A method for shortening service processing time between PDT digital cluster switching centers

Abstract

The present invention discloses a method for shortening the service processing time between PDT digital cluster switching centers. Multiple switching centers share mobile user data and equipment network topology information through a database. Multiple switching centers can all play the role of group call controllers. The rules stipulate that the switching center to which the base station that initiates each group call belongs is a temporary group call controller. The temporary group call controller searches for base stations to which users registered in the current call group belong in the entire network, and directly forwards the call to all base stations that need to participate. In this way, only one switching center in the current call group participates in service processing. Due to the lack of participation of multiple switching centers, the service processing delay of the switching center and the network delay through multiple switching centers are reduced. Without changing the network delay, the time for establishing a group call across switching centers and the time for switching across zones are shortened, the user experience is improved, the probability of group call conflicts is reduced, and the command and dispatch efficiency of the entire network is improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method for shortening service processing time between PDT digital cluster switching centers. Background Art

[0002] The PDT digital trunking communication system consists of base stations and switching centers. The IP network is used to interconnect the switching center and the base station, and the switching center and the switching center, forming a large network to achieve roaming and cross-regional, and is widely used in emergency and other industries. One of the characteristics of the PDT digital trunking communication system that is superior to public network communication is that it supports fast one-to-many calls. The network quality requirements in the "Police Digital Trunk (PDT) Communication System Engineering Technical Specifications" clearly point out the service time for call establishment. Under the condition that the network delay is not more than 50ms, the group call establishment time within the same switching center is ≤300ms, and the group call establishment time across switching centers is ≤500ms. It can be seen that the PDT digital trunking has a strict assessment of the service time for group call establishment.

[0003] The process of establishing a group call between traditional PDT digital trunking switching centers is as follows: multiple switching centers in the PDT digital trunking system manage their own base stations and handle their own mobility management and other services. The group call controller can only be undertaken by one of the interconnected switching centers, namely, switching center 2. After the group call establishment request is transmitted to the group call controller, it is then transmitted by the group call controller to each related base station through each switching center. Voice transmission and handover during the call process also need to be implemented through the participation of multiple switching centers. The traditional handover process is as follows: base station 1 receives a handover request initiated by the mobile station to base station 2, and the handover request is transmitted to switching center 1, switching center 2 and base station 2 in sequence through the link. After the corresponding service channel is established in base station 2, the channel information is transmitted back to switching center 2, switching center 1 and base station 1 in sequence through the link. Finally, base station 1 notifies the corresponding mobile station of the handover.

[0004] It can be seen that the traditional group call establishment, voice transmission and handover require the participation of multiple switching centers, and there are too many links, resulting in long delays in group call establishment and handover, and poor user experience. In addition, in the push-to-talk data trunking communication system, if the cross-switching center group call establishment time approaches or reaches the maximum limit of 500ms, there will be a noticeable delay, and there is even a high probability of group call conflicts between cross-switching centers. Summary of the invention

[0005] The present invention is mainly to solve the problem of long delay in establishing group calls and handover between traditional PDT digital clusters across switching centers, and provides a method for shortening service processing time between PDT digital cluster switching centers. Without changing the network delay, the method improves user experience and reduces the probability of group call conflicts by shortening the time for establishing group calls across switching centers. It solves a series of problems such as group call establishment delay, voice transmission delay, handover delay, and dropped calls, and improves the command and dispatch efficiency of the entire network.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions.

[0007] A method for shortening service processing time between PDT digital cluster switching centers comprises the following steps: Step S1: Multiple switching centers and their respective base stations are normally connected to the Internet; in the PDT digital trunking communication system, multiple switching centers manage their own base stations respectively and handle their own mobility management and other services. The switching centers and base stations of the entire network are interconnected using an IP network plane and can communicate with each other; Step S2: multiple switching centers share network topology information and mobile user data through a database; multiple switching centers in the PDT digital trunking communication system share mobile user data and device network topology information through a database, which is equivalent to each switching center being able to perceive all base station information and mobile user data in the entire network through data interaction; Step S3: The base station sends the group call establishment request to the switching center to which it belongs. The switching center assumes the role of a temporary group call controller according to the rules and forwards the group call establishment request to the base station to which the users of the current call group belong. After receiving the group call establishment request, the base station allocates channel resources, establishes the call, and then replies a call establishment response to the temporary group call controller. The response is finally routed to the call initiator base station, and the call is finally established. Step S4: During a call, if handover is required, the base station sends a handover request to its switching center, and the switching center forwards the handover request to the base station at the destination of the handover. After the base station processes the handover request, it returns the allocated channel resource information to the switching center as a response, and the response is finally routed back to the base station that initiated the handover to realize the handover.

[0008] The present invention provides a method for shortening the service processing time between PDT digital cluster switching centers. Without changing the network delay, the method improves the user experience by shortening the cross-switching center group call establishment time and the inter-zone switching time, reduces the probability of conflict when two switching centers initiate the group call at the same time, solves a series of problems such as group call establishment delay, voice transmission delay, inter-zone switching delay, dropped calls, etc., and improves the command and dispatch efficiency of the entire network.

[0009] Preferably, in step S2, multiple switching centers in the PDT digital trunking communication system share network topology information and mobile user data through a database, and each switching center can perceive all base station information and mobile user data in the entire network through data interaction. In this application, multiple switching centers share network topology information and mobile user data through data interaction.

[0010] Preferably, in step S3, multiple switching centers in the PDT digital trunking communication system can serve as temporary group call controllers, and it is agreed that the switching center to which the base station initiating the group call belongs is the temporary group call controller, and the temporary group call controller is responsible for the mobility management and call routing of users in the group. In the present application, the switching center to which the base station initiating the group call belongs is defined as a temporary group call controller, and the temporary group call controller is responsible for the mobility management and call routing of users in the group. Only one switching center is required to participate in the service processing. Due to the lack of participation of multiple switching centers, the service processing delay of the switching center and the network delay through multiple switching centers are reduced.

[0011] Preferably, in step S3, the temporary group call controller searches for base stations in the entire network to which users registered in the current call group belong, and directly forwards the call to all base stations that need to participate. In the present application, the temporary group call controller can perceive the base station information of the entire network through data interaction, so the temporary group call controller can manage the base stations of the entire network, and the temporary group call controller directly sends the group call establishment request to the base station to which the users in the call group belong.

[0012] Preferably, the specific process of step S3 includes the following steps: Step S31: the calling terminal initiates a group call establishment request from the calling base station, and the group call establishment request is routed from the calling base station to the calling switching center to which it belongs. The calling switching center acts as a temporary group call controller of the current calling group according to the rules, and directly forwards the group call establishment request to the called base station to which the current calling group user belongs; Step S32: After receiving the group call establishment request, the called base station allocates channel resources, establishes the call, and then replies a call establishment response to the calling switching center, which then routes the call establishment response to the calling base station, and the call is established; Step S33: After the call is established, the calling terminal starts to speak, and the voice is forwarded from the calling base station to the calling switching center, and then forwarded by the calling switching center to the called base station, and finally forwarded by the called base station to the called terminal participating in the call through the air interface.

[0013] In this application, only one switching center of the current call group participates in the group call service processing, but the group call service is established normally. Due to the lack of participation of multiple switching centers, the service processing delay of the switching center and the network delay through multiple switching centers are reduced, achieving the purpose of shortening the group call establishment time.

[0014] Preferably, the base station and the neighboring base station know each other's control channel number and wireless location identification number through the configuration of the network, and send the control channel number and wireless location identification number to the terminals of the base stations through the air interface. Base station 1 and base station 2 are neighboring base stations. Through the configuration of the network, base station 1 and base station 2 already know each other's control channel number and wireless location identification number. Assume that the control channel of base station 1 is c1 and the wireless location identification number is b1, and the control channel of base station 2 is c2 and the wireless location identification number is b2, and they have been sent to the terminals of their respective base stations through the wireless air interface.

[0015] Preferably, in step S4, if the terminal in the call finds that the signal quality of the receiving base station has deteriorated, background monitoring is started. When the signal quality reaches the handover threshold, the terminal applies to the base station for handover, and requests handover to the neighboring base station. The handover request carries the wireless location identification number of the neighboring base station. If the terminal in the call finds that the signal quality of the receiving base station has deteriorated, background monitoring is started. When the signal quality reaches the handover threshold, a handover request is initiated.

[0016] Preferably, the specific process of step S4 includes the following steps: Step S41: The terminal initiates a handover request from the base station, and the handover request is routed from the base station to the corresponding switching center. The switching center routes the handover request to a neighboring base station corresponding to the wireless location identification number according to the wireless location identification number in the handover request; Step S42: After processing the handover request, the neighboring base station returns the allocated channel resource information as a response to the switching center, and the switching center then routes the handover request response to the base station; Step S43: After receiving the response to the handover request, the base station forwards the channel resource information allocated by the neighboring base station corresponding to the new cell to the terminal via the air interface, and the terminal completes the handover to the new cell.

[0017] In this application, only one switching center in the current call group participates in the inter-zone service processing, but the inter-zone service is established normally. Due to the lack of participation of multiple switching centers, the service processing delay of the switching center and the network delay through multiple switching centers are reduced, achieving the purpose of shortening the inter-zone switching time.

[0018] As a preferred embodiment, in step S1, the whole network switching center and the whole network base stations are interconnected by IP network plane and can communicate with each other. The PDT digital trunking communication system consists of a switching center and base stations, and each switching center manages its own base stations, including mobility management, calls, cross-zone and other services.

[0019] Preferably, in step S3, the temporary group call controller queries the local base station where the current call group users are distributed and the base stations of other switching centers through shared data, and directly sends the group call establishment request to all base stations participating in the group call. The group call establishment includes within the same switching center and across switching centers.

[0020] Therefore, the advantages of the present invention are: (1) Only one switching center in the current call group participates in service processing, but the service is established normally. Since there are fewer switching centers involved, the service processing delay of the switching center and the network delay through multiple switching centers are reduced, thus achieving the purpose of shortening the service processing time. (2) Without changing the network delay, the time for establishing a group call across switching centers and the time for handover across different zones are shortened, thereby improving the user experience and reducing the probability of conflict caused by two switching centers initiating the same group call at the same time. This solves a series of problems such as delay in establishing a group call, delay in voice transmission, delay in handover across different zones, and dropped calls, thereby improving the command and dispatch efficiency of the entire network. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the process of establishing a group call and voice transmission between PDT digital trunkings across switching centers in an embodiment of the present invention.

[0022] Figure 2 It is a flow chart of the inter-zone switching process of the PDT digital cluster across switching centers in an embodiment of the present invention.

[0023] Figure 3 It is a flow chart of the process of establishing a group call and transmitting voice between traditional PDT digital clusters across switching centers in the comparative example of the present invention.

[0024] Figure 4 It is a flow chart of the inter-zone switching process of the traditional PDT digital cluster across switching centers in the comparative example of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] Embodiment 1.

[0027] A method for shortening service processing time between PDT digital cluster switching centers comprises the following steps: Step S1: Multiple switching centers and their respective base stations are normally connected to the Internet; in the PDT digital trunking communication system, multiple switching centers manage their own base stations respectively and handle their own mobility management and other services. The switching centers and base stations of the entire network are interconnected using an IP network plane and can communicate with each other; Step S2: multiple switching centers share network topology information and mobile user data through a database; multiple switching centers in the PDT digital trunking communication system share mobile user data and device network topology information through a database, which is equivalent to each switching center being able to perceive all base station information and mobile user data in the entire network through data interaction; Step S3: The base station sends the group call establishment request to the switching center to which it belongs. The switching center assumes the role of a temporary group call controller according to the rules and forwards the group call establishment request to the base station to which the users of the current call group belong. After receiving the group call establishment request, the base station allocates channel resources, establishes the call, and then replies a call establishment response to the temporary group call controller. The response is finally routed to the call initiator base station, and the call is finally established. Step S4: During a call, if handover is required, the base station sends a handover request to the switching center to which it belongs. The switching center forwards the handover request to the base station at the destination of the handover. After the base station processes the handover request, it returns the allocated channel resource information to the switching center as a response. The response is finally routed back to the base station that initiated the handover to realize the handover.

[0028] This embodiment provides a method for shortening the service processing time between PDT digital cluster exchange centers. In the PDT digital cluster communication system, multiple exchange centers share mobile user data and equipment network topology information through a database, which is equivalent to each exchange center being able to perceive all base station information and mobile user data in the entire network through data interaction. Multiple exchange centers in the PDT digital cluster communication system can all play the role of group call controllers. The rules stipulate that the exchange center to which the base station that initiates each group call belongs is a temporary group call controller. The temporary group call controller searches the base stations to which the users registered in the current call group belong in the entire network, and directly forwards the call to all base stations that need to participate. In this way, only one exchange center in the current call group participates in service processing, but the service is established normally. Due to the lack of participation of multiple exchange centers, the service processing delay in which the exchange center participates and the network delay through multiple exchange centers are reduced, thereby achieving the purpose of shortening the service processing time. Without changing the network delay, by shortening the time for establishing group calls across switching centers and the time for inter-zone switching, the user experience is improved, and the probability of conflict caused by two switching centers initiating the group call at the same time is reduced. This solves a series of problems such as group call establishment delay, voice transmission delay, inter-zone switching delay, and dropped calls, thereby improving the command and dispatch efficiency of the entire network.

[0029] In step S1, the switching center and base stations of the whole network are interconnected by IP network plane and can communicate with each other. The PDT digital trunking communication system consists of switching centers and base stations. Each switching center manages its own base stations, including mobility management, calls, cross-zone and other services.

[0030] In step S2, multiple switching centers in the PDT digital trunking communication system share network topology information and mobile user data through a database, and each switching center can perceive all base station information and mobile user data in the entire network through data interaction. In this embodiment, multiple switching centers share network topology information and mobile user data through data interaction.

[0031] In step S3, multiple switching centers in the PDT digital trunking communication system can serve as temporary group call controllers, and it is agreed that the switching center to which the base station initiating the group call belongs is the temporary group call controller, and the temporary group call controller is responsible for the mobility management and call routing of users in the group. In this embodiment, the switching center to which the base station initiating the group call belongs is defined as the temporary group call controller, and the temporary group call controller is responsible for the mobility management and call routing of users in the group. Only one switching center is required to participate in service processing. Due to the lack of participation of multiple switching centers, the service processing delay of the switching center and the network delay through multiple switching centers are reduced.

[0032] In step S3, the temporary group call controller searches for base stations in the entire network to which users registered in the current call group belong, and directly forwards the call to all base stations that need to participate. In this embodiment, the temporary group call controller can perceive the base station information of the entire network through data interaction, so the temporary group call controller can manage the base stations of the entire network, and the temporary group call controller directly sends the group call establishment request to the base station to which the users in the call group belong.

[0033] In step S3, the temporary group call controller queries the local base station where the current call group users are distributed and the base stations of other switching centers through shared data, and directly sends the group call establishment request to all base stations participating in the group call. The group call establishment includes within the same switching center and across switching centers.

[0034] The specific process of step S3 is as follows: Figure 1 As shown, the following steps are included: Step S31: the calling terminal initiates a group call establishment request from base station 1, the group call establishment request is routed from base station 1 to the switching center 1 to which it belongs, the switching center 1 acts as a temporary group call controller of the current calling group according to the rules, and directly forwards the group call establishment request to base station 2 to which the current calling group user belongs; Step S32: After receiving the group call establishment request, base station 2 allocates channel resources, establishes a call, and then replies a call establishment response to switching center 1, which then routes the call establishment response to base station 1, and the call is established; Step S33: After the call is established, the calling terminal starts to speak, and the voice is forwarded from base station 1 to switching center 1, and then forwarded by switching center 1 to base station 2, and finally forwarded by base station 2 to the called terminal participating in the call through the air interface.

[0035] In this embodiment, only one switching center of the current call group participates in the group call service processing, but the group call service is established normally. Since there are fewer switching centers involved, the service processing delay of the switching center and the network delay through multiple switching centers are reduced, thereby achieving the purpose of shortening the group call establishment time.

[0036] The base station and the neighboring base stations know each other's control channel number and wireless location identification number through the configuration of the network, and send the control channel number and wireless location identification number to the terminals of the base stations through the air interface. Figure 2 As shown, base station 1 and base station 2 are adjacent base stations. Through the network configuration, base station 1 and base station 2 already know each other's control channel number and wireless location identification number. Assume that the control channel of base station 1 is c1, the wireless location identification number is b1, the control channel of base station 2 is c2, the wireless location identification number is b2, and they have been sent to the terminals of their respective base stations through the wireless air interface.

[0037] In step S4, if the terminal in the call finds that the signal quality of the receiving base station has deteriorated, background monitoring is started. When the signal quality reaches the handover threshold, the terminal applies to the base station for handover, requesting handover to the neighboring base station, and the handover request carries the wireless location identification number of the neighboring base station. If the terminal in the call finds that the signal quality of the receiving base station has deteriorated, background monitoring is started. When the signal quality reaches the handover threshold, a handover request is initiated.

[0038] The specific process of step S4 is as follows: Figure 2 As shown, the following steps are included: Step S41: The terminal initiates a handover request from base station 1, and the handover request is routed from base station 1 to its switching center 1. Switching center 1 routes the handover request to base station 2 corresponding to the wireless location identification number according to the wireless location identification number in the handover request; Step S42: after processing the handover request, base station 2 returns the allocated channel resource information to switching center 1 as a response, and switching center 1 then routes the handover request response to base station 1; Step S43: after receiving the response to the handover request, base station 1 forwards the channel resource information allocated by base station 2 corresponding to the new cell to the terminal via the air interface, and the terminal completes the handover to the new cell.

[0039] In this embodiment, only one switching center in the current call group participates in the inter-zone service processing, but the inter-zone service is established normally. Since there are fewer switching centers involved, the service processing delay of the switching center and the network delay through multiple switching centers are reduced, achieving the purpose of shortening the inter-zone switching time.

[0040] Comparative Example 1.

[0041] For the convenience of description, the exchange center is referred to as the exchange.

[0042] The process of establishing a group call and transmitting voice between traditional PDT digital trunking switches: The PDT digital trunking system consists of switches and base stations. Each switch manages its own base stations, including mobility management, calls, and cross-zone services. The typical service of the PDT digital trunking system is group calling. Multiple terminals participate in a call. The terminals in the group should be called out regardless of the base station range of any switch they are registered in. In order to manage the calling range of group users, the PDT digital trunking system defines the role of group call controller, which is responsible for the mobility management and call routing of users in the group. Figure 3 The middle is borne by exchange 2; 1. Figure 3 In the process, the terminal initiates a group call establishment request from base station 1, and the group call establishment request is routed from base station 1 to switch 1 (establishment transmission delay 1 is generated here); since switch 1 is not the group call controller of this call group, switch 1 will query DNS to determine the IP information of group call controller switch 2 (this process generates establishment processing delay 1), and then route the group call establishment request to switch 2 (establishment transmission delay 2 is generated here); as a group call controller, switch 2 may manage other switches participating in the call in addition to managing base station 2 (omitted in this solution). Switch 2 finds that there are users registered in base station 2 in the call group, so it forwards the group call establishment request to base station 2 (this process generates establishment processing delay 2, and establishment transmission delay 3 is generated in the process of transmitting the group call establishment request from switch 2 to base station 2); 2. After receiving the group call establishment request, base station 2 allocates channel resources, establishes the call, and then replies to switch 2 for call establishment response. The response is routed to switch 1 and base station 1 in turn, and the call is finally established. 3. After the call is established, the calling terminal starts speaking, and the voice is forwarded from base station 1 to switch 1 in sequence (generating voice transmission delay 1); after switch 1 receives the voice, it determines that the voice should be forwarded to switch 2 (generating voice processing delay 1, and voice transmission delay 2 is generated during the transmission of voice from switch 1 to switch 2); after switch 2 receives the voice, it determines that the voice should be forwarded to base station 2 (generating voice processing delay 2, and voice transmission delay 3 is generated during the transmission of voice from switch 2 to base station 2); finally, the voice is forwarded by base station 2 to the terminals participating in the call via wireless.

[0043] The handover process between traditional PDT digital trunking switches: Base station 1 and base station 2 are adjacent base stations. Through the configuration of the network, base station 1 and base station 2 have known each other's control channel number and location identification number. Assume that the control channel of base station 1 is c1, the wireless location identification number is b1, and the control channel of base station 2 is c2, the wireless location identification number is b2, and they have been sent to the terminals of their respective base stations through the wireless air interface; 1. Figure 4 In, the call has been established; 2. The terminal in the call finds that the signal quality of receiving base station 1 has deteriorated, and starts background monitoring. When the signal quality reaches the handover threshold, the terminal applies to base station 1 for handover, and requests to handover to base station 2. The request carries the wireless location identification number b2 of base station 2. Base station 1 sends the handover request to switch 1, and a handover request delay 1 is generated here; 3. After receiving the handover request from base station 1, switch 1 searches for switch 2 where b2 is located according to the wireless location identification number b2 in the request, which generates a handover processing delay 1. The handover request is routed to switch 2, which generates a handover request delay 2. 4. After receiving the handover request, the switch 2 searches for the IP address and other related information of the base station 2 according to the wireless location identification number b2 of the base station 2 in the request. Here, the handover processing delay 2 is generated. In the process of routing the handover request to the base station 2, the handover request delay 3 is generated. 5. After processing the handover request, base station 2 returns the allocated channel resource information to switch 2 as a response, which generates a handover response delay 3; 6. After receiving the inter-zone response from base station 2, switch 2 processes the response, which generates inter-zone response processing delay 2, and routes the response back to switch 1, which generates inter-zone response delay 2. 7. After receiving the inter-zone response from exchange 2, exchange 1 processes the response, which generates inter-zone response processing delay 1, and routes the response back to base station 1, which generates inter-zone response delay 1. 8. After receiving the response to the handover request, base station 1 sends the channel allocation information of the new cell (base station 2) to the terminal through the air interface, and the terminal completes the handover to the new cell.

[0044] Embodiment 2.

[0045] The method of reducing the time of establishing group calls and handover between cross-zone switches in the PDT digital trunking scheme mainly includes: multiple switches in the PDT digital trunking system manage their own base stations respectively and handle their own mobility management and other services; the switches and base stations in the whole network are interconnected by IP network plane and can communicate with each other; Multiple switches in the PDT digital trunking system share mobile user information and device network topology information through a database, which means that each switch can perceive all base station information and mobile user data in the entire network through data interaction; Multiple switches in the PDT digital trunking system can act as group call controllers. The rules stipulate that the switch to which the base station that initiates each group call belongs is the temporary group call controller. The temporary group call controller searches for base stations in the entire network to which users registered in the current call group belong, and directly forwards the call to all base stations that need to participate. In this way, only one switch in the current group participates in service processing, but the service is established normally. Due to the lack of participation of multiple switches, the service processing delay of the switch participation and the network delay through multiple switches are reduced, achieving the purpose of shortening the group call establishment time and handover.

[0046] The process of establishing group calls and voice transmission between PDT digital trunking switches in this solution is as follows: The PDT digital trunking system consists of switches and base stations. Each switch manages its own base station, including mobility management, calls, cross-zone services, etc. The typical service of the PDT digital trunking system is group calling, in which multiple terminals participate in a call. The terminals in the group should be called out regardless of the base station range where they are registered. In order to manage the calling range of group users, the PDT digital trunking system defines the role of group call controller, which is responsible for the mobility management and call routing of users in the group. Figure 1 The call is initiated by switch 1 or switch 2. 1. Figure 1 In the example, the terminal initiates a group call establishment request from base station 1, and the group call establishment request is routed from base station 1 to switch 1 (here establishment transmission delay 1 is generated); since switch 1 assumes the group call controller of the call group according to the rules, switch 1 can manage base station 2; switch 1 finds that there are users registered in the call group at base station 2, so it initiates a group call establishment request to base station 2 (this process generates establishment processing delay 1, and the group call establishment request is transmitted from switch 1 to base station 2. Establishment transmission delay 2); 2. After receiving the group call establishment request, base station 2 allocates channel resources, establishes a call, and then replies a call establishment response to switch 1, and the response is finally routed to base station 1, and the call is finally established; 3. After the call is established, the calling terminal starts speaking, and the voice is forwarded from base station 1 to switch 1 in sequence (generating voice transmission delay 1); after switch 1 receives the voice, it determines that the voice should be forwarded to base station 2 (generating voice processing delay 1, and voice transmission delay 2 is generated during the transmission of voice from switch 1 to base station 2); finally, base station 2 forwards the voice to the terminals participating in the call via wireless.

[0047] The handover process between PDT digital trunking switches in this solution is as follows: Base station 1 and base station 2 are adjacent base stations. Through the configuration of the network, base station 1 and base station 2 have known each other's control channel number and location identification number. Assume that the control channel of base station 1 is c1, the wireless location identification number is b1, and the control channel of base station 2 is c2, the wireless location identification number is b2, and they have been sent to the terminals of their respective base stations through the wireless air interface; 1. Figure 2 In, the call has been established; 2. The terminal in the call finds that the signal quality of receiving base station 1 has deteriorated, and starts background monitoring. When the signal quality reaches the out-of-zone threshold, the terminal applies to base station 1 for out-of-zone access, and requests to be out-of-zone to base station 2. The request carries the wireless location identification number b2 of base station 2, and an out-of-zone request delay 1 is generated here; 2. After receiving the handover request from base station 1, exchange 1 can directly look up the IP address and other related information of b2 according to the wireless location identification number b2 in the handover request, because exchange 1 has synchronized the information of base station 2 of exchange 2. Here, handover processing delay 1 is generated, and the handover request is routed to base station 2, and handover request delay 2 is generated. 3. After processing the handover request, base station 2 returns the allocated channel resource information to switch 1 as a response, which generates a handover response delay 2; 4. After receiving the inter-zone response from base station 2, switch 1 processes the response, which generates inter-zone response processing delay 1, and routes the response back to base station 1, which generates inter-zone response delay 1. 5. After receiving the response to the handover request, base station 1 sends the channel allocation information of the new cell (base station 2) to the terminal through the air interface, and the terminal completes the handover to the new cell.

[0048] It can be seen that the group call establishment delay and voice transmission delay of the two solutions can be calculated separately: Traditional solution ( Figure 3 ) The process of group call establishment and voice transmission is base station 1->switch 1->switch 2->base station 2; The group call establishment delay: T 建立 =T 建立传输时延1 +T 建立处理时延1 +T 建立传输时延2 +T 建立处理时延2 +T 建立传输时延3 ; The group call voice delay: T 语音 =T 语音传输时延1 +T 语音处理时延1 +T 语音传输时延2 +T 语音处理时延2 +T 语音传输时延3 ; Refer to the minimum network requirements in the "GAT 1368-2017 Police Digital Trunking (PDT) Communication System Engineering Technical Specifications": If the network transmission delay is 50ms, the establishment transmission delay is 50ms; the establishment processing delay is an average of 10ms; the voice transmission delay is 50ms; the voice processing delay is an average of 1ms; Then T 建立 =50ms+10ms+50ms+10ms+50ms=170ms; Then T 语音 =50ms+1ms+50ms+1ms+50ms=152ms; The present invention ( Figure 1 ) The process of group call establishment and voice transmission is base station 1-> switch 1-> base station 2; The group call establishment delay: T' 建立 =T 建立传输时延1 +T 建立处理时延1 +T 建立传输时延2 ; T' 建立 =50ms+10ms+50ms=110ms; The group call voice delay: T' 语音 =T 语音传输时延1 +T 语音处理时延1 +T 语音传输时延2 ; T' 语音 =50ms+1ms+50ms=101ms; Comparing the group call establishment time of the present invention with the traditional group call establishment time, the group call establishment time of the present invention is shorter by T 建立处理时延2 and T 建立传输时延3 Comparing the present invention with the traditional group call voice delay group call voice delay, the present invention has less voice transmission delay T 语音处理时延2 and T 语音传输时延3 time; according to actual data, the traditional group call establishment delay of 170ms is greater than the group call establishment delay of 110ms of the present invention, and the traditional group call voice delay of 152ms is also greater than the group call voice delay of 101ms of the present invention. Therefore, the present invention can achieve the effect of reducing the group call establishment time and voice transmission delay.

[0049] It can be seen that the handover delay of the two schemes can be calculated separately: Traditional solution ( Figure 4 ) The handover process is base station 1-> switch 1-> switch 2-> base station 2-> switch 2-> switch 1-> base station 1; its handover delay is: T 越区 =T 越区请求时延1 +T越区处理时延1 +T 越区请求时延2 +T 越区处理时延2 +T 越区请求时延3 +T 越区响应时延3 +T 越区响应处理时延2 +T 越区响应时延2 +T 越区响应处理时延1 +T 越区响应时延1 ; Refer to the minimum network requirements in the "GAT 1368-2017 Police Digital Trunking (PDT) Communication System Engineering Technical Specifications": the network transmission delay is 50ms, the cross-zone request delay and cross-zone response delay are 50ms, and the cross-zone processing delay and cross-zone response processing delay are 10ms on average; Then T 越区 =50ms+10ms+50ms+10ms+50ms+50ms+10ms+50ms+10ms+50ms=340ms; The present invention ( Figure 2 ) The handover process is base station 1->switch 1->base station 2->switch 1->base station 1; Its handover delay: T' 越区 =T 越区请求时延1 +T 越区处理时延1 +T 越区请求时延2 +T 越区响应时延2 +T 越区响应处理时延1 +T 越区响应时延1 ; T' 越区 =50ms+10ms+50ms+50ms+10ms+50ms=220ms; Comparing the handover time of the present invention with the traditional handover time, the handover time of the present invention is shorter by T 越区处理时延2 , T 越区请求时延3 , T 越区响应处理时延2 and T 越区响应时延3 , according to actual data, T 越区 T' 越区 The extra 120 ms, therefore, the present invention can achieve the effect of reducing the handover delay.

[0050] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for shortening service processing time between PDT digital cluster switching centers, characterized in that: The following steps are involved: Step S1: multiple switching centers and their respective base stations are connected to the network; Step S2: multiple switching centers share network topology information and mobile user data through a database; Step S3: The base station sends a group call establishment request to the switching center to which it belongs. The switching center, as a temporary group call controller, forwards the group call establishment request to the base station to which the user of the current calling group belongs to establish a call; Step S4: During a call, if a handover is required, the base station sends a handover request to the switching center to which it belongs, and the switching center forwards the handover request to the base station at the handover destination to implement the handover.

2. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, characterized in that: In step S2, multiple switching centers in the PDT digital trunking communication system share network topology information and mobile user data through a database, and each switching center can perceive all base station information and mobile user data in the entire network through data interaction.

3. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, characterized in that: In step S3, multiple switching centers in the PDT digital trunking communication system can serve as temporary group call controllers. It is agreed that the switching center to which the base station initiating each group call belongs is the temporary group call controller, which is responsible for mobility management and call routing of users in the group.

4. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, characterized in that: In step S3, the temporary group call controller searches for base stations to which users registered in the current call group belong in the entire network, and directly forwards the call to all base stations that need to participate.

5. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, 3 or 4, characterized in that: The specific process of step S3 includes the following steps: Step S31: the calling terminal initiates a group call establishment request from the calling base station, and the group call establishment request is routed from the calling base station to the calling switching center to which it belongs. The calling switching center acts as a temporary group call controller of the current calling group according to the rules, and directly forwards the group call establishment request to the called base station to which the current calling group user belongs; Step S32: After receiving the group call establishment request, the called base station allocates channel resources, establishes the call, and then replies a call establishment response to the calling switching center, which then routes the call establishment response to the calling base station, and the call is established; Step S33: After the call is established, the calling terminal starts to speak, and the voice is forwarded from the calling base station to the calling switching center, and then forwarded by the calling switching center to the called base station, and finally forwarded by the called base station to the called terminal participating in the call through the air interface.

6. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, characterized in that: The base station and the neighboring base stations know each other's control channel number and wireless location identification number through the configuration of the network, and send the control channel number and wireless location identification number to the terminals of the base stations through the air interface.

7. A method for shortening service processing time between PDT digital cluster switching centers according to claim 6, characterized in that: In step S4, if the terminal in the call finds that the signal quality of the receiving base station deteriorates, background monitoring is started. When the signal quality reaches the handover threshold, the terminal applies to the base station for handover to a neighboring base station. The handover request carries the wireless location identification number of the neighboring base station.

8. A method for shortening service processing time between PDT digital cluster switching centers according to claim 7, characterized in that: The specific process of step S4 includes the following steps: Step S41: The terminal initiates a handover request from the base station, and the handover request is routed from the base station to the corresponding switching center. The switching center routes the handover request to a neighboring base station corresponding to the wireless location identification number according to the wireless location identification number in the handover request; Step S42: After processing the handover request, the neighboring base station returns the allocated channel resource information as a response to the switching center, and the switching center then routes the handover request response to the base station; Step S43: After receiving the response to the handover request, the base station forwards the channel resource information allocated by the neighboring base station corresponding to the new cell to the terminal via the air interface, and the terminal completes the handover to the new cell.

9. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, characterized in that: In step S1, the switching center of the entire network and the base stations of the entire network are interconnected using an IP network plane and can communicate with each other.

10. A method for shortening service processing time between PDT digital cluster switching centers according to claim 1, 2, 3 or 4, characterized in that: In step S3, the temporary group call controller searches the local base stations where the current calling group users are distributed and the base stations of other switching centers through shared data, and directly sends the group call establishment request to all base stations participating in the group call.

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