Quantitative Analysis on the Feasibility and Benefits of Local Licensing

Abstract: In-building connectivity in enterprises and vertical industries will emerge as an important use case of future 5G mobile services, given the fact that 80% of the traffic is generated indoor [1]. However, spectrum solution to this use case, which is unlicensed spectrum, may not be able to secure spectrum availability for large traffic demand as well as critical use case due to the nature of Listen-before-Talk (LBT) protocol. To cope with that, several novel spectrum sharing schemes have been discussed recently. One approach is to grant exclusive access to a spectrum in limited geographical area, or so called local licensing. It is motivated to reduce external interference from multiple networks that operates in a common area. This thesis evaluated such approach in terms of QoS improvement compared to unlicensed spectrum. To carry out the evaluation, two type of network deployment were simulated in three different scenarios: unlicensed case (LBT-based system in overlapping deployment) intermediate case (LBT-based system in non-overlapping deployment) local licensed case (non-LBT system network in non-overlapping deployment) By simulating these three simulation scenarios, we have been able to compare two vari- ables (usage of LBT and deployment type) one by one. Comparing the first case (unlicensed) and third case (local licensed), the local li- censed case’s throughput does not decrease as rapidly as unlicensed case’s throughput when the traffic load increases. Local licensed case has 130% higher system capacity than unlicensed case in 10 Mbps QoS requirement. Between LBT and deployment type, LBT has more significant impact on the result. The increase of traffic load in LBT-based system caused a much significant increase in interference compared to non-LBT based system. LBT-based system performed well in low traffic, giving twice as much through- put as the third case, but the throughput also decrease rapidly as the traffic increase. Comparing the first and second case, the throughput gain of separating the deployment was not significant in LBT-based system. All in all, we proved that local licensing is worthwhile in term of QoS improvement compared to unlicensed case, given that the traffic load is high enough.