Toward Efficient Uplink Access in 6G LEO Satellite Networks: A Heartbeat-Based Design

초록

Low Earth orbit (LEO) satellite integration is a key component of 6G non-terrestrial networks, but uplink (UL) access in LEO is fundamentally constrained by long round-trip time (RTT), rapid Doppler variation, and finite beam dwell time. For intermittent session traffic, the dominant cost is no longer a single random-access (RA) collision, but the repeated cold-start re-entry required after idle periods. Existing approaches therefore fail at opposite extremes: contention-based random access suffers from RTT-amplified retries, while terrestrial contention-free schemes assume warm synchronization or persistently reserved resources. This article identifies an intermediate UL access regime for session-oriented intermittent traffic and proposes a connection-lite (CL) mechanism that maintains lightweight access readiness rather than persistent resource reservation. By coupling synchronization refresh with access signaling through a periodic heartbeat, CL enables micro-grant-based UL transmission while reducing repeated RA and idle resource waste. Numerical results show that, for bursty session traffic, CL achieves substantially lower access delay and resource overhead compared to conventional schemes, making it a promising UL-access mode for satellite-enabled 6G networks. © 2002-2012 IEEE.

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