Is it possible to get >150mbps with 11n on 2.4Ghz and 20Mhz?

Hi,

Although I posted a little awhile ago, asking whether or not to wait to
get some 11n equipment, I've been curious, and one of my laptops already
has an 802.11n adapter (an Intel 4965agn), and I was an 11n router on
sale (a Buffalo WHR-G300N), so I figured that I'd "dip my toes" into the
11n waters.

The Buffalo router arrived this week, and I've been testing with my laptop.

At first, I was only able to get 54mbps, but after some tweaking of the
router and the adapter settings, I was able to get between 130mbps and
144mbps.

I've been doing research on this, and found that:

- The Buffalo router is a 2.4Ghz router only (but able to use either
20Mhz or 40Mhz channels).

- The 4965agn chipset is apparently designed to specifically not use
40Mhz channels on 2.4Ghz.

So, at least with the 4965agn, I'm limited to 2.4Ghz and 20Mhz channels.

From searching and testing, it appears that I can't get >~130 -
150mbps, but I have not been able to find any technical information that
says that at 2.4Ghz and 20Mhz channels, the maximum connection speed is
limited to <150mbps.

So, I was wondering if anyone can either provide any definitive
information or cite a reference about this, explaining why 150mbps is
the limit for 11n using 2.4Ghz and 20Mhz channels?

FYI, I have another 11n adapter, a Belkin PCCARD, and I was able to get
270mbps connections, using 2.4Ghz and 40Mhz channels, but I guess that
I'd like to either really understand why the 4965agn can't do that, or
figure out how to get it to connect at >150mbps.

Thanks,
Jim

ohaya wrote:
> Hi,
>
> Although I posted a little awhile ago, asking whether or not to wait to
> get some 11n equipment, I've been curious, and one of my laptops already
> has an 802.11n adapter (an Intel 4965agn), and I was an 11n router on
> sale (a Buffalo WHR-G300N), so I figured that I'd "dip my toes" into the
> 11n waters.
>
> The Buffalo router arrived this week, and I've been testing with my laptop.
>
> At first, I was only able to get 54mbps, but after some tweaking of the
> router and the adapter settings, I was able to get between 130mbps and
> 144mbps.
>
> I've been doing research on this, and found that:
>
> - The Buffalo router is a 2.4Ghz router only (but able to use either
> 20Mhz or 40Mhz channels).
>
> - The 4965agn chipset is apparently designed to specifically not use
> 40Mhz channels on 2.4Ghz.
>
> So, at least with the 4965agn, I'm limited to 2.4Ghz and 20Mhz channels.
>
> From searching and testing, it appears that I can't get >~130 -
> 150mbps, but I have not been able to find any technical information that
> says that at 2.4Ghz and 20Mhz channels, the maximum connection speed is
> limited to <150mbps.
>
> So, I was wondering if anyone can either provide any definitive
> information or cite a reference about this, explaining why 150mbps is
> the limit for 11n using 2.4Ghz and 20Mhz channels?
>
> FYI, I have another 11n adapter, a Belkin PCCARD, and I was able to get
> 270mbps connections, using 2.4Ghz and 40Mhz channels, but I guess that
> I'd like to either really understand why the 4965agn can't do that, or
> figure out how to get it to connect at >150mbps.
>
> Thanks,
> Jim
>


Hi,

I'm continuing to research the questions above, and I just found this
for the Linksys WRT400:

https://www.sonystyle.com/webapp/wcs...specifications

Note under "Receive Sensitivity", it shows:

2.4GHz
11Mbps: -86dBm @ Typical
54Mbps: -71dBm @ Typical
130Mbps (20MHz): -70dBm@ Typical
270Mbps (40MHz): -66dBm@ Typical
5GHz
54Mbps: -67dBm @ Typical
130Mbps (20MHz): -68dBm@ Typical
270Mbps (40MHz): -62dBm@ Typical

that *seems* to imply 130mbps connections with 2.4GHz/20Mhz, and
>130mbps (i.e., 270mbps) connections only with 2.4Ghz/40Mhz and
5Ghz/40Mhz.

There's no explanation of why no >130mbps with 2.4Ghz/20Mhz though ...

Jim

ohaya wrote:

> I've been curious, and one of my laptops already has an 802.11n adapter
> (an Intel 4965agn), and I was an 11n router on sale (a Buffalo WHR-G300N)

> At first, I was only able to get 54mbps, but after some tweaking of the
> router and the adapter settings, I was able to get between 130mbps and
> 144mbps.

I'm curious. How do you get 130Mbps out of an AP with only 100Mbps ethernet?
Are you using some sort of link aggregation [like LACP]?

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alexd wrote:
> ohaya wrote:
>
>
>>I've been curious, and one of my laptops already has an 802.11n adapter
>>(an Intel 4965agn), and I was an 11n router on sale (a Buffalo WHR-G300N)
>
>
>>At first, I was only able to get 54mbps, but after some tweaking of the
>>router and the adapter settings, I was able to get between 130mbps and
>>144mbps.
>
>
> I'm curious. How do you get 130Mbps out of an AP with only 100Mbps ethernet?
> Are you using some sort of link aggregation [like LACP]?
>


Hi,

Sorry, but I probably wasn't being clear. The numbers I mentioned
weren't for throughput. Those numbers were just what Windows (7) was
showing for the connection speed. I haven't done any throughput type
testing yet (e.g., with iperf). Since this is the 1st time I'm working
with any 11n equipment, I'm just trying to get the connection "speed"
numbers first.

Jim

LR wrote:
> On 26/09/2009 19:54, alexd wrote:
>
>> ohaya wrote:
>>
>>> I've been curious, and one of my laptops already has an 802.11n adapter
>>> (an Intel 4965agn), and I was an 11n router on sale (a Buffalo
>>> WHR-G300N)
>>
>>
>>> At first, I was only able to get 54mbps, but after some tweaking of the
>>> router and the adapter settings, I was able to get between 130mbps and
>>> 144mbps.
>>
>>
>> I'm curious. How do you get 130Mbps out of an AP with only 100Mbps
>> ethernet?
>> Are you using some sort of link aggregation [like LACP]?
>>
> He is probably referring to his wireless utilities reported link speed
> rather than actual data throughput. Given that his Intel adapter is
> restricted to 20MHz channels in the 2.4GHz band he is unlikely to get
> more than 80Mbps data throughput so there shouldn't be any problem with
> having only 100 Mbps Ethernet.


LR,

Yes, you're correct. That was what I meant...

Jim