Reservation arbitrated access for efficient service integration over dual-bus metropolitan area networks

Dual-bus metropolitan area networks (MANs) are well suited to provide broad -band network access and network interconnection over a city area by functi oning as distributed broadband multiplexers between existing corporate/publ ic networks, multi-media terminals, and broadband integrated services' digi tal networks employing an asynchronous transfer mode. The authors address t he important problem of integrating time-sensitive and non-time-sensitive t raffic over MANs. In the proposed integration scheme, time-sensitive variab le bit-rate isochronous (VBRI) traffic, such as voice and video, is statist ically multiplexed over the MAN by a novel, reservation-arbitrated (RA) acc ess protocol, while non-time-sensitive asynchronous traffic, such as data, is transported over the residual bandwidth by queue-arbitrated access. RA a ccess allows a VERI traffic source to capture and reserve some isochronous channels on a bandwidth-on-demand basis. Compared to previously proposed re servation protocols, RA access is fair, provides a better isochronous trans port service, and is compatible to the slot format of the existing IEEE 802 .6 MAN standard. The system performance is analysed by an approximate theor etical model and computer simulations. Results indicate that the proposed i ntegration scheme can be engineered to meet the stringent quality of servic e requirements of the time-sensitive VERI traffic, while providing a satisf actory service to the non-time-sensitive data traffic and ensuring efficien t bandwidth utilisation.