5G for Nepal Telecom

Wireless communication has witnessed extensive growth. Internet of things (IoT), device-to-device communication, sensing devices in roadways, ultra-reliable and low-latency communications are being operated and the demand for higher data throughputs is ever increasing. The long term growth in mobile telephony will no longer be limited by the number of people. In such scenario, 5G will be the most appropriate option for future telephony and wireless data services. However, in the context of Nepal, spectrum allotment for such a useful wireless technology is yet to be finalized. Despite all challenges, Nepal Telecom cannot lag behind in implementing 5G. Therefore, Nepal Telecom is moving ahead very soon with a few 5G sites as the pilot sites.

1. Introduction

The Global System for Mobile Communication (GSM) sparked a disruptive innovation in the communication technology in 1990s through the use of digital wireless systems and providing services like short-messaging and lower speed data. Before this digital technology, popularly called 2G, cellular technologies were analog which became available in the 1980s.
Under the International Mobile Telephone 2000 ((IMT-2000) project, International Telecommunication Union (ITU) specified the 3G requirements with significant voice capacity and digital networks able to provide 144 kbps (when in movement) to 2 Mbps (indoor). However, from the early 2010s, 3G started declining in usage as 4G and 5G are growing rapidly.
In the context of Nepal Telecom, from the establishment of first telephone lines in 1916 to the establishment of digital telephone exchange in 1983 and from the launching of GSM service in 1999 to the introducing of 3G services in 2007, Nepal Telecom has certainly laid important milestones in the history of Nepalese telecommunication. Moreover, the company launched WiMAX service in 2012 and 4G/ LTE service in 2017. Currently (January 2020), Nepal Telecom is focusing in the massive deployment of high speed 4G/LTE system all over the country. Wireless technology is like a flowing river and particularly in the cellular technology, substantial changes and innovations are happening every decade. When a disruptive change happens, hardware and software manufactures reduce the manufacturing of old equipment and related software, and they increase the production of new ones. On the other hand, consumers expect the sunshine of the latest, innovative and more useful products. It is often the service providers like Nepal Telecom that gets sandwiched between the demand of the new products and the supply of the old ones. Therefore, standing on the firm ground of 4G LTE, Nepal Telecom needs to look ahead in the field of 5G.

2. Evolution

The first mobile networks 1G, emphasizing voice service, was deployed in 1980s with analog technologies such as Advanced Mobile Phone Service (AMPS) and Nordic Mobile Telephone (NMT). The first digital technology for voice and circuit-switched data, followed by packet switched data was deployed in 1990s. Services introduced were SMS and low rate data. Examples are IS-95 CMDA, IS-136, and GSM, GPRS, EDGE etc.

The 3G came into scene in 2000 with ITU’s IMT-2000 requirements. 3G technologies included CDMA2000, 1x EVDO, UMTS-HSPA and WiMAX. ITU’s initial designation for 4G is IMT-Advanced, with its first deployment in 2010. The primary technologies include IEEE 802.16m and LTE Advanced with the capability to operate in up-to40MHz radio channels and with very high spectral efficiency. ITU has defined the technical requirements for IMT-2020 or 5G and 3GPP is developing the specifications. Currently, there are more than 88 countries including South Korea, China and UK, which are actively investing in 5G.

3. 5G Concepts

The long-term growth in mobile telephony should not be limited by population. This is the reason Internet of Things (IoT) capabilities are being endorsed by 4G LTE and the upcoming 5G. Figure 1 depicts the growth of mobile subscriptions over some years to come. Utilization of more spectrums with the aim for greater efficiency is constantly forcing new research and advancements in the current releases of 3GPP. The main factors include radio access to great amounts of new spectrum including the following:
i. Unlicensed frequency range
ii. Small cells to be used for mass deployment
iii. New network architectures (Network
Function Virtualization or NFV, Mobile Edge Computing, Network Slicing etc.)
iv. Artificial intelligence and machine learning
v. Equal support for things and people.

Frequencies starting around 30 GHz are the new prospects. In spite of the physical properties of high frequencies wave viz. penetration loss and propagation limitation, technologies like carrier aggregation, massive MIMO (Multiple Inputs Multiple Outputs), beam steering, network slicing are supposed to combat with such issues. In fact, 5G will be a viable option to fixed-access technologies like ADSL, FTTH and dedicated fiber internet. Figure 2 shows the ITU use case model and figure 3 shows the possible applications of 5G.

The potential applications of 5G comprise ultrahigh definition video transmission, healthcare, cloud gaming, vehicular infotainment, video surveillance, education, smart cities, augmented and virtual reality, and manufacturing and industrial applications. Higher throughputs, lower latency and edge computing will make augmented and virtual reality smooth over 5G. Health care devices can be implanted into the bodies, telemedicine and robotic surgery applications need a communication technology like 5G. Vehicle to infrastructure, vehicle to vehicle communications, sensing devices in roadways can make use of 5G technology more effectively. Some of the 5G capabilities include

i. Support up to a million devices per square kilometer ii.
ii. Network slicing for the exact QoS required
iii. Private network deployment using 5G New
Radio Unlicensed (NR-U),
iv. Private edge clouds
v. Machine learning and artificial intelligence

The features of 5G include Multi-Gbps peak data rates while emphasizing uniform coverage and the support for existing cellular bands and frequencies above 6 Hz. In the context of Nepal Telecom, 5G is the most viable option. It accentuates methods to bring together the existing 4G LTE frameworks with the features provided by 5G.
As already mentioned higher-order MIMO antenna arrays, beam forming and beam tracking compensate for poorer propagation. The 5G architecture comprises mainly two parts the new Radio Network (NG-RAN) supporting the New Radio (NR) and the 5G core Network (5GC). 3GPP Release-15 is the first complete set of 5G standards; Release-16 and Release-17 aim to be specifications ready around 2021/22. The 5G core provides an access-independent interface to be used with any relevant access technology as well as technologies not indicated by 3GPP; fixed access for example.

The 5G core architecture comes with a brand new set of interfaces between the radio and the core networks. These are N2 and N3 protocols. N2 is used for signaling and N3 is used for user data parts. These protocols of 5G are based on the S1 protocol defined by 3GPP for 4G LTE. Thus, the 5G architecture does not specifically address the backwards compatibility for devices and LTE radio access; however, the 4G LTE specifications were complemented in order to support N2 and N3 interfaces as the new radio (NR). There are three 3GPP architecture options available for 5G.

a. LTE support for the 5G architecture.
b. Support for the combinations of LTE and NR access
c. Architecture based on an evolution of LTE/EPC.
5GC architecture is very similar to and, at the same time, very different from the EPC architecture. The similarity exists in the user data processing parts and the integration with 3GPP radio access networks. The signaling only functionality is the part of the network that creates the difference. Nepal Telecom can make use of the current 4G LTE network while implementing the 5G network in coming future.

4. NTA’s role

Nepal Telecom Authority (NTA) has to specify the frequency range so that the service providers can implement 5G extensively. However, until January 2020, no such frequencies for 5G were allocated by NTA. However, the policies of NTA clearly allow the utilization of technology neutrality. Nepal Telecom can make use of the radio frequency parameters of the current 4G network and/or ISM band and perform the spectrum harmonization until the frequency policies of NTA become mature enough for the new 5G technology.

5. Current Status of Nepal Telecom

Within four months (from October, 2019 to January, 2020), Nepal Telecom has done a massive deployment of over 1600 4G LTE sites in more than 65 districts of Nepal. This is yet another milestone in the history of the communication field in Nepal. The company is going strong towards the carpet coverage of the country with good voice quality and high data throughputs.

As mentioned before, the telecommunication business cannot be standstill in one technology when a newer technology has come into the field. Therefore, Nepal Telecom has planned four 5G sites, as a start, along with its latest 4G project where 5G can be an upgrade in the core NFV platform.

6. Major Challenges

i. 5G will be operating on higher frequency bands and the spectrum usage of 5G for Nepal has not been declared by NTA. Spectrum management will be the biggest challenge.

ii. The capabilities of 5G might not be fully utilized because Nepal is not a fully industrialized country. However, things and machines with artificial intelligence and systems that require low-latency communications are growing independently in Nepal as well. Sooner or later, consumers will demand the ultra-fast speed of their data network wirelessly. Moreover, Nepal is also moving forward towards industrialization.

iii. A strong backbone transmission network is required in order to carry the heavy amounts of data traffic created by 5G. Nepal Telecom is currently installing high capacity radio stations and optical fiber networks along with the RTDF projects of NTA.

iv. The high frequency spectrum implies small coverage. More cell towers may be required to get the same coverage as 3G or 4G. However, the antenna of 5G will be small and less power consuming and the technology can integrate with WiFi and 4G.

7. Conclusion

For a country, lack of full industrialization should not be a reason to delay 5G implementation. 5G technology is a disruptive innovation and its specifications will make the technology prevalent in the next decade. The current network of 4G will serve as a companion for the future network of 5G. History has shown us that 3G coexisted with 2G and 4G coexisted with 3G. Nepal Telecom which is currently busy in deploying 4G should not worry about the future technology of wireless telephony as 5G will also coexist with 4G LTE where the latter will provide the underpinning for the former. Combination of 4G and 5G technologies will also create the more effective provision of service: 4G for coverage and 5G for throughputs.

The article is extracted from Nepal Telecom Smarika-2076

Er. Sanjeev Ghimire
Senior Engineer, Nepal Telecom