DTN-based free-space optical and directional RF networks

With the growth in demand for capacity from users in wireless networks and the scarcity of available RF spectrum, directional networks are expected to provide effective solutions. Directional RF antennas offer increased capacity over omni-directional antenna networks and some emerging highly-directional networks like free-space optical communication (FSOC) systems will be an important part of future networking infrastructures. The ability to construct and manage an optical network has challenges such as topology control involving the scheduling of pointing, acquisition and tracking events. In many of these directional systems, especially in FSOC where links may be fragile, this will result in an intermittently-connected network, though of tremendous capacity on a per-link basis. This paper establishes delay (or disruption) tolerant networking (DTN) algorithms for such networks and evaluates these new algorithms with mobility, communications constraints, network traffic loads and quality of service (QoS) provisions.