JP2000069544A - Radio resource allocation control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of the using efficiency of a radio resource by connecting plural radio terminals through radio lines with one radio base station, allowing the radio terminals to share radio frequencies among the radio terminals, and directly transmitting the allocation of radio channels to the radio terminals by using the radio channels. SOLUTION: A transmission and reception branching filter 2 operates a switching operation for introducing a radio signal captured by an antenna 1 to a receiver 5, and for switching a radio signal from a transmitter 4 to the antenna 1. A frequency synthesizer 3 operates channel switching by switching the transmission frequencies of the transmitter 4 or changing the frequencies of the local transmitter of the receiver 5 and switching the reception frequencies. When a message detecting part 6 detects a channel allocation request signal from among the reception signals of the receiver 5, it informs a control part 7 of the detected result. The control part 7 controls each part based on this signal, and transmits an assignment message by using an assignable empty channel from the using situation of a resource and the situation of the presence or absence of interference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to control when a radio base station allocates a radio channel to a radio terminal,
In particular, a radio resource allocation control method that can quickly perform radio channel allocation notification, does not require the transfer of long information about radio channels to be allocated, and therefore can improve the use efficiency of radio resources compared to the related art According to.

[0002]

2. Description of the Related Art In recent years, multimedia services have gained attention in access wireless communication. In the multimedia wireless communication, the frequency use efficiency is improved by providing a service with a variable transmission rate according to the service.

For example, TDMA (Time Division Mult)
In the ipule Access) system, the number of channels allocated to one user is changed according to the user information speed in order to make the transmission speed variable, thereby realizing multimedia communication.

In such a radio access system, in order to perform communication efficiently without collision between radio terminals, the communication band and communication time of all radio terminals providing a service are concentrated in one radio base station. A method of performing dynamic control is adopted. Information related to control such as allocation of radio resources managed in the radio base station is usually transmitted and received by providing a control channel separately from a communication channel.

In particular, when one user uses a plurality of radio channels at the same time as described above, conventionally, one channel is logically used as a control channel from among the radio channels in use, or is used for communication. A physically independent control channel was provided separately from the channel.

[0006] As a method of notifying the assigned channel, a control message in which a number for identifying the assigned channel is described and transmitted using the control channel. The channel identification number is displayed using the channel number itself in a system with a small number of designated channels, and using a bitmap when the number of designated channels is large.

[0007]

In the case of the conventional control method as described above, a control channel logically or physically different from the communication channel is required for control.
If one radio channel is reduced to flexibly cope with a variable transmission rate, the number of channels increases, so that there are problems such as a longer number representing a channel and a longer control message.

According to the present invention, a control message used for notification of an allocation channel or the like becomes longer and the time required for allocation becomes longer, or the transmission capacity of the control channel itself becomes larger and radio resource utilization efficiency decreases. It is an object of the present invention to realize a radio channel assignment control method capable of avoiding the problem.

[0009]

According to the invention, the above-mentioned object is solved by the means described in the claims. That is, according to the first aspect of the present invention, a plurality of wireless terminals are connected to one wireless base station by wireless lines, the wireless terminals share a wireless frequency between the wireless terminals, and the assignment of wireless channels is performed by the wireless base station. In a wireless communication system that performs centralized control,

When the radio base station notifies the radio terminal of a radio channel determined to be allocated to the radio terminal as an empty channel, the radio terminal directly uses the radio channel determined to allocate the notification content to the radio terminal. This is a radio resource allocation control method for transmitting to a terminal.

According to a second aspect of the present invention, in the wireless resource allocation control method according to the first aspect, the wireless terminal transmits a wireless channel allocation request for communication (hereinafter also referred to as a transmission request) to the wireless base station side. Thereafter, all unused channels of the wireless terminal are placed in a reception state, an assignment notification is waited, and the channel that has received the assignment notification from the wireless base station is used as a communication channel.

According to a third aspect of the present invention, in the wireless resource allocation control method according to the first or second aspect, the wireless terminal is in a state of waiting for a wireless channel allocation notification or transmitting using the channel. Is determined, and the transmission / reception state of the wireless channel is switched.

According to a fourth aspect of the present invention, an antenna is connected to the antenna and the antenna is connected to a transmitter.
A transmission / reception splitter for switching whether to connect to a receiver, a transmitter for transmitting a signal to a wireless terminal, a receiver for receiving a signal from the wireless terminal, and a frequency synthesizer for switching a transmission / reception frequency. ,

When receiving a channel assignment request from a wireless terminal, a wireless channel to be assigned to the wireless terminal is determined, and the wireless channel number is directly transmitted to the wireless terminal using the wireless channel. And a control unit that controls the transmission / reception splitter to set the radio channel in a reception state.

According to a fifth aspect of the present invention, there is provided an antenna, wherein the antenna is connected to the antenna and the antenna is connected to a transmitter.
A transmission / reception duplexer for switching whether to connect to a receiver, a transmitter for transmitting a signal to the radio base station apparatus, a receiver for receiving a signal from the radio base station apparatus, and for switching a transmission / reception frequency Frequency synthesizer and

After transmitting the channel assignment request to the radio base station apparatus, all available radio channels are set to a reception state, and a notification from the radio base station apparatus is waited for on these radio channels. And a control unit for controlling the transmission / reception duplexer to set the radio channel in a transmission state when notified from the radio base station apparatus.

As described above, according to the present invention, when a wireless channel is allocated, when the wireless base station notifies the wireless terminal of the channel, a control channel is not used, and a wireless channel identification number or the like is used. Rather, it is notified directly by the radio channel to be assigned, and the radio terminal switches all unused radio channels to the reception state and waits,
The most characteristic feature is that communication is started using the radio channel that has received the notification from the radio base station as the specified assigned channel.

According to the present invention, since this configuration does not require a control channel at the time of notification of allocation and directly notifies using a radio channel to be allocated, information of an identification number related to a radio channel to be allocated is provided. Since there is no need to transfer such information, there is an effect that the control can be simplified and the use efficiency of radio resources can be improved.

[0019]

FIG. 1 is a diagram showing a control procedure in a radio base station and a radio terminal according to the present invention. The control algorithm of each of the radio base station and the radio terminal is shown in more detail as a flowchart in FIGS. 3 and 6 described below, but this figure shows both control procedures at the same time.

In the figure, the vertical line on the left side shows the control of the radio terminal, and the vertical line on the right side shows the control of the radio base station. The type of signal and its direction are indicated by line segments with arrows. I have. First, the wireless terminal transmits a transmission request message to the wireless base station. Thereafter, in order to receive the allocation message, all available slots are switched to reception and the message is awaited.

However, there is a slot being used. If you ’re making a request to allocate slots in addition to that,
The in-use slot continues communication, and the other in-use slots are switched to reception. The transmission request message includes a function of notifying a necessary band to the radio base station.

FIG. 1 shows an example in which three slots, ie, two slots for uplink and one slot for downlink are required. The transmission request message can be transmitted on another channel using random access or the like. If there is a slot in communication, the slot in use is
It can also be used to temporarily transmit a transmission request.

The radio base station receives a transmission request from a radio terminal, performs an allocation process, and searches for an allocatable slot. FIG. 1 shows a case where the slots that can be allocated are 1, 2, and 3. The wireless base station transmits an assignment message to slots 1, 2, and 3 based on the result.

When the wireless terminal receives an assignment message from slots 1, 2, and 3, the reception state of waiting for an assignment message for all slots is stopped.
The transmission is switched to the transmissions 2 and 3, and an allocation reception confirmation message for confirming the reception of the allocation message on the base station side is transmitted.

Thereafter, in order to start communication, slot 1
And 2 are switched to transmission, and slot 3 is switched to reception, and data transmission / reception is started. Since the radio base station enters the communication state after receiving the confirmation message, slots 1 and 2
Is switched to reception, and the slot 3 is switched to transmission to transmit and receive data. By performing the allocation control according to such a procedure, the wireless base station and the wireless terminal can start communication.

FIG. 2 is a block diagram showing an example of the configuration of a radio base station embodying the present invention. In the figure, numeral 1 is an antenna, 2 is a transmission / reception splitter, 3 is a frequency synthesizer, 4 is a transmitter, 5 is a receiver, 6 is a message detector,
Reference numeral 7 denotes a control unit.

The transmission / reception splitter 2 is controlled by the control unit 7
A switching operation such as guiding a radio signal captured by the antenna 1 to the receiver 5 or outputting a radio signal from the transmitter 4 to the antenna 1 is performed. The frequency synthesizer 3 performs channel switching by switching the transmission frequency of the transmitter 4 or changing the frequency of the local oscillator of the receiver 5 to switch the reception frequency according to an instruction from the control unit 7.

When the message detecting section 6 detects a channel assignment request signal from the received signal of the receiver 5, it notifies the control section 7 of the signal. The control unit 7 controls the above-described units based on the detection signal, and performs the following control relating to communication with the wireless terminal as shown in FIG.

FIG. 3 is a flowchart showing control at the time of channel assignment in the radio base station. (S-1) to (S-
The display of 7) corresponds to the display in the following description. Hereinafter, with reference to these drawings, when the wireless terminal side transmits to the wireless base station side a transmission request including information on an allocated band based on the user information rate in order to transmit user information as a transmitting side, The operation of the base station will be described.

The same procedure can be applied to the case where the radio base station side is the transmitting side and the case where transmission and reception are performed simultaneously between the radio base station and the radio terminal. As shown in FIG. 3, the wireless base station first receives a transmission request from a wireless terminal (S-
1). At this time, the transmission request message may be transmitted to the radio base station by random access, or may be a method of temporarily or partially using a used channel for control during communication. it can.

Further, the transmission request includes information on the transmission rate requested by the user, and the band or the number of radio channels to be allocated on the radio base station side can be calculated. However, since the transmission request message does not require a channel identification number, the required message length is short.

The wireless base station that has received the transmission request searches for a free channel (S-2). In this process, since the management of the radio resources is performed intensively at the radio base station side, it is possible to immediately judge from the resource use status and the presence / absence status of the interference which are always grasped (S-3). Then, if there is an available free channel, an allocation message is transmitted using the available free channel (S-
4).

When there are a plurality of free channels and a plurality of channels are allocated at the same time, the same message is transmitted to each channel. Further, the message only includes a terminal ID (Identification) for identifying the wireless terminal and a message type that can be identified as an assignment message, and does not require a channel number or the like for identifying a channel.

FIG. 4 shows an example of the structure of a message. As shown in the figure, the message is a wireless terminal identifier (terminal ID).
8 and a message type (in this case, channel assignment) 9. After transmitting the assignment notification message shown in FIG. 4, the radio base station switches the radio channel from the transmission state to the reception state (S-5).

This is for receiving a message for notifying the reception of the assignment message transmitted from the wireless terminal (S-6). This process is also a process performed to receive user data when the channel is designated as a channel in the downlink direction. After receiving the message reception notification from the wireless terminal, communication is started (S-
7). That is, when the channel is designated as a downlink channel, reception of user data is started in a reception state.

When the channel is designated as an uplink channel, the channel is switched to a transmission state and transmission of user data is started. When the channel is designated as a downlink channel, it is possible to substitute the reception of user data instead of receiving the assignment message.

FIG. 5 is a block diagram showing an example of the configuration of a wireless terminal embodying the present invention. In FIG.
1 is an antenna, 12 is a transmission / reception splitter, 13 is a frequency synthesizer, 14 is a transmitter, 15 is a receiver, 17 is a control unit,
Reference numeral 18 denotes a channel assignment message detection unit.

The transmission / reception branching filter 12 performs a switching operation such as guiding a radio signal captured by the antenna 11 to the receiver 15 or outputting a radio signal from the transmitter 14 to the antenna 11 in accordance with an instruction from the control unit 17. Do. Frequency synthesizer 13
Performs channel switching by switching the transmission frequency of the transmitter 14 or changing the reception frequency by changing the frequency of the local oscillator of the receiver 15 according to an instruction from the control unit 17.

When the channel assignment message detecting section 18 detects a channel assignment message signal from the received signal of the receiver 15, it notifies the control section 17 of the detection. The control unit 17 controls each of the above units based on the detection signal,
As shown in FIG. 6, the following control relating to communication with the radio base station is performed.

FIG. 6 is a flowchart showing control at the time of channel assignment in the wireless terminal. (S-1) to (S-
The display of 8) corresponds to the display in the following description. Hereinafter, with reference to these drawings, in order to transmit user information, the radio terminal side transmits a transmission request including information on the allocated band based on the user information rate to the radio base station side. The operation will be described.

As shown in FIG. 6, after transmitting a transmission request (S-1), the wireless terminal sets an unused channel to a receiving state to receive an allocation notification (S-2). In the case of the allocation process for the first time after the start-up of the wireless terminal, all channels are unused, so that all channels are set to the reception state.

In a system in which communication has already been started and a communication band has been added or a connection has been added and a plurality of connections have been made at the same time, all unused channels other than those in communication are set to the reception state. When a channel assignment message is received from the wireless base station (S-3), the channel receiving the assignment message is used for communication as the assigned channel.

For this reason, the channel receiving the assignment message is switched to the transmission state (S-5). Then, it receives the assignment message and transmits a message for notifying the radio base station that the communication can be started (S
-6), communication is started (S-7). That is, when the channel is designated as the uplink direction by the received assignment message, the channel is switched to the reception state so that the user can receive user data after notifying the communication start state.

When the channel is designated as the up direction, the user data may be transmitted instead of transmitting a message for notifying the radio base station that the communication can be started. It is possible. Further, in the previous (S-4), the channel in the reception state in which the allocation message has not been received is set as an unused channel (S-8).

When the wireless terminal sets all unused channels in the receiving state to receive the assignment message and is in a waiting state for the assignment message, some unused channels are used by other wireless terminals and are not used. Receiving a transmission signal from a base station or another wireless terminal occurs.

However, even in this case, in a normal radio system, since each channel is scrambled for each radio terminal for secrecy, the radio terminal can recognize only interference and not an assignment message. Therefore, this does not cause a malfunction.

[0047]

In a wireless communication system for transmitting data or the like, a wireless band (slot) is usually changed according to a change in the amount of data.
Are allocated flexibly for effective frequency utilization. That is, if the amount of data to be transmitted increases, the number of slots increases, and if the amount decreases, the number of slots decreases. In this case, as the fluctuation width of the data amount matches the change width of the wireless band, the frequency use efficiency can be improved.

For this reason, it is necessary to provide a channel configuration capable of flexibly coping with fluctuations in traffic such as data and data volume by minimizing the change width of the radio band. For example, 1TDM
When 200 slots are provided in the A frame and 200 channels are configured, a channel number for identifying 200 channels is required.

To cope with high-speed transmission, 20
It is necessary to simultaneously assign several tens of channels out of the zero channels. In order to realize this, it is necessary to form a channel indication area with 200 bits and set a bit corresponding to a channel number to be assigned to 1.

Further, another 200 bits are required to distinguish between transmission and reception. Therefore, for channel identification. 400 bits will be used,
Considering the overhead of the message, the message becomes considerably long, and cannot be transmitted in one frame of one radio channel, and the message must be transmitted and received in several frames.

On the other hand, according to the present invention, since a channel identifier is not required, a short message is sufficient, and the time for transmitting and receiving a message is short. Further, since the same message may be transmitted and received to a plurality of channels, the processing load can be reduced.

Further, according to the conventional method, when the assignment message cannot be received normally due to interference in the radio section, etc.
Communication cannot be started at all. However, according to the present invention, since the assigned message is simultaneously transmitted to a plurality of channels, even if a certain channel cannot receive a message normally due to interference, another channel that has been normally received starts communication. Therefore, the throughput can be improved as compared with the conventional method.

Although the message used in the conventional method is long, it is susceptible to interference. However, in the case of the present invention, only a short message is required, so that it is less susceptible to interference. Further, before starting communication, the wireless terminal usually performs processing for checking whether the channel is usable. That is, a method of guaranteeing quality after the start of communication by performing interference detection before starting use is often used.

However, according to the present invention, the normal reception of the assignment message is equivalent to the confirmation that there is no interference. There is an advantage that the control can be simplified and speeded up since the process becomes unnecessary and the process regarding the interference detection can be omitted.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of control of a wireless base station and a wireless terminal according to the present invention.

FIG. 2 is a block diagram illustrating an example of a configuration of a wireless base station implementing the present invention.

FIG. 3 is a flowchart showing control at the time of channel assignment in a radio base station.

FIG. 4 is a diagram showing an example of the configuration of a message.

FIG. 5 is a block diagram illustrating an example of a configuration of a wireless terminal that implements the present invention.

FIG. 6 is a flowchart showing control at the time of channel assignment in a wireless terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Antenna 2, 12 Transmitting / receiving splitter 3, 13 Frequency synthesizer 4, 14 Transmitter 5, 15 Receiver 6 Message detection part 7, 17 Control part 8 Message is radio terminal identifier 9 Message type 18 Channel allocation message detection part

Claims (5)

[Claims] 1. A plurality of wireless terminals are connected to one wireless base station by a wireless line, the wireless terminals share a wireless frequency among the wireless terminals, and centralized control of wireless channel assignment is performed by the wireless base station. In a wireless communication system, in response to a channel assignment request from a wireless terminal, when the wireless base station notifies the wireless terminal of a wireless channel determined to be allocated as an empty channel to the wireless terminal, the notification content is transmitted to the wireless terminal. A radio resource allocation control method, wherein a radio channel is directly transmitted to a radio terminal using a radio channel determined to be allocated to the radio terminal. 2. A wireless terminal, after transmitting a wireless channel allocation request for communication to a wireless base station, sets all unused channels of the wireless terminal to a receiving state, waits for an allocation notification, 2. The radio resource allocation control method according to claim 1, wherein the channel receiving the allocation notification is a communication channel. 3. The wireless terminal according to claim 1, wherein the wireless terminal determines whether the wireless terminal is in a state of waiting for an assignment notification of a wireless channel or in a state in which transmission is to be performed using the channel, and switches transmission and reception for the wireless channel. 3. The radio resource allocation control method according to 2. 4. An antenna, a transmission / reception splitter connected to the antenna and switching between connecting the antenna to a transmitter and a receiver, and a transmitter for transmitting a signal to a wireless terminal A receiver for receiving a signal from a wireless terminal, a frequency synthesizer for switching a transmission / reception frequency, and upon receiving a channel assignment request from the wireless terminal, determining a wireless channel to be assigned to the wireless terminal. Using the wireless channel, transmitting the wireless channel number directly to the wireless terminal, and then controlling the transmission / reception duplexer to put the wireless channel into a receiving state, and a control unit. Wireless base station device. 5. An antenna, a transmission / reception splitter connected to the antenna for switching between connection of the antenna to a transmitter and connection to a receiver, and transmission / reception splitter for transmitting a signal to a radio base station apparatus. A transmitter, a receiver for receiving a signal from a wireless base station device, a frequency synthesizer for switching a transmission / reception frequency, and an available wireless channel after transmitting a channel assignment request to the wireless base station device All in a receiving state, and waits for a notification from the radio base station apparatus on those radio channels. A control unit for setting a channel to a transmission state.