How a transportable makes a call, and why there are different generations of mobile communications? (upbeat music) Let’s explore the technology behind mobile communications.
How a transportable makes a call
When you speak on your phone, your voice is picked up by your phone’s microphone. The microphone turns your voice into a digital signal with the assistance of the MEMS sensor and IC. The digital signal contains your voice in the kind of zeros and ones. An antenna inside the phone receives these zeros and ones and transmits them within the kind of electromagnetic waves. Electromagnetic waves transmit the zeros and ones by altering the wave characteristics, such as the amplitude, frequency, phase, or combinations of those. How a transportable makes a call, For example, within the case of frequency, zero and one are transmitted by using low and high frequencies respectively. So, if you’ll find the simplest way to transmit these electromagnetic waves to your friend’s phone, you would be ready to establish a call. However, electromagnetic waves are incapable of traveling long distances. They lose their strength because of the presence of physical objects, electrical equipment, and some environmental factors. In fact, if there have been no such issues, even then, electromagnetic waves wouldn’t stick with it forever, due to the Earth’s curved structure. To overcome these issues, cell towers were introduced, using the concept of cellular technology. How a transportable makes a call
In cellular technology, a geographical region is split into hexagonal cells with each cell having its own tower and frequency slot. Generally, these cell towers are connected through wires, or more specifically, fiber cables. These fiber cables are laid under the bottom of the ocean, to provide national or international connectivity. The electromagnetic waves produced by your phone are picked up by the tower in your cell and convert them into high-frequency light pulses. These light pulses are carried to the bottom transceiver box, located at the bottom of the tower for further signal processing, After processing, your voice signal is routed towards the destination tower. Upon receiving the pulses, the destination tower radiates it outwards in the kind of electromagnetic waves, and your friend’s phone then receives the signal. This signal undergoes a reverse process, and your friend hears your voice. So, it’s true that mobile communications are not entirely wireless, they do use a wired medium too. How a transportable makes a call, This is how mobile communications are distributed. However, there was a giant issue that we intentionally left unanswered. Mobile communication is merely successful when your tower transfers the signal to your friends tower. But how does your tower know in which cell tower area your friend is located? Well, for this process, the cell tower gets help from something called a mobile switching center. The MSC is the central point of a bunch of cell towers. Before moving further, let’s explain more information about the MSC. When you purchase a SIM card, all the subscription information is registered in an exceedingly specified MSC. How a transportable makes a call This MSC is going to be your home MSC. The home MSC stores information like service plans, your current location, and your activity status. If you progress outside the range of your home MSC, the new MSC, which serves you instead, is known as a far off MSC. As you enter a far off MSC region, it communicates together with your home MSC. In short, your home MSC always knows which MSC area you’re in. To understand within which cell location the subscriber is within the MSE area, the MSC uses some techniques. One way is to update the subscriber location after a specific period. When the phone crosses a predefined number of towers, the location update is again done. The last one amongst these is when the phone is turned on. Let’s attempt to understand all of those procedures with an example. Suppose, Emma wants to call John. When Emma dials John’s number, the call request arrives at Emma’s home MSC. Upon receiving John’s number, the request is going to be forwarded to John’s home MSC. Now, John’s MSC checks for his current MSC. If John is in his home MSC, the call requests are going to be immediately sent to his current cell location, and it checks whether John is acting on another call, or if his mobile is transitioned. If everything is positive, John’s phone rings, and the call is going to be connected. However, if John isn’t in his home MSC, John’s home MSC simply forwards the decision request to the foreign MSC. The foreign MSC will follow the previously explained procedure to locate John’s phone, and will then establish the decision. How a transportable makes a call, Now, let’s discuss why the frequency spectrum is quite important in transportable communications. How a transportable makes a call, To transfer zeros and ones in electronic communication, each subscriber is allocated a frequency range. However, the frequency spectrum available for cellular communications is sort of limited, and there are billions of subscribers. How a transportable makes a call, This issue is solved with the assistance of two technologies, one frequency slot distribution, and two, multiple access techniques. In the first technique, different frequency slots are carefully allocated to different cell towers. In the multiple access technique, this frequency slot is efficiently distributed amongst all the active users within the cell area. Now, the large question. Why are there different generations of transportable technologies?
1G originally allowed users, for the primary time, to carry a phone without a cable attached thereto. But 1G suffered from two major problems. The first problem was that the wireless transmission was in an analog format. Analog signals that are easily altered by external sources. So, it provided poor voice quality and poor security. How a transportable makes a call
The second problem was that it used the frequency division multiple access technique, which used the available spectrum in an inefficient way. These factors paved the way for the second generation of mobile communications, 2G used digital multiple access technologies, namely TDMA, or CDMA technology. The second generation also introduced a revolutionary data service, SMS, and internet browsing. How a transportable makes a call
3G technology was focused on giving a better data transfer speed. It used a WCD multiple access technique, along with a rise in bandwidth. To achieve this, the 3G speed of two Mbps allowed the transfer of knowledge for uses such as GPS, videos, voice calls, et cetera. 3G was a large step within the transformation of the essential phone to a smartphone. Next came 4G, which achieved speeds of 20 to 100 Mbps. How a transportable makes a call, This was suitable for prime resolution movies and tv. This higher speed was made possible due to the OFD multiple access technology, and MIMO technology. MIMO uses multiple transmitter-receiver antennas inside both the itinerant and therefore the towers. The next generation of mobile communication, 5G, to be unrolled soon, will use enhanced MIMO technology and millimeter waves. How a transportable makes a call, It will provide seamless connectivity to support the net of things, such as driverless cars and smart homes. Would you wish to find out how a touchscreen works? Please take a look at this video. Please do not forget to buy Learn Engineering, and your support at patreon.com is invaluable. How a transportable makes a call,