Introduction

I worked for two years in the field of wireless networks, more specifically Wi-Fi. I’m writing this article to share my experience of this little-known area of IT, how to become an expert quickly, some tools and talk about money.

The market

Wi-Fi is everywhere these days, in offices, museums, tourist attractions, warehouses, cold storage rooms and so on. The market is therefore fairly large and dominated by big players, whether manufacturers (Cisco, Aruba, etc.) or large companies with a department dedicated to auditing and deploying Wi-Fi infrastructures for other customers, but real expertise is rare.

The company I worked for was a small one with 5 people, but it had a very wide remit, because I travelled all over France and sometimes even outside our borders (Belgium, Spain, etc.). Despite its small size, I was lucky enough to work for the Louvre, Fnac, XPO, Inter marché… Which just goes to show that this is a market with very little expertise.

Now let’s talk money 🤑 Money shouldn’t be the vector that pushes you into this field but it’s a subject that interests a lot of people so we might as well talk about it. The pain encountered by clients with their wireless network, the lack of expertise and the short-term assignments generate around €500/600 per day on average (for a single consultant and without travel expenses) but can exceed 4 figures sometimes which becomes quite substantial when you consider that I was a work-study student at the time.

But this amount comes from the fact that knowledge and skills are lacking on the market.

Skills

Wi-Fi is studied far too little in schools, and it’s practically necessary to be trained in-house or on your own. For example, on several occasions during an audit, I was the third or fourth service provider to work on the same customer’s site, and sometimes even came after the manufacturer himself because he hadn’t found anything. I always managed to find a few faults, provided I looked a little further into the infrastructure (other network equipment, virtualisation, etc.) because the problem was sometimes felt at the level of the Wi-Fi network but because of a misconfiguration of another tool or piece of equipment at a higher layer (waves are part of layer 1 of the OSI model).

In addition to the obvious Wi-Fi-related skills (the various protocols, terminal configuration, frame capture, etc.), experience in the field is extremely valuable, as you often have to investigate customer terminals in order to optimise their use, something you can’t learn any other way.

Finally, the most effective tools for studying a wireless network are proprietary software, so it’s quite difficult to learn on your own without investing your own money. Although there are trial versions, the main functions are often blocked and it will always be necessary to buy acquisition keys in order to analyse the surrounding waves.

Tools

In this section I will not talk about the basic equipment that all engineers or network administrators must have, but more about tools specific to the field.

Wave analysis is largely dominated by one player: Ekahau. This company produces and sells hardware for ‘capturing waves’ and analysing them with its software suite. Below is an illustration of a study/simulation of the layout of a new Wi-Fi network:

👇 And here is a representation of an audit phase, with the black line representing the auditor’s path:

Other equipment can be useful, such as poles and batteries for testing wave propagation:

And of course the holy grail, Wireshark, which will always be a solid tool, although I would refer you to an article to customise it to make your Wi-Fi audits easier.

Pros

In this section I’m going to tell you what I liked most about my job:

• Designing new infrastructure frequently: although audits were in the majority, design was an important part of my work. It’s always fun to do build work frequently.
• Different client contexts: between a museum, a hospital and a cold store, the needs and constraints are very different, which implies dedicated technical choices and the use of specific equipment between clients.
• Pedagogy: as explained above, few people understand how a wireless network works, which means that there is a lot of sharing of knowledge; this is always very rewarding.
• Customer contact

Cons

Now let’s get to the negative part, of course these are my feelings and I don’t pretend to share a general opinion. Here are the things I didn’t like about it:

• Too much travel: although wireless networks improve user mobility, it is necessary to travel to customers' premises for the audit phases. As I mentioned earlier, the lack of expertise means that you have to travel all over France, and even to neighbouring countries, which for me was a burden in the long run.
• The problems are often the same: layer 1 (the waves) is almost always at fault during an audit, often due to disruptive elements, poor propagation or overlapping channels. Otherwise, it’s the Wi-Fi client (terminal) that is faulty, poorly configured or not optimised.
• The lag in automation: like the network in general (despite the fact that Ansible is gaining ground), there is too little industrialisation in equipment configuration and debugging, despite the availability of APIs; but things are starting to change, so if you’re interested in the subject of Wi-Fi automation you can listen to this podcast.

The community

As you’ve probably realised, this environment is a niche area, so there aren’t many content creators. So I don’t have any French resources to recommend, but there are a few people and media that you can follow across the Atlantic:

• People: François Vergès, Rowell Dionicio
• Blog: Semfio
• Podcast: Clear to Send

Conclusion

Despite a rather negative last part, I don’t regret at all this experience, it gave me a lot in many respects, but as you may have understood I put an end to this adventure at the end of my apprenticeship for the reasons mentioned and others more personal.

I don’t have any more articles planned on this subject, but if you’re interested in the subject and want to find out more, I might be tempted. Just let me know!