FITL upgrading strategy for B-ISDN

NTT is developing a family of optical subscriber systems, named IFOS (Integrated Fiber-Optic Subscriber System). The scenario of upgrading fiber-in-the-loop (FITL) systems toward a full B-ISDN system using IFOS is discussed. A basic subscriber system model is introduced to separate service independent portion (access system) from the subscriber system. Based on the proposed model, upgrading of the service independent access system using asynchronous transfer mode (ATM) is discussed. The system configuration of IFOS is also addressed. >