Monday, April 18, 2011

Cisco WCS calibrating location tracking for wireless clients

The Wireless Control System Configuration Guide goes over how to manage RF Calibration Models, but it does not however describe how long the process takes, or what exactly it entails. I will endeavor to describe the process according to how I've calibrated RF models.  I do not know if how I'm doing this is correct, this has been a matter of trial and error. You don't get the opportunity to calibrate RF deployments too often, and the number one reason for that is most likely how long it takes to complete the calibration.


I haven't had much luck using the linear calibration model, so I use the point calibration model instead. I configure my wireless card to operate as an 802.11a client for one set of point calibrations throughout the facility, then I configure it to operate as an 802.11b/g client (only) for the second pass at the calibration process.


I don't stop calibrating the floor area until I have covered the floor area with data points from one corner of the floor to the other. I don't know if this is necessary given the paragraph above, but the data collected across the floor area appears as "complete" to a customer reviewing the RF calibration.

Recently I did a full calibration of a 34,000 square foot facility. The deployment consisted of 11 3500i series CleanAir access points.  The time to calibrate from beginning to end was approximately 4 hours.  Two hours to calibrate for the 5GHz frequency, and two hours to make a second pass to calibrate for the 2.4GHz frequency. Each point calibration location sampling took at least two minutes to complete.

Neither of the design/configuration guides tells you exactly what you're supposed to do with the laptop when you're using the point collection model, unless you're really supposed to pirouette while holding the laptop. I tried to follow this example for the first calibration I did - it just ended up making me dizzy. Now I stand in one place and change the laptop orientation while changing the direction I'm facing. I've found that if I hold the laptop in the same orientation the data point collection fails quite often.

I made a video showing all the stages of the calibration process to help explain how the process is done, and the method I've used for collecting data points.


There are several important bits of information spread throughout the WCS 7.0 Configuration Guide and the Wi-Fi Location-Based Services 4.1 Design Guide.  I will list them below.

"Due to an open caveat1 concerning the use of dual-band calibration clients and performing a location calibration data collection on both bands simultaneously, it is recommended that calibration data collection be performed for each band individually at this time. When using a dual-band client, use either of the following alternatives:
1.Perform the calibration data collection using a single laptop equipped with a Cisco Aironet 802.11a/b/g Wireless CardBus Adapter (AIR-CB21AG) on each band individually. For example, proceed to disable the 5 GHz band and complete the data collection using the 2.4 GHz band only. Then, disable the 2.4 GHz band and enable the 5 GHz band, and proceed to repeat the data collection using the 5 GHz band only.
2.Perform the calibration using two people and two laptops. Each laptop should have a Cisco AIR-CB21AG and be associated to the infrastructure using a different band. The two calibration operators may operate independently; there is no need for them to visit each data point together. In this way, a complete calibration data collection can be performed across both bands in half the amount of time as option #1 above."

and

"Temporarily disable Dynamic Transmit Power Control (DTPC) prior to conducting calibration data collection. DTPC must be disabled separately for each band using either the controller GUI, the controller CLI or WCS for each controller whose registered access points are expected to participate in calibration data collection. After calibration data collection has been performed, DTPC should be re-enabled for normal production operation.

Ensure that the WLAN to which your calibration client will associate is configured to support Aironet Information Elements (Aironet IE). Doing so will enable the use of unicast radio resource measurement requests during calibration data collection for more efficient operation."

According to the WCS Configuration guide: "Only Intel and Cisco adapters have been tested. Make sure the Enable Cisco Compatible Extensions and Enable Radio Management Support are enabled in the Cisco Compatible Extension Options."

Also of note from the WCS Configuration guide: "The calibration status bar indicates data collection for the calibration as done, after roughly 50 distinct locations and 150 measurements have been gathered. For every location point saved in the calibration process, more than one data point is gathered. The progress of the calibration process is indicated by two status bars above the legend, one for 802.11b/g/n and one for 802.11a/n."


Saturday, April 2, 2011

The Impossible Project -new- PX 680 Film



The Impossible Project just celebrated their first year in business, and with that - a recent beta testing is under way of their new PX 680 color film. This color film is rated ASA 600 for all the 600 series Polaroid cameras languishing in closets all across the globe. 


I've had a Polaroid One Step Flash since the early '90s and I've been eagerly anticipating a replacement to the Polaroid 600 film.  Old stock of Polaroid 600 film can still be found on eBay, but I've been buying old stock Softtone Spectra film from The Impossible Project to help fund their quest to reverse engineer all types of Polaroid film.




I purchased a couple of packs of the PX 70 Color Shade First Flush film and got shooting with my trusty 600 camera.  I have to be honest, I was disappointed in the results.  I was hoping for the same rich colors I'd gotten with old Polaroid film, and the film from TIP wasn't quite there yet. The colors were washed out, and regardless of which camera I used (SX-70 or the 600 camera) I just didn't see the saturation of color I remembered.




The old stock Polaroid film was very contrasty and the colors were very rich and vivid. Of course when the film was freely available on store shelves, it was usually out of my price range.  I only have a few shots from all the years it was being made - I couldn't afford to buy it nearly as often as I'd like. The best series of pictures came from a trip to Mardi Gras back in 1992.




Well, all that changed today.  My shipment of the PX 680 film arrived on March 31st, but I waited to crack it open until today.  I took my 600 camera to the local Central Market grocery store. They have a great produce section full of all kinds of vibrant colors just waiting to be used for test shots.




Perhaps Saturday wasn't the best idea for this, but in any case I was able to use up the whole pack of film. I will say that the pictures develop very slowly. I'd guess that they take at least 2 minutes to completely develop. I used the 600 camera on the middle exposure setting, and all these pictures were taken indoors under grocery store lighting with the camera's flash. I shielded them from the store lighting after shooting the picture, then put them in my purse to develop while I moved on to the next subject.






The PX 680 film worked well for saturated oranges and reds. The yellows were a bit washed out, and the dark purples of the potatoes turned out a lot darker than they actually were.






The carrots looked great all lined up and tightly bound in purple rubber bands. The picture turned out a bit dark. For the next pack of film I shoot indoors, I might try moving the exposure bar over to the "light" setting so the pictures come out a bit brighter.








Overall, I think my favorite picture is of the rhubarb and radishes. The difference in the reds and purples in the bunch of radishes is noticeable, and the rhubarb is a bit out of focus. I like it.






I wanted to take a picture of the roses in the the floral section, but the lady working there told me that Central Market doesn't allow photography in the floral section, or any other section of the store for that matter. I can't imagine why. What do they care if someone snaps a picture of their plums? So as I was leaving the store I used my last shot in the garden section. Pink flowers.




I'm looking forward to the next release of PX 680 film - it is much, much closer to the Polaroid 600 film I remember. This is a remarkable accomplishment from the crew at The Impossible Project. In only a year they've been able to reverse engineer color instant film for one of the most common instant cameras ever made.

Friday, April 1, 2011

Cisco IOS Bridge link with EAP-FAST and WPAv2 security

I've setup many a bridge link in a lab environment just to test the functionality of a bridge link config.  Often I need to refer to a working configuration to determine what is wrong with a non working bridge link.  Here is a working bridge link configuration for both the ROOT and NON-ROOT bridges.

This config was used on a pair of Cisco 1242 access points where I was using the dot11 radio 0 (2.4GHz) interface for the bridge link.  The same configuration can be used on the dot11radio 1 (5GHz) interface as well, just substitute the interface name of your choosing into the following template.



The configuration commands below are all that is necessary to establish a working bridge link secured with EAP-FAST authentication and WPAv2 security.


The configuration is also sorted into the order in which the commands can be configured via the CLI over a console connection.  The commands will show up in their proper place when you execute the show run command after you've applied the configuration.  Don't forget to wr when you're done!



hostname ROOT_AP
aaa new-model
!
radius-server host [ROOT AP IP ADDRESS] auth-port 1812 acct-port 1813 key 0 [RADIUSKEY]
!
aaa group server radius [SERVER GROUP NAME]
 server [ROOT AP IP ADDRESS] auth-port 1812 acct-port 1813
!
aaa authentication login eap_methods group [SERVER GROUP NAME]
!
radius-server local
  nas [ROOT AP IP ADDRSS] key 0 [RADIUSKEY]
  user [USERNAME] password 0 [PASSWORD]
!
access-list 700 permit [NONROOT DOT11 0 INTERFACE MAC ADDRESS]   0000.0000.0000
access-list 700 deny   0000.0000.0000   ffff.ffff.ffff
!
dot11 association mac-list 700
!         
dot11 ssid [BRIDGE LINK SSID]
   vlan [VLAN NUMBER]
   authentication open eap eap_methods 
   authentication network-eap eap_methods 
   authentication key-management wpa
   infrastructure-ssid
!
interface Dot11Radio0
 !
 encryption vlan [VLAN NUMBER] mode ciphers aes-ccm 
 !
 station-role root bridge
 l2-filter bridge-group-acl
!
interface Dot11Radio0.[VLAN NUMBER]
 encapsulation dot1Q [VLAN NUMBER] native
 no ip route-cache
 bridge-group 1
 bridge-group 1 input-address-list 700
 bridge-group 1 spanning-disabled
!
interface FastEthernet0.[VLAN NUMBER]
 encapsulation dot1Q [VLAN NUMBER] native
 no ip route-cache
 bridge-group 1
 bridge-group 1 spanning-disabled
!
interface BVI1
 ip address [IP ADDRESS] [SUBNET MASK]
!
ip default-gateway [DEFAULT GATEWAY IP ADDRESS]

---------
hostname NONROOT_AP
!
eap profile [PROFILE NAME]
method fast
dot1x credentials [PROFILE NAME]
username [USERNAME]
password 0 [PASSWORD]
!
access-list 700 permit [ROOT DOT11 0 INTERFACE MAC ADDRESS]   0000.0000.0000
access-list 700 deny   0000.0000.0000   ffff.ffff.ffff
!
dot11 association mac-list 700
!
dot11 ssid [BRIDGE LINK SSID]
   vlan [VLAN NUMBER]
   authentication open eap eap_methods 
   authentication network-eap eap_methods 
   authentication key-management wpa
   dot1x credentials [PROFILE NAME]
   dot1x eap profile [PROFILE NAME]
   infrastructure-ssid
!
interface Dot11Radio0.[VLAN NUMBER]
 encapsulation dot1Q [VLAN NUMBER] native
 no ip route-cache
 bridge-group 1
 bridge-group 1 input-address-list 700
 bridge-group 1 spanning-disabled
!
interface FastEthernet0.[VLAN NUMBER]
 encapsulation dot1Q [VLAN NUMBER] native
 no ip route-cache
 bridge-group 1
 bridge-group 1 spanning-disabled
!
interface BVI1
 ip address [IP ADDRESS] [SUBNET MAKS]
!
ip default-gateway [DEFAULT GATEWAY IP ADDRESS]

Making Wireless Sexy - HourglassAire

I recently received an invite to attend a special pre-launch webinar held by a new wireless company called HourglassAire.  Their company motto is "Making Wireless Sexy" so I made sure I wasn't going to miss the webinar, cause I had no idea what they meant by that, nor how it would be possible to make wireless sexy.  I thought maybe they'd heard about Etherealmind's comments on how ugly access points were and had come up with a new antenna form factor..


To quote Hu Heff, the company founder "We've heard you loud and clear. We know access points and antennas are ugly, and we have come up with a solution to make a wireless install an attention getter and be a focal point instead of trying to hide the hardware. We know wall mounted antenna solutions aren't optimal, but we're betting you won't care." He followed up with  "We're anticipating a surge in orders for our custom antenna solution.  We call them the 36x23:35."






The HourglassAire antenna kit starts shipping today.  It includes two short antenna radomes and a craft knife set.  






For now, you can choose from either a Raquel Welch or a Catherine Bach poster, but HourglassAire has future plans to offer Natalie Portman posters for patch antenna installs.
I'm not quite sure what to make of this.  HourglassAire certainly makes the wireless deployment the focal point of any building, and one upside I can think of is that everyone would know exactly where the access points were installed. I don't think this antenna solution is suitable for every workplace environment, but I can see it being a big hit in automotive repair shops.