Adaptive Mobile Cloud Computing to Enable Rich Mobile Multimedia Applications

With worldwide shipments of smartphones (487.7 million) exceeding PCs (414.6 million including tablets) in 2011 [1], and in the US alone, more users predicted to access the Internet from mobile devices than from PCs by 2015 [2], clearly there is a desire to be able to use mobile devices and networks like we use PCs and wireline networks today. However, in spite of advances in the capabilities of mobile devices, a gap will continue to exist, and may even widen, with the requirements of rich multimedia applications. Mobile cloud computing can help bridge this gap, providing mobile applications the capabilities of cloud servers and storage together with the benefits of mobile devices and mobile connectivity, possibly enabling a new generation of truly ubiquitous multimedia applications on mobile devices: Cloud Mobile Media (CMM) applications. In this paper, we look at early trends, and opportunities and benefits for new CMM applications and services. We analyze the challenges imposed by mobile cloud computing that need to be addressed to make CMM applications viable, including response time, user experience, cloud computing cost, mobile network bandwidth, and scalability to large number of CMM users, besides other important cloud computing issues like energy consumption, privacy, and security. We illustrate the challenges using Cloud Mobile Gaming (CMG), an approach that enables rich multiplayer Internet games on mobile devices, where compute intensive tasks like graphic rendering are executed on cloud servers in response to gaming commands on a mobile device, and the resulting video has to be streamed back to the mobile device in near real time, making it one of the most challenging CMM applications. Subsequently, we focus in this paper on developing adaptive mobile cloud computing techniques to address the CMG challenges. Specifically, we propose a rendering adaptation technique, which can dynamically vary the richness and complexity of graphic rendering depending on the network and cloud computing constraints, thereby impacting both the bit rate of the rendered video that needs to be streamed back from the cloud server to the mobile device, and the computation load on the CMG servers. Experiments conducted on a cellular network demonstrate that our proposed technique can significantly improve user experience, and ensure scalability of the CMG approach in terms of both network bandwidth and server computational need.