Upstream information arriving through a user terminal in a satellite link is efficiently scheduled through a modified Demand Assigned Multiple Access (DAMA) algorithm such that data packets arriving at the user terminal are concatenated to form a larger frame for transmission and the concatenated packet is held in a first queue disposed ahead of a second queue, where the data in the second queue cannot be modified (typically a hardware queue), sufficient to allow the second queue to be emptied. In a specific embodiment, all packets arriving at the user terminal since a prior piggyback request are concatenated so that all currently known packets (up to a preselected limit) are accounted for by each succeeding piggyback request. Since it is desirable to concatenate all packets that arrive at the user terminal since the last piggyback request, the piggyback request according to the invention covers all currently known packets (up to the preselected limit) in the user terminal. The held-back packets are released or dumped to the second queue by a trigger operative according to a map, the map being a grant allocation schedule. This mechanism handles instances where the second queue is not able to handle all known packets.