A satellite system for broadband communication utilizing load balancing of satellite modems between physical forward sub-channels. The bandwidth requirements of the various satellite modems allocated to a domain are analyzed. Satellite modems, which can be moved between various physical forward sub-channels, are moved among physical forward sub-channels of a plurality of domains to balance loading between domains and/or physical forward sub-channels within domains. Buffering and latency are monitored in the subscriber modem termination system (SMTS) to allow dividing physical forward channel delay either uniformly or according to tiers of quality of service.