TC Technology LLC v. Sprint Corporation
1:16-cv-00153
D. Del.Sep 22, 2017Background
- TC Technology sued Sprint and Print Spectrum alleging infringement of U.S. Patent No. 5,815,488, which claims a method for multiple remote locations to share a channel to transmit data to a central location.
- Representative claim (claim 2) requires: mapping groups of bits to transform coefficients tied to particular orthogonal baseband frequencies allocated to each remote, inverse transform to time-domain blocks, modulation on a common carrier frequency, reception, demodulation using in-phase/quadrature carriers, and reconstruction via an orthogonal transform.
- The parties submitted a joint claim-construction brief and the court heard oral argument; the opinion resolves construction of several disputed claim terms.
- Disputes centered on: whether frequency "allocation" must be variable over time, the plain meaning of "allocated to," the meaning of "transform coefficient(s)," and the meaning/precision of "quadrature signals."
- The court applied the Phillips/Markman framework, relying primarily on intrinsic evidence and declining to import narrowing limitations from the specification where not required by the claims.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| "the subsets of baseband frequencies allocated to each remote location being mutually exclusive" | Means subsets have no overlap in a time slot; allocation is variable by data demand | Each subset assigned to only one remote per time slot (no overlap) | Court: construed as plain meaning — "for any given time slot, no individual baseband frequency is allocated to more than one remote location" (parties agreed before hearing) |
| "allocated to the remote location" (whether allocation must be variable) | "Allocated" requires variable assignment depending on relative data to transmit | No variability requirement; specification’s examples are permissive and a fixed allocation is disclosed | Court: plain and ordinary meaning; declined to import a variable-allocation limitation from the specification |
| "transform coefficient(s)" | Plain meaning | A symbol representing group of bits assigned to a baseband frequency | Court: "value used as an input to a transform" (parties agreed at argument) |
| "quadrature signals" | Plain meaning | Signals that differ in phase by ninety degrees | Court: adopt defendants’ construction — "signals that differ in phase by ninety degrees" (subject to implementation imprecision if later needed) |
Key Cases Cited
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir.) (specification and intrinsic record guide claim construction)
- Markman v. Westview Instruments, Inc., 52 F.3d 967 (Fed. Cir.) (claim construction is a matter of law guided by intrinsic evidence)
- Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (Sup. Ct.) (factual findings in claim construction reviewed for clear error)
- Renishaw PLC v. Marposs Societa 'per Azioni, 158 F.3d 1243 (Fed. Cir.) (claims must be read in context of the whole patent)
- Osram GmbH v. Int'l Trade Comm'n, 505 F.3d 1351 (Fed. Cir.) (claim interpretations that exclude inventor's device are rarely correct)