British Telecommunications plc (BT) (NYSE: BTY; London: BTA) isn't too happy about the way some of its U.S. competitors have been passing gas.

Well, sort of. Specifically, BT is picking a legal fight with several U.S. phone companies over a patent that describes a method of installing fiber optic lines in telecom networks. Earlier this month, the carrier filed suits in a Delaware court against SBC Communications Inc. (NYSE: SBC), Qwest Communications International Inc. (NYSE: Q), Verizon Communications Inc. (NYSE: VZ), Broadwing Inc. (NYSE: BRW), Touch America Holdings Inc. (NYSE: TAA), and Level 3 Communications Inc. (Nasdaq: LVLT).

"BT takes the protection of its extensive and valuable intellectual property assets very seriously," writes a BT spokeswoman, via email. "We have approached the companies concerned over their use of BT's blown cable patents but, in the absence of satisfactory responses, have litigated to enforce our rights."

The patents in question -- 4691896 and 4948097 -- describe a way of sending glass fibers through conduit by, quite literally, passing gas through the conduit or pathway that the fiber needs to follow. The gas needed, according to the patent, is typically nitrogen or air.

The patents, in typical pointy-headed terms, describe how a carrier can move the optical fibers along a path by "fluid drag of a gaseous medium passed through the pathway in the desired direction of advance." [Ed. note: Thanks, Sherman! You're welcome, Mr. Peabody!]

This fiber installation method is said to be easier and put less strain on the optical cables and fibers than conventional methods, which include pulling cable with a rope through a cable duct, the patents claim. In addition, blowing cable makes it easier to add fibers and wires to routes where more capacity is needed.

The lawsuits' defendants couldn't be reached immediately for comment.

— Phil Harvey, Senior Editor, Light Reading