CN1567793A - A method for implementing cluster service in CDMA system - Google Patents

Abstract

The invention discloses a method for realizing trunking services in a Code Division Multiple Access (CDMA) system, which is characterized in that a base station on the network side of the CDMA system broadcasts service parameter messages of the cell, and the network side at least includes a base station and a dispatching station, The method also includes: when a user sends a group call request, the network side allocates forward resources for it, and dynamically allocates reverse resources for the user who sends the group call, and the corresponding user uses the reverse resources allocated by the system to perform services, and the services pass Occupy the forward resources for broadcasting, and release the reverse resources when the user service is completed. This method can coexist with CDMA services, and requires little modification and requirements for network equipment and terminals; it can realize two-way authentication between terminals and users; because it supports terminal handover, it can realize business continuity and effective Sexuality; since the broadcast is controlled by the dispatcher by occupying forward resources, it can realize the functions of forced insertion and forced removal.

Description

A method for realizing trunking service in code division multiple access system

technical field

The invention relates to a wireless communication system, in particular to a method for realizing trunking services in a code division multiple access (CDMA) system.

Background technique

Trunking wireless dedicated mobile communication system is a relatively economical and flexible command and dispatch communication system developed in recent years. It is widely used in government agencies, energy transportation, airport terminals, industrial and mining enterprises, fire police, water conservancy and Military and other units to meet the needs of internal communication of each unit.

Trunked wireless dedicated mobile communication system, hereinafter referred to as trunking system, is a mobile communication system in which many users automatically share a small number of wireless channels and use these channels dynamically. The system effectively increases the utilization efficiency of the communication channel, thereby improving the utilization rate of the frequency and expanding the user capacity. Through the sharing of frequencies, the shortage of frequency resources is alleviated to a certain extent, and the system centrally manages and controls base stations, which can effectively reduce the cost of network construction for users. The trunking system is established based on the relay technology of the public telephone network and the two traffic statistical laws of communication users. Each user only occupies a small part of the total available time of the channel; the probability of multiple communication users occupying the channel at the same time is very small.

Therefore, the most important feature of the trunking system is that it enables a large number of users to share relatively limited frequency resources without affecting each other. Immediately assign a communication channel to the user, and once the communication is over, release the channel immediately, and the system can provide the channel to others for continued use. This dynamic allocation of frequencies effectively pools the available time of all channels, thereby providing each user with the maximum available working time and minimizing channel congestion.

With the development of science and technology, users hope to use the same terminal to realize different types of communication services, that is, normal mobile communication services can be realized through a user terminal in a network, and at the same time, due to the needs of trunking services, it can also be used through the original user terminal to achieve. At present, the CDMA system has been widely used. But so far, the trunking service has not been realized in this system, so it is a technical development direction of the public mobile communication system to provide professional dispatching function in the CDMA system.

Contents of the invention

In view of this, the object of the present invention is to provide a method for realizing trunking service in CDMA system, so that it can realize trunking service in CDMA system.

A method for realizing trunking services in a code division multiple access system, the base station in the network side of the CDMA system broadcasts the service parameter message of the cell, and the network side includes at least a base station and a dispatcher, the method comprising:

A. The user terminal monitors the service parameters broadcast by the base station, and sends a group call request to the network side;

B. After receiving the group call request, the network side allocates forward resources for the user;

C. The network side allocates reverse resources for the user terminal sending the service request, the user terminal performs the service by occupying the forward resource, and the service is broadcast by occupying the reverse resource;

D. The user terminal service is completed, and the reverse resource is released.

The forward resource in step B is a forward shared channel, and the reverse resource in step C is a reverse traffic channel.

In step C, when the user terminal occupies the reverse traffic channel for service, if the user terminal moves over to the target base station, the network side switches the user terminal to the target base station.

The switching further includes:

After detecting that the pilot channel sent by the target base station exceeds the threshold, the user terminal sends a request message to the dispatcher to switch to the destination base station through the source base station; after receiving the request message, the dispatcher notifies the destination base station to prepare corresponding wireless resources;

The target base station establishes a forward shared channel and a reverse traffic channel with the user terminal; the user terminal starts monitoring the forward shared channel of the target base station; the target base station broadcasts the same content as the forward shared channel of the source base station;

In the step D, the user terminal releases the reverse traffic channel with the target base station.

Before allocating the reverse traffic channel for the user terminal, the user terminal moves to the target base station in the network, and the step C further includes: the user terminal will perform handover, and report the handover result and user information to the dispatcher tower.

Before switching,

If the target base station has established the scheduling group corresponding to the user terminal, the dispatcher assigns the user terminal to monitor the forward shared channel through the target base station;

If the target base station does not establish a scheduling group corresponding to the user terminal, the target base station establishes a forward shared channel with the user terminal, and sends forward shared channel parameters to the user terminal, assigning the user terminal to monitor the the forward shared channel.

Said step B further comprises:

The network side sends a broadcast paging message to the terminal side, and the user terminal receiving the broadcast paging message sends a request message to the network side to join the dispatching group.

Said step B further comprises:

B1. After receiving the request message from the user terminal to join the dispatching group, the network side judges whether the user terminal has passed the authentication, if it passes the authentication, then execute step B2, otherwise, start to authenticate with the user terminal If the authentication passes, execute step B2, otherwise, the cluster business fails;

B2. The network side determines whether to approve the user terminal to join the scheduling group according to the user information and the saved permission information for joining the scheduling group. If approved, the network side instructs the user terminal to monitor the forward shared channel, otherwise, the user terminal Send a decline to join message.

Said step C further comprises:

Multiple user terminals send preemption request messages to the network side. After receiving multiple preemption request messages, the dispatcher determines to allocate a reverse traffic channel to a user terminal according to the stored user priority, and then sends a forward shared channel to the user terminal. The assignment message allows the user terminal to perform services.

The method further includes: the user terminal in the dispatching group notifies the dispatching station of exiting the dispatching group by pressing a button.

Described step A further comprises:

A1. After receiving the group call request, the network side starts to perform authentication with the user terminal;

A2. The network side notifies the user terminal of the authentication result. After the user terminal receives the authentication result, it judges whether it has passed the authentication. If it passes, step B is executed; otherwise, the cluster service fails;

The authentication is two-way authentication between the user terminal and the network side, or one-way authentication on the user terminal by the network side.

The invention realizes the trunking service by dynamically allocating the reverse service channel. As can be seen from the foregoing process, the present invention has the following advantages and characteristics:

1) In the CDMA system, the trunking service can be realized, and it can coexist with the CDMA service, which requires little modification and requirements for network equipment and terminals;

2) Two-way authentication between the terminal and the user can be realized;

3) Since terminal handover is supported, business continuity and effectiveness can be achieved when crossing areas in the business state and monitoring state;

4) Because the forward shared channel broadcast is controlled by the dispatcher, it can realize the functions of forced insertion and forced removal.

Description of drawings

Fig. 1 is the schematic diagram of realizing the networking structure of the present invention;

Fig. 2 is a schematic flow chart of establishing a group call in the present invention;

Fig. 3 is a schematic flow diagram of joining a scheduling group in the present invention;

FIG. 4 is a schematic flow diagram of multi-user preemption in the present invention;

FIG. 5 is a schematic flow diagram of switching a user terminal in a call state;

FIG. 6 is a schematic flow diagram of a user terminal switching in a non-talking state;

FIG. 7 is a schematic diagram of an internal state of a dual-mode terminal used in the present invention.

Detailed ways

The core content of the present invention is: when a user terminal sends a group call request, the network side establishes a forward shared channel, and dynamically allocates a reverse traffic channel for the user terminal that sends a group call, and the corresponding user uses the reverse traffic channel allocated by the system to talk , the call voice is broadcast through the forward shared channel, and when the call is completed, the reverse traffic channel is released. Here, the network side includes at least a dispatcher and a base station.

Referring to FIG. 1 , the network structure for implementing the present invention includes a dispatcher, a base station, and a user terminal. A dispatcher can include several base stations, and a base station can include several user terminals. Here, the dispatcher implements the group call control protocol, provides the dispatcher with dynamic dispatch group calls, such as forced insertion and forced removal, and supports authentication between user terminals and the network. The dispatcher may exist independently as an independent server and device, or it may be set in MSC. The user terminal can be a dual-mode terminal, which supports CDMA voice service and data service, and also supports PTT trunking service; it can also only support PTT trunking service, but has the basic functions of a CDMA terminal.

When the dispatching group is not established in the system, the process of establishing the dispatching group for the first time is called a group call; after the dispatching group is established, if there are still users who want to join the dispatching group, it is called joining the dispatching group; when the user terminal in the dispatching group After moving from the source base station to the destination base station, the user terminal needs to be handed over; when the scheduling group is established, multiple users send call requests to the system at the same time or within a certain period of time, which is called multi-user preemption. In addition, the services referred to in the present invention include data services and voice services.

The trunking service of the present invention will be described in detail below from the aspects of group calling, joining a dispatching group, multi-user preemption, handover, etc., and taking voice service as an example.

Referring to Figure 2, the specific process of a group call is as follows:

Step 201, the base station that supports the trunking service sends the service parameters of this cell through the forward overhead message (Overhead Message), and broadcasts its own ability to support the trunking service to all user terminals in the base station;

Step 202, when the user terminal is turned on, it monitors the forward Overhead Message message, finds that the cell supports the trunking service, and sends a registration message of the trunking service to the dispatcher; after the dispatcher receives the message, it starts to communicate with the user terminal. Authentication, to verify the legitimacy of the user terminal, and notify the user terminal of the authentication result;

Step 203, after the user terminal receives the authentication result, if the authentication result is successful, the user can send an application to establish a group call message to the base station by pressing a button on the user terminal; if the authentication result is authentication failure, the user terminal cannot A group call request message is sent, and the group call fails;

Step 204: After receiving the group call request message sent by the user terminal, the base station establishes a forward shared channel, and at the same time establishes a reverse traffic channel with the user terminal sending the group call, and then sends the forward shared channel and reverse traffic to the user terminal channel parameters. At the same time, the base station pages other user terminals through the broadcast message of the paging channel, and other user terminals receiving the group call can determine whether to join the dispatching group. At this time, if the user terminal that requests to join the scheduling group has passed the authentication with the network side, it can directly send a request to join the scheduling group to the network side to join the scheduling group, and the base station will send the request to the network side after receiving the request. It sends the parameters of the forward shared channel.

Step 205, the user terminal is talking on the reverse service, and the voice information is broadcast on the forward shared channel after being exchanged by the dispatcher station;

Step 206, when the call is completed, the user terminal releases the reverse traffic channel, waits for other users to talk, or presses the button again to apply for the next call.

It can be seen from the above process that the user terminal can join the scheduling group in two ways. One is that the user terminal actively applies to join an established dispatching group or initiates a group call; the other is that the user terminal chooses to join the dispatching group after receiving a group call from another user.

In a cell that supports scheduling groups, if a scheduling group has been established and a forward shared channel is established, a single user can choose to join the scheduling group.

Referring to Figure 3, the specific process for a user to join a scheduling group is as follows:

Step 301, the user terminal sends a request message to join the scheduling group. After receiving the request, the user terminal judges whether the user has passed the authentication. After passing, execute step 302, otherwise, directly execute step 302;

Step 302, the user terminal sends a request message to the base station to join the dispatching group, which contains user identity information; after receiving the message, the dispatcher determines whether the user terminal can join the dispatching group according to the user information and the information such as the authority to join the dispatching group stored by itself If possible, the base station sends a forward shared channel assignment message to instruct the user terminal to monitor the forward shared channel, otherwise, sends a refusal to join message;

Step 303, after receiving the channel assignment message, the user terminal monitors the forward shared channel.

Referring to Figure 4, in a cell that supports scheduling groups, a scheduling group has been established, and the specific process of multi-user preemption is as follows:

Step 401, multiple user terminals send a reverse preemption request message to the dispatcher through the base station;

Step 402, after the dispatcher receives the message, it determines which user can be in the reverse call according to the user's priority and other information, and sends a forward shared channel assignment message to the determined user who can carry out the reverse call, and sends a forward shared channel assignment message to other users. The user sends a rejection message;

Step 403, after receiving the channel assignment message, the user terminal talks on the reverse traffic channel, and broadcasts on the forward shared channel after being exchanged by the dispatcher station;

Step 404, the user terminal finishes talking, releases the reverse traffic channel, waits for other users to talk, or initiates a new short-term call again.

Since the user terminal can move at any time, when the user terminal moves beyond a certain area, handover will be performed. There are two cases of handover, one is that the user terminal is in the reverse call process, and the reverse traffic channel soft handover can be performed, and the soft handover process is similar to the soft handover of CDMA; the other is in the non-talk state The user terminal, that is, there is no call in the reverse direction, and the forward traffic channel is monitored. In this case, handover is performed and a cross-cell handover mechanism is provided. For the second case, when handover is performed, the user terminal reports the handover event to the target base station, and the target base station decides whether to establish a forward shared channel according to the situation of the new cell, and notifies the user terminal to start monitoring the forward shared channel and common channel of the new cell , and the content of the forward shared channel and common channel of the new cell is the same as that of the original cell.

The base station 1 that supports the dispatching group has established a dispatching group, and the user terminal monitors the forward shared channel; as shown in Figure 5, the specific process of the user terminal handover is as follows:

Step 501, the user terminal presses a button to send a reverse preemption request message and obtains the right to speak, the user talks through the reverse traffic channel, and the voice information is exchanged by the dispatcher station and then broadcast on the forward shared channel;

Step 502, the user terminal moves across the area to the coverage area of base station 2, and when it detects that the pilot channel of base station 2 exceeds a certain threshold, it reports to base station 1, and base station 1 notifies the dispatcher to perform soft handoff processing, and the dispatcher judges according to the database that the base station should be 2 process and notify base station 2 to prepare corresponding wireless resources;

Step 503, base station 2 establishes the forward shared channel and the reverse traffic channel with the user terminal, and base station 1 notifies the user terminal to perform soft handover of the reverse traffic channel, and starts monitoring the forward shared channel of base station 2 at the same time, the base station The forward shared channel broadcast content of 2 is the same as the forward shared channel broadcast content of base station 1;

Step 504 , the user completes the call, and releases the reverse traffic channel with the base station 2 .

Referring to Fig. 6, if the user terminal is in the state of no reverse call, the specific process of switching is as follows:

Step 601, the user terminal moves from the coverage area of base station 1 to the coverage area of base station 2, the user terminal performs handover, and reports the handover result and user information to the dispatcher through base station 2;

Step 602, if the base station 2 has established the dispatching group corresponding to the user terminal, that is, there is already a forward shared channel broadcast, the dispatcher will instruct the base station 2 to send a channel assignment message, instructing the user terminal to monitor the forward shared channel; if the base station 2 does not Establish a scheduling group corresponding to the user terminal, base station 2 will establish a forward shared channel, and at the same time send an assignment message to the user terminal, which contains channel parameters of the forward shared channel;

Step 603, the base station 2 broadcasts the information of the dispatching group supported by the cell through the forward shared channel, that is, sends the dispatching group information on the forward shared channel through the service parameter message in the forward overhead message.

If the user terminal wants to withdraw from the dispatching group or cluster service, the system will have two ways to ensure the monitoring of the user terminal. One is that before the user terminal exits the dispatching group or other cluster services, it needs to send a signaling to the dispatcher by pressing a button, clearly declaring that it will withdraw from the dispatching group or cluster service; the other is that for normal shutdown, the user terminal must Send an exit command to notify the dispatcher. The dispatcher or base station keeps a timer for each user terminal that joins the cluster service. The time of the timer can be slightly longer than the survival time of each dispatching group. The timer should be refreshed when there is any message interaction between the user terminal and the system , becomes invalid when the user terminal declares to quit the service. If the timer expires, the system will set the user as "inactive"; the base station or dispatcher will continuously monitor the use of wireless channels in each cell. After determining that all users have exited the service state, the dispatcher will instruct the base station to release the air channel of this cell for other purposes, such as establishing a new dispatching group and performing CDMA services.

The authentication referred to in the present invention may be one-way authentication performed by the network side on the user terminal, or two-way authentication performed between the user terminal and the network side. Moreover, the user terminal needs to perform authentication in two situations. One is after the user terminal is powered on; the other is that the user terminal moves from an area that does not support the trunking service to an area that supports the trunking service. For these two cases, to be more precise, once the user terminal detects the forward overhead message and finds that the cell supports the trunking service, it will initiate a registration message for the trunking service, and the dispatcher will communicate with the user terminal after receiving the message. Authenticate.

Referring to shown in Figure 7, the user terminal referred to in the present invention is a dual-mode terminal, which can be divided into CDMA Idle state, CDMA Idle call state, Idle state and Idle call state. The specific process of transition between the four states is as follows:

1) Migration from CDMA Idle state to Idle state: The user terminal in the CDMA Idle state monitors the service parameter message broadcast in the forward Overhead Message by the cell supporting the trunking service, and finds that the cell supports the trunking service, and the user terminal will initiate the trunking service. Business registration, authentication between the system and the user terminal; then the user terminal joins the dispatching group; after joining the dispatching group, the user terminal monitors the forward shared channel of the dispatching group in the Idle state. Of course, the broadcasted service parameter message will be ignored for common CDMA user terminals, so the trunking service cannot be realized.

2) Migration between the idle state and the call state: the user presses a button to apply for a reverse call, and through preemption and adjudication by the dispatcher, the dispatcher instructs the user to start a short reverse call; after the call is completed, the user terminal releases the reverse call. The business channel returns to the Idle state.

3) Migration from Idle state to CDMA Idle state: without turning off the power supply, the dispatcher is notified by pressing a button to send a message of exiting the dispatching group or cluster service, and the state transitions to the CDMA Idle state at the same time.

4) Idle and call state transfer to CDMA call state: the user terminal in the call state can be notified by the base station through Flash message or Data Burst message, the user chooses whether to answer, and transfers to the CDMA call processing flow.

The method for realizing the trunking service of the present invention, through minor transformation of network equipment and terminals, while providing CDMA voice and data services, can also provide various functions of the original large-scale professional trunking, and at the same time will not significantly reduce the CDMA system efficiency. Moreover, the trunking service is not limited to providing ordinary voice services, but can also transmit data services and other services, such as short message services.

The present invention ensures that a corresponding wireless link is established when there is a service through a dynamic scheduling group, and releases a corresponding wireless channel when there is no cluster service in the cell to reduce the impact of the cluster service on the CDMA service and improve resource utilization; at the same time, the dynamic channel mode is used to reduce Reverse link interference; the state transition mode ensures that the terminal can receive CDMA incoming calls in the mode, and the user can choose whether to answer and transfer to the corresponding service; in the CDMA mode, the user terminal can also receive the call of the dispatching group of the cluster in time And choose to automatically or manually switch to the corresponding business mode; the security mechanism of the CDMA system can be used to provide channel-level encryption between dispatching groups, and the encryption of business data can also be added.

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 (12)

1, a kind of method that realizes group service in code division multiple access (CDMA) system is characterized in that, the service parameters message of this sub-district of base station broadcast in the cdma system network side, and network side comprises base station and dispatching desk at least, this method may further comprise the steps:

A. user terminal monitors the service parameter of base station broadcast, sends the group calling request to network side;

B. after network side is received this group calling request, for this user distributes the forward direction resource;

C. network side is that the user terminal that sends service request distributes reverse resource, and described user terminal carries out business by taking the forward direction resource, and business is broadcasted by taking reverse resource;

D. described teleservice finishes, the releasing reverse resource.

2, method according to claim 1 is characterized in that, the resource of forward direction described in the step B is a forward shared channel, and reverse resource is a reverse traffic channel described in the step C.

3, method according to claim 2 is characterized in that, when user terminal took reverse traffic channel and carries out business in step C, if described user terminal moves to the purpose base station in the district more, then network side switched to the purpose base station with described user terminal.

4, method according to claim 3 is characterized in that, described switching further comprises:

User terminal monitors after the pilot channel that sends the purpose base station exceeds thresholding, sends the request message that switches to the purpose base station to dispatching desk by source base station; After dispatching desk is received this request message, notice purpose base station preparation corresponding radio resource;

Forward shared channel and reverse traffic channel between foundation of purpose base station and the described user terminal; User terminal begins to monitor the forward shared channel of purpose base station; Described purpose base station broadcast and source base station forward shared channel identical content;

Reverse traffic channel between user terminal release and the purpose base station among the described step D.

5, method according to claim 2, it is characterized in that, before distributing reverse traffic channel for user terminal, described user terminal is distinguished the purpose base station that moves in the network more, described step C further comprises: user terminal will carry out handover, and switching result and user profile are reported dispatching desk.

6, method according to claim 5 is characterized in that, before switching,

If the purpose base station has been set up the dispatch group of described user terminal correspondence, then dispatching desk is by purpose base station assigned user terminal monitoring forward shared channel;

If the dispatch group of described user terminal correspondence is not set up in the purpose base station, then the purpose base station set up and described user terminal between forward shared channel, and send the forward shared channel parameter to user terminal, the described user terminal of assignment is monitored described forward shared channel.

7, method according to claim 2 is characterized in that, described step B further comprises:

Network side sends broadcast paging messages to end side, receives that the user terminal of broadcast paging messages sends the request message that adds dispatch group to network side, adds dispatch group.

8, method according to claim 7 is characterized in that, described step B further comprises:

After B1, network side are received the request message of the adding dispatch group that described user terminal sends, judge whether described user terminal passes through authentication, if pass through authentication, execution in step B2 then, otherwise beginning is carried out authentication with described user terminal, if authentication is passed through, execution in step B2, otherwise, the group service failure;

B2, network side are according to the authority information of the adding dispatch group of user profile and preservation, determine whether to ratify described user terminal and add described dispatch group, if approval, then network side indicating user terminal monitoring forward shared channel, otherwise, send refusal to user terminal and add message.

9, method according to claim 2 is characterized in that, described step C further comprises:

A plurality of user terminals send to network side and seize request message, dispatching desk receive a plurality of seize request message after, User Priority according to storage is defined as user terminal distribution reverse traffic channel, send the forward shared channel assignment message to this user terminal then, allow this user terminal to carry out business.

10, method according to claim 1 is characterized in that, this method further comprises: the user terminal in the dispatch group withdraws from dispatch group by button to the dispatching desk notice.

11, method according to claim 1 is characterized in that, described steps A further comprises:

After A1, network side were received this group calling request, beginning was carried out authentication with described user terminal;

Whether A2, network side after user terminal is received described authenticating result, judge self by authentication with the authenticating result informing user terminal, if pass through, and execution in step B, otherwise, the group service failure;

12, method according to claim 11 is characterized in that, described authentication is to carry out two-way authentication between user terminal and the network side, or network side unilateral authentication that user terminal is carried out.

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