Complex sentence: Communication Services for the Deaf is a non-profit company based in Sioux Falls, South Dakota that provides services nationwide, and is a major provider of Telecommunications Relay Service and Video Relay Service in cooperation with Sprint Nextel.
Split into simpler sentences: Communication Services for the Deaf is a non-profit company based in Sioux Falls, South Dakota. CSD provides services nationwide, and is a major provider of Telecommunications Relay Service and Video Relay Service in cooperation with Sprint Nextel.