Ex Parte Kahana et al

Patent Trial and Appeal Board

Feb 7, 2013

11216625 (P.T.A.B. Feb. 7, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte EMANUEL KAHANA, ROBERT J. CORKE,
DANIEL G. PRYSBY, and RON ROTSTEIN

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Appeal 2010-008185
Application 11/216,625
Technology Center 2400
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Before ERIC B. CHEN, JUSTIN BUSCH, and
GEORGIANNA W. BRADEN, Administrative Patent Judges.

BRADEN, Administrative Patent Judge

DECISION ON APPEAL

Appeal 2010-008185
Application 11/216,625

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This is an appeal
1
under 35 U.S.C. § 134(a) from the Final Rejection
of claims 1, 2, 5, and 10-16. We have jurisdiction under 35 U.S.C. § 6(b).
Claims 21-23 were withdrawn from consideration. Claims 3-4, 6-9, and 17-
20 were cancelled.
We affirm.

STATEMENT OF THE CASE
Appellants’ Invention
Appellants’ invention relates to a method for dynamically adapting a
clear channel assessment threshold of a wireless communications channel
based on a status of a busy channel indicator, and controlling the clear
channel assessment threshold in a wireless local area network. (Abstract;
Spec. [0001]; Br. 11.)

Exemplary Claim
Claims 1 and 13 are independent. Independent claim 1 is
representative of the invention, and is reproduced below with disputed
limitations in italics:
1. A method for dynamically adapting a clear channel assessment
threshold of a wireless communications channel, the method
comprising the steps of:
indicating a busy status, using a busy channel indicator, as a
result of a comparison using an initial clear channel assessment
threshold;
measuring a first time interval during which the busy channel
indicator indicates the busy status;

1
The Real Party in Interest is Motorola, Inc.
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comparing the first time interval to a first predetermined time
value; and
increasing the clear channel assessment threshold by a first
predetermined value when the first time interval exceeds the first
predetermined time value.

Examiner’s Rejections
Claims 1, 2, 5, and 10-16 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Blosco (US 2006/0046739 A1) in view of Tang (US
7,403,539 B1). (Ans. 5.)

ISSUE 1
Restriction of claims: 21-23
Appellants argue that claims 21-23 were withdrawn from
consideration as being directed to a non-elected invention, but the
requirement of electing group I or group II was not proper. (App. Br. 10-
12.)
Issue 1: Whether the Restriction Requirement and the withdrawal of
claims 21-23 from consideration were improper?

ANALYSIS
Appellants present arguments and seek our review of the Examiner’s
restriction requirement of claims (App. Br. 10-12). The propriety of a
restriction requirement is, however, a petitionable matter reviewable by
petition to the Technology Center Director. See 37 C.F.R. § 1.444; MPEP
§§ 818.03(c), 1002.02(c)(2), and 1201. Petitionable issues are not subject to
review by the Board. See In re Berger, 279 F.3d 975, 984-85 (Fed. Cir.
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2002). Accordingly, we have no opinion concerning the propriety of the
restriction requirement.
ISSUE 2
Rejection of claims: 1, 2, 5, and 10-16
Appellants contend that the claim limitations “measuring a first time
interval during which the busy channel indicator indicates the busy status;
comparing the first time interval to a first predetermined time value; and
increasing the clear channel assessment threshold by a first predetermined
value when the first time interval exceeds the first predetermined time
value” are not taught or suggested in the combination of Blosco and Tang.
(Br. 13-18.)

Issue 2: Has the Examiner erred in determining that the combination
of Blosco and Tang teaches or suggests “measuring a first time interval
during which the busy channel indicator indicates the busy status; comparing
the first time interval to a first predetermined time value; and increasing the
clear channel assessment threshold by a first predetermined value when the
first time interval exceeds the first predetermined time value.” as recited in
independent claims 1 and 13?

ANALYSIS
We are unpersuaded by Appellants’ argument (Br. 13-18) that the
combination of Blosco and Tang fail to teach or suggest “measuring a first
time interval during which the busy channel indicator indicates the busy
status; comparing the first time interval to a first predetermined time value;
and increasing the clear channel assessment threshold by a first
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predetermined value when the first time interval exceeds the first
predetermined time value,” as recited in independent claims 1 and 13.
Appellants generally provide arguments that attack individual aspects
of each reference, rather than the rejections as articulated by the Examiner
based on the combined teachings of the references. (Br. 13-18.) For
instance, Appellants assert that Blosco teaches a method to adjust the
detection sensitivity threshold for an 802.11 complaint wireless transceiver
and/or the receiver communication sensitivity threshold. (Br. 13.) In
particular, Appellants argue that “it is clear that Blosco’s method of
adjusting a station’s detection sensitivity threshold is quite different from
Appellants’ claimed method” (Br. 14), and that in each method of Blosco
“the STA [] determines the detection sensitivity increase in proportion to the
approximate separation from [the] STA [] to [the] AP… Generally, the
adjustment increase to the STA [] default detection sensitivity is
proportionate to the estimated physical separation increase.” (Br. 14-15,
emphasis in original). Yet, Appellants have provided an insufficient
explanation as to why Blosco does not meet specific claim limitations or
why the combination of Blosco and Tang do not fall within the scope of the
claim language, especially in light of the Examiner’s finding that:
Blosco et al. discloses to adjust detection cell radius by waiting until
a predetermined number of CTS messages are received within a
predetermined time period (first predetermined time value) (Blosco
et al.; [0086]; [0054]); increasing the clear channel assessment
threshold by a first predetermined value (reduce/increase the size of
a cell for a desired (first predetermined value) amount (10%);
Blosco et al.; [0086]; [0054], where size of a cell changed by
changing clear channel assessment (CCA) threshold; [0043],
[0044], [0047]; Blosco et al.;) based on the first predetermined time
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value (by waiting until a predetermined number of CTS messages are
received within a predetermined time period (Blosco et al.; [0086];
[0054])). According to Tang et al. (Tang et al.; column 2, lines 41-60;
(802.11/802.11b CCA guidelines)), CCA shall report a busy
medium upon detecting any received energy above the ED
threshold. Therefore, when CTS messages are received in the system
of Blosco et al., CCA shall report a busy medium according to Tang et
al., because CTS messages are valid messages, and when each CTS
message is received CCA shall report a busy medium according to
802.11/802.11 b CCA guidelines, as evidenced by Tang et al.
(Ans. 20, emphasis in original.)

Instead, Appellants simply disagree with the Examiner that “the
teachings of Tang at col. 2, lines 41-60 somehow make up for the
deficiencies of the Blosco teaching” (Br. 15), arguing:
[t]here is no teaching in col. 2, lines 41-60 or anywhere else in
Tang of the limitations recited in claims 1 and 13 of “measuring
a first time interval during which the busy channel indicator
indicates the busy status; comparing the first time interval to a
first predetermined time value; and increasing the clear channel
assessment threshold by a first predetermined value when the
first time interval exceeds the first predetermined time value.”
(Br. 16.) Appellants also argue that “Tang at most discloses after a gain
change over time exceeds an energy detection threshold, an energy threshold
validation signal is set to true, and this condition might cause a busy channel
indication to also be set to true by a CCA unit.” (Br. 17, emphasis in
original.)
Further, Appellants’ arguments do not address the Examiner's finding
that:
When CTS messages are received in the system of Blosco et al.,
CCA shall report a busy medium according to Tang et al.,
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because CTS messages are valid messages, and when each
CTS message is received CCA shall report a busy medium
according to 802.11/802.11b CCA guidelines, as evidenced by
Tang et al. Blosco et al. and Tang et al. directed to the 802.11
systems (Blosco et al.; Abstract; Tang et al.; column 2, lines 41-
60; (802.11/802.11 b CCA guidelines)). Blosco et al. discloses
to adjust detection cell radius by waiting until a predetermined
number of CTS messages are received within a predetermined
time period (first predetermined time value) (Blosco et al.;
[0086]; [0054]). Therefore system of Blosco et al. waits a
predetermine time period. Waiting for a predetermine time
period is well known to one of ordinary skilled in art.
Measuring and comparing of a time interval features, not
explicitly taught, but inherent in the system of Blosco et al., as
outlined above. According to Blosco et al. during
predetermined time interval CTS messages are received, and in
view of Tang et al. busy medium is reported according to
802.11/802.11 b standard.

(Ans. 25-26.) The Examiner finds that “measuring and comparing of a time
interval features, not explicitly taught, but [is] inherent in the system of
Blosco et al.” and, therefore “it would have been obvious to one of ordinary
skill in the art at the time the applicants’ invention was made to enable
device taught by Blosco et al. with the a [sic] busy channel indicator, as
taught by Tang et al.” (Ans. 21.) We agree with the Examiner because
adjusting a detection cell radius by waiting until a predetermined number of
CTS messages are received within a predetermined time period (first
predetermined time value) (Blosco [0054], [0086]), requires that the system
described by Blosco be able to measure and compare time intervals.
Appellants also contend that “there is no mention in the Tang
reference of increasing either of these threshold values.” (Br. 18.)
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However, the Examiner does not rely on Tang for this disputed claim
limitation, but rather cites to Blosco and finds that:
Blosco et al. discloses increasing the clear channel assessment
threshold by a first predetermined value (reduce/increase the
size of a cell for a desired (first predetermined value) amount
(10%); Blosco et al.; [0086]; [0054], where size of a cell
changed by changing clear channel assessment (CCA)
threshold; [0043] [0044]) based on the first predetermined time
value (by waiting until a predetermined number of CTS
messages are received within a predetermined time period
(Blosco et al.; [0086]; [0054])), where measuring and
comparing of a time interval features, not explicitly taught, but
inherent in the system of Blosco et al. Therefore, when CTS
messages are received in the system of Blosco et al., CCA shall
report a busy medium according to Tang et al., because CTS
messages are valid messages, and when each CTS message is
received CCA shall report a busy medium according to
802.11/802.11b CCA guidelines.
(Ans. 29-30, emphasis in original.)
The arguments presented by Appellants appear to attack the
references individually, rather than in combination. (Br. 15-18.)
Nonobviousness cannot be established by attacking the references
individually when the rejection is predicated upon a combination of prior art
disclosures. See In re Merck & Co., Inc., 800 F.2d 1091, 1097 (Fed. Cir.
1986). Further, in attacking the references individually, Appellants fail to
address the Examiner’s actual rejections to establish an insufficiency in the
combined teachings of the references and show the Examiner has erred in
his determination of obviousness. Thus, Appellants have not persuaded us
the Examiner erred in finding the combination of Blosco and Tang teaches
and/or suggests the invention as recited in claims 1 and 13.
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Accordingly, we sustain the rejection of independent claims 1 and 13
under 35 U.S.C. § 103(a). Appellants have not presented any substantive
arguments with respect to dependent claims 1, 2, 5, 10-12, and 14-16 and
thus, these fall with their respective independent claims. Therefore, we
sustain the rejection of claims 1, 2, 5, and 10-16 under 35 U.S.C. § 103(a).

DECISION
The Examiner’s decision to reject claims 1, 2, 5, and 10-16 is
affirmed.
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).

AFFIRMED

ELD