JP2009033647A - Communication apparatus and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communications apparatus for achieving efficient channel maintenance and communication band maintenance, by suppressing the occurrence of unwanted channel assignment and unwanted channel release by a radio base station. <P>SOLUTION: A plurality of communication channels are concurrently assigned from a radio base station to a communications apparatus (radio mobile station), and the communications apparatus transmits data to the radio base station on the plurality of communication channels assigned. A control section (channel selection section) 3 of the communications apparatus selects a communication channel for transmitting data from among the plurality of communication channels and transmits data from a transmission section 2 regarding the selected communication channel. When the non-use time for a non-used communication channel exceeds a prescribed time, the control section (channel selection section) 3 selects a non-used communication channel over the prescribed time, preferentially, rather than other communication channels; and when there are a plurality of non-used communication channels after a prescribed time has elapsed, the channel of the longest non-use time is selected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication apparatus that performs communication using a plurality of channels and a communication method thereof.

  A radio mobile station capable of multi-channel communication secures a plurality of channels at the same time, and selects the most efficient channel for each data transmission. The packet-divided transmission data is written in an RLC (Radio Link Control) buffer associated with the selected channel and transmitted by radio control processing. The most efficient channel refers to a channel that has a low error rate, a high SINR (Signal to Interference plus Noise Ratio) of a received signal, and can maintain a high transfer rate. If the amount of remaining data in the RLC buffer exceeds a predetermined value, the channel efficiency is considered low, and the selection priority is low.

Furthermore, in order to maintain high frequency utilization efficiency, the radio base station considers a channel unused for a predetermined period of time to be unnecessary or excessive channel allocation, and releases the channel allocation or from the radio base station on that channel. A confirmation message is transmitted to the wireless mobile station, and when there is no response message from the wireless mobile station, it is determined as an unnecessary channel and the channel assignment is released. As a result, the radio resource is maintained in a highly efficient use, and the released channel is used for reassignment to another radio mobile station.
JP-A-9-163442

  Usually, the difference between the maximum amount of transmission data corresponding to the reserved bandwidth and the amount of transmission data is small, so that the remaining data amount in the RLC buffer (data queue) is more than the channel selection based on the transfer rate for each channel. Based on channel efficiency based channel selection is performed. However, as shown in FIG. 4, immediately after the additional allocation of channels, there is a margin in the bandwidth width secured for the transmission request data amount. FIG. 4 is a diagram for explaining the relationship between the passage of time, the amount of transmission data, the number of allocated channels, and the acquired bandwidth. For this reason, the channel selection factor is mainly the transfer rate for each channel, and the channel selection is biased. As a result, a channel that is not selected as a communication channel is generated, and if it exceeds a predetermined time, it may be released as an unnecessary channel by the radio base station. When the channel release occurs, the radio bandwidth for the transmission data is insufficient, so that the channel request process is started again. As a result, the bandwidth is gradually expanded while repeating the channel assignment and the channel release. During this time, radio resources are consumed due to control messages for channel assignment, and the efficiency of the entire system is reduced.

  As a solution to this, it is possible to use the confirmation message (transmission instruction signal) described in Patent Document 1, but bandwidth consumption due to this confirmation message occurs, and the efficiency of the entire system also decreases.

  The present invention has been made in view of such problems, and an object of the present invention is to suppress the occurrence of unnecessary channel allocation and unnecessary channel release by a radio base station, and to maintain efficient channels. Another object of the present invention is to provide a communication device and a communication method capable of maintaining the communication band.

  In order to achieve the above object, the communication device of the present invention is a communication device in which a plurality of communication channels are simultaneously allocated from a communication partner device, and data is transmitted to the communication partner device using the allocated communication channels. A channel selection unit that selects a communication channel for transmitting data to the communication partner side device from a plurality of communication channels, and the communication channel selected by the channel selection unit. A transmission unit for transmitting, and when the unused time for an unused communication channel has passed a predetermined time, the channel selection unit converts the unused communication channel for which the predetermined time has passed to another The selection is performed with priority over the communication channel.

  When there are a plurality of unused communication channels that have passed the predetermined time, the channel selection unit selects the communication channel having the longest unused time from the plurality of unused communication channels that have passed the predetermined time. It is preferable.

  Moreover, it is preferable that the channel selection unit selects the communication channel based on the channel efficiency of the communication channel when there is no unused communication channel that has passed the predetermined time. In this case, more specifically, the channel efficiency of the communication channel is grasped, and based on the grasped channel efficiency, it is determined whether the channel selection priority of the communication channel is high. It is preferable to select a communication channel determined to have a high channel selection priority.

  In addition, when there are a plurality of communication channels determined to have a high channel selection priority, the channel selection unit preferably selects a communication channel with the longest unused time from the plurality of communication channels.

  Further, when there is no communication channel with a high channel selection priority, the channel selection unit is the communication channel with the longest unused time among the communication channels determined to have a low channel selection priority based on the determination result. Is preferably selected.

  The communication method of the present invention is a communication method of a communication device that is simultaneously assigned a plurality of communication channels from a device on the communication partner side, and transmits data to the device on the communication partner side using the assigned plurality of communication channels. A step of selecting a communication channel for transmitting data to the communication partner side device from a plurality of communication channels; a step of transmitting the data on the selected communication channel; A step of selecting an unused communication channel for which the predetermined time has passed in preference to other communication channels when the unused time for the communication channel has passed a predetermined time. To do.

  The present invention suppresses the occurrence of unnecessary channel allocation and unnecessary channel release by the radio base station by optimizing channel selection in a radio mobile station that can simultaneously use a plurality of communication channels. Efficient channel maintenance and communication band maintenance can be realized.

  Embodiments of the present invention will be described with reference to the drawings. The communication apparatus of the present invention is a radio mobile station that is assigned a plurality of communication channels simultaneously from a radio base station and communicates with the radio base station using the assigned plurality of communication channels. FIG. 1 is a functional block diagram showing a schematic configuration of a wireless mobile station (mobile phone terminal) as a communication apparatus of the present invention. The wireless mobile station includes a receiving unit 1, a transmitting unit 2, and a control unit (channel selection). Part) 3, a display part 4, an input part 5, a microphone 6, and a speaker 7. FIG. 2 is a diagram illustrating a configuration of an RLC buffer provided in the control unit 3.

  The control unit (channel selection unit) 3 includes a channel selection elapsed time calculation unit 31, a channel efficiency grasping unit 32, a channel selection elapsed time classification unit 33, a channel efficiency classification unit 34, and a channel selection determination unit 35. And a function of selecting a communication channel for transmitting data to the radio base station from a plurality of communication channels. The transmission unit 2 transmits data to the radio base station through the selected communication channel determined by the channel selection determination unit 35.

  The channel selection elapsed time calculation unit 31 measures the unused time (standby time) for each communication channel. The unused time is measured by the following procedure. As shown in FIG. 2, a radio mobile station capable of multi-channel communication has a stream for each channel, and an RLC buffer as a data queue is provided for each stream. A plurality of channels can be assigned to one wireless mobile station, and the width of the communication band per wireless mobile station varies depending on the number of assigned channels. At the time of data transmission, the transmission data is divided into packets and written in the RLC buffer corresponding to the channel determined by the channel selection determination unit 35 from the channels allocated by the radio base station. The written transmission data is sequentially read from the buffer and transmitted from the transmission unit 2. If there is an ACK response from the radio base station for the transmitted data, the transmission is confirmed by receiving this ACK response. The radio mobile station includes a timer (not shown) for measuring the unused time for each channel, and the channel selection elapsed time calculating unit 31 measures the unused time for each channel using the timer. The timer is cleared when transmission data is written to the RLC buffer after channel selection. Therefore, the unused time represents the elapsed time since the previous channel selection.

  The channel selection elapsed time classification unit 33 classifies each communication channel according to whether or not the unused time (standby time) has passed a predetermined time. If the unused time is equal to or longer than the predetermined time, it is classified into the high priority group, and if it is less than the predetermined time, it is classified into the low priority group. The predetermined time may be acquired by a message from the radio base station, or a predetermined time registered in advance with the radio mobile station may be used.

  The channel efficiency grasping unit 32 grasps the channel efficiency for each communication channel. Specifically, a determination value Cp for grasping the channel efficiency is calculated. This determination value Cp is calculated by the equation Cp = Qs / Qm. Qs is the remaining data amount of the RLC buffer (data queue) provided for each channel, and Qm is a communication modulation class for each channel, and is a fixed value defined for each modulation class. If the determination value Cp is low, it means that the remaining data amount of the RLC buffer in the modulation class for each channel is small. This means that the error rate in the channel is low, that is, the SINR of the received signal is high and the transfer rate is high. Can be maintained (meaning that the corresponding channel is a highly efficient channel). The channel efficiency classification unit 34 determines whether or not the determination value Cp exceeds a predetermined value, and classifies each communication channel based on the determination result. If the determination value Cp is less than the predetermined value, it is classified into a high priority group (group with high channel efficiency), and if the determination value Cp is equal to or greater than the predetermined value, the low priority group (channel efficiency is higher than that of the high priority group). The lower group).

  When there is a communication channel whose unused time (standby time) has passed a predetermined time, the channel selection determination unit 35 selects the communication channel with priority over other communication channels. When there are a plurality of unused communication channels that have passed the predetermined time, the communication channel having the longest unused time is selected from the plurality of unused communication channels that have passed the predetermined time.

  In addition, when there is no unused communication channel that has passed a predetermined time, the channel selection determination unit 35 selects a communication channel based on the channel efficiency of the communication channel. More specifically, the channel efficiency of the communication channel is grasped, and based on the grasped channel efficiency, it is determined whether the channel selection priority of the communication channel is high. If the determination result indicates that the channel selection priority is high. Select the determined communication channel. When there are a plurality of communication channels determined to have a high channel selection priority, the communication channel having the longest unused time is selected from the plurality of communication channels. When there is no communication channel with a high channel selection priority, a communication channel with the longest unused time is selected from communication channels determined to have a low channel selection priority based on the determination result.

  FIG. 3 is a flowchart for explaining the operation of the control unit (channel selection unit). First, the channel selection elapsed time calculation unit 31 measures the unused time (standby time) for each communication channel, and the channel selection elapsed time classification unit 33 compares the predetermined time acquired in advance with the measured unused time. It is discriminated whether the time has passed for a predetermined time or more, and the channels having passed the predetermined time or more are classified into the first high priority group, and the channels having the time less than the predetermined time are classified into the first low priority group (step 100). Next, the channel selection determining unit 35 determines whether or not there is a channel belonging to the first high priority group (step 101), and if there is a channel belonging to the first high priority group, the first The channel with the longest unused time in the high priority group is selected as the transmission channel (step 102).

  If there is no channel belonging to the first high priority group in step 101, the channel efficiency grasping unit 32 grasps the channel efficiency for each communication channel. This grasping process is performed by calculating the determination value Cp as described above. Then, the channel efficiency classification unit 34 uses the determination value Cp calculated by the channel efficiency grasping unit 32 to compare with a predetermined value acquired in advance. In this comparison process, it is determined whether or not the determination value Cp exceeds a predetermined value, and channels below the predetermined value are classified into the second high priority group, and channels above the predetermined value are classified into the second low priority group ( Step 103). Next, the channel selection determining unit 35 determines whether or not there is a channel belonging to the second high priority group (step 104). If there is a channel belonging to the second high priority group, the second is selected. The channel with the longest unused time in the high priority group is selected as the transmission channel (step 105). If there is no channel belonging to the second high priority group in step 104, the channel having the longest unused time in the second low priority group is selected as the transmission channel (step 106).

  In the above-described embodiment, the control unit 3 executes the software program so that the channel selection elapsed time calculation unit 31, the channel efficiency grasping unit 32, the channel selection elapsed time classification unit 33, the channel efficiency classification unit 34, Although the channel selection determination unit 35 is realized, these may be realized by hardware.

  The present invention relates to a wireless mobile station that can use a plurality of communication channels simultaneously, by optimizing channel selection, thereby suppressing the occurrence of unnecessary channel allocation and channel release by the wireless base station. The channel assigned by the station can be maintained. As a result, the speed of multiplicity by channel assignment is high, and a high communication speed can be maintained.

It is a functional block diagram which shows schematic structure of the radio | wireless mobile station (mobile telephone terminal) as a communication apparatus of this invention. It is a figure which shows the structure of the RLC buffer provided in the control part. It is a flowchart explaining operation | movement of a control part (channel selection part). It is a figure explaining the relationship between time passage, the amount of transmission data, the number of allocation channels, and the acquisition band.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception part 2 Transmission part 3 Control part 4 Display part 5 Input part 6 Microphone 7 Speaker 31 Channel selection elapsed time calculation part 32 Channel efficiency grasping part 33 Channel selection elapsed time classification part 34 Channel efficiency classification part 35 Channel selection determination part

Claims (7)

A communication device that is simultaneously assigned a plurality of communication channels from a device on the communication counterpart side, and that transmits data to the device on the communication counterpart side using the assigned plurality of communication channels,
A channel selection unit for selecting a communication channel for transmitting data to the communication partner side device from a plurality of communication channels;
A transmission unit for transmitting the data on the communication channel selected by the channel selection unit,
The channel selector
When an unused time for an unused communication channel has exceeded a predetermined time, the unused communication channel after the predetermined time has been selected is given priority over other communication channels. Communication device. The channel selector
When there are a plurality of unused communication channels that have passed the predetermined time, a communication channel having the longest unused time is selected from a plurality of unused communication channels that have passed the predetermined time. The communication apparatus according to claim 1. The channel selector
The communication apparatus according to claim 1, wherein when there is no unused communication channel that has passed the predetermined time, the communication channel is selected based on channel efficiency of the communication channel. The channel selector
The channel efficiency of the communication channel is grasped, and based on the grasped channel efficiency, it is determined whether the channel selection priority of the communication channel is high. As a result of the determination, the channel selection priority is determined to be high. 4. The communication apparatus according to claim 3, wherein the communication channel is selected. The channel selector
The communication channel according to claim 4, wherein when there are a plurality of communication channels determined to have a high channel selection priority, a communication channel having the longest unused time is selected from the plurality of communication channels. Communication device. The channel selector
When there is no communication channel having a high channel selection priority, a communication channel having the longest unused time is selected from communication channels determined to have a low channel selection priority from the determination result. The communication apparatus according to claim 4. A communication method of a communication apparatus, wherein a plurality of communication channels are simultaneously assigned from a communication partner apparatus, and data is transmitted to the communication partner apparatus using the plurality of allocated communication channels,
Selecting a communication channel for transmitting data to the communication counterpart device from a plurality of communication channels;
Transmitting the data on the selected communication channel;
If the unused time for the unused communication channel has passed a predetermined time, the unused communication channel for which the predetermined time has passed is selected in preference to other communication channels; and
A communication method for a communication apparatus, comprising:

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