JPH0937339A - Method for allocating radio communication channel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the availability of frequency by previously setting required quality for every communication kind, discriminating a channel corresponding to a required communication kind, then retrieving the channel and allocating the retrieved channel to a mobile station. SOLUTION: An area 3 is constituted of zones 1, 2 and the zones 1, 2 are respectively constituted of base stations 4, 6. Plural mobile stations 5, 7 exist in the system and the station 7 is connected to the station 6 through a radio channel. When a connection request is outputted from the station 5, the station 4 discriminates its connection kind based upon the signal outputted from the station 5. The station 4 measures the receiving level of a signal from the station 5 and calculates the power ratio of an interference wave to a required wave of each radio communication channel based upon the receiving level of the signal and the interference wave receiving level in each radio communication channel. When the calculated value satisfies required quality, the radio communication channel is allocated to the mobile station 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio channel allocation method for dynamically allocating radio channels as needed in a mobile communication system in which a service area is composed of a plurality of radio zones.

[0002]

2. Description of the Related Art In a mobile communication system that covers a service area with a plurality of wireless zones, a conventional dynamic channel allocation method is to allocate a plurality of commonly used wireless channels to each wireless zone, and to allocate wireless communication channels from mobile stations. Each time a request is made, whether or not the wireless communication channel to be allocated is used in another wireless zone is searched by measuring the interference wave level of the wireless communication channel, and the required quality as the communication path of the wireless communication channel is determined. If it is determined that the required quality is satisfied, the wireless communication channel is allocated. At this time, the wireless communication channels are allotted with a constant required quality regardless of the communication types of the wireless communication channels such as voice and data to be performed.

[0003]

In the conventional mobile communication system, when quality deterioration due to interference occurs during communication due to a change in radio propagation path such as movement of a mobile station or movement of a vehicle, quality deterioration is avoided. In order to do so, it has an interference avoidance function such as switching communication channels. However, in this control, since communication channels are switched, communication must be temporarily cut off. This means
In particular, in the data communication service, loss of transmission data is caused, resulting in an increase in control load for retransmission control of loss data and a decrease in data transmission throughput.

As a countermeasure against this, it is considered that the required quality of the wireless communication channel is set high and the wireless communication channel is assigned so as not to fall below the required quality even if the level of the interference wave increases to some extent. To be However, this method reduces the utilization efficiency of the wireless communication channels and increases the number of required system channels. This is because the wireless communication channel, such as voice communication, which is allowed to switch to some extent, that is, the wireless communication channel whose required quality is lower than the wireless communication channel for data communication, is not included in the communication content. This is because the wireless communication channels are assigned with a uniform and high required quality regardless of the relation, so that the utilization efficiency of the communication channels is reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a radio communication channel allocation method for a mobile communication system with high frequency utilization efficiency of radio communication channels. Also, in data communication and the like, a probability of occurrence of channel switching control that causes loss of transmission data is reduced, a control load for data retransmission control is reduced, and a data transmission throughput is improved. The purpose is to

[0006]

According to the present invention, in a mobile communication system, the required quality for each communication type is satisfied based on the communication type information of a wireless communication channel issued by a mobile station to a wireless base station. It is characterized by allocating a wireless communication channel.

According to the present invention, two-way communication is performed between a radio base station and a mobile station via a radio line, and when a communication connection request is made from the mobile station, a required quality is set as a communication path. In a wireless communication channel allocation method for selecting and allocating a satisfying wireless communication channel, when a desired wave-to-interference wave power ratio is used as the required quality, when the wireless base station receives a communication connection request from the mobile station. To determine the communication type requested by the mobile station based on the control signal from the mobile station and measure the reception level of the control signal of the communication connection request from the mobile station, and the reception level of this control signal and each The desired wave-to-interference wave power ratio of each wireless communication channel is calculated based on the interference wave reception level in the wireless communication channel, and the calculated desired wave-to-interference wave power ratio value is calculated from the mobile station. When satisfying the required quality corresponding to the communication type for which the signal connection request, assigns the wireless communication channel to the mobile station.

According to the present invention, in a mobile communication system,
The required quality is set according to the type of communication such as data communication, voice, and fax that the mobile station requests from the wireless base station. When the mobile station makes a communication connection request, the wireless base station allocates a wireless communication channel by searching for a communication path that satisfies the required quality according to the type of communication requested by the mobile station for connection. As a result, it is possible to improve the frequency utilization efficiency of the wireless communication channel as compared with the method of uniformly setting the required quality for each communication type and allocating the wireless communication channel. Further, in the data communication service, the loss of the transmission data is caused. Since the probability of occurrence of the channel switching control that occurs is reduced, the control load for data retransmission control can be reduced, and the data transmission throughput can be improved.

[0009]

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

FIG. 1 shows the configuration of a mobile communication system according to an embodiment of the present invention. The service area 3 includes a wireless zone 1 and a wireless zone 2. The wireless zone 1 is configured by the wireless base station 4, and the wireless zone 2 is configured by the wireless base station 6. In this mobile communication system, there are a plurality of mobile stations, and the mobile station 5 is
In the wireless zone 1, the mobile station 7 exists in the area of the wireless zone 2. The mobile station 7 has a communication path set by the wireless base station 6 and a wireless communication channel.

FIG. 2 shows the configuration of a radio base station, which includes an antenna 20 and a transmission / reception unit (TR) including a modulation / demodulation function.
X) 21, a baseband processing unit 22 that performs generation of a transmission signal, detection and processing of a reception signal, a reception level measurement unit 23 that measures a reception level of a radio channel reception signal, and controls the operation of the entire circuit. A control unit 24, a storage unit 25 that stores a required quality value corresponding to each communication type (communication content) of a wireless communication channel, and a processing unit that performs analysis of a signal transmitted from a mobile station and processing related to wireless communication channel allocation. 26 and.

FIG. 3 shows a call connection sequence in a mobile communication system in which the present invention is implemented. That is, when a call connection request is generated from a mobile station to perform communication, the mobile station sends a radio base station a control channel,
Send a communication channel request signal. When the wireless base station receives this communication channel request signal, it searches for a wireless communication channel that satisfies the required quality according to the wireless communication channel allocation algorithm, and if a wireless communication channel that satisfies the required quality is found, the mobile station notifies the mobile station. On the other hand, the wireless base station allocates a wireless communication channel by the communication channel allocation signal.

Here, the feature of the present invention is that
When there is a communication connection request from the mobile station 5, the radio base station 4 determines the communication type requested by the mobile station 5 based on the control signal from the mobile station 5 and requests the communication connection from the mobile station 5. The signal reception level of the control signal is measured, and the desired wave-to-interference wave power ratio of each wireless communication channel is calculated based on the received level of this control signal and the interference wave reception level of each wireless communication channel. When the value of the power ratio of the wave-to-interference wave satisfies the required quality corresponding to the communication type for which the mobile station has requested the communication connection, the wireless communication channel is assigned to the mobile station 5.

First, in the present embodiment, the required quality value is stored in the storage unit 25 in the radio base station 4 for each communication type. FIG. 4 shows the storage state of the required quality value for each communication type. The communication type A1 is the required quality value C1, the communication type A2 is the required quality value C2, and so on.
Up to the communication type Am, the required quality of the wireless communication path is stored for each communication type.

Next, the operation of assigning a wireless communication channel in the embodiment of the present invention will be described.

Now, the mobile station 5 is
Making a request for a wireless communication channel will be described.
In order for the mobile station 5 to make a request for a wireless communication channel to the wireless base station 4, the mobile station 5 transmits a communication channel request signal to the wireless base station by a link channel establishment request signal on the wireless control channel. . This signal is also accompanied by communication type information of the wireless communication channel, and the wireless base station 4 determines the reception level of the signal by the reception level measuring unit 2
In addition to the measurement at 3, the processing unit 26 analyzes the signal to read the communication type of the wireless communication channel requested by the mobile station 5.

FIG. 9 shows an example of signal coding on this control channel, which is a signal form including message type, communication type, and mobile station number. FIG.
An example of the meaning of this signal coding is shown. Voice communication, data communication, FAX, etc. are set as the communication type. As a result, if the message type 4 bits is the bit format “0001”, it is found that the signal is a communication channel request signal, and the subsequent communication type 4
If the bit is “0001”, it can be determined that it is “voice”.

The processing unit 26 reads out the required quality value for each communication type stored in the storage unit 25 in the wireless base station 4 in advance, and acquires the required quality value corresponding to the communication type of the wireless communication requested this time from the mobile station. Obtain the quality value C. For example,
When the communication type of the requested wireless communication is A1, the required quality value is found to be C1. Here, as the required quality value, for example, a required CIR (desired wave to interference wave power ratio) is used.

It is assumed that the type of wireless communication requested by the mobile station 5 is A1 and the reception level of the communication channel request signal received by the wireless base station is B. FIG. 5 shows CI calculated from the interference wave reception level of each wireless communication channel measured by the wireless base station 4 and the reception level B (desired wave reception level) of the communication channel request signal.
The state of R is shown. The CIR is calculated by CIR = (desired wave reception level B) / (interference wave reception level). This CIR is calculated for each wireless communication channel.

The interference wave reception level of each radio communication channel may be measured when the radio base station receives a request for the radio communication channel from the mobile station, or may be continuously measured. Since it is only necessary to measure the interference wave reception level when the wireless base station continuously monitors the state of the wireless communication channel, there is an advantage that no special measurement step is required.

The processing unit 26 in the radio base station 4 calculates the CIR of each radio communication channel (1 to n), and exceeds the required quality value C of the communication type A previously obtained. To search. When a wireless communication channel that exceeds the required quality value C1 is searched, the wireless communication channel is assigned to the mobile station 5 that requested the communication channel with the communication type A1. The communication channel already used as the communication channel for the wireless base station 4 is not searched.

FIG. 6 is a flow chart for explaining this radio communication channel allocation operation. The wireless base station excludes communication channels in use from 1 in order of communication channels,
A search is made to see if the required quality value corresponding to the communication type is satisfied, and if a communication channel K that satisfies the required quality value is found, it is assigned and the required communication channel corresponding to the communication type is assigned to the system. If there is no communication channel that satisfies the quality, the mobile station is notified of that fact.

FIG. 7 illustrates the conditions of simulation for confirming the effect of the present invention. here,
As the CIR of the required quality value, "30d
B "," 20 dB "for voice communication calls (3 in the conventional method)
0 dB) is set. FIG. 8 shows the result of comparison with the conventional method according to this. According to the result of this simulation, a wireless communication channel is allocated with a uniform required quality for both voice communication calls and data communication calls with a call loss rate of 3%. According to the present invention, it is possible to secure 2.5 times the traffic as compared with the case where

[0024]

As described above, according to the present invention, since the wireless communication channels are assigned based on the required quality for each communication type of the wireless communication channels, a mobile communication system with high frequency utilization efficiency of the wireless communication channels is realized. it can. Further, in communication that requires a high-quality wireless communication channel such as data communication, since a high-quality wireless communication channel is allocated, the probability of occurrence of channel switching control that causes loss of transmission data decreases, and The control load for retransmission control is reduced, and the data transmission throughput can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a mobile communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a configuration of a wireless base station suitable for implementing the present invention.

FIG. 3 is a diagram showing a call connection sequence in a mobile communication system in which the present invention is implemented.

FIG. 4 is a diagram showing a storage state of required quality values for each communication type of a wireless communication channel.

FIG. 5 is an interference wave reception level and C for each wireless communication channel.
The figure which shows the relationship with IR.

FIG. 6 is a flowchart illustrating an operation of assigning a wireless communication channel.

FIG. 7 is a diagram showing simulation conditions.

FIG. 8 is a diagram showing a result of simulation.

FIG. 9 is a diagram showing an example of a signal format of a control channel.

FIG. 10 is a diagram showing an example of bit formats of control signals, message types, and communication types.

[Explanation of symbols]

 1 and 2 radio zone 3 service area 4 and 6 radio base station 5 and 7 mobile station 20 antenna 21 transceiver unit (TRX) 22 baseband processing unit 23 reception level measuring unit 24 control unit 25 storage unit 26 processing unit

Claims (3)

[Claims] 1. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a communication connection request is made from the mobile station, a required quality is satisfied as a communication path. In a wireless communication channel allocation method for selecting and allocating a wireless communication channel, a required quality is set for each communication type requested by the mobile station, and the wireless base station receives a communication connection request from the mobile station. At this time, it is necessary to determine the communication type requested by the mobile station, search for a wireless communication channel that satisfies the communication quality corresponding to this communication type, and assign the wireless communication channel to the mobile station that has made a communication connection request. A characteristic wireless communication channel allocation method. 2. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a communication connection request is made from the mobile station, a required quality as a communication path is satisfied. In a wireless communication channel allocation method for selecting and allocating a wireless communication channel, the wireless base station requests the mobile station based on a control signal from the mobile station when there is a communication connection request from the mobile station. The received communication level of the control signal of the communication connection request from the mobile station is measured and the reception level of this control signal and the interference wave reception level of each wireless communication channel are used for each wireless communication channel. When the desired wave-to-interference wave power ratio is calculated, and the calculated desired wave-to-interference wave power ratio value satisfies the required quality corresponding to the communication type for which a communication connection request has been made from the mobile station. Wireless communication channel assignment method characterized by allocating the radio communication channel to the mobile station. 3. The wireless communication channel allocation method according to claim 2, wherein the wireless base station constantly and continuously measures the interference wave reception level in each wireless communication channel.