Nearly a year after Packet Tread LLC launched its first and only litigation campaign to date, suing over 15 major electronics makers, the NPE has filed its second wave of cases, this time hitting ADTRAN, Avaya, Cisco, Polycom, Mitel, Panasonic, and four others. As in its previous filings, Packet Tread’s complaints accuse the defendants of infringing a single patent related to echo cancellation in a voice and data modem (6,310,864). But while Packet Tread’s first round of suits targeted mobile devices, including smartphones and tablets, the NPE’s latest suits focus on VoIP and IP phones.