CN101378552B - Automatic switchover technology for MPT1327 analog cluster communication terminal call between base stations - Google Patents

Abstract

The present invention provides an MPT1327 analog trunking communication terminal automatic switching technology across base stations. When the terminal is locked to the system, it first searches for the base station number of the locking system. When the field strength signal is weaker than the set threshold value, it starts background scanning. The order is based on the order in which the 4 overlapping coverage base stations are written in the switching table. When the call ends and the user goes offline, the control channel of the overlapping coverage base station that has just been switched to is detected first, and if the registration conditions are met, re-register. If the control channel is not successfully registered, it will scan according to the scanning mode set by the terminal until it finds a channel that meets the conditions and re-registers. By improving the existing technology, the present invention enables the terminal to automatically select a base station with a strong signal when it is in the overlapping coverage area of the base stations, and can switch freely after going online in the overlapping coverage area of multiple base stations, and can always maintain the strongest field strength The call on the base station guarantees the quality of the voice, and there will be no loss of lock once the signal becomes weak.

Description

MPT1327 analog trunking communication terminal cross-base station call automatic switching technology

(1) Technical field

The invention relates to communication technology, in particular to a communication terminal communication technology across base stations.

(2) Background technology

There are problems in the existing technology: in the past, when the MPT1327 analog trunking terminal calls across base stations, it is getting farther and farther away from the coverage area of the original base station, and the automatic voice switching of this call cannot be completed in the coverage area of the new base station. If the overlapping coverage area is disconnected, the terminal searches for the base station again, and can initiate a call again after registration.

(3) Contents of the invention

The purpose of the present invention is to provide a MPT1327 analog trunking communication terminal which can automatically select a base station with a strong signal and ensure uninterrupted calls by improving the existing MPT1327 analog trunking communication system and terminal technology, so that when the terminal moves and talks in the overlapping coverage area of the base station Cross-base station call automatic switching technology.

The purpose of the present invention is achieved like this:

1. Basic content and parameters

The terminal supports automatic voice switching across 24 base stations at most. Each base station can have 4 overlapping coverage base stations. Corresponding to each base station in the terminal, one system code parameter, two control channel parameters, two traffic channel parameters, and four overlapping coverage base stations are set. At least one of the 2 control channels of each base station must exist in the control channel table or the flexible channel plan table (mainly depends on whether the scan mode of the control channel table or the scan mode of the flexible channel plan is adopted). The traffic channel written in the switching table (the switching table is used to store the relevant information of 24 base stations) should correspond to the traffic channel of the system to ensure that the correct traffic channel of the base station can be locked. A maximum of 10 smooth group call signs can be set, and each group call sign can be associated with any or all of the 24 base stations.

The background scanning of the overlapping coverage base station (the background scanning is the process of removing the overlapping coverage base station during the normal call of the traffic channel when the local field strength signal is relatively weak) is controlled by several parameters:

Start switching level: refers to a fixed level value set in advance. The field strength of this channel is weaker than the set value, and the background scanning program is started;

Switching threshold level difference: refers to the difference between the field strength of the channel set in advance and the field strength of the overlapping coverage base station. When the field strength of the overlapping coverage base station is stronger than the field strength of this channel by the set difference, switch to the overlapping coverage base station channel;

Switching time interval: the time interval between the terminal searching for the first overlapping coverage base station and the next overlapping coverage base station;

Transmitting to receiving time interval: The terminal is in the transmitting state, and when the set time is up, it will change to the time value of the receiving state.

2. Brief description of the realization principle

When the terminal is locked to the system, it first searches for the base station number of the locked system. Only when the base station number is found, can the four overlapping coverage base stations associated with it be confirmed. The terminal goes online in the overlapping coverage area. When the field strength signal is weaker than the set threshold value, it starts background scanning. The scanning sequence is based on the order in which the 4 overlapping coverage base stations are written in the switching table. When the associated When the field strength signal of the overlapping coverage base station is stronger than that of the locking base station, if it is in the receiving state, it will directly lock to the base station with strong signal. If it is in the transmitting state, it needs to send a signaling Maint1 on the locked base station to inform the system that the base station is not in the transmitting state. After that, it can lock on the overlapping coverage base station with a strong signal, and send the signaling Maint0 to inform the system that the base station is here To transmit. When the call is over and offline, first detect the control channel of the overlay base station just switched to, and re-register if the registration conditions are met. If the control channel is not successfully registered, it will scan according to the scanning mode set by the terminal until it finds a channel that meets the conditions and re-registers.

3. Implementation method

Combined with Figure 1 for a detailed flow chart of the receiving state:

1. When the MPT analog trunking terminal is locked to the system, it starts to search the traffic channel switching table, and finds the corresponding base station number from the table by locking to the system code of the system. The system code is the unique identification of the base station number. If it cannot be found The base station number corresponding to the system code, if the base station is not written in the description table, it will not enter the background scan.

2. When the base station number is found, the currently locked base station is confirmed. By locking the base station, search for 4 overlapping coverage base stations, and judge whether the control channel of each overlapping coverage base station is in the specified table (if it is a control channel table scan mode or section scan mode, then it should be in the control channel table. If it is a flexible channel plan scan mode, it should be in the flexible channel plan table.) If both control channels are not in the specified table, then put this The overlapping coverage base station is blank, which means that the overlapping coverage base station is not associated, and this base station will not be scanned during background scanning.

3. After the terminal is online, if it is judged that the group attribute is a smooth group and it is in the receiving state, it will enter the background scanning process.

4. First determine the group number of the smoothing group, and search for the overlapping coverage base station number through the group number. This overlapping coverage base station includes several or all of the 24 base stations. It is mainly used to control when calling this group number. Only the associated base stations can respond, and the unassociated base stations will not go online.

5. Determine the 4 overlapping coverage base stations of the locked base station respectively. If the 4 overlapping coverage base stations are all empty, it means that the base station has not written the overlapping coverage base station, and will not enter the background scan.

6. Determine the specific position of the traffic channel in the table. Make a mark so that you can lock the corresponding position when switching. If not found, it means that the traffic channel is not in the list, and background scanning will not be performed.

7. "Channel switching time" is mainly to control the scanning time interval between overlapping coverage base stations. For example: After scanning the first overlapping coverage base station, the second overlapping coverage base station cannot be scanned until the set "switch channel time" arrives.

8. Here is to detect the field strength of the traffic channel of the base station. If the detected field strength value is stronger than the set "switching level" field strength value, it will not enter the background scanning, and the "switching channel" will be reset at this time. "Time" is used to control the field strength of the channel to be detected next time.

9. If the detected field strength value is weaker than the set "switching level" field strength value, it is necessary to detect the field strength of the overlapping coverage base station. Before the detection, it is first necessary to determine which overlapping coverage base station is to be detected. The default is The first overlapping coverage base station is detected first.

10. After determining the overlapping coverage base station, search for several parameters of the overlapping coverage base station: including system code, control channel, and traffic channel, so as to update related parameters in case of subsequent locking. According to step 6, it can be judged which traffic channel should be locked. For example: if the traffic channel of this channel is the first channel, then the overlapping coverage base station is also locked to the first channel.

11. Lock the overlapping coverage base station, detect the field strength value of the overlapping coverage base station, if the field strength of the overlapping coverage base station is weaker than the set field strength value, then do not switch, exit the scanning state, and record the serial number of the overlapping coverage base station at this time, so that When scanning next time, the next overlapping coverage base station with this sequence number is taken as the starting state.

12. If the field strength of the overlapping coverage base station is stronger than the set field strength value, lock the channel of the overlapping coverage base station. And set the overlapping coverage base station as the current base station, update relevant parameters, and continue to start background scanning on this channel.

Combined with the flow chart of the launch state in Figure 2, describe in detail:

1. If the terminal goes online with a smooth group and is in the transmitting state, start the timer to control the time from transmitting to receiving. Here, the transmission and reception time is dynamically changed, and the length of time is automatically calculated according to the strength of the field strength. It changes in a linear relationship, and some parameters can be set to control the change of the slope through the frequency writing software.

2. When the time for transmitting to receiving is up, it will switch to the receiving state, and at this time, the entire process of receiving will be followed.

3. If it detects that the field strength of this channel is stronger than the set threshold level, if it does not meet the conditions for entering the background scan, it will revert to the transmitting state, and re-enable the timer to calculate the time to return to receiving next time.

4. It detects that the field strength of this channel is weaker than the set threshold level value, and meets the conditions for entering the background scan. It will lock to the overlapping coverage base station and detect the field strength of the overlapping coverage base station. Detect that the field strength of the overlapping coverage base station is weaker than the set threshold level, and does not meet the locking conditions, it will re-lock back to the original channel, switch to the transmitting state, and re-enable the timer to calculate the time to switch back to receiving next time.

5. If the overlapping coverage base station meets the conditions, it will be locked to the overlapping coverage base station. Before locking, it must first lock back to this channel, send a signaling Maint1 to the system, and notify the system to stop sending on this channel. After receiving the signaling, the system will Do the corresponding processing.

6. Lock to the overlapping coverage base station, send signaling Maint0, and notify the system to transmit on this base station.

7. Set the overlapping coverage base station as the current base station, update relevant parameters, and continue to start background scanning on this channel.

The advantage of the present invention is that it can switch freely after the overlapping coverage area of multiple base stations goes online, and can always keep talking on the base station with the strongest field strength, which ensures the quality of the voice and will not lose the lock once the signal becomes weak. . Compared with the previous technology, it not only saves time, but also improves work efficiency, especially at critical moments, it can keep talking without dropping the line. Before this technology, after the overlapping coverage area goes online, when the signal of the locked base station is weak, it will not go to the base station with a strong signal to lock it. It will not re-signal until the normal call can not be carried out or the lock is lost. Re-establish the call after channel scanning and locking.

(4) Description of drawings

Fig. 1 is a flow chart of the receiving state of the present invention;

Figure 2 is a flow chart of the launch state;

FIG. 3 is a schematic diagram of a process of simulating a cross-area call transfer of a field terminal.

(5) Specific implementation methods

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

Combined with FIG. 3 , this figure simulates the process of cross-area call transfer of field terminals. At this time, the overlapping coverage base stations of base station 3 are base stations 1, 2, 4, and 5. Assuming that the terminal is handed over from base station 3 to base station 5, the implementation process is described below:

Receive status:

The terminal locks on base station 3. After establishing a smooth group call, it goes online to traffic channel 1 of base station 3, and detects the field strength of traffic channel 1 of base station 3. When the field strength is weaker than the set value, the scanning overlaps and covers the base station. The sequence is carried out according to the order in which the four overlapping coverage base stations are written in the switching table, and the corresponding traffic channel 1 is scanned sequentially, and when the traffic channel 1 of the base station 5 meets the conditions, it is locked. After the call is over, the terminal will return to the control channel. First, it will select two control channels of the base station 5 to lock. If the locking condition is not met, it will scan according to the scanning method set by the terminal.

Launch status:

When the PTT is pressed and speaking, if the scanning is completed, the scanning process is the same as the receiving state. Now it is about to switch from base station 3 to base station 5. First, send signaling Maint1 on base station 3 to inform the system that the channel is no longer in the talking state, and then send signaling maint0 on base station 5 to notify the system that the channel is in the talking state .

If the called smoothing group only includes base stations 3, 4, and 5, it will only switch between base stations 3, 4, and 5. Although the overlapping coverage base stations include base stations 1 and 2, it will not switch to base stations 1 and 2.

When the present invention scans overlapping coverage base stations, there will be a very short time intermittent, but it will not affect the call. The specific break time is as follows:

1. Delay test for stable transmission and reception field strength detection

Table 1. Delay test data for stable transmission and reception field strength detection

time(ms) Stability (the number of differences from the actual field strength) 200 normal 150 normal 140 normal 135 normal 130 basically normal 125 3～4dBm 100 10dBm

2. The theoretical value of receiving state time interval

1) The field strength of this channel is stronger than the set value

no time gap

2) The field strength of this channel is weaker than the set value, and the field strength of overlapping coverage base stations is also weaker than the set value

Table 2 The theoretical value of receiving state time interruption

Locking overlapping coverage base stations Wait for the field strength to stabilize Lock with this base station 20ms 35ms 20ms+30ms

3) The field strength of this channel is weaker than the set value, the field strength of the overlapping coverage base station is stronger than the set value, locked to the overlapping coverage base station

Table 3 The theoretical value of receiving state time interruption

Locking overlapping coverage base stations Wait for the field strength to stabilize

20ms 35ms+30ms

3. The theoretical value of the time interval between transmission and reception

1) The field strength of this channel is stronger than the set value

Table 4 Theoretical values of transmit-to-receive time intervals

Transmit -> Receive (locked phase-locked loop) Receive field strength stabilization time Receive -> Transmit (locked phase-locked loop) 20ms 135ms 50ms

2) The field strength of this channel is weaker than the set value, and the field strength of overlapping coverage base stations is also weaker than the set value

Table 5 Theoretical values of transmit-to-receive time intervals

Send -> Receive (PLL) stable schedule Overlapped coverage base station detection time Receive -> send (PLL) 20ms 135ms 60ms 50ms

3) The field strength of this channel is weaker than the set value, the field strength of the overlapping coverage base station is stronger than the set value, locked to the overlapping coverage base station

Table 6 Theoretical values of transmit-to-receive time intervals

Send -> Receive (PLL) stable schedule Overlapped coverage base station detection time Receive -> send (PLL) Maint1(off) Transition-associated launch (PLL) Maint0(on) 20ms 135ms 55ms 20ms 83ms 20ms 83ms

4. Actual test data

Table 7 Actual test data table

Claims (1)

1. A MPT1327 analog trunking communication terminal cross-base station call automatic switching method is characterized in that: the MPT1327 analog trunking communication terminal locks to the system, first searches for the base station number of the locking system, and confirms its associated 4 overlapping coverage base stations; When the coverage area is online, when the field strength signal is weaker than the set threshold value, the background scan will be started. The scanning sequence is in accordance with the order in which the 4 overlapping coverage base stations are written in the switching table. When the associated overlapping coverage base station is detected When the field strength signal of the base station is stronger than that of the locked base station, if it is in the receiving state, it will directly lock to the strong signal base station; if it is in the transmitting state, it will send a signaling Maint1 on the locked base station to inform the system that the base station is not in the transmitting state. After that, the overlapping coverage base station with strong signal can be locked, and the signaling Maint0 is sent to notify the system to transmit at this base station. Registration conditions, re-registration; if the control channel is not successfully registered, it will scan according to the scanning method set by the terminal until it finds a channel that meets the conditions and re-registers; the MPT1327 analog trunking communication terminal supports up to 24 base stations Voice automatic switching, each base station can have 4 overlapping coverage base stations, corresponding to each base station in the terminal, there is one system code parameter, two control channel parameters, two traffic channel parameters, and four overlapping coverage base stations; each At least one of the two control channels of the base station must exist in the control channel table or the flexible channel plan table; the traffic channel written in the switching table used to store the relevant information of the 24 base stations must be the same as the traffic channel of the system Correspondingly, a maximum of 10 smooth group call signs can be set, and each group call sign can be associated with any or all of the 24 base stations; When the receiving state is stated: (1) When the MPT1327 analog trunking communication terminal is locked to the system, it starts to search the traffic channel switching table, and finds the corresponding base station number from the table by locking to the system code of the system. The system code is the unique identification of the base station number, if The base station number corresponding to the system code cannot be found, indicating that the base station is not written in the table, and the background scan will not be entered; (2) When the base station number is found, the currently locked base station is confirmed. By locking the base station, four overlapping coverage base stations are searched to determine whether the control channel of each overlapping coverage base station is in the specified table; if two control channels If none of them are in the specified table, then leave this overlapping coverage base station blank, indicating that this overlapping coverage base station is not associated, and this base station will not be scanned during background scanning; (3) After the terminal is online, it is judged that the group attribute is a smooth group, and it is in the receiving state, then enter the background scanning process; (4) First determine the group number of the smoothing group, and search for the overlapping coverage base station number through the group number. This overlapping coverage base station includes several or all of the 24 base stations, and is used to control when calling this group number. The associated base station can respond, and the unassociated base station will not go online; (5) Determine the 4 overlapping coverage base stations of the locked base station respectively. If the 4 overlapping coverage base stations are all empty, it means that the base station does not write the overlapping coverage base station, and then do not enter the background scan; (6) judge the specific position of the traffic channel in the table, and mark it in case of locking the corresponding position when switching; if not found, then explain that this traffic channel is not in the table, then do not carry out background scanning; (7) "Channel switching time" is mainly to control the scanning time interval between overlapping coverage base stations; (8) Detect the field strength of the traffic channel of the base station. If the detected field strength value is stronger than the set "switching level" field strength value, it will not enter the background scanning, and the "switching channel time" will be reset at this time , used to control the field strength of the channel for the next detection; (9) If the detected field strength value is weaker than the set "switching level" field strength value, the field strength of the overlapping coverage base station must be detected. Before detection, it is first necessary to determine which overlapping coverage base station is to be detected; (10) After determining the overlapping coverage base station, search for several parameters of the overlapping coverage base station: including system code, control channel, and traffic channel, to update relevant parameters in case of subsequent locking; according to step (6), it can be judged that it should be locked to which traffic channel; (11) Lock the overlapping coverage base station, detect the field strength value of the overlapping coverage base station, if the field strength value of the overlapping coverage base station is weaker than the set field strength value, then do not switch, exit the scanning state, record the overlapping coverage base station serial number at this time, So that the next overlapping coverage base station with this serial number is the initial state when scanning next time; (12) If the field strength of the overlapping coverage base station is stronger than the set field strength value, then lock the overlapping coverage base station channel, and set the overlapping coverage base station as the current base station, update relevant parameters, and continue to start background scanning on this channel; When the launch state is: (1) If the terminal goes online with a smooth group and is in the transmitting state, start the timer to control the time from transmitting to receiving; (2) When the time for transmitting to receiving is up, it will switch to the receiving state, and at this time, the entire process of the previous receiving will go through; (3) It detects that the field strength of this channel is stronger than the set threshold level, and does not meet the conditions for entering the background scan, it will re-transmit to the transmitting state, and re-enable the timer to calculate the time to return to receiving next time; (4) Detect that the field strength of this channel is weaker than the set threshold level, and meet the conditions for entering the background scan, it will lock to the overlapping coverage base station, and then detect the field strength of the overlapping coverage base station; If the predetermined threshold level is weak and does not meet the locking conditions, it will re-lock back to the original channel, switch to the transmitting state, and re-enable the timer to calculate the time to switch back to receiving next time; (5) If the overlapping coverage base station meets the conditions, it will be locked to the overlapping coverage base station. Before locking, it must first lock back to this channel, send a signaling Maint1 to the system, and notify the system to stop sending on this channel. After the system receives the signaling will be dealt with accordingly; (6) Lock to the overlapping coverage base station, send signaling Maint0, and notify the system to transmit on the base station; (7) Set the overlapping coverage base station as the current base station, update relevant parameters, and continue to start background scanning on this channel. the

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