6 1/2 types of Wi-Fi
There are different PHY types or Wi-Fi types which are simply put different standards of use for each frequency. There are currently 6 Wi-Fi types or standards available today. The standards for Wi-Fi are defined by the IEEE in 802.11. The following are amendments to the 802.11 standards.
Wi-Fi 1 (802.11b)
802.11b or Wi-Fi 1 as it has recently been deemed. Was ratified by the IEEE in 1999. This technology is limited to 2.4Ghz only. It had a max bandwidth of 11Mbps.
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| Wi-Fi 1 distance from the router. With free space path loss. https://www.imgtec.com/blog/802-11b-802-11b-question/ |
This technology is extremely outdated and holds back Wi-Fi networks from optimal performance. While all routers and Access Points(AP) are capable of supporting Wi-Fi 1, it is strongly encouraged to remove this support from your network. I will cover details of why later. If you happen to have something that is from the early 2000s that is still working and on the Wi-Fi, you might need to leave it active or the device might lose internet capabilities. If you do have a device like this...I urge you to upgrade the device....yesterday.
Wi-Fi 2 (802.11a)
Wi-Fi 2 was ratified in 1999. This standard uses the 5Ghz frequency only and has a bandwidth of up to 54Mbps. It is not vital to turn this standard off in routers or APs these days however it is not the best of the available technologies out there. While this technology was available in the early 2000s there are not many consumer devices that utilized the 5Ghz frequency as Wi-Fi 1 was a cheaper technology. Wi-Fi 2 is using another technology called OFDM(Orthogonal Frequency Division Multiplexing). This is getting a little technical so I will leave the explanation of what that is for another time.
Wi-Fi 3 (802.11g)
Wi-Fi 3 was ratified in 2003. This standard brought the OFDM technology of 802.11a but operated on the 2.4Ghz frequency similar to 802.11b. It has a bandwidth limit of up to 54Mbps as well. This was a big jump for consumers in the mid-2000s. The routers and APs were getting better as well with better transmit power and receive sensitivity. This is when the consumer or home Wi-Fi was beginning to become more mainstream. I remember in my own home when my parents got the blue Cisco home router with the two antennae. I never fully understood it at the time, most of our devices were still wired, but it was always intriguing to me. I remember I logged into the router to look at and play with the settings.
Wi-Fi 4 (802.11n)
Wi-Fi 4 was ratified in 2009. This standard introduced a new technology, MIMO (Multiple Input Multiple Output) which allows transmitters and receivers to work simultaneously. This standard can potentially reach a speed of 300Mbps. With the right router or AP that has three antennas, it can reach 450Mbps while utilizing MIMO. This was a widely utilized standard, it provided a great speed increase while utilizing both the 2.4Ghz and 5Ghz frequencies. Many home routers are still running this technology and don't even know it. For many this is enough, those of us who need speed...continue below.
Wi-Fi 5 (802.11ac)
Wi-Fi 5 was ratified in 2014. This is a massive jump in technology for Wi-Fi. Not only are we getting speeds up to 2.3Gbps with the right environment setup. This is achieved through utilizing 5Ghz only and increasing the size of the width of the channels up to 160Mhz. Wi-Fi 5 also introduced Transmit beamforming which simply put directs the transmitted data towards a client, making communications more efficient. Another technological increase was the advancement of MIMO, which was able to send and transmit simultaneously to a single client, to MU-MIMO (Multiple User Multiple Input Multiple Output), which allowed a simultaneous send and transmit to multiple clients at a time. This does not affect the speed of one person individually but the speed and efficiency of the network as a whole. This is currently the best widely available Wi-Fi standard. Most client devices and routers/APs are capable of Wi-Fi 5. It is important to note that there was a "refresh" of Wi-Fi 5. It is known as 802.11ac wave2. This was introduced in 2016 and is the technology that can reach those higher gigabit speeds. More changes came in Wave 2 but that can be covered another time.
Wi-Fi 6 (802.11ax)
Wi-Fi 6 was adopted in 2019. This technology is a spectrum efficiency standard. While it increases speeds up to a whopping 11Gbps in ideal situations its primary goal is higher efficiency. One of the ways it becomes more efficient is through a more coordinated utilization of the RF spectrum. Simply put before Wi-Fi 6, if a device is communicating with a router, it transmits its packets and waits for a response. When the frequency is clear the next device gets to request to send its data packets. Wi-Fi 6 adds OFDMA, Orthogonal Frequency Division Multiple Access, which allows multiple devices to transmit at once. If device A is sending a small amount of data that only uses half the bandwidth of the channel, device B can send some of its data in the unused bandwidth allowing more efficiency of the overall network. This efficiency is for both 2.4GHz and 5 GHz. There is much more detail to go into, but that is for another post. For now, here is a link to a good white paper on it: 802.11ax.
Wi-Fi 4 (802.11n)
Wi-Fi 4 was ratified in 2009. This standard introduced a new technology, MIMO (Multiple Input Multiple Output) which allows transmitters and receivers to work simultaneously. This standard can potentially reach a speed of 300Mbps. With the right router or AP that has three antennas, it can reach 450Mbps while utilizing MIMO. This was a widely utilized standard, it provided a great speed increase while utilizing both the 2.4Ghz and 5Ghz frequencies. Many home routers are still running this technology and don't even know it. For many this is enough, those of us who need speed...continue below.
Wi-Fi 5 (802.11ac)
Wi-Fi 5 was ratified in 2014. This is a massive jump in technology for Wi-Fi. Not only are we getting speeds up to 2.3Gbps with the right environment setup. This is achieved through utilizing 5Ghz only and increasing the size of the width of the channels up to 160Mhz. Wi-Fi 5 also introduced Transmit beamforming which simply put directs the transmitted data towards a client, making communications more efficient. Another technological increase was the advancement of MIMO, which was able to send and transmit simultaneously to a single client, to MU-MIMO (Multiple User Multiple Input Multiple Output), which allowed a simultaneous send and transmit to multiple clients at a time. This does not affect the speed of one person individually but the speed and efficiency of the network as a whole. This is currently the best widely available Wi-Fi standard. Most client devices and routers/APs are capable of Wi-Fi 5. It is important to note that there was a "refresh" of Wi-Fi 5. It is known as 802.11ac wave2. This was introduced in 2016 and is the technology that can reach those higher gigabit speeds. More changes came in Wave 2 but that can be covered another time.
Wi-Fi 6 (802.11ax)
Wi-Fi 6 was adopted in 2019. This technology is a spectrum efficiency standard. While it increases speeds up to a whopping 11Gbps in ideal situations its primary goal is higher efficiency. One of the ways it becomes more efficient is through a more coordinated utilization of the RF spectrum. Simply put before Wi-Fi 6, if a device is communicating with a router, it transmits its packets and waits for a response. When the frequency is clear the next device gets to request to send its data packets. Wi-Fi 6 adds OFDMA, Orthogonal Frequency Division Multiple Access, which allows multiple devices to transmit at once. If device A is sending a small amount of data that only uses half the bandwidth of the channel, device B can send some of its data in the unused bandwidth allowing more efficiency of the overall network. This efficiency is for both 2.4GHz and 5 GHz. There is much more detail to go into, but that is for another post. For now, here is a link to a good white paper on it: 802.11ax.
Wi-Fi 6e
This is where the 1/2 a PHY comes in. Wi-Fi 6e which was adopted in 2020 is the opening of 1,200MHz of the 6GHz frequency for public use. This will provide greater speeds with a higher frequency, however, there are not many home use cases at the moment for this. These consumer devices and APs are not readily available yet. There are many enterprise-level APs already hitting the market with 6GHz capabilities.
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| Example of OFDM vs. OFDMA. OFDMA is being used by Wi-Fi 6. |
The Future
This list is just the beginning, the future of Wi-Fi is bright and endless. There will always be an ever-increasing need for wireless connectivity. There are many things we can improve upon and I am looking forward to what is to come. I will do another post sometime soon on the future of Wi-Fi and some of the improvements we can make. Thank you.
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