What we published

Delayed Offloading Benefit? - Presented at ACM MobiHoc 2014

What if a mobile device can put downloading of volume data such as video, apps, and system updates in the background and continue downloading them whenever WiFi connection becomes available? If this can be unawarely while a user is moving, it will be possible for users to save a lot of cellular data cost. How much can be saved through what process is first in-depth studided!

ACM MobiHoc (Acceptance ratio < 12%) is one of flagship ACM conferences on networking, which is run by rigorous papers of 10 pages.

Smart mobile devices are generating a tremendous amount of data traffic that is putting stress on even the most advanced cellular networks. Delayed offloading has recently been proposed as an efficient mechanism to substantially alleviate this stress. The idea is simple. It allows a mobile device to delay transmission of data packets for a certain amount of time, while it searches WiFi (or similarly femtocell) networks to offload the data during the time. When the time expires, it completes the remaining portion of the delayed transmission through the cellular network that is available at the moment. In this paper, we develop an analytical framework using an embedded Markov process for the delayed offloading system, which provides a closed-form expression for estimating how much data generated by the users can be offloaded to WiFi networks from cellular networks even when there are non- Markovian data arrivals and service interruptions. We provide extensive numerical studies with various ranges of delay, service interruption time, arrived data, and service rate. These numerical studies show that the current deployment of WiFi networks measured from a metropolitan city is capable of offloading about 80% of the generated data with 30 minutes of delay and 1 Mbps of WiFi data rate, but increasing the data rate does not help improve the amount of offloading. Further studies using this framework on two new deployment strategies of WiFi networks in the near future give guidance on how to upgrade WiFi networks by revealing that the amount of offloading for 30 minutes of delay and 1 Mbps of data rate can be drastically improved to about 90% or 98% according to the strategy.