JP2677238B2 - Channel assignment processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel assignment processing system in a mobile communication system in which a radio base station has a plurality of channels.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a mobile communication system using a conventional channel assignment processing method.

As shown in FIG. 5, a mobile communication system using a conventional channel assignment processing system has a plurality of mobile stations a1 to an and a plurality of radio base stations that provide services to the mobile stations a1 to an. b1 to bn and the radio base station b1
To bn and is mainly composed of a mobile switching center 110 which performs a switching operation for the mobile units a1 to an.
In the wireless base station b1, an antenna c1 for transmitting and receiving radio waves, a modulation / demodulation / amplification device d1 for modulating, demodulating and amplifying communication signals, and a channel CH0 assigned to the wireless base station b1. To CHn, respectively, and transmitting / receiving devices e1-1 to e1-n for measuring the electric field intensity received from the mobile devices a1 to an at a constant cycle, transmitting / receiving devices e1-1 to e1-n, and a mobile switching center. A mobile switching center interface device f1 for exchanging signals with 110, and a control device g for performing channel control according to the received electric field strength measured by the transmission / reception devices e1-1 to e1-n.
1 are provided in the control device g1, and a reception field strength comparison unit j1 that compares the reception field strengths measured by the transmission / reception devices e1-1 to e1-n, and a reception field strength comparison unit. A control unit h1 having a function of determining an initial access channel or a communication channel based on the comparison result of the received electric field strength at j1 is provided.

There are two types of channel assignment processing methods in the above-mentioned mobile communication system.

(Prior Art 1) Before calling from the mobile stations a1 to an to the radio base station b1, one of the channels assigned to the local station is initially accessed by the control unit g1 in advance. -The channels are set independently, and the other empty channels are set as communication channels.

Further, in the received electric field strength comparison section j1,
Mobile device a on each channel set as the communication channel
The received field strengths from 1 to an are compared.

When an initial access is made to the initial access channel of the radio base station b1 from any one of the mobile stations a1 to an, the received electric field strength is the smallest in the received electric field strength comparing section j1. The determined channel, that is, the influence of the interference wave is the least, and the high-quality channel is assigned as the communication channel,
Communication operation is performed.

After that, when the initial access is again issued from the mobile devices a1 to an, the above operation is repeated, and the communication operation between the mobile devices a1 to an and the radio base station b1 is performed.

(Prior Art 2) Before a call is made from the mobile units a1 to an to the radio base station b1, the reception field strength comparing unit j1 preliminarily receives from the mobile units a1 to an on all channels assigned to the local station. The received electric field strengths are compared, and the channel determined to have the smallest received electric field strength is set as the control channel for initial access.

When an initial access is issued to the control channel of the radio base station b1 from any of the mobile stations a1 to an, the initial access channel is directly assigned as a communication channel and a communication operation is performed. .

After that, when the initial access is again issued from the mobile devices a1 to an, the above operation is repeated, and the communication operation between the mobile devices a1 to an and the radio base station b1 is performed.

[0012]

However, the above-mentioned conventional channel assigning method has the following problems.

In the channel assigning method described in the prior art 1, since the setting of the initial access channel is not made dynamically on the basis of the received electric field strength of each channel, the communication is more effective than the initial access channel. There is a risk that the received electric field strength of the empty traffic channel that can be used as a channel will become large. In that case, the reception sensitivity of the communication channel will be worse than that of the initial access channel, and the initial access will succeed. However, there is a possibility that access to the communication channel may fail due to the influence of the interference wave, resulting in call loss.

In order to prevent this, the received electric field strength of the channel set as the initial access channel is measured every time the mobile station issues an initial access,
Of the remaining channels of the radio base station, the channel with the received electric field strength smaller than the received electric field strength of the initial access channel must be set as the communication channel, which increases the delay time until the service is provided. There is a problem that it ends up.

In the channel assigning method described in the prior art 2, since a preset initial access channel is set as a communication channel after initial access is issued from the mobile station, a certain mobile station is set. If another mobile station similarly makes an initial access to the wireless base station before the initial access is made to the wireless base station and the communication operation is performed, the mobile station that later made an access to the wireless base station It becomes impossible to set the communication channel. Therefore, when one mobile device issues an initial access to the wireless base station, the communication operation between the mobile device and the wireless base station is started,
Unless a new initial access channel is set up, it is not possible to issue initial access to the wireless base station from other mobile devices, which causes a delay in providing services. is there.

The present invention has been made in view of the problems of the above-mentioned conventional technique, and reduces the delay time until the service is provided, but the deterioration of the quality due to the influence of the interference wave or the like. It is an object to provide a channel assignment processing method that can be prevented.

[0017]

In order to achieve the above object, the present invention controls a plurality of mobile units, a plurality of channels for performing a communication operation with the mobile units, and a communication operation in each of the channels. A channel assignment processing method for a mobile communication system, comprising: a radio base station having a control device, wherein a service is provided from the radio base station to the mobile device. Are reception field strength comparison means for comparing the reception field strengths in the respective channels, threshold setting means for setting a threshold value which is the reception field strength at which the communication operation is possible, and the reception field strength. Among the received electric field strengths compared by the comparison means, the received electric field having the largest magnitude within the range smaller than the threshold value set by the threshold value setting means. Of the maximum received electric field strength channel detecting means for detecting a channel of the same degree, and the channel detected by the maximum received electric field strength channel detecting means as an initial access channel used for initial access from the mobile device. And a control means for setting a free channel other than the initial access channel as a communication channel.

Further, the control means is characterized in that, when there is an initial access from the mobile device, the control means is used for the communication operation in order from the channel having the smallest received electric field strength among the communication channels.

Further, the control means receives the initial access from the mobile device when there is no free channel as the communication channel.
The feature is that the access channel is set as it is as a communication channel.

Further, when there is only one empty channel, the control means makes initial access to the one channel regardless of the magnitude of the received electric field strength.
It is characterized by setting as a channel.

[0021]

According to the present invention configured as described above, the electric field strength received from the mobile station in each channel is compared in advance before the mobile station calls the radio base station, and the size of the radio base station is determined. The channel with the highest received field strength within the value is detected. Then, the control means sets the channel having the maximum received electric field strength within the threshold value to the initial access channel to which the mobile station makes an initial access. Also,
An empty channel other than the initial access channel is set as a communication channel, and a channel having a small received electric field strength, that is, a channel having a small influence of an interference wave is actually used for communication operation.

When an initial access is received from the mobile device when there is no available communication channel, the initial access channel is set as the communication channel as it is.

When only one empty channel is available, the empty channel is set as the initial access channel regardless of the magnitude of the received electric field strength.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a mobile communication system using the channel assignment processing system of the present invention.

As shown in FIG. 1, the mobile communication system using the channel assignment processing method in the present embodiment has a plurality of mobile units A1 to A7 and a plurality of wireless units that provide services to the mobile units A1 to A7. It is mainly composed of base stations B1 to Bn and a mobile switching center 10 connected to the radio base stations B1 to Bn and performing a switching operation for the mobile units A1 to A7. In the wireless base station B1, an antenna C1 for transmitting and receiving radio waves, a modulator / demodulator / amplifier D1 for performing modulation, demodulation and amplification operations of communication signals, and a channel CH0 assigned to the wireless base station B1. To CH7 respectively, and transmitting / receiving devices E1-1 to E1-7 for measuring the received electric field strength from the mobile units A1 to A7 at a constant cycle.
And the transmission / reception devices E1-1 to E1-7 and the mobile switching center 10
There are provided a mobile switching center interface device F1 for exchanging signals with and a control device G1 for performing channel control by the received electric field strength measured by the transmission / reception devices E1-1 to E1-7. In the control device G1, a reception electric field intensity comparison unit J1 which is a reception electric field intensity comparison unit that compares the reception electric field intensity measured by the transmission / reception devices E1-1 to E1-7, and a reception electric field intensity comparison unit J1. The control unit H1 is a control unit having a function of determining an initial access channel or a communication channel based on the comparison result of the received electric field strengths, and a threshold setting unit that sets a threshold value of the received electric field strengths. Threshold setting section K1
And based on the comparison result in the reception electric field strength comparing unit J1 and the threshold setting result in the threshold setting unit K1,
There is provided a maximum reception field strength channel detection unit L1 which is a maximum reception field strength channel detecting means for detecting a channel having a maximum reception field strength within a threshold value.

The operation of the channel assignment processing system in the above configuration will be described below.

First, the processing operation performed in advance before the access from the mobile stations A1 to A7 to the radio base station will be described.

A transmitter / receiver E1 corresponding to CH0 to CH7
-1 to E1-7, the mobile device A1 of each uplink channel
The received electric field strength from A7 to A7 is measured in a constant cycle, and the measured results are stored until the predetermined number of times of measurement is reached.

When the number of times of measurement reaches the set number of times, the transmission / reception storage devices E1-1 to E1-7 calculate the average values of the past measured values stored until then, and the calculated average values are respectively calculated. Is transmitted to the control device G1 as the received electric field strength of the channel.

When the transmission of the received electric field strength is completed, the measured values stored in the transmitter / receivers E1-1 to E1-7 until then are erased, and the storage of a new measurement result is started.

As described above, the transmitter / receivers E1-1 to E-1
From 1-7, the received electric field strength in each channel is sent to the control device G1 in a constant cycle.

The received electric field strengths of the respective channels sent to the control device G1 are respectively calculated by the received electric field strength comparison unit J.
1, and the channel having the maximum received electric field strength is detected in the maximum received electric field strength channel detection unit L1. However, the maximum reception electric field strength is set to a value that does not reach the reception electric field strength at which the communication cannot be set, which is set in the threshold value setting unit K1.

FIG. 3 is a diagram showing a channel state management table in the first embodiment of the present invention.

The comparison result in the reception electric field strength comparison unit J1 (see FIG. 1), the threshold value set in the threshold value setting unit K1 (see FIG. 1), and the reception electric field strength maximum channel detection unit L1 (see FIG. 1). A channel state management table as shown in FIG. 3 is created based on the detection result in (see).

In the control unit H1 (see FIG. 1), based on the channel state management table shown in FIG. 3, the channel having the maximum received electric field strength within the range smaller than the threshold value is initially accessed. As the channels, channels other than the initial access channel are set as the communication channels, and the communication operations of the mobile device are sequentially assigned from the idle communication channel with the smallest received electric field strength.

In FIG. 3, since the channel having the maximum received electric field strength within the threshold value is CH0, when CH0 is set as the initial access channel and the initial access from the mobile station is issued. , CH4 having the smallest received electric field strength is assigned as the communication channel.

Next, the processing operation after the mobile stations A1 to A7 make access to the radio base station will be described.

FIG. 2 is a sequence diagram showing the first embodiment of the present invention in chronological order. The symbols in parentheses in FIG. 2 represent the channel numbers used at that time. .

The radio base station B1 refers to the latest channel state management table, and within the range smaller than the threshold value, an empty channel with the maximum received electric field strength (CH0 in the figure).
Is set as the initial access channel, and CH0
Is set as the initial access channel on the downlink CH0.

Then, from the mobile station A1 to the radio base station B1
Assume that an initial access is issued to CH using CH0. It is also assumed that before the wireless base station B1 returns a response to the initial access to the mobile device A1, the initial access is also issued from the mobile device A2 using CH0 which is also the initial access channel. .

Then, the control unit H1 (see FIG. 1) sets the channel having the minimum received electric field strength (CH4 in the figure) and the second smallest channel (CH3 in the figure) as respective communication channels, and the radio base station B1. From mobile A1
To the mobile station A2, followed by CH3 to allow the mobile station A2 to use CH4 as a communication channel.
A response is returned permitting to use as the communication channel.

After that, the mobile device A1 starts communication using CH4, and the mobile device A2 starts communication using CH3.

After that, as a result of referring to the newly updated channel state management table by the control unit H1 (see FIG. 1), the empty channel with the maximum received electric field strength within the range smaller than the threshold is CH6. If it is determined, the initial access channel is changed from CH0 to CH6, and the fact that CH6 is set as the initial access channel is displayed on downlink CH6.

(Second Embodiment) In the first embodiment, the channel assignment method in the case where there is an empty channel other than the initial access channel in the radio base station B1 has been described, but in the second embodiment, A channel assignment method when all channels other than the initial access channel are being used for communication in the radio base station B1 will be described.

FIG. 4 is a diagram showing a channel state management table in the second embodiment of the present invention.

In FIG. 4, channels other than the initial access channel CH0 are mobile stations A1 to A6.
(See FIG. 1) All are in use.

When the mobile station A7 (see FIG. 1) issues an initial access to the radio base station B1 in the state of FIG. 4, the control unit H1 (see FIG. 1) causes the initial access channel CH0. Is directly assigned to the mobile device A7 (see FIG. 1) as a communication channel.

Thereafter, among CH0 to CH7, if CH6 first ends communication and becomes an empty channel, CH6 is initially accessed by the control unit H1 (see FIG. 1) regardless of the magnitude of the received electric field strength. Set to channel.

[0050]

Since the present invention is constructed as described above, it has the following effects.

According to the first aspect of the present invention, the initial access channel used for initial access is not a fixed channel and can be selected from all available channels, and the initial access is successful. The mobile station is assigned a channel having a smaller received electric field strength than the initial access channel as a communication channel. Therefore, it is possible to prevent the quality from being deteriorated due to the influence of the interference wave and the like, while reducing the delay time until the service is provided.

According to the second aspect of the invention, when there is an initial access from the mobile device, the communication channels are used in order from the channel having the smallest received electric field strength for the communication operation. It is possible to realize a high quality channel assignment method.

According to the third aspect of the present invention, the initial access channel is set as it is as the communication channel when the mobile station receives the initial access when there is no available communication channel. Even if there is no free channel as a communication channel, it is possible to provide a service to a mobile device without causing a delay time.

According to the fourth aspect of the invention, when there is only one empty channel, the empty channel is initially accessed regardless of the magnitude of the received electric field strength.
Since the channel is configured, it is possible to provide the service to the mobile device without causing a delay time even when there is only one free channel.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a mobile communication system using a channel assignment processing system of the present invention.

FIG. 2 is a sequence diagram showing a time series of the first embodiment of the present invention.

FIG. 3 is a diagram showing a channel state management table in the first example of the present invention.

FIG. 4 is a diagram showing a channel state management table in the second embodiment of the present invention.

FIG. 5 is a block diagram of a mobile communication system using a conventional channel assignment processing method.

[Explanation of symbols]

 10 mobile switching center A1 to A7 mobile unit B1 to Bn radio base station C1 to Cn antenna D1 modulation / demodulation / amplification device E1-1 to E1-7 transceiver device F1 mobile switching center interface device G1 control device H1 control unit J1 received electric field Strength comparison unit K1 Threshold setting unit L1 Received field strength maximum channel detection unit

Claims (4)

(57) [Claims] 1. A mobile base station comprising: a plurality of mobile devices; a plurality of channels for performing communication operations with the mobile devices; and a radio base station having a control device for controlling communication operations on the respective channels. On the other hand, a channel assignment processing method of a mobile communication system in which a service is provided from the wireless base station using the channel, wherein the control device compares reception electric field strengths of the respective channels with each other. An electric field strength comparison means, a threshold value setting means for setting a threshold value that is a reception electric field strength that enables the communication operation, and a reception electric field strength compared by the reception electric field strength comparison means, A maximum reception field strength channel for detecting a channel having a maximum reception field strength within a range smaller than the threshold value set by the threshold value setting means. The detection means and the channel detected by the reception electric field strength maximum channel detection means are set as an initial access channel used for initial access from the mobile device, and the channels other than the initial access channel are set. And a control means for setting an idle channel as a communication channel. 2. The channel assignment processing method according to claim 1, wherein the control means, in the case of initial access from the mobile device, sequentially from the channel having the smallest received electric field strength among the communication channels. A channel assignment processing method characterized by being used for communication operation. 3. The channel assignment processing method according to claim 1 or 2, wherein the control means receives an initial access from the mobile device when there is no idle channel as the communication channel. A channel assignment processing method, wherein the initial access channel is set as it is as a communication channel. 4. The channel assignment processing method according to claim 1 or 2, wherein the control means, when the empty channel has only one channel, regardless of the magnitude of the received electric field strength,
A channel assignment processing method characterized by setting a channel as an initial access channel.