Aug 13, 2019 By Team YoungWonks *
Mobile phone technologies Given that we live in an age where we can’t imagine a life without mobile phones, it is important to understand the basics of mobile technology, its evolution and how it works today.
To understand this, first let’s look at what is a mobile. A mobile phone, also called a cell, cell phone or a hand phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.
What is Mobile Technology?
Mobile technology refers to the technology used on a mobile phone; in other words, it is the technology that makes cellular communication possible. The rawest form of this technology has been the mobile code-division multiple access (CDMA) technology. It is a kind of platform that works through transmitters that can send data at the same time on a single channel; this technology has evolved rather quickly over the years. Since the 2000s, the mobile device has seen many avatars: it has gone from being not much more than a simple two-way pager to being a mobile phone, GPS navigation device, an embedded web browser and instant messaging client, and a handheld gaming console. Experts say that the future of computer technology lies in mobile computing with wireless networking. Today, mobile computing through tablets are also commonplace.
History of Mobile Technology
Before we move on to discussing the latest mobile technology in use, let’s take a brief look at the history of mobile technology.
It was in the year 1973 that the first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola. Some years later, in 1979, Nippon Telegraph and Telephone (NTT) launched the world's first cellular network in Japan. Four years on, in 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone.
Since then, worldwide mobile phone subscriptions have grown by leaps and bounds. While the earlier models have been feature phones - phones fitted with not so advanced hardware - today smartphones - mobile phones with stronger hardware capabilities, extensive mobile operating systems and multimedia functionality in addition to basic phone functions such as voice calls and text messaging - are also popular.
Evolution of Mobile Phone Technology
If one had to trace the evolution of mobile phones through the years, perhaps the first mention should be that of the mobile radio phone, also called the 0G phone. These were telephone systems of the wireless type that preceded the modern cellular mobile technology.
1G: First Generation
Next comes 1G, short for the first generation of wireless mobile telecommunications. It refers to the analog telecommunications standards that were introduced in the 1980s and were in use until they were replaced by 2G telecommunications. Japan was the first country to have a commercially automated 1G cellular network; it was launched by Nippon Telegraph and Telephone (NTT) in 1979. It started out initially in Tokyo and in five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network. In 1983, the 1G network was introduced in the USA by Chicago-based Ameritech with the Motorola DynaTAC mobile phone. Many nations then followed in the early to mid-1980s, including the UK, Mexico and Canada. It is said that as of 2018, the only 1G cellular network still in operation is a limited NMT service in Russia. The maximum download speed here was said to be 2.4 Kbps (Kilobytes per second).
2G: Second Generation
2G (or 2-G) phones boast several main advantages when compared to their predecessors. For one, radio signals on 1G networks are analog, whereas radio signals on 2G networks are digital. Not surprisingly, 2G soon took over and replaced 1G phones. For starters, in 2G phones, the conversations are digitally encrypted. Second, 2G systems are way more efficient on the spectrum allowing for far greater mobile phone penetration levels. And also equally important is the fact that 2G phones were the first ones to have data services, starting with SMS (Short Message Service) plain text-based messages. So it was 2G technology that allowed mobile phone networks to provide services such as text messages, picture messages and MMS (Multimedia Message Service). Maximum theoretical download speed for the phones from this generation is up to 0.3 Mbps (Megabits per second) and maximum theoretical upload speed is up to 0.15 Mbps. Below we look at a few key 2G mobile technologies.
In 1991, 2G cellular networks were commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj). GSM, or Global System for Mobile Communications, is a standard developed by the European Telecommunications Standards Institute (ETSI) to spell out the protocols for second-generation (2G) digital cellular networks used by mobile phones and tablets. Developed as a replacement for first generation (1G) analog cellular networks, GSM is known for having set, for the first time, a common standard for Europe for wireless networks. It was also adopted by several non-European nations. The GSM standard was initially meant for a digital, circuit-switched network optimized for full duplex voice telephony. Over time, this description has gone on to include data communications.
b. Digital AMPS
Digital AMPS (D-AMPS) refers to IS-54 and IS-136, both of which are 2G mobile phone systems, a kind of iteration of the North American 1G / analog mobile phone system Advanced Mobile Phone System (AMPS). D-AMPS uses AMPS channels and makes possible a smooth transition between digital and analog systems in the same area. The digital system boasts increased capacity as it divides each 30 kHz channel pair into three time slots and digitally compresses the voice data, thus producing three times the call capacity in a single cell.
In the ’90s, D-AMPS - also known as TDMA, short for time division multiple access - was prevalent throughout the Americas, particularly in the United States and Canada. It thrived on a common multiple access technique used in most 2G standards, including GSM. Today, D-AMPS has mostly been replaced by GSM/GPRS or CDMA2000 technologies.
Developed by Qualcomm and adopted as a standard by the Telecommunications Industry Association in the year 1995, Interim Standard 95 (IS-95) is a 2G mobile telecommunications standard. It is the first ever CDMA-based digital cellular technology and hence called cdmaOne. In other words, this standard uses Code Division Multiple Access (CDMA), a channel access method for digital radio, so as to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites.
And how exactly does CDMA function? CDMA is basically a digital radio system that transmits streams of bits (PN codes). It allows several radios to share the same frequencies. Unlike the TDMA used in 2G GSM, all radios here get to be active all the time, since network capacity does not directly limit the number of active radios. So with more phones being served by fewer cell-sites, CDMA-based standards have a clear economic edge over TDMA-based standards. In North America, the technology found a rival in Digital AMPS (IS-136, a TDMA technology) and was then replaced by IS-2000 (CDMA2000), a later CDMA-based standard.
2G has been succeeded by newer technologies such as 2.5G, 2.75G, 3G, 4G and 5G. But 2G networks are still used in many parts of the world. Various carriers have declared that 2G technology in the United States is in the process of being shut down so that those radio bands can be re-purposed by them for newer technologies.
d. 2.5G (Second and a half generation)
General Packet Radio Service (GPRS) is used to describe 2G-systems that have a packet-switched domain along with the circuit-switched domain. Given that bundling of timeslots is used for circuit-switched data services too, GPRS doesn’t always offer provide faster services. This 2G cellular technology when used with GPRS is often referred to as 2.5G, in that it is a technology between the second (2G) and third (3G) generations of mobile telephony. Here the data transfer speed is moderate thanks to the use of unused time division multiple access (TDMA) channels in, say, the GSM system.
e. 2.75G (EDGE / Enhanced Data Rates for GSM Evolution)
GPRS networks have given way to EDGE (or Enhance Data Rates for GSM Evolution) networks. Considered a pre-3G radio technology, it is also known as 2.75G. It is essentially a digital mobile phone technology that allows better data transmission rates as a backward-compatible extension of GSM. EDGE was initially deployed on GSM networks in the US by the telecom company AT&T in the year 2003.
3G: Third Generation
3G, short for third generation, is the third generation of wireless mobile telecommunications technology. It is the upgrade for 2G and 2.5G GPRS networks, for faster internet speed, as determined on the basis of a set of standards used for mobile devices and mobile telecommunication networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. 3G technology is used in wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV. 3G telecommunication networks are those that support services providing an information transfer rate of at least 0.2 Mbit/s. Maximum theoretical download speed for the phones from this generation is up to 4.9xN Mbps and maximum theoretical upload speed is up to 1.8xN Mbps (where N: number of 1.25 MHz carriers).
Later 3G releases, often called 3.5G and 3.75G, also provide mobile broadband access of several Mbit/s to smartphones and mobile modems in laptop computers.
3.5G mobile technology, also known as High Speed Packet Access (HSPA), is a combination of two mobile protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA). It is known for being an improvement on the performance of 3G mobile telecommunication networks. A further enhanced standard rolled out by the standards organization 3GPP is the Evolved High Speed Packet Access, also known as HSPA+.
3.75G mobile technology is the second phase of HSPA which has been introduced in 3GPP release 7 and being further bettered in later 3GPP releases. HSPA+ can achieve data rates of up to 42.2 mbps for uploads. It introduces antenna array technologies such as beamforming and multiple-input multiple-output communications (MIMO).
CDMA2000 (also known as C2K or IMT Multi Carrier (IMT MC)) is a 3G mobile technology standard used for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible successor to second-generation cdmaOne (IS-95) set of standards and used especially in North America and South Korea.
4G: Fourth Generation
Among the latest mobile Internet access standards today, 4G is, as the name suggests, the fourth generation of broadband cellular network technology. A 4G system must provide capabilities defined by the International Telecommunication Union (ITU). Amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television are among its potential and current applications. Maximum theoretical download speed for the phones from this generation is up to to 1 Gbps (Gigabits per second) and maximum theoretical upload speed is up to 376 Mbps.
Long-Term Evolution or LTE is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and HSPA technologies. Commonly marketed as 4G LTE and Advance 4G, it increases the capacity and speed using a different radio interface together with core network improvements; i.e. using new DSP (digital signal processing) techniques and modulations.
5G: Fifth Generation
5G refers to the fifth-generation cellular network technology that provides broadband access. These are digital cellular networks, where the service area covered by providers is divided into small geographical areas called cells. Analog signals representing sounds and images are digitized in the phone, converted by an analog to digital converter and transmitted as a stream of bits. The industry standard association 3GPP describes any system using 5G NR (5G New Radio) software as 5G, a definition that has been in use since late 2018. Some of the initial yet fairly substantial deployments are the ones made in South Korea in April 2019.
In the US, telecom company Verizon has offered 5G service on a limited number of base stations in Chicago and Minneapolis. It is said that in May this year, download speeds in Chicago ranged from 80 to 900 Mbps, while upload speeds varied between 12 to 57 Mbps. It was also reported the same month that Verizon’s 5G service would regularly hit 1 Gbps in some areas.
What the future holds
5G technology is yet to replace 4G but there are several concerns cropping up around the use of these networks. There are, for instance, surveillance concerns, particularly the espionage fears experienced by foreign users relying on Chinese equipment. The health concerns too are attracting attention. In fact, while there already has been much talk about the adverse effects of radiation from mobile phones and cell phone towers (think reports about 4G mobiles causing headaches, fatigue and irritability), 5G radiation is being said to be even more dangerous, mainly because 5G uses higher microwave frequencies ranging from 2.6Ghz to 28Ghz, as compared to the frequencies between 700-2500Mhz that are usually used by 4G. What’s more, the higher millimeter wave used in 5G does not easily penetrate objects, and this means that 5G will need the installation of antennas every few hundred meters, thus increasing the potential exposure and danger to people in general.
Keeping this in mind, some countries are actively taking precautionary steps. For instance, in April 2019, the radiation laws in Brussels, Belgium were invoked to stop a 5G trial. In Geneva, Switzerland, a planned upgrade to 5G was stopped due to the same reason. 5G critics continue to emphasize how the millimeter wave frequencies used by 5G have not yet been extensively tested on the general public. At the same time, it is important to note that the Swiss Telecommunications Association (ASUT) has stated that their studies have not been able to establish a connection between 5G frequencies and adverse health effects.
*Contributors: Written by Vidya Prabhu; Lead image by: Leonel Cruz