Revamping Networks: Upgrading backhaul set-ups to meet high speed data demand

The accelerated roll-out of high speed data services has made backhaul revamping a key priority for operators. High capacity backhaul networks are needed for handling a range of new functionalities like quality of service and resilience management. As a result, several new trends have emerged in the backhaul space, including a strategic shift towards deploying more fibre. Industry experts comment on the key trends in backhaul network deployment, operator challenges in migrating to all-IP and the key growth drivers…

How have operators’ backhaul requirements changed over the past few years? What are the key trends in this space?

 

Brijendra K. Syngal

The backhaul requirements have changed significantly in the past few years in terms of network architecture as capacity requirements have grown manyfold owing to the rising demand for high speed data services.

 

 

 

Vishant Vora

There has been significant uptake of wireless broadband data services, especially in urban areas, driven largely by customers’ messaging and browsing needs. India is also witnessing a paradigm shift in messaging and browsing with video now becoming a significant component of the overall mobile data traffic.

 

 

Bijender Yadav

Initially, backhaul was required only for carrying voice traffic. The maximum backhaul requirement per site was 2 Mbps and it was even shared amongst three or four sites in the case of less utilised sites. Now, with the roll-out of 3G and 4G services, these requirements have increased manyfold.

What backhaul strategies can operators deploy to better meet the growing demand for mobile broadband in the country?

Brijendra K. Syngal

The choice of backhaul technology must take into account parameters such as capacity, cost, reach and the need for resources such as spectrum, optical, wiring, and right of way (RoW). Wired backhaul is a very expensive solution, and is difficult to deploy in remote areas, thus making wireless or satellites a more suitable and viable option. Multi-hop wireless architecture can overcome the hurdles of wired solutions to create large and efficient coverage areas. Further, a wireless or satellite backhaul solution is able to offer carrier-grade services, which may not be feasible with wired backhaul connectivity.

Vishant Vora

With the increase in data volumes, there is a need to evolve city and national backhaul networks from low-capacity to high-capacity superhighways, with capacities of more than 100 Gbps. Fibre is the best technology for such superhighways. How­ever, it brings with it challenges with respect to capital investments and operations. Connectivity to the last mile can be achieved through a combination of optical fibre and wireless technologies such as IP microwave radios.

Bijender Yadav

In order to better meet the growing demand for mobile broadband in the country, operators need to deploy more fibre for backhaul as microwave has capacity limitations. We deploy backhaul in two stages – first, at the aggregation nodes of smaller rings (access rings) comprising 5-7 sites and then, for bringing these aggregation nodes back to the central point. Typically, we use microwave for backhaul at access rings and then from the aggregation node onwards, we use fibre. Therefore, we have a network that is a mix of microwave and fibre. Earlier, we could use microwave for backhaul at both the stages. Going forward, given the increasing capacity requirements, we would need fibre at every site unless we get high capacity microwave links and more spectrum for microwave.

How will the microwave-fibre mix in backhaul deployment change over the next few years?

Brijendra K. Syngal

One cannot depend on a single technology or solution in this dynamic and always changing scenario. Several parameters such as deployment costs and time to implement should guide the adoption of the relevant technology.

Vishant Vora

Both fibre and microwave will play a significant role in operators’ networks over the next few years. India has the opportunity to embrace microwave technology that can support up to ten times the capacity of the current microwave radios (subject to regulatory and spectrum clearances). The greater the deployment of high-capacity microwave in the last mile, the lesser will be the need for fibre.

Bijender Yadav

Fibre deployment has always been challenging. Earlier, one had to pay only government RoW charges for laying fibre and these were not very high. Now, these charges have increased significantly, and one also has to pay private RoW charges.

Going forward, some kind of harmonisation in microwave spectrum is required as there is no parity in its distribution at present. Moreover, since this spectrum is not auctioned and comes free with the telecom licence, operators who were allotted the 15 GHz spectrum continue to maintain it and the newer entrants do not have too much left in the microwave space.

What are the key challenges faced by operators in upgrading their backhaul networks or migrating to all-IP networks?

Brijendra K. Syngal

As data rates increase, the range of wireless network coverage reduces, thus inc­reasing the investment costs for building infrastructure.

Vishant Vora

Fibre deployments are extremely expensive. Moreover, the process for obtaining approvals for digging and roll-outs is cumbersome. The conventional 2G service has been operating on legacy backhaul technologies; therefore, the transition from existing legacy to new technology backhaul requires the migration of existing services without any negative impact on the customer. The transformation needs to be carried out across the country. Vodafone India is undertaking backhaul transformation while rolling out 3G and 4G services. Meanwhile, the new-age 3G/4G networks are heavily dependent on IP technologies and hence there is a significant need for engineers who have expertise in this field.

Bijender Yadav

The key challenge faced by operators in migrating to all-IP networks is that of legacy equipment. Since we started with time division multiplexing (TDM), we still have a lot of TDM equipment that needs to be converted into all-IP. We may first need to move to a hybrid network (TDM plus IP) before going for all-IP networks. However, newer operators can start with all-IP networks since they don’t have a legacy to carry. At Sistema Shyam Tele­Ser­vices Limited (SSTL), we started with all-IP networks from day one.

What opportunities will projects such as Smart Cities and Digital India create for the backhaul segment?

Brijendra K. Syngal

These two projects, along with the internet of things, will create massive backhaul network requirements at the user level, integration points and centres where data would be used or processed for applications and transactions, etc.

Vishant Vora

Smart cities are a mechanism to connect citizens with the government and the community at large. It is a widely established fact that broadband connectivity has a strong correlation with GDP improvement in countries. Mobile broadband will bring in the much-needed citizen inclusion in driving economic growth. For broadband connectivity to be successful, there is a significant demand for high-capacity backhaul. This is akin to highways for a road network or rail network in a high speed train network.

Bijender Yadav

If the scope of the Smart Cities and other projects is limited to providing public Wi-Fi, it would not help in the growth of the backhaul segment.

For smart cities, we need smart backhaul and dedicated corridors for laying a robust fibre network with no government RoW or private RoW charges. Globally, big smart cities have adopted this strategy.

What will be the key growth drivers for the backhaul market in India in the coming years?

Brijendra K. Syngal

Higher economic growth, particularly the expansion of segments like e-governance, will be the key growth driver for the backhaul market in India in the coming years. However, in order to keep pace with the increasing demand, an adequate quantity of spectrum must be made available for backhauling. This would require policy initiatives such as spectrum refarming.

Vishant Vora

With sub-Rs 10,000 price points, smartphone adoption has gained momentum in urban centres, which has contributed significantly to increasing broadband consumption in the country. Vodafone India has made major investments in fibre and wireless technologies to improve customer experience in targeted urban areas. Going forward, video consumption on mobile will be a key driver for growth on mobile networks, which will have a direct bearing on backhaul demand. These demands will get fulfilled through a combination of 3G, 4G and 5G technologies in the future. In addition, there is a significant entrepreneurial drive in India with initiatives such as Start-up India. This will stimulate the small and medium enterprise segment, which will fuel the need for high-capacity superhighways.

Bijender Yadav

The market for backhaul will not see any growth per se, going forward, but only evolution. The backhaul equipment will evolve in order to cater to the growing demand for mobile broadband for applications like e-governance. The migration to all-IP networks will also happen eventually, but it will take five to six years for the older operators to get rid of the legacy equipment.