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Claim Construction Clash Leads to Invalidity Reprieve, PTAB Litigation Blog

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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, inter alia, differing standards across the forums in defense of its claims, noting that “in federal courts, accused infringers must prove each patent claim invalid by clear and convincing evidence, whereas petitioners in IPRs only need to establish unpatentability by a preponderance of evidence.” Id. at 6.  The District Court granted defendant’s motion on some claims, but not others.

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