Access to information and digital services on the go has grown with the proliferation of mobile devices and various types of wireless networks. This trend brings an opportunity for individuals to access digital content, share resources, and communicate anywhere anytime facilities. However, the connectivity coverage rate did not go hand in hand with the trends of mobile phone penetration rate, and there is connectivity coverage disparity among developed countries and developing ones. This motivates that infrastructure-less networks such as Delay Tolerant Networks(DTNs ) to play an alternative communication approach and to be leveraged in different application scenarios. The characteristics of this kind of networks (i.e., intermittent connectivity and transient end to end path) create a challenging problem in routing data. For example, to deliver a given message towards destination node/groups of nodes, the routing scheme uses a storecarry- forward and utilizes different heuristics to select a potential forwarder node/intermediate node. This survey paper mainly focuses on presenting insights about recent trends in routing approaches in Delay Tolerant Social Network, and the performance of routing issues.It also provides a comprehensive overview of routing protocols in Delay Tolerant Social Network and examines the various routing taxonomies, and potential application use cases where DTSN suitable.

Keywords : Delay Tolerant Network; Forwarding; Routing Scheme; Opportunistic; Social-Aware ; Infrastructure-Less Network; Routing Taxonomies; Routing Issues