Summary
Modems are a critical piece of technology that allows your computer to communicate with the outside world. They come in two varieties, dedicated modems and gateways. Gateways are single device that holds both a modem and router. When a gateway fails, you must replace the entire unit, the modem and router, even if one of the components is still functioning.
Introduction
Chances are, if you are reading this via wi-fi, you are using a modem! A modem is a device that converts digital signal to analog signal, and vice-versa. In this article, the word “signal” is synonymous with data or information, after all, data is what the signal is carrying. Short for modulator-demodulator, modems are everywhere you look, and there’s a good reason why. Modems convert signals so that they can be transmitted over telephone lines. The more information your modem can process, the faster your internet will be, up to the limits of the plan you purchased from your internet service provider (ISP). Over time, modems have evolved, but in this article, we’ll cover modern, cable modems and talk about our picks for the best modems for your situation.
FIBER OPTIC INTERNET DISCLAIMER: If you have or are planning to get fiber optic internet, you will need to talk to your service provider about what “Last Mile Connection” they support. This will help you avoid purchasing unnecessary equipment if you decide not to rent equipment from your ISP. Some fiber optic services providers, like Verizon and their Fiber Optic Internet Service (FiOS), provide technology that eliminates the need for customers to purchase or lease a modem. For example, I use Verizon FiOS and run an internet cable straight from the Verizon-provided equipment to my router.
We don’t have an article on routers yet, but when we do, you can find it here.
Digital Versus Analog Signal
First, let’s cover a digital versus and analog signal. It’s simple, and I will assume you have heard the term “binary.” In technology, it means a value of either a 1 or 0, on or off. In fact, if you dig deep enough into your computer and information itself, it’s all either a 1 or a 0, and the job of the computer is to convert these 1’s and 0’s to the instructions and information that produce this webpage. Accordingly, a digital signal is either a 1, or a 0, meaning the signal is either on, or it’s off. The job of a modem is to convert information from an analog signal into 1’s and 0’s so that your computer (used in a general sense here) can handle the rest.
Analog signals are continuous, meaning they are always on, and in a graph (no math, I promise), they look like a sine wave. They transmit information using frequencies, which is why you could listen to your favorite radio station long before the digital age by “tuning” the radio dial to adjust your antenna to receive signal on the desired frequency, like 97.3 KRQ, Tucson’s Number One Hit Music Station. Unless you are a cable technician or are pursuing a physics or engineering degree, that’s all you need to know for this conversation.
Here is a diagram that shows what this whole process looks like. If you look carefully, you can see the digital signal flatlines when it is on or off.
Why Are Modems Necessary?
Well, in the olden days, they didn’t design telephone lines to transmit computer (digital) data because it didn’t exist. Modems overcome that issue and leverage the existing telephone wire and pole infrastructure. Just like technology in general, modems have evolved over the years. For the purposes of this article, all that is important to know is that people couldn’t place or receive phone calls from their wired, home telephone when someone was using the internet until the late 1990s or early 2000s. Today, modems are effectively silent, you plug in the power cord and your internet connection, connect your modem to your router (or gateway, more on that later), and off it goes.
Modems Today
Modems today are seriously fast. A standard 1 Gigabit/second modem, which is by no means the top of the range on today’s market, can process 233,114% more information per second than the standard 56 kilobyte/second modems of the 1990s.
Dedicated Modems Versus Gateways
Modems today come in two flavors, a stand-alone modem, which means you need to purchase a router separately, and gateways, which is a modem-router combination housed in a single piece of equipment. Two for the price of one? Great! Not so fast. While modem and router combinations can blanket your home with the warm glow of high-speed internet using a single device, they have limitations, which are mostly price and the range of coverage. Remember, your modem is simply a signal converter. Your router is what provides the wireless and/or wired connection. Unless you are physically connecting computers and televisions to your router with an ethernet cable, then the wireless coverage and speed provided by your router is something you should care about, especially in distant bedrooms or while sitting on your front porch. Typically, the wi-fi coverage and speeds that gateways provide leave something to be desired until you reach into the upper price tiers. The bottom line is that because gateways are not dedicated devices for either purpose, in our experience, they often fall short in router performance. One theory on this is because modem technology is more affordable for companies to produce, router technology is where companies can cut costs to provide affordable products.
Tech Topics Explained loves gateways, but if you are in anything larger than 1500 sq. ft house or apartment, you’ll need to shop carefully to make sure a faraway bedroom on the third floor can use the wi-fi you’re paying for or consider going with dedicated devices.
Modem technology is affordable; and unless you are doing seriously internet-intensive work and have purchased the Cadillac of internet plans, you can get away with spending $50 for a modem that will likely be viable for another 2-4 years. For $100, you can get a modem that will be viable for 5-7 years.
A quick note on going cheap here. You don’t want to spend money on something that currently JUST meets your needs. You want to pony up the extra $25 or $50 to get something that will be viable as ISPs offer faster and faster internet. A good rule of thumb is to get something that will handle at least double the speed of your current internet plan. If you find a good deal on something that will support triple your internet plan’s speed or is 1 Gigabit per second (Gbps) or faster, then splash the cash. An extra $25 or $50 may yield MANY extra years of service depending on how quickly ISPs are upgrading infrastructure and internet speeds in your area. Keep in mind, the internet speed growth prospectus for major cities looks much different from rural areas.
Other Things to Keep in Mind
Be sure to check that your ISP supports the modem you intend on buying. While the modem might market itself as being compatible with major ISPs, it never hurts to check directly with you ISP, as ISPs publish lengthy lists of compatible modems. In addition, some internet providers will certify modems for use on their internet plans. Just be sure that if you choose a modem recommended by an internet plan, it does not contain Intel Puma 5, 6, or 7 computer chips, as described below. The ISP will likely list other compatible modems and you should choose from those, so long as they support your internet plan and do not use Intel Puma 5, 6, and 7 chips.
The Puma Vulnerability
Puma is a line of computer chips used in modems and produced by Intel. You’ll want to steer clear of any device that uses Puma 5, 6, or 7 chipsets, as they have resulted in at least one lawsuit for modem manufacturer Arris. In addition, it is a flaw that will be difficult to truly fix because it involves the chip’s firmware. For a list of modems that use the Puma chipset, and are therefore disqualified from our recommendations, click here.
16×4, 24×8, 32×8, What Do the Numbers Mean?
When shopping for modems, you will likely see these numbers in the title, because they are how modems are categorized and the higher the numbers, the faster the modem. They refer to the amount of information the router can receive, (the first number), and send (the second number). Respectively, these values are referred to as downstream and upstream, which if you simply replace the words download and upload, are self-explanatory. The one difference is that downloading is faster than uploading, so downstream channels can support 40 Megabits per second (Mbps), while upstream channels can support 30.75 Mbps. If we do the math, a 16×4 modem can download a maximum of 640 Mbps and upload a maximum of 123 Mbps, while a 32×8 modem can do 1280 downstream and 320 upstream. Keep in mind, these are theoretical limits. The observed maximums are lower, so a 16×4 modem will likely only be useful up to 300 Mbps internet plans, and a 24×8 will likely only be good up to 800 Mbps.