Data-bundling proxy to aggregate transmissions for energy-constrained devices.

Typically, when there is no traffic on a wireless link, the connection is closed and the link enters a sleep mode. To resume communication, connection establishment is needed before starting data transmission. Since connection establishment/close (and the mode change between sleep and active modes) are expensive in terms of delay and energy consumption, it is desirable to reduce such actions particularly for energy-constrained devices. In this paper, we propose to aggregate (i.e., postponing and buffering) multiple transmissions into a single transmission of an aggregated chunk, which we call data-bundling. Intrinsically, there is a trade-off between the delay induced by postponing transmission and the degree of energy consumption reduction. To optimize this trade-off, the bundling duration must be chosen properly. Our scheme adopts the N-gram model to exploit the traffic generation pattern to determine the bundling duration adaptively. In particular, the traffic generation of each application is considered individually and so that our scheme is effective even in case various heterogeneous applications are mixed. Our scheme is implemented as a transparent proxy, which has minimal dependency on the underlying system. Extensive evaluations in Android-OS platforms using real application traffic show the effectiveness of the proposed scheme.