Patent ID: 8488584
Filing Date: 2013-07-16
Classification: H04L,H04W

Abstract:
1. A wireless communication system comprising a child node and a parent node, wherein the improvement comprises: when a first packet is transmitted from the child node to the parent node based on an IEEE 802.15.4/ZigBee standard, the child node transmitting the first packet to the parent node by way of point-to-point transmission, and when a second packet is transmitted from the parent node to the child node based on the IEEE 802.15.4/ZigBee standard, the parent node transmitting a synchronization signal with a specified flag periodically for connection maintenance and synchronous control, and the child node receiving the second packet, transmitted by way of broadcasting, from the parent node in response to the synchronization signal with the specified flag set to one; wherein the child node sends a request signal to the parent node for re-transmitting the second packet as the child node fails to receive the second packet in a certain period after receiving the synchronization signal, and wherein the parent node re-transmits the second packet to the child node by way of point-to-point transmission in response to the request signal.