Void Avoidance Scheme for Real-Time Data Dissemination in Irregular Wireless Sensor Networks

Abstract

The real-time data dissemination is based on a minimum delivery speed of each hop on the end-to-end shortest distance in order to ensure to reach the destination within the desired time deadline in hop-by-hop fashion. In other words, the schemes depend not only on single hop-delay, but also on the distance between the source and destination. However, the performance of the real-time data dissemination could suffered from some "Voids" in the irregular sensor network which blocks the data forwarding. Namely, the voids lengthen the delivery path and the time for detour the voids. These extended delivery path and time aggravate real-time data dissemination success ratio because the additional distance and time increment were not considered in the calculated minimum delivery speed at source node. To deal with this phenomenon, there are detouring methods of voids such as perimeter routing, back pressure. Although the methods enable a void detouring of data packets, the real-time data dissemination success ratio have not improved much because of a many control message to detour voids. To solve this problem, we propose void avoidance scheme for real-time data dissemination. In our scheme, nodes surrounding a void could detect. This void information are transmitted to whole sensors in the network by broadcasting. When a source transmits data to sink, the source uses the void information to find certain point for avoiding voids by the shortest distance. Thus, the source could set desired speed toward the destination via the point without facing a voids. Performance evaluation shows that our scheme provides better real-time dissemination success ratio in practical environments.