Patent ID: 7356360

Claim:
A radio communication system comprising: a plurality of communication units in a radio network, wherein one of the plurality of communication units is a master and operates in a master mode and other communication units are slaves and operate in a slave mode, wherein a transition into a Sniff mode is allowed during operation in the slave mode, wherein each of the plurality of communication units includes a battery as driving power, wherein each slave in the Sniff mode communicates with the master during a Sniff duration in every Sniff period, and each Sniff duration includes two or more Sniff slots, wherein the communication unit operating in the master mode stops transmission/reception operations in synchronization with all slaves in the Sniff mode which are out of the Sniff duration, and wherein the Sniff periods of the communication units operating in the slave mode are substantially in synchronization and in phase with each other or out of chase with each other.