JP3171332B2 - Wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system that can continue relaying when a radio wave arrived after interruption of a radio wave over a prescribed period is not a radio wave for a channel setting procedure. SOLUTION: A repeater discriminates whether or not a radio wave received after interruption of a radio wave from a slave set over a prescribed period is a radio wave for a channel setting procedure and continues the relaying when the repeater discriminates that the radio wave is not the radio wave for the channel setting procedure. Thus, the repeater is provided with a 1st discrimination means S4 that discriminates whether or not the radio wave from the slave set is interrupted over a prescribed period, a 2nd discrimination means S7 that discriminates whether or not the radio wave received after the interruption of the radio wave is the radio wave for the channel setting procedure in response to the result of the 1st discrimination means, and a speech continuing means S5 that continues the relaying in response to the 2nd discrimination means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system having a function of relaying radio equipment for a radio telephone of, for example, a specified low power radio station. And a wireless communication system capable of continuing the communication.

[0002]

2. Description of the Related Art The radio equipment for a radio telephone of a specified low power radio station is defined as follows by the Radio Law and related ministerial ordinances and notifications.

[0003] The communication accumulated time limit function is described as follows.
No communication will be performed after the elapse of seconds ”(Ministry of Posts and Telecommunications Notification No. 49, 1989). The same frequency as the radio wave emitted by the radio station (for duplex and semi-duplex systems,
No emission of radio waves of the transmission frequency corresponding to the reception frequency) (Ministry of Posts and Telecommunications Notification No. 49, 1989). Note that emission of radio waves for setting a communication path before entering a call is permitted.

[0004] The half-duplex communication system is a communication system in which one end of a communication path is a simplex system and the other end is a duplex system. A system having a repeater also corresponds to the semi-duplex system.

[0005] In the case of a system having a repeater, a radio wave from the slave is converted to a different frequency by the repeater and transmitted. For example, when the slave unit 1 talks with the slave unit 2 via the repeater, the radio wave of the frequency F1 transmitted from the slave unit 1 is converted by the repeater into a radio wave of the frequency F2 different from the frequency F1, and 2 is transmitted. Therefore, the slave unit 1
Starts a call, the following series of operations called "call path setting procedure" is performed. 1) The slave 1 performs carrier sensing on the reception frequency F2 of the slave 2. That is, it is checked whether the reception frequency F2 of the slave unit 2 is empty. 2) If the slave unit 1 cannot receive the radio wave of the frequency F2,
After transmitting the radio wave of the frequency F1 for a moment (about 50 milliseconds) to indicate the start of the call to the repeater, the transmission is temporarily stopped. This is because the relay unit determines that the slave unit 1 is “in use” if the slave unit 1 is transmitting when the repeater performs carrier sense thereafter. 3) The repeater performs carrier sense on the frequency F1, and checks whether the frequency F1 of the slave 1 is empty. 4) If the repeater cannot receive the radio wave of the frequency F1,
Transmission starts at frequency F2. 5) The slave unit 1 detects the radio wave of the frequency F2 from the repeater,
Transmission starts at frequency F1. 6) The repeater receives the radio wave of the frequency F1 from the slave 1 and transmits it as the radio wave of the frequency F2. 7) The slave unit 2 receives the radio wave of the frequency F2 from the repeater.

Here, the above-mentioned call limit by the communication accumulated time timer is added. 1) The call accumulated time timer of the repeater and the slave units 1 and 2 is started from the time when the communication path is set as described above. . 2) Each slave unit resets the talk time timer when the radio wave of the repeater is interrupted for 2 seconds or more. This ends the call. 3) When the interruption of the call is within 2 seconds, it is determined that the call is in progress. 4) When a call is made after the call is over, the call path setting operation is performed again.

As described above, in the conventional wireless communication system, when the repeater cannot receive radio waves for more than 2 seconds, the call is terminated. Also, there has been a problem that the call is terminated even when radio waves from the slave unit do not reach the repeater due to radio interference such as fading.

This will be described more specifically with reference to FIG. Now, as shown in FIG. 2A, the slave unit 1 located near the limit of the communicable area A of the repeater R becomes the communicable area A.
Is making a call with the child device 2 in the terminal, and the child device 1
As shown in (b) of FIG. 2, it is assumed that transmission is performed from time t1 to time t4. However, since the slave 1 is near the limit of the talkable area A, the radio wave from the slave 1 may not be able to be received by the repeater due to, for example, fading or the presence of an obstacle (from time t2 to time t3). period). If the period during which the input of the radio wave to the repeater is interrupted is 2 seconds or more, the repeater R terminates the relay operation, so that the communication path set between the slaves 1 and 2 is set. Is canceled, and the call of the slave 1 after the time t2 does not reach the slave 2.

[0009]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems of the conventional wireless communication system, and an object of the present invention is to solve the problem when radio waves are interrupted for a predetermined period. Another object of the present invention is to provide a radio communication system for a specific low-power radio station, for example, in which relaying is continued when radio waves arriving thereafter are not radio waves for a call path setting procedure.

[0010]

In order to achieve the above object, the present invention is a wireless communication system including a plurality of slave units and at least one repeater, wherein the repeater is a slave unit. It is determined whether the received radio wave is the radio wave for the call path setting procedure after the radio wave from is interrupted for a predetermined period, and if the radio wave is not the radio wave for the call path setting procedure, the relay is continued. A wireless communication system, comprising:

The means includes: first determining means for determining whether the radio wave from the slave unit has been interrupted over the predetermined period; and responding to the first determining means, the first determining means determines whether the radio wave has been interrupted. A second determining unit for determining whether the radio wave received from the slave unit is a radio wave for a communication path setting procedure, and a call continuation unit for continuing the relay in response to the second determining unit. It can be realized by providing.

[0012]

When the repeater detects that the radio wave from the slave unit has been interrupted for a predetermined period, the repeater determines whether the subsequently received radio wave is a radio wave for a call path setting procedure,
If it is not such a radio wave, the relay is continued.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of a repeater in a radio communication system according to the present invention will be described below with reference to FIG. 1 by taking the operation of a repeater in a radio telephone radio equipment of a specified low power radio station as an example. explain. In FIG. 1, a communication path is set between two slave units via a repeater, the repeater is performing a relay operation (step S1), and a radio wave from the slave unit on the transmitting side is transmitted. Is normally received and relayed (step S2). When the radio wave from the slave unit on the transmitting side is interrupted and the radio wave to the repeater is interrupted while such a relay operation is being performed (step S3), the repeater stops the radio wave within 2 seconds. It is determined whether there is (Step S4). The period during which the radio wave was interrupted is within 2 seconds,
That is, if the repeater receives a new radio wave within 2 seconds (YES in step S4), the repeater continues the relay operation as before (step S5).

However, when the interruption of the radio wave continues for 2 seconds or more (NO in step S4), the repeater determines whether or not the call integration time is within 3 minutes (step S6).
Next, it is determined whether the radio wave received at the time when the interruption of the radio wave is resolved is a radio wave of a communication path setting procedure for newly starting communication, or a radio wave of a call that has been continued until now. That is, if it is determined in step S6 that the integrated call time is within 3 minutes (YES in step S6),
The repeater determines whether the radio wave newly arriving from the slave unit is "a radio wave transmitted only for a moment" to start a call,
That is, it is determined whether or not the radio wave is for setting a new communication path (step S7).

As a result of the determination in step S7, if the received radio wave is not a radio wave for setting a communication path when the interruption of the radio wave is resolved (NO in step S7), the repeater continues the relay operation up to now. . However, when the radio wave received after the interruption of the radio wave is a radio wave for setting a communication channel (YES in step S7), the repeater performs an operation for setting a communication channel between the slave units according to the communication channel setting procedure. Start (step S8).

On the other hand, when it is determined in step S6 that the integrated call time exceeds 3 minutes (N in step S6).
In O), the repeater ends the relay operation between the slaves (step S9).

As described above, even when the radio wave to be sensed is interrupted for a certain period of time for any reason, as long as the call totaling time does not exceed 3 minutes, the repeater can cancel the interruption of the radio wave. If the received radio wave is not a radio wave for setting the call path, the relay device operates to continue the previous relay operation, so the radio wave emitted by the slave unit does not reach the repeater for a certain period of time for some reason. The relay does not end even when it occurs.

[0018]

As described above, according to the present invention, when the repeater detects that the radio wave from the slave unit has been interrupted for a predetermined period, the repeater receives the radio wave after the interruption to perform the communication path setting procedure. It is configured to judge whether the signal is a radio wave or not, and if it is not such a radio wave, the relay is continued.Therefore, the radio wave from the slave unit may not reach the repeater for a predetermined period due to radio interference such as fading. Even so, there is a special effect that the relay can be reliably continued as long as the call continues.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining the operation of a repeater in a wireless communication system according to the present invention.

FIGS. 2A and 2B are diagrams for explaining the drawbacks of the conventional wireless communication system, and FIG. 2A shows a case where a handset on the transmitting side is near the limit of a talkable area. (B) is a time chart of the operation.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 H04Q ⁷ /04-7/38

Claims (2)

(57) [Claims] 1. A wireless communication system comprising a plurality of slave units and at least one repeater, wherein the repeater receives a radio wave received after a radio wave from the slave unit is interrupted for a predetermined period. What is claimed is: 1. A wireless communication system comprising: means for judging whether or not a radio wave is for a channel setting procedure, and when determining that the radio wave is not for a channel setting procedure, continuing a relay operation. 2. The first means for judging whether the radio wave from the slave unit has been interrupted for the predetermined period, and the radio wave interruption in response to the first judgment means. A second determination unit that determines whether the radio wave received from the slave unit later is a radio wave for a communication path setting procedure, and a call continuation unit that continues relaying in response to the second determination unit; The wireless communication system according to claim 1, comprising: