Allowing bit errors in speech over wireless LANs

Wireless LANs are becoming commonplace because of their ease in providing mobile communication. As use of IEEE 802.11 continues to expand, support for voice will Preprint submitted to Elsevier Science 2 December 2004 become a desirable feature. Supporting voice conversations over a packet network is more challenging than over current circuit switched wired networks. These challenges are particularly difficult due to the erroneous nature of a wireless channel. The IEEE 802.11 MAC layer standard requires that the receiver not accept a packet with any bit error; the source must retransmit all packets received with errors. However, digitized voice data can tolerate some error and loss without noticeable degradation in call quality. By forcing error-free reception of speech, scarce bandwidth and energy are unnecessarily expended, and the delay of the packets increases. In this paper we explore allowing bit errors in voice packets over IEEE 802.11 networks. We propose two strategies for allowing these errors and demonstrate that they both result in improved performance.