JPH0653892A - Device and method for selecting zone of mobile terminal for radio telephone system - Google Patents

Abstract

PURPOSE:To provide a zone selecting system of a mobile terminal for a radio telephone system by calling the mobile terminal so that the traffic balance of respective zones can be always obtained in the case of mobile body communication constituted of small zones. CONSTITUTION:The number of remaining calling channels is transmitted from each base station 2 to the mobile terminal 1 as system information through a termination control channel. The terminal 1 tunes to the termination control channel transmitted from each base station 2 by its tuning part 11 for tuning to the frequency of a terminating/transmitting/calling channel and measures a control channel receiving level from each base station by its electric intensity measuring part 12. A control part 14 selects a base station 2 having the highest receivable receiving level and having the largest number of remaining calling channels to be usable and calls the selected base station 2. Consequently traffic balace among respective zones can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zone selection apparatus and method for mobile terminals for wireless telephone systems.

[0002]

2. Description of the Related Art Conventional mobile communication is, for example, in a car telephone, a plurality of car telephone exchanges connected to a fixed telephone network which is an existing facility, and a plurality of radio line controls for each of these car telephone exchanges. The radio network controller is connected to a plurality of base stations. The base station receives the wireless communication from the mobile station loaded with the mobile terminal that has moved into the zone as the service area in charge, and connects to the fixed telephone network through the above-mentioned wireless line control station and car switching center. , It adopts a small zone configuration that performs circuit connection exchange with the intended other party. This small zone structure enables geographically repeated use of the same frequency and effective use of radio waves. In addition, the radio channels used for telephone calls, which are located in each radio zone, that is, the number of telephone channels is determined according to the geographical distribution of traffic, and the telephone channels are downlink (base station transmission / mobile station reception). ) And upstream (mobile station transmission / base station reception) divided frequency bands. As a modulation method for transmitting a voice signal in a speech channel, a narrowband analog F that has undergone baseband signal processing such as emphasis and compander.
The M method is used. Adjacent channel spacing in this case, 12.5kH _Z in the following 470MH _Z bands, 800M
In the H _Z band has become a 25kH _Z. The control channel is used to appropriately allocate this call channel according to the call request of each subscriber. The control signal transmitted on the control channel uses a digital signal.

The mobile terminal comprises a tuning section for tuning to a designated frequency, an electric field strength measuring section for measuring a signal strength of the frequency, and a system information reading section for reading a signal carried at the frequency. Zone selection consisting of the tuning section, the electric field strength measuring section, the system information reading section and the control section for determining the wireless zone in which the mobile terminal is located and selecting the wireless zone with a high reception level and an empty channel. The device performs the following determination process. When the mobile terminal becomes inaccessible due to the access control class instructed to the mobile terminal from the base station in the first zone with the high reception level identified by the electric field strength measuring unit, the second zone with the next highest reception level I am trying to choose.

The zone selection device of this mobile terminal will be described in detail with reference to FIGS. FIG. 3 is a block configuration diagram of a conventional zone selecting device, and FIG. 4 is a flowchart explaining the operation of the zone selecting device.

3 and 4, the tuning unit 31 to which the antenna is connected has a function of tuning to the frequency instructed by the control unit 34, and the electric field strength measuring unit 32 is the tuning unit 31.
The control unit 34 is connected to the control unit 34 and the system information reading unit 33, and the received electric field strength of the control channel carrying the system information is measured from the tuned frequency signal of the tuning unit 31 (step 41). It has the function of reporting. The system information reading unit 33 is the control unit 3
4 has a function of reading the system information from the control channel (step 42) and outputting the read system information to the control unit 34 when instructed by 4. The control unit 34 decodes this system information (step 4
3) However, if this decoding cannot be performed correctly, the control channel number is incremented (step 45) and the process returns to the above (step 42) and the system information reading unit 33 is supplied with the system information of the control channel having the next highest electric field strength. Read. On the contrary, when the system information read in (step 43) can be correctly decoded, it is checked whether the access control class is accessible (step 4).
4). If the access is impossible here, the control channel number is incremented (step 45) to cause the system information reading unit 33 to read the system information of the control channel having the next stronger electric field strength. That is, the control unit 3
Reference numeral 4 indicates the second highest frequency of the electric field strength to the tuning unit 31 to tune to that frequency, and the processes of steps 43 and 44 are sequentially repeated. If it is accessible in the second access control class in step 44, the call is made to the second zone.

[0006]

In such a conventional mobile phone zone selection method of a radio telephone system, access traffic flow control is performed and traffic balance between base stations is not performed until traffic congestion begins. Have begun. For this reason, a large number of mobile terminals are present in one zone, and although there are idle call channels in other adjacent zones, calls are concentrated in that zone, traffic balance is lost, and call loss may occur. There is. Therefore, there is a problem that a good call service cannot be provided.

Therefore, an object of the present invention is to eliminate such conventional problems and preferentially select the zone having the highest reception level in the zone selection for making a call, and also to set the vacancy of each zone. A zone selection device and method for a mobile terminal for a wireless telephone system, which compares the number of communication channels and selects a zone having a higher reception level and the largest number of remaining communication channels to balance the traffic of each zone. To do.

[0008]

A first solving means of the present invention for solving the above-mentioned problems is a tuning section for tuning to a designated frequency, and an electric field strength measuring section for measuring a reception level of the frequency. , A zone selection of a mobile terminal for a wireless telephone system, comprising a system information reading unit for reading system information transmitted from a base station by a control channel, and a tuning unit, an electric field strength measuring unit, and a control unit for controlling the system information reading unit In the method, the tuning unit is tuned to the frequency of the control channel transmitted from a plurality of the base stations, and the electric field strength measuring unit measures the radio wave reception level at the time of tuning, and the control channels are arranged in descending order of reception level. Depending on the rearrangement step and the result of this step, from the control channel with the highest reception level to the control channel with the smallest reception level in order. A step of causing the system information reading unit to read the system information of the control channel by receiving a predetermined number of reception tunes, and further determining whether or not the system information can be decoded; The step of holding the call channel number information is compared with each of the held idle call channel number information, and the control channel having the largest number of idle call channels and the highest reception level is selected and used as a calling zone. And a step of performing.

A second solution of the present invention for solving the above-mentioned problems is to use a tuning unit that tunes to a designated frequency, an electric field strength measuring unit that measures a reception level of the frequency, and a control channel from a base station. In a zone selection device of a mobile terminal for a wireless telephone system, comprising a system information reading unit for reading transmitted system information, the tuning unit is tuned to the frequency of the control channel transmitted from a plurality of the base stations, and at the time of tuning. Sorting means for rearranging the control channels in the order of height of the reception level by measuring the radio wave reception level by the electric field strength measuring unit, and the result of this sorting means is that the reception level in descending order from the control channel with the highest reception level. The system information reading unit reads the system information of the control channel by receiving and tuning a predetermined number of control channels. Decoding determination means for determining whether or not this system information can be decoded, information holding means for holding information on the number of empty call channels included in the system information when decoding is possible, and each of the held empty call channels It is characterized by further comprising a control unit configured to compare the number information and select the control channel having the largest number of idle call channels and the highest reception level as a calling zone.

[0010]

The present invention has a structure as shown in FIG. 1, and its operation is shown in the flow chart of FIG. Each base station 2 sends the number of remaining communication channels to the mobile terminal 1 as system information on the incoming control channel. The mobile terminal 1 performs the following processing by each means. First, the sorting means (step 100) tunes to the incoming control channel frequency transmitted from each base station 2 by the tuning unit 11 which tunes to the incoming / outgoing / speech channel frequency, and controls channel reception level from each base station 2. Is measured by the electric field strength measuring unit 12. Then, according to the measured reception level, the respective control channels are arranged in descending order of reception level. further,
The decoding judgment means (steps 102, 103) receives the control channels in order from the one with the highest reception level according to the height of the arranged reception levels, and receives the system information sent from the base station 2 on the control channel. The system information reading unit 13 reads it, and the control unit 14 decodes it. When the system information can be decoded, the information holding means (step 105) holds the system information. The selecting means (steps 107 to 109) compares the number of remaining communication channels included in the system information of each control channel held by the information holding means, and the base station 2 having a higher receivable reception level, Moreover, the base station 2 having the largest number of remaining communication channels that can be used is selected, and the base station 2 enters the standby state of the call origination state (step 109). When a call is generated, the call is made using the system information when the standby state was entered in step 109. This acts to balance the traffic in each zone.

[0011]

Next, an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the operation of the mobile terminal 1.

In FIG. 1B, the mobile terminal 1 has a tuning section 11 to which an antenna 15 is connected, an electric field strength measuring section 12 and a control section 14 connected to the tuning section 11, and an electric field strength measuring section 12. And a zone information selection device including a system information reading unit 13 connected to the control unit 14. The tuning unit 11 has a function of tuning to a frequency instructed by the control unit 14, and measures the electric field strength. The unit 12 has a function of measuring the reception level of the frequency tuned by the tuning unit 11 and reporting it to the control unit 14. The system information reading unit 13 has a function of reading system information from a received signal and outputting the information to the control unit 14 when instructed by the control unit 14. The control unit 14 is the tuning unit 1 described above.
1, electric field strength measuring unit 12 and system information reading unit 13
To control the zone selection.

The base station 2 that communicates with the mobile terminal 1 in the zone in charge is a control unit 21, a control channel transmission unit 22 and a control channel reception unit 23, which are connected to the control unit 21, respectively. And an audio channel section 24. The audio channel unit 24 includes a plurality of audio channel transmitting / receiving units 24 _{1 to} 24 _h . A transmitting antenna 25 is connected to the control channel transmitting unit 22, a receiving antenna 26 is connected to the control channel receiving unit 23, and antennas 27 _{1 to} 27 _h are connected to the respective voice channel transmitting / receiving units 24 _{1 to} 24 _h. Has been done. The control channel transmitter 22 outputs the system information (region information, transmission control channel information, incoming signal, channel designation signal, etc.) output from the controller 21.
The mobile station 1 has a function of transmitting (information reported from the base station to each mobile terminal) on the incoming control channel, and the control channel reception unit 23 has a function of receiving a call from the mobile terminal 1. The control unit 21 manages the call state and the like of the voice channel unit 24, constantly monitors the number of remaining voice channels, coats the remaining number of call channels with system information data, and outputs the data to the control channel transmission unit 22. have. Then, the mobile terminal 1 can know the number of remaining communication channels of the base station 2 from the system information transmitted by the control channel transmitter 22.

The operation of the above arrangement will be described below.

When the mobile terminal 1 is powered on, the control section 14 reads the frequencies of the respective incoming control channels from the designated item ROM which holds the frequencies of the plurality of incoming control channels which can be used by the mobile terminal 1. The signals are sequentially output to the tuning unit 11. The tuning unit 11 sequentially tunes to the frequency of each incoming control channel, and receives each received signal from the electric field strength measuring unit 1.
2 to measure the reception level at each control channel frequency. Then, the electric field strength measurement unit 12 reports the reception level of each control channel frequency to the control unit 14 (step 100). Then, the control unit 14 sets the control channel number N to 1 (step 101), that is, it means to try to receive the control channel having the highest reception level. The control unit 14 instructs the tuning unit 11 to specify the control channel frequency that was the reception level of the order corresponding to the number N, and tunes to that frequency. The system information reading unit 13 reads the system information of the control channel having the Nth highest reception level (step 102), and the control unit 14
Output to. The control unit 14 decodes the read system information (step 103). If the system information cannot be correctly decoded here, the number N is incremented (step 104) and the process returns to step 102 to tune the tuning unit 11 to the control channel frequency with the N + 1th highest received level, and from the control channel. Read system information. On the contrary, when the system information can be correctly decoded in step 103, the number of communicable remaining communication channels included in the system information is held in the RAM or the like (step 105). The number of remaining communication channels represents the number of remaining communication channels of the base station 2 transmitting the control channel, that is, each zone.

Next, the control unit 14 controls the control channel number N.
And a match with a predetermined maximum value N _MAX is determined (step 106). If the control channel number N is not equal to N _MAX , the control channel number N is incremented in step 104, and the process returns to step 102. Next, the system information is read and decoded in synchronization with the control channel frequency having the higher reception level. If it can be decoded, the number of remaining communication channels included in the system information is held in the same manner (steps 103 to 105). Here, N _MAX is a threshold value for determining whether to read system information in synchronization with control channels having reception levels up to the N _MAX order in order from the control channel having the highest reception level.

In step 106, the control channel number N is N
_The case of being equal to _MAX will be described. With this N = N _MAX , the RAM holds a plurality of remaining communication channel numbers included in the system information for each control channel for which the system information has been correctly decoded. That is, the number of callable channels of the base station corresponding to each reception level is held. Then, the sizes of the remaining communication channels of each base station are compared, and the control channel having the maximum number of usable communication channels, that is, the base station is selected (step 107). If there are two or more base stations having the largest number of remaining communication channels, the base station having the highest reception level is selected from the base stations, and the following standby state is entered. The control unit 14 activates the timer, and the step 1
The base station selected in 07 is allowed to make a call. This call-enabled state is maintained until the timer times out. When the timer times out, the process returns to step 100, the above processing is performed again, and the base station having the largest number of new idle call channels,
Moreover, the base station having the highest reception level is selected. That is, the data held in step 107 is updated. In this way, a base station with many idle communication channels and a high reception level is detected and detected at regular intervals, and a call is made using the zone of that base station, so the traffic balance of each zone is Can be optimized.

In the above embodiment, the system information of the once-selected optimum base station is held for a certain period of time by the processing of steps 108 to 110.
The system information of the selected base station is retained in the memory without using the timer by the processing of steps 110 to 110,
Then, the process immediately returns to step 100, and steps 100 to 107 for performing the above process again are continuously repeated. If the control unit 14 receives a call request in the middle of the process, the process is interrupted and interrupted, You may make a call by the system information regarding the base station hold | maintained at the memory.

[0019]

As described above, the present invention utilizes the fact that the number of remaining channels is sent from the base station to the mobile terminal on the incoming control channel, and the mobile terminal determines the reception level of the incoming control channel sent from each base station. We measured and compared the number of remaining channels of each receivable base station, and added the control to make a call by selecting the zone of the base station with the highest reception level and the largest number of remaining communication channels. , It is possible to prevent the traffic from being concentrated in one zone by making a call from the mobile terminal in a constantly traffic-balanced manner in each zone.

[Brief description of drawings]

FIG. 1 relates to an embodiment of the present invention and is a configuration block diagram thereof.

FIG. 2 is a flowchart explaining the operation of the embodiment of the present invention.

FIG. 3 is a block diagram of a conventional example.

FIG. 4 is a flowchart of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mobile terminal 2 Base station 11 Tuning section 12 Electric field strength measuring section 13 System information reading section 14 Control section 21 Control section 22 Control channel transmitting section 23 Control channel receiving section 24 Voice channel section 31 Tuning section 32 Electric field strength measuring section 33 System information reading unit 34 Control unit

Claims (2)

[Claims] 1. A tuning unit that tunes to a designated frequency, a field strength measuring unit that measures a reception level of the frequency, a system information reading unit that reads system information transmitted from a base station by a control channel, A zone selection method for a mobile terminal for a wireless telephone system, comprising: a tuning section, a field strength measuring section, and a control section for controlling a system information reading section, wherein the tuning section is set to a frequency of the control channel transmitted from a plurality of the base stations. Tuned, the radio wave reception level at the time of tuning is measured by the electric field strength measuring section, and the control channels are rearranged in the order of high reception level, and the result of this step is from the control channel with the highest reception level in order. The system information of the control channel is tuned by receiving a predetermined number of reception channels up to the control channel having a small reception level. The information reading unit reads the information, and further determines whether this system information can be decoded. If the system information can be decoded, the number of empty call channel information included in the system information is held. Comparing the call channel number information, and selecting the control channel having the largest number of idle call channels and the highest reception level as a calling zone, the mobile phone for a wireless telephone system. Terminal zone selection method. 2. A tuning unit that tunes to a designated frequency, an electric field strength measuring unit that measures a reception level of the frequency, and a system information reading unit that reads system information transmitted from a base station by a control channel. In the zone selection device of a mobile terminal for a wireless telephone system, the tuning unit is tuned to the frequency of the control channel transmitted from the plurality of base stations, and the electric wave reception level at the time of tuning is measured by the electric field strength measuring unit. Sorting means for rearranging the control channels in descending order of reception level, and a system of control channels in which a predetermined number of reception channels are tuned and tuned from the control channel with the highest reception level to the control channels with decreasing reception levels according to the result of the sorting means. Whether information can be read by the system information reading unit and this system information can be decoded The number of idle call channels is compared by comparing the information of each of the available idle call channels held by the decoding determination means for determining A zone selecting device for a mobile terminal for a wireless telephone system, comprising: a control unit configured to select the control channel having the highest number and the highest reception level as a calling zone.