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`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 1 of 28
`
`EXHIBIT 6
`EXHIBIT 6
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 2 of 28
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US007903608B2
`
`c12) United States Patent
`Gan et al.
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 7 ,903,608 B2
`*Mar. 8, 2011
`
`(54) APPROACH FOR MANAGING THE USE OF
`COMMUNICATIONS CHANNELS BASED ON
`PERFORMANCE
`
`(75)
`
`Inventors: Hongbing Gan, Carlton North (AU);
`Bijan Treister, Kew (AU); Efstratios
`Skafidas, Coburg (AU)
`
`(73) Assignee: Bandspeed, Inc., Austin, TX (US)
`
`GB
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 43 days.
`
`This patent is subject to a terminal dis(cid:173)
`claimer.
`
`(21) Appl. No.: 12/352,595
`
`(22) Filed:
`
`Jan.12,2009
`
`(65)
`
`Prior Publication Data
`
`US 2009/0122837 Al
`
`May 14, 2009
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 11/397,443, filed on
`Apr. 3, 2006, now Pat. No. 7,477,624, which is a
`continuation of application No. 09/948,488, filed on
`Sep. 6, 2001, now Pat. No. 7,027,418.
`
`(60) Provisional application No. 60/264,594, filed on Jan.
`25, 2001.
`
`(51)
`
`Int. Cl.
`(2009.01)
`H04W 4100
`(52) U.S. Cl. ........................................................ 370/329
`(58) Field of Classification Search ........... 370/328-339
`See application file for complete search history.
`
`(56)
`
`References Cited
`
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`Primary Examiner - Frank Duong
`(74) Attorney, Agent, or Firm -Hickman Palermo Truong
`& Becker LLP; Samuel S. Broda
`
`(57)
`
`ABSTRACT
`
`An approach for selecting sets of communications channels
`involves determining the performance of communications
`channels. A set of channels is selected based on the results of
`performance testing and specified criteria. The participant
`generates data that identifies the selected set of channels and
`provides that data to other participants of the communications
`network. The participants communicate over the set of chan(cid:173)
`nels, such as by using a frequency hopping protocol. When a
`specified time expires or monitoring of the performance of the
`channel set identifies poor performance of the set of channels,
`the participant selects another set of channels for use in com(cid:173)
`munications based on additional performance testing. By
`selecting channels based on the initial performance testing
`and performance monitoring, the communications network
`adaptively avoids channels with poor performance.
`
`5 Claims, 11 Drawing Sheets
`
`COMMUNICATIONS NETWOOK.200
`
`MASTER.2111
`
`I "MCR\12 I
`I TRANSCEIVER
`I
`
`I PROCE&Sffilli I
`m I
`I
`
`SLAVE.22D.
`
`SLAVE.23_0_
`
`1
`
`222
`
`I MEMORY
`I PROCESSO~ I
`I TRPNSCEI~ I
`
`I ME"°"Y 2321
`I PROCESSOR 231 I
`I TRmSCE"':a, I
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 3 of 28
`
`US 7,903,608 B2
`Page 2
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`.... 455/63.2
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`OTHER PUBLICATIONS
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`"Multiuser OFDM", by E. Lawrey, (pp. 761-764).
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`15 .3 Standard," Project IEEE P802 .15 Working Group for Wireless
`Personal Area Networks (WPANs), Sep. 2000, XP 00220853, pp .
`1-57.
`Jeyhan Karaoguz, "Multi-Rate QAM Physical Layer (8-40 Mbps)
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`Group for Wireless Personal Area Networks (WPANs), Oct. 20,
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`"Clean Version of Amended Claims for Response to Official Comm.
`From Patent Examiner," EPO Patent Application No. 02709170.1,
`pp. 1-15, 2004.
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`pp. 1-5, ICICS '99.
`Gan et al., Adaptive Frequency Hopping Implementation Proposals
`forIEEE 802.15 Y2WPAN, pp. 1-28 Nov. 2000, downloaded at http://
`grouper.ieee. org/ groups/ 802/15 /pub/2 000 IN ovOO /0036 7 rO P80 2-
`15_TG2-Adaptive-Frequency -Hopping.ppt.
`The International Bureau ofWIPO, "Notification Concerning Trans(cid:173)
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`ing date Jul. 12, 2010.
`* cited by examiner
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 4 of 28
`
`U.S. Patent
`
`Mar.8,2011
`
`Sheet 1of11
`
`US 7 ,903,608 B2
`
`100
`
`I
`
`DETERMINE PERFORMANCE OF
`COMMUNICATIONS CHANNELS
`110
`
`SELECT A SET OF COMMUNICATIONS
`CHANNELS
`lli
`
`REDETERMINE PERFORMANCE OF
`COMMUNICATIONS CHANNELS
`.118
`
`SELECT A NEW SET OF
`COMMUNICATIONS CHANNELS
`122
`
`Cl~ '1 A
`I IU1 II"'\
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 5 of 28
`
`U.S. Patent
`
`Mar.8,2011
`
`Sheet 2of11
`
`US 7 ,903,608 B2
`
`SELECT A NEW SET OF
`COMMUNICATIONS CHANNELS
`142
`
`GENERATE NEW DATA THAT
`IDENTIFIES THE NEW SET OF
`COMMUNICATIONS CHANNELS
`144
`
`PROVIDE THE NEW
`IDENTIFICATION DATA TO THE
`PARTICIPANT
`
`146
`
`COMMUNICATE WITH THE
`PARTICIPANT OVER THE NEW SET
`OF COMMUNICATIONS CHANNELS
`148
`
`DETERMINE PERFORMANCE
`DATA OF COMMUNICATIONS
`CHANNELS
`13.Q_
`I
`SELECT A SET OF
`COMMUNICATIONS CHANNELS
`132
`
`I
`GENERA TE CHANNEL
`IDENTIFICATION DATA THAT
`IDENTIFIES THE SET OF
`COMMUNICATIONS CHANNELS
`1M
`
`I
`PROVIDE THE CHANNEL
`IDENTIFICATION DATA TO THE
`PARTICIPANT
`I
`COMMUNICATE WITH THE
`PARTICIPANT OVER THE SET OF
`COMMUNICATIONS CHANNELS
`13..8.
`
`136
`
`I
`REDETERMINE THE
`PERFORMANCE OF THE
`COMMUNICATIONS CHANNELS
`14.Q_
`
`I
`
`FIG. 1 B
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 6 of 28
`
`U.S. Patent
`
`Mar.8,2011
`
`Sheet 3of11
`
`US 7 ,903,608 B2
`
`COMMUNICATIONS NETWORK 2QQ
`
`MASTER.210_
`
`MEMORY
`212
`
`PROCESSOR
`214
`
`I TRANSCEIVER
`
`216 I
`
`SLAVE 220
`
`MEMORY
`222
`
`PROCESSOR
`224
`
`TRANSCEIVER
`226
`
`SLAVE 230
`
`MEMORY
`
`232
`
`PROCESSOR
`23A
`
`TRANSCEIVER
`236_
`
`FIG. 2
`
`

`

`

`

`

`

`

`

`

`

`

`

`

`

`

`

`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 15 of 28
`
`US 7,903,608 B2
`
`1
`APPROACH FOR MANAGING THE USE OF
`COMMUNICATIONS CHANNELS BASED ON
`PERFORMANCE
`
`PRIORITY CLAIMS AND RELATED
`APPLICATIONS
`
`5
`
`This application claims domestic priority under 35 U.S.C.
`§120 as a continuation of U.S. non-provisional application
`Ser. No. 11/397,443, filed Apr. 3, 2006, now U.S. Pat. No.
`7,477,624 entitled "APPROACH FOR MANAGING THE
`USE OF COMMUNICATIONS CHANNELS BASED ON
`PERFORMANCE," naming Hongbing Gan, Bijan Treister,
`and Efstratios Skafidas as inventors, which in tum claims
`domestic priority under 35 U.S.C. §120 as a continuation of
`U.S. non-provisional application Ser. No. 09/948,488, filed
`Sep. 6, 2001, now U.S. Pat. No. 7,027,418 entitled
`"APPROACH FOR SELECTING COMMUNICATIONS
`CHANNELS BASED ON PERFORMANCE," naming
`Hongbing Gan, Bijan Treister, and Efstratios Skafidas as
`inventors, which in turn claims domestic priority from prior
`U.S. Provisional Patent Application Ser. No. 60/264,594,
`filed on Jan. 25, 2001, titled "ADAPTIVE FREQUENCY
`HOPPING-A COEXISTENCE MECHANISM FOR A
`FREQUENCY HOPPING COMMUNICATION SYSTEM 25
`TO COEXIST WITH NON-FREQUENCY-HOPPING
`COMMUNICATION SYSTEMS SHARING THE SAME
`FREQUENCY BAND," naming as inventors Hongbing Gan,
`Bijan Treister, and Efstratios Skafidas, the entire disclosures
`of both of which is hereby incorporated by reference for all
`purposes as if fully set forth herein.
`This application is related to: (1) non-provisional applica(cid:173)
`tion Ser. No. 10/052,019, filed Jan. 16, 2002, and issued as
`U.S. Pat. No. 7,222,166 on May 22, 2007, entitled
`"APPROACH FOR MANAGING COMMUNICATIONS
`CHANNELS BASED ON PERFORMANCE AND TRANS(cid:173)
`FERRING FUNCTIONS BETWEEN PARTICIPANTS IN A
`COMMUNICATIONS ARRANGEMENT," naming Bijan
`Treister, Hong bing Gan, and Efstratios Skafidas as inventors,
`(2) co-pending non-provisional application Ser. No. 09/948, 40
`499, filed Sep. 6, 2001, entitled "APPROACH FOR MAN(cid:173)
`AGING COMMUNICATIONS CHANNELS BASED ON
`PERFORMANCE," naming Bijan Treister, Hongbing Gan,
`and Efstratios Skafidas as inventors, and (3) non-provisional
`application Ser. No. 09/939,105, filed Aug. 24, 2001, and
`issued as U.S. Pat. No. 7,310,661 on Dec. 18, 2007, entitled
`"APPROACH FOR TRANSFERRING FUNCTIONS
`BETWEEN PARTICIPANTS IN A COMMUNICATIONS
`ARRANGEMENT," naming Bijan Treister, Hongbing Gan,
`and Efstratios Skafidas as inventors.
`
`FIELD OF THE INVENTION
`
`2
`participants. As used herein, the term "participant" refers to a
`device or mechanism that communicates with other devices
`or mechanisms. In some communications network arrange(cid:173)
`ments, one of the participants is designated as a master par-
`ticipant, or simply as the "master." The master generally
`initiates and controls communications with the other partici(cid:173)
`pants, which are conventionally referred to as slave partici(cid:173)
`pants, or simply as "slaves." Masters may also be assigned
`other functions to perform. Although a master participant
`10 typically performs additional functions than the other partici(cid:173)
`pants, any participant is capable of performing these func(cid:173)
`tions if elected as the master participant.
`A frequency hopping (FH) protocol is an approach for
`wireless communications in a communications network that
`15 uses a frequency hopping signal transmission technique in
`which information or data is transmitted over a set of frequen(cid:173)
`cies in a communications frequency band. A frequency hop(cid:173)
`ping communications system is a system that uses a FH
`protocol. The order in which the communications network
`20 hops among the set of frequencies is known as the hopping
`sequence.
`In contrast to FH systems, a non-frequency hopping (NFH)
`system is simply a communications system whose carrier
`does not hop over a set of frequencies. A typical NFH system
`may occupy a portion of the communications frequency band
`corresponding to several frequencies used by an FH system.
`With the FH approach, the frequency band is broken up
`into separate frequencies, often referred to as "channels." The
`FH system transmits data on one channel, hops to the next
`30 channel in the hopping sequence to transmit more data, and
`continues by transmitting data on subsequent channels in the
`hopping sequence. The switching of frequencies may occur
`many times each second. The use of an FH protocol helps to
`reduce problems with interference from other communica-
`35 tions systems and other interference sources. Frequency hop(cid:173)
`ping also helps with fading of transmissions and power con(cid:173)
`sumption and also provides security for the transmission so
`that others may not intercept the data being transmitted
`because others do not know the hopping sequence.
`An example of a frequency hopping protocol is the Institute
`of Electrical and Electronics Engineers (IEEE) 802.15.1
`Wireless Personal Area Network Standard, which is based on
`the Bluetooth™ wireless personal area network (WPAN)
`technology from the Bluetooth Special Interest Group. The
`45 BLUETOOTH trademarks are owned by Bluetooth SIG, Inc.,
`U.S.A. The Bluetooth protocol uses 79 individual randomly
`chosen frequency channels numbered from 0 to 78 and
`changes the frequencies 1600 times per second. Examples of
`NFH systems include the IEEE 802 .11 b Wireless Local Area
`50 Network (WLAN) and the IEEE 802.15.3 next-generation
`WPAN, both of which operate in the 2.4 GHz Industrial,
`Scientific, Medical (ISM) band, which is an unlicensed por(cid:173)
`tion of the radio spectrum that may be used in most countries
`by anyone without a license
`An FH communications system may be either point-to(cid:173)
`point, meaning that communications paths are provided from
`one participant to another participant, or point-to-multipoint,
`meaning that communications paths are provided from one
`participant to multiple participants.
`Typically one device of the network, such as the master,
`determines the hopping sequence that will be used by all
`participants of the network. The other participants of the
`network, such as slaves, are time synchronized with the mas(cid:173)
`ter to maintain communications with the master. For example,
`65 the Bluetooth and IEEE 802.15.1 frequency hopping proto(cid:173)
`cols are point-to-multipoint systems in which the frequency
`hopping sequence is determined by the physical address of
`
`The present invention generally relates to communications
`systems, and more particularly to managing the use of com- 55
`munications channels based on channel performance.
`
`BACKGROUND
`
`The approaches described in this section are approaches 60
`that could be pursued, but not necessarily approaches that
`have been previously conceived or pursued. Therefore, unless
`otherwise indicated, the approaches described in this section
`are not prior art to the claims in this application and are not
`admitted to be prior art by inclusion in this section.
`A communications network is any system or mechanism
`that provides forthe exchange ofinformation or data between
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 16 of 28
`
`US 7,903,608 B2
`
`3
`the master and the phase of hopping is determined by the
`master's clock. The "physical address" of the master is a
`unique identifier, such as a media access control (MAC)
`address, that identifies the device anywhere in the world on a
`network.
`Some FH communications system are configured such that
`certain devices transmit at specified times or timeslots. For
`example, slaves may respond to the master at assigned
`timeslots. As another example, in a Bluetooth FH communi(cid:173)
`cations system, the master may transmit at even-numbered 10
`timeslots on the hopping sequence and the slaves listen at
`those regular intervals. The master will address one slave (or
`all slaves in a "broadcast" mode), and the addressed slave
`returns back to the master at the next odd-numbered timeslot.
`A preamble, which is known to all the participants of the 15
`FH network, is used to identify the network and for the slaves
`to synchronize with the master. For example, inB!uetoothand
`IEEE 802.15.1, the known preamble is called the "channel
`access code."
`One problem with frequency hopping communications 20
`systems is that coexistence problems arise between the FH
`communications system and NFH communications systems
`that operate in the same frequency band. While the FH com(cid:173)
`munications system hops over the entire frequency band, the
`NFH communications systems occupy separate parts of the 25
`frequency band. When the FH communications system hops
`over part of the frequency band occupied by an NFH com(cid:173)
`munications system, there may be interference between the
`systems. Although the use of a FH protocol helps to lessen the
`interference problem because not all of the FH channels will 30
`interfere with other communications systems, there neverthe(cid:173)
`less remains interference on those channels that coincide with
`the NFH communications systems. An example of the inter(cid:173)
`ference situation is the coexistence problem between the fre(cid:173)
`quency hopping IEEE 802.15.1 WPAN and the non-fre- 35
`quency hopping IEEE 802.11 b Wireless Local Area Network
`(WLAN) because both share the 2.4 GHz ISM band.
`Further, because of the dynamic nature of interference due
`to the use of devices at different times and locations, eventu(cid:173)
`ally all FH charmels will experience some degree of interfer- 40
`ence at some time. Interference may change depending on
`when the communications systems use the band and the rela(cid:173)
`tive locations of the participants of each system to partici(cid:173)
`pants of another system. Because the participants may be
`mobile, interference may vary depending on the movements 45
`of the participants of one system relative to the locations of
`participants of other systems. In addition, interference may
`arise from other sources, such as some consumer appliances
`like microwave ovens, resulting in a degradation of perfor(cid:173)
`mance of the FH communications system.
`Interference results in data transmission errors, such as an
`increase in the bit error rate (BER) or the loss of data packets,
`resulting in reduced transmission quality and performance
`and the need to retransmit the data.
`One approach for managing the coexistence problem is to 55
`increase the power used in the transmissions so that the other
`interfering system have less of an impact on the system trans(cid:173)
`mitting at the increased power. However, this increased power
`approach drains batteries used by the participants, and thus
`the required power increase may be impractical. Also, the
`increased power approach only benefits the system using the
`increased power and results in a bigger interference impact on
`other systems.
`Another approach for managing the coexistence problem is
`to skip a "bad" channel that suffers from interference, such as
`by moving onto the next channel in the sequence or by jump(cid:173)
`ing to another randomly selected channel. However, this skip-
`
`4
`ping approach does not necessarily avoid other bad charmels
`because the next channel used may also have an interference
`problem. Also, known "bad" and "good" channels may
`change over time due to the transient nature of some types of
`interference.
`Based on the need for wireless communications and the
`limitations of conventional approaches, an approach for man(cid:173)
`aging interference in communications system, such as the
`coexistence problem between frequency hopping communi(cid:173)
`cations systems and non-frequency hopping communications
`systems, that does not suffer from the limitations of the prior
`approaches is highly desirable.
`
`SUMMARY OF THE INVENTION
`
`Techniques are provided for selecting sets of communica(cid:173)
`tions channels based on charmel performance. According to
`one aspect of the invention, a method selects communications
`channels for a communications system. A set of communica(cid:173)
`tions charmels is selected based on the performance of the
`communications charmels and channel selection criteria.
`Then another set of communications channels is selected
`based on a later performance of the communications charmels
`and the charmel selection criteria.
`According to another aspect of the invention, a method is
`provided for communicating with a participant. A set of com(cid:173)
`munications channels is selected based on the performance of
`the communications channels and a performance criterion.
`Identification data that identifies the set of communications
`channels is generated and provided to the participant. The set
`of communications charmels is used for communicating with
`the participant according to a frequency hopping protocol.
`According to other aspects, another set of communications
`channels is selected in a similar manner when a specified
`criterion is satisfied, including but not limited to, after expi(cid:173)
`ration of a specified length of time, when the performance of
`at least one of the channels in the set of channels satisfies
`another performance criterion, or when a specified number of
`the set of channels satisfies yet another performance criterion.
`According to one aspect of the invention, a communica-
`tions device is used in a network that communicates via a
`frequency hopping protocol. The communications device
`includes a memory that has identification data that identifies
`a set of communications channels that is selected based on
`channel performance and a performance criterion. The com(cid:173)
`munications device includes a transceiver that is communi(cid:173)
`catively coupled to the memory and that is configured to
`transmit and receive, based on the identification data, over the
`set of charmels, according to a frequency hopping protocol.
`50 The communications device includes a processor for gener(cid:173)
`ating a measurement of channel performance based on receiv(cid:173)
`ing a packet from another device and transmitting another
`packet to the other device that contains data indicating the
`measurement of charmel performance.
`According to another aspect, another communications
`device is used in a network that communicates via a frequency
`hopping protocol. The communications device includes a
`memory for storing sequences of instructions and a processor
`communicatively coupled to the memory. When the proces-
`60 sor executes the instructions, the instructions cause the pro(cid:173)
`cessor to determine the performance of communications
`channels and then select a set of charmels based on the per(cid:173)
`formance and a performance criterion. The processor gener(cid:173)
`ates and stores in the memory data that identifies the set of
`65 channels and transmits the data to another communications
`device. The communications device includes a transceiver
`that is communicatively coupled to the memory and that is
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 17 of 28
`
`US 7,903,608 B2
`
`6
`In the following description, various embodiments of the
`invention are described in the following sections:
`I. OVERVIEW
`II. TESTING CHANNEL PERFORMANCE
`A. Special Test Packets
`B. Received Signal Strength Indicator (RSSI)
`C. Preamble Correlation
`D. Header Error Check (HEC)
`E. Cyclic Redundancy Check (CRC)
`F. Packet Loss Ratio (PLR)
`G. Forward Error Correction (FEC)
`H. Other Channel Performance Testing Considerations
`III. CHANNEL CLASSIFICATION
`IV. COMMUNICATING SELECTED CHANNELS TO
`PARTICIPANTS
`V. IMPLEMENTING ADAPTIVE FREQUENCY HOP(cid:173)
`PING
`VI. MONITORING CHANNELS
`VII. MESSAGE SEQUENCING AND EXAMPLE
`IMPLEMENTATION
`VIII. IMPLEMENTATION MECHANISMS
`
`I. Overview
`
`5
`configured to transmit and receive, based on the data, over the
`set of channels according to a frequency hopping protocol.
`According to another aspect of the invention, a communi(cid:173)
`cations channel selector apparatus is provided. The apparatus
`is configured to determine channel performance at one time
`and select based on that performance a set of channels based
`on channel selection criteria. The apparatus is configured to
`then determine the channel performance at a later time and
`select another set of channels based on that latter performance
`and the channel selection criteria.
`According to other aspects, the invention encompasses a
`system, a computer-readable medium, and a carrier wave
`configured to carry out the foregoing functions.
`
`10
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`15
`
`20
`
`The present invention is depicted by way of example, and
`not by way oflimitation, in the figures of the accompanying
`drawings and in which like reference numerals refer to similar
`elements and in which:
`FIG. lA is a flow diagram that depicts an approach for
`selecting sets of communications channels based on channel
`performance, according to an embodiment of the invention;
`FIG. lB is a flow diagram that depicts an approach for
`communicating with a participant using a set of good chan- 25
`nels, selected according to an embodiment of the invention;
`FIG. 2 is a block diagram that depicts a communications
`network, according to an embodiment of the invention;
`FIG. 3A is a block diagram that depicts an example format
`of a standard packet, according to an embodiment of the 30
`invention;
`FIG. 3B is a block diagram that depicts a master test packet
`that is sent by a master to slaves to test channel performance,
`according to an embodiment of the invention;
`FIG. 3C is a block diagram that depicts a slave test packet 35
`that is sent by a slave to a master to provide channel perfor(cid:173)
`mance measurements and to test channel performance,
`according to an embodiment of the invention;
`FIG. 4 is a block diagram that depicts a good channel
`packet sent by a master to slaves to identify a set of selected 40
`channels, according to an embodiment of the invention;
`FIG. SA is a block diagram that depicts the loading of a set
`of channels into a channel register, according to an embodi(cid:173)
`ment of the invention;
`FIG. SB is a block diagram that depicts the replacement of 45
`bad channels with good channels in a default set of channels
`in a channel register, according to an embodiment of the
`invention;
`FIGS. 6A, 6B, and 6C are flow diagrams that depict
`example message sequencing for implementing adaptive fre(cid:173)
`quency hopping, according to an embodiment of the inven(cid:173)
`tion; and
`FIG. 7 is a block diagram that depicts a computer system
`upon which embodiments of the invention may be imple(cid:173)
`mented.
`
`A novel approach for managing network communications
`generally involves selecting sets of communications channels
`based on channel performance. An initial set of channels is
`selected based on one or more selection criteria at the start-up
`of the communications network. Additional sets of channels
`are then periodically selected to adaptively avoid interfer-
`ence.
`FIG. lA is a flow diagram that depicts an approach for
`selecting sets of communications channels based on channel
`performance, according to an embodiment of the invention.
`In block 110, the performance of a set of available commu-
`nications channels is determined. For example, for a commu(cid:173)
`nications system that uses 100 channels, some or all of the
`100 channels may be tested to determine channel perfor(cid:173)
`mance. Other systems using the same frequency band may
`interfere with several of the 100 channels.
`In block 114, a set of communications channels to be used
`is selected based on the channel performance determined in
`block 110, one or more performance criteria, and one or more
`selection criteria. For example, a communications system
`may experience interference on channels 3 through 5 from
`one communications system and on channels 50 through 54
`from another communications system. The channel testing
`may indicate a high bit error rate (BER) on those channels.
`50 Channels may be classified by comparing the test results to
`the performance criteria. For example, the performance cri(cid:173)
`teria may be a specified value, or a specified threshold. If the
`BER for a channel exceeds the specified threshold, the chan(cid:173)
`nel is classified as "good," whereas channels with a BER that
`55 does not exceed the specified threshold are classified as
`"bad." The reason why a bad channel's performance does
`exceed the specified threshold may be due to a variety of
`reasons, including but not limited to, the channel being used
`by another communications system or noise from other inter-
`60 ference sources, such as microwave ovens.
`After classifying the performance of the channels, a set of
`channels is selected based on the selection criteria. For
`example, the selection criteria may be to select the good
`channels but not the bad channels. Thus, by selecting the set
`of good communications channels, the communications sys(cid:173)
`tem performing the channel selection may avoid interference
`present on the bad channels.
`
`DETAILED DESCRIPTION
`
`An approach for selecting sets of communications chan(cid:173)
`nels based on channel performance is described. In the fol(cid:173)
`lowing description, for the purposes of explanation, numer(cid:173)
`ous specific details are set forth in order to provide a thorough
`understanding of the present invention. It will be apparent,
`however, that the present invention may be practiced without
`these specific details. In other instances, well-known struc- 65
`tures and devices are depicted in block diagram form in order
`to avoid unnecessarily obscuring the present invention.
`
`

`

`Case 1:20-cv-00765-DAE Document 40-6 Filed 10/17/22 Page 18 of 28
`
`US 7,903,608 B2
`
`7
`Although this example describes the use of a particular
`type of performance criteria to classify channels and particu(cid:173)
`lar type of selection criteria to select from the classified chan(cid:173)
`nels, other approaches may be used to select a set of channels.
`For example, channels may be selected based on comparing
`performance results to one or more criteria without first clas(cid:173)
`sifying the channels. Also, other criteria may be used, for
`example, that particular channels are, or are not, to be selected
`regardless of the test results.
`In block 118, the performance of the communications
`channels is determined again by additional testing. This addi(cid:173)
`tional testing may be initiated according to a specified sched(cid:173)
`ule, such as the expiration of specified time period, or the
`additional testing may be initiated as a result of monitoring
`and detecting new interference among the selected set of
`channels, such as from another communications system that
`previously did not cause interference. For example, in the
`communications system example above, the additional test(cid:173)
`ing may be performed over some or all of the original 100
`channels.
`In block 122, a new set of communications channels is
`selected based on the channel performance determined in
`block 118 in a manner similar to that of block 114 above. For
`example, the new set of channels may be based on selecting
`channels that are good when the additional testing of block
`118 is performed. The new set of channels may be different
`than the good channels selected in block 112 because new
`interference typically may be present from other systems that
`were not being used at the time of the first testing of block 110
`or that were not in sufficient proximity at the time of the first 30
`testing of block 110 to cause sufficient interference to result in
`the channels being classified as bad.
`According to other aspects of the invention, the determi(cid:173)
`nation and re-determination of channel performance depicted
`by blocks 110and118 may be performed by a different entity 35
`or device than the selection of the channels depicted in blocks
`11