Ex Parte Welnick et al

Board of Patent Appeals and Interferences

Mar 23, 2012

10626184 (B.P.A.I. Mar. 23, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte WILLIAM E. WELNICK, WILLIAM P. ALBERTH, JR., and
BRIAN D. STORM
____________

Appeal 2010-001584
Application 10/626,184
Technology Center 2600
____________

Before SCOTT R. BOALICK, JOHN A. JEFFERY, and
CARLA M. KRIVAK, Administrative Patent Judges.

JEFFERY, Administrative Patent Judge.

DECISION ON APPEAL

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Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1, 4-13, and 17-19.1 We have jurisdiction under 35
U.S.C. § 6(b). We affirm-in-part.

STATEMENT OF THE CASE
Appellants’ invention allocates neighboring pilot signals received
from neighboring base stations to a candidate set for a wireless
communications device. The allocation can be based on criteria such as the
strength of the received signals over a period of time. Further, the allocation
criteria can be dynamically changed based on the number and strength of
signals in an active set. Thus, if the number or strength of active signals
drops below a certain threshold, neighbor signals can be added to the
candidate set more quickly. See generally Spec. 4:9–6:19. Claims 1 and 9
are illustrative with key disputed limitations emphasized:
1. A method in a wireless communications device that allocates
neighbor signals to a candidate set, the method comprising:
determining a number of signals in an active set;
allocating signals to the candidate set more quickly when the number
of signals in the active set is less than a threshold number than when the
number of signals in the active set is greater than the threshold number.

9. A method in a wireless communications device that allocates
neighbor signals to a candidate set based on criteria considered over at least
one scanning period, the method comprising:
determining a number of signals in an active set;
when the number of signals in the active set is greater than a
threshold number, allocating neighbor signals to the candidate set using
criteria considered over more than one scanning period;

1 The Examiner indicates that claims 2 and 3 recite allowable subject matter
and therefore withdrew the rejection of those claims. Ans. 2, 9.
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when the number of signals in the active set is less than the threshold
number, allocating neighbor signals to the candidate set using criteria
considered over fewer scanning periods than when the number of signals in
the active set is greater than the threshold number.

The Examiner relies on the following as evidence of unpatentability:
Krause
Joshi
US 6,160,799
US 2004/0203838 A1
Dec. 12, 2000
Oct. 14, 2004
(filed Dec. 5, 2002)

THE REJECTION
The Examiner rejected claims 1, 4-13, and 17-19 under 35 U.S.C.
§ 103(a) as unpatentable over Joshi and Krause. Ans. 3-9.2

CONTENTIONS
The Examiner finds that Joshi discloses every recited feature of claim
1 and cites Krause as additional support for teaching allocating signals to the
candidate set more quickly when the number of signals in the active set is
not greater than a threshold number. Ans. 3-5. Regarding claim 9, the
Examiner finds that Joshi discloses every recited feature including allocating
signals to the candidate set using criteria considered over more than one
scanning period, and cites Krause as additional support with respect to other
features. Ans. 5-8.
Appellants argue that neither Joshi nor Krause discloses controlling
how quickly signals are added to the candidate set based on the number of
signals in the active set, as recited in claim 1. Br. 4-5. Appellants also argue

2 Throughout this opinion, we refer to (1) the Appeal Brief filed March 28,
2007, and (2) the Examiner’s Answer mailed June 19, 2007.
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that Joshi does not disclose allocating signals to a candidate set based on
criteria considered over a number of scanning periods, as recited in claim 9.
Br. 8-9. Appellants argue other limitations of various claims indicated in the
issue statement below. The issues before us, then, are as follows:

ISSUES
Under § 103, has the Examiner erred by finding that Joshi and Krause
collectively would have taught or suggested:
(1) allocating signals to a candidate set more quickly when the
number of signals in an active set is less than a threshold number, as recited
in claim 1?
(2) when the number of signals in the active set is less than the
threshold number, allocating signals to the candidate set more quickly only
when the number of signals in the active set is less than a threshold number,
and when the quality of a strongest active signal is less than a first signal
quality threshold, as recited in claim 4?
(3) allocating signals to the candidate set more quickly only when the
number of signals in the active set is less than a threshold number and when
a most energetic rake finger has an energy greater than an energy threshold,
as recited in claim 6?
(4) allocating signals to the candidate set when the number of signals
in the active set is less than a threshold number based on consideration of
signal promotion criteria for not more than one scanning period, as recited in
claim 7?
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(5) allocating signals to a candidate set using criteria considered over
more than one scanning period when the number of signals in an active set is
greater than a threshold number, as recited in claim 9?

FINDINGS OF FACT (FF)
1. Joshi discloses that a mobile station maintains an active set, a
candidate set, and a non-candidate neighbor set. Joshi ¶ 0053. The active
set includes base stations with the strongest pilot signals, and all active set
base stations use the same pilot signal frequency. Joshi ¶ 0054. The mobile
station places non-candidate base stations in the candidate set if their pilot
signals exceed a given strength, but either fail to reach the minimum strength
for the active set or do not use the same frequency as the active set members.
Joshi ¶¶ 0055-56. Joshi determines membership of the active set and the
candidate set during “on-frequency” and “off-frequency” searches. Joshi ¶
0057.
2. Joshi conducts off-frequency searching if a condition is met.
Specifically, if the count of base stations in an active set exceeds a
prescribed number, for example, one, there is a sufficient number of active
set base stations, and off-frequency searching is not as critical as when the
active set is under-populated. In this case, off-frequency searching is
unnecessary. Joshi ¶ 0065; Fig. 9.
3. Joshi discloses that even if off-frequency searching is warranted
based on the prescribed number of active set base stations, off-frequency
searching may still be unnecessary if the maximum signal-to-noise ratio of
pilot signals from the active set of base stations meets a prescribed decibel
level. Joshi ¶ 0066; Fig. 9.
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4. Joshi discloses that a mobile station conserves battery power by
managing the timing and selective performance of off-frequency searches
for base station pilot signals with frequencies that differ from the pilot
signals of the active set. Joshi ¶ 0020. If off-frequency searching is found
to be unnecessary, avoidance of off-frequency searching saves considerable
power and time because the mobile station is not required to re-tune its
transceiver to any off-frequencies. Joshi ¶ 0069.
5. Joshi discloses that in an IDLE state the mobile station alternates
between wakeup and sleep cycles. Joshi ¶ 0045. During a wakeup period,
which may be five seconds, the mobile station searches for pilot signals of
possibly nearby base stations. Joshi ¶ 0046; Fig. 8.
6. Krause discloses that a mobile station must quickly determine
which neighbor pilots to promote to a candidate set to ensure that the
strongest pilots will remain in the active set, for example, in a rapidly
changing environment such as when the active pilots are rapidly shadowed
when the mobile station goes around the corner of a large building. Krause,
col. 2, ll. 40-56.
7. Krause discloses that the mobile station can implement a rake
receiver comprised of a plurality of finger receivers. Krause, col. 3, ll. 41-
55; Fig. 1. A searcher receiver sweeps the pilot signals of an active pilot and
determines the strength of each as a ratio of pilot energy to total power
spectral density in the received bandwidth, expressed in decibels. Krause,
col. 4, ll. 1-9; Fig. 1.

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ANALYSIS
Claims 1 and 8
Based on the record before us, we find no error in the Examiner’s
obviousness rejection of representative claim 1, which recites, in pertinent
part, “allocating signals to the candidate set more quickly when the number
of signals in the active set is less than a threshold number.”
Joshi promotes non-candidate signals to a candidate set of signals by
performing off-frequency searching, wherein off-frequency searching is
performed if the number of signals in an active set does not exceed a certain
threshold. See FF 1-2. If the threshold is exceeded, off-frequency searching
is unnecessary. FF 2. Given that the thrust of Joshi’s disclosure is to save
power, unnecessary off-frequency searching should be minimized, if
performed at all. See FF 4. Thus, in Joshi’s invention, signals can be
allocated to the candidate set when there are not enough signals in the active
set, and not allocated when there are enough active set signals. This
teaching alone is a sufficient basis to conclude that the disputed limitation
would have been obvious because allocating signals if a certain condition is
met and not allocating signals if the condition is not met is the epitome of
allocating signals more quickly in the former situation than the latter. But
even if such “unnecessary” off-frequency searching were conducted (a
circumstance not precluded by Joshi’s step 913 in Figure 9), it would be less
critical (hence “unnecessary”) than the off-frequency search dictated by step
912 in Figure 9. As such, the Examiner’s point (Ans. 11-13) that these less-
critical off-frequency searches would be performed less often than their
more critical counterparts is well taken, particularly in view of the need to
conserve power, as noted above.
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Krause further bolsters the obviousness conclusion by teaching that it
is important to quickly promote neighbor signals to a candidate set when in
danger of losing active set signals (FF 6)—a teaching that reasonably
comports with the functionality of Joshi’s Figure 9. See FF 2-3.
We are therefore not persuaded that the Examiner erred in rejecting
claim 1, and claim 8 not separately argued with particularity.

Claims 4 and 5
Appellants argue that neither Joshi nor Krause allocates signals to the
candidate set more quickly based on the number of signals in the active set
and whether the quality of the strongest active signal is less than a signal
quality threshold. Br. 6. We disagree. Joshi discloses that the decision to
perform off-frequency searching can be based on the number of signals in
the active set and whether the signal-to-noise ratio (i.e., the quality)of the
strongest active set signal meets a predetermined threshold. See FF 2-3. We
are therefore not persuaded that the Examiner erred in rejecting claim 4, and
claim 5 not separately argued with particularity.

Claim 6
Appellants argue that Joshi does not allocate signals to the candidate
set based on the number of signals in the active set and based on rake finger
energy. Br. 6-7. However, the Examiner relies on Krause for teaching a
rake receiver. Ans. 8-9, 14-16. Krause determines the energy strength of
each active pilot signal received in a finger of the rake receiver as measured
in decibels. See FF 7. Appellants’ arguments focus solely on Joshi, and do
not address the Examiner’s position (Ans. 14-16) based on the collective
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teachings of Joshi and Krause. See Br. 6-7. Thus, absent argument or
evidence to the contrary, we find that it would have been obvious to modify
Joshi’s allocation criteria (see FF 2-3) in view of Krause. Namely, one of
ordinary skill in the art would have been motivated to use the decibel level
of the strongest active pilot signal from a finger of Krause’s rake receiver
(see FF 7), in place of the decibel level of Joshi’s strongest signal-to-noise
ratio, along with the number of active set signals as the criteria for
determining whether to perform off-frequency searching. We are therefore
not persuaded that the Examiner erred in rejecting claim 6.

Claim 7
Appellants argue that Joshi is silent regarding the number of scanning
periods over which signal promotion criteria are considered, and thus does
not allocate signals to the candidate set based on consideration of the criteria
for not more than one scanning period. Br. 7-8. Appellants, however, do
not address in a Reply Brief the Examiner’s finding that Joshi discloses
periodic intervals—referred to as “wakeup periods”—during which off-
frequency searching takes place. See Ans. 16-17. We agree with the
Examiner that Joshi’s wakeup period constitutes a scanning period because
searching for pilot signals takes place during this period. See id.; FF 5.
Further, as discussed above, searching for signals such as off-frequency
signals can result in allocating signals to the candidate set if certain criteria
are met. See FF 1-3. Thus, Joshi’s allocation of signals to the candidate set
can be based on considering signal promotion criteria over one wakeup
period, that is, not more than one scanning period. We are therefore not
persuaded that the Examiner erred in rejecting claim 7.
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Claims 9-13
We do not, however, sustain the Examiner’s obviousness rejection of
independent claim 9 which recites, in pertinent part, “when the number of
signals in the active set is greater than a threshold number, allocating
neighbor signals to the candidate set using criteria considered over more
than one scanning period.”
We agree with Appellants that Joshi does not consider criteria over
more than one scanning period. Br. 8-9. While Joshi searches for pilot
signals during a wakeup period (FF 5), the Examiner has not shown that
Joshi considers the criteria for allocating such signals to the candidate set
over multiple wakeup periods. That is, on this record, we cannot say that
Joshi’s mobile station wakeup periods are anything more than independent
events where scanning for pilot signals meeting certain criteria begins anew.
Further, the Examiner does not rely on Krause to cure this deficiency. See
Ans. 5-8, 17-20.
We are therefore constrained by this record to find that the Examiner
erred in rejecting independent claim 9, and dependent claims 10-13 for
similar reasons.
Claims 17-19
Based on the record before us, we find no error in the Examiner’s
obviousness rejection of representative claim 17, which recites, in pertinent
part, “dynamically changing the signal allocation criteria based on either a
number of signals in an active signal set or on a signal quality of a strongest
signal in the active signal set.”
We first note that the recited limitation is similar to the claim 1
limitation discussed above. Specifically, claim 1 recites allocating signals to
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the candidate set more quickly based the number of signals in the active set.
Claim 17, however, is broader than claim 1 in this respect because claim 17
does not require that the signal allocation criteria be changed in a particular
way (e.g., that signals be allocated more quickly), just that the signal
allocation criteria be changed somehow based on the number of signals in
the active set. Further, although changing the signal allocation criteria based
on a signal quality of a strongest signal in the active signal set is an optional
feature of claim 17 (due to the alternative “either . . . or” language), we note
the presence of a similar feature in claim 4 as discussed above. Thus,
Appellants’ arguments regarding claim 17 (Br. 10-12) are not persuasive for
the reasons previously discussed with respect to claims 1 and 4.
We are therefore not persuaded that the Examiner erred in rejecting
claim 17, and claims 18 and 19 not separately argued with particularity.

CONCLUSION
Under § 103, the Examiner erred in rejecting claims 9-13, but did not
err in rejecting claims 1, 4-8, and 17-19.

ORDER
The Examiner’s decision rejecting claims 1, 4-13, and 17-19 is
affirmed-in-part.
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-IN-PART

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