Differentiated Management Strategies for Multi-Hop Multi-Path Heterogeneous Connectivity in Mobile Environments

The widespread availability of mobile devices with multiple wireless interfaces, such as UMTS/GPRS, IEEE 802.11a/b/g and Bluetooth, is pushing for the support of multi-homing and multi-channel connectivity, also enabled by multi-hop cooperative paths to the Internet. The goal is to transparently allow the synergic exploitation of "best" connectivity opportunities available at runtime, by enabling cooperative connectivity, extended wireless coverage, and effective load balancing (for both energy and bandwidth consumption). To this purpose, we claim the need for innovative, lightweight, and proactive evaluation metrics for connectivity management by exploiting application-level awareness of expected node mobility, path throughput, and energy availability. To demonstrate the effectiveness of these solution guidelines for Multi-hop Multi-path Heterogeneous Connectivity (MMHC), we have designed, implemented, and thoroughly evaluated our evaluation metrics on top of the MMHC middleware, which are original because they i) enable the management of multiple multi-hop paths, also made up by heterogeneous wireless links, ii) support connectivity management decisions depending on dynamically gathered context indicators, and iii) can proactively trigger management operations with limited overhead. The extensive set of reported results, from both simulations and real testbed, provides a useful guide for the full understanding of how, to what extent, and which context-based evaluation metrics can enable effective MMHC management in differentiated application/deployment scenarios.