JP2009152880A - Radio communications method and radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication method and a radio communication system for actualizing highly efficient communication from a viewpoint of transmission delay time from data generation in each radio communication terminal to data transmission to a radio base station apparatus in a radio communication system in which almost all communication is occupied with data transmitted to the radio bas station apparatus from the radio communication terminal. <P>SOLUTION: The radio base station apparatus 1a can shorten the transmission delay time of a radio communication terminal deteriorated in transmission delay time by assigning, based on the transmission delay time of each radio communication terminal 2a-m (m=1, 2, 3, ..., n), channels for transmitting an area assigning request signal when the radio communication terminal holds the transmitting data and also assigning channels for transmitting an band assigning request signal to the radio communication terminal at the timing based on the transmission delay time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio communication method and a radio communication system in which a large number of radio communication terminals and one radio base station apparatus communicate with each other by random access, for example.

  In a TDMA-TDD (Time Division Multiple Access-Time Division Duplex) method, which is a wireless communication method between a conventional wireless communication terminal and a wireless base station device, communication is started between the wireless base station device and each wireless communication terminal. Prior to this, after a bandwidth for transmitting and receiving data is allocated to each wireless communication terminal, actual transmission and reception of data is started (for example, see Non-Reference Document 1).

  In recent years, in a wide range of fields such as equipment control, traffic management, distribution management, food / agriculture management, earthquake monitoring, medical welfare, etc., a short-range wireless communication system with a radius of about 10 to 100 meters using wireless tags and GHz band wireless communication Ubiquitous wireless networks such as home short-range wireless communication systems have become widespread. In the future, with the development of applications and services, an increase in the number of users using such short-range wireless communication systems is expected. Therefore, in order to provide various applications and services to a larger number of users, a wide area ubiquitous network that expands the service area is attracting attention. In addition, this network includes wireless base stations connected to a wired network and countless wireless communication terminals scattered in a wide area, and the wireless communication terminals directly communicate with the wireless base stations.

By the way, the wireless communication terminal of such a network is a battery-driven, low-power consumption / low-function terminal having a minimum function such as data measurement and measurement data transmission. Exists. As communication characteristics, the amount of uplink communication that transmits data from a radio communication terminal to a radio base station is dominant, the number of radio communication terminals with which the radio base station communicates is large, and the network performance is reduced. In order to improve, there is a feature that communication is performed in various wireless communication terminals and various data formats.
Atsushi Ohta, Fusao Fufu, Shingo Mochizuki, Jun Kurosaki, Toshimitsu Tsuji, Osamu Kagami, Yoshihiro Umehira, “Development of 5 GHz Band Advanced Wireless Access (AWA) System”, IEICE 2000 Communication Society Conference Proceedings 1 September 2000, B-5-39, p. 327

  However, in the wireless communication system in which the amount of uplink communication is dominant as described above, data transmitted from each wireless communication terminal increases, and various wireless communication terminals and various data formats are used. Thus, the communication opportunities of the wireless communication terminals are biased. The uneven communication opportunity leads to an increase in the time for transmission data of the wireless communication terminal to reach the wireless base station apparatus, and there is a problem that the delay characteristics fluctuate greatly. In particular, in a wireless communication system in which many wireless communication terminals using the same bandwidth allocation request method exist, it takes a long time to complete transmission to the wireless base station apparatus after data to be transmitted from the wireless communication terminal is generated. There is a problem that the fluctuation of the delay characteristic becomes remarkably large and the quality of service (QoS) of communication is lowered.

  The present invention has been made to solve the above problems, and its purpose is that a large number of wireless communication terminals communicate with one wireless base station, and most of the data transmission from the wireless communication terminals to the wireless base station is performed. In wireless communication occupying a large amount of communication, a communication service is provided by giving a communication opportunity to a wireless communication terminal whose transmission delay time, which is the time from generation of transmission data to transmission to a wireless base station device, has deteriorated An object of the present invention is to provide a wireless communication method and a wireless communication system that can prevent deterioration in quality and maintain fairness, that is, fairness.

  In order to solve the above problem, the present invention comprises a plurality of radio communication terminals, a radio base station device, a radio channel connecting the radio communication terminal and the radio base station device, and the radio channel comprises a plurality of frames. The frame is divided into a downlink for transmitting information from the radio base station apparatus to the radio communication terminal and an uplink for transmitting information from the radio communication terminal to the radio base station apparatus, and the uplink is The wireless communication terminal is divided into a demand assignment section in which a signal is transmitted from the wireless base station apparatus and a random access section in which a bandwidth allocation request signal is transmitted without the wireless communication terminal being allocated from the wireless base station. In the wireless communication system, the wireless base station device generates the transmission data for each wireless communication terminal after the transmission data is generated. A transmission delay time that is a time required for transmission to the line base station is measured, and a transmission delay time that is a difference in the transmission delay time between the wireless communication terminal and another wireless communication terminal for each wireless communication terminal A transmission delay measuring unit that calculates a disparity; a determination unit that determines whether or not a transmission delay time difference of the wireless communication terminal is equal to or greater than a predetermined value; and the wireless that is a target of determination based on a determination result of the determination unit A bandwidth control unit that allocates the uplink demand assignment section control channel to the communication terminal; and a wireless transmission unit that notifies the wireless terminal that the uplink demand assignment section control channel is allocated to the wireless communication terminal; And the wireless communication terminal uses the uplink demand assignment section control channel assigned to the bandwidth control unit to transmit the bandwidth allocation request signal. Which is a wireless communication system, characterized by transmitting to the wireless base station apparatus.

  Further, the present invention is the above-described invention, wherein the wireless communication terminal further transmits the bandwidth allocation request signal including information indicating that a plurality of transmission data is held to the uplink random access section control. Whether or not the determination unit further holds a plurality of transmission data included in a band allocation request signal transmitted by the wireless communication terminal. The wireless communication system is characterized by allocating the uplink demand assignment section control channel using information indicating whether or not.

  Further, the present invention is the above-described invention, wherein the radio base station apparatus further transmits the band allocation request signal when a transmission delay time difference between the radio communication terminals is a predetermined value or more. A polling unit that determines whether or not the uplink demand assignment section control channel is allocated to the wireless communication terminal in a first period, and the bandwidth control unit further determines whether to determine the channel based on a determination result of the polling unit. The wireless communication system is characterized by allocating the uplink demand assignment section control channel for transmitting the band allocation request signal to the target wireless communication terminal.

  Further, according to the present invention, in the invention described above, the polling unit further determines the first period based on a transmission delay time of the wireless communication terminal and a transmission delay time difference between the wireless communication terminals. Is a wireless communication system.

  Further, according to the present invention, in the above-described invention, the polling unit further determines the first period based on a transmission delay time of the wireless communication terminal and a transmission data generation frequency of the wireless communication terminal. Is a wireless communication system.

  The present invention also includes a plurality of radio communication terminals, a radio base station device, a radio channel connecting the radio communication terminal and the radio base station device, the radio channel comprising a plurality of frames, and the frame comprising the radio It is divided into a downlink for transmitting information from a base station device to the wireless communication terminal and an uplink for transmitting information from the wireless communication terminal to the wireless base station device, and the uplink is transmitted by the wireless communication terminal to the wireless communication terminal. A radio communication system that is divided into a demand assignment section in which a signal is transmitted from a base station apparatus and a random access section in which a band allocation request signal is transmitted without being allocated from the radio base station. In the wireless communication method in the above, the wireless base station device performs the transmission after the transmission data is generated for each wireless communication terminal. A transmission delay time that is a time required for transmission to a base station is measured, and a transmission delay time difference that is a difference in the transmission delay time between the wireless communication terminal and another wireless communication terminal for each wireless communication terminal Calculating the radio base station apparatus, the radio base station apparatus determining whether or not the transmission delay time difference between the radio communication terminals is equal to or greater than a predetermined value, and the radio base station apparatus determining whether the determination result of the determination unit is Allocating the uplink demand assignment section control channel to the wireless communication terminal to be determined on the basis of the determination, and the wireless base station apparatus assigns the uplink demand assignment section control channel to the wireless communication terminal. Notifying the wireless terminal of the assignment, and the wireless communication terminal transmits the uplink demand assertion assigned to the bandwidth control unit. It is a wireless communication method characterized by a step of transmitting the bandwidth allocation request signal using the down interval control channel to the radio base station apparatus.

  Further, the present invention provides the uplink random access section control channel according to the above-described invention, wherein the bandwidth allocation request signal including information indicating that the wireless communication terminal holds a plurality of transmission data. And the uplink demand assignment section control channel, and the radio base station apparatus holds a plurality of transmission data included in a band allocation request signal transmitted by the radio communication terminal And determining to allocate the uplink demand assignment section control channel using information indicating whether or not the wireless communication method is used.

  Further, according to the present invention, in the above-described invention, the radio base station apparatus transmits the band allocation request signal when the transmission delay time difference between the radio communication terminals is a predetermined value or more. Determining whether or not to allocate a demand assignment section control channel of a link to the wireless communication terminal in a first period; and the wireless base station apparatus is determined by the determination result of the polling unit And a step of allocating the uplink demand assignment section control channel for transmitting the band allocation request signal to the radio communication terminal.

  Further, the present invention is the above described invention, wherein the radio base station apparatus determines the period based on a transmission delay time of the radio communication terminal and a transmission delay time difference between the radio communication terminals. A wireless communication method characterized by comprising:

  Further, the present invention is the above described invention, wherein the radio base station device determines the first cycle based on a transmission delay time of the radio communication terminal and a transmission data generation frequency of the radio communication terminal. A wireless communication method characterized by comprising:

  According to the present invention, for example, each wireless communication terminal can transmit the transmission data to the transmission data when the transmission data is generated so that the transmission delay time, which is the time from the generation of the transmission data to the transmission to the radio base station apparatus, can be measured. The frame counter information is added, and the radio base station apparatus measures the transmission delay time based on the added information. Based on the transmission delay time of each radio communication terminal, the radio base station apparatus gives an opportunity to transmit a band allocation request signal to the radio communication terminal whose transmission delay time has deteriorated. In addition, when a wireless communication terminal whose transmission delay is deteriorated holds a plurality of transmission data, an opportunity to obtain a data transmission band is provided. Further, after a wireless communication terminal having a deteriorated transmission delay finishes data transmission, it gives an opportunity to obtain a band for data transmission after a predetermined time has elapsed. By doing in this way, the radio | wireless communication method and radio | wireless communications system which make it possible to prevent the deterioration of the service quality of communication can be provided.

  Hereinafter, with reference to FIGS. 1-14, the radio | wireless communications system which is embodiment of this invention is demonstrated. In this embodiment, TDMA-TDD (Time Division Multiple Access-Time Division Duplex) is applied as an access method. In addition, as a MAC (Media Access Control) protocol, a dynamic slot access (DSA) method, which is one of centralized control methods with high resource utilization efficiency that can accommodate as many wireless communication terminals as possible, is applied. . Further, the Stop & Wait method is applied as an automatic repeat request (ARQ). Here, the automatic retransmission request Stop & Wait method is a method of performing data transmission in which when one piece of data is transmitted, it waits until an arrival confirmation is received and new data is transmitted after the arrival confirmation is received. If arrival confirmation is not performed or if there is an error in the received data, the data is transmitted again assuming that data transmission has not been performed correctly.

  FIG. 1 is a schematic diagram illustrating a configuration of a wireless communication system 100. The wireless communication system 100 includes a wireless base station device 1, a wireless communication terminal 2-1, a wireless communication terminal 2-2, a wireless communication terminal 2-3, ..., a wireless communication terminal 2-n. Here, any one of the wireless communication terminal 2-1, the wireless communication terminal 2-2, the wireless communication terminal 2-3,..., The wireless communication terminal 2-n is connected to the wireless communication terminal 2-m (m = 1, 2). , 3, ..., n). Hereinafter, description will be given using the wireless communication terminal 2-m.

  FIG. 2 shows a MAC frame configuration used in the MAC protocol of the wireless communication system 100. The MAC frame is composed of a downlink for transmitting data from the radio base station apparatus 1 to the radio communication terminal 2-m and an uplink for transmitting data from the radio communication terminal 2-m to the radio base station apparatus 1. The broadcast section has a demand assignment section, and the uplink has a demand assignment section and a random access section. The broadcast section is a Bch (Broadcast channel) including the base station ID and frame number of the wireless base station apparatus 1 in the wireless communication terminal 2-m and a link in the demand assignment section for each link of the wireless communication terminal 2-m. Fch (Frame channel) including information indicating the allocated bandwidth, RFch (Random access Feedback channel) indicating the result of the random access request in the previous MAC frame, the start position of the random access section of the MAC frame, and the number of slots. is doing. The demand assignment section included in the downlink and the demand assignment section included in the uplink have a plurality of Cch (Control Channel) and a plurality of Dch (Data Channel). Further, the random access section included in the uplink has a plurality of Rch (Random Channel).

  Here, the uplink Cch is fixed for transmitting control information for each link of the radio communication terminal 2-m such as a bandwidth allocation request (RREQ: Resource Request) and an automatic retransmission request from the radio communication terminal 2-m. It is a long channel. The uplink Dch is a variable-length channel for transmitting transmission data. The uplink Rch is a fixed-length channel for the radio communication terminal 2-m to transmit a band allocation request signal. Further, when the radio communication terminal 2-m transmits a band allocation request signal using the uplink Rch, each radio communication terminal 2-m avoids a collision with the band allocation request signal of the other radio communication terminal 2-m. Therefore, for example, using an exponential back-off algorithm, a transmission standby time that is a back-off time is autonomously determined, and a bandwidth allocation request signal is transmitted after the transmission standby time has elapsed. When the bandwidth allocation request signal transmitted from the wireless communication terminal 2-m collides with the bandwidth allocation request signal of another wireless communication terminal 2-m, the wireless communication terminal 2 is set again after the transmission standby time has elapsed. -M transmits a bandwidth allocation request signal again.

  FIG. 3 shows an example of an uplink communication procedure of the wireless communication system 100. When data to be transmitted exists in the buffer, the radio communication terminal 2-m receives the downlink RFch in frame 1, and the uplink Rch start position and the uplink Rch slot included in the received RFch. Read the number. Then, the radio communication terminal 2-m transmits a bandwidth allocation request RREQ to the radio base station apparatus 1 based on the read uplink Rch start position and the number of uplink Rch slots. In frame 2, the radio base station apparatus 1 transmits the reception confirmation of the band allocation request signal of the radio communication terminal 2-m to the radio communication terminal 2-m using downlink RFch. Also, the radio base station apparatus 1 transmits uplink Dch allocation information based on the band allocation request signal to the radio communication terminal 2-m using the downlink Fch. The radio communication terminal 2-m reads the uplink Dch position and allocation amount permitted to be used included in the downlink Fch, and transmits data to be transmitted on the uplink Dch to the radio base station apparatus 1. To do. In frame 3, the radio base station apparatus 1 transmits the arrival confirmation (ACK) of the transmission data transmitted by the radio communication terminal 2-m in frame 2 on the downlink RFch, and the radio communication terminal 2-m confirms the arrival confirmation. And data transmission is completed.

(First embodiment)
FIG. 4 is a schematic block diagram illustrating a schematic configuration of the wireless communication system 100a according to the first embodiment and an internal configuration of a part related to band control of the wireless base station device 1a.
The radio communication system 100a includes a radio base station apparatus 1a, a radio communication terminal 2a-1, a radio communication terminal 2a-2, a radio communication terminal 2a-3, ..., a radio communication terminal 2a-n. Here, any one of the wireless communication terminal 2a-1, the wireless communication terminal 2a-2, the wireless communication terminal 2a-3,..., The wireless communication terminal 2a-n is connected to the wireless communication terminal 2a-m (m = 1, 2). , 3, ..., n). Hereinafter, description will be given using the wireless communication terminals 2a-m.
The radio base station apparatus 1a includes a determination unit 11a, a frame counter unit 12, a transmission delay measurement unit 13, a radio transmission unit 14, a band control unit 15a, a radio reception unit 16a, an antenna 17, and a radio communication terminal information storage unit 19a.

The determination unit 11 a receives the transmission delay time difference information of the received data input from the transmission delay measurement unit 13. Further, the determination unit 11a receives the bandwidth allocation request signal received by the uplink Rch and the uplink Cch, information indicating the completion of data transmission, and the value of the Piggyback field from the radio reception unit 16a. Here, the Piggyback field is a field that is attached to the bandwidth allocation request and further indicates the bandwidth allocation request, and is information indicating that a plurality of transmission data is held.
Further, the determination unit 11a determines whether or not the radio communication terminal 2a-m allocates an uplink Cch for transmitting the band allocation request signal, based on the input transmission delay time information and the value of the Piggyback field, The result is output to the bandwidth controller 15a.

The frame counter unit 12 generates frame counter information for uniquely identifying a MAC frame, and outputs the frame counter information to the wireless transmission unit 14 and the transmission delay measurement unit 13.
The transmission delay measuring unit 13 receives the frame counter information at the time of transmission data generation included in the transmission data received from the wireless communication terminals 2a-m from the wireless reception unit 16a, and the current frame counter information is input from the frame counter unit 12. Is done. The transmission delay measurement unit 13 calculates a difference between the frame counter information input from the wireless reception unit 16a and the frame counter information input from the frame counter unit 12, and the calculated difference is transmitted to the wireless communication terminal 2a-m. Delay time. The transmission delay measurement unit 13 records the measured transmission delay time in the wireless communication terminal information storage unit 19a. Further, the transmission delay measuring unit 13 reads out the transmission delay time of each of the wireless communication terminals 2a-m from the wireless communication terminal information storage unit 19a, performs statistical processing using a sliding average process, and the transmission of transmission data. The transmission delay time difference information indicating the difference in the transmission delay time information of the completed wireless communication terminals 2a-m is calculated, and the transmission delay time difference information is output to the determination unit 11a.

The wireless transmission unit 14 transmits information indicating that the uplink Cch or the uplink Dch for transmitting the bandwidth allocation request information is allocated to the wireless communication terminals 2a-m and confirmation of arrival of the received information. Information is input from the bandwidth controller 15a. The wireless transmission unit 14 receives the current MAC frame counter information from the frame counter unit 12. Further, the wireless transmission unit 14 transmits data via the antenna 17 according to the format of the MAC frame, with the control information added with the MAC frame counter information.
The bandwidth control unit 15a generates bandwidth allocation information based on the bandwidth allocation request signal input from the wireless reception unit 16a and the determination unit 11a, and outputs the generated information to the wireless transmission unit 14.
The radio reception unit 16a receives a band allocation request signal and transmission data from each radio communication terminal 2a-m via the antenna 17 according to the format of the MAC frame. In addition, the wireless reception unit 16 a outputs frame counter information at the time of generation of the transmission data to the transmission delay measurement unit 13 from the received transmission data. In addition, the wireless reception unit 16a outputs the received band allocation request signal to the band control unit 15a, and outputs the value of the Piggyback field included in the band allocation request signal to the determination unit 11a.
The wireless communication terminal information storage unit 19a stores the transmission delay time information of each wireless communication terminal 2a-m input from the transmission delay measurement unit 13.

FIG. 5 is a schematic block diagram showing an internal configuration of a part related to the bandwidth request of the radio communication terminals 2a-m. The wireless communication terminal 2a-m includes a wireless reception unit 21-m, a transmission control unit 22a-m, a wireless transmission unit 23-m, a buffer unit 24-m, a transmission data generation unit 25-m, and an antenna 26-m.
The radio reception unit 21-m receives information from the radio base station apparatus 1a via the antenna 26-m according to the format of the MAC frame, and outputs frame counter information included in the downlink Bch to the buffer unit 24-m. To do. In addition, the radio reception unit 21-m outputs information indicating band allocation to the band allocation request signal of the radio base station apparatus 1a to the transmission control unit 22a-m.
The transmission control unit 22a-m receives information indicating band allocation and transmission data arrival confirmation information from the wireless reception unit 21-m. Also, the transmission control unit 22a-m transmits the bandwidth allocation request signal on the uplink Rch, and when another radio communication terminal 2a-m also transmits the bandwidth allocation request signal and a signal collision occurs, the transmission waiting time After the elapse of time, the band allocation request signal is transmitted again. In addition, the transmission control unit 22a-m receives information indicating whether or not there is information to be transmitted stored in the buffer unit 24-m from the buffer unit 24-m. The transmission control unit 22a-m outputs information indicating a bandwidth allocation request having a Piggyback field to the wireless transmission unit 23-m based on information input from the buffer unit 24-m or the wireless reception unit 21-m.

The radio transmission unit 23-m transmits a band allocation request signal and transmission data to the radio base station apparatus 1a via the antenna 17 according to the format of the MAC frame.
The buffer unit 24-m receives the frame counter information of the current MAC frame from the wireless reception unit 21-m. The buffer unit 24-m receives transmission data from the transmission data generation unit 25-m, and adds frame counter information to the input transmission data.
The transmission data generation unit 25-m generates transmission data and outputs it to the buffer unit 24-m.

  The radio base station apparatus 1a measures the transmission delay time using the frame counter information included in the transmission data received from the radio communication terminals 2a-m, and determines the difference from the transmission delay time of the other radio communication terminals 2a-m. A certain transmission delay time difference is calculated. When the transmission delay time difference exceeds a predetermined threshold, the wireless communication terminal 2a-m is referred to as a wireless communication terminal 2a-m having a deteriorated transmission delay time. In order to shorten the transmission delay time of the radio communication terminal 2a-m whose transmission delay time has deteriorated, the radio base station apparatus 1a transmits a band allocation request signal so as to increase communication opportunities to the radio communication terminal 2a-m. Is assigned. Further, when there is transmission data in addition to the transmission data for which the wireless communication terminal 2a-m requests bandwidth allocation, the wireless communication terminal 2a-m sets the Piggyback field included in the bandwidth allocation request signal, and the bandwidth allocation request Send information. The radio base station apparatus 1a refers to the value of the Piggyback field, and allocates an uplink Cch that transmits a band allocation request signal to the radio communication terminal 2a-m. In this way, by reducing the transmission delay time of the wireless communication terminals 2a-m whose transmission delay time has deteriorated, the deterioration of the transmission delay characteristic of the wireless communication system 100a is prevented, the deterioration of communication service quality is suppressed, and fairness is maintained. To do.

Next, an additional band allocation step, which is an operation of performing uplink Cch allocation for the radio base station apparatus 1a to transmit an additional band allocation request to the radio communication terminals 2a-m whose transmission delay time has deteriorated, will be described with reference to FIG. It demonstrates using the flowchart shown in FIG.
When the data transmission from the radio communication terminal 2a-m to the radio base station apparatus 1a is completed, the radio reception unit 16a outputs information indicating the completion of the data transmission to the determination unit 11a. The determination unit 11a starts the band additional allocation determination based on the Piggyback field value. Based on the transmission delay time difference information of the wireless communication terminals 2a-m on which the data transmission is performed, which is input from the transmission delay measurement unit 13, the determination unit 11a deteriorates the transmission delay time of the wireless communication terminals 2a-m. It is determined whether or not (step Sa1).

When the determination unit 11a determines that the transmission delay time difference information input from the transmission delay measurement unit 13 is less than a predetermined threshold (step Sa1-No), the transmission delay time of the wireless communication terminal 2a-m Is not degraded, no additional bandwidth allocation is performed. If the determination unit 11a determines that the transmission delay time difference information input from the transmission delay measurement unit 13 exceeds a predetermined threshold (step Sa1-Yes), the wireless communication terminal 2a-m This is the wireless communication terminal 2a-m whose time has deteriorated. The determination unit 11a determines whether or not the Piggyback field of the completed data transmission band allocation request signal is set (step Sa2). When the determination unit 11a determines that the Piggyback field has been set (step Sa2-Yes), the determination unit 11a assigns an uplink Cch that can make an additional bandwidth allocation request to the wireless communication terminal 2a-m. Is output to the bandwidth controller 15a (step Sa3). Further, when the determination unit 11a determines that the Piggyback field is not set (step Sa2-No), the determination unit 11a allocates an uplink Cch for performing an additional bandwidth allocation request to the wireless communication terminal 2a-m. Absent.
Through the above-described operation, the radio base station apparatus 1a allocates an uplink Cch for performing an additional band allocation request to the radio communication terminal 2a-m that has performed data transmission after data transmission is completed.

Next, a bandwidth allocation request step, which is an operation in which the radio communication terminal 2a-m transmits a bandwidth allocation request (RREQ: Resource Request) signal, will be described with reference to the flowchart of FIG.
When the transmission data is generated by the transmission data generation unit 25-m and output to the buffer unit 24-m, the wireless communication terminal 2a-m starts the transmission operation of the band allocation request signal. The buffer unit 24-m outputs information indicating that there is transmission data to the transmission control unit 22a-m. When the information is input from the buffer unit 24-m, the transmission control unit 22a-m transmits the bandwidth allocation request signal to the uplink Rch after the transmission standby time has elapsed. Num is set (step St1). The radio reception unit 21-m receives downlink Bch, Fch, and RFch via the antenna 26-m, and outputs the received information to the transmission control unit 22a-m (step St2).

  The transmission control unit 22a-m determines whether or not an uplink Cch is allocated based on the information input from the radio reception unit 21-m (step St3). When the transmission control unit 22a-m determines that an uplink Cch is allocated (step St3-Yes), the transmission control unit 22a-m indicates that the band allocation request signal is transmitted using the allocated Cch. Is transmitted to the wireless transmission unit 23-m, and the wireless transmission unit 23-m transmits a band allocation request signal using the allocated uplink Cch and terminates (step St6). At this time, if there is a plurality of transmission data in the buffer unit 24-m, the transmission control unit 22a-m sets the Piggyback field of the band allocation request signal.

When the transmission control unit 22a-m determines that the uplink Cch is not allocated (step St3-No), the transmission control unit 22a-m transmits the counter BO. Num is the number of slots in the random access section. It is determined whether it is larger than Num (step St4). The transmission control unit 22a-m receives the counter BO. Num is RA. When it is determined that the number is equal to or less than Num (step St4-No), the transmission control unit 22a-m sends the BO. Information indicating that the bandwidth allocation request is transmitted in the slot indicated by Num is output, and the radio transmission unit 23-m transmits the bandwidth allocation request signal on the uplink Rch and ends (step St7). In addition, the transmission control unit 22a-m performs BO. Num is RA. If it is determined that it is larger than Num (step St4-Yes), the transmission control unit 22a-m determines that the counter BO. Num to RA. Num is decreased, and the process returns to Step St2 (Step St5).
The radio communication terminals 2a-m repeat the above steps until the bandwidth allocation request signal is transmitted using the uplink Cch or the uplink Rch.
With the above operation, the wireless communication terminals 2a-m transmit a band allocation request signal.

Next, a sequence for transmitting information from the radio communication terminals 2a-m of the radio communication system 100a to the radio base station apparatus 1a will be described with reference to FIG. As a premise that the sequence of FIG. 8 is started, the wireless communication terminal 2a-m has two pieces of first and second transmission data to be transmitted, and the wireless communication terminal 2a-m has a wireless communication with a deteriorated transmission delay time. It is assumed that the terminal 2a-m.
In frame 1, the above-described bandwidth allocation request step is performed in order to transmit the first information in the radio communication terminal 2a-m, and the transmission control unit 22a-m of the radio communication terminal 2a-m receives an input from the buffer unit 24-m. In accordance with the received information, information indicating a bandwidth allocation request is output to the wireless transmission unit 23-m. As a result, the radio transmission unit 23-m of the radio communication terminal 2a-m transmits a band allocation request signal to the radio base station apparatus 1a using Rch. At this time, since there is the second transmission data in addition to the transmission data corresponding to the bandwidth allocation request signal, the transmission control unit 22a-m sets the Piggyback field, and the wireless transmission unit 23-m sets the Piggyback field. A band allocation request signal is transmitted to the radio base station apparatus 1a.

  In frame 2, the radio receiving unit 16a of the radio base station apparatus 1a receives the band allocation request signal of the radio communication terminal 2a-m, and outputs information indicating the band allocation request to the band control unit 15a. The bandwidth control unit 15a wirelessly transmits information indicating that the uplink Dch is allocated to the bandwidth allocation request signal of the wireless communication terminal 2a-m and information indicating the result of the bandwidth allocation request signal using the downlink RFch. To the unit 14. The wireless transmission unit 14 transmits the information to the wireless communication terminals 2a-m. As a result, the radio reception unit 21-m of the radio communication terminal 2a-m allows the link of the radio communication terminal 2a-m that has been allocated using the downlink Fch, the allocation start position of the uplink demand assignment section, and the allocation. Information on allocated bandwidth including channel type, allocated bandwidth, etc. is received. The wireless reception unit 21-m of the wireless communication terminal 2a-m outputs the received information to the transmission control unit 22a-m, and the transmission control unit 22a-m is based on the information input from the wireless reception unit 21-m. The instruction information for transmitting the transmission data held by the unit 24-m in the allocated band Dch is output to the wireless transmission unit 23-m. Based on the information input from the transmission control unit 22a-m, the radio transmission unit 23-m transmits transmission data to the radio base station apparatus 1a using the assigned uplink Dch.

In frame 3, upon receiving the first transmission data from the radio communication terminal 2a-m, the radio reception unit 16a of the radio base station apparatus 1a outputs information indicating that the transmission data has been received to the band control unit 15a. The bandwidth control unit 15a outputs information indicating that the transmission data arrival confirmation information is transmitted to the wireless communication terminal 2a-m to the wireless transmission unit 14, and the wireless transmission unit 14 transmits the wireless communication terminal 2a-m according to the information. The arrival confirmation information is transmitted on the downlink Cch.
The transmission confirmation unit 22a-m of the wireless communication terminal 2a-m receives the arrival confirmation information via the wireless reception unit 21-m, and completes transmission of the first transmission data.

When the transmission of the first transmission data is completed, the radio base station apparatus 1a performs the above-described additional band allocation step for the radio communication terminals 2a-m. As a result, the radio base station apparatus 1a determines to allocate the uplink Cch for the band allocation request signal to the radio communication terminals 2a-m.
In the frame N (N ≧ 4), the bandwidth control unit 15a of the radio base station apparatus 1a outputs information indicating Cch allocation to the radio transmission unit 14. The wireless transmission unit 14 transmits the band allocation information to the wireless communication terminals 2a-m using the downlink Fch. The transmission control unit 22a-m of the radio communication terminal 2a-m receives information indicating band allocation via the radio reception unit 21-m, and wirelessly transmits a band allocation request signal using the allocated uplink Cch. It transmits to the base station apparatus 1a.

  In the frame N + 1 (N ≧ 4), the bandwidth control unit 15a of the radio base station apparatus 1a receives the bandwidth allocation request signal using the uplink Cch via the radio reception unit 16a, and the bandwidth allocation request signal The arrival confirmation information and information indicating uplink Dch allocation are output to the wireless transmission unit 14. The wireless transmission unit 14 transmits the information input from the bandwidth control unit 15a to the wireless communication terminals 2a-m. The transmission control unit 22a-m of the wireless communication terminal 2a-m receives information indicating uplink Dch assignment via the wireless reception unit 21-m, and uses the assigned Dch to transmit second transmission data. Is transmitted to the wireless transmission unit 23-m. Based on the information input from the transmission control unit 22a-m, the radio transmission unit 23-m transmits the second transmission data to the radio base station apparatus 1a using the assigned uplink Dch. The wireless reception unit 16a of the wireless base station device 1a receives the second transmission data from the wireless communication terminals 2a-m.

In frame N + 2 (N ≧ 4), information indicating that transmission data has been received is output to band controller 15a. The bandwidth control unit 15a outputs information indicating that the transmission data arrival confirmation information is transmitted to the wireless communication terminal 2a-m to the wireless transmission unit 14, and the wireless transmission unit 14 transmits the information to the wireless communication terminal 2a-m according to the information. The arrival confirmation information is transmitted on the downlink Cch.
The transmission control unit 22a-m of the wireless communication terminal 2a-m receives the arrival confirmation information via the wireless reception unit 21-m, and the transmission of the second transmission data is completed.

  With the configuration of the first embodiment described above, a Piggyback field that is information indicating that the wireless communication terminal 2a-m holds other transmission data is added to the band allocation request signal in the uplink / random access section. As a result, the radio base station apparatus 1a gives the radio communication terminal 2a-m whose transmission delay time has deteriorated an opportunity to transmit a band allocation request signal, and causes the radio communication terminal 2a-m to perform data transmission. As a result, it is possible to shorten the transmission delay time of the wireless communication terminal 2a-m, prevent the deterioration of communication service quality, and maintain fairness.

  In the above-described embodiment, a method other than the Stop & Wait method may be used as the automatic retransmission request method. For example, the Selective Repeat method may be applied. In this case, since a bandwidth allocation request signal for a plurality of data channels can be transmitted, it is only necessary to provide a Piggyback field in the uplink Rch bandwidth allocation request signal. In the Stop & Wait method, data is transmitted while confirming arrival of data one by one, whereas in the Selective Repeat method, a plurality of data channels are requested by one band allocation request signal using Rch. For this reason, it is sufficient to provide the Rch band allocation request signal with the Piggyback field to prevent deterioration of the transmission delay time. Here, the Selective Repeat method is a data transmission method in which, after transmitting a plurality of data, the receiver side requests to retransmit only information that could not be received correctly.

(Second Embodiment)
FIG. 9 is a schematic block diagram illustrating a schematic configuration of the wireless communication system 100b according to the second embodiment and an internal configuration of a part related to band allocation of the wireless base station device 1b.
The wireless communication system 100b includes a wireless base station device 1b, a wireless communication terminal 2a-1, a wireless communication terminal 2a-2, a wireless communication terminal 2a-3, ..., a wireless communication terminal 2a-n. Here, any one of the wireless communication terminal 2a-1, the wireless communication terminal 2a-2, the wireless communication terminal 2a-3,..., The wireless communication terminal 2a-n is connected to the wireless communication terminal 2a-m (m = 1, 2). , 3, ..., n). The wireless communication terminal 2a-1, the wireless communication terminal 2a-2, the wireless communication terminal 2a-3, ..., the wireless communication terminal 2a-n have the same configuration, and will be described below using the wireless communication terminal 2a-m. .

The radio base station apparatus 1b includes a determination unit 11b, a frame counter unit 12, a transmission delay measurement unit 13, a radio transmission unit 14, a band control unit 15b, a radio reception unit 16b, an antenna 17, a polling unit 18b, and a radio communication terminal information storage unit. 19b.
The frame counter unit 12, the transmission delay measurement unit 13, the wireless transmission unit 14, the antenna 17, and the wireless communication terminals 2a-m (m = 1, 2, 3,..., N) have the same configuration as in the first embodiment. The same reference numerals are given, and different configurations will be described below.
The determination unit 11b receives the transmission delay time difference information of the wireless communication terminals 2a-m that have completed transmission of transmission data from the transmission delay measurement unit 13. In addition, the determination unit 11b receives the value of the Piggyback field of the bandwidth allocation request signal received by the uplink Cch input from the radio reception unit 16b. Further, the determination unit 11b transmits the band allocation request signal to the wireless communication terminal 2a-m that has transmitted the band allocation request signal based on the input transmission delay time difference information and the value of the Piggyback field of the band allocation request signal. It is determined whether uplink Cch is allocated. If the determination unit 11b determines to allocate an uplink Cch, the determination unit 11b outputs a request to allocate an uplink Cch to the wireless communication terminal 2a-m to the bandwidth control unit 15b.
The bandwidth control unit 15b receives a Dch bandwidth allocation request from each wireless communication terminal 2a-m from the wireless reception unit 16b, and receives an uplink Cch allocation request from the determination unit 11b and the polling unit 18b to the wireless communication terminal 2a-m. Is entered. Further, the bandwidth control unit 15 b generates bandwidth allocation information based on the input Cch allocation request and outputs the bandwidth allocation information to the wireless transmission unit 14.

The radio reception unit 16b receives a band allocation request signal and transmission data from each radio communication terminal 2a-m via the antenna 17 according to the format of the MAC frame. Further, the wireless reception unit 16b outputs the bandwidth allocation request information through the uplink Cch and Rch from each wireless communication terminal 2a-m to the bandwidth control unit 15b and the determination unit 11b. Further, the radio reception unit 16b outputs frame counter information when transmission data is included in transmission data included in the uplink Dch transmitted from each radio communication terminal 2a-m to the transmission delay measurement unit 13. In addition, the wireless reception unit 16b outputs information indicating the completion of data transmission to the determination unit 11b.
The polling unit 18b reads the transmission delay time information of the wireless communication terminals 2a-m from the wireless communication terminal information storage unit 19b. In addition, the polling unit 18b transmits information indicating that an uplink Cch for allocating a bandwidth allocation request signal to the wireless communication terminals 2a-m is allocated to the bandwidth control unit 15b in accordance with the set polling timing. Output.
The wireless communication terminal information storage unit 19b stores transmission delay time information and polling timing of each wireless communication terminal 2a-m.

  As in the first embodiment, the second embodiment has a bandwidth request using a random access channel and a bandwidth request using a piggyback field, and the radio base station apparatus 1b performs radio transmission at a timing based on transmission delay time information. Polling that gives the communication terminals 2a-m (m = 1, 2, 3,..., N) an opportunity to make a bandwidth request is performed. In this way, the transmission delay time is shortened by increasing the opportunities to transmit the transmission data of the wireless communication terminals 2a-m whose transmission delay time is deteriorated, the communication service quality is prevented from being lowered, and the fairness of the communication service quality is maintained. To do.

  Also, unlike the first embodiment, the Piggyback field is provided only for the band allocation request signal using the upstream Cch. This change is to give the wireless terminal 2a-m an opportunity for an additional bandwidth allocation request by polling without performing an additional bandwidth allocation request using the additional bandwidth allocation request signal via the Rch. Thereby, it is possible to avoid that the transmission data transmission opportunities are extremely biased to the wireless communication terminals 2a-m whose transmission delay time has deteriorated.

Next, an additional allocation polling timing update step, which is an operation in which the radio base station apparatus 1b performs additional allocation of a band to a radio communication terminal whose transmission delay time has deteriorated, will be described with reference to the flowchart of FIG.
When data transmission from the wireless communication terminals 2a-m to the wireless base station device 1b is completed, the wireless reception unit 16b outputs information indicating the completion of data transmission to the determination unit 11b. The determination unit 11b starts determining whether or not to perform additional bandwidth allocation. The determination unit 11b uses the transmission delay time difference information of the wireless communication terminal 2a-m that has performed the data transmission from the transmission delay measurement unit 13, and determines whether or not the transmission delay time of the wireless communication terminal 2a-m has deteriorated. Is determined (step Sb1). When it is determined that the input transmission delay time difference information exceeds a predetermined threshold (step Sb1-Yes), the transmission delay time of the wireless communication terminal 2a-m has deteriorated, and the determination unit 11b is completed. It is determined whether or not the Piggyback field of the data transmission band allocation request signal has been set (step Sb2). If the transmission delay time difference information is less than a predetermined threshold, the transmission delay time of the wireless communication terminal 2a-m has not deteriorated, and the determination unit 11b determines that no additional band allocation is performed and ends. (Step Sb1-No).

  In the data transmission immediately before the wireless communication terminal 2a-m, when the Piggyback field is set (step Sb2-Yes), the determination unit 11b can make an uplink request for additional bandwidth allocation to the wireless communication terminal 2a-m. The information indicating that the Cch is assigned is output to the bandwidth control unit 15b (step Sb3). When the piggyback field is not set (step Sb2-No), the determination unit 11b does not perform uplink Cch allocation for requesting additional bandwidth allocation to the wireless communication terminal 2a-m, but sets the polling timing. To do.

Next, the determination unit 11b outputs, to the polling unit 18b, information indicating an update of timing for performing polling for assigning an uplink Cch that can transmit an additional band allocation request signal to the wireless communication terminal 2a-m. The polling unit 18b transmits the polling timing information and transmission delay time information of the wireless communication terminal 2a-m stored in the wireless communication terminal information storage unit 19b, and the transmission delay time of the wireless communication terminal 2a-m that has not deteriorated the transmission delay time. Read information. Further, the polling unit 18b calculates polling timing correction information based on the read transmission delay time information, and updates the polling timing information of the wireless communication terminal 2a-m using the calculated correction information. The polling unit 18b records the updated polling timing information in the wireless communication terminal information storage unit 19b (step Sb4). In addition, the polling unit 18b uses the updated polling timing information to start a timing generation operation for polling the wireless communication terminal 2a-m (step Sb5).
The new polling timing is changed, for example, so that the transmission delay time of the wireless communication terminal 2a-m whose transmission delay time has deteriorated approaches the transmission delay time of the wireless communication terminal 2a-m whose transmission delay time has not deteriorated. Do. The timing is generated because, for example, the polling unit 18b includes a timer, and when the timer expires, the polling unit 18b transmits an additional bandwidth allocation request signal to the wireless communication terminal 2a-m to the bandwidth control unit 15a. There is a method of outputting information indicating that an uplink Cch is allocated.
The above-described operation is an operation for performing additional band allocation to the radio communication terminal 2a-m performed when transmission of transmission data from the radio communication terminal 2a-m to the radio base station apparatus 1b is completed.

  Next, a sequence for transmitting information from the radio communication terminals 2a-m, which have been given an opportunity to transmit a band allocation request signal by polling, to the radio base station apparatus 1b in the radio communication system 100b will be described with reference to FIG. As a premise that the sequence of FIG. 11 is started, the wireless communication terminal 2a-m has two pieces of first and second information to be transmitted, and the transmission delay time of the wireless communication terminal 2a-m is deteriorated. To do.

  In frame 1, the polling unit 18b of the radio base station apparatus 1b outputs information indicating that an uplink Cch is allocated to the bandwidth control unit 15b according to the polling timing. The bandwidth control unit 15b transmits, via the wireless transmission unit 14, information indicating that the uplink Cch input from the polling unit 18b is allocated to the wireless communication terminals 2a-m using the downlink Fch. The transmission control unit 22a-m of the wireless communication terminal 2a-m receives information indicating the allocation of the uplink Cch with the downlink Fch via the radio reception unit 21-m. Based on the input Cch allocation information, the transmission control unit 22a-m outputs information indicating transmission of a band allocation request signal in which the Piggyback field is set to the radio transmission unit 23-m. Based on the information input from the transmission control unit 22a-m, the radio transmission unit 23-m transmits a band allocation request signal to the radio base station apparatus 1b using the allocated Cch.

  In frame 2, the bandwidth control request 15b from the wireless communication terminal 2a-m is input to the bandwidth controller 15b of the wireless base station device 1b via the wireless receiver 16b. The band control unit 15b outputs the band allocation request signal arrival confirmation information and information for allocating the uplink Dch to the radio communication terminals 2a-m to the radio transmission unit 14. Based on the information input from the bandwidth control unit 15b, the wireless transmission unit 14 transmits the arrival confirmation information and information indicating that the uplink Dch is allocated to the wireless communication terminal 2a-m using the downlink Fch. The transmission control unit 22a-m of the wireless communication terminal 2a-m receives the arrival confirmation information and the uplink Dch assignment information via the wireless reception unit 21-m, and 1 is assigned to the assigned uplink Dch. The information which shows transmitting the 1st transmission data to the wireless base station apparatus 1b is output to the wireless transmission part 23-m. Based on the information input from the transmission control unit 22a-m, the wireless transmission unit 23-m transmits the first transmission data to the wireless base station device 1b using the uplink Dch.

In frame 3, the bandwidth control unit 15b of the radio base station apparatus 1b assigns the first transmission data arrival confirmation information received from the radio communication terminals 2a-m and the downlink Cch for transmitting the arrival confirmation information. Information to be output to the wireless transmission unit 14. The wireless transmission unit 14 transmits information indicating the Cch assignment to which the arrival confirmation information is transmitted to the wireless communication terminals 2a-m using the downlink Fch. Further, the wireless transmission unit 14 transmits the arrival confirmation information to the wireless communication terminals 2a-m using the downlink Cch. The transmission control unit 22a-m of the wireless communication terminal 2a-m receives the arrival confirmation information on the downlink Cch via the wireless reception unit 21-m. Thus, transmission of the first transmission data is completed.
Also, the determination unit 11b of the radio base station apparatus 1b performs the above-described additional allocation polling timing update step upon completion of data transmission of the first transmission data, and allocates an additional band to the radio communication terminals 2a-m. It is determined that the uplink Cch to be assigned is allocated.

  In frame N (N ≧ 4), the bandwidth control unit 15b of the radio base station apparatus 1b wirelessly transmits information indicating that an uplink Cch is allocated to the radio communication terminals 2a-m based on the determination of the determination unit 11b. To the unit 14. Based on the information input from the bandwidth control unit 15b, the wireless transmission unit 14 transmits information indicating that an uplink Cch is allocated to the wireless communication terminal 2a-m to the wireless communication device 2a-m. Information indicating uplink Cch allocation is input to the transmission control unit 22a-m of the wireless communication terminal 2a-m via the wireless reception unit 21-m. The transmission control unit 22a-m transmits the bandwidth allocation request signal via the uplink Cch allocated to the radio base station apparatus 1b via the radio transmission unit 23-m. At this time, since there is no transmission data other than the transmission data corresponding to the band allocation request signal in the radio communication terminal 2a-m, the radio communication terminal 2a-m does not set the Piggyback field of the band allocation request signal.

  In the frame N + 1 (N ≧ 4), the bandwidth control unit 15b of the radio base station device 1b allocates the arrival confirmation information of the input bandwidth allocation request signal and the uplink Dch via the radio reception unit 16b. The indicated information is output to the wireless transmission unit 14. The wireless transmission unit 14 transmits the information input from the bandwidth control unit 15b to the wireless communication terminals 2a-m using downlink Fch. The transmission control unit 22a-m of the wireless communication terminal 2a-m receives information indicating uplink Dch assignment via the wireless reception unit 21-m. The transmission control unit 22a-m outputs information indicating an instruction to transmit the second transmission data to the wireless transmission unit 23-m using the assigned Dch. The radio transmission unit 23-m transmits the second transmission data to the radio base station apparatus 1b using the assigned Dch. The wireless reception unit 16b of the wireless base station device 1b receives the second transmission data from the wireless communication terminals 2a-m.

In frame N + 2 (N ≧ 4), information indicating that transmission data has been received is output to band controller 15b. The bandwidth control unit 15b outputs information indicating that the transmission data arrival confirmation information is transmitted to the wireless communication terminal 2a-m to the wireless transmission unit 14, and the wireless transmission unit 14 transmits the wireless communication terminal 2a- according to the input information. The arrival confirmation information is transmitted to m.
The transmission control unit 22a-m of the wireless communication terminal 2a-m receives the arrival confirmation information via the wireless reception unit 21-m, and the transmission of the second transmission data is completed.
Further, the radio base station apparatus 1b performs the additional allocation polling timing update step shown in FIG. 10 with the completion of the data transmission.

As described above, with the configuration of the second embodiment described above, not only the bandwidth allocation request signal is transmitted in the uplink / random access period, but also the radio base station apparatus 1b has the radio communication terminal 2a- whose transmission delay time has deteriorated. The transmission delay of the wireless communication terminal 2a-m whose transmission delay time has deteriorated by giving the opportunity to transmit the band allocation request signal to m in the uplink demand assignment section and causing the wireless communication terminal 2a-m to perform data transmission Time can be shortened, deterioration of communication service quality can be prevented, and fairness can be maintained.
Note that a method other than the Stop & Wait method may be used as the automatic retransmission request method. For example, when the Selective Repeat method is used, a plurality of data channels can be requested for transmission data with a single bandwidth allocation request signal. Therefore, transmission delay time can be deteriorated only by providing a Piggyback field in the uplink Rch bandwidth allocation request signal. Enough to prevent.

(Third embodiment)
FIG. 12 is a schematic block diagram illustrating a schematic configuration of the wireless communication system 100c according to the third embodiment and an internal configuration of a part related to band allocation of the wireless base station device 1c.
The wireless communication system 100c includes a wireless base station device 1c, a wireless communication terminal 2c-1, a wireless communication terminal 2c-2, a wireless communication terminal 2c-3, ..., a wireless communication terminal 2c-n. Here, any one of the wireless communication terminal 2c-1, the wireless communication terminal 2c-2, the wireless communication terminal 2c-3, ..., the wireless communication terminal 2c-n is connected to the wireless communication terminal 2a-m (m = 1, 2). , 3, ..., n). The wireless communication terminal 2c-1, the wireless communication terminal 2c-2, the wireless communication terminal 2c-3, ..., the wireless communication terminal 2c-n have the same configuration, and will be described below using the wireless communication terminal 2c-m. .

The radio base station apparatus 1c includes a frame counter unit 12, a transmission delay measurement unit 13, a radio transmission unit 14, a band control unit 15c, a radio reception unit 16c, an antenna 17, a polling unit 18c, and a radio communication terminal information storage unit 19c. Note that the frame counter unit 12, the transmission delay measurement unit 13, the wireless transmission unit 14, and the antenna 17 have the same configurations as those in the first embodiment and are denoted by the same reference numerals, and different configurations will be described below.
The bandwidth control unit 15c receives a bandwidth allocation request for each wireless communication terminal 2c-m from the wireless reception unit 16c, and receives information indicating bandwidth allocation for allocating an uplink Cch from the polling unit 18c to the wireless communication terminal 2c-m. Is done. Further, the bandwidth control unit 15 c generates bandwidth allocation information based on the input bandwidth allocation and outputs it to the wireless transmission unit 14.
The radio reception unit 16c receives the band allocation request signal and the transmission data from each radio communication terminal 2a-m via the antenna 17 according to the format of the MAC frame. Further, the wireless reception unit 16c outputs the bandwidth allocation request information through the uplink Cch and Rch from each wireless communication terminal 2c-m to the bandwidth control unit 15c. Further, the radio reception unit 16c outputs frame counter information to the transmission delay measurement unit 13 when transmission data included in transmission data included in the uplink Dch transmitted from each radio communication terminal 2c-m is generated. To do.

The polling unit 18c receives information indicating completion of data transmission from the wireless reception unit 16c. The polling unit 18c receives the transmission delay time difference information of the wireless communication terminal 2c-m that has completed data transmission from the transmission delay measurement unit 13. Also, the polling unit 18c reads out the transmission delay time information of the wireless communication terminal 2c-m and the number of data transfers performed during a predetermined period from the wireless communication terminal information storage unit 19c. Also, the polling unit 18c outputs information indicating that an uplink Cch for transmitting a band allocation request signal to the radio communication terminal 2c-m is allocated to the band control unit 15c according to the set polling timing. .
The wireless communication terminal information storage unit 19c stores transmission delay time information performed at the end of each wireless communication terminal 2c-m, the number of times of data transmission performed in the past fixed period, and polling timing.

FIG. 13 is a schematic block diagram showing an internal configuration of a part related to a bandwidth allocation request of the radio communication terminal 2c-m. The wireless communication terminal 2c-m includes a wireless reception unit 21-m, a transmission control unit 22c-m, a wireless transmission unit 23-m, a buffer unit 24-m, and a transmission data generation unit 25-m.
The radio reception unit 21-m, the transmission control unit 22c-m, the radio transmission unit 23-m, the buffer unit 24-m, and the transmission data generation unit 25-m are the same as those in the first embodiment and the second embodiment. The same reference numerals are given, and different configurations will be described below.
The transmission control unit 22c-m receives information indicating bandwidth allocation and transmission data arrival confirmation information from the radio reception unit 21-m. Also, the transmission control unit 22a-m transmits the bandwidth allocation request signal on the uplink Rch, and when another radio communication terminal 2a-m also transmits the bandwidth allocation request signal and a signal collision occurs, the transmission waiting time After the elapse of time, the band allocation request signal is transmitted again. In addition, the transmission control unit 22a-m receives information indicating whether or not there is information to be transmitted stored in the buffer unit 24-m from the buffer unit 24-m. The transmission control unit 22a-m outputs information indicating a bandwidth allocation request to the wireless transmission unit 23-m based on the information input from the buffer unit 24-m or the wireless reception unit 21-m.

  The radio base station apparatus 1c according to the third embodiment includes a radio communication terminal 2c-m (m = 1, 2, 3,..., N) whose transmission delay time has deteriorated at a timing based on the transmission delay time and the number of transmission data occurrences. Polling that gives the opportunity to transmit a bandwidth allocation request signal. The radio communication terminal 2c-m can not only transmit the bandwidth allocation request signal through the uplink Rch, but can also transmit the bandwidth allocation request signal through the uplink Cch given by polling, so that the bandwidth can be allocated. Increase the transmission delay time and prevent deterioration of communication service quality. Further, unlike the second embodiment, the piggyback field is not provided in the band allocation request signal, and the polling timing is set based on the transmission delay time of each wireless communication terminal 2c-m and the number of occurrences of data transmission.

Next, a polling timing update step, which is an operation of updating the polling timing performed by the radio base station apparatus 1c and performing additional allocation of a band to the radio communication terminal 2c-m having a deteriorated transmission delay time, will be described with reference to the flowchart of FIG. To do.
When data transmission from the wireless communication terminal 2c-m to the wireless base station device 1c is completed, the wireless reception unit 16c outputs information indicating the completion of data transmission to the polling unit 18c. The polling unit 18c reads the transmission delay time difference information of the wireless communication terminal 2c-m that has performed the data transmission from the wireless communication terminal information storage unit 19c. Further, the polling unit 18c determines whether or not the transmission delay time of the wireless communication terminal 2c-m that has performed the data transmission has deteriorated (step Sc1). When the polling unit 18c determines that the transmission delay time difference information of the wireless communication terminal 2c-m exceeds a predetermined threshold (step Sc1-Yes), the polling unit 18c adjusts the polling timing (step Sc2). . When the polling unit 18c determines that the transmission delay time difference information of the wireless communication terminal 2c-m is less than a predetermined threshold value (step Sc1-No), the transmission delay time of the wireless communication terminal 2c-m deteriorates. Therefore, the process is terminated without setting polling for allocating uplink Cch for performing additional bandwidth allocation.

The polling unit 18c transmits the polling timing information of the terminal from the wireless communication terminal information storage unit 19c, the number of data transmissions performed in the past certain period, and the transmission delay time of the wireless communication terminal 2c-m that has not deteriorated the transmission delay time. Reads information and the number of data transmissions performed in a certain period in the past. The polling unit 18c calculates polling timing correction information based on the read transmission delay time information, and updates the new polling timing information of the wireless communication terminal 2c-m using the calculated correction information. The polling unit 18c records the updated polling timing information in the wireless communication terminal information storage unit 19c. In addition, the polling unit 18c uses the updated polling timing information to start a timing generation operation for polling the wireless communication terminal 2c-m (step Sc3).
The new polling timing is performed using the calculated correction information. For example, when the number of data transmissions of the wireless communication terminal 2c-m is N times greater than the number of data transmissions of the wireless communication terminal 2c-m whose transmission delay time has not deteriorated, the new polling timing is deteriorated in the transmission delay time. The wireless communication terminal 2c-m that has not been changed is changed so as to approach 1 / N of the transmission delay time. Further, for timing generation, for example, the polling unit 18c includes a timer, and when the timer expires, the polling unit 18c allocates an uplink Cch for transmitting an additional bandwidth allocation request signal to the wireless communication terminal 2c-m. There is a method of outputting information indicating this to the bandwidth control unit 15c.

Next, a sequence in the wireless communication system 100c for transmitting information from the wireless communication terminal 2c-m with a deteriorated transmission delay time given a bandwidth request opportunity by polling to the wireless base station device 1c will be described with reference to FIG.
In frame 1, the polling unit 18c of the radio base station apparatus 1c outputs information indicating that an uplink Cch is allocated to the bandwidth control unit 15c according to the polling timing. The bandwidth control unit 15c transmits the uplink Cch assignment information input from the polling unit 18c to the wireless communication terminal 2c-m using the downlink Fch via the wireless transmission unit 14. The transmission control unit 22c-m of the wireless communication terminal 2c-m receives information indicating the allocation of the uplink Cch with the downlink Fch via the wireless reception unit 21-m. The transmission control unit 22c-m outputs information indicating that the bandwidth request signal is transmitted using the assigned uplink Cch to the wireless transmission unit 23-m. Based on the information input from the transmission control unit 22c-m, the radio transmission unit 23-m transmits a band allocation request signal to the radio base station device 1c using the allocated Cch.

  In the frame 2, the bandwidth control request signal from the wireless communication terminal 2c-m is input to the bandwidth control unit 15c of the wireless base station device 1c via the wireless reception unit 16c. The bandwidth control unit 15c transmits, to the wireless transmission unit 14, the arrival confirmation information of the bandwidth allocation request signal, information indicating allocation of the downlink Cch that transmits the arrival confirmation information, and information indicating allocation of the uplink Dch. Output. Based on the information input from the bandwidth control unit 15c, the wireless transmission unit 14 transmits arrival confirmation information and information indicating that an uplink Dch is allocated to the wireless communication terminal 2c-m. The transmission control unit 22c-m of the radio communication terminal 2c-m receives the arrival confirmation information and the uplink Dch allocation information via the radio reception unit 21-m, and transmits the transmission data to the radio base station according to the allocation information. Information indicating transmission to the station apparatus 1c is output to the wireless transmission unit 23-m. Based on the information input from the transmission control unit 22c-m, the radio transmission unit 23-m transmits transmission data to the radio base station apparatus 1c using the uplink Dch.

In frame 3, the bandwidth control unit 15c of the radio base station apparatus 1c transmits information indicating that the downlink Cch for transmitting the arrival confirmation information of the transmission data received from the radio communication terminal 2c-m is allocated to the radio transmission unit 14. Output. The wireless transmission unit 14 transmits information indicating the Cch assignment to which the arrival confirmation information is transmitted to the wireless transmission terminal 2c-m using the downlink Fch. In addition, the wireless transmission unit 14 transmits the arrival confirmation information to the wireless communication terminal 2c-m via the downlink Cch. The transmission control unit 22c-m of the wireless communication terminal 2c-m receives the arrival confirmation information on the downlink Cch based on the downlink Fch information via the wireless reception unit 21-m.
This completes the transmission of information from the wireless communication terminal 2c-m to the wireless base station device 1c. The radio base station apparatus 1c performs the above-described polling timing update step for the radio communication terminal 2c-m that has performed the data transmission upon completion of the data transmission.

  According to the wireless communication system 100c of the third embodiment described above, polling is performed on the wireless communication terminal 2c-m having a deteriorated transmission delay time, and the opportunity to perform data transmission to the wireless communication terminal 2c-m is increased. It is possible to shorten the transmission delay time of the wireless communication terminal 2c-m and prevent the deterioration of communication service quality.

In the first embodiment and the second embodiment, when determining a wireless communication terminal having a deteriorated transmission delay time, the transmission delay time difference is measured for each wireless communication terminal 2a-m. The wireless communication terminals 2a-m may be divided into a plurality of groups, and statistical processing may be performed on a group basis to measure the transmission delay time difference. Moreover, you may measure the transmission delay time difference between a group and each radio | wireless communication terminal 2a-m, or between groups.
In the third embodiment, when determining a wireless communication terminal having a deteriorated transmission delay time, the transmission delay time difference is measured for each wireless communication terminal 2c-m. However, the wireless communication terminal 2c- m may be divided into a plurality of groups, and statistical processing may be performed on a group basis to measure the transmission delay time difference. Moreover, you may measure the transmission delay time difference between a group and each radio | wireless communication terminal 2c-m, or between groups.

  The above-described radio base station apparatus and radio communication terminal have a computer system inside. Then, the uplink Cch allocation for transmitting the band allocation request signal to the radio communication terminal performed by the radio base station apparatus and the transmission process of the band allocation request signal performed by the radio communication terminal are in the form of a program. It is stored in a computer-readable recording medium, and the above processing is performed by the computer reading and executing this program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

1 is a schematic diagram of a wireless communication system 100. FIG. It is a figure which shows the frame structure used with the MAC protocol of embodiment. It is a sequence diagram which shows a communication procedure. It is the schematic of the radio | wireless communications system 100a of 1st Embodiment, and the schematic block diagram which shows the internal structure of the part regarding the band control of the radio base station apparatus 1a. It is a schematic block diagram which shows the internal structure of the part regarding the band allocation request | requirement of radio | wireless communication terminal 2a-m of embodiment. 6 is a flowchart showing an uplink Cch allocation operation for the radio base station apparatus 1a of the first embodiment to transmit an additional band allocation request signal to a radio communication terminal whose transmission delay time has deteriorated. It is a flowchart which shows the operation | movement which the radio | wireless communication terminal 2a-m of embodiment transmits a band allocation request signal. It is a sequence diagram which shows the operation | movement which transmits transmission data from the radio | wireless communication terminal 2a-m of 1st Embodiment to the radio base station apparatus 1a. It is the schematic of the radio | wireless communications system 100b of 2nd Embodiment, and the schematic block diagram which shows the internal structure of the part regarding the band control of the radio base station apparatus 1b. It is a flowchart which shows the operation | movement of allocation of the uplink Cch for the radio base station apparatus 1b of 2nd Embodiment to transmit an additional band allocation request signal to the radio | wireless communication terminal with which transmission delay time deteriorated. It is a sequence diagram which shows the operation | movement which transmits transmission data from the radio | wireless communication terminal 2a-m of 2nd Embodiment to the radio base station apparatus 1b. It is the schematic of the radio | wireless communications system 100c of 3rd Embodiment, and the schematic block diagram which shows the internal structure of the part regarding the band control of the radio base station apparatus 1c. It is a schematic block diagram which shows the internal structure of the part regarding the band allocation request | requirement of the radio | wireless communication terminal 2c-m of embodiment. It is a flowchart which shows the operation | movement of allocation of the uplink Cch for the radio base station apparatus 1c of 3rd Embodiment to transmit an additional band allocation request signal to the radio | wireless communication terminal in which transmission delay time deteriorated. It is a sequence diagram which shows the operation | movement which transmits transmission data from the radio | wireless communication terminal 2c-m of 3rd Embodiment to the radio base station apparatus 1c.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio base station apparatus 1a Radio base station apparatus 1b Radio base station apparatus 1c Radio base station apparatus 2-m Radio communication terminal 2a-m Radio communication terminal 2c-m Radio communication terminal 11a Judgment part 11b Judgment part 12 Frame counter part 13 Transmission Delay measurement unit 14 Wireless transmission unit 15a Band control unit 15b Band control unit 15c Band control unit 16a Wireless reception unit 16b Wireless reception unit 16c Wireless reception unit 17 Antenna 18b Polling unit 18c Polling unit 19a Wireless communication terminal information storage unit 19b Wireless communication terminal Information storage unit 19c Wireless communication terminal information storage unit 21-m Wireless reception unit 22a-m Transmission control unit 22c-m Transmission control unit 23-m Wireless transmission unit 24-m Buffer unit 25-m Transmission data generation unit 26-m Antenna 100 wireless communication system 100a wireless communication system 100b Wireless communication system 100c Wireless communication system

Claims (10)

A plurality of radio communication terminals, a radio base station device, a radio channel connecting the radio communication terminal and the radio base station device, the radio channel comprising a plurality of frames, and the frame from the radio base station device to the radio It is divided into a downlink for transmitting information to a communication terminal and an uplink for transmitting information from the radio communication terminal to the radio base station apparatus, and the uplink is assigned from the radio base station apparatus by the radio communication terminal. In a wireless communication system that is divided into a demand assignment section in which a signal is transmitted and a random access section in which a bandwidth allocation request signal is transmitted without the wireless communication terminal being allocated from the wireless base station,
The wireless base station device
Measures a transmission delay time that is a time required from the generation of the transmission data for each wireless communication terminal to transmission to the wireless base station, and the wireless communication terminal and the other wireless communication for each wireless communication terminal A transmission delay measuring unit that calculates a transmission delay time difference that is a difference between the transmission delay times with a communication terminal;
A determination unit that determines whether or not a transmission delay time difference between the wireless communication terminals is equal to or greater than a predetermined value;
A bandwidth control unit that allocates the uplink demand assignment section control channel to the wireless communication terminal that has been determined based on the determination result of the determination unit;
A wireless transmission unit for notifying the wireless terminal that the uplink demand assignment section control channel has been allocated to the wireless communication terminal;
The wireless communication terminal is
Transmitting the bandwidth allocation request signal to the radio base station apparatus using the uplink demand assignment section control channel allocated to the bandwidth controller;
A wireless communication system. In the wireless communication system,
The wireless communication terminal further includes:
The band allocation request signal including information indicating that a plurality of transmission data is held is transmitted using the uplink random access section control channel and the uplink demand assignment section control channel,
The determination unit further includes:
Determining to allocate the uplink demand assignment section control channel using information indicating whether or not the transmission data included in the band allocation request signal transmitted by the wireless communication terminal is held.
The wireless communication system according to claim 1. In the wireless communication system,
The radio base station device further includes:
When the transmission delay time difference between the wireless communication terminals is equal to or greater than a predetermined value, the uplink demand assignment section control channel for transmitting the bandwidth allocation request signal is transmitted to the wireless communication terminal in the first period. A polling unit for determining whether to allocate,
The bandwidth control unit further includes:
Allocating the uplink demand assignment section control channel for transmitting the bandwidth allocation request signal to the wireless communication terminal that is the target of determination based on the determination result of the polling unit,
The wireless communication system according to claim 1, wherein the wireless communication system is a wireless communication system. In the wireless communication system,
The polling unit further includes:
The first period is determined based on a transmission delay time of the wireless communication terminal and a transmission delay time difference between the wireless communication terminals,
The wireless communication system according to claim 3. In the wireless communication system,
The polling unit further includes:
The first period is determined based on a transmission delay time of the wireless communication terminal and a transmission data generation frequency of the wireless communication terminal.
The wireless communication system according to claim 3. A plurality of radio communication terminals, a radio base station device, a radio channel connecting the radio communication terminal and the radio base station device, the radio channel comprising a plurality of frames, and the frame from the radio base station device to the radio It is divided into a downlink for transmitting information to a communication terminal and an uplink for transmitting information from the radio communication terminal to the radio base station apparatus, and the uplink is assigned from the radio base station apparatus by the radio communication terminal. In a wireless communication method in a wireless communication system, a demand assignment section in which a signal is transmitted and a random access section in which a bandwidth allocation request signal is transmitted without the wireless communication terminal being assigned from the wireless base station,
The radio base station apparatus measures a transmission delay time, which is a time required from the generation of the transmission data for each radio communication terminal to the transmission to the radio base station, and the radio base station apparatus Calculating a transmission delay time difference that is a difference in the transmission delay time between the communication terminal and the other wireless communication terminal;
The wireless base station device determining whether or not a transmission delay time difference between the wireless communication terminals is a predetermined value or more;
The radio base station apparatus assigning the uplink demand assignment section control channel to the radio communication terminal to be determined based on a determination result of the determination unit;
Notifying the radio terminal that the radio base station apparatus has allocated the uplink demand assignment section control channel to the radio communication terminal;
The wireless communication terminal transmits the bandwidth allocation request signal to the wireless base station device using the uplink demand assignment section control channel allocated to the bandwidth controller;
A wireless communication method comprising: In the wireless communication system,
The bandwidth allocation request signal including information indicating that the wireless communication terminal holds a plurality of transmission data, the uplink random access section control channel and the uplink demand assignment section control channel. Using and transmitting,
Using the information indicating whether the radio base station apparatus holds a plurality of the transmission data included in the band allocation request signal transmitted by the radio communication terminal, the uplink demand assignment section control channel is set. Determining to assign;
The wireless communication method according to claim 6, further comprising: In the wireless communication system,
When the radio base station apparatus has a transmission delay time difference of the radio communication terminal equal to or greater than a predetermined value, the uplink demand assignment section control channel for transmitting the band allocation request signal is transmitted to the radio communication terminal. Determining whether to assign to a terminal in a first period;
The wireless base station device assigning the uplink demand assignment section control channel for transmitting the bandwidth assignment request signal to the wireless communication terminal determined by the determination result of the polling unit;
The wireless communication method according to claim 6 or 7, characterized by comprising: In the wireless communication system,
The radio base station apparatus determines the first period based on a transmission delay time of the radio communication terminal and a transmission delay time difference between the radio communication terminals;
The wireless communication method according to claim 8, further comprising: In the wireless communication system,
The radio base station apparatus determines the first period based on a transmission delay time of the radio communication terminal and a transmission data generation frequency of the radio communication terminal;
The wireless communication method according to claim 8, further comprising:

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