The utility of shared access licences for private wireless access networks

Abstract

The increasing need for available spectrum has innovated development towards spectrum sharing techniques that allow shared access to be commercialised and used for private networks based on Long-term evolution (LTE). Licensed shared access (LSA) is one example of a spectrum sharing architecture that can quell the demand for more spectrum. Two noteworthy developments in LSA to date are: Shared access licences (SALs) and Citizens Broadband Radio Service (CBRS). Anticipating spectrum access technology developments under 5G, the Office of communications (Ofcom) in the UK created SAL, allowing licenced spectrum sharing and reuse. In the United States (USA), the use of CBRS has attracted much attention in recent auctions. However, the capabilities of networks using shared access techniques are not well understood given the high level of freedom. This dissertation aims to determine the utility of SALs in PWANs. First, a comparison is made between spectrum sharing architectures to find the best representative architecture for Private wireless access networks (PWANs). A simulation model is constructed to study the use of SALs for private networks. Various LTE network planning parameters, such as LTE channel bandwidth, channel amount, transmit power, coverage area, channel capacity, spectral efficiency, and SAL cost are evaluated to determine the utility of a PWAN using an LTE network under SAL regulations. Results indicate an opportunity in the 3.8-4.2-GHz band for using private LTE networks under SAL regulations by analysing the theoretical capacity, coverage area, system efficiency and SAL cost to define the utility of the PWAN. A fundamental tradeoff is discovered in the amount of LTE channels under a SAL and the allowed power output under current regulations, as well as a core trade off for PWANs between the coverage area of the network and the network capacity. Results show that low-power SAL regulations are best suited for smaller LTE channel

bandwidths in a small cell configuration, while a medium-power SAL is best suited for a fixed-base station network. The dimensioning of both these network scenarios is discussed. PWANs give new opportunities for secure access networks. New applications of shared access are promising with current 4G and 5G implementations in the market, resulting in newly available spectrum that can be used with currently available chipsets.