Trials@uspto.gov
`571-272-7822
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` Paper 25
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`Entered: March 10, 2014
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`BROADCOM CORPORATION
`Petitioner
`
`v.
`
`TELEFONAKTIEBOLAGET L. M. ERICSSON
`Patent Owner
`
`
`Case IPR2013-00636
`Patent 6,424,625
`
`
`
`Before KARL D. EASTHOM, KALYAN K. DESHPANDE, and
`MATTHEW R. CLEMENTS, Administrative Patent Judges.
`
`
`CLEMENTS, Administrative Patent Judge.
`
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
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`571-272-7822
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` Paper 25
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`Entered: March 10, 2014
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`BROADCOM CORPORATION
`Petitioner
`
`v.
`
`TELEFONAKTIEBOLAGET L. M. ERICSSON
`Patent Owner
`
`
`Case IPR2013-00636
`Patent 6,424,625
`
`
`
`Before KARL D. EASTHOM, KALYAN K. DESHPANDE, and
`MATTHEW R. CLEMENTS, Administrative Patent Judges.
`
`
`CLEMENTS, Administrative Patent Judge.
`
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
`
`
`
`
`
`
`
`Case IPR2013-00636
`Patent 6,424,625
`
`
`I.
`
`INTRODUCTION
`
`Broadcom Corporation (“Petitioner”) filed a petition requesting inter
`
`partes review of claim 1 of U.S. Patent No. 6,424,625 (Ex. 1001, “the ’625
`
`patent”). Paper 3 (“Pet.”). Telefonaktiebolaget L. M. Ericsson (“Patent
`
`Owner”) filed an election to waive its preliminary response. Paper 19. We
`
`have jurisdiction under 35 U.S.C. § 314.
`
`The standard for instituting an inter partes review is set forth in
`
`35 U.S.C. § 314(a), which provides as follows:
`
`THRESHOLD.—The Director may not authorize an inter
`partes review to be instituted unless the Director determines
`that the information presented in the petition filed under section
`311 and any response filed under section 313 shows that there
`is a reasonable likelihood that the petitioner would prevail with
`respect to at least 1 of the claims challenged in the petition.
`
`Upon consideration of the petition, we determine that the information
`
`presented by Petitioner establishes that there is a reasonable likelihood that
`
`Petitioner would prevail in showing unpatentability of claim 1 of the ’625
`
`patent. Accordingly, pursuant to 35 U.S.C. § 314, we institute an inter
`
`partes review of claim 1 of the ’625 patent.
`
`A. Related Proceedings
`
`Petitioner and Patent Owner indicate that the ’625 patent is involved
`
`in a case captioned Ericsson Inc., et al. v. D-LINK Corp., et al., Civil Action
`
`No. 6:10-cv-473 (E.D. Tex.) (“Texas Litigation”). Pet. 1-2; Paper 6 at 1.
`
`Patent Owner also identifies an appeal at the Federal Circuit captioned
`
`Ericsson Inc., et al. v. D-LINK Corp., et al., Case Nos. 2013-1625, -1631,
`
`-1632, and -1633. Paper 6 at 1. Petitioner also has filed two petitions for
`
`2
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`Case IPR2013-00636
`Patent 6,424,625
`
`inter partes review of related patents: IPR2013-00601 (U.S. Patent No.
`
`6,772,215), IPR2013-00602 (U.S. Patent No. 6,466,568). Pet. 2.
`
`B. The ’625 patent
`
`The ’625 patent relates generally to Automatic Repeat Request (ARQ)
`
`techniques for transferring data in fixed/wireless data networks. Ex. 1001,
`
`col. 1, ll. 7-9. ARQ techniques are commonly used in data networks to
`
`ensure reliable data transfer and to protect data sequence integrity. Id. at
`
`ll. 13-15. The integrity of data sequence is normally protected by
`
`sequentially numbering packets and applying certain transmission rules. Id.
`
`at ll. 20-22. By doing so, the receiver receiving packets can detect lost
`
`packets and thereby request that the transmitter retransmit the affected data
`
`packets. Id. at ll. 15-20. According to the ’625 patent, there were three
`
`main ARQ schemes: Stop-and-Wait; Go-Back-N; and Selective Reject. Id.
`
`at ll. 23-25. All three provide a mechanism for transferring packets to a
`
`receiver in a data network in an appropriate order. Id. at ll. 25-27.
`
`Normally, it is desirable to transfer all packets without data loss. Id.
`
`at col. 3, ll. 46-47. Sometimes, however, sending significantly delayed
`
`packets provides no benefit—e.g., where the delay causes the information in
`
`the packets to become outdated and therefore useless to the receiver. Id. at
`
`ll. 47-51. Examples of delay-sensitive applications are, e.g., telephony,
`
`video conferencing, and delay-sensitive control systems. Id. at ll. 51-53.
`
`According to the ’625 patent, prior art ARQ methods did not recognize and
`
`allow for situations where data packets have a limited lifetime and therefore
`
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`Case IPR2013-00636
`Patent 6,424,625
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`fail to minimize bandwidth usage by not sending (or resending) significantly
`
`delayed or outdated data packets. Id. at col. 4, ll. 9-13.
`
`To address these issues, the ’625 patent discloses an ARQ technique
`
`that minimizes bandwidth usage by accounting for data packets that have an
`
`arbitrary but limited lifetime. Id. at col. 4, ll. 16-19. Exemplary
`
`embodiments of the invention include enhanced “Go-Back-N” and
`
`“Selective Reject” techniques that discard outdated data packets. Id. at
`
`ll. 21-25. In an exemplary embodiment of the invention, the progress of a
`
`bottom part of a sender window of the transmitter is reported to the receiver
`
`in order to allow the receiver to properly skip packets which do not exist
`
`anymore because they have been discarded. Id. at col. 5, ll. 15-21. Thus,
`
`the receiver can be commanded to skip or overlook the packets that have
`
`been discarded or, in other words, to release any expectation of receiving the
`
`packets that have been discarded. Id. at ll. 22-27. In the case where the
`
`transmitter discards a packet, it orders the receiver to accept the next packet
`
`by setting a Receiver Packet Enforcement Bit (“RPEB”) in the ARQ header
`
`of the next packet and sending the packet to the receiver. Id. at ll. 28-32.
`
`When the receiver receives the packet, the RPEB will cause the receiver to
`
`accept the packet. Id. at ll. 32-33.
`
`Figure 8 is reproduced below.
`
`
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`Case IPR2013-00636
`Patent 6,424,625
`
`Figure 8 shows ARQ packet 810 with ARQ header 812 and data portion
`
`818. Id. at ll. 33-35. Header 812 includes RPEB 814 and k-bit sequence
`
`number N(S) 816. Id. at ll. 35-37. RPEB 814 may be used in a variety of
`
`situations. Id. at ll. 41-43. For example, if a NACK is sent by a receiver,
`
`received by the transmitter, and is valid for one discarded data packet, then
`
`the next data packet to be retransmitted can have RPEB set to TRUE. Id. at
`
`ll. 43-48. In another example, if a retransmission timer expires and one or
`
`more data packets have been discarded, the next incoming data packet to be
`
`transmitted (or the first data packet to be retransmitted) can have RPEB set
`
`to TRUE. Id. at ll. 49-53. If RPEB is TRUE and the difference between the
`
`sequence number and the Expected Sequence Number (ESN) of the next
`
`packet to be received is less than the window size (i.e., half the maximum
`
`sequence number), the packet will be accepted and forwarded to a higher
`
`layer (as long as the data in the packet is also correct). Id. at col. 5, ll. 62-63;
`
`col. 6, ll. 32-36. In this way, the various embodiments of the invention
`
`increase throughput of a communications system using ARQ packets by
`
`discarding outdated packets. Id. at col. 9, ll. 60-62.
`
`C. Exemplary Claim
`
`Claim 1, the sole challenged claim, is reproduced below:
`
`A method for discarding packets in a data network
`1.
`employing a packet transfer protocol including an automatic
`repeat request scheme, comprising the steps of:
`
`a transmitter in the data network commanding a receiver
`in the data network to a) receive at least one packet having a
`sequence number that is not consecutive with a sequence
`number of a previously received packet and b) release any
`
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`Patent 6,424,625
`
`
`expectation of receiving outstanding packets having sequence
`numbers prior to the at least one packet; and
`
`the transmitter discarding all packets for which
`acknowledgment has not been received, and which have
`sequence numbers prior to the at least one packet.
`
`D. References Relied Upon
`
`Petitioner relies upon the following references:
`
`Garrabrant
`
`US 5,610,595
`
`Mar. 11, 1997
`
`Andreas Hettich, “Development and performance
`evaluation of a Selective Repeat-Automatic Repeat Request
`(SR-ARQ) protocol for transparent, mobile ATM access”
`(April 17, 1996) (diploma paper, Aachen Tech.
`University)(“Hettich”)
`
`Walke
`
`Kemp
`
`DE 19543280
`
`May 22, 1997
`
`US 6,621,799
`
`Sept. 16, 2003
`(filed Oct. 5, 1998)
`
`Hettich (English language translation)1
`
`Walke
`
`
`DE 19543280
`(English translation) 2
`
`May 22, 1997
`
`Dimitri Bertsekas, et al., DATA NETWORKS, Prentice-Hall,
`1987, pp. 58-74 (“Bertsekas”)
`
`Ex. 1002
`
`Ex. 1003
`
`Ex. 1004
`
`Ex. 1005
`
`Ex. 1007
`
`Ex. 1008
`
`Ex. 1012
`
`E. The Asserted Grounds of Unpatentability
`
`Petitioner argues that claim 1 is unpatentable based upon the
`
`following grounds:
`
`
`
`1 All references in this decision to “Hettich” are to the English translation
`(Ex. 1007) of the German thesis.
`2 All references in this decision to “Walke” are to the English translation
`(Ex. 1008) of the German patent publication.
`6
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`Case IPR2013-00636
`Patent 6,424,625
`
`
`Reference[s]
`
`Garrabrant (Figures 8A and 8B)
`
`Garrabrant (Failure Recovery)
`
`Hettich
`
`Walke
`
`Kemp
`
`Bertsekas, Go-Back-N Technology,
`Walke, and the Teaching to Discard
`Packets in an ARQ System
`
`II. ANALYSIS
`
`A. Claim Construction
`
`Basis
`
`§ 102
`
`§ 102
`
`§ 102
`
`§ 103
`
`§ 102
`
`§ 103
`
`In an inter partes review, claim terms in an unexpired patent are
`
`interpreted according to their broadest reasonable construction in light of the
`
`specification of the patent in which they appear. 37 C.F.R. § 42.100(b);
`
`Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756, 48,766 (Aug. 14,
`
`2012). Also, claim terms are given their ordinary and customary meaning,
`
`as would be understood by one of ordinary skill in the art in the context of
`
`the entire disclosure. In re Translogic Tech., Inc., 504 F.3d 1249, 1257
`
`(Fed. Cir. 2007).
`
`1. Preamble
`
`Petitioner proposes that the preamble of claim 1 should not be
`
`construed to limit claim 1. Pet. 17-18. Specifically, Petitioner argues that
`
`the terms used in the preamble are not later referred to or necessary to
`
`understand the body of claim 1, and that the preamble merely states the
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`Patent 6,424,625
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`purpose or intended use of the invention. Id. at 17. Petitioner further argues
`
`that, during prosecution of the ’625 patent, the Patent Owner did not rely on
`
`the preamble to distinguish the prior art. Id. at 18. On this record, because
`
`claim 1 defines a structurally complete invention in the claim body and uses
`
`the preamble only to state a purpose or intended use for the invention, we
`
`agree that the preamble does not limit claim 1.
`
`2. “commanding”
`
`Petitioner argues that “commanding” should be construed to mean “an
`
`instruction represented in a control field to cause an addressed device to
`
`execute a specific control function.” Pet. 18-19 (emphasis and internal
`
`quotation marks omitted). Petitioner’s proposed construction is similar to
`
`the definition of “command” from the IEEE Dictionary. Pet. 19 n.3 (citing
`
`Ex. 1011, 214-215). Petitioner argues that this construction is consistent
`
`with the claims and specification of the ’625 patent, which describes the
`
`commanding step being carried out by an enforcement bit (“RBEP bit”). Id.
`
`(citing Ex. 1001, Abstract, claim 3). Petitioner argues that the definition
`
`proposed by Patent Owner in the Texas Litigation was overly broad because
`
`one of ordinary skill would not understand a packet to be a command to
`
`receive simply because the receiver receives it. Pet. 19-20 (citing Ex. 1006
`
`¶ 38). The ’625 patent states that, “the receiver can be commanded to skip
`
`or overlook the packets which have been discarded, or in other words, to
`
`release any expectation of receiving the packets which have been discarded.”
`
`Ex. 1001, col. 5, ll. 22-25 (emphasis added). The ’625 patent further
`
`explains that, “[i]n the case where the transmitter discards a packet, it orders
`
`8
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`Case IPR2013-00636
`Patent 6,424,625
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`the receiver to accept the next packet, by setting a certain Receiver Packet
`
`Enforcement Bit (RPEB) in the ARQ header of the next packet and sending
`
`the packet to the receiver.” Id. at ll. 28-32. The result is that, “[w]hen the
`
`receiver receives the packet, the RPEB bit will cause the receiver to accept
`
`the packet.” Id. at ll. 32-33. Thus, not every packet “commands” the
`
`receiver to perform the rest of the claimed limitation; only a packet whose
`
`RPEB bit is set “commands” the receiver to do so. We are, therefore,
`
`persuaded that “commanding” does not encompass merely receiving.
`
`Moreover, Petitioner’s proposed construction is consistent with how a
`
`person of ordinary skill in the art would have understood the term at the time
`
`that the ’625 patent was filed. See Ex. 1011, 214-215. Accordingly, we
`
`construe “commanding” to mean “an instruction represented in a control
`
`field to cause an addressed device to execute a specific control function.”
`
`B. Claim 1 – Anticipated by Garrabrant
`
`Petitioner argues that claim 1 is unpatentable under 35 U.S.C.
`
`§ 102(b) as anticipated by Garrabrant. Pet. 28-37. In support of this ground
`
`of unpatentability, Petitioner provides detailed explanations as to how each
`
`claim limitation is disclosed by Garrabrant, and relies upon the Declaration
`
`of Dr. Bims. Id. (citing Ex. 1006 ¶¶ 47-70).
`
`Garrabrant (Exhibit 1002)
`
`Garrabrant describes a method and apparatus for transmitting data in a
`
`packet radio communication system having data sources, destinations, and
`
`intermediate repeaters. Ex. 1002, Abstract. According to a packet protocol,
`
`a sequence index is used to prevent duplicate packets from being received by
`
`9
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`Patent 6,424,625
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`requiring that the sequence number fall within a sequence number window at
`
`each device. Id. The sequence number window is incremented each time a
`
`packet is received. Id. The sequence number also is used to cause the
`
`retransmission of packets that are lost, at which time the sequence number
`
`window in the devices that are affected are reset to allow transmission of the
`
`lost packet. Id.
`
`Figure 7A is reproduced below.
`
`
`
`Figure 7A illustrates a window used with the packet radio communication
`
`system of the present invention according to the protocol of the present
`
`invention before the transmission of a message. Id. at col. 9, ll. 9-13. The
`
`window has circle 140 with sequence numbers on the circumference of the
`
`circle representing the possible values that can be contained in a set of
`
`possible sequence numbers. Id. at ll. 13-16. Some predetermined fraction of
`
`the set of possible sequence numbers constitutes the set of sequence numbers
`
`in “valid” window 142, and the set of remaining possible sequence numbers
`
`10
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`Patent 6,424,625
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`constitutes the set of sequence numbers in “rejection” window 144. Id. at
`
`ll. 20-24.
`
`When the message source does not receive a response (“UA”)
`
`acknowledging receipt of the transmitted message, the message is
`
`retransmitted for a certain predetermined number of times. Id. at col. 10,
`
`ll. 4-8. A source unit and a destination unit will allow as many messages as
`
`there are in “valid” window 142 to become lost while still maintaining
`
`synchronization. Id. at ll. 15-17.
`
` Figures 8A and 8B, reproduced below, show what happens if five
`
`packets are lost. Id. at ll. 17-18.
`
`
`
`Figure 8A illustrates rejection window 160 in circle set of acceptable
`
`sequence numbers 162 at a destination unit of the packet radio
`
`communication system before the rejection window is updated in response
`
`to the receipt of a “lost” message. Id. at ll. 18-24. Figure 8B illustrates
`
`rejection window 170 in circle set of acceptable sequence numbers 172 at
`
`the destination unit after the rejection window is updated in response to the
`
`11
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`Case IPR2013-00636
`Patent 6,424,625
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`receipt of a “lost” message. Id. at ll. 24-28. In Figure 8A, it is assumed that
`
`out of 8 packets sent, packets 0 and 1 were successfully received to define
`
`“valid” window 164 and packets 2 through 6 were lost. Id. at ll. 28-30. As a
`
`result, “valid” window 164 did not advance further. Id. at ll. 30-32. Each
`
`time a packet was transmitted, the sender unit incremented its sequence
`
`count. Id. at ll. 32-34. However, because these packets were lost, the
`
`destination unit did not receive them and “valid” window 164 is still set
`
`between 2 and 17. Id. at ll. 34-37. When packet 7 eventually arrives at the
`
`destination unit, it falls within “valid” window 164 and is accepted by the
`
`destination unit. Id. at ll. 37-39. The destination unit then sets its internal
`
`sequence count to 8 as shown in Figure 8B and slides its “valid” window
`
`164 to the position of “valid” window 174, shown in Figure 8B, to allow
`
`packets 8 through 23. Id. at ll. 39-42.
`
`Analysis
`
`In light of the arguments and evidence, Petitioner has established a
`
`reasonable likelihood that claim 1 is unpatentable as anticipated by
`
`Garrabrant.
`
`For example, independent claim 1 recites
`
`a transmitter in the data network commanding a receiver in the
`data network to a) receive at least one packet having a sequence
`number that is not consecutive with a sequence number of a
`previously received packet and b) release any expectation of
`receiving outstanding packets having sequence numbers prior to
`the at least one packet.
`
`Garrabrant discloses sending a “lost” message that instructs the
`
`receiver to move its window forward upon receipt of the next received
`
`12
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`Case IPR2013-00636
`Patent 6,424,625
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`packet. Ex. 1002, Figs. 8A, 8B; col. 10, ll. 14-42. In the example illustrated
`
`in Figures 8A and 8B, the “lost” message instructs the receiver to receive a
`
`packet (packet 7) having a sequence number that is not consecutive with a
`
`sequence number of a previously received packet (packets 0 and 1), and
`
`release any expectation of receiving outstanding packets having sequence
`
`numbers prior to the at least one packet (i.e., moving “valid” window
`
`forward to allow packets 8 through 23, thereby giving up on packets 2
`
`through 5). Id.
`
`Claim 1 also recites “the transmitter discarding all packets for which
`
`acknowledgment has not been received, and which have sequence numbers
`
`prior to the at least one packet.” Garrabrant discloses that the sender
`
`discards packets 2 through 6 after retransmitting each a certain
`
`predetermined number of times. Id. at col. 10, ll. 7-8, 16, 23-25; see also id.
`
`at Fig. 12, col. 12, ll. 43-44 (“A flow chart of an algorithm which may be
`
`used to discard repeated packets is shown in FIG. 12.”).
`
`Conclusion
`
`We are persuaded that Petitioner has established a reasonable
`
`likelihood that it would prevail in showing that claim 1 is unpatentable as
`
`anticipated by Garrabrant.
`
`C. Claim 1 – Anticipated by Hettich
`
`Petitioner argues that claim 1 is unpatentable under 35 U.S.C.
`
`§ 102(b) as anticipated by Hettich. Pet. 37-41. In support of this ground of
`
`unpatentability, Petitioner provides detailed explanations as to how each
`
`13
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`Patent 6,424,625
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`claim limitation is disclosed by Hettich, and relies upon the Declaration of
`
`Dr. Bims. Id. (citing Ex. 1006 ¶¶ 79-90).
`
`Hettich (Exhibit 1007)
`
`Hettich describes a new link access protocol based on known ARQ
`
`protocols and adjusted for the special requirements of the Mobile Broadband
`
`System (“MBS”) project. Ex. 1007, 4-5. Specifically, Hettich discloses an
`
`Adaptive Selective Repeat (“ASR”) ARQ protocol that is a modified
`
`Selective Reject (“SR”) ARQ and uses a Selective Reject (SREJ) PDU to
`
`request an individual frame again. Id. at 29-30. Hettich further discloses a
`
`Delay PDU that “is used to inform receivers that cells have been discarded.”
`
`Id. at 34. The Delay PDU “is sent in the opposite direction instead of an
`
`acknowledgement”—i.e., from transmitter to receiver—and has RN (the
`
`lowest frame number that has not yet been correctly received) set equal to
`
`SN, where SN is the highest number of all of the discarded cells. Id. at 28,
`
`34. If the receiver receives a Delay PDU, it stops waiting for cells with
`
`sequence numbers less than or equal to RN. Id. at 35. The receiver then
`
`shifts its window and issues a corresponding acknowledgement. Id.
`
`Analysis
`
`In light of the arguments and evidence, Petitioner has established a
`
`reasonable likelihood that claim 1 is unpatentable as anticipated by Hettich.
`
`For example, independent claim 1 recites
`
`a transmitter in the data network commanding a receiver in the
`data network to a) receive at least one packet having a sequence
`number that is not consecutive with a sequence number of a
`previously received packet and b) release any expectation of
`
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`
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`receiving outstanding packets having sequence numbers prior to
`the at least one packet.
`
`Hettich discloses that the Delay PDU is a command to a receiver to
`
`shift its window, thereby releasing any expectation of receiving packets
`
`having sequence numbers less than or equal to SN and allowing the receiver
`
`to receive packets with sequence numbers greater than SN. Pet. 34-35.
`
`Claim 1 also recites “the transmitter discarding all packets for which
`
`acknowledgment has not been received, and which have sequence numbers
`
`prior to the at least one packet.” Hettich discloses that the transmitter sets
`
`RN=SN in the Delay PDU, where “SN is the highest number of all the
`
`discarded cells,” and “there cannot be valid (not discarded) cells with lower
`
`sequence numbers.” Id. at 34. Thus, the transmitter discards all packets
`
`with sequence numbers below SN.
`
`Conclusion
`
`We are persuaded that Petitioner has established a reasonable
`
`likelihood that it would prevail in showing that claim 1 is unpatentable as
`
`anticipated by Hettich.
`
`D. Claim 1 – Obvious over Walke
`
`Petitioner argues that claim 1 is unpatentable under 35 U.S.C.
`
`§ 103(a) as obvious over Adams. Pet. 41-47. In support of this ground of
`
`unpatentability, Petitioner provides detailed explanations as to how each
`
`claim limitation is taught or suggested by Walke, and relies upon the
`
`Declaration of Dr. Bims. Id. (citing Ex. 1006 ¶¶ 91-99).
`
`15
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`Walke (Exhibit 1008)
`
`Walke describes a mobile communication system in which
`
`Asynchronous Transfer Mode (“ATM”) network cells can be transmitted via
`
`a radio interface with a quality of service comparable to that achieved
`
`ordinarily by a fixed network of similar capacity. Ex. 1008, col. 3. Walke
`
`discloses “specific measures to ensure that the required connection-specific
`
`quality of service parameters ‘maximum ATM cell-loss rate’ and ‘maximum
`
`ATM cell delay’ are complied with,” namely, “error-correction processes
`
`involving automatic repeat request (ARQ) processes.” Id. The error
`
`correction process according to the invention uses an improved selective
`
`repeat (SR) algorithm by using a Selective Reject (SREJ) order to request
`
`retransmission of individual ATM cells. Id. at col. 11. In one embodiment
`
`of the error correction process, the sending station can reject ATM cells that
`
`have exceeded their maximum permitted delay. If a receiver issues a
`
`retransmission request for an ATM cell, but the cell reaches its maximum
`
`delay in the meantime, the sender rejects the ATM cell. Id. at col. 12. The
`
`sender informs the receiver that this ATM cell will not be retransmitted by
`
`using a delay order, which is treated as an acknowledgement, but is
`
`generated by the sender and sent to the receiver. Id. at cols. 12-13. The
`
`receipt sequence number N(R) in this command is set to the sequence
`
`number of the rejected ATM cell. Id. The delay command is piggybacked
`
`by an N frame and, as a result, the N frame becomes a delay frame. Id.
`
`Figure 9 of Walke is reproduced below.
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`Figure 9 shows an exemplary protocol sequence showing the treatment of
`
`outdated ATM cells. Id. at cols. 12-13. ATM cell RR(0, X) is received
`
`correctly. Id. ATM cell RR(1, X) is not received correctly. ATM cell
`
`RR(2, X) is received correctly. Id. The receiver sends a selective reject
`
`message SREJ(X, 1) indicating that ATM cell RR(1, X) was not received.
`
`Id. The transmitter decides to discard ATM cell RR(1, X) so it sends
`
`DELAY(4, 1) to the receiver. The DELAY message “tells the receiver not
`
`to wait for anything else on frame 1 and it is able to widen its receive
`
`window.” Id. at col. 13.
`
`Analysis
`
`In light of the arguments and evidence, Petitioner has established a
`
`reasonable likelihood that claim 1 is unpatentable as obvious over Walke.
`
`For example, independent claim 1 recites
`
`a transmitter in the data network commanding a receiver in the
`data network to a) receive at least one packet having a sequence
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`17
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`number that is not consecutive with a sequence number of a
`previously received packet and b) release any expectation of
`receiving outstanding packets having sequence numbers prior to
`the at least one packet.
`
`Walke teaches a DELAY message that instructs the receiver to receive
`
`a packet (i.e., packet #4 in the example of Figure 9) and release expectation
`
`of receiving an outstanding packet (i.e., packet #1 in the example of Figure
`
`9) having a sequence number prior to the at least one packet. Id. at cols. 12-
`
`13.
`
`Claim 1 also recites “the transmitter discarding all packets for which
`
`acknowledgment has not been received, and which have sequence numbers
`
`prior to the at least one packet.” Petitioner acknowledges that, in the
`
`example of Figure 9,
`
`packet #4 is consecutive with a previously received packet #3,
`and the DELAY(4,1) message causes the receiver to release
`packet #1, but not packets #2 and #3 (and thus not “all packets
`… [that] have sequence numbers prior to the at least one
`packet” as recited in Claim 1 of the ‘625 patent).
`
`Pet. 44 (alteration in original). However, Petitioner argues that, “[i]t would
`
`have been inherent in the system disclosed in Walke that many possible sets
`
`of packets are sent and acknowledged.” Id. at 44-45 (citing Ex. 1006 ¶¶ 87,
`
`88). Dr. Bims testifies as follows:
`
`87. One of ordinary skill in the art would have understood that
`Walke renders obvious challenged claim 1. The teachings of
`Walke effectively disclose many different scenarios for lost
`packets - one by itself, multiple consecutively, etc. When
`sending packet #0 through packet #6 as shown in FIG. 9 of
`Walke, any combination of packets could be lost and could time
`out. Further, in a burst of data, there will always be a first, and
`
`18
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`often a last packet and intermediate packets. It would be
`readily apparent that just the first, or just the last, or just one
`intermediate, or any combination could be lost.
`
`In the specific example, the DELAY message (DELAY (4, 1) is
`in the form of DELAY(n, n-3), but it could have been
`DELAY(n, n-2) or DELAY(n, n-4), or any other combination
`of packet numbers. If the situation is such that the DELAY
`message is DELAY(n, n-1), the system in Walke would
`perform the method of causing the receiver to “receive at least
`one packet having a sequence number that is not consecutive
`with a previously received packet” (the n packet), and for the
`transmitter to “discard[] all packets for which acknowledgment
`has not been received, and which have sequence numbers prior
`to the at least one packet”, as claimed in claim 1 of the ‘625
`patent.”
`
`88. For example, if after sending RR(1,X) there was some
`delay in transmission, e.g., due to packet #1 being the last frame
`in a burst. In this case, the timer to retransmit would time out
`as shown in Figure 9 of Walke, and the next packet to be sent
`could be packet 2. Thus, the message would be DELAY(2,1).
`(See, e.g., Walke, Section 2.6, Ex. 1008). In that case, packet
`#2 would not be consecutive with a previously received packet
`#0, and the receiver would release expectations of receiving all
`the non-acknowledged outstanding packets, i.e., packet #1.
`(See, e.g., Walke, Section 2.6, Ex. 1008). Further, it would be
`possible to retransmit packet 2 and at the same time indicate the
`discarding of packet #1. In each case, the effect of the DELAY
`command is for the receiver to “no longer wait[] on [packet] 1”
`– i.e., to release any expectations [of receiving packet #1].
`(See, e.g., Walke, FIG. 9, Ex. 1008). . . .
`
`Ex. 1006 ¶¶ 87, 88. We are persuaded by the above-quoted analysis of Dr.
`
`Bims.
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`Conclusion
`
`We are persuaded that Petitioner has established a reasonable
`
`likelihood that it would prevail in showing that claim 1 is unpatentable as
`
`obvious over Walke.
`
`E. Other Grounds
`
`Petitioner also asserts the following grounds of unpatentability:
`
`Reference[s]
`
`Kemp
`
`Bertsekas, Go-Back-N Technology,
`Walke, and the Teaching to Discard
`Packets in an ARQ System
`
`Basis
`
`§ 102
`
`§ 103
`
`Pet. 48-54. Those asserted ground are redundant in light of the
`
`determination that there is a reasonable likelihood that the challenged claim
`
`is unpatentable based on the grounds of unpatentability on which we
`
`institute an inter partes review. See 37 C.F.R. § 42.108(a).
`
`III. CONCLUSION
`
`For the foregoing reasons, we determine that the information
`
`presented in the petition establishes that there is a reasonable likelihood that
`
`Petitioner would prevail in establishing the unpatentability of claim 1 of the
`
`’625 patent.
`
`The Board has not made a final determination on the patentability of
`
`the challenged claim.
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`Accordingly, it is
`
`IV. ORDER
`
`ORDERED that pursuant to 35 U.S.C. § 314, an inter partes review is
`
`hereby instituted as to claim 1 of the ’625 patent on the following grounds:
`
`1. 35 U.S.C. § 102 as anticipated by Garrabrant;
`
`2. 35 U.S.C. § 102 as anticipated by Hettich;
`
`3. 35 U.S.C. § 103 as obvious over Walke;
`
`
`
`FURTHER ORDERED that all other grounds raised in Petitioner’s
`
`petition are denied because they are deficient for the reasons discussed
`
`above;
`
`FURTHER ORDERED that pursuant to 35 U.S.C. § 314(d) and
`
`37 C.F.R. § 42.4, notice is hereby given of the institution of a trial on the
`
`grounds of unpatentability authorized above; the trial commences on the
`
`entry date of this decision; and
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`FURTHER ORDERED that an initial conference call with the Board
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`is scheduled for 2:00 PM Eastern Time on April 1, 2014; the parties are
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`directed to the Office Patent Trial Practice Guide3 for guidance in preparing
`
`for the conference call, and should be prepared to discuss any proposed
`
`changes to the Scheduling Order entered concurrently herewith and any
`
`motion the parties anticipate filing during the trial.
`
`
`
`
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`3 Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756, 48,765-66 (Aug.
`14, 2012).
`
`21
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`Case IPR2013-00636
`Patent 6,424,625
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`For PETITIONER:
`
`Dominic E. Massa
`Michael A. Diner
`WILMER CUTLER PICKERING HALE AND DORR LLP
`dominic.massa@wilmerhale.com
`michael.diener@wilmerhale.com
`
`For PATENT OWNER:
`
`Peter J. Ayers
`J. Christopher Lynch
`LEE & HAYES PLLC
`peter@leehayes.com
`chris@leehayes.com
`
`
`22
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`
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