My MBP doesn't connect to 802.11n networks

Question

My MBP doesn't connect to 802.11n networks

Software Versions:
Menu Extra: 6.2 (620.24)
configd plug-in: 6.2 (620.15.1)
System Profiler: 6.0 (600.9)
Network Preference: 6.2 (620.24)
AirPort Utility: 5.4.2 (542.23)
IO80211 Family: 3.1 (310.6)
Interfaces:
en1:
Card Type: AirPort Extreme
Firmware Version: Atheros 5416: 2.0.19.8
Locale: Korea
Country Code: KR
Supported PHY Modes: 802.11 a/b/g
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 149, 153, 157, 161
Status: Connected
Current Network Information:
SSD87:
PHY Mode: 802.11g
BSSID: 0:25:bc:8a:3f:51
Channel: 11
Network Type: Infrastructure
Security: WPA2 Personal
Signal / Noise: -58 dBm / -96 dBm
Transmit Rate: 54
Other Local Wireless Networks:
SSD875G:
PHY Mode: 802.11n
BSSID: 0:25:bc:8a:3f:52
Channel: 157
Network Type: Infrastructure
Security: WPA2 Personal
Signal / Noise: -55 dBm / -96 dBm
SSD875G:
PHY Mode: 802.11n
BSSID: 0:1f:5b:86:e9:74
Channel: 157
Network Type: Infrastructure
Security: WPA2 Personal
Signal / Noise: -58 dBm / -96 dBm

==============================================

From the information above, my MBP doesn't access 802.11n network after install Mac OS X 10.6 Snow Leopard and all of updates.

Snow Leopard changes Phy mode of 'Atheros 802.11n WL card' to 802.11g, and It works fine as 11n under 10.5.8 Leopard.

What makes this situation?

Message was edited by: xeon.thebrick

MBP late 2006 2.2, Mac OS X (10.6.2)

Posted on Feb 20, 2010 11:43 AM

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Answer 1

Kappy

Level 10

361,741 points

Feb 20, 2010 11:57 AM in response to xeon.thebrick

I'm not sure I see your conclusion from the posted info. The information shows your card supports 802.11a/b/g and 802.11n.

if you open System Profiler and select Airport under the Network heading in the sidebar you should see that the card supports all four modes. If you open Network Utility in your Utilities folder and select the interface for the wireless card from the drop down menu it will report the connection speed. Assuming your router supports 802.11n you should see 130 or 270 Mbps for the connection speed depending on whether you are using the 5 GHz channels as selected in your router's configuration. If you have any iPod or iPhone that you sync, then you must set the router to use only the b/g/ and n compatibility modes at 2.4 GHz because iPods and iPhones do not support 802.11n.

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Answer 2

Feb 20, 2010 2:23 PM in response to Kappy

I have an AEBS Early 2009 Model, so I can use both 2.4Ghz and 5Ghz at the same time.

http://img.ly/wTA
http://img.ly/wTB

null

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Answer 3

Kappy

Level 10

361,741 points

Feb 20, 2010 2:32 PM in response to xeon.thebrick

Well, again you've not provided any information suggesting your network is not running 802.11n, so I can't see how there's a problem. Your router is configured to run b/g/n compatible mode at 2.4 GHz.

As I said open Network Utility and select the Airport connection to see what your network speed is. If it's 130 or 270 Mbps then you are running at 802.11n speed. Otherwise I can't see that you have a problem.

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Answer 4

Feb 20, 2010 5:17 PM in response to Kappy

Here are some links that shows my problem.

Airport connections
2.4 GHz Mode
http://img.ly/wVy (Ariport Utility)
http://img.ly/wVw (Ariport Status in menu bar)

5 GHz Mode
http://img.ly/wVx (Ariport Utility)
http://img.ly/wVv (Ariport Status in menu bar)
and also it strangely works with 5GHz as 802.11a mode and transmit rate is just 6

Message was edited by: xeon.thebrick

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Answer 5

Kappy

Level 10

361,741 points

Feb 20, 2010 8:08 PM in response to xeon.thebrick

What else is on your network? Do you have at least one other device that only can connect at 802.11b/g speed? If you do then the slowest device on the network sets the speed.

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Answer 6

Feb 20, 2010 10:17 PM in response to Kappy

My family's Dell Studio laptops can use 130Mbps Speed in a same network, so I think it's not a problem of AEBS. (and my family bought those two dell's in Korea and designed for KR market same as my MBP Late2006)

Most of Late 2006 MBP Users in Korea have same problem, and their MBP has same airport card as me
(they neither can't connect any 802.11n networks after using Snow Leopard.)

Interfaces:
en1:
Card Type: AirPort Extreme
Firmware Version: Atheros 5416: 2.0.19.8
Locale: Korea
Country Code: KR
Supported PHY Modes: 802.11 a/b/g
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 149, 153, 157, 161

Message was edited by: xeon.thebrick

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Answer 7

Kappy

Level 10

361,741 points

Feb 21, 2010 9:32 AM in response to xeon.thebrick

Perhaps you should take your omputer in for a check-up. There may be a hardware problem. I doubt there's a problem with SL since all my computers use SL and have no wireless connection problems to an AEBS.

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Answer 8

defecta

Level 1

16 points

Mar 25, 2010 9:04 PM in response to xeon.thebrick

I have a simliar problem but have just recently found out why I cant connect to N networks by scrutinising the kernel.log in Console

For some unknown reason the country code for my airport changes from AU (default) to something random. I have no idea what is causeing it but when my country code changes to 'TW' the list of supported channels does NOT include channel 36. Channel 36 is the channel of my 5Ghz wireless N network at home.

Check your logs and see if you have the same problem. (search for 'country code' to find the relevant entries)

I am yet to find the cause of this issue and a solution for it. Any help would be great. 🙂

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Answer 9

Dogcow-Moof

Level 8

36,185 points

Mar 25, 2010 11:27 PM in response to defecta

defecta wrote:
For some unknown reason the country code for my airport changes from AU (default) to something random. I have no idea what is causeing it but when my country code changes to 'TW' the list of supported channels does NOT include channel 36. Channel 36 is the channel of my 5Ghz wireless N network at home.

This is due to 802.11d country codes.

Because different countries have different frequency allowances, when a compliant device is looking for SSIDs, it passively listens for beacon packet data to find out which country its in and sets the appropriate country code for transmit purposes.

The most likely reason for your difficulty is a neighbor has an illegal Taiwan (TW) market router and that's what's screwing up your ability to connect to your legal router at the speed/frequency you would like.

You might want to try turning your AirPort off and on a few times in the menu bar and see if you eventually connect to your router with the correct country code set.

If you're curious, you can see the ISO country codes here:

http://www.iso.org/iso/englishcountry_names_and_codeelements

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Answer 10

defecta

Level 1

16 points

Mar 26, 2010 2:23 AM in response to Dogcow-Moof

William Kucharski wrote:

defecta wrote:
For some unknown reason the country code for my airport changes from AU (default) to something random. I have no idea what is causeing it but when my country code changes to 'TW' the list of supported channels does NOT include channel 36. Channel 36 is the channel of my 5Ghz wireless N network at home.

This is due to 802.11d country codes.

Because different countries have different frequency allowances, when a compliant device is looking for SSIDs, it passively listens for beacon packet data to find out which country its in and sets the appropriate country code for transmit purposes.

The most likely reason for your difficulty is a neighbor has an illegal Taiwan (TW) market router and that's what's screwing up your ability to connect to your legal router at the speed/frequency you would like.

You might want to try turning your AirPort off and on a few times in the menu bar and see if you eventually connect to your router with the correct country code set.

If you're curious, you can see the ISO country codes here:

http://www.iso.org/iso/englishcountry_names_and_codeelements

Hi William,

Thanks for your informative reply.

Is there any way you know of to stop or force the airport to 'XX' so I don't have this issue?

I have tried turning the airport of and on repeatedly to see what happens when I was diagnosing this issue. I have logs of it connecting as GB, US, FR TW and of course AU. Only TW ommits channel 32 of all the varying country codes it sets itself to.

It is quite possible that the majority of the people in my apartment building have never setup their routers correctly which could explain the varying country codes perhaps?

My next step is to run KisMAC to find out which SSID has the offending country code. =]

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Answer 11

Dogcow-Moof

Level 8

36,185 points

Mar 26, 2010 8:47 AM in response to defecta

defecta wrote:
It is quite possible that the majority of the people in my apartment building have never setup their routers correctly which could explain the varying country codes perhaps?

My next step is to run KisMAC to find out which SSID has the offending country code. =]

There is no way to "force" a country code - that would actually be illegal in most countries as you would now have a "primary" device capable of breaking your country's frequency allocation rules.

Technically it's also a violation to broadcast on say, the UK's frequencies, but in that case your machine isn't the primary violator.

The issue isn't that the routers aren't setup correctly; in fact few if any consumer routers allow you to set the country code. The problem is when someone buys a router from a web site in the UK, moves from the US and brings their router, is a student from France and brings their router, etc. Many people don't realize that moving from one country to another may well mean that you have to purchase a new router to avoid violating laws, and many (particularly Internet-based) retailers don't realize that selling a router made for sale in Taiwan in another country is equally illegal.

This is becoming a larger and larger issue as prior to the past year or two many if not most Wi-Fi adapters either ignored country codes altogether or were hard-coded to the frequencies used in their country of original purchase.

Now with 802.11d compatibility, you end up in situations like this; Windows PCs are running into the same problems if you have one of the very latest Wi-Fi cards/drivers that even supports 802.11d. 😟

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Answer 12

defecta

Level 1

16 points

Mar 26, 2010 11:24 AM in response to Dogcow-Moof

So by the virtue of my MacBook being compliant with the 802.11d standard I am open to these issues? And from the way you are explaining it it sounds like Apple is ahead of the curve with implementing 802.11d compliance?

Would it be legal to write an app or driver that you can set ignore certain problem country codes when you want it to? Because something like this would help my issue also rather than playing lotto each time I turn my MacBook on or wake it from sleep, hoping it will see my wireless network first.

I had a very quick look at kisMAC and scanned my neighbouring networks but couldn't easily see it identifying what country code was being broadcast. Does any now if KisMAC can do such a thing? Or do I just need to scour the dumpfile or whatever they call it to find it, (if it's even human readable)?

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Answer 13

Dogcow-Moof

Level 8

36,185 points

Mar 27, 2010 2:03 AM in response to defecta

defecta wrote:
So by the virtue of my MacBook being compliant with the 802.11d standard I am open to these issues? And from the way you are explaining it it sounds like Apple is ahead of the curve with implementing 802.11d compliance?

They're not ahead of the curve +per se+, but as an example many Windows XP machines are behind the curve if you will.

Would it be legal to write an app or driver that you can set ignore certain problem country codes when you want it to? Because something like this would help my issue also rather than playing lotto each time I turn my MacBook on or wake it from sleep, hoping it will see my wireless network first.

Unfortunately, I'm not a lawyer and not in Australia so I couldn't begin to guess at what is legal and what's not in this arena.

However, there is no interface to the driver to be able to manually set a country code, so the point may be moot.

I don't know what kisMAC can and cannot display, but the country code is broadcast within the 802.11 beacon frame and/or probe response frame if the frame's dot11MultiDomainCapabilityEnabled option is true, so you may want to try looking at its output of beacon frames.

Three octets make up the country code - the two character country code and a third octet which is one of:

* An ASCII space character (0x20) if the regulations under which the 802.11 station is operating encompass all environments in the country.

* An ASCII ‘O’ character (0x4F) if the regulations under which the 802.11 station is operating are for an outdoor environment only.

* An ASCII ‘I’ character (0x49) if the regulations under which the 802.11 station is operating are for an indoor environment only.

The way the 802.11d standard specifies this all works is:

9.9.1 Operation upon entering a regulatory domain

A STA that is enabled for operation across regulatory domains shall default to passive scanning when it has lost connectivity with its ESS. Passive scanning is performed using only the receive capabilities of the station and is, thus, compatible with regulatory requirements. The timeout for determining the loss of connectivity is system dependent and beyond the scope of this standard.

When a STA enters a regulatory domain, it shall passively scan to learn at least one valid channel, i.e., a channel upon which it detects IEEE Std 802.11 frames. The Beacon frame contains information on the country code, the maximum allowable transmit power, and the channels to be used for the regulatory domain. Optionally, the Beacon frame may also include, on a periodic basis, the regulatory information that would be returned in a Probe Response frame. Once the STA has acquired the information so that it is able to meet the transmit requirements of the regulatory domain, it shall transmit a Probe Request to an AP to gain the additional regulatory domain information contained in the Probe Response frame, unless the information was previously received in a Beacon fame. The STA then has sufficient information available to configure its PHY for operation in the regulatory domain.

http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=946610&userType=inst

Note that this spec dates to 2001, so it's hardly something "new," just something that wasn't necessarily widely supported.

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