JPH08275233A - Restoration method for speech at deteriorated reception electric field - Google Patents

Abstract

PURPOSE: To continue speech without redialing by a subscriber by processing re-allocation of a radio channel for prescribed time without immediate interruption processing of call connection when the continuity of speech becomes disable. CONSTITUTION: When a mobile terminal equipment 10 moves a location where a signal of a radio channel cannot reach such as behind a radio obstacle, a received electric field of a radio channel 40 in the mobile terminal equipment 10 and the radio base station 20 is deteriorated and a speech via the radio base station 20 cannot be continued. When the mobile terminal equipment 10 detects speech continuous disable state, 'radio channel re-allocation' is displayed on its own display device, a transmission output of a radio wave is maximized to enhance the probability of the signal sent by itself to reach the radio base station 20, radio channel allocation identical to that on the occurrence of a call is started and then a timer is started for a prescribed time. Then, the mobile terminal equipment 10 successful to re-allocation of the radio channel stops the timer, the indication on the display device is finished and the speech state is restored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method in mobile communication, and more particularly to a method for recovering a call when a received electric field deteriorates.

[0002]

2. Description of the Related Art In a mobile communication system, when a call is cut off once due to a change in a received electric field of a radio channel used for the call, a call disconnection process is immediately performed, and when a call is desired to continue, a new call is newly added. I had to call.

In a cordless telephone having a master unit connected to a telephone line and a slave unit capable of communicating with the master unit wirelessly, it is detected that the master unit has no electric field received from the slave unit, Example of providing a function to hold the call circuit and announce to the other party on the telephone line side that the received electric field is gone, and to notify the user when the handset detects that the received electric field is gone There is. (JP-A-1-196947)

[0004]

SUMMARY OF THE INVENTION An object of the present invention is not to immediately disconnect a call connection even if a call cannot be temporarily made due to deterioration of a received electric field, and to wait for recovery of the received electric field to continue the call. It is possible.

[0005]

According to the method of recovering a call when a received electric field is deteriorated according to the present invention, when a received electric field in at least one of a mobile station and a base station is deteriorated and it becomes impossible to continue a call, a call is made immediately. The wireless channel is reassigned for a certain period of time without continuing the connection disconnection process to continue the call. The wireless channels used for the wireless channel reallocation processing include the wireless channels that have already been allocated and are in use. The radio channel reassignment process is performed according to the same procedure as the radio channel assignment process when a call is generated. In this case, the ARQ error control method is applied,
Further, it is desirable to increase the transmission power of either or both of the mobile station and the base station. Further, it is desirable that the wireless channel reallocation processing be performed while notifying both subscribers who were in a call of that fact.

[0006]

In mobile communication, radio wave propagation conditions may fluctuate as the mobile station moves, and the propagation path may be temporarily blocked by an obstacle so that the call cannot be continued. In such a case, it is not necessary to perform a handover to an adjacent base station, and if there is no interruption of the propagation path due to an obstacle, the deterioration of the received electric field will be naturally restored and a call can be made in many cases.

The application of the ARQ error control method and the increase of the transmission power are intended to allow the reallocation processing similar to the radio channel allocation processing at the time of a call to be smoothly performed when the electric field is restored. By notifying the subscriber that the call is being performed, care will be taken so that the subscriber will not perform unnecessary recall processing.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a mobile communication system to which the restoration method of the present invention is applied, and FIGS. 2 and 3 are flowcharts of operations of a mobile terminal and a wireless exchange in this embodiment, respectively.

The mobile communication system of FIG. 1 has a radio base station 20.
Are connected to the fixed or mobile terminal 50 through a wired communication system, the wireless exchange 30 has an announcement trunk 31, and the announcement trunk 3
1 and call paths 32 and 33 for connecting the wireless base station 20 to a wired communication system.

In FIG. 1, the mobile terminal 10 is connected to the terminal 50 via the radio base station 20 by the radio channel 40 and the call path 33 of the radio exchange 30. When the mobile terminal 10 moves to a place where the radio channel does not reach, such as behind a radio obstacle, the mobile terminal 10 and the radio base station 20
The received electric field of the wireless channel 40 in the above-mentioned deteriorates, and the communication via the wireless base station 20 cannot be continued. then,
As shown in FIG. 2, when the mobile terminal 10 detects that the call cannot be continued (S101), the mobile terminal 10 displays "reassigning wireless channel" on its own display (S102), maximizes the radio wave transmission output (S103), and The probability that the signal transmitted by the wireless terminal will reach the wireless base station 20 is increased, wireless channel allocation similar to that at the time of the call generation is started, and then a timer is started for a certain period of time. Further, as shown in FIG. 3, when the wireless exchange 30 receives a report that the call cannot be continued from the wireless base station 20 (S30).
1) The call path 33 is switched to the call path 32, and connection to the announcement trunk 31 starts notification to the terminal 50 as an announcement of "reassignment of wireless channel" (S302). Furthermore, wireless switch 3
0 starts the procedure of reassigning the radio channel to the mobile terminal 10 (S303), and activates the timer for a certain period of time (S304). Even if the mobile terminal 10 moves to a place where it can receive the above-mentioned signal sent from the wireless exchange 30, the signal for wireless channel re-allocation is taken into consideration considering that the case where the transmission quality of the wireless channel is not good continues. The wireless exchange 30 that has detected an error in the data in the sequence
(Or the mobile terminal 10) sends the data retransmission request (ARQ) of the error portion to the mobile terminal 10 (or the wireless exchange 3).
0). The mobile terminal 10 that has received the retransmission request
(Or the wireless exchange 30) retransmits only the data of the portion requested to be retransmitted. By performing such retransmission control, the probability that the wireless channel can be reallocated is increased. The mobile terminal 10 that has succeeded in reassigning the wireless channel (S1
06 Yes), the timer is stopped (S107), the display on the display is terminated (S108), and the call state is restored. The wireless exchange 30 receives the signal from the wireless base station 20 indicating that the wireless channel reallocation has been successful (S305 Y
es), the timer is stopped (S306), the call path 32 between the terminal 50 and the announcement trunk 31 is switched to the call path 33, the announcement is ended (S307), and the state returns to the call state. If the timer times out without succeeding in reassigning the wireless channel (S
106 No, S305 No), the mobile terminal 10 and the wireless exchange 30 release the resources used for the call (S
201, S401), and returns to the NULL state.

[0011]

As described above, according to the present invention, when a mobile terminal moves to a place where the wireless channel in use does not reach, the call connection is not immediately disconnected and a call is generated for a certain period of time. In the case where the mobile terminal moves to the place where the radio wave reaches within the time while performing the wireless channel reallocation processing in the same procedure as the wireless channel allocation processing in , ARQ retransmission control, transmission power increase, and other techniques are used to increase the probability of successful wireless channel reassignment processing and restore the call, so that the subscriber can continue the call without re-calling.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a mobile communication system to which a recovery method of the present invention is applied.

FIG. 2 is a flowchart of the operation of the mobile terminal in the embodiment of the present invention.

FIG. 3 is a flowchart of the operation of the wireless exchange according to the embodiment of the present invention.

[Explanation of symbols]

10 Mobile Terminal 20 Wireless Base Station 30 Wireless Switch 31 Announcement Trunk 32, 33 Call Path 40 Wireless Channel 50 Terminal (Fixed Terminal or Mobile Terminal) S101 to S107, S201 Processing Step of Mobile Terminal S301 to S307, S401 Processing of Wireless Switch Step

Claims (6)

[Claims] 1. A method for recovering a call when a reception electric field deteriorates in a mobile communication system, wherein a reception electric field in at least one of a mobile station and a base station of a radio channel in communication deteriorates and it becomes impossible to continue the call. A method for recovering a call when a received electric field is deteriorated, wherein a call is reassigned for a certain period of time without interruption to immediately disconnect the call and the call is continued. 2. The method for recovering a call when a received electric field deteriorates according to claim 1, wherein the radio channel used for the reassignment process of the radio channel is a radio channel which has already been assigned and is in use. 3. The method for recovering a call when a received electric field deteriorates according to claim 1 or 2, wherein the wireless channel reallocation processing is performed according to a procedure similar to the wireless channel allocation processing when a call is generated. 4. The reassignment process of the radio channel comprises:
The method for recovering a call when a received electric field is deteriorated according to any one of claims 1 to 3, which is performed while applying an RQ error control method. 5. The reception according to claim 1, wherein the reassignment process of the radio channel is performed by increasing the transmission power of one or both of the mobile station and the base station. How to recover calls when the electric field deteriorates. 6. The wireless channel reallocation process is performed while notifying both subscribers who were in a call that the wireless channel reallocation process is being performed.
A method for recovering a call when the reception electric field deteriorates according to the item.