A new AAL protocol for time-critical UDP traffic over wireless ATM networks

This paper describes the design and performance of a new AAL protocol (AAL-UDP) for UDP/IP over wireless ATM networks. The wireless links are characterized by higher error rates and burstier error patterns in comparison with the fiber-based links for which ATM was designed. The purpose of AAL-UDP is to support time-critical UDP traffic over wireless ATM networks. The key ideas in the design consist of no discard at AAL level and header protection with sequence number mechanism. The UDP/IP header is repeated for reliability, because it contains the most important information such as address and port number. The proposed AAL has been validated using a software emulator on the simulated wireless ATM network. The simulation results show that the AAL-UDP provides significant improvement in throughput as well as application level performance compared to the conventional AAL 5 case.