The accelerated roll-out of high speed data services and the surge in data traffic has made backhaul revamping a key priority for operators. While the backhaul network of operators has traditionally been dominated by microwave, the proliferation of 4G and voice over long term evolution (VoLTE) services is paving the way for more fibre-based deployments. Currently, the level of fiberisation in India is abysmally low in comparison to other countries. This must change if operators are to meet the growing data demands of users. Apart from the fiberisation of backhaul, operators have shown an increasing interest in information protocol (IP)-based architecture for their backhaul network transformation. In fact, Reliance Jio Infocomm Limited (RJIL), the latest entrant in India’s telecom market, has already established an all IP-based telecom network. Further, Bharti Airtel and Vodafone India have partnered with Juniper and Cisco to transform their respective legacy backhaul networks and make them future-ready. Meanwhile, software-defined networking (SDN) and network functions virtualisation (NFV) technologies are also gaining traction. A look at the key trends in the backhaul space in India and the way ahead…
Evolution of backhaul networks
At present, operators rely heavily on microwave (75-80 per cent) for their backhaul requirements. While microwave served as an adequate backhauling medium in the 2G era, the transformation to 4G called for a backhaul network capable of supporting huge volumes of data. In light of the evolution of backhaul technologies in developed economies, a healthy mix of microwave and fibre seems to be the ideal choice for India. This is because the virtually unlimited capacity and extensive reach of fibre helps in establishing a high-capacity backhaul network. Operators like RJIL, Bharti Airtel and Vodafone India have recognised this and have started undertaking large-scale fibre roll-outs for their backhaul networks. However, deploying wired backhaul in remote areas is expensive and difficult. In such cases, wireless or satellite would be a more viable option, along with a multi-hop architecture to ensure large and efficient coverage of backhaul networks. A wireless or satellite backhaul solution could offer carrier-grade services, which may not be feasible with wired backhaul connectivity. Operators such as Bharti Airtel, Vodafone India, Reliance Communications, Bharat Sanchar Nigam Limited and Aircel have already deployed satellite backhaul solutions to cater to users in the remote regions of the country. In addition to satellite-based backhaul, the unused white space on TV spectrum could be used to backhaul data from village Wi-Fi clusters in order to provide broadband access.
As the industry gears up for the launch of 5G, operators need to prepare their backhaul networks for carrying exponential amounts of data.
Adoption of SDN and NFV
Along with fibre and satellite, technologies like SDN and NFV have also emerged as key solutions to revamp backhaul networks. SDN and NFV solutions support self-organising functionalities in the backhaul network. SDN solutions help make the complex backhaul network easier to manage by implementing a variety of software management protocols that automatically manage the network’s traffic based on its dynamic physical attributes. Further, SDN can automatically re-route traffic during peak times in order to ease congestion and keep the data traffic flowing. It can also make the network more efficient and keep operational costs in check by managing link usage.
Backhaul for small cells
The increasing need for ubiquitous indoor and outdoor connectivity has led operators to step up their small cell deployments. However, the key issue that they face while deploying a small cell network pertains to backhaul development. There is no one-size-fits-all solution for small cell backhaul. Therefore, a trade-off among capacity, coverage and cost often needs to be made. Backhaul networks for small cells can be established using any of the three mediums – bonded copper, fibre or wireless microwaves. Each of these has its advantages and disadvantages. Fibre connections provide the highest throughputs, but can be expensive without an already established infrastructure. DSL or copper provides limited data rates and requires pre-established networks. Wireless, on the other hand, requires navigation through varying line-of-sight conditions. Therefore, suitable solutions needs to be developed for small-cell backhaul. While the small cell backhaul equipment market is currently at a nascent stage, it is expected to be valued at around $4 billion by 2020, as per industry experts.
Exploring new spectrum bands
The most prominent solutions for meeting backhaul requirements for small cell deployment are millimetre wave technologies like E-band (70-80 GHz) and V-band (60 GHz). The E-band is suitable for high density and high capacity wireless backhaul applications and is ideal for small cell links of 300-500 metres. Further, it offers a wide spectrum range (10 GHz) and very high capacities similar to fibre. The E-band also solves the spectrum congestion problem in urban and suburban areas where spectrum is slowly running out. Meanwhile, the V-band is suitable for links in the 300-500 metre range and reduces intersystem interference. Further, spectrum in the V-band can be delicensed and used for backhaul to support multi-gigabit throughputs. In addition to small cell backhaul, the E-band and V-band could also play a crucial role in establishing a robust backhaul network for 5G networks. However, the government will have to make this spectrum available to operators in order to leverage its potential to improve backhaul networks.
Upcoming opportunities
The introduction of new technologies like 5G and internet of things is going to significantly alter the backhaul requirements of operators. In addition to the evolving technology landscape, the government’s Digital India initiative and the Smart Cities Mission have emerged as the key growth drivers for backhaul. The aim of providing seamless connectivity under these initiatives will significantly increase the backhaul network requirements at the user level, integration points and data centres. The launch of public Wi-Fi solutions under these programmes will further increase the demand for a robust backhaul network.
Testing and optimisation
After backhaul revamping and modernisation, operators need to maintain these networks and ensure optimal usage. This calls for adequate investment in network testing and optimisation, providing a significant impetus to the testing and measurement (T&M) market. T&M vendors enable operators to test their backhaul networks for quality and experience. As technology is continuously evolving, T&M vendors also help operators test their backhaul architecture for new services and applications. Further, with the launch of VoLTE services, the testing of the end-to-end integrated measurement system and signalling over the backhaul network have also emerged as key focus areas for T&M vendors. Going forward, as the industry gears up for the launch of 5G, operators need to prepare their backhaul networks for carrying exponential amounts of data, thereby creating a plethora of opportunities for T&M vendors.
Challenges and the way ahead
The telecom backhaul space in India is expected to evolve at a rapid pace in the future. However, the deployment of suitable backhaul solutions will not be devoid of challenges. The cost of installation and maintenance of backhaul solutions needs to be optimised without compromising on the quality of service. This calls for accurate forecast of data traffic and capacity optimisation to maximise the return on investment in existing network nodes. It is particularly relevant in areas where the network serves a small subscriber base. Further, regulatory challenges like licensing for E-band/V-band microwave spectrum and high right-of-way charges for laying fibre continue to affect the development of robust backhaul infrastructure. The industry requires a collaborative approach. Thus, all key stakeholders including the government, operators and equipment vendors need to make concerted efforts towards establishing future-ready backhaul networks that are capable of supporting the emerging technologies.
