In communication engineering, Ultra NarrowBand (UNB) systems are those in which the channel has a very narrow bandwidth.Thethingsnetwork.org, https://www.thethingsnetwork.org/forum/uploads/default/original/1X/3b1c1ae4a925e9aa897110ccde10ec61f3106b87.pdf
Technical characteristics
An ultra narrowband receiver is highly selectiveUnderstanding Radio Receiver Selectivity | Electronics Notes, Website title: Electronics-notes.com, URL: https://www.electronics-notes.com/articles/radio/radio-receiver-selectivity/basics.php and can reject noise and interference which may enter the receiver outside its narrow bandwidth, enabling an acceptable signal-to-noise ratio 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 spectrumWhat is DSSS | Direct Sequence Spread Spectrum, https://www.electronics-notes.com/articles/radio/dsss/what-is-direct-sequence-spread-spectrum.php and chirp spread spectrum,IEEE Computer Society, (August 31, 2007). IEEE Standard 802.15.4a-2007. New York, NY: IEEE, URL: https://ieeexplore.ieee.org/document/4299496 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 HzAnteur, Mehdi; Deslandes, Vincent; Thomas, Nathalie; Beylot, Andre-Luc (December 2015). Ultra Narrow Band Technique for Low Power Wide Area Communications. IEEE Global Communications Conference (GLOBECOM). doi:10.1109/GLOCOM.2015.7417420, URL; https://ieeexplore.ieee.org/document/7417420 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.ETSI TR103 435 System Reference document (SRdoc); Short Range Devices (SRD) Technical characteristics for Ultra Narrow Band (UNB) SRDs operating in the UHF spectrum below 1 GHz https://www.etsi.org/deliver/etsi_tr/103400_103499/103435/01.01.01_60/tr_103435v010101p.pdf
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, with UNB being one of the technologies that have been used to implement Low-Power Wide Area Networks.Low Power Wide Area Networks: An Overview, Published in 2015 IEEE Global Communications Conference (GLOBECOM) https://ieeexplore.ieee.org/document/7815384/ Short, infrequent transmissions with low transmit power can enable long-life, battery-powered operation of UNB devices connected in a LPWAN.Fenix.tecnico.ulisboa.pt, https://fenix.tecnico.ulisboa.pt/downloadFile/1689244997257704/extended_abst.pdf
UNB LPWAN often operate on VHF or UHF frequencies where radio signal propagation characteristics are suited to typical UNB applicationsSub 1GHz wireless LAN propagation path loss models for urban smart grid applications, https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6167392 with ranges of 10 km or greater.‘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 They may be deployed in a shared spectrum (ISM band) Itu.int, https://www.itu.int/en/ITU-R/study-groups/workshops/RWP1B-SRD-UWB-14/Presentations/International,%20regional%20and%20national%20regulation%20of%20SRDs.pdf
Typical properties of UNB devices operating in the UHF spectrum below 1 GHz have been described by ETSI;ETSI TR103 435 System Reference document (SRdoc); Short Range Devices (SRD) Technical characteristics for Ultra Narrow Band (UNB) SRDs operating in the UHF spectrum below 1 GHz, https://www.etsi.org/deliver/etsi_tr/103400_103499/103435/01.01.01_60/tr_103435v010101p.pdf 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