Expected WiFi Speeds

After designing a company’s network, Meter tests the network for adequate coverage, reliability, and speed. We also hold internet service providers (ISPs) accountable to the service-level agreements (SLAs) they give our customers. Through our work, we’ve noticed companies are typically given a theoretical expectation of WiFi performance that, in practice, is more consistent with wired connections.

This post will explain how to think about the speeds you actually need.

How WiFi speed is measured

When purchasing a business internet connection or network hardware (e.g., access points, security appliance), the price will include a specific data rate quoted in Mbps or Gbps. This refers to the amount of data that can be transmitted on your network per second.

When an ISP quotes a 500 Mbps symmetrical connection, they’re telling you that you’ll be able to download and upload 500 megabits of data per second; if the connection is asymmetrical, download and upload speeds will differ with download typically being quicker. Similarly, an access point that advertises 1.6 Gbps is claiming that it’s theoretically possible for the network to enable 1.6 gigabits of data transfer per second. For reference, watching a YouTube video at 1080p HD uses ~5 Mbps. 

But, given the limitations of WiFi compared to wired internet connections, in both cases your actual data rate will be much lower than what you’re quoted.

Why WiFi is slower than wired

WiFi allows you to connect to a network wirelessly using radio waves. A client device (e.g., smartphone, laptop, etc.) sends data via radio waves to an access point, which connects to the broader internet and responds to your device via radio waves.

Wired connections send data via electrical pulses over a physical cable. You can give any client device a direct internet connection by connecting it to a router via an ethernet cable.

By transmitting data “through the air”, WiFi is more susceptible to failure. For example, the distance your device is from the nearest access point, the line of sight your device has to an access point, overlapping WiFi channels, dynamics of WiFi protocols, and device limitations all contribute to WiFi performance issues.

Distance

As you roam farther from the access point your device is connected to, the signal strength of the radio waves used by WiFi degrades. Even if you place multiple access points around your space to always ensure a short distance to an access point, client devices prioritize maintaining a WiFi connection, so they tend to stick to the access point they’ve been communicating with rather than shift to the new nearest access point.

Physical interference

Client devices need a clear line of sight to an access point to receive adequate WiFi signal. This can be interrupted by physical interferences like glass, concrete, metal, and brick. Also, radio waves emitted by devices and access points can bounce off objects in your space, causing the signal to be received more than once and in a difficult to decipher format.

Competition from other devices

Since WiFi bands are a shared resource, only one device can communicate on a channel at any given time. Client devices must wait for the channel to be clear to send data, otherwise their data will collide. As a result, each client device only gets a portion of the bandwidth; for example, a 100 Mbps connection shared between five online devices means each device gets 20% of the bandwidth.

Reality of speed tests

After understanding the reality of WiFi speeds, it’s important to note:

1. Network reliability must be taken into account along with WiFi speeds, and
2. You likely don’t need WiFi speeds anywhere close to what you’re quoted.

Network reliability

Taking a speed test doesn’t provide the full picture. Speed tests are usually taken with a single device after a network has been built. While this can identify issues of distance and physical interference, it doesn’t reveal other issues that crop up when an entire workplace is using a network. For instance, an access point may have its power set too high causing competition between too many devices, or adjacent access points may be configured to use the same channel causing devices on both access points to overlap. It’s important to consider the reliability of the network in conjunction with speeds sampled.

Speeds you realistically need

Meter supports many fast growing technology companies with high data usage from both sales and engineering teams. Amidst all of the Zoom calls and data set uploads, we find companies use a much lower data rate than they’re quoted from their ISP or network hardware manufacturer. 

This is not to say you should buy the internet connection or network hardware with the lowest quoted data rate. As mentioned, ISPs can’t always meet their SLAs and network hardware is grossly overoptimistic. We typically recommend internet connections in the range of 250 Mbps to 1 Gbps and use network hardware that we design and manufacture. If you need guaranteed internet speed and reliability at desks, we recommend installing wired ethernet drops.

In short, WiFi has inherent limitations that lower its speed and reliability such as distance to an access point, physical and channel interference, device competition, requirements of WiFi protocols, and device flaws. Fortunately, we need speeds much lower than what we’re sold.

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