Some approaches to improve the qos of delay tolerant networks

Abstract

Delay Tolerant Networks (DTNs) are non-deterministic networks that do not have prior knowledge about partitioned networks. Such networks are mainly characterized by intermittent and/or opportunistic connectivity between nodes due to dynamic topology or resource constraints. Particularly, the source-destination path might never stay alive and only the capability of exploiting node movements could assure the delivery of a message. Store carry and forward is used to overcome the problem of intermittent connectivity and when employed optimum buffer utilization, bandwidth management and energy consumption methods need to be adopted to improve the Quality of Service (QoS) of DTNs. Numerous research studies have proved that, finding the candidate node to relay messages based on the availability of resources such as energy, buffer or bandwidth results in improved performance of the protocol. Moreover various parameters and methods to identify the candidate node are considered, to obtain knowledge for routing decisions in DTNs. Various combinations of parameters including the availability of resources as a vital parameter and adopting suitable method to make optimum use of scarce resources need to be addressed. Further, utilization of resources can be analyzed. These are the grey areas that are identified through literature survey while analyzing the QoS in DTNs. Thus, the identified research gap holds the potential to explore further through detailed studies. This research deals with designing of four algorithms their simulations, analyses and comparing the performance metrics with existing protocols. The proposed routing protocols increase packet delivery ratio and decrease delivery latency, considering utilization of different resources. iv Energy Efficient Energy Hole Repelling (EEEHR) algorithm is proposed with different cluster sizes based on sink location and choosing Cluster Head (CH) based on residual energy to prevent occurrence of energy holes. Fuzzy Based Energy Efficient Opportunistic Forwarding (FBEEOF) pro