902 F.3d 1372
Fed. Cir.2018Background
- IV sued T‑Mobile and others for infringement of U.S. Patent No. 6,640,248, which claims an "application-aware" MAC‑layer resource allocator that assigns bandwidth to IP flows based on application QoS requirements.
- The patent describes the MAC‑layer allocator (PRIMMA) obtaining application‑type or QoS info from OSI layers 3, 4, or 7; some dependent claims expressly recite layer‑3/4/7 sources.
- The parties disputed claim construction for "application‑aware resource allocator" (whether it must use application‑layer 7 info) and indefiniteness of a means‑plus‑function limitation requiring allocation "so as to optimize end user application IP QoS requirements."
- The district court adopted T‑Mobile’s narrow construction requiring the allocator take into account application‑layer 7 information, struck IV’s infringement contentions for failing to follow that construction, and granted summary judgment of non‑infringement; it also held the means‑plus‑function claim indefinite.
- IV appealed the claim construction and indefiniteness rulings to the Federal Circuit.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Construction of "application‑aware resource allocator" (claim 1) | Term means allocate resources based on application type; application type can be determined from OSI layer 3, 4, or 7. | Must require using application‑layer 7 information when allocating bandwidth. | Reversed district court: phrase has its plain meaning; allocator may use info from layer 3, 4, or 7 to determine application type. |
| Construction of "application‑aware MAC layer" (claim 20) | Same as above: identifying application type may use layer 3/4/7 info. | Same as above: must use layer 7 when allocating. | Same holding as claim 1: not limited to layer 7. |
| Prosecution history disavowal | No clear disavowal; statements cited are ambiguous and other prosecution statements and added dependent claim 19 confirm broader scope. | Prosecution statements explicitly distinguished prior art by referencing awareness of layer‑7 information, disavowing broader scope. | No clear and unmistakable disavowal found; prosecution history did not restrict claims to layer‑7 only. |
| Indefiniteness of means‑plus‑function "optimize end user application IP QoS" (claim 20) | Specification provides sufficient structure and context to render the function definite; court should identify corresponding structure. | "Optimize QoS" is purely subjective; the function is indefinite. | Affirmed district court: function uses a subjective term of degree tied to user preferences and is indefinite; no need to identify structure. |
Key Cases Cited
- Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (2015) (claim construction: review and role of intrinsic/extrinsic evidence)
- Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014) (patent claims must inform skilled artisan of scope with reasonable certainty)
- Thorner v. Sony Comput. Entm’t Am. LLC, 669 F.3d 1362 (Fed. Cir. 2012) (claims given ordinary meaning in context)
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (claim construction principles and reliance on specification/prosecution history)
- Epistar Corp. v. Int’l Trade Comm’n, 566 F.3d 1321 (Fed. Cir. 2009) (disavowal requires clear and unmistakable statements)
- Rambus Inc. v. Infineon Techs. AG, 318 F.3d 1081 (Fed. Cir. 2003) (disfavoring constructions that render dependent claims meaningless)
- Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 (Fed. Cir. 2005) (terms of degree that are purely subjective may render claims indefinite)
- Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364 (Fed. Cir. 2014) (means‑plus‑function definiteness and review of subjective claim language)