Without question, the number of wireless Internet of Things (IoT) standards seems too numerous to count. With so many in existence, how can one decide which to use for a given application? Doing just that is the objective of Keysight Technologies’ new application note, “The Menu at the IoT Café: A Guide to IoT Wireless Technologies.” The application note discusses several topics, such as both short- and long-range wireless, unlicensed and licensed bands, and more.
The application note first discusses the various short-range wireless technologies, such as Bluetooth and ZigBee. Bluetooth and ZigBee devices operate in the unlicensed industrial-scientific-medical (ISM) bands; specifically, the 2.4-GHz band is the most commonly used ISM frequency band. The document also associates short-range wireless standards with personal area networks (PANs), which typically have ranges of about 10 to 30 meters.
Wi-Fi is then discussed in greater detail. Since Wi-Fi has existed for a long time, there are many suppliers of chip and modules. Designers therefore have many options in terms of hardware components. The application note describes various forms of Wi-Fi: 802.11b, 802.11g, 802.11a, 802.11n, and 802.11ac.
Next, long-range wireless standards are discussed. One technology described is LoRa, which uses sub-1-GHz frequencies in unlicensed spectrum. The application note points out how LoRa signals can penetrate deep into buildings and reach locations not accessible when using higher frequency equipment. Another technology described, Sigfox, is a proprietary radio protocol that operates in the sub-1-GHz frequency bands.
The next topic presented is licensed spectrum, which in this case refers to cellular data networks. These networks involve spectrum and control access that have been purchased by operators to provide voice and data connections. Two IoT technologies mentioned that use licensed spectrum are narrowband-IoT (NB-IoT) and Cat-M1. NB-IoT is a low-data-rate, long-range technology. Cat-M1 offers higher data rates than NB-IoT. Finally, hybrid networks are discussed, as these networks combine short-range PAN and long-range protocols into a single network.
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