Evaluation of the Route Optimization for NEMO in Satellite Networks
Network Mobility (NEMO) has been proposed to efficiently manage the mobility of the group of hosts that are moving together as a mobile network. NEMO Basic Support Protocol (BSP) suffers from the problem of inefficient route. A number of route optimization schemes have been proposed in the literature to solve the problem. The schemes are mainly based on four approaches – Delegationbased, Hierarchical, Source routing and BGP-assisted. The approaches have been evaluated in the literature in terms of various performance metrics. The selection of a route optimization approach for NEMO in terrestrial networks is straight forward from the evaluations that implicitly assume NEMO in such networks. However, the selection of a route optimization approach requires additional evaluations for NEMO architecture that has been proposed for satellite networks to manage the mobility of Internet Protocol-enabled devices onboard satellites. The requirement for the additional evaluations results from the satellite network characteristics, such as long delay links, the link asymmetry, and power constraints. In addition, the availability of multiple connections for mobile networks in satellite networks requires the use of multihoming, a feature to support multiple connections in NEMO, with the route optimization. There are only a few route optimization schemes that consider multihoming. In this work, we discuss the desired characteristics of a route optimization scheme for satellite networks, and the requirements for incorporating multihoming into each of the approaches for the route optimization. Based on the characteristics, previous evaluations and the requirements for multihoming, we analyze the approaches to find suitable route optimization approaches for NEMO in satellite networks. Results show that delegation-based and hierarchical approaches are more suitable for NEMO in satellite networks compared to the other two approaches. In addition, the relative advantages and disadvantages among the approaches are also shown in terms of the desired characteristics. Thus, our analysis lays the basis for the future research to select a suitable scheme for the route optimization in NEMO for satellite networks.