Short-range device

A short-range device (SRD), described by ECC Recommendation 70-03, is a radio-frequency transmitter device used in telecommunication for the transmission of information, which has low capability of causing harmful interference to other radio equipment. 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 their users. Short-range wireless technologies include Bluetooth, Wi-Fi, near-field communication (NFC), LPWAN, ultra-wideband (UWB) and IEEE 802.15.4. They are implemented by chips fabricated as RF CMOS integrated circuit (RF circuit). , short-range wireless chips ship approximately billion units annually, with Bluetooth accounting for over 55% of shipments and Wi-Fi around 35% of shipments. 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. According to ECC Rec. 70-03, there are several annexes which encapsulate specific usage patterns, maximum emission power and duty cycle requirements. 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). Although this band falls under the Short Range Device umbrella, it is being used in Low-Power Wide-Area Network (LPWAN) wireless telecommunication networks, designed to allow long-range communications at a low bit rate among things (connected objects).