Date Added: Jan 2012
In this paper, the authors study the utility of opportunistic communication systems with the co-existence of network infrastructure using three real experimental deployments. They study how some important performance metrics change with varying degrees of infrastructure and mobile nodes willing to participate in the opportunistic forwarding. In doing so, they observe phase transitions in the utility of infrastructure and opportunistic forwarding respectively at different points in the design space. They discuss the implications that this has for the design of future network deployments and how this observation can be used to improve network performance, while keeping cost at a minimum.