Skip to main content

802.11n flavours explained

Most 802.11n enabled Access Points out there advertise themselves as follow: 2x3:2,  2x2:2. Ever wonder what these numbers mean?
Well here is what I make out from them:
You will find 802.11n with the following flavors:

1x1:1
1x2:2
2x2:2
2x3:2
3x3:2

Where:
TxR:S

T - Transmit
R - Receive
S - Spatial

The spatial is your "money". Each spatial equates to 150mb, so you will see 3x3:3 equates to 450 mb.Thats why with Cisco APs and others, you will only ever get 300 with xXx:2.

Let me add further, 2 on the transmit means you will use no more than 2 antennas to TX on. 3 on the receive means you will use 3 antennas to rx on. The spatial is your streams. if you have a 2 stream AP, that means its the most number of streams network will have, that too if your environment is favourable to use 2 streams, just because it can do 2, doesn't mean it will always do 2.

802.11n although by standard could support  600 4x4:4, its VERY unlikely we will see that in the enterprise. Atheros mentioned they will not support development of the 4x4:4 chip. Why you ask ? They said that 802.11ac should be a quick ratification.  802.11ac, you will be able to do 8x8:8, hence GIG over wireless.

Hope it helps.

Comments

Post a Comment

Popular posts from this blog

Cisco: Resetting Forgotten Password

I was actually made to write this blog after I end up buying a password protected Cisco 2500 router from Ebay. My room mate collected it and straight away tried to connect it to HyperTerminal as he wanted to test his newly learnt skills from CCNA classes. But more to his disappointment, the router was password protected and it was not until evening when I returned home after work. If you do end up in a similar situation, before you start have your snacks, roll up your sleeves and be prepared for a good 3-4 hrs of command line drill. Alright.. my bad.. it won’t take this long, it’s actually easier than it looks and can only take a max of 2 minutes if you got all the right stuffs with you. And here is how we do it in easy steps: 1) Connect to your router via console. 2) Power reset the Router. 3) When the router boots again, Press "Ctrl + Break” or “Ctrl +Pause”(Hyper-terminal/Putty). Pause/Break is actually the same key. And make sure to do this with in within 60 sec. And if ...
Post a Comment
Read more

What is this mystical network!

There is a lot written about networks but most of the times when it comes to Basic questions like "What is a network?"(in regards to information technology), most of us will end up saying "A group of different devices that can intercommunicate in an intelligent manner (of-course you may find some that can only give you a shrug,like me)". When I asked myself all I got were random images of pcs and boxes connected via lines, bolts and clouds. Actually what we should concentrate on is what the network does instead of what the network really is? I still remember asking my high school teacher about this cloud. All I was told was that it's Internet: network of networks. Most of us will be pretty satisfied with the above definition of network but read it again, it tells us about what network is made of, and not what network exactly is. Let's take an example from the latest movie I watched, Shrek: the far away kingdom, where King stamps a letter and give ...
Post a Comment
Read more

Virtualization

The word "Virtualization" on its own, is too wide to discuss. But to cut it short, its a process of making one thing look like another. For our purposes we are referring to the ability of a computer to be split into multiple parts where the parts are (relatively) indistinguishable from the whole. For example, running different Linux environment on a single machine. Virtualization is often posed as a tool to over ride accustomed practice to having dedicated environments for each application, due to this one application per server deployment model, the majority of systems are grossly under-utilised like CPU utilization below 10% is normal. By virtualizing the physical hardware so that many “servers” can run simultaneously on the same physical machine we can drive utilisation much higher, to 50% or more. Hope it help!
Post a Comment
Read more