from the United States Patent and Trademark Office, Patent
Trial and Appeal Board in No. IPR2015-01367.
Garrett Spears, Baker & Hostetler LLP, Houston, TX,
argued for appellants. Also represented by Gregory Matthew
McCloskey, Cesari and McKenna, LLP, Boston, MA.
Leroy Pickard, Sterne Kessler Goldstein & Fox, PLLC,
Washington, DC, argued for appellee. Also represented by Lori
Reyna, Taranto, and Chen, Circuit Judges.
Inc. and Telefonaktiebolaget LM Ericsson appeal the final
written decision of the U.S. Patent and Trademark
Office's Patent Trial and Appeal Board, finding that
claims 1-3, 6-9, and 12-14 of U.S. Patent No. 5, 602, 831 are
not unpatentable under 35 U.S.C. § 103. Because we
conclude that the Board improperly did not consider portions
of Ericsson's Reply, we vacate and remand.
Intellectual Ventures I LLC ("Intellectual
Ventures") owns U.S. Patent No. 5, 602, 831 ("the
'831 patent"), entitled "Optimizing packet size
to eliminate effects of reception nulls." The '831
patent expired on March 31, 2015.
'831 patent is directed to increasing the reliability of
a wireless communications system when a wireless receiver is
moving by minimizing the effects of burst errors that occur
at the receiver. '831 patent, Abstract; id. col.
1 ll. 5-8. The moving wireless communications devices
disclosed in the '831 patent transmit information via
packets containing bits of information. Signal fading or
signal drop-outs result in transmission errors in which some
or all of the bits in the packet are not successfully
received by the receiver. The '831 patent refers to these
transmission errors as "burst errors" or
"nulls." Id. col. 1 ll. 23-29. Although
nulls occur randomly, they can be predicted based on various
signal drop characteristics, such as the speed the receiver
is moving. For instance, at slow speeds, nulls are generally
wider and the amount of time between nulls is longer, whereas
at higher receiver speeds, the nulls are narrower and occur
more frequently. See id. col. 2 ll. 24-28.
'831 patent describes various techniques in the prior art
for reducing the effects of burst errors and nulls, including
error correction techniques, retransmission, transmitting
over multiple frequencies, and using multiple transmitter
stations in various locations. Id. col. 1 l. 35-col.
2 l. 11. The patent further notes that "[a]nother
technique for reducing the effects of burst errors involves
interleaving multiple message packets together thus creating
better burst error correction capabilities."
Id. col. 2 ll. 4-6. Interleaving is a coding
technique by which data is read into a two-dimensional
register (e.g., columns of characters) column-by-column, and
then read out of the register row-by-row. J.A. 4.
Interleaving multiple packets spreads out the effect of
errors due to signal drops, such that any dropped signal
will, at most, create only a loss of a small portion in each
packet, rather than the loss of an entire packet. Regarding
the prior art, the '831 patent notes that the efficacy of
interleaving in reducing the effects of burst errors for
portable receivers is limited when the size of the
interleaved packet does not change: "transmitting a
single interleaved packet size for varying signal drop-out
conditions is not completely effective in minimizing burst
error effects." '831 patent col. 2 ll. 4-11.
'831 patent discloses new methods of mitigating the
effects of signal drops, specifically by encoding packets
into packet blocks by interleaving the packets together into
a register, and varying the number of packets encoded into
each packet block according to signal drop characteristics,
such as the speed at which the receiver is moving.
Id. col. 2 ll. 17-21, 34-48. Because of the
interleaving, any burst errors are distributed between all
packets in the packet block, which can then be decoded more
easily. Id., Abstract; id. col. 7 ll.
17-38. The '831 patent makes clear that the technique of
"interleaving" was known in the art:
Interleaving packets together is known in the art.
However, varying the number of bytes in each packet
interleaved together according to receiver speed is novel and
provides substantial advantages over existing interleaving
Explaining further, the interleaving process discussed above
increased the number of bytes in each packet successfully
received by the receiver. However, if the speed of motion of
the receiver changes, the signal drop-out characteristics
also change as previously shown in FIGS. 3-5. Thus, the
packet block size shown in FIG. 9 (9 packets) may not improve
reception reliability at a new receiver travel speed.
. . . .
To prevent more than one burst error (null) from occurring in
any one packet block, the transmitter again adjusts the
packet block size according to the ...