communication engineering Telecommunications Engineering is a subfield of electrical engineering which seeks to design and devise systems of communication at a distance. The work ranges from basic circuit design to strategic mass developments. A telecommunication engine ...

, Ultra NarrowBand (UNB) systems are those in which the

channel Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Austral ...

has a very narrow

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

Technical characteristics

An ultra narrowband receiver is highly selective and can reject noise and interference which may enter the receiver outside its narrow bandwidth, enabling an acceptable

signal-to-noise ratio Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in deci ...

to be achieved with a relatively weak received signal. Consequently, transmitter power levels can be low and the effective range of transmissions may be greater than would typically be the case for technologies which do not provide such selectivity. Some other radio technologies, such as direct sequence spread spectrum and

chirp spread spectrum In digital communications, chirp spread spectrum (CSS) is a spread spectrum technique that uses wideband linear frequency modulated chirp pulses to encode information. A chirp is a sinusoidal signal whose frequency increases or decreases over ...

, employ alternative approaches to selectively extract signals from interference and noise. Typical UNB systems operate with a bandwidth of a few 10s to a few 100s Hz and are used for the transmission and reception of digital signals. The use of highly selective filters in UNB receivers can provide very effective rejection of UNB signals from other UNB devices on adjacent carrier frequencies, permitting the operation of many devices in a limited geographical area.

UNB LPWAN

UNB technology is often used where links from very high numbers of devices are needed, with relatively small amounts of data being exchanged on each link. Some such applications can be found in the

Internet of things The Internet of things (IoT) describes physical objects (or groups of such objects) with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other comm ...

, with UNB being one of the technologies that have been used to implement Low-Power Wide Area Networks. Short, infrequent transmissions with low transmit power can enable long-life, battery-powered operation of UNB devices connected in a

LPWAN A low-power wide-area network (LPWAN or LPWA network) is a type of wireless telecommunication wide area network designed to allow long-range communications at a low bit rate among things (connected objects), such as sensors operated on a battery ...

. UNB LPWAN often operate on VHF or UHF frequencies where radio signal propagation characteristics are suited to typical UNB applications with ranges of 10km or greater..They may be deployed in a shared spectrum (

ISM band The ISM radio bands are portions of the radio spectrum reserved internationally for industrial, scientific and medical (ISM) purposes, excluding applications in telecommunications. Examples of applications for the use of radio frequency (RF) ener ...

) Typical properties of UNB devices operating in the UHF spectrum below 1 GHz have been described by

ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...

; whilst specific UNB-based protocols for the implementation of LPWAN have also been standardised (alongside others) by ETSI.‘Short Range Devices; Low Throughput Networks (LTN); Protocols for radio interface A’ https://www.etsi.org/deliver/etsi_ts/103300_103399/103357/01.01.01_60/ts_103357v010101p.pdf

References

Computer-mediated communication {{telecomm-stub