Telefonaktiebolaget LM Ericsson (publ)

Patent Trials and Appeals Board

Jun 11, 2021

2020001806 (P.T.A.B. Jun. 11, 2021)

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.
15/509,001 03/06/2017 Mattias Frenne 3000-596 6316
27820 7590 06/11/2021
WITHROW & TERRANOVA, P.L.L.C.
106 Pinedale Springs Way
Cary, NC 27511
EXAMINER
CUNNINGHAM, KEVIN M
ART UNIT PAPER NUMBER
2461
NOTIFICATION DATE DELIVERY MODE
06/11/2021 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):
patents@wt-ip.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte MATTIAS FRENNE, JUNG-FU CHENG, DANIEL LARSSON,
HAVISH KOORAPATY, and SOROUR FALAHATI
Appeal 2020-001806
Application 15/509,001
Technology Center 2400
Before ALLEN R. MacDONALD, MICHAEL J. ENGLE, and
SCOTT RAEVSKY, Administrative Patent Judges.
ENGLE, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1–7 and 9–15, which are all of the claims pending in the
application. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies Telefonaktiebolaget LM Ericsson
(publ) as the real party in interest. Appeal Br. 2.
Appeal 2020-001806
Application 15/509,001

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TECHNOLOGY
The application relates to “scheduling a control channel” in wireless
communications. Spec. 1:5–7, 10–12. For these communications, the
application proposes using a technology in which an “unlicensed . . .
spectrum is used as an extension to the licensed spectrum.” Id. at 2:14–19,
8:27–28. However, an “[u]nlicensed spectrum can, by definition, be
simultaneously used by multiple different technologies.” Id. at 8:28–29,
2:23–24. Therefore, “[p]rior to occupying a channel in an unlicensed band,
the network needs to check the availability of the channel by means of LBT
[i.e., Listen-Before-Talk].” Id. at 9:4–5, 2:23–25. On the other hand,
“[w]hen the network has already accessed a channel, it may, in the following
and adjacent transmission time interval, start transmission immediately, e.g.
from symbol 0, without performing LBT.” Id. at 9:5–7. The start time of
the control channel therefore may depend on whether LBT is performed, but
the “communication terminal” may not know in advance whether LBT is
being performed because that is decided by the “radio access node,” not the
communication terminal. Id. at 9:8–11. The claims here therefore propose a
configuration for the communication terminal “to monitor at least two start
positions for the control channel.” Id. at claim 1.
ILLUSTRATIVE CLAIM
Claim 1 is illustrative and reproduced below with certain limitations
in dispute underlined:
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Application 15/509,001

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1. A method performed by a radio access node for scheduling a
control channel to a communication terminal in a wireless
communication network; wherein the radio access node serves
the communication terminal in at least one of a first cell on a
carrier of a licensed or unlicensed spectrum, and the
communication terminal is further served in a second cell on a
carrier of an unlicensed spectrum, comprising:
- configuring the communication terminal with a
configuration, which configuration defines that the
communication terminal is to monitor at least two start
positions for the control channel intended for the
communication terminal, a first start position being used
by the radio access node when the radio access node does
not perform a Listen Before Talk, LBT, process and a
second start position being used by the radio access node
when the radio access node does perform a LBT process;
- determining whether a LBT process is to be performed or
not in the second cell;
- scheduling, based on whether the LBT process is to be
performed in a subframe on the second cell or not, the
control channel with a start position in the subframe out of
the at least two start positions; and
- transmitting control information on the control channel as
scheduled to the communication terminal.
REFERENCES
The Examiner relies on the following references as prior art:
Name Reference Date
Damnjanovic US 2015/0245327 A1 Aug. 27, 2015
Kaur US 2015/0131536 A1 May 14, 2015
Kim (“Kim2”) US 2014/0036889 A1 Feb. 6, 2014
Kim (“Kim1”) US 2014/0112289 A1 Apr. 24, 2014
Park US 2015/0223208 A1 Aug. 6, 2015
Appeal 2020-001806
Application 15/509,001

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REJECTIONS
The Examiner makes the following rejections under 35 U.S.C. § 103.
The Examiner withdrew the rejection under 35 U.S.C. § 101. Ans. 3.
Claims References Final Act.
1, 4, 6, 7, 9, 13–15 Kim1, Damnjanovic, Kim2 3
2, 3, 10–12 Kim1, Damnjanovic, Kim2, Park 9
5 Kim1, Damnjanovic, Kim2, Kaur 10
ISSUE
Did the Examiner err in finding Kim1, alone or in combination with
Kim2, teaches or suggests “the communication terminal is to monitor at least
two start positions for the control channel intended for the communication
terminal, a first start position being used by the radio access node when the
radio access node does not perform a Listen Before Talk, LBT, process and
a second start position being used by the radio access node when the radio
access node does perform a LBT process,” as recited in claim 1?
ANALYSIS
Claim 1 recites a radio access node configuring a communication
terminal with a configuration defining that “the communication terminal is
to monitor at least two start positions for the control channel intended for
the communication terminal, a first start position being used by the radio
access node when the radio access node does not perform a Listen Before
Talk, LBT, process and a second start position being used by the radio
access node when the radio access node does perform a LBT process.”
We are not persuaded by Appellant’s arguments that there is a
“fundamental difference” between what Kim1 discloses and the claimed
limitation. See Appeal Br. 21–24.
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Application 15/509,001

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The Specification discloses that “[t]he control information for a given
communication terminal is transmitted using one or multiple Physical
Downlink Control Channels (PDCCH)” and “[t]ypically the control region
may comprise many PDCCH carrying control information to multiple
communication terminals simultaneously.” Spec. 3:26–32; see also id. at
5:13–15. “The PDCCH . . . is used to carry Downlink Control Information
(DCI) in a scheduling DCI message such as scheduling decisions and power-
control commands.” Id. at 4:29–31.
For Kim1, the Examiner relies on “PDCCH” as the claimed “control
channel” and “carrier sensing” as the claimed “Listen Before Talk” (LBT).
Final Act. 3–4. In particular, the Examiner finds that “Kim1 discloses a
PDCCH can be transmitted at the start of a sub-frame, Para [0192]/Fig. 18
and can also be transmitted starting after carrier sensing is performed, Para
[0206]/Fig. 20, which means there are at least two starting locations for
transmitting the PDCCH.” Ans. 3–4. Appellant likewise concedes that
“PDCCH in different locations depending on whether or not LBT is
performed” is “disclosed in Kim1.” Appeal Br. 22. Thus, there is no
dispute that Kim1 discloses multiple starting locations for PDCCH based on
whether carrier sensing (i.e., LBT) is performed.
The next question is whether Kim1 teaches or suggests the
communication terminal (i.e., the “user equipment” or “UE” in Kim1)
monitoring at least two start positions for the control channel (i.e., PDCCH).
The Examiner sets forth two ways that Kim1 teaches or suggests this.
The Examiner’s first approach involves deciding where within a
control region a particular PDCCH will go. See Ans. 4–5. For background,
Appellant explains that
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a PDCCH comprises multiple Control Channel Elements
(CCEs). Each CCE comprises 9 Resource Element Groups
(REGs). Each REG contains 4 contiguous (in frequency)
Resource Elements (REs). CCEs have a logical index number,
are distributed across the system bandwidth, and are located
within the PDCCH region of the subframe. The PDCCH region
of the subframe can contain multiple PDCCHs.
Appeal Br. 23 (footnote omitted). Kim1 supports Appellant’s description.
Kim1 ¶¶ 68, 71–72, Table 1. In particular, Kim1 discloses that “a plurality
of PDCCHs can be transmitted within a control region” and a “UE can
monitor a plurality of the PDCCHs.” Id. ¶ 68. However, “[t]he number of
CCEs used for a transmission of a specific PDCCH varies” from one to eight
depending on which of four “PDDCH formats” is used for that specific
PDCCH. Id. ¶¶ 71–72, Table 1. According to Kim1, the UE is “not
informed” which particular format is used, so the UE has to perform “blind
decoding” to look for its PDCCH. Id. ¶ 74. Kim1 explains that “decoding
all available CCEs used for a DL according to each PDCCH format may
become a big burden to the UE,” so Kim1 proposes narrowing the number of
decoding attempts by defining a “search space.” Id. ¶ 74. “In particular, the
search space is a set of candidate PDCCHs consisted of CCEs where the UE
should perform a decoding attempt on an aggregation level.” Id. ¶ 75, Table
2. “Each UE monitors (performing a decoding attempt on a set of PDCCH
candidates according to an available DCI format) the UE-specific search
space” and checks whether certain values there are valid. Id. ¶ 77.
Appellant argues that Kim1 discloses “telling the UE which CCEs to
decode within a PDCCH of a known location,” but argues that is different
than “notifying the UE where the PDCCH may be located.” Appeal Br. 23.
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Application 15/509,001

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We are not persuaded by Appellant’s argument. Assuming a control
region exists at a known location, Appellant has not sufficiently explained
why checking specific CCEs within a control region for a valid PDCCH is
any different than checking different “start positions” for PDCCH. As
Appellant states, “CCEs are found at various, well-defined locations within
the control channel of the subframe in the time domain.” Reply Br. 3
(emphasis omitted).
Appellant does suggest that “looking for the start of a control channel
in two different locations in time as claimed” is somehow different from
Kim1’s search space for CCEs “distributed across the system bandwidth in
the frequency domain.” See Reply Br. 3–7 (some emphasis omitted). We
note, however, that the claims only recite a “start position” without
specifying whether that position is in the time domain or frequency domain.
Appellant further argues that the Examiner’s determination above
“presumes that the beginning of the subframe is also known,” which may not
be the case when doing LBT. See Reply Br. 6. The Examiner, however,
also proposes a second approach that combines Kim1 with Kim2.
According to the Examiner, “Kim2 discloses information regarding
carrier sensing may be shared beforehand between the eNB and the UE, . . .
and the carrier sensing position may be indicated in the form of an offset.”
Ans. 6 (citing Kim2 ¶ 202). “This means the UE knows beforehand if a sub-
frame is configured with a carrier sensing instance.” Id. “In view with
Kim1, the first start position of the PDCCH is at the conventional location,
at the start of the sub-frame, when no carrier sensing is performed and the
second PDCCH start position, is after the carrier sensing when carrier
sensing is performed in that sub frame.” Id. (citing Kim1 ¶ 206, Fig. 20).
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Application 15/509,001

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Although Kim2 discloses indicating the start location of PDSCH (Physical
Downlink Shared Channel), “Fig. 20 [of Kim1] discloses the PDCCH can be
in the PDSCH region, right after performing carrier sensing (i.e. second start
location).” Id. at 6–7. Thus, the Examiner determines that it would have
been obvious to one of ordinary skill in the art that the start location for
PDSCH in Kim2 also would be the start location for PDCCH as in Kim1.
Id. at 6.
Appellant has not persuaded us of error in the Examiner’s
combination. Although Kim2 alone does not teach or suggest the disputed
limitation, see Reply Br. 9–10, Appellant has not explained why the
Examiner’s combination of Kim1 and Kim2 would not teach or suggest
monitoring two start positions for PDCCH, one at the beginning of the
subframe if no LBT is performed and another after an offset if LBT is
performed, where PDCCH is in the PDSCH region as in Kim1.
Appellant argues claims 4, 7, 9, and 13–15 are patentable through
their dependence on claim 1. Appeal Br. 26. For the reasons discussed
above for claim 1, we are not persuaded of error.
Appellant argues Park and Kaur do not cure the deficiencies of Kim1,
Damnjanovic, and Kim2. Appeal Br. 27–28. For the reasons discussed
above, we are not persuaded Kim1, Damnjanovic, and Kim2 are deficient.
Accordingly, we sustain the Examiner’s rejections of claims 1–7 and
9–15. See 37 C.F.R. § 41.37(c)(1)(iv).
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Application 15/509,001

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OUTCOME
The following table summarizes the outcome of each rejection:
Claim(s)
Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 4, 6, 7,
9, 13–15
103 Kim1, Damnjanovic,
Kim2
1, 4, 6, 7,
9, 13–15

2, 3, 10–12 103 Kim1, Damnjanovic,
Kim2, Park
2, 3, 10–12
5 103 Kim1, Damnjanovic,
Kim2, Kaur
5
Overall
Outcome
1–7, 9–15
TIME TO RESPOND
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.
§ 1.36(a)(1)(iv).
AFFIRMED