Receiving data in a sensor network
View Patent ↗A sensor network has a plurality of wireless sensors which transmit to an intermediate receiving device which relays data to a central server. A method is provided for receiving data packets at the intermediate receiving device from a plurality of the transmitting devices. Data packets are sensed on a communication medium at the receiving device and the total traffic intensity of data packets from the transmitting devices is estimated. A detection threshold for data packets is provided and adapted as a function of the total intensity. The receiving device receives data packets with a signal strength above the current detection threshold.
1. A method for receiving data packets from a plurality of transmitting devices at a receiving device, comprising:
sensing data packets transmitted on a communication medium;
estimating a total traffic intensity of data packets generated by the transmitting devices;
defining a detection threshold for receiving data packets as a function of the total traffic intensity;
ignoring data packets with a received signal strength below the detection threshold; and
receiving data packets with a received signal strength above the detection threshold;
wherein when the total traffic intensity is low, the detection threshold is decreased;
wherein when the total traffic intensity increases, the detection threshold is increased;
wherein the detection threshold is defined for every data packet sensed;
wherein the method includes estimating a utilization at the receiving device and defining the detection threshold to maximize the utilization;
wherein the traffic intensity is estimated by a packet duration divided by an average idle time at the receiving device;
wherein the utilization at the receiving device is estimated by a packet duration divided by an average time between two successful packet receptions;
wherein the total traffic intensity and the utilization are continually updated;
wherein the method includes maintaining a list of active transmitting devices and their received signal strengths;
wherein the total traffic intensity is maintained at about 75% of the physical layer data rate and the utilization is maintained at about 22%; and
wherein the detection threshold is increased if it is detected a predetermined number of times in succession that the total traffic intensity is greater than 75% and the utilization is less than 22%, and wherein the detection threshold is decreased if the total traffic intensity is less than 75% and the utilization is less than 22%.