Last Post: January 26, 2012:
Hi fellow Wi-Fi Guys and Gals!
I'm a little confused at the data sheet for the Intel Centrino Wireless-N 1030.
It states it is 1x2 and has a tx of 150Mbps and a rx of 300Mbps (so MCS 15)
However i cannot get it to reach past 65Mbps(which i think is correct with a MCS of 7).
Intel do not state the SS number, just 1x2...Is it just marketing BS from Intel or am I getting confused??
Just to get the ball rolling:
The following link gives the data sheet for the Intel Centrino Wireless n 1030 device. Let?s see what we can find:
? Up to 5x faster and 2x range1
A note about the speed and range is given below:
?1 Based on the theoretical bandwidth maximum enabled by 1x2 802.11n implementations with 1 transmit and 2 receive spatial streams. Actual wireless throughput and/or range will vary depending on your specific operating system, hardware and software configurations. Check with your PC manufacturer for details.?
Driver issues can cause rates to ?not be what you wanted them to be?.
Now, we note that the device operates at 2.4 GHz. Actually we don?t note it !! It doesn?t say anything about frequency range on the data sheet !! In order to find out what frequency the thing actually operates at, we have to dig up other material:
Note that it still doesn?t directly tell us that it is 2.4 GHz only. We have to imply that from the fact that it is not dual band.
I?m sure they must have accidentally left it out???..
For engineers, this is not much of a problem, but for someone who is simply ?going to Best Buy? and looking for a device like this, ?300 Mbps? would stand out like a sore thumb. ?Sounds good to me?.
So, not quite ?marketing BS?, just some fine print and some missing information from the main company data sheet !!
In order to get 300 Mbps performance at 2.4 GHz, we would need to utilize 40 MHz channel bonding. This is not a good idea at 2.4 GHz and can cause a lot of problems.
If we are not utilizing 40 MHz channel bonding at 2.4 GHz ( it is normal not to use it ), then the maximum possible data rate UNDER IDEAL CONDITIONS would be 144.40 Mbps with 2 receive spatial streams. Very few systems use a 400 ns guard interval, so that would leave us with a maximum of 130 Mbps for that scenario.
Both the STA and AP need to agree on certain parameters ( there is an exchange of capabilities in various special information elements which tell each other what they are both capable of ).
802.11n thrives on multipath, and it?s performance degrades when multipath is not ?sufficient?. Your environment is important too, in terms of interference.
What AP are you working into ? Do you have any sort of a config screen that you can access for the device ?
Dave, I appreciate your feed back.
Indeed 40MHz on the 2.4 is not ideal, I'm just testing the chipset for a client.
It would just be nice for the vendor to put in as much information as possible.
Never the less I will fire up a Omnipeeks tomorrow morning and look at the supported rates.
You're welcome Stuart
Some more stuff:
Can you let us know what type of AP you are connecting to ?
On a personal level, I don't like what a lot of the manufacturers do in the home retail market. The average person going into Best Buy wouldn't know 40 MHz from a hole in the ground, just as I wouldn't know the difference between a model XYZ welding device and an ABC one. In other words, we all have areas in which we are clueless.
Without mentioning manufacturers, I've seen boxes at Best Buy with 300 Mbps !!! stamped on them. Catches the eye pretty quick. Then you notice the tiny little number which refers you to a tiny little piece of text ".....under ideal conditions etc etc ".
"How long are you going to work today ?"
"Up to eight hours"
"How much fuel will I get with these X dollars ?"
"Oh, up to ten gallons....."
When we're paying, vagueness is not much fun.
I'd be very careful about what it says in the previous. In theory, 802.11n is supposed to play nicely with everyone, but there have been cases of 2.4 GHz operation with 40 MHz causing all sorts of problems.
A "similar-ish" one:
The APs in use are Ruckus 7962, 7363 and 7762-S.
Thanks for the further links. I will filter through them today.
Sometimes, depending upon drivers etc, when WMM and/or AES are not implemented, you can get the data rate "locked" at 54 Mbps ( in other words, the "old" a and g rates ). With your case, we're seeing an MCS rate. It may still be worthwhile checking configs.
Let us know how you get on.
WPA2 AES OFDM-only with a min bss rate of 6(not that it is relevant)
Latest driver but still only 65Mbps, So I'm guessing MCS7 is the highest index supported.