  Dynamic spectrum sharing can provide many benefits to wireless networks
operators. However, its efficiency requires sophisticated control mechanisms.
The more context information is used by it, the higher performance of networks
is expected. A facility for collecting this information, processing it and
controlling base stations managed by various network operators is a so-called
Radio Environment Map (REM) subsystem. This paper proposes REM-based schemes
for the allocation of base stations power levels in 4G/5G networks, while
considering interference generated to a licensed network. It is assumed that
both networks have different profiles of served users, e.g., area of their
positions and movement, which opens opportunities for spectrum sharing. The
proposed schemes have been evaluated by means of extensive system-level
simulations and compared with two widely adopted policy-based spectrum sharing
reference schemes. Simulation results show that dynamic schemes utilizing rich
context information, outperforms static, policy-based spectrum sharing schemes.
