Help with puzzling wifi range problem on Macbook Pro

My new MBP seems to be extremely finicky about the S/N ratio of the WiFi signal. I had to set the transmit power to 25% to bring the noise floor down and suddenly it works good. That one adjustment brounght my noise down from 20 to 13. Maybe open the app at

/System/Library/CoreServices/Applications/Wireless\ Diagnostics.app

use menu to open “Utilities” window and select “Performance” tab to track your S/N.

You will probably see less range but better quality signal. I don’t know if the Comcast router has a power level adjustment but worth a try. This is really a resut of such increasingly congested airwaves, as our bubble of range shrinks every year.

It could be a channel assignment issue, or other problems, I will include a number of links that may help.

AirPort Utility 6.x: Items that can interfere with a Wi-Fi network

Wi-Fi: How to troubleshoot Wi-Fi connectivity

Mac OS X 10.6: If you can’t connect to the Internet

OS X Mountain Lion: Resolve IP address conflicts

I have to say that my Comcast WiFi internet is pretty bad even under the best of circumstances. Video stalls, slow pages, audio buffering. And I am about 30 feet from the router. Please note that Comcast does not guarantee any speed over wireless, only through an ethernet cable. Which is pretty frustrating since my new Macbook doesn’t even have an ethernet port.

Since it seems the modem-router’s WiFi radio overmodulates, I guess the only solution is to buy a dedicated router and plug it into ethernet on the modem, thus bypassing the Comcast router. If I had known the situation would be this bad, I would have bought separate devices from the start.

A lot of helpful information can be gleaned by holding Option and clicking in the WiFi Icon on the menuBar, like this:

.

What do you get for Phy mode, channel, RSSI, Transmit Rate?

How many other Networks do you see?

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Make sure that you are at least 5 channels away from any others

Most people who live in neighborhoods or apartments are not blessed with so few WiFi transmitters to contend with. There are no clear channels for most people, even assuming the user knows how to optimize their router, which most people don’t.

I would also explain that I am FCC licensed amateur radio operator K5ZNextra class. I know how radios work and how electromagnetic waves behave. Every diagnostic and symptom tells me there is some incompatibility between my MBPs radio and specifically the Comcast modem-router. In another discussion I gave some technical information about the problem which I spent several day diagnosing while using two different Comcast "Docsis 3" routers.

I have not seen this WiFi problem when using Airport or other standard routers like Linksys or Netgear. The OP didn’t say what router they are using. My suspicions tell me that Apple is moving in the direction of a very sensitive power-saving radio while ISPs are trying to blast the neighborhoods with powerful WiFi. The result is that my poor Macbook can’t get a good signal.

WiFi: On

Turn Wi-Fi Off

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√ Bennet-AlderAssociates

PHY Mode: 802.11n

BSSID:

Channel: 149 (5 GHz)

Security: None

RSSI: -62

Transmit Rate: 300

MCS Index: 15

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Join Other Network

Create Network

Open Network Preferences

Open Wireless Diagnostics