(Robert Kneschke)

SAN FRANCISCO—Texas-based patent assertion firm Bluebonnet Telecommunications LLC is staging new offensive.

Bluebonnet, which has been targeting smartphone makers since last year, sued nine companies Tuesday in the Eastern District of Texas. The latest complaints against network equipment companies, follow previous rounds of suits brought in June 2013 and January 2014 against smartphone makers such as Apple Inc., Google Inc., Samsung Electronics, and Nokia Inc.

Bluebonnet is represented by Antonelli, Harrington & Thompson of Houston, a plaintiffs firm founded in 2009 by three Weil, Gotshal & Manges alums.

The latest spate of suits names Avaya Inc., Cisco Systems, Inc., Grandstream Networks Inc., Linksys LLC., Panasonic Corp., Polycom Inc., Toshiba America Information Systems Inc., VTech Communications Inc. and Yealink Network Technology Co.

The suits, which call for a permanent injunction and damages, accuse the defendants of induced infringement, contributory infringement and willful infringement of patents related to the activation of telephony features, such as call forwarding and call barring, and ringer silencing.

The patents—No. 5,485,511 and No. 6,400,814—were originally issued in 1996 and 2002 to divisions of to Siemens Corp.

Bluebonnet has also alleged infringement as to some defendants of a patent that purportedly covers the airplane mode feature.

Several companies sued in 2013 have moved to dismiss the case for failure to state a claim.

Google’s lawyers from Jones Day in Chicago, Dallas, and Palo Alto, Calif. complained in a Jan. 2 filing that Bluebonnet had made “non-specific and generic allegations.”

“The patents concern features of a smartphone … but Bluebonnet never alleges that any of those features among the hundreds of features in a smartphone have been used by a customer,” the lawyers state.

Bluebonnet fired back in a Jan. 21 response stating, “It strains common sense for defendants to suggest that ubiquitous and well-known features, such as airplane mode, are not actually used by defendants’ smartphone customers.”