Koninklijke Philips NV v Asustek Computer Inc. & Ors

In assessing obviousness, the court must consider the skilled person’s common general knowledge and the technical choices presented by the prior art. A proposal for a shared fractional dedicated channel was obvious to modify by omitting dedicated pilot bits where those bits were not technically necessary for the relevant power-control and synchronisation functions. The loss of optional functionality, including user-specific beamforming and closed-loop transmit diversity with antenna verification, was a straightforward trade-off against improved code utilisation. Commercial reasons for retaining compatibility features did not make the technical modification non-obvious.

The claimant alleged that three patents concerning HSPA-compatible mobile telecommunications systems were essential to the UMTS standard. This judgment concerned the validity of European Patent (UK) No. 1 685 659 following Trial B. There was no issue as to essentiality or infringement.

The defendants challenged the patent for obviousness over a Nortel contribution proposing a fractional dedicated physical channel, read with an earlier Nortel contribution. The claimant proposed amendments to claim 1 and relied on the amended claims. The central issue was whether omitting dedicated pilot bits from the proposed fractional dedicated channel was obvious to the skilled person at the priority date.

1. Outcome. The proposed amended claim 1 was obvious over Nortel October. The Patent was invalid.

2. The skilled person was someone working on improvements to the physical-layer aspects of UMTS Release 5, particularly HSDPA, and focused on developing the Standard rather than merely implementing its completed provisions. That person would nevertheless be aware of implementation issues, including cost, complexity and performance.

3. The only material difference between Nortel October and amended claim 1 was that Nortel October retained pilot bits in the fractional dedicated channel. The skilled person knew that dedicated pilot bits were not technically necessary for measuring signal quality for power control or for maintaining synchronisation. The skilled person also knew from common general knowledge that cdma2000 used power-control bits rather than dedicated pilot bits for the relevant measurement.

4. Dedicated pilot bits were technically necessary for user-specific beamforming and for closed-loop transmit diversity with antenna verification, but those were optional features and were more beneficial for higher-power channels. The fractional dedicated channel was intended to be a low-power channel. Omitting the pilot bits therefore presented an obvious choice: improved code utilisation at the cost of those optional capabilities. The possibility of retaining alternative slot structures did not alter that conclusion.

5. The prior proposal’s emphasis on maximum backwards compatibility reflected commercial reasons for acceptance within the standard-setting process. It did not make the technical omission non-obvious. The secondary evidence, including earlier consideration of removing pilot bits to free capacity, reinforced the conclusion reached from the primary evidence.

6. The court approached the defendants’ expert evidence with caution because of a risk of hindsight, but concluded that the claimant’s expert evidence was substantially consistent with it and that the conclusion was not dependent on hindsight. The amendments were allowed if necessary, and the Patent was held invalid.