I think that problems several people (including qspb) have are router specific. As you see from my earlier post I get consistently about 4MB/s (4,3MB/s max) without any gimmicks, which is clearly better than 802.11g.

Though compiling the newest wl12xx module and using the latest firmware could be useful. Atleast we might get real AP mode for our N9's. You can grab the sources (and the firmware) from http://linuxwireless.org/en/users/Drivers/wl12xx if you want give it a try.

See some of the kernel work planned in other threads...

In qspb's case, the issue became a non-issue after a re-flash, he then consistently got perf. roughly in the ballpark one would expect.
See posts I linked to in my prior post....

Would that enable "full" n mode?

Might be a little different from others however as one of the guy mentioned in the thread that the WiFi speed slows down in device active mode.

I can confirm thats happening with me too. I tried transferring a 18mb file with Winscp and the top download speed was 3MBps when device was locked and idle. However I tried to copy the same file again while keeping my N9 active by just changing the home screens and the speed dropped to 700KBps.

I know this test is not very reliable but still I can confirm that the speed varies in Idle & Active mode. This happen in both N & G mode.

As Jalyst suggested that a reflash can do wonders but I don't want to do reflash just because I don't want to set up my phone again. (Tired)

Can someone please guide me how they have overcome the above issue?

Cheers

Oh, I'm afraid I can't describe it "step by step", because I don't feel too enthusiastic about describing methods of using Linux. I mentioned some hostapd settings - there're plenty of how-to's and manual pages on the net about configuring hostapd. If u have a wireless router (not wireless USB-dongle, like me) you don't have to configure hostapd or any other related software. I used hostapd just to show the configuration of Wi-Fi network to test (QoS, HT capabilities, etc). And as for tools like wget, iperf and many others - there are several man pages on the net too. And of course, u can use ping - it's seems to be simple (according to nemric's post).

No updates. There's only [HT20] support, according to iw's output. My aim was to reach maximum transfer rate, and I've managed to reach ~3MB/s. Surprisingly, I haven't managed to reproduce "screen bug" on my phone. And as for the driver - I think there is no need in recompiling driver, because there's no hardware support of [HT40+].

The TI WL1273 chip (supposedly used in the N9) supports a maximum bitrate of 65 Mb/s according to these specs pages: (1) http://www.ti.com/product/wl1273-tiwi5 (2) http://www.lsr.com/wireless-products/tiwi5

My N9 is able to connect at 65 Mb/s on the 2.4GHz band, but it is useless on the 5GHz band. On 5GHz, the connection drops and re-connects every 2 seconds. Can anybody tell me why that is?

Could be that the AP you're connecting to is sh1t, could be a raft of factors...
Plenty of folks connect to 5Ghz without issue, even in this very thread....
Remember that although 5ghz has better throughput, it also has much less range (esp. the older forms) than 2.4Ghz.
So make sure you're not expecting better performance than 2.4Ghz at 2.4Ghz range.
Oh & of course confirm that the AP is dual-band, & ideally simultaneous dual-band (i.e dual radio).

Thread is kind of old, but i just found something weird that happens on my workplace's network.

Wifi is configured as G, using a Symbol Wireless Switch with many Acces Ports

When in connect my N9 to this network performance is awful, i can't even open a decent ssh session to the phone.

Pinging to the N9 from my Linux workstation gives a lot of lost packets and response times from 1200ms to 8000ms.

But... if i start a scp transfer from my PC to the N9, voila!, as soon as the transfer begins the connection becomes fully responsive and the ping times go around 50ms.

At first i thought i had to do with the N9's cpu going into idle mode because of the low load of the sshd daemon, so i got some apps running in background, but it seems like that made no difference.

dmesg doesn't give me anything weird, no errors or warnings.

On the other hand, my N900 works like a charm with my work's wifi. hahaha.

2 alvian:
65 Mbit/s is a theoretical bandwidth. Standard G with 54 Mbit/s bandwidth allows to connect at 2.6 Mbytes/s (real speed), so if we extrapolate 54 Mbit/s to 65 Mbit/s bandwidth, it seems that real speed will be about 3 - 3.1 Mbytes/s (exactly what I was able to achieve with [HT20+][SHORT-GI-20] some time ago).
But I always get irritated when I try to find out what exact wireless chip is built in N9: TI WL1273 chip seems to have a number of modifications. You see, there is no Bluetooth 4.0 available on N9. Perhaps, built-in chip supports BT 4.0, but the current driver doesn't. I don't know.
What is for your question about 5GHz connection, the problem seems to be a hardware-specific. I faced this problem on 2GHz sometimes ago. I used two different wireless cards (from different manufacturers), based on Atheros chips, to set up an AP. Hostapd settings were constant, except the wireless card's interface id. One of the cards allowed me to get stable 2.6 - 3.1 Mbytes/s connection, and the other one worked extremely unstable - the speed changed from 1 to 2.8 Mbytes/s every 2 - 3 seconds. So... what if you test 5GHz with some other router?

2 jalyst
Simultaneous dual-band connection is also very interesting to investigate.

2 ejcrashed
Weird... but what if QoS causes the issue? Can you disable QoS on the router side and try to test it one more time?

I know, folks are waiting for some news from me. Okay, recently I tried to launch my AP on channel 14 (2484 MHz). I managed to unlock channel 14 on AP side and launch hostapd without any issues, but i'm not able to scan on channel 14 with my N9. There is no channel 14 in frequences-list (iw list) at all. But I think it's driver-specific, so now I'm trying to find out how to compile wl12xx, wlcore and wl1271 drivers for N9. I tried to compile compat-wireless directly in the terminal, but unsuccessfully: I get errors during compilation.

I have some news.
Recently I tried to follow that excellent how-to to compile a custom kernel. I did almost the same, but I used 3072 megabytes of additional space instead of 2222. My aim was to enable channel 14 support, so I edited ./drivers/net/wireless/wl12xx/main.c file and added string
to an appropriate place (just an example of code). I also edited ./drivers/net/wireless/wl1251/main.c file and added string
to an appropriate place too. Also I enabled CONFIG_CFG80211_INTERNAL_REGDB option and placed custom regdb file to ./net/wireless/db.txt (read this). In that file I replaced regulatory rules for each of the country with
(This can be useful for people, who face problems when trying to connect to AP working on a particular 5GHz channel).
I compiled kernel and modules. Flashed the kernel. Rebooted. Of course, I removed wireless-regdb and crda packages (to use internal regdb instead). Then I was able to find my AP working on channel 14 and I was able to connect. But the speed was very disappointing: 400 - 780 KBytes/s. I can't understand the reason of such behaviour. The problem seems to be very complicated (maybe, I also need to calibrate?)

But at least we know we can recompile the kernel and we know we can modify wireless driver to get a better performance. The kernel is very old (2.6), the newer kernels look a bit more enthusiastic (for example, there is channel 14 support in wl12xx driver for kernel 3.3). So, we can look through the driver code and make some improvements on 802.11n performance too. Also we can try to compile newer kernels for N9.