Abstract:
In the present invention, before data transmission, a “connection”, between a requesting end and a destination end, identified by a traffic flow identifier (FID) is established or modified through traffic flow management. Therefore, when the requesting end and the destination end perform data transmission on the traffic flow, the FID alone can sufficiently serve as the identifier, so as to save the need of carrying the destination end identifier in each exchanged data packet, thereby simplifying the operation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     1) This application claims the priority of CN Application No. 201110081288.6 filed on Mar. 31, 2011 and titled “A WIRELESS COMMUNICATION METHOD”, which is incorporated herein by reference in its entirety. 
     2) This application claims the priority of CN Application No. 201110188606.9 filed on Jul. 6, 2011 and titled “TRAFFIC FLOW ESTABLISHMENT METHOD AND DEVICE AND TRAFFIC FLOW CHANGE METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     3) This application claims the priority of CN Application No. 201210027851.6 filed on Feb. 8, 2012 and titled “TRAFFIC FLOW ESTABLISHMENT METHOD AND DEVICE AND TRAFFIC FLOW CHANGE METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     4) This application claims the priority of CN Application No. 201210027916.7 filed on Feb. 8, 2012 and titled “TRAFFIC FLOW MANAGEMENT METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     5) This application claims the priority of CN Application No. 201210027852.0 filed on Feb. 8, 2012 and titled “TRAFFIC FLOW DELETING METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     6) This application claims the priority of CN Application No. 201210036754.3 filed on Feb. 17, 2012 and titled “TRAFFIC FLOW ESTABLISHMENT METHOD AND DEVICE AND TRAFFIC FLOW CHANGE METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     7) This application claims the priority of CN Application No. 201210038757.0 filed on Feb. 17, 2012 and titled “TRAFFIC FLOW MANAGEMENT METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     8) This application claims the priority of CN Application No. 201210038079.8 filed on Feb. 17, 2012 and titled “TRAFFIC FLOW DELETING METHOD AND DEVICE”, which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     This invention belongs to the field of wireless communication, particularly related to traffic flow establishing method and device, and traffic flow changing method and device. 
     BACKGROUND OF THE INVENTION 
     In recent years, wireless communication systems have been developed rapidly. For example, wireless Local Area Network (WLAN) technologies based on IEEE 802.11 (i.e. WiFi), a Bluetooth system based on IEEE 802.15, and Femto technologies oriented to indoor applications that are derived from a mobile communication system have been widely used. 
     The WiFi technology based on IEEE 802.11 is the most extensively used wireless network transmission technology at present. A WiFi system is defective for its relatively low system efficiency and significant waste of wireless resources due to the employment of a Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) mechanism. An essential reason for such a defect lies in that the CSMA/CA mechanism is a random multi-access mechanism based on competition, and there exist competitions for the access right to wireless resources between a Central Access Point (CAP) and a Station (STA) or between different STAs due to the CSMA/CA mechanism. Simultaneous competitions for a wireless channel will result in a collision, thus leading to the wireless resource waste. To avoid such collision, the CSMA/CA mechanism requires the CAPs or STAs to retreat randomly from the competition for the wireless channel. If all of the CAPs and STAs retreat, the wireless channel is not utilized even it is idle, causing significant waste of the wireless channel. Therefore, the system efficiency of IEEE 802.11 is relatively low. For example, although the peak rate at the physical layer in an IEEE 802.11g system may reach 54 Mbps, the reachable peak rate of a large-packet download service at the Transmission Control Protocol (TCP) layer is no more than 30 Mbps. Despite of the above defects, the IEEE 802.11 system is flexible and does not rely on a centralized control mechanism, so that the device costs are relatively low. 
     A Femto technology based on 3GPP standards, which is derived from a mobile communication system, is a new technology intended for indoor coverage. Since about 70% of data services is conducted in doors according to data statistics of the 3G system, an indoor high-speed data access solution is especially important. A Femto base station, which is named as a Pico Base Transceiver Station, is small in volume (like in WiFi technologies) and flexible in deployment. The Femto base station inherits almost all features of a mobile communication system due to its derivation from the mobile communication system. Considering its limited coverage range and a relatively small number of access users, the Femto device is designed with a decreased processing capability, to reduce the device costs. In terms of a duplexing manner, Femto base stations may operate in two duplexing mechanisms, i.e. a Frequency Division Duplexing (FDD) and a Time Division Duplexing (TDD), just like the mobile communication system. Because FDD uplink and downlink carrier resources are symmetric, certain resource waste is caused for a data service in a FDD system due to a service feature that uplink and downlink data flow of the data service are asymmetric. In a TDD system, however, both uplink and downlink operate at the same carrier, and different wireless resources are allocated for the uplink and downlink through the division of time resources, thus the TDD system can be more suitable for a data service characterized by asymmetric uplink and downlink service demands, in comparison with an FDD system. In the mobile communication system (including a Femto system), however, due to the static allocation of uplink and downlink resources in the TDD duplexing manner, it is difficult to implement dynamic matching between service demands and resource division in the case of various data services with different demands, such as web surfing, mobile videos and mobile games. Due to the employment of a centralized control mechanism based on scheduling, and hence there is no wireless resource waste that is caused by competition collision between the Base Station or CAP and a User Equipment or between User Equipments and random retreat, the Femto technology is advantageous for a higher link efficiency in comparison with the WiFi technology. 
     Data transmission in wireless communication system, refers to the communication Correspondent Node complete data transmit-receive through interaction, this interaction can be the interaction between the network side and terminal, also can be the interaction between the terminal. 
     In order to make management more fine, hope to respectively transmit different data based on multiple links in the communication Correspondent Nodes. Namely, data transmission is based on the traffic flow. Thus the requirement of the traffic flow management is existing. 
     SUMMARY OF THE INVENTION 
     In view of this, this invention aims to provide management method and device for traffic flow, including establishing method and device for traffic flow, and change method and device for traffic flow. 
     To attain the above and related objects, one or more embodiments include the features that will be illustrated in detail below and specifically recited in the claims. The following illustration and drawings illustrate some exemplary aspects in detail; moreover, it only indicates some of the various modes in which the principle of each embodiment may be applied. Other benefits and novel features will be apparent from the following detailed illustration in conjunction with the drawings, and all the embodiments disclosed intend to contemplate all these aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is the flow chart indicating the establishing method for traffic flow specified in this invention; 
         FIG. 2  is the flow chart indicating the change method for traffic flow specified in this invention; 
         FIG. 3  is the reference model of a wireless communication system of enhanced ultra-high throughput wireless local area network (EUHT) system; 
         FIG. 4  shows components of access system of EUHT system; 
         FIG. 5  shows the process of transmission and reception of protocol data between STA and CAP; 
         FIG. 6  is the flow chart indicating the methods of creating uplink traffic flow and sending data specified in the embodiment of this invention; 
         FIG. 7  is the structure diagram of dynamic service establishing request frame specified in the embodiment of this invention; 
         FIG. 8  is the structure diagram of dynamic service establishing response frame specified in the embodiment of this invention; 
         FIG. 9  is the flow chart indicating the methods of changing uplink traffic flow and sending data specified in the embodiment of this invention; 
         FIG. 10  is the flow chart indicating the methods of establishing downlink traffic flow and sending data specified in the embodiment of this invention; 
         FIG. 11  is the flow chart indicating the methods of changing downlink traffic flow and sending data specified in the embodiment of this invention; 
         FIG. 12  shows the structure of the first traffic flow establishing device specified in this invention; 
         FIG. 13  shows the structure of the device shown in  FIG. 12  when it is at the CAP side; 
         FIG. 14  shows the structure of the device shown in  FIG. 12  when it is at the STA side; 
         FIG. 15  shows the structure of the second traffic flow establishing device specified in this invention; 
         FIG. 16  shows the structure of the device shown in  FIG. 15  when it is at the CAP side; 
         FIG. 17  shows the structure of the first traffic flow changing device specified in this invention; 
         FIG. 18  shows the structure of the device shown in  FIG. 17  when it is at the CAP side; 
         FIG. 19  shows the structure of the device shown in  FIG. 17  when it is at the STA side; 
         FIG. 20  shows the structure of the second traffic flow changing device specified in this invention; 
         FIG. 21  shows the structure of the device shown in  FIG. 20  when it is at the CAP side; 
         FIG. 22  is the flow chart indicating the management method for traffic flow specified in this invention; 
         FIG. 23  shows the structure of the first traffic flow management device specified in this invention; 
         FIG. 24  shows the structure of the device shown in  FIG. 23  when it is at the CAP side; 
         FIG. 25  shows the structure of the device shown in  FIG. 23  when it is at the STA side; 
         FIG. 26  shows the structure of the second traffic flow management device specified in this invention; 
         FIG. 27  shows the structure of the device shown in  FIG. 26  when it is at the CAP side; 
         FIG. 28  is the flow chart indicating the method to delete the traffic flow specified in this invention; 
         FIG. 29  is the flow chart indicating the method to delete the uplink traffic flow specified in this invention; 
         FIG. 30  shows the structure of dynamic service deleting request frame specified in the embodiment of this invention; 
         FIG. 31  is the flow chart indicating the method to delete the uplink or downlink traffic flow specified in this invention; 
         FIG. 32  shows the structure of the deleting device for the first traffic flow specified in this invention; 
         FIG. 33  shows the structure of the device shown in  FIG. 32  when it is at the CAP side; 
         FIG. 34  shows the structure of the second traffic flow deleting device specified in this invention; 
         FIG. 35  shows the structure of the device shown in  FIG. 34  when it is at the CAP side; 
         FIG. 36  is the flow chart indicating the first method to establish traffic flow specified in this invention; 
         FIG. 37  is the flow chart indicating the second method to establish traffic flow specified in this invention; 
         FIG. 38  is the flow chart indicating the first method to change traffic flow specified in this invention; 
         FIG. 39  is the flow chart indicating the second method to change traffic flow specified in this invention; 
         FIG. 40  is the flow chart indicating the third method to establish traffic flow specified in this invention; 
         FIG. 41  is the flow chart indicating the fourth method to establish traffic flow specified in this invention; 
         FIG. 42  is the flow chart indicating the third method to change traffic flow specified in this invention; 
         FIG. 43  is the flow chart indicating the fourth method to establish traffic flow specified in this invention; 
         FIG. 44  is the flow chart indicating the first method to delete traffic flow specified in this invention; 
         FIG. 45  is the flow chart indicating the second method to delete traffic flow specified in this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The description below and accompanying drawings fully illustrate specific embodiments of the invention, to enable one skilled in the art to implement the embodiments. Modifications, such as structural, logical, electrical and process modifications, can be made in other embodiments. The embodiments only represent some possible variations. Individual components or functions are optional and the operation order is variable, unless it is otherwise stated specifically. A part and certain feature of some embodiments may be included in or replaced by a part and certain feature of other embodiment. The scope of the embodiments of the invention includes the whole scope of the claims and all obtainable equivalents thereof. Herein, these embodiments of the invention may be individually or generally represented by the term “invention” for the sake of convenience; moreover, if more than one invention is disclosed actually, it is not intended automatically to limit the application scope to any individual invention or inventive concept. 
       FIG. 1  is the flow chart indicating the establishing method for traffic flow specified in this invention. The process includes: 
     Step  11 : send dynamic service establishing request with traffic flow identifier (FID) and destination identifier. 
     Step  12 : receive response to dynamic service establishing request. 
     Through Step  11 ˜Step  12 , establish traffic flow corresponding to the above FID, which can be uplink traffic flow or downlink traffic flow. 
     After the establishing of traffic flow, it&#39;s available to send traffic data via created traffic flow with corresponding FID; it&#39;s not required to carry destination identifier each time when sending data, but only use the above FID to guide data transmission. 
       FIG. 2  is the flow chart indicating the change method for traffic flow specified in this invention. The process includes: 
     Step  21 : send dynamic service change request with destination identifier, FID and new service parameters. 
     According to new service parameters, it&#39;s available to change current service parameters corresponding to FID and destination identifier. 
     Step  22 : receive response to the said dynamic service change request. 
     Through Step  21 ˜Step  22 , change traffic flow corresponding to the above FID, which can be uplink traffic flow or downlink traffic flow. 
     After modifying the traffic flow, it&#39;s available to send service data via modified traffic flow corresponding to the said FID; it&#39;s not required to carry destination identifier each time when sending data, but only use the above FID to guide data transmission. 
     Establishment of the above traffic flow and change of traffic flow are collectively referred to traffic flow management, wherein traffic flow change can be treated as establishing of traffic flow in special case, that is, establishing traffic flow with the original FID. 
     As can be seen, through traffic flow management, this invention creates or modifies the “connection” between request side and destination via FID identifier before data transmission; therefore, when data is transmitted via traffic flow between request side and destination, it&#39;s available to only use FID as identifier, without having to carry destination identifier in interaction with each data packet, which simplifies the operation. 
     In the following embodiments, newly defined EUHT system at present is used as application background.  FIG. 3  is a reference model of EUHT system. 
     The system reference model shown in  FIG. 3  mainly refers to air interface reference model, including: media access control (MAC) layer and physical (PHY) layer. Main functions of each layer are summarized as follows: 
     {circle around (1)} MAC layer includes adaptation sublayer and MAC sublayer. 
     Adaptation Sublayer: mainly include the functions of mapping and conversion between external network data and MAC service data unit (MSDU) in this part. MSDU mentioned here refers to the information delivered as a unit between MAC service access points (SAP). Specifically, adaptation sublayer has the following functions: 
     Receive service data unit (SDU) from upper layer; 
     Classify the SDU received from upper layer; 
     Send the PDU generated at adaptation sublayer to MAC sublayer; 
     Receive adaptation sublayer SDU from peer entity. 
     MAC sublayer: in addition to the function of media access control, it also provides the functions of system management and control, and support to specific features of PHY layer. Specifically, MAC sublayer has basic functions of management of control plane and data plane. 
     Management of control plane includes the following features: 
     System configuration: manage system configuration message, and interact system configuration information with terminal; 
     Wireless Resource management: mainly complete service scheduling function, assign resources based on service parameters and channel conditions, and functions such as load balancing, and access control; 
     Network-entry Management: responsible for initialization and access processes, and producing information required by access process, including: access code selection and capability negotiation, etc.; 
     Service Quality (QoS) Management: manage QoS parameters, and maintain the functions of establishing, change and deletion of each traffic flow; 
     Power Saving Management: manage to switch STA without service into sleep status, and switch from sleep status to activation status; 
     PHY layer control: mainly include the following sub-functions 
     Channel management: include channel switching, management of spectrum measurement and message report; 
     Multiple input and multiple output (MIMO) management: channel detection mechanism; and identification and selection of MIMO work modes; 
     Link self-adaption: channel quality information (CQI) measurement and feedback; MCS selection and feedback; power control and management. 
     Data plane includes the following features: 
     Automatic Repeat-request (ARQ): acknowledgement and retransmission operations for MPDU at MAC layer or fragmentation/aggregation MPDU; 
     Fragmentation/reassembly: according to the scheduling result, the sending end performs fragmentation processing on upper layer service data unit and then sends it to the next processing module, and the receiving end reassembles and recovers multiple fragments; 
     MPDU generation: package upper layer service unit into basic MAC frame, and send it to the next processing module; 
     MPDU aggregation: according to the scheduling result, the sending end performs aggregation operation on upper layer service data unit. 
     {circle around (2)} PHY layer: mainly includes PHY transmission mechanism that maps MAC protocol data unit (MPDU) onto corresponding physical channel, such as orthogonal frequency division multiplexing (OFDM) and multiple input and multiple output (MIMO) technologies. Here MPDU refers to the data unit exchanged between two peer MAC entities using the PHY layer service. 
       FIG. 4  shows components of access system of EUHT system, including central access point (CAP) and station (STA), wherein STA can be for various data devices, such as: PDAs, laptops, cameras, mobile phones, tablets and pad and so on. As shown in  FIG. 2 , STA 1  and STA 2  are connected to CAP via air interface protocol, and CAP establishes communication with existing external network (such as IP backbone network, Ethernet) via wired or wireless media. Wherein, CAP protocol consists of MAC layer and PHY layer. STA protocol consists of Application lay, transmission control (TCP) layer, network (IP) layer, MAC layer and PHY layer. 
     Based on the protocol composition shown in  FIG. 4 ,  FIG. 5  shows the process of transmission and reception of protocol data between STA and CAP, namely: when STA wants to send data to CAP, STA first has to process and package application data (such as VoIP, video, etc.) through application layer, TCP/IP layer, and sends it to adaptation sublayer in form of IP packets, which is converted, mapped and divided into traffic flows by adaptation sublayer, and then sent to MAC sublayer. Through fragmentation, encryption, framing, and aggregation and other operations, MAC sublayer sends data to PHY layer, and finally PHY maps to wireless channel for data transmission. 
     The connection between the request side and destination in this invention requires separate establish uplink and downlink traffic flows. 
     As an alternative embodiment,  FIG. 6  is the flow chart indicating the methods of creating uplink traffic flow and sending data specified in the embodiment of this invention. The process includes: 
     Step  61 : CAP receives dynamic service establishing request frame carried with FID and destination MAC address sent by STA. 
     In this embodiment, destination MAC address is used as destination identifier. Here destination can be either CAP, or other STA within CAP scope. 
     In this embodiment, dynamic service establishing request is realized by dynamic service establishing request frame. 
       FIG. 7  is the structure diagram of dynamic service establishing request frame specified in the embodiment of this invention. The dynamic service establishing request frame includes: frame control field, FID field, service type field, direction field, service guarantee rate field, destination MAC address field, FID maximum buffer capability field, and FCS field.  FIG. 7  also shows the examples of number of bits occupied by each field. The frames shown in  FIG. 7 , except for those of frame control field and FCS field, are known as frame body. 
     The meaning of each field shown in  FIG. 7  is described below: 
     {circle around (1)} the above frame control field includes identifier associated with the frame type, indicating that the frame is a dynamic service establishing request frame. 
     {circle around (2)} the above FCS field is a checksum field. 
     {circle around (3)} the above FID field indicates FID. 
     {circle around (4)} the above service type field indicates the service type of the traffic flow to be created. 
     QoS parameters of traffic flow are as follows: 
     Service type, is a parameter uniquely identifying the type of service; 
     Service priority, is a parameter specifying the priority assigned to the traffic flow. For two given traffic flows, if all QoS parameters except for priority are the same, the traffic flow with higher priority will have lower latency and higher cache. 
     Service guarantee rate, is a parameter defining the basic rate to guarantee the service. The unit of this parameter is bits per second, and it matches the SDU input at IP adaptation layer. This parameter does not include MAC overhead. 
     Maximum service rate is a parameter describing the maximum service rate that the system can provide to the service, which can be used for rate shaping. Extra data exceeding this rate will be discarded by CAP. The unit of this parameter is bits per second, and it matches the SDU input at IP adaptation layer. This parameter does not include MAC overhead. 
     In this embodiment, the MAC layer defines eight service types according to QoS parameters of services, which can be further divided into categories, namely reserved resource class and non-reserved resource class, as shown in the following Table 1. Wherein, service types 1 to 4 belong to reserved resource class, the transmission rate of which will be guaranteed by the system; while service types 5 to 8 belong to non-reserved resource class, the transmission rate of which will not be guaranteed by the system. 
     
       
         
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 Packet 
                   
               
               
                   
                 Loss 
                   
               
             
          
           
               
                 Service 
                 Resource 
                   
                 Delay 
                 Rate 
                   
               
               
                 Type 
                 Type 
                 Priority 
                 Budget 
                 Budget 
                 Service Examples 
               
               
                   
               
             
          
           
               
                 0 
                 Reserved 
                 2 
                 100 
                 ms 
                 10-2 
                 Voice conversation 
               
               
                 1 
                 Resource 
                 4 
                 150 
                 ms 
                 10-3 
                 Video session 
               
               
                   
                   
                   
                   
                   
                   
                 (Real-time streaming 
               
               
                   
                   
                   
                   
                   
                   
                 service) 
               
               
                 2 
                   
                 3 
                 50 
                 ms 
                 10-3 
                 Real-time games 
               
               
                 3 
                   
                 5 
                 300 
                 ms 
                 10-6 
                 Non-session video 
               
               
                   
                   
                   
                   
                   
                   
                 (cached streaming 
               
               
                   
                   
                   
                   
                   
                   
                 service) 
               
               
                 4 
                 Non-Reserved 
                 1 
                 100 
                 ms 
                 10-6 
                 Signaling 
               
               
                 5 
                 Resource 
                 6 
                 100 
                 ms 
                 10-3 
                 Interactive game 
               
               
                 6 
                   
                 7 
                 300 
                 ms 
                 10-6 
                 Video (cached streaming 
               
               
                   
                   
                   
                   
                   
                   
                 service) 
               
               
                   
                   
                   
                   
                   
                   
                 TCP-based service (e.g., 
               
               
                   
                   
                   
                   
                   
                   
                 WWW, FTP, P2P file 
               
               
                   
                   
                   
                   
                   
                   
                 sharing, etc.) 
               
               
                 7 
                   
                 8 
                 1000 
                 ms 
                 10-6 
                 Background E-Mail 
               
               
                   
                   
                   
                   
                   
                   
                 receiving, file download, 
               
               
                   
                   
                   
                   
                   
                   
                 and file print, and other 
               
               
                   
                   
                   
                   
                   
                   
                 services with lower 
               
               
                   
                   
                   
                   
                   
                   
                 requirements on 
               
               
                   
                   
                   
                   
                   
                   
                 transmission time 
               
               
                   
               
             
          
         
       
     
     {circle around (5)} The above direction field indicates the traffic flow to be created is uplink traffic flow or downlink traffic flow. Through this field CAP can directly be informed of the direction of the traffic flow to be created. 
     {circle around (6)} The above service guarantee rate field indicates the basic rate of guaranteed service in bits per second. It matches the SDU input at IP adaptation layer. This parameter does not include MAC overhead. As the actual application may have many different types of services, such as voice service and real-time session specified in Table 1, through this field it can indicate the service guarantee rate of each service expected by STA, thus enhancing the flexibility of application. For service type corresponding to non-reserved resources listed in Table 1, STA can also report its expected service guarantee rate. 
     {circle around (7)} The above destination MAC address field indicates the destination MAC address. Through this field CAP can be directly informed of the destination corresponding to dynamic service establishing request. Here destination may be CAP itself, or another STA within the CAP scope. 
     {circle around (8)} The above FID maximum buffer capability field indicates the number of MPDUs with maximum CAP buffers expected by STA. 
     The above service type and service guarantee rate are collectively referred to service parameters. 
     Step  62 : CAP sends dynamic service establishing response frame to STA. 
     In this embodiment, service establishing response is realized by dynamic service establishing response frame. 
     Corresponding to the dynamic service establishing request frame structure shown in  FIG. 7 ,  FIG. 8  shows the structure of dynamic service establishing response frame specified in the embodiment of this invention, including: frame control field, FID field, service type field, reservation field, service guarantee rate field, service maximum rate field, FID maximum buffer capability field and FCS field.  FIG. 8  also gives examples of number of bits occupied by each field. 
     The meaning of each field listed in  FIG. 8  is shown below: 
     {circle around (1)} the above frame control field includes identifier related to frame type, which indicating that the frame is dynamic service establishing response frame. 
     {circle around (2)} the above FCS field is a checksum field. 
     {circle around (3)} the above FID field has the same content with that of dynamic service establishing request frame. 
     {circle around (4)} the above service type field has the same content with that of dynamic service establishing request frame. 
     {circle around (5)} the above service guarantee rate field indicates the service guarantee rate value allowed by CAP. CAP can adjust the service guarantee rate in the dynamic service establishing request frame. The adjustment is mainly based on the adequacy of current resources to provide the service guarantee rate. For the service type of reserved resource, if current resources are limited and cannot guarantee the service guarantee rate reported in dynamic service establishing request frame, CAP can adjust the STA-reported service guarantee rate based on the actual situation. For the service type of non-reserved resource, regardless of whether STA reports service guarantee rate in dynamic service establishing request frame, CAP will directly adjust the STA-reported service guarantee rate to 0; however, when current resource provides said service guarantee rate to reserved resource service and has more remaining resources, CAP can assign resources for STA-requested services, and indicate assigned resources to STA. 
     For the service type of reserved resource, after STA parses the field, it&#39;s available to decide whether to continue the data transmission. Assuming that the parsed service guarantee rate is less than the reported service guarantee rate, STA may choose not to proceed with data transmission. 
     For service type of non-reserved resource, if CAP allocates resource, STA may choose to use the allocated resources for data transmission. 
     {circle around (6)} the service maximum rate field indicates the maximum service rate that can be provided by the system for requested service. It&#39;s for rate shaping. The extra data exceeding this rate will be discarded. The unit is bits per second, and it matches the SDU input at IP adaptation layer. This parameter does not include MAC overhead. The maximum service rate is preset value. 
     {circle around (7)} FID maximum buffer capability field indicates the maximum number of cached MPDUs in CAP. The value in this field can be the value reported in dynamic service establishing request frame, or the value adjusted by CAP according to actual situation. 
     CAP records FID, destination MAC address and corresponding service parameters, as well as maximum service rate and other information. 
     Further, after correctly receive dynamic service establishing response frame, STA can send acknowledgement to CAP; Specifically, STA can send ACK to CAP, or send group acknowledgement (GroupAck) to CAP. This invention embodiment provides a group acknowledgement method. The group acknowledgement frame includes management control frame indicator bit, and bitmap corresponding to different traffic flows of the same user. Here STA can fill in the above management control frame indicator bit the instruction that indicates whether the dynamic service establishing response frame is correctly received. During the follow-up data transmission based on traffic flow, STA can use the bitmap in the group acknowledgement frame to send the acknowledgements for different traffic flows to CAP. 
     Step  63 : STA uses CAP-allocated uplink transmission resources to send data. 
     There are three ways to achieve this step: 
     1) by sending independent resource request, STA can request uplink transmission resources from CAP; Further, after CAP correctly receives independent resource request, it&#39;s available to send acknowledge to STA; 
     2) when CAP has sufficient resources, CAP can actively query each STA and allocate uplink transmission resource; 
     3) If STA currently has other service data transmission tasks, it&#39;s available to carry resource request in service data frame, and request uplink transmission resource from CAP; Further, after CAP correctly receives carried resource request, it&#39;s available to send acknowledgement to STA. 
     CAP indicates uplink transmission resource assigned to STA through control channel (CCH). 
     Through the above Step  61 ˜Step  63 , uplink traffic flows are created and data is sent based on the uplink traffic flows. 
     As an alternative embodiment, uplink traffic flow has similar change process as the above  FIG. 6 .  FIG. 9  is the flow chart indicating the methods of modifying uplink traffic flow and sending data specified in this invention. The dynamic service change request frame includes the same fields as shown in  FIG. 7 , while dynamic service change response frame includes the same fields as shown in  FIG. 8 . When modifying uplink traffic flows, provided the FID and destination identifier carried in dynamic service change request frame are recorded by CAP, and what are carried in dynamic service change request frame are new service parameters, such as new service type and new service guarantee rate, CAP can, after receiving dynamic service change request frame, appropriately adjust new service parameters based on current resources. See above contents for adjustment method. Then CAP will change current service parameters corresponding to recorded FID and destination identifier to adjusted new service parameters, and carry modified service parameters in dynamic service change response frame and then send it to STA. When carrying new service parameters in dynamic service change request frame, the FID maximum buffer capability carried therein can either be a new value, or the original value. 
     As an alternative embodiment,  FIG. 10  is the flow chart indicating the methods of creating downlink traffic flow and sending data specified in the embodiment of this invention. The process includes: 
     Step  101 : STA receives the FID and destination MAC address carried in dynamic service establishing request frame and sent from CAP. 
     In this embodiment, dynamic service establishing request is realized by dynamic service establishing request frame. 
     In this step, dynamic service establishing request frame includes the same fields as shown in  FIG. 7 , and the contents in each field are almost the same, except that the FID maximum buffer capability field indicates the number of MPDUs with maximum STA buffers expected by CAP. 
     Here destination MAC address refers to the STA that receives dynamic service establishing request frame. 
     Step  102 : STA sends ACK to CAP. 
     In this step, STA directly sends ACK to CAP, and saves FID and destination identifier and various parameters carried in dynamic service establishing request frame. 
     In this step, STA can also send GroupAck. 
     Step  103 : STA receives the data sent from CAP, while be notified the downlink transmission resource that sends the data. 
     Through CCH, CAP can send data while indicating downlink transmission resources. 
     Through the above steps  101 ˜ 103 , downlink traffic flows are created and data is sent via downlink traffic flows. 
     As an alternative embodiment, the change process for downlink traffic flows is similar with that specified in the above  FIG. 10 .  FIG. 11  is the flow chart indicating the method to change downlink traffic flows in this invention. The dynamic service change request frame includes the same fields as shown in  FIG. 7 . However when modifying downlink traffic flows, provided the FID and destination identifier carried in dynamic service change request frame are recorded by STA, and what are carried in dynamic service change request frame are new service parameters, such as new service type and new service guarantee rate, STA will update various new service parameters corresponding to saved FID and destination identifier. When carrying new service parameters in dynamic service change request frame, the FID maximum buffer capability carried in dynamic service change request frame can be either a new value, or the original value. 
     An example of a method of this invention is shown below. Assuming that a CAP has multiple STAs, when two STAs require data transmission, it&#39;s available to use the method of this invention. Fox example, when STA 1  and STA 2  within the scope of CAP require data transmission, STA 1  first creates uplink traffic flow with CAP. During the process of establishing uplink traffic flow, CAP is informed that the destination is STA 2 , and then it can establish downlink traffic flow with STA 2 . As CAP has cache capacity, when CAP creates downlink traffic flow with STA 2 , STA 1  can send data to CAP; when downlink traffic flow is created, CAP forwards the data sent from cached STA 1  to STA 2 . The process of STA 2  sending data to STA 1  is almost the same, i.e., first creating uplink traffic flow from STA 2  to CAP; secondly, creating downlink traffic flow from CAP to STA 1 ; then creating data to be sent from STA 2  to STA 1  via traffic flow. 
     The first traffic flow establishing device specified in this invention is located at the request side. And the request side can be either at the STA side, or at the CAP side. 
       FIG. 12  shows the structure of the first traffic flow establishing device specified in this invention. The device includes: request sending unit  121  and response receiving unit  122 . 
     Request sending unit  121  sends dynamic service establishing request carrying destination identifier and FID. 
     Response receiving unit  122  receives the response to dynamic service establishing request. 
     When the first traffic flow establishing device specified in this invention is at the CAP side, as an alternative embodiment, its structure is as shown in  FIG. 13 . The device includes: request sending unit  131 , response receiving unit  132 , service parameter provision unit  133 , direction information provision unit  134 , buffer capacity provision unit  135  and monitoring unit  136 . 
     Request sending unit  131  sends dynamic service establishing request carrying destination identifier and FID. 
     Response receiving unit  132  receives the response to dynamic service establishing request. The response received by response receiving unit  132  to dynamic service establishing request is ACK or GroupAck. 
     Service parameter provision unit  133  is used to send service parameters to request sending unit  131  for further sending with dynamic service establishing request. 
     Direction information provision unit  134  is used to send the information indicating the direction of the traffic flow to be created and request sending unit  131 . The unit  131  will further send it with dynamic service establishing request. 
     Buffer capacity provision unit  135  is used to provide FID maximum buffer capability to request sending unit  131 , which will further send it with dynamic service establishing request. FID maximum buffer capability indicates the number of MPDUs of dynamic service establishing request with maximum cache at the receiving end. 
     Monitoring unit  136  is used to monitor response receiving unit  132  within preset number of frames after request sending unit  131  sends dynamic service establishing request. If response receiving unit  132  does not receive the said response, request sending unit  131  will be notified to re-send dynamic service establishing request. On this basis, request sending unit  131  will package and send dynamic service establishing request as MPDU. When re-sent dynamic service establishing request exceeds the maximum number of MPDU re-transmissions, the dynamic service establishing request will be discarded, and traffic flow deletion device will be informed to perform operations. 
     When the first traffic flow establishing device specified in this invention is at the STA side, as an alternative embodiment, its structure is shown in  FIG. 14 . This device includes: request sending unit  141 , response receiving unit  142 , acknowledgement unit  143 , service parameter provision unit  144 , direction information provision unit  145 , buffer capacity provision unit  146  and monitoring unit  147 . 
     Request sending unit  141  sends dynamic service establishing request carrying destination identifier and FID. 
     Response receiving unit  142  receives the response to dynamic service establishing request. The response to dynamic service establishing request received by response receiving unit  142  is dynamic service establishing response carrying the said FID. Further, the dynamic service establishing response received by response receiving unit  142  can also carry maximum service rate that can be provided by the system. 
     Acknowledgement unit  143  is used to send ACK or GroupAck that indicates whether dynamic service establishing response is correctly received. 
     Service parameter provision unit  144  is used to send service parameters to request sending unit  141 , which will be further sent with dynamic service establishing request. On this basis, dynamic service establishing response can also carry adjusted service parameters. 
     Direction information provision unit  145  is used to send the information that indicates the direction of uplink or downlink traffic flows to be created to request sending unit  141 , which will be further sent with dynamic service establishing request. 
     Buffer capacity provision unit  146  is used to provide FID maximum buffer capability to request sending unit  141 , which will be further sent with dynamic service establishing request. The said FID maximum buffer capability indicates the number of MPDUs of the said dynamic service establishing request with maximum cache at the receiving end. 
     Monitoring unit  147  is used to monitor response receiving unit  142  after request sending unit  141  sends dynamic service establishing request within the preset number of frames; if response receiving unit  142  does not receive the said response, inform request sending unit  141  to end this process. 
     Alternatively, regardless of whether the first traffic flow establishing device specified in this invention is at the STA side or the CAP side, this device can further include: a data transmission unit, that is used to send service data via the traffic flow created with the said FID. 
     Alternatively, regardless of whether the first traffic flow establishing device specified in this invention is at the STA side or the CAP side, it can only include either of direction information provision unit and buffer capacity provision unit. 
     The second traffic flow establishing device specified in this invention is at the request receiving end, and the request receiving end can be either at the STA side, or at the CAP side. 
       FIG. 15  is the structural diagram of the second traffic flow establishing device specified in this invention. This device includes: request receiving unit  151  and response sending unit  152 . 
     Request receiving unit  151  is used to receive dynamic service establishing request carrying destination identifier and FID. 
     Response sending unit  152  is used to send the response to the said dynamic service establishing request. 
     When the second traffic flow establishing device specified in this invention is at the STA side, the dynamic service establishing request received by request receiving unit  151  can also carry service parameters. Response sending unit  152  sends ACK or GroupAck. 
     When the second traffic flow establishing device specified in this invention is at the CAP side, as an alternative embodiment, its structure is shown in  FIG. 16 . This device includes: request receiving unit  161 , response sending unit  162 , receipt acknowledgement unit  163 , monitoring unit  164 , service parameter adjustment unit  165  and service maximum rate acknowledgement unit  166 . 
     Request receiving unit  161  is used to receive dynamic service establishing request carrying destination identifier and FID. 
     Response sending unit  162  is used to send the response to the said dynamic service establishing request. What is sent from response sending unit  162  is the dynamic service establishing response with the said FID. 
     Receipt acknowledgement unit  163  is used to receive ACK or GroupAck that indicates if the said dynamic service establishing response is correctly received. 
     Monitoring unit  164  is used to monitor receipt acknowledgement unit  163  after response sending unit  162  sends the said dynamic service establishing response within preset number of frames. If receipt acknowledgement unit  163  does not receive ACK or GroupAck, it will notify response sending unit  163  to re-send the said dynamic service establishing response. On this basis, response sending unit  162  will package and send dynamic service establishing response as MPDU. When the said re-send times exceed the maximum MPDU re-send times, discard dynamic service establishing response, and notify traffic flow deletion device to perform operations. 
     Service parameter adjustment unit  165  is used to adjust the service parameters carried in dynamic service establishing request, and send adjusted service parameters to response sending unit  162 , which will be then sent with the said response. 
     Service maximum rate acknowledgement unit  166  is used to confirm the maximum service rate provided by the system, and send it to response sending unit  162 , which will be then sent with the said response. 
     Alternatively, regardless of whether the second traffic flow establishing device specified in this invention is at the STA side or at the CAP side, it can further include: data transmission unit, that is used to receive the service data sent via the traffic flows created with the said FID. 
     Alternatively, regardless of whether the second traffic flow establishing device specified in this invention is at the STA side or at the CAP side, the dynamic service establishing request received at the request receiving unit can carry direction information and/or FID maximum buffer capability, wherein the said direction information indicates that the traffic flow to be created is uplink or downlink, and the said FID maximum buffer capability indicates the number of MPDUs of the said dynamic service establishing request with maximum cache at the receiving end. 
     The first traffic flow change device specified in this invention is at the request side. The request side can be located at the CAP side, or at the STA side. 
       FIG. 17  is the structural diagram of the first traffic flow change device specified in this invention. This device includes: request sending unit  171  and response receiving unit  172 . 
     Request sending unit  171  sends dynamic service change request carrying destination identifier, FID and new service parameters. 
     Response receiving unit  172  receives dynamic service change response carrying the said FID. 
     As an alternative embodiment, when the first traffic flow change device specified in this invention is at the CAP side, its structure is shown in  FIG. 18 . This device includes: request sending unit  181 , response receiving unit  182 , monitoring unit  183 , direction information provision unit  184  and buffer capacity provision unit  185 . 
     Request sending unit  181  sends dynamic service change request carrying destination identifier, FID and new service parameters. 
     Response receiving unit  182  receives dynamic service change response carrying the said FID. The response received by response receiving unit  182  is ACK or GroupAck. 
     Monitoring unit  183  is used to monitor response receiving unit  182  after request sending unit  181  sends dynamic service change request within the preset frame. If response receiving unit  182  does not receive the said response, notify request sending unit  181  to re-send dynamic service change request. On this basis, request sending unit  181  will package and send dynamic service change request as MPDU. When the re-sent dynamic service change request exceeds the Maximum MPDU re-send times, discard dynamic service change request, and notify traffic flow deletion device to perform operations. 
     Direction information provision unit  184  is used to send the direction information that indicates if the modified traffic flow is uplink or downlink to request sending unit  181 , which will be further sent via dynamic service change request. 
     Buffer capacity provision unit  185  is used to provide FID maximum buffer capability to request sending unit  181 , which will be sent with dynamic service change request. The said FID maximum buffer capability indicates the number of MPDUs with maximum cache expected by the said dynamic service change request at the receiving end. 
     As an alternative embodiment, when the first traffic flow change device specified in this invention is at the STA side, its structure is shown in  FIG. 19 . This device includes: request sending unit  191 , response receiving unit  192 , acknowledgement unit  193 , and monitoring unit  194 , 
     Request sending unit  191  sends dynamic service change request carrying destination identifier, FID and new service parameters. 
     Response receiving unit  192  receives dynamic service change response carrying the said FID. The response received by response receiving unit  192  is dynamic service change response. Further, this dynamic service change response carries modified service parameters. Further more, this dynamic service change response carries the maximum service rate supported by the system. 
     Acknowledgement unit  193  is used to send ACK or GroupAck indicating if the said dynamic service change response is correctly received. 
     Monitoring unit  194  is used to monitor response receiving unit  192  after request sending unit  191  sends dynamic service change request within preset frame. If response receiving unit  192  does not receive the said response, notify request sending unit  191  to end this process. 
     Direction information provision unit  195  is used to send the direction information that indicates whether the modified traffic flow is uplink or downlink to request sending unit  191 , which will be further sent via dynamic service change request. 
     Buffer capacity provision unit  196  is used to provide FID maximum buffer capability to request sending unit  191 , which will be further sent via dynamic service change request; The said FID maximum buffer capability indicates the number of MPDUs with maximum cache expected by the said dynamic service change request at the receiving end. 
     Alternatively, regardless of whether the first traffic flow change device specified in this invention is at the CAP side or at the STA side, this device can also include: data transmission unit, that is used to send service data via the traffic flow with modified FID. 
     The second traffic flow change device specified in this invention is at the request receiving end, the request receiving end can be either at the STA side, or at the CAP side. 
       FIG. 20  is the structural diagram of the second traffic flow change device specified in this invention. This device includes: request receiving unit  201  and response sending unit  202 . 
     Request receiving unit  201  is used to receive dynamic service change request carrying destination identifier, FID and new service parameters. 
     Response sending unit  202  is used to send the response to the said dynamic service change request. 
     As an alternative embodiment, when the second traffic flow change device specified in this invention is at the STA side, the response sent from response sending unit  202  is ACK or GroupAck. 
     As an alternative embodiment, when the second traffic flow change device specified in this invention is at the CAP side, its structure is shown in  FIG. 21 . This device includes: request receiving unit  211 , response sending unit  212 , receipt acknowledgement unit  213 , monitoring unit  214 , change unit  215 , and service maximum rate provision unit  216 , 
     Request receiving unit  211  is used to receive dynamic service change request carrying destination identifier, FID and new service parameters. 
     Response sending unit  212  is used to send the response to the said dynamic service change request. The response sent from response sending unit  212  is dynamic service change response carrying the said FID. 
     Receipt acknowledgement unit  213  is used to receive ACK or GroupAck that indicates whether dynamic service change response is correctly received. 
     Monitoring unit  214  is used to monitor receipt acknowledgement unit  213  after response sending unit  212  sends dynamic service change response within preset number of frames. If receipt acknowledgement unit  213  does not receive ACK or GroupAck, notify response sending unit  212  to re-send dynamic service change response. On this basis, response sending unit  212  will send dynamic service change response as MPDU. When the said re-send exceeds maximum MPDU re-send times, discard dynamic service change response, and notify traffic flow deletion device to perform operations. 
     Change unit  215  is used to determine reserved resource for the traffic flow to be modified according to new service parameters; adjust the said new service parameters according to the said reserved resource; change the current service parameters corresponding to the said FID and destination identifier according to the adjusted new service parameters, and send the modified service parameters to response sending unit  212 , which will be further sent via dynamic service change response. 
     Service maximum rate provision unit  216  is used to confirm the maximum service rate supported by the system, and send to response sending unit  212 , which will be then sent with the said response. 
     Alternatively, regardless of whether the second traffic flow change device specified in this invention is at the STA side or at the CAP side, this device can further include: data transmission unit, that is used to receive the service data sent on the traffic flows with modified FID. 
     Alternatively, regardless of whether the second traffic flow change device specified in this invention is at the STA side or at the CAP side, dynamic service change request received at request receiving unit can also carry direction information and/or FID maximum buffer capability; wherein, the said direction information indicates whether the traffic flow to be modified is uplink or downlink; the said FID maximum buffer capability indicates the number of MPDUs of the said dynamic service establishing request with maximum cache at the receiving end. 
     Alternatively, when the first traffic flow establishing device specified in this invention and the first traffic flow change device are at the STA side, this device can also include: resource request unit that is used to request uplink transmission resource for send service data. 
     Alternatively, when the first traffic flow establishing device specified in this invention and first traffic flow change device are at the STA side, this device can also include: resource acquisition unit that is used to acquire uplink transmission resource of send service data through active polling. 
     Alternatively, when the first traffic flow establishing device specified in this invention and the first traffic flow change device are at the CAP side, this device can also include: resource indication unit that is used to send the said service data, while indicating downlink transmission resource of send service data. 
     Alternatively, when the second traffic flow establishing device specified in this invention and the second traffic flow change device are at the CAP side, this device can also include: resource allocation unit is used to allocate uplink transmission resource of send service data according to the request. 
     Alternatively, when the second traffic flow establishing device specified in this invention and the second traffic flow change device are at the CAP side, this device can also include: polling unit is used to allocate uplink transmission resource of send service data through active polling. 
     This invention also provides a type of traffic flow management method.  FIG. 22  is the flow chart indicating the traffic flow management method specified in this invention. The process includes: 
     Step  221 : send dynamic service management request carrying FID and FID maximum buffer capability. 
     Here FID maximum buffer capability refers to the number of MPDUs of the receiving end with maximum buffer that is expected by the request side. The request side can be either CAP or STA. 
     Step  222 : receive the response to dynamic service management request. 
     As can be seen, in the traffic flow management method provided in this invention, on the one hand it enables each traffic flow to have their respective buffer capacity, and finer and more flexible management; on the other hand, it support request traffic flow management whilst buffer capacity negotiation, which simplifies operation process. 
     As an alternative embodiment, traffic flow management method provided in this invention is traffic flow establishing method, including the following two situations: 
     First, uplink traffic flow establishing and data transmission methods include the following steps: 
     Step  1 : CAP receives STA-sent dynamic service establishing request frame with FID and FID maximum buffer capability. 
     In this embodiment, dynamic service establishing request is realized by dynamic service establishing request frame. 
     The frame body of dynamic service establishing request frame specified in this step includes FID field and FID maximum buffer capability field, and can also include either or more of service type field, direction field, service guarantee rate field and destination MAC address field. These fields have the same meanings with the foregoing. The structures of all the above fields in the frame body are the same as that in  FIG. 7 . 
     Step  2 : CAP sends dynamic service establishing response frame to STA. 
     The service establishing response specified in this embodiment is realized by dynamic service establishing response frame. 
     In the frame body of dynamic service establishing response frame specified in this step, in addition to FID field and FID maximum buffer capability field, it also includes either or more of service type field, service guarantee rate field and service maximum rate field. These fields have the same meanings with the foregoing. The structures of all the above fields in the frame body are the same as that in  FIG. 8   
     The service parameters carried by dynamic service establishing response frame (through service type field and service guarantee rate field) can be service parameters adjusted by CAP for dynamic service establishing request frame. Detailed adjustment method is illustrated above. 
     The FID maximum buffer capability carried by dynamic service establishing response frame can be the same as that of dynamic service establishing request frame, or the FID maximum buffer capability of dynamic service establishing request frame as adjusted by CAP. 
     CAP records FID, destination MAC address and corresponding service parameters, service maximum rate and other information. 
     Further, STA can send ACK or GroupAck to CAP after correctly receiving dynamic service establishing response frame. 
     Through the above steps  1 ˜ 2 , it can not only complete uplink traffic flow establishing, but also negotiate the FID maximum buffer capability, which eliminates the need for separate negotiation of FID maximum buffer capability and simplifies the operation process. 
     Step  3 : STA uses uplink transmission resource allocated by CAP to send data. 
     The change process of uplink traffic flow is similar to the above step  1 ˜ 2 , except that what is sent by STA is dynamic service change request frame with the same structure of dynamic service establishing request frame, and FID of dynamic service change request frame is recorded by CAP. According to the parameters in dynamic service change request frame, CAP updates the FID maximum buffer capability and/or service parameters corresponding to the recorded FID. Alternatively, CAP can adjust the FID maximum buffer capability and/or service parameters in dynamic service change request frame before the update operation. 
     Second, downlink traffic flow establishing and data transmission methods include the following steps: 
     Step  1 ′: STA receive CAP-sent dynamic service establishing request frame carrying FID and FID maximum buffer capability. 
     In this embodiment, dynamic service establishing request is realized by dynamic service establishing request frame. 
     The frame body of dynamic service establishing request frame specified in this step includes FID field and FID maximum buffer capability field, and also includes either or more of service type field, direction field, service guarantee rate field and destination MAC address field. These fields have the same meanings with the foregoing. The structures of all the above fields in the frame body are the same as that in  FIG. 7 . 
     Step  2 ′: STA sends ACK to CAP. 
     In this step, STA directly feeds back ACK to CAP, and saves FID and destination identifier as well as various parameters in dynamic service establishing request frame. 
     In this step, STA can also send GroupAck to CAP. 
     Through the above steps  1 ′˜ 2 ′, it can not only complete downlink traffic flow establishing, but also negotiate FID maximum buffer capability, which eliminate the need for separate negotiation of FID maximum buffer capability and simplifies the operation process. 
     Step  3 ′: STA receives the data sent from CAP, and acquire the downlink transmission resource that sends the data. 
     The change process for downlink traffic flows is similar with the above Step  1 ′˜ 2 ′, except that what&#39;s sent by CAP is dynamic service change request frame with the same structure as dynamic service establishing request frame, and FID in dynamic service change request frame is recorded by STA. STA updates FID maximum buffer capability and/or service parameters corresponding to the recorded FID according to the parameters in dynamic service change request frame. 
     This invention also provides two types of traffic flow management devices. 
       FIG. 23  is the structural diagram of the first traffic flow management device specified in this invention. This device is at the request side, including: request sending unit  231  and response receiving unit  232 . 
     Request sending unit  231  is used to send dynamic service management request carrying traffic flow identifier FID and FID maximum buffer capability. 
     Response receiving unit  232  receives the response to dynamic service management request. 
     As an alternative embodiment, when the first traffic flow management device specified in this invention is at the CAP side, its structure is shown in  FIG. 24 . This device includes: request sending unit  241 , response receiving unit  242 , parameter provision unit  243  and monitoring unit  244 . 
     Request sending unit  241  is used to send dynamic service management request carrying traffic flow identifier FID and FID maximum buffer capability. 
     Response receiving unit  242  receives the response to dynamic service management request. The response to dynamic service management request received by response receiving unit  242  is: acknowledgement that indicates if the said dynamic service management request is correctly receives. 
     Parameter provision unit  243  is used to send either or more of destination identifier, service parameters and direction information to request sending unit  241 , which will carry and send via dynamic service management request. The said direction information indicates whether the traffic flow is uplink or downlink. 
     Monitoring unit  244  is used to monitor response receiving unit  242  after request sending unit  241  sends dynamic service management request within preset number of frames. If response receiving unit  242  does not receive the said response, notify request sending unit  241  to re-send dynamic service management request. On this basis, request sending unit  241  will package and send dynamic service management request as MPDU. When re-sent dynamic service management request exceeds the Maximum MPDU re-send times, discard dynamic service management request, and notify traffic flow deletion device to perform operations. 
     As an alternative embodiment, when the first traffic flow management device specified in this invention is at the STA side, its structure is shown in  FIG. 25 . This device includes: request sending unit  251 , response receiving unit  252 , acknowledgement unit  253 , parameter provision unit  254  and monitoring unit  255 . 
     Request sending unit  251  is used to send dynamic service management request carrying traffic flow identifier FID and FID maximum buffer capability. 
     Response receiving unit  252  receives the response to dynamic service management request. the response to dynamic service management request received by response receiving unit  252  is: dynamic service management response carrying the said FID. 
     Acknowledgement unit  253  is used to send acknowledgement that indicates whether the said dynamic service management response is correctly received. 
     Parameter provision unit  254  is used to send either or more of destination identifier, service parameters and direction information to request sending unit  251 , which will carry and send via dynamic service management request; wherein the said direction information indicates whether the traffic flow is uplink or downlink. On this basis, further, when dynamic service management request carries service parameters, dynamic service management response can also carry adjusted service parameters. 
     Monitoring unit  255  is used to monitor response receiving unit  252  after request sending unit  251  sends dynamic service management request within preset number of frames. If response receiving unit  252  does not receive the said response, notify request sending unit  251  to end this process. 
       FIG. 26  is the structural diagram of the second traffic flow management device specified in this invention. This device is at the receiving end. This device includes: request receiving unit  261  and response sending unit  262 . 
     Request receiving unit  261  is used to receive dynamic service management request carrying FID and FID maximum buffer capability. 
     Response sending unit  262  is used to send the response to dynamic service management request. 
     As an alternative embodiment, when traffic flow management device is at the STA side, the said response to dynamic service management request is: acknowledgement that indicates whether the said dynamic service management request is correctly received. On this basis, further, the said dynamic service management request also carries either or more of destination identifier, service parameters and direction information, including the said direction information that indicates whether the traffic flow to be created is uplink or downlink. 
     As an alternative embodiment, when traffic flow management device at the CAP side, its structure is shown in  FIG. 27 . This device includes: request receiving unit  271 , response sending unit  272 , receipt acknowledgement unit  273 , monitoring unit  274  and service parameter adjustment unit  275 . 
     Request receiving unit  271  is used to receive dynamic service management request carrying FID and FID maximum buffer capability. 
     Response sending unit  272  is used to send the response to dynamic service management request. The response to dynamic service management request sent by response sending unit  272  is: dynamic service management response carrying the said FID and FID maximum buffer capability. 
     Receipt acknowledgement unit  273  is used to receive acknowledgement that indicates whether the said dynamic service management response is correctly received. 
     Monitoring unit  274  is used to monitor receipt acknowledgement unit  273  after response sending unit  272  sends dynamic service management response within preset number of frames. If receipt acknowledgement unit  273  does not receive the said acknowledgement, trigger response sending unit  272  to re-send dynamic service management response. On this basis, response sending unit  272  will package and send dynamic service management response as MPDU. When the said re-send exceeds maximum MPDU re-send times, discard dynamic service management response, and notify traffic flow deletion device to perform operations. 
     The said dynamic service management request also carries either or more of destination identifier, service parameters and direction information. Service parameter adjustment unit  275  is used to, when dynamic service management request carries service parameters, confirm reserved resource according to the service parameters in dynamic service management request, adjust the service parameters in dynamic service management request according to the said reserved resource, and send adjusted service parameters to response sending unit  272 , which will then send with dynamic service management response. 
     This invention also provides a type of traffic flow deletion method.  FIG. 28  is the flow chart indicating the method to delete the traffic flow specified in this invention. The process includes: 
     Step  281 : send dynamic service deletion request carrying FID and direction information; direction information indicates whether the traffic flow to be deleted is uplink traffic flow or downlink traffic flow. 
     The sending end of dynamic service deletion request can be either STA or CAP, wherein in the dynamic service deletion request sent from STA, direction information indicates uplink traffic flow, while in dynamic service deletion request sent from CAP, direction information can either indicate uplink traffic flow, or downlink traffic flow. 
     Step  282 : receive the response to dynamic service deletion request. 
     As can be seen, through the direction information carried in dynamic service deletion request, this invention enables CAP to not only delete its downlink traffic flow after completion of its service transmission, but also actively delete STA-related uplink traffic flow, thus avoiding long-time occupation of traffic flow resources by STA in case of no service for a long time or in case of exception. In addition, STA can delete its uplink traffic flow after completion of service transmission. 
     As an alternative embodiment,  FIG. 29  is the flow chart indicating the method to delete the uplink traffic flow specified in this invention. The process includes: 
     Step  291 : CAP receives dynamic service deletion request carrying FID and direction information frame sent from STA. 
     In this embodiment, dynamic service deletion request is realized by dynamic service deletion request frame. 
       FIG. 30  shows the structure of dynamic service deletion request frame specified in the embodiment of this invention. The dynamic service deletion request frame includes frame control field, FID field, direction field and FCS field. Wherein the identifier in frame control field which is related to frame type indicates that the frame is dynamic service deletion request frame, FID field indicates the FID of the traffic flow to be deleted, direction field indicates that the traffic flow to be deleted is uplink traffic flow, and FCS field is a checksum field.  FIG. 30  also illustrates the number of bits occupied by each field. 
     Step  292 : CAP sends dynamic service deletion response frame to STA. 
     The structure of dynamic service deletion response frame is the same as dynamic service deletion request frame, and each field has the same contents. 
     Step  293 : CAP receives ACK that is sent after STA correctly receives dynamic service deletion response frame. 
     In this step, STA can also send GroupAck to CAP. 
     Through the above steps  291 ˜ 293 , CAP and STA will respectively delete recorded FID and related information, and end the data transmission on deleted traffic flow. 
     As an alternative embodiment,  FIG. 31  is the flow chart indicating the method to delete the uplink or downlink traffic flow specified in this invention. The process includes: 
     Step  311 : STA receives CAP-sent dynamic service deletion request carrying FID and direction information frame. 
     In this embodiment, dynamic service deletion request is realized by dynamic service deletion request frame. Here, the structure of dynamic service deletion request frame is the same as shown in  FIG. 25 , except that when CAP deletes downlink traffic flow, direction field indicates the downlink traffic flow, and when CAP deletes uplink traffic flow, direction field indicates the uplink traffic flow. 
     Step  312 : STA sends ACK to CAP. 
     In this step, STA can also send GroupAck to CAP. 
     Through the above steps  311 ˜ 312 , CAP and STA will respectively delete recorded FID and related information, and end data transmission on deleted traffic flow. 
     This invention also provides two types of traffic flow deletion devices. 
       FIG. 32  shows the structure of the first traffic flow deletion device specified in this invention. This device includes: request sending unit  321  and response receiving unit  322 . 
     Request sending unit  321  is used to send dynamic service deletion request carrying FID and direction information. Direction information indicates that the traffic flow to be deleted is uplink or downlink. 
     Response receiving unit  322  is used to receive the response to dynamic service deletion request. 
     As an alternative embodiment, when the first traffic flow deletion device of this invention is at the CAP side, its structure is shown in  FIG. 33 . This device includes: request sending unit  331 , response receiving unit  332  and monitoring unit  333 . 
     Request sending unit  331  is used to send dynamic service deletion request carrying FID and direction information. Direction information indicates that the traffic flow to be deleted is uplink or downlink. 
     Response receiving unit  332  is used to receive the response to dynamic service deletion request. The response to dynamic service deletion request received by response receiving unit  332  is: acknowledgement indicating that the said dynamic service deletion request is correctly received. 
     Monitoring unit  333  is used to monitor response receiving unit  332  after request sending unit  331  sends dynamic service deletion request within preset number of frames. If response receiving unit  332  does not receive the said response, trigger request sending unit  331  to re-send dynamic service deletion request. On this basis, request sending unit  331  will package and send dynamic service deletion request s MPDU. When re-send dynamic service deletion request exceeds maximum MPDU re-send times, discard dynamic service deletion request. 
     As an alternative embodiment, when the first traffic flow deletion device of this invention is at the CAP side, it&#39;s available to receive notification regarding the two types of traffic flow establishing devices or two types of traffic flow change devices specified in this invention which are also at the CAP side, and start to perform operations. 
     As an alternative embodiment, when the first traffic flow deletion device of this invention is at the CAP side, it&#39;s available to receive notification regarding the two types of traffic flow management devices which are also at the CAP side, and start to perform operations. 
     As an alternative embodiment, when the first traffic flow deletion device of this invention is at the STA side, its structure is shown in  FIG. 33 , except that the response to dynamic service deletion request received by response receiving unit  332  is dynamic service deletion response carrying the said FID and direction information, and when monitoring unit  333  does not receive the said response at response receiving unit  332 , it will notify request sending unit  331  to end this process. 
       FIG. 34  is structural diagram of the second traffic flow deletion device in this invention. This device includes: request receiving unit  341  and response sending unit  342 . 
     Request receiving unit  341  is used to receive dynamic service deletion request carrying FID and direction information. Direction information indicates that the traffic flow to be deleted is uplink or downlink. 
     Response sending unit  342  is used to send the response to dynamic service deletion request. 
     As an alternative embodiment, when traffic flow deletion device is at the CAP side, its structure is shown in  FIG. 35 . This device includes: request receiving unit  351 , response sending unit  352 , receipt acknowledgement unit  353  and monitoring unit  354 . 
     Request receiving unit  351  is used to receive dynamic service deletion request carrying FID and direction information. Direction information indicates that the traffic flow to be deleted is uplink or downlink. 
     Response sending unit  352  is used to send the response to dynamic service deletion request. The response to dynamic service deletion request is: dynamic service deletion response carrying the said FID and direction information. 
     Receipt acknowledgement unit  353  is used to receive acknowledgement indicating that the said dynamic service deletion response is correctly received. 
     Monitoring unit  354  is used to monitor receipt acknowledgement unit  353  after response sending unit  352  sends dynamic service deletion response within preset number of frames. If receipt acknowledgement unit  353  does not receive the said acknowledgement, trigger response sending unit  352  to re-send the said dynamic service deletion response. On this basis, response sending unit  352  will package and send dynamic service deletion response as MPDU. When the said re-send exceeds maximum MPDU re-send times, discard the said dynamic service deletion response. 
     Alternatively, when the traffic flow deletion device is at the STA side, the said response to dynamic service deletion request is: acknowledgement indicating that the said dynamic service deletion request is correctly received. 
     The following describes how this invention handles exceptions in traffic flow management. 
     Exception handing may use the following system setting parameters: 
     1, maximum waiting interval of traffic flow response frame: indicate the tolerable maximum number of frames to wait after STA sends traffic flow management request frame. As an example, default value can be set to 4; 
     2, maximum waiting frame interval for acknowledgement of downlink traffic flow request frame: indicate tolerable maximum number of frames to wait after CAP sends traffic flow management request frame. As an example, default value can be set to 4; 
     3, maximum waiting frame interval for acknowledgement of traffic flow response frame: indicate tolerable maximum number of frames to wait after CAP sends traffic flow management response frame. As an example, default value can be set to 4; 
     4, Maximum MPDU re-send times: indicate maximum times for re-sending certain MPDU. As an example, default value can be set to 5; 
     5, STA&#39;s maximum number of consecutive failure times allowed by CAP: indicate the number of failure times of certain STA allowable by CAP. As an example, default value can be set to 20. 
     In the traffic flow management, this invention has the following exception handling measures: 
     1, for uplink traffic flow management, when at the STA side, after sending request frame STA waits for “maximum waiting interval of traffic flow response frame”. If it does not receive CAP-sent response frame, it&#39;s deemed that this traffic flow management process fails, and STA will launch another new traffic flow management process. When at the CAP side, after sending response frame CAP waits for “maximum waiting frame interval for acknowledgement of traffic flow response frame”. If it does not receive ACK or GroupAck sent from STA, re-send response frame until the number of resends exceeds maximum MPDU re-send times. At this time CAP will initiate the traffic flow deletion process. 
     2, for downlink traffic flow management, after sending request frame CAP waits for “maximum waiting frame interval for acknowledgement of downlink traffic flow request frame”. If it does not receive ACK or GroupAck sent from STA, it&#39;s deemed that this traffic flow management process fails, and re-send the request frame until the number of re-sends exceeds maximum MPDU re-send times. At this time CAP will initiate the traffic flow deletion process. 
     3, during the above exception handling process, after CAP sends MPDU or group MAC protocol data unit (G-MPDU) to STA, if no proper acknowledgement of any MPDU is received, it&#39;s deemed as failure and failure counter will be started. If the subsequent MPDU or G-MPDU sent to the STA still fails, it will accumulate the number of failures. If any proper acknowledgement of any MPDU is received, the counter will be cleared. If the accumulative value exceeds the “maximum number of sending failures of STA allowable by CAP”, CAP will deem that the STA has exception, and will remove it from the list of active STAs. 
     When the above CAP sends MPDU to STA, it can be that CAP packages the response frame or request frame of certain traffic flow of STA as MPDU and send it to STA. 
     When the above CAP sends G-MPDU to STA, it can be that CAP sends response frame or request frame of traffic flow  1  for STA, and sends together with the data frame of traffic flow  2  to STA. 
     In exception handling method, this invention uses frame number for timing, which is more precise than that of timer. 
     This invention also provides a method for traffic flow establishing, as shown in  FIG. 36 . This method includes: 
     Step  361 : generate dynamic service establishing request carrying FID and destination identifier; 
     Step  362 : send the said dynamic service establishing request. 
     This invention also provides another method for traffic flow establishing, as shown in  FIG. 37 . This method includes: 
     Step  371 : generate dynamic service establishing response carrying FID; 
     Step  372 : send the said dynamic service establishing response. 
     As an alternative embodiment, the above dynamic service establishing request may adopt the dynamic service establishing request frame as shown in  FIG. 7 . The above dynamic service establishing response may adopt the dynamic service establishing response frame shown in  FIG. 8 . 
     For the traffic flow establishing methods shown in  FIGS. 36 and 37 , this invention also provides two devices for traffic flow establishing, including generation unit and sending unit, wherein is used for generating the information to be generated in the generation step in relevant method, while the sending unit is used for sending the information generated in generation unit. 
     This invention also provides a method for traffic flow change, as shown in  FIG. 38 . This method includes: 
     Step  381 : generate dynamic service change request carrying FID, destination identifier and new service parameters; 
     Step  382 : send the said dynamic service establishing request. 
     This invention also provides another method for traffic flow change, as shown in  FIG. 39 . This method includes: 
     Step  391 : generate dynamic service change response carrying FID; 
     Step  392 : send the said dynamic service change response. 
     As an alternative embodiment, the above dynamic service change request may adopt dynamic service change request frame with the same structure as shown in  FIG. 7 . The above dynamic service change response may adopt the dynamic service change response frame as shown in Figure. 
     For the methods for traffic flow change as shown in  FIG. 38  and  FIG. 39 , this invention also provides two types of devices for traffic flow change, including generation unit and sending unit, wherein the generation unit is used for generating the information to be generated in the generation step in relevant method, while the sending unit is used for sending the information generated in generation unit. 
     This invention also provides a method for traffic flow establishing, as shown in  FIG. 40 . This method includes: 
     Step  401 : generate dynamic service establishing request carrying FID and FID maximum buffer capability; 
     Step  402 : send the said dynamic service establishing request. 
     This invention also provides another method for traffic flow establishing, as shown in  FIG. 41 . This method includes: 
     Step  411 : generate dynamic service establishing response carrying FID and FID maximum buffer capability; 
     Step  412 : send the said dynamic service establishing response. 
     As an alternative embodiment, the above dynamic service establishing request may adopt the dynamic service establishing request frame shown in  FIG. 7 ; the above dynamic service establishing response may adopt the dynamic service establishing response frame shown in  FIG. 8 . 
     For the methods for traffic flow establishing shown in  FIGS. 40 and 41 , this invention also provides two types of devices for traffic flow establishing, including generation unit and sending unit, wherein generation unit is used for generating the information to be generated in the generation step in relevant method, while the sending unit is used for sending the information generated in generation unit. 
     This invention also provides a method for traffic flow change, as shown in  FIG. 42 . This method includes: 
     Step  421 : generate dynamic service change request carrying FID and FID maximum buffer capability; 
     Step  422 : send the said dynamic service change request. 
     This invention also provides another method for traffic flow change, as shown in  FIG. 43 . This method includes: 
     Step  431 : generate dynamic service change response carrying FID and FID maximum buffer capability; 
     Step  432 : send the said dynamic service change response. 
     As an alternative embodiment, the above dynamic service change request may adopt the dynamic service change request frame with the same structure as shown in  FIG. 7 , and the above dynamic service change response may adopt the dynamic service change response frame as shown in  FIG. 8 . 
     For the methods for traffic flow change shown in  FIG. 42  and  FIG. 43 , this invention also provides two types of devices for traffic flow change, including generation unit and sending unit, wherein generation unit is used for generating the information to be generated in the generation step in relevant method, while the sending unit is used for sending the information generated in generation unit. 
     This invention also provides a method for traffic flow deletion, as shown in  FIG. 44 . This method includes: 
     Step  441 : generate dynamic traffic flow deletion request carrying FID and direction information; 
     Step  442 : send the said dynamic traffic flow deletion request. 
     This invention also provides another method for traffic flow deletion, as shown in  FIG. 45 . This method includes: 
     Step  451 : generate dynamic traffic flow deletion response carrying FID and direction information; 
     Step  452 : send the said dynamic traffic flow deletion response. 
     As an alternative embodiment, the above dynamic service deletion request and dynamic service deletion response may adopt the frame with the structure shown in  FIG. 30 . 
     For the methods for traffic flow deletion shown in  FIG. 44  and  FIG. 45 , this invention also provides two types of devices for traffic flow deletion, including generation unit and sending unit, wherein generation unit is used for generating the information to be generated in the generation step in relevant method, while the sending unit is used for sending the information generated in generation unit. 
     It should be understood that the specific order or hierarchy of the steps in the process disclosed is only an example of the exemplary method. It should be understood that the specific order or hierarchy of the steps in the process may be re-arranged based on design preferences, without departing from the scope of the invention. The appended method claims provide various step factors in an exemplary order, but are not limited to the specific order or hierarchy. 
     In the above detailed description, various features are combined in a single embodiment for the sake of simplification of the disclosure. This disclosing manner should not be interpreted as reflecting such an intention that: the embodiment of the claimed subject requires more features than those stated clearly in each claim. On the contrary, as reflected in the appended claims, the invention may be in a state with less features than all features of a single disclosed embodiment. Therefore, the appended claims are hereby incorporated in the detailed description clearly, and each claim independently presents an individual preferred implementation solution of the invention. 
     The above description includes the examples of one or more embodiments. However, it is impossible to exhaust all potential combinations of the components and methods in describing the above embodiments, but it should be understood by one skilled in the art that components and methods of each embodiment may be further combined and arranged. Therefore, the embodiments described herein intend to contemplate all such changes, modifications and variations that fall into the scope of the appended claims. In addition, the term “comprise” used in the specification or the claims is similar to the term “include”, just like the interpretation of the term “include” in the claims as a connection word. Additionally, any term “or” used in the claims or the specification intends to represent a “nonexclusive or”.