So, the first place that we start to use FDMA in mobile wireless phone technology was in what we call 0G, or zero generation. And yes, that has evolved today to the 3G and 4G standards that we see. But it had to all start somewhere. And while they probably didn't call it 0G back then, we today refer to it as the 0th generation or the precursor to the first generation. So, the first 0G system was called MTS, or Mobile Telephone System, and that came about in 1946, by Bell Telephone. And this was an FTMA system, and it basically linked the mobile and the wireless communications to the telephone system, which was already established. And that's how people would make their calls. And you actually needed a physical operator. If you were on one end, you would make a call. And you would send a call to the operator, and you would tell the operator who you wanted to dial, then the operator would connect you, or make the physical connection here, between your cables so that you guys could speak. And so, then in 1964, the improved mobile telephone system came about, and that eliminated the need for an operator. That was much more convenient, because then you didn't have to have an intermediate call, where you would have to speak to the operator to have him physically connect your calls together. And so, don't be deceived, though, because back then, these mobile phones, we can't call them cellphones. You really can't call them mobile phones either, because they were really car phones. It not that you could carry around in your hands. They were very expensive, reserved for successful lawyers, rich movie stars people on those sorts and nothing that you could carry around by today's standards. They would be sitting in your, in your vehicles. And this is actually a 0G phone here that would have plugged into the MTS or the IMTS back then and this isn't a car phone, but you can see it's really large. It's basically land line phone, but not really a land line, but it looks just like a land line phone that you would see in your house. So, they didn't develop the technology to make these things much smaller, and so we started to develop what was called the transistor and very high-scale, high-speed small electronics that we'll talk about soon. So, the first handheld phone came in 1973 from Motorola, they came up with the first ever hands held phone. A guy by the name of Martin Cooper was convinced that mobile phones were the wave of the future and though a lot of people didn't believe that he obviously was right. And so, but if you look at a comparison between an iPhone today, and what this first phone was called, or this DynaTAC back in 1973. It's the DynaTAC, d, y, n, a, t, a, c. You can see how much larger, and how much more inconvenient it would have been to carry that phone around. But this is technically a hand-held phone, and you can carry it around and walk around with it. And while the iPhone today, in 2012, weighs less than a third of a pound, this weighed close to two pounds. So, it would be very, very heavy. And the iPhone you can buy, depending upon your cellular carrier and so on, for $150 today. This DynaTAC costed close to $3000. So, still, it was pretty expensive way back then, very, very hard to afford phone. And this is in not even today's dollars this is in 1973 dollars. And, well an iPhone can offer you hours of uninterrupted service, and not only can you call, or text message, or go on the internet on your smartphones. This only had the call function, and you could only for a maximum of 30 minutes talk to someone before you'd have to go back and recharge your phone. And so, for these reasons here, as well as capacity issues, as we'll speak of in a second. We didn't really start switching over to handheld phones that everybody could buy or use and carry around with them until the mid-1990s. So, they were just way too expensive and there were many capacity issues back then, so we'd stayed largely with car phones up until then.