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OFDMA On or Off? Should You Enable OFDMA On Your Router?

OFDMA (Orthogonal Frequency Division Multiple Access) came after OFDM (Orthogonal Frequency Division Multiplexing). These two WiFi technologies make wireless communication better. However, OFDMA is a step up because it lets multiple devices send data simultaneously.

OFDMA On or Off?

If you are wondering whether you should enable OFDMA or not, it is important to first understand its benefits. We will be discussing that and more in the below post. So, if you are eager to learn more about OFDMA in routers, you should give this article a read.

What is OFDMA?

OFDMA is an important part of making WiFi 6. It supports multiple users in digital modulation technology. Both OFDMA and OFDM take data and break it into tiny packets, which makes it easier to send data simply.

OFDMA is a step ahead of OFDM as it divides the communication channel into smaller bits called subcarriers, allowing it to send those tiny packets of data to multiple devices all at once. The best part is that these pieces don’t have to wait in line as they are sent right away.

In downlink OFDMA, the router can use different groups of sub-carriers to send pieces to different clients, which helps keep things moving smoothly and quickly. This is a decentralized and flexible method of communication, which helps boost network efficiency and speed.

Importance of OFDMA

OFDMA is a key feature in the world of 802.11ax. To put it simply, it’s like a smart way of managing WiFi that helps many devices communicate with the WiFi router at the same time.

OFDMA splits the WiFi spectrum into pieces and gives each piece to different users. Instead of the usual WiFi traffic where everyone kind of competes to send their data, 802.11ax schedules things so they don’t bump into each other. This makes better use of WiFi resources and makes things work way better.

Traditional WiFi can get a bit messy when lots of devices are around, and when short packets are sent. This leads to more problems like block ACKs, contention, preambles, IFS, and collisions.

The good thing is that OFDMA groups many users into a single bundle and makes the WiFi work in two ways. It can either give the whole WiFi channel to just one user at a time or split it up and give pieces to many users all at once. This works great for things that don’t need much bandwidth and makes WiFi faster, and more efficient.

How Does It Work?

The whole process is like a puzzle where the channels are divided into smaller subcarriers, which are spaced apart in a way that they don’t mess with each other, and that’s why they call it “orthogonal.”

WiFi 5 is a 20 MHz channel that is made of 64 of these 312.5 kHz subcarriers, and they all work together to send data to just one client. WiFi 6 changes the game as it makes the spaces between subcarriers smaller, from 312.5 kHz down to 78.125 kHz, and that allows us to use 256 of them.

The subcarriers are grouped into “RUs,” which stands for Resource Units. The Wi-Fi router can take that 20 MHz channel and divide it into 242, 106, 52, or 26 RUs.

The router decides the number of RUs to use and in what combinations. So, it could give the whole channel to one client if needed or split it up to talk to multiple clients at once. For example, it might use an 8 MHz sub-channel for one client and 5 MHz for three others, as long as they all have WiFi 6.

Advantages and Disadvantages of OFDMA

OFDMA is often hailed as a game-changer in WiFi 6, bringing a bunch of benefits to the table. However, it’s not all sunshine and rainbows. Here’s a breakdown of the pros and cons.

Advantages

The main advantages include:

  • Reduced Latency

One of the big advantages of OFDMA routers is their ability to cut down on delays. This is important for things that need to happen in real time, like video calls, online gaming, or IoT.

  • More Speed

By splitting a single channel into many small subcarriers and giving them to different users, OFDMA can crank up the total speed of your network.

  • Increased Network Capacity

It lets multiple users receive and send data at the same time, making the network more efficient. It increases the network capacity to handle more devices without slowing down.

  • Power Efficient

OFDMA helps devices like tablets and phones use less power when sending and receiving data, making your battery last longer.

  • Backward Compatible

You can turn on OFDMA on your router without ditching your old devices. They can still connect, even if they are not compatible with WiFi 6 or WiFi 7.

Disadvantages

Some of the drawbacks of OFDMA are:

  • Requires A New Router

OFDMA in Wi-Fi 6 (802.11ax) is not supported by older routers. So, you will need to spend on a new router to enjoy the perks.

  • Resource Intensive

OFDMA is a bit more complicated than the older OFDM. That means routers using it need more CPU power to handle the same amount of data.

The advantages of OFDMA are availed only when you set up your network right. It’s a good idea to check your network with a WiFi analyzer app.

OFDMA vs MU-MIMO

OFDMA and MU-MIMO, two Wi-Fi technologies, make it possible for several devices to communicate with a single router at the same time. They achieve this in different ways. For instance, OFDMA divides a channel into smaller bits, while MU-MIMO uses multiple antennas to create multiple data paths.

MU-MIMO and OFDMA work best when they are paired together, making them a game-changer in the Wi-Fi scene. MU-MIMO excels in high-data scenarios, like intense online gaming and streaming HD videos. It’s highly efficient at boosting network capacity. Meanwhile, OFDMA shines when it comes to low-data tasks, such as using IoT gadgets, thanks to its low latency.

Things To Know About OFDMA

Here are some things that you should know about the OFDMA WiFi technology:

#1. Single AP Can Accommodate Up To 74 Clients

WiFi 6 goes beyond the standard 20 MHz channel and can divide channels into 160, 80, and 40, MHz. Most businesses opt for 20 MHz channels, allowing up to nine clients to connect to one AP at the same time. Generally, narrower channels are preferred to reduce reliability and performance issues by minimizing channel interference. You could have 74 clients connected to one AP, but that’s more of an exception than the rule.

#2. Support For High-Bandwidth Apps

WiFi 6 brings an efficient network and higher data speeds. This means businesses can now run applications on WiFi 6 that were previously too demanding for wireless connections. 

Think about 4k videos and even more exciting stuff like immersive applications using virtual reality. What used to be mainly for gamers is now making waves in healthcare, retail, industrial design, and other fields. WiFi 6 opens up a world of possibilities, and OFDMA tech is a big player in making it all happen.

Final Words

The growth of WiFi standards is the result of our ever-expanding wireless demands. OFDMA steps in to tackle performance challenges by giving each device its very own sub-channel. This feature makes OFDMA routers a valuable investment for anyone striving to enjoy the ultimate online experience, making it well worth the extra cost.