Providing enhanced cellular coverage in public transportation with smart relay systems

This paper introduces a notion of coordinated and cooperative relay systems (CCRS) for providing enhanced cellular coverage in highly populated public transportation such as passenger trains, cruise ships, etc. This notion considers a closed group of relay nodes and cells thereof, deployed together for particular service area of interest, as a new interconnected-and-extended network entity of advanced cellular systems - the CCRS. The CCRS may be set up on the run and connected to donor cellular network(s) with multiple mobile wireless backhaul links in a coordinated and controlled manner. This is in order to optimize, for examples, duplexing operation in relaying, load balancing and capacity sharing, as well as mobility management of the CCRS which serves a huge number of mobile users aboard of transportation. This paper addresses challenges as well as architecture alternatives and enhancements for incorporating the CCRS into advanced cellular networks such as 3GPP LTE-A systems. This paper also shows some methods to explore notable amounts of time-space and user diversities associated with the CCRS and performance gains of the CCRS.