Delay-Differentiated Gossiping in Delay Tolerant Networks

Delay Tolerant Networks are increasingly being envisioned for a wide range of applications. Many of these applications need support for quality of service (QoS) differentiation from the network. This paper proposes a method for providing probabilistic delay assurances in DTNs. In particular, the paper presents a method called Delay- Differentiated Gossiping to assure a certain probability of meeting the packets' delay requirements while using as little network resources as possible. The idea is to adapt a set of forwarding probabilities and time-to-live parameters to control the usage of network resources based on how the delay requirements are being met. Empirical results evaluating the effectiveness of the proposed method are also included. The results show that there are simple ways of assuring the delay requirements while making effective use of the network resources.