Wireless signals are one of the most widely used communication options, from your favorite local TV and radio stations to your cellular phone. Some of the most crucial wireless technologies, the ones that run your home internet and the increasing number of smart devices on the Internet of Things or IoT are regulated by a range of wireless protocols. Depending on their usage, their range might be as much as several miles or as little as a few inches.
Wide-Area Internet Options
If you don't live in an area that's served by conventional internet providers, your options traditionally have been limited to dial-up or satellite, neither of which is especially good at modern, rich internet content. Wireless technology can bridge this gap in a few different ways, providing service where it wouldn't otherwise be available.
Home Service Through LTE
In areas where cable and fiber internet aren't economical, the same LTE technology that provides internet coverage on your cellphone can be harnessed to provide wireless internet to home users as well. It can be delivered over the existing cellular network by the major carriers or by independent service providers who opt to put up their own towers. Speeds vary among providers, with the current 4th-generation technology, 4G, giving speeds of up to a respectable 100 Mbps, while the forthcoming 5G technology could theoretically reach 10 Gbps.
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Line-of-sight internet services use what boils down to a high-powered version of conventional Wi-Fi, which transfers its signal from point to point using highly directional antennas. Because it beams its signals to a tightly focused point, this type of service is less likely to interfere with other devices and can use a higher-power signal that would otherwise be illegal under FCC regulations. Speeds are typically up to 25 Mbps, which is acceptable for most uses if not ideal.
Internet for Devices Over Wide Areas
With the rise of the Internet of Things and its horde of smart and semi-smart devices, there's also a need for wireless technology that can work with a huge number of those low-power devices over large urban and suburban areas. LTE technology can work for those, too, though its power consumption is relatively high. A competitive technology is the Long-Range Wide Area Network protocol or LoRaWAN with a range of a couple of miles in urban settings and up to three times that in less dense suburban areas.
IEEE and the Wi-Fi Protocol
Like many things electrical, the wireless technology you use around your house is based on design specifications laid out by the Institute of Electrical and Electronic Engineers, or IEEE. In this case, the actual specification is called 802.11, and it has been upgraded over the years to reflect – and encourage – improvements in the technology. Those changes are described by adding letters, such as g, n or ac after the number. For convenience, those variations in the spec are referred to as wireless g, wireless n, wireless ac and so on.
A Quick Wireless Network Guide
Your home Wi-Fi is known properly as a wireless local area network or WLAN, but most people just call it Wi-Fi and leave it at that. A Wi-Fi network revolves around a central networking device, called an access point, which provides two-way communications with every device that's attached to the network. Each device, in turn, needs to have a wireless network interface card, or NIC, to communicate with the access point. The wireless protocols they use vary widely in range and performance and are getting better with each generation.
2.4 GHz Band vs. 5 GHz Band
Most Wi-Fi communication takes place in two distinct bands of radio frequencies, the 2.4 GHz band and the 5 GHz band. These bands are minimally regulated, and they're used for a variety of consumer devices from baby monitors to cordless phones. They're good at different things. Frequencies in the 5 GHz band can carry more data more quickly, but those in the 2.4 GHz band have longer range, and they're better at going through walls. Historically 2.4 GHz has been used in more devices, but that means 2.4 GHz frequencies are more crowded and prone to interference.
Early Wi-Fi With Wireless A and B
The earliest versions of the 802.11 Wi-Fi specification to reach the market were wireless a and b, which were standardized in the late '90s and became actual products early in the 2000s. Each used a different band. Wireless b used the 2.4 GHz band, and it was capable of networking at speeds of up to 11 megabits per second and range of up to 150 feet. Wireless a used the 5 GHz band and had throughput of up to 54 Mbps, but its range was only 25 to 75 feet. Wireless b's better range and relatively low cost made it the more popular of the two.
Mainstream Wi-Fi With Wireless G
The first Wi-Fi protocol to have wide success in the consumer marketplace was 802.11g or wireless g. It used the same 2.4 GHz band as wireless b, so it was compatible with older gear using that standard, but at 54 Mbps it now offered performance comparable to wireless a networks. That was good enough for most home users, and wireless g was hugely popular during the first decade of the 2000s.
Improved Performance With Wireless N
As Wi-Fi became more useful and popular, users needed better performance to handle video streaming and other demanding applications. The 802.11n specification, which came along in 2009, addressed that with some important technical tweaks, mostly revolving around Multiple-Input Multiple-Output antennas or MIMOs, which allowed for speeds of up to 300 Mbps. It also offered channel bonding, the option of using separate channels for upstream and downstream traffic, which boosted potential throughput – at least in theory – to 600 Mbps. It used both 2.4 and 5 GHz frequencies, so it was backward compatible with devices using wireless a, b, and g.
Wireless AC Ups the Ante
The wireless ac specification, dating from 2014, refined that technology further through the use of multi-user MIMO technology or MU-MIMO. This provides base speeds of up to 433 Mbps per channel, and with channel bonding, it's theoretically possible to have wireless network speeds well into the gigabits, or thousands of Mbps. Wireless ac itself operates solely in the 5 GHz band, but many manufacturers include wireless n circuitry as well to keep their routers compatible with wireless b, g and n.
Special Purpose Wireless Protocols
There are a couple of 802.11 protocols that aren't used for general purpose Wi-Fi networks, but for specific device-to-device communications. Wireless ad, for example, uses the 60 GHz band and is very fast indeed – potentially up to 6.7 GHz – but within a range of just 10 or 11 feet. It's best used in situations that require high throughput between devices near one another. Wireless ah, also known as Wi-Fi HaLow, uses the lower 900 MHz band to provide extended range with throughput limited to a maximum of 347 Mbps. It's intended to provide longer-range signals for low-power devices such as smart appliances and other IoT applications.
Wireless AX Is Just Around the Corner
The demand for improved Wi-Fi network performance won't be going away anytime soon – quite the opposite – so there's a newer IEEE spec arriving in the marketplace. It's called wireless ax, and it uses some digital sleight-of-hand to increase throughput. It doubles the width of each wireless channel available and allows signals to use just the portions of each channel it needs, making the whole system more efficient. It offers up to four times the range and six times the performance of wireless ac, at least in theory, and –important for the IoT – supports many more devices at the same time.
A Change in Wi-Fi Branding
Although the specifications used for Wi-Fi are defined by the engineers of the IEEE, the term "Wi-Fi" itself and the Wi-Fi logo are owned by a consortium of manufacturers known as the Wi-Fi Alliance. Engineers may be perfectly happy identifying standards with letters and numbers, but manufacturers and their marketing departments like to keep things simple and memorable. That's why the Wi-Fi Alliance has announced new branding, renaming wireless n as Wireless 4, ac as Wireless 5, and ax as Wireless 6. That kind of numbering system is used for everything from cellphones to movie franchises, so it should be easier for consumers to remember.
Device-Oriented Wireless Protocols
Not all wireless protocols are meant to cover large areas or to provide wide-ranging communications capability. Some of the most useful are short-range standards meant to help low-power devices interact with each other. These might affect how you interact with a computer, phone or other devices, or how devices talk to one another directly.
Direct Radio Frequency Communications
Some of the simplest forms of wireless technology, including a standard wireless mouse and keyboard, don't use a formal wireless protocol at all. They transmit directly over a preset radio frequency, instead. Older devices use the 27 MHz frequency, also used for radio-controlled toys. It has poor range but is perfectly fine for devices that share a desk. Newer versions use the 2.4 GHz band and can be used farther away, which is great if you're sitting well back from a giant monitor.
Bluetooth Is More Versatile
RF devices need their own receiver to work, but Bluetooth doesn't, which is why Bluetooth technology is more versatile. Bluetooth is based on another IEEE wireless specification, 802.15.1, which is described as being for personal area networks. Personal area networks are intended to replace wires and cables in and around a single person or workspace. Bluetooth is a technology used in this type of network because it connects reliably, uses relatively little power, and can support up to eight devices simultaneously.
How Bluetooth Works
Bluetooth connects devices on a slice of the 2.4 GHz band. When devices are first connected or paired through Bluetooth, they create a unique security code as a sort of secret handshake between them. After they're paired, they reconnect automatically in the future and don't require any additional setup. Bluetooth data throughput is relatively low, so it's mostly used for input and output devices such as mice and keyboards, speakers, and microphones and headsets.
Bluetooth Low Energy
Low power consumption was always part of the Bluetooth specification because cordless devices are battery-operated by necessity, but even standard Bluetooth uses too much battery power for some applications. A revised version, Bluetooth Low Energy or BLE, caters to that segment of the market by cutting bandwidth and range to reduce energy consumption. It's frequently used in fitness bands and smartwatches, for example, and has the potential for use with IoT devices as well.
Near-Field Communications, or NFC, is the shortest-range of all wireless protocols. It operates over a distance of just a few inches, using very low-power chips. You know it as the technology used in tap-to-pay apps for your phone, including Apple Pay, Google Pay and Samsung Pay. It's also widely used in security key cards and similar applications.
Wireless Protocols for the IoT
Other wireless protocols are cropping up to meet the needs of individual smart devices, and the Internet of Things collectively. These aren't consumer-oriented as such, though the products they enable certainly are. A few of the more prominent ones include:
- Thread: This wireless protocol became part of Google's portfolio when it bought home-automation leader Nest. Based on the IEEE's 802.15.4 wireless standard, it's used in Nest's smoke detectors and automation devices. Other vendors can opt to use Thread if they want to be compatible with products in the Nest ecosystem.
- Zigbee and Zigbee Pro: Zigbee and Zigbee Pro operate on the 2.4 GHz and 900 MHz bands and can potentially support thousands of devices at a time in any given site. Unlike Thread, Zigbee is backed by a consortium of hundreds of manufacturers.
- ZWave and ZWave Plus: Another important protocol for IoT use is ZWave, which is similar to Zigbee but designed to be simpler and less costly to implement. It operates on the 800 and 900 MHz bands, which offer good range and less interference than the 2.4 GHz band. It was created by Danish company Zensys but now has wide support from manufacturers.
- MQTT: Message Queue Telemetry Transport is designed for low-power, low-throughput devices such as relatively "dumb" sensors, which don't need the kind of data throughput required for interactive "smart" IoT devices.