As if the pay-TV market isn't challenging enough, here's another nuisance for service providers to wrestle with -- Synchview has lobbed lawsuits at a handful of US cable operators and a top OTT-TV provider over allegations that they are infringing on an old DVR-related patent.

Those that are meeting with the pointy end of a recent string of lawsuits on the patent in various US courts include Cox Communications, Charter Communications, Altice USA and Hulu. Synchview has previously gone after several US pay-TV providers that use set-tops and DVRs powered by TiVo software.

The patent being asserted by Synchview is No. 5,788,882: "Systems and methods for storing a plurality of video streams on re-writable random-access media and time- and channel-based retrieval thereof."

As some of the archaic terms in the patent might suggest, it's an old patent, filed in April 1998, granted in September 2004, with James L. Geer and Ivan H. Darius listed as the inventors. The abstract describes a DVR as being a combinatioj of a "mass data storage unit that concurrently and continuously receives and digitally stores a plurality of channels," and a viewer, "coupled to the mass data storage unit, that retrieves a portion of one of the plurality of channels from the mass data storage unit based on a received command and presents the portion on a video display device."

Atlanta-based Synchview is an affiliate of IP Investments Group, known as a "non-practicing entity" -- a company that has patents and other intellectual property but has no intention of creating products from it. Others might refer to it with the more disparaging label of "patent troll."

Update: The operators being targeted by Synchview appear to be getting some help. Unified Patents, an organization focused on deterring what it believes are unsubstantiated or invalid assertions in defined technology "zones" (CableLabs is a member), challenged the Synchview patent at the Patent Trial and Appeal Board (PTAB) last year. In the request for an inter partes review of several claims in the patent, United Patents argues in part that "channel surfing in the past using video-on-demand services, including those employing digital video recorders, and 'catch-up viewing' were already known features of digital recording systems." Unified Patents also argues that the "Challenged Claims are obvious over the prior art cited herein, and therefore, should be found unpatentable."

Based on what Light Reading could find, here's a snapshot of the MVPDs facing recent lawsuits filed by Synchview, and a few that were served with lawsuits last year (we've asked an attorney representing Synchview to alert us if there are others):

Those lawsuits have emerged as Comcast and TiVo continue to battle it out in the courts over several asserted TiVo/Rovi patents covering DVR technologies and lawsuits that are taking particular aim at Comcast's X1 platform. (See TiVo Preparing to Separate Its Products & Licensing Businesses and TiVo-Comcast Legal Fight Has No End in Sight.)

— Jeff Baumgartner, Senior Editor, Light Reading