (3, 1), due to OTAPA The SID/NID group in the PRL of the MS has been modified, so the MS can still switch to implement a normal call, but can no longer roam to a farther extent. ,

The above is a specific embodiment of the present invention for CDMA WLL. In the foregoing process, there are two more extended messages that need to be further described.

The implementation of the present invention needs to extend the standard A1 interface of the CDMA system. Since the A1 interface of the CDMAWLL system is no longer a standard interface for interfacing with the mobile switch, the standard interface for interfacing with the LE is the V5 interface provided by the RAC-VCN; It becomes the internal interface between RAC-BSC and RAC-VCN, so this extension does not affect system compatibility for CDMAWLL. The first message that needs to be extended by the present invention is the Assignment Request message of the Al interface, that is, the IE roaming restriction authorized cell decision indication single byte type, and the value TRUE or FALSEo RAC-VCN uses the IE, indicating whether the RAC-BSC needs to use this IE. The handover of the call occurs to perform roaming restriction authorization cell decision. If necessary, after the handover occurs, the cell in the current active set after soft handover, or the new cell after hard handover is used as the roaming restriction authorized cell, and reported to the RAC-VCN; if not, the roaming restriction authorization cell decision is not made. , keep the original switching process unchanged.

The message that needs to be extended and modified by the present invention is the Handoff Complete message of the A1 interface, that is, the IE is the Cell Identifier List. When the handover is a hard handover, the RAC-BSC uses the extended Handoff Complete message to report the roaming restriction authorized cell list. The optional IE is the A1 interface standard IE, and the cell type is CELL ID 7. Figure 2 shows the Type Length Value ("TLV") format of the standard Al interface. In addition, when the handover is a soft handover, the RAC-BSC notifies the RAC-VCN through the standard HandoffPerformed message, that is, the definition of the HandoffPerformed message Cell Identifier List as the roaming restriction authorization cell list. The HandoffPerformed message is a standard A1 interface message, and the IE contained in it contains the Cell Identifier List. When the roaming restriction authorized cell needs to be reported, the roaming restricted authorized cell list is reported to the RAC-VCN through the Cell Identifier List, and the interface message does not need to be changed, but is used as a carrier for reporting information during soft handover.

It is to be noted that the present invention can be applied to a CDMA full mobile network in addition to the case applicable to the first embodiment, and a second embodiment for such a case will be briefly described below.

In the first embodiment, the technology of the CDMA WLL is based on the CDMA system, and the WLL is in the module division mode of RAC-BSC. RAC-VCN, and the CDMA full mobile network corresponds to the RAC-BSC and the RAC-VCN. They are BSC and Core Net ("CN" for short). Actually, RAC-BSC and RAC-VCN are simplified of BSC and CN, so in the second embodiment, only RAC-BSC in Figure 1 is needed. It can be changed to BSC, RAC-VCN to CN, other messages are the same, and the steps are basically the same, and the technical solution of implementing cell border user roaming restriction based on the handover algorithm can be realized. This article will not go into details.

Although the invention has been illustrated by reference to certain preferred embodiments of the invention And the description, but it will be apparent to those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

Rights request

A method for implementing user roaming restriction, comprising:

A sets the user device to an unbound state;

C binds the user equipment to the roaming restriction 4 Manchester cell.

The method for implementing user roaming restriction according to claim 1, wherein in the step B, when the handover is a soft handover, the signal quality involved in the handover may meet the call requirement. The cell is a cell in the user equipment activation set.

The method for implementing user roaming restriction according to claim 1, wherein in the step B, when the handover is a hard handover, the signal quality involved in the handover may meet the call requirement. A cell is a cell before and after handover.

The method for implementing user roaming restriction according to claim 1, wherein the step A includes:

The method for implementing user roaming restriction according to claim 4, wherein before the step B, the method further includes:

The method for implementing user roaming restriction according to claim 1, further comprising:

After the user equipment is bound, the user equipment is set as a normal user.

When the user equipment ends the call, if the duration of the user equipment in the unbound state exceeds a predetermined threshold, the user equipment is bound to the cell where the current call is made.

The method for implementing user roaming restriction according to any one of claims 1 to 7, wherein when applied to a code division multiple access wireless local loop, the step B includes:

The B1 radio access controller-virtual core network sends an extended assignment request message to the radio access controller-base station controller, and the message is added on the basis of the standard assignment request message to indicate whether handover of the current call needs to be performed. An information element for performing a roaming restriction 4 Manchester cell decision;

B2, the radio access controller-base station controller responds to the extended assignment request message, establishes a traffic channel, and performs a call;

After the B4 handover is completed, the radio access controller-base station controller notifies the radio access controller-the virtual core network of the cell involved in the handover, and the signal quality is likely to satisfy the call requirement, as the roaming restriction authorization. Community.

The method for implementing user roaming restriction according to claim 8, wherein in the step B4, when the handover is a hard handover, the radio access controller-base station controller is extended. Handoff Complete" message, notifying the radio access controller-virtual core network, the message adds an optional "cell identity list" information element to the standard "Handoff Complete" message for reporting the roaming restriction authorized cell list The "cell identification list" information element is an "A1" interface standard information element, and the cell type adopts "CELL ID 7".

The method for implementing user roaming restriction according to claim 8, wherein in the step B4, when the handover is a soft handover, the radio access controller-base station controller passes the standard " Handoff Performed" message notifying the radio access controller-virtual core network that the cell listed in the "Cell Identity List" information element in the message acts as the roaming restriction authorized cell.

The method for implementing user roaming restriction according to any one of claims 1 to 7, wherein when applied to a code division multiple access full mobile network, the step B includes:

The B1 core network sends an extended assignment request message to the base station controller, where the message adds an information element for indicating whether a handover restriction authorization cell decision needs to be performed on the handover of the current call, based on the standard assignment request message; B2, the base station controller responds to the "distributed request message", establishes a traffic channel, and performs a call;

During the B3 call, the base station controller performs signal quality measurement with the user equipment, and performs cell handover when the signal quality is poor;