Multi-operator mobile relaying: Effect of shared spectrum allocation

In this paper, a method for a multi-operator mobile relay node (RN) for cellular networks on a bus or train is proposed. The introduction of RNs enables an improvement in the spectral efficiency because an antenna with higher gain than that of user equipment (UE) can be installed in an RN. However, installing different RNs for different operators is not efficient because of the large amount of space needed to install multiple RNs in a bus. This problem can be solved by sharing the RN among multiple operators. In addition, we propose a system of dynamic spectrum allocation among the operators for RN-UEs communication. By allocating bandwidth to operators depending on the link quality, the effective use of radio resources can be achieved. This resource allocation problem can be discussed in terms of the theory of bargaining. We evaluate dynamic spectrum allocation, based on the Nash bargaining solution (NBS), using computer simulations. As a result, considering fairness among the operators, the total throughput can be improved by approximately 20% compared with the situation where multiple operators install different RNs individually.