Wednesday, August 29, 2018

How to test your RADIUS configuration on the Cisco 5508 controller without having APs and clients.

How to test your RADIUS configuration on the Cisco 5508 controller without having APs and clients.

Authentication problems are pretty common when configuring the WLAN controller to authenticate users on a WLAN against a RADIUS server.

When configuring the WLAN controller, you have to create the WLAN itself on the controller, and then create the RADIUS Authentication and Accounting configurations as well.  This is where most of the problems lie.  If the RADIUS keys do not match, the users will not be able to get on the WLAN.

Create the WLAN according to your requirements:

   

Create the RADIUS Authentication and Accounting configurations:

 

Go back to the WLAN and add/select the AAA servers you just created:

With the WLAN completely configured to your requirements (meaning, configure the other requirements on the other tabs for the WLAN) it is time to test.  One way would be to use an AP and a client and try to join the WLAN.  However, if you are remote, and configuring the WLANs for future deployments, not being onsite presents a challenge when testing the RADIUS configuration on the WLAN Controller.

This document assumes you are comfortable with command line access into the WLAN Controller. 

We are going to use the “test aaa radius” command to test the scenario mentioned in the paragraph above.  We are going to use a fictitious username and password of “juser” & “mypassword”.  Since we just created the WLAN, we know it is WLAN ID #5, and there is no AP Group, so we will use “default-group”.  We just created the RADIUS server configuration, and its server index is #1.

Here is the syntax of the command:

Test aaa radius username juser password mypassword wlan-id 5 apgroup default-group server-index 1

Next, you have to issue a command, “test aaa show radius” to see if everything is working correctly: (your session will tell you the command to issue, as seen here:

 

Here’s a successful authentication test output:

(Cisco Controller) >test aaa show radius

Radius Test Request

  Wlan-id........................................ 5

  ApGroup Name................................... default-group

  Server Index................................... 1

Radius Test Response

Radius Server         Retry Status

-------------         ----- ------

192.168.100.100            1   Success

Authentication Response:

  Result Code: Success

 

Here’s an unsuccessful authentication test output:

(Cisco Controller) >test aaa show radius

Radius Test Request

  Wlan-id........................................ 5

  ApGroup Name................................... default-group

  Server Index................................... 1

Radius Test Response

Radius Server         Retry Status

-------------         ----- ------

192.168.100.100            1   Success

Authentication Response:

  Result Code: Authentication failed (this is wrong username/password)

 

Here’s an unsuccessful authentication test output because controller cannot reach server:

(Cisco Controller) >test aaa show radius

Radius Test Request

  Wlan-id........................................ 5

  ApGroup Name................................... default-group

  Server Index................................... 1

Radius Test Response

Radius Server         Retry Status

-------------         ----- ------

192.168.100.100            6   No response received from server (this is self-explanatory)

Authentication Response:

  Result Code: No response received from server (this is self-explanatory)

 

Here’s how to test RADIUS Fallback:

Make sure it is configured:

Make sure both authentication servers are listed in the WLAN profile

Then go back to where we were in testing:

(Cisco Controller) >test aaa show radius

Radius Test Request

  Wlan-id........................................ 5

  ApGroup Name................................... default-group

  Server Index................................... 1

Radius Test Response

Radius Server         Retry Status

-------------         ----- ------

192.168.100.100            6   No response received from server

192.168.100.101            1   Success

Authentication Response:

  Result Code: Success

 

 

 

 

 

 

Tuesday, July 24, 2018

How to remedy the non-digitally signed driver issue with AirMagnet and Windows 10

If you’re a WLAN Engineer, you likely have a lot of Wireless tools in your arsenal.  At the last wireless conference I went to, I took the CWAP course, and we installed Omnipeek on our laptops.  Many of us had an issue where we had to configure our laptops to be able to install a driver that was not digitally signed.

 

One of my tools is AirMagnet Wi-Fi Analyzer.  I have been upgrading my toolbox and decided to install the software on my new machine, which is a Dell with Windows 10 on it.  I downloaded the same old multi-adapter kit drivers that I had done in the past, but this time the Proxim 8494 adapter was not seen when I launched it.  I looked in the Device Manager and found the dreaded exclamation point.

 

I remembered back to the CWAP class, and that we had a similar issue.  I tried the “fix” that we had done in class to no avail.  I tried everything that Google told me to do.  Still nothing.  Admitting defeat, I called Netscout support and explained my issue.

 

It turns out there is a digitally signed driver that will make this problem go away!  The gal on the other end of the conversation pointed out to me that there is a digitally signed driver on the Downloads page.  It doesn’t say “digitally signed” anywhere on the description, but it does state Windows 10.  I downloaded and installed it and it fixed the issue.   The digitally flavored driver to download is the one my red arrow is pointing to.

 

Saturday, July 21, 2018

Outdoor GPS site survey - using Ekahau ESS/GPS & Venvolt MK1

 

Most WLAN Engineers I know don’t have to do outdoor APoS surveys very often, however when you need to, this post might come in handy. 

The last time we did an outdoor survey, we used a lightweight Cisco 1532i series access point, a small PoE+ switch, a Cisco 2504 WLAN controller and a fairly large UPS to power it all.  We learned that an AC inverter plugged into a 12v power outlet in a vehicle just didn’t work for us and would not charge the UPS when driving from point A to point B.  We had to look for power outlets and drag long extension cords around – which might get damaged if people drive over them. 

This time, we changed it up a bit.  Our task was to test a Cisco 1532e series access point with an external directional antenna.  For this, we purchased the new Ventev Venvolt MK1 power supply that can supply PoE+ (802.3af & 802.3at) power to an autonomous AP that requires 802.3at power – for hours on a single charge.  We loaded the autonomous code on to the access point and then configured it like you would an autonomous AP during an APoS survey. 

We used the same old survey cart and telescoping pole that we always use, mounted everything like you would expect it to see on an outdoor wall or pole, and plugged it into the new Venvolt MK1.  A few minutes later, the AP was online and ready to go.  Here’s what the rig looked like:

 

 We configured our Ekahau ESS site survey software to do an outdoor survey.  There are a few HowTo’s floating around on how to do it.  I must admit, we spent the previous day getting ESS to work with the GPS adapter.  We had to download drivers, etcetera, and go through all the motions to get it working.  It wasn’t simply plugging in the GPS receiver and running out the door.  That said, spend the time to get all of that working first.  I used a BU-353 GPS receiver, if you are wondering.  Set an hour or two aside the day before (or longer) and get that working.  Do not wait until you are in the parking lot with your AP up high on a pole and then decide to embark on that task.  You might need access to the Internet to get the drivers, etc.  Familiarize yourself with how to use ESS with a GPS outdoors – figure out how to start and stop the survey, etc.  Practice with it at home if you live in a quiet neighborhood, or in a park, or somewhere else where someone won’t call the police on you.

When you are setting up your project, you need three locations in a triangle on your “floor plan” before you start surveying.  We were indoors when creating the project, and we figured out that when looking at maps.google.com, it was giving us the coordinates in Decimal degrees, and ESS wanted Degrees, minutes and seconds (DMS). 

We searched around and found this website to convert decimal degrees to DMS: https://www.latlong.net/lat-long-dms.html  I believe if you install Google Earth on your laptop, it will give you the requirements you need in the format ESS wants.  We didn’t want to go that route – just our preference. 

We also used the same website where we got the “floor plan” to measure the distance between two corner parking spaces, and then used that measurement in our project.  Worked beautifully. 

I cannot stress enough to set everything up before you go out on-site to do your survey!

With our project ready to go in ESS this is what we looked like: 

 Our first “driveabout” was to see how much energy would be behind the panel antenna.  We aimed the antenna to the south, put the GPS and Wi-Fi adapter on the roof of the car and started driving around.  As we expected, we had some RF propagation behind the panel antenna, seen below: 

Why is this important?  Keep in mind all the channels that we use/don’t use, and if this antenna is on a pole, it is susceptible to interference from that direction.  Since our application will be pole mounted, we mounted it on a pole to see what might happen in the installed environment.  If we were going to install this antenna on a brick wall, we would have parked our survey rig up against a brick wall and walked the other side.

For our next driveabout, we moved the survey rig to an area that had a row of small trees between the rows of parking.  I think it is rather obvious where the trees are:

The point of this is to see how far the 5 GHz signal will propagate outside, when impeded by a number of small trees.  That distance is about 100 feet.  The fewer the trees, the farther the signal goes.  We have to keep in mind that these trees are going to likely grow in the future, so if we were covering this parking lot, we would have to plan for that.  One thing to note – having trees is not necessarily a bad thing.  Having attenuation outdoors keep your cell sizes smaller – all part of a carefully crafted RF plan.

Our third test spot was closer to the road that is more like a long hallway in a building with less attenuation.  As you can see from the graphic below, the signal traveled almost twice as far in that spot:

From this testing, we learned a few things:

  • We now have a good feeling of how the antenna’s RF propagates.
  • Height and antenna down-tilt affects the size and shape of the cell.
  • Trees attenuate RF which affects the cell size.
  • We measured the 2.4 GHz cell size, which was larger, but won’t be using it for the deployment and will be turned off.
  • Outdoor site surveys attract Police cars.
  • *Keep in mind the transmit power and channel selections may increase/decrease the cell size. 

To sum it all up – a little planning at the beginning of an outdoor deployment may save a lot of time and money in the long run, since installing outdoor Wi-Fi gear can be expensive.

 

 

 

 

 

 

Monday, July 9, 2018

A Healthcare WLAN build from start to finish - and why it should be built as designed

In March of 2015, I did a blogpost “5GHz WLAN Site Survey AP power settings - What you want, don't want, and don't care about.”  In this post, our goal was to find out the best minimum and maximum transmit power setting of a particular access point’s 5 GHz radio.  That post can be found here: http://justdowifi.blogspot.com/2015/03/5ghz-wlan-site-survey-ap-power-settings_7.html

We needed to determine the Wi-Fi coverage area of the access point at a particular transmit power that was going to be deployed in a building on a large hospital campus.  This coverage area data was used to model the WLAN using Ekahau’s Site Survey software.  In the blog post from 2015, we determined that the min/max transmit power would be 8 dBm and 14 dBm, respectively, and would provide the following -67 dBm cell coverage:



When modeling a WLAN with Ekahau’s ESS software, we need to choose a wall type.  In order to properly determine wall type/attenuation value, you need to measure the attenuation of the walls/doors/floors, etc.  This technique is taught in the Ekahau ECSE class and has probably been explained in a few WLAN Engineer blogs.  In the past I used a battery powered access point, but now I use an Odroid for that job.  More on that Odroid can be found here: http://www.morefrag.com/odroid/Odroid%20WLPC%20Excercises%20%5BFinal%5D.pdf  Other WLAN Designers/Engineers are using a new and improved single board computer, which can be found here: http://www.wlanpi.com/
Basically, you need a signal source – in my case, the battery operated Odroid and something to read the signal strength on the other side of the wall.  My wall measuring kit contains an Odroid single board computer, a Leica laser measuring tool to get accurate distances, a Netscout Aircheck G2 to read the signal strength, and of course, a clipboard with the floor plans on them for me to write on.  I bought the zipper case, the foam, etcetera, and made my own carrying case with places for everything to go so that I would notice when I forgot to put something back in its place.  I find it is the easiest way to not leave some of my tools behind.  Here’s my kit:

Use the signal source and signal strength meter to measure the RF attenuation in free space (about 20-25 feet apart) and then with a wall between the source and meter.  Same goes when measuring floor attenuation – bring the meter to the room beneath you and read the signal strength.  You can do the math to figure out how much attenuation is in the wall/floor and that information can be used when modeling and designing your WLAN.  This is outlined below.

Place your signal source in an office and walk through the open door into the hallway and measure the signal with your meter.  For this example, let’s say your signal meter reads -56 dBm.  Now move your signal source to the other side of the room, away from the door, and walk back to the hallway, closing the door behind you.  While standing in the hallway, opposite from the signal source, read your meter.  If your meter now reads -59 dBm, you know that your wall has 3 decibels of attenuation.  You may find a small tripod works well for consistency when positioning your RF source.  The image shamelessly boosted from one of Devin Akin’s presentations.



You will need to annotate the wall attenuation values however you see fit.  This information will be used later, so standardize how you do it so you’ll remember what your symbols mean.  When you feel you know the attenuation value of the different kinds of walls, you can then use the data to model your WLAN design.  If you have CAD files, you can import them for your project and you can assign attenuation values of the walls at that time and always modify as needed afterwards.


We looked at the construction of the facility and determined the wall types – most all of the walls were 3 dB since this was a wing with patient rooms and construction was similar throughout.

In healthcare, wall measurements can be tricky.  Most every hospital I have designed Wi-Fi for has been under some sort of renovation at that time.  Imaging departments, Operating rooms and other areas must not be overlooked when measuring wall types – assuming the entire hospital has 3 dB walls could be a costly mistake.  Many office areas have lead in the walls because the area used to be an imaging department.  During the renovation, the lead was never removed.  MRI areas are usually enclosed with a metal mesh, and block RF from going through.

Since many hospitals use location based WLANs to triangulate assets, we typically design the facility to meet those requirements.  This usually means we start at perimeter of the facility and work our way in when designing the wireless network.  We typically design to a given signal strength (RSSI) for the RTLS solution, combined with capacity calculations from our voice and data requirements.

Many large organizations with thousands of access points never statically employ the power and channel plan that was is in the original WLAN design.  The design often turns out to be “this is what your WLAN could look like if you follow these directions,” however most organizations simply choose a channel width, channel lineup and min/max transmit power and let RRM take care of the channel plan.  This is the case with this design as well.
This WLAN was designed almost three years ago, and is now built and up and running.  The power and channel plan is being controlled by RRM, and the WLAN Validation survey was completed recently with Ekahau ESS and the Sidekick.

Here is an overview of the Network Issues from our 5 GHz, 20 MHz channel width WLAN design.  The purple areas are the areas highlighting the areas where we have overlapping channels.  Notice that most of the channel overlapping occurs in hallways or other open areas where the RF is not attenuated as much.



Here is the same Network Issues view from within ESS of the Validation Survey.  The Validation Survey is a WLAN survey of what is actually built and up and running.



You may be thinking, “hey, wait a minute! Why are they different?”  The answer is “what is deployed is not actually what was designed.”  If we take the original design and modify the channel plan to match what RRM is doing, look what happens:



Look familiar?  Of course it does!  We have now modified our WLAN design to mimic what RRM is going, and they show similar results.  This is actually good news!  This means that we got it right.  From this point on, we are going to compare our design (using RRM’s channel plan) to the validation survey to see if they are similar.  If so, we know we did our design correctly.

Let’s look at a few other views, comparing what was design to what is actually up and running.
The graphic on the left is from the APoS survey, the one on the right is from the Validation Survey.  They match – now that’s good news!


This design had a requirement for what is known as “Secondary Coverage.”  Secondary coverage is a typical requirement for VoWi-Fi handsets so they can roam properly throughout a facility.

Here is our designed Secondary Coverage:


Here is our Validation Survey’s Secondary Coverage: (They’re pretty close).


For those of you who have access to Cisco Prime Infrastructure, you may have heard WLAN Engineers state that we want to see “mostly 3’s and 4’s” on our Cisco Prime maps.  If you are curious how much power is on each access point, see my previous post on Cisco 3802i series power levels.  The post with the power levels can be found here: http://justdowifi.blogspot.com/2018/07/cisco-3802i-series-power-levels.html


Now that we have shown that our implemented wireless network matches our modified designed network by matching the design to the actual implementation, let’s see how a nicely designed network can be implemented incorrectly.  Keep in mind this is the same design we started out with.  Here’s the design at 11 dBm transmit power, UNII bands 1,2 &3, with 20 MHz channels.


First off, we’ll make it better by including more channels in the lineup.  We will incorporate some of the U-NII-1, 2a, 2c&3 channels.  Notice the channel overlap literally disappears!  The purple color indicates channel overlap.



Using the same channel lineup as the original design, I am going to “virtually” login to the WLAN controller and turn on 40 MHz channels.  Look what happens!


Keep in mind that channel overlap is not a good thing.  Reconfiguring a WLAN without actually going into the original design and running some “what-if’s” could negatively affect your wireless network.

Another thing to mention is the channel overlap doesn’t always come from your access points.  If you are in a metropolitan area with older buildings, your 40 MHz and 80 MHz channels might interfere with your neighbors across the alley and the floors above and below you, depending on the age/construction of the building.  If your access points are interfering with your neighbors that likely means their access points are interfering with yours as well. Using a 20 MHz channel plan in a dense environment may actually increase your throughput!



Saturday, July 7, 2018

Cisco 3802i series power levels

For those of you in Cisco shops and need to know the power level of the access point when on different channels, this post is for you.

This is a list of the Cisco 3802i power levels per Channel scraped from the WLAN controller.

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Friday, September 8, 2017

Using your WLPC Odroid for APoS and wall attenuation measurements

If you are a WLAN professional, you have probably heard about other Wi-Fi Engineers using wall attenuation values when modeling the WLAN during your Ekahau ESS software to design the project.  Short story, instead of using the default values in the software or doing a full AP-on-a-stick survey, the engineer takes a signal source and meter on-site and “measures” the wall attenuation to properly model and design the WLAN. 

 

I was recently on-site during construction of an extremely large, brand new hospital – with the intention of measuring the wall attenuation values since construction was at the point where we could do so.  In the past, I used a Buffalo access point that was powered by a cell phone charger – however this time I had an Odroid that I borrowed from a friend that attended the WLAN Professionals conference earlier this year.  At the conference, they built and configured an Odroid single board computer that did all kinds of nifty things that a WLAN Engineer might want.

 

If you have never been to a WLAN Professionals conference, I urge you to check it out.  Browse here for more informations.  https://www.wlanpros.com/thewlpc/

 

For more information on the odroid at the conference, here is the link:

 

https://www.wlanpros.com/maker-session-odroid-throughput-test-computer-build-configure-testing-jerry-olla-ferney-munoz-wlpc-phoenix-2017/

 

Now back to measuring wall attenuation!  In the past, I used a Buffalo access point and my Netscout Aircheck G2 to get the job done.  If you own Ekahau ESS and are not sure how to measure wall attenuation, the process of measuring walls is taught in the Ekahau ECSE class. 

 

This time, I had the Odroid on a battery, along with @WiFi_Princesa at the helm of the G2 and my Android with Wi-Fi Analyzer on my clipboard.  During the wall measuring process, I discovered that I was getting the same decibel values that I would expect if I was doing an AP-on-a-stick survey.  I did not expect the same results, since I assumed the Odroid would have a much smaller footprint than an actual enterprise access point’s coverage area.

 

That got me thinking.  I wanted to know the actual coverage area of the Odroid so I could compare it to an enterprise access point, such as a Cisco 3602i series.  When I do an AP-on-a-stick survey, I normally set my AP to channel 36, with a power level of 3.  I equate the power level of 3 to approximately 11 dBm.

 

I took the Odroid to a validation survey the following day, and set the AP on the ceiling to a 20 MHz channel width with a power level of 3.  I set the Odriod directly beneath the AP, and proceeded to do my validation survey.  After playing with the output power of the Cisco AP on the ceiling, I determined that the Odriod has the same coverage pattern as a Cisco AP on UNII-1 with power level of 3.

 

Here are the heat maps of the Cisco 3602i and the Odroid.  Conclusion – I think I can use an Odroid to simulate a Cisco 3602i’s coverage pattern when doing both APoS and wall attenuation measuring missions.

 

Here is the Cisco 3602i at  -65 dBm

 

 

 

Here is the Odroid at  -65 dBm

 

 

 

What do you think?  Will you use an Odoid to simulate an enterprise AP?