Date Added: Jan 2012
Causally ordered message delivery is a required property for several distributed applications particularly those that involve human interactions (such as teleconferencing and collaborative work). In this paper, the authors present an efficient protocol for causal ordering in mobile computing systems. This protocol requires minimal resources on mobile hosts and wireless links. The proposed protocol is scalable and can easily handle dynamic change in the number of participating mobile hosts in the system. Their protocol, when compared to previous proposals, offers a low unnecessary delay, low message overhead and optimized handoff cost.