Satellite architecture: bent-pipe vs regenerative payload, ISL, gateway

How Satellite Payloads Process Signals

Satellite payloads fall into two fundamental categories based on how they handle received signals. A bent-pipe transponder simply amplifies the uplink signal, shifts it to a different frequency band, and retransmits it on the downlink — acting as a relay mirror in the sky. A regenerative payload goes further by demodulating, decoding, processing, and re-encoding the signal onboard, effectively placing a base station or router in orbit. This distinction has profound implications for link budget, latency, routing flexibility, and the complexity and cost of the satellite itself.