TOBASCO: an innovative approach for upgrading CATV fiber-coax networks for broadband interactive services

To introduce broadband interactive services in a fiber-coax CATV network with high splitting ratio, a high-density wavelength multiplexing upgrading strategy in combination with conventional TDMA techniques is presented. It features flexible network reconfiguration via wavelength reassignment at the fiber terminating network units, a high interactive services capacity per user, and improved network scalability. On the fiber part of the network the interactive channels are carried in baseband, time-multiplexed (in ATM) in a number of wavelength channels. The article gives an overview of the most distinctive characteristics of TOBASCO. The system architecture as well as the evolutionary upgrade path are presented. The implications of the flexible wavelength allocation scheme on the network topology and, in particular, dynamic assignment strategies are analyzed. Finally, the field trial to be carried out in Gent is discussed