Service integration in CRMA: a simulative analysis

A simulation-based analysis of the integration of VBR video and voice traffic in a cyclic-reservation multiple-access (CRMA) network is reported. The video sources are characterized via a trace of the output of a real codec. As VBR video applications can tolerate extremely low packet loss rates (<10^-8), a conservative bandwidth allocation scheme that assigns high priority to the VBR sources and ensures for this class of traffic a bandwidth close to the peak rate has been chosen. Voice traffic is allocated to the low priority level in such a way as to have a complete utilization of the network capacity. The sensitivity of the quality of service (QoS) to the correlation between video sources is studied. The simulation results indicate that, for both classes of traffic, a QoS that is acceptable for service integration is obtained. However, voice traffic experiences a 99th percentile of the access delay (≈80 ms) which may not be acceptable in an internetworking environment. It is shown that by managing internet voice as VBR video this problem is overcome. The dependence of the QoS parameter values on the video source characterization is analyzed