JPH05167515A - Tracking exchange processing system for cordless mobile telephone set - Google Patents

Abstract

PURPOSE:To simplify the system configuration and operation by interrupting a talking momentarily only for a time required to transfer definite control information with a radio wave and keeping the talking enable state at all times for a time when a mobile station, a base station or a center are in processing. CONSTITUTION:The base station 2 always operates a control channel 21 to be ready to receive a tracking exchange request signal at any time. When the tracking exchange request signal is received from a mobile station 1, the station 2 activates a CPU 24 and reports that the signal is received to a center. Furthermore, the base station 2 fetches an IF output from the channel 21 to the CPU 24 via a buffer amplifier 23 and measures the electric field strength while making the strength into a digital numeral and sends the measured value to the center together with the report. The center selects a base station whose electric field strength is highest and sends a tracking exchange insulation to the base station. Thus, the base station for the tracking exchange is decided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless mobile telephone tracking exchange processing system.

[0002]

2. Description of the Related Art As is well known, when a cordless mobile phone moves to another wireless service area during a call, a channel is switched to a new wireless area in order to keep the call. Moreover, it is necessary to switch the wired line corresponding to the old and new wireless channels. In this specification, the switching of the communication channel to the new wireless area is called a tracking exchange process.

FIG. 1 is a schematic diagram for explaining a general tracking exchange process. In the figure, 1 is a mobile station which is a cordless mobile telephone, 2a is a base station A, 2b is a base station B,
Reference numeral 3 indicates a center which is a radio control station. Each base station 2 constantly monitors the communication channel of the mobile station 1 in communication, and the mobile station moves from the service area A to B as shown by the arrow in the figure.
When moving to the service area of 1), the reception level in the service area A decreases. When the base station A detects this, it notifies the center 3 of the reception level deterioration. The center 3 notified of the deterioration of the reception level from the base station A instructs the peripheral base stations to monitor the reception level, and the peripheral base station 2 reports the monitoring result to the center 3. Upon receiving the report, the center 3 determines that the base station with the highest reception level is the base station 2 in the movement area, captures an empty wireless channel in this base station 2, and switches the channel.

Next, a recent tracking exchange processing system will be described. In order to switch the call to the new wireless area as described above, it is necessary to select the new base station 2 and switch the channel. If you try to do this only with a normal operation control modem, the time (3 seconds to 10 seconds) during this period,
You have to cut off the call temporarily. Therefore, a recent tracking exchange processing system is equipped with a tracking exchange control modem that uses an out-of-band signal in addition to a normal operation control modem, and a new base station 2 is selected for this tracking exchange control. The system uses a modem to block calls as much as possible.

[0005]

As described above, the conventional tracking exchange processing system for a cordless mobile telephone is equipped with a tracking exchange control modem in addition to the normal operation control modem, so that a call can be transmitted. Since the system is designed to perform the tracking and exchange processing without interruption as much as possible, the system configuration and operation are complicated, and it takes time to develop the device and the system itself becomes expensive.

That is, there is no standardized modem for tracking exchange control that uses a voice call out-of-band signal,
And a fourth-order Butterworth LPF, a fourth-order Tchebycheff LPF, and the like.
In addition, when the mobile station detects the need for tracking exchange, the tracking exchange control modem notifies the base station, and when a new base station after tracking is determined, switches to the normal operation control modem to make a call. Special hardware for switching between the two modems is required to indicate the channel number.

The present invention has been made to solve the above problems, and does not use a tracking exchange control modem,
Moreover, it is an object of the present invention to provide a tracking exchange processing system for a cordless mobile telephone, which performs tracking exchange control while blocking calls as much as possible.

[0008]

According to the tracking exchange processing system of a cordless mobile telephone according to the present invention, due to the software configuration, the call is interrupted only during the time when the fixed control information is wirelessly transmitted and received. During the processing time of the base station and the center, the control to maintain the call-enabled state is always performed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of the configuration of the apparatus according to the present invention. In the figure, 1 is a mobile station, 10 is a wireless module in the mobile station, 11 is an IF detection output,
12 is also a comparator, 13 is also a mobile station CPU
Indicates. Further, 2 is a base station, 21 is a control channel in the base station, 22 is also IF detection output, 23 is also buffer amplifier, 24 is base station CPU, and 25 and 26 are communication channels. The control channel 21 and the call channels 25 and 26 are respectively the CPU 2
The wireless module that operates in No. 4 is configured as hardware.

Next, the operation of this embodiment will be described. First, the determination of the tracking exchange time performed by the mobile station 1 when the mobile station 1 moves from the A service area to the B service area will be described. As shown in FIG. 1, when the mobile station 1 is located in the service area of A and communication is sufficiently possible by communicating with the base station A, the electric field received from the base station A is strong,
Therefore, the output of the comparator 12 maintains HIGH, and the HIGH output of the comparator 12 causes the CPU 13
Keeps talking to the wireless module 10.

When the mobile station 1 moves in the direction of the arrow in the drawing and approaches the boundary of the service area, the level of the electric field received from the base station A decreases, the IF detection output 11 decreases, and the comparator 12 outputs. Output is from HIGH to LOW
Changes to. This change is caught by the CPU 13 and C
The PU 13 operates to activate the tracking exchange processing program, and thereafter the mobile station 1 shifts to the tracking exchange processing.

Next, the process from the determination of the tracking exchange time by the mobile station 1 to the determination of the base station 2 after the tracking will be described with reference to the timing chart of FIG. FIG. 3A is a timing chart for explaining the operation of this embodiment, where the CPU 13 is the comparator 1
When the output of 2 changes to LOW, the wireless module 10 is operated to change the channel from the call channel to the control channel, and the tracking exchange request signal 3 is used using this control channel.
Send 0. When the trace exchange request signal 30 has been transmitted, the wireless module 10 is operated to return to the call channel (the call channel in communication with the base station A) before the control channel, and the call is restarted. This state is shown at 31 in FIG.

Further, each base station 2 is in a state of being able to receive the tracking exchange request signal 30 at any time by operating the control channel 21 at all times, and when receiving the tracking exchange request signal 30 from the mobile station 1, the CPU 24 respectively. To notify the center 3 that the tracking exchange request signal 30 has been received. Further, at this time, each base station 2 sends the IF output from the control channel 21 to the CPU 24 via the buffer amplifier 23.
Is input to the A / D conversion input port (not shown) of the above, and the electric field strength is digitized and measured, and the measured value is sent to the center 3 together with the above-mentioned notification. Then, the center 3 selects the base station 2 (which is the base station B in FIG. 1) having the strongest electric field strength in response to the notification sent from each base station 2, and the base station B is used as the call continuation base station. As a result, a tracking exchange instruction is sent to the base station B. As described above, the base station to be tracked and exchanged is determined.

Finally, the establishment of a communication channel between the mobile station 1 and the new base station B in FIG. 1 will be described.
The CPU 13 switches the channel from the call channel 31 to the control channel at a predetermined timing, and sends the tracking exchange response signal 32 using this control channel. Each base station 2
As described above, since the control channel 21 is always kept in a receivable state, the tracking exchange response signal 32 is received by each base station 2, but each base station 2 receives this tracking exchange response signal 32. Upon reception, the tracking exchange response signal 32 is checked whether or not the own station is the base station instructed to perform the tracking exchange from the center 3, and the own station is instructed to perform the tracking exchange in the base station (base station B). If so, the tracking exchange instruction signal 33 is sent to the mobile station 1. The tracking exchange instruction signal 33 is sent by operating the wireless module in the control channel 21 by the CPU 24.

Then, when the mobile station 1 receives the tracking exchange instruction signal 33, it operates the CPU 13 to switch the channel to the call channel, and continues the call with the base station B. As described above, the tracking exchange process from the base station A to the base station B is performed. Note that both the base station A and the base station B can communicate with each other in the vicinity of the service area boundary, and the mobile station 1 in the above-mentioned timing, that is, during the call 31 switches the channel to the control channel and sends the tracking exchange response signal 32. The timing to do can be set appropriately. For example, it may be after a lapse of a processing period that can be predicted as a certain time in advance, or at a time when the electric field strength from the base station A further weakens. FIG. 3B is a diagram showing the operation of the conventional system that does not use the tracking exchange control modem. In this case, the call is cut off for about 3 to 10 seconds of the processing period. In the embodiment of FIG. 3 (A), the call state is ensured even during the processing period, so that a momentary interruption of about 1 second will suffice.

[0016]

As described above, the tracking exchange processing system of the cordless mobile telephone according to the present invention can perform the tracking exchange control without using the modem for tracking exchange control and without blocking the call as much as possible. It is possible to simplify the system configuration and operation without using software,
There is an effect that the development period can be shortened and an inexpensive system can be provided.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a general operation of a tracking exchange process.

FIG. 2 is a block diagram showing an embodiment of a device configuration according to the present invention.

FIG. 3 is a diagram showing operation timings of an example of the present invention and a conventional system.

[Explanation of symbols]

 1 mobile station 2a base station A 2b base station B 3 center 30 tracking exchange request signal 32 tracking exchange response signal 33 tracking exchange instruction signal

Claims (1)

[Claims] 1. When a plurality of base stations form a wireless service area at predetermined intervals and a mobile station composed of a cordless mobile telephone moves, the wireless control is performed between the mobile station and the base station. In a tracking exchange processing system of a cordless mobile phone that exchanges information with each other and sequentially switches the call channel to correspond to a new wireless service area, the communication of the above control information is only confirmed information due to the software configuration. Is to be transmitted and received wirelessly, and the call channel is switched to the control channel for this transmission / reception time to interrupt the call momentarily.While the mobile station, the base station and the center are processing, the call channel is always selected. A tracking exchange processing system for a cordless mobile phone, comprising: a means for maintaining a call-enabled state.