Effects of handshake hop length of unidirectional links on the lifetime of wireless sensor networks

Most of the data transfer mechanisms designed for wireless sensor networks (WSNs) work only on bidirectional links, yet, there are some mechanisms capable of utilizing unidirectional links which have been caused by transmission power heterogeneity. Employment of a multi-hop reverse path for acknowledgement delivery is the key concept in these designs. If the maximum reverse path length is allowed to take larger values then the number of usable unidirectional links increases. Increasing the number of available links leads to better energy balancing and longer network lifetime. But is it necessary to keep the reverse path length large to achieve maximum network lifetime possible? In this study, we investigate the effects of reverse path length in WSNs with unidirectional links induced by transmission power heterogeneity on network lifetime through a novel mixed integer programming (MIP) framework. Our results show that reverse path length has significant impact on WSN lifetime.