cellular networks
A cellular network is a radio network that is distributed over a land area. These are recognized as cells. Each cell is served on a fixed location transceiver which is referred to as the cell site or base station. When these cells are joined together, they provide radio coverage over a vast geographic area. These enable many transceivers like mobile phones, pagers, etc. to communicate with each other. This enables the base station to communicate via fixed transceivers and telephones anywhere in the network. Cellular transmission is known as cellular radio. The network is made using many low-power base stations for transmission. Each station includes a limited area and is divided into smaller parts known as cells.
Different Cellular Networks
The first mobile radio-telephone known as 0-G was invented in the 1940s. But the actual journey of mobile telecommunication technology started many years before that when Alexander Graham Bell invented and patented wired telephones in 1876. Even before the telegraph was first used in the 17th century. From wired telephone to wireless communication was a great change. This revolution was first called mobile radio-telephone but when the next wireless generations got created it was called pre-cellular or 0g pioneers. For this big step forward was Motorola and bell systems typically giving birth to 0-G in the 1940s, it first used push-to-talk. When we press a button to speak and leave that button to listen to the other side is called push-to-talk technology.
It then got improved and MTS(Mobile telephone service) IMTS(Improved Mobile telephone service) and AMTS(Advanced Mobile telephone service) was introduced which gave full-duplex support and higher voice quality.
At that time telephones were too huge to carry by people. They were mounted on cars putting the antennas senders and transceivers at the back and the phone on the front side. After a while, the briefcase version of them came out which was more convenient. Although 0-G was a remarkable change, it could not be used by everyone.
1st Generation Technology
In 1979 first generation(1G) of mobile telecommunications unlocked wireless doors to everyone. It was first commercially released in Tokyo, Japan, in 1979 by private entity Nippon telegraph and telephone. In five years Japan was the first independent nation fully wireless connected. In 1981 NMT(Nordic Mobile Telephone) system made 1g available in Denmark Finland Norway and Sweden. It also introduced the first international roaming and empowers people in various countries to speak wirelessly. In 1983 Motorola Dyna TAC mobile phone was first used in Chicago, U.S., and then slowly all the work typically began experiencing the wireless world. Generated signals can be modulated either digitally or by analog technology. The first generation used analog signals to transfer information and was only allowing voice calls facility with a maximum speed of 2.4-kilobits per second for data transfer.
The 1g cell towers had an extremely low frequency of 150 megahertzes was operated which led to great coverage but equally high latency and battery consumption. The voice quality was not also broadly acceptable. The 1-G telephone could be carried and used by normal people. At that time they even didn’t look too big but compared to today’s modern technology they viewed absolutely hugely.
After the First Generation mobile technology, people felt the need for more. Over 10 years engineering also got advanced, and the outcome was 2g technology. The second generation of mobile technology was a remarkable achievement opening the doors to current developments.
Features
1. The first generation networks were launched under several brand names including Advanced mobile phone systems(AMPS) in the USA in 1983.
2. It was built on Analog signals.
3. It was using Frequency division multiple access (FDMA).
4. Can call freely within a network.
5. The speed limit was 2.4 kilobits per second which were quite low, but it was at least good enough for voice communication.
Limitations
1. The large and bulky size made it unhandy.
2. Battery drainage issues because there were a lot of components that were not based on the recent semiconductor devices, so they were consuming a lot of power.
3. Low SNR that is the signal-to-noise ratio resulting in bad voice quality.
4. Poor encryption and security.
5. Poor handoff i.e. Call drops often on mobility.
2G Cellular Networks
After ten years the second generation of mobile technology was a big achievement opening the doors to current evolutions. 2G includes various standards starting with GSM or global systems for mobile communication. It was first released in Finland in 1991 by Radiolinja, now a part of Elisa Oyj. The most significant change was properly implementing digital modulation instead of analog technology. It typically used TDMA and CDMA or time division multiple access and code division multiplexes for multiplexing and 900 megahertz frequency. What are 2g speeds? This communicating technology enables the maximum speed of 14.4 kilobits per second both in downlink and uplink. It, too, extends the possibility to include SMS or short message service to voice calls and also increases the necessary quality of voice calls. Mobile phones also got way smaller.
The architecture of GSM carrier networks is the base architecture of future mobile technologies in the next generation. According to the architecture, if a cell phone in one city wants to call another cell phone in another city, it first had to send information to the supporting Base Transceiver Station(BTS). A collection of BTS’s was controlled by one Base Station Controller(BSC) which is a higher tier in GSM networks. All BSC were orchestrated and controlled by the Mobile Switching Center(MSC), which was responsible for managing the whole network, routing calls, and messages between subnetworks. It used its own databases and intercommunication in order to receive that information after the BTS forwarded the packet to the BSC and then the BSC to the MSC. The MSC was responsible to find the BSC supporting the destination mobile phone. It forwarded the packet to that BSC and then that to the BTS connected to that phone and then finally the destination phone receives the first part of data from the BTS. Now the connection is established between two phones and the following parts of the data follow this path, it is also called the circuit switching paradigm.
The next 2G standard technology was General Packet Radio Service(GPRS). It was first standardized and released by ETSI in 1993. The big difference was the use of packet switching technology where all information to be sent to the destination was divided into packets and all packets could be sent in parallel. This standard reached the maximum speed of 53 kilobits per second in the downlink and 26 kilobits per second in the uplink. This speed lets GPRS introduce MMS or multimedia message service which gave the user the capability to send media like pictures. It also supported Internet Protocol i.e. IP to connect to the internet. In the architecture of the GPRS Network, mobile devices had to be properly equipped with GPRS modems, and the network in addition provided a GPRS gateway towards the World Wide Web. The recognizable symbol for GPRS networks was the letter G.
The last 2g standard was the edge which is also called 2.75 G. It was introduced by AT&T in 2003 and the maximum speed was 236 kilobits per second for downlink and 59 kilobits per second for uplink. It used 8PSK encoding and the symbol for that was E. 2G technology introduced digital modulation and packet switching which opened the doors towards high-speed connection.
Feature
1. The second-generation network is also known by the name of global system for mobile communication that is GSM, and it was launched in 1991 in Finland.
2. The major difference between first-generation and second-generation was the digital signals. 2nd generation had digital signals, and it uses Quadrature Phase Shift Keying (QPSK).
3. The application of short message services and digital encryption was enabled that allows more security and encryption in 2g networks as compared to the 1g Network.
4. It was based on time division multiple access. The time was divided so that each user was given a specific time in which it can communicate. Moreover, the uplink and downlink can also communicate based on different time slots on the same frequency channel.
5. An important feature is the concept of cellular technology which enables multiple access, multiple voices, or data connections into a single radio channel.
6. 2G networks provide better quality communication.
7. This technology also came with a reliable horizontal hand-off. Horizontal handoff is simply the handoff between the same technologies that is if we are using a cellular network, and again we’re moving towards a cellular network, so that kind of switch is the horizontal handoff. It also had a vertical handoff and that is simply if you are in a cellular network, but you are streaming some data but at the same time you also have a broadband Wi-Fi availability in your given location; so you could have a handle handoff between the base station and the Wi-Fi or the broadband technology.
8. It has a speed improvement to 64 kilobits per second from 2.4 kilometers per second of 1-G Network.
Limitations
1. Receiver sensitivity in Time Division Multiplexing(TDMA) systems was a major issue.
2. Bad for video data.
3G Network Technology
3-G was introduced in 1998, the third generation of mobile networks aimed at increasing network speed. The first standards’ technology of 3G was WCDMA and UMTS. 3G was first released in Japan by an NTT in 1998, but it was not commercially released. The first commercial release was in South Korea by SK telecom in 2001. What is a 3g? The frequency band of 3g used CDMA technology or code division multiplexes for multiplexing and followed the packet switching paradigm using three main frequency bands of 850,1900 and 2100 megahertz.
WCDMA standard was based in GSM, but UMTS was a new standard by the 3rd Generation Partnership Project(3GPP) and was used mainly in Europe. The maximum speed of 3g internet depended on the device’s mobility. For moving devices like a mobile phone in the cars or on the trains, it reached the maximum speed of around 384-kilo bits per second while for non-moving devices speed was around 2 megabits per second.
Having a tremendous increase in communication speed 3G introduced video calling mobile internet and streaming services. Another significant change with 3g was people did not pay typically based on considerable time to operate the outstanding services. It allows users to pay based on the amount of data transferred. The third generation after a while introduced two other standards known as HSPA or 3.5 G and HSPA+ or 3.75 G. HSPA was the enhanced version of WCDMA technology with the maximum theoretical speed of 5.76 megabits per second for uplink and 14.4 megabits per seconds for downlink.
But in practicality, the speed was around 200 kilobits per second for uplink and 500 kilobits per second downlink. The symbol for HSPA was the letter H. HSPA+ was the evolved version of HSPA and used MIMO, which is the multiple input multiple outputs. It used more than one antenna for sending and receiving data. It increased the network speed to a value of 22 megabits per second for uplink and 168 megabits per second for downlink.
Features
1. It includes integrated high-quality audio-video and data. Video conference, Mobile TV, Internet access.
2. Enabled broadband and IP technology.
3. Uses Code Division Multiple Access(CDMA).
4. Horizontal handoff but not vertical.
5. The data speed of 3g improved to 2 megabits per second from 144 kilobits per second in 2.5 G.
Limitations
1. More Base Stations are required as compared to a 2g network. Hence, more capital and operational expenditure.
2. 3G phones were quite expensive.
3. It needed high bandwidth requirements
4. High-quality video streaming with high latency.
4G Network Technology
What is LTE 4g? The Fourth Generation of wireless technology(4G) is also known as LTE. The standardization of LTE was started in 2004 by ITU and in 2005 the specification was released, and the deployment process started. In 2009, the first commercial release of fourth-generation(4G) LTE networks was available in Oslo-Norway and Stockholm-Sweden. It also included another standard named WIMAX which was standardized by IEEE. The standard was called IEEE 802.1. 4G was released in June 2006 in South Korea. LTE was the winning 4G technology. It has two main standards technology LTE and WiMax. LTE works as packet-switching based on IP or internet protocol. It uses Orthogonal Frequency Division Multiple Access or OFDMA and Multiple Input Multiple Outputs(MIMO).
4g vs LTE – The maximum speed test for 4g technology depending on the specific standard varies tremendously. For LTE download speed goes up to 100 megabits per second and for uplink, it goes up to 50 megabits. LTE advanced can reach the maximum download speed for 4g of 1 gigabit per second while this value is around 500 megabits per second for uplink. For WiMAX, the maximum download speed doesn’t go more than 128 megabits per second. LTE supports a very big range of frequencies from 700 to 2600 megahertz. The frequency of 4g and IP packet switching made data transfer possible with low latency. Possessing high speed and low latency LTE supports an enormous variety of use cases such as –IP telephone or voice over IP, 3d television support, video conferencing with multiple participants, easy and fast web access from mobile devices, HD mobile TV, online gaming, and even cloud computing. Soon with new technology ideas such as IoT or the Internet of Things, smarts cities and massive sensors driverless cars, and even remote surgery and operations, the need for a more advanced wireless technology showed up.
Features
1. Long Term Evolution (LTE), and its another version called LTE advanced was the first all packet-switched technology.
2. Multimedia anytime anywhere- Mobile TV, online gaming, cloud computing all of these features are enabled in the 4th generation.
3. It is using Orthogonal Frequency-Division Multiple access for the downlink and single carrier frequency division multiple access for the uplink.
4. It is operating at two different bands in the downlink and uplink, so it is a half-duplex system.
5. Supports horizontal and vertical handoff. It is able to hand over between different base stations and also across the technologies that are 4g to the broadband, Wi-Fi router.
6. The speed increases from 2 megabits per second to 200 megabits per second in 4G.
Limitations
1. Internet of Things(IoT) and massive connectivity not ensured. 4G gives a good data rate but it
cannot enable a lot of devices to be connected to a network.
2. It cannot accommodate massive antennas in the base station while 4G has multiple antennas, but it does not have massive and in a structure.
3. The latency for augmented reality or virtual reality games(AR/VR) and healthcare applications is quite high.
Also, Read – Tesla inventions that will surprise you!
5G Network Technology
The Fifth Generation uses a new Radio Global Standard for air interface and the 5g release date was supposed to be in 2020. Some test versions were being deployed all around the world, but it was not commercially released. It uses Time-Division duplexing instead of frequency division duplexing or FTD, and it allocates a one-time slot for uplink per each three downlink time slots. 5g v 4g -The big changes in comparison with previous technologies are beamforming and massive MIMO. It utilizes an extremely wide frequency range, and it is the first time 5G has introduced various standards for different use cases. The first cell phone technology that was basically launched is from Samsung. The Samsung Galaxy S10 enables the excess of 5g network launched in 2019.
