JP2006067090A - Method, device and program for service quality guarantee and recording medium recording the program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To guarantee the quality of services using a wireless LAN by realizing fairness of the communication while improving throughput of a relay base station device even if a transmission rate and an application used by many terminals are different in the wireless LAN. <P>SOLUTION: A packet classifying means 11 classifies a packet on the basis of identification information (a type of application executed by a terminal 43, the transmission rate of a wireless channel which can be used by the terminal 43, and the data amount of a packet transmitted/received by the terminal 43) described in the packet. The type of queue 12 is specified from the identification information. A packet storing means 13 stores the classified packet in the proper queue 12. A schedule managing means 14 selects the queue 12 for transmitting the packet, decides timing for transmitting the packet, and informs a packet transmitting means 15 of the queue 12 and the timing. The packet transmitting means 15 transmits the packet to a transmission means 422 from the informed queue 12 at the informed timing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a service quality guarantee method, a service quality guarantee device, and a communication system using a service quality guarantee program for guaranteeing service quality in communication using a wireless local area network (LAN).

The standardization of the wireless LAN is being standardized as IEEE 802.11 by the IEEE (The Institute of Electrical and Electronics Engineers). One of them, IEEE 802.11e, has been studied for standardization, and a standardization plan has been published as a draft (draft) (see Non-Patent Document 1).
IEEE802.11e is a specification that is being studied for the purpose of transmitting music and moving images to a terminal in real time and with high quality using a wireless LAN. This defines an additional function for complementing lEE802.11a (up to 54 Mbps transmission in the 5 GHz band). The additional function based on IEEE 802.11e is a function for guaranteeing QoS (Quality of Service) in the wireless LAN, and regulates transmission band control and communication delay time control.

  Before describing IEEE 802.11e, the configuration of the wireless LAN will be briefly described first. As shown in FIG. 6, the wireless LAN constitutes a part of a network 41, and an access point (hereinafter abbreviated as “AP”) 42, which is a relay base station apparatus, and an AP 42 via a wireless line. And a terminal 43 that performs communication. The terminal 43 can change the AP 42 to be connected by moving. In FIG. 6, two APs and three terminals are shown, but the number of APs and terminals is not limited to this.

  In IEEE 802.11e, as a transmission band control technique for guaranteeing QoS, a priority control type (Enhanced Distributed Channel Access, hereinafter referred to as “EDCA”) and a bandwidth guarantee type (HCF Controlled Channel Access, hereinafter referred to as “ (Abbreviated as “HCCA”).

The EDCA classifies packets transmitted between the AP 42 and the terminal 43 according to priority and stores them in a queue. The EDCA preferentially starts from a queue storing high priority packets (high priority queue). In this method, a packet is transmitted and transmitted to the terminal 43.
Specifically, as shown in the EDCA configuration diagram of FIG. 7, the EDCA packet classification means 51 provided in the AP 42 is described in “QoS Control” in the header portion of the packet received via the network 41. The packets are classified according to the priorities set, and stored in a queue 52 set for each class. In FIG. 7, four classes of queues 52 of “background, best effort, voice, and moving image” are listed in order of increasing priority. The stored packet is transmitted from each queue 52 by the transmission means 53 and transmitted to the terminal 43 by a CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method. When the timings at which packets are transmitted from a plurality of transmission means 53 overlap, the schedule management means 54 gives priority to the packets sent from the queue 52 having a high priority.
In this case, for the queue 52 storing packets with high priority, the schedule management means 54 sets both the priority coefficient used for CSMA / CA and the amplitude of the random number to be small, so it is probable to wait for transmission. Since the time is shortened, packet communication can be preferentially performed.

  However, in EDCA, the time that one terminal can occupy and use a wireless line (wireless line occupation time) is calculated from the number of packets transmitted in a certain time and its data size. If the number of terminals existing in the vicinity of one AP increases, the radio channel occupation time that one terminal can use in one communication is reduced probabilistically. Even for a high priority service, a predetermined radio channel occupation time cannot be secured, and therefore a series of packets may not be transmitted reliably, and as a result, it is difficult to guarantee quality of service (QoS). Has the problem of becoming.

On the other hand, HCCA classifies packets for each destination terminal, stores them in a queue, and manages the radio channel occupation time when transmitting packets from the queue to the corresponding terminal, thereby guaranteeing the quality of service. It is.
Specifically, as shown in the configuration diagram of HCCA in FIG. 8, the packet classification means 61 provided in the AP 42 is a terminal of the transmission destination terminal 43 described in the header part of the packet received via the network 41. Packets are classified according to identification information (for example, IP address, MAC address, etc.), and stored in a queue 62 installed for each terminal 43. The stored packet is transmitted from each queue 62 by the transmission means 63 and transmitted to the terminal 43. The transmission to the terminal 43 is performed according to the schedule management of the wireless line in consideration of the packet transmission time by the schedule management means 64.

When EDCA and HCCA are compared, EDCA has the above-mentioned problems, so HCCA is effective from the viewpoint of reliably ensuring QoS.
However, HCCA defines 8 as the maximum number of queues that can be installed in the AP. This is because, for example, HCCA is a wireless LAN for services that transmit high definition television (HDTV) video within a limited range, such as home use, with 1 to 2 terminals. This is due to the assumption of the use of. As described above, in HCCA, a queue is set for each terminal, so the maximum number of terminals is also eight. For this reason, when nine or more terminals request connection to the AP of the wireless LAN at the same time, HCCA cannot cope. In hot spot service, which is one of the important applications of wireless LAN, when an unspecified number of terminals use various applications to request connection to AP at the same time, HCCA is used. It cannot be used. As described above, in a public-facing wireless LAN in which the number of terminals that request connection is not constant and is expected to increase, it is difficult to guarantee the quality of service using HCCA.

In order to solve the above problem, in HCCA, a method is proposed in which the queue used for the terminal accessing the AP and the queue used for the terminal transmission speed are changed instead of setting a queue for each terminal. When this method is used, it is possible to guarantee the quality of service using HCCA in a public-facing wireless LAN in which the number of terminals that require connection is increased (see Non-Patent Document 2).
“Draft Supplement to STANDARD FOR Telecommunications and Information Exchange Between Systems- LAN / MAN Specific Requirements- Part11: Wireless Medium Access Control (MAC) and Physical Layer (PHY) specifications: Medium Access Control (MAC) Enhancements for Quality of Service (QoS) ”IEEE 802 Committee of the IEEE Computer Society, Draft 5.0, March 2003 Minoru Matsumoto and Akira Kurokawa (NTT), “Study of QoS guaranteed realization method in wireless access network”, IEICE Technical NS2003-300, IN2003-255, March 2004

By the way, in a wireless LAN defined by IEEE802.11a and IEEE802.11b, which are targets for complementing the functions of IEEE802.11e, the transmission quality of the wireless channel deteriorates as the distance between the AP and the terminal increases. For this reason, in these types of wireless LANs, in order to maintain transmission quality, the transmission speed of the wireless line is reduced as the distance between the AP and the terminal increases (hereinafter this is referred to as “falling”). "Back").
Specifically, in the case of IEEE802.11b, the transmission speed of the wireless line changes in four stages according to the distance between the AP and the terminal due to fallback. In the case of IEEE802.11a, the transmission speed of the wireless line changes in 8 steps. As a result, the transmission rates that can be used by a plurality of terminals that request connection to the same AP are not all the same.

The method of Non-Patent Document 2 has been made in view of such problems, and there are many terminals that request connection to an AP in a wireless LAN, and the transmission rates that can be used by each terminal are all the same. Even if there is not, it is possible to suppress the number of queues installed in the AP and guarantee the quality of service using the wireless LAN. Further, when the communication interval of the terminal accessing the AP is constant and the communication data amount is also the same size, it is possible to easily manage the schedule of the packet transmission interval of the AP queue. .
However, if the communication interval of the terminal accessing the AP is irregular and the communication data amount is a different size as in the Web access service, the packet transmission interval of the AP queue varies from terminal to terminal. Therefore, there is a problem that the number of queues, which is a feature of Non-Patent Document 2, cannot be reduced. Therefore, it is necessary to use HCCA and EDCA according to Non-Patent Document 2 and use different queues depending on the application used by each terminal accessing the AP.

However, since the EDCA of Non-Patent Document 1 uses different queues depending on the applications used by the terminals, if the same AP radio channel is shared between terminals using different applications at different transmission speeds, the division of the radio channel usage time is reduced. There is a problem that the throughput of the AP decreases because the loss increases and the finite wireless line cannot be used efficiently.
In addition, there is a trade-off relationship between improvement in utilization efficiency of the radio channel occupation time and fairness of communication of terminals using EDCA for each AP. In other words, when packets are sent preferentially from a specific queue in order to improve the utilization efficiency of the radio channel occupation time, if there are a large number of terminals stored in the queue, other low priority queues are used. Packet transmission is reduced, and as a result, it is difficult to realize fairness of communication of a terminal accessing the AP.

  The present invention has been made in view of such problems, and there are many terminals that request connection to an AP in a wireless LAN, and the transmission rates and applications that can be used by each terminal are not all the same. Even if it exists, it aims at providing the means which can implement | achieve fairness of communication, improving the throughput of AP, and guarantees the quality of the service using wireless LAN.

  In order to solve the above-described problems, the present invention uses the following method, apparatus, program, and recording medium on which the program is recorded.

  According to the first aspect of the present invention, there is provided a service quality assurance method for assuring the quality of service for a terminal by a service quality assurance device, wherein packet classification means for classifying a packet is based on identification information described in the packet. A procedure for classifying packets, a packet storage means for storing packets, a procedure for storing packets classified by the packet classification means in a queue of the same type as the identification information, and a schedule management for managing a schedule for sending packets A means for determining a queue for sending a packet and a timing for sending a packet from the queue, and notifying the determined queue and timing to the packet sending means for sending the packet; and a packet sending means However, from the queue notified from the schedule management means Also in the notified timing, it was decided to include the steps of sending a packet.

The service quality assurance method is executed in a relay base station device or a dedicated device connected to the relay base station device. Identification information to be referred to when the packet classification means classifies the packet is described in the packet header.
The queue is the type of application required for realizing the service predetermined by the contract between the service user and the service provider using the wireless LAN, the required transmission speed of the wireless line, and the packet data to be transmitted and received Necessary types and numbers are determined from the quantity, etc., and installed.
Since the packets classified in the installed queue are stored, the number of queues matches the number classified by the packet classification means. The packet storage means stores the classified packets in a queue of a type that matches the identification information referenced when classifying. When the schedule management unit detects that the packet is stored in the queue, the schedule management unit sequentially registers the detected queue and calculates a transmission time required for transmitting the packet.
The schedule management means determines the queue for sending packets and the timing for sending the packets based on the registration information and the transmission time, and notifies them to the packet sending means. The packet sending means sends a packet at a designated timing from a designated queue in accordance with the notification from the schedule management means.

  According to the second aspect of the present invention, the schedule management means changes the transmission order and packet transmission amount of each queue based on a threshold relating to the data amount of the packet, and sets the transmission order and packet transmission amount of the queue to the packet. A procedure for notifying the sending means is further included.

In the invention described in claim 3, the identification information described in the packet includes the type of application executed by the terminal, the transmission speed of the wireless line that can be used by the terminal, and the data amount of the packet transmitted and received by the terminal. .
It is possible to determine whether the identification information is the type of application, the transmission speed of the wireless line, and the amount of data sent and received, depending on the type of application, whether the application is affected by the difference in the transmission speed of the terminal. Packets are classified based on the transmission speed of the wireless line necessary for transmission and the data amount of transmitted / received packets.

In the invention according to claim 4, the type of queue is defined by the type of application executed by the terminal, the transmission speed of the wireless line that can be used by the terminal, and the data amount of packets transmitted and received by the terminal.
The type of queue is the type of application, the transmission speed of the wireless line, and the data amount of transmitted / received packets, in addition to being able to determine the 802.11e technology (HCCA or EDCA) depending on the type of application, In the case of HCCA, it is possible to determine whether or not the application is affected by the difference in the transmission speed of the terminal, and the type of queue is determined based on this, the transmission speed of the wireless line, and the data amount of the transmitted and received packets It was decided to install.

In the invention according to claim 5, for a packet identified to use HCCA based on the type of application, a queue to be stored is specified in relation to a use application and a transmission rate of a wireless line that can be used by a terminal. It was decided.
Also, for packets that are identified to use EDCA based on the type of application, a value obtained by dividing the transmission rate of the wireless channel that can be used by the terminal by the data amount of the transmitted / received packet (“wireless channel transmission rate”). ”÷“ data amount of transmitted / received packet ”) is calculated, and a queue to be stored with a predetermined threshold is specified.
In this case, if “transmission speed of wireless channel” ÷ “data amount of transmission / reception packet” is a large value, the wireless channel usage time of this packet will be short, so this packet is stored in the queue with high priority. The In addition, when “transmission speed of wireless channel” ÷ “data amount of transmission / reception packet” is a small value, the wireless channel usage time of this packet will be long, so this packet is stored in a low priority queue. .

In the inventions according to claims 6 and 7, after the packet storage means selects a queue based on the type of application described in the packet, the wireless circuit that can be used by the terminal described in the packet The queue is selected based on the transmission rate or the transmission rate of the transmitted and received packets.
The selection of a queue for storing a packet is first made based on the IEEE 802.11e technology (HCCA or EDCA) used by the packet, which is specified by referring to the type of application. Thereafter, when HCCA is selected (in the case of claim 6), a packet of an application in which a change in the transmission speed of the wireless line affects the quality of service is queued based on the transmission speed available to the terminal. Is selected. On the other hand, when EDCA is selected (in the case of claim 7), the queue is selected based on the value of “transmission speed of wireless channel” ÷ “data amount of transmission / reception packet”.

In the invention according to claim 8, the schedule management means calculates the radio channel occupation time by the terminal communicating as schedule management, and based on the calculated radio channel occupation time, the packet is sent from the queue. The transmission timing is generated, and the packet is transmitted from the queue at the timing of transmitting the packet.
For packets stored in the queue for which HCCA has been selected, the radio line occupation time required for transmitting the packets is calculated to guarantee the bandwidth at the time of transmission, the order of packets to be transmitted, and the timing for transmission , And based on this, the schedule management means sends out the packet from the queue at the generated timing.

For packets stored in the queue for which EDCA is selected, packets are preferentially transmitted from a queue having a large “wireless line transmission rate” ÷ “data amount of transmitted / received packets”. At this time, a high priority queue may increase the ratio of the packet transmission amount.
In addition, a transmission waiting time threshold is set for each queue. In other words, because packets are preferentially transmitted from a queue with a large "wireless line transmission rate" ÷ "transmission / reception packet data amount", a wait with a small "wireless line transmission rate" ÷ "transmission / reception packet data amount" If the packet cannot be transmitted even if the queue exceeds the threshold of the transmission waiting time, the packet is transmitted from a queue having a small “wireless line transmission rate” ÷ “data amount of transmission / reception packet”. Also, the ratio of the packet transmission amount of the queue with high priority is increased.

  In the invention according to claim 9, the service quality assurance device classifies the packet based on the identification information described in the packet, and the packet classified by the packet classification unit is the same type as the identification information. The packet storing means for storing in the queue, the queue for sending the packet, and the timing for sending the packet from the queue are determined, and the determined queue and timing are notified to the packet sending means for sending the packet. The schedule management means and the packet sending means for sending packets at the same notified timing from the queue notified from the schedule managing means are provided.

In the invention according to claim 10, the service quality assurance device classifies the packet based on the identification information described in the packet, and the packet classified by the packet classification unit is the same type as the identification information. A packet storing means for storing in a queue, and a packet sending means for sending the packet at the same notified timing from a queue notified from a schedule managing means connected to the relay base station device over a network, The management means determines the queue for sending packets and the timing for sending packets from the queue, and notifies the packet sending means of the determined queue and timing.
The service quality assurance device is configured as a part of the relay base station device or as a part of the device connected to the relay base station device. The content is the same as the service quality assurance method.

  The invention described in claim 11 is a program that causes a computer to execute the service quality assurance method according to any one of claims 1 to 8.

  In the invention described in claim 12, a program for causing a computer to execute the service quality assurance method described in any one of claims 1 to 8 is recorded on a computer-readable recording medium. Examples of the recording medium include a hard disk, a CD-ROM, a DVD, a flexible disk, and a memory.

  According to the present invention, packets are classified according to priority of transmission, and packets are stored in a queue according to priority by setting a queue according to priority. As a result, even when there are a large number of terminals and the transmission speeds and applications that can be used by each terminal are not all the same, it is possible to suppress an increase in the queue, and it is possible to use wireless lines by a plurality of terminals. Time division loss can be suppressed. As a result, by managing the packet transmission schedule, it is possible to prevent a decrease in the line occupation time and to efficiently use the wireless line, and to provide a quality-guaranteed service using the wireless LAN. It can be used.

  According to the present invention, a threshold for a packet data amount is set in each queue, and when the threshold is exceeded, the communication of a terminal accessing each AP is changed by changing the packet transmission order and the packet transmission amount. It is possible to achieve fairness.

  According to the present invention, the priority at the time of transmitting a packet can be defined based on the type of application executed by the terminal, the transmission speed of the wireless line usable by the terminal, and the amount of data transmitted and received by the terminal.

  According to the present invention, the queue can be set based on the type of application executed by the terminal, the transmission speed of the wireless line that can be used by the terminal, and the amount of data transmitted and received by the terminal.

  According to the present invention, according to the priority of packets, a queue for storing communication packets using an application in which fluctuations in the transmission speed of the wireless line do not affect the quality of service, and the transmission speed of the wireless line Packets of communications using applications whose fluctuations affect the quality of service can be stored separately in queues that store for each transmission speed of the wireless line, and "wireless transmission speed" ÷ "send / receive" The amount of packet data ”is calculated, and the length of the radio channel occupation time can be known from the magnitude of this value, and can be stored separately in a queue for storing each radio channel occupation time.

  According to the present invention, it is possible to select a queue and store a packet in accordance with the priority defined by the type of application, the transmission speed of the wireless line, and the data amount of transmitted / received packets.

According to the present invention, by sending a packet from a queue and transmitting it to a terminal at a timing generated from the calculated radio channel occupation time, it is possible to secure a radio channel and transmit the packet, Since the division loss of the usage time can be suppressed, it is possible to guarantee the quality of service while using the wireless line efficiently.
In addition, a threshold for packet transmission waiting time is set for each queue, and if the threshold is exceeded, packets are sent from a queue with a small "wireless transmission rate" ÷ "data amount of transmitted / received packets" At the same time, it is possible to realize fairness of communication of each terminal for each relay base station apparatus by increasing the ratio of the packet transmission amount of the queue with high priority.

  According to the present invention, by sharing the schedule management means between service quality assurance devices, it is possible to reduce the cost of the service quality assurance device and the costs associated with facility management and failure recovery.

  According to the present invention, a service quality assurance method can be executed by a computer.

  According to the present invention, a program for causing a computer to execute the service quality assurance method can be recorded on a computer-readable recording medium. Moreover, a program can be run with a computer by making it read into a computer.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. Note that FIG. 6 will be referred to as needed.

<< Device configuration >>
FIG. 1 is a configuration diagram of a service quality assurance device 1 that guarantees service quality using a wireless LAN according to an embodiment of the present invention. The service quality assurance device 1 is configured inside an AP 42 that is a wireless LAN relay base station device.

The service quality assurance device 1 includes a packet classification unit 11 that classifies packets, a queue 12 that stores packets, a packet storage unit 13 that stores packets in the queue 12, and a schedule management that manages a schedule for sending packets. Means 14 and packet sending means 15 for sending packets from the queue 12 are configured. Note that reception of packets via the network 41 and transmission of packets to the terminal 43 use reception means 421 and transmission means 422 which are network connection devices that the AP 42 has conventionally provided.
The packet classifying unit 11 includes identification information described in the header of the packet, specifically, the type of application executed by the terminal 43, the transmission speed of the wireless line usable by the terminal 43, and the packet transmitted and received by the terminal 43. The packets are classified based on the amount of data.

The queue 12 temporarily stores the packets classified by the packet classification unit 11 before transmitting them to the terminal 43. The types of applications used by the service and executed by the terminal 43, the transmission speed of the wireless line that can be used by the terminal 43, and the transmission and reception of the terminal 43 are determined by the contract between the service user and the service provider The type of the queue 12 is defined from the data amount of the packet to be transmitted. The specified type of queue 12 is installed in the service quality assurance device 1 in advance.
The packet storage means 13 identifies the packet classified by the packet classification means 11 at the time of packet classification (the type of application executed by the terminal 43, the transmission speed of the wireless line usable by the terminal 43, the terminal 43 Judging from the data amount of packets to be transmitted / received), it is stored in an appropriate queue 12.

The schedule management unit 14 selects a queue 12 to send a packet, determines a timing for sending a packet from the queue 12, and notifies the packet sending unit 15 of the queue 12 and the timing.
Based on the notification from the schedule management unit 14, the packet transmission unit 15 transmits a packet from the selected queue 12 to the transmission unit 422 at a determined timing.

  Each means constituting service quality assurance device 1 is realized by a CPU (Central Processing Unit) executing a program stored in a predetermined memory built in service quality assurance device 1.

<Packet classification means>
The packet classification by the packet classification unit 11 is performed according to the following criteria.
First, the packet classifying means 11 uses HCCA (bandwidth guarantee type) or EDCA (priority control type) when transmitting a packet based on the type of application described in the packet header. Method).

In the case of an application using HCCA, fluctuations in the transmission speed of the wireless line caused by the movement of the terminal or radio wave interference have little influence on the quality of service using the wireless LAN (hereinafter referred to as “transmission speed non-transmission”). Dependent application ”packet or a packet whose application has a great influence on the quality of service using wireless LAN (hereinafter referred to as“ transmission speed dependent application ”). Classify into:
The transmission rate independent application includes, for example, an application used in VoIP (Voice over Internet Protocol). Further, the transmission rate dependent application includes, for example, an application used under a QoS guarantee type service such as streaming communication.

Since the packet of the transmission rate-independent application does not depend on the transmission rate, the classification is determined by this. Since the packet of the transmission rate dependent application depends on the transmission rate, it is further classified based on the transmission rate. In other words, the packet classification unit 11 further classifies the transmission rate-dependent application packet based on the transmission rate necessary for executing the application described in the header. However, in practice, there are various transmission rates necessary for executing the application, and therefore, a standard in which a plurality of transmission rates are combined into one is set, and packets corresponding to the standard may be classified.
For example, in the case of streaming communication, the standards of transmission rates of 300 kbps and 600 kbps are set, the packets whose transmission rates of 200 kbps, 300 kbps, and 400 kbps are described in the header are classified into the transmission rates of 300 kbps, and the transmission rates of 600 kbps are classified into , Packets whose transmission speeds are 500 kbps, 600 kbps, and 700 kbps are classified in the header.

An application that uses EDCA is an application that is less strict with respect to QoS than an application that uses HCCA (hereinafter referred to as “best effort communication”), and is classified as a packet that uses EDCA.
In the best-effort communication, the packet classification unit 11 divides the transmission rate of the wireless channel of the terminal 43 by the data amount of the packet transmitted / received by the terminal 43 (“wireless channel transmission rate” ÷ “data amount of transmitted / received packet”). Packet). That is, this value is compared with a predetermined threshold value for classification.
For example, in the case of Web access, three types of threshold values are set, and the values of “wireless line transmission speed” ÷ “data amount of transmitted / received packets” are 100, 1,000, and 10,000, respectively, and packets within the threshold values are set. Classify.

<Queue>
The queue 12 is a queue structure on a memory for temporarily storing packets for waiting for the transmission order to the terminal 43, and is set in advance based on a contract between a service user and a service provider. Is done. The contract defines the service used by the service user.
Specifically, a queue 12 is provided for each type of application required for executing a service determined by a contract in advance. Further, depending on the type of application, transmission determined from the type of AP 42 used in the wireless LAN. A queue 12 is set up for each speed. The identification information used for classifying the packets described above needs to match one of the types of the queue 12.

  For example, in the case where there are three types of services determined in advance by contract, VoIP, streaming communication, and Web access, a queue 12 (A) is installed to store VoIP packets that are not significantly affected by fluctuations in transmission speed. Further, in the streaming communication affected by the fluctuation of the transmission speed, a queue 12 (B / C) for storing packets for each transmission speed is installed. For Web access, a queue 12 (D / E) for storing packets for each threshold value of “wireless line transmission rate” ÷ “data amount of transmitted / received packets” is installed.

<Packet storage means>
The packet storage means 13 is a packet classified by the packet classification means 11 based on the transmission speed-independent application packet, the packet classified based on the transmission speed of the transmission speed-dependent application, or “transmission speed of the wireless line” ÷ “transmission / reception packet” The packets of the best effort communication classified for each threshold value of the “data amount” are stored in the queue 12 of the same type with the application type, the transmission speed of the wireless line, and the data amount of the transmitted and received packets.

<Schedule management means>
The schedule management means 14 selects a queue 12 for sending packets, and performs schedule management for determining the timing for sending packets from the selected queue 12.
Specifically, the schedule management means 14 is information relating to the quality of service defined by the contract between the service user and the service provider (for example, QoS guarantee type / best effort type, wireless line necessary for QoS guarantee) Occupancy time, guarantee delay time necessary for QoS guarantee, etc.) are managed for each terminal 43 using the service. On that basis, the schedule management means 14 preferentially selects the queue 12 for storing the packets of the transmission rate dependent application, and the radio line necessary for transmitting the packets sent from the queue 12 to the terminal 43. The occupation time is calculated in consideration of information related to QoS (radio line occupation time necessary for QoS guarantee, guarantee delay time necessary for QoS guarantee, etc.). The schedule management unit 14 manages the calculated wireless line occupation time in the order in which packets are transmitted to the terminal 43. When the schedule management means 14 receives a notification from the packet sending means 15 that the transmission of the packet to the terminal 43 has been completed, the schedule management means 14 determines the next packet sending timing using the QoS information and sends it next. The packet sending means 15 is notified together with the queue 12.

In addition, the queue 12 for storing the packet of the transmission rate independent application is selected in the idle time during which the packet of the transmission rate dependent application is not transmitted, and the queue 12 and the timing of sending the packet from the queue 12 are selected. Is sent to the packet sending means 15.
Further, the queue 12 for storing the packets of the application of the best effort communication is selected in the idle time during which the packets of the transmission rate dependent application and the transmission rate independent application are not transmitted. The queues are selected in order from the queue with the largest threshold value of “wireless line transmission rate” ÷ “data amount of transmitted / received packets”, and the packet transmission unit 15 is notified with the ratio of the packet transmission amount increased. In order to increase the ratio of the amount of packet transmission, there is a method in which a plurality of packets transmitted to the same terminal are continued. It is not always necessary to increase the ratio of the packet transmission amount, and notification may be made for each packet.

<Operation of the device>
Next, the operation of the service quality assurance device according to the embodiment of the present invention includes the case of transmitting a packet of a transmission rate dependent application, the case of transmitting a packet of a non-transmission rate application, and the best effort communication. This will be described separately for the case of transmitting the packet.

<Transmission of packets for transmission rate dependent applications>
First, a case where a transmission rate dependent application packet is transmitted will be described.

[Packet storage]
The operation of storing packets will be described using the sequence chart shown in FIG. 2A (see FIG. 1 as appropriate). The packet classification unit 11 of the service quality assurance device 1 receives a packet from the packet reception unit 421 of the AP 42 (step S100). Then, the packets are classified based on the type of application described in the header of the received packet and the transmission speed of the wireless line that can be used by the terminal 43 (step S101), and sent to the packet storage means 13 (step S102). . The packet storage means 13 stores the packet received from the packet classification means 11 in the queue 12 (queue B / C in FIG. 1) of the same type as the type of application and the transmission speed of the wireless line used at the time of packet classification. (Step S103). The queue 12 storing the packet notifies the schedule management means 14 of this (step S104). Upon receiving the notification, the schedule management means 14 first determines whether the notification source queue 12 is a queue 12 for storing transmission rate-independent application packets or a queue 12 for storing transmission rate-dependent application packets. Alternatively, it is determined whether the queue 12 stores the best effort communication (step S105). Information for the determination is included in, for example, a notification interface from the queue 12 to the schedule management unit 14.

  As a result of the determination, when the queue 12 stores the packet of the transmission rate dependent application, the schedule management unit 14 transmits the packet from the notification source queue 12 using information on the quality of service determined by the contract. The wireless line occupation time required for transmitting the packet is calculated (step S106). The schedule management unit 14 manages the calculated wireless line occupation time on the internal table in the order of notification from the queue 12.

[Send packet]
A packet sending operation will be described with reference to the sequence chart shown in FIG. 2B (see FIG. 1 as appropriate). When the schedule management means 14 receives a notification from the packet sending means 15 that the transmission of the packet to the terminal 43 is completed, the schedule management means 14 selects the queue 12 to send the packet next and based on the managed radio line occupation time. The packet transmission timing is determined, and the queue 12 and timing are notified to the packet transmission means 15 (step S200).
The packet sending means 15 requests the selected queue 12 to send packets at the determined timing (step S201), and the queue 12 sends the packets in the order in which the packets are stored, and sends the packets. The data is sent to the means 15 (step S202). The packet sending means 15 receives a packet from the queue 12 (queue B / C) and sends it to the sending means 422 included in the AP 42 (step S203). Then, the packet sending unit 15 notifies the schedule management unit 14 that the packet transmission has been completed (step S204).

<Transmission of packets for transmission rate independent applications>
Next, a case where a transmission rate-independent application packet is transmitted will be described. As described above, the transmission of the transmission rate independent application packet is performed while the transmission of the transmission rate dependent application packet is not executed.

[Packet storage]
A packet storage operation will be described with reference to the sequence chart shown in FIG. 3A (see FIG. 1 as appropriate). The packet classification unit 11 of the service quality assurance device 1 receives a packet from the packet reception unit 421 of the AP 42 (step S300). Then, it is classified based on the type of application described in the header of the received packet and the transmission speed of the wireless line that can be used by the terminal 43 (step S301), and sent to the packet storage means 13 (step S302). The packet storage means 13 stores the packet received from the packet classification means 11 in the queue 12 (queue A in FIG. 1) of the same type as the application type and the transmission speed of the wireless line used at the time of packet classification ( Step S303). The queue 12 storing the packet notifies the schedule management means 14 of this (step S304). Upon receiving the notification, the schedule management means 14 first determines whether the notification source queue 12 is a queue 12 for storing transmission rate-independent application packets or a queue 12 for storing transmission rate-dependent application packets. Alternatively, it is determined whether the queue 12 stores the best effort communication (step S305).

  As a result of the determination, if the queue 12 stores packets of transmission rate-independent application, the schedule management unit 14 does not depend on transmission rate until there is a free time during which packets of the transmission rate-dependent application are not transmitted. It waits for transmission of the packet of the type application (step S306).

[Send packet]
The packet transmission operation will be described with reference to the sequence chart shown in FIG. 3B (see FIG. 1 as appropriate). When the idle time during which the packet of the transmission rate dependent application is not transmitted is generated, the schedule management unit 14 notifies the packet transmission unit 15 of the queue 12 for transmitting the packet and the transmission timing (step S400).
The packet sending means 15 requests the notified queue 12 to send a packet at the notified timing (step S401), and the queue 12 (queue A) follows the order in which the packets are stored. To the packet sending means 15 (step S402). The packet sending means 15 receives the packet from the queue 12, and sends it to the sending means 422 provided in the AP 42 (step S403). Then, the packet sending unit 15 notifies the schedule management unit 14 that the packet transmission has been completed (step S404).

<When transmitting best-effort communication application packets>
Next, a case where a packet of an application for best effort communication is transmitted will be described.

[Packet storage]
The packet storage operation will be described with reference to the sequence chart shown in FIG. 4A (see FIG. 1 as appropriate). The packet classification unit 11 of the service quality assurance device 1 receives a packet from the reception unit 421 of the AP 42 (step S500). Then, based on the type of application described in the header of the received packet, the transmission speed of the wireless line that can be used by the terminal 43, and the value of “wireless transmission speed” ÷ “data amount of transmission / reception packet” The packets are classified (step S501) and sent to the packet storage means 13 (step S502). The packet storage means 13 uses the packet received from the packet classification means 11 for the type of application used at the time of packet classification, the transmission speed of the wireless line, and the “transmission speed of the wireless line” ÷ “data amount of transmitted / received packet”. Store in the queue 12 of the same type as the value threshold (queue D / E in FIG. 1) (step S503). The queue 12 storing the packet notifies the schedule management means 14 of this (step S504). Upon receiving the notification, the schedule management means 14 first determines whether the notification source queue 12 is a queue 12 for storing transmission rate-independent application packets or a queue 12 for storing transmission rate-dependent application packets. Alternatively, it is determined whether the queue 12 stores the best effort communication (step S505).

  As a result of the determination, when the queue 12 stores the packets of the application of the best effort communication, the schedule management unit 14 has a free time during which the packets of the transmission rate dependent application and the transmission rate independent application are not transmitted. Until the packet of the application of the best effort communication is waited (step S506).

[Send packet]
The packet transmission operation will be described with reference to the sequence chart shown in FIG. 4B (see FIG. 1 as appropriate). When an idle time in which packets of the transmission rate dependent application and the transmission rate independent application are not transmitted is generated, the schedule management unit 14 notifies the packet transmission unit 15 of the queue 12 for transmitting packets and the transmission timing. (Step S600).
The packet sending unit 15 requests the notified queue 12 to send a packet at the notified timing (step S601). The queue 12 (queue D / E) increases the ratio of the packet transmission amount of the queue D having a large threshold value of “wireless transmission rate” ÷ “data amount of transmission / reception packet”, and transmits the packet as a packet. The data is sent to the means 15 (step S602). This means that a packet transmission time is short, that is, a packet transmitted to the terminal 43 located at a short distance from the AP 42 is preferentially sent to the packet sending means 15. Note that it is not always necessary to increase the ratio of the packet transmission amount, and it may be transmitted for each packet. The packet sending means 15 receives the packet from the queue 12, and sends it to the sending means 422 provided in the AP 42 (step S603). Then, the packet sending unit 15 notifies the schedule management unit 14 that the packet transmission has been completed (step S604).
Thereafter, the packet transmission of the queue E having a small threshold value of “wireless transmission rate” ÷ “data amount of transmission / reception packet” is performed in the same procedure.

  With reference to the sequence chart shown in FIG. 5, a description will be given of a packet transmission operation when the transmission waiting time threshold set for each queue is exceeded (see FIG. 1 as appropriate). If the queue E with a small threshold of “wireless line transmission rate” ÷ “data amount of transmitted / received packets” exceeds the transmission waiting time threshold, packet transmission cannot be performed. In order to achieve fairness, the schedule management means 14 notifies the packet sending means 15 of the queue 12 for sending packets and the sending timing (step S700).

The packet sending means 15 requests the queue 12 notified from the schedule management means 14 to send a packet at the same notified timing (step S701), and the queue 12 (queue D / E). Sends a packet in the queue E having a small threshold value of “wireless transmission rate” ÷ “data amount of transmission / reception packet” and sends it to the packet sending means 15 (step S702). The packet sending means 15 receives the packet from the queue 12 and sends it to the sending means 422 provided in the AP 42 (step S703). Then, the packet sending unit 15 notifies the schedule management unit 14 that the packet transmission has been completed (step S704).
Thereafter, in the same procedure, packets in queue D having a large threshold value of “wireless line transmission rate” ÷ “data amount of transmitted / received packets” are transmitted. At this time, the ratio of the packet transmission amount of the queue D is increased. Note that it is not always necessary to increase the ratio of the packet transmission amount, and transmission may be performed for each packet.

  As described above, the operation of the service quality assurance device is carried out when a transmission rate-dependent application packet is transmitted, a transmission rate-independent application packet is transmitted, and a best-effort communication application packet is transmitted. I explained it separately.

  Accordingly, the service quality assurance device includes a queue for storing transmission rate-dependent application packets, a queue for storing transmission rate-independent application packets, and a queue for storing best-effort communication application packets. Can be used to reduce the number of queues installed in the service quality assurance device, improve the AP wireless link utilization efficiency, and use the additional functions provided by IEEE 802.11e. By doing so, it becomes possible to guarantee the quality of service using the wireless LAN.

  A terminal that accesses each AP by setting a threshold for packet transmission waiting time in each queue for best effort communication and changing the ratio of packet transmission order and packet transmission amount when the threshold is exceeded. It becomes possible to realize fairness of communication.

  The service quality assurance device according to the embodiment of the present invention can be realized by a computer and a program, and can be provided by recording the program on a computer-readable recording medium. It is. It is also possible to provide the program via a network.

<< Other embodiments >>
An example of the preferred embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, the following embodiments can be considered.
In the above embodiment, the service quality assurance device 1 is described as being configured inside the AP 42 of the wireless LAN. However, the entire or part of the service quality assurance device 1 is configured to be connected to the AP 42 by wireless or wired. You may make it do. For example, the schedule management means 14 considered to be a common function of each service quality assurance device 1 is connected to the network 41 as one device, and the service quality assurance device 1 (such as the queue 12) in each AP 42 is connected to that device. May request schedule management. According to this, by sharing the schedule management means 14, it is possible to reduce the cost of the service quality assurance device 1 and the cost of facility management and failure recovery.

It is a block diagram of the service quality assurance apparatus which guarantees the quality of the service using wireless LAN which concerns on embodiment of this invention. It is a sequence chart which shows operation | movement of the service quality assurance apparatus which concerns on embodiment of this invention. (A) shows storage of a packet when transmitting a packet of a transmission rate dependent application. (B) shows transmission of a packet when transmitting a packet of a transmission rate dependent application. It is a sequence chart which shows operation | movement of the service quality assurance apparatus which concerns on embodiment of this invention. (A) shows the storage of a packet when transmitting a packet of a transmission rate independent application. (B) shows transmission of a packet when transmitting a packet of a transmission rate independent application. It is a sequence chart which shows operation | movement of the service quality assurance apparatus which concerns on embodiment of this invention. (A) shows the storage of the packet when transmitting the packet of the application of the best effort communication. (B) shows transmission of a packet when transmitting a packet of a best effort communication application. It is a sequence chart which shows operation | movement of the service quality assurance apparatus which concerns on embodiment of this invention. In particular, when transmitting a packet of an application for best effort communication, transmission of a packet when a transmission waiting time threshold set in each queue is exceeded will be described. It is a figure which shows the structure of wireless LAN. It is a figure which shows the structure of a priority control type (EDCA) system. It is a figure which shows the structure of a band guarantee type | mold (HCCA) system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Service quality assurance apparatus 11 Packet classification means 12 Queue 13 Packet storage means 14 Schedule management means 15 Packet transmission means 42 Access point, AP (relay base station apparatus)
421 receiving means 422 transmitting means

Claims (12)

Service quality assurance in a relay base station apparatus connected to a terminal via a wireless line, by guaranteeing the quality of service for the terminal by a service quality assurance apparatus having a plurality of queues of one type or different types A method,
A packet classification means for classifying the packet, the procedure for classifying the packet based on the identification information described in the packet;
A packet storage means for storing the packet, a procedure for storing the packets classified by the packet classification means in a queue of the same type as the identification information;
A schedule management means for managing a schedule for transmitting the packet determines a queue for transmitting the packet and a timing for transmitting the packet from the queue, and the determined queue and timing are used for the packet for transmitting the packet. A procedure for notifying the sending means;
The packet sending means sends out the packet at the same notified timing from the queue notified from the schedule managing means;
A service quality assurance method comprising: A procedure in which the schedule management unit changes the transmission order and packet transmission amount of each queue based on a threshold relating to the data amount of the packet, and notifies the packet transmission unit of the transmission order and packet transmission amount of the queue. The service quality assurance method according to claim 1, further comprising: The identification information described in the packet is
The type of application executed by the terminal;
The transmission speed of the wireless line that can be used by the terminal,
The amount of packet data transmitted and received by the terminal;
The service quality assurance method according to claim 1 or 2, characterized by comprising: The queue type is:
The type of application executed by the terminal;
The transmission speed of the wireless line that can be used by the terminal,
The amount of packet data transmitted and received by the terminal;
The service quality assurance method according to any one of claims 1 to 3, characterized by: The service quality assurance device, as the queue,
For packets that are identified to use HCCA, which is a bandwidth-guaranteed transmission bandwidth control method, from the application type, fluctuations in the transmission speed of the radio channel that can be used by the terminal do not affect the quality of the service. A queue for storing packets of communication using the application;
For a packet that is also identified as using HCCA, a packet for communication using an application in which fluctuations in the transmission speed of the wireless line that can be used by the terminal affect the quality of service is transmitted on the wireless line. A queue to store for each speed;
For each packet that is identified to use EDCA, which is a priority control type transmission band control method, based on the type of application, for each threshold value obtained by dividing the transmission rate of the wireless line that can be used by the terminal by the data amount of the transmitted / received packet A queue to store in
The service quality assurance method according to claim 4, further comprising: The packet storage means includes
After selecting the queue based on the type of application described in the packet, and further selecting the queue based on the transmission rate of the radio line that can be used by the terminal described in the packet. The service quality assurance method according to claim 4 or 5, characterized in that: The packet storage means includes
After selecting the queue based on the type of application described in the packet, the queue is further determined based on the transmission rate of the wireless line usable by the terminal and the data amount of the transmitted / received packet described in the packet. The service quality assurance method according to claim 4 or 5, wherein a matrix is selected. The schedule management means manages the schedule as follows:
A procedure for calculating a time for which the terminal occupies the wireless line by performing communication;
Generating a timing for sending the packet from the queue based on the calculated time to occupy the wireless line;
A procedure for sending the packet from the queue at a timing of sending the packet;
The service quality assurance method according to claim 1, wherein the service quality assurance method is executed by including the following. A relay base station apparatus connected to a terminal via a wireless line, comprising a plurality of queues configured of one or different types, and a service quality assurance apparatus that guarantees the quality of service for the terminal,
Packet classification means for classifying the packet based on the identification information described in the packet;
Packet storage means for storing the packets classified by the packet classification means in a queue of the same type as the identification information;
A queue for sending the packet, a timing for sending the packet from the queue, and a schedule management means for notifying the determined queue and timing to the packet sending means for sending the packet;
From the queue notified from the schedule management means, packet sending means for sending the packet at the same notified timing;
A service quality assurance device comprising: A relay base station apparatus connected to a terminal via a wireless line, comprising a plurality of queues configured of one or different types, and a service quality assurance apparatus that guarantees the quality of service for the terminal,
The service quality assurance device includes:
Packet classification means for classifying the packet based on the identification information described in the packet;
Packet storage means for storing the packets classified by the packet classification means in a queue of the same type as the identification information;
Packet sending means for sending the packet at the same notified timing from the queue notified from the schedule management means network-connected to the relay base station device,
With
The schedule management means includes
A service quality assurance device characterized by determining a queue for transmitting the packet and a timing for transmitting the packet from the queue, and notifying the determined queue and timing to the packet transmission means.   A service quality assurance program for causing a computer to execute the service quality assurance method according to any one of claims 1 to 8.   A computer-readable recording medium storing a program for causing a computer to execute the service quality assurance method according to any one of claims 1 to 8.

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