JP3422692B2 - Radio resource allocation control method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control when a wireless base station allocates a wireless channel to a wireless terminal,
In particular, a wireless resource allocation control method capable of promptly notifying allocation of wireless channels, does not require transfer of long information about allocated wireless channels, and therefore can improve utilization efficiency of wireless resources as compared with conventional methods. Pertain to.

[0002]

2. Description of the Related Art In recent years, multimedia services have attracted attention in access wireless communication. In multimedia wireless communication, frequency utilization 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 method, in order to make the transmission rate variable, the number of channels assigned to one user is changed according to the user information rate to realize multimedia communication.

In such a radio access system, in order to efficiently perform communication without causing collision between radio terminals, one radio base station concentrates the communication band and communication time of all the radio terminals that provide services. The method of dynamically controlling is adopted. Information about control such as allocation of radio resources managed by the radio base station is usually transmitted and received by providing a control channel separately from the communication channel.

Particularly, as described above, when one user uses a plurality of wireless channels at the same time, conventionally, one of the currently used wireless channels is logically used as a control channel or for communication. A control channel physically independent from the channel was provided.

Further, as a method of notifying an assigned channel, a control message in which a number for identifying an assigned channel is described is constructed and transmitted using a control channel. The channel identification number is displayed by using the channel number itself in a system with a small number of channels to be specified and with a bitmap when there are many channels to be specified.

[0007]

In the conventional control method described above, a control channel which is logically or physically different from the communication channel is required for control.
If one radio channel is reduced in order to flexibly support a variable transmission rate, the number of channels increases, so that there is a problem that the number for indicating a channel becomes long and the control message becomes long.

According to the present invention, the control message used for notification of the allocation channel becomes long and the time required for allocation becomes long, and the transmission capacity of the control channel itself becomes large, and the utilization efficiency of radio resources decreases. It is an object of the present invention to realize a radio channel allocation control method capable of avoiding the above.

[0009]

According to the invention, the aforesaid problems are solved by the means defined in the claims. That is, according to the invention of claim 1, a plurality of wireless terminals are connected to one wireless base station by a wireless line, the wireless terminals share a wireless frequency between the wireless terminals, and the wireless channel is allocated by the wireless base station. In a wireless communication system that performs centralized management control,

The wireless terminal assigns a wireless channel for communication.
Send a request (hereinafter also referred to as a transmission request) to the wireless base station side
Then put all unused channels of the wireless terminal into the receiving state.
And wait for the allocation notification.

The radio base station then checks the radio base station from the radio terminal.
In response to the channel allocation request, the wireless base station sets an empty channel.
Channel that was decided to be assigned to the wireless terminal by
By using the determined wireless channel
The wireless terminal is configured to use the channel that has received the allocation notification from the wireless base station as a communication channel.

[0012] The second aspect of the present invention, in the radio resource allocation control method according to claim 1, or the wireless terminal is in a state to be transmitted using the channels or is assigned notification waiting state of the radio channel It is configured to judge and switch the transmission / reception state for the wireless channel.

[0013]

[0014]

According to a third aspect of the present invention, an antenna is connected to the antenna and the antenna is connected to a transmitter.
In order to switch the transmission / reception frequency, a transmission / reception duplexer that switches whether to connect to the receiver, a transmitter for transmitting a signal to the radio base station device, a receiver for receiving a signal from the radio base station device Frequency synthesizer,

After transmitting the channel allocation request to the radio base station apparatus, all the available radio channels are set to the receiving state, and the notification from the radio base station apparatus is waited on those radio channels. And a control unit that controls the transmission / reception demultiplexer to put the wireless channel into a transmission state when the wireless base station device notifies the wireless terminal device.

As described above, the present invention does not use the control channel and uses the identification number of the radio channel when the radio base station notifies the radio terminal of the radio channel when allocating the radio channel. Wireless channel to allocate without
Le, notify stated at allocating radio channels, in a radio terminal, and waiting to switch all unused radio channel in the reception state, specifies the radio channel which received the notification from the radio base station Assigned channels,
The main feature is to start communication.

With this configuration, the present invention does not require a control channel for assignment notification, and assigns it.
Should a radio channel, since the notification by using a radio channel to be assigned the, with no need to transfer such numbers of information for identification of the radio channels, can make control and concise to be assigned, This brings about an effect that the utilization efficiency of wireless resources can be improved.

[0019]

1 is a diagram showing a control procedure in a radio base station and a radio terminal according to the present invention. The control algorithms of the radio base station and the radio terminal are shown in more detail as flow charts in FIGS. 3 and 6 described later, 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 wireless terminal and the vertical line on the right side shows the control of the wireless base station. The type of signal and its direction are shown by line segments with arrows. There is. First, the wireless terminal transmits a transmission request message to the wireless base station. After that, in order to receive the allocation message, all available slots are switched to reception and the message is waited for.

However, there is a slot in use. If you're requesting to add to it and allocate slots,
The slot in use continues communication, and the other slots that are not in use are switched to reception. The transmission request message includes a function of notifying the radio base station of the required band.

The case of FIG. 1 is an example of the case where three slots, that is, two slots for upstream and one slot for downstream are required. Further, the transmission request message can be transmitted by another channel using random access or the like. If there is a slot in communication,
It can also be used to temporarily transmit a transmission request.

The wireless base station receives the transmission request from the wireless terminal, performs allocation processing, and searches for an allocatable slot. The case of FIG. 1 shows the case where the allocatable slots are 1, 2, and 3. The radio base station transmits an allocation message to slots 1, 2, 3 based on this result.

When the allocation message is received from slots 1, 2, and 3 in the wireless terminal, the reception state waiting for allocation messages for all slots is stopped,
Switching 2 and 3 to transmission, an allocation reception confirmation message for confirming the reception of the allocation message on the base station side is transmitted.

After this, 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. In the radio base station, since the communication state is established after receiving the confirmation message, slots 1 and 2
Switches to reception, and switch 3 to transmission to send and receive data. By performing allocation control according to such a procedure, communication can be started in the wireless base station and the wireless terminal.

FIG. 2 is a block diagram showing an example of the configuration of a radio base station that implements the present invention. In the figure, numeral 1 is an antenna, 2 is a duplexer, 3 is a frequency synthesizer, 4 is a transmitter, 5 is a receiver, 6 is a message detector,
Reference numeral 7 represents a control unit.

The transmission / reception duplexer 2 is instructed by the control section 7 to
Switching operations are performed such as guiding the radio signal captured by the antenna 1 to the receiver 5 and outputting the radio signal from the transmitter 4 to the antenna 1. The frequency synthesizer 3 performs channel switching by switching the transmission frequency of the transmitter 4 or 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 detection unit 6 detects a channel allocation request signal from the reception signals of the receiver 5, it informs the control unit 7 of it. The control unit 7 controls each of the above units based on the detection signal to perform the following control relating to communication with the wireless terminal, as shown in FIG.

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

The same procedure can be performed when the wireless base station side becomes the transmitting side and when the wireless base station and the wireless terminal simultaneously perform transmission and reception. As shown in FIG. 3, first, the wireless base station receives a transmission request from the wireless terminal (S-
1). At this time, the message of the transmission request may be a method of transmitting to the wireless base station by random access, a method of temporarily using the channel in use during communication, or a method of partially using it for control. 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 can be calculated on the radio base station side. However, since this transmission request message does not require a channel identification number, the required message length is short.

The radio base station receiving the transmission request searches for an empty channel (S-2). In this processing, since the wireless resources are centrally managed on the wireless base station side, it is possible to immediately judge from the status of resource usage and the status of interference that are always known (S-3). If there is a vacant channel that can be allocated, an allocation message is transmitted using the vacant channel to be allocated (S-
4).

When there are a plurality of empty 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) that identifies the wireless terminal and a message type that can identify the assignment message, and a channel number or the like for identifying the channel is not necessary.

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

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

When the channel is designated as an upstream channel, the transmission state is switched to and the transmission of user data is started. When the channel is designated as the downlink channel, the user data may be received instead of receiving the allocation message.

FIG. 5 is a block diagram showing an example of the configuration of a wireless terminal embodying the present invention. In the figure, numeral code 1
1 is an antenna, 12 is a duplexer, 13 is a frequency synthesizer, 14 is a transmitter, 15 is a receiver, 17 is a controller,
Reference numeral 18 represents a channel assignment message detection unit.

The transmission / reception duplexer 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 according to an instruction from the control unit 17. To do. Frequency synthesizer 13
The channel switching is performed by switching the transmission frequency of the transmitter 14 or changing the frequency of the local oscillator of the receiver 15 to switch the reception frequency according to an instruction from the control unit 17.

When the channel assignment message detection section 18 detects a channel assignment message signal from the received signal of the receiver 15, it informs the control section 17 of it. 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 wireless base station is performed.

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

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

In the case of a system which has already started communication and has a plurality of connections at the same time by adding a communication band or adding connections, all unused channels other than during communication are set to the receiving state. When the channel allocation message is received from the wireless base station (S-3), the channel that has received the allocation message is used for communication as the allocated channel.

Therefore, the channel that has received the allocation message is switched to the transmission state (S-5). Then, the allocation message is received, and a message for notifying the wireless base station that communication is ready to be started is transmitted (S
-6), communication is started (S-7). That is, when the received allocation message specifies the channel as the upstream direction, the channel is switched to the reception state so that the user data can be received after the communication startable state is notified.

When the channel is designated as the upstream direction, user data may be transmitted to start communication instead of transmitting a message for notifying the wireless base station that communication is ready to start. It is possible. Also, in the above (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 puts all unused channels into the reception state to receive the allocation message and is in the allocation message waiting state, some unused channels are in use by other wireless terminals and wireless Reception of a transmission signal from a base station or another wireless terminal occurs.

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

[0047]

EFFECT OF THE INVENTION In a wireless communication system for transmitting data, etc., a wireless band (slot) is usually set in accordance with fluctuations in the data amount.
The frequency allocation is done flexibly and the frequency is effectively used. That is, if the amount of data to be transmitted is large, the number of slots is increased, and if it is small, the number of slots is decreased. In this case, the frequency utilization efficiency can be improved as the variation width of the data amount and the variation width of the wireless band match.

For this reason, it is necessary to have a channel configuration capable of flexibly coping with fluctuations in traffic such as the amount of data and the amount of data, with the change width of the radio band being as small as possible. 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.

In order to support high speed transmission, 20
It is also necessary to simultaneously allocate several tens of channels out of 0 channels. In order to realize this, it is necessary to configure a channel designation 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. It will use 400 bits,
Considering the overhead of the message, the message becomes quite long and cannot be transmitted in one frame of one radio channel, and the message must be transmitted / received in several frames.

On the other hand, in the present invention, since the channel identifier is unnecessary, a short message can be used, so that the time for message transmission / reception can be shortened. Further, since the same message may be transmitted and received on a plurality of channels, the processing load can be reduced.

Further, in the conventional method, when the allocation message cannot be normally received due to interference in the wireless section,
Communication cannot be started at all. However, according to the present invention, since the allocation message is simultaneously transmitted to a plurality of channels, even if the message cannot be normally received due to interference on one channel, the other channels which have been normally received start communication. Therefore, the throughput can be improved as compared with the conventional method.

Since the message used in the conventional method is long, it is susceptible to the influence of interference. However, in the case of the present invention, the short message is sufficient, and thus the influence of the interference is less likely to occur. Further, before starting communication, the wireless terminal usually performs a process of checking whether or not the channel is usable. That is, a method of guaranteeing quality after the start of communication is often used by detecting interference before the start of use.

However, according to the present invention, the normal reception of the allocation message is equivalent to the confirmation that the interference does not exist. Therefore, the interference detection before the start of communication performed by the conventional method is performed. There is an advantage that the control can be made simple and quick because it becomes unnecessary and the process related to the interference detection can be omitted.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an example of a configuration of a radio base station that implements the present invention.

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

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

FIG. 5 is a block diagram showing 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 allocation in the wireless terminal.

[Explanation of symbols]

1,11 antenna 2,12 duplexer 3,13 frequency synthesizer 4,14 transmitter 5,15 receiver 6 Message detector 7,17 Control unit 8 Message is wireless terminal identifier 9 Message type 18 Channel allocation message detector

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Claims (3)

(57) [Claims] 1. A wireless system in which a plurality of wireless terminals are connected to one wireless base station by a wireless line, the wireless terminals share a wireless frequency between the wireless terminals, and wireless channel allocation is centrally managed and controlled by the wireless base station. In a communication system, a wireless terminal sends a request for allocation of a wireless channel for communication to a wireless base station.
After transmitting to the ground station side, all unused channels of the wireless terminal are
In the partial reception state, the radio base station waits for an allocation notification, and the radio base station responds to a channel allocation request from the radio terminal by assigning a radio channel determined to be allocated to the radio terminal as an empty channel by the radio base station. The channel is notified of the allocation to the wireless terminal, and the wireless terminal receives the allocation notification from the wireless base station.
A radio resource allocation control method, wherein the selected channel is used as a communication channel . 2. A wireless terminal, to determine whether the allocation notification waiting state should be transmitted by using the channel is in a state of a radio channel, according to claim 1 for switching transmission and reception of the radio channel Radio resource allocation control method. 3. An antenna, a transmission / reception duplexer which is connected to the antenna and switches between connection of the antenna to a transmitter or connection to a receiver, and a signal for transmitting a signal to a radio base station apparatus. A transmitter, a receiver for receiving signals from the wireless base station device, a frequency synthesizer for switching the transmission / reception frequency, and a wireless channel that can be used after transmitting a channel allocation request to the wireless base station device. All in a receiving state, wait for a notification from the wireless base station device on those wireless channels, and when any wireless channel receives a notification from the wireless base station device, control the transmission / reception duplexer to A wireless terminal device, comprising: a control unit that sets a channel to a transmission state.