RTLS

Ekahau RTLS Solution Experience

Wireless has become a transport method for various technologies in the recent years that help realize a quicker ROI on their deployment. One of those that has over the past few years gained higher adoption rates is Real Time Location Services, or RTLS. RTLS is a means of joining traditional passive RFID technology with wireless technology. Traditional passive RFID operates on various frequencies and is most commonly known for door access cards. Inside your plastic card is a RFID chip that when it enters a magnetic field operating at the proper frequency “activates” and passes along an identifier that is used by the backend systems to grant access for example. In order for traditional RFID to work you need to have fixed readers or mobile readers located through out your facility. For example you may place a pair of readers on a doorway to know if an item or person entered or exited an area. You can also use mobile readers to quickly generate an inventory count of items located in a room. While this as been a great system for many years greater needs for efficiencies have led to the creation of wireless RFID (RTLS) technologies.

 

The idea behind RTLS is the same regardless of what tag vendor you choose to go with. Vendors will typically couple a passive style RFID tag with an active wireless component. This wireless component varies from vendor to vendor in how it relays the information to the wireless network. Our first vendor I took a look at was Ekahau. You may know them more so for their wireless Site Survey application they developed, but they are actually an RTLS company at their core. Ekahau started as an RTLS company and their engineers found that they needed to have a way to verify and calibrate a network for RTLS so their wireless Site Survey application was born.

 

The core of the Ekahau RTLS system is based on the following items:

  • Ekahau RTLS Controller (ERC)
  • Ekahau Vision
  • Ekahau T301, TSc, TS2, and HS1 tags

The Ekahau system is a multi-vendor solution that can work with a number of wireless vendors such as Cisco, Aruba, Meru, and others. There are multiple modes for the tags that allow this to be possible which is configureable by the end installer. Ekahau tags can work in a “blink” mode where they simply pass a small packet up that signals who they are, RSSI levels, and data message packets such as telemetry data for temperature. Their tags can also function in an ELP mode where they actively associate to the wireless network as a client device, this allows bi-directional communication with the tags. The tags can also function in a hybrid mode, combining these two concepts only associating to the network at a configureable interval to do maintenance updates such as configuration changes. As of this writing care needs to be taken though as the tags currently shipping at 802.11b devices and require the lower data rates (1 & 2Mbps) to be enabled. If you use the tags in CCX blink mode you will be required to have a Cisco Mobility Services Engine installed and configured on your network in order to receive the data messages.

 

The first thing you’ll want to do is setup the ERC. This is a very straightforward process simply following through the wizard answering the questions as you go. You can enable your ERC for multiple data sources such as a Cisco WLC directly, Cisco MSE, Aruba, etc. This allows you to use the same ERC for multiple vendor networks if you are running such as setup as I am in my lab. The ERC is the main database backend that stores all the location data for your tags and or wireless clients (yeah, a wireless client can be tracked as well!). You will use the Ekahau Site Survey software with the RTLS features enabled (File -> Preferences) to upload your building data to the ERC. I did find a downside to using the Cisco WLC directly, it appears that any APs you have in monitor mode only will not assist you in location services. When you use the Ekahau Site Survey tool I did not see a way to add monitor mode APs unless you flip them to local mode, perform a survey, and then flip back to monitor mode. But I’m not sure if flipping them back to monitor mode then removes them from calculations with the ERC.

 

Getting your Ekahau RTLS system up and running with tags can be cumbersome, during my initial setup I experience multiple issues trying to use the existing T301 activator as well as the new Tag Activator 3. When using the T301 activator you need to use their NIC-300 PCMCIA adapter which is a standard Atheros adapter. The activator will ask you for your ERC IP address, maintenance interval, as well as wireless network settings such as SSID, security (open, WPA2-PSK, and WEP supported), and tag IP settings. When you put the activator into activation mode you simply press the button combination for your tag to start the activation process. On a T301W (wristband tag) for example this is pressing the small button with a pin. If successful you will see the tag in the activator screen and the tag will blink its LED green 3 times. Once the tag is activated you should see it in the ERC console.

 

If you are using sensor tags the configuration/setup wasn’t as painful but required the use of a flimsy USB adapter. Ekahau provides you with a USB extension cable and a small USB to .1mm pin header. I would much rather see this be the cable with the pin header on one end and standard USB on the other with a 1m length in between. This would work better and hopefully not have random disconnects that I was experiencing with the adapter. On the HS1 and TS2 sensor tags the header is located on the outside of the tag as well as the on/off switch (make sure you turn it on!) making setup fairly quick in terms of connecting. On the TSc cube tag however the header and on/off switch is located inside the unit requiring you to disassemble the housing and pulling the bare PCB boards out. If you wonder why your TSc tag has a magnet attached to the top this is why, as you pull the top off while having the magnet sitting on top the PCB board will be pulled out of the housing for you, bizarre yes!

 

The final piece that I want to talk about is Ekahau Vision. This is the main GUI application that your end users would use to locate assets and check tag sensor data. This application is Flash HEAVY so it won’t work on Apple iPhone or iPad devices. The overall look and feel of the Vision software is very lacking. There is a lot of potential but it doesn’t seem to flow and I found it a pain to use. I would like to see a rewrite of the application using standard HTML code and not relying on Flash.

 

A major plus for Ekahau is their API. The ERC features a full access API that allows you to pretty much obtain any and all information regarding the system, this will allow you to create your own HTML based app that would be able to operate on Apple devices for example or Cisco IP Phones. This is something that I am currently looking at and hope to have some sample applications available in the future.

 

At the end of the day the Ekahau system has a lot of pros but a lot of cons as well that make it hard to operate and deploy efficiently, especially from a VAR side of things where you are trying to make a profit on the install/configuration. Ekahau has some good tags, but they are a mixture of various WiFi chip manufactures cobbled onto their tag boards which could introduce multiple sources of issues. The ERC platform performs well and is easy to setup/configure, if we can get a new Vision app and easier to activate tag process I think Ekahau could have a great product.

 

*******DISCLAIMER*******

While I was provided with an EDK for review this did not guarantee a positive review or influence the outcome of this blog post in any shape or form. The EDK was merely provided as a way to evaluate the product fully to be able to provide real world experience.

 

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Blake Krone

Blake Krone

Cisco CCIE #31229 (Wireless) and CWNE #152, all around tech junkie, code poet. Connecting people with cans and strings.

2 Comments

  1. Bryant Broder
    March 19, 2012 at 9:36 am — Reply

    Nice job Blake, your unbiased opinion was refeshing

  2. […] more details on the Ekahau RTLS solution please see our recent blog post and visit […]

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