What OS X signal strength test apps exist to measure Wi-Fi networking?

Question

Is there a way I can get more details on the strength of my Wi-Fi signal?

I'm looking for either an app I can download or a system command that I can run in terminal that will expose the noise of other signals that aren't mine and may be occupying the same channel as my current network.

Answer 1

Apple provides two tools that most people find very adequate for normal network scanning and troubleshooting. One is graphical and the other command line based.

• /System/Library/CoreServices/Applications/Wireless\ Diagnostics.app (on newer OS) and /System/Library/CoreServices/Wi-Fi\ Diagnostics.app (on older OS)
• /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport

The former will draw a very nice graph of signal and noise for you and can perform wireless scans, Bonjour service mapping (both locally and across the internet IPv4 and IPv6), ARP, and just about anything that the normal network utility tool does except for port scanning.

I symlink the airport command into /usr/local/bin so that you can call it from any shell.

Air:~ me$ ls -l  /usr/local/bin/airport 
lrwxr-xr-x  1 root  wheel  89 Apr  4  2012 /usr/local/bin/airport -> /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport

The terminal command is more useful for scanning and changing the way your device joins networks than getting signal or noise information, but airport -I does dump details that normally are shown when you hold the option key and click on the Wi-Fi icon in the menu bar (such as MCS, RSSI, Noise, and transmit rates).

If you want more powerful tools, start with these professional quality and reasonably priced apps:

• WiFi Notifications - free and simple notifications to narrow down when significant events happen on WiFi
• WiFi Signal - runs in your menu bar
• WiFi Explorer - full analysis and nice graphs - slightly more expensive

Answer 2

You might also try iStumbler.

I use it, and it does show channels and noise.

The site describes wifi features as:

• Lists visible wireless networks with complete information.
• Inspector shows detailed information including a high-resolution graph, notes, extended properties and samples.
• Always displays the connected network, even if it's private.
• Graphically indicates network type and encryption status.
• Signal and noise graphed over time for the selected network.
• Connection monitor for connected network.

Answer 3

To simply show the strength of the WiFi network you are connected to you can alt+click on the Airport icon. Look for the text RSSI, it will show a negative number. The closer to zero it is, the stronger your signal. This answer might help you as well: https://superuser.com/questions/21827/rssi-value-of-wifi-connection-how-to-interpret

Answer 4

I usually use one of these:

• Airlock, a great freeware dashboard widget (http://www.pimley.net/projects/#airlock):

  

• Wi-Fi Diagnostics (/System/Library/CoreServices/Wi-Fi Diagnostics.app), an application included in Mac OS X since 10.7 "Lion" (see http://subrosasoft.com/blog/tips-and-tricks/hidden-wi-fi-diagnostics-tool-in-mac-os-x-10-7-lion):

  

  The WiFi scan (from File>Network Utilities) shows signal strength and noise:

  

Answer 5

I would recommend WiFi Explorer from the Mac App Store. It shows signal and noise, as well as SNR measurements for all the networks in range. It also has a nice visualization to determine channel conflict and overlapping. It's not free but it's worth the couple of bucks.

Scan, find, and troubleshoot wireless networks with WiFi Explorer.

Quickly identify channel conflicts, overlapping and other factors (e.g. configuration issues) that may be affecting the connectivity and/or performance of your wireless network in homes, offices and other sites.

Find open, ad-hoc and even rogue access points. WiFi Explorer detects 802.11a/b/g/n wireless networks and supports 2.4 and 5 GHz channel bands, as well as 20 and 40 MHz channels.

Get an insight into the network details: name (SSID), MAC address (BSSID), device manufacturer, signal strength (RSSI), noise, channel, band, security configuration, supported data rates and much more.

Monitor signal strength of each network over time and export metrics (average, maximum signal strength, etc.) and network details to CSV file format.

Answer 6

For me the easiest solution was to use terminal. It's free and there's no installation necessary.

while x=1; do /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I | grep CtlRSSI; sleep 1; done

then you'll get output like this.

 agrCtlRSSI: -74
 agrCtlRSSI: -75
 agrCtlRSSI: -74

You can then walk closer to and further from the router to see the value change. Press ctrl-c to stop.

For reference, agrCtlRSSI stands for "Aggregated Control Received Signal Strength Indicator"

-30 to -50 dBm: Excellent
-50 to -60 dBm: Good
-60 to -70 dBm: Decent
-70 and lower: Weak

Answer 7

Netspot might be what you need I got this the other day but have not had the time to use it yet. Not sure of the price now, I got it for free from the app store.

https://itunes.apple.com/us/app/netspot-wifi-survey-wireless/id514951692?mt=12

This app is designed for laptops so you can survey the area which you have to map. Hope this helps.