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Community Member

High density WLAN scenario

Hello,

Next week I'm facing a high density WLAN scenario, so I'm gathering info related to WLAN config advices, expected issues, etc. I've read Cisco WLAN High Density WLAN guide, but I'm still having questions about how my WLAN network will react to a high density scenario, i. e. auditorium with 800 seats. I'm planning 4-5 APs, maybe one in each corner and one in the middle.

My gear is Cisco WLC 5508 v7.4.100 with a mixture of 3600, 2600 and 1142 APs. I'm a bit doubtful about certain issues, related to high number of devices (specially iPhones and Android phones) trying to get connected to WLAN network. Regarding radio frequency planning, allow only high modulation levels, is there any other config I can set in order to force wireless clients to stop trying to associate to a certain AP? Is client-balancing setting working well with iPhone and Android phones?

My other concerns are about what info and graphics should I watch in real-time in Cisco Prime. Certanly, number of clients per Ap, but, anything else?If I get AP saturation, how should I react? Moving or adding APs? Rising modulation level?

Any advice will be greatly appreciated.

Kind regards,

Libera TAC team.

15 REPLIES
Bronze

High density WLAN scenario

Hi,

i would advise to go to other version than 7.4.100.0 since it has a defect for the power level on the AP.

Community Member

High density WLAN scenario

Yahya,

Can you please elaborate? What are the issues with it? I thought I had some strange ghosts with 3600 APs configured manually at certain transmit power reboot with wrong settings. Is that what you mean?

Thank you.

Bronze

High density WLAN scenario

Hi,

the issue is with TPC in the RRM, the AP's get lower power than expected, resulting a lower coverage area than expected.

and since you are using it in auditorium, then having sufficent power matters.

i am sorry i dont recall the defect exactly but i am sure its on the 7.4.100.0

Community Member

High density WLAN scenario

Use patch antenna to aim certain area, confirm the coverage one at a time.

Make sure 3 channels in 2.4GHz not overlapping

Lower Tx power, so each AP only cover smaller area.

You can set Max allowed to some AP to force client to other APs if you see necessary.

Watch backbone traffic not hitting limit.

Testing all kind client devices you can collect b4 meeting starts.

Good luck, let us know your experiences.

Community Member

High density WLAN scenario

Libera Team,

I have a similar deplyment in a month or so. During site survey I planned some of the APs below the seating raws (under the floor) and some in the corner/sides using low gain antennas. I am planning to generally follow the Cisco High Density Deployment guide.

My guess is the retransmissions is what you'd be watching for during the events. Each channel probably should reveal somewhat like 5-7% retransmissinos. As for the rest I agree with Lin: low TX, minimize CCI, force clients to other APs. All that is in the guide.


Good luck and let us know how it goes!

Community Member

High density WLAN scenario

Hi all,

Thank you very much for the tip about 7.4.100. I'm stucked in this version because of 1600 APs, should I upgrade to 7.4.110?

One more question, will load balancing work with new iPads, iPhones, high-end Androids? As far I know, first-gen iPad doesn't provide CCX extensions, but I have no info about newer models. Medical congresses are full iPads, so I think it would be my workhorse in next event.

Kind regards,

Libera TAC team.

VIP Purple

High density WLAN scenario

Yes, go for 7.4.110.0 as it is the stable code in 7.4.x.  Below link will give you some information abouts bugs we hit while we were having 7.4.100.0 & 7.4.100.60

http://mrncciew.com/2013/02/10/day-0-with-wlc-7-4-code/

Regarding load balance, I would not suggest to do that

HTH

Rasika

**** Pls rate all useful responses *****

Bronze

High density WLAN scenario

Hi,

generally the Apple are not CCX certified, you can check that from show cliet detail for any client.

and the load balancing does not require CCX certified client.

so the load balancing works the same for both CCX and non-CCX clients.

Community Member

High density WLAN scenario

Hi all,

Thank you very much for your tips, I've just finished high density scenario with no serious issues. Our two main lecture halls had two different approaches: one lecture hall with high density AP deployment (one 3600, one 2600, two 1142) and removed data rates and MCS, and the other with only two APs (one 3600 and one 1142) and no RF profile configured.

I tried to obtain reports regarding those two different approaches, and compare them, but I can't find proper Cisco Prime reporting about RSSI in time, or channel utilization in time, or any other report that could help me to determine that our first approach (the one with high density AP and removed lower data rates) is better than the second one. I think there were less people than expected, so both solutions worked, but maybe next time we're out of luck..

Kind regards,

Libera-TAC Team

Community Member

High density WLAN scenario

Hi,

Wich data rates did you disable? I have some problems on a high density scenario, I have several APs placed on a 12 floor building and I have yet disabled 1 to 11 Mbps but APs on same channel still hear each other too high even they have 3 floors between them. If I decrease transmit power, clients get low signal

best regards

Hall of Fame Super Blue

Re: High density WLAN scenario

Wich data rates did you disable?

Disable 802.11 b/g data rates up to 12 Mbps.  Make 18 Mbps as Mandatory and the rest Supported.

APs on same channel still hear each other too high even they have 3 floors between them.

Enable TPCv1 and DPC. 

Hall of Fame Super Silver

Re: High density WLAN scenario

Just to add... Explain your scenario? This topic is HD wireless. Do you have a dense wireless deployment or do you have high density of clients or both.

Can you also post your

show advanced 802.11b txpower
show advanced 802.11a txpower

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
Community Member

Re: High density WLAN scenario

I disable 1,2,5.5,6,9 and 11 Mbps, 2 to 54 are supported, TPCv1 is enable, but I´m using fixed power because the WLC assigned low power and clients get low signal. Now I´m testing an area using 1-24 Mbps as disable and 36, 48 Mbps as supported and 54 Mbps as mandatory, do you think that with this set up will we be able to manage high power level?

Here, we have serveral clients into small areas, so we have lot of APs for the amount of clients.

(Cisco Controller) >show advanced 802.11b txpower

Leader Automatic Transmit Power Assignment

  Transmit Power Assignment Mode................. AUTO

  Transmit Power Update Interval................. 600 seconds

  Transmit Power Threshold....................... -65 dBm

  Transmit Power Neighbor Count.................. 3 APs

  Min Transmit Power............................. -10 dBm

  Max Transmit Power............................. 30 dBm

  Transmit Power Update Contribution............. SNI..

  Transmit Power Assignment Leader............... WLC.MARTI.CORPO (172.17.250.50)

  Last Run....................................... 102 seconds ago

  TPC Mode....................................... Version 1

  TPCv2 Target RSSI.............................. -67 dBm

  TPCv2 VoWLAN Guide RSSI........................ -67.0 dBm

  TPCv2 SOP...................................... -85.0 dBm

  TPCv2 Default Client Ant Gain..................   0.0 dBi

  TPCv2 Path Loss Decay Factor...................   3.6

  TPCv2 Search Intensity......................... 10 Iterations

AP Name                          Channel    TxPower       Allowed Power Levels   

--More-- or (q)uit

-------------------------------- ---------- ------------- ------------------------

AP.CORPO.P11.OESTE                6          3/8 (17 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P11.NORTE               *1         *7/8 ( 5 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P11.SUR                 *1         *7/8 ( 5 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P10.NORESTE              11         6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.NORESTE               1          7/7 ( 4 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P8.SURESTE               11         6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P7.NORTE                *1         *7/8 ( 5 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P10.SURESTE              6          6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P10.SUROESTE             11         5/8 (11 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.SUROESTE              1          5/7 (10 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P6.NORESTE               6          6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P7.OESTE                 11         6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.NOROESTE              11         5/8 (11 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P6.NOROESTE              1          5/7 (10 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P6.SURESTE               1          6/7 ( 7 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P6.SUROESTE              6          5/8 (11 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P12.SUROESTE             1          4/7 (13 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P12.NOROESTE             11         4/8 (14 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P12.SURESTE              11         6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.TERRAZA.SUR              6          6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P7.SUR                  *1         *7/7 ( 4 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P9.NORTE                *6         *7/7 ( 4 dBm) [22/19/16/13/10/7/4/4]

--More-- or (q)uit

AP.CORPO.P9.SUR                  *1         *6/8 ( 8 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P9.OESTE                 1          6/7 ( 7 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P12.NORESTE              1          6/7 ( 7 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.TERRAZA.NORTE           *11        *1/8 (23 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P1.NORTE                 11        *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P1.SUR                   1         *1/7 (22 dBm) [22/19/16/13/10/7/4/4]

AP.CORPO.P10.NOROESTE             6          5/8 (11 dBm) [23/20/17/14/11/8/5/2]

(Cisco Controller) >show advanced 802.11a txpower

Leader Automatic Transmit Power Assignment

  Transmit Power Assignment Mode................. AUTO

  Transmit Power Update Interval................. 600 seconds

  Transmit Power Threshold....................... -70 dBm

  Transmit Power Neighbor Count.................. 3 APs

  Min Transmit Power............................. -10 dBm

  Max Transmit Power............................. 30 dBm

  Transmit Power Update Contribution............. SNI..

  Transmit Power Assignment Leader............... WLC.MARTI.CORPO (172.17.250.50)

  Last Run....................................... 223 seconds ago

  TPC Mode....................................... Version 1

  TPCv2 Target RSSI.............................. -67 dBm

  TPCv2 VoWLAN Guide RSSI........................ -67.0 dBm

  TPCv2 SOP...................................... -85.0 dBm

  TPCv2 Default Client Ant Gain..................   0.0 dBi

  TPCv2 Path Loss Decay Factor...................   3.6

  TPCv2 Search Intensity......................... 10 Iterations

AP Name                          Channel    TxPower       Allowed Power Levels   

--More-- or (q)uit

-------------------------------- ---------- ------------- ------------------------

AP.CORPO.P11.OESTE               *40        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P11.NORTE               *36        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P11.SUR                 *40        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P10.NORESTE             *153       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.NORESTE              *161       *3/8 (17 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.SURESTE              *40        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P7.NORTE                *48        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P10.SURESTE             *36        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P10.SUROESTE            *149       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.SUROESTE             *36        *2/5 (11 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P6.NORESTE              *153       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P7.OESTE                *149       *3/8 (17 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P8.NOROESTE             *48        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P6.NOROESTE             *161       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P6.SURESTE              *36        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P6.SUROESTE             *40        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P12.SUROESTE            *36        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P12.NOROESTE            *48        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P12.SURESTE             *161       *3/8 (17 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.TERRAZA.SUR             *157       *1/8 (23 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P7.SUR                  *157       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P9.NORTE                *40        *2/5 (11 dBm) [14/11/8/5/2/2/2/2]

--More-- or (q)uit

AP.CORPO.P9.SUR                  *161       *4/8 (14 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P9.OESTE                *153       *2/8 (20 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P12.NORESTE             *36        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.TERRAZA.NORTE           *44        *1/8 (23 dBm) [23/20/17/14/11/8/5/2]

AP.CORPO.P1.NORTE                *44        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P1.SUR                  *64        *1/5 (14 dBm) [14/11/8/5/2/2/2/2]

AP.CORPO.P10.NOROESTE            *161       *1/8 (23 dBm) [23/20/17/14/11/8/5/2]

Hall of Fame Super Silver

Re: High density WLAN scenario

Set your min tx to 9 dbi and your Max to 17. You will have to disable the radio prior to setting this.

Min Transmit Power............................. -10 dBm
Max Transmit Power............................. 30 dBm


Sent from Cisco Technical Support iPhone App

-Scott
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