JP2003273880A - Time scheduling method and base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a time scheduling method and a base station capable of providing best effort type communication for general subscriber station, while providing high quality and high-speed communication by securing a lowest band and latency to a specific subscriber station when traffic increases. <P>SOLUTION: A time scheduling method in a fixed radio access system wherein one base station and a plurality of subscriber stations perform communication in time-sharing multiple access method in a fixed place, configured that a scheduling means assigns a band, by perceiving a minimum band successively from subscriber stations having high priority to those having low priority, based on a priority order management table wherein priority of respective subscriber stations is written, and the assigning is repeated until all prepared and assignable band is assigned. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time scheduling method and a base station, and more particularly, it provides a best-effort type communication to general subscriber stations when traffic increases, while providing a specific subscription. The present invention relates to a time scheduling method and a base station capable of providing high quality and high speed communication by guaranteeing a minimum bandwidth and a latency for a mobile station. In this specification, the band means a time slot in a radio frame.

[0002]

2. Description of the Related Art In recent years, in addition to electronic mail and file transfer, fixed wireless access services for providing video and audio having a large amount of data have been rapidly increasing. The communication system that provides this fixed wireless access service is generally
A large service area is provided as a whole by arranging a large number of cells, which are relatively small service areas using one base station.

Therefore, in such a communication system, a plurality of radio lines are formed between a base station and a plurality of subscriber stations, but the plurality of radio lines are connected to each other in order to effectively use the frequency. Use a common frequency channel.

In order to use a common frequency for a plurality of subscriber stations, it is necessary to control so that radio signal interference (collision) does not occur. In order to prevent this interference, a plurality of communications may be separated according to the difference in transmission time.

An example of such a separated communication system is C
SMA (Carrier Sense Multipl)
e Access: Carrier detection multiple access) / CA (Co
collision avoidance) and T
DMA is known.

[0006] CSMA / CA performs carrier sensing based on the reception level, and confirms that the frequency used is not used by another station before transmitting. Therefore, although CSMA / CA has a hidden terminal problem in which each subscriber station transmits without noticing the existence of other stations and causes interference, CSMA / CA will not be described in further detail in this specification. .

In TDMA, all communication is controlled by the base station so that radio signal interference (collision) does not occur, and the time slot used for data communication between the base station and a plurality of subscriber stations is also provided in the base station. Are managed collectively.

FIG. 9 is a diagram showing a configuration example of a radio frame in a communication system adopting TDMA / TDD. In FIG. 9, TS11 (Time Slot 1
1) is an area that can be accessed by all subscriber stations. Frame structure information, information for supervisory control, and arbitration of a time slot request randomly transmitted from each subscriber station in TS14 described later. Control signal for
This is a time zone in which the base station notifies the time slot assigned by the time scheduling in response to the time slot request transmitted from the subscriber station in TS14.

TS12 is a time zone for transmitting user data in the downlink direction from the base station to each subscriber station. This time slot and the time slot of TS15 described later are for each subscriber by time scheduling of the base station. Assigned to station.

The TS 13 measures the propagation delay time caused by the distance difference between the base station and a plurality of subscriber stations, adjusts the transmission timing of the radio signal transmitted from each subscriber station, and adjusts the radio signal at the reception of the base station. It is a time zone for controlling so that signals do not collide. Further, the TS13 also transmits an upstream supervisory control signal.

TS14 is a time zone for the subscriber station to request a time slot for transmitting user data in the upstream direction to the base station, and the base station responds to the request made in this time slot. Assign time slots for user data transmission to subscriber stations. And
The base station uses the time slot for user data transmission as TS.
The subscriber station is notified at 11, and the subscriber station transmits user data using the notified time slot.

TS15 is a time zone for transmitting the user data. TS16 is a guard time for preventing interference, which is set at the boundary between the uplink and the downlink. Conventionally, in a communication system employing such TDMA / TDD, round-robin control is performed as the time scheduling in order to ensure fairness in communication quality and communication speed among subscriber stations. The round robin control will be briefly described below with reference to FIGS. 10 and 11.

FIG. 10 is a diagram for explaining the outline of the round robin control, and FIG. 11 is a diagram showing the round robin control algorithm. In round-robin control, the number of time slots (number of bands) that the base station allocates to subscriber stations
The maximum value of is set uniformly for all subscriber stations.

In the round robin control, the base station sequentially allocates time slots from the subscriber station with the smallest subscriber station number. In this way, in conventional time scheduling, since round robin control was adopted,
Each subscriber station uses the time slots assigned by the base station based on the maximum value and the order, and stores user data in the downlink direction from the base station to the subscriber station, which is accumulated in the buffer of each subscriber station and Upward user data from the subscriber station to the base station is exchanged with the base station.

[0015]

However, in this conventional time scheduling, since a time slot is assigned to each subscriber station according to the above-mentioned uniformly determined minimum bandwidth and a fixed order in advance, a plurality of subscribers are required to join the base station. The bandwidth and latency are not guaranteed when the traffic with the other station increases.

Therefore, the conventional time scheduling cannot prevent the user data transfer from being delayed on average. Such a delay in user data transfer is not a problem in the existing TCP / IP protocol that provides e-mail, file transfer, etc., but as mentioned at the beginning, in recent years there has been a rapid increase in the volume of data such as video and audio. In the fixed wireless access service using the real-time protocol, which provides
It's a problem.

In view of the above situation, the present invention provides a general subscriber station with best-effort communication when traffic increases, and a specific subscriber station with a minimum bandwidth and An object of the present invention is to provide a time scheduling method and a base station that can provide high quality and high speed communication by guaranteeing latency.

[0018]

According to the present invention, the above problems can be solved by the means described in the claims. That is, the invention according to claim 1 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the method comprising: Based on the priority management table that describes the priority of each subscriber station, the means grasps the minimum number of bands in order from the subscriber station with a high priority to the subscriber station with a low priority, and allocates the bandwidth. In the time scheduling method, the allocation is repeated until all the allocatable bands prepared for one radio frame are allocated.

According to the invention of claim 1, the band is
Since the minimum number of bands is grasped and assigned, the minimum band can be guaranteed for a specific subscriber station. According to the invention described in claim 1, since the bands are allocated in order from the subscriber station with high priority to the subscriber station with low priority,
Latency of high priority subscriber stations can be guaranteed.

According to the first aspect of the invention, since the allocation is repeated until all the allocatable bands prepared in one radio frame are allocated, no band is wasted.

The invention according to claim 2 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method. The sum of the minimum number of bands guaranteed to subscriber stations is set so that it does not exceed the number of allocatable bands prepared in one radio frame, and the scheduling means describes the priority of each subscriber station. Based on the priority management table, the lowest number of bands is allocated in order from the subscriber station with the highest priority to the subscriber station with the lowest priority, and the number of allocatable bands prepared in one radio frame is allocated. In the time scheduling method, characterized in that the above-mentioned allocation is repeated until all are allocated.

According to the invention of claim 2, claim 1
In addition to the invention described in (1), since the sum of the minimum number of bands guaranteed to subscriber stations is set so as not to exceed the number of allocatable bands prepared in one radio frame, priority is set. Even for low subscriber stations, some minimum bandwidth and latency can be guaranteed.

The invention according to claim 3 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method. Based on the priority management table in which the priority of each subscriber station is described, the scheduling means requests the required bandwidth from the subscriber station with the highest priority to the subscriber station with the lowest priority in order. If the number is equal to or less than the number of allocatable bands, the required number of bands can be allocated. If the number of required bands exceeds the allocatable band, the minimum number of bands can be allocated. A time scheduling method characterized in that the above-mentioned allocation is repeated until all of the different band numbers are allocated.

According to the third aspect of the present invention, if the required number of bands required to transmit the user data is less than or equal to the allocatable band number, the required number of bands is the number of bands to which the required number of bands is allocatable. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the third aspect of the present invention, since the bandwidth is allocated in order from the subscriber station with high priority to the subscriber station with low priority, the latency of the subscriber station with high priority is guaranteed. You can

According to the third aspect of the invention, since the allocation is repeated until all the allocatable bands prepared in one radio frame are allocated, no band is wasted.

The invention according to claim 4 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, The sum of the minimum number of bands guaranteed to subscriber stations is set so that it does not exceed the number of allocatable bands prepared in one radio frame, and the scheduling means describes the priority of each subscriber station. Based on the priority management table, if the number of required bands required to transmit user data is in order from the subscriber station with the highest priority to the subscriber station with the lowest priority If the requested number of bands exceeds the number of allocatable bands, the minimum number of bands is allocated, and all of the allocatable bands prepared in one radio frame are allocated. It is a time scheduling method and repeating the allocation to that.

According to the invention of claim 4, claim 3
In addition to the invention described in (1), since the sum of the minimum number of bands guaranteed to subscriber stations is set so as not to exceed the number of allocatable bands prepared in one radio frame, priority is set. Even for low subscriber stations, some minimum bandwidth and latency can be guaranteed.

The invention according to claim 5 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, Scheduling means, for subscriber stations guaranteed minimum bandwidth, based on the table that describes the priority of each subscriber station,
Subscriber stations that know the minimum number of bands in order from subscriber stations with high priority to subscriber stations with low priority and allocate bandwidth, and for those subscriber stations whose minimum bandwidth is not guaranteed, guarantee the minimum bandwidth. The time scheduling method is characterized by allocating the remaining band evenly after the end of the band allocation.

According to the invention of claim 5, the band is
Since the minimum number of bands is grasped and assigned, the minimum band can be guaranteed for a specific subscriber station. According to the invention described in claim 5, since the bands are allocated in order from the subscriber station with high priority to the subscriber station with low priority,
Latency of high priority subscriber stations can be guaranteed.

According to the fifth aspect of the invention, for the subscriber stations whose minimum bandwidth is not guaranteed, the remaining bandwidth after the end of the bandwidth allocation for the subscriber stations whose minimum bandwidth is guaranteed is fairly allocated. , Minimum bandwidth is not guaranteed It is possible to fairly guarantee the minimum bandwidth and latency of subscriber stations.

The invention according to claim 6 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method. The sum of the minimum band numbers for subscriber stations for which the minimum band is guaranteed is
The scheduling means is set so as not to exceed the number of allocatable bands prepared for one radio frame.
For subscriber stations with guaranteed minimum bandwidth, the minimum bandwidth is grasped in order from subscriber stations with high priority to subscriber stations with low priority, based on a table describing the priority of each subscriber station. For a subscriber station whose minimum bandwidth is not guaranteed, a time scheduling method characterized by fairly allocating a surplus bandwidth after the end of the bandwidth allocation for the subscriber station whose minimum bandwidth is guaranteed. is there.

According to the invention of claim 6, claim 5
In addition to the invention described in (1), since the sum of the minimum number of bands guaranteed to subscriber stations is set so as not to exceed the number of allocatable bands prepared in one radio frame, priority is set. Even for low subscriber stations, some minimum bandwidth and latency can be guaranteed.

The invention according to claim 7 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, Scheduling means, for subscriber stations guaranteed minimum bandwidth, based on the table that describes the priority of each subscriber station,
If the required number of bands required to transmit user data is less than or equal to the allocatable band in order from the subscriber station with the highest priority to the subscriber station with the lowest priority, the required band number is allocated If the number of available bands is exceeded, allocate the minimum number of bands, and for subscriber stations whose minimum bandwidth is not guaranteed, fair the surplus bandwidth after the end of the bandwidth allocation for subscriber stations that are guaranteed the minimum bandwidth. It is a time scheduling method characterized by allocating.

According to the invention described in claim 7, if the required number of bands required to transmit the user data is equal to or less than the allocatable band number, the required number of bands is the number of bandwidths to which the required number of bands can be allocated. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the invention described in claim 7, the bandwidth is allocated in order from the subscriber station having a high priority to the subscriber station having a low priority, so that the latency of the subscriber station having a high priority is guaranteed. You can

According to the invention as set forth in claim 7, for the subscriber stations for which the minimum bandwidth is not guaranteed, the remaining bandwidth after the end of the bandwidth allocation for the subscriber stations for which the minimum bandwidth is guaranteed is fairly assigned. , Minimum bandwidth is not guaranteed It is possible to fairly guarantee the minimum bandwidth and latency of subscriber stations.

The invention according to claim 8 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, The sum of the minimum band numbers for subscriber stations for which the minimum band is guaranteed is
The scheduling means is set so as not to exceed the number of allocatable bands prepared for one radio frame.
For subscriber stations with guaranteed minimum bandwidth, user data is transmitted in order from subscriber stations with high priority to subscriber stations with low priority, based on a table describing the priority of each subscriber station. If the required number of required bandwidths is less than or equal to the allocatable bandwidth, the required number of bandwidths is allocated. If the required number of bandwidths exceeds the allocatable bandwidth, the minimum number of bandwidths is allocated, and the minimum bandwidth is not guaranteed. A time scheduling method is characterized in that a surplus band after the end of the band allocation for a subscriber station in which a minimum band is guaranteed is allocated fairly to the mobile station.

According to the invention of claim 8, claim 6
In addition to the invention described in (1), since the sum of the minimum number of bands guaranteed to subscriber stations is set so as not to exceed the number of allocatable bands prepared in one radio frame, priority is set. Even for low subscriber stations, some minimum bandwidth and latency can be guaranteed.

The invention according to claim 9 is a time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, The scheduling means sets M indicating the priority to 0 indicating the highest priority, and sets the number of uplink radio bands COUNT_U indicating the number of bands that can be allocated to the uplink and the downlink indicating the number of bands that can be allocated to the downlink. Step S11 of setting the number of wireless bands COUNT_D to 0, and the scheduling means comparing the number of downlink wireless bands COUNT_D with the total number of bands DMAX that can be allocated to the downlink whether the allocation of all the downlink wireless bands is completed. And the scheduling means determines that the allocation is When it is determined that the allocation has been completed, it is determined whether or not the allocation of the uplink radio band is completed by comparing the number of uplink radio bands COUNT_U and the total number of bands UMAX that can be assigned to the uplink, and the allocation is determined. If it is determined that the bandwidth allocation is completed, the bandwidth allocation is terminated, whereas if it is determined that the bandwidth allocation is not completed, the processing proceeds to step S24 described below, and the scheduling means determines in step S12 that the downlink wireless bandwidth is When it is determined that the allocation of the subscribers has not been completed, the relative subscriber station number N in the priority management table is set to
Step S14 of setting the subscriber station entered at the top of the priority management table to 1 and the scheduling means accesses the priority management table,
Step S15 of obtaining an absolute subscriber number SUB_No based on the priority and the relative subscriber station number N;
The scheduling means accesses the bandwidth management table in step S15, and based on the absolute subscriber station number obtained in step S15, the minimum downlink allocation number D_M.
Total data amount of IN and downlink subscriber station buffer D_DA
Step S16 of acquiring TA, and the scheduling means acquires the minimum downlink allocation number D_MIN and the total data amount D_D of the downlink subscriber station buffer acquired in step S15.
If the total data amount D_DATA exceeds the minimum downlink bandwidth D_MIN as a result of the comparison in step S17, the scheduling means allocates the downlink radio bandwidth to the minimum downlink allocation number D_MIN. The step S18 of advancing to step S20 described later, and the scheduling means sets the total data amount D_D.
If the ATA has not yet exceeded the minimum downlink band number D_MIN, the downlink wireless band is allocated to the total data amount D_DATA, and the process proceeds to step S21 described later in step S19,
The scheduling means assigns the number of allocated bands D_DA to COUNT_D indicating the total number of allocated downlink radio bands.
The step S20 of adding TA and subtracting the allocated band number D_DATA from the total number D_DATA of band requests from the subscriber stations, and the scheduling means,
A step S21 of adding the number of allocated bands D_MIN to COUNT_D indicating the total number of allocated downlink wireless bands and subtracting the allocated number of bands D_MIN from the total number of band requests D_DATA from subscriber stations, Whether all band allocation has been completed is determined by comparing the number of uplink radio bands COUNT_D and the total number UMAX of bands that can be allocated to the uplink, and when it is determined that the allocation has been completed, The process proceeds to step S22, where it is determined whether or not all the uplink radio bands have been allocated by comparing the number of downlink radio bands COUNT_D with the total number DMAX of bands that can be allocated to the downlink, and the allocation is completed. If it is determined that the time slot is allocated, the time slot allocation is terminated. On the other hand, if it is determined that the processing has not ended, step S23, which proceeds to step S12, and the scheduling means accesses the band management table, and based on the absolute subscriber number obtained in step S15 Step S of acquiring the allocation number U_MIN and the total data amount U_DATA of the downlink subscriber station buffer
24, and the scheduling means performs the step S24.
The step S25 of comparing the minimum number of uplink allocation U_MIN acquired in step S25 with the total amount of data U_DATA in the buffer of the downstream subscriber station, and the scheduling means performs the step S2.
If the total data amount U_DATA exceeds the minimum number of upstream bands U_MIN as a result of the comparison in 5, the upstream wireless band is allocated to the minimum number of upstream allocations U_MIN, and the process proceeds to step S28 described later and the scheduling unit The amount of data U_DATA goes up and the minimum number of bands U
If _MIN has not been exceeded yet, the total amount of data U_
An upstream radio band is assigned to DATA, and step S2 described below is performed.
Step S27 to proceed to 9 and the scheduling means,
COUNT_U indicating the total number of allocated uplink radio bands
To the step S28 of adding the allocated band number U_DATA and subtracting the allocated band number U_DATA from the total number U_DATA of band requests from the subscriber stations, and the scheduling means to COUNT_U indicating the total number of allocated uplink radio bands, Step S2 of adding the allocated band number U_MIN and subtracting the allocated band number U_MIN from the total number U_DATA of the band requests from the subscriber stations.
9, the scheduling means N indicating the relative number of subscriber stations and the total number N_MA of subscriber stations accommodated in the base station.
When it is determined that all subscriber stations entered in the priority M have been subjected to the uplink and downlink radio band allocation processing by comparing with X, and that all subscriber stations have not been processed. While proceeding to step S31,
When it is determined that the processing has been performed for all subscriber stations, the process proceeds to step S32, and the scheduling means increments the relative subscriber station number N to determine whether or not the next entry is made in the priority. S31 for processing the subscriber stations of M_, and the scheduling means M_ indicating the priority M and the lowest priority.
END is compared with all the subscriber stations accommodated in the base station to determine whether or not the uplink and downlink radio band allocation processing has been performed, and the scheduling means performs all in step S32. When it is determined that the uplink and downlink radio band allocation processing is not performed at the priority of, the priority M is incremented and the subscriber station entering the next priority is processed, When it is determined in step S32 that the scheduling of all the priorities has been completed, the priority M is set to 0 and the above-described processing is repeated in step S33, and the scheduling means uses the steps S11 to S33. Step S34 which repeats the above steps until all of the wireless bands are allocated,
Is a time scheduling method.

According to the ninth aspect of the present invention, if the required number of bands required to transmit the user data is equal to or less than the allocatable band number, the required number of bands is the number of bandwidths to which the required number of bands can be allocated. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the invention of claim 9, the bandwidth is allocated in order from the subscriber station having a high priority to the subscriber station having a low priority, so that the latency of the subscriber station having a high priority is guaranteed. You can

According to the invention described in claim 9, since the allocation is repeated until all of the allocatable bands prepared in one radio frame are allocated, no band is wasted.

According to the tenth aspect of the present invention, there is provided the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate by a time division multiple access method at a fixed location. , Based on the priority management table that describes the priority of each subscriber station, the lowest number of bandwidths is grasped in order from the subscriber station with the highest priority to the subscriber station with the lowest priority, and one radio is assigned. A base station having a scheduling means for repeating the allocation until all of the allocatable bands prepared in the frame are allocated.

According to the tenth aspect of the present invention, since the band is allocated by grasping the minimum number of bands, the minimum band can be guaranteed for a particular subscriber station. According to the invention as set forth in claim 10, since the bands are allocated in order from the subscriber station having a high priority to the subscriber station having a low priority, the latency of the subscriber station having a high priority can be guaranteed.

According to the tenth aspect of the invention, since the allocation is repeated until all the allocatable bands prepared in one radio frame are allocated, no band is wasted.

The invention according to claim 11 is the base station in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, A priority management table that sets the total number of minimum bandwidth guaranteed to subscriber stations so that it does not exceed the number of allocatable bandwidths prepared in one radio frame, and describes the priority of each subscriber station. Based on the above, the lowest bandwidth number is allocated in order from the subscriber station with high priority to the subscriber station with low priority, and the bandwidth is assigned, and all the assignable bandwidth numbers prepared in one radio frame are assigned. The base station is characterized in that it has a scheduling means for repeating the above-mentioned allocation until it is received.

According to the eleventh aspect of the invention, in addition to the tenth aspect of the invention, the sum total of the minimum number of bands guaranteed to the subscriber stations is prepared in one radio frame. Since it is set so as not to exceed the number of bands that can be allocated, it is possible to guarantee a certain minimum band and latency even for subscriber stations with low priority.

The invention according to claim 12 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, Based on the priority management table that describes the priority of each subscriber station, the required number of bands required to transmit user data can be assigned in order from subscriber stations with high priority to subscriber stations with low priority. If the required number of bands exceeds the number of allocatable bands, the minimum number of bands is assigned, and if the number of allocatable bands provided in one radio frame is The base station is characterized by having a scheduling means for repeating the allocation until all are allocated.

According to the twelfth aspect of the present invention, if the required number of bands required to transmit the user data is less than or equal to the allocatable band, the required number of bands is the number of bands to which the required number of bands can be allocated. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the twelfth aspect of the present invention, since the bandwidth is allocated in order from the subscriber station with high priority to the subscriber station with low priority, the latency of the subscriber station with high priority is guaranteed. You can

According to the twelfth aspect of the invention, since the allocation is repeated until all of the allocatable bands prepared in one radio frame are allocated, no band is wasted.

The invention according to claim 13 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, A priority management table that sets the total number of minimum bandwidth guaranteed to subscriber stations so that it does not exceed the number of allocatable bandwidths prepared in one radio frame, and describes the priority of each subscriber station. Based on the, from the subscriber station with high priority to the subscriber station with low priority,
If the required number of bands required to transmit user data is less than or equal to the allocatable band, the required number of bands is allocated, and if the required number of bands exceeds the allocatable band, the minimum number of bands is allocated, and The base station is characterized by having a scheduling means for repeating the allocation until all of the allocatable bands prepared in one radio frame are allocated.

According to the thirteenth aspect of the present invention, in addition to the twelfth aspect of the invention, the total sum of the minimum band numbers guaranteed to the subscriber stations is prepared in one radio frame. Since it is set so as not to exceed the number of bands that can be allocated, it is possible to guarantee a certain minimum band and latency even for subscriber stations with low priority.

The invention described in claim 14 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, For subscriber stations with guaranteed minimum bandwidth, the minimum bandwidth is grasped in order from subscriber stations with high priority to subscriber stations with low priority, based on a table describing the priority of each subscriber station. A subscriber station whose minimum bandwidth is not guaranteed is provided with a scheduling means for evenly allocating the remaining bandwidth after the end of the bandwidth allocation for the subscriber station whose minimum bandwidth is guaranteed. It is a base station.

According to the fourteenth aspect of the present invention, since the band is allocated by grasping the minimum band number, it is possible to guarantee the minimum band for a specific subscriber station. According to the fourteenth aspect of the present invention, since the bands are allocated in order from the subscriber station having a high priority to the subscriber station having a low priority, the latency of the subscriber station having a high priority can be guaranteed.

According to the invention as set forth in claim 14, for the subscriber stations for which the minimum bandwidth is not guaranteed, the remaining bandwidth after the end of the bandwidth allocation for the subscriber stations for which the minimum bandwidth is guaranteed is fairly assigned. , Minimum bandwidth is not guaranteed It is possible to fairly guarantee the minimum bandwidth and latency of subscriber stations.

The invention as set forth in claim 15 is a base station in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, The total number of minimum bandwidths guaranteed for each subscriber station is set so that it does not exceed the number of allocatable bandwidths prepared in one radio frame. Based on a table that describes the priority of stations, subscriber stations that know the minimum number of bands in order from subscriber stations with higher priorities to subscriber stations with lower priorities and that are not guaranteed Is a base station characterized by having a scheduling means for evenly allocating the remaining band after the end of the band allocation for the subscriber station whose minimum band is guaranteed.

According to the invention described in claim 15, in addition to the invention described in claim 14, the sum total of the minimum band numbers guaranteed to the subscriber stations is prepared in one radio frame. Since it is set so as not to exceed the number of bands that can be allocated, it is possible to guarantee a certain minimum band and latency even for subscriber stations with low priority.

The invention according to claim 16 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access system, For subscriber stations with guaranteed minimum bandwidth, user data is transmitted in order from subscriber stations with high priority to subscriber stations with low priority, based on a table describing the priority of each subscriber station. If the number of required bandwidths required for is less than or equal to the allocatable bandwidth,
If the requested number of bands exceeds the number of bands that can be allocated, the minimum number of bands is allocated, and for subscriber stations for which the minimum band is not guaranteed, there is a surplus after the above-mentioned band allocation for subscriber stations for which the minimum band is guaranteed. The base station is characterized by having a scheduling means for evenly allocating the band.

According to the sixteenth aspect of the present invention, if the required number of bands required to transmit the user data is equal to or less than the allocatable band number, the required number of bands is the number of bands to which the required number of bands can be allocated. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the sixteenth aspect of the present invention, since the bandwidth is allocated in order from the subscriber station with high priority to the subscriber station with low priority, the latency of the subscriber station with high priority is guaranteed. You can

According to the sixteenth aspect of the present invention, with respect to the subscriber stations whose minimum bandwidth is not guaranteed, the remaining bandwidth after the end of the bandwidth allocation for the subscriber stations whose minimum bandwidth is guaranteed is fairly assigned. , Minimum bandwidth is not guaranteed It is possible to fairly guarantee the minimum bandwidth and latency of subscriber stations.

The invention according to claim 17 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed place by a time division multiple access system, The total number of minimum bandwidths guaranteed to subscriber stations is set so that it does not exceed the number of allocatable bandwidths prepared in one radio frame. Based on the table that lists the priority of each user station, the number of required bandwidths required to transmit user data is set to be less than or equal to the allocatable bandwidth in order from subscriber stations with high priority to subscriber stations with low priority. If there is a subscriber station whose minimum bandwidth is guaranteed, and the minimum bandwidth is guaranteed if the required bandwidth exceeds the allocatable bandwidth, the subscriber station whose minimum bandwidth is guaranteed is the subscriber station whose minimum bandwidth is guaranteed. about A base station, characterized in that it comprises a scheduling means for fairly allocating bandwidth left over after serial bandwidth allocation ends.

According to the seventeenth aspect of the present invention, in addition to the fifteenth aspect of the invention, the sum total of the minimum band numbers guaranteed to the subscriber stations is prepared in one radio frame. Since it is set so as not to exceed the number of bands that can be allocated, it is possible to guarantee a certain minimum band and latency even for subscriber stations with low priority.

The invention according to claim 18 is the base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, Is set to 0 indicating the highest priority, and the number of uplink radio bands COUNT_U indicating the number of bands that can be assigned to the uplink and the number DOWN_D of downlink radio bands that indicates the number of bands that can be assigned to the downlink are set. Step S11 for setting to 0
And whether or not all of the downlink radio bands have been allocated by comparing the number of downlink radio bands COUNT_D with the total number of bands DMAX that can be allocated to the downlink, S12, and the allocation is completed. If it is determined that all the allocation of the uplink radio band is completed, it is judged by comparing the number of uplink radio bands COUNT_U with the total number UMAX of bands that can be allocated to the uplink, and the allocation is completed. If it is judged that the allocation of the downlink radio band is completed, on the other hand, if it is judged that the allocation of the downlink radio band is not completed, the process proceeds to step S24 described later and the step S12. When it is determined, the relative subscriber station number N in the priority management table is set to the head of the priority management table. In step S14, which represents the subscriber station being entered, the priority management table is accessed, and the absolute subscriber number SUB_No is obtained based on the priority and the relative subscriber station number N. The bandwidth management table is accessed in step S15 and step S15, and the minimum downlink allocation number D_MIN and the total data amount D_DATA in the downlink subscriber station buffer are acquired based on the absolute subscriber station number obtained in step S15. In step S16, the minimum downlink allocation number D_MIN acquired in step S15 is compared with the total data amount D_DATA in the downlink subscriber station buffer in step S17.
If the total data amount D_DATA exceeds the downlink minimum bandwidth number D_MIN as a result of the comparison in step S17, the downlink wireless bandwidth is assigned to the downlink minimum assignment number D_MIN, and the process proceeds to step S20 described later.
8 and the total data amount D_DATA is the minimum downlink band number D_M
If it has not exceeded IN, the total data amount D_DA
The downlink radio band is assigned to TA, and the number of assigned bands D_DAT is assigned to COUNT_D that indicates the total number of assigned downlink radio bands in step S19 that proceeds to step S21 described below.
Step S20 of adding A and subtracting the allocated number of bands D_DATA from the total number of requested bandwidths D_DATA from the subscriber station, and the number of bands D_MIN allocated to COUNT_D indicating the total number of allocated downlink radio bands.
And subtracting the allocated band number D_MIN from the total number D_DATA of band requests from the subscriber stations, and assigning to the uplink channel number COUNT_D and whether or not the allocation of the uplink radio band is completed. If the determination is made by comparing the total number of available bands UMAX, and if it is determined that the allocation has been completed, the process proceeds to step S23, and it is determined whether all the allocation of the uplink radio band is completed. The number of wireless bands COUNT_D is compared with the total number DMAX of bands that can be assigned to the downlink, and when it is determined that the assignment has been completed, the time slot assignment is finished while the time slot is finished. If it is determined that the bandwidth management table does not exist, the process proceeds to step S23, which proceeds to step S12. And access, uplink minimum allocation number based on the absolute subscriber number obtained in step S15 u_M
IN and downlink subscriber station buffer total data amount U_DA
Step s24 of acquiring TA and step S24
In the case where the total amount of data U_DATA exceeds the minimum number of upstream bands U_MIN as a result of the step S25 of comparing the minimum number of uplink allocation U_MIN obtained in In step S26, the uplink radio band is allocated to the minimum number of uplink allocations U_MIN, and the process proceeds to step s28 described below. If the total amount of data U_DATA has not exceeded the minimum number of uplink bands U_MIN, the total amount of data U
Allocate an uplink radio band to _DATA, and step S below
In step S27, the number of allocated bands U_
The total number U of bandwidth requests from subscriber stations is added by adding DATA
Step S28 of subtracting the allocated number of bands U_DATA from _DATA, and adding the allocated number of bands U_MIN to COUNT_U indicating the total number of allocated uplink radio bands to obtain the total number of band requests U_DATA from the subscriber stations.
Step S of subtracting the allocated number of bands U_MIN from
29 is compared with N, which indicates the relative number of subscriber stations, and the total number N_MAX of subscriber stations accommodated in the base station, and the uplink and downlink of all subscriber stations entered in the priority M are compared. Determine whether the wireless band allocation process has been performed,
If the processing has not been performed for all subscriber stations, the process proceeds to step S31. If it is determined that the processing has been performed for all subscriber stations, step S32.
To step S30, the relative subscriber station number N is incremented to perform processing for the next subscriber station entered in the priority, and the priority M and the lowest priority are shown. Comparing with M_END, for all subscriber stations accommodated in the base station,
If it is determined in step S32 that the uplink and downlink radio band allocation processing has not been performed, and if it is determined that the uplink and downlink radio band allocation processing has not been performed for all priorities, priority is given to The subscriber station entering the next priority is incremented by one and the processing is performed on the subscriber station while the above step S32 is performed.
When it is determined that the scheduling of all the priorities has been completed, the priority M is set to 0 and the above-described processing is repeated in step S33 and steps S11 to S33 are performed in the wireless band. The base station is characterized by having a scheduling means for performing step S34 which is repeated until all are allocated.

According to the eighteenth aspect of the present invention, if the required number of bands required to transmit the user data is equal to or less than the allocatable band number, the required number of bands is the number of the required band numbers that can be assigned. Since the minimum number of bandwidths is assigned when the number of channels exceeds, the minimum bandwidth can be guaranteed for a particular subscriber station even if the traffic is congested.

According to the eighteenth aspect of the present invention, the bandwidth is allocated in order from the subscriber station having a high priority to the subscriber station having a low priority, so that the latency of the subscriber station having a high priority is guaranteed. You can

According to the eighteenth aspect of the present invention, the allocation is repeated until all of the allocatable bands prepared in one radio frame are allocated, so that no band is wasted.

[0070]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a scheduling method and a base station apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 is a diagram showing a configuration example of a communication system to which the present invention is applied. The communication system provides a fixed wireless access service to a plurality of subscriber stations. The fixed base station 11 and a plurality of subscriber stations communicate with each other via a wireless line. The base station 11 is connected to the network 10 by wire. Therefore, each subscriber station 21 can access the network 10 via the base station 11. As the network 10, for example, I
A P network can be used.

The base station 11 and the plurality of subscriber stations 21 have a T
Bidirectional communication is performed by DMA / TDD. A plurality of subscriber stations 21 have a common radio frequency, and by using different time slots (that is, FIG. 5 described later).
(Using the radio frame shown in FIG. 2) to communicate with the base station 11.

FIG. 5 is a diagram showing a configuration example of a radio frame according to the embodiment of the present invention. In FIG. 5, TS1
Reference numeral 1 denotes a downlink header area that can be simultaneously received by a plurality of subscriber stations. This downlink header area includes the following areas. That is, a frame structure area for the base station to notify each subscriber station of the structure of the radio frame, a monitoring / control area for the base station to monitor / control each subscriber station,
A slot demand arbitration area for arbitrating slot demand (slot demand is randomly transmitted from multiple subscriber stations to a base station), for notifying allocation of uplink time slots to each subscriber station This is the upstream data area.

In the slot demand area, the subscriber station requests the base station for a time slot (band) for transmitting the user data stored in the transmission buffer of the subscriber station (band request). The base station stores the band requested by the subscriber station. Then, the base station performs scheduling, allocates a time slot to the subscriber station that requested the band, and notifies this in the uplink data area.

FIG. 4 is a diagram showing a configuration example of the base station according to the embodiment of the present invention. As shown in FIG.
1 includes an antenna 12, a high frequency circuit 32, and a communication control circuit 33. The high frequency circuit 32 is the receiver 4
1, a transmitter 42 and a switch 43 are provided. The communication control circuit 33 includes a modulation / demodulation circuit 51, a MAC.
(Media access control) Layer control circuit 52, L
LC (logical link control) layer control circuit 51,
Communication interface circuit 54, scheduling circuit 5
5, priority management table 61, bandwidth management table 6
2. A downlink subscriber station transmission buffer 63 is provided.

The communication interface circuit 54 is connected to the network shown in FIG. LLC layer control circuit 52
Incorporates a buffer for temporarily storing the data of the transmission signal and the reception signal. In addition, the LLC layer control circuit 53 distributes the signal received from the communication interface 54 to the corresponding subscriber station and generates a wireless packet.

The MAC layer control circuit 52 assigns a device identification ID (MACID) at the layer 2 level to the data and uses the scheduling circuit 55 to dynamically set the time slot (band) of the upstream and downstream data areas. , Allocate efficiently.

The modulation / demodulation circuit 51 includes a MAC layer control circuit 52.
The base layer signal input from the high frequency circuit 32 is modulated and output to the high frequency circuit 32, and the received signal of the intermediate frequency input from the high frequency circuit 32 is demodulated to the MAC layer control circuit 5
Output to 2.

The transmitter 42 of the high frequency circuit 32 frequency-converts the intermediate frequency signal input from the modulation / demodulation circuit 51 into a radio frequency, power-amplifies the radio frequency high frequency signal, and receives the radio frequency signal by the switch 12. The received signal is input through the switch 43, amplified by a built-in low noise amplifier, frequency-converted to an intermediate frequency, and output to the modulation / demodulation circuit 51.

A priority management table 61 and a bandwidth management table 62 are connected to the scheduling circuit 55. FIG. 6 is a diagram showing an example of the priority order management table. In the priority management table 61, subscriber stations are classified by priority, and subscriber stations with higher priority are entered from the top. Bands are assigned to subscriber stations entered at level 0 with the highest priority, and then to subscriber stations entered at level 1. And finally, level M_E
Bandwidth is allocated to the subscriber stations that are entered in the ND.

The link destination subscriber station information at each level stores a subscriber station number for identifying the subscriber station entered at that level. This subscriber station number is the subscriber station number of each subscriber station. It is a pointer to the bandwidth management table 62.

FIG. 7 is a diagram showing an example of the band management table according to the embodiment of the present invention. Bandwidth management table 6
2 holds the bandwidth allocation information for each subscriber, as described above. Specifically, the bandwidth management table 62 is a SUB_No indicating the subscriber station number, the priority (0 to M) entered in the priority management table 61,
Minimum number of upstream bands U_MIN, minimum number of downstream bands D_MI
It holds N, the latest value U_DATA of the total number of bandwidth requests, and the latest value D_DATA of the total amount of data in the transmission buffer of the subscriber station to the base station, which is accumulated in the base station.

A subscriber station whose minimum number of bands is set to 2 or more is guaranteed in the number of bands in communication with the base station. On the other hand, best-effort service is provided to subscriber stations whose minimum bandwidth is not guaranteed. In this embodiment, the minimum number of upstream and downstream bands of the subscriber station to which the best effort service is provided is 1.

In the present embodiment, the total number of U_MIN and D_MIN across all subscriber stations is set so as not to exceed the total number of bands of upstream data areas and downstream data areas in one radio frame. To do. This is because it is possible to allocate a certain amount of bandwidth to a subscriber station having a low priority when the traffic is light.

FIG. 8 is a diagram showing a specific example of band allocation operation in the downlink. The subscriber station No. 2 (N = 2) having the highest priority is assigned to the subscriber station No. 2 with the lowest downlink bandwidth D_MIN.
Is assigned, the lowest downlink bandwidth of the subscriber station is assigned to the subscriber station No. 3 (N = 3) having the next highest priority. Finally, subscriber station No. 1 (N = 1) or subscriber station 25 with no bandwidth guarantee (that is, the lowest priority)
As described above, the lowest band number (1) is assigned to the fourth channel (N = 254).

Although a specific example of the band allocation operation in the downlink is shown in FIG. 8, the same operation can be performed in the case of the uplink. Figure 1
2 and 2 are flowcharts showing scheduling according to the embodiment of the present invention. This scheduling is performed by the MAC layer control circuit 52 and the scheduling circuit 55.
It is realized by and. This scheduling starts at the timing synchronized with the radio frame interval.

The user data stored in the subscriber station buffer 63 of the base station 11 is stored in the priority table 6 described above.
1. According to the bandwidth management table 62, the scheduling is performed, and the base stations are transmitted to the subscribers in order from the subscriber station having the highest priority.

In FIG. 1 and FIG. 2, N indicates a relative subscriber station number for identifying the subscriber station among the subscriber stations entered in a certain priority, and N_MAX.
Indicates the total number of subscriber stations accommodated in the base station 11. D
_DATA is the amount of data accumulated in the downlink subscriber station buffer 63, and U_DATA is the bandwidth management table 62.
Shows the total number of bandwidth requests from each subscriber station, that is, the amount of data in the transmission buffer accumulated in each subscriber station. U_MIN and D_MIN indicate the minimum and maximum bandwidths of each subscriber station recorded in the bandwidth management table, respectively.

After the main scheduling is started at the timing synchronized with the radio frame, the scheduling means sets M indicating the priority to 0 indicating the highest priority in step S11. In addition, the number of uplink radio bands indicating the number of bands that can be allocated to the uplink is COUNT_
U, and COUNT_D is 0, which is the number of downlink radio bands that indicates the number of bands that can be allocated to the downlink.

The scheduling means carries out step S12.
In, whether all downlink radio band allocation has been completed,
The determination is made by comparing the number of downlink radio bands COUNT_D and the total number DMAX of bands that can be assigned to the downlink. When the scheduling means determines that the allocation has been completed, the process proceeds to step S13, and it is determined whether the allocation of the uplink wireless bands is completed or not and the total number of bands COUNT_U that can be allocated to the uplinks. Judge by comparing with UMAX. The scheduling means ends the allocation of the time slot (band) when it determines that the allocation is completed.
If it is determined that it has not ended, the process proceeds to step S24, and allocation of the upstream radio band is started.

The scheduling means carries out step S12.
If it is determined that the downlink radio band has not been allocated, the process proceeds to step S14, and the relative subscriber station number N in the priority management table 61 is entered at the head of the priority management table. Set to 1 to indicate the subscriber station being served.

The scheduling means carries out step S15.
Then, the priority management table 61 is accessed, and the absolute subscriber number SUB_No is obtained based on the priority and the relative subscriber station number N. If (M = 1, N = 0), the absolute subscriber station number SUB_No of the subscriber station with the highest priority
Can be obtained.

The scheduling means carries out step S16.
Then, in step S15, access the bandwidth management table,
Based on the absolute subscriber station number obtained in step S15, the minimum downlink allocation number D_MIN and the total data amount D_DATA of the downlink subscriber station buffer are acquired, and step S1
Compare in 7.

If the total data amount D_DATA exceeds the minimum downlink band number D_MIN as a result of the comparison, the scheduling means allocates the downlink radio band to the minimum downlink allocation number D_MIN (step S18), and step S2.
Go to 0. The scheduling means performs step S20.
, COUNT_ indicating the total number of downlink radio bands allocated
The number of allocated bands D_DATA is added to D.

Also, the total number D of bandwidth requests from subscriber stations
Subtract the allocated bandwidth number D_DATA from _DATA. As a result, the total number of bandwidth requests from the subscriber stations D_D
ATA is updated to the latest value.

On the other hand, when the total data amount D_DATA has not yet exceeded the minimum downlink band number D_MIN, the scheduling means allocates the downlink radio band to the total data amount D_DATA (step S19), and proceeds to step S21. In step S21, the scheduling means adds the allocated number of bands D_MIN to COUNT_D indicating the total number of allocated downlink radio bands. Also, the number of allocated bands D_MIN is subtracted from the total number of band requests D_DATA from the subscriber stations. As a result, the total number of band requests D_DATA from the subscriber stations is updated to the latest value.

The scheduling means carries out step S22.
Then, it is determined whether or not the allocation of the uplink radio bands has been completed by comparing the number COUNT_D of the uplink radio bands with the total number UMAX of the bands that can be assigned to the uplink. When the scheduling means determines that the allocation has been completed, the scheduling means proceeds to step S23, and determines whether or not the allocation of the uplink wireless bands has been completed, the number of downlink wireless bands COU.
The determination is made by comparing NT_D with the total number DMAX of bands that can be allocated to the downlink. The scheduling means ends the time slot allocation when it determines that the allocation is completed. If it is determined that the processing has not been completed, the process proceeds to step S12, and downlink radio band allocation is started.

The scheduling management means uses step s.
In step 24, the bandwidth management table is accessed and step S1
Based on the absolute subscriber number obtained in step 5, the minimum number of uplink allocation U_MIN and the total amount of data U in the downlink subscriber station buffer
_DATA is acquired, and the process proceeds to step S25 for comparison.

If the total data amount U_DATA exceeds the minimum number of uplink bands U_MIN as a result of the comparison, the scheduling means allocates an upstream radio band to the minimum number of uplink allocations U_MIN (step S26), and step S2.
Go to 8. The scheduling means is step S28.
, COUNT_ indicating the total number of assigned uplink radio bands
The number of allocated bands U_DATA is added to U. Further, the allocated band number U_DATA is subtracted from the total band request number U_DATA from the subscriber stations. As a result, the total number U_DATA of bandwidth requests from the subscriber stations is updated to the latest value.

On the other hand, if the total amount of data U_DATA has not yet exceeded the minimum number of upstream bands U_MIN, the scheduling means allocates the upstream radio band to the total amount of data U_DATA (step S27), and proceeds to step S29. The scheduling means sets COUNT_U indicating the total number of uplink radio bands allocated in step S29 to
The number of allocated bands U_MIN is added. Also, the allocated band number U_MIN is subtracted from the total number U_DATA of the band requests from the subscriber stations. As a result, the total number U_DATA of bandwidth requests from the subscriber stations is updated to the latest value.

The scheduling means carries out step S30.
Then, N, which indicates the relative number of subscriber stations, is compared with the total number N_MAX of subscriber stations accommodated in the base station, and uplink and downlink radios for all subscriber stations entered in the priority M are compared. It is determined whether bandwidth allocation processing has been performed. If not processed for all subscriber stations,
In step S31, the relative subscriber station number N is incremented and the process is performed for the next subscriber station entered in the priority.

The scheduling means carries out step S30.
When it is determined that the processing has been performed for all subscriber stations, the process proceeds to step 32, the priority M is compared with M_END indicating the lowest priority, and all the subscribers accommodated in the base station are compared. It is determined whether or not the uplink and downlink radio band allocation processing has been performed for the personnel station.

The scheduling means carries out step S32.
When it is determined that the uplink and downlink radio band allocation processing is not performed for all the priorities, the priority M is incremented and the processing is performed for the subscriber station entering the next priority. Do it.

On the other hand, when the scheduling means determines in step S32 that the scheduling of all the priorities is completed, it sets the priority M to 0 and repeats the above-mentioned processing. In the present embodiment, the above process is repeated until all the wireless bands are assigned.

According to the present embodiment, the subscriber stations are assigned the radio bands in order from the subscriber station with the highest priority and in the form in which the minimum bandwidth is guaranteed. Therefore, according to the present embodiment, it is possible to perform scheduling that guarantees the minimum bandwidth and latency of a subscriber station having a high priority even under a congested traffic condition.

Further, according to the present embodiment, the allocation of the wireless band is repeated until all the wireless bands are allocated. Therefore, according to the present embodiment, the wireless band can be efficiently allocated without waste.

[0107]

As described above, according to the present invention,
Bandwidth can be assigned to a specific subscriber station with guaranteed minimum bandwidth and latency. Therefore, according to the present invention, while providing the best-effort communication to general subscriber stations in the fixed wireless access service that provides a large amount of data such as video and audio, which is rapidly increasing in recent years, , Can provide high quality and high speed communication to specific subscriber stations.

[Brief description of drawings]

FIG. 1 is a flowchart (1/2) showing scheduling according to an embodiment of the present invention.

FIG. 2 is a flowchart (2/2) showing scheduling according to the embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a communication system to which the present invention is applied.

FIG. 4 is a diagram showing a configuration example of a base station according to the embodiment of the present invention.

FIG. 5 is a diagram showing a configuration example of a radio frame according to the embodiment of the present invention.

FIG. 6 is a diagram showing an example of a priority management table.

FIG. 7 is a diagram showing an example of a band management table according to the embodiment of the present invention.

FIG. 8 is a diagram showing a specific example of band allocation operation in the downlink.

FIG. 9 is a diagram showing a configuration example of a radio frame in a communication system adopting TDMA / TDD.

FIG. 10 is a diagram illustrating an outline of round robin control.

FIG. 11 is a diagram showing a round robin control algorithm.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukihide Mizumoto             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation (72) Inventor Fumio Murakami             5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan             Wireless Co., Ltd. F term (reference) 5K033 AA01 CA11 CB06 CB17 DA01                       DA17                 5K067 AA12 BB21 EE10 EE13 EE24                       EE63 EE66 HH22 JJ17 JJ43

Claims (18)

[Claims] 1. A time scheduling method in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the scheduling means comprises each subscriber. Based on the priority management table that describes the priority of the stations, the lowest number of bands is grasped in order from the subscriber station with the highest priority to the subscriber station with the lowest priority, and the bandwidth is allocated to one radio frame. A time scheduling method, characterized in that the allocation is repeated until all of the allocatable bands are allocated. 2. A time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the method being guaranteed to the subscriber stations. The total number of minimum bandwidths is set so as not to exceed the number of allocatable bandwidths prepared for one radio frame, and the scheduling means is based on the priority management table that describes the priority of each subscriber station. , From the subscriber station with the highest priority to the subscriber station with the lowest priority in order of allocating the bandwidth by recognizing the minimum number of bandwidths, until all of the allocatable bandwidths prepared in one radio frame are assigned. A time scheduling method characterized by repeating allocation. 3. A time scheduling method in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the scheduling means comprises each subscriber. The number of bandwidths required to transmit user data, in order from subscriber stations with high priority to subscriber stations with low priority, based on the priority management table that describes the priority of stations. If the number of required bandwidths is below, the minimum number of bandwidths is assigned if the number of required bandwidths exceeds the allocatable bandwidth number, and all of the allocatable bandwidth numbers prepared for one radio frame are assigned. A time scheduling method, characterized in that the above-mentioned allocation is repeated until it is received. 4. A time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, which guarantees the subscriber stations. The total number of minimum bandwidths is set so as not to exceed the number of allocatable bandwidths prepared for one radio frame, and the scheduling means is based on the priority management table that describes the priority of each subscriber station. , From a subscriber station with a high priority to a subscriber station with a low priority, if the required bandwidth number required to transmit user data is less than or equal to the allocatable bandwidth, the required bandwidth number is If the number of allocatable bands is exceeded, the minimum number of bands is allocated, and the allocation is performed until all of the allocatable bands prepared in one radio frame are allocated. Time scheduling method, characterized in that return Ri. 5. A time scheduling method in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the scheduling means has a minimum bandwidth. As for guaranteed subscriber stations, the lowest band number is grasped in order from the subscriber station with high priority to the subscriber station with low priority based on the table describing the priority of each subscriber station A time scheduling method characterized in that, for subscriber stations whose allocation and minimum bandwidth are not guaranteed, the remaining bandwidth after the completion of the bandwidth allocation is uniformly allocated to the subscriber stations whose minimum bandwidth is guaranteed. 6. A time scheduling method in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, and a minimum bandwidth is guaranteed. For the subscriber stations for which the sum of the minimum bandwidth numbers for the subscriber station is set so as not to exceed the allocatable bandwidth number prepared for one radio frame and the scheduling means guarantees the minimum bandwidth, Based on the table that describes the priority of each subscriber station, the lowest bandwidth is allocated in order from the highest priority subscriber station to the lowest priority subscriber station, and the lowest bandwidth is not guaranteed. Regarding subscriber stations, a time schedule characterized by allocating the remaining bandwidth fairly after the end of the bandwidth allocation for the subscriber station whose minimum bandwidth is guaranteed. Ring method. 7. A time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the scheduling means has a minimum bandwidth. For guaranteed subscriber stations, it is necessary to transmit user data in order from subscriber stations with high priority to subscriber stations with low priority, based on a table describing the priority of each subscriber station. If the number of request bands is equal to or less than the allocatable band number,
If the requested number of bands exceeds the number of bands that can be allocated, the minimum number of bands is allocated. A time scheduling method characterized by allocating the allocated bandwidth fairly. 8. A time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the subscription guaranteeing a minimum bandwidth. For the subscriber stations for which the sum of the minimum bandwidth numbers for the subscriber station is set so as not to exceed the allocatable bandwidth number prepared for one radio frame and the scheduling means guarantees the minimum bandwidth, The number of bands that can be allocated as the required number of bands for transmitting user data in order from subscriber stations with high priority to subscriber stations with low priority, based on a table that describes the priority of each subscriber station. If the number of required bands is
If the requested number of bands exceeds the number of bands that can be allocated, the minimum number of bands is allocated, and for subscriber stations for which the minimum band is not guaranteed, there is a surplus after the above-mentioned band allocation for subscriber stations for which the minimum band is guaranteed. A time scheduling method characterized by allocating the allocated bandwidth fairly. 9. A time scheduling method in a fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the scheduling means assigns priority to each other. The value M is set to 0, which indicates the highest priority, and the number of uplink radio bands COUNT_U indicating the number of bands that can be assigned to the uplink and the number of downlink radio bands COUNT_D indicating the number of bands that can be assigned to the downlink are set to 0. Step S11
And the scheduling means determines whether or not all the downlink radio bands have been allocated by comparing the number of downlink radio bands COUNT_D with the total number of bands DMAX that can be assigned to the downlink, S12, and the scheduling means When it is determined that the allocation has been completed, it is determined whether the allocation of the upstream radio band is completed by comparing the number of upstream radio bands COUNT_U and the total number of bands UMAX that can be allocated to the uplink. When it is determined that the allocation is completed, the bandwidth allocation is terminated, while when it is determined that the allocation is not completed, the processing proceeds to step S24 described later, and the scheduling means is configured to execute the step S12. If it is determined that the downlink radio band has not been allocated, the priority management Step S1 of setting the N is the relative subscriber station number in table, the 1 representing the subscriber stations that are entered in the top of the priority management table
4 and the scheduling means accesses the priority management table and obtains the absolute subscriber number SUB_No based on the priority and the relative subscriber station number N.
15, and the scheduling means accesses the bandwidth management table in step S15, and based on the absolute subscriber station number obtained in step S15, the minimum downlink allocation number D_M.
Total data amount of IN and downlink subscriber station buffer D_DA
The step S16 of acquiring TA and the step S17 of the scheduling means comparing the minimum downlink allocation number D_MIN and the total data amount D_DATA of the downlink subscriber station buffer acquired in step S15.
When the total data amount D_DATA exceeds the minimum downlink bandwidth number D_MIN as a result of the comparison in step S17, the scheduling means determines the minimum downlink allocation number D_MIN.
A downlink radio band is assigned to MIN, and step S20 described below is performed.
If the total data amount D_DATA has not yet exceeded the minimum downlink bandwidth number D_MIN, the process proceeds to step S18
A downlink radio band is allocated to the total data amount D_DATA, and the scheduling means proceeds to step S21 described below, and the scheduling unit assigns the number of allocated bands D_DA to COUNT_D indicating the total number of the downlink radio bands allocated.
Step S20 of adding TA and subtracting the allocated band number D_DATA from the total number D_DATA of the band requests from the subscriber stations, and the scheduling means the number of bands D_MIN allocated to COUNT_D indicating the total number of allocated downlink radio bands.
And subtracting the allocated number of bands D_MIN from the total number of requested bandwidths D_DATA from the subscriber station, and the scheduling means determines whether the allocation of all upstream radio bands has been completed by using the number of upstream radio bands COUNT_D. The determination is made by comparing with the total number UMAX of bands that can be allocated to the uplink, and when it is determined that the allocation has been completed, the process proceeds to step S23.
Then, it is determined whether or not the allocation of the uplink radio bands is completed by comparing the number of downlink radio bands COUNT_D with the total number of bands DMAX that can be assigned to the downlink,
When it is determined that the allocation is completed, the time slot allocation is completed, while when it is determined that the allocation is not completed, the process proceeds to step S12, and the scheduling means stores the time in the bandwidth management table. Step S for accessing and acquiring the minimum number of uplink allocation U_MIN and the total amount of data U_DATA of the downlink subscriber station buffer based on the absolute subscriber number obtained in step S15.
24, and the scheduling means compares the minimum number of uplink allocation U_MIN acquired in step S24 with the total data amount U_DATA of the buffer of the downstream subscriber station in step S25.
If the total data amount U_DATA exceeds the minimum upstream bandwidth U_MIN as a result of the comparison in step S25, the scheduling means determines the minimum upstream allocation U_MIN.
The uplink radio band is assigned to MIN, and the step S2 described later is performed.
In step S26, the scheduling means determines that the total data amount U_DATA has not exceeded the upstream minimum bandwidth number U_MIN.
The uplink radio band is allocated to the total data amount U_DATA, and the procedure proceeds to step S29 described below in step S27, and the scheduling means assigns the number of allocated bands U_DA to COUNT_U indicating the total number of the uplink radio bands allocated.
Total number of bandwidth requests from subscriber stations U_D
Step S28 of subtracting the allocated band number U_DATA from the ATA, and the scheduling means assigns the allocated band number U_MI to COUNT_U indicating the total number of allocated uplink radio bands.
Add N and total number of bandwidth requests from subscriber stations U_DA
Step S29 of subtracting the allocated band number U_MIN from TA, and the scheduling means compares N, which indicates the relative number of subscriber stations, with the total number N_MAX of subscriber stations accommodated in the base station, and sets the priority to M. It is determined whether the uplink and downlink radio band allocation processing has been performed for all the subscriber stations that have been entered, and if the processing has not been performed for all subscriber stations, the process proceeds to step S31 while all subscriptions are performed. If it is determined that processing has been performed for the personnel station,
The step S30 of advancing to step S32, the scheduling means increments the relative number of subscriber stations N, and performs the processing for the next subscriber station entered in the priority, and the scheduling means Step S32 of comparing the priority M with M_END indicating the lowest priority to determine whether the uplink and downlink radio band allocation processing has been performed for all subscriber stations accommodated in the base station; When the scheduling means determines in step S32 that the uplink and downlink radio band allocation processing has not been performed for all priorities, the priority M is incremented and the next priority is entered. While performing the processing for the subscriber stations that are present,
When it is determined that the scheduling of all the priorities has been completed, the priority M is set to 0 and the above-described processing is repeated in step S33, and the scheduling means performs the steps from step S11 to step S33. Repeating step S34 until all of the wireless bands are allocated, and a time scheduling method comprising: 10. A base station in a fixed wireless access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the priority of each subscriber station is set. Based on the priority management table described above, the lowest bandwidth number is sequentially allocated from the subscriber station with the highest priority to the subscriber station with the lowest priority, and the bandwidth is allocated, so that it is possible to allocate the bandwidth prepared in one radio frame. A base station comprising a scheduling means for repeating the allocation until all of the number of bands are allocated. 11. A base station in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the base station being guaranteed to the subscriber stations. The total number of minimum bandwidths is set so that it does not exceed the number of allocatable bandwidths prepared in one radio frame, and priority levels are set based on the priority management table that describes the priority level of each subscriber station. Scheduling that repeats the above allocation until all the allocatable bandwidths prepared in one radio frame are allocated by recognizing the minimum number of bandwidths in order from the subscriber station with the highest priority to the subscriber station with the lowest priority. A base station comprising means. 12. A base station in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the priority of each subscriber station is set. Based on the priority management table described above, if the required number of bands required to transmit the user data is equal to or less than the allocatable band number, in order from the subscriber station with high priority to the subscriber station with low priority, The number of required bands is assigned the minimum number of bands if the required number of bands exceeds the number of allocatable bands, and the allocation is performed until all of the allocatable bands prepared in one radio frame are allocated. A base station having a scheduling unit that repeats. 13. A base station in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the base station being guaranteed to the subscriber stations. The total number of minimum bandwidths is set so that it does not exceed the number of allocatable bandwidths prepared in one radio frame, and priority levels are set based on the priority management table that describes the priority level of each subscriber station. In order from the subscriber station with the highest priority to the subscriber station with the lowest priority, if the required number of bands required to transmit user data is less than or equal to the allocatable band, the required number of bands is If the number exceeds the maximum number, the minimum bandwidth number is allocated, and a scheduling means for repeating the allocation until all the allocatable bandwidth numbers prepared in one radio frame are allocated is provided. Said base station. 14. A base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the base station having a guaranteed minimum bandwidth. For each subscriber station, based on the table that describes the priority of each subscriber station, the lowest bandwidth number is grasped in order from the subscriber station with high priority to the subscriber station with low priority, and the bandwidth is allocated, and A base station having a scheduling means for evenly allocating a surplus band after the end of the band allocation for the subscriber station whose minimum band is not guaranteed. 15. A base station in a fixed radio access system in which one base station and a plurality of subscriber stations communicate by a time division multiple access method at a fixed location, which is the minimum guaranteed by the subscriber station. For subscriber stations that are set so that the total number of bands does not exceed the number of allocatable bands prepared in one radio frame, and the minimum bandwidth is guaranteed, the priority of each subscriber station is noted. Based on the table, the lowest band number is allocated in order from the subscriber station with the highest priority to the subscriber station with the lowest priority, and the lowest bandwidth is guaranteed for subscriber stations where the lowest bandwidth is not guaranteed. A base station having a scheduling means for evenly allocating the remaining band after the band allocation is completed for the subscriber station. 16. A fixed radio access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein the base station is a guaranteed minimum bandwidth. For each subscriber station, based on the table that describes the priority of each subscriber station, the number of requested bands required to transmit user data is calculated in order from the subscriber station with the highest priority to the subscriber station with the lowest priority. If the number of bands that can be allocated is less than or equal to the number of bands that can be allocated, the number of requested bands is allocated. If the number of requested bands exceeds the number of bands that can be allocated, the minimum number of bands is allocated. The base station is characterized in that it has scheduling means for evenly allocating the remaining band after the band allocation is completed for the subscriber station that is guaranteed. 17. A base station in a fixed wireless access system in which one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, the base station being guaranteed to the subscriber stations. For subscriber stations that are set so that the total number of minimum bandwidths does not exceed the number of allocatable bandwidths prepared in one radio frame, and the minimum bandwidth is guaranteed, write the priority of each subscriber station. Based on the table, if the number of request bands required to transmit user data is less than or equal to the allocatable band in order from the subscriber station with high priority to the subscriber station with low priority, , If the required number of bands exceeds the number of allocatable bands, allocate the minimum number of bands, and for subscriber stations where the minimum bandwidth is not guaranteed, after the above-mentioned bandwidth allocation for subscriber stations with the minimum bandwidth guaranteed Base station, characterized in that it comprises a scheduling means for assigning the excess bandwidth fairly. 18. The base station in a fixed radio access system, wherein one base station and a plurality of subscriber stations communicate at a fixed location by a time division multiple access method, wherein M indicating a priority is the maximum. The number of uplink radio bands COUNT_U indicating the number of bands that can be assigned to the uplink and the number of downlink radio bands COUNT indicating the number of bands that can be assigned to the downlink, while being set to 0 indicating priority.
_D is set to 0 in step S11, and whether or not all downlink radio bands have been assigned is determined by comparing the number of downlink radio bands COUNT_D and the total number of bands DMAX that can be assigned to downlinks, S12, When it is determined that the allocation has been completed, it is determined whether all the allocations of the upstream wireless bands have been completed.
_U and the total number of bands U that can be allocated to the uplink U
The determination is made by comparing with MAX, and when it is determined that the allocation is completed, the bandwidth allocation is completed,
If it is determined that the processing has not ended, step S2 described below is performed.
When it is determined in step S13 to proceed to step 4 and in step S12 that the downlink radio band has not been allocated, the relative subscriber station number N in the priority management table is set to the priority management table. Step S14, which represents the subscriber station entered at the beginning of the, and accesses the priority management table to determine the absolute subscriber number based on the priority and the relative subscriber station number N. S
In step S15 for obtaining UB_No, the bandwidth management table is accessed in step S15,
Based on the absolute subscriber station number obtained in step S15, the minimum downlink allocation number D_MIN and the total data amount D_DATA of the downlink subscriber station buffer are acquired in step S.
16 and the minimum downlink allocation number D_M acquired in step S15.
IN and total amount of data in downlink subscriber station buffer D_DATA
And step S17 of comparing the total data amount D with the result of the comparison in step S17.
If _DATA exceeds the minimum downlink band number D_MIN, the downlink radio band is allocated to the minimum downlink allocation number D_MIN, and the process proceeds to step S20 described below.
If the total data amount D_DATA has not yet exceeded the minimum downlink band number D_MIN, the downlink wireless band is assigned to the total data amount D_DATA, and step S19 proceeds to step S21 described below, and the total number of assigned downlink wireless bands is shown. COUNT_D
To the number of allocated bandwidths D_DATA and subtracting the number of allocated bandwidths D_DATA from the total number of bandwidth requests D_DATA from the subscriber stations in step S2.
0, and a step S21 of adding the number of allocated bands D_MIN to COUNT_D indicating the total number of allocated downlink wireless bands and subtracting the number of allocated bands D_MIN from the total number of band requests D_DATA from the subscriber station; Whether or not all of the above have been allocated by comparing the number of uplink radio bands COUNT_D and the total number of bands UMAX that can be assigned to the uplink,
If it is determined that the allocation has been completed, step S
The process proceeds to step S22, and it is determined whether all the uplink radio bands have been allocated by comparing the number of downlink radio bands COUNT_D with the total number DMAX of bands that can be assigned to the downlink,
When it is determined that the allocation is completed, the time slot allocation is completed, while when it is determined that the allocation is not completed, the process proceeds to step S12, step S23, and the bandwidth management table is accessed, Based on the absolute subscriber number obtained in step S15, the minimum number of uplink allocation U_
Total data amount U_D of MIN and downlink subscriber station buffer
Step s24 of acquiring ATA, and the minimum number of uplink allocation U_MI acquired in step S24
Step S25 of comparing N with the total data amount U_DATA of the downlink subscriber station buffer, and the total data amount U as a result of the comparison in Step S25.
If _DATA exceeds the minimum number of upstream bands U_MIN, the minimum number of upstream allocations U_MIN is allocated to the upstream radio band, and the process proceeds to step s28, which will be described later.
If the total amount of data U_DATA has not yet exceeded the minimum number of upstream bands U_MIN, the total amount of data U_DATA is assigned with an upstream radio band, and the process proceeds to step S29 described below in step S27. COUNT_U
Is added to the number of allocated bands U_DATA, and the number of allocated band U_DATA is subtracted from the total number of band requests U_DATA from the subscriber station S28 and COUNT_U indicating the total number of allocated uplink radio bands
To the step S29 of adding the allocated band number U_MIN and subtracting the allocated band number U_MIN from the total number of band requests U_DATA from the subscriber stations; The total number N_MAX of subscriber stations that are present is compared to determine whether or not the uplink and downlink radio band allocation processing has been performed for all subscriber stations entered in the priority M, and processing is performed for all subscriber stations. If not, the process proceeds to step S31. If it is determined that all subscriber stations have been processed, step S30 proceeds to step S32, and the relative subscriber station number N is incremented. , Step S31 for processing the next subscriber station entered in the priority, and M_E indicating the priority M and the lowest priority. By comparing the D, all subscriber stations that are accommodated by the base station,
Step S32 of determining whether the uplink and downlink radio bandwidth allocation processing has been performed, and if it is determined in step S32 that the uplink and downlink radio bandwidth allocation processing has not been performed for all priorities, priority is given to The priority M is incremented, and the subscriber station entering the next priority is processed. On the other hand, if it is determined in step S32 that the scheduling of all the priorities is completed, the priority M is set. Set to 0 and repeat the above process Step S33
And a step S34 of repeating the steps S11 to S33 until all the radio bands are allocated, and a scheduling means for executing the step S34.