Delay Optimisation for Multimedia Application in a Wireless Network Control System (WNCS)

Abstract

This paper mathematically modelled email, voice, Internet Browsing traffic (using inter-arrival rates and packet size) individually and then in a shared network (a combination of the Voice, Internet Browsing and Email to the same network/queue) in congested and non-congested conditions under scheduled and unscheduled state. The traffic is then modelled with wireless nodes with the UDP/IP protocol stack. When scheduling is applied, packets arriving from different sources are distributed evenly over time; this is most effective with constant arriving packets but should help with other traffic types. This paper aims to determine the effectiveness of evenly distributed packet arrival times on different traffic types under congested and non-congested network condition. Also, the paper analysed how closely the measured simulated queuing delay and queue size replicates the theoretical estimation. The results show that the measured simulated delated was close to theoretical for the Voice application. However, the margin of error increases with increasing network load. The network performance improved when scheduling was applied. The measured delay and queue size for Internet Browsing is challenging to predict theoretically because of the bursty nature of the traffic. However, it performs better when scheduling was applied. Moreso, the combined traffic of Voice, email, and internet browsing in a shared network performed better after scheduling was applied.