We would very soon be able to download a full-length HD movie to our phone in a matter of seconds rather than minutes. And video chats will be so immersive that it will feel like we can reach out and touch the person right through the screen. Certainly, we are going to embrace a more connected world with IoT expected to grow exponentially over the years. The IoT refers to the billions of physical objects around the world that are connected to the internet, collecting and sending data. It will need a network that can accommodate billions of connected devices. All this will become possible with the next generation of cellular technology, called 5G.
Generations of cellular phones
The first generation, called 1G mobile technology, was introduced in 1980s, was analogue in nature and had a low bandwidth of 30 kHz. Functioning on circuit switching principle, could provide voice calls only. Its speed was limited to 2.4 kilobits per second (kbps) and offered very low levels of spectrum efficiency. The size of the devices used with 1G technology was quite large. Therefore, mobile phones based on this technology were not handy and were installed in cars etc.
The second generation (2G), based on digital technology, was started in Finland in 1991, had a higher channel bandwidth (30-200 kHz) and was significantly efficient on the spectrum as compared to 1G technology. Besides voice calls, it offered services, such as SMS, text messages, picture messages and MMS. The 2G technology offered service with a speed of 64 kbps. All text messages sent over 2G phones were digitally encrypted hence there was greater data security than 1G.
The 3G technology brought about a quality change in the voice and text messages had much higher bandwidth (15- 20 MHz) than to 1G or 2G technology. This technology uses circuit switching for voice calls and packet switching for sending data and text messages. Services like web browsing, email, video downloading, picture sharing, etc. are offered by 3G with data transfer speed varying from 384 kbps to 2 Mbps.
The first 3G network was launched in Japan in year 2001 then South Korea and Europe and then this technology reached the US in 2003. By December 2007, one hundred ninety 3G networks were operating in forty countries of the world. With BSNL offering its services in Bihar, 3G technology was introduced in India in the year 2008. Then, in 2010, MTNL brought 3G service to Delhi and Mumbai.
The 4G mobile service brought about a revolution in the field of mobile telecommunication. This technology totally functions on packet technology for voice calls as well as for sending data and text messages. It offers a bandwidth of 100 MHz and can have a minimum speed of 100 Mbps, which can go to the maximum limit of 1 Gbps. These are, however, theoretical limits. In India, the practically available 4G speed is typically between 2 and 10 Mbps with different networks providing different speeds. Although 4G was introduced in 2009, no network was officially designated as 4G before 2011. Of course, there were some devices which were designated as 4G, but they did not fulfill the standards fixed by the International Telecommunication Union (ITU). In 2011, only LTE-A (Long Term Evolution-Advanced) and WiMax Release 2.0 were officially designated as 4G.
The 4G mobile technology operates at high frequency (2-6 GHz) and has a bandwidth of 100 MHz. It has about double the download speed of 3G. The high speed of 4G makes it appropriate for high-speed applications such as HD mobile TV, video conferencing and 3D TV, etc.
5G Mobile Technology: The fifth generation (5G) of mobile communication targets high data rate, reduced latency, energy saving, cost reduction, higher system capacity and massive device connectivity. Today, 5G is purely a concept as the global standard for this technology is yet to be evolved. One of the key goals to be achieved with 5G technology is far better levels of connectivity and coverage and data rate of 10 Gbps. In contrast, the 4G networks currently in service can achieve peak data rate of 1 Gbps though in practice it is never that fast. 5G allows downloading of an 8 gigabyte HD movie in 6 seconds compared to 7 minutes it would take with 4G and more than an hour with 3G.
Another key goal with 5G technology is ultra-low latency. Currently, with 4G, the latency rate is 50 ms; but 5G will reduce it down to less than 1 ms. This will be particularly important for activities requiring quick response, such as virtual reality (VR), 4 k video streams, driverless cars, factory robots, Internet of Things (IoT), online gaming and broadcast like services. It will also aid life-line communication in times of natural disaster.
Challenges in the way of 5G
Other than the challenge for evolving a globally acceptable standard for 5G, much higher bandwidth-possibly 1-2 GHz-also poses new challenges for handset development where a maximum frequency of around 6 GHz and bandwidth of 100 MHz are currently in use. The 5G technology operates under a frequency spectrum which is much higher than that of the 4G technology and has never been used for mobile before. While 4G operates at frequencies of 2-6 GHz, 5G operates between 3-300 GHz. Such higher frequencies are bound to present some real challenges in terms of the circuit design, the technology, and the way the system is used. As frequency is inversely proportional to wavelength, using such high-frequency radio waves means that the waves operating in this region are millimeter (mm) waves. The problem with millimeter waves is that they are unable to cross solid objects. Therefore, buildings or trees act like obstacles for these waves. Even bad weather like rain or presence of humidity in air can cause interference and consequent absorption of waves. As a result, the waves suffer a great deal of attenuation leading to the weakening of the signal with distance.
The ultimate result of this absorption of the waves by the obstacles coming in their way is poor connectivity. In order to offset this, mini base stations are required to be set up near big network towers to transmit signals, avoiding the obstacles. These low powered base stations catch the signal from the big towers and sense the frequency to transfer the signals to communication devices like mobile phones, etc.
Along with base stations, antenna technology with Massive MIMO (Multiple Input and Multiple Output) needs to be pressed into service. The concept is to use large antenna arrays at base stations to simultaneously serve many autonomous terminals. This reduces errors and also increases the efficiency of a network. However, installing antennas with such characteristics will be a huge task towards building of infrastructure for 5G. Further, issues around spectrum, which had already been witnessed with 4G, may likely to crop up.
Fixing standard for 5G
The standard for 5G has not been finalised yet. Therefore, first the standard has to be finalised before the first networks based on this standard can be rolled out. This is necessary because pre-standard networks bring their own sets of problems as had been the experience with 4G also. The work on development of a global standard and technologies for 5G has been going on with standard bodies including the 3GPP, ITU and IEEE as well as universities, public bodies and special interest groups, all having their inputs.
One needs to wait and see which global standard is finally going to be accepted. In the meantime, research on developing the technologies for 5G has been going on in many institutions, organisations and even universities of many countries.
India’s way forward
As far as India is concerned, the government is confident of rolling out 5G in tandem with global markets in the coming years and is making all efforts to keep the timeline for the next generation technology, which could have an economic impact of more than $1 trillion in the country. The DoT is pushing hard to bring 5G to India as soon as it is available for commercial roll-out globally. DoT had willfully excluded China telecom equipment vendor Huawei for these trials, though earlier, in February 2018, Huawei had conducted 5G trials in laboratory with Bharti Airtel in India, where it achieved broadband speed of more than 3 Gbps in 3.5 GHz spectrum band. In year 2018, it was claimed by CEO of Huawei India, that DoT has again invited them to conduct trials in busy and dense areas of two cities of India including Delhi.
There is no gainsaying the fact that the advent of 5G in our country will bring new revolution in the field of mobile communication and will change the way network coverage is provided to the subscribers. But, older technologies 4G, 3G and even 2G will not totally lose their utility. Many people in rural areas are still using 2G networks. High-speed internet is still something unknown to them. We will have to wait and see how the things unfold after 5G comes to the country. But it is certain that 5G technology will bring revolutionary change in the field of cellular telecommunication.
Disclaimer: The views and opinions expressed in this article are the personal opinions of the author. The facts, analysis, assumptions and perspective appearing in the article do not reflect the views of GK.