Enabling smartphone-based HD video chats by cooperative transmissions in CRNs

Abstract

Smartphones have been equipped with the cameras that can shoot HD videos, and the video chat apps such as Skype are becoming popular. We can, therefore, intuitively predict the trend that users are expecting to enjoy HD video chats via utilizing their smartphones. Most of the current Internet services, however, cannot support the live HD video transmissions because of their low uplink rate. In order to overcome this limit, we propose to offload the uplink transmissions to cooperative users via cognitive radio networks. Specifically, we first divide the video stream into several substreams according to the H.264/SVC standard and the cooperative users' uplink rates. Then, the cooperative users are selected by employing our proposed optimal multiple stopping method. Finally, the substreams are assigned to the selected cooperative users by a 0-1 Knapsack-based allocation algorithm. The simulation results demonstrate that our proposed scheme can successfully support 720P HD video chats.

A Mobile Cloud Computing Framework Integrating Multilevel Encoding for Performance Monitoring in Telerehabilitation

“…Moreover, NetBalancer was used to control the Internet upload speed of the laptop to simulate the environment with different conditions of the Internet. We limited the upload speed from 80 to 800 Kbps with a step of 80 Kbps for testing because the upload speed on 3G/4G is about 0.45 Mbps to 1.93 Mbps [48]. Eventually, we recorded the average energy utilized to transfer one frame of the encoded data with each respective speed.…”