Showing posts with label Ekahau. Show all posts
Showing posts with label Ekahau. Show all posts

Thursday, 7 September 2017

Ekahau’s “Game Changer”: Your New Survey BFF

The phrase “game changer” is banded around a great deal by our good friends in sales and marketing. It seems to accompany  just about every new product or service that they may introduce. Being a techie (and a rather reserved Brit), I’m not one for throwing around such emotional, bombastic language lightly. But after having been given early access to a new product from Ekahau, I’m going to say it: yes…this is a “game changer”. Read on to find out why…

(Download a PDF of this article here)


If you’re a current user of Ekahau Site Survey (or any wireless survey product come to think of it), you’ll be familiar with the ritual of assembling your survey dongle collection each time you need to perform a wireless survey.

To correctly survey, you’ll need at least two dongles gathering Wi-Fi RF data (one per band), together with one or two spectrum analysis dongles scanning both bands of the Wi-Fi spectrum.

In most cases, all of the dongles are invariably connected to USB ports of your survey laptop or tablet. But hold on…does your laptop even have that many USB ports..? No? Ah…so you’ll need a USB hub to ensure you have enough USB ports. Hmmmm…but how do you carry a USB hub festooned with adapters AND your laptop during the survey…? Well, we’re all highly skilled engineers - we can fashion something with a Velcro fixing, or maybe some carefully crafted wire twists, or even buy a cleverly designed hub holder.

Whatever your survey multi-dongle solution, it’s likely to end up looking something like this:

Figure 1 - Say goodbye to your dongle forest?

Ok, so we’ve cleverly managed to attach our survey-dongle paraphernalia to our laptop and we’re ready to survey! However, we’d better not hang around whilst doing our survey. All of those power-hungry  USB devices are going to be sucking the juice out of our laptop battery at a rate of knots, significantly shortening the amount of time we have before our laptop battery is exhausted under the strain of these unwelcome power-leeches.

Prior to commencing our survey we also, finally, have to offer up a prayer to the gods of Wi-Fi. We pray that our dongles are fully functioning, have incurred no damage from rattling around in our laptop bag and will serve us faithfully until the end of our survey. We also pray that dongles sticking out at right angles from our laptop are not going to be snapped off by one of the many employees we’ll be trying to avoid, not to mention the many other obstacles we may not notice while focused on our laptop screen (you know the ones…filing cabinets, coat stands, cubicle partitions, door frames…etc. etc.)

A Better Way

Well, I’m here to tell you that there is a new product available from Ekahau that will solve all of these issues…and more! I’ve seen the future folks in the shape of their new “Sidekick” appliance, and it could well be your new survey BFF (Best Friend Forever).

Our friends at Ekahau have put their thinking caps on and created an industry-first for the wireless surveying world. They’ve created a new “one-stop-shop” appliance for all your survey needs. They have designed and created an appliance that will replace all of your survey adapters with a single device that you simply sling over your shoulder. Imagine that! A device that replaces your spectrum and Wi-Fi dongles in a single unit! And, it gets better…imagine that it was self-powered to save your laptop battery AND only needed a single USB connection to your survey laptop or tablet!!! Excited yet..? :)

The Ekahau Sidekick

Ekahau have long been known as a very responsive company who actively solicit feedback from their customers. Not only do they solicit feedback, they actually act on it and incorporate the suggestions received in to their product. They’re also incredibly innovative, ploughing new features in to their product at rapid pace.

The new Sidekick device is a significant departure for Ekakau. They have moved from the realms of pure software development in to hardware. The new device has been designed and manufactured by Ekahau to meet the growing requirements in complexity of hardware required to effectively and efficiently perform wireless site surveys. Rather than requiring survey engineers to precariously balance a laptop festooned with a variety of dongles at all angles, they have come up with a device that is easy to use and simplifies the whole survey process.

Figure 2 – Yep, here it  is: The Sidekick
The unit itself is unlike anything you may will used for surveying before. It’s probably slightly larger than one of those larger lithium batteries you may use to charge your laptop or tablet (It comes in at just over 6.5 inches square). It’s also a similar weight. But, as it’s slung over your shoulder during use, its size and weight are not too much of an issue. 

Figure 3 - SK with standard CD case for reference

I was provided with a pre-production prototype for my assessment. I decided to put it on the scales to see how it measures up. I believe the final production model will be of similar specification:

Figure 4 - The SK weighs in at around 2lb 5oz (including strap)
Weighing in at just over 2 pounds (including the shoulder strap), it may sound like it’s a whole lot heavier that a handful of dongles, but imagine having the option of a lighter laptop with smaller batteries, or even using a Windows tablet for your survey work. Slinging the Sidekick over your shoulder and having a lighter survey platform feels like a very attractive proposition!

Figure 5 - The Sidekick artfully modelled by a very attractive model who is available for swimwear shoots

How Do I Use It?

As a techie, I must admit to having found the SK disappointingly easy to use   It literally is just a case of powering up the SK, connecting it via a single USB cable to your laptop and firing up your copy of Ekahau ESS. That’s it. Throw the SK over your shoulder and start surveying. You use ESS in exactly the same way as you’ve always used it. The adapters built-in to the SK are shown on the ESS GUI in the same way as the external adapters you will have used previously. Instead of having 2 spectrum adapters, a single dual-band spectrum adapter is included. The SK adapter display in ESS is shown below.
Figure 6 - SK adapters shown in ESS
In addition to the adapter indicators you’re used to seeing in ESS, the other addition you may notice is the battery indicator that shows how much charge the SK has left. I believe the SK is rated to perform for at least 8 hours of survey time. During my testing I didn’t get an opportunity to survey for extended periods, but I left mine switched on all day with ESS running and it lasted well over 8 hours.

The adapter configuration controls are the same as you usually expect to see in ESS, but there are new names for the SK adapters and we now only have a single, dual band spectrum adapter. 

Figure 7 - The usual adapter controls but with the SK adapters now available
Beyond these updates, ESS looks almost unchanged in terms of the user experience of driving the ESS application itself.

Figure 8 - ESS when using the Sidekick - no real change here


What’s Inside?

You may well be wondering what’s inside this new box of tricks. I don’t have any technical specs for the unit, but I can tell you what I’ve observed and managed to wheedle out of the Ekahau team.

 For Wi-Fi signal scanning, there are two adapters. One will generally run on the 2.4GHz band, and the other on the 5GHz band – this is the default behaviour when you fire up ESS with the Sidekick. These are built-in to the unit – there are no external antennas, dongles or other external attachments. I was concerned about their location and the effects of RF shielding due to internal components etc. on their performance, but am assured they are around the edge of the casing to ensure there are no propagation issues.

In addition to the Wi-F NICs, there is spectrum analysis “capability” of some type. This is another of the huge “wins” that the SK provides. Previously, spectrum scanning has been limited to the output of Metageek DBx adapters. Although they do a fine job, ESS has always been limited to the data resolution that they are able to provide. The new spectrum capability provides much higher resolution of both bands. This is obviously due to the new custom hardware that Ekahau have developed and that they now have the power to control. It’s immediately obvious from looking at the scan rates available that this is a massively enhanced capability.

I have no idea what the roadmap for this product entails, but I’d be surprised if it didn’t involve further significant enhancements in the area of spectrum analysis. The processing power that is now obviously available must provide significant options in this area.      
As mentioned previously, the SK is self-powered, so obviously has a pretty capable internal battery. Beyond this rudimentary analysis of the internals, I have little additional information. It also obviously has significant processing capability, but no details were available to me.


What does it look like?

I was provided with a beta unit for my assessment and testing. I believe the final production units will be very similar, so though it would be nice to provide a few close-up shots so that you can see what this baby looks like close up:

Figure 9 - USB cable connection, charging socket, charge indicator and heatsink (top)

Figure 10- On/off button, power on/off indicator & activity indicator
Figure 11 - Rear of Sidekick showing strap attachment options


I’ve already touched on some of the advantages that the SK will bring to my own surveying work, but I think it’s worth listing them all:
  • The SK is self-powered unit that is independent of the survey laptop. This means there will be no drain on laptop battery from the 4 passive adapters generally needed for surveying (i.e. 2 x NIC-300 & 2 x DBx). This is going to mean a much improved laptop battery life. I guess you can survey for longer with your current laptop or move to a lighter laptop or maybe even a Windows tablet?

  • The Sidekick is very easy to use. There’s no USB hub requirement and no plugging adapters in & out. You literally just plug the SK in to a USB port on your laptop and you’re good to go. No more bags of adapters, cables and velcro strips, just one unit to plug in to your survey laptop.

  • The SK has 2 matched Wi-Fi adapters that are very similar to each other in terms of tolerance and performance. When using external adapters, even adapters of the same brand and model may vary by several dB in terms of the measurements that they report. This is due to the wide tolerances that are accepted as part of their manufacturing process. This can lead to inconsistent results depending on which adapters you or your team may use. The SK adapters are manufactured to much tighter tolerances, meaning that results are subject to far less variation compared to their off-the-shelf low-tolerant counterparts. This will allow for survey data to be comparable between surveys performed by different teams or individuals (as long as they were using a Sidekick unit). I wrote at some length about this is an article earlier this year, which I suggest you check out ( For me this is one of the major game-changers that the SK provides, though many folks involved in surveying are not even aware of this issue

  • Spectrum analysis is significantly improved when using the SK compared to DBx adapters. Data resolution is massively improved which makes the ESS/SK combo a dammed fine Spectrum  Analyser in its own right, comparable with other Spectrum Analyzers at the higher end of the Wi-Fi Spec An market.

  • The ESS/SK combo provides an easier, less obtrusive survey experience. If you compare the current experience of surveying with a multitude of antennas sticking out of your laptop at a variety of angles, it provides a huge improvement in the ease of surveying. There is no more dodging obstructions, snagging passers-by or snapping off USB NICs as you mis-judge a door width. Your survey setup is far less obtrusive and easier to manoeuvre. It will attract far less attention (and accompanying inane questioning about whether you are going to improve cell phone coverage) when walking the length and breadth of any facility you are surveying.


    In addition to the benefits that it brings to the party, there are also obviously other, new aspects to consider with the introduction of the Sidekick unit.

    • Cost: Wireless surveying (certainly in the UK anyhow) is an activity that seems to be constantly subject to significant pressure in terms of the pricing of services. Organizations generally seem reticent to invest in the time that’s required to perform a comprehensive survey. They generally want it done quickly and as cheaply as possible. The organizations who provide surveying services are often expected to invest heavily in their survey equipment and software and still work at very low margins for the services they provide. The pricing of the Sidekick unit will be very important to these organizations. On top of the existing costs they incur, the SK may be quite a challenging investment for these organizations, particularly if they have sizeable engineering teams.
    • Hardware Support: Providing rapid support for the SK hardware will be a key requirement for those who make the investment in the hardware. If the unit should fail, then getting a replacement to avoid lost productivity time will be paramount. For those who are existing ESS users, they will no doubt be able to fall back to their existing dongles in the interim. However, new users without backup hardware will need to be confident that they can get a replacement unit promptly if required. Having only the SK for surveying represents a potential single point of failure that wasn’t quite so much of a concern previously.
    • Weight: The SK unit weighs in a just over 2 pounds. This isn’t a significant weight, but when you’re walking, potentially miles per day, then any additional weight is potentially unwelcome – it all adds up! My own opinion on this is that over time this will become less of a consideration. As survey laptops or tablets are refreshed, then the option of using tablets or laptops with smaller (and hence lighter) batteries will be leveraged, meaning that the overall load carried by the surveyor will be very similar to the current survey kit. If you add in the fact that the SK can be carried over the should or perhaps in a back-pack or on a belt, it feels as though the better distribution of load is, in-fact, a longer-term net benefit.
    • New Product Line: I am not, by nature, an early adopter. I like my hardware and software to be relatively mature before taking the plunge with anything new. I’ve have been stung too many times by “the latest & greatest’ offerings from larger organizations who really should do an awful lot better. Ekahau have a very good history of rapid, stable software development. Sure, they’ve had their issues, but I’ve always been able to get a workaround or fix in very reasonable timescales. However, Ekahau is known as  a software company who leverage 3rd party hardware to gather data from the “real world”. As well as introducing a brand new paradigm in terms of wireless surveying, they are also re-inventing themselves as a hardware company too. I’m not aware that they have done this through acquisition, so I assume they are creating this hardware for themselves…for the first time. The pre-production unit I was supplied performed very well. There were some issues with one or two aspects of its operation (which I’m assured will be fixed by the time it leaves the factory gates), but in the main it felt solid & reliable. Ekahau will no doubt learn a few lessons with their initial foray in to hardware development and supply, but it feels like they have done a pretty reasonable job.
    • Heat: The SK has the capability to kick out some pretty significant heat during operation. Once it has been fired up for a few minutes, the cleverly located heat-sink gets pretty warm to the touch – not enough to burn, but you could warm your hands very quickly on a cold day. This is obviously one of the trade-offs of having a self-contained piece of high-performance hardware with a high capacity battery built-in. Ekahau have done a superb job of dissipating the heat using the heatsink located on the top face of the unit. The heatsink is in the centre of the top-most face that faces away from the body of the survey engineer. Its centralized position also ensures it has minimal impact on the antennas that are located around the edges of the SK casing.

    The Future

    With the ground-breaking shift that the Sidekick provides for Wi-Fi surveying, I can’t help but think about future possibilities that it might provide. I have no concrete inside information about how the product will develop in the future, but the shift from a handful of off-the-shelf passive components to a custom-designed, self-powered device with processing capabilities obviously opens up some mouth-watering possibilities.

    The leap in capabilities around spectrum analysis is an obvious area where the product could be improved to match the capabilities of competing products. Fingerprinting of non-Wi-Fi signals to identify specific types of interferers is an obvious enhancement that would continue the “game-changing” meme for this product.

    Once you start to consider the possible applications that a self-contained, high spec unit like the SK could theoretically provide, some very exciting possibilities spring to mind. The possibilities around data storage, of new applications running on the device or perhaps offloading of some tasks to the SK unit provide some exciting possibilities for the future. It raises the question of whether lower-spec of even new form-factor survey devices could be a future option.

    This really feel likes a huge gamechanger in the market place. Obviously, in reality, the market will determine whether there is an appetite for such a device. As a Wi-Fi enthusiast, the SK is a very exciting addition to our arsenal of Wi-Fi test equipment. But, it will subject to the economic realities and the sometimes-harsh fickleness of real-world commercial organizations. There will be many “techies” like myself who will love this new concept from day one of its release. But, it will be down to the SK itself to deliver enough ROI for organizations to be willing to make the investment if it is to survive long term.


    Disclosure: I was loaned an evaluation pre-production beta unit for this review. No compensation was received for this article (though discounts or hardware donations would be most welcome  :) ).

    Thursday, 10 September 2015

    Measuring Obstruction Losses For WLAN Predictive Modelling

    I recently attended the Ekahau Certified Survey Engineer (ECSE) training course, presented by Keith Parsons. In addition to learning about using Ekahau Site Survey  (ESS), Keith also shared some valuable insights in to best practice wireless LAN design and surveying techniques. One of these insights was a best practice approach to measuring loss through obstructions and attenuation areas, such as doors, walls and warehouse racking, when gathering data for a WLAN predictive model.  In this article, I’ll share the details of that approach and some mistakes you might be making in your own measuring approach.

    Please visit the Ekahau blog site to see my guest posting for the full details on this topic.

    Monday, 12 May 2014

    Performing A WiFi Survey For A Building That Doesn't Exist (Yet)

    I was recently involved in some work for an organization that had a newly constructed building to expand their, already sizable, campus. The building was a new, state-of-the-art facility that would require ubiquitous WiFi network coverage for a range of devices, including wireless voice handsets.

    Like many organisations, they were faced with the challenge of specifying the wireless equipment that they would require long before the building had even started construction. In order to secure the funding they would need for the new wireless infrastructure components (i.e. APs, wireless controllers, licensing), they had to try to anticipate what the new wireless network would look like, taking account of the services that they would require.

    The organisation realised that they would require a few more access points than might be usually expected for basic data services over wireless, but had taken a best guess at how many APs they might require and where they might go. When we walked in to the new facility with all of the APs deployed as per their "best guess", it was immediately obvious that the APs were all too close together and there was massive co-channel interference throughout the facility. Turning off a few radios relieved some of the immediate pain, but it was obvious a major re-think of the 'design' would be required, with many APs requiring a move or even removing altogether.

    In a brand new facility that had just been handed over from the building contractor, this was definitely not good news. It's amazing how unpopular you can become when you have to move APs and juggle brand new ceiling tiles that already have holes drilled through them to for AP data cables. The same applies for breaching and making-good fire-breaks between rooms in a new-build, just because you need to move an AP between rooms to a new position.

    This experience reminded me that not everyone may have heard about predictive wireless surveying, or even if they have, they may not understand its value or how it is achieved.

    In summary, a predictive wireless survey allows complete a wireless survey of a building or area by using scaled plans of the area that requires WiFi coverage. It requires specialist survey software that allows building plans to be imported, obstructions (such as walls) to be added to the plans and 'virtual' APs to be added to the plan. The survey software then performs some very fancy calculations to give a modelled view of what the WiFi coverage of the APs might look like.

    This is obviously a great approach when having to design a wireless network for a building that hasn't even been built yet. By carefully modelling the environment that the wireless network will be deployed into, a reasonably accurate network can be designed just from building plans. This method isn't going to create a survey report with the same accuracy as a physical survey performed on-site, but it's going to give you a very good indication of the final network is likely to look like. It will certainly allow you to build a very accurate bill of materials for the final deployment.

    Although there will generally be a charge for a survey of this type, the cost is likely to be very minor compared to the costs of over or under-provisioning that a 'best guess' approach will yield. There are also the additional costs down the line around re-deployment, additional cabling, additional licensing etc. that you will avoid with a well planned design method. The cost of a predictive survey is likely to be dwarfed by the cost of an poorly designed/anticipated wireless network - this could be many thousands, or tens of thousands of dollars in wasted hardware, licensing and man-hours, compared to the very modest cost of a predictive survey.

    The one caveat I would advise when choosing a supplier to provide a you with a predictive survey (also known as a desktop survey) is to use one that uses staff with at least CWNA certifications. Many less-qualified suppliers may get hold of a copy of wireless survey software and 'give it their best shot'. But, to use the tools effectively, you really do need to understand RF propagation, WiFi design principles (such as capacity planning) and best-practice approaches (e.g. avoiding co-channel interference, hidden node issues etc.). Without wanting to labour the point too much, don't be swayed too much by suppliers who claim to have 'vendor-level' certifications that enable them to perform survey work - the vast majority still have very little in terms of survey knowledge and a pitiful level of RF ( have be warned).

    A Predictive Survey

    So, how do we actually perform a wireless survey for a building that doesn't exist yet? I'll present a number of screen-shots from the Ekahau wireless planner survey tool. The Ekahau survey tool allows both on-site surveys using a traditional "AP-on-a-stick" surveys, together with (predictive) desktop surveys that we have discussed above.

    To perform a predictive survey, one thing we absolutely must have is building plans of the area to be covered by the new wireless deployment. Without accurate building plans that can be scaled to represent the final real-world building, it is not possible to accurately model the final environment and correctly show the coverage and performance of the WiFi network.

    Once we have an electronic copy of the floor-plans for our survey area, we can import it in to the Ekahau tool. The first thing was have to do is to calibrate the plans so that we have an accurate indication of the size of the area being surveyed - this is usually done by entering a measurement for one wall of the building. Without this initial accurate measurement, the predicted coverage areas for the survey are pretty much meaningless. The software calculations for RF signal levels rely on the distance of each area on the floor plan from the access point - if the distance is incorrectly calibrated then the RF coverage will be inaccurate.

    Fig 1 - Imported Floor Plan (with calibration of one wall shown)

    In the example we're going to look at, we're going to do a very quick and dirty survey to show the principles of the predictive technique. In our case, we're going to be looking for coverage in all office areas, providing basic RF coverage down to -67dBm in all areas on the 5GHz band. We're looking for an SNR of 25dB (or better) in all areas too. A real survey would be a little more specific than this, but this will be good enough for the purposes of our example.

    The next thing we need to do is to draw in the building structure of the floor plan to build up a model which will start to reflect the actual construction of the building (as closely as we can). Walls, doors, windows, lift shafts etc. can be added across the floor plan by tracing their outline with the appropriate building material that is provided in the survey software. The survey software provides typical losses that will be experienced through each type of material so that the RF losses around the building may be calculated by the survey software.

    In our example, I've added in the outline of the building, together with some internal walls and doors (the gray and brown lines overlaid on the plan).

    Fig 2 - Floor plan with building materials added

    Once we have added in the building structure, our next step is to start to add in some access points to start to see the coverage we might achieve as we place them in various positions. The first thing that I need to do is to select the AP and antenna that I intend to deploy. The Ekahau tool has a massive range of access points and antennas to choose from. In this case, I'm going to select a Cisco AP2600i, which has an internal antenna.

    In the screen-shot below, I've placed an AP in the top left of the plan to see the coverage that it gives me. The graduated colours show the signal strength as the RF signal radiates out from the AP, going from high (green) to low (red). Where the coloured coverage pattern ends is where edge of our cell may be found - note the legend in the bottom right of the graphic which shows our -67dBm cut-off selection (which is one of our design criteria):

    Fig 3 - Initial Access point placement

    This coverage is probably a little more than I would ideally like, so I'd like to reduce the coverage area of the AP. I can quickly edit the transmit power of the AP and see the effect on coverage as I wind the power down by 3dB:

    Fig 4 - Initial Access Point Placement (reduced power)

    I can now proceed with adding a few more access points to give me the level of coverage I'm looking for. As well as adjusting the transmit power for each access point, I can also assign channel number for both the 2.4GHz and 5GHz bands. This is useful in assessing my co-channel interference, to understand if I can achieve a viable channel plan across the building.

    In the screen-shot below, you can see a number of APs placed across the floor-plan with the appropriate channels settings displayed for both bands:

    Fig 5 - All APs placed showing signal coverage for 5GHz

    Now that we've placed our APs, we can see the coverage that they would provide when deployed in these positions. We can now look at other aspects of the predicted deployment to see if it meets our design criteria. For instance, do we meet the 25dB SNR requirement across the floor? If we switch the display filter to show signal to noise ratio (SNR), we can see what the predicted SNR might look:

    Fig 6 - Signal to Noise Ratio

    Again, looking at the legend at the bottom right of the screen-shot, we can see that our lower cut-off (which is a design minimum) is set to 25dB.  The red areas show where we are close to our lower limit. Although we are close to our limit in a number of areas, we nonetheless meet the design criteria in all office areas.

    Finally, we'll do a quick check to see if our channel plan is causing any co-channel interference between access points . Co-channel interference (CCI) is caused when a coverage area has two or more APs on the same channel that may be heard by a client in that area. CCI is undesirable as it causes contention across the APs and clients within that area, lowering the overall throughput on that particular channel. In our example, we can see that we have no co-channel interference on the 5GHz band (again, note the legend showing that only 1 AP can be heard in all areas):

    Fig 7 - Co-channel Interference on 5GHz

    As this doesn't make a very interesting result, here's the same screen for the 2.4GHz band. The yellow blobs indicate where we might experience co-channel interference. We might like to look at moving our APs, adjusting power levels or maybe even turning off some of our 2.4GHz radios if we decide that this an issue for us:

    Fig 8- Co-channel Interference on 2.4GHz

    Well that's pretty much all I want to cover around doing a predictive survey. We've really only scratched the surface of what is possible with predictive surveys, but you can hopefully begin to understand how we can build a model of the RF environment for a building and then how a WiFi network would be deployed and might perform in that environment. There are many more aspects that we could consider around other factors such as capacity planning and 3 dimensional building planning (for multi-floor deployments), but we'll leave those for another time (or, even better see further examples over on the Ekahau web site)

    It has to be emphasized that the results of a predictive survey are only as good as the data that is supplied to the RF model that is built. Unless the walls and obstructions traced on the report are accurate, then the clever RF calculations performed by the survey software  to show RF coverage and other characteristics will be inaccurate. 

    A predictive survey is generally unlikely to be as accurate as a physical survey conducted on site, but it certainly provides a very good indication of what might be expected for a building that has yet to be built. This can be invaluable for putting together an initial bill of materials, together with estimates for cabling and switch infrastructure requirements for the new wireless network.

    Hopefully, this has given you a 'taster' of the value of predictive surveys for buildings that have yet to be built, or perhaps buildings that are undergoing a major refurb and are not accessible at the time when new kit needs to be specified and ordered.