OBU (On Board Unit) and short-range radios
An inexpensive trailer detection on 2400 MHz radio modules is indeed already published. http://www.gsm-modem.de/M2M/m2m-faq/trailer-detection-active-rfid/
Through the use of ICs, which were developed for consumer products, the bill of materials is very low.
Last week, a GSM / ISM Bridge required based on Linux. A GPS module is also a part the M2M system. The rough structure shows picture as below.
The active RFID tags will get the same 868 / 915 MHz transceiver or just transmitter only. For a quick start, we take radio modules for smart metering with WirelessM-Bus protocol. Radio module for wireless Metering-Bus meter often have to work up to 12 years from battery. It is thereby proven, cost-effective, energy-saving wireless technology. To reduce costs further in the mass production, the radio modules can be replaced by ICs.
This post aroused your interest? Do you have a similar task? Do you have a different task based on radio? I look forward to any feedback or new task to harald.naumann (at) gsm-modem.de