the licensing pool related to the 801.11 standard and related Specification. Grouping Throughout the trial, plaintiffs adhered to the strategy to group the accused products when providing evidence of infringement. Plaintiffs argued that grouping of products when submitting evidence was proper based on their expert's testimony saying that "different versions of the same product will typically support the same feature set". However, the district court was very careful to accept the evidence based on the grouping strategy, explaining that plaintiffs' argument that three separate patents had been infringed by more than 260 products of Netgear made it not easy to prove which components of which allegedly infringing products actually infringed which portions of the three patents. Opinion of The district court and The court of appeals The District Court for Western District of Wisconsin (The district court) denied all of the three motions for summary of judgment filed by plaintiffs and granted motion for summary judgment of non-infringement by Netgear. Analysis of the Courts on US patent 952 Patent claim analysis (Clarification of the terms used in claim) US patent 4,975,952 claims a method of transmitting data in a wireless network, specifically fragmenting large messages into smaller messages to avoid resending large amounts of data if network transmission errors occur and, thus, to transfer data more reliably. Patent infringement analysis by the district court Phillips urged that Netgear indirectly infringed its patents and was liable for contributory infringement. First, with respect to the indirect infringement, the district court concluded that Netgear could not indirectly infringe plaintiff's patent since there were no evidence that the patent is directly infringed by the third parties. The court acknowledged that end users could enable fragmentation through software control and therefore might infringed the patents at issue. However, because fragmentation is merely an optional component of the IEEE 802.11 specification and Netgear products did not enable fragmentation by default, the court could not find any explicit circumstantial evidences that third parties indeed infringed the 952 patent. Second, the district court decided that Netgear did not contribute to the infringement. To prove the contributory infringement by Netgear, plaintiff submitted the notice letters sent by Via Licensing pool to Netgear as evidence that Netgear had recognized that it infringed the 952 patent. However, the district court held "the notice letters sent by Philips prior to the instant suit were not sufficient to establish the knowledge and intent