Written on the Ipswich-to-London train and dispatched to silicon.com via a free wi-fi hotspot in the capital at 12.5Mbps later the same day.
We all swim in a sea of radiation from radio and TV broadcasters, mobile phones, public mobile radio, walkie-talkies, games consoles, wi-fi and much more. Monitoring where the radiation hotspots are can tell us a lot about people and sections of our society.
As I travel the planet, I periodically scan the airwaves for signals and wireless activity. This habit is usually motivated by pure interest but sometimes it allows me to diagnose connectivity problems in real time. The results are always interesting, and sometimes very surprising.
To illustrate the diversity of recent scans, I have selected four very extreme examples in the 2.4GHz wi-fi band. The first is a UK retirement community, where it would appear no one is communicating.
The second example is right at the other end of the age spectrum, with a cluster of teens and younger children online with a variety of devices. Here the electronic and verbal communication was intense, continuous and augmented by a lot of physical interaction through keyboards and screens.
The third example is a secure facility operated by a company where all communication and access was tightly controlled and monitored. Here we can see definite evidence of control. Surprisingly, it was suggested that there was no radiation on, in, or off the site.
However, I could see some activity – authorised or not – and I would guess it was for specific and specialised purposes and involved a great deal of encryption and protection.
The reality is that containing or keeping all radiation out is a really big and difficult problem. Even a Faraday cage will leak, and tinfoil is…
…very poor. In fact, it is almost impossible to get to zero emissions. Electromagnetic fields are like water – they always seem to find a way of leaking in and out.
Another fact is that just about all our electronic devices radiate – they are not designed to be transmitters as such, but they radiate all the same.
My final example is a fairly typical modern working environment in which mobile individuals operate in offices in and around a conventional building. What’s most striking about this environment is the sporadic nature of connectivity and the bursts of activity between individuals, groups and those remote from the site.
This graph highlights a few interesting aspects of the modern IT environment in almost all companies. First, there is the security nightmare of knowing who is online and what they are doing. Secondly, the capacity limitations and potential for interference and contention always present with wireless communication are clearly illustrated.
Perhaps I should point out that these pictures are just static shots of the dynamic spectra that appear on my screen. It’s interesting to watch that information as it changes because it imparts an enhanced impression of what’s actually happening.
What might we conclude here? It’s certainly possible to identify different communities in a society and their most likely activities at any given time. You can see where money is being generated, important information is held, and where commercially sensitive activities are being undertaken.
Perhaps more importantly, you can see where the bright young minds of the future are being shaped and tested by the latest technology. These youngsters are going to arrive in the workplace all trained, fired up, ready to go, and with different attitudes and expectations.
The really telling experiment in another decade will be to see if the spectrum shown in Figure 4 has mutated to something looking far more like Figure 2.