Patent ID: 8391198
Filing Date: 2013-03-05
Classification: H04L,H04W

Abstract:
1. A reliable synchronization apparatus within a multicast and broadcast service (MBS) zone, said MBS zone having m sync executers (SEs) and said m SEs belonging to n retransmission zones respectively, m>n≧1, each retransmission zone having a selected leader SE and un-selected SEs being member SEs of the selected leader SE, said apparatus comprising: n selected leader SEs; and a sync controller, wherein in each retransmission zone, when said sync controller multicasts a sync ruler to all SEs in said retransmission zone, the leader SE not having received said sync ruler unicasts a NACK message to said sync controller to request retransmitting said sync ruler, said sync controller retransmits said sync ruler and triggers an election of a new leader SE to update leader SE information and multicasts new leader SE information to all SEs in said retransmission zone, and each member SE not having received said sync ruler unicasts a NACK message to the leader SE of said retransmission zone or said sync controller to request retransmitting said sync ruler.