(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/0090924 A1
`(43) Pub. Date:
`May 13, 2004
`Giaimo et al.
`
`US 20040090924A1
`
`(54)
`
`METHOD AND APPARATUS FOR WIRELESS
`ROUTHING ON A PLURALITY OF
`DIFFERENT WIRELESS CHANNELS
`
`(76) Inventors: Edward C. Giaimo, Bellevue, WA
`(US); John P. Pennock, Sammamish,
`WA (US); Paramvir Bahl, Sammamish,
`WA (US); Pradeep Bahl, Redmond,
`WA (US)
`Correspondence Address:
`LAW OFFICES OF RONALD M. ANDERSON
`Suite 507
`600 - 108th Avenue N.E.
`Bellevue, WA 98004 (US)
`Appl. No.:
`10/701,762
`
`Filed:
`
`Nov. 4, 2003
`Related U.S. Application Data
`(63) Continuation-in-part of application No. 10/428,218,
`filed on May 2, 2003.
`Continuation-in-part of application No. 09/953,980,
`filed on Sep. 17, 2001.
`Continuation-in-part of application No. 09/954,087,
`filed on Sep. 17, 2001.
`
`(21)
`(22)
`
`Publication Classification
`
`(51) Int. Cl." ............................. H04L 12/26; H04Q 7/00
`(52) U.S. Cl. ........................... 370/252; 370/338; 370/328
`
`(57)
`
`ABSTRACT
`
`To provide enhanced quality of Service (QoS) communica
`tion capability, a wireleSS network is implemented in which
`different channels are used for conveying different types of
`data and in which wireleSS devices are Selectively operated
`in either an infrastructure or ad hoc mode automatically
`Selected to make best use of the available communication
`bandwidth. For example, a wireleSS device for a computer
`can be operated Selectively as a client wireleSS device that is
`in communication with a legacy acceSS point in an infra
`Structure mode on one channel, while using one or more
`different channels to communicate Selectively in either ad
`hoc mode or infrastructure mode with client devices. To
`make efficient use of wireless devices, IEEE 802.11a or
`802.11g wireleSS devices are used for communicating audio/
`video data on one channel, while an IEEE 802.11b wireless
`device is used on a different channel for communicating web
`page data.
`
`
`
`
`
`
`
`CABLE OR
`DSL
`MODEM
`
`
`
`EEE 802.11b
`WRELESS
`BASE STATION,
`ETHERNET
`SWITCH
`
`ETHERNE
`
`50
`
`
`
`AUDIO
`SYSTEM 8.
`SPEAKERS
`
`WIDEO
`DAA
`
`2.11g
`PC
`
`42b
`42a
`FT MULTIMEDIA
`A45%zyl-42c PC
`
`IEEE 802.11g
`WIDEO
`DAA
`
`ELEVISION
`MONITOR
`
`TELEVISION
`MONITOR
`
`DELL
`EXHIBIT 1008 - PAGE 1
`
`

`

`Patent Application Publication May 13, 2004 Sheet 1 of 9
`
`US 2004/0090924 A1
`
`CLENT 5
`
`CH. 1
`
`O CLIENT 4
`
`
`
`CLIENT 6
`
`CH. 1
`
`O CLIENT 3
`
`CLIENT 2
`
`\to
`
`CLENT 1
`ALLCLIENTS COMMUNICATE IN
`NFRASTRUCTURE MODE WITH AP
`
`FIG. IA (PRIOR ART)
`
`CLIENT 5
`SMART WIRELESS
`ROUTINGAP MODE
`
`
`
`
`
`CLIENT 4
`
`FRASTRUTURE
`TO CLIENT 5 CH. 11
`
`COMMUNICATES WITH
`CLIENTS 1, 5, & 3 IN
`INFRASTRUCTURE MODE
`
`NFRASTRUTURE
`TO CLIENT 5
`CH. 11
`
`
`
`CLENT 6
`
`
`
`
`
`CLIENT 3
`
`CLENT 2
`
`7D HOC CLIENT 1
`TO CLENT 2
`CH. 6
`
`u
`
`10
`
`CLIENT 1
`SMART WIRELESS
`ROUTING AD HOC MODE
`FIG. IB
`
`DELL
`EXHIBIT 1008 - PAGE 2
`
`

`

`Patent Application Publication May 13, 2004 Sheet 2 of 9
`
`US 2004/0090924 A1
`
`30
`
`1500
`
`54 MBPS
`
`32
`
`1 MBPS
`
`TIME
`
`FIG. 2A (PRIOR ART).
`
`ra
`
`32
`
`1500
`1500
`1500
`1500
`1500
`1500
`. BYTES BYTES BYTES BYTES BYTES BYTES
`54 MBPS
`
`1500 BYTES
`a Mady
`WU
`wd
`
`TIME
`
`FIG. 2B (PRIOR ART)
`
`O-A-2 CLIENT 2
`
`FIG. 3 (PRIOR ART)
`
`CHX
`
`CHY
`
`1500
`1500
`1500
`1500
`1500
`1500
`BYTES BYTES BYTES BYTES BYTES BYTES
`54 MBPS LOW LATENCY, HIGH THROUGHPUT
`32
`32
`
`30
`
`re
`
`1 MBPS
`
`HIGH LATENCY, LOW THROUGHPUT
`
`34
`
`100
`100
`100
`100
`100
`100
`CHZ BYTES BYTES BYTES BYTES BYTES BYTES
`1 MBPS
`LOWLATENCY, LOW THROUGHPUT
`
`TIME
`FIG. 4
`
`DELL
`EXHIBIT 1008 - PAGE 3
`
`

`

`Patent Application Publication May 13, 2004 Sheet 3 of 9
`
`US 2004/0090924 A1
`
`
`
`IEEE 802.11b.
`WIRELESS
`BASE STATION/
`ETHERNET
`SWITCH
`
`RUCTUR
`
`
`
`
`
`CABLE OR
`DSL
`MODEM
`
`
`
`
`
`AUDIO/VIDEO
`SERVER
`22a s
`
`
`
`
`
`
`
`
`
`
`
`50
`
`AUDIO
`SYSTEM 8,
`SPEAKERS
`
`FIG. 5
`
`IEEE 802.11g
`VIDEO
`DATA
`
`
`
`TELEVISION
`MONITOR
`
`TELEVISION
`MONITOR
`
`DELL
`EXHIBIT 1008 - PAGE 4
`
`

`

`Patent Application Publication May 13, 2004 Sheet 4 of 9
`
`US 2004/0090924 A1
`
`TO BROADBAND
`CONNECTION ORLAN LEGACY
`WIRELESS
`ACCESS
`POINT
`
`
`
`60
`
`CH. Y
`
`LEGACY LINK
`INFRASTRUCTURE
`
`
`
`CLIENT
`
`
`
`LEGACY LINK
`NFRASTRUCTURE
`CH.Y
`
`4b.
`
`
`
`
`
`
`
`
`
`
`
`CLIENT/
`MEDIA
`SERVER
`
`MEDIA
`CH. X (2) - EG
`AD HOCOR INFRA
`STRUCTURE MODE
`
`OPERATES AS AN ACCESS
`POINT (MEDIA SERVER) ORAS
`A CLIENT DEVICE & INEITHER
`AD HOCOR INFRASTRUCTURE
`MODES
`
`
`
`CH. X
`
`
`
`
`
`64a
`
`
`
`MEDIA
`CLIENT
`
`
`
`FIG. 6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`802.11 RF
`TRANSMITTER/
`RECEIVER
`
`WAN
`INTERFACE (IF
`BASE STATION)
`
`
`
`
`
`
`
`65
`
`PROCESSOR
`
`ETHERNET
`TRANSCEIVER
`
`MAC 8, PHY
`
`MEMORY
`
`
`
`
`
`
`
`FIG. 7
`
`ETHERNET
`SWITCH (IF
`BASE STATION)
`BASE STATION/
`ACCESS POINT
`
`
`
`DELL
`EXHIBIT 1008 - PAGE 5
`
`

`

`Patent Application Publication May 13, 2004 Sheet 5 of 9
`
`US 2004/0090924 A1
`
`
`
`
`
`
`
`START (INFRA
`STRUCTURE
`MODEON
`CHANNELA)
`
`CLIENT AOR CLENT B
`SENDS REQUEST TO
`ACCESS POINT TO
`COMMUNICATE WITH THE
`OTHER NAD HOC MODE
`
`
`
`72
`
`
`
`ARE
`CLIENTS WITHIN
`RANGE OF EACH
`OTHER2
`
`YES
`l
`ACCESS POINT
`PROVIDES CHANNEL,
`SEC. PARAMETERS, AND
`PERMANENT/
`TRANSITORY STATUS OF
`CHANGE IN MODE
`
`NO
`
`REGUEST
`IS DENIED
`
`78
`
`CONTINUE INFRA
`STRUCTURE MODE
`COMMUNICATION
`
`ACCESS POINT UPDATES
`ITS ROUTING TABLE TO
`INDICATE THAT CLIENTS
`A & B CAN COMMUNICATE
`
`
`
`
`
`
`
`
`
`
`
`
`
`CLIENTS A & B SETUP
`AND CONNECT ON
`WRELESS CHANNEL B
`WITH PARAMETERS
`PROVIDED
`
`
`
`NEED TO COMMUN.
`WITH ACCESS
`
`CHANGE TO INFRA
`STRUCTURE
`MODE OF
`COMMUNICATION
`
`CONTINUE AD
`HOC MODE OF
`COMMUNICATION
`
`92
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`FIG. 8
`
`DOES
`THER CLIEN
`NEED TO COMMUN.
`WITH THE
`
`
`
`COMMUNICATE
`WITH ACCESS
`POINT IN INFRA
`STRUCTURE MODE
`ON CHANNEL A
`
`DELL
`EXHIBIT 1008 - PAGE 6
`
`

`

`Patent Application Publication May 13, 2004 Sheet 6 of 9
`
`US 2004/0090924 A1
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`START
`
`100
`
`120
`
`SET CHANNEL
`USE (CUT) TABLE
`TO ALLZERO BITS 130
`
`
`
`START AT FIRST
`CST ENTRY
`
`NITIALIZE WIRELESS
`NETWORK
`
`
`
`122
`
`DISCOVER STATUS OF 102
`
`
`
`SET ACCESS
`POINT LIST (APL)
`TO ALL ZERO BITS
`
`READ RF BAND 8,
`CHANNEL NO. PAR
`134
`PROGRAM WI-F
`
`
`
`SEAN
`
`P
`
`
`
`
`
`124-SETCHANNEL
`
`SCAN TABLE (CST)
`
`YAN Arras
`POINT LIST TO
`ENABLE LEGACY
`ACCESS POINT
`COMMUNIC.
`
`
`
`
`
`IDENTIFY BEST
`LEGACY ACCESS
`106
`POINT TO ASSOCIATEY
`WITH FOR
`COMMUNIC.
`
`OFFER ACCESS
`POINT SERVICES
`
`DATA
`COMMUNICATION
`
`110
`
`FOREACHENTRY IN
`CHANNEL SCANTABLE,
`FILL-N DATA BASED
`ON COUNTRY DOMAIN
`
`RECORD DATAN
`CURRENT CST
`ENTRY
`
`O
`
`YES
`
`REDISCOVERY & RE-12
`CONFIGURATION
`
`u
`102
`
`DONE
`
`FIG. 9
`
`DELL
`EXHIBIT 1008 - PAGE 7
`
`

`

`Patent Application Publication May 13, 2004 Sheet 7 of 9
`
`US 2004/0090924 A1
`
`150
`
`
`
`152
`
`INITIALIZE
`DATA FOR
`APL INFO
`
`
`
`STARTAT
`FIRST ENTRY
`OF CST
`
`
`
`S
`CURRENT
`CHANNEL
`USABLE
`
`
`
`PRESENT INFO FOR
`CURRENT CST ENTRY
`TO USER
`
`
`
`
`
`USER WANT TO
`USE CURRENT AP
`
`SET USE TO TRUE 164
`
`166
`
`802.11 SIGNAL D
`BEST SIGNAL IN
`
`168
`SET AP FOUND TO
`TRUE, SET BEST
`SIGNAL TO 802.11
`SIGNAL SET BEST AP
`INDEX TO CURRENT
`CST ENTRY NO.
`
`ASK USER FOR
`SECURITY KEY 8, SET
`SECURITY KEY IN CST
`ENTRY NO TO VALUE
`SPECIFIED BY USER
`
`YES
`
`INCREMENT NO
`CST ENTRY
`NO.
`
`
`
`104
`
`FIG. 12
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`DELL
`EXHIBIT 1008 - PAGE 8
`
`

`

`Patent Application Publication May 13, 2004 Sheet 8 of 9
`
`US 2004/0090924 A1
`
`
`
`CREATE NEW ENTRY IN
`CUT & SET INFO IN CUT
`ENTRY
`
`ASSOCATE TO
`SELECTED AP USING
`INFO IN CST SPECIFIED
`BY CST INDEX
`
`190
`
`192
`
`SET FREE CHANTO
`FALSE & LEAST RF
`TO +127 DBM
`
`STARTING AT A
`FIRST ENTRY IN CST,
`SEARCH FOR OPEN
`CHANNEL WITH NO
`SIGNIFICANT RF
`ENERGY
`
`
`
`CONTINUE WITH NEXT
`STEP
`
`108
`\.
`
`106 FIG. 13
`
`
`
`
`
`
`
`194
`
`
`
`IS
`CURRENT
`CHANNEL
`USABLE
`
`SET VALUES INAPL
`FROM CST ENTRY
`
`NO
`
`200
`
`
`
`
`
`NCREMENT
`TABLE ENTRY NO.
`
`108
`
`u
`FIG. I.4A
`
`DELL
`EXHIBIT 1008 - PAGE 9
`
`

`

`Patent Application Publication May 13, 2004 Sheet 9 of 9
`
`US 2004/0090924 A1
`
`202
`
`FREE CHANNEL
`
`204
`
`SEARCH FOR OPEN
`CHANNEL STARTING
`AT FIRST ENTRY OF
`
`CHANNEL
`USABLE
`
`S
`FREE CHANNEL
`FALSE?
`
`
`
`
`
`
`
`
`
`
`
`
`
`218
`
`CREATE NEW
`ENTRY IN CUT
`
`SET BEST CHAN
`INDEX TO DEFAULT
`CHANNEL
`
`SET VALUES INAPL
`FROM CST ENTRY
`
`
`
`INCREMENT
`TABLE ENTRY NO.
`
`ADVERTISE MAP
`FUNCTIONALITY USING
`INFO N CST SPECIFIED
`BY CST INDEX
`
`
`
`
`
`conTINUE WITH 222
`NEXT STEP
`
`108
`
`FIG. I.4B
`
`DELL
`EXHIBIT 1008 - PAGE 10
`
`

`

`US 2004/0090924 A1
`
`May 13, 2004
`
`METHOD AND APPARATUS FOR WIRELESS
`ROUTHING ON A PLURALITY OF DIFFERENT
`WIRELESS CHANNELS
`
`RELATED APPLICATIONS
`0001. This application is a continuation-in-part of prior
`copending U.S. patent applications, Ser. No. 10/428,218,
`filed May 2, 2003, Ser. No. 09/953,980, filed Sep. 17, 2001,
`and Ser. No. 09/954,087, filed Sep. 17, 2001, the benefit of
`the filing dates of which is hereby claimed under 35 U.S.C.
`S120.
`
`FIELD OF THE INVENTION
`0002 The present invention generally relates to the rout
`ing of wireleSS communications through a client on a
`wireleSS network, and more specifically, pertains to a
`method and a System for employing a client device to
`communicate with a plurality of other wireleSS devices on
`different channels, to route communications from one wire
`leSS AP to another wireleSS device, or to enhance commu
`nications with the other wireleSS devices.
`
`BACKGROUND OF THE INVENTION
`Wireless communications have become increas
`0.003
`ingly common for networking client devices together in
`offices and homes. An example of a simple conventional
`wireless network 10 is shown in FIG. 1. Wireless network
`10 includes a wireless base station/Ethernet Switch 12 that
`also functions as a router. This base Station is coupled to a
`cable modem or digital subscriber line (DSL) modem 14 and
`enables each client computing device on a local area net
`work (LAN) to share a broadband Internet connection to
`Internet 16. The base station may include several Ethernet
`Switch ports for use in connecting to wired client computing
`devices. For example, one Such port is shown connected by
`an Ethernet cable 20 to a personal computer (PC) 18a having
`a monitor 18b and a keyboard 18c. The network also
`includes a computer 22a (with a monitor 22b and a keyboard
`22c), a laptop 24, and another computer 26a (with a monitor
`26b and a keyboard 26c); and each of these client computing
`devices are in wireleSS communication with the base Station.
`0004 Although existing Institute of Electrical & Elec
`tronics Engineers (IEEE) 802.11 equipment is well Suited
`for browsing the Internet and Sharing bulk data Such as
`computer files, it does not handle the real-time Streaming of
`audio/video (A/V) particularly well. This is becoming an
`increasingly important concern, because users are capturing
`and Storing photos, music, and Video in consumer electronic
`devices and PCs to a greater extent and have expressed the
`desire to organize, display, and playback this information on
`existing electronic devices Such as TVS, Stereos, telephones,
`and other types of consumer electronic (CE) devices that can
`be coupled to a network. The most convenient way of
`connecting these devices in an existing office or home
`environment is wirelessly, using low-cost IEEE 802.11
`(Wi-Fi) equipment.
`0005 Wireless networks can employ several different
`frequency bands and data rates, with different nominal
`transmission characteristics, depending upon the Standard
`employed. These different Standards are all encompassed
`under the IEEE 802.11 specification that generally defines
`how wireless networks operate. Thus, the IEEE 802.11a
`
`Standard provides for transmissions at 5 GHZ, and data rates
`up to 54 Mbps using Orthogonal Frequency Division Mul
`tiplexing (OFDM), while the more ubiquitous IEEE 802.11b
`Standard, which provides for transmissions at 2.4 GHZ and
`data rates up to 11 Mbps, using direct Sequence spread
`spectrum modulation. The recently approved IEEE 802.11g
`standard is an extension of the IEEE 802.11b standard and
`also employs data rates up to 54 Mbps within the 2.4 GHz
`band, using OFDM technology. Wireless devices that are
`compliant with the 802.11g Standard are also compliant with
`the 802.11b standard, and some wireless devices are now
`available that are universally compliant with all three Stan
`dards.
`0006. However, mixing devices designed for different
`IEEE 802.11 standard data rates typically has a significant
`disadvantage. Specifically, use of an 802.11b compliant
`wireless device on a conventional wireless LAN that has
`wireleSS devices with 802.11g capabilities causes the net
`work to operate inefficiently, Substantially reducing the data
`rate of all of the 802.11g wireless devices on the LAN. The
`current Standard allocates bandwidth poorly, allowing an
`equal number of packets for each client. Thus, as indicated
`in FIG. 2A, a first wireless device that employs the 802.11
`gstandard may transmit a 1500 byte data packet 30 at up to
`54 Mbps, and then must wait while a second wireless device
`transmits a 1500 byte data packet 32 at about 1 Mbps using
`the 802.11b standard (note that the nominal maximum
`802.11g data rate, 54 Mbps, and 802.11b data rate, 11 Mbps,
`are typically not achieved due to Signaling overhead, com
`pression, error correction, collision detection, propagation
`conditions or distance between the Second wireleSS device
`and the intended recipient). As a result, the effective
`throughput and latency on this radio channel is degraded.
`The first wireleSS device data packets are still being trans
`mitted at 54 Mbps, but must wait for a 1 Mbps packet to be
`sent before the next packet can be sent at 54 Mbps. In the
`time the first device is waiting for the 1 Mbps packet, it
`could have sent another 54 times (i.e., 54 Mbps/1 Mbps)
`more packets, each containing 1500 bytes! Effectively, the
`first device's throughput is reduced to 1 Mbps (54 Mbps 1/
`55), Since it can only send one packet in the same time it
`normally would have sent 55 packets. Similarly, the second
`wireless device throughput is still 1 Mbps, but is slightly less
`since it must it must wait for the 54 Mbps packet (1
`Mbps*54/55). If the two effective throughputs are added
`together, the Sum is an aggregate link Speed of 2 Mbps.
`0007 To address this latency problem, it has been pro
`posed that the 802.11 Specification be changed So that a
`higher speed wireleSS device is able to transmit more data
`packets before the channel is released to a slower Speed
`wireless device. This so-called “Burst Mode” solution can
`be understood by reference to FIG. 2B, where the first
`wireless client device is enabled to transmit “N' 1500 byte
`data packets 30 at 54 Mbps before the wireless channel is
`made available to the Second, Slower wireleSS device to
`transmit one 1500 byte data packet 32 at the lower data rate.
`For example, when burst mode “N” is 10 packets, the
`effective throughput for the 54 Mbps device is improved
`from 1 Mbps to about 8.5 Mbps, but is still at only 16% of
`the nominal maximum. The 1 Mbps device throughput is
`decreased to about 0.8 Mbps, for a total aggregate link Speed
`of about 9.3 Mbps. Also, this solution requires the use of
`jitter buffers for data Storage of packets in order to "average
`
`DELL
`EXHIBIT 1008 - PAGE 11
`
`

`

`US 2004/0090924 A1
`
`May 13, 2004
`
`out the impact of Slower wireleSS devices on the data rate
`of higher Speed wireleSS devices.
`0008. A better approach would be to segregate wireless
`devices of the same general bandwidth requirements and
`payload types on independent wireleSS channels. For
`example, all of the wireleSS devices that transmit/receive at
`a slower Speed might be assigned to Channel A, while those
`that transmit/receive at a higher speed are assigned to
`Channel B. Channel A would thus have a high latency and
`low throughput, but Channel A would have a low latency
`and high throughput. Channel A would thus be more Suitable
`for transferring conventional web pages or audio data, while
`Channel B would be more suitable for transferring video
`data packets. Devices operating on either channel could
`approach a much higher efficiency, i.e., two devices com
`peting on a pure 54 Mbps channel withoutburst mode would
`each be 50% efficient. However, enabling communication
`between the wireleSS devices operating on the different
`channels createS problems for conventional wireleSS devices
`used on typical wireless networks. Wireless APs and wire
`less clients usually contain only one radio (transmitter/
`receiver) and are therefore only able to maintain one radio
`channel at a time. There is currently no provision in the art
`for Seamlessly communicating data packets between client
`devices that operate on different channels with a single
`radio.
`0009. Another problem that has not been addressed in the
`prior art is that wireless traffic from one wireless client to
`another wireleSS client on the same AP in an infrastructure
`network must travel first to the AP before reaching the
`intended client, causing the data to be transmitted and
`received twice. Further, all the wireless clients of the AP
`compete for the same bandwidth since they use the same
`wireleSS channel. These problems are particularly prevalent
`in Single AP networks, Such as homes or Small businesses,
`but can also be found in multiple AP networks. Typically, a
`wireless home network 10 with a single AP12 in infrastruc
`ture mode might appear as shown in FIG. 1A.
`0010. As shown in FIG. 1A, all of the clients are asso
`ciated with the AP on the same channel. In order for client
`1 to communicate with client 2, it must transmit to the AP
`first, and the AP must retransmit to client 2. Even if the link
`is unused, this arrangement effectively halves the through
`put, Since the data travels through the AP, and the AP cannot
`Simultaneously receive and transmit on the same channel.
`So, if client 1 and client 2 were both associated to the AP on
`channel 1 at a rate of 54 Mbps, the nominal maximum rate
`they can transmit to each other is 27 Mbps. Further, if one
`of the other clients is transmitting data at the same time, the
`transmission competes with the other clients on both “hops.”
`For example, if client 3 were transmitting during the time
`that client 1 is transmitting to client 2 via the AP, the
`throughput is degraded by another 50% on each hop, cre
`ating an overall throughput of about 13.5 Mbps. If both
`client 1 and 2 are within WireleSS range of one another, a
`better approach is for client 1 to transmit directly to client 2
`on a different independent channel at the full 54 Mbps. There
`is currently no provision in the art for an infrastructure
`network as shown in FIG. 1A to statically or dynamically
`allocate a new channel between clients 1 and 2 and Still
`remain a part of the network.
`0.011) A related problem that also has not been addressed
`in the prior art is the ability to automatically enable wireleSS
`
`devices to Selectively communicate in an infrastructure
`mode (like the exemplary conventional wireless network 10
`in FIG. 1) and in an ad hoc mode 36, as shown in FIG. 3.
`In the ad hoc mode, client 1 is directly in wireleSS commu
`nication with client 2, without need for an AP or base station
`to Serve as a central point to facilitate communication
`between the two wireless device. In the infrastructure mode,
`wireleSS client devices currently communicate with a
`Selected AP or a base Station on a Single channel, as shown
`in FIG. 1A. Also, in infrastructure mode, data packets
`communicated between a first wireleSS client device and a
`Second wireleSS client device must be transmitted through an
`AP or base station and then to the intended recipient. This
`centralized approach uses twice the bandwidth that would be
`required if the first wireleSS device were instead to commu
`nicate the data packets directly to the Second wireleSS client
`device in ad hoc mode. The first and Second wireleSS client
`devices currently cannot be automatically Selectively oper
`ated in the infrastructure mode or ad hoc mode. Instead, a
`user at each client wireleSS device typically manually
`employs a configuration program to change the mode in
`which the wireleSS client device is operating each time a
`change from one mode to the other is desired. Also, to avoid
`using the bandwidth of other wireless devices that are
`communicating in the infrastructure mode, two wireleSS
`devices that are communicating in the ad hoc mode should
`use a different channel than those communicating in the
`infrastructure mode, and this channel is typically manually
`Selected when manually changing the mode of a wireleSS
`device to the ad hoc mode.
`0012. The problems discussed above become more
`apparent when the existing wireleSS technology is used to
`address the new Quality of Service (QoS) standards being
`developed by the IEEE 802.11e Working Group. These new
`Standards provide methodologies for delivering end-to-end
`Streaming of data from Servers to clients. Practically Speak
`ing, deploying these new Standards using existing wireleSS
`equipment and communication techniques is a challenge.
`Also, engineering and testing a full end-to-end System
`capable of conveying Such a variety of data is a daunting
`task. A new technology or approach is needed to enable a
`modular and Smooth migration from legacy non-QoS sys
`tems to the full QoS systems of the future.
`0013 Thus, there is clearly a need for wireless data
`Systems that automate the Selection of channels and the
`wireleSS modes used, the determination as to whether to
`operate as an AP or a client device, and the data rates
`employed on Specific channels, to optimize the use of the
`available bandwidth as a function of the type of data being
`communicated and the needs of Specific wireleSS devices
`that are communicating. Currently, the IEEE 802.11 speci
`fication of itself does not provide an acceptable Solution to
`the problems discussed above, and the Solutions that have
`been proposed in the prior art to address these problems are
`either incomplete or inadequate.
`
`SUMMARY OF THE INVENTION
`In consideration of the inefficiency that exists in
`0014.
`current wireleSS networks with wireleSS devices having
`different data rate capabilities and the need to transfer
`different types of data, the present invention makes more
`effective use of the available bandwidth by enabling the
`wireleSS devices to connect directly to each other on an
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`May 13, 2004
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`independent wireleSS network, either temporarily or perma
`nently, for the purposes of increased QoS in data transferS.
`The present invention creates more efficient variations than
`the typical Star-topology with a wireleSS AP at the center and
`its wireleSS clients all communicating through the AP at the
`hub. Further, the present invention provides ways to create
`efficiencies without enhancing every element in the System,
`So that the wireleSS network can continue to operate with
`current state of the art devices. The devices are allowed to
`directly connect to each other in either ad hoc or infrastruc
`ture modes, as most appropriate, and also devices of like
`data rate are enabled to communicate, as appropriate for
`transferring Specific types of data. It is not necessary for a
`user to manually Selectively operate a wireleSS device in a
`particular mode when communicating with a Selected other
`wireleSS device, because the present invention automatically
`facilitates the communication protocol between two wireleSS
`devices when needed.
`0.015 A first aspect of the present invention is directed to
`a method for achieving a better use of available wireleSS
`communication bandwidth and is called "Smart Wireless
`Routing.” The Smart Wireless Routing method includes the
`Step of employing an infrastructure mode for wireleSS com
`munication between a wireless AP and a first wireless client
`device on a first wireleSS channel. In response to a need to
`communicate data between the first wireleSS client device
`and a Second wireleSS client device, a wireleSS communica
`tion with the second wireless client device is selectively
`automatically enabled in an ad hoc or infrastructure mode
`over a Second wireleSS channel that is at a different fre
`quency than the first wireleSS channel. If ad hoc mode is used
`for the Second wireleSS channel, the first wireleSS device is
`a peer of the Second wireleSS device and the mode of
`communication is called “Smart Wireless Routing Ad Hoc
`Mode.” If infrastructure mode is used, the first wireless
`device acts as a "Surrogate” AP for the Second wireleSS
`device and operates in “Smart Wireless Routing AP mode.
`Smart Wireless Routing AP mode has additional advantages
`compared to the ad hoc mode. For example, additional
`wireleSS devices beyond the Second wireleSS device can
`connect to the first wireleSS device. Also, if additional
`wireleSS devices do not Support an ad hoc connection, or
`cannot automatically Switch from operating as an infrastruc
`ture wireleSS client to an ad hoc peer-to-peer client, the first
`wireleSS device can operate in infrastructure mode as it did
`with the original AP Data are then communicated between
`the first wireleSS client device and the Second wireleSS client
`device over the Second wireleSS channel, using this new
`direct connection. This aspect of the present invention is
`clearly illustrated in a wireless network 10" in FIG. 1B.
`0016 AS was noted in the discussion of FIG. 1A, there
`are disadvantages in using the current State of the art when
`clients 1 and 2 need to exchange data. First if both remain
`associated to the AP, the effective bandwidth is halved
`because the data must travel on two “hops.” Second, if other
`wireleSS clients Such as clients 3, 4, 5, or 6 are communi
`cating at the same time that wireleSS clients 1 and 2 are in
`communication, there is competition for bandwidth and
`overall QoS is degraded. In the present invention, the first
`wireleSS client is designed to enable it to remain associated
`with the AP in infrastructure mode, while creating either a
`new independent ad hoc connection to a Second client or
`presenting itself as a "Surrogate” AP that provides an infra
`structure connection for other wireless clients. In FIG. 1B,
`
`client 1 is operating in Smart WireleSS Routing ad hoc mode
`with client 2, while client 5 is operating in Smart Wireless
`Routing AP mode with clients 4 and 6. This improvement
`alleviates the problems discussed above. First, data being
`communicated to the Smart Wireless Routing device form
`the Secondary clients does not require the extra “hop'
`through the AP. The bandwidth can the be fully utilized so
`that communication occurs at full Speed and is not halved.
`Second, the new wireleSS connection is on an independent
`channel So that wireless traffic from other clients does not
`compete for bandwidth or disturb the QoS. Further, the new
`wireless channels can optimize the link's QoS for the
`Specific type of data that is to be communicated. For
`example, if client 1 and client 2 commonly share bandwidth
`intensive media files, the QoS of the direct connection can
`be optimized for media streaming. If clients 4, 5, and 6
`commonly need low-latency gaming data to be exchanged,
`the QoS for that channel can be optimized for real-time
`gaming data.
`0017. The method also provides for simultaneous main
`tenance of two wireleSS connections on two independent
`channels in the first wireless client device with Smart
`Wireless Routing. The wireless device maintains one chan
`nel to the network AP (infrastructure mode) and another
`channel, either in “surrogate” AP (infrastructure) mode or in
`peer-to-peer (ad hoc) mode, to the Secondary wireless
`device(s). One channel is linked to the network AP (infra
`Structure mode) and another channel, with the first client
`device operating either in "Surrogate” AP (infrastructure)
`mode or in peer-to-peer (ad hoc) mode, linked to the Second
`wireless device. The first wireless client device with Smart
`WireleSS Routing can Subsequently be automatically
`changed to operate in the ad hoc mode for retransmitting
`buffered data packets that have previously been received by
`the first wireless client device from the wireless AP, to the
`Second client wireless device. The first wireless client device
`can be automatically changed to operate in the infrastructure
`mode for retransmitting buffered data packets to the wireleSS
`AP that have previously been received by the first wireless
`client device from the Second wireleSS client device.
`0018. It may be that the second wireless client device is
`unable to directly communicate with the wireless AP at an
`acceptable data rate, e.g., due to intervening structural
`elements or because of distance. Instead, the present inven
`tion enables the Second wireleSS client device to communi
`cate with the wireless AP indirectly through the first client
`wire device. A different data rate can be employed for the
`communication between the wireless AP and the first wire
`leSS client device, than for the communication between first
`wireleSS client device and the Second client device.
`0019. Different QoS link properties can be employed for
`communicating different type of data packets between the
`first wireleSS client device and the Second wireleSS client
`device, than for the type of data packets communicated
`between the wireless AP and the first wireless client device,
`and may also be used for communicating different size of
`data packets between the first wireleSS client device and the
`Second wireless client device, than between the wireless AP
`and the first wireless client device.
`0020 Optionally, a plurality of different wireless trans
`mitters/receivers can be employed at the first wireleSS client
`device. In this case, one wireless transmitter/receiver is
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`US 2004/0090924 A1
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`Selectively Set to operate in the infrastructure mode on the
`first wireleSS channel, and the other wireleSS transmitter/
`receiver is Selectively Set to operate in infrastructure or ad
`hoc mode on the second wireless channel. The method then
`further includes the Step of transmitting instructions from the
`wireless AP to the first wireless client device to control
`operation of each wireleSS transmitter/receiver.
`0021 Another important function of the present inven
`tion is the ability to Selectively operate a wireleSS device
`either as a client device or Station that communicates with an
`AP or as an AP that manages its own Set of client devices or
`Stations. In a wireleSS network, additional APS can option
`ally be used, So that each AP preferably operates on a
`different wireleSS channel and is Selectively coupled in
`communication with an external network over either a wire
`or a wireleSS link.
`0022. The method further includes the step of providing
`a plurality of Servers that are each Selectively automatically
`coupled in communication with an external network when
`communication with the external network is required. Data
`Stored on the Servers are then wirelessly communicated to
`wireless client devices from the servers over different wire
`leSS channels. The ServerS also preferably communicate with
`different wireless client devices on the different wireless
`radio channels using at least one of a plurality of different
`types of data, different sizes of data packets, different data
`rates, and different wireleSS communication Standards. Each
`of the plurality of ServerS Selectively communicates with an
`AP using the infrastructure mode and the first wireless
`channel, when communication with the external network is
`required.
`0023. Another aspect of the present invention is directed
`to a memory medium Storing machine readable instructions
`for carrying out the Steps of the method discussed above.
`0024. Still another aspect of the present invention is
`directed to a wireless AP that controls wireless client devices
`so as to efficiently use available bandwidth for wireless
`communications over a network. The wireless AP includes
`a memory in which machine instructions are Stored, a
`wireleSS transmitter and receiver, which are capable of
`transmitting on a plurality of different wireleSS channels, and
`a processor that is coupled to the memory and which
`executes the machine instructions to carry out a