One of the more interesting product demos/start-up ideas out there right now is Artemis and their pCell technology. They had slightly uncloaked their idea a year ago, almost by accident, but then last month their founder did a full-blown demo. Here is a link to that demo.
Once you dig into what they are proposing, it gets very interesting very quickly. I want to walk through their technology here, but I also I need to do a follow up post looking at how the company is positioning itself, because their marketing effort leaves open many questions as to how they achieve what they demonstrate.
First the basics. A common topic for me has been the idea that our wireless networks are getting pretty clogged. It is almost impossible to install a new base station in most regions now, so instead the operators are looking for ways to ‘densify’ their networks, or install a large number of much smaller pieces of equipment that cover smaller areas.
The root of the problem is that we are running out of ways to increase wireless speeds. Each advance of the wireless standard (i.e. 2G to 3G to 4G) has involved manipulating the radio waves in some new way to cram more data into the same piece of radio spectrum. A good analogy here is TV channels. Once upon a time TVs came with dials, and you had to turn the dial to switch channels. Channel 7 is ABC, Channel 4 is NBC, etc. Imagine if you could use that one channel to broadcast two channels, so you have Channel 7A is ABC and Channel 7B ABC Sports. Do that enough times and you have systems that can handle a lot of traffic, each wireless generation has split that channel many times.
We achieve this through some pretty heavy computations. The people who designed the standards (i.e. the 3GPP) have done some really clever things to achieve the speeds we have today. They do not just manipulate the channel or frequency of the signal, they also manipulate the amplitude, phase, and timing of the signal. I am running out of analogies here, but put simply the standards have found many ways to divide up the spectrum so that each phone connecting to the network gets its own signal, and that signal contains much more data than in the past.
Unfortunately, we are starting to bump up against the laws of physics. As you can imagine, as you divide up a frequency you eventually reach a point of diminishing returns where each signal gets too small to carry as much data as before you divided it up. This limit is known as Shannon’s Law, and I mention it because it features heavily in the pCell demo. Put plainly, Artemis claims that they have found a way to ‘sidestep’ (their words) Shannon’s Law, and the way they achieve this is really clever, if it works.
That’s probably enough for now. In my next post, I will look at what Artemis is proposing to get around this problem.
