On Thursday, Samsung filed its fourth response to Apple’s charge of “slavish” imitation: A suit in a California federal court alleging infringement by Apple (AAPL) of 10 Samsung communications patents.

“Samsung has mounted a swift and strong response to Apple’s initiative,” writes Foss Patent’s Florian Mueller. “The speed with which Samsung responded to Apple’s lawsuit in four different jurisdictions (in three of them within a week, and in the fourth one in less than two weeks) suggests that Samsung expected and, consequently, prepared for this.”

Apple’s complaint focused on elements of the patented look and feel of the iPhone and iPad that ended up in Samsung devices running Google’s (GOOG) Android OS. Samsung, which has a deep intellectual property portfolio of its own, has accused Apple of infringing on patents covering the underlying technology of cellular telephony, such as a particular method for “channel coding and multiplexing in CDMA communication system.”

The diagram above is from a Mueller PDF that lays out the legal battlelines step by step as they unfolded. His list of the Samsung patents (with links) is copied below the fold.

• U.S. Patent No. 7,675,941 on a “Method and apparatus for transmitting/receiving packet data using pre-defined length indicator in a mobile communication system”
• U.S. Patent No. 7,362,867 on an “apparatus and method for generating scrambling code in UMTS mobile communication system”
• U.S. Patent No. 7,447,516 on a “method and apparatus for data transmission in a mobile telecommunication system supporting enhanced uplink service”
• U.S. Patent No. 7,200,792 on an “interleaving apparatus and method for symbol mapping in an HSDPA mobile communication system”
• U.S. Patent No. 7,386,001 on an “apparatus and method for channel coding and multiplexing in CDMA communication system”
• U.S. Patent No. 7,050,410 on an “apparatus and method for controlling a demultiplexer and a multiplexer used for rate matching in a mobile communication system”
• U.S. Patent No. 6,928,604 on a “turbo encoding/decoding device and method for processing frame data according to QOS”
• U.S. Patent No. 6,292,179 on a “software keyboard system using trace of stylus on a touch screen and method for recognizing key code using the same”
• U.S. Patent No. 7,009,626 on a “systems and methods for generating visual representations of graphical data and digital document processing”
• U.S. Patent No. 7,069,055 on a “mobile telephone capable of displaying world time and method for controlling the same”

Also on Fortune.com:

• Samsung countersues Apple
• Steve Jobs would sue his sister…
• Who’s suing whom, Apple vs. Motorola edition

[Follow Philip Elmer-DeWitt on Twitter @philiped]