License free Radio Telemetry

SRD860 – 869 License free radio operation
In Europe, 863 to 870  MHz band has been allocated for license free radio operation using FHSS, DSSS, or analog modulation with either a transmission duty cycle of 0.1%, 1% or 10% depending on the band.
Short-range devices are low-power transmitters typically limited to 25–100 mW effective radiated power (ERP) or less, depending on the frequency band, which limits their useful range to few hundred meters, and do not require a license from its user.
Applications for short-range wireless devices include power meters and other remote instrumentation, RFID applications, radio-controlled models, fire, security and social alarms, vehicle radars, wireless microphones and earphones, traffic signs and signals (including control signals), remote garage door openers and car keys, barcode readers, motion detection, and many others.

The European Commission mandates through CEPT and ETSI the allocation of several device bands such as the Pan-European license free 869 MHz band for these purposes. The Output Power and Duty Cycle restricts the parameters of their use, and provides guidelines for avoiding radio interference.

900 MHz band license free radio
The 33-centimeter or 900 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio on a secondary basis. It ranges from 902 to 928 MHz and is unique to ITU Region 2. The International Telecommunication Union (ITU), in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum. Region 2 covers the Americas, Greenland and some of the eastern Pacific Islands.
It is primarily used for very local communications as opposed to bands lower in frequency. However, very high antennas with high gain have shown 33 centimeters can provide good long range communications almost equal to systems on lower frequencies such as the 70 centimeter band. The 70 centimeter band is the 430.000 – 440.000 MHz UHF band.

2400 MHz ISM license free radio
The industrial, scientific and medical (ISM) radio bands are radio bands (portions of the radio spectrum) reserved internationally for the use of radio frequency (RF) energy for industrial, scientific and medical purposes other than telecommunications. In recent years the fastest-growing uses of these bands have been for short-range, low power communications systems. Radio frequencies in the ISM bands have been used for communication purposes, although such devices may experience interference from non-communication sources.
Frequencies used by Satel are in the following range: 2.4015 GHz … 2.4815 GHz with a total of 27 channels and a 100mW Output Power.
In recent years ISM bands have also been shared with (non-ISM) license free radio error-tolerant communications applications.