Cloud-End Issues
A four-level architecture [9] is well recognized in cloud design, including Data Centers Layer, IaaS (Infrastructure as
a Service) Layer, PaaS (Platform as a Service) Layer, and SaaS (Software as a Service) Layer. For the proposed MCG
system, the cloud-end is providing a GaaS. The most critical open research issues in GaaS include:1) VM Design: In cloud computing, how to visualizer distributed resources is one of the most critical issues for VM design. However, the resource requirement for each game session in an MCG system does not impose a heavy load,so that multiple VMs commonly reside in a single server.Therefore, scheduling of parallel tasks in a server is an important topic, since the gaming procedures are always sensitive to round-trip time (RTT). Moreover, each VM running in the cloud is a request handler for its corresponding mobile client. In order to cope with the operating environments of the mobile devices, VMs should synchronize themselves in time. However, frequent updates might cost a large amount of data transmissions over wireless networks, which may potentially decrease the overall system performance.Therefore, how to design a flexible and efficient VM remains an open issue