Experimental Measurement of the Capacity for VoIP Traffic in IEEE 802.11 WLANs

We measured the capacity for VoIP traffic in an 802.11b test-bed and compared it with the theoretical capacity and our simulation results. We identified factors that have been commonly overlooked in past studies but affect experiments and simulations. We found that in many papers the capacity for VoIP traffic has been measured via simulations or experiments without considering those factors, showing different capacity in each paper. After these corrections, simulations and experiments yielded a capacity estimate of 15 calls for 64 kb/s CBR VoIP traffic with 20 ms packetization interval and 34 calls to 36 calls for VBR VoIP traffic with 0.39 activity ratio.