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USB Wi-Fi Adapter 101

Wi-Fi Standards

802.11ac is the current Wi-Fi standard. It uses both the 2.4GHz band (like 802.11b and 802.11g) and the 5GHz band (like 802.11n). The next standard, 802.11ad, is reportedly due this fall and adds a third frequency to the mix (60GHz) and is designed for high bandwidth over short distances.

With 802.11ac as the current Wi-Fi standard, 802.11n-based gear is quite affordable. Naturally, you'll ask yourself whether you should save some money on that older equipment. While you can certainly get acceptable performance from 802.11n, at this point I'd recommend springing for the more modern standard. Much of the early price premium is gone, and 802.11ac does offer some benefits, detailed below.

Within modern 802.11n and 802.11ac Wi-Fi adapters, there are several different speed tiers:

Type2.4GHz Mb/s5GHz Mb/s
N150150N/A
N300300N/A
N600300300
N900450450
AC600150433
AC1000300650
AC1200300867
AC19006001300

Notice that adding throughput from the 2.4GHz and 5GHz bands gives you the equivalent nomenclature. For example, N600 is precisely the sum of 300 and 300. However, the math is not as clean for AC1200 since 300 and 867 give us a sum of 1176. This gets rounded to a nice even AC1200, which is easier to remember.

  • unityole
    hey, in the picture of the disassembled cisco USB wifi module, which model is that?
    Reply
  • Achoo22
    a computer needs to be connected to its network, and in turn the Internet, to be truly useful
    I got this far, then tuned out.
    Reply
  • SuperVeloce
    a computer needs to be connected to its network, and in turn the Internet, to be truly useful
    I got this far, then tuned out.
    okay, I see you don't get what the intended audience in this article is. i'll re-word that for you: "a multimedia family / office work computer needs to be connected to its network..."
    Reply
  • SamSerious
    USB extension cables are often causing problems. I'd never extend a cable by more than one meter and make sure it is a very high quality cable or the voltage will lower dramatically causing the device not to work properly anymore. Or you have to get yourself an active USB expander which is usually quite a bit more expensiv.

    On the other hand, antenna cables are even worse to extend...
    Reply
  • jacobian
    You think you need USB3 to drive a 802.11ac network adapter at full speed? Please. You couldn't have been more confused. Let's say we're talking about a two stream AC device, so theoretically it's capable of 867mbps throughput in 5GHz band. However, much of that number pertains to the "physical layer" information transfer, the chatter that ensures that your data is transferred accurately, under optimal condition (e.g. 6 ft from the router). At TCP/IP level, the throughput will be much lower, even if the distance is short, somewhere in the neighborhood of 100-300mbps, depending on your luck. In other words, a lot less than USB2 can handle.

    You see, the wireless data transfer rates are basically a big marketing scam because half of more of that data transfer rate will disappear due to weakening signal with distance or on the physical layer chatter. Wireless is not like wired Ethernet, where saying 100Mbps really means that you will actually see TCP/IP data transferred nearly at that rate. In the wi-fi world, the marketing can say they sell you a "gigabit ac1750 router (or adapter)", and in real life you may well end up with just 100Mbps or slower data throughput. If you get 200mbps or more, you should be jumping from joy.
    Reply
  • ZeusGamer
    I'm using a dual band PCI Express wi-fi module. For some reason, it's much better than my ethernet connection. Could be because my killer port is only single band rather than dual. I've not lagged one bit with this accessory and I've been using it for at least 8 - 9 months now.
    Reply
  • user_friendly
    Id like to point out that having an external usb wifi can get really hot and malfunction. Its not inside of an air circulated case, so mine tends to get blazingly hot. i have the n600 which i can game on and have no problems. Moslty
    Reply