  Low earth orbit (LEO) satellite communication networks have been considered
as promising solutions to providing high data rate and seamless coverage, where
satellite beam management plays a key role. However, due to the limitation of
beam resource, dynamic network topology, beam spectrum reuse, time-varying
traffic arrival and service continuity requirement, it is challenging to
effectively allocate time-frequency resource of satellite beams to multiple
cells. In this paper, aiming at reducing time-averaged beam revisit time and
mitigate inter-satellite handover, a beam management problem is formulated for
dynamic LEO satellite communication networks, under inter-cell interference and
network stability constraints. Particularly, inter-cell interference
constraints are further simplified into off-axis angle based constraints, which
provide tractable rules for spectrum sharing between two beam cells. To deal
with the long-term performance optimization, the primal problem is transformed
into a series of single epoch problems by adopting Lyapunov optimization
framework. Since the transformed problem is NP-hard, it is further divided into
three subproblems, including serving beam allocation, beam service time
allocation and serving satellite allocation. With the help of conflict graphs
built with off-axis angle based constraints, serving beam allocation and beam
service time allocation algorithms are developed to reduce beam revisit time
and cell packet queue length. Then, we further develop a satellite-cell service
relationship optimization algorithm to better adapt to dynamic network
topology. Compared with baselines, numerical results show that our proposal can
reduce average beam revisit time by 20.8% and keep strong network stability
with similar inter-satellite handover frequency.
