ABSTRACT
In this section, we present a detailed description of our cloud-based grid algorithm. Firstly, we define the clouds by the normal rate to compute the overlaying terrain within a grid. Then the multicast clouds of the current regions in the system are dynamically allocated and then are distributed hosts trigger hosts. The proceeding is the same as in the region method, but different from the fixed grid-based scheme, which statically assigns multicast cloud groups to all of the terrain in the grid. The method of this paper is novel because only those cloudgrids includes at least one overlaying terrain of publishing federate and subscribing federate. These clouds are assigned to a multicast group, and when the messages sent by the cloud grid system are triggered, the federates will join or leave the appropriate clouds. The appropriate clouds are defined with cloud algorithm. Only when at least one overlaying cloud grid is created, Publishers will join and transmit on one cloud and the subscribers will join and listen on one group if there is at least one publisher transmitting on that group. There are dual advantages in this technique: one is reducing the data which senders transmitting, and the other is reducing the amount of multicast cloud groups t a federate joining, because only when at least one overlaying cloud grid is created, the cloud groups are joined and data are sent.
