CBR Channels on a DQRAP-based HFC Network

DQRAP (Distributed Queueing Random Access Protocol), is a multiple access protocol that offers a throughput equal to the offered traffic up to a load of one with a lesser delay than any other multiple access protocol. DQRAP utilizes three control minislots and two distributed queues: transmission and collision resolution, to provide this performance for all values of "a", i.e., the size of the network is immaterial. This paper describes: (a) how DQRAP can act as the switching fabric for a distributed ATM switch serving an HFC (hybrid fiber-coax) network; and (b) how CBR (constant bit rate) traffic is supported on our distributed ATM switch, i.e., a DQRAP/ATM switch. Simulation results representing the operation of a DQRAP/ATM switch operating in two modes: (a) The control minislots in dataslots allocated to CBR traffic are utilized in the reservation process; and (b) the control minislot capacity in those slots is allocated to CBR data.