Ex Parte Zhong et al

Patent Trial and Appeal Board

Jan 30, 2018

14107721 (P.T.A.B. Jan. 30, 2018)

United States Patent and Trademark Office
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.
14/107,721 12/16/2013 Degang Zhong HW 83171082US14 7150
74365 7590 02/01/2018
Slater Matsil, LLP/HW/FW/HWC
17950 Preston Road, Suite 1000
Dallas, TX 75252
EXAMINER
LAMBERT, DAVID W
ART UNIT PAPER NUMBER
2636
NOTIFICATION DATE DELIVERY MODE
02/01/2018 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
uspatent@huawei.com
docketing @ slatermatsil. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte DEGANG ZHONG, SULIN YANG, SHENPING LI, and
ZEBIN LI
Appeal 2017-009557
Application 14/107,7211
Technology Center 2600
Before ROBERT E. NAPPI, CATHERINE SHIANG, and
JAMES W. DEJMEK, Administrative Patent Judges.
DEJMEK, Administrative Patent Judge.
DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from a Final Rejection of
claims 1-18. We have jurisdiction over the pending claims under 35 U.S.C.
§ 6(b).
We affirm.
1 Appellants identify Huawei Technologies Co., Ltd. as the real party in
interest. Br. 2.
Appeal 2017-009557
Application 14/107,721
STATEMENT OF THE CASE
Introduction
Appellants’ disclosed and claimed invention is generally directed to
“controlling optical power of a passive optical network.” Spec. ^ 2.
According to the Specification, an automatic power control (APC) loop is
used to ensure the stability of the transmitted optical power and manage to
the power budget of a network link. Spec. ^ 4. As part of the APC, output
optical power is monitored and the APC adjusts a bias current of the optical
source according to the monitoring result. Spec. ^ 4. Additionally, the
Specification states it is well-known to use an optical time domain
reflectometer (OTDR) to perform optical fiber network tests and for fault
location. Spec. ^ 5. In a disclosed embodiment, during an OTDR test, a test
signal is superimposed on regular communication data. Spec. ^ 6. The
relative strength of the test signal is less than the communication data.2
Spec. ^ 6. To prevent the automatic adjustment of the output optical power
from significantly weakening the intensity of the OTDR test signal, as part
of Appellants’ claimed invention, when a test signal is detected, the APC is
suspended such that the power monitoring result is ignored and the bias
current of the optical source is maintained at a preset target value. Spec.
11 6-8.
Claim 5 is representative of the subject matter on appeal and is
reproduced below with the disputed limitation emphasized in italics'.
5. An optical source driver, comprising:
a controller;
2 As an example range, the Specification states that the strength of the test
signal may be between 5 and 30% of the strength of the communication
data. Spec. ^ 6.
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Appeal 2017-009557
Application 14/107,721
a bias current adjustment unit coupled to the controller;
and
an optical power monitoring unit coupled to the controller;
wherein the optical power monitoring unit is configured to
monitor output optical power of an optical source and provide an
output optical power monitoring result to the controller; and
wherein the controller is configured to detect whether a
preset test control signal is received so that when the preset test
control signal is not received, the bias current adjustment unit is
controlled to adjust a bias current of the optical source according
to the output optical power monitoring result to implement
automatic power control and so that when the preset test control
signal is received, the bias current adjustment unit is controlled
to maintain the bias current of the optical source at a preset
target value by ignoring the output optical power monitoring
result.
The Examiner’s Rejections
1. Claims 5-9 stand rejected under 35 U.S.C. § 102(b) as being
anticipated by Bartur et al. (US 2005/0201761 Al; Sept. 15, 2005)
(“Bartur”). Final Act. 4-6.
2. Claims 1^1 and 10-18 stand rejected under 35 U.S.C. § 103(a)
as being unpatentable over Bartur and Wong (US 5,077,729; Dec. 31, 1991).
Final Act. 6-15.
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Appeal 2017-009557
Application 14/107,721
ANALYSIS3
Rejection under 35 U.S.C. § 102
Appellants argue that Bartur, as relied on by the Examiner, does not
anticipate claim 5 because Bartur fails to disclose maintaining the bias
current of the optical source at a preset target value by ignoring the output
optical power monitoring result. Br. 4-5. In particular, Appellants contend
Bartur only discloses that during a test scenario, the bias control is set to a
maximum value but does not further disclose ignoring the output optical
power monitoring result. Br. 5 (citing Bartur 10). Further, Appellants
assert Bartur cannot ignore the power monitoring result even if the bias
power control were set to a maximum value. Br. 5. Appellants contend this
is because Bartur’s microcontroller adjusts the bias control input based on
the output power signal. Br. 5 (citing Bartur 27).
Bartur is generally directed to detecting and localizing fault conditions
in an optical fiber system. Bartur 8. Bartur discloses the use of an Optical
Time Domain Reflectometer to localize a fault based on detected reflections
along an optical path. Bartur 6. Additionally, Bartur describes an optical
transceiver as comprising, on the transmit side, a laser diode and a laser
driver providing a drive signal to the laser diode. Bartur 9, 26. Bartur
also describes using a back facet monitor photodiode to monitor the output
power. Bartur 27. Figure 2 of Bartur is illustrative and is reproduced
below.
3 Throughout this Decision we have considered the Appeal Brief, filed
January 3, 2017 (“Br.”); the Examiner’s Answer, mailed on April 14, 2017
(“Ans.”); and the Final Office Action, mailed August 5, 2016 (“Final Act.”),
from which this Appeal is taken.
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Appeal 2017-009557
Application 14/107,721
s
Figure 2 of Bartur is a block diagram of an optical transceiver. Bartur ^ 18.
As shown in Figure 2, data to be transmitted (16) is provided to Laser Driver
(114), which drives output Laser Diode (110). See Bartur 26-27. The
output optical power is monitored by back facet diode (116). Bartur 27.
The output from the Back Facet Diode is provided (via 117) to the
Microcontroller (118), which adjusts a laser bias control input to Laser
Driver (114). Bartur 27. Bartur explains that the bias (and modulation)
control signals from the Microcontroller (118) allow the Laser Driver (114)
to respond to variations in Laser Diode (110). Bartur 27.
However, in test mode (i.e., when Transmitter Disable (115) is
enabled), Bartur discloses the transmitter blocks the external data (16) from
affecting the output of Laser Driver (114). Bartur 27. Bartur also
discloses that in the test mode, the Microcontroller (118) sets the bias to the
Laser Driver (114) “in order to drive the highest possible impulse into the
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Appeal 2017-009557
Application 14/107,721
fiber.” Bartur ^ 36. Bartur describes the Microcontroller providing the bias
level in the test mode as running “open loop”—i.e., without using the output
optical power monitoring result from Back Facet Diode (116). Bartur 36.
Based on our review of Bartur, we agree with the Examiner’s findings
and explanation of Bartur’s operation. See Final Act. 4-5; Ans. 14-19. In
particular, we agree that Bartur describes operation in two distinct modes of
operation—a normal (i.e., data transport) mode and a test mode. Ans. 14.
During normal operation, the bias current from the Microcontroller is based
on the signal received from the Back Facet Diode, which monitors the output
optical power of the Laser Diode. Ans. 14-15. As discussed above, we
agree with the Examiner that during the test mode of operation, “the
microcontroller 118 does not adjust the laser bias control input based on the
monitored laser output power signal.” Ans. 16. Instead, the Microcontroller
sets the bias level to a preset value (e.g., a maximum value) independent of
the monitored laser output power signal. Ans. 16-17. Further, we agree
with the Examiner’s interpretation of “ignoring the output optical power
monitoring result” as “not acting upon the results of optical power
monitoring” because under the broadest reasonable interpretation of the
limitation, the Examiner correctly interprets the claimed “ignoring” as “not
acting upon.” Ans. 18.
For the reasons discussed supra, we are unpersuaded of Examiner
error. Accordingly, we sustain the Examiner’s rejection of independent
claim 5. Additionally, we sustain the Examiner’s rejection of claims 6-9,
which depend therefrom and were not argued separately. See Br. 6.
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Appeal 2017-009557
Application 14/107,721
Rejection under 35 U.S.C. § 103
Regarding the Examiner’s rejection under 35 U.S.C. § 103(a) of
independent claims 1,11, and 15, Appellants advance the same argument
that Bartur does not teach ignoring the output optical power monitoring
result during a test period to maintain the bias current of the optical source at
a preset target value. Br. 6. Additionally, Appellants assert that Wong does
not cure the alleged deficiencies of Bartur. Br. 6.
For the reasons discussed supra regarding our review and the
Examiner’s findings of Bartur, we are unpersuaded of Examiner error. As
such, Wong is not required to teach or suggest the disputed limitation.
Accordingly, we sustain the Examiner’s rejection of independent claims 1,
11, and 15. Additionally, we sustain the Examiner’s rejection of claims 2—4,
10, 12-14, and 16-18, which depend therefrom and were not argued
separately. See Br. 6.
DECISION
We affirm the Examiner’s decision rejecting claims 1-18.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 41.50(f)(2016).
AFFIRMED
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