When WLANs are designed, many Wi-Fi Engineers use an AP-on-a-stick to survey the site so see how the signals propagate. Therefore, the access point needs to be set to a particular power, and that is what is usually going to be deployed as well. I have seen many Engineers use either 25mW or 50 mW for their surveys. The end goal is to match the transmit power of the access point to the transmit power of the Wi-Fi client.
When deployment time comes, they set the WLAN controller’s radio resource management (RRM) transmit power control (TPC) minimum and maximum setting to 25 mW (14 dBm) and 50 mW (17 dBm) respectively.
Since this practice has been common for the last ten years, many WLAN controllers out there are set to those numbers. This setting worked well for the Cisco 3502, 3602 & 3702s on most channels.
Screenshots of power reference charts are from Brian Long’s website at http://blong1wifiblog.blogspot.com/
As you can see, RRM will allow the access points to be at either 17 dBm or 14 dBm on most channels
And it works somewhat well for the Cisco 3702 – the AP will only have one power setting to choose from on UNII-1 channels:
Now lets take a look at the Cisco 3800 series access point. I placed a 3802i series AP on each channel and used the CLI to scrape the information to create this table.
To see the actual output from the WLC, scroll down to the end of this post.
As you can see, there are quite a few channels out of the lineup that are stuck on one power setting, since the power level sits between 14 dBm and 17 dBm, which is the min/max in the WLC. That could be a problem if you want your controller to make a power/channel plan for your deployment.
Since my goal is to allow the controller to “turn the power up or down a notch”, I looked at the other power levels and came up with a power plan that would allow two power levels for each channel. This meant I had to increase my maximum transmit power to 18 dBm, and lower my minimum transmit power to 13 dBm.
I didn’t leave channel 165 out by accident. The 3802 did not support that channel at the time of the screen scrape.
Channel 36
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 22 dBm
Tx Power Level 2 .......................... 19 dBm
Tx Power Level 3 .......................... 16 dBm
Tx Power Level 4 .......................... 13 dBm
Tx Power Level 5 .......................... 10 dBm
Tx Power Level 6 .......................... 7 dBm
Tx Power Level 7 .......................... 4 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 40
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 22 dBm
Tx Power Level 2 .......................... 19 dBm
Tx Power Level 3 .......................... 16 dBm
Tx Power Level 4 .......................... 13 dBm
Tx Power Level 5 .......................... 10 dBm
Tx Power Level 6 .......................... 7 dBm
Tx Power Level 7 .......................... 4 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 44
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 22 dBm
Tx Power Level 2 .......................... 19 dBm
Tx Power Level 3 .......................... 16 dBm
Tx Power Level 4 .......................... 13 dBm
Tx Power Level 5 .......................... 10 dBm
Tx Power Level 6 .......................... 7 dBm
Tx Power Level 7 .......................... 4 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 48
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 22 dBm
Tx Power Level 2 .......................... 19 dBm
Tx Power Level 3 .......................... 16 dBm
Tx Power Level 4 .......................... 13 dBm
Tx Power Level 5 .......................... 10 dBm
Tx Power Level 6 .......................... 7 dBm
Tx Power Level 7 .......................... 4 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 52
Tx Power
Num Of Supported Power Levels ............. 6
Tx Power Level 1 .......................... 17 dBm
Tx Power Level 2 .......................... 14 dBm
Tx Power Level 3 .......................... 11 dBm
Tx Power Level 4 .......................... 8 dBm
Tx Power Level 5 .......................... 5 dBm
Tx Power Level 6 .......................... 2 dBm
Channel 56
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 60
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 64
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 20 dBm
Tx Power Level 2 .......................... 17 dBm
Tx Power Level 3 .......................... 14 dBm
Tx Power Level 4 .......................... 11 dBm
Tx Power Level 5 .......................... 8 dBm
Tx Power Level 6 .......................... 5 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 100
Tx Power
Num Of Supported Power Levels ............. 6
Tx Power Level 1 .......................... 17 dBm
Tx Power Level 2 .......................... 14 dBm
Tx Power Level 3 .......................... 11 dBm
Tx Power Level 4 .......................... 8 dBm
Tx Power Level 5 .......................... 5 dBm
Tx Power Level 6 .......................... 2 dBm
Channel 104
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 108
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 112
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 19 dBm
Tx Power Level 2 .......................... 16 dBm
Tx Power Level 3 .......................... 13 dBm
Tx Power Level 4 .......................... 10 dBm
Tx Power Level 5 .......................... 7 dBm
Tx Power Level 6 .......................... 4 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 116
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 120
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 124
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 128
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 132
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 18 dBm
Tx Power Level 2 .......................... 15 dBm
Tx Power Level 3 .......................... 12 dBm
Tx Power Level 4 .......................... 9 dBm
Tx Power Level 5 .......................... 6 dBm
Tx Power Level 6 .......................... 3 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 136
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 20 dBm
Tx Power Level 2 .......................... 17 dBm
Tx Power Level 3 .......................... 14 dBm
Tx Power Level 4 .......................... 11 dBm
Tx Power Level 5 .......................... 8 dBm
Tx Power Level 6 .......................... 5 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 140
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 20 dBm
Tx Power Level 2 .......................... 17 dBm
Tx Power Level 3 .......................... 14 dBm
Tx Power Level 4 .......................... 11 dBm
Tx Power Level 5 .......................... 8 dBm
Tx Power Level 6 .......................... 5 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 144
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 20 dBm
Tx Power Level 2 .......................... 17 dBm
Tx Power Level 3 .......................... 14 dBm
Tx Power Level 4 .......................... 11 dBm
Tx Power Level 5 .......................... 8 dBm
Tx Power Level 6 .......................... 5 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 149
Tx Power
Num Of Supported Power Levels ............. 7
Tx Power Level 1 .......................... 19 dBm
Tx Power Level 2 .......................... 16 dBm
Tx Power Level 3 .......................... 13 dBm
Tx Power Level 4 .......................... 10 dBm
Tx Power Level 5 .......................... 7 dBm
Tx Power Level 6 .......................... 4 dBm
Tx Power Level 7 .......................... 2 dBm
Channel 153
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 23 dBm
Tx Power Level 2 .......................... 20 dBm
Tx Power Level 3 .......................... 17 dBm
Tx Power Level 4 .......................... 14 dBm
Tx Power Level 5 .......................... 11 dBm
Tx Power Level 6 .......................... 8 dBm
Tx Power Level 7 .......................... 5 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 157
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 23 dBm
Tx Power Level 2 .......................... 20 dBm
Tx Power Level 3 .......................... 17 dBm
Tx Power Level 4 .......................... 14 dBm
Tx Power Level 5 .......................... 11 dBm
Tx Power Level 6 .......................... 8 dBm
Tx Power Level 7 .......................... 5 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 161
Tx Power
Num Of Supported Power Levels ............. 8
Tx Power Level 1 .......................... 23 dBm
Tx Power Level 2 .......................... 20 dBm
Tx Power Level 3 .......................... 17 dBm
Tx Power Level 4 .......................... 14 dBm
Tx Power Level 5 .......................... 11 dBm
Tx Power Level 6 .......................... 8 dBm
Tx Power Level 7 .......................... 5 dBm
Tx Power Level 8 .......................... 2 dBm
Channel 165
Not supported
Thanks for this info - great work! My standard 5GHz TPC settings for a voice or voice/location deployment are 12dBm min and 16dBm max. I don't like seeing APs run at max power ever, and if you dig into the AP's show controller output, you'll also see that the higher powers are only supported at lower speeds or MCS rates. I'm OK with the fact that my APs only have a single supported power level on some channels (9 of the 24 channels), because I feel like the AP layout/design can accommodate the failure of a single AP (so RRM turning up an AP by 3dB really doesn't buy me much). Also, if you dig into the show controller output, check the section "Max per-path TxPower at modulation (at operation condition)". That's a real eye opener, and my takeaway is that the Cisco power levels they show in dBm are grossly oversimplified and lie to us all. Every AP after the 3502 shares this "white lie" of power output, because of the way the FCC forces the vendors to account for output power with multiple TX streams. Anyway, keep up the great work! Would love to see a follow-up on the 2.4GHz power levels, at least for channels 1/6/11. My TPC min/max recommendation for 2.4GHz is 7/14dBm, with most APs running at the bottom of that range unless half of the 2.4GHz radios are disabled. I like to keep the 5GHz radios at least 3dB stronger than 2.4GHz (and ideally more like 4-5dB stronger).
ReplyDelete☑️DO YOU WANT TO RECOVER YOUR LOST FUNDS ON BINARY OPTIONS AND BITCOIN INVESTMENTS??? OR YOU NEED A LEGIT HACKING SERVICE ?? TAKE YOUR TIME TO READ🔘
Delete☑️ The COMPOSITE CYBER SECURITY SPECIALISTS have received numerous complaints of fraud associated with websites that offers an opportunity to buy or trade binary options and bitcoin investments through Internet-based trading platforms. Most Of The complaints falls into these Two categories:
1.🔘 Refusal to credit customers accounts or reimburse funds to customers:
These complaints typically involve customers who have deposited money into their binary options trading account and who are then encouraged by “brokers” over the telephone to deposit additional funds into the customer account. When customers later attempt to withdraw their original deposit or the return they have been promised, the trading platforms allegedly cancel customers’ withdrawal requests, refuse to credit their accounts, or ignore their telephone calls and emails.
2.🔘Manipulation of software to generate losing trades:
These complaints allege that the Internet-based binary options trading platforms manipulate the trading software to distort binary options prices and payouts in order to ensure that the trade results in a Loss. For example, when a customer’s trade is “winning,” the countdown to expiration is extended arbitrarily until the trade becomes a loss.
☑️ Most people have lost their hard earned money through binary options and bitcoin investments, yet they would go to meet fake recovery Experts unknowingly to help them recover their money and they would end up losing more money in the process. This Is Basically why we (COMPOSITE CYBER SECURITY SPECIALISTS) have come to y’all victim’s rescue. The clue is most of these Binary option brokers have weak Database security, and their vulnerabilities can be exploited easily with the Help of our Special HackTools, Root HackTools And Technical Hacking Strategies because they wouldn’t wanna spend money in the sponsorship of Bug bounty Programs which would have helped protect their Database from Unauthorized access to their Database, So all our specialists do is to hack into the Broker’s Database via SQL Hook injections & DNS Spoofing, Decrypt your Transaction Details, Trace the Routes of your Deposited Funds, Then some Technical Hacking Algorithms & Execution Which we cant explain here would follow then you have your money recovered. 💰 💰 ✔️✔️
☑️All our Specialists are well experienced in their various niches with Great Skills, Technical Hacking Strategies And Positive Online Reputations And Recommendations
They hail from a proven track record and have cracked even the toughest of barriers to intrude and capture all relevant data needed by our Clients.
We have Digital Forensic Specialists, Certified Ethical Hackers, Software Engineers, Cyber Security Experts, Private investigators and more. Our Goal is to make your digital life secure, safe and hassle free by Linking you Up With these great Professionals such as JACK CABLE, ARNE SWINNEN, SEAN MELIA, DAWID CZAGAN, COSTELLO FRANK And More. These Professionals are Well Reserved Professionals who you can hardly get their audience EXCEPT you reach them through us or any Other Cyber Security Company.
All You Need to Do is to send us a mail and we’ll Assign any of these specialists to Handle your Job immediately.
☑️ Below Is A Full List Of Our Services:
* FUNDS RECOVERY ON BINARY OPTIONS AND BITCOIN INVESTMENTS
* WEBSITE HACKING
* CREDIT CARD MISHAPS
* PHONE HACKING (giving you Unnoticeable access to everything Happening on the Target’s Phone)
* CLEARING OF CRIMINAL RECORDS
* SOCIAL MEDIA ACCOUNTS HACKING
☑️ CONTACT:
••• Email:
composite.cybersecurity@protonmail.com
🔘2020 © composite cybersecurity specialists
🔘Want faster service? Contact us!
🔘All Rights Reserved ®️
I don't like seeing APs at max power either. Agree with you on lower speeds at higher power - not sure why anyone would want an indoor AP running at max power, unless there was a specific requirement for it. A proper RF design is critical when limiting ourselves to a min/max, as you well know. Unfortunately I see it all the time where no design was done, and APs were just installed with the Coke can circle on the floor plans.
ReplyDeleteI have never understood why the power levels on the controllers are done this way. I think someone decided to dumb it down a few notches - I would have preferred "the truth".
I don't have a plan to do anything with 2.4 GHz in the near future. I agree that 5 GHz should be stronger than 2.4 GHz in hopes that the clients will choose to join the 5 GHz WLAN if they SSID is configured for both bands.
thanks for sharing information,good blog..
ReplyDeleteCISCO WebEx
CISCO Video Conferencing
Meraki Wireless Access Points
Thanks to easybinarysolutions@gmail.com, I was able to recover all my stolen bitcoin lost through a fake broker. If you find yourself in a similar situation and you need professional help, don't hesitate to contact them.
ReplyDelete