A Time-Based Fairness Approach for Coexisting 5G Networks in Unlicensed Bands

Standardization activities have already begun on 5G to support very high system requirements. A common consensus toward achieving these targets is to permit transmission over a wide spectrum range. The departure from a dedicated licensed-only spectrum regime to a shared spectrum model poses new challenges for next generation mobile communication systems. Cognitive Radio Technologies is an enabler for such opportunistic spectrum utilization. Coexistence will be inevitable in licensed shared and unlicensed bands and thus one key problem requiring solutions is efficient resource allocation in a dynamic spectrum access regime. Fairness is a performance metric in sharing of resources among wireless systems and research gaps in fair spectrum allocation problems need to be addressed. In this paper a time-based fairness analysis is conducted to study under a random user distribution scenario, the performance level with respect to throughput and channel occupancy time across all coexisting networks. Time-based fairness is achieved by selection of an optimal contention window for all contenders on the unlicensed channel. Early numerical results show that a time- based fairness approach to coexistence significantly improves overall system throughput and channel utilization.