For a long time I was not a huge fan of predictive planning. I put this down in most part to a lack of an appropriate tool and also the influence of an employer. Much of my early design years were spent performing AP-on-a-stick RF signal readings. The good thing about having done countless surveys of this kind is the experience gained in understanding how RF is effected by different surfaces. I know first hand how walls that look the same can attenuate the RF of Wi-Fi in weird and wonderful ways, differing from one wall to the next. Also, how some windows seems to reflect signal more than others. The factual evidence you gain builds your working knowledge of how RF propagates through different spaces - and it’s all “factual" until your colleagues laptop shows wildly different results in the same exact software.
Predictive planning was thrust upon me when it was decided (by an employer) that physical presence on site was not feasible for every design. With inadequate tools this process was difficult, if not futile. The estimated signal propagation just never felt trustworthy so a conservative signal adjustment allowed for ever so slightly better educated guesswork. I wouldn’t dare try to estimate the margin of error. From a professional standpoint we know that this simply isn’t excusable, but as long as we learn from our mistakes, right?
As my design and planning work has evolved I have a huge preference for a hybrid approach. Most of the upfront planning work is done in a predictive planning tool - now i have an industry standard application - and I will always visit a site where possible to get a visual understanding for scale, construction and layout. I like to see a space and visualise areas to try and think like a client and an AP from a transmission perspective. For high AP mount positions I like to get up there and scope the coverage zone out from that point of view. This can sound pretty weird when explaining my purpose to an uninitiated person who is accompanying me on a walk-through a site. It gets even weirder when I point my arms out in varying angles to determine an appropriate directionality of an antenna. If something needs testing I’ll either rig up a generic AP for rapid testing but there is a piece of me that still yearns for an AP on a Stick test once in a while, but it’s so inconvenient. Once a deployment is done tuning can only be done with real surveyed data. Capture-test-capture and repeat if necessary. The software available today has amazing visual analysis capabilities which make channel and transmit power tuning a much more achievable task.
I look forward to the day when I can open up a case and deploy multiple miniature drones which will map out environments RF characteristics both pre and post implementation. We’re basically there technologically. Someone should productise this, I’d like to work for them!
Very High Density venue environments are my favourite to design for. There is a real mixture of adjacent and non-adjacent spaces to account for each with different capacities and mountable surfaces. The complexity and challenge of these designs make them an endless learning experience. I’ve worked on designs for convention and exhibition centres, sports stadiums, horse racing venues and auditoriums. My approach to designing these spaces has largely remained consistent over the years even though the deployed technology has changed drastically. I require many visits to site, hours analysing maps and floor plans and multiple nights of disturbed dream-filled nights of sleep with the occasional moments of epiphany. It is not uncommon for a solution to a complex design to be masterminded through sleep.
To overcome a great deal of design challenges I must acknowledge many colleagues and mentors. Through technology I have bridged international gaps and brought experts in to the environment with me with tools such as Skype and FaceTime so they can see the spaces I need to cover and observe the obstructions we can utilise. I once found an iPad application which allowed me to record a video and narration of a rudimentary sketch of an area while I explained my trigonometry based analysis of a space and how I might cover it with particular angled directional antenna. The trials of many before me has made much of the work in this space more approachable and comprehendible. Even vendor documentation is improving to allow for better communication with customers. Validated reference designs and the like really help to educate readers (both designers and customers) but also enhance dialogue surrounding expectations.
No design is truly complete without measuring the most important metric. The metric of user experience is difficult to quantify and inherently burdensome to measure. These metrics, when they are collected, should be easily correlated to performance events as monitored at an infrastructure level yet even this data, in 2017, can be hard to come by. This topic is commonly discussed in our industry's conferences and online forums and will take time and experts at all levels to solve together. Being part of this type of collaboration is the pinnacle of all the years of experience and training that we go through in our careers. It’s inspiring to meet with peers who are willing to strive openly with others to enhance outcomes.
Written by Matt Sutherland
We build and optimise networks. Continuous learning is our secret to being good. Along the learning journey we will share things here...