Sharing mobile airwaves is one of many approaches to address accelerating consumer demand that is straining today’s mobile networks. This study by Peter Rysavy of Rysavy Research, in conjunction with Mobile Future, examines some of the challenges presented by sharing.
While clearing spectrum for commercial use is the preferred path forward, government and industry spectrum sharing may be a necessary approach in certain spectrum bands. The analysis outlines existing spectrum sharing technologies, but cautions that those technologies do not solve the problems needing to be addressed for contemplated sharing scenarios.
To address the multifold challenges of spectrum sharing and ensure meaningful progress, the paper details specific recommendations based on sharing scenarios, some of which include:
In the case of most government users relocating, with some users remaining and sharing with non-federal users (e.g., as in the AWS-3 band):
- The government needs to use realistic and real world interference assumptions;
- Industry and government need to agree upon realistic propagation models;
- Industry and government should take advantage of the recently established trusted-agent process; and
- Government should vacate as many systems as possible from the spectrum and adopt simple sharing and coordination approaches.
In the case of sharing being managed by a combination of coordination/protection zones and dynamic access technologies (e.g., as contemplated in the 3.5 GHz band):
- Ongoing measurements should be considered to progressively refine models and protection zones;
- Geographic protection zones should protect incumbent users rather than new entrants;
- The Spectrum Access System (SAS) should not exercise direct control of networks;
- SAS rules should assume the appropriate use-case scenarios to protect against co-channel interference;
- Rules should segment spectrum to minimize the possibility of general access users interfering with users that have priority over general access users; and,
- Spectrum allocations should be assigned to priority service providers on a longer-term (non-varying) basis.