Abstract

Hybrid fiber/coax (HFC) networks that combine analog lightwave feeder technology and low-cost and broadband coaxial cables are presently very popular systems for broadband access applications.^1-2 Conventional HFC networks were designed primarily for distributed broadcast services. Two-way capability is achieved using diplexers and separate upstream amplifiers to pre-provision the traditional upstream frequency band of 5-40 MHz. However, this small upstream bandwidth, and potential channel impairment caused by ingress noise in that band, limit services that can be provided. Also, although aggressive system design has shown that 1-GHz total system bandwidth is possible, in practice this is limited by coax amplifiers (550 MHz or 750 MHz).

© 1996 Optical Society of America