JP2010074346A - Method and apparatus performing express-forwarding frames having multiple fragments - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, a device and a computer program product for express-forwarding frame having multiple fragments. <P>SOLUTION: A timer (NAV) is maintained at each node of a wireless Local Area Network (LAN). At least two fragments of a frame are designated as Time Sensitive Quality of Service (TSQ) frame fragments to be express-forwarded. A duration field of each of the TSQ frame fragments is incremented by a first predetermined time increment (DT0) before the TSQ frame fragments are forwarded. The TSQ frame fragments are transmitted when a last frame fragment is ready to be transmitted. A response is received from the second node, wherein non-forwarding neighboring nodes each set their NAV according to a value equal to the duration field of the response. The second node attempts forwarding of the TSQ frame fragments when an acknowledgement for receipt of the TSQ frame fragments is completed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention claims the benefit of US Provisional Patent Application No. 60/972817, filed Sep. 17, 2007, which is incorporated herein by reference in its entirety.

  The Wireless Local Area Network (WLAN) has become ubiquitous. The increase in Wireless Local Area Network (WLAN) requirements is driving the development of new technologies to provide higher throughput. This increase is largely due to the increased number of users and applications that desire wireless transmission, but not to the emergence of new applications that require higher transmission rates along a single connection between two points, but not so much. to cause.

  In wireless local area networks (LANs), a radio channel can be reserved for transmission of a single frame or sequence of frames known as TXOP (transmission opportunity), while TXOP has been introduced In the 802.11 standard including IEEE 11e correction, IEEE standard 802.11 (registered trademark) -2007 (revision of IEEE standard 802.11-1999), and Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification Asynchronous distributed random channel access method as described is used.

  In such an environment, both the source and destination of the transmission broadcast a reservation period to establish an interference neighborhood. A TXOP is a sequence of frames transmitted between a pair of nodes following a single contention for a channel. The TXOP holder, which is the node that initiates TXOP, can transmit contention free after the first transmission to the responder, which is the node that receives the frame in TXOP.

  To date, there are two basic ways to reserve a channel for TXOP in a wireless LAN. One way to perform reservation is by using frame-by-frame reservation. According to the 802.11 distributed channel access MAC protocol, RTS / CTS frames are used to notify neighbors of the start of reservation. Instead, the duration field of the first frame of TXOP is set to a time interval that is long enough to reserve a channel for transmission of subsequent frames. The reservation time is extended for each frame by updating the length of the reservation with each data frame and subsequent acknowledgment. The result of frame-by-frame reservation is that if the reservation is denied, it does not require cancellation.

  Another way to perform reservations in a wireless LAN is by using start-to-finish reservations. If the channel reservation time cannot be extended from frame to frame, the channel must be reserved for the entire sequence of transmissions from start to end at the time of the reservation request. If the reservation request is denied or if the time remains reserved at the completion of the transmission, the reservation must be negated.

  Start-to-finish reservation applies to any combination of nodes (ie, mesh points / Access Points (AP) / stations). A node reserves a channel to encompass the entire sequence of transmissions destined for one destination or various different destinations, possibly including a response from the destination. If reservation is not allowed, or when the transmission sequence is complete, the securing node releases the remaining reservation time by canceling the reservation.

  To avoid collisions, each node maintains a NAV for the traffic channel that is set up according to the received reservation request and response. NAV is defined as the time period during which a node must stop transmitting on a traffic channel. It is updated by the Duration field value of the received transmission that can be maintained by each station and act as a response to the TXOP reservation request or reservation request. The reservation request from the transmission source is either accepted or denied by the destination, and a notification is sent to the transmission source. The response includes the reserved duration remaining in the Duration field to notify the neighbor to the destination node. Applications for wireless networks include Voice Over Internet Protocol (VoIP) and multimedia (Voice and / or Video), collectively referred to as VoIP / Multimedia. VoIP / multimedia applications require a certain quality of service (QoS) to maintain a sufficient quality of communication. Latency can be a problem with VoIP / multimedia. Satisfying QoS requires a short full end-to-end over-the-air delay. The 802.11e correction to the IEEE 802.11 standard incorporated in the 2007 edition of the standard provides a mechanism for reducing over-the-air delay from transmission in a wireless LAN. These are single hop transmissions. The 802.11e mechanism may not be appropriate to meet latency requirements in wireless networks with multiple hop transmissions. A wireless mesh network is such a network.

  The wireless mesh may be an Ad hoc mode mesh (not attached to a wired network) or an infrastructure mode mesh (attached to a wired network). In general, both source and destination traffic at the mesh and traffic boundaries from / to the wired network can exist simultaneously on the mesh. The latency / jitter limit for voice traffic across the wired network is lower (40-50 milliseconds) than the latency / jitter limit for traffic staying on the wireless mesh (175-200 milliseconds). The mesh involves a multi-hop flow. A mesh backbone network is a multi-hop network. The multi-hop path delay is at least a multiple of the single hop delay. A wireless mesh operating on a single channel has a novel collision behavior that can affect the near latency experienced by connecting the ends across the air. The dissemination of hidden nodes and the interaction of contention-based access with multi-hop flow imposes an increase in latency beyond what non-mesh experience suggests for both meshes and nearby WLANs. Hidden nodes remain hidden after retrying and their transmissions are dropped. High correlation of sequentially forwarded frames in a multi-hop flow causes excessive delay for transmissions involved in collisions. Correction is required on the mesh side for backward compatibility and contention based access protocols for continuous use. For QoS traffic, a multi-hop delay must satisfy the same latency constraints as a single hop delay. Therefore, correction is necessary to reduce the over-the-air latency. The goal is to reduce the delay experienced by the longest multi-hop path by forwarding frames along the multi-hop path in an accelerated manner.

Frames can be fragmented into pieces that are small enough to cross over links that have a Maximum Transmission Unit (MTU) that is smaller than the original frame size. MTU refers to the size (in bytes) of the largest packet or frame that a given layer of the communication protocol can pass through previously. If the receiving host receives the fragmented packet, it must reassemble the packet and pass it to a higher layer. Reassembly occurs only at the receiving host. Fragmenting can result in excessive retransmissions when a fragment undergoes packet loss, and trusted protocols such as TCP retransmit all fragments to recover from the loss of a single fragment Must.
US Provisional Patent Application Publication No. 60/972817

  One way to reduce delay in the wireless mesh is by providing performance readiness. The nodes and links in the mesh network must have sufficient performance to prevent traffic buffers that are built anywhere in the network. Proper preparation involves the use of multiple radios at highly traffic intensive nodes to match the traffic profile.

  Another way to reduce delay in the wireless mesh is by providing congestion control. Reducing the transmission rate and rerouting the traffic can alleviate congestion if preparation is considered. Even with proper preparation, the speculative statistical nature of traffic can produce short-term fluctuations that can cause congestion at a given node.

  MAC layer prioritized transmission of forwarded QoS traffic across the mesh helps to reduce end-to-end delay along multi-hop paths when considering congestion control and performance provisioning. For fast forwarding, QoS traffic requires the highest priority access when forwarded over multiple hop paths. Lower priority access is used for all other traffic. EDCA provides access priority for a single channel. However, further priorities are not possible with EDCA. Higher priority 802.11e traffic (VO / VI) already uses the highest priority access category. A different mechanism is needed for forwarded QoS traffic.

  Conventional mechanisms such as those described above suffer from various deficiencies. Embodiments of the present invention provide a mechanism and technique that significantly eliminates such deficiencies and provides express forwarding of frames having multiple fragments designated as time sensitive QoS (TSQ) frames.

  In a particular embodiment of the method for providing express forwarding of frames with multiple fragments, the method includes a method for each node of a plurality of nodes in a wireless LAN during which each node must stop transmitting on the channel. Including maintaining a timer (NAV) set for the corresponding time period that must be met. The method includes designating at least two fragments of a frame as a Time Sensitive Quality of Service (TSQ) frame fragment to be transferred from a first node to a second node of the plurality of nodes; Further comprising incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before being transferred by the first node. The method also includes sending the TSQ frame fragment by the first node to the second node when the last frame fragment of the frame fragment is ready to be transmitted. The method additionally includes receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes each set their NAV according to a value equal to the duration field of the response, and the second The node attempts to transfer the TSQ frame fragment when the acknowledgment of reception of the TSQ frame fragment is completed.

  Other embodiments include a computer readable medium having computer readable code thereon for providing express transfer of a frame having a plurality of fragments. The computer-readable medium maintains a timer (NAV) set at each respective node of the plurality of nodes of the wireless LAN, during which the respective node must stop transmitting on the channel. Including instructions. The computer-readable medium includes instructions for designating at least two fragments of a frame as a Time Sensitive Quality of Service (TSQ) frame fragment to be transferred from a first node to a second node of the plurality of nodes; Instructions for incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node. The computer readable medium also includes instructions for transmitting the TSQ frame fragment by the first node to the second node when the last frame fragment of the frame fragment is ready to be transmitted. The computer-readable medium additionally includes instructions for receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes each set their NAV according to a value equal to the duration field of the response. The second node attempts to transfer the TSQ frame fragment when the acknowledgment of reception of the TSQ frame fragment is completed.

  Still other embodiments include computerized devices configured to process all the method operations disclosed herein as embodiments of the present invention. In such an embodiment, the computerized device includes a memory system, a processor, and a communication interface in an interconnection mechanism that connects these components. A memory system, as described herein, provides express transfer of a frame having a plurality of fragments and, when executed on a processor (eg, when implemented), is described herein as an embodiment of the present invention. Encoded in a process that operates as described herein in a computerized device to perform all of the method embodiments and operations described in FIG. Thus, any computerized device that performs or is programmed to perform the processes described herein is an embodiment of the present invention.

  Other configurations of the embodiments of the invention disclosed herein include a software program for performing the steps and operations of the method embodiments outlined above and disclosed in detail below. More particularly, a computer program product, when executed on a computerized device, provides an associated operation that provides an express transfer of a frame having a plurality of fragments as described herein. 1 is an embodiment having a computer readable medium containing computerized computer program logic. When implemented on at least one processor having a computing system, the computer program logic causes the processor to perform the operations (eg, methods) set forth herein as an embodiment of the invention. Such an arrangement of the present invention typically includes firmware or microcontroller in an optical medium (eg, CD-ROM), floppy or hard disk, or one or more ROM or RAM or PROM chips. Placed or encoded on a computer-readable medium, such as code, Application Specific Integrated Circuit (ASIC), or other media such as a downloadable software image in one or more modules, shared libraries, etc. Provided as software, code, and / or other data structures. Software or firmware or other such configuration is computerized to cause one or more processors in a computerized device to perform the techniques described herein as embodiments of the invention. Can be installed on the installed device. A software process operating on a group of computerized devices, such as a data communication device or group of other entities, can also provide the system of the present invention. The system of the present invention can be distributed among many software processes on several data communication devices, or all processes can run on a small set of dedicated computers or only one computer. it can.

  It is understood that embodiments of the present invention can be implemented strictly as a software program, as software and hardware, or as hardware and / or circuitry alone, such as within a data communication device. As described herein, features of the present invention are described in New Jersey, Lincroft's Avaya Inc. Can be used in a data communication device and / or software system for such a device, such as a device manufactured by.

  Note that the different features, techniques, configurations, etc. discussed in this disclosure can be implemented independently or in combination. Thus, the present invention can be implemented and considered in many different ways.

  It should also be noted that this summary portion of the specification does not identify every embodiment and / or additional novel aspect of the disclosure or claimed invention. Instead, this summary only provides a preliminary discussion of the different embodiments and new corresponding points for the prior art. For further details, elements, and / or possible aspects (substitutions) of the present invention, the reader is directed to the detailed description portion of the present disclosure and corresponding drawings, as further discussed below.

  The foregoing will become apparent from the following more detailed description of preferred embodiments of the invention, as illustrated in the accompanying drawings, in which like reference numerals refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

  Express forwarding is a technique used to reduce the delay for a specified frame along a multi-hop path by ensuring that the forwarding node incurs less delay than a single hop transmission. For a single channel mesh, forwarding delay is reduced by reserving a channel for transmission that is forwarded for a sufficiently long time interval to allow the next forwarding node to seize the channel. . Immediate access is granted to nodes other than the first node on the multi-hop path that forwards QoS traffic as such.

  Frames to be expressly transmitted are designated as time sensitive QoS (TSQ) transmissions. Certain flags can be used to mark a transmission as being express transferred, depending on criteria for TSQ transmission and / or information available along its path. The TSQ designation can be supplied by the application, for example, the TSQ frame can be a frame with a specified user priority (eg, VO). Alternatively, the TSQ designation can also be supplied by the originating node, for example if there is a distinction between ad hoc and infrastructure traffic, all voice frames originating from or destined for the portal will be It is designated as TSQ by the node. The TSQ designation can be used for yet other criteria.

  In order to process an express transferred frame, a known time increment DT0 is added to the value of the Duration field when the TSQ frame is transferred. The Duration field of the ACK (if any) returned for the TSQ frame received at the destination node is set based on the Duration field of the received frame. All nodes that know the transmission other than the receiving node set their NAV according to the Duration field of the received transmission. If the receiving node forwards the frame, it will subtract DT0 from the Duration value of the received frame before setting its NAV and receive it when the acknowledgment of receipt of the TSQ frame is complete Attempts to transmit a TSQ frame. DT0 should be long enough to allow the forwarding node to process the received frame and prepare it for transmission on the next hop. It must be at least a time slot length.

  Referring now to FIG. 1, FIG. 10 shows the timing of frames that are expressly transferred between several nodes. Nodes 1-5 are shown having a 3-hop path for express forwarded frames going from node 1 to node 2, from node 2 to node 3, and then from node 3 to node 4. Node 5 is a non-forwarding adjacent node. Each node maintains a NAV for channel 12. The first frame 14 is designated as an express transferred frame to be transferred from the node 1 to the node 2. The Duration field is set to a longer value than usual when a frame is transmitted to a forwarding node of a multi-hop route. Forwarding nodes 2 and 3 transmit when they complete the acknowledgment of the received frame. In an alternative embodiment of the invention, forwarding nodes 2 and 3 adjust the Duration value in the received frame by subtracting the increment when setting their NAV. The non-forwarding adjacent node, for example, the node 5 sets its NAV according to the received Duration field. Therefore, node 2 does not set its NAV as the intended receiving node for the forwarded frame. Thus, node 2 has access to channel 12 before node 5 does, and node 2 can access the channel and forward frames before node 5, so the frames are forwarded more quickly. Is done. Thus, node 2 can transmit when transmission and acknowledgment is complete, while the NAV of node 5 set to the value of the Duration field is the value when the received frame is acknowledged. It has DT0.

  Contention is reduced when TSQ frames are forwarded to all forwarding nodes other than the first node on the path. Neighboring node NAVs are still set in at least one time slot when a new forwarding node is ready to transmit (unless there is any independent NAV setting request), thus they are Have the node transmit before any of them without competing for the channel.

  The forwarding node may perform a Controlled Channel Access (CCA) before attempting transmission. This therefore avoids collisions with other nodes that do not know the TSQ transmission received to set the NAV. If the channel is busy, the forwarding node backs off the delay from the short contention window CWmin (EF).

  TXOP allows multiple frames to be transmitted with a single contention. TXOP can be used with express transfers. The combination reduces contention and collisions along the transfer path. The value of the Duration field of each frame of TXOP to be transferred is incremented by DT0. A TXOP can include a mix of frames that are exclusively TSQ frames, or some frames are express transferred and other frames are not express transferred. Frames to be express transferred are flagged as TSQ. Preferably, TXOP TSQ frames should be transmitted before non-TSQ frames in order to reduce the processing delay of the receiving node's TSQ frames and thereby allow their immediate forwarding. All TSQ frames in a given TXOP should be transmitted to the same node. The Duration field of the ACK (if any) for each TXOP frame received at the destination node is set based on the received frame. The receiving node can transmit quickly following the completion and acknowledgment of the TXOP. Transfer of a frame in a received TXOP starts when the NAV ends, and the end of the NAV occurs once the entire TXOP is received and acknowledged. The forwarding of the frame in the received TXOP may include the separation of the frame into different TXOPs according to the next hop destination node. If the buffered frame at the receiving node of the same access classification as the received TXOP is sent to the same node as the forward TXOP and the size of the incremented TXOP does not exceed the TXOP limit for the access classification, such The frame can be transmitted with the forwarded TXOP.

  RTS / CTS is a mechanism for reducing the influence of hidden terminals that are common in wireless meshes. RTS / CTS protection can be used in connection with express transfers. The combination reduces contention and collisions in the transfer path. The RTS of the time-sensitive QoS frame is flagged as TSQ and the RTS Duration field is increased by the increment DT0. The node to which the RTS is addressed responds with a CTS having a Duration value set based on the Duration field of the received RTS. If the node receiving the RTS has to forward an RTS protected frame, it forwards on acknowledgment of the RTS protected frame. Transfer of the received frame or TXOP begins when the NAV ends, and the end of the NAV occurs once the frame or TXOP is received and acknowledged. The express forwarding mechanism works even when the receiving node does not need to observe its NAV after receiving an acknowledgment of the frame. Express forwarding gives preferential access to TSQ marked frames across all other traffic.

  Other embodiments include multi-channel express transfers. An example is shown in environment 20 of FIG. When attempting to send a CC-RTS on the Control Channel, if the NAV of the channel is not supposed to end within a time interval equal to AIFR (pre-interval for reservation), the reserved data If the channel is busy, the node may not transmit or subtract backoff delay. When responding to a CC-RTS with CC-CTS, the NAV of the channel will end within a time interval equal to (AIFR-RTS Tx Time) (RTS Tx Time is the transmission time of CC-RTS). If not, the node must refuse to reserve if the indicated data channel is busy. The length of the AIFR depends on the access priority of CC-RTS / CC-CTS. Longer AIFR is used for higher access priority.

  In a given scenario, a frame can be fragmented into pieces that are small enough to pass on a ring with a Maximum Transmission Unit (MTU) that is smaller than the original frame size. MTU refers to the maximum packet or frame size (in bytes) that a given layer of the communication protocol can pass forward. If the receiving host receives the fragmented packet, it must reassemble the packet and pass it to a higher layer. Reassembly occurs only at the always receiving host. When a fragment is subject to packet loss, fragmenting can result in excessive retransmissions, and reliable protocols such as TCP retransmit all fragments to recover from the loss of a single fragment Must.

  In order to provide express forwarding for multiple fragments, when multiple fragments of a frame are transmitted, the express forwarding node starts transmission only at the end of the last fragment. The duration field value of each fragment of the frame to be transferred is incremented by DT0 and the fragment is designated TSQ. The ACK duration field for each fragment received at the destination node is set based on the received fragment duration. The NAV at the node to which the fragment is transferred is set by subtracting DT1 from the Duration field value of the received frame if the frame is to be transferred. The transfer of received fragments begins when the NAV ends, and NAV termination occurs once all fragments have been received and acknowledged.

  A flowchart of a particular embodiment of the presently disclosed method is shown in FIG. The rectangular elements are designated herein as “processing blocks” and represent computer software instructions or groups of instructions. Instead, processing blocks represent steps performed by a functionally equivalent circuit, such as a digital signal processor circuit or an application specific integrated circuit (ASIC). The flowchart does not represent the syntax of any particular programming language. Rather, the flowcharts show the functional information necessary for those skilled in the art to manufacture circuitry and generate computer software to perform the necessary processing according to the present invention. It should be noted that many routine program elements such as loop and variable initialization and temporary variable usage are not shown. It will be understood by those skilled in the art that the specific sequence of steps described is merely exemplary and can be modified without departing from the spirit of the invention unless otherwise indicated herein. Is done. Thus, unless stated otherwise, the steps described below are not ordered and, when possible, the steps can be performed in any convenient or desirable order. Means.

  Referring now to FIG. 3, a particular embodiment of a method 100 for performing express transfer of frames having multiple fragments is shown. The method 100 begins at processing block 102, which is set at each respective node of the plurality of nodes of the wireless LAN, during which each node must stop transmitting on the channel. To maintain a programmed timer (NAV).

  Processing block 104 describes designating at least two fragments of a frame as a Time Sensitive Quality of Service (TSQ) frame fragment to be expressly transferred from a first node to a second node of the plurality of nodes. . Frames can be fragmented into pieces that are small enough to pass over links that have a Maximum Transmission Unit (MTU) that is smaller than the original frame size. The MTU refers to the maximum packet or frame size (in bytes) that a given layer of the communication protocol can pass through previously. As indicated at process block 106, the TSQ frame fragment designation is provided by at least one of the application and the originating node.

  Processing block 108 details incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node.

  Processing block 110 discloses transmitting the TSQ frame fragment by the first node to the second node when the last frame fragment of the frame fragment is ready to be transmitted. As further indicated by processing block 112, transmitting the TSQ frame fragment by the first node to the second node further includes transmitting when the second node's NAV terminates.

  Processing block 114 discloses receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes each set their NAV according to a value equal to the duration field of the response, The node attempts to transfer the TSQ frame fragment when acknowledgment of receipt of the TSQ frame fragment is complete. Processing block 116 states that receiving a response from the second node includes receiving an acknowledgment (ACK) for each frame fragment received by the second node. Processing block 118 details that the duration field of the ACK is set based on the received fragment duration value.

  Processing continues to processing block 120, where the second node's NAV determines a second predetermined time increment (DT1) from the period value of the received frame when the received frame is to be transferred. ) Is set by decrementing.

  Processing block 122 indicates that incrementing the duration field of the TSQ frame fragment by the first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node is not performed for the last hop. Is described.

  FIG. 4 is a block diagram illustrating an example computer system 300 (node) for performing the express transfer function 340 and / or other related processes for performing the different functionality described herein. It is.

  As shown, the example computer system 300 includes an interconnect 311 that couples a memory system 312, a processor 313, an input / output interface 314, and a communication interface 315.

  As shown, the memory system 312 is encoded with the express transfer application 340-1. The express transfer application 340-1 may be software code (eg, in memory or other computer readable, such as disk) that supports functionality in accordance with different embodiments described herein. Code stored in a medium).

  During operation, the processor 313 of the computer system 300 initiates, performs, implements, interprets, or otherwise executes the logical instructions of the express transfer application 340-1 via the interconnect 311. Access the memory system 312. The implementation of the express transfer application 340-1 generates processing functionality in the express transfer application 340-2. In other words, express transfer application 340-2 represents one or more portions (or the entire application) of express transfer application 340-1 executing within processor 313 of computer system 300 or executing on processor 313.

  In addition to the express transfer application 340-2, it should be noted that the embodiments herein include the express transfer application 340-1 itself (ie, logical instructions and / or data that are not implemented or executed). . The express transfer application 340-1 can be stored on a computer readable medium such as a floppy disk, a hard disk, or an optical medium. The express transfer application 340-1 may be a memory type as executable code in firmware, read only memory (ROM), or in this example memory system 312 (eg, in Random Access Memory or RAM). It can also be stored in the system.

  In addition to these embodiments, it should also be noted that other embodiments herein include the implementation of express transfer application 340-1 within processor 313 as express transfer application 340-2. Those skilled in the art will appreciate that computer system 300 includes software and hardware components such as operating systems that control other processes and / or allocation and use of hardware resources associated with computer system 300. Understand what you can do.

  Devices or computer systems that integrate processors include, for example, personal computers, workstations (eg, Sun, HP), personal digital assistants (PDAs), handheld devices such as cell phones, laptops, handheld computers , Or other devices that can be integrated with a processor that can operate as provided herein. Accordingly, the devices provided herein are not exclusive and are provided for purposes of illustration and not limitation.

  References to “a microprocessor” and “a processor” or “the microprocessor” and “the processor” can communicate in a stand-alone and / or distributed environment, and as such If one or more processors can be configured to operate on one or more processor-controlled devices, which can be similar or different devices, via wired or wireless communication with other processors It can be understood that it includes one or more microprocessors that can be configured to communicate. The use of such “microprocessor” and “processor” terms is thus the central processing unit, arithmetic logic unit, application specific integrated circuit (such as examples given without limitation) ( IC) and / or a task engine can also be understood.

  Further, unless otherwise specified, the reference to the memory can be internal to the processor-controlled device, can be external to the processor-controlled device, and can be external to the processor-controlled device. And can include accessible memory elements and / or components and / or can be accessed via a wired or wireless network using various communication protocols and is not otherwise specified, Such memory can be arranged to include a combination of external and internal memory devices where it can be continuously and / or partitioned based on the application. Thus, a reference to a database may include one or more memory associations where such reference may include commercially available database products (eg, SQL, Informix, Oracle) and also dedicated databases. Other structures for associated memory, such as links, queues, graphs, trees, etc. can be included, which can be understood and such structures are provided without limitation.

  If not otherwise provided, a reference to a network can include one or more intranets and / or the Internet, as well as virtual networks. It can be appreciated that references to microprocessor instructions or microprocessor-executable instructions herein in accordance with the foregoing include programmable hardware.

  Unless stated otherwise, the use of the term “substantially” means that such deviations, as will be understood by those skilled in the art, as understood by the precise relationship, situation, arrangement, orientation, and / or other features It can be construed to include such deviations to the extent that they do not significantly affect the disclosed methods and systems.

  Throughout this disclosure, the use of the article “one” to modify a noun is used for convenience and may include one or more modified articles unless specifically stated otherwise. Can be understood.

  That element, component, module, and / or component described and / or otherwise communicated with, associated with, and / or drawn in other ways through drawings based thereon are described herein in other ways. Can be understood to be so communicated, associated and / or based on direct and / or indirect methods.

  Although the methods and systems have been described in connection with specific embodiments thereof, they are not so limited. Many obvious modifications and variations may be apparent in light of the above teachings. Many further changes in the details, materials, and arrangement of parts described and shown herein can be made by those skilled in the art.

  It will be apparent to those skilled in the art that preferred embodiments of the present invention have been described and that other embodiments incorporating these concepts can be used. Further, the software included as part of the present invention can be implemented in a computer program product including a computer usable medium. For example, such computer usable media includes a readable memory device such as a hard disk device, CD-ROM, DVD-ROM, or computer diskette having computer readable program code segments stored thereon. Devices can be included. The computer-usable medium may also include any optical, wired or wireless communication link having program code segments carried thereon as digital or analog signals. Therefore, it is suggested that the invention not be limited to the described embodiments, but rather should be limited only by the spirit and scope of the appended claims.

It is a figure which shows the timing of the express transmission frame between several nodes. It is a figure which shows the timing of multiple channel express transmission. 4 is a flow diagram of a particular embodiment of a method for performing an express transfer of a frame with multiple fragments according to an embodiment of the present invention. FIG. 2 illustrates an exemplary computer system architecture for a computer system that performs express transfer of frames with multiple fragments according to embodiments of the invention.

Claims (21)

A method,
A process of maintaining a timer (NAV) set in each of a plurality of nodes of a wireless local area network (LAN) during which a corresponding time period during which each node must stop transmission on the channel When,
A process of designating at least two fragments of a frame as a Time Sensitive Quality of Service (TSQ) frame fragment to be expressly transferred from a first node to a second node of the plurality of nodes;
Incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node;
Transmitting the TSQ frame fragment to the second node by the first node when the last frame fragment of the frame fragment is ready to be transmitted;
Receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes each set their NAV according to a value equal to the duration field of the response; The node attempts to transfer the TSQ frame fragment when the acknowledgment of reception of the TSQ frame fragment is completed.   The method of claim 1, wherein the TSQ frame fragment designation is provided by at least one of an application and an originating node.   The process of incrementing the duration field of the TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node is not performed for the last hop. The method according to 1.   The method of claim 1, wherein transmitting the TSQ frame fragment by the first node to the second node further comprises transmitting when the NAV of the second node ends.   The method of claim 1, wherein receiving a response from the second node includes receiving an acknowledgment (ACK) for each frame fragment received by the second node.   6. The method of claim 5, wherein the ACK duration field is set based on a received fragment duration value.   The NAV of the second node is set by decrementing a second predetermined time increment (DT1) for the duration value of the received frame when the received frame is to be transferred. The method of claim 1. A computer readable medium having computer readable code thereon for providing express transfer of a frame having a plurality of fragments,
To maintain a timer (NAV) set in each of a plurality of nodes in a wireless local area network (LAN), during which the respective node must stop transmission on the channel. And instructions
An instruction for designating at least two fragments of a frame as a Time Sensitive Quality of Service (TSQ) frame fragment to be expressly transferred from a first node to a second node of the plurality of nodes;
Instructions for incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node;
Instructions for transmitting the TSQ frame fragment by the first node to the second node when the last frame fragment of the frame fragment is ready to be transmitted;
An instruction for receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes set their NAVs according to a value equal to the duration field of the response, respectively, A computer readable medium comprising instructions for attempting to transfer the TSQ frame fragment when the acknowledgment of receipt of the TSQ frame fragment is completed.   The computer-readable medium of claim 8, wherein the TSQ frame fragment designation further comprises instructions provided by at least one of an application and an originating node.   Incrementing the duration field of the TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node is a command not executed for the last hop. The computer readable medium of claim 8 further comprising:   The method of claim 8, wherein transmitting the TSQ frame fragment by the first node to the second node further comprises transmitting further when the NAV of the second node ends. Computer readable media.   9. The computer of claim 8, wherein the process of receiving a response from the second node further comprises instructions comprising a process of receiving an acknowledgment (ACK) for each frame fragment received by the second node. A readable medium.   The computer-readable medium of claim 12, wherein the period field of the ACK further comprises an instruction set based on a received fragment period value.   The NAV of the second node is set by decrementing a second predetermined time increment (DT1) for the duration value of the received frame when the received frame is to be transferred. The computer-readable medium of claim 8, further comprising instructions. A computer system,
Memory,
A processor;
A communication interface;
An interconnection mechanism for coupling the memory, the processor, and the communication interface;
The memory is encoded with an express transfer application that, when executed by the processor, provides an express transfer process for processing information, the express transfer process being executed by the computer system. The following operations can be executed,
An operation of maintaining a timer (NAV) set in each of a plurality of nodes of a wireless local area network (LAN) during which a corresponding time period during which each node must stop transmission on the channel When,
Designating at least two fragments of a frame as Time Sensitive Quality of Service (TSQ) frame fragments to be expressly transferred from a first node to a second node of the plurality of nodes;
Incrementing the duration field of each TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node;
Sending the TSQ frame fragment to the second node by the first node when the last frame fragment of the frame fragment is ready to be transmitted;
Receiving a response from the second node, wherein non-forwarding neighboring nodes of the plurality of nodes each set their NAV according to a value equal to the duration field of the response; The computer system, wherein the node attempts to transfer the TSQ frame fragment when the acknowledgment of reception of the TSQ frame fragment is completed.   The computer system of claim 15, wherein the TSQ frame fragment designation is provided by at least one of an application and an originating node.   The process of incrementing the duration field of the TSQ frame fragment by a first predetermined time increment (DT0) before the TSQ frame fragment is transferred by the first node is not performed for the last hop. 15. The computer system according to 15.   16. The computer system according to claim 15, wherein the process of transmitting the TSQ frame fragment by the first node to the second node further comprises a process of transmitting when the NAV of the second node ends. .   The computer system of claim 15, wherein the receiving a response from the second node includes receiving an acknowledgment (ACK) for each frame fragment received by the second node.   The computer system according to claim 19, wherein the period field of the ACK is set based on the received fragment period value.   The NAV of the second node is set by decrementing a second predetermined time increment (DT1) for the duration value of the received frame when the received frame is to be transferred. The computer system according to claim 15.

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