CN100403849C - Group call communication system and method thereof - Google Patents

Abstract

The invention relates to mobile communication technology, and discloses a group call communication system and method thereof, so that the group call service in the mobile communication network has high reliability. In the present invention, at least two layers of networks are overlapped and covered in the same group call area, and a group call control center resides in each layer of networks. The anchor group call control center is determined by the terminal or fixed dispatcher that initiates the group call, establishes, controls and manages the group call, and the other group call control centers are relay group call control centers. Terminals can reside in the same layer of networks, and each overlapping overlay network works in a master-backup mode; terminals can also reside in different layers of networks, and each overlapping overlay network works in a load-sharing manner. When the network of each layer works in the active/standby mode, if the terminals in the active network and the standby network initiate a group call at the same time, the group call control center in the active network is triggered as the anchor group call control center, and the group call control center in the standby network Reject the group call and accept the trunk request.

Description

Group call communication system and method thereof

technical field

The invention relates to mobile communication technology, in particular to a group call communication system and method thereof.

Background technique

Since the birth of the analog mobile communication system in the 1980s, mobile communication has developed rapidly around the world in just two decades. With the successive introduction of the first to third generation mobile communication systems, the impact of mobile communication on human life and work increasing day by day.

The biggest difference between mobile communication and fixed telephone communication is that the user is in a mobile state, which means that the coverage of the mobile communication network must meet the mobility of the user. Therefore, the Global System for Mobile Communication (Global System for Mobile Communication, referred to as "GSM") ) as an example, the coverage of the GSM network has expanded from large cities to small and medium-sized cities, and from commercial and user-intensive areas in urban centers to suburban areas. While solving the problem of nationwide coverage of the network, it has also realized the automatic roaming of GSM nationwide.

The GSM system consists of three interconnected main subsystems, which are connected to users through a certain network interface. The three subsystems are Base Station Subsystem (BSS for short), Network and Switching Subsystem (NSS for short), and Operation Supporting Subsystem (OSS for short). The mobile station (MobileStation, "MS" for short) subsystem is generally regarded as a part of the BSS. The mobile station is a practical device for users in the GSM mobile communication network. The types of mobile stations mainly include vehicle-mounted stations and handheld stations (mobile phones).

In the GSM system, the BSS is responsible for providing and managing the transmission path between the NSS and the MS, especially including the radio interface management between the MS and the functional entities of the GSM system. The NSS is responsible for the management of communication services, ensuring that MS establishes communication with related public communication networks or with other MSs. That is to say, the NSS does not directly communicate with the MS, and the BSS does not directly communicate with the public communication network. MS, BSS and NSS form the physical part of the GSM system. OSS provides operators with the control, maintenance and management of these actual operating parts.

Among them, the BSS is composed of two functional entities, the Base Transceiver Station (BTS for short) and the Base Station Controller (BSC for short). BTS is responsible for wireless transmission, BSC is responsible for control and management.

BTS is a base transceiver station and an important part of BSS. It is controlled by the BSC, completes the conversion between the BSC and the wireless channel, and realizes the wireless transmission of the air interface between the BTS and the MS and related control functions. BTS is mainly composed of baseband unit, carrier frequency unit, control unit and antenna feeder unit. The baseband unit is mainly used for necessary voice and data rate adaptation and channel coding; the carrier frequency unit is mainly used for modulation/demodulation and the transmission and reception of radio frequency signals; the control unit is used for BTS operation and maintenance. The antenna feeder unit is mainly used for splitting/combining of radio frequency signals and converting radio frequency signals into electromagnetic waves or converting electromagnetic waves into radio frequency signals.

The BSC is the control part of the BSS, which completes the management of various interfaces and undertakes the management of wireless resources and wireless transmission parameters. BSC is mainly composed of the following parts: the management, control and processing part of the relevant interface; the public processing part; the switching part.

The BSS is composed of one BSC and one or more BTSs, and one BSC can control dozens of BTSs according to traffic demands. The BTS can be directly connected to the BSC, or can be connected to the BSC through a remote control connection through a Base Interface Equipment ("BIE").

The core of the GSM network is the mobile switching center (Mobile Switching Center, referred to as "MSC"), which controls all BSC services, provides switching functions and connections with other functions in the system, and provides interface functions with fixed networks. Users are connected with mobile users, mobile users and fixed network users. MSC from the three databases in the system, namely Home Location Register (Home Location Register, referred to as "HLR"), Visiting Location Register (Visit Location Register, referred to as "VLR") and Authentication Center (Authentication Center, referred to as "AUC") Get all data needed for user location registration and call request. In addition, MSC also requests to update part of the data in the database according to its latest acquired information. As the core of the network, MSC also supports functions with mobile features such as location registration, handover, and automatic roaming, as well as other network functions.

With the increasingly perfect function of GSM and private network or common network trunking system based on GSM technology system, more and more user-friendly functions are born, such as voice over IP (Voice over IP, referred to as "VoIP" for short) that supports network group calls. )technology

VoIP technology refers to the technology that converts voice signals into digital voice packets of a certain length, and adopts the method of store and forward to exchange and transmit in the form of packets.

A network using VoIP technology can support network group calls. The so-called network group calls refer to initiating calls to some or all users in a group through the calling user or administrator. The method of initiating a call is that the message initiated by the calling party carries the address or number information of all called users; or the call request message initiated by the calling party only carries the network group ID, and the network side uses the group ID corresponding to the network group ID. User information in the group, initiate a call to each called party. Using the network group ID to make a call can effectively reduce the communication traffic of the user equipment to the group control center when the call is initiated, because it is no longer necessary to send the address or number information of each called user. The time effect is more obvious, which brings great convenience to users.

Nowadays, the group call function is used in many systems, such as GSM for Railway Mobile Communication System (GSM for Railway, referred to as "GSM-R"). GSM-R is a system facility designed, built and used directly for railway transportation production and railway information services. It mainly completes functions such as railway dispatching communication, station communication, emergency communication, section communication, official communication, and transportation information transmission. Among them, the voice service in train dispatching adopts the function addressing, location-based addressing, group call, broadcast call, emergency call and other functions of the GSM-R system, which can provide railway transportation command voice communication services, and realize point-to-point calls and point-to-point emergency calls. calls, broadcast calls, group calls, rail emergency calls and multiparty calls.

However, since the GSM system initially serves public communication and basically does not involve safety applications, non-safety-related communication systems have much lower reliability requirements than safety-related communication systems. For example, GSM-R will carry train control information. Since these control information are used for train control or monitoring, once a problem occurs in the system, it may cause train delays at least, and may cause safety problems at worst.

Therefore, how to meet the high reliability requirements of group calls for safety-related applications has become an urgent problem to be solved for the private network or shared network trunking system based on the GSM technology system.

At present, the private network or shared network cluster system based on the GSM technology system generally uses a single network coverage, that is, there is only one layer of network coverage in the same area. On this basis, GSM-based trunking private network and trunking public network adopt a single-anchor MSC, a single dispatcher, and a single-layer network coverage to provide group call services. The group call communication system based on the GSM technical system covered by a single network includes a GSM network, which has its fixed mobile network number (Mobile Network Code, referred to as "MNC"), and also includes an MSC, a dispatcher, and a BSC. , the BSC can control one or more BTSs.

The reliability of the group call based on the above GSM system depends solely on the quality of the software and hardware of the equipment and the wireless transmission environment. When the MSC, dispatcher and single-layer network coverage fail, the trunk group call service will be interrupted, and the MSC is the entire group call. The call control center of the call, when the MSC fails, the entire group call will not be possible at all. In order to ensure the reliability of GSM system group calls, the hardware or software development of single network coverage equipment or products adopts strict safety product development related reliability, quality and safety control processes and design methods, and puts forward very strict requirements on product equipment. Requirements for reliability and safety indicators, especially for MSC's software and hardware reliability and safety requirements. It is hoped that the reliability and security of group calls in the GSM system can be guaranteed by improving the reliability of single-network coverage equipment.

In practical application, the above solution has the following problem: the reliability of the group call service in the mobile communication network cannot be guaranteed.

The main reason for this situation is that there are significant differences between the hardware or software development process and product design methods of GSM single network coverage equipment or products and the development process and product design methods of general public communication equipment manufacturers. It is difficult to implement, and it will become very difficult to improve the reliability of the equipment after reaching a certain performance, and the cost will increase exponentially, so it cannot meet the strict reliability and safety index requirements for the equipment of the product. There is always a certain probability of failure in the software and hardware of MSC or single-layer network equipment. When the MSC, dispatcher and single-layer network coverage fail, the trunking group call service will be interrupted. In particular, MSC is the entire group call When the MSC breaks down, the entire group call cannot be carried out at all, and the security and reliability of the group call service cannot be guaranteed.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a group call communication system and method thereof, so that the group call service in the mobile communication network has high reliability.

To achieve the above object, the present invention provides a group call communication system, comprising:

At least two mobile communication networks overlap and cover the same group call area;

A plurality of group call terminals reside in one of the networks respectively, and reside in the other networks when the network in which they reside is faulty;

Each of the networks includes a group call control center, wherein when a terminal or a dispatcher initiates a group call, the group call control center to which it belongs is triggered to be an anchor group call control center, which is used to establish, control and manage the group call, and other The group call control center triggers the relay group call control center that is the anchor group call control center to establish group calls within its jurisdiction under the control of the anchor group call control center.

Wherein, the system also includes at least two fixed dispatching stations, respectively connected to different group call control centers, one of which is the main fixed dispatching station, and the other fixed dispatching stations are standby fixed dispatching stations; when the terminal When a group call is initiated, the active fixed dispatcher joins the group call first, and if the active fixed dispatcher fails, the standby fixed dispatcher joins the group call.

In addition, in the system, the terminal preferably resides in the same network, the network is the main network, and other networks are the backup networks of the network.

In addition, in the system, when the terminals residing in each of the networks initiate a group call at the same time, the group call control center in the active network is triggered to be an anchor group call control center, and the The group call control center in the standby network rejects the group call in the network because the group call is busy, and becomes the relay group call control center.

In addition, in the system, in the configuration information on the network side, the active network is configured to initiate a group call by using an immediately assigned channel, and the standby network is configured to initiate a group call by using a delayed assigned channel.

In addition, in the system, the terminals preferentially reside in different networks, and the networks share loads with each other.

In addition, in the system, the mobile communication network includes a global system for mobile communication network, a code division multiple access network (such as a broadband code division multiple access network, a time division synchronous code division multiple access network, a code division multiple access 2000 network, etc.), Personal handheld telephone system network, wireless local area network, microwave access global interoperability network, and trunking communication network.

In addition, in the system, the mobile communication network is a private network or public network based on the global mobile communication technology system, and the group call control center is a mobile switching center.

In addition, in the system, the dispatching station includes a fixed dispatching station and a mobile dispatching station.

In addition, in the system, each of the networks includes an independent base station on the network side; or,

Each of the networks shares the same base station on the network side.

The present invention also provides a group call communication method, comprising the following steps:

Each group call terminal selects one of the overlapping mobile communication networks to camp on;

When the current network where the terminal resides fails, the terminal resides on other networks;

When the terminal initiates a group call, when the terminal or dispatcher initiates a group call, the group call control center it belongs to triggers as the anchor group call control center, establishes, controls and manages the group call, and other group call control centers trigger as the anchor group call control center The trunk group call control center of the group call control center performs group call establishment within its jurisdiction under the control of the anchor group call control center.

Through comparison, it can be found that the main difference between the technical solution of the present invention and the prior art is that at least two layers of networks are overlapped and covered in the same group call area, and a group call control center resides in each layer of network. The anchor group call control center is determined by the terminal or fixed dispatcher that initiates the group call, establishes, controls and manages the group call, and the other group call control centers are relay group call control centers.

Terminals can reside in the same layer of networks, and each overlapping overlay network works in a master-backup mode; terminals can also reside in different layers of networks, and each overlapping overlay network works in a load-sharing manner.

When the network of each layer works in the active/standby mode, if the terminals in the active network and the standby network initiate a group call at the same time, the group call control center in the active network is triggered as the anchor group call control center, and the group call control center in the standby network Reject the group call and accept the trunk request. In addition, the active network can be configured as an immediate channel assignment method, and the backup network can be configured as a delayed channel assignment method.

When a network fails, terminals in the faulty area choose other non-faulty networks to reside in.

The fixed dispatching stations are respectively connected to the different layers of the network, so that the fixed dispatching stations work in the active and standby mode. When the failure or the group call control center it is connected to fails, the standby fixed dispatching station will replace the main fixed dispatching station to work.

Each network layer can use independent base stations or share the same base station.

This difference in technical solutions has brought obvious beneficial effects, that is, when the first-tier network covering the group call area or its group call control center fails, the terminals in the faulty area can reside on other non-faulty networks When initiating a group call, the group call control center in other non-failure networks is responsible for the establishment, control and management of the group call, which ensures that the terminals in the group call area can normally realize the group call function, and solves the problem in the mobile communication network. The reliability of the group call service only depends on the software and hardware quality of the product equipment and the wireless transmission environment. The multi-layer network and the backup of multiple group call control centers greatly improve the reliability of the group call service. For example, in the group call area covered by the single-layer 99.9999% of the group call service availability of terminals in the group call area where the layer network is repeatedly covered and the group call control center resides in each layer network meets the needs of railway emergency calls, fire emergency calls, public security and armed police emergency operations, and emergency linkage emergency operations. Group call services that require high reliability, such as group calls.

By residing all terminals in the same network layer, each network layer with overlapping coverage can work in active/standby mode, and the assignment mode of the active network where the terminal resides is set to immediate assignment, and the assignment of other backup networks The method is set to delay assignment, so that while improving the reliability of the group call service, there is no additional demand for frequency resources, which meets the needs of building a high-reliability trunking communication network within limited frequency band resources.

The mechanism that the fixed dispatching station works in the active and standby mode further improves the stability and reliability of the group call service.

By sharing the same base station in different networks, the cost of the system network can be appropriately saved while improving reliability.

Description of drawings

Fig. 1 is a schematic diagram of a group call communication system according to the present invention;

2 is a schematic diagram of a group call communication system according to a first embodiment of the present invention;

3 is a flowchart of a method for group call communication according to the first embodiment of the present invention;

4 is a schematic diagram of using the main fixed dispatching station when a terminal in the main network initiates a group call in the group call communication system according to the first embodiment of the present invention;

5 is a schematic diagram of using a standby fixed dispatcher when a terminal in the active network initiates a group call in the group call communication system according to the first embodiment of the present invention;

Fig. 6 is a schematic diagram of using the main fixed dispatching station when a terminal in the backup network initiates a group call in the group call communication system according to the first embodiment of the present invention;

7 is a schematic diagram of using a standby fixed dispatcher when a terminal in the standby network initiates a group call in the group call communication system step according to the first embodiment of the present invention;

Fig. 8 is a schematic diagram of failure of the group call control center in the group call communication system according to the first embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The core of the present invention is that the group call communication system includes at least two mobile communication networks, which overlap and cover the same group call area, and a plurality of group call terminals reside in one of the networks respectively, and when the network in which they reside fails, Residing in other networks, each network contains a group call control center. When a terminal or dispatcher initiates a group call, the group call control center it belongs to triggers as an anchor group call control center, which is used to establish, control and manage the group call control center. For group calls, other group call control centers trigger the relay group call control center that is the anchor group call control center to establish group calls within its jurisdiction under the control of the anchor group call control center.

Specifically, as shown in FIG. 1 , the group call communication system of the present invention is covered by two layers of networks, and the two layers of network coverage positions and sizes can be different, overlapping and covering the same group call area. Each group call area requiring high reliability is covered by two network layers, network coverage layer 1 and network coverage layer 2. Each group call network coverage layer contains several cells, and each group call network coverage layer There are independent fixed dispatching station, MSC, Visitor Location Register (VLR for short), Group Call Register (GCR for short) and BSS. Wherein, the MSC is the group call control center of the group call communication system, and the GCR stores all cell lists in the two-layer network coverage layers of the above group call area. Normally, the two overlays of the group call system work in active/standby or load sharing mode. Multiple group call terminals reside on the group call network overlay 1 or group call network overlay 2 respectively. When the group call network When a terminal or dispatcher in coverage layer 1 initiates a group call, the group call control center MSC1 to which it belongs is triggered as the anchor group call control center, which is used to establish, control and manage the group call, and MSC2 is triggered as the anchor group call control center. The follower group call control center is used to set up group calls within the jurisdiction of the anchor group call control center under the control of the anchor group call control center. When the group call network coverage layer 1 fails, the group call terminals in the faulty area camp on the group call network coverage layer 2. Similarly, when a terminal or dispatcher in the faulty area initiates a group call on the group call network coverage layer 2, the group call control center MSC2 to which it belongs is triggered as the anchor group call control center to establish, control and manage the group call, and MSC1 is triggered as The trunk group call control center of MSC2 establishes group calls within its jurisdiction under the control of MSC1.

In order to better express the present invention, the following describes the group call communication system according to the first embodiment of the present invention according to the principles of the present invention.

As shown in FIG. 2 , the group call communication system in this embodiment includes two mobile communication networks overlapping and covering the same group call area. Multiple group call terminals preferentially reside in the same mobile communication network, the network is the main network, and another network is the standby network of the network. In the configuration information on the network side, the primary network is configured to initiate a group call by using an immediately assigned channel, and the standby network is configured to initiate a group call by using a delayed assigned channel. The active network and the standby network respectively include their own group call control center and BSS. The active network includes group call control center 1 and BSS1, and the standby network includes group call control center 2 and BSS2. The corresponding GCR of each group call control center stores a list of cells under the jurisdiction of the group call control center in the group call area, and the group call control center 1 stores the group call control center 2 as a trunk group call control center, and the group call The control center 2 stores the group call control center 1 as a trunk group call control center. In addition, the group call communication system also includes two fixed dispatching stations, each of which is connected to a different group call control center. One of the fixed dispatching stations is the main fixed dispatching station and is connected to the group call control center 1. One fixed dispatching station is a standby fixed dispatching station, which is connected with the group call control center 2 . Normally, the main dispatching station is used. When the main fixed dispatching station fails, the standby dispatching station can work instead of the main dispatching station. Through the mechanism that the fixed dispatching station works in the active and standby mode, the stability and reliability of the group call service are further improved. reliability.

Before the terminal or dispatcher initiates a group call, set the main network as the home network in each terminal, and set the backup network as the visited network so that each group call terminal preferentially resides on the main network, and when the main network fails to reside on the backup network. When a terminal or dispatcher initiates a group call, the group call control center in the network it belongs to triggers as the anchor group call control center, and the group call control center in another network triggers as the trunk group call control center of the anchor group call control center center. The anchor group call control center establishes and controls and manages the group call according to the channel assignment method stored in the corresponding GCR, and the trunk group call control center, under the control of the anchor group call control center, according to the channel assignment method stored in the corresponding GCR Establish group calls within its jurisdiction. The anchor group call control center calls the active fixed dispatcher to join the group call first. If the active fixed dispatcher fails, the anchor group call control center calls the standby fixed dispatcher to join the group call. When terminals residing in different layers of networks initiate a group call at the same time, the group call control center in the active network triggers as the anchor group call control center, and the group call control center in the backup network rejects the group call because the group call is busy. The group call within the network becomes the trunk group call control center.

The system of this embodiment has been described above, and the method of this embodiment will be described in detail below.

As shown in FIG. 3 , in step 310 , each group call terminal preferentially camps on the primary network according to preset settings. Specifically, before starting the group call, the main network can be set as the home network in each group call terminal, and the standby network can be set as the visited network, so that each group call terminal can preferentially camp on its home network according to the setting, That is the primary network. In order to prevent the group call communication system from increasing the reliability of the group call service and increasing the additional demand for frequency resources, in the configuration information on the network side, the primary network is configured to use the immediately assigned channel method to initiate group calls. The standby network is configured to initiate a group call using a delayed assignment channel to save limited frequency resources.

In step 320, the network side judges whether the active network where each group call terminal currently resides is faulty, if the active network is not faulty, then enters step 330, if the active network is faulty, then enters step 340.

In step 330, when a terminal or a dispatcher initiates a group call, the group call control center 1 is triggered as an anchor group call control center, and the group call control center 2 is triggered as a relay group call control center. Specifically, when a terminal or dispatcher initiates a group call, the group call control center in the network to which it belongs triggers as the anchor group call control center, and another group call control center triggers as the relay group call of the anchor group call control center. The control center, that is, the group call control center 1 in the active network is triggered as the anchor group call control center, and the group call control center 2 in the backup network is triggered as the trunk group call control center. The anchor group call control center, that is, the group call control center 1, uses the channel assignment method stored in the corresponding GCR1 to establish and control and manage the group call; the relay group call control center, that is, the group call control center Center 2, under the control of the anchor group call control center, uses the delayed channel assignment method to establish group calls within its jurisdiction according to the channel assignment method stored in the corresponding GCR2. The anchor group call control center calls the active fixed dispatcher to join the group call first, as shown in Figure 4. If the main fixed dispatching station fails, the anchor group call control center calls the standby fixed dispatching station to join the group call through the relay group call control center, as shown in FIG. 5 .

In step 340, each group call terminal in the fault area camps on the standby network. That is to say, each group call terminal in the failure area of the active network resides in its visited network, that is, the standby network, according to the previous settings. Then go to step 350 .

In step 350, when each mobile terminal or dispatcher in the backup network initiates a group call, it is judged whether any terminal in the active network simultaneously initiates a group call. Specifically, when each mobile terminal or dispatcher in the backup network initiates a group call, there may be terminals in the active network that initiate a group call at the same time, and both parties trigger their group call control center as the anchor group call control center at the same time, and report to the other party The group call control center sends a relay group call control center processing request message. If the group call control center 2 in the backup network receives the processing request message from the trunk group call control center, it indicates that there are terminals in the active network that simultaneously initiate a group call, and enter step 360. If the message is requested, go to step 370.

In step 360, the group call control center 2 in the standby network rejects the group call. Specifically, in step 350, the group call control center 2 receives the trunk group call control center processing request message from the group call control center 1, indicating that there are terminals in the active network that simultaneously initiate a group call. The control center 1 gives priority to the anchor group call control center, and the group call control center 2 rejects the group call because the group is busy, and accepts the group call relay request of the anchor group call control center as the group call relay request. The trunk group call control center establishes group calls within its jurisdiction under the control of the anchor group call control center.

If it is judged by step 350 that there is no terminal in the active network that initiates a group call at the same time, then enter step 370, maintain the state that the group call control center 2 is the anchor group call control center in step 350, and send the group call in the active network The control center 1 triggers the control center as a trunk group call. The anchor group call control center, that is, the group call control center 2, uses the delay assignment channel method to establish and control and manage the group call according to the channel assignment method stored in the corresponding GCR2; the relay group call control center, that is, the group call control center Center 1, under the control of the anchor group call control center, according to the channel assignment method stored in the corresponding GCR1, uses the method of immediately assigning channels to establish group calls within its jurisdiction. The anchor group call control center calls the active fixed dispatcher to join the group call first, as shown in Figure 6. If the active fixed dispatching station fails, the anchor group call control center calls the standby fixed dispatching station to join the group call, as shown in FIG. 7 .

It should be noted that, as shown in FIG. 8, if the group call control center 1 in the active network fails, that is, the entire active overlay network fails, then in step 320, all mobile terminals camp on the backup network, and when the backup network When each mobile terminal or dispatching station initiates a group call, the anchor group call control center, that is, the group call control center 2, calls the standby fixed dispatching station to join the group call, and independently establishes, controls and manages the group call. When the first-tier network covering the group call area or its group call control center fails, the terminals in the faulty area are camped on other non-faulty networks, and when a group call is initiated, the group call in other non-faulty networks The control center is responsible for the establishment of the group call and the method of control and management, which ensures that the terminals in the group call area can normally realize the group call function, and solves the problem that the reliability of the group call service in the mobile communication network only depends on the software and hardware quality of the product equipment And wireless transmission environment problems.

In addition, it is worth mentioning that the mobile communication network described in this embodiment is a private network or a public network based on the global mobile communication technology system, including a GSM network and a Code Division Multiple Access (CDMA) network. , Wideband Code Division Multiple Access (WCDMA for short) network, Time Division Synchronous Code Division Multiple Access (TD-SCDMA for short) network, Code Division Multiple Access 2000 (Code Division Multiple Access 2000 (CDMA2000 for short) network, Personal Handyphone System (PHS for short) network, Wireless Local Area Network (WLAN for short), Worldwide Interoperability for Microwave Access (Worldwide Interoperability for Microwave Access, referred to as "WiMAX") network, and cluster communication network and so on.

In this embodiment, the group call control center may be an MSC or other equipment. If the group call control center is on the BSC side, it may be a BSC. In this embodiment, the dispatching station includes a fixed dispatching station and a mobile dispatching station.

The second embodiment of the present invention is substantially the same as the first embodiment, the only difference being that in the group call communication system of the first embodiment, the two-layer network is in the master-backup relationship, and each group call terminal is preferentially camped in the master network, The active network and the standby network work in an active-standby manner. In the group call communication system of this embodiment, there is no distinction between the two layers of networks, each group call terminal preferentially resides in a different network, and the two layers of networks share loads with each other. Both layers of network can be configured to initiate a group call by immediately assigning a channel, or both can be configured to initiate a group call by using a delayed assigning channel.

The third embodiment of the present invention is substantially the same as the first embodiment, the only difference being that in the group call communication system of the first embodiment, the two-layer networks respectively include independent base stations on the network side. In the group call communication system of this embodiment, the two-layer network shares the same base station on the network side, and the two-layer network can be simulated by using different frequency points and the like. By sharing the same base station in different networks, the cost of the system network can be appropriately saved while improving reliability.

All the above embodiments use a two-layer network, which is a relatively practical way, but the present invention can also use a network with more layers. One of the layers can be set as the main network, and the other can be used as the backup network, and load sharing can also be performed in each layer of the network. Usually, each cell in each network layer has an equivalent corresponding cell with basically the same physical coverage in other layer networks, but it is also possible to adopt a method in which cells in each layer network do not correspond.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the present invention. The spirit and scope of the invention.

Claims (11)

1. A group call communication system, comprising:

at least two mobile communication networks, overlapping and covering the same group calling area;

the group calling terminals reside in one of the networks respectively, and reside in other networks when the resident network fails;

each network comprises a group calling control center, wherein when a terminal or a dispatching desk initiates a group calling, the group calling control center which the terminal or the dispatching desk belongs to is triggered to be an anchor group calling control center for establishing and controlling and managing the group calling, and other group calling control centers are triggered to be relay group calling control centers of the anchor group calling control center for performing group calling establishment in the jurisdiction range under the control of the anchor group calling control center.

2. The group call communication system according to claim 1, wherein said system further comprises at least two fixed dispatching stations, each connected to a different group call control center, wherein one fixed dispatching station is a primary fixed dispatching station, and the other fixed dispatching stations are backup fixed dispatching stations; when the terminal initiates a group call, the main fixed dispatching station preferentially joins the group call, if the main fixed dispatching station fails, the standby fixed dispatching station joins the group call.

3. The group call communication system according to claim 1, wherein said terminals reside preferentially in a same network, the network being a primary network and the other networks being backup networks for the network.

4. The group call communication system according to claim 3, wherein when said terminals respectively residing in said networks initiate group call simultaneously, said group call control center in said primary network triggers to become an anchor group call control center, and said group call control center in said backup network rejects group call in said network to become a relay group call control center due to busy group call.

5. The group call communication system according to claim 3, wherein in the configuration information of the network side, the active network is configured to initiate the group call using an immediate assignment channel mode, and the standby network is configured to initiate the group call using a delayed assignment channel mode.

6. The group call communication system according to claim 1, wherein said terminals preferentially reside in different networks, and the networks share load with each other.

7. The group call communication system according to any of claims 1 to 6, wherein the mobile communication network comprises a global system for mobile communication network, a code division multiple access network, a personal hand-held telephone system network, a wireless local area network, a worldwide interoperability for microwave access network, and a trunked communication network;

the code division multiple access network includes: wideband code division multiple access networks, time division synchronous code division multiple access networks, and code division multiple access 2000 networks.

8. The group call communication system according to claim 7, wherein the mobile communication network is a private network or a public network based on the global system for mobile communications technology, and the group call control center is a mobile switching center.

9. The group call communication system according to any of claims 1 to 6, wherein said dispatching stations comprise fixed dispatching stations and mobile dispatching stations.

10. The group call communication system according to any of claims 1 to 6, wherein each of said networks comprises an independent base station on a network side; or,

the networks share the same base station on the network side.

11. A method of group call communication, comprising the steps of:

each group calling terminal selects one from each overlapped mobile communication network to reside;

when the current resident network of the terminal fails, the terminal resides in other networks;

when the terminal initiates group calling, the terminal or the dispatching desk initiates group calling, the group calling control center which the terminal belongs to triggers is an anchor group calling control center, the group calling is established and controlled and managed, other group calling control centers trigger a relay group calling control center of the anchor group calling control center, and the group calling establishment in the subordinate scope is carried out under the control of the anchor group calling control center.

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