Article I : A brief introduction to Wi-Fi
If you’re like me, then not knowing how a technology is doing what it does causes some frustration. You want to know how to optimize your WiFi but need a little more detail on what’s actually going on. Well my friend, you have found a great place to start!
This article is the first of three in a short series on how to optimize your home Wi-Fi experience.
This first article will look at these basics:
- What is 802.11x ?
- How your router and devices communicate
- Channels
- Antennae
Standards
The first thing we come to when exploring WiFi is the standard that defines it. The IEEE is a governing body that helps define and keep standards so all our electronic devices play nicely together, and 802.11 is the standard that defines how wireless networks should operate.
(The term WiFi actually refers to a trademarked brand held by the WiFi-Alliance, who restrict its branding to devices that meet their wireless standards of operation.)
Q: So 802.11 is the IEEE standard, but what are those letters trailing afterwards?
A: The letters (e.g. 802.11ac) refer to the specific generation of the standard with which the device complies. As technology progresses the IEEE takes in new proposals and ‘refines’ the standard to include advances in an updated, agreed-upon version.
It’s important to understand that older devices are only capable of operating at the speeds allowed by the standard that was current at the time they were produced. For example, a device from around 2010 could be 802.11b/g only and not capable of the wireless speeds a newer 802.11ac device could reach.
Simplified progression: 802.11b/g > 802.11n > 802.11ac
Check out this great little article for a little more clarity.
Think ‘Walkie Talkie’
Unlike Ethernet, a WiFi connection is only half-duplex. Basically, what this means is that only ONE DEVICE can transmit on the wireless network at a time. Think of it as if your wireless router has one walkie talkie and your device has the other. When the router is transmitting signal your device has no option but to let it finish before it transmits back to the router.
Further, if you have multiple devices trying to use the WiFi at the same time they ALL have to wait their turn to ‘speak’. (This is the main reason that Ethernet [hardwiring] should be preferred when available.) So, the more devices you have fighting for attention, the longer each has to wait to ‘get a turn’.
*If you want to see this in action, simply go load a YouTube video and watch the little gray bar at the bottom of the video ‘jump’ each time your device ‘gets a turn’ and it buffers the video. Lesson learned: Plug it in as the first option
Channels
One of the features of the 802.11 standard are channels. Wait, back up… before that I should mention that there are 2 main frequency bands used in the 802.11 standards. 2.4GHz and 5GHz. I’m sure you’ve seen these numbers before so let’s dive in a bit.
2.4GHz
2.4GHz has been the more common band used for many years. Being a lower frequency it will transmit further than the 5GHz band (similar to bass notes in sound/music). However, it has become increasingly congested. Technologies like WiFi, baby monitors, car alarms, microwaves, and cordless home phones are a few examples that can cause interference on this set of frequencies.
The 2.4GHz has 11 available channels in the US, and up to 14 for other places in the world. Why does the US have less? Ask the IEEE and US Federal Communications Commission (FCC). Anyhow, our channels go to 11…
These channels overlap, so if you set two devices on adjacent channels (i.e. 2 and 3) they interfere with each other in the real world, causing issues. Most routers when they are powered off and then on will scan these channels and pick the ‘clearest’. This is usually the best option and requires no setup on your part.
If you were to log into your router and mess with the 2.4GHz channels, your best bet is channel 1, 6, or 11. These are the most ‘isolated’ channels available and generally offer the best result on the 2.4GHz band.
5GHz
The 5GHz band has become more widely used since the 802.11n standard (which can use both the 2.4GHz and 5GHz), and is the only band supported in the 802.11ac standard.
5GHz channels were created without overlap (unless you channel bond, which is outside the scope of this article), meaning this band offers more ‘spacious’ channels. This is the preferred connection for any device you may have, especially if you live in an apartment (God help your poor wireless devices in that congested nightmare!!!) Remember though, some devices do not have the capability to communicate on this band.
“How many antennas this thang got?”
Adding more antennae can seem a bit like making your amp go to eleven. Wireless devices started with one single antenna and some now have up to 4 or 5.
Calm down Dave… As you may guess more is better in this case. More antennas means your devices can communicate more clearly and with a larger bandwidth per transmision. This works through a method called MIMO, which stands for Multiple In Multiple Out.
To simplify MIMO for the sake of this article, I like to think of the fact that humans have two ears which operate similarly to the way these antennae work. Our brain takes the input from each ear and sums it together in order to better understand what we are hearing (and also determine directionality). In a similar fashion MIMO uses multiple antennae to better transmit and receive signal.
- The antenna don’t have to be on the outside, most modern routers and devices have several antennae located inside the device itself
Note that while MIMO uses multiple antennae, it does not support multiple connections at the same time. You have to get a router that specifically states it has Multiple User — MIMO or MU-MIMO or “AC Wave 2” which supports such a thing (this is a topic for another conversation, could be helpful in certain situations but not necessary for most home applications).
All this talk about antennae and such is mostly informative. The important thing to know is that older devices with fewer antennae are not capable of speed testing at the rates a newer device might reach.
For Heaven's sake, wrap it up already
In the end, knowing what all those numbers and letters mean as well as understanding that WiFi is a half-duplex technology is a step towards a better experience for all. This information coupled with a solid grasp on good Router Placement and how Multiple Routers/Extenders can hurt more than help will guide you to an existence where you don’t even think about your connection.
If you enjoyed this article, be sure to checkout the rest of the series:
Article II : Location, Location, Location
Article III : One Router To Rule Them All
Thoughts? Questions? Please start a conversation below!
