Communication Mechanisms For Message Delivery In Heterogeneous Networks Prone To Episodic Connectivity

We present an efficient message delivery framework, called MeDeHa, which enables communication in an internet connecting heterogeneous networks that is prone to disruptions in connectivity. MeDeHa is complementary to the IRTF’s Bundle Architecture: besides its ability to store messages for unavailable destinations, MeDeHa can bridge the connectivity gap between infrastructure-based and multi-hop infrastructure-less networks. It benefits from network heterogeneity (e.g., nodes supporting more than one network and nodes having diverse resources) to improve message delivery. For example, in IEEE 802.11 networks, participating nodes may use both infrastructureand ad-hoc modes to deliver data to otherwise unavailable destinations. It also employs opportunistic routing to support nodes with episodic connectivity. One of MeDeHa’s key features is that any MeDeHa node can relay data to any destination and can act as a gateway to make two networks inter-operate or to connect to the backbone network. The network is able to store data destined to temporarily unavailable nodes till the time of their expiry. This time period depends upon current storage availability as well as quality-of-service needs (e.g., delivery delay bounds) imposed by the application. We showcase MeDeHa’s ability to operate in environments consisting of a diverse set of interconnected networks and evaluate its performance through extensive simulations using a variety of scenarios with realistic synthetic and real mobility traces. Our results show significant improvement in average delivery ratio and a significant decrease in average delivery delay in the face of episodic connectivity. We also demonstrate that MeDeHa supports different levels of qualityof-service through traffic differentiation and message prioritization.