Backhaul is a critical component of the entire telecom network architecture as it is responsible for providing speed and capacity. However, due to greater uptake of data services, telecom backhaul networks are under an increasing amount of stress. Data-centric services have a greater impact on the network as compared to voice services, which the network originally intended to handle.

The surge in data demand is rapidly changing the backhaul needs of telecom operators and is posing a number of challenges as enhancing the backhaul capacity or migrating to a new backhaul technology can involve significant capex. Such inv­estment is an added burden for the already financially stressed operators who are facing flat revenues and high levels of debt.

4G and the backhaul challenge

According to an industry report, data services currently account for nearly 85 per cent of network usage, but only 40 per cent of network revenue. Thus, operators are witnessing a less-than-commensurate increase in their revenues owing to the rise in data uptake. With the growing data demand, operators need to make their networks data-ready to deliver better customer service. For this purpose, a robust backhaul network is required. Therefore, even as operators’ subscriber bases grow, they are unable to cost-effectively meet the increasing traffic. In a scenario where data services are far outpacing voice in terms of demand, ARPUs from data services are not enough to offset the need for increasing capacity and the associated capex and opex.

Another major challenge is dealing with legacy backhaul in network architecture. The massive jump in data speeds when transitioning from 3G to 4G is one of the primary reasons for the increase in demand for backhaul capacity in recent times. While multiple T1/E1 copper circuits and microwave links were sufficient for 3G backhaul, for 4G, operators need to deploy higher-capacity backhaul solutions. This, however, requires replacing the legacy networks, which is a complex task. In fact, network complexity will only increase in the long run, as more next-generation long term evolution (LTE), and 5G radio access networks are launched. This also means that legacy networks would coexist with new technologies in the immediate future, adding yet another dimension to network operations.

In order to survive in the highly competitive Indian telecom market, it is imperative that operators offer outstanding customer experience. In view of this, mobile backhaul solutions play a significant role and need to be flexible and scalable in order to meet the demands of a rapidly changing technological environment. Another key backhaul-related challenge faced by operators is the limited spectrum availability. Network vendors go to great lengths to maximise the aggregate throughput in the limited quantum of wireless spectrum available in their networks. As a result, there is a substantial need for cost-effective non-radio frequency solutions that can move backhaul off overworked wireless frequencies. Moreover, there are challenges associated with frequency interference, non-line of sight and larger hop distances that operators face with respect to managing their backhaul networks.

The way forward

Given these concerns, mobile operators are re-evaluating their approach to backhaul networks. Most operators have migrated from a mix of legacy transport systems and multiple leased lines to packet-based technologies in order to support greater capacity at a lower cost.

However, this requires replacing the legacy transmission equipment, which does not support internet protocol (IP). Therefore, operators will have to undertake new transport planning for successful and cost-effective migration to an all-IP network. The IPfication of both legacy and next-generation radio equipment is necessary to move to pure-IP backhaul play.

As networks evolve and next-generation technologies become widespread, operators will have to deploy a disruptive combination of backhaul solutions to differentiate themselves from their competitors. However, apart from enabling a transition of legacy backhaul networks, these solutions should also be cost-effective.

At present, the backhaul space is characterised by the presence of a number of vendors, technologies and topologies. With both real and virtual networks poised to co-exist, mobile backhaul requirements will only become more complicated going forward. Therefore, the current backhaul architecture needs to evolve so that operators can seamlessly migrate to advanced networks such as LTE-Advanced and offer a better mobile user experience.