Following on yesterday post looking at the “5 reasons why 5g is the Future“:
3. IoT Technology
The article claims that the number of IoT will skyrocket in the next decade (I agree), that many of these IoT will end up in the home (sure), that they will lead to a revolution in manufacturing, agriculture and retail (it is already happening), that healthcare will be profoundly changed by IoT (yes, but there are a few more tech evolution that will lead to a revolution in Healthcare in the coming decades) including the widespread penetration of remote surgery (I’ve some doubts here, see below).
The shift from 3G to 4G brought a very important feature for IoT: 4G allows a direct IP communications, that means the possibility to have a much simpler chip (read cheaper) that can be used to establish a wireless communication and this is crucial for IoT that in many cases have to have a very low price, hence any additional cost may not be affordable.
5G is not providing any breakthrough that is relevant for IoT. Yes, it is foreseen the deployment of smaller cells (this is required by the higher frequency, particularly the ones in the 20+GHz) and in turns this leads to smaller power requirements for transmission, a huge bonus for many IoTs that have to struggle with the power budget. However this lower power requirement is a direct consequence of the size of the cell (theoretically we have an increase at the second power, as cell dimension increases, in practice it may be as high as a fourth power due to obstacles, clearly the smaller the cell the less likely there are many obstacles to signal propagation). If we were to deploy smaller 4G cells they would work as well as the 5G ones.
An advantage to some IoT is the possibility to use the 20+GHz spectrum because this means much smaller antennas, but those frequencies will not be available everywhere so it remains to be seen if IoT manufacturers will go for them (they will be mostly used for fixed wireless communication).
Another advantage is the possibility to cluster, under the 5G umbrella, Bluetooth and WiFi communications (in principle ZigBee as well) and that is surely providing a boost in connectivity options for IoT. However, if you have a WiFi or a Bluetooth coverage you can (and you do) use the gateway as a connection point to a 4G network. One could imagine that some 5G cells will embed WiFi and even Bluetooth connectivity but it is not clear if an Operator would implement this solution (since the easiest way, and cheaper for the Operator, would be to use an existing gateway to connet with its 5G network).
The boost in capacity is clearly important (see point 4) but it might be relevant for just a very little subset of IoT. The majority of them, consisting of sensors, do not need high capacity, sending short messages once in a while, and in many cases these IoT will be clustered in a local network with local processing capabilities that will aggregate and shrink the amount of data that are sent to the big network via a wireless link. This is likely to be the case in the majority of healthcare body sensors.
The final point I like to make is about telesurgery. One of the 5G selling points is its lower latency, below 10ms, 5 times better than 4G. However this latency is referred to the pure network (and considering mostly the radio parts) not taking into account the distance of the sending and receiving point. In telesurgery the distance becomes an issue and independently of the technology chosen you have to add the time it takes the electromagnetic radiation to move from A to B.
If you are transmitting from Rome to London (1,900km) you are taking about 6 ms that will have to be added to the network latency. Rome to Buenos Aires? Add 37ms.
It still seems very little extra delay, however, if you are a surgeon performing telesurgery and you want to feel the tissue you are virtually touching with your virtual scalpel you need a response time of the order of 1ms (because that is how our sense of touch works). Even assuming a telesurgery from Rome to London the reaction time due to the propagation of the electromagnetic field is 12 ms (you need to factor both ways, action and reaction). So the propagation time is the real hurdle in telesurgery. Of course you can accept to have reduced sensations but you cannot, in certain kind of surgery, accept too much decrease.
There are studies going on to create virtual presence introducing fixed time delays to overcome these issues, and when those studies will provide effective solutions than you will be able to accept delays in the order of 500ms (probably). Well, at that point using 5G or 4G won’t make that much difference.