Survivable wireless ATM network architecture

Amidst the rapid growth of wireless broadband networks, little attention has been paid to wireless network survivability issues. We propose a survivable wireless ATM network architecture that allows it to survive from a single base station failure condition, by redirecting a failure cell's traffic via its six neighboring cells. We present two failure-handling schemes for the proposed architecture. The first scheme is a bandwidth reservation (BR) scheme that is targeted at achieving high survivability by reserving bandwidths at appropriate locations in the network. The second scheme is a best-effort (BE) scheme that does not perform any reservation, and is targeted at achieving high bandwidth utilization. Simulation results show that the BR scheme achieves good survivability as expected. On the other hand, the BE scheme provides better utilization while having slightly lower average survivability. The decrease in average survivability for the BE scheme is not tremendous, largely due to its flexibility in the use of spare bandwidths from neighboring cells when a failure occurs. However, the BE scheme requires more frequent update messages between the switches in order to update each other about the amount of bandwidth that they could provide for failure-handling. We have also considered important issues, such as switchover time and data integrity, for our proposed schemes.