Harman Patil (Editor)

Short Range Devices

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Short Range Devices (SRD) is a ECC Recommendation 70-03 which describes radio frequency transmitter devices used in telecommunication for the transmission of information, which have low capability of causing harmful interference to other radio equipment.

Contents

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 for these purposes, restricts the parameters of their use, and provides guidelines for avoiding radio interference.

Frequency bands

According to ECC Rec. 70-03, there are several annexes which encapsulate specific usage patterns, maximum emission power and duty cycle requirements.

SRD860

In Europe, 863 to 870  MHz band has been allocated for license-free operation using FHSS, DSSS, or analog modulation with either a transmission duty cycle of 0.1%, 1% or 10% depending on the band, or Listen Before Talk (LBT) with Adaptive Frequency Agility (AFA).

As of December 2011, unrestricted voice communications are allowed in the 869.7-870.0 MHz band with channel spacing of 25 kHz or less and maximum power output of 5 mW ERP.

SRD860 handheld transceivers were briefly available in mid 2000s, however they did not offer dual-band compatibility with PMR446 and LPD433 bands. As of 2012, they have been put off-market.

References

Short Range Devices Wikipedia