Upstream information arriving through a gateway from a user terminal in a satellite link subject to propagation delay is efficiently scheduled through a modified Demand Assigned Multiple Access (DAMA) algorithm such that arriving data packets arriving at the software queue at the user terminal are concatenated to form a large frame for transmission to improve efficiency. A piggyback request replacing a conventional DAMA contention request for the succeeding packet is issued to request bandwidth allocation for the succeeding concatenated packet. In a specific embodiment, all packets up to the physical request limit arriving at the user terminal since a prior piggyback request or contention request are concatenated so that all currently known packets (up to that limit) are accounted for by the next piggyback request.