Monday, July 15, 2019

My Ekahau Sidekick offsets

 

Ekahau users that use the Sidekick have probably discovered that the Sidekick “hears” better than other devices?  How much better, you ask?

 

Since I do a lot of validation surveys, I decided to do a comparison between four devices.  The 5 GHz Vocera “communicator” badge that is deployed quite a bit in Healthcare, the “Netscout” AirCheck G2 (in parenthesis because I heard that Netscout doesn’t own that product anymore though the name is still on the box), my handy dandy Samsung Galaxy S7 Edge (that just so happens to be the platform used by a company that deploys Google Glasses), and my trusty Sidekick.

 

My main concern was “what is my Vocera offset” for doing surveys to determine if the WLAN is voice quality.  So, we took two Vocera badges and put them side by side, and during our testing, averaged the two into one measurement.  I must say this was easy, since the Vocera badges usually agreed with each other within one dB.

 

We tried not to skew the results in any way.  We didn’t look at previous results during the testing.  We didn’t look at other results and compare while testing.  We simply walked through a medical office building and randomly stopped in areas and took readings.  This was intentional, as we didn’t want to add “intelligence” into the equation.  We even took measurements in the basement, where coverage was minimal.  When complete, we added them up and divided by the number of readings.  Very simple.

 

Sometimes we throw out “highs and lows”, and average the rest.

 

When using the data we gathered, not tossing out the highs and lows, our offsets came out like this:

 

Vocera                 -11.66 db

AirCheck G2        -13.44 dB

Galaxy S7 Edge   -13.66 dB

 

When using the data we gathered, tossing out one high and one low, our offsets came out like this:

 

Vocera                 -12.00 db

AirCheck G2        -13.14 dB

Galaxy S7 Edge   -13.28 dB

 

Moving forward, I feel as though a 12 dB offset can be used in my environment when looking at the WLAN surveys with Vocera communicators in mind.

 

Actual readings walking a floor of a medical office building:

 

Ch:         Vocera  G2          S7           Sidekick

 

44           -46         -49         -55         -40

 

44           -77         -75         -76         -64

 

64           -61         -56         -56         -46

 

56           -69         -74         -76         -55

 

52           -68         -69         -74         -59

 

36           -73         -74         -75         -62

 

161        -68         -66         -60         -53

 

36           -70         -79         -76         -59

 

48           -78         -84         -90         -67        

 

 

dB Difference between each device and SK

 

Ch:         Vocera  G2          S7           Sidekick (original dB reading)

 

44           6             9             15           -40

 

44           13           11           12           -64

 

64           15           10           10           -46

 

56           14           19           11           -55

 

52           9             10           15           -59

 

36           11           12           13           -62

 

161        15           13           7             -53

 

36           11           20           17           -59

 

48           11           17           23           -67     

 

 

 

 

 

   

Monday, June 3, 2019

How to get B&W white floor plans for your survey

 

Many times I get floor plans that are not the color that I prefer.  I love black and white floor plans – I like to survey with black and white, plan when them in black and white, and if I need to upload them into a NMS, such as Cisco Prime, I fell they look much nicer as well.  I do this because I use colors for the heat maps in Ekahau Pro, and I feel this is a much cleaner look.  But how do we get them into B&W without spending a lot of time on them?

 

I wanted to share how I convert my plans to B&W when I get a colored PDF, such as the snippet of the floor plan below I received recently.  This was a PDF, and as you can see, it has a lot of red walls on there.  Using the Microsoft Snipping Tool, I snipped the floor plan from the drawing and I sanitized it quickly, removing names, etc, by using the “Custom Pen” and selecting the color white.  It takes a few minutes to figure out how to do this, but when you do, it works well.  For me it does, anyway.

 

 

Next, the floor plan needs to be saved.  I save it as a .jpg file, then close it.  Now I open it in Microsoft Paint, and then save it as a monochrome bitmap.  See below:

 

 

 

 

Now the floor plan is saved in black and white.  I close Microsoft Paint and then reopen the file again in Microsoft Paint, saving it as a .jpg.  I do this last step because I sometimes find it doesn’t upload properly into Cisco Prime.

 

This only takes a few minutes and is well worth in if you want clean black and white floor plans without spending hours and hours on them, or spending a lot of money of software that will do it for you.  There is a slight degradation on some floor plans, so you’ll have to see if this is good enough for you.

 

 

 

 

Saturday, April 13, 2019

Comparing Ekahau Connect to the laptop surveying style

I have been using Ekahau for Wi-Fi surveying for some time now, and up until last week I have been using a 13” Dell Inspiron 5000 laptop that flips into a tablet when I want it.  I connect the Ekahau Sidekick to the laptop via USB cable, sling the Sidekick over my shoulder and start walking.  Easy, right?

 

If you are unsure what a Sidekick is you can read about it here: https://www.ekahau.com/products/sidekick/overview/  Not to understate all that it can do, it has two Wi-Fi radios, a spectrum analyzer, a long lasting battery, and now it has storage available inside.  Before the Sidekick, we walked around with a USB hub hanging out of our laptops with a spectrum analyzer or two hanging off it, along with a couple of USB Wi-Fi adapters as well.  All of that was depleting the laptop battery.

 

Wi-Fi engineers are always looking for ways to lighten the load (since we do a lot of walking) when surveying.  We want longer surveying times between charging – usually starting out in the morning and hoping our batteries will last until lunch time so we can charge up.  Unfortunately our batteries rarely get fully recharged over the tiny lunch breaks we take.  Some engineers carry identical laptops with them, and survey until the battery is low then stop and save the survey, transfer it to the fully charged laptop so they can continue surveying and put the other laptop on the charger.

 

Those days are no longer necessary anymore.  Ekahau released a new product called Ekahau Connect.  This allows you to create your WLAN survey project and upload it to the cloud so you never lose your project file.  Then you use an iPad that is also linked to the cloud – it downloads your survey project file and you can now survey with an iPad and the Ekahau Sidekick.  Here’s more on Ekahau Connect:  https://www.ekahau.com/products/ekahau-connect/overview/

 

Why would you want to survey with an iPad?  It weighs less than half as much as my laptop, and is of similar size.  I bought a 12.9” iPad Pro for the job, and when sitting side by side, they look to be about the same.  The iPad, however, is much lighter and a lot easier to maneuver when walking through a building, dodging people and squeezing into areas where you want to gather a data point.  Truth be told, I probably could have purchased a smaller iPad, since it’s almost too big.

 

Since the iPad isn’t as “rugged” as my laptop, I purchased a rubber-like case for it that has a folding handle.  I had to modify it slightly to accommodate the adapter cable to connect to the Sidekick since the iPad doesn’t have the same USB connector as the laptop.  I found the rubber-like case on eBay for something like twenty bucks.

 

During the launch of the new Ekahau Connect, we heard how much better it was, so I decided to test drive it on a validation survey.  I walked the same exact floor twice – once with version 9.2.4 of Ekahau Site Survey running on my Dell laptop with the Sidekick connected, then I walked it again with the iPad and Sidekick.  Now it is time to compare – keeping in mind the same human (me) walked the floor twice.  I tried to replicate the walking path and did not try to walk any faster than I normally do. Now let’s see the results:

 

Here’s the iPad survey.  The red dots are the actual locations of the access points. I would say that is pretty accurate most of the time – within 5 feet or so.

 

 

Here’s the Dell running 9.2.4.  Not sure why the upper left red dot’s AP landed in the middle of the drawing, a good 100 feet away.  I looked at the survey path and there’s nothing funny about it.  Ignoring that, I would say that when comparing, the new Ekahau Pro 10 is more accurate with AP placement.

 

 

 

Now let’s compare walk time:

 

Here’s what the iPad survey time looked like:

 

Here’s what the laptop survey time looked like:

 

Nearly identical – which means carrying an iPad didn’t allow me to unconsciously walk any faster.  I didn’t try to walk any faster, however I can see how the iPad took me two minutes longer since I was not used to carrying an iPad.  I also had to disable the auto-rotate on the iPad since I noticed my survey would flip upside down when walking around because the iPad is so much lighter and I could carry it easier.

 

It is difficult to measure arm, wrist and general comfort when comparing the two.  I feel the iPad is much easier to survey with, for sure.  Since I didn’t survey all day, I was not able to compare battery usage, however I did notice that after having my iPad on, I used less than ten percent of my battery.  Most Sidekick owners already know that it will last for about 8 hours before it needs recharging, and the iPad appears as though it will last even longer.  I can say for certain the strain from carrying an iPad is much less than carrying my laptop.  The specs on my laptop state it is 3 pounds 6 ounces, and the iPad is a pound and a half with the rubber case.

 

My next post will be a validation of a 180,000 square foot building – we expect that survey to take all day and we will test the longevity of the iPad & Sidekick’s battery.

 

 

 

 

Saturday, April 6, 2019

Setting TPC levels for Cisco 3802 deployments

 

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

 

 

 

 

 

Sunday, March 10, 2019

My modified wifistand for APoS surveys

I just wanted to share what I have done with my WiFiStand for APoS surveys. The WiFi stand can be purchased here:  https://wifistand.com/

 

I started out years ago doing AP-on-a-Stick (AP0S) surveys and trying all kinds of mounts, etc, to get the best rig I could make.  I used to use a flexible extension for a painter’s pole, with a slight modification to keep the rig stable when raised up to a ceiling grid.  I bought some “rare earth magnets” on eBay and taped them to the extension pole so it would cling to a ceiling grid when raised up.  I did not outfit this rig so the AP would be supported by the grid by the magnets – I only used the magnets to keep the grid stable when I raised it to the ceiling so the setup would not accidentally fall over.  Here is a picture of my flexible painter’s pole clinging to a metal rail all by itself with an AP attached.

 

 

Here is what that rig looked like from the side:

 

 

After acquiring a WiFiStand, I had the idea of a modification similar to my painter’s pole rig.  Same kind of rare earth magnet stability, and a painter’s pole adapter.  Here’s what I came up with:

 

I found this paint roller with the same dimension as a ¼-20 bolt, so I purchased it.  It was under ten bucks.

 

 

I cut the rolling part off and was left with the stem:

 

 

I have a tap and die set, so I started threading the stem to ¼-20.  This only took about fifteen minutes.  It was a lot easier than I thought, to be honest.

 

 

This was the first time I have ever put thread on anything, so please don’t judge.  And to be honest, if I can do it, so can you.  It isn’t perfect, but it is my first time threading anything.  I think it definitely does the trick.

 

 

I started to screw it into the WiFi stand, and it works.  It was actually too easy.

 

 

Here is the entire rig, assembled.

 

 

Next I glued some rare earth magnets to the rig for stability, just like my old rig.  Again, this is not to hold the entire rig from the ceiling grid – it is just there to keep everything from tipping over.  I used Gorilla glue to affix magnets to both sides of the frame, and then gave it a quick coat of paint to cover up the magnets and glue.  Here it is:

 

 

Just to show how these magnets can make a rig more stable, I am going to show how strong the magnets are.  Here is the WiFi stand holding a Cisco 2802 series access point to a metal railing without any support other than the magnets.  Again, I do not recommend using magnets to support an APoS.  I simply use them to keep my rig more stable – and it works like a charm.

 

 

 

Wednesday, January 16, 2019

Comparing Ekahau Sidekick to other tools

 

 

I’m going to start this post with saying that the idea for this post came from the rssicompared.com website where I have posted some data.  This was more of “me, out in the field”, but this time I had a little extra time, a pad of paper, and some help from @WiFi_Princesa

 

We heard reports of bad Wi-Fi coverage for the Cisco 8821 series phones.  We both thought, “horsefeathers”.  Not on my watch!

 

We went onsite, and sat where the red dot is indicated below.  On the table were a few Wi-Fi clients/tools:

 

My Ekahau Sidekick

Netscout G2

Cisco 8821

Samsung S7 Edge

 

We had heard of “lousy Wi-Fi coverage” in the room with the red dot is located.  In order to prove it is not the network, we have to prove it is something else.  We made a rudimentary table of signal strength (since that is what was reported) on the devices we had with us:

 

Device:                 8821                     G2                         Sidekick                S7 Edge

 

AP #4                    -64                        -68                        -57                        -65

 

AP #5                    -70                        -75                        -65                        -72

 

AP #6                    -78                        -75                        -66                        -76

 

 

First of all, we learned that signal strength was not the problem, since we designed it for -67 dBm, and we met the requirement’s signal strength of -64 dBm.  Things are not always as they seem, since the strongest AP was #4, when you might expect one of the other two would be stronger.

 

The second thing we learned is that the farther we were from an access point, the more the results varied.

 

We also learned the Ekahau Sidekick “heard” anywhere from 5 to 10 dB better than the other devices.

 

Since all we can do is average out the set of clients, we are going to say that the Ekahau Sidekick can hear about 8dB better than some other popular devices.

 

Our next quest (in a later post) is going to see how an AP can see the other access points, since we need to know how the Cisco access points can hear each other.

 

Saturday, October 6, 2018

Comparing my Proxim 8494 to my Sidekick

This blogpost is simple.  I used to use a Proxim 8494 for surveys, now I use my Sidekick.  All I wanted to know if how my SK and Proxim 8494 compared.
I recently did a 5 GHz validation survey of a new healthcare facility WLAN with requirements of Cisco Voice and Aeroscout RTLS – only this time I walked it twice.  Once with Sidekick, once with the Proxim.  Here are the results: (I will put Proxim on left, SK on right).  I’m using Primary 5 Ghz signal strength at -65 dBm for your viewing pleasure.  Why only 5 GHz?  Ask Devin Akin…
Here's AP number one.
  
I’m not going to show every AP.  There’s no point, since my goal is to see how they compare, so I know what I am looking at.
I will now skip to another part of the building:
 
And now for another area.  Keep in mind… These surveys were done on the same day, same time (one before the other) with the same machine.  Only thing different was the survey adapter.  Same human, wearing the same ballcap and same tennis shoes.
  
 
Now that I have my results, I can clearly see that my Proxim and my Sidekick are somewhat similar in the way they receive the signals from the WLANs they are surveying/validating.
I know that many of you are like me and might have several Proxim 8494 adapters, and when surveying with them you may have seen different results.  When I discovered this, I started to use only one Proxim for validations – not two or three in a USB hub configuration, since I didn’t “trust” my multiple adapter configuration.  But that’s just me.
 
Again.  The point of this blogpost is simple. I just wanted to see how my “survey adapter” I have been using for way too many years compares to my Sidekick.  I am not trying to say “only use one Proxim for validations”, or “STOP - go buy a Sidekick immediately” (I’m sure Ekahau would like that, however).  What we all hope for is that all Sidekicks are baselined/benchmarked/created-equal.  What I mean by that is that if my Sidekick saw the WLAN at -65 dBm in a certain area, that your Sidekick will see the same thing.  I think we all know that our Proxim 8494 adapters are not exactly created equally.  I am in no way trying to say anything negative about the Proxim adapter.  I am trying to compare apples to apples, however, and I feel that apples from the same orchard/tree/harvest might taste the same.  I have a half dozen Proxim adapters, and they all seem to see the world differently – much like all the humans I know.  And you know who you are.
 
I don’t have two Sidekicks.  If I did, you can bet I would perform this same “experiment” with my SK and anyone that wanted to send me their SK for a few days.  Better put your name on it, though.
Another thing to mention:  You can always “see” how different adapters see the same exact signal – just go do rssicompared.com and take a look for yourself.  I know that all APs and clients are not created equally, and they all seem to see the world differently.  Better yet, add some data of your own!
 
My best advice:  Know your APs, know your WAN requirements, know your client adapters, know your applications.
 
There will be a Rev2 of this post.  The building has another section, and I am going to survey that three times - once with SK, once with my other Proxim, and a third time with another adapter that I have not chosen yet.  When complete, I will compare those results as well.