Unapproved IEEE Draft Cable-Tv Access Method and Physical Layer Specification (PAR Withdrawn)

To provide for digital communication services over a branching bus system constructed from fiber and/or coaxial cable, as used in the cable TV distribution networks. The traffic types will be constant bit rate(CBR), variable bit rate(VBR); connection-oriented(CO) and connectionless(CL) data. Sources both in the headend and within the network will be provided for; transmission may be one-to-one, one-to-many, many-to-one, and many-to-many. By specifying a MAC and PHY(s), the standard will be architecturally consistent with 802 compatibles LANs. Compatibility with emerging technologies such as video compression and ATM will also be maintained insofar as consistent with efficiency and good economics. Coexistence with existing analog video transmission and with forthcoming digitally-encoded television signals will be maintained. It is expected that the standard will allow for flexibility in the assignment of frequencies for transmission to and from the headend. Both symmetric and asymmetric data flows will by provided for, with data rates consistent with the capabilities of the media; distances to approximately 160 kilometers round trip will be accommodate.