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`US007573820B2
`
`c12) United States Patent
`Krishnaswamy et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7 ,573,820 B2
`Aug. 11, 2009
`
`(54) TECHNIQUES TO CONTROL DATA
`TRANSMISSION FORA WIRELESS SYSTEM
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`(75)
`
`Inventors: Dilip Krishnaswamy, Roseville, CA
`(US); Curtis Jutzi, Lake Oswego, OR
`(US); Eugene P. Matter, Folsom, CA
`(US)
`
`(73) Assignee: Intel Corporation, Santa Clara, CA
`(US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 484 days.
`
`(21) Appl. No.: 11/171,589
`
`(22) Filed:
`
`Jun.29,2005
`
`(65)
`
`Prior Publication Data
`
`US 2007/0002742Al
`
`Jan.4,2007
`
`(51)
`
`Int. Cl.
`(2006.01)
`GOlR 31108
`(2006.01)
`G06F 11100
`(2006.01)
`H04J 1116
`(2006.01)
`H04L 1100
`(52) U.S. Cl. ....................... 370/235; 370/360; 370/242;
`370/395.52; 370/230; 370/349; 455/423;
`455/428; 455/63.3; 455/9; 455/199.1
`( 58) Field of Classification Search . ... ... ... ... .. .. 3 70/349,
`370/231, 235, 253, 252, 310, 332, 395.1,
`370/395.52, 360, 318, 229, 230, 395.2; 455/512,
`455/513, 509
`See application file for complete search history.
`
`5/1996 Yamaguchi et al ....... 379/32.04
`5,515,418 A *
`6,829,215 B2 * 12/2004 Tornar ........................ 370/223
`7,245,582 Bl*
`7/2007 Roberts eta!. .............. 370/217
`2003/0118107 Al*
`6/2003 Itakuraetal. .......... 375/240.19
`2003/0126238 Al*
`7/2003 Kohno et al. ................ 7091220
`2003/0189920 Al* 10/2003 Erami et al.
`................ 370/351
`2004/0214602 Al* 10/2004 Aoyama ..................... 455/561
`1/2005 Gopalakrishnan
`200510013303 Al*
`et al.
`..................... 370/395.21
`2005/0058068 Al*
`3/2005 Ben Ali et al. .............. 370/230
`2005/0268324 Al* 12/2005 An ............................. 725/152
`612006 Nishihara ................... 370/389
`2006/0120365 Al*
`2006/0198301 Al*
`912006 Airy et al .................... 370/229
`2006/0251086 Al* 1112006 Ha et al. ..................... 370/401
`
`* cited by examiner
`Primary Examiner-Huy Q Phan
`(74) Attorney, Agent, or Firm-Kacvinsky LLC
`
`(57)
`
`ABSTRACT
`
`A system, apparatus, method, and article including a control
`module to manage transmission of packets in a channel of a
`wireless network. The control module to receive real-time
`information about the channel. The control module to adapt
`transmission of said packets based on the information. Other
`embodiments are described and claimed.
`
`20 Claims, 4 Drawing Sheets
`
`314
`
`316
`
`318
`
`320
`
`322
`
`Number
`
`Length
`
`Time Out
`
`Priority
`
`Transport
`Protocol
`
`DISH, Exh. 1008, p. 1
`
`

`
`U.S. Patent
`
`Aug. 11, 2009
`
`Sheet 1of4
`
`US 7,573,820 B2
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`

`
`U.S. Patent
`
`Aug. 11, 2009
`
`Sheet 2 of 4
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`

`
`U.S. Patent
`
`Aug. 11, 2009
`
`Sheet 3 of 4
`
`US 7,573,820 B2
`
`302
`
`310
`
`303
`
`330
`
`304
`
`305
`
`306
`
`307
`
`308
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`340
`
`350
`
`360
`
`370
`
`380
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`Module 300
`
`FIG. 3A
`
`312 \
`
`314
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`316
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`318
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`320
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`322
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`Number
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`
`FIG. 38
`
`DISH, Exh. 1008, p. 4
`
`

`
`U.S. Patent
`
`Aug. 11, 2009
`
`Sheet 4 of 4
`
`US 7,573,820 B2
`
`Start
`
`,,
`
`Monitor channel conditions
`402
`
`,,
`Receive information associated with
`the channel
`404
`
`, r
`
`Receive a list of pending packets
`available for transmission
`406
`,,
`
`Generate an output signal based on
`the channel information and the list
`of pending packets
`408
`
`H c End
`
`FIG. 4
`
`DISH, Exh. 1008, p. 5
`
`

`
`US 7,573,820 B2
`
`1
`TECHNIQUES TO CONTROL DATA
`TRANSMISSION FORA WIRELESS SYSTEM
`
`BACKGROUND
`
`2
`improve performance in wireless communication devices,
`and to increase overall wireless communication system per(cid:173)
`formance.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 illustrates one embodiment of a system.
`FIG. 2 illustrates one embodiment of a component.
`FIG. 3A illustrates one embodiment of a module.
`FIG. 3B illustrates one embodiment of a packet quintuplet.
`FIG. 4 illustrates one embodiment of a logic flow.
`
`DETAILED DESCRIPTION
`
`15
`
`Various communication systems exist today to allow elec(cid:173)
`tronic devices such as computers to communicate and
`exchange data and other types of information such as voice
`and multimedia communications (e.g., video, sound, data) 10
`over local and distributed networks. Various wireless com-
`munication systems, such as Wireless Local Area Networks
`(WLAN) also allow mobile computers to communicate with
`each other and other computers connected to Wide Area Net-
`works (WAN) such as Internet. Interactive multimedia com(cid:173)
`munications transferred across wireless communication sys(cid:173)
`tems require high bandwidth due to the data rates and pay load
`size. For example, real-time multimedia videoconferencing
`sessions over a wide-area wireless Internet connection 20
`requires high data throughput of large payloads, and there(cid:173)
`fore, the wireless network requires high bandwidth.
`Furthermore, in multimedia streaming data is transferred
`in a stream of packets that are interpreted as they arrive for
`"just-in-time" delivery of multimedia information. In such
`multimedia streaming applications WLANs offer several
`challenges. In a wireless network channel, dynamic variation
`in the channel conditions due to noise, interference, and path
`loss effects impact data throughput and packet loss, and hence 30
`affects the overall performance of the network. Dynamic
`changes in the number of users in the network each with
`varying data rate requirements also result in varying degrees
`of contention and collision in the network and may impact the
`amount of bandwidth available per user or per packet flow.
`Data throughput reduction and packet loss due to poor
`channel or link conditions may require that wireless commu(cid:173)
`nication devices connected to wireless communications sys(cid:173)
`tems attempt packet retransmissions at the data link layer, i.e., 40
`medium access control (MAC) layer in the Open Systems
`Interconnection (OSI) protocol stack. Wireless communica(cid:173)
`tion systems also may allow link adaptation and a choice of
`different modulation and coding schemes at the data link
`(MAC) layer or at the physical (PHY) layer that may be used 45
`for data transmission over the wireless medium. In a wireless
`communication system, multimedia applications may
`include prioritized packets. For example, video packet
`streams transferred over the wireless communication system
`include some packets that may be of higher priority than other
`packets. Transmission of prioritized video packets may cause
`transmission delays in the wireless network. In addition, any
`action taken by the network to process a given packet will
`almost always depend on the transport protocol being used.
`For example, the wireless network will treat transmission of
`packets using the Real Time Protocol (RTP) over UDP trans(cid:173)
`port protocol differently from transmissions over TCP, for
`example. Furthermore, there may be a need to provide infor(cid:173)
`mation regarding aborted packet further
`transmission
`attempts at the MAC/PHY layer to upper layers in the proto(cid:173)
`col stack. In addition, there may be a need to monitor and
`develop trends of multiple packet retransmission attempts
`over the wireless communications system and provide intel(cid:173)
`ligent processing operations in the protocol stack may to 65
`address these inter-related functionalities. Accordingly, there
`is a need for techniques to improve such operations, to
`
`FIG. 1 illustrates one embodiment of a system. FIG. 1 may
`illustrate a block diagram of a system 100, for example.
`System 100 may be a distributed system. System 100 may
`comprise, for example, a communication system having mul(cid:173)
`tiple nodes. A node may comprise any physical or logical
`entity having a unique address in system 100. Examples of a
`node may include, but are not necessarily limited to, a com-
`puter, server, workstation, laptop, ultra-laptop, handheld
`computer, telephone, cellular telephone, personal digital
`assistant (PDA), router, switch, bridge, hub, gateway, wire-
`25 less access point, and so forth. The unique address may com(cid:173)
`prise, for example, a network address such as an Internet
`Protocol (IP) address, a device address such as a MAC
`address, and so forth. The embodiments are not limited in this
`context.
`The nodes of system 100 may be arranged to communicate
`different types of information, such as media information and
`control information. Media information may refer to any data
`representing content meant for a user, such as voice informa(cid:173)
`tion, video information, audio information, text information,
`35 numerical information, alphanumeric symbols, graphics,
`images, and combinations thereof, for example. Control
`information may refer to any data representing commands,
`instructions or control words meant for an automated system.
`For example, control information may be used to route media
`information through a system, or instruct a node to process
`the media information in a predetermined manner.
`The nodes of system 100 may communicate media and
`control information in accordance with one or more proto(cid:173)
`cols. A protocol may comprise a set of predefined rules or
`instructions to control how the nodes communicate informa(cid:173)
`tion between each other. The protocol may be defined by one
`or more protocol standards as promulgated by a standards
`organization, such as the Internet Engineering Task Force
`(IETF), International Telecommunications Union (ITU), the
`50 Institute of Electrical and Electronics Engineers (IEEE), and
`so forth. For example, system 100 may operate in accordance
`with various wireless local area network (WLAN) protocols,
`such as the IEEE 802.11 series of protocols, including the
`IEEE 802.lla, 802.llb, 802.lle, 802.llg, 802.lln, and so
`55 forth. In another example, system 100 may operate in accor(cid:173)
`dance with various wireless metropolitan area network
`(WMAN) mobile broadband wireless access (MBWA) pro(cid:173)
`tocols, such as a protocol from the IEEE 802.16 or 802.20
`series of protocols. In another example, system 100 may
`60 operate in accordance with various wireless personal area
`networks (WPAN), for example include IEEE 802.16e, Blue
`Tooth, and the like, in which adaptation can be applied using
`different MCS and MAC retry, packet prioritization, for
`example.
`In various embodiments, for example, system 100 may
`operate in accordance with one or more wireless protocols,
`including, for example, cellular protocols in accordance with
`
`DISH, Exh. 1008, p. 6
`
`

`
`US 7,573,820 B2
`
`3
`one or standards. These cellular standards may comprise, for
`example, Code Division Multiple Access (CDMA), CDMA
`2000, Wideband Code-Division Multiple Access
`(W-CDMA), Enhanced General Packet Radio Service
`(GPRS), among other standards, for example. The embodi(cid:173)
`ments, however, are not limited in this context.
`Referring again to FIG. 1, system 100 may comprise a
`wireless communication system. In one embodiment, system
`100 may comprise a WLAN or WMAN system operating in
`accordance with the IEEE 802.11, 802.16 or 802.20 series of 10
`standard protocols. In one embodiment, for example, system
`100 may comprise a WLAN system operating with a number
`ofhigh throughput (HT) wireless devices arranged to operate
`in accordance with one or more of the IEEE-802.lln pro(cid:173)
`posed standards. The embodiments are not limited in this 15
`context.
`In various embodiments, system 100 may comprise a wire(cid:173)
`less communication system. In one embodiment, system 100
`may comprise a Worldwide Interoperability for Microwave
`Access (WiMax) system operating in accordance with the
`IEEE 802.16 standard protocols. Those skilled in the art will
`appreciate that similarities at the MAC/PHY layer between
`WiMax and WLAN systems operating in accordance with
`their respective protocols, allow embodiments of system 100
`to be adapted to operate as a WiMax system. WiMax may be
`considered a certification mark for products that pass confor(cid:173)
`mity and interoperability tests for the IEEE 802.16 standards.
`Those skilled in the art will appreciate that WiMAX is a
`standards-based wireless technology that provides high(cid:173)
`throughput broadband connections over long distances. 30
`WiMAX can be used for a number of applications, including
`"last mile" broadband connections, hotspots, and cellular
`backhaul, and high-speed enterprise connectivity for busi(cid:173)
`ness. The embodiments, however, are not limited in this con(cid:173)
`text.
`In one embodiment, system 100 may provide cross-layer
`optimization and manage communications across the layers
`of the OSI protocol stack. In one embodiment, a common
`information base may be used to share information between
`layers of the OSI protocol stack, for example. For example,
`embodiments of system 100 may provide real-time channel
`or link adaptation at the MAC layer to adapt to varying chan(cid:173)
`nel or link conditions in system 100. The choice of the trans(cid:173)
`port layer such as TCP or UDP also may impact overall
`network performance. Accordingly, embodiments of system
`100 may provide elements or components to adapt to varying
`conditions in system 100 when processing scalable multime(cid:173)
`dia applications, for example. Utilization of the physical, data
`link, transport, and application layer facilities in a selected
`protocol stack also may provide improved capacity in system
`100. Node-level cross-layer optimization techniques may be
`used to manage end-to-end state and policies across the layers
`of a particular protocol stack, such as, for example, the OSI
`protocol stack for transmission of packets over system 100.
`The embodiments are not limited in this context.
`In one embodiment, system 100 may include one or more
`wireless communication devices, such as nodes 110, 120,
`150. Nodes 110, 120, 150 all may be arranged to communi(cid:173)
`cate information signals using one or more wireless transmit(cid:173)
`ters/receivers ("transceivers") or radios, which may involve
`the use of radio frequency communication via IEEE 802.11
`Frequency Hopping Spread Spectrum (FHSS) or Direct
`Sequence Spread Spectrum (DSSS) schemes, for example.
`Nodes 110, 120, 150 may communicate using the radios over
`wireless shared media 160 via multiple inks or charmels
`established therein. For example, the radios may be arranged
`to operate using the 2.45 Gigahertz (GHz) Industrial, Scien-
`
`4
`tific and Medical (ISM) band of wireless shared media 160.
`Other operating bands may be used as well. Information
`signals may include any type of signal encoded with infor(cid:173)
`mation, such as media and/or control information. Although
`FIG. 1 is shown with a limited number of nodes in a certain
`topology, it may be appreciated that system 100 may include
`more or less nodes in any type of topology as desired for a
`given implementation. The embodiments are not limited in
`this context.
`In one embodiment, system 100 may include nodes 110,
`120. Nodes 110, 120 may comprise fixed devices having
`wireless capabilities. A fixed device may comprise a gener(cid:173)
`alized equipment set providing connectivity, management,
`and control of another device, such as mobile devices.
`Examples for nodes 110, 120 may include a wireless access
`point (AP), base station or node B, router, switch, hub, gate-
`way, media gateway, and so forth. In one embodiment, for
`example, nodes 110, 120 may comprise access points for a
`WLAN system. Although some embodiments may be
`20 described with nodes 110, 120 implemented as an AP by way
`of example, it may be appreciated that other embodiments
`may be implemented using other wireless devices as well.
`In one embodiment, AP 110, 150 also may provide access
`to a network 170 via wired communications media. Network
`25 170 may comprise, for example, a packet network such as the
`Internet, a corporate or enterprise network, a voice network
`such as the Public Switched Telephone Network (PSTN),
`among other WANs, for example. The embodiments are not
`limited in this context.
`In one embodiment, system 100 may include node 150.
`Node 150 may comprise, for example, a mobile device or a
`fixed device having wireless capabilities. A mobile device
`may comprise a generalized equipment set providing connec(cid:173)
`tivity to other wireless devices, such as other mobile devices
`35 or fixed devices. Examples for node 150 may include a com(cid:173)
`puter, server, workstation, notebook computer, handheld
`computer, telephone, cellular telephone, personal digital
`assistant (PDA), combination cellular telephone and PDA,
`and so forth. In one embodiment, for example, node 150 may
`40 comprise a mobile device, such as a mobile station (STA) for
`a WLAN. In a WLAN implementation, the combination of an
`AP and associated stations may be referred to as a Basic
`Service Set (BSS). Although some embodiments may be
`described with STA 150 implemented as a mobile station for
`45 a WLAN by way of example, it may be appreciated that other
`embodiments may be implemented using other wireless
`devices as well. For example, node 150 also may be imple(cid:173)
`mented as a fixed device such as a computer, a mobile sub(cid:173)
`scriber station (MSS) for a WMAN, and so forth. The
`50 embodiments are not limited in this context.
`Nodes 110, 120, 150 may have one or more wireless trans(cid:173)
`ceivers and wireless antennas. In one embodiment, for
`example, nodes 110, 120, 150 may each have multiple trans(cid:173)
`ceivers and multiple antennas. The use of multiple antennas
`55 may be used to provide a spatial division multiple access
`(SDMA) system or a multiple-input multiple-output (MIMO)
`system in accordance with one or more of the IEEE 802.1 ln
`proposed standards, for example. Multiple transmitting
`antennas may be used to increase data rates in a channel or to
`60 increase range and reliability of data transmitted in a channel
`without an increase in data rates. Data rates also may be
`increased by using multiple antennas to transmit data in mul(cid:173)
`tiple channels at the same time. Multiple receiving antennas
`may be used to efficiently recover transmitted data. The
`65 embodiments are not limited in this context.
`In general operation, the nodes of system 100 may operate
`in multiple operating modes. For example, nodes 110, 120,
`
`DISH, Exh. 1008, p. 7
`
`

`
`US 7,573,820 B2
`
`5
`150 may operate in at least one of the following operating
`modes: a single-input-single-output (SISO) mode, a mul(cid:173)
`tiple-input-single-output (MISO) mode, a single-input-mul(cid:173)
`tiple-output (SIMO) mode, and/or in a MIMO mode. In a
`SISO operating mode, a single transmitter and a single
`receiver may be used to communicate information signals
`over a wireless shared medium 160. In a MISO operating
`mode, two or more transmitters may transmit information
`signals over wireless shared media 160, and information sig(cid:173)
`nals may be received from wireless shared media 160 by a
`single receiver of a MIMO system. In a SIMO operating
`mode, one transmitter and two or more receivers may be used
`to communicate information signals over wireless shared
`media. In a MIMO operating mode, two or more transmitters
`and two or more receivers may be used to communicate
`information signals over wireless shared media 160. A chan(cid:173)
`nel 162, link, or connection may be formed using one or more
`frequency bands of wireless shared medium 160 for transmit(cid:173)
`ting and receiving packets 164. The embodiments are not
`limited in this context.
`In system 100, STA 150 may communicate with various
`AP, such as AP 110, 120. To communicatewithAP 110 or AP
`120, STA 150 may first need to associate with a given AP.
`Once STA 150 is associated with an AP, STA 150 may need to
`select a data rate for packets with media and control informa(cid:173)
`tion over wireless shared media 160. STA 150 may select a
`data rate once per association, or may periodically select data
`rates to adapt to transmitting conditions of wireless shared
`media 160. Adapting data rates to transmitting conditions
`may sometimes be referred to as rate adaptation operations. 30
`A WLAN such as system 100 may operate at a number of
`different data rates or data throughputs. For example, original
`802.11 systems using DSSS radios offered only two physical
`data rates of 1 Megabits per second (Mbps) or 2 Mbps. Cur(cid:173)
`rent WLAN systems operating in accordance with a number 35
`oforthogonal frequency division multiplexing (OFDM) tech(cid:173)
`niques, however, may support a wide range of data rates of up
`to 54 Mbps or more in the 2.4 GHz region. Other potentially
`higher data rates and transmit modes may be available as well.
`Examples of such WLAN systems may include 802.1 lg and 40
`802.lln systems.
`In one embodiment, system 100 may comprise scalable
`and adaptable elements or components to communicate pack-
`ets 164 via channel 162. In one embodiment, packets 164 may
`comprise multimedia streaming information, for example. 45
`Dynamic variations in channel 162 conditions due to noise,
`interference, and path loss may impact data throughput and
`may cause loss of packets 164 during transmission. Further(cid:173)
`more, dynamic changes in the number of users in system 100
`each with varying data rate requirements may result in a 50
`varying degree of contention and collision in system 100 and
`may impact the available bandwidth per user or per packet
`flow. Accordingly, system 100 nodes 110, 120, 150 may
`require components that are adaptable in real-time at the
`MAC layer that can adaptively select an appropriate transport 55
`layer protocol, such as TCP or UDP, to adapt to varying
`conditions in system 100. Nodes 110, 120, 150 may be
`adapted to scalable multimedia applications to improve the
`performance of system 100 under varying conditions. In one
`embodiment, capacity improvements in physical and data 60
`channel layers of system 100 as well as adaptations of the
`application and transport layers may be achieved with cross(cid:173)
`layer interaction between protocols layers such as the appli(cid:173)
`cation layer, transport layer, MAC layer, and PHY layer based
`on knowledge of current system 100 conditions. Scalability in 65
`multimedia representations helps system 100 to adapt to such
`dynamically varying constraints. Node-level and cross-layer
`
`6
`optimizations also may be considered to manage end-to-end
`state and policies across the various layers of the OSI protocol
`stack, for example.
`Due to reductions in data throughput and loss of packets
`because of poor channel or link conditions nodes 110, 120,
`150 comprising wireless communication devices connected
`to wireless shared media 160 via channel 162 may attempt
`retransmissions of packets 164 at the MAC layer, for
`example. Embodiments of system 100 nodes 110, 120, 150
`10 also may provide an adaptable channel 162 and a choice of
`different modulation and coding schemes at the MAC layer or
`at the PHY layer to transmit data over wireless shared media
`160. In multimedia applications streaming video packets may
`be transferred over system 100. Some of these streaming
`15 video packets may be of higher priority than other packets,
`which may result in transmission delays associated with pri(cid:173)
`oritized video packets. In addition, nodes 110, 120, 150 of
`system 100 may select a suitable transport protocol, such as
`RTP over UDP or TCP, to decide a particular action regarding
`20 a given packet, for example. In one embodiment, nodes 110,
`120, 150 may comprises components to collect information
`associated with packets aborted for further transmission
`attempts at the MAC/PHY layer and may provide such infor(cid:173)
`mation to upper layers in the protocol stack. In addition,
`25 multiple packet retransmission attempts over system 100 may
`be monitored and a trend may be developed to provide intel(cid:173)
`ligent processing operations in the protocol stack to address
`these inter-related functionalities.
`Accordingly, in one embodiment, system 100 may com(cid:173)
`prise component 108 in associated nodes 110, 120, 150 to
`implement techniques to improve packet 164 flow over chan(cid:173)
`nel 162 in system 100 in order to improve overall perfor(cid:173)
`mance in nodes 110, 120, 150, and to increase overall system
`100 performance. In one embodiment wireless communica-
`tion devices such as nodes 110, 120, 150 associated with
`system 100 may attempt packet 164 retransmissions at the
`MAC layer. System 100 also may allow channel 162 adapta(cid:173)
`tion and may provide a choice of different modulation and
`coding schemes at the MAC or the PHY layer that may be
`used for packet 162 transmission via channel 162 over wire(cid:173)
`less shared media 160. In one embodiment, system 100 may
`transmit prioritized packets. For example, some video packet
`streams transferred over system 100 may comprise priori(cid:173)
`tized packets where some packets have a higher priority than
`other packets. Transmission delays associated in the trans(cid:173)
`mission of such prioritized packets may impact the overall
`bandwidth and performance of system 100. In addition, the
`particular transport protocol may be considered in deciding
`what action to take for a given packet 164. In one embodi(cid:173)
`ment, RTP over UDP may be used as the transport protocol. In
`one embodiment, information associated with aborted packet
`164 retransmission attempts of packets at the MAC/PHY
`layer may be provided to the upper layers in the protocol
`stack. In addition, if component 108 detects a significant
`number of consecutive packet errors and attempts multiple
`packet 164 retransmissions, system 100 may attempt more
`robust transmission schemes, for example. In one embodi(cid:173)
`ment, component 108 may monitor this trend and use it as an
`early warning indicator of failing channel conditions in sys(cid:173)
`tem 100. In one embodiment, component 108 may execute
`intelligent processing operations in the protocol stack to pro-
`vide
`the
`inter-related functionalities discussed above.
`Accordingly, techniques to improve such intelligent process(cid:173)
`ing operations may therefore improve overall performance of
`nodes 110, 120, 150 and component 108 in system 100.
`Component 108 may be described in more detail with refer-
`ence to FIG. 2. In one embodiment, priority packets may be
`
`DISH, Exh. 1008, p. 8
`
`

`
`US 7,573,820 B2
`
`7
`mapped according to retry count where higher priority data
`packets may be retried based on the available scheduled dead(cid:173)
`line and where lower priority data packets either may be
`retried less frequently or may be discarded, for example. In
`one embodiment, an overall "delay buffer budget" may be
`maintained by the transmitting side and a receive playback
`buffer limit may be maintained on the receiver. The embodi(cid:173)
`ments, however, are not limited in this context.
`FIG. 2 illustrates one embodiment of a component. FIG. 2
`may illustrate a block diagram for component 108 of system 10
`100, for example. Component 108 may be implemented as
`part of nodes 110, 120 or 150 as described with reference to
`FIG. 1. As shown in FIG. 2, component 108 may comprise
`multiple elements, such as processor 210, switch (SW) 220,
`transceiver array 230, and memory 290. In one embodiment, 15
`component 108 also may comprise module 300. Some ele(cid:173)
`ments may be implemented using, for example, one or more
`circuits, components, registers, processors, software subrou(cid:173)
`tines, or any combination thereof. Although FIG. 2 shows a
`limited number of elements, it can be appreciated that more or 20
`less elements may be used in component 108 as desired for a
`given implementation. The embodiments are not limited in
`this context.
`In one embodiment, component 108 may include trans(cid:173)
`ceiver array 230. Transceiver array 230 may be implemented
`as, for example, a MIMO system. MIMO system 230 may
`include two transmitters 240a and 240b, and two receivers
`250a and 250b. Although MIMO system 230 is shown with a
`limited number of transmitters and receivers, it may be appre(cid:173)
`ciated that MIMO system 230 may include any desired num(cid:173)
`ber of transmitters and receivers. The embodiments are not
`limited in this context.
`In one embodiment, transmitters 240a-b and receivers
`250a-b ofMIMO system 230 may be implemented as OFDM 35
`transmitters and receivers. Transmitters 240a-b and receivers
`250a-b may communicate packets 164, 174, respectively,
`with other wireless devices over chamiels 162, 172, respec(cid:173)
`tively. For example, when implemented as part of AP 110 or
`AP 120, transmitters 240a-b and receivers 250a-b may com- 40
`municate packets 162, 164 with STA 150. When imple(cid:173)
`mented as part of STA 150, transmitters 240a-b and receivers
`250a-b may communicate packets 164, 174 with AP 110 or
`AP 120. The packets may be modulated in accordance with a
`number of modulation schemes, to include Binary Phase Shift 45
`Keying (BPSK), Quadrature Phase-Shift Keying (QPSK),
`Quadrature Amplitude Modulation (QAM), 16-QAM,
`64-QAM, and so forth. The embodiments are not limited in
`this context.
`In one embodiment, transmitter 240a and receiver 250a
`may be operably coupled to an antenna 260, and transmitter
`240b and receiver 250b may be operably coupled to antenna
`270. Examples for antenna 260 and/or antenna 270 may
`include an internal antenna, an onmi-directional antenna, a
`monopole antenna, a dipole antenna, an end fed antenna, a
`circularly polarized antenna, a micro-strip antenna, a diver(cid:173)
`sity antenna, a dual antenna, an antenna array, a helical
`antenna, and so forth. In one embodiment, system 100 may be
`implemented as a MIMO based WLAN comprising multiple
`antennas to increase throughput and may trade off increased
`range for increased throughput. MIMO-based technologies
`may be applied to other wireless technologies as well.
`Although in one embodiment system 100 may be imple(cid:173)
`mented as a WLAN in accordance with 802.1 la/b/g/n proto(cid:173)
`cols for wireless access in an enterprise, other embodiments
`in use in the enterprise may include reconfigurable radio
`technologies and/or multiple radios (e.g., multiple transceiv-
`
`8
`ers, transmitters, and/or receivers), for example. The embodi(cid:173)
`ments are not limited in this context.
`In one embodiment, component 108 may include a proces(cid:173)
`sor 210. Processor 210 may be implemented as a general
`purpose processor. For example, processor 210 may comprise
`a general purpose processor made by Intel® Corporation,
`Santa Clara, Calif. Processor 210 also may comprise a dedi(cid:173)
`cated processor, such as a controller, microcontroller, embed-
`ded processor, a digital signal processor (DSP), a network
`processor, an input/output (I/O) processor, a media processor,
`and so forth. The embodiments are not limited in this context.
`In one embodiment, processor 210 may comprise module
`300. In one embodiment, module 300 may comprise an adap(cid:173)
`tive cross-layer manager to control the transmission of pack(cid:173)
`ets 164, 17 4 in chamiels 162, 172, respectively, of a wireless
`network such as system 100. In one embodiment module 3 00
`may receive real-time information about channels 162, 172
`from a lower physical layer in the protocol stack, such as the
`PHY layer (i.e., OSI Physical Layer 1), and may receive
`packets 164, 174 from upper layers of the protocol stack. For
`example, module 300 may receive packets 164, 17 4 from any
`one of OSI layers 3-7 (i.e., Network Layer 3, Transport Layer
`4, Session Layer 5,