RUCKUS WIRELESS, INC., CISCO SYSTEMS, INC., Plaintiffs-Appellees
INNOVATIVE WIRELESS SOLUTIONS, LLC, Defendant-Appellant
Appeals from the United States District Court for the Western District of Texas in Nos. 1:13-cv-00492-LY, 1:13-cv-00504-LY, Judge Lee Yeakel.
Matthew Yungwirth, Duane Morris LLP, Atlanta, GA, argued for plaintiffs-appellees. Also represented by L. Norwood Jameson; Diana Sangalli, Houston, TX.
Jonathan Daniel Baker, Farney Daniels PC, San Mateo, CA, argued for defendant-appellant. Also represented by Michael D. Saunders, Georgetown, TX.
Before Prost, Chief Judge, Reyna, Circuit Judge, and Stark, Chief District Judge. 
Reyna Circuit Judge
Innovative Wireless Solutions ("IWS") appeals the final judgment of non-infringement of the district court in the Western District of Texas. IWS challenges the district court's conclusion that the asserted patent claims are limited to wired rather than wireless communications. Because we find no error in the district court's construction, we affirm.
IWS owns U.S. Patent Nos. 5, 912, 895; 6, 327, 264; and 6, 587, 473 ("Terry patents"). The patents are a line of continuations beginning with the '895 patent. All share the '895 specification.
In April 2013, IWS commenced a litigation campaign against several dozen hotels and coffee shops doing business in the Eastern District of Texas. IWS alleged that each defendant infringed the Terry patents by providing WiFi Internet access to its customers using off-the-shelf WiFi equipment sold by Ruckus and Cisco ("Ruckus"). Ruckus responded by filing for declaratory judgment of invalidity and non-infringement in the Western District of Texas. On the issue of non-infringement, Ruckus argued that its wireless equipment does not infringe the Terry patents because the Terry patents are limited to wired rather than wireless communications.
The Terry patents concern techniques for providing access to a local area network (LAN) from a relatively distant computer. '895 patent col. 3 ll. 13–31. A LAN is a group of computers connected by a shared short-range transmission medium and configured to communicate using a given LAN protocol. Id. col. 1 ll. 13–31. When two computers on the LAN transmit onto the medium concurrently, they create interference known as a "collision, " and the concurrent communications may be lost. Id. col. 3 ll. 47–53. To deal with these collisions, a LAN protocol may define a contention scheme. Id. col. 8 ll. 4– 25. For instance, in a "collision detection" scheme, a transmitting computer that detects a collision waits for a given period before reattempting the transmission. Id. col. 7 ll. 66–67, col. 8 ll. 1–18. "Carrier Sense Multiple Access with Collision Detection" (CSMA/CD) is an IEEE standard LAN protocol that uses collision detection. Id.; id. col. 1 ll. 25-33.
The further apart two devices are on a LAN, the longer it takes transmissions between those devices to traverse the transmission medium. Id. col. 1 ll. 61–67, col. 2 ll. 1–18. When the devices are sufficiently far apart, the long transmission delays may render collision detection ineffective. Id. col. 8 ll. 26–43. Consequently, it is not practical to use LAN protocols with collision detection over long distances, such as those spanned by telephone lines. Id.
The Terry patents describe an approach by which a computer may communicate with a LAN over the long distances covered by telephone lines. The inventors propose using a collision avoidance scheme rather than a collision detection scheme. Id. col. 9 ll. 32–51. Under the avoidance scheme, a "master" modem in the LAN dictates the timing of one-way communications between the master modem and a "slave" modem in the distant computer. Id. Although the patents only describe connecting the master and slave modems over physical wires, such as a telephone line, the claims recite that the two modems are connected via a "communications path." Claim 1 of the '895 patent is representative:
1. A method of providing communications with a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) network via a bidirectional communications path, comprising the steps of:
at a first end of the communications path, providing a CSMA/CD interface to the network, buffering information packets received from the network via the interface in a first buffer, supplying information packets from the first buffer to the communications path, and supplying control information to the communications path;
at a second end of the communications path, buffering information packets received via the communications path in a second buffer, receiving the control information from the communications path, buffering information packets to be supplied via the communications path to the network in a third buffer, and supplying information packets from the third buffer to the communications path in dependence upon the control information; and
at the first end of the communications path, supplying information packets received via the communications path to a fourth buffer, and supplying the information packets from the fourth buffer to the network via the interface;
wherein the control information and the dependence on the control information for supplying information packets from the third buffer to the communications path are arranged to avoid collisions on the communications path between in-formation packets communicated from the first buffer to the second buffer and information packets communicated from the third buffer to the fourth buffer.
Id. col. 21 ll. 5–37 (claim 1). The Terry patents make no mention of wireless communication.
The central dispute during claim construction was whether the recited "communications path" captures wireless communications or is limited to wired communication. The district court adopted the latter view by construing "communications path" to mean "communications path utilizing twisted-pair wiring that is too long to permit conventional 10BASE-T or similar LAN (Local Area Network) interconnections." Cisco Sys., Inc. v. Innovative Wireless Sols., LLC, No. 1:13-CV-00492-LY, 2015 WL 128138, at *8 (W.D. Tex. Jan. 8, 2015). The district court reasoned that the specification's "repeated reference to two-wire lines and telephone lines emphasizes that the inventor was focused on this transmission medium as the core of the new technology, " and it therefore concluded that, in view of the entire specification, "the Terry Patents are solely focused on communicating information packets long distances over wired communication paths." Id. at *7. The district court found particularly persuasive a passage from the written description regarding the scope of alternative embodiments. That passage states that, "although as described here the line 12 is a telephone subscriber line, it can be appreciated that the same arrangement of master and slave modems operating in accordance with the new protocol can be used to communicate Ethernet frames via any twisted pair wiring which is too long to permit conventional 10BASE-T or similar LAN interconnections." Id. The district court considered this passage evidence that the inventors contemplated different types of communication paths but chose to limit those types to "any twisted-pair wiring that is too long to permit conventional LAN interconnections." Id. at 8.
Based on the district court's construction, the parties stipulated jointly to a final judgment of non-infringement. IWS appeals the construction limiting the term ...