Claim Construction Clash Leads To Invalidity Reprieve

In XR Communications, LLC v. D-Link Systems, Inc. Et. Al., a judge in the Central District of California found that certain asserted claims claiming to wireless communication technology were barred by the doctrine of collateral estoppel based on the PTAB finding similar claims of a related patent unpatentable in an inter partes review. XR Commc'ns, LLC v. D-Link Sys., Inc., No. 8:17-cv-00596, ECF No. 313 (C.D. Cal. Apr. 18, 2022). The defendant, D-link Systems, Inc., argued that plaintiff XR Communications' ("XR") asserted claims 3-5 and 12 of XR's '728 patent were barred by the doctrine of collateral estoppel, as they were "materially the same as" claims 5-7 of the '296 patent (the '728 patent's parent), which were cancelled by the PTAB in IPR proceedings.¹ Id at 3, 5. D-link also argued "'XR had a full and fair opportunity to litigate [these issues in the IPR proceedings], and the [PTAB] reached a final judgment on the merits.'" Id. at 5. Patent Owner XR cited, int