To support seamless communications for roaming users over heterogeneous wireless networks, mobile ad-hoc networks (MANETs) are receiving a special interest in the research community due to its infrastructure-less nature. MANETs can help to achieve a seamless service for users roaming over areas with no coverage from other wireless networks. As a result, MANETs are a key access network component of the super node system that employs the delay tolerant network (DTN) architecture to address user mobility issues. Within the super node system, a dominating-set routing technique is proposed to improve message delivery over MANETs and to achieve better resource utilization. The performance of the dominating set routing technique depends on estimation accuracy of the probability of a future contact between nodes. This paper studies how node mobility can be modeled and used to better estimate the probability of a contact. We derive a distribution for the node-to-node inter-meeting time, and present numerical results to demonstrate that it can be used to improve the dominating-set routing technique performance.