Ex Parte Wang et al

Patent Trial and Appeal Board

Jun 3, 2013

10729804 (P.T.A.B. Jun. 3, 2013)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
10/729,804 12/05/2003 Linghsiao Wang 013628.00637 (S-296) 2268
77339 7590 06/04/2013
JACKSON WALKER (CONEXANT)
901 MAIN STREET, SUITE 6000
DALLAS, TX 75202
EXAMINER
MADAMBA, GLENFORD J
ART UNIT PAPER NUMBER
2451
MAIL DATE DELIVERY MODE
06/04/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte LINGHSIAO WANG and CRAIG BARRACK
____________

Appeal 2011-001866
Application 10/729,804
Technology Center 2400
____________

Before MARC S. HOFF, DEBRA K. STEPHENS, and
MIRIAM L. QUINN, Administrative Patent Judges.

QUINN, Administrative Patent Judge.

DECISION ON APPEAL

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Application 10/729,804

2

Appellants appeal under 35 U.S.C. § 134(a) (2002) from a rejection of
claims 1-27. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

STATEMENT OF THE CASE
The invention relates to traffic management in packet-switched
communications networks, and, in particular, to controlling traffic
conveyance rates at an edge of a communication network. Spec. ¶ [01].
1

Details of the appealed subject matter, with disputed claim language
emphasized, are recited in independent claims 1, 9, 16, and 24, reproduced
below from the Claims Appendix of the Appeal Brief:
2

1. An egress rate controller monitoring content traffic
transmitted from an edge network node of a packet-switched
communications network node comprising:
a. a leaky bucket having an initial maximum number of
tokens which decreases as packets are received in an associated
output buffer at a reception token rate for transmission, wherein
a size of the leaky bucket is less than or equal to a size of the
associated output buffer;
b. a plurality of token availability threshold level registers
specifying a corresponding plurality of token amounts defining
token availability regions; and

1
References to Appellants’ Specification (“Spec.”) are directed to the
Specification filed on December 5, 2003.
2
References to the Appeal Brief (“App. Br.”) are directed to Appellants’
Appeal Brief filed on December 24, 2009, and references to the Reply are
directed to the Reply Brief filed on May 19, 2010.
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c. a packet transmission suppression controller selectively
suppressing transmission of a packet having a traffic class
association based on a current token availability level being
within a token availability region specifying transmission
suppression of packets of the traffic class.
9. An ingress rate controller monitoring content traffic
received at an edge network node of a packet-switched
communications network node comprising:
a. a leaky bucket having an initial maximum number of tokens
which decreases as packets received at a reception token rate
are accepted;
b. a plurality of token availability threshold level registers
specifying a corresponding plurality of token amounts defining
token availability regions;
c. a plurality of packet discard probability registers, each
packet discard probability register specifying a probability with
which packets of a specific traffic class are to be dropped when
a current token availability level is within a token availability
region, and
d. a packet acceptance controller selectively randomly
discarding packets having a traffic class association based on
the current token availability level being within a token
availability region specifying random packet discard of packets
of the traffic class.
16. A method of effecting egress rate control comprising the
step of:
selectively suppressing packet transmission for a packet of a
particular traffic class when a current token availability level of a
leaky bucket tracking packet transmissions is between two token
availability threshold levels of a plurality of token availability
threshold levels, wherein the token availability threshold levels
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correspond to predetermined egress rate control responses to
bandwidth utilization with respect to packet traffic classes.
24. A method, of effecting ingress rate control comprising
the step of:
selectively randomly discarding packets of a particular traffic
class when a current token availability level of a leaky bucket tracking
packets is between two token availability threshold levels of a
plurality of token availability threshold levels, wherein the token
availability threshold levels correspond to predetermined ingress rate
control responses to bandwidth utilization with respect to packet
traffic classes.

As evidence of unpatentability of the claimed subject matter, the
Examiner relies on the following references at pages 4 to 25 of the Answer:
3

Elwalid US 5,978,356 Nov. 2, 1999
Carter US 2003/0035374 A1 Feb. 20, 2003
Gracon US 6,987,732 B2 Jan. 17, 2006
Patel US 7,126,913 B1 Oct. 24, 2006
Lee US 7,349,403 B2 Mar. 25, 2008
The Examiner provides the following grounds of rejection, of which
Appellants seek review:
(1) Claims 1-8, 11, and 17-23 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Carter, Patel, and Elwalid (Ans. 4-11);

3
References to the Examiner’s Answer (“Ans.”) are directed to the Answer
mailed on March 19, 2010.
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(2) Claim 16 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Carter, Patel, and Lee (Ans. 11-13); and
(3) Claims 9-10, 12-15, and 24-27 stand rejected under 35 U.S.C.
§ 103(a) as being unpatentable Carter, Patel, Gracon, and Lee (Ans.
13-25).
ISSUES
Based on Appellants’ arguments, the dispositive issues on appeal are:
(a) Whether the Examiner erred in rejecting independent claim 1 for
obviousness over Elwalid because it fails to teach or suggest the
limitation “wherein a size of the leaky bucket is less than or equal to a
size of the associated output buffer;”
(b) Whether the Examiner erred in rejecting independent claim 9 for
obviousness over Lee because it fails to teach or suggest the limitation
“a plurality of packet discard probability registers, each packet discard
probability register specifying a probability with which packets of a
specific traffic class are to be dropped when a current token
availability level is within a token availability region;”
(c) Whether the Examiner erred in rejecting independent claim 16 for
obviousness over Lee because it fails to teach or suggest the limitation
“wherein the token availability threshold levels correspond to
predetermined egress rate control responses to bandwidth utilization
with respect to packet traffic classes;” and
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(d) Whether the Examiner erred in rejecting independent claim 24 for
obviousness over Lee because it fails to teach or suggest the limitation
“wherein the token availability threshold levels correspond to
predetermined ingress rate control responses to bandwidth utilization
with respect to packet traffic classes.”
ANALYSIS
We have reviewed the Examiner’s rejection in light of Appellants’
contentions. Further, we have reviewed the Examiner’s response to
Appellants’ arguments. Appellants did not argue separate patentability of
the dependent claims 2-8, 10-15, 17-23, and 25-27. Therefore, except for
our ultimate decision, these claims are not discussed further herein.
We concur with the conclusions reached by the Examiner and provide
the following discussion supporting our decision.
CLAIM 1
Appellants contend that the Examiner erred in finding that Elwalid
discloses the recited limitation of “wherein a size of the leaky bucket is less
than or equal to a size of the associated output buffer.” App. Br. 5-6.
Appellants argue that the passages cited by the Examiner in support of the
rejection do not show that the alleged size of the leaky bucket, BT (the size
of Elwalid’s token buffer) is less than or equal to the size of the associated
output buffer. App. Br. 6.
The Examiner responds that Elwalid expressly teaches the disputed
limitation. Ans. 27. In particular, the Examiner finds that Elwalid teaches a
relationship between the size of the leaky bucket, BT, and the size of the
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buffers in the shaper, i.e. the shaper token buffer size (BTS) and the shaper
data buffer size (BDS). Ans. 27. This relationship is expressly taught at
column 11, lines 30-33, where Elwalid provides that BDS > BT – BTS. See
Ans. 7, 27. This mathematical relationship supports the Examiner’s finding
that the size of Elwalid’s leaky bucket, BT, is less than or equal to the size of
the buffers in Elwalid’s shaper, BDS and BTS, which comprise the recited
“associated output buffer.” See Ans. 27. As such, Appellants’ argument –
that the Examiner erred in finding the disputed limitation in Elwalid – is
unpersuasive.
Appellants argue in the Reply that claim 1 recites “an” associated
output buffer while the Examiner relies on a combination of two buffers.
Reply 2. Appellants also argue that the token buffer in Elwalid is not a
leaky bucket as recited. We are not persuaded by either argument.
Appellants’ argument in the Reply Brief is not commensurate with the
scope of the claim as there is no requirement there that there be a single
buffer for the recited “associated output buffer.” The article “an” preceding
the phrase “associated output buffer” does not limit the claims to any
particular number of buffers, and has been held to mean, in patent parlance,
“one or more” in an open ended claim, which claim 1 is. See Baldwin
Graphic Sys., Inc. v. Siebert, Inc., 512 F.3d 1338, 1342 (Fed. Cir. 2008)
(holding that “an indefinite article ‘a’ or ‘an’ in patent parlance carries the
meaning of ‘one or more’ in open ended claims containing the transitional
phrase comprising” unless a patentee has “‘evidence[d] a clear intent’ to
limit ‘a’ or ‘an’ to ‘one’” (quoting KCJ Corp. v. Kinetic Concepts, Inc., 223
F.3d 1351, 1356 (Fed. Cir. 2000)).
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As for the argument that Elwalid’s token buffer is not the recited
leaky bucket, we are not persuaded. Elwalid teaches in Figure 3 that the
dual leaky bucket regulator (“DLBR”) comprises a token buffer. Elwalid,
fig. 3. That token buffer “is capable of holding BT tokens. Elwalid, col. 5,
l. 16. Elwalid also states that “[t]okens are supplied to the token buffer 30 at
rate r, and a token is used when a data packet is output from the DLBR 16.”
Elwalid, col. 5, ll. 17-20. As the Examiner finds (Ans. 6, 26-27), and we
agree, these descriptions meet the limitation of “a leaky bucket having an
initial maximum number of tokens which decreases as packets are received
in an associated output buffer.” Therefore, we are not persuaded the
Examiner erred in so finding.
Accordingly, we sustain the rejection of independent claim 1.
CLAIM 9
Appellants contend that the Examiner erred in rejecting claim 9
because Lee fails to disclose “a plurality of packet discard probability
registers, each packet discard probability register specifying a probability
with which packets of a specific traffic class are to be dropped when a
current token availability level is within a token availability region”
[hereinafter the “probability registers limitation”]. App. Br. 10-11.
Appellants argue that although Lee discloses registers depicted in Figure 2
as item 211, those registers neither “specify[] a probability with which
packets of a specific traffic class are to be dropped” nor are “related to the
drop probability.” App. Br. 11. We are not persuaded by Appellants’
arguments.
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The rejection points to the Instruction and State Registers 226a-c,
illustrated in Figure 4 of Lee. Ans. 16. Lee describes that these registers
hold instructions and state information, which is fetched when an incoming
information element arrives at the processor. Lee, col. 9, ll. 51-55 (cited in
the Answer at page 16). The Examiner also shows that the processor
handling the policy control (PCU 250) includes a pipeline with various
stages, one of which is the EXE stage. Lee, fig.5; col. 10, ll. 17-28 (cited in
Ans. 16). That EXE stage utilizes instructions fetched from the registers to
perform complex functions such as policing the information element
segment. Lee, col. 10, ll. 47-53 (cited in Ans. 16). The EXE stage also
includes a storage congestion metering unit which performs calculations of
the drop probability for the received information element. Lee, col. 56, ll.
23-55 (cited in Ans. 16). The format of the instructions and state
information stored in the registers and accessed at the EXE stage is depicted
in Figures 36 and 37. Lee, figs. 36-37 (Examiner cited to Figure 37 Ans.
16). Therefore, although the passages on which the Examiner relies on are
lengthy and spread throughout the reference, Lee, nevertheless, describes in
detail the relevant operation of the EXE stage and states that the EXE stage
uses registers for its operation. As such, Appellants have not provided
sufficient evidence to persuade us of error by the Examiner in finding that
Lee discloses the probability registers limitation.
Accordingly, we sustain the rejection of independent claim 9.
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CLAIM 16
Appellants contend that the Examiner erred in finding that Lee
discloses “the token availability threshold levels correspond to
predetermined egress rate control responses to bandwidth utilization with
respect to packet traffic classes.” App. Br. 8-9. In Appellants’ view, Lee
fails to teach “token availability threshold levels” and “predetermined egress
rate control responses.” We do not agree with Appellants’ contentions.
First, Appellants fail to point out sufficient evidence to persuade us
that Lee’s minimum/maximum thresholds do not teach the limitation of
token availability threshold levels. And, though not relied on to support our
decision, we note, as a cumulative reference, that the Examiner finds the
limitation of “token availability threshold levels” is well known in the art, as
admitted by Appellants in the Background of the Invention. Ans. 31 (citing
Spec. ¶ [0015-0016]).
Second, we agree with the Examiner’s finding that the
minimum/maximum thresholds are in effect for controlling and policing the
data packet flow, i.e. accepting or discarding data packets. Ans. 30.
Furthermore, Lee teaches that the packet flow determinations are for a traffic
class. See Lee, col. 5, ll. 31-45. Such actions – accept or discard packets –
are consistent with the scope of “egress rate control responses,” which
Appellants describe in one embodiment of the Specification as “selectively
halting the scheduling of lower priority traffic classes for transmission as the
bucket is depleted of tokens.” Spec. ¶ [36]. As such, we are not persuaded
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by Appellants’ arguments that the Examiner erred in finding that Lee teaches
the disputed limitation.
Accordingly, we sustain the rejection of independent claim 16.
CLAIM 24
Appellants contend that the Examiner erred in finding that Lee teaches
the limitation of “the token availability threshold levels correspond to
predetermined ingress rate control responses to bandwidth utilization with
respect to packet traffic classes.” App. Br. 12-13. Appellants argue that Lee
does not teach “token availability threshold levels” and “predetermined
ingress rate control responses.” Id. We do not agree with Appellants’
conclusions.
First, Appellants do not show sufficient evidence to persuade us that
Lee’s minimum/maximum thresholds do not meet the recited “token
availability threshold levels.” Second, as stated supra with respect to claim
16, we find no error in the Examiner’s determination that Lee teaches
controlling and policing the data packet flow. The Examiner points out, and
we agree, that the policing of packet flow is performed for both ingress and
egress, and that the actions of discarding or accepting the packet flow based
on the threshold determinations meets the disputed claim limitation. Ans.
30-31. Again, this finding is consistent with Appellants’ description of the
“ingress rate control response,” an example of which is to “drop all lowest
priority traffic class packets” when the threshold level is below a minimum
(Spec. ¶ [49]).
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Accordingly, we sustain the Examiner’s rejection of independent
claim 24.
CONCLUSION
We conclude that Appellants have not shown error in the Examiner’s
findings and conclusions concerning the obviousness of independent claims
1, 9, 16, and 24. Therefore, we sustain the rejection of claim 1 under 35
U.S.C. § 103(a) over Carter, Patel, and Elwalid, and we group dependent
claims 2-8 with claim 1. See 37 C.F.R. § 41.37(c)(1)(vii). We also sustain
the rejection of independent claims 9, 16, and 24 under 35 U.S.C. § 103(a)
over combinations with Lee, and group therewith dependent claims 10-15,
17-23, and 25-27. See 37 C.F.R. § 41.37(c)(1)(vii).
DECISION
We affirm the Examiner’s decision to reject claims 1-27.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRM

ELD