JP3315790B2 - Receiving unit management control method for multiple fixed stations - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving unit management control system for a plurality of fixed stations in a 1 mW working private communication system.

[0002]

2. Description of the Related Art A 1 mw working private communication system has 40
One of the 0 MHz band low-power indoor radios, a main station fixed station having an operation unit, a plurality of slave station fixed stations connected to the main station fixed station by wire and distributed in the premises, and several persons moving within the premises. And mobile devices (referred to as portable devices) each of which is carried by more than ten workers, and it is possible to communicate between the operating device, the portable devices, and the portable devices. Each of the portable devices is assigned a communication channel frequency and a tone frequency of tone squelch, and it is possible to individually make a one-to-one call. However, for work communication, it is preferable to be able to intercept another person's call, It also has a conference call function. Master station,
Each fixed station of the slave station has a receiving device in which a plurality of receiving units of a single communication path corresponding to the number of portable devices and corresponding to the respective channels to be used are mounted, and the received demodulated output is used as a modulated wave. And a transmitting device for transmitting a wireless signal to a portable device of a communication partner or all portable devices.

FIG. 1 is a block diagram of a conventional 1 mW working private communication system. The fixed stations 2 and 3 are also provided with transmission devices, but are not shown. In the 1 mW working private communication system, the master fixed station 2 and the slave fixed station 3 have a wireless section of the portable device 1 and a wired section of an operation device (wireless terminal) 4 provided in the master fixed station 2 (communication line 8). And communication line control via the data line 9) in the following procedure. (1) The portable device 1 in the zone C transmits a call channel frequency signal and tone squelch tone assigned to itself to the fixed stations 2 and 3 as a call request. (2) Portable device 1 in a plurality of receiving units 5 of each fixed station
Receive and detect the traffic channel signal and the tone, respectively. (3) The processor 6 provided in each fixed station controls the receiving unit selecting means 7 to control each receiving unit (1) to
(N) A receiving unit that periodically searches for the speech channel frequency and tone detection status by a polling method, and detects an assigned speech channel frequency signal and tone whose received field strength (RSSI) is greater than or equal to a threshold. Then, the communication path between the controller 4 and the portable device 1 is opened by the receiving unit selecting means 7. (4) The zone switching request is generated due to a decrease in the received field strength (RSSI), and the master station issues a received field data measurement request to all the slave stations to switch to the slave station of the receiving unit having the highest field strength detected. Do.

[0004]

However, the above conventional control method has the following problems. (1) The portable device 1 is located in zone C where zone A and zone B overlap.
When selecting one of the adjacent fixed stations provided with the receiving unit having the same communication channel frequency and the same tone frequency, the connection process of the communication path takes time due to the polling method. (2) Further, the master station fixed station 2 centrally manages the communication path control of the receiving unit of the slave station fixed station 3 by a polling method every time a press talk call (PTT) is performed.
There has been a problem that call quality is reduced by the press talk call (PTT).

[0005] An object of the present invention is to solve a decrease in call quality during a press talk call, and a master station fixed station 2 centrally manages a slave station fixed station 3 using a difference between a call channel frequency signal and a tone detection timing. It is an object of the present invention to provide a receiving unit management control method for a plurality of fixed stations, which can shorten the switching connection processing time at the time and can select and connect the receiving unit having the maximum receiving level instantaneously.

[0006]

In order to achieve this object, a plurality of fixed station receiving unit management and control systems according to the present invention are provided with a main station fixed station and a distributed arrangement connected to the main station fixed station. A plurality of slave fixed stations, any of the fixed stations according to the radio channel frequency and tone squelch frequency assigned in advance by moving within the service area consisting of each wireless zone of the master fixed station and the plurality of slave fixed stations. A plurality of portable devices that communicate with each other via the main station fixed station and the plurality of slave station fixed stations, each corresponding to a plurality of communication paths assigned to the plurality of portable devices. A plurality of receiving units, and the main station fixed station controls connection switching between the plurality of portable units by selectively connecting the plurality of receiving units. In the receiving unit management control method for a number of fixed stations, each of the master station fixed station and the plurality of slave station fixed stations has a predetermined threshold value obtained by digitally converting the reception electric field levels of the plurality of receiving units. First storage means for storing electric field detection data indicating whether the received value is larger or smaller than the threshold value as compared with a value, and tone squelch detection data indicating whether tone detection has been performed for the plurality of receiving units. And a storage means for detecting the received electric field levels of the plurality of receiving units at a periodic electric field detection timing and detecting the tone output at a tone detection timing delayed by a required time length from the electric field detection timing. A processor for storing electric field detection data and tone squelch detection data in the first storage means and the second storage means, respectively. And a support, the main station fixed station, the portable device when entering or for press-to-talk communication when moved to another zone, the plurality of between the front Symbol field detection timing and the tone detection timing The electric field detection data is collected from the slave station and the receiving unit satisfying the three conditions of the electric field detection data, the communication path switching instruction, and the tone squelch detection data is selected, and connection switching control of the communication path is performed. It has a configuration characterized by the following.

That is, the gist of the technical means of the present invention is as follows. A memory area for storing the received electric field level of each receiving unit is provided in the RAM 24 of each fixed station.
An area for storing the reception electric field level threshold of each reception unit is provided in the E ² PROM 25 of each fixed station. Each fixed station is provided with a memory area for storing electric field detection data. Each fixed station is provided with a memory area for storing tone detection data.

[0008]

FIG. 2 is a block diagram of a fixed station for realizing the system of the present invention and a memory content diagram, and FIG. 3 is an operation flowchart of the present invention. The control method of the present invention will be described with reference to FIGS. (1) The value of the reception electric field level threshold value of each reception unit 5 is stored in advance in the E ² PROM 25 as shown in FIG. (2) The processor 23 periodically converts the received electric field levels detected by the plurality of receiving units 5 (1) to (5) by the receiving unit control means 21 into digital values by the A / D converter 22, and receives the digital values. The electric field data is stored in the RAM 24 as shown in FIG. (3) The processor 23 reads the stored digital reception electric field data from the RAM 24, E ² PROM 25
And converts the result into bit data of "1" with an electric field and "0" without an electric field, as the electric field detection data as shown in FIG. To be stored.

FIG. 4 is a timing chart when the PTT is depressed during a press-talk call (PTT), and FIG. 5 is a communication path control protocol. (4) main station fixed station between the difference T ₁ of the electric field detection timing and tone detection timing for slave base station, as shown in FIG. 5 performs speech path control process collects field data. (5) The transmission time T ₃ between the master fixed station and the slave fixed station is T
Consider the timing of ₁ and the processing time of each fixed station. Therefore, the processing time T _A is represented by the following formula.

[0010]

(Equation 1) (6) The master station fixed station transmits an electric field transmission request signal from its controller to the slave station fixed station. The slave fixed station receiving this transmits the electric field detection data. (7) The master station receiving the electric field detection data totals the call status of each slave station fixed station, detects a tone, and transmits a call path switching instruction to the slave station fixed station of the receiving unit having the electric field detection data. .

FIG. 6 is a system block diagram of tone squelch detection and a configuration diagram of detected data, and FIG. 7 is a flowchart of tone squelch detection. (8) The processor 23 periodically detects the tone of each receiving unit 5 by the receiving unit control means 21. (9) FIG.
As shown in (B), the data is converted into bit data of "1" with tone detection and "0" without tone detection and stored in the RAM 24 as tone squelch detection data. (10) The operating device 4 provided in the main fixed station instantaneously selects a receiving unit having a suitable condition based on the electric field detection data collected from each substation fixed station, the communication path switching instruction, and the tone squelch detection data, and performs a call. Open the road. That is, there are three communication path opening (connection) conditions: electric field detection data (6), communication path switching instruction (7), and tone squelch detection data (9).

[0012]

According to the present invention, it is possible to prevent a decrease in call quality at the time of a press talk when a plurality of fixed station systems of a 1 mW working private communication system are operated. Further, it is possible to prevent a decrease in call quality at the time of zone switching due to movement of the portable device.

[Brief description of the drawings]

FIG. 1 is a conventional system block diagram.

FIG. 2 is a block diagram and a memory contents diagram for explaining detection of a reception electric field level according to the present invention.

FIG. 3 is a reception electric field detection flowchart of the present invention.

FIG. 4 is a timing chart when a PTT is pressed in a press talk call according to the present invention.

FIG. 5 is a communication path control protocol of the present invention.

FIG. 6 is a block diagram and a data configuration diagram for explaining tone squelch detection of the present invention.

FIG. 7 is a flowchart of tone squelch detection according to the present invention.

[Explanation of symbols]

1 portable device 2 main station fixed station 3 slave fixed station 4 manipulator 5 receiving unit 6 processor 7 reception unit selection means 8 call line 9 data lines 21 receiving unit selecting unit 22 A / D converter 23 processor 24 RAM 25 E ² PROM

Claims (1)

(57) [Claims] 1. A service comprising a master station fixed station, a plurality of slave station fixed stations connected to the master station fixed station and distributed, and respective radio zones of the master station fixed station and the plurality of slave station fixed stations. In a communication system comprising a plurality of portable devices that move within an area and communicate with each other via any of the fixed stations by using a radio channel frequency and a tone squelch frequency assigned in advance, the main station fixed station and Each of the plurality of slave fixed stations is provided with a plurality of receiving units respectively corresponding to a plurality of communication paths assigned to the plurality of portable devices, and the master fixed station is selectively connected between the plurality of receiving units. A receiving unit management control system for a plurality of fixed stations for controlling connection switching between the plurality of portable units, wherein the plurality of fixed stations are connected to each other. First, a value obtained by digitally converting the reception electric field levels of the plurality of reception units is compared with a preset threshold value, and electric field detection data indicating whether the value is larger or smaller than the threshold value is stored. Storage means, second storage means for storing tone squelch detection data indicating whether tone detection has been performed for the plurality of receiving units, and detecting received electric field levels of the plurality of receiving units at periodic electric field detection timings And detecting the tone output at a tone detection timing delayed by a required time from the electric field detection timing, and storing the electric field detection data and the tone squelch detection data in the first storage means and the second storage means, respectively. And a processor that performs communication when the portable device moves to another zone or press-talk communication. Input, before Symbol field detection timing and the field detection data from said plurality of slave stations fixed station collects between the tone detection timing, 3 and electric field detection data communication path switching instruction and the tone squelch detection data for A receiving unit management control method for a plurality of fixed stations, wherein the receiving unit satisfying two conditions is selected to perform connection switching control of the communication path.