As a result of increasing demand and regulatory changes, access system
s are undergoing significant expansion. Although wireless and copper-b
ased systems are being deployed, fiber access systems provide the best
conduit for broadband services. Significant deployment and trials of
Hybrid Fiber-Coax (HFC) and Switched Digital Video (SDV) systems are u
nderway, and additional architectures are being considered for future
upgraded networks. We review the progress in this field, and indicate
where enabling device technologies can provide key functions.