The next service class is that of MMTC or massive machine type communications. Also alternatively known as mIoT or massive IOT. And if you eyeball this name for a minute, massive machine type communications, you might get a sense of what it means and you will be right in most cases in that. This particular service class is meant for devices or applications that are mostly unmanned. For example, our phones or tablets are devices that we closely interact with on a daily basis. Whereas there are many other types of devices that will also benefit from network connectivity devices that human beings either don't directly interact with or interact with on a very infrequent basis. Imagine for example, your utility meter, your kitchen appliances. You certainly don't use your utility meter as often as you use your phone or tablet. Extending that use case further, imagine all the peripheral devices that exist around us. For example, our fitness tracker, smart home devices, garage door openers and apart from that many other industrial devices such as sensors, industrial camera, industrial robotic vehicles, etc. All those devices which otherwise wouldn't connect to a network under the umbrella of mMTC, those devices will now also be provided with reliable network connectivity regardless of where they are, whether they are in the home or whether they are in an industry. So the basic tenet of mMTC is to connect not just people but they're worlds in that connect not just their phones and tablets, but also connect with each other. The devices that as human beings are surrounded by on a daily basis. Even if we may not be aware of the existence of the device. mMTC is the umbrella that enables such electronic devices to communicate with the network and enter with each other. And because we are going to connect under this umbrella, many many more devices of different types than we did before. Stands to reason that the expected device density for mMTC will be significantly higher than that for EMB for example, because you might have just a few 100 phones in a given square mile or square kilometer. But imagine how many fitness trackers you would have, how many utility meters, how many kitchen appliances, how many smart home devices you will have in a given squared kilometer or a square mile. And if you do the math, even the most conservative number comes to more than a few 100,000 devices, per squared kilometer. Reasonably capped at about one million devices per squared kilometer. And the synonym that I mentioned for mMTC massive IOT, that is where it comes from. I hope all of you know what IOT internet of things that is essentially your devices communicating with each other. And once you scale that paradigm on a massive stage like one million devices in a given area, that is what leads us to the paradigm of massive IOT also known as mMTC, or massive machine type communication. Now, the fact that those million devices could be located anywhere and not just in our hands, tells us that at least some of those devices may be located far away from the nearest base station. Or they may be located in challenging coverage conditions. For example, look at your utility meter, that utility meter is likely going to be in a narrow alleyway between two houses. Or imagine fire sensor that has deployed somewhere deep inside a forest in order to detect and alert us about any wildfires. You cannot reasonably expect that those devices can have really pristine channel conditions simply because of the operating conditions that they're deployed in. The corollary of that fact is that nor can you expect anybody to go to the forest every week and recharge or change the batteries on the fire sensor that you have dropped in there. And that would indicate that that fire sensor would have to operate on the same battery supply for days or weeks or months or even years on it. And that requires us to fundamentally rethink our protocol design to make those protocols more power conservative rather than aggressive in terms of data transmissions. And that plays out well because most of these mMTC devices won't have significant data requirements. Imagine your utility meter, once again, what kind of data it would need to transmit just like what my IOT is, what time of the day it is and what is my current electrical readings? That data doesn't require more than a few mbps of throughput. However, it does require a reliable connection, no matter how challenging the coverage conditions get. And that is the reason why the fundamental emphasis of mMTC is on power conservation and simplicity of protocols instead of spirit or spectral efficiency. And given that protocols have been simplified, the mMTC devices in general tend to be very simple and low cost as compared to the devices we are used to visualizing for eMBB, such as phones or tablets.
