JP2006129044A - Radio packet control method, access point, and terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve throughput and delay time, and to equalize transmission chance of uplink and downlink, in a radio network system for bidirectional communication of radio packet between one access point and a plurality of terminals. <P>SOLUTION: An access point comprises a plurality of transmission buffers corresponding to a plurality of respective terminals, to independently operate channel accesses for packet transmission from transmission buffers to corresponding terminals. The terminal transmits by adding a packet with information (next packet information) about presence or size of the packet which is scheduled to be transmitted next. The access point extracts and registers the next packet information of that terminal when receiving the packet transmitted from the terminal, and registers the next packet information of the transmission buffer when the packet addressed to the terminal is transmitted, for management. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radio packet control method, an access point, and a terminal that perform radio packet communication by random access between an access point and a plurality of terminals.

  In congestion control in wireless packet communication, there is an ICMA method in which the uplink channel traffic from the terminal to the base station is measured by the base station, and control parameters corresponding to the traffic are notified to the terminal (Non-patent Document 1). In this ICMA method, congestion control is performed according to the following procedure.

  The base station observes the state of the uplink channel and notifies the terminal of an idle signal or busy signal indicating the state of the channel on the downlink. When the terminal receives a busy signal, the terminal refrains from transmitting packets until an idle signal is received. When performing this control, the terminal uses two parameters, a transmission standby limit p for refraining from packet transmission and a transmission limit q for reducing transmission packets when a packet is generated. The base station holds an optimal p and q control table according to the traffic, and notifies the parameters of p and q according to the measured traffic.

  In another congestion control in wireless packet communication, the uplink channel packet unsuccess rate from the terminal to the base station is measured by the base station, and a control parameter corresponding to the packet unsuccess rate is notified to the terminal and the ICMA / ICMA / There is a CD system (Non-Patent Document 2). In this method, a threshold for the packet failure rate that maximizes the obtained throughput is provided based on the packet failure rate characteristics. The base station notifies a parameter that is a transmission limit of the terminal based on the relationship between the measured packet failure rate and the threshold value.

  Further, there is a CSMA / CA with ACK method for access control in wireless packet communication (Non-Patent Document 3). In this scheme, carrier sense is performed in a certain period (DIFS) before the transmission terminal starts transmission. If the channel is busy, it waits until it becomes idle, and then performs carrier sense again in the DIFS period. After the channel has been idle over the DIFS period, a random number is generated within the CW (Contention Window) range, a random time (backoff time) based on the random value is set, and the channel is idle. If so, the back-off time is subtracted in units of time slots, and back-off control is performed to transmit a packet when it finally becomes 0. Thereby, equalization of transmission opportunities between the transmission terminals is achieved. The destination terminal that has received the packet transmits an ACK to the transmitting terminal, and the transmitting terminal determines that the packet transmission was successful by receiving the ACK. Process. The probability of re-collision is reduced by binary exponential backoff that doubles the CW range of backoff control for each retransmission.

In access control using a plurality of buffers in wireless packet communication, there is an EDCA (Enhanced Distributed Channel Access) system (Non-patent Document 3). In this method, a plurality of buffers corresponding to packet priorities are prepared, and packets with high priorities are preferentially transmitted. Each buffer operates a DCF (Distributed Coordination Function) with a priority function independently, and a packet having a high priority is transmitted when an internal collision occurs.
H. Kayama, T. Hattori, H. Yoshida, "Adaptive control for random access traffic in mobile radio systems", IEEE Trans on Vehicular Technology, vol. 42, no. 1, pp. 87-93, Feb. 1993 H. Yoshino, "An Adaptive Congestion Control for Random Accesss Channels in Mobile Communication Systems", IEICE Trans on Communications, vol.E86-B, no.2, pp.732-742, Feb. 2003 Anders Lindgren, Andreas Almquist, and Olov Schelen, "Quality of Service schemes for IEEE 802.11 wireless LANs-an evaluation", In Special Issue of the Journal on Special Topics in Mobile Networking and Applications (MONET) on Performance Evaluation of Qos Architectures in Mobile Networks, 8 (3): 223-235, June 2003

  In a wireless network system in which one access point and a plurality of terminals exist and the same wireless channel is shared between the uplink and the downlink, there are the following problems in the congestion control in the conventional wireless packet communication. First, it is necessary to grasp the characteristics of each method in advance. Furthermore, it is necessary to consider the state of the terminal and untransmitted packets existing in the terminal. It is necessary to support communication sharing a wireless channel in both directions.

  In addition, access control by the conventional CSMA / CA with ACK method is widely used in wireless LANs and the like. However, since control at the time of congestion is not performed, the downlink throughput particularly decreases at the time of congestion, Furthermore, there is a problem that the delay time increases rapidly. The conventional access control by the EDCA method is a method for performing priority control, and the difference in uplink and downlink transmission opportunities has not been improved.

  The present invention improves throughput and delay time in a wireless network system in which the same wireless channel is shared between an access point and a plurality of terminals in uplink and downlink and wireless packet communication is performed by random access. An object of the present invention is to provide a radio packet control method, an access point, and a terminal capable of equalizing uplink and downlink transmission opportunities.

  The present invention provides a wireless packet control method for a wireless network system that performs bidirectional communication of wireless packets between one access point and a plurality of terminals. The access point includes a plurality of transmission buffers respectively corresponding to the plurality of terminals. The channel access operation for transmitting a packet addressed to the corresponding terminal from each transmission buffer is performed independently.

  As a result, packet transmission from the access point to each terminal can be distributed during congestion, and the number of transmissions can be increased.

  Further, the terminal adds the size or presence / absence information (next packet information) of the packet scheduled to be transmitted next to the packet and transmits the packet, and the access point receives the packet transmitted from the terminal. The next packet information of the terminal is extracted and registered, and the next packet information of the transmission buffer is registered and managed when a packet addressed to the terminal is transmitted.

  Thereby, it is possible to grasp the uplink and downlink congestion levels of the wireless network by using the next packet information of each terminal and each transmission buffer registered in the access point.

  In addition, when the access point receives a packet transmitted from the terminal, the access point uses the next packet information other than the next packet information of the terminal that transmitted the packet among the next packet information of each terminal and the next packet information of each transmission buffer. Based on this, the release delay indicating the waiting time until the terminal transmits the next packet is calculated, the calculated release delay is added to the reception response signal for the packet, and the transmission is performed. When a reception response signal with a delay added is received, control is performed to refrain from packet transmission during the release delay period.

  As a result, control is performed to refrain from packet transmission during the release delay period calculated according to the degree of congestion of the uplink and downlink for the terminal that transmitted on the uplink, and transmission to other terminals and access points. Rights can be distributed and packet transmissions can be distributed.

  In addition, the access point transmits a packet addressed to the terminal, and when the reception response signal transmitted from the terminal is received, the access point transmits the packet out of the next packet information of each terminal and the next packet information of each transmission buffer. Based on the next packet information other than the next packet information in the transmission buffer, a release delay indicating a waiting time until the transmission buffer transmits the next packet is calculated, and packet transmission from the transmission buffer in the release delay period is performed. Control to refrain from.

  As a result, the transmission buffer of the access point that transmitted the packet to the terminal is controlled to refrain from packet transmission during the release delay period calculated according to the degree of congestion of the uplink and downlink, and transmitted to other terminals. A transmission right can be given to the buffer and each terminal, and packet transmission can be distributed.

  Further, by combining the release delay for each terminal and the release delay for each transmission buffer of the access point, it is possible to equally grant transmission rights to each terminal and each transmission buffer, and equalize the uplink and downlink transmission opportunities. be able to.

  The present invention relates to a transmission buffer for storing transmission packets to be transmitted to a plurality of terminals in an access point of a wireless network system that performs two-way communication of wireless packets between one access point and a plurality of terminals, Next packet information extraction unit that receives transmitted packets and extracts next packet information from the received packets; next packet information extracted from received packets and next packet information of packets transmitted from transmission buffer The packet information management unit sets the release delay to be set in the terminal based on the next packet information managed by the next packet information management unit by receiving the received packet, and the next packet information management by receiving the reception response signal Set in the access point based on the next packet information managed by A release delay calculating unit for calculating a release delay, a reception response signal generating unit for adding a release delay to be set in the terminal calculated by the release delay calculating unit to a reception response signal for the received packet, a carrier sense, a reception response signal And a transmission control unit that performs release delay management based on the release delay set for the access point calculated by the transmission delay and the release delay calculation unit for each transmission buffer.

  The present invention relates to a wireless network system terminal that performs bidirectional communication of wireless packets between one access point and a plurality of terminals, a transmission buffer that stores packets to be transmitted to the access point, and a transmission buffer that is transmitted from the transmission buffer. The next packet information management unit that manages the next packet information of the packet and a reception response signal to which a release delay set by the access point is set for the terminal is transmitted to the packet transmitted to the access point. Release delay extracting unit for extracting release delay set in terminal, reception response signal generating unit for generating reception response signal for packet transmitted from terminal, carrier sense, transmission of reception response signal to access point, next packet information Packet with additional packet information obtained from the management unit And a transmission control unit that performs release delay management based on the transmission and release delays extracted by the release delay extractor.

  The present invention relates to a wireless network system that performs two-way communication of wireless packets between one access point and a plurality of terminals. In a congested state, the present invention transmits packets from each terminal to the access point, and transmits from the access point to each terminal. Packet transmission can be performed one by one in order. Thereby, occurrence of collision can be reduced, throughput and delay time can be improved, and uplink and downlink transmission opportunities can be equalized.

(Configuration example of wireless network system, access point, terminal)
FIG. 1 shows a configuration example of a wireless network system, an access point, and a terminal to which the wireless packet control method of the present invention is applied. 1 (1) shows a configuration example of a wireless network system, FIG. 1 (2) shows a configuration example of an access point, and FIG. 1 (3) shows a configuration example of a terminal.

  In FIG. 1 (1), a plurality of terminals 20-1, 20-2 are arranged in a wireless zone formed by an access point (AP) 10, and the access point 10 and the plurality of terminals 20-1, 20-2 are connected. In the meantime, wireless packet access control and congestion control are performed by the wireless packet control method of the present invention.

  In FIG. 1 (2), an access point (AP) 10 includes an antenna 11, a transmission / reception unit (TRX) 12 connected to the antenna 11, a baseband processing unit (BB) 13 sequentially connected to the transmission / reception unit 12, A control unit 14 and an interface unit (I / F) 15 are included. In FIG. 1 (3), the terminal 20 includes an antenna 21, a transmission / reception unit (TRX) 22 connected to the antenna 21, a baseband processing unit (BB) 23 sequentially connected to the transmission / reception unit 22, a control unit 24, and An interface unit (I / F) 25 and an interface unit 25 and a personal computer (PC) 26 connected via interface means such as USB, infrared communication port, Bluetooth, PCMCIA (Personal Computer Memory Card International Association), etc. The

(Configuration example of the control unit 14 of the access point 10)
FIG. 2 shows a configuration example of the control unit 14 of the access point 10. In the figure, the control unit 14 includes transmission buffers 41-1 and 41-2 that store transmission packets to be transmitted to a plurality of terminals 20-1 and 20-2, respectively, and next packet information extraction that extracts next packet information from the received packets. Unit 42, next packet information management unit 43 that manages the next packet information extracted from the received packet and the next packet information of the packet transmitted from the transmission buffer, and is managed by the next packet information management unit 43 upon reception of the packet or the reception response signal The release delay calculating unit 44 calculates the release delay set for the terminal or the release delay set for the access point based on the next packet information that is set, and the release delay calculating unit 44 calculates the reception response signal for the received packet. A reception response signal generation unit 45 for adding a release delay set in the terminal, Athens, receiving transmission of the response signal, and the transmission control unit 46 for the release delay management based on the release delay set in the access point calculated in the transmit and release delay calculation section 44 of the packet per transmission buffer.

(Configuration example of the control unit 24 of the terminal 20)
FIG. 3 shows a configuration example of the control unit 24 of the terminal 20. In the figure, a control unit 24 is added to a transmission buffer 51 for storing a transmission packet to be transmitted to the access point 10, a next packet information management unit 52 for managing next packet information of a packet transmitted from the transmission buffer, and a reception response signal. Release delay extraction unit 54 for extracting the release delay, reception response signal generation unit 55 for generating a reception response signal for the received packet, carrier sense, transmission of the reception response signal, and next packet information obtained from next packet information management unit 52 The transmission control unit 53 performs transmission delay management based on the transmission of the added packet and the release delay extracted by the release delay extraction unit 54.

(Processing procedure when receiving an access point packet)
With reference to a configuration example of the control unit 24 of the access point 10 shown in FIG. 2 and a flowchart shown in FIG. 4, a processing procedure at the time of receiving an access point packet according to the wireless packet control method of the present invention will be described.

  When the access point receives the packet transmitted from the terminal, the next packet information extracting unit 42 extracts the next packet information added to the received packet (S1, S2). The next packet information management unit 43 registers the next packet information of the terminal extracted by the next packet information extraction unit 42 (information on the size or presence of the next packet scheduled to be transmitted from the terminal to the access point). (S3). When the access point transmits a packet to the terminal, the next packet information management unit 43 receives the next packet information in the transmission buffer 41 (the size or presence of the packet scheduled to be transmitted next from the access point to the terminal). (S19 in FIG. 5 described later). Thus, the next packet information is sequentially registered in the next packet information management unit 43 every time a packet is transmitted from the transmission buffers 41-1 and 41-2 and the terminals 20-1 and 20-2.

  Next, the release delay calculation unit 44 out of the next packet information of each terminal and the next packet information of the access point registered in the next packet information management unit 43, the next packet other than the next packet information of the terminal that transmitted the packet. A release delay is calculated based on the information (S4). The reception response signal generation unit 45 adds the release delay calculated by the release delay calculation unit 44 to the reception response signal for the received packet (S5). The transmission control unit 46 transmits the reception response signal with the release delay added to the transmission terminal (S6).

(Processing procedure when sending packet of access point)
Next, with reference to a configuration example of the control unit 24 of the access point 10 shown in FIG. 2 and a flowchart shown in FIG. 5, a processing procedure at the time of packet transmission of the access point by the wireless packet control method of the present invention will be described.

  When there is a packet in the transmission buffer 41, the transmission control unit 24 waits until a release delay is set in the transmission buffer (S11, S12). If no release delay has been set or the release delay has passed, it is determined whether or not an untransmitted packet already exists when the packet arrives at the transmission buffer 41 (S13). If there is no packet, access control without back-off control is performed, and if there is an untransmitted packet, access control including back-off control is performed. That is, if there is no untransmitted packet, it waits until the channel becomes idle over the DIFS period due to carrier sense (S14). Thereafter, it is confirmed whether or not an internal collision with respect to accesses from a plurality of transmission buffers has occurred (S17). On the other hand, if there is an untransmitted packet or if the channel becomes busy during the DIFS period even if there is no untransmitted packet, it waits until the channel becomes idle over the DIFS period (S15). . Thereafter, when the channel is idle, back-off control is performed to subtract the back-off time and wait until it becomes 0 (S16). Thereafter, it is confirmed whether or not an internal collision with respect to accesses from a plurality of transmission buffers has occurred (S17).

  If there is no internal collision, the next packet information management unit 43 registers the next packet information in the transmission buffer 41 that transmits the packet (S19), and transmits the packet (S20). On the other hand, if an internal collision has occurred, it is determined whether there is a transmission buffer that has acquired the transmission right (S18). For example, if there is a transmission buffer that has acquired the transmission right by priority, Next packet information is registered (S19), and the packet is transmitted (S20). If there is no transmission buffer that has acquired the transmission right, the process returns to the carrier sense in S15.

  The release delay calculation unit 44 and the transmission control unit 46 confirm whether or not a reception response signal has been received after packet transmission (S21). When the reception response signal is received within a predetermined time, the release delay calculation unit 44 determines the next packet information and access point of each terminal registered in the next packet information management unit 43 in S3 of FIG. 4 and S19 of FIG. Of the next packet information, the release delay is calculated based on the next packet information other than the next packet information of the transmission buffer that transmitted the packet (S22). On the other hand, when the reception response signal is not received within the predetermined time, the retransmission processing is performed after returning to the carrier sense of S15. The transmission control unit 46 sets the calculated release delay for the transmission buffer that has received the reception response signal of the transmitted packet (S23).

(Processing procedure for terminal packet transmission)
Next, with reference to a configuration example of the control unit 24 of the terminal 20 shown in FIG. 3 and a flowchart shown in FIG. 6, a processing procedure at the time of packet transmission of the terminal by the radio packet control method of the present invention will be described.

  If there is a packet in the transmission buffer 51 and the release delay is set, the transmission control unit 53 waits until it elapses (S31, S32). If no release delay is set or the release delay has elapsed, it is determined whether or not an untransmitted packet already exists when the packet arrives at the transmission buffer 51 (S33). If there is no packet, access control without back-off control is performed, and if there is an untransmitted packet, access control including back-off control is performed. That is, if there is no untransmitted packet, it waits until the channel becomes idle over the DIFS period by carrier sense (S34). Thereafter, the next packet information is added to the transmission packet (S37). On the other hand, if there is an untransmitted packet or if the channel becomes busy during the DIFS period even if there is no untransmitted packet, it waits until the channel becomes idle for the DIFS period (S35). . Thereafter, when the channel is idle, back-off control is performed to subtract the back-off time and wait until it becomes 0 (S36). Thereafter, the next packet information is added to the transmission packet (S37).

  The transmission control unit 53 transmits the packet with the next packet information added to the access point (S38). The transmission control unit 53 and the release delay extraction unit 54 confirm whether or not a reception response signal has been received after packet transmission (S39). When the reception response signal is received within the predetermined time, the release delay extraction unit 54 extracts the release delay from the reception response signal (S40). On the other hand, when the reception response signal is not received within the predetermined time, the retransmission processing is performed after returning to the carrier sense of S35. The transmission control unit 53 sets the extracted release delay (S41).

(Example of packet transmission / reception using release delay)
Next, a packet transmission / reception example using a release delay according to the wireless packet control method of the present invention will be described with reference to time charts shown in FIGS.

  In the terminal 20-1, packets P1A-1, P1A-2, P1A-3,... Are generated at time t1, and in the terminal 20-2, packets P2A-1, P2A-2, P2A-3,. Will occur. Further, at the access point 10, the packets PA1-1, PA1-2, PA1-3,... Arrive at the transmission buffer 41-1 at time t3, and the packet PA2-1, at the transmission buffer 41-2 at time t2. PA2-2, PA2-3, ... arrive.

  First, in order to transmit packets from the terminals 20-1 and 20-2 and the transmission buffers 41-1 and 41-2 of the access point 10, carrier sense is started. Here, in the terminal 20-2 in which the packet is generated at the earliest time (t0), the channel becomes idle over the DIFS period. In the terminal 20-2, since there is no untransmitted packet when the packet P2A-1 arrives at the transmission buffer 51, the packet P2A- to which the next packet information (information regarding P2A-2) is added without performing backoff control. 1 is transmitted to the access point 10. The above processing of the terminal 20-2 corresponds to S31, S32, S33, S34, S37, and S38 of FIG. Since the transmission buffers 41-1 and 41-2 of the other terminal 20-1 or the access point 10 are busy with packet transmission from the terminal 20-2 during the DIFS period, the process proceeds from S14 to S15 in FIG. Alternatively, the carrier sense is continued from S34 to S35 in FIG.

  The access point 10 extracts and registers the next packet information from the received packet P2A-1. After receiving packet P2A-1 and elapse of SIFS (<DIFS), a reception response signal (ACK) with a release delay added is transmitted to terminal 20-2. Here, the next packet information registered in the next packet information information management unit 43 of the access point 10 is only information related to the packet P2A-2 of the terminal 20-2, and the next packet information other than the terminal that transmitted the packet is Therefore, the release delay calculated by the release delay calculation unit 44 is “0”. The above processing of the access point 10 corresponds to S1, S2, S3, S4, S5 and S6 in FIG.

  Next, the terminal 20-2 that has received the ACK from the access point 10 extracts and sets the release delay added to the ACK, but here the release delay is “0” and is not set. The processing of the terminal 20-2 corresponds to S39, S40, and S41 in FIG.

  Next, after DIFS has passed since the transmission / reception of ACK was performed, the transmission buffers 41-1 and 41-2 and the terminals 20-1 and 20-2 each perform back-off control. Here, since 1, 3, 2, and 5 are selected as backoff times (BT), the packet PA1-1 existing in the transmission buffer 41-1 having the smallest BT is transferred from the access point 10 to the terminal 20-. 1 to send. At this time, the next packet information (information regarding PA1-2) of the transmission buffer 41-1 is registered in the next packet information management unit 43 of the access point 10. The above processing of the access point 10 corresponds to S15, S16, S17, S19, and S20 of FIG.

  Next, the terminal 20-1 that has received the packet PA 1-1 transmits a reception response signal (ACK) after SIFS has elapsed, and is received by the access point 10. The release delay calculation unit 44 of the access point 10 that has received the ACK calculates the release delay based on the next packet information registered in the next packet information management unit 43 and sets it as the release delay of the transmission buffer 41-1. Here, the next packet information registered in the next packet information management unit 43 is information regarding the packet P2A-2 of the terminal 20-2 and the packet PA1-2 of the transmission buffer 41-1, and the transmission buffer that has transmitted the packet. Except for the next packet information 41-1, the release delay D1 based on the packet P2A-2 of the terminal 20-2 is calculated and set. That is, the transmission buffer 41-1 sets a release delay for suppressing its own transmission in order to give a transmission right to the terminal 20-2 having the next transmission packet. The above processing of the access point 10 corresponds to S21, S22, and S23 of FIG.

  After the next DIFS elapses, the transmission buffer 41-2 and the terminals 20-1 and 20-2 each perform back-off control. Here, since the remaining backoff times (BT) are 2, 1, and 4, respectively, the packet P1A-1 existing in the terminal 20-1 having the smallest BT is transmitted to the access point 10. At this time, the next packet information (information on P1A-2) is added to the packet P1A-1. Note that although the terminal 20-2 is given the transmission right by the release delay D1 of the transmission buffer 41-1, the transmission right is given to the terminal 20-1 by the back-off control. Such mismatches are then gradually resolved.

  The access point 10 extracts and registers the next packet information from the received packet P1A-1. After receiving packet P1A-1 and elapse of SIFS (<DIFS), a reception response signal (ACK) with a release delay added is transmitted to terminal 20-1. Here, the next packet information registered in the next packet information information management unit 43 of the access point 10 includes the packet P2A-2 of the terminal 20-2, the packet PA1-2 of the transmission buffer 41-1, and the terminal 20-1. This is information on the packet P1A-2, and the release delay D2 based on the packet P2A-2 of the terminal 20-2 and the packet PA1-2 of the transmission buffer 41-1 is excluded except for the next packet information of the terminal 20-1 that transmitted the packet. Calculated and added to the ACK.

  Next, the terminal 20-1 that has received the ACK from the access point 10 extracts and sets the release delay D2 added to the ACK. Here, the release delay D2 based on the packet P2A-2 of the terminal 20-2 and the packet PA1-2 of the transmission buffer 41-1 is set.

  On the other hand, since the release delay D1 for the terminal 20-2 set in the transmission buffer 41-1 continues even after the packet transmission from the terminal 20-1, the access point 10 to the terminal 20-1 After DIFS 4 has elapsed since the ACK transmission, the transmission buffer 41-2 and the terminal 20-2 each perform back-off control. Here, since the remaining back-off time (BT) is 1 and 3, respectively, the packet PA2-1 existing in the transmission buffer 41-2 having the smallest BT is transmitted from the access point 10 to the terminal 20-2. To do. At this time, the next packet information (information on PA2-2) is added to the packet PA2-1.

  Next, the terminal 20-2 that has received the packet PA2-1 transmits a reception response signal (ACK) after the SIFS has elapsed, and is received by the access point 10. The release delay calculation unit 44 of the access point 10 that has received the ACK calculates the release delay D3 based on the next packet information registered in the next packet information management unit 43, and sets it as the release delay D3 of the transmission buffer 41-2. To do. Here, the next packet information registered in the next packet information management unit 43 includes the packet P2A-2 of the terminal 20-2, the packet PA1-2 of the transmission buffer 41-1, the packet P1A-2 of the terminal 20-1, A release delay D3 is calculated and set based on the next packet information excluding the next packet information of the transmission buffer 41-2 that has transmitted the packet, which is information regarding the packet PA2-2 of the transmission buffer 41-2.

  Similarly, packet transmission / reception, ACK transmission / reception, and release delay setting are repeated, and uplink and downlink between the transmission buffers 41-1 and 41-2 of the access point 10 and the terminals 20-1 and 20-2 are repeated. Will be given equal transmission opportunities.

The figure which shows the structural example of a wireless network system, an access point, and a terminal. The figure which shows the structural example of the control part 14 of the access point 10. FIG. The figure which shows the structural example of the control part 24 of the terminal 20. FIG. The flowchart which shows the process sequence at the time of the packet reception of an access point. The flowchart which shows the process sequence at the time of the packet transmission of an access point. The flowchart which shows the process sequence at the time of the packet transmission of a terminal. The time chart which shows the example of packet transmission / reception using release delay.

Explanation of symbols

10 Access point (AP)
11 Antenna 12 Transceiver (TRX)
13 Baseband processor (BB)
14 Control unit 15 Interface unit (I / F)
20 Terminal 21 Antenna 22 Transceiver (TRX)
23 Baseband processing unit (BB)
24 Control unit 25 Interface unit (I / F)
26 Personal computer (PC)
41 transmission buffer 42 next packet information extraction unit 43 next packet information management unit 44 release delay calculation unit 45 reception response signal generation unit 46 transmission control unit 51 transmission buffer 52 next packet information management unit 53 transmission control unit 54 release delay extraction unit 55 reception Response signal generator

Claims (6)

In a wireless network system that performs bidirectional communication of wireless packets between one access point and a plurality of terminals,
The access point has a plurality of transmission buffers respectively corresponding to the plurality of terminals, and independently performs channel access operations for transmitting packets addressed to the corresponding terminals from the transmission buffers. Wireless packet control method. The radio packet control method according to claim 1,
The terminal adds information on the size or presence of a packet scheduled to be transmitted next (hereinafter referred to as “next packet information”) to the packet, and transmits the packet.
When the access point receives a packet transmitted from the terminal, it extracts and registers the next packet information of the terminal, and registers the next packet information of the transmission buffer when transmitting a packet addressed to the terminal. And a wireless packet control method. The radio packet control method according to claim 2,
When the access point receives a packet transmitted from the terminal, the access point uses the next packet information other than the next packet information of the terminal that transmitted the packet among the next packet information of each terminal and the next packet information of each transmission buffer. Based on this, a release delay indicating a waiting time until the terminal transmits the next packet is calculated, the calculated release delay is added to the reception response signal for the packet, and transmitted.
The radio packet control method, wherein the terminal that has transmitted the packet refrains from transmitting the packet during the release delay period when receiving the reception response signal with the release delay added. The radio packet control method according to claim 2,
When the access point transmits a packet addressed to the terminal and receives a reception response signal transmitted from the terminal, the access point transmits a packet out of the next packet information of each terminal and the next packet information of each transmission buffer. Based on the next packet information other than the next packet information in the transmission buffer, a release delay indicating a waiting time until the transmission buffer transmits the next packet is calculated, and packet transmission from the transmission buffer in the release delay period is performed. A wireless packet control method characterized by refraining from. In an access point of a wireless network system that performs two-way communication of wireless packets between one access point and a plurality of terminals,
A transmission buffer for storing transmission packets to be transmitted to the plurality of terminals;
Receiving a packet transmitted from the terminal and extracting next packet information from the received packet; and
A next packet information management unit for managing next packet information extracted from the received packet and next packet information of a packet transmitted from a transmission buffer;
Based on the next packet information managed by the next packet information management unit by receiving the received packet, a release delay to be set in the terminal is set, and managed by the next packet information management unit by receiving a reception response signal A release delay calculating unit that calculates a release delay to be set in the access point based on the next packet information being
A reception response signal generation unit for adding a release delay to be set in the terminal calculated by the release delay calculation unit to the reception response signal for the reception packet;
A transmission control unit that performs release delay management based on carrier sense, transmission of the reception response signal, transmission of a packet for each transmission buffer, and release delay set in an access point calculated by the release delay calculation unit. An access point characterized by that. In a wireless network system terminal that performs bidirectional communication of wireless packets between one access point and a plurality of terminals,
A transmission buffer for storing packets to be transmitted to the access point;
A next packet information management unit for managing next packet information of a packet transmitted from the transmission buffer;
A release delay extraction unit that transmits a reception response signal to which a release delay set by the access point is set for the terminal to the packet transmitted to the access point, and extracts a release delay set for the terminal from the reception response signal When,
A reception response signal generating unit that generates a reception response signal for the packet transmitted from the terminal;
Carrier sense, transmission of a reception response signal to the access point, transmission of a packet added with next packet information obtained from the next packet information management unit, and release delay management based on the release delay extracted by the release delay extraction unit And a transmission control unit for performing the transmission.

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