Ex Parte HE

Board of Patent Appeals and Interferences

Sep 26, 2003

09124278 (B.P.A.I. Sep. 26, 2003)

1
The opinion in support of the decision being entered today was
not written for publication and is not binding precedent of the
Board.
Paper No. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte LINHAI HE
__________
Appeal No. 2002-0874
Application 09/124,278
___________
ON BRIEF
___________
Before HAIRSTON, FLEMING, and LEVY, Administrative Patent Judges.
FLEMING, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the final rejection of
claims 1 through 32, all the claims pending in the instance
application.
Invention
The invention relates to a push-out technique for shared
memory buffer management in network nodes. See page 1 of
Appellant’s specification. A weighted queue length is maintained
Appeal No. 2002-0874
Application 09/124,278
2
in memory for each queue stored in the shared memory buffer.
When a new data packet arrives at the network node to be stored
in its appropriate queue and the buffer is full, a data packet is
removed from the queue having the largest weighted queue length.
This makes room in the buffer for the newly arrived data packet
to be stored in the appropriate queue. See page 3 of Appellant’s
specification. The weighted queue length is maintained by
adjusting the weighted queue length of a queue by an amount equal
to the weight assigned to the traffic class of the data packet.
These weights may be provisioned in order to implement different
loss priorities among the traffic classes. See page 4 of
Appellant’s specification. With reference to figure 3, the
weighted queue length is calculated as follows. First, each
traffic class is assigned a weight based on its loss priority,
the small weights corresponding to high priorities. This weight
assignment may be provisioned on a per output port basis so that
the same traffic class at different output ports may have
different priorities. A weighted queue length is maintained for
each connection queue stored in the buffer. When a data packet
associated with a particular connection arrives at the network
node, the data packet is stored in the associated connection
queue and the weighted queue length of the connection queue is
Appeal No. 2002-0874
Application 09/124,278
3
incremented by an amount equal to the weight assigned to the
traffic class of the connection. Similarly, when a data packet
associated with a particular connection departs from the network
node, the data packet is removed from the associated connection
queue and the weighted queue length of the connection queue is
decremented by the amount equal to the weight assigned to the
traffic class of the connection. See page 6 of Appellant’
specification.
Claim 1 is representative of Appellant’s claimed invention
and is reproduced as follows:
1. A method for managing a shared memory buffer in a
network node comprising the steps of:
maintaining a weighted queue length for each of a plurality
of queues stored in said shared memory buffer, said weighted
queue length for each of said plurality of queues being a
function of the type of data in the queue and the amount of data
in the queue; and
upon receipt of a new data item to be added to a first one
of said queues when said shared memory buffer is full:
determining a second one of said queues based on weighted
queue length;
removing a data item from said second queue; and
adding said new data item to said first queue.
Appeal No. 2002-0874
Application 09/124,278
1 Appellant filed an appeal brief on June 29, 2001.
Appellant filed a reply brief on January 23, 2002. The Examiner
mailed an Office Communication on April 5, 2002, stating that the
reply brief has been entered.
4
References
The references relied on by the Examiner are as follows:
Varma et al. (Varma) 5,959,993 Sep. 28, 1999
(Filing date Sep. 13, 1996)
Chao, “An ATM Queue Manager Handling Multiple Delay and Loss
Priorities” IEEE 1995, pp. 652-659.
Rejection at Issue
Claims 1 through 32 stand rejected under 35 U.S.C. § 103 as
being unpatentable over Varma in view of Chao.
Throughout the opinion, we make reference to the briefs1 and
answer.
OPINION
With full consideration being given to the subject matter on
appeal, the Examiner’s rejection and the arguments of the
Appellant and the Examiner, for the reasons stated infra, we
reverse the Examiner’s rejection of claims 1 through 32 under
35 U.S.C. § 103.
Appeal No. 2002-0874
Application 09/124,278
5
In rejecting claims under 35 U.S.C. § 103, the Examiner
bears the initial burden of establishing a prima facie case of
obviousness. In re Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443,
1444 (Fed. Cir. 1992). See also In re Piasecki, 745 F.2d 1468,
1472, 223 USPQ 785, 788 (Fed. Cir. 1984). The Examiner can
satisfy this burden by showing that some objective teaching in
the prior art or knowledge generally available to one of ordinary
skill in the art suggests the claimed subject matter. In re
Fine, 837 F.2d 1071, 1074, 5 USPQ2d 1596, 1598 (Fed. Cir. 1988).
Only if this initial burden is met does the burden of coming
forward with evidence or argument shift to the Appellant.
Oetiker, 977 F.2d at 1445, 24 USPQ2d at 1444. See also Piasecki,
745 F.2d at 1472, 223 USPQ at 788.
An obviousness analysis commences with a review and
consideration of all the pertinent evidence and arguments. “In
reviewing the [E]xaminer’s decision on appeal, the Board must
necessarily weigh all of the evidence and argument.” Oetiker,
977 F.2d at 1445 24 USPQ2d at 1444. “[T]he Board must not only
assure that the requisite findings are made, based on evidence of
Appeal No. 2002-0874
Application 09/124,278
6
record, but must also explain the reasoning by which the findings
are deemed to support the agency’s conclusion.” In re Lee, 277
F.3d 1338, 1344, 61 USPQ2d 1430, 1434 (Fed. Cir. 2002).
We note that independent claims 1, 9 and 17, each recite a
weighted queue length. Specifically, claims 1 and 9 recite “said
weighted queue length for each of said plurality of queues being
a function of the type of data in the queue and the amount of
data in the queue”. Claim 17 recites “adjusting a weighted queue
length of a queue by a weight value when adding a data packet to
or removing a data packet from said queue”.
Appellant argues that neither Varma or Chao teach or suggest
a weighted queue length as claimed. See page 8 of the Brief. In
particular, Appellant argues that Varma’s Weighted Fair Queuing
(WFQ) does not read on Appellant’s claimed weighted queue length.
Appellant points out that, because the claimed weighted queue
length is determined by the combination of weights assigned to
the traffic class of the connection queue and the number of data
packets in the connection queue, the weighted queue length will
continuously change as data packets are added and removed from
the connection queue. On the other hand, the Varma patent
teaches the use of WFQ where the weight of a connection is
predetermined and does not change as the data packets are added
Appeal No. 2002-0874
Application 09/124,278
7
or removed. Appellant argues that the Varma patent does not
teach or suggest weighted queue lengths as recited in Appellant’s
claims. See pages 9 and 10 of the brief.
Appellant further argues that, unlike WFQ systems,
Appellant’s system using the weighted queue length concept of the
present invention permits the weighted queue length of individual
queues to change as data packets are added or removed from the
individual queues. Appellant argues that this definition of
weighted queue lengths is clearly supported in the specification
at page 6, line 22 through page 7, line 13, which states:
A weighted queue length is maintained for each connection
queue stored in the buffer. When a data packet associated
with a particular connection arrives at the network node,
the data packet is stored in the associated connection queue
and the weighted queue length of the connection queue is
incremented by an amount equal to the weight assigned to the
traffic class of the connection. Similarly, when a data
packet associated with a particular connection departs from
the network node, the data packet is removed from the
associated connection queue and the weighted queue length of
the connection queue is decremented by an amount equal to
the weight assigned to the traffic class of the connection.
. . . When a new data packet arrives and finds that the
shared memory buffer is full, the connection queue having
the largest weighted queue length is selected and a data
packet is removed from that connection queue.
Appellant argues that accordingly, since the weights of the
individual queues in WFQ systems do not change as data is added
Appeal No. 2002-0874
Application 09/124,278
8
or removed from the individual queues, WFQ is not the same as the
weighted queue length of the claimed invention. See pages 3 and
4 of Appellant’s reply brief.
The Examiner argues that Varma does teach weighted queue
lengths as claimed. In particular, the Examiner points us to
column 7, lines 45 through 67. See pages 8 and 9 of the
examiner’s answer.
Upon our review of Varma, and in particular column 7, lines
45 through 67 of Varma, we fail to find that Varma teaches
Appellant’s claimed weighted queue length for each of the said
plurality of queues being a function of type of data in the queue
and the amount of data in the queue as recited in Appellant’s
claims. Varma teaches that a queue assigned a priority of zero
will have a greater priority than a queue assigned a priority of
one. Furthermore, Varma discloses that the controller 38 chooses
the first priority group starting from zero for transmission.
The controller 38 implements Round-Robin within priorities. From
our review of Varma, we fail to find that Varma teaches
Appellant’s claimed weighted queue length for each of plurality
Appeal No. 2002-0874
Application 09/124,278
9
of queues being a function of a type of data in a queue and the
amount of data in a queue. Therefore, we will not sustain the
Examiner’s rejection of claims 1 through 32 under 35 U.S.C.
§ 103.
REVERSED
KENNETH W. HAIRSTON )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
MICHAEL R. FLEMING )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
STUART S. LEVY )
Administrative Patent Judge )
MRF:pgg
Appeal No. 2002-0874
Application 09/124,278
10
Synnestvedt & Lechner, LLP
2600 Aramark Tower
1101 Market Street
Philadelphia, PA 19107-2950