I recently had a
coworker ask me how to improve the wireless in his home. He says he has two
standalone APs on opposite ends of the house and coverage is horrible. He
explained that both APs were older and didn’t have the latest advancements
available in 802.11ac. Trying to get information about how he set them up was
difficult. I hadn't realized before now
how complicated Wi-Fi could be to someone that hasn’t studied it. After asking
a few questions… "what channel are the APs on? Do the APs support 2.4 and
5 Ghz? Are you using WEP,WPA or WPA2? " I came away with the following.
- Two APS
- One AP was set to "b" radio and the other to "g"
- Two SSIDs differently named with different passwords , one on each AP
- Both APs were set to the same channel (not sure which one)
Having studied Wi-Fi
but not knowing his system, I was able to point out a few issues and make some
suggestions.
- Don’t set the radios to "b" or "g". If they have "n" capability that’s the best if they need to be set to anything
- Each AP should be on a different channels in 2.4 choose either 1, 6 or 11
- If it has a 5Ghz radio make sure to set those channels differently also
- You only need 20mhz wide channels in both 2.4 and 5Ghz
- If possible set the SSIDs to WPA2-AES
Along with the
suggestions came some explaining. I'll keep it short and simple.
- 2.4 and 5GHz are frequency bands that device radios can communicate on.
- Channels are within each frequency band and are used to separate transmission domains. Much like radio stations, two can't broadcast on the same channel at the same time otherwise you'll get collisions on media and have a hard time hearing anything.
- Channels can be set to different widths to allow more data to be passed (20, 40, 80 160MHz)
- WPA2-AES is the best security at the moment (WPA3 is around the corner). For 802.11n or ac data rates you need to have WP2-AES or higher(future) set. Otherwise your just going to get 802.11a or g data rates.
The one thing I
think any new person to wireless needs to understand is the lettering
designation and what frequency band they work on. 802.11 a,b,g,n,ac don’t all
work on both 2.4 and 5GHz, only one of the 802.11 amendments specified support
for both bands. Here is how it breaks down.
2.4GHz - b, g, n
5GHz - a, n, ac
As you see 802.11n
is the only amendment that had support for both bands. This caused confusion
back in the day when purchasing equipment. What we noticed was anything that
had a wireless card capable of 802.11n support wasn’t always a 5Ghz capable. We
needed to look for cards that said WiFi a/b/g/n. Seeing that the WiFi card had
the "a" designation told us that it supported 5Ghz and seeing the
"b" designation meant it supported 2.4Ghz.
