The term ‘up to’ gets used quite frequently in broadband performance circles, but defining it can be very difficult to do. What exactly does ‘up to’ mean when Comcast and other companies use it and how can it really mean that when it comes to something that should be as scientific as networking? These are good questions, and to understand the answer it is important to recognize all of the factors that contribute to the answer: distance and attenuation, electrical margins, and network load.
Why Distance Matters
Most modern networks are a combination of fiber optic bundles and electrical wiring. The longer a signal must travel to get to and from the end user, the more opportunities there are for errors. Additionally, it takes far more money to move a signal a greater distance than it does a short one; and the cost is not linear. This fact is compounded when speed is brought into the issue as faster communications means more simultaneous streams and/or greater precision. Either way, the complexity of speed and distance can be volatile cocktail.
The degradation of electrical performance over distance can be referred to as attenuation, and it is worth noting that the more fiber a network has, the better the chances are that attenuation impacts only a smaller part of the network. This means that the closer fiber is to the residence, the less the chance is that attenuation would be impactful. Some services such as Verizon’s FiOS bring fiber right to the door, eliminating this problem altogether. Sadly, this is the exception rather than the rule. As a result, greater speeds and lower distances for electrical signals to travel. This means that part of determining what ‘up to’ means in a very real sense means understanding how much of a role electrical wiring plays in any given area, but that is unfortunately not as easily done as said.
What is Margin
Electrical wires that carry data signals are also subject to electric noise. The difference between electrical signal and background noise is measured in electrical decibels, a logarithmic form of expression. As speed increases, margins drop as a natural consequence. Consider the following as a great example: suppose you and a friend were having a nice quiet discussion on a park bench on a quiet morning. The difference between your voices and the background noises is great, so you can speak a little quicker or move further apart and still be heard easily without raising your voice. Move that same conversation into the local mall on Black Friday, and the background noise would make the conversation all but impossible; you would have to slow down and move closer to be heard.
A similar story exists between the margins between signal and background noise; faster speeds are only capable in situations when line quality is great and/or distances are short. While distance is not going to chance, line quality will vary from time to time and may be highly dependent upon load. This means that the ‘up to’ promises are likely to be filled more often when less electrical competition exists, and that means neighbors cannot be using heavily unless the network is well-financed. This is one of the primary reasons why bandwidth caps still exist; data hogs can ruin the experience for everyone.
Even if signal quality is great, that does not necessarily mean that the networking components deployed to an area are up to the task. Again usage patterns are going to play a key role. Networking components can offer additional data to and from certain ports that lead to certain consumers, but ultimately that network device has its own performance limitations. This is yet another reason why broadband providers are instituting data caps and watching for those that abuse limitless data plans; ultimately these people put additional strain not only on wires, but on the devices that route and manage network signals.
Determining How Fast ‘Up To’ Is
The bottom line is that there are several factors that determine just how big the difference is between bottom line performance and the ‘up to’ limits. The trick to nailing them down is to use tools like broadband speed tests to see what you are actually getting. If your speed test offers feedback that goes to the national government, it is highly suggested that you participate as these tests help determine what kinds of government aid broadband providers qualify for. The government aims to provide plenty of financial assistance to broadband providers that actually deliver on high performance networks, and a modicum of honesty from actual users helps more than anything else.