JP2000253017A - Radio packet control station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform priority control corresponding to the kind of data necessary to communication quality assurance by receiving a data packet string to be transmitted to plural radio stations in each radio station of a different destination, acquiring and storing priority control information, performing allocation transmission according to the contents of the stored priority control information and controlling the transmission sequence of the data packet string according to the contents of the priority control information. SOLUTION: An access point(AP) adopts an access control system which varies the cycle period between a contention free period, a contention period and a distributed coordination function, and a point coordination function. This makes it possible to send a packet scheduled by a wired side to a radio terminal while maintaining the schedule and communication quality can consequently be assured. The AP receiving a data packet to a self-station first confirms a service class and decides whether or not to assure the quality of it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio packet control station (access point station) for controlling a plurality of radio stations for performing radio packet communication. In particular, the present invention provides a non-contention access control period in which the radio packet control station centrally controls and manages the contention, and a contention access control period in which the radio station and the radio packet control station autonomously compete and transmit radio packets. The present invention relates to a radio packet control station in a packet communication system that repeats periodically.

[0002]

2. Description of the Related Art As a radio access system to which the present invention is applied, there is a radio access system defined by the IEEE 802 committee.
The access method in the AN system is typical. This specification is based on “IEEE P802, Dra
ft Standard for Wireless
Access LAN Medium AccessC
control (MAC) and Physical
Layer (PHY) Specification, P
802.11D 8.0, 1 May 1998 ". In the following, this regulation is referred to as "IEEE80
2.11 standard ".

[0003] Regarding the MAC layer access method,
It is described in the “IEEE 802.11 standard”. Regarding contention access control, CSMA / CA (Carrier Sense) in which a plurality of wireless terminals transmit data while performing carrier sense so that packet collision does not occur.
Mu1tiple Access Collision
DCF (Distr) using the Aidance method
ibuted Coordination Function
ion, distributed control procedure), and for non-contention access control, PCF (P
oint Coordination Function
n, a centralized control procedure) is described in the IEEE 802.11 standard, so that the former will be referred to as DCF and the latter as PCF, and the contention access state period provided by DCF will be referred to as CP (Contention). P
eriod), and the period of the non-contention access state provided by the PCF is referred to as CFP (Contention F).
ree Period), and DCF and PCF
_Is referred to as CFP _Interval .

[0004] Regarding PCF, "IEEE80
In the “2.11 standard”, as shown in FIG. 1, options are defined in DCF, so when PCF is used as a method of controlling access to an AP, it is used in combination with DCF.

FIG. 2 shows an example of a conventional wireless access system, D which is described in "IEEE 802.11 standard".
It is a figure showing operation in CF. In this example, there are three wireless stations (STAs, stations). The figure shows a state after the data transmission of the STA1 has been completed, and the horizontal axis shows the passage of time. In the figure, IFS is a time for determining that the wireless medium is free, and is SIFS, PIFS, DIFS, EIFS in the order of short time, that is, in the order of higher access priority.
And four types of IFS.

First, after the transmission of STA1, the entire system waits for a period of DIFS, and then STA2 and STA3 further wait for a random interval.

[0007] Of STA2 and STA3, STA2
STA2 sends data to ST
Send to A1. This causes the STA3 to postpone data transmission because the wireless medium is busy. STA3 is S
After the transmission of TA2 is completed, transmission is attempted after waiting for the DIFS period.
Since it is transmitted with a SIFS interval shorter than FS,
STA3 postpones the transmission again. Then, after the ACK transmission is completed and DIFS further elapses, this time, ST1
Since the waiting time of A3 is reduced, STA3 can transmit data. With the above mechanism,
A response packet can be reliably transmitted without collision under a race condition.

FIG. 3 is an explanatory diagram of another example of a conventional wireless access method, which is an access method of a MAC layer using a DCF and a PCF in combination with each other as described in the “IEEE 802.11 standard”. The figure shows two radio stations (STA1, S
TA2) share the same frequency, and non-contention access is realized by the PCF. The horizontal axis indicates the passage of time.

In FIG. 3, an AP (access point) has a polling list in advance, and a PIF
The poll frame is transmitted to the first polled wireless station STA1 at the S frame interval. Upon receiving the poll frame addressed to itself, STA1 transmits a data frame to STA2 at the SIFS frame interval.

After receiving the data frame from STA1, STA2 receives the data frame at the SIFS frame interval after receiving the data.
Send CK. Then, the AP polls the STA to which the next access right is given at PIFS frame intervals.

[0011] The above series of operations is performed by the CF-End
Until the frame is transmitted or at a predetermined
Reach large time CF_Max_Duration
And the non-conflict period CFP is set. This CF
P is the first set CFP _IntervalRepeat with
And CFP_IntervalCFP ended in
Later, at least one frame of data can be transmitted
Is allocated to the DCF control shown in FIG.

As described above, CFP by centralized control PCF of AP
Are alternately provided with the CP by the DCF. CFP
In, only STAs on the polling list, which are priorities of SIFS and PIFS, can access, and the AP performs centralized control using a poll frame. On the other hand, CP
Low-priority STAs can access it. Priority control becomes possible by the mixture of the two.

[0013]

SUMMARY OF THE INVENTION In a wireless LAN,
In order to execute downlink data transmission from the wired server to the wireless terminal while maintaining a constant communication quality, priority control, packet scheduling, and a series of packet sequences (flows) from the wired side for which communication quality is guaranteed. A wireless packet control station that unifies functions such as packet switching
(Access point station, AP station)
The following problems arise.

The functions of the priority control and the packet scheduling here are represented by a system defined by the IEEE 802 committee. This regulation is based on the IEEE
P802D Annex H, Design C
onsidationsfor Traffic
Class Expediting and Dyna
mic Multicast Filtering,
P802D, 25 May 1998 ". Hereinafter, this rule is referred to as “IEEE802.
1D standard ".

In order to provide the AP with the function of the IEEE 802.1D standard, as described in the section of the prior art, the CSMA / IEEE 802.11D standard is used.
It is necessary to use both the DCF using the CA method and the PCF using priority control by polling, and preferentially assign a non-contention period by the PCF to data to be guaranteed.

By the way, the priority control necessary for the bandwidth guarantee means the priority control according to the type of data. This is because, even if the receiving STA is the same, the transmitted data changes every moment, and the priority of the data flow becomes higher or lower each time. However, as shown in FIG. 3, the method of using DCF and PCF together and performing priority control by PCF is based on an S-type determined in advance on a polling list.
The "access opportunity" is preferentially given to the TA, but not the priority of the type of data that changes with time. Therefore, it is not possible to provide a guarantee for the type of data. Considering the frequency of use of communication that requires a certain communication quality, such as bandwidth guarantee and maximum delay time guarantee, this is considered to be the highest in downlink communication from the wired server to the wireless mobile terminal, If priority cannot be given to data, downlink data cannot be transmitted forever, which is considered to be a major problem.

In the conventional method, the priority is not determined according to the type of data flow, and a certain S
To give priority to TA, CF by PCF
P, CP by DCF, and C, which is the CFP repetition period
The FP _Interval does not need to be changed with time and is a fixed value when the polling list is created.

However, in order to guarantee the communication quality, it is necessary to cope with a data flow whose type and number change with time, and there is a problem that it cannot be realized by using a conventional fixed value. .

Further, in the system using both PCF and DCF shown in FIG. 3, the period of CFP is CF-END and CFF.
_Max_Duration.
On the other hand, the end of DCF is determined by CFP as shown in FIG.
_This is performed at the end of the _interval . And the next P
During the CF period, the wireless media free is set to PIFS shorter than DIFS
Will be started after waiting for the period. Therefore, D
When a packet is transmitted at the end of the CP provided by the CF, the CP is extended accordingly. CFP _{Int
Since the eval} is constant, the CFP is shortened by the length of the CP. Here, "I
Among the types of flows to be guaranteed described in the “EEE802.1D standard”, there is a guarantee of the maximum bandwidth as well as a guarantee of the minimum bandwidth. However, when trying to guarantee the maximum delay time using PCF, C
Since P can be extended, a minimum bandwidth can be guaranteed, but a maximum delay time cannot be guaranteed.

Accordingly, an object of the present invention is to provide a radio packet control station using a radio packet scheduling method capable of performing priority control according to the type of data necessary for guaranteeing communication quality.

[0021]

According to the present invention, there are provided a plurality of radio stations for performing radio packet communication and a radio packet control station for supervising the plurality of radio stations. Packet control in a packet communication system in which a non-contention access control period for automatically controlling and managing, and a contention access control period for the radio station and the radio packet control station to autonomously compete and transmit radio packets are repeated at a fixed cycle. Station, a packet receiving means for receiving a data packet sequence to be transmitted to a plurality of radio stations for each destination radio station, and priority control information (guarantee information such as a minimum bandwidth and a maximum delay time) from the received data packet sequence. Priority control information storage means for acquiring and storing the data packet sequence according to the content of the stored priority control information. A radio packet control station provided with a transmission distribution control means for distributing transmission in either of the access control periods and a transmission order control means for controlling a transmission order of the data packet sequence according to the contents of the stored priority control information. Is done.

The downlink communication from the radio packet control station (AP) to the radio terminal uses contention-based access control and non-contention-based access control as access control methods, and guarantee information such as a minimum bandwidth and a maximum delay time. According to the contents of the priority control information, the data packet sequence is distributed so as to be transmitted in either the non-contention access control period or the contention access control period, and these are unitarily controlled by the AP, so that the wired side of the wireless LAN can be controlled. Data transmission from the terminal to the terminal on the wireless side is performed by assuring a certain communication quality, and the traffic can be made more efficient.

When the priority control information of the data packet sequence is guarantee information including at least the minimum bandwidth or the maximum delay time, the transmission distribution control means distributes the data packet sequence to the non-contention access control period and transmits the data packet sequence. When the priority control information of the packet sequence is of the best-effort type, in particular, with no provision for communication quality, it is preferable that the data packet sequence is configured to be distributed to the competitive access control period and transmitted.

When the data packet sequence to be transmitted from the radio packet control station to the radio station has a high priority, the information packet judging device further comprises information amount judging means for judging the information amount of the data packet sequence. However, if the radio packet control station determines that there is no room to poll the radio station during the non-contention access control period, the radio packet control station is configured not to poll the radio station during the non-contention access control period. Is also preferable.

There are N (N is 2 or more) flows, which are a series of data packet strings distributed in the non-contention access control period, and the priority control information of the data packet string is guarantee information of the maximum delay time. And when there are two or more types of maximum delay times, N and repetition of the flow requiring the shortest maximum delay time guarantee in the non-contention access control period of the data packet sequence requiring the maximum delay time guarantee A period control means for controlling a repetition period of the non-contention access control period and the contention access control period so that the product of the number Z does not exceed the maximum value of the number of packets that can be transmitted within the non-contention access control period. Is also preferred.

The packet communication system has a radio packet control station AP connected to a wired network and a radio station STA that is dependent on the radio packet control station and performs radio packet communication. The AP and all STAs use a common radio channel. At this time, a period in which the STA autonomously determines whether transmission is possible and allows a packet collision to transmit a wireless packet and performs non-contention access control by polling the STA by the AP in a certain period. By repeatedly instructing these periods and periods by control information broadcast by the AP, unitary control in wireless packet communication is performed.

Here, when the AP receives the data packet sequence including the information indicating the allowable transfer delay time of the data arriving from the wired side, the AP acquires, stores, and stores the allowable transfer delay time therein. The transmission order of the wireless packets to the STA is changed according to the allowable transfer delay time. Then, even if the contention access control period is extended at the end of the contention access control period and the contention access control period is extended due to the transmission of the packet of the maximum length, it arrives at the AP to maintain the guarantee of the allowable transfer delay time. The contention access control period is calculated by subtracting the margin of the packet transmission size at the end of the contention access period and the time until the next packet is transmitted from the minimum value of the allowable transfer delay time of the packet. Determine. On this basis, the flow composed of a series of best-effort type packet sequences in which the communication quality is not guaranteed and the transmission speed changes according to the status of the transmission channel resources is used during the contention access control period, A flow, which is a series of packets in which a maximum delay time is guaranteed, is assigned to a non-contention access control period, and
If the data sent from the STA to the STA has a high priority and a long packet length, the AP does not poll the STA at least once during the non-contention access control period.
By not granting the access right to, it is possible to give priority to downlink data transmission.

In the above wireless packet scheduling, when there are a plurality of types of allowable transfer delay time of a flow allocated to the non-contention access control period, and when the number of flows further increases, the allowable transfer delay time of each flow is increased. Depending on the number of flows and the number of those flows, the repetition cycle of the contention access control period and the non-contention access control period is not changed without changing the contention access control period. Keep order and extend the transmission time as much as possible. Also, when the number of flows allocated in the non-contention access control period decreases, the minimum necessary time for the flow to be guaranteed must be set according to the allowable transfer delay time of each flow and the number of those flows. Until then, the non-contention access control period is set short. Then, the information of the order determined as described above is reported to the subordinate STAs by the control information of the AP.

As described above, by restricting the access right of the STA by polling according to the type of transmitted data and setting CFP, CP and CFP _Interval , communication quality assurance on the wire side can be guaranteed at the MAC layer level. Can be realized by the control in.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a radio packet control station (AP) according to an embodiment of the present invention described below, CFP, CFP
An access control method that makes P and CFP _Interval variable is adopted. As a result, the packet scheduled on the wired side can be sent to the wireless terminal while maintaining the schedule, and as a result, communication quality assurance that was difficult in the past can be performed.

FIG. 4 is a flowchart showing an access control procedure in the AP of this embodiment.

As shown in the figure, the AP that has received a data packet addressed to its own station first checks the service class provided for the data packet and determines whether or not the service class should be quality-assured. to decide.

If the received packet is a best-effort type that does not require quality assurance,
_Interval is set to an initial set value T, and as shown in FIG. 5, the contention period CP is set to the maximum value in order to increase traffic efficiency.

To make CP the maximum value means that CFP
The non-competitive period CFP of the length in the _Interval "IE
The minimum value described in the “EE802.11 standard” is set as a period obtained by adding the length of the first beacon frame and the length of the CFP-End frame to twice the maximum packet length.

In addition, when guarantee is required but guarantee of maximum delay time is not required and only guarantee of minimum bandwidth is requested, the flow requesting at the same time as the requested bandwidth value is requested. After confirming the number, CFP
The duration of the CFP in _Interval "IEEE80
2. Change from the minimum value to the maximum value defined in the “2.11 standard”.

On the other hand, if the quality to be guaranteed is the maximum delay time, the maximum delay time to be guaranteed in the radio line is As
ec and Bsec, and their relationship is B = kA
(K: integer). Then, in the repetition period T of the contention access control period CP and the non-contention access control period CFP, the number of each flow is NA,
NB, and the number of repetitions ((T-CP) / A and (T-CP) /
The integer values of B are ZA and ZB, respectively, the transmission speed of the wireless line is M bit / sec, and the packet size is L bi
Let t. The above settings are shown in FIG.

Priority of a plurality of data flows to be guaranteed
Are the same (A = B), CFP _IntervalTo
Use the initial setting value as described above, and
The delay time of the line side packet and the period of the CP are set.

Wireless-side packet delay time + CP ≦ wireline-side packet maximum delay time (1) Further, the setting of the CP period assumes that one maximum-length packet is transmitted at the end of a preset CP period. It is necessary to reserve a margin for that. FIG. 7 shows a setting method in consideration of the extension of the CP.

Further, packet transmission is performed by limiting the number of flows NA so as to satisfy the following expression so as to guarantee the maximum delay time required in the CFP _Interval .

(NA + NB) * ZA = (M * (T-CP)) / L (2) Next, the quality to be guaranteed is the maximum delay time, and the flow for obtaining the maximum delay time guarantee for a plurality of classes is performed simultaneously. AP
And the relationship between the allowable transfer delay times is A <B
, First, the number of flows N of the maximum delay time Asec
A and the number of flows NB in Bsec are confirmed. Next, for the flow of the maximum delay time Asec having a high priority, (1)
The contention access control period CP is set according to the equation.

Here, the maximum delay times Asec and Bse
If the number of flows NA and NB of c satisfies the expression (2), the number of flows NA and NB is limited within the determined CFP range without changing the CFP _Interval T from the initial setting value. The packet is transmitted to the STA.

When the numbers of flows NA and NB of the maximum delay times Asec and Bsec are (NA + NB) * ZA> (M * (T-CP)) / L (3), the CFP _Interval T is set to (2 )
If the expression (2) is satisfied, packet transmission to the STA is performed. If the expression is not satisfied, the number of flows NA and NB is limited and the expression (2) is satisfied, and then the STA is transmitted. Is transmitted.

The above operation makes it possible to implement the present invention.

As described above, a flow arriving at the AP includes both a guaranteed flow and a non-guaranteed flow. In this embodiment, the scheduling and switching of this flow are performed by the AP.

Here, Flow1 and Flow4 are defined as flows for which the maximum delay time needs to be guaranteed, Flow2 and Flow4.
Let w5 be a flow for which a minimum bandwidth guarantee is required, and F1ow3 be a best-effort flow.

FIG. 8 shows packet transmission with time as an example of the radio packet scheduling method in the present embodiment. In this example, since the flow Flow2 requiring the minimum bandwidth guarantee has entered the AP, the AP gives polling to the dependent wireless station STA1 in the CFP during the non-contention access control period, and To give access to
w2 is transmitted to STA2.

FIG. 9 shows packet transmission as time elapses as another example of the radio packet scheduling method in the present embodiment. This example shows a flow (Flow2) that needs to guarantee the minimum bandwidth to be transmitted to STA2.
And Flow5) increase, and the entire period of CFP
This is a case in which data transmission of ow2 and Flow5 has to be applied. Here, by not polling the STA1 at all, the entire period of the CFP can be allocated to the data transmission of Flow2 and Flow5.

As described above, the AP determines the number of times of polling to STA1 with reference to the number of flows that need to be guaranteed to STA2, and does not give any polling when the number of guaranteed flows increases.

Next, the scheduling in the case where the number of radios is congested and polling is not performed as shown in FIG. 9 will be described.

FIG. 10 shows packet transmission as time elapses as still another example of the wireless packet scheduling method in the present embodiment. In this example, since different reserved flows Flow1 and Flow3 have entered the AP, the AP separates the flows and transmits Flow1 which needs to guarantee the highest priority maximum delay time to the wireless station STA2. . Also, since Flow1 needs to be continuously transmitted within a certain maximum delay time, CFP and CP are determined so as to satisfy the condition represented by Expression (1). For CFP _Interval ,
Since the maximum delay time is guaranteed only for Flow1, there is no need to change it. Under the order of Flow1, the best effort type Flow3 that does not need to be guaranteed is transmitted as a result of contention with other accesses within the CP period.

FIG. 11 shows packet transmission as time elapses as still another example of the wireless packet scheduling method according to the present embodiment. This example uses the AP
Flow1 and F that need to guarantee different maximum delay times
This is the case when low4 arrives. First, at the time of scheduling performed by the AP, first, Flow1 and Flow4
It is necessary to satisfy Expression (1) together with
Extending the FP _Interval increases the degree of freedom in scheduling. However, since the value of CP is determined by the shortest maximum delay time, it is kept at a fixed value. On this operation, the AP sends F1ow1 and Flow4 to the wireless stations STA3 and STA2, respectively, with delay times T3 and T3, respectively.
The transmission is performed at intervals such that T2 becomes the maximum delay times A and B. Furthermore, the best effort type F which does not need guarantee
1ow3 is transmitted within the CP period.

FIG. 12 shows packet transmission as time elapses as still another example of the wireless packet scheduling method according to the present embodiment. In this example, F1ow2 and Flow3 that do not need the maximum delay time arrive at the AP. In the scheduling in the AP in this case, the period of the CFP is allocated by an amount that satisfies the guaranteed minimum bandwidth of Flow2, and the other access time is set to CP for traffic efficiency,
The best effort type Flow3 is transmitted as a result of the competition during this period. Moreover, because it is not necessary for the maximum delay time _{guarantees, CFP In terval} can remain in the initial setting value.

As described above, by observing the order determined on the wired side by the scheduling and switching of the AP, it is possible to guarantee the communication quality on the wireless LAN, which has not been realized conventionally.

As described above, in the present embodiment, P
In a wireless access method using both CF and DCF,
If the wired side needs to guarantee the maximum delay time and there are flows of multiple priority classes, CFP and CFP
_{By making the Interval} variable depending on the number of flows and the ratio of mixture, it is possible to guarantee the maximum delay time, which is difficult to guarantee. Further, a plurality of flow for obtaining the guaranteed even require the maximum delay time ensured by a fixed value CFP _{Inter val} when seeking the benefit of the same priority class, CFP if the maximum delay time ensured unsolicited fixed value Toshikatsu CFP the _{I nterval}
By shortening the length of the traffic, it is possible to guarantee the quality and at the same time increase the traffic efficiency.

Further, since the AP does not poll the STA, the STA is not given an access right to the AP, and can preferentially transmit data packets in the downlink direction from the AP to the STA.

The embodiments described above are merely examples of the present invention, and do not limit the present invention. The present invention can be embodied in various other modified forms and modified forms. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0057]

As described above in detail, according to the present invention, in the downlink communication from the radio packet control station (AP) to the radio terminal, contention access control and non-contention access control are used as access control methods. In accordance with the contents of priority control information such as guarantee information such as a minimum bandwidth and a maximum delay time, the data packet sequence is sorted so as to be transmitted in either the non-contention access control period or the contention access control period, and the AP By controlling these in a unified manner, data transmission from a wired terminal to a wireless terminal in a wireless LAN is performed while assuring a certain communication quality, and traffic efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a MAC architecture.

FIG. 2 is a diagram illustrating an example of a conventional wireless access system.

FIG. 3 is a diagram illustrating another example of a conventional wireless access system.

FIG. 4 is a diagram illustrating an access control procedure in an AP according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of an access control method in an AP in the embodiment of FIG.

FIG. 6 is a diagram illustrating two flows for obtaining a guarantee of a maximum delay time in the embodiment of FIG. 4;

FIG. 7 is a diagram illustrating another example of the access control method in the AP in the embodiment of FIG.

FIG. 8 is a diagram illustrating an example of a wireless packet scheduling method.

FIG. 9 is a diagram illustrating another example of a wireless packet scheduling method.

FIG. 10 is a diagram illustrating still another example of the wireless packet scheduling method.

FIG. 11 is a diagram illustrating still another example of the wireless packet scheduling method.

FIG. 12 is a diagram illustrating still another example of the wireless packet scheduling method.

[Explanation of symbols]

NA Number of flows guaranteed by maximum delay time Asec NB Number of flows guaranteed by maximum delay time Bsec ZA CFP of flow guaranteed by maximum delay time Asec
Number of repetitions in the ZB CFP of the flow guaranteed by the maximum delay time Bsec
Number of repetitions within Wi 1 Bandwidth required by one flow Ni Number of flows requesting bandwidth M Transmission speed of wireless line (bit / sec) T Repetition period of contention access control period and non-contention access control period T2 Wireless terminal STA2 Delay time of a packet sent to the wireless terminal STA3 delay time of the packet sent to the wireless terminal STA3 α Extension from the initial setting value of the CFP _Interval CP contention access control period CFP non-contention access control period T _margin The value of the margin used when determining the CP CFP_Max_Duration Maximum value of CFP L Packet size STA Wireless terminal IFS Time to determine that wireless medium is free AP Access point

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04Q 7/26 7/30 (72) Inventor Masataka Iizuka 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Japan Inside Telegraph and Telephone Co., Ltd. (72) Inventor Hitoshi Takanashi 3-192, Nishi-Shinjuku, Shinjuku-ku, Tokyo Japan Inside Telegraph and Telephone Co., Ltd. (72) Masahiro Morikura 3-192, Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation F term (reference)

Claims (4)

[Claims] 1. A non-contention access control period in which a plurality of wireless stations performing wireless packet communication and a wireless packet control station controlling the plurality of wireless stations are controlled by the wireless packet control station in a centralized manner. And a contention access control period in which the wireless station and the wireless packet control station autonomously compete and transmit wireless packets and repeat at a constant cycle. Packet receiving means for receiving a data packet sequence to be transmitted to the radio station for each destination radio station; priority control information storage means for acquiring and storing priority control information from the received data packet sequence; and storing the stored priority control information. Transmitting the data packet sequence in one of the non-contention access control period and the contention access control period according to the content of And a transmission order control unit for controlling a transmission order of the data packet sequence according to the contents of the stored priority control information. 2. When the priority control information of the data packet sequence is guarantee information including at least a minimum bandwidth or a maximum delay time, the transmission distribution control unit distributes the data packet sequence to a non-contention access control period. When the priority control information of the data packet sequence is of a best-effort type with no particular provision on communication quality, the data packet sequence is distributed to the contention access control period and transmitted. The radio packet control station according to claim 1, wherein: 3. When a data packet sequence transmitted from a radio packet control station to a radio station has a high priority,
The apparatus further includes an information amount determining unit that determines an information amount of the data packet sequence, and the information amount determining unit determines that the wireless packet control station cannot afford to poll the wireless station during the non-contention access control period. The radio packet control station according to claim 1, wherein the radio packet control station is configured not to poll the radio station during the non-contention access control period. 4. A flow of a series of data packets distributed in a non-contention access control period, wherein the number of flows is N (N is 2
Above), and when the priority control information of the data packet sequence is guarantee information of the maximum delay time, and there are two or more types of the maximum delay time, the N and the maximum delay time guarantee are The product of the flow requiring the shortest maximum delay time guarantee in the required data packet sequence and the number of repetitions Z in the non-contention access control period does not exceed the maximum value of the number of packets that can be transmitted in the non-contention access control period. The radio packet control station according to claim 1, further comprising a cycle control means for controlling a repetition cycle of the non-contention access control period and the contention access control period.