Wireless Speed

[iwod]

The first thing i notice ASUS AC66U review actually shows up to 500Mbps throughput during the review. But when i look it up in the Router Chart, the Maximum was only 3xx Mbps.

Am i missing something?

Also why each generation are we further away from the theoretical maximum speed? I know there are overhead etc, but the 5Ghz is a lot less nosy, if not clean compared to 2.4Ghz, at 1750Mbps, even 50% should be 875 Mbps. And we are not even close to that.

 

[TonyH]

Hi,
No, you are not missing any thing. Radio signal is not like signal on copper. All those numbers are max. theoretical ones. In real life, it ain't be that. RF and antenna engineering is still mostly cut and try type endeavor. Another analogy is in audio, when you get a pair of speakers based on tech specs. alone, they don't always sound satisfactory.

 

[stevech]

All 802.11 WiFi..

If your WiFi device reports that is is connected at, say, 100Megabits/sec (Mbps), then the net yield at the IP data level is about 60% of that. Overhead and error correction redundancy in the data costs.

"Wireless isn't a thousand times harder than wired, its a million times harder."

 

[TonyH]

Hi,
Way back once I worked on tropo links. Signal level we're dealing was -110dbm
and up. That is with 100KW TX, triple diversity with RX front ended with parametric amp.
Good olden fun days.....

 

[Fraoch]

Wireless has a huge amount of overhead. There's a lot of wireless packets that aren't actually data...take marketing numbers with a grain of salt and measure actual speed instead. Until recently, there wasn't even much of a point to having gigabit ports on a wireless AP* because delivering over 100 Mbps over wireless just wasn't possible. Wireless AC is capable of that now, but wireless n was barely capable of this.

Wired networking is much, much, much more efficient and can almost saturate the entire link.

(* as opposed to a router where wired clients and >100 Mbps WAN connections will benefit)

 

[iwod]

What i am thinking is like,
If my laptop is directly infront of the router, positioned perfectly so both antenna are in line of sight or in best performance scenario, i will still not get 50% of max speed. Hence in best case scenario there will still be a 50% overhead?

Just wondering.

 

[stevech]

Hi,
Way back once I worked on tropo links. Signal level we're dealing was -110dbm
and up. That is with 100KW TX, triple diversity with RX front ended with parametric amp.
Good olden fun days.....

when was that? I did tropo scatter in my Army days

 

[stevech]

What i am thinking is like,
If my laptop is directly infront of the router, positioned perfectly so both antenna are in line of sight or in best performance scenario, i will still not get 50% of max speed. Hence in best case scenario there will still be a 50% overhead?

Just wondering.

overhead is fixed. No matter the signal strength. In WiFi, overhead is such that your IP layer throughput is 60-70% of the WiFi bit rate.

Data Rate varies by signal strength BOTH was, and from waiting due to busy channel.

 

[TonyH]

Hi,
I was military civilian. FRC-39 and MRC-85, Long lines FRC-109 m/w network, etc. Back in the '60's in Korea with 8th Army 308th LL Bn and to SE Asia during the war in 'Nam. I belonged to ICS, SE Asia. Been HAM since '50's HM1AY/VE6CGX. After I quit DOD, I joined Honeywell, retired in '96. I definitely can say in low level signal situation noise becomes a BIG factor, s/n ratio, or ICN(idle channel noise), etc.

 

[iwod]

So do LTE has less overhead? I was testing the newest and latest LTE CAT 4 in shops, possibly one of the best scenario since they have in shop mobile antenna.

In a theoretical 150Mbps , the phone / USB were both getting close to 130Mbps download speed.

That is less then 20% overhead.

 

[stevech]

So do LTE has less overhead? I was testing the newest and latest LTE CAT 4 in shops, possibly one of the best scenario since they have in shop mobile antenna.

In a theoretical 150Mbps , the phone / USB were both getting close to 130Mbps download speed.

That is less then 20% overhead.

Jargon overload. To me, "LTE" is Long Term Evolution - 4G cellular. Nothing to do with WiFi or LANs. LTE in the US, from Verizon, is usually 5-10Mbps down and 3-5Mbps up, varies by signal strength and time of day.

LTE is too costly to replace wired Internet service in an office or some such where you use many GB per month.

Beware Mbps and MBps (the latter is byte/sec and there are 8 bits per byte).

150Mbps and so are WiFi speeds, not related to LTE.

LTE Cat 4 is a new term to me.