Tx Power Control (TPC)

[mdaigle]

       Does it make sense to set the controller > wireless > 802.11a/n to fixed 1 and 802.11b/g/n to fixed 2?

[Yahya Jaber]

Hi,

why would you do this? it makes sense if you have the AP's on lower power levels.

did you perform a site survey? changing the power levels to 1&2 will not make the RRM Algorithm perform correctly, and might cause coverage issues.

how does your site look like?

tell us the whole story

[Leo Laohoo]

Does it make sense to set the controller > wireless > 802.11a/n to fixed 1 and 802.11b/g/n to fixed 2?

Initially, I'd be tempted to ask you the age-old question of "why".

But now I've come to realize that not all wireless clients are built correctly.  For example, some knuckle-head have deployed ASCOM phones.  Unfortunately, ASCOM don't know how to code wireless.  This means that you have to disable automatic TPC and automatic DCA.  ASCOM wants channels and power to be HARD SET to manual.  This is just like deploying automous AP.

So, unless you have applications that require you to manually set TPC, then you have no choice.  But I'd prefer setting TPC and DCA to auto.

[Amjad Abdullah]

If there is no reason to keep them as static, why don't you set the power levels to automatic?

Rating useful replies is more useful than saying "Thank you"

[mdaigle]

This was a summer project and the site survey said that the AP's would be best to be placed in the buidlings hallways but when the students got back to campus in the fall they were lots of complations so they vendor suggested to place it all to the static levels. He also suggested to place the 

DCA Channel List for 802.11 a/n

36, 40, 44, 48, 52, 56, 60, 64, 149, 153, 157, 161

DCA Channel List for 802.11 b/g/n

1, 6, 11

which made sense to me.  But still not conformtable with the static TPC so I thought to see what others suggestions and thoughts were on the subject.

Since than I have tweeted these setting for

Channel Assignment Method - Automatic > Interval: 10 minutes > Anchor Time: 0

made the change to Channel Assignment Method - Automatic > Interval: 4 hours > Anchor Time: 8   

802.11 a/n

Avoid Foreign AP interference > enable
Avoid Cisco AP Load > enable  ---  made this change cuz what this is saying is Don't disturb APs that have many many clients on it to change and drop them.
Avoid non-802.a noise > enable

802.11 b/g/n

Avoid Foreign AP interference >  -- removed the enable cuz what this is saying is don't exclude a channel as there are only 3 for this band any way.

Avoid Cisco AP Load > enable  -- made this change cuz what this is saying is Don't disturb APs that have many many clients on it to change and drop them.

Avoid non-802.a noise > enable

I just want others thoughts on this subject as I don't have anyone as my peers to discuss it with?

Thanks.

[Scott Fella]

So there is the issue. The survey was done to provide coverage... What power level was the survey performed on. Placing APs in the hallway only and using RRM is a no go for me. You will either have to hard set the TX power or at least set the min TX power threshold to the min DB that they surveyed on. On the 2.4ghz you will have a lot of co channel interference due to the placement of the AP's in the hallways. RRM doesn't know what the coverage is in the rooms by the exterior wall. So that is my 2 cents.

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[mdaigle]

Hi Scott,

Below is the list of test equipment, site survey tools, Access Point, and Wireless Card used in the survey performed

• Tablet Mobile Laptop
o Operating System: Windows Vista, Tablet Edition
o Power Source: 4.0AHr Battery + external battery
• Cisco 1142 Access Point w/ 12v Rechargeable Portable Battery
o Manufacture: Cisco
o Model: AIR-AP1142N-A-K9
o Power: 100mW
o Data Rates Supported:
 802.11b: 1 Mbps, 2 Mbps, 5.5 Mbps , 11 Mbps,
 802.11g/a: 6, 9, 12, 18, 24, 36, 48, and 54 Mbps
 802.11n: MCS0-MCS15 (HT20/HT40)
o Antenna Gain:
 2.4GHz – 3x internal 4.0 dBi antennas
 5GHz – 3x internal 3.0 dBi antennas
o Description: 2.4/5GHz 802.11a/b/g/n Access Point w/ modular radios bays
• Orinoco 11a/b/g Combo Gold Card
o Manufacture: Proxim
o Model: 8481
o Description: 2.4-Ghz and 5-Ghz Client Card
o Power: 40mW
• Netgear 802.11a/b/g Wireless PC Card
o Manufacture: Netgear
o Model: WAG511
o Description: 2.4-Ghz and 5-Ghz Client Card
o Power: 40mW
• AirMagnet Laptop Wireless Analyzer
o Manufacture: AirMagnet
o Model: Laptop Trio version 3.0
o Description: 802.11a/b/g Analysis System

Coverage Requirements
This section is to document expected coverage throughout survey areas. The following tolerances are to be expected through all areas to be surveyed, though interference and physical constraints may leave certain areas without coverage.
1. Maintain -65dBm cell radius
2. Maintain at least 11 Mbps of available link speed at all times for data clients as well as voice clients operating on 802.11b, with data rates as great as 54Mbps for clients operating on 802.11g or 802.11a
3. Maintain an AP coverage overlap of at least 15% to 20%.
4. Maintain a minimum signal-to-noise ratio (SNR) of 25 dB
5. Deploy no more than one AP per overlapping channel set, channel separation must be greater than 19dBm

recommended these power settings:
Radio
Power Setting
802.11b – 2.4GHz
75mW
802.11g – 2.4GHz
100mW
802.11a – 5GHz
100mW

Found this doc -- Cisco Document ID: 71113 but it does not apply to the controller code that I am running 7.0.235.3

The question is the students are not happy with the wireless in the area and someone of course says lets just add more AP's which of course I believe will not help if anything will add to more of the problem of co channel interference. 

What would be nice is where can I find and read on suggestions\tips for large wireless networks that are deployed what are some good proven practices.

Learn from others and make some adjustments and see if it help instead of just adding more AP's.

Thank you.
Maria

[Scott Fella]

Surveying is a work of art I have to say. Requirements for a survey is standard but you have to understand RF. Can this survey be the issue, it can be but might not be the only problem. Can you post the show WLAN

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[mdaigle]

(WiSM-slot2-2) >show wlan summary

Number of WLANs.................................. 5

WLAN ID  WLAN Profile Name / SSID               Status    Interface Name
-------  -------------------------------------  --------  --------------------
1        airfalcon / airfalcon                  Enabled   conadmin63
2        bguest / bguest                        Enabled   conguest252
3        macfalcon / macfalcon                  Disabled  conoldfalcon244
4        gamefalcon / gamefalcon                Enabled   game248
5        wireless-testing / jarjess             Enabled   game248

(WiSM-slot2-2) >show wlan ?

      Displays the configuration of a WLAN.
apgroups       Display all AP Groups information defined in the system.
foreignAp      Displays the configuration for support of Foreign Access Points.
summary        Displays a summary of all WLANs.

(WiSM-slot2-2) >show wlan foreignAp ?

(WiSM-slot2-2) >show wlan foreignAp

Foreign AP support is not enabled.

(WiSM-slot2-2) >show wlan WLAN id

Incorrect input! Use 'show wlan [apgroups/summary//foreignAp>]'

(WiSM-slot2-2) >

(WiSM-slot2-2) >show wlan apgroups

Total Number of AP Groups........................ 2

Site Name........................................ default-group
Site Description.................................

WLAN ID          Interface          Network Admission Control          Radio Policy
-------          -----------        --------------------------         ------------
1               conadmin63           Disabled                          None
2               conguest252          Disabled                          None
3               conoldfalcon244      Disabled                          None
4               game248              Disabled                          None
5               game248              Disabled                          None

AP Name             Slots  AP Model             Ethernet MAC       Location          Port  Country  Priority
------------------  -----  -------------------  -----------------  ----------------  ----  -------  --------

Site Name........................................ milfennoanobnocnod-168
Site Description................................. mil, fen, noa, nob, noc, nod

WLAN ID          Interface          Network Admission Control          Radio Policy
-------          -----------        --------------------------         ------------

--More-- or (q)uit
1               milfennoanobnocnod-168Disabled                          None
2               conguest252          Disabled                          None
4               game248              Disabled                          None

AP Name             Slots  AP Model             Ethernet MAC       Location          Port  Country  Priority
------------------  -----  -------------------  -----------------  ----------------  ----  -------  --------
mil109-i             2     AIR-LAP1142N-A-K9    00:22:bd:18:33:ed          mil109-i  LAG   US       1
nod02                2     AIR-LAP1142N-A-K9    00:22:bd:18:34:e7             nod02  LAG   US       1
fen415               2     AIR-LAP1142N-A-K9    00:22:bd:18:52:b6            fen415  LAG   US       1
fen113               2     AIR-LAP1142N-A-K9    00:22:bd:18:52:47            fen113  LAG   US       1
fen315               2     AIR-LAP1142N-A-K9    00:22:bd:18:53:00            fen315  LAG   US       1
fen021               2     AIR-LAP1142N-A-K9    00:22:bd:18:5d:d7            fen021  LAG   US       1
fen410               2     AIR-LAP1142N-A-K9    00:22:bd:18:53:47            fen410  LAG   US       1
nod01                2     AIR-LAP1142N-A-K9    00:22:bd:18:34:d2             nod01  LAG   US       1

[George Stefanick]

Hallway designs are ugly .. Thing of the past ..

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[mdaigle]

ugly I agreed but this is what is installed and working from????