The champion of consumer connectivity, the latest version of Wi-Fi has further improved accessibility and throughput for users, and these changes are also relevant to wireless sensor networks.

Wi-Fi has a complicated history. This is perhaps not surprising, as radio technology represents a convergence of many innovations, four of which stand out the most. The first was a pioneering packet radio network developed in Hawaii in the 1970s that connected seven campuses on four islands in the archipelago, ensuring they could all communicate with each other through Oahu's central computer.

Second, in 1985, the FCC officially made the 2.4GHz spectrum, along with other allocations, for unlicensed industrial, scientific, and medical use. The move encourages business organizations to consider how to take advantage of this new radio resource.

Then, in the 1990s, radio astronomy scientists at the Commonwealth Scientific and Industrial Research Organization in Australia came up with a way to overcome the multipath problem that affects indoor high-throughput radio communications. This invention laid the foundation for wireless local area networks and paved the way for widespread Wi-Fi deployment.

Finally, the Institute of Electrical and Electronics Engineers established a standards committee responsible for defining the physical layer and media access control specifications for the wireless local area network protocol IEEE802.11. The target application is wireless Ethernet, which uses radio frequency technology to connect computers together in a way pioneered by wired networks.

The committee's work resulted in the first version of the Wi-Fi specification, IEEE802.11-1997, published in June 1997. A subsequent revision of the standard in 1999 introduced the technology on which the current version of Wi-Fi is primarily based. The Wi-Fi Alliance was formed to commercialize the technology.

Power and Deployment Challenges

Today, the fifth key event affecting the evolution of Wi-Fi is the Internet of Things. In 1999, when the first version of Wi-Fi was officially adopted, the term was coined by Kevin Ashton, an executive dedicated to promoting rfid, two years before the word was born. time of year. Today, connecting billions of devices or items to the established Internet is largely accomplished through wireless technology.

For short-range IoT networks, protocols such as Bluetooth Low Energy, Thread, Zigbee, etc. take the load. And IoT WAN, cellular IoT, and LoRaWAN are proving to be good options.

But what about Wi-Fi? At first glance, it appears to be perfect for wireless networks that require greater range than short-range, low-power protocols provide, but not the kilometer range of WAN technology. However, Wi-Fi has some considerable drawbacks in IoT applications.

The first problem is power consumption. Wi-Fi is primarily designed for high throughput, which consumes battery power. By contrast, IoT wireless technologies typically try to limit talk time to extend battery life, thereby minimizing maintenance. This comes at the cost of reduced throughput, but this is hardly a problem for sensors and actuators that rarely send small amounts of data.

Second, Wi-Fi encounters difficulties in dense deployment scenarios. As we enter the public hotspots of busy malls and libraries, many of us are familiar with patched services that consumers generally tolerate, but industrial networks of hundreds of sensors are another story.

Built for the Internet of Things

Today, a version of Wi-Fi with the technical name IEEE802.11ax known as Wi-Fi6, promises to address the flaws that have hindered widespread adoption of the technology in the Internet of Things. The Wi-Fi Alliance approved Wi-Fi-6 earlier this year, which is specifically designed to meet the requirements of dense deployments, including public and industrial deployments. The new version offers several enhancements, but the main ones are improvements in throughput and spectral efficiency, which allow for more network connections while still maintaining good service.

For example, with the new Orthogonal Frequency Division Multiple Access (OFDMA) feature, devices can use less than one channel bandwidth, sharing bandwidth with other devices on the network to increase capacity. In addition, these technological advancements allow for faster response to connected units. While previous versions of Wi-Fi struggled to handle multiple sensors, Wi-Fi 6 can easily manage large sensor networks consisting of hundreds of devices.

Wi-Fi 6 also brings key technological advancements to smart home and industrial applications. The advancement, known as Target Wake Time (TWT), is a significant step up from the energy-saving efforts of previous generations of Wi-Fi.

When using TWT technology, the client device negotiates a wake-up time with an access point (ap). Therefore, the client does not need to stay awake to maintain the wireless connection. Therefore, the AP can aggregate a large number of client requests into fewer trigger transmission opportunities. The benefits of doing so are more efficient, contention-free channel access and significant client device power savings, up to 80% in comparable applications. This makes IoT devices with long battery life more practical.

Wi-Fi 6 also brings improved security via Wi-Fi Protected Access (WPA) 3, although this is a separate introduction to Wi-Fi 6. WPA3 uses the Synchronized Authentication by Equality (SAE) protocol, replacing the older WPA2 protection common pre-shared key protocol. SAE prevents some possible brute force attacks against routers using PSK.

Another key advantage of Wi-Fi 6 is that it provides IoT sensors connected directly to the cloud through a router without paying additional data subscription fees. Additionally, the technology's higher throughput compared to other short-range wireless solutions enables new use cases such as wireless security cameras, high-quality video doorbells, and more. The extra throughput can also be used to complement Bluetooth when transferring large amounts of data, such as music streaming in wearables.

Smart Home Wi-Fi

The Connectivity Standards Alliance, an organization that aims to alleviate the challenges of connecting devices using disparate wireless protocols, supports Wi-Fi 6 as a foundational technology for the smart home. Matter is the Alliance's unified IP-based connectivity protocol, designed to run on Wi-Fi 6 and earlier, in addition to Ethernet and Thread.

CSA plans to introduce "border routers" widely. Such devices are not a new concept. However, until now, vendors have been forced to develop their own solutions. This product is a specific type of router that uses other physical layers like Wi-Fi to provide connectivity from an IEEE802.15.4 network to neighboring networks. Border routers can be routinely embedded in items such as smart speakers and lighting fixtures, making Internet Protocol (IP)-based connections more convenient for both providers and consumers.

Industrial Wi-Fi 6 products are just starting to hit the market. In a few years, however, we will see short-range wireless, Wi-Fi6, and cellular IoT complement each other to build the large, robust, and low-latency networks IoT needs to deliver on its promise.