Commscope Technologies LLC v SOLiD Technologies, Inc.

Patent claims are construed purposively in the context of the patent and the common general knowledge. Apparatus claims may require suitability for connection, while claims expressed in terms of units being connected require an actual connection. “Comprising” remains open-ended, and broad claim language should not be narrowed merely to avoid prior art.

For anticipation, the prior art must clearly and unambiguously disclose every claim feature, including what is necessarily implicit to the skilled person. A document must be read as a whole, including its general teaching, figures and preferred embodiment. A claim may be obvious where the skilled person could make routine modifications using common general knowledge, including known network architectures and techniques for managing digital overflow.

CommScope brought patent infringement proceedings concerning two patents relating to digital distributed antenna systems. SOLiD counterclaimed for invalidity, and CommScope applied to amend both patents.

The EP626 dispute was settled and the relevant claims and counterclaim were discontinued, although an amendment application remained. The trial principally concerned EP850, including construction of claims 1 and 7, anticipation and obviousness over the Korean patent application Oh, and infringement. The court also considered whether it retained jurisdiction to determine the EP626 amendment application after the related proceedings had been discontinued.

1. Construction. Claim 1 was an apparatus claim. The phrase “to communicatively couple” required the host unit to be suitable for connection, whereas claim 7 required the specified units actually to be connected. “Communicatively coupled” covered direct and indirect connections. “Comprising” had its conventional open-ended meaning.
2. The references to an original RF signal and an ADC did not limit claim 1 to a single RF signal or a single ADC. The claim covered multiple identifiable RF signals, each processed by its own ADC, with corresponding reverse-path reconstruction. The specification used “signal” and “spectrum” inconsistently and did not justify a narrower construction.
3. Validity of EP850. The skilled person would read Oh as disclosing, at different levels of generality, a digital optical repeater with multiple remote units and digital summing in the reverse path. Figure 1 necessarily implied digital summing because analogue summing would defeat the document’s digital-transmission teaching. Oh therefore clearly and unambiguously disclosed a single-channel digital DAS with more than one slave unit and digitally summed reverse-path signals.
4. Claim 1 was anticipated by Oh. Alternatively, if the claim were confined to a single-channel system, the necessary modifications to Oh were routine and obvious. Claim 7 was also obvious. Expansion units, suitable network topologies and standard methods of dealing with digital overflow formed part of the common general knowledge.
5. EP626 amendment. Under sections 74 and 75 of the Patents Act 1977, the court had jurisdiction when the amendment application was issued, but lost it when the infringement claim and invalidity counterclaim were discontinued without qualification. The consent order directing the application to be heard did not preserve jurisdiction retrospectively. The application could be brought before the Comptroller.
6. The court observed that an unconditional amendment application did not, without a clear and considered concession, necessarily require revocation of the unamended patent. That issue was academic.
7. EP850 was invalid and had to be revoked. If valid, SOLiD’s Genesis system would have infringed.