The document discusses different generations of cordless telephone systems including CT0, CT1, CT2, CT3, DECT, PHS, PACS, PCS and PWTS. It provides details on the operating principles, features and applications of each system. CT0 operates at 916/960MHz using FM modulation. CT2 uses TDMA/TDD and supports two-way calling. DECT is commonly implemented as an office wireless PBX connected to the PSTN. It offers speech and data transmission up to 300kbps. While various cordless systems were used in Tanzania in the past, DECT is now commonly used in offices and PHS declined due to lower cellular costs.