Patent ID: 8477659

Claim:
An audio/video communication system, comprising plural network terminals, wherein each of the network terminals has a communication node used to participate in a communication group and a stand-by node used to participate in a stand-by group; every node in the communication group has a first lower node connector and a second lower node connector, and is arranged to store a first value indicating a number of nodes in a first side diverging from the first lower node connector and a second value indicating a number of nodes in a second side diverging from the second lower node connector; a new node is added to the communication group such that the first value and the second value stored in each node in the communication group will be substantially equal to each other, in order to automatically regulate connections among nodes in the communication group to define a balanced binary tree structure; data sent from a node in the communication group reaches all the other nodes in the communication group within a time in proportion to a logarithm of the number of nodes in the communication group; every node in the communication group sends a total number of lower nodes including itself to its higher node at regular time intervals; and the higher node stores the total number as the first value indicating the number of node in the first side diverging from the first lower node connector or the second value indicating the number of node in the second side diverging from the second lower node connector.