Nokia Corp v Interdigital Technology Corp

Patent essentiality is determined by construing the claims and the relevant technical standard in their proper context. A claim is essential only where compliance with the standard necessarily requires use of the claimed invention. Technical features which the standard leaves optional, or internal implementation choices which it does not mandate, do not establish essentiality. A negative declaration may properly be granted where it has practical utility, including utility in licensing negotiations. The court distinguished between a claim directed to setting transmitter power and one directed to adjusting power responsively: only the latter was essential to the specified open-loop power-control procedure.

Nokia sought declarations that inventions claimed in four InterDigital patents were not essential intellectual property rights for the European 3GPP FDD standard. The action concerned patents relating to open-loop power control, multiple global pilot channels, and transmit antenna diversity. The court considered claim construction, the relationship between the claims and the mandatory requirements of the standard, and whether declaratory relief would serve a useful purpose. The Court of Appeal had earlier held that the court had jurisdiction to entertain the claim, subject to the discretionary question whether relief should be granted: [2006] EWCA Civ 1618.

1. Negative declarations. Following Messier Dowty v Sabena SA [2000] 1 WLR 2040, the grant of a negative declaration is discretionary and depends principally on whether it will serve a useful purpose. The declarations sought would be relevant and influential in licensing negotiations. The possibility of a “Limb 2” essentiality case and the evolution of later standards could not justify refusing relief where InterDigital had not advanced such a case.
2. Construction and essentiality. Claims must be construed through the eyes of the skilled person, with the standard used to identify the practical issues but not to distort the claim. Essentiality requires that compliance with the standard necessarily involve the claimed features. The standard’s silence about internal receiver architecture did not mandate a particular implementation.
3. ’610 and ’807 patents. The apparatus claim of ’610, and the corresponding claims of ’807, required a responsive variable-gain or equivalent adjustment indicating an increase or decrease. The standard’s initial-power calculation specified the power to be used rather than determining a gain in that sense. Those claims were therefore not essential. Claim 6 of ’610 was different: its requirement to adjust transmitter power responsively to the comparison signal covered the standard’s open-loop power-control procedure and was infringed by that procedure. The invention was essential to that extent.
4. ’749 patent. The standard’s measurement of CPICH signals from different cells did not involve a predetermined set of global pilots received in discrete intervals corresponding to particular high-power pilot transmissions. The secondary synchronisation codes formed part of a sequence carrying information, not multiple global pilot signals. Claim 13 was not essential.
5. ’777 patent. The standard did not require the chip-code identifiers, filtering and combining arrangements, or adaptive pilot weighting required by the claim. Its performance requirements did not establish that those internal processes were mandatory. The claims were not essential.
6. The action succeeded to the extent indicated. The precise form of the declarations was reserved for further submissions.

1. Court of Appeal: held that the court had jurisdiction to entertain the claim for negative declarations, subject to the exercise of discretion: [2006] EWCA Civ 1618.
2. High Court (Patents Court): found claim 6 of EP(UK) 0515610 essential to the standard, but found the other claims and patents in issue inessential. Declarations were to be settled after submissions.