Noise Margin and How It Impacts Your Internet Speeds

Imagine this: you’re at your desk at work and your internet connection suddenly slows down. Maybe you’re at home and you just want to watch a funny video that someone sent to you but the video just won’t load – and neither will anything else. While you may be tempted to just pick up the phone and call your ISP or go spend a fortune upgrading your router and other equipment, the problem may actually be something that you can solve yourself, without having to contact your ISP or spend a fortune on new equipment. If you have ADSL internet, your problem may be the noise margin. Read on to find out how this could be impacting your internet speeds.

What is Noise Margin?

Noise margin – also known as SNR margin or noise margin – is a measure of the difference between actual signal-noise ratio (or SNR) and the minimal SNR required for syncing. So what does all of this mean? Let’s break it down in a way that’s more easily understood.

Signal-to-noise ratio, or SNR, is the ratio between the signal – or the meaningful information – and noise, which is background interference. This noise could be attributed to a variety of things, including but not limited to distortion and crosstalk.

If your noise is too high, you will experience interference with your ADSL. This could include problems with syncing and other issues that significantly delay your internet speeds, which isn’t ideal and can be quite frustrating. In order to avoid this issue, you have to make sure that your noise margin is right where it should be, with noise significantly reduced for best performance.

How Is Noise Measured and What’s Good (or Bad)

The SNR is measured in decibels. Anything at or below 6 dB is bad. You will experience lots of interference and difficulties with syncing. 7db to 10db is considered “fair.” It isn’t the best and will likely have interference. Any variations in conditions can lead to increased noise and cause connection issues. 11dB to 20dB is considered experiences very few sync problems, unless there is a large variation in conditions. 20dB to 28dB is considered excellent, while 29dB is outstanding.

This isn’t the only value you need to know, however. You’ll also need to calculate the SNR margin. Once you know your SNR, you’ll be able to calculate your SNR margin.

Calculating Your SNR Margin

Your SNR margin is the difference between your actual SNR and the lowest SNR needed to sync at a specific speed. This isn’t a difficult calculation at all once you’ve determined actual SNR.

Here’s an example:

Your actual SNR is 40dB.

The required SNR to sync at 8Mbit/s is 35dB.

Simply subtract the two values, and you’ll find that your margin is 5dB.

As a rule of thumb, higher margin numbers translate to cleaner signals. Anything below 6dB is considered bad, so in this example, there is a clear problem. The higher the number, the better, but in general, anything above 6dB should be fine.

Router Settings

Some routers provide information for you about your SNR. You may be able to access SNR upstream and downstream traffic statistics that you can check out and monitor to ensure performance. Not all routers have this option, and you’ll have to consult your owner’s manual or manufacturer’s website to find out if and how this information can be accessed.

How Do I Improve My Margin?

So you’ve done the calculations and you’ve found that your margin falls below 6dB. If you’ve noticed interference, you definitely know that this is a problem that you need to address. But how do you raise your margins? It may be easier than you think.

First, understand that there are many conditions that contribute to this line interference. It could be something expected, like peak times for your provider. This crowding can lower your number. But other things, including home appliances, devices installed on telephone lines, and even lighting can contribute to this interference. This doesn’t mean you have to change out your lights and stop using your small kitchen appliances. There are other ways to get around this problem.

The first thing you can consider is purchasing a new router. The router that you purchase must be able to handle lower SNR margins, so make sure that you do your research. Look for online reviews, check manufacturers’ websites, or even ask a tech-savvy friend for recommendations.

You can also purchase filters that can be used on your ASDL lines. Again, make sure to research your options before you go out and spend a lot of money on something that may not perform as expected.

The faceplate to your cable line may be old, so you can check that too. That’s one inexpensive fix.

The lines in your home or building may be old, so these may need to be replaced. Contact your provider to find out what, if anything, they can do. If you rent, you’ll also want to speak to your landlord about options.

Finally, if worse comes to worse, you may have to consider switching providers. If nothing else is working or someone in your building or neighborhood have success with their service, this may be a possibility for you. While it may seem like a hassle, you don’t want to continue to pay for service that underperforms, do you?

Final Thoughts

Interference and bad connections can be a pain, but you shouldn’t just accept this as your fate. By considering the SNR and SNR margin, you can find and troubleshoot your connection to get rid of unwanted interference. Do you have a question about noise margin or SNR, or perhaps a helpful tip for those struggling with excess noise? Leave a comment below!


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