It is not very often in one’s lifetime that we get to be a bystander of a revolution, and actually know the date that the revolution started. With the introduction of the new iPhone 11 family, we are all unwittingly and as of today, unknowingly watching just as a new revolution begins.
All right already – what is this next “must have” revolution that you haven’t heard of and you don’t think you’ll care about? In day-to-day vernacular it is often called WMS based upon UWB. Huh? Where-Is-My-Stuff; WMS. What is interesting about the new iPhone is that it includes a UWB chip. It uses what is called an underlay radio technology first approved by the FCC on Valentine’s Day in 2002. Over $500M of venture capital was spent in the mid-2000s to utilize this UWB spectrum – and most would say that these investments were on the wrong use cases. Ironically, the original use case for UWB is in fact the WMS one that Apple is enabling. Being able to find your stuff – with a high degree of accuracy – and while you are at it, use the radio link for some wireless data chit chat. Interestingly, due to the physics of UWB, if you recall the Shannon-Hartley theorem, channel capacity is proportional to the bandwidth of the channel multiplied by the log of the SNR+1. That means two things. First, it means UWB has the potential to carry a lot of information. It also means that if you limit the channel capacity, the power required will be extraordinarily low. Ideal for battery-powered devices – whether they are asset tags, cell phones or other mobile devices.
But what’s so special about UWB? For our purposes it communicates over a huge chunk of spectrum, at power levels lower than the RF energy leaking out of your toaster, in the form of special purpose ultra-wide “radar pulses”. You remember your college signal processing class, and the Fourier transform of a pulse and sin(x)/x stuff of course. That means you can intuit that a very sharp nanosecond-like RF pulse will propagate, bounce off an object, and on its return flight to the transmitter (your new and awesome iPhone 11 Pro Max) will have such a distinctively sharp signal edge that a chip can count the speed and time of flight within <8 inches of the location of the object. It also means that a phone can locate a known object, . . . the WMS object, that is tagged by a UWB chip; and said WMS can respond such that the phone will know precisely where it is – along the line of sight, that is. But, with a bit of trickery, it is possible to play an electronic game of “warmer, colder” and quickly locate the WMS item. For the power levels allowed under the European, US, Japanese, and other UWB rules, the distance for UWB location is limited – but, it is easy to make it work at 100 meters. Said differently, it can be an incredible form of indoor GPS; even though it won’t find the keys you left at a friend’s house.
All well and good. At first, the WMS revolution might seem a bit underwhelming. You don’t lose your keys THAT often, and you haven’t lost your phone recently. But then again, that is the type of reaction humans also had to the first wheel. Expanding our thinking a bit – how else might WMS be useful? How about finding high value assets in a hospital – like a dementia patient or a mobile X-ray machine? How about finding your car in the parking garage? How about a student pressing a panic button while crossing campus, and giving authorities ultra-accurate tracking while dynamically zooming in with video surveillance to the right location? You get the idea – there are thousands of possibilities. What if this same chip was far more power-efficient than Bluetooth or Wi-Fi, yet capable of speeds up to 25 Mbps? That could be pretty useful. If you want Google Glasses that are very low power, yet can deal with compressed high resolution video – UWB is the way to go. Aside from earbuds or AirDrop, it is hard to see where Apple will take this – but the potential is there for lots of new use cases.
None of us of course knows how Apple plans to begin this WMS revolution. It will likely start modestly. Then the ecosystem will get going. Followed by new and novel ideas and products popping up that you’ll no longer be able to live without. Then, for most humans, the thousand-year-old question of WMS will start to have a real answer. This revolution will be like the Apple app store. At first a novelty, and then one of life’s necessities. Another example: remember when Google Maps came to your phone? Now you can’t live without it. That is where the WMS revolution is going as well.