Change Awareness in Opportunistic Networks

The metrics of information latency and reach ability are widely used for measuring information flow in opportunistic networks. We present an alternative measure that looks at the amount of information updates or changes, which is an important and yet relatively unexplored metric for characterizing opportunistic networks. In this paper, we propose a novel concept to measure information freshness - how much the latest information received differs from the most up-to-date information on the sender. Based on the information freshness, the awareness on how information propagated may have changed, or change awareness, can be computed. Change awareness can be exploited to design efficient algorithms, in particular, data aggregation algorithms. Evaluation on real world traces shows that change awareness based solutions can achieve similar results as data aggregation algorithm with connection oracles.