ABSTRACT
Basically all data transmission mechanisms can be divided into two parts: (1) pushbased data broadcasting and (2) pull-based data dissemination. The origin of pushbased data broadcasting arises from solving the asymmetry of wireless communication channels. In push-based systems, the server periodically broadcasts a set of data items to all clients, without any client intervention. The clients just listen to the downlink channel to obtain its required data items. The server broadcasts data items according to this schedule. The data item to be broadcast next is chosen again by a scheduling policy without client intervention. Indeed, this saves bandwidth in the resource-constrained uplink wireless channels, but it suffers from wasting resources in downlink wireless channels by repeatedly transmitting the less popular items.
