Seamless Service Handoff Based on Delaunay Triangulation for Mobile Cloud Computing

Mobile cloud computing is a promising technique that shifts the data and computing service modules from individual devices to a cloud architecture. When the service is executed in the cloud clone, the data transfer between the mobile terminal (MT) and its clone requires low end-to-end communication delay. However, it is very difficult to predict the speed and direction of an MT in a timely fashion. Thus, the service handoff between different access points (APs) may cause long handoff delay. To address this issue, we propose a proactive service handoff mechanism using the Delaunay triangulation (called as DTSHM mechanism). The DTSHM constructs all the APs into a Delaunay triangulation topology. For an MT located in a Delaunay triangle, its next handoff procedure only happens between the three vertices (i.e. APs) of this triangle no matter how it moves. It is because the circumcircle of each Delaunay triangle does not contain any other APs in its interior. Thus, a Delaunay triangle is characterized as the master-standby service model which is composed of a master AP and two standby APs. In the DTSHM, The cloud clone in advance authenticates and buffers the required data packets of an MT in the standby APs. Thus, the clone can quickly handoff the cloud service from the source AP to the target AP when the handoff process is triggered. The simulation results and the performance analysis show that the DTSHM works very well.