The proposed cooperative packet delivery approach is related to the concept of delay-tolerant networks (DTNs), in this section, we review the related work on delay tolerant and cooperative data transmission in wireless networks. DTNs are characterized by long transmission delay, high error rates, intermittent connectivity, and existence of multiple unreliable links . Vehicular delay tolerant networks (VDTNs) constitute an important class of DTNs. In a social-based privacy preserving packet forwarding protocol for VDTNs, called SPRING, was presented. The main idea is to deploy roadside BSs at the intersections according to the social centrality information in a VDTN. This social relation-based roadside base station placement approach can improve the packet delivery ratio in store-and-forward-based VDTNs. a method for mobile node grouping based on social network analysis. The main problem of coalition formation is that the computational complexity increases exponentially when the number of nodes increases. Hence, the main objective of the proposed SNA-based mobile node grouping is to reduce the complexity of coalition formation when there are many mobile nodes participating in the cooperative data delivery scheme. The key mechanism of the SNA-based mobile node grouping is to filter out some mobile nodes which will not contribute to the cooperative packet delivery a coalitional game framework for carry-and-forward-based cooperative packet delivery to mobile nodes in a hybrid wireless network. The mobile nodes are rational to form coalitions to maximize their individual payoffs. A continuous-time Markov chain model has been developed to obtain the packet delivery delay and the expected cost of mobile nodes for cooperative packet delivery. The packet delivery delay and the expected cost depend on the probability that each mobile node will help other mobile nodes in the same coalition.