Intelligent network sensor system

A sensor tag for use in a sensor system, the tag comprising:

• a transmitter;
• an energy harvesting unit operable to convert incident RF energy to direct current (DC) including RF energy from a RF emitter and RF energy from one or more ambient sources;
• a storage unit operable to store recovered DC power;
• one or more sensors for sensing and logging data;
• a controller coupled to the energy harvesting and storage units, the one or more sensors and the transmitter, to communicate data from in the form of a Bluetooth Low Energy (BLE) advertising packet using energy previously harvested and stored by the energy harvesting and storage unit,
• wherein the tag determines the charge energy for each of a plurality of frequencies transmitted from the RF emitter executing an sweep algorithm and identifies one of the plurality of frequencies as the one frequency that produced more charge energy that any other of frequencies of the plurality of frequencies.

A method for use in a sensor system having a tag, an RF emitter and a device, the method comprising:

• performing, by the RF emitter, a sweep algorithm in which the RF emitter transmits RF energy at a plurality of frequencies;
• determining, by the tag, charge energy for each of the plurality of frequencies;
• identifying, by the tag, one of the plurality of frequencies as the one frequency that produced more charge energy that any other of frequencies of the plurality of frequencies;
• determining which frequency among the plurality of frequencies provides a best power transfer efficiency (PTE) for the tag.