In this paper, a large-scale Gbit/s metropolitan area network (MAN) based o
n hierarchical ring topologies has been investigated. The network is consti
tuted by backbone and local rings,which are connected by bridges. In the ne
twork, traffic congestion may occur in bridges due to the mismatch of trans
mission speed between backbone and local rings. To cope with the issue, a s
cheme based on a cyclic reservation-based access method is proposed for the
medium access control (MAC) protocol of the network. With the scheme, the
protocol can both achieve the fair access of network bandwidth and resolve
the traffic congestion in bridges, Particularly, this approach reduces the
implementation complexity and cost and enhances efficiency of the global ne
twork. Finally, several simulative experiments are performed, and some opti
mistic results are revealed. (C) 2000 Elsevier Science B.V. All rights rese
rved.