Can someone explain the wireless jargon?

[Wanderer]

Hello, my goal here is to learn more about wireless networking. I am confused about many things and can't find the right article/guide to answer my questions. I'll just dive in.

My first question is what does it mean for a wireless N to operate at 300 Mbps? 300 Mbps is a speed correct? Then what is bandwidth? Theoretically, if a single client is connect to the AP, does this mean he can use the full wireless bandwidth? And if two clients were connected, the full bandwidth would be shared right?

Now I know this isn't true because transferring files between two clients in the same AP is painfully slow. Usually, my transfer speeds are about 2.5 MBps or 20 Mpbs. Why is it so slow when so much bandwidth is available? I don't want to bring WAN in, but sometimes my internet speed is faster than LAN transfer, and this drives me insane.

Another scenario I tried was plugging in a secondary computer via Ethernet. With my laptop being the only client connected to the AP, in theory, shouldn't the file transfer speed be close to 300 Mbps (ignoring hard drive limits)? However, I only achieved speeds of about 5 MBps or 40 Mbps, which is very disappointing if I ever wanted to run a server.

I may have been ignoring another thing, and it has to do with throughput. I have no idea what this term means, but it seems to be yet another word to describe speed. When looking at the router chart in SNB, what does it mean for a router to have a certain throughput for 5 GHz uplink at 40 MHz B/W? It would be nice if someone can define uplink, downlink, and updown throughput. The channel width 40 MHz and three stream also add to the confusion.

It would be awesome if someone can answer my questions, or just link me to an in-depth article if you do not want to type things out. At least, let me know what router I should look for in the wireless charts if I want the fastest file transfer speed between wireless client to wired, and between two wireless client, as I described before.

For reference, I own the Asus RT-N16 as my main router running a 2.4GHz wireless N. Attached is a Netgear WNDR3300 running 5GHz wireless N. It is extremely congested in the 2.4GHz spectrum where I live. Sorry for the long text.

 

[overdrive31]

Wireless is just for convenience, it is so susceptible to interference you cannot rely on it to consistently perform at it's optimum.

For most of your questions this or this should answer them.

You claim your link rate as being 300Mbps(dual stream N @ 40MHz), yet your testing shows speeds relative to single stream N @ 20MHz. Could you be confused from speeds offered by the router(300Mbps) and the actual link rate limit of said laptop(based on testing I say single stream N @ 20MHz or 65Mbps)? Maybe your expectations were focused on the speed rating of the router, thinking you were connecting @ 300Mbps only because the router was advertised as supporting such. The client must support such speeds as well to perform as expected. Wireless client to client test was just half that of the single wireless to wired test because the available wireless bandwidth gets shared between the two when they both consume bandwidth at the same time.

Bandwidth is the theoretical speed capability and throughput is an actual measured speed. The speed charts will list 2.4GHz/5GHz up, down, and up/down link and this usually means dual stream, but does include some that are just single stream. Then you have the results for just three stream. The up link is measured speed of data leaving the client, down link is measured speed of data being received by the client, and up/down link is measured speed of both up and down at one time using more than one client.

You should turn off 40MHz on the 2.4GHz radio(causes more congestion and problems for you and your neighbors), only use 40MHz mode with the 5GHz radio(can't reach out enough to crowd neighbors and has more spectrum to support it easily).