wazmac || What's with the Gigahertz?

<<< Wireless Networks

When you immerse yourself in discussions regarding wireless access points (WAPs), you very quickly discover that the radios that power newer WAPs operate at two different frequencies – 5 Gigahertz (Ghz) and 2.4 Ghz. (Ghz is a measurement of radio frequency.)

There are many devices in your home (or school) that make use of the 2.4 Ghz spectrum – portable phones, microwave ovens, etc. All these devices can cause interference to your data network if it is operating on the same frequency.

Newer ‘n’ channel WAPs introduced the 5 Ghz band to escape the radio clutter of the 2.4 Ghz band. Most of these newer WAPs include dual radios, offering both frequencies to cater for a mix of newer mobile devices and older devices that don’t operate in the 5 Ghz range.

What’s the diff…
2.4 Ghz		5 Ghz
802.11 ‘b’ and 802.11 ‘g’ networks operate in the 2.4 Ghz Band; 802.11 ‘n’ networks can operate in both 2.4 Ghz and 5 Ghz bands; Older mobile devices can only connect to 2.4 Ghz networks; 2.4 Ghz band is used by many devices (microwave ovens, and portable phones, etc) that cause interference; 2.4 Ghz networks do not offer the same ‘speed’ as 5 Ghz networks; 2.4 Ghz WAPs have a greater range than WAPs operating in the 5 Ghz range (See comparisons below).		802.11 ‘n’ and ‘ac’ WAPs have dual radios to operate in both the 2.4 Ghz and 5 Ghz bands; Newer mobile devices can connect to both 2.4 Ghz and 5 Ghz networks; The 5 Ghz band is less ‘cluttered’ than the 2.4 Ghz band; 5 Ghz networks offer ‘faster’ data transfer speeds; 5 Ghz WAPs have a lesser range than 2.4 Ghz networks (see comparisons below); 5 Ghz networks are more prone to signal loss through walls and other barriers.

Testing the theory
To compare the differences in the real world, I ran some basic Internet speed tests, using speedtest.net, over: Ethernet; 2.4 Ghz wireless; 5 Ghz wireless. I conducted the wireless tests multiple times from two locations (relative to the WAP)… the first test in the same room as the WAP; the second test upstairs and one room away from the WAP, through a timber floor and a timber/plasterboard wall. I used the same equipment for each test….. 2013 MacBook Same remote server in Sydney; NBN fibre internet connection – 100 Mb/s max.
Results
As you would expect, the Ethernet connection was the fastest, and provides a ‘base level’ speed for comparison with the wireless tests. I ran the wireless tests three times in each location and they did vary a little – the results below are typical speeds. The 2.4 Ghz wireless speeds were reasonably consistent throughout the building, while the 5 Ghz wireless speeds varied from being nearly as fast as Ethernet near the WAP, to slower than the 2.4 Ghz connection when testing upstairs, one room away from the access point…..
Ethernet
Connected directly to Ethernet
2.4 Ghz Wireless
Same room as WAP	Upstairs, one room away from WAP
5 Ghz Wireless
Same room as WAP	Upstairs, one room away from WAP

You can see from the results above that the speed of the 5 Ghz wireless drops off considerably as you move away from the WAP, compared to the 2.4 Ghz wireless.

I tested this a few times, and received similar results.

In fact the 5 Ghz speeds dropped even more dramatically when moving just a little further away, or moving to a different location/orientation in the same room.

Fortunately most new WAPs are dual band, and most modern mobile devices are auto-sensing and can adjust to operate on the band that provides the best signal.