JP2008271119A - Band assignment method and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a band assignment method which guarantees a request QoS and improves band use efficiency. <P>SOLUTION: The band assignment method includes a step in which terminal stations 8-1 to 8-3 monitor terminal remaining amounts that are storage amounts of transmission data, and transmit the terminal remaining amounts, a QoS type that indicates a band guarantee request, the QoS information of the transmission data included with communication time interval information that indicates a request related to a communication time interval and a transmission rate to a base station 1. In addition, the base assignment method also includes a step in which the base station 1 allocates an upload band to the terminal stations 8-1 to 8-3 based on the QoS information and the terminal remaining amounts, and notifies the terminal stations 8-1 to 8-3 of the assignment results. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bandwidth allocation method and a communication system when performing QoS (Quality of Service) control.

  Conventionally, in a QoS control technique in a wireless communication system in which a base station assigns communication time to a plurality of terminal stations, for example, as disclosed in Patent Document 1 below, communication time is assigned based on a QoS type. It was. In the technology of Patent Document 1 below, the base station communicates with the terminal station according to the data communication status (CBR: Constant Bit Rate, VBR: Variable Bit Rate, ABR (Available Bit Rate, UBR: Unspecified Bit Rate)). The bandwidth is allocated by scheduling according to the situation.

JP 2001-223716 A

  However, according to the above conventional technique, since the amount of residual (residual) data for each terminal station is not taken into consideration, for example, a communication type such as UBR where the data transmission rate is indefinite and the data generation cycle is indefinite. When a terminal station is connected, bandwidth (communication time) is allocated even when there is no uplink data. For this reason, there has been a problem in that no communication time occurs, resulting in a decrease in the throughput of the entire system.

  The present invention has been made in view of the above, and guarantees required QoS, suppresses the occurrence of no-communication time, improves bandwidth utilization efficiency, and maintains the fairness of traffic. An object of the present invention is to obtain a bandwidth allocation method and a communication system that can perform the above-described process.

  In order to solve the above-described problems and achieve the object, the present invention monitors the terminal residual amount that is the accumulated amount of transmission data by the terminal station, and indicates the terminal residual amount and the QoS indicating the bandwidth guarantee request. A terminal information transmission step of transmitting to the base station, the communication information of the transmission data including the communication time interval information indicating a request regarding the type and the communication time interval, and the transmission rate; and the base station transmits the QoS information and the terminal A scheduling step of allocating an uplink band to the terminal station based on a residual amount and notifying the terminal station of the allocation result.

  According to the present invention, the terminal station transmits QoS information including the residual data amount and the QoS type to the base station, and the base station allocates the communication time to the terminal station based on the QoS information. As a result, the required QoS is guaranteed, the occurrence of no-communication time is suppressed, the bandwidth utilization efficiency is improved, and the fairness of the traffic can be maintained.

  Hereinafter, embodiments of a bandwidth allocation method and a communication system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a functional configuration example of a first embodiment of a communication system according to the present invention. As shown in FIG. 1, the communication system according to the present embodiment includes a base station 1, terminal stations 8-1 to 8-3, and devices 9-1 to 9-3. The base station 1 is connected to the upper network 7. The host network 7 and the devices 9-1 to 9-3 communicate via the base station 1 and the terminal station. In this embodiment, the number of terminal stations is three, but the number of terminal stations is not limited to this, and may be an arbitrary number.

  The base station 1 according to the present embodiment includes a wired access unit 2 that transmits and receives data to and from the upper network 7 and a wireless access that wirelessly transmits and receives data to and from the terminal stations 8-1 to 8-3. Unit 3, a transmission queue unit 4 which is a buffer for storing transmission data to terminal stations 8-1 to 8-3, and a buffer for storing reception data from terminal stations 8-1 to 8-3 The receiving queuing unit 5 and the scheduling unit 6 that performs communication scheduling for the terminal stations 8-1 to 8-3.

  In addition, the terminal station 8-1 of the present embodiment includes a device access unit 10 that transmits and receives data to and from the device 9-1 and a wireless access unit 11 that wirelessly transmits data to and from the base station 1. A transmission queue unit 12 that is a buffer for storing transmission data to the base station 1, a reception queue unit 13 that is a buffer for storing reception data from the base station 1, and a QoS type to the base station 1. , A bandwidth request unit 14 that generates information for notifying the base station 1 of information including the residual queue amount (data amount accumulated in the transmission queue unit 12) and the like. The terminal station 8-2 and the terminal station 8-3 have the same functional configuration as the terminal station 8-1.

  Next, the bandwidth allocation method in the present embodiment will be described. In the present embodiment, for the sake of explanation, each of the terminal stations 8-1 to 8-3 transmits and receives a single QoS type data. First, the terminal station 8-1 notifies the base station 1 of the QoS information including the QoS type and the residual queue amount by the following procedure.

  First, the uplink will be described. The device access unit 10 of the terminal station 8-1 receives the transmission data from the device 9-1 and outputs it to the transmission queue unit 12. The bandwidth request unit 14 monitors the accumulation amount (residual queue amount) of the transmission queue unit 12. Then, the bandwidth request unit 14 outputs the QoS information including the QoS type of the transmission data, the guaranteed transmission interval, and the transmission rate, and the residual queue amount to the wireless access unit 11. Then, the wireless access unit 11 transmits the QoS information and the residual queue amount to the base station 1 as wireless signals. Here, the operation has been described by taking the terminal station 8-1 as an example, but the terminal stations 8-2 and 8-3 also transmit QoS information to the base station 1 by a similar operation.

  The radio access unit 3 of the base station 1 receives the radio signal transmitted from the terminal station 8-1 and performs reception processing, and outputs the QoS information and the remaining queue amount to the scheduling unit 6. The scheduling unit 6 performs communication scheduling with the terminal stations 8-1 to 8-3 according to a scheduling procedure to be described later based on the QoS information and the residual queue amount, and the assignment result to each terminal by the scheduling is transmitted to the radio access unit 3. Output to. The radio access unit 3 transmits the assignment result as a radio signal to the terminal stations 8-1 to 8-3. The bandwidth request units 14 of the terminal stations 8-1 to 8-3 obtain the allocation result via each wireless access unit 11.

  Thereafter, the terminal stations 8-1 to 8-3 and the base station 1 perform communication according to the allocation result. Specifically, taking the case where the terminal station 8-1 performs data transmission as an example, first, the bandwidth request unit 14 of the terminal station 8-1 extracts transmission data from the transmission queue unit 12 based on the allocation result. To the wireless access unit 11. The wireless access unit 11 transmits the transmission data as a wireless signal. The radio access unit 3 of the base station 1 receives the radio signal transmitted from the terminal station 8-1, performs reception processing, and outputs the transmission data after the reception processing to the reception queue unit 5. Then, the wired access unit 2 extracts transmission data from the reception queue unit 5 and transmits it to the upper network 7.

  Next, the downlink will be described. When the wired access unit 2 of the base station 1 receives the transmission data from the upper network 7, it outputs the transmission data to the transmission queue unit 4. The transmission queue unit 4 is stored for each destination (terminal stations 8-1 to 8-3) of transmission data. The scheduling unit 6 monitors the residual queue amount for each destination of the transmission queue unit 4. Then, scheduling is performed according to a scheduling procedure described later. Based on the scheduling result, the transmission data is extracted from the transmission queue unit 4 and output to the wireless access unit 3. The radio access unit 3 transmits transmission data as radio signals to the terminal stations 8-1 to 8-3.

  The radio access unit 11 of the terminal station 8-1 receives the radio signal transmitted from the base station 1, performs reception processing, and outputs transmission data to the reception queue unit 13. Then, the device access unit 10 extracts the transmission data from the reception queue unit 13 and transmits it to the device 9-1. The operations of the terminal stations 8-2 and 8-3 are the same as the operation of the terminal station 8-1.

  Next, a scheduling procedure in the scheduling unit 6 will be described. In the present embodiment, as the QoS type, three types are used: minimum bandwidth guarantee that requires communication over the minimum bandwidth, fixed bandwidth guarantee that requires a fixed bandwidth, and no bandwidth guarantee. To do. Further, each type is divided into a case where there is a request for a guaranteed transmission time interval and a case where there is no request. In the present embodiment, when the QoS type is the minimum bandwidth guarantee and the fixed bandwidth guarantee, the QoS type is included in each guaranteed bandwidth QoS information, and when the guaranteed transmission time interval is requested, the required guarantee is provided. The transmission time interval is included in the QoS information. Here, the case where the parameters indicating the states of the terminal stations 8-1 to 8-3 and the base station 1 are assumed as follows will be described as a specific example.

(A) Band assignment period (SuperFrame time) (Bi) of the assumed parameter system of the base station 1: 5 ms
Unit slot time (time of 1 slot) (St): 4 μs / slot
Number of unallocated slots per system bandwidth allocation period (overhead such as Beacon) (So): 45 slots
Number of overhead slots per transmission frame (overhead independent of the amount of transmission data such as preamble and guard interval) (Fo): 5 slots

(B) Assumed parameter QoS type of terminal station 8-1: Guaranteed minimum guaranteed bandwidth (Rb (1)): 10 Mbps
Guaranteed transmission interval (Ri (1)): No transmission rate (transmission data amount per unit slot) ((Ud (1)): 2500 bits / slot
Residual Queue amount (QL (1)): 1500 Kbit

(C) Assumption parameter QoS type of terminal station 8-2: Minimum guaranteed bandwidth (Rb (2)): 5 Mbps
Guaranteed communication time interval (Ri (2)): 20 ms
Transmission rate (transmission data amount per slot) ((Ud (2)): 500 bits / slot
Residual Queue amount (QL (2)): 2500 Kbit

(D) Assumed parameter QoS type of terminal station 8-3: No bandwidth guarantee (Rb (3))
Guaranteed bandwidth: None (best effort)
Guaranteed transmission interval (Ri (3)): None Transmission rate (transmission data amount per unit slot) (Ud (3)): 300 bits / slot
Residual Queue amount (QL (3)): 6000 Kbit

  When the above conditions are assumed, the base station 1 performs scheduling in the following steps 1 to 6.

  Step 1: The scheduling unit 6 acquires the QoS type included in the QoS information notified from each terminal station 8-1 to 8-3. Then, QoS information whose QoS type is guaranteed minimum bandwidth or fixed bandwidth is selected, and for each selected QoS information, allocation data based on the transmission rate, guaranteed communication time interval and system bandwidth allocation period (SuperFrame time) Each slot number is calculated. At this time, the calculation formula differs depending on whether or not a guaranteed transmission interval is requested. When there is a request for a guaranteed transmission interval, the following equation (1) is satisfied. Calculate according to (2).

Allocated transmission data amount per bandwidth allocation cycle Ds (n) = Rb (n) × Bi
Number of allocation data slots per bandwidth allocation cycle Vbs (n) = Da (n) / Ud (n) (1)

Transmission data amount per guaranteed communication time interval Dr (n) = Rb (n) × Ri (n)
Number of assigned data slots per guaranteed communication time interval Vbr (n) =
Dr (n) / Ud (n) (2)

  Note that n is a number for identifying QoS information, and the number of data slots assigned to communication corresponding to the nth QoS information is Vb (n). In this case, since the terminal stations 8-1 to 8-3 and the QoS information correspond one-to-one, n is the same as the terminal number, and the QoS information of n = 1, n = 2, and n = 3 is the terminal. Assume that the stations correspond to the stations 8-1, 8-2, and 8-3.

  When the numerical values assumed in (A) to (D) are added to the above formulas (1) and (2) and calculated as a specific example, the result is as follows. Here, since the QoS types of the terminal station 8-1 and the terminal station 8-2 are guaranteed minimum bandwidth, the number of data slots is calculated for these two. For the terminal station 8-1, since there is no request for a guaranteed communication time interval, the number of data slots per system bandwidth allocation period is obtained. Vbs (1) = 5 [ms] × 10 [Mbps] / 2500 [Bit / slot) = 20 [slot].

  Further, since the terminal station 8-2 has a request for a guaranteed communication time interval and is 20 ms, the number of data slots in the guaranteed communication time interval is obtained, and Vbr (n) = 5 [ms] × 20 [Mbps] / 500 [bit / slot] = 200 [slot].

Step 2: The number of remaining allocation slots is calculated by subtracting the overhead of Beacon, the number of data slots of the total data calculated in Step 1, and the overhead for each transmission frame from the total number of data slots in the system bandwidth allocation cycle. To do. Specifically, first, the total number of slots per system bandwidth allocation period is obtained according to the following equation (3).
Total number of slots per bandwidth allocation cycle Sa = Bi / St (3)

Then, from the obtained Sa, the number of remaining assignable slots Se is obtained according to the following equation (4).
Se = Sa−periodic overhead So
-Fo x number of frames transmitted within a period (here, the number of QoS information)
− (ΣVbs (n) + ΣVbr (n)) (4)

  Note that ΣVbs (n) indicates the addition of all Vbs (n) calculated for the QoS information for which no guaranteed communication time interval is requested in step 1, and ΣVbr (n) is required for the guaranteed communication time interval in step 1. Shows the addition of all Vbs (n) calculated for the current QoS information.

When the above numerical values (A) to (D) are entered and specifically calculated,
Sa = 5 [ms] / 4 [μs / slot] = 1250 [slot]
Se = 1250 [slot] −45 [slot] −5 [slot] × 3
−20 [slot] −200 [slot] = 970 [slot] (5)

Step 3: For each QoS information, the residual queue amount and the transmission rate corresponding to the QoS information are used to convert the residual queue amount into a slot number according to equation (6) to obtain the residual slot number Ls (n).
Ls (n) = QL (n) ÷ Ud (n) (6)

When Ls (n) is obtained as a specific example using the above numerical values (A) to (D), the following equation (7) is obtained.
Ls (1) = QL (1) ÷ Ud (1)
= 1500 [Kbit] ÷ 2500 [bit / slot]
= 600 [slot]
Ls (2) = QL (2) ÷ Ud (2)
= 2500 [Kbit] / 500 [bit / slot]
= 5000 [slot]
Ls (3) = QL (3) ÷ Ud (3)
= 6000 [Kbit] / 300 [bit / slot]
= 20000 [slot] (7)

Step 4: For QoS information whose QoS type is minimum bandwidth guarantee, the number of data slots calculated in Step 1 is subtracted from the number of remaining slots calculated in Step S3, and the subtracted value is the number of remaining slots Lsr (corresponding to the QoS information) n). At this time, the number of remaining slots Lsr (n) is calculated according to the following equation (8), depending on the QoS type and whether there is a request for a guaranteed communication time interval.
When QoS type is guaranteed minimum bandwidth or fixed bandwidth, and there is no request for guaranteed communication time interval:
Lsr (n) = Ls (n) −Vbs (n)
When QoS type is guaranteed minimum bandwidth or fixed bandwidth, and there is a request for guaranteed communication time interval:
Lsr (n) = Ls (n) −Vbr (n)
When QoS type does not require bandwidth guarantee:
Lsr (n) = Ls (n) (8)

When calculating as a specific example using the numerical values of (A) to (D), the following equation (9) is obtained.
Lsr (1) = 600 [slot] −20 [slot] = 580 [slot]
Lsr (2) = 5000 [slot] −200 [slot] = 4800 [slot]
Lsr (3) = 2000 [slot] (9)

Step 5: For the QoS information other than the fixed bandwidth guarantee (minimum bandwidth guarantee, no bandwidth guarantee), the remaining slot number calculated in the step is changed according to the ratio of the remaining slot numbers obtained according to the above equation (8). Assigned to communication corresponding to QoS information. The allocated slot number (remaining distribution slot number Ds (n)) for communication corresponding to each QoS information is calculated according to the following equation (10). At this time, it is calculated by rounding off the decimal part.
Residual slot ratio = Rs (1): Rs (2): Rs (3):...
Ds (n) = Se × (Rs (n) / ΣRs (i)) (10)

When calculating as a specific example using the numerical values of (A) to (D), the following equation (11) is obtained.
Residual slot ratio = 580: 4800: 20000
Ds (1) = 970 × (580 / (580 + 4800 + 20000) [slot]
≒ 22 [slot] (rounded down after the decimal point)
Ds (2) = 970 × (4800 / (580 + 4800 + 20000) [slot]
≒ 183 [slot]
Ds (3) = 970 × (20000 / (580 + 4800 + 20000) [slot] = 764 [slot] (11)

Step 6: The total of the result calculated in Step 1 and the result calculated in Step 5 is classified according to the QoS type and whether or not there is a request for a guaranteed communication time interval as shown in the following equation (12). Ask. And let the calculated | required numerical value be the total slot number (As (n)) allocated to each communication corresponding to QoS information in the band allocation period of the system.
When QoS type is guaranteed minimum bandwidth or fixed bandwidth, and there is no request for guaranteed communication time interval:
As (n) = Ds (n) + Vbs (n)
When QoS type is guaranteed minimum bandwidth or fixed bandwidth, and there is a request for guaranteed communication time interval:
As (n) = Ds (n) + Vbr (n)
When QoS type does not require bandwidth guarantee:
As (n) = Ds (n) (12)

Using the numerical values of (A) to (D) described above as a specific example, the following formula (13) is obtained.
As (1) = 22 + 20 [slot] = 42 [slot]
As (2) = 183 + 200 [slot] = 383 [slot]
As (3) = 764 [slot] (13)

  In the above scheduling procedure, an example of allocation for uplink data has been described. However, for the downlink, in the above procedure, instead of the remaining queue amount of each of the terminal stations 8-1 to 8-3, the base station Similar allocation can be implemented by using a residual queue amount of one. In this case, if the transmission rate differs between the uplink and the downlink, the calculation may be performed using the downlink transmission rate held by the base station 1.

  In this embodiment, each of the terminal stations 8-1 to 8-3 performs communication of a single QoS type data, but one terminal station performs communication of a plurality of QoS types. In this case, it can be performed in the same manner as this embodiment. In this case, each of the terminal stations 8-1 to 8-3 generates and notifies QoS information for each QoS type, and the scheduling unit of the base station 1 may perform allocation for each QoS information according to the above-described scheduling procedure. .

  As described above, in the present embodiment, the terminal stations 8-1 to 8-3 transmit the QoS information including the QoS type, the guaranteed transmission interval, and the transmission rate, and the residual queue amount to the base station 1, and the base station 1 The scheduling unit 6 assigns slots to communications corresponding to the QoS information based on the QoS type, the guaranteed transmission interval, the transmission rate, and the residual queue amount. For this reason, the required QoS can be guaranteed, the occurrence of no communication time can be suppressed, the bandwidth utilization efficiency can be improved, and the fairness of the traffic can be maintained.

Embodiment 2. FIG.
A bandwidth allocation method according to the second embodiment of the present invention will be described. A functional configuration example of the communication system of the present embodiment is the same as that of the first embodiment shown in FIG. Hereinafter, description of the same parts as those in the first embodiment will be omitted, and parts different from those in the first embodiment will be described.

  In the present embodiment, the terminal stations 8-1 to 8-3 add the residual que amount to the transmission data and transmit it when transmitting the uplink data. Since the QoS information is an item that does not change with time, it is not necessary to transmit it every allocation period. However, since the remaining Queue amount varies with time, it needs to be transmitted with a certain frequency. Because.

  According to the scheduling procedure described in the first embodiment, when the QoS type is no bandwidth guarantee request and there is no guarantee communication time interval request, the terminal station has a residual queue amount of “0”. In this case, the base station 1 does not assign the uplink data slot to the terminal station in the bandwidth allocation period. In such a state, the terminal station can no longer transmit uplink data, and even if data is stored in the transmission queue 12, no data slot is allocated, so the residual queue amount cannot be transmitted. The state where the data slot is not allocated continues.

  Therefore, in this embodiment, in order to avoid such a state, a base using an Aloha slot for bandwidth request (a slot used only for bandwidth request for each bandwidth allocation period of the system) instead of a data slot. The remaining Queue amount is transmitted to the station 1.

  Here, if the remaining queue amount is transmitted only with the Aloha slot only when the following condition 1 or condition 2 is satisfied, frequent transmission of the remaining queue amount can be avoided. Here, in order to determine the condition 2, the transmission queue unit 12 is provided with a timer that starts when data accumulation is started, and when a preset timer time elapses, a bandwidth request is made. It is assumed to notify the unit 14.

Condition 1: When the residual queue amount exceeds a preset threshold value of the residual queue amount.
Condition 2: When a timer value started when data accumulation in the transmission queue unit 12 starts exceeds a preset timer time.

  By judging the condition 1, since a slot is not allocated to a small amount of data transmission (the slot is not allocated unless a certain amount of data is accumulated), the overhead can be suppressed and the throughput of the entire system can be improved. Appears as an effect.

  In the case of transmitting only when the condition 1 is satisfied, it is not possible to cope with the case where the host application that performs communication requests guarantee of the delay time. However, the delay time can be guaranteed by determining the condition 2. Furthermore, the condition 1 and the condition 2 can avoid frequent use of the Aloha slot for bandwidth request, and as a result, congestion of the Aloha slot is reduced.

  As described above, in the present embodiment, the terminal stations 8-1 to 8-3 store data in the transmission queue unit 12 when the residual queue amount exceeds a preset threshold value of the residual queue amount. The residual queue amount is transmitted using the Aloha slot when the timer value started at the time of starting the time exceeds a preset timer time. For this reason, even when the residual queue amount becomes “0”, the residual queue amount can be transmitted, the overhead can be suppressed, and the congestion of the Aloha slot can be reduced.

  As described above, the bandwidth allocation method and communication system according to the present invention are particularly suitable for a wireless communication system in which a base station allocates communication time to a plurality of terminal stations and performs QoS control.

It is a figure which shows the function structural example of Embodiment 1 of the communication system concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base station 2 Wired access part 3,11 Wireless access part 4,12 Transmission Queue part 5,13 Reception Queue part 6 Scheduling part 7 Host network 8-1 to 8-3 Terminal station 9-1 to 9-3 Equipment 10 Equipment Access unit 14 Bandwidth request unit

Claims (10)

The terminal station monitors the terminal residual amount, which is the accumulated amount of transmission data, and includes the terminal residual amount, the QoS type indicating the bandwidth guarantee request, the communication time interval information indicating the request for the communication time interval, and the transmission rate. A terminal information transmission step of transmitting QoS information of transmission data to a base station;
A scheduling step in which the base station allocates an uplink band to the terminal station based on the QoS information and the terminal residual amount, and notifies the terminal station of the allocation result;
A bandwidth allocation method comprising: A base station residual amount monitoring step in which the base station monitors a base station residual amount that is an accumulation amount of transmission data addressed to the terminal station;
Further including
2. The bandwidth allocation method according to claim 1, wherein in the scheduling step, a downlink bandwidth is further allocated to the terminal station based on the QoS information and the residual amount of the base station. There are three QoS types: minimum bandwidth guarantee, fixed bandwidth guarantee, and no bandwidth guarantee,
3. The bandwidth allocation method according to claim 1, wherein when the QoS type is guaranteed minimum bandwidth or guaranteed fixed bandwidth, the QoS information further includes a guaranteed bandwidth. The communication time interval information is two, that is, a communication time interval request and a communication time interval request,
4. The bandwidth allocation method according to claim 3, wherein when the communication time interval information includes a request for a communication time interval, the QoS information further includes a required communication time interval. The scheduling step includes
In the case where the QoS type is guaranteed minimum bandwidth or fixed bandwidth, for each QoS information, data for calculating the number of data slots allocated within the bandwidth allocation period based on the transmission rate, communication time interval, and system bandwidth allocation period Slot number calculation step;
A remaining allocation slot number calculating step of subtracting a total value of all the data slot numbers calculated in the predetermined overhead slot number and the slot number calculating step from the band allocation period, and setting the result as the remaining allocation slot number;
In the case of uplink, the number of remaining slots is calculated based on the terminal residual amount and the transmission rate for each QoS information, and in the case of downlink, the number of remaining slots based on the base station residual amount and the transmission rate. A retention slot number calculating step for calculating
When the QoS type is guaranteed minimum bandwidth, the number of data slots calculated in the data slot number calculation step is subtracted from the number of remaining slots corresponding to the QoS information for each QoS information, and the result is obtained as the number of remaining slots. A remaining slot number calculating step,
The QoS type is allocated to the QoS information with minimum bandwidth guarantee or no bandwidth guarantee, and the remaining allocation slot number is allocated based on the number of remaining slots corresponding to the QoS information, and the QoS type is for QoS information with fixed bandwidth guarantee. A remaining allocation slot allocation step in which the distribution value of the number of remaining allocation slots is 0;
For each QoS information, the slot allocation that adds the remaining allocation slot number allocated in the remaining allocation slot allocation step to the data slot number calculated in the slot number calculation step, and allocates the addition result to the communication corresponding to the QoS information. Steps,
The band allocation method according to claim 4, further comprising:   6. The bandwidth allocation method according to claim 1, wherein in the terminal information transmission step, the QoS information and the terminal residual amount are added to the transmission data for transmission.   7. The bandwidth allocation method according to claim 6, wherein, in the terminal information transmission step, the terminal residual amount is further notified using an Aloha slot for requesting bandwidth allocation.   In the terminal information transmission step, when the terminal residual amount exceeds a predetermined threshold set in advance, or when a predetermined time has elapsed from the start of accumulation of transmission data, the terminal residual amount is The band allocation method according to claim 7, wherein notification is performed using the Aloha slot. Monitor the terminal residual amount for each type of transmission data,
Transmitting the QoS information and the terminal residual amount for each type of the transmission data;
The bandwidth allocation method according to any one of claims 1 to 8, wherein a bandwidth is further allocated to the terminal station for each QoS information. The terminal station
Monitoring the terminal residual amount which is the amount of transmission data stored in the local station, QoS type indicating bandwidth guarantee request, communication time interval information indicating a request for communication time interval, and QoS information of the transmission data including transmission rate; Bandwidth request means for outputting the terminal residual amount of transmission data corresponding to the QoS information;
Radio access means for transmitting the QoS information and the terminal residual amount to a base station;
With
The base station
Scheduling means for allocating an uplink band to transmission data corresponding to the QoS information based on the QoS information and the residual amount, and notifying a result of the allocation to the terminal station;
A communication system comprising:

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