Since the first network roll-out in 2009, 4G services have gained significant ground globally. According to the Global Mobile Suppliers Association (GSA), 581 operators across 186 countries have commercially launched 4G long term evolution (LTE) networks as of end-January 2017. Meanwhile, the number of LTE subscriptions has increased from 1.07 billion as of end-2015 to around 1.68 billion at the end of 2016.

There has been a significant surge in 4G data traffic as well. As per the Cisco Virtual Networking Index, while 4G represented only 26 per cent of mobile connections in 2016, 4G traffic accounted for 69 per cent of the total mobile data traffic. On the other hand, 3G represented 33 per cent of the total mobile connections, but only 24 per cent of the total traffic.

Currently, a 4G connection generates four times more traffic on average than a 3G connection. There are two reasons for the higher usage per device on 4G. First, many 4G connections today are for high-end devices, which consume higher data. Second, higher speeds encourage the adoption and usage of high-bandwidth applications. Thus, a smartphone with a 4G connection is likely to generate signifi­cantly more traffic than that with a 3G or 3.5G connection. Meanwhile, the 1800 MHz spectrum band continues to remain the most common band for 4G, accounting for more than 47 per cent of global LTE deployments.

Wide variations in 4G speed and coverage

While operators worldwide are pushing the boundaries in terms of LTE speed and coverage, the progress differs in different parts of the world.

As per a report on the state of LTE released by OpenSignal in November 2016, in terms of the proportion of time users have consistent access to LTE, South Korea is in the leading position, with users being able to connect to LTE 95.71 per cent of the time. It is followed by Japan with 4G availability of 92.03 per cent. Countries such as the Philippines and Sri Lanka score extremely low in 4G availability, where consistent 4G signals are available less than 45 per cent of the time.

While the majority of the countries analysed in the report had speeds well over 20 Mbps, the relatively slow connections of some of the largest countries in the world brought down the global average to 17.4 Mbps. Singapore offers the highest average 4G download speed of 45.86 Mbps, foll­owed by South Korea (45.77 Mbps) and Hungary (40.61 Mbps). At the lower end of the 4G speed scale are countries such as India and Saudi Arabia, which offer average 4G download speeds of less than 7 Mbps. It should be noted that 4G speeds in a country depend on a number of factors, including the quantity of 4G spectrum utilised, adoption of new 4G technologies like LTE-Advanced (LTE-A), network density and network congestion. The countries that have built LTE-A networks and have a large proportion of LTE-A-capable devices tend to have the fastest speeds.

Though there are several countries that are performing well in both 4G speed and availability, a high score in one category does not necessarily mean a high score in the other. Several countries have impressive 4G speeds but low availability, and vice versa. For instance, the majority of Turkey’s LTE networks went online only in April 2016, but these were launched on multiple frequency bands and used the latest LTE-A techniques, thereby offering superfast connections. However, users can find an LTE signal only half the time as the country is still building out its 4G infrastructure. On the other hand, the US was among the first countries to adopt LTE technology and has built one of the most extensive 4G infrastructures in the world, and hence scores extremely high on 4G availability. However, the country still lags in terms of spectrum and technology. It cannot yet match up to the new LTE-A networks that are being deployed in many other countries.

Key issues and challenges

Although operators are rolling out LTE services on a large scale, many challenges still need to be overcome for successful network deployment and high consumer adoption. These include:

  • Spectrum harmonisation: LTE infrastructure is being deployed on different spectrum bands in different countries and by different operators in the same country. Thus, the burden of providing seamless global roaming shifts to terminals (mobile devices) in order to support multiple frequency bands is leading to increased costs and complexity. This pro­cess is time-consuming and inefficient.
  • Maintenance of multiple networks: Most operators that have launched LTE networks have both 2G and 3G networks in service. While they will continue to operate the three networks simultaneously in the near term, the 2G/3G networks operating on GSM technology are likely to be shut down in the long term. This will lead to a significant loss in roaming revenues for operators as 80 per cent of worldwide users are still on GSM technology. Switching off GSM networks will enable operators to refarm that spectrum, but there are many strict regulations regarding refarming in different countries.
  • Traffic management: LTE is deployed on higher spectrum bands for maximum bandwidth potential and spectral efficiency, thereby giving higher data speeds. However, these gains will eventually be dwarfed by the faster rate of data traffic growth. According to AT&T Wireless, a 3G-enabled iPhone typically generates as much data traffic as 30 basic feature phones and it is much higher in the case of LTE-enabled phones. Moreover, with the growth in data traffic, mobile operators need to offload internet traffic at the edge of their networks and not carry that traffic to their core networks.
  • Backhaul augmentation: The limited availability of spectrum has been a key challenge for wireless networks. In the case of LTE, though, the capacity bottleneck has shifted from the air interface to the backhaul link between base stations and the core network. Thus, operators need to make significant investments in backhaul infrastructure when deploying LTE. To comprehensively address the backhaul challenge, oper­ators will have to use the full range of technologies including microwave, fibre/Ethernet, community access television Ethernet and Wi-Max, thereby increasing the cost burden.
  • Voice over LTE (VoLTE): A key advantage of LTE is the converged evolved packet core (EPC), which has the ability to carry all types of traffic – voice, video and data. However, most standardisation processes have focused on LTE’s data aspects, neglecting voice. Different operators have accorded different levels of priority to this issue, with some early adopters considering data-only services for initial LTE roll-outs. The full opex and capex benefits of a converged EPC can only be realised when all traffic types are carried over a single and unified core. The issue of VoLTE standardisation gets even more complicated during the interlocking process of VoLTE with different types of legacy networks such as GSM, HSPA, CDMA2000, Wi-Max and Wi-Fi.

Future outlook

The global LTE landscape is evolving at an astonishing pace. GSA expects the number of commercial LTE networks to reach 635, and LTE connections to surpass 1 billion by the end of 2017. Further, 65 per cent of the world population is expected to be covered by LTE by the end of 2019. While the Asian market as a whole was slightly late to adopt LTE, it is expected to see a significant adoption rate particularly in India and China, which are estimated to account for almost 47 per cent of the total global demand. Further, according to Cisco, 4G networks will account for 53 per cent of the total wireless connections by 2021, and 79 per cent of the total mobile data traffic.

Going forward, ubiquitous and high speed 4G networks need to become a global phenomenon rather than performing satisfactorily in only a few developed countries.