In the end CDMA was approved as the 2G standard. And those solutions like DPC and the Soft handoff didn't directly cause it to become a standard, they certainly helped it to operate more efficiently once it was in practice. We should also point out a few compelling advantages of CDMA over TDMA. Which became more apparent around this time. One is a tenfold improvement over the original analogue capacity, which TDMA did not have. TDMA, if you remember only has like a three times improvement over analogue. But Coopcom was saying that CDMA had a ten times improvement and they would experiment with that and found that out from their field trials. So, it wasn't quite the 40 times that they had thought but ten times is still way better than the three times, and so they would note that, so this is one way. Another way that they said that it was better was in terms of security. [NOISE] It's very hard to listen in on someone's conversation if you don't know what their code is, because you'd have to figure that out in order to reconstruct and decrypt the message. Another one is better voice quality. So, CDMA, they were saying had better voice quality. And last but not least is longer battery life. And to see this one, just note that under a TDMA scheme, or an FDMA slash TDMA scheme, your cellphone, which is in a cell at any given time, is the only one that's currently transmitting. So, we don't share time and frequencies at the same time, so we can't have multiple users transmitting within a cell on the same frequency at the same time. So, during the time where you have the channel to yourself, you can transmit as loudly as you want to that base station. So you can, it doesn't matter because there's no one else that would be interfering with you. So, by doing this the power levels on TDMA and FDMA phones were much, much higher. And higher power level, we alluded to this briefly before, means that you have, that your battery runs out and drains much quicker. But under CDMA, we can keep the power levels much lower because we come up with a power level that works for everyone in the network, and, then that's a bigger advantage right there. So finally, in 1993, CDMA was approved by the CTIA as a 2G cellular standard. So, TDMA was still one of the standards, but CDMA then became the next one. And so, it was originally released under the name of IS-95. That was the technical name for it. With revisions that came out, IS-95A, and IS-95B. And the brand name for it was called cdmaOne. So it sounds a lot nicer to say than IS-95. And, and though we have largely moved up to 3G standards which do solely use CDMA, IS-95 and its revisions are still in use in part of the world in the 800 megahertz frequency range. So, let's briefly take a look at where we are today in terms of cellular technology. This chart shows the number of mobile subscriptions in blue, and the population in red, by year, in the United States. And it goes from 1989, back when TDMA was approved as the first 2G standard. Up until 2011, and starting around 2010 is where we started to see the emergence of 4G technology. So, you can see the drastic increase on the number of mobile subscriptions by year, since 2G and digital cellular really started to emerge. So, around year 2000, we had the emergence of the 3G standard. It keeps in tune with the idea that around every ten years, there's a call for a new standard, so in 1990 it was 2G and in 2000 it was 3G and in 2010 it was 4G more or less, roughly speaking. And 3G has two main variants that are used, UMTS, which is primarily in parts of Europe. As well as CDMA2000, which is used in the US as well as Korea primarily. What's important to note is that both of these are CDMA technologies. So, 3G is solely based on CDMA technology, and it's still widely in use today. And with the emergence of 3G technology as well as the rise of Apple into the cellular market, we saw the emergence of a smartphone. And these smartphones were really in tune with what was originally proposed as 3G standards, where a 3G cellphone was supposed to, in addition to being able to call and text. They were supposed to be able to have Internet access and be able to watch mobile TV. And do a lot of the functions that your cell phone can currently do today. And so, the rise of the smartphone came about as a result of the 3G standard. As well as the emergence of Apple, into this market. So, the number of smartphone users in the US as of 2012 was about 116 million. [SOUND]. So there are a lot of smartphone users in the US nowhere near the total number of mobile subscriptions. But by 2016, this number is expected to go up to almost 200 million. So, this is in 2012, and this is by 2016, which uuu. So, you'd see really a major increase in the amount of smartphone users that we have in the United States.
