How do you force a 5 GHz wifi connection?

Question

Wifi networks are often set up in dual-band mode, with the same SSID served on both 2.4 GHz and 5 GHz bands. I'd like to always use the 5 GHz band (due to interference with Bluetooth and other devices that degrades performance). How do I force Mac OS X to use the 5 GHz base station? (I do not have admin access to the network, so I can't just assign the 5 GHz network a different SSID.)

Note that this question is not asking how to force a particular flavor of 802.11, rather it is asking how to force a particular frequency band.

Answer 1

In short: you can not force a frequency band in OS X 10.9 Mavericks. (On 10.5 you could...)

You want to connect to the device using Basic Service Set Identification (BSSID) instead of the regular Service Set Identification (SSID). Connecting to a BSSID will connect you to a specific device regardless of the connection strength. Connecting to SSID will only connect you to a specific network name and if similar network names are available, it would connect to the best signal/noise ratio. It must be noted that your OS X chooses the wlan, not your router, and OS X switches to the strongest signal available (2.4GHz or 5GHz).

To find a specific SSID and BSSID combination, you can run:

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport scan

Before OSX 10.6 you could connect to a specific BSSID using:

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport --associate=XXX --bssid=YYY

Where XXX is the SSID/network name and YYY the MAC address of the base station you want to talk to.

On OS X 10.6 and beyond it is no longer possible to connect to BSSID directly. There is no known API for this and no third party Software exists that can do this. So you need to change your 5GHz SSID to a unique name or you need to go back to OS X 10.5, or you can change the 2.4GHz channel from within the router. I think these options are non-valid in your case.

UPDATE As maxim points out, you can force a frequency band and use that to fix to 5GHz.

On linux you can use iwconfig, but this tool is not available for OS X.

Answer 2

This is a partial-temporary solution. Basically, if the frequencies are on different channel numbers then it is possible to "set" the particular wifi band (worked on OSX Mavericks).

High-level overview:

1. Find the channel numbers of 5 GHz and 2.4 Ghz. Are they different? if yes proceed to step 2.
2. Set 5 GHz channel number using airport command.

Detailed instructions:

1. Open Wireless Diagnostics.app (it is located in /System/Library/CoreServices/Applications).

2. In the application menu select Window->Utilities (or press cmd+2).Utilities window should appear.

3. Select WiFi Scan from Utilities window and press Scan Now button. This will show you all available networks, info about them and your active connection.

4. Now, verify that BSSIDs of 2.4 and 5 Ghz with the same network name are on different channel numbers. If so, then most likely you can change the band by setting the channel number of the desired frequency band. Alternatively for steps 1-4, just type in the terminal

   sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport /usr/sbin/airport -s
   

5. Turn Wifi off on your computer

6. Open the Terminal.app and type:

   sudo /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport --channel=**num**
   

   where **num** is the channel number to set. This command will only work under administrator account (so make sure that you are log as an Administrator i.e. su YourAdministratorAccount)

7. Turn Wifi On and connect to the network again

8. You can check your active connection by Alt+Clicking on the WiFi icon on the OSX menu bar, re-scanning with Wireless Diagnostics or using the terminal :-).

That's all!

Answer 3

For 10.11.x, because the options for controlling the Broadcom driver are limited, you will want to first disable roaming,

sudo defaults write /Library/Preferences/com.apple.airport.opproam disabled -bool true

Then make a mesh out of maybe 1/2" chicken wire and stick it over your laptop to penalize the 2.4 GHz signal. Once you are able to connect to the 5 GHz AP,

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I

you can remove the mesh and hopefully OSX will not switch BSSID.

http://www.compliance-club.com/archive/keitharmstrong/990810n.gif

Answer 4

I've spent some time on this issue and can attest that the only way to force a computer to the 5 GHz band is set up the 5 GHz band with a separate name.

Otherwise, the computer will auto connect to 5 GHz if it's close to the access point. At 15-20 feet away depending on obstructions, the computer will connect to 2.4 GHz if you use the same SSID for each band.

Apple tech support says that's the way it is, but you could certainly contact them to see if anything has changed recently...

Sorry.

Answer 5

My work need me to force my Macbook Air to link at specific channel of 5GHz and for some reason, I can't use airport utility achieve that.

My workaround is using Airtool to force my Macbook Air wireless interface to work at specific 5GHz channel or 2.4GHz channel and channel bandwidth (20Mhz/40Mhz).

It works as my expectation and maybe it can solve part of your situation.

My Macbook Air is running OS X 10.10.

Answer 6

The only other alternative to using different network names that I've heard of is using iStumbler to manually select the 5GHz signal to connect to.

Answer 7

Solution with 2.4ghz/5ghz network with same ssid.

If you are already connected to the 2.4 ghz network, you can set just the channel on your airport card, works in latest version of macOS Sierra 10.12.3 (2017-03-19)

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport --channel=52

I've set the channel 52 which is used by my 5ghz network.

Answer 8

Most devices choose the strongest signal. So set the 5GHz AP(s) to maximum power and then just diminish the broadcast power of the 2.4GHz AP(s) until 5GHz is seen to be preferable.

The price you pay is that any 2.4-only devices will have even more problems with congestion. But perhaps escaping congestion on most devices is worth that.

Answer 9

http://www.adriangranados.com/apps/airtool

hey i got Airtool as recommended above, it works a treat as a tool for 'targeting' certain network channels, i now have my macs 'force' selecting the best channel in my household/neighbourhood zone, and the 'alt'+ airport icon shows the channels DL speeds so any necessary changes to set to different channels can be done easily in Airtool - highly recommended, free/donateware so i chipped them a few dollars as I've been annoyed by the lack of speeds at home, or rather the mac airport choosing inferior channels on a day to day basis - FWIW i logged the best and worst channels for a few weeks and assuming my neighbours don't keep switching channels nearby i should hope to get the best speeds

Answer 10

Why not use the same SSID, but give different password for 5GHz, vs 2.4GHz, that way you know what you are connecting to :D

Answer 11

Writing this as of August 2023 - Mac OS 14 Sonoma

Force 5 GHz WiFi Connection on macOS

If you're experiencing issues with your Mac connecting to the slower 2G band on routers that share SSID between 5G/2G (like the Google Wifi Nest), here's a guide to help you force a 5 GHz connection.

Identifying the 5G Channel

1. Check Current Band: Hold option and click on the wifi icon on the macOS status bar. This will display the band you are currently connected to.
2. Scan WiFi Channels: Use the following command to list all channels your WiFi is operating on:

   /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport scan
   

   From the results, identify the channels corresponding to 5G and 2G. For instance, in my case, 5G was on channel 36 and 2G was on channel 11.

Switching to the 5G Channel

Once you've identified the 5G channel (e.g., channel 36), follow these steps:

1. Turn off WiFi.
2. Run the following command, replacing 36 with your 5G channel number:

   sudo /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport -c=36
   

3. Turn WiFi back on.

Checking JoinMode Setting

It's also a good idea to check the `JoinMode` setting:

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport prefs

Ensure it's set to Preferred. If not, you can set it using:

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport prefs JoinMode=Preferred

Conclusion

With these steps, you should be able to enjoy a faster 5 GHz connection on your Mac.

Note: Always exercise caution when using sudo commands. Ensure you understand the command's purpose and potential impact.

Additional Notes

macOS (like many operating systems) has its own algorithms for choosing which WiFi band to connect to, based on a variety of factors including signal strength, interference, and past connection history. The instructions provided are a way to manually force the connection to a specific channel, but it's not a permanent solution.

Here are a few additional suggestions to help ensure a more consistent 5 GHz connection:

• Separate SSIDs: If possible, configure your router to broadcast separate SSIDs for the 2.4 GHz and 5 GHz bands. This way, you can choose to connect to the 5 GHz band explicitly.
• Router Placement: Ensure your router is placed in an optimal location. 5 GHz signals don't penetrate walls and other obstacles as well as 2.4 GHz signals. If you're closer to the router, your device is more likely to choose the 5 GHz band.
• Update Firmware: Ensure your router's firmware is up to date. Manufacturers often release updates that improve performance and connection stability.
• Network Prioritization: In the Network settings on your Mac, you can prioritize which networks to connect to first. If you have separate SSIDs for 2.4 GHz and 5 GHz, make sure the 5 GHz network is at the top of the list.
• Forget Network: If you've previously connected to both the 2.4 GHz and 5 GHz bands, forget the 2.4 GHz network in your WiFi settings to prevent your Mac from connecting to it.
• Third-Party Tools: There are third-party applications available that can give you more control over your WiFi connection on macOS. One such tool is "WiFi Explorer," which provides detailed information about networks and can help diagnose issues. Remember, while the 5 GHz band offers faster speeds, its range is shorter than the 2.4 GHz band. If you're far from the router or there are many obstacles in the way, your Mac might choose the 2.4 GHz band because it provides a more stable connection, even if it's slower.

Answer 12

There are some apps (like WiFi Scanner) that will let you join the 5GHz band in case Mac OS chose the 2.4GHz one.

Answer 13

Simple, get a router with support for band-steering. It will take care of moving your 5Ghz devices (if advertised in capability) to 5Ghz bands.

Answer 14

Lets say you want to use the same SSID on both radios (bands). This is important if you want your devices to communicate (say a printer is being shared on the 2.4 GHz via Bonjour). On the router management software, you may have the option to control how devices associate with the radios (bands). On DD-WRT for instance, you can enable MAC level filtering (allow/permit a MAC(s) or block/prevent MAC(s) from associating). In my setup, I have only allowed (Permit mode) one old legacy Apple airport to connect to my 2.4 GHz SSID. This forces the newer clients to connect to the 5 GHz radio even if the 2.4 looks tastier (better signal). Elegant enough for me. Here's a nice link on how to only permit certain devices (note, you will see both interfaces on your router): https://snaz.com/adding-security-to-your-wifi-network-with-a-mac-white-list/