Ronny Lam


2.4GHz WiFi Is Exhausted, Move to 5GHz

I’ve stumbled across two great articles in success, both focussing on WiFi. The first one is from Tom Hollingsworth where he explains very well why the 5GHz spectrum is so much better than the current 2.4GHz WiFi spectrum.

The 2.4GHz spectrum is awash with interference sources from every angle.  Microwave ovens, cordless telephones, and wireless video cameras are only part of the problem.  There are only three non-overlapping channels in 2.4GHz.  That means you’ve got a 33% chance of interfering with surrounding devices.  If you’ve got one of those fancy consumer devices that can do channel aggregation at 2.4GHz, the available channels decrease even further … On the other hand, 5GHz has twenty three non-overlapping channels available.  That’s more than enough to satisfy the more dense AP deployments required to provide similar coverage patterns while at the same time providing for high speed throughput with channel aggregation.

The second blog is from Brent Salisbury who I first met in a Packetpushers Virtual Symposium about Network Programmability. Brent is advocating that companies should be focusing on more wireless deployments and that, of course, the 5GHz band is the better choice for that.

But the biggest tip Brent is giving is:

Start thinking like a carrier. One of the number one ways service providers make money is from over subscription … The traditional wired edge, does not allow for oversubscription of the network, it is one port and one host. Wireless networking allows for oversubscription since the air is a shared medium that all clients attach to. Don’t let shared medium scare you like it used to me. 802.3ac has begun to solve the wireless duplexing problem and the 5GHz spectrum has helped with client density issues as compared to 2.4GHz of the old.

The oversubscription part is true, but that also counts within wired networks. Shared links, like the ones to wiring closets can be oversubscribed. Most networks are designed that way. For wireless networks it is more obvious though.