Patent ID: 7738413

Claim:
A power efficient wireless system for a sensor network comprising: a) at least one access point including a processor and a transceiver configured to transmit signals to and receiving signals from a plurality of sensor nodes, b) a plurality of sensor nodes each including a processor and a transceiver configured to receive signals from the access point and transmitting data packets to the access point, and c) a communication network including wireless one hop broadcast of downlink signals from the access point to the plurality of sensor nodes, wherein the downlink signals are broadcast by the access point using a transmission power having a range covering the plurality of sensor nodes, and multi-hop transmission of at least some uplink signals that originate from the plurality of sensor nodes to the access point through a plurality of channels using time division multiple access and assigned to the sensor nodes by the access point using a scheduling mechanism, wherein the at least some uplink signals are transmitted by the plurality of sensor nodes using another transmission power having a range covering each sensors' neighboring nodes, and further wherein the transmission power used by the access point to broadcast downlink signals is higher than the transmission power used by the plurality of sensor nodes to transmit the at least some uplink signals.