Wireless communication is a category of technology that can send or receive digitized messages without a direct connection. Combining computer processing with the basic principle allows more complex messages between the systems at faster speeds.
At its core, wireless communication requires just two things: a generated signal from a transmitter and a receiver capable of interpreting that signal without a connecting medium such as wires, cables, or an atmosphere. That broad definition includes things like the infrared sensor on a television or a hand sign.
In modern usage, wireless communication most likely refers to devices that have a combination of a radio transmitter, a radio receiver, and digital processing equipment.
Wireless technology has seen rapid progress in nearly every metric used to evaluate them. Flashing a light in Morse code is a form of wireless communication, if a rudimentary one. Alexander Graham Bell invented the photophone in 1880, a device that used light to transmit audio signals without a wire. The first demonstration of a radio frequency being used for wireless telegraphy occurred in 1866 by Dr. Mahlon Loomis, and practical applications for the radio signals steadily emerged over the 20th century.
The television also offers an interesting look at the long-term evolution of wireless technology. First, the buttons had to be physically operated. Then, infrared light signals emitted by remotes could be interpreted by the television to change the channel from afar. Now, newer TVs increasingly come with remotes that use radio waves instead.
The most common devices considered to be wireless communication technology transmit data over as radio waves to avoid the line-of-sight issues with light-based signals.
Cellular technology could be called the oldest sibling of modern wireless communication tech. Electromagnetic waves travel between tall towers, satellites in orbit, and devices that are sending and receiving the radio waves. It is primarily used to connect mobile devices like cellular phones and their younger and more tech-heavy siblings, smartphones. Despite its age, the technology has been steadily improving to meet the demands of the Age of Information with the 4G and 5G networks.
The Wireless Fidelity (WiFi) communication technology has been helping devices talk to one another since 1997. Wi-Fi routers allow devices like computers and smartphones to form networks that share information and resources. An Internet connection is the most commonly shared resource on WiFi networks, but sizable offline networks can create modern supercomputers through the radio waves.
Bluetooth Low Energy (BLE) is a more energy efficient version of Bluetooth (BT), a form of wireless communication that sees significant use for ad hoc connectivity between two devices in relatively close proximity, such as pairing headphones to smartphones. Most equipment that can connect via BT will accept BLE connections.
LoRa is a shortening of "Long Range". The newest connectivity method of the four, the spry upstart specializes in transmitting small packets of data over long distances with minimal power requirements. Like WiFi, LoRa can be used to create private networks, but it is geared towards devices that don't transmit as much data as computers or cellular phones, known generally as the Internet of Things (IoT). The LoRa Wide Area Network (LoRaWAN) governs the software end of the technology.
Wireless communications have seen rapid adoption in the consumer, business, industrial, scientific, and government sectors. The below list is by no means exhaustive, but it covers some of the most common examples.
Humanity has garnered many of its greatest achievements through collaboration, and wireless communication technology has propelled that ability to levels that would shock the minds of people from the past. Billions of people are connected every day through messaging applications and social media sites. For examples in other sectors, a business meeting can take place anywhere at any time, legal documents can be filed from the field, and research data can be uploaded as soon as it's acquired.
Video streaming has steadily become an everyday part of life for many people, and it is predicted to account for 84% of all Internet traffic in 2022. Over half of all Internet traffic goes through mobile devices using either cellular or WiFi connections, and many desktops and laptops use WiFi networks for their Internet access. By raw usage, this is the most common application of all.
In the past, setting up a remote monitoring system required extensive wiring and a central hub. WIFI-enabled cameras can now be purchased for relatively low costs and placed around a site as needed. Additional features like solar panels and WiFi access points to extend the range make it cost-efficient even for large, outdoor spaces.
Other types of sensors are also easier to place around a site when they don't need wires. For example, small medical monitors can keep an eye on a patient's heart rate and other vital signs for concerning changes and pattern analysis.
Bluetooth allows wireless keyboards, headphones, and similar devices to connect without a tangle of wires spreading over the work area. Since the devices are typically used in conjunction, the equipment can be made with lower power draw that extends the operating life to reasonable durations.
A connection with more range can send control signals to devices further away, such as those used in advanced unmanned aerial vehicles.
Bluetooth and Wifi are considered to be short range wireless network devices. The most common Bluetooth implementations have the shortest range amongst wireless technologies, reaching only as far as 10 meters before the signal degrades to the point of inoperability. A less used version has an even shorter range of just 1 meter.
WiFi has a bit more range than the typical Bluetooth devices, covering about the size of an apartment if indoors. That range can drop with significant interference from other devices or construction.
With the highest class of Bluetooth devices, the range tremendously increases to roughly 100 meters while still falling short of the long range technologies.
LoRa devices have a considerable range of about 10 miles with no obstacles and about 3 miles within a busy area like a city. If not for the low throughput, LoRa would allow for fast deployment of wide area communications.
The range of cellular wireless communications is extensive, both when comparing the range of any single device and the coverage area of the network. The range does vary with the form of connection used, though.
A standard cell phone call might be able to go as far as 45 miles, but a 4G tower needs to be within 10 miles of a smartphone to have a reliable signal. For much of the world, it's possible to stay within tower range even when travelling, so the functional range of devices that talk over the network is much longer.
The 5G network has a substantially shorter range of under 500 meters, pushing it closer to the shorter category. While it does make setting up the network harder, more 5G towers are constantly being activated to expand the network coverage.
Selecting a wireless technology for a project involves evaluating the available technologies against the desired functionality and usage metrics like the implementation cost, energy usage, intended location, distance between devices, and information security.
Wireless technology is accessible at consumer prices, but the cost can still be substantial on larger projects. The true cost of any technology upgrade also may not be apparent for a while. Technology that can easily be repurposed can cut the costs of future projects, but maintenance and unforseen issues will take away additional resources.
Newer tech will also tend to be more expensive, like the relatively high cost of a LoRa gateway compared to a Wi-Fi router. Some technologies will cost more when implementing them as a new device, such as the hefty cost for testing and certification of cellular devices by PTCRB. The cost varies according to the testing lab chosen, but it can easily surpass five figures.
The amount of power a technology uses impacts the function lifespan and operating costs of the attached device. With wireless technology, the amount of power used is strongly related to the amount of information being transmitted, though other factors influence the exact rate.
BLE has the lowest power consumption in this list, followed by LoRa. Both have much smaller data throughput. Wi-Fi comes in ahead of cellular on power consumption, which is why a smartphone battery will last longer with the cellular service turned off.
Static devices may have access to a consistent energy source, negating concerns about battery life. Mobile applications and usage in remote areas will require time and planning for recharging and supplying replacement batteries as needed.
The radio coverage range of the devices varies, and interference at the project site can degrade the signal further. More details on range can be found in the previous section, but it's important to get measurements accurate to at least a meter or yard if using WiFi or Bluetooth.
Radio signals do not care what devices listen to them. As long as the receiver catches the signal, it can interpret the results and show them to whoever's operating it. The advent of wireless networks also spurred malicious hacking tactics like wardriving to hunt for networks with poor security.
Encryption is the only way to stop any receiver in range of a wireless network from understanding the message, but encryption methods increase the size of the data being sent. The increased throughput need is less of an issue for WiFi and cellular systems, if still a concern.
WiFi routers have multiple encryption methods built into them, but those alone may not be enough. WPA2 was once thought to be functionally unhackable, but researchers eventually found a vulnerability. Vulnerabilities have also revealed themselves for the encryption used in 4G cellular. Bluetooth uses a rudimentary encryption method, but the low range of the devices makes it difficult to use as a primary hacking point. The LoRa Alliance says their security is at "AES-128 strength", which also has known vulnerabilities.
Additional security steps like encryption at a different layer of the tech stack or intentionally adding interference at select locations can mitigate these risks, but anyone using wireless technology should be aware of them.
LoRa's particular niche of long range and low power has developers looking to the stars. A company called Wyld Networks has an upcoming sensor that allows LoRa devices to communicate with satellites. With a clear sky, a LoraWAN network could span the entire globe. The low bandwidth will likely keep it from outright replacing cell service in smartphones, but smaller devices are ripe for connectivity.
Expect to see continued improvements in Bluetooth's range, functionality, and power consumption, especially in more common examples of Bluetooth devices.
An audio version of BLE released in 2020 allows the creation of Bluetooth-enabled headphones with significantly improved battery life or a leaner profile with a smaller battery. In addition to the energy consumption improvements, the upgrade adds the ability to broadcast audio to multiple devices
In Bluetooth 5, a new configuration option allows the device operator to lower the packet size in exchange for a longer transmission range without otherwise compromising the functionality. A test by Nordic Semiconductors successfully transmitted a signal at over a kilometer using the setting.
The Wi-Fi Alliance has been touting the improvements upcoming in Wi-Fi 6 as an answer to the higher demand from networks as the IoT expands, streaming trends continue, and businesses continue to incorporate work-from-home and hybrid work models. The recent WiFi HaLow certification also offers a WiFi solution for IoT needs by reducing power consumption and increasing the networking range.
The capabilities of the cellular network will be extended to more devices through DECT-NR+, The protocol sets the stage for smarter equipment to have the same range that LoRa grants to those with minimal data needs.
Wired connections will continue to have a place in the technology toolkit, but taking away the wires bring such a wide array of benefits with a manageable increase in security risk. It may seem like the available connectivity options are constantly changing, and that's because they are. From project managers to individual customers, its important that everyone understands how these networking tools operate to get the best and safest use of them.