Source: http://www.google.com/patents/US7912026?ie=ISO-8859-1&dq=6275268
Timestamp: 2015-03-04 00:42:22
Document Index: 299241245

Matched Legal Cases: ['Application No. 60', 'art 11', 'art 11', 'art 11', 'art 11', 'art 11', 'art 11']

Patent US7912026 - Throughput in multi-rate wireless networks using variable-length packets and ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsIn a wireless communication network having a plurality of devices operating at different data rates that contend for access to the network, an apparatus is provided that assigns network access parameters so as to control throughput on the network....http://www.google.com/patents/US7912026?utm_source=gb-gplus-sharePatent US7912026 - Throughput in multi-rate wireless networks using variable-length packets and other techniquesAdvanced Patent SearchPublication numberUS7912026 B2Publication typeGrantApplication numberUS 12/715,118Publication dateMar 22, 2011Filing dateMar 1, 2010Priority dateOct 30, 2001Also published asUS7248604, US7672284, US20030081628, US20070263657, US20100157966Publication number12715118, 715118, US 7912026 B2, US 7912026B2, US-B2-7912026, US7912026 B2, US7912026B2InventorsGary L. Sugar, William R. Seed, Anthony T. CollinsOriginal AssigneeIpr Licensing, Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (4), Non-Patent Citations (10), Referenced by (1), Classifications (26), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetThroughput in multi-rate wireless networks using variable-length packets and other techniques
US 7912026 B2Abstract
In a wireless communication network having a plurality of devices operating at different data rates that contend for access to the network, an apparatus is provided that assigns network access parameters so as to control throughput on the network.
1. A wireless device configured to access a wireless network according to a network access control parameter, the wireless device comprising a processor configured to process the parameter by including an assigned maximum data packet length for transmitting data according to a variable packet length control scheme, such that a greater data packet length is assigned for higher data rate devices and a smaller packet length is assigned for lower data rate devices.
2. The wireless device as in claim 1, wherein the wireless device is further configured to receive an assigned maximum data packet length such that the device transmits data using data packets.
3. The wireless device as in claim 1, wherein the assigned data packet length is equal to Lmax/(Rf/Ri), where Lmax is the maximum packet length for any device on the network, Rf is the rate of the fastest device and Ri is the rate of the device.
4. The wireless device as in claim 1, wherein the wireless device is configured to receive an assigned contention window size as the network access control parameter.
5. The wireless device as in claim 4, wherein the wireless device is configured to use the assigned contention window size to access the network.
6. The wireless device as in claim 1, wherein the device is further configured to receive an assigned larger contention window on a condition that the device is a lower data rate device and an assigned smaller contention window on a condition that the device is a higher data rate device.
7. A method for use in a wireless station (STA) contending to access a wireless network, the method comprising configuring a control processor to adjust a network access parameter and to access wireless network according the network access parameter, wherein the parameter includes an assigned maximum data packet length for transmitting data according to a variable packet length control scheme, such that a greater data packet length is assigned for higher data rate devices and a smaller packet length is assigned for lower data rate devices.
8. The method as in claim 7, further comprising receiving an assigned maximum data packet length such that the wireless device transmits data using data packets.
9. The method as in claim 7, wherein the assigned data packet length is equal to Lmax/(Rf/Ri), where Lmax is the maximum packet length for any device on the network, Rf is the rate of the fastest device and Ri is the rate of the device.
10. The method as in claim 7, further comprising receiving an assigned contention window size as the network access control parameter.
11. The method as in claim 7, further comprising using the assigned contention window size to access the network.
12. The method as in claim 7, further comprising receiving an assigned larger contention window on a condition that the STA is a lower data rate device and an assigned smaller contention window on a condition that the STA is a higher data rate device. Description
This application is a continuation of U.S. application Ser. No. 11/880,204, filed Jul. 20, 2007 which in turn is a continuation of U.S. patent application Ser. No. 10/065,494, filed Oct. 24, 2002, now U.S. Pat. No. 7,248,604, which claims priority to U.S. Provisional Patent Application No. 60/330,755, filed Oct. 30, 2001, the entirety of which is incorporated herein by reference as if fully set forth.
To illustrate this, with reference to FIG. 1, an example system 10 is shown having N STAs 120, where N=20. For example, there are ten 1 Mbps STAs and ten 54 Mbps STAs on a CSMA/CA WLAN. Each STA is attempting to upload a file to (or download a file from) a server via the WLAN AP 110. It is assumed each STA 120 uses a 2 KB MSDU size. To simplify the analysis, assume zero MAC overhead (i.e., MAC header, acknowledgements, DIFS, etc. take zero time). The following relations hold for this example.
Ts=Packet duration for �slow� users=2048*8/1=16,384 μs
Tf=Packet duration for �fast� users=2048*8/54=303 μs=Ts/54
To generalize, assume there are Ns low data rate users and Nf high data rate users of a CSMA/CA WLAN. The following relations are given:
Throughput for slow data rate user=Rs*Ts/(Ns*Ts+Nf*Tf)=Rs*M/ (Ns*M+Nf)≈Rs/Ns (since Ns*M usually>>Nf)
Systems and methods, as described, improve system throughput of a wireless network by adjusting a network access parameter used by devices when accessing the network. One technique is to assign packet lengths to each user in such a way as to ensure that all users transmit packets of equal duration. The packet duration for all users is set based on a maximum packet size at the fastest user data rate in the network. Thus, under this methodology, fixed-duration transmissions (from the STA to the AP or from the AP to the STA) are enforced (which implies different packet lengths for different user data rates) instead of fixed-length packets (duration=time, length=bytes) for each user. In practice, the user-rate specific packet size, determined for each user based on the desired fixed-duration, is set as a maximum packet size for that user. However, the user does not always have to transmit at that maximum packet size. A packet size of less than the maximum packet size may be used, which will further benefit average throughput.
FIG. 1 is a block diagram of an example wireless communication system where throughput improvement techniques may be useful.
FIG. 1 illustrates an example system where a wireless local area network (WLAN) 100 consisting of an access point (AP) 110 and a plurality of stations (STAs) (STA1-STAN) 120. The AP 110 may interconnect to a wired LAN 130, and ultimately, through a router 140, to the Internet 150.
FIG. 3 illustrates an example AP 110 and a STA 120. In general, the AP 110 comprises a control processor 112, a baseband signal processor 114 and a radio transceiver 116. (It should be understood that the control processor 112 and the baseband signal processor 114 may be implemented on a single processing device.) The AP 110 receives signals from, and transmits signals to, the STAs 120 via one or more antennas 118. The processor 112 routes the received data from the STAs, and also directs outgoing data to the appropriate STA. In addition, the processor 112 in the AP 110 may execute a network throughput control process, described hereinafter, to control the average throughput on the WLAN 100. A network administration computer 160 may be coupled to the AP 110 (through the wired LAN 130 shown in FIG. 1) to provide supervisory and administrative control of the WLAN 100. Thus, the network throughput control process may be executed on the network administration computer 160 in addition to, or instead of, the AP 110. The AP 110 sends network access control parameter messages to one or more STAs 120. The network access control parameter message informs the STA 120 to alter a network access parameter, described hereinafter. The term base device is a more general term that refers to an access point, or in the context of a non-WLAN type of wireless network, another wireless device that may be fixed and may have additional computing power and supervisory control over the access to the network by other devices.
Generally, assuming there are M data rates in the system, R1<R2<. . . < RM, and Ni STAs/users at rate Ri, i=1, . . . , M. The maximum packet length for rate RM users is set to LM=Lmax, where Lmax is the maximum supported MSDU size in bytes (for example, Lmax=2304 bytes for 802.11). The maximum packet length for rate Ri users is set to Li=Lmax/(RM/Ri), i=1, . . . , M-1. This ensures that all packets are of equal duration, namely, Lmax/RM.
FIG. 6 shows a process 400 for updating a network access control parameter (e.g., maximum packet size or contention window size) for devices operating on the network. An IEEE 802.11 network is an example wireless network, but it should be understood that a similar process may be used in any other wireless network. In the context of 802.11, a method for updating maximum MSDU size at each STA involves adjusting the maximum transmit packet size at the Data-Link Protocol Interface (DLPI) between the network layer (e.g., IP) and the Logical Link Control (LLC) layer. This can be performed manually by a network administrator by updating the maximum packet size at each STA (via a message sent by the AP), or automatically by the AP sending an over-the-air message directing each STA to update its maximum packet size. No change to the 802.11 standard rules is required.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS6118788Oct 15, 1997Sep 12, 2000International Business Machines CorporationBalanced media access methods for wireless networksUS6285662May 14, 1999Sep 4, 2001Nokia Mobile Phones LimitedApparatus, and associated method for selecting a size of a contention window for a packet of data systemUS6404772Jul 27, 2000Jun 11, 2002Symbol Technologies, Inc.Voice and data wireless communications network and methodUS6965942Jan 12, 2001Nov 15, 20053Com CorporationMethod and system for improving throughput over wireless local area networks with a dynamic contention windowNon-Patent CitationsReference1Cali et al., "Dynamic Tuning Of The IEEE 802.11 Protocol To Achieve Theoretical Throughput Limit", IEEE/ACM Transactions On Networking, vol. 8, No. 6, (Dec. 2000).2LAN MAN Standards Committee of the IEEE Computer Society, "Information Technology-Telecommunications And Information Exchange Between Systems-Local And Metropolitan Area Networks-Specific Requirements-Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications", ANSI/IEEE Std 802.11, 1999 Edition (R2003), (Reaffirmed Jun. 12, 2003).3LAN MAN Standards Committee of the IEEE Computer Society, "Information Technology�Telecommunications And Information Exchange Between Systems�Local And Metropolitan Area Networks�Specific Requirements�Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications", ANSI/IEEE Std 802.11, 1999 Edition (R2003), (Reaffirmed Jun. 12, 2003).4LAN/MAN Standards Committee of the IEEE Computer Society, "Supplement To IEEE Standard For Information Technology-Telecommunications And Information Exchange Between Systems-Local And Metropolitan Area Networks-Specific Requirements, Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications, High-Speed Physical Layer In The 5 GHz Band", IEEE Std 802.11a-1999(R2003), (Reaffirmed Jun. 12, 2003).5LAN/MAN Standards Committee of the IEEE Computer Society, "Supplement To IEEE Standard For Information Technology-Telecommunications And Information Exchange Between Systems-Local And Metropolitan Area Networks-Specific Requirements-Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications: Higher-Speed Physical Layer Extension In The 2.4 GHz Band", IEEE Std 802.11b-1999 (R2003), (Reaffirmed Jun. 12, 2003, Approved Sep. 16, 1999).6LAN/MAN Standards Committee of the IEEE Computer Society, "Supplement To IEEE Standard For Information Technology�Telecommunications And Information Exchange Between Systems�Local And Metropolitan Area Networks�Specific Requirements, Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications, High-Speed Physical Layer In The 5 GHz Band", IEEE Std 802.11a-1999(R2003), (Reaffirmed Jun. 12, 2003).7LAN/MAN Standards Committee of the IEEE Computer Society, "Supplement To IEEE Standard For Information Technology�Telecommunications And Information Exchange Between Systems�Local And Metropolitan Area Networks�Specific Requirements�Part 11: Wireless LAN Medium Access Control (MAC) And Physical Layer (PHY) Specifications: Higher-Speed Physical Layer Extension In The 2.4 GHz Band", IEEE Std 802.11b-1999 (R2003), (Reaffirmed Jun. 12, 2003, Approved Sep. 16, 1999).8Satapathy et al., "Spectrum Sharing Without Licenses: Opportunities And Dangers", Proceedings Of The Telecommunications Policy Research Conference (TPRC), pp. 1-19, (1996).9Vaduvur Bharghavan, "Performance Evaluation Of Algorithms For Wireless Medium Access", IEEE International Computer Performance And Dependability Symposium IPDS'98, pp. 142-149, (1998).10Wang et al., "Achieving Fairness In IEEE 802.11 DFWMAC With Variable Packet Lengths", A Presentation At GLOBECOM, (San Antonio, Texas, Nov. 26, 2001).Referenced byCiting PatentFiling datePublication dateApplicantTitleUS8879448 *Dec 26, 2007Nov 4, 2014Samsung Electronics Co., Ltd.Apparatus for controlling power of WiMedia media access control device and method using the same* Cited by examinerClassifications U.S. Classification370/338International ClassificationH04L12/28, H04W4/00, H04L12/56Cooperative ClassificationH04L47/765, H04W28/22, H04L47/822, H04L47/824, H04L12/5695, H04L47/826, H04L47/15, H04L47/762, H04W84/12, H04W28/12, H04L47/10European ClassificationH04W28/12, H04W84/12, H04W28/22, H04L12/56R, H04L47/82B, H04L47/76A, H04L47/82D, H04L47/10, H04L47/76B, H04L47/82F, H04L47/15Legal EventsDateCodeEventDescriptionOct 31, 2014REMIMaintenance fee reminder mailedOct 4, 2011CCCertificate of correctionRotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services