The telecom backhaul network has so far been dominated by microwave. However, as the sector moves from voice-led to data-led growth, microwave-based backhaul infrastructure will not be sufficient to deal with the increasing capacity needs. Therefore, rapidly increasing mobile data and voice usage, coupled with the adoption of newer technologies like 3G and 4G have made it crucial to have a strong backhaul network in place.
The majority of Indian telecom sites currently use microwave radio technology for backhauling their data to their core network. A key reason for this is that 2G has been in use for a long time. With the large-scale adoption of 3G, microwave backhaul has become congested and overloaded. Further, with the rapid pace of 4G deployment, microwave backhaul will soon prove to be a highly inefficient way to backhaul data to the core network. In such a scenario, it is important that operators explore more efficient backhaul technologies to continue delivering seamless services to their subscribers.
Types of backhaul technologies in use
Copper: Traditionally, copper-based cables have been used by operators to meet their backhaul requirements. While these can support transmission speeds of up to 1.5-2 Mbps, they cannot be scaled up to provide adequate bandwidth for next-generation technologies. Hence, copper-based solutions are fast losing out in the market.
- Microwave: Currently, microwave is the most dominant technology in use. This is mainly because it facilitates cost efficient and faster deployment of mobile broadband services. Over the years, microwave has been able to provide speeds of up to 1 Gbps as a result of greater spectrum availability. However, as the industry witnesses greater demand for capacity and higher download speeds, microwave technology will prove to be inadequate.
- Optical fibre: This technology has been present for some time now but has not gained much traction in India as far as its deployment for telecom backhaul is concerned. Using fibre in the backhaul network can help telecom tower sites backhaul huge volumes of data to the core network. In addition, fibre backhaul networks can ensure seamless voice and data connectivity across 2G, 3G, and 4G/long term evolution (LTE) technologies.
- Satellite: Satellite backhaul technology is used primarily in rural areas, which have limited access to wired broadband connectivity. These solutions typically support only 2G and do not provide the capacity required for 3G and 4G technologies. The deployment of this solution remains limited. However, solution providers are using techniques such as data compression, byte-level caching and predictive cache loading to tackle higher data traffic.
Fibre deployment to pick up
Fibre deployment for backhaul has so far remained limited in India, with less than 20 per cent sites being fiberised as compared to 70-80 per cent sites in a developed country. This is mainly because of the high costs involved in the roll-out of fibre networks and the issues in obtaining right of way.
However, as newer technologies such as 4G and Wi-Fi hotspots are introduced and inducted into the mainstream, it will become important to deploy a backhaul network that provides larger capacity. In fact, operators are fast realising the potential benefits of fibre and have increased their investments in it. For instance, Bharti Airtel has increased its optical fibre network from 193,625 km as of December 2014 to 205,901 km as of December 2015. Similarly, Idea Cellular has been consistently investing in optical fibre cable transmission networks to tap the potential of wireless broadband. It has currently laid out and energised over 105,600 km of fibre. Vodafone India, too, has laid nearly 45,000 km of fibre network. The operator has recently given a contract to Ericsson for managing its fibre network. It expects to benefit from Ericsson’s global expertise in the segment. Aircel also claims to have made its network robust and more resilient with the addition of capacity, and is providing more redundancy in its fibre while simultaneously expanding its fibre footprint.
Apart from providing enhanced backhaul capability to operators, fibre can also prove to be a good business case for tower companies, which can provide end-to-end managed services in the fibre value chain. According to Deloitte, tower companies can offer fibre backhaul solutions with their own fibre assets to telecom operators, roll out micro cell sites for LTE services and provide economical last mile tower-based solutions for over-the-top services. However, tower companies need to work with the government and municipalities for this and develop the required skill sets like network operations and maintenance, configuration, performance security and monitoring.
As a result of the growing capacity demand driven by initiatives such as Digital India and Smart Cities, the telecom backhaul requirements are also going to increase. Telecom infrastructure is expected to play an integral role in this digital revolution as connectivity forms the backbone of these initiatives.
In order to tackle the growing traffic on macro sites, operators are likely to off-load traffic and adopt more flexible means that can provide both coverage and capacity rather than opting for a large number of new sites.
Apart from private initiatives, the government too is making investments in the expansion of backhaul networks. A key initiative in this regard is the National Optical Fibre Network project, which aims at deploying fibre overhaul across 100,000 gram panchayats. The government will lease out this network to operators for providing last mile connectivity.
Emerging needs
Nokia’s annual India Mobile Broadband Index report shows that mobile traffic in India grew by 50 per cent during 2015. As per the report, a growing device ecosystem and increased adoption of multimedia services are likely to boost traffic further with the roll-out of 4G LTE networks across the country in the coming months. Thus, it is clear that data adoption is set to rise, driving the need for a strong backhaul network. A typical backhaul solution must be such that it is able to transport more traffic to accommodate the increases in data throughput demanded by users. Moreover, backhaul must transport this traffic with low latency in order to prevent a negative impact on users’ quality of experience. In addition, it should be cost-effective, easy to install, have a small footprint and be able to adapt to a challenging environment.
Operators are experimenting with different solutions for backhauling their traffic. For instance, Bharti Airtel has tied up with ECI Telecom to expand its mobile backhaul transport capabilities across India to support the increasing demand for bandwidth. The operator will deploy ECI Telecom’s Neptune family of products that will enable it to migrate its mobile networks from 2G to 3G to 4G, and eventually to LTE-A. Neptune offers a powerful, efficient, E2E metro-core and aggregation solution for high-performance L1 to L3 services through the convergence of IP (internet protocol), elastic MPLS (multiprotocol label switching), Ethernet (MEF CE2.0 certified), optical transport network and wavelength-division multiplexing. The platform will evolve to support NFV (network functions virtualisation) services and SDN (software-defined networking) applications, which are likely to become necessary in the future. Similarly, in August 2015, Vodafone India launched a Wi-Fi offloading application to shift data traffic away from the cellular network and help decongest it. The application, called Vodafone Wi-Fi Connect, comes into effect when a user enters Vodafone’s Wi-Fi zones in Delhi and Mumbai. The operator has set up about 100 such zones in the two cities. Meanwhile, other operators are also considering Wi-Fi offloading as a viable solution that can be deployed along with the existing macro base-station network, resulting in more spectrum availability for data usage.
Going forward, the industry is likely to witness widespread commercial deployment of 5G technology, which will further add to the capacity of telecom networks. It is important for the industry to evaluate the impending challenges and requirements pertaining to backhaul networks. It goes without saying that backhaul infrastructure will need to evolve to become robust enough to support high-speed data without compromising on the user experience.
