Scaling Up LTE Backhaul

We have witnessed the Indian telecom industry's dramatic voice-centric growth. Now, it is gearing for the second innings of the spectacular ‘data' growth and the entire ecosystem is curiously awaiting for the striking story to unfold. Operators are at this focal point; and they ought to set the stage with a few crucial pre-requisites. One of the key elements is to have an efficient and robust mobile backhaul network that not only ensures seamless voice but also data connectivity across 2G, 3G, and 4G/LTE technologies.

Mobile backhaul is essentially very crucial. All these technologies-2G, 3G, and LTE will co-exist and once LTE is in place, it will multiply the data deluge. As we transition from voice-centric services to data-centric telecom world, mobile operators ought to focus on upgrading the existing legacy network
systems.

From the past couple of years, mobile operators are experiencing unprecedented growth in demand for mobile broadband and mobile internet. This mobile internet phenomenon is global. Although there are variances per country, per operator, in the timeline, and in the extent to which the operators are willing or able to address this; one thing that is universally agreed upon is mobile backhaul network, which appears to be the most vulnerable to this change and needs re-engineering. Mobile providers are currently experiencing a huge rise in mobile backhaul capacity that addresses their current and future service requirements We have witnessed the Indian telecom industry's dramatic voice-centric growth.

Now, it is gearing for the second innings of the spectacular ‘data' growth and the entire ecosystem is curiously awaiting for the striking story to unfold. Operators are at this focal point; and they ought to set the stage with a few crucial pre-requisites. One of the key elements is to have an efficient and robust mobile backhaul network that not only ensures seamless voice but also data connectivity across 2G, 3G, and 4G/LTE technologies.

Mobile backhaul is essentially very crucial. All these technologies-2G, 3G, and LTE will co-exist and once LTE is in place, it will multiply the data deluge. As we transition from voice-centric services to data-centric telecom world, mobile operators ought to focus on upgrading the existing legacy network
systems.

From the past couple of years, mobile operators are experiencing unprecedented growth in demand for mobile broadband and mobile internet. This mobile internet phenomenon is global. Although there are variances per country, per operator, in the timeline, and in the extent to which the operators are willing or able to address this; one thing that is universally agreed upon is mobile backhaul network, which appears to be the most vulnerable to this change and needs re-engineering.

Mobile providers are currently experiencing a huge rise in mobile backhaul capacity that addresses their current and future service requirements Derek Long, head, Communication Services & Mobile Broadband, Ericsson India stated, "LTE technology has higher capacity than its predecessor. Operators must ensure that backhaul network is robust and redundant. They should ensure synchronization else it would impact quality and throughput.

A significant percentage of backhaul networks in India carry or dimensioned to carry voice traffic, which is required to be upgraded in a phased manner to carry high speed data that is made available over the air by LTE.

Data transforms Backhaul The mobile providers are currently experiencing large increases in mobile backhaul capacity to address their current and future service requirements. In addition to high speed data, video will be the key driver for backhaul networks.

According to Sanjay Nayak, MD, Tejas Networks, "Cell sites/ telecom networks can transport huge quantity of data only if they are fiberized. The fundamental problem in India is that the amount of fiber that reaches cell sites is very low, it is less than 20%. Whereas in China, cell sites connected on fiber is close to 50- 60%, in major cities of the US and Japan it is around 80-90%."

The microwave technology which is currently deployed by operators for backhauling 2G has been upgraded to 3G, but it will soon run out of gaps as soon as we move 3G data or 4G. So in order to leapfrog and address backhauling issues, operators have to establish cell sites on fiber. Until now operators rely on microwave radio technology for backhaul which will give limited data experience.

But there is a unique and technical backhaul challenge posed to operators because 2G, 3G, and 4G will have to coexist. LTE is purely data, while in 2G, and 3G the major chunk are voice services and voice revenues. Therefore, they cannot discard the legacy-TDM technology which is very useful, cost effective, and best for carrying voice. For carrying data, packet transport is very ideal. Nayak says, "Packet transport is the right technology if there is pure data. In order to map both voice and data, hybrid technology on fiber is best for backhauling. It will carry TDM traffic/voice traffic natively on TDM and data traffic natively in data. And operators who have only pure data can use pure packet network technology.

In packet transport there are 2 prominent backhauling technology- MPLS/TP and IP/MPLS." Providing a high quality video viewing experience by integrating the transport networks with CDN architecture will be very critical. The acceleration in video deployments increases the need to address the primary challenges of service providers looking for IP-based video transport solutions, including how to deliver video service-level requirements and how to effectively manage and monitor the video transport service.

Aman Roy Chowdhury, MD, Radwin Wireless Solutions says, "LTE would be offered in 2-3 Ghz in India and a network outlay model over a single RAN model is expected to be deployed by the operators. This model would entail LTE base station to be deployed close to customers to provide throughput efficiency."

"NLOS small cell Point-to-Point and Point-to-Multipoint solutions are available in the licensed and unlicensed sub-6 GHz bands (2.x, 3.x and 5.xGHz) and combine the most advanced airinterface technologies. The carrier-grade systems backhaul traffic from LTE/3G small cells in NLOS, severe multi-path, and high interference conditions, and can be deployed on street furniture such Mas traffic lights, light poles, and building walls," he adds.

The costs and expenditures associated with providing this increasing bandwidth have not being linearly matched by revenue growth. The primary objective is to increase the bandwidth while simultaneously reducing the cost per bit. Existing infrastructure will neither scale to the required bandwidth nor meet the cost reduction requirement. In the present scenario, IP/Ethernet-based backhaul has evolved to be a mandatory requirement. The LTE is an evolution towards all- IP architecture and will fundamentally change how mobile backhaul networks are built in the future. The availability of Ethernet-enabled NodeBs and the evolution towards LTE pushes IP awareness further into the edge of the mobile
network.

Mobile operators are beginning to view these backhaul networks like carrier Ethernet environments offering multiple concurrent services. LTE will make demands on the underlying transport in areas such as security, IPv6, distributed intelligence, multicast, synchronization, QoS, fast convergence, instrumentation, and management. The transport technology choices of today will be important for future evolution of the mobile architecture.

The LTE evolution demands a lot of intelligence and flexibility in the underlying network. LTE all packet network requires the network to be fault-resilient, similar to traditional TDM or SONET based networks where high availability/uptime is a must-have requirement. Service faults must be rapidly detected and reported before they impact the user. In addition, voice and data packets must be measured for throughput. Referring to LTE business models, Samar Mittal, head of sales development, India region, Nokia Siemens Networks says, "The business model for the Indian operators for successful LTE play in our opinion is one of co-existence and interoperatibility as well as focus on customer experience. We believe that 2G/3G/LTE/ Wi-Fi are all complementing technologies for the growth of mobile broadband."