HetNet: The Best Bet For Network Congestion?

The bandwidth requirement in the country is ever increasing and sooner or later the Indian operators would need to go for heterogenous networks.

The biggest driver of movement towards hetnet is the increase in mobile broadband consumption in the country. This is evident from the recent report by Nokia Siemens Networks which says that the data traffic increased by more than 54 percent in the first half of the current calendar year. The report further says that the data consumtion will double by mid-2013. The GSM Association (GSMA) also estimates the Indian broadband subscriber base will reach 110 million in the next three years growing more than eight folds.

The recent launch of 4G services by Bharti Airtel Ltd. and significant reduction of 3G tariff by major operators like Bharti Airtel Ltd., Vodafone India and Idea Cellular Ltd. also points to the fact that the Indian operators are finally making efforts to push data. (See MTNL Set To Deploy Femtos, Aircel to Trial Next-Gen Hotspots, and 3G, LTE To Drive Small Cell Deployment.)

However, this also raises an important question: Is the current wireless network of the country sturdy enough to handle the data boom? And if not then what is the possible solution left for the operators to prevent network congestion without increasing their capital expenditure? (See Poor Network Hampering 3G Growth: Study.)

In this scenario, the networks of the country are going to go through a transformation. The operators would need to move from the traditional macro cells to adopt small cells. The network landscape will change with the data surge.

Some of the operators have already started working in this direction. Bharti Airtel has conducted a trial for small cells recently. The company also deployed pico cells of ip.access to upgrade its GSM network. Tata Teleservices is working with Vanu Networks and Idea is also in the process of conducting a trial of small cells.

The operators will have to switch to HetNet sooner or later because the data will boom and the spectrum price is costly. The biggest challenge is the backhaul part as it is questionable whether or not the backhaul of the operators is strong enough to handle the adoption of small cells or not, says Katyayan Gupta, Analyst with Forrester Research.

Backhaul is one of the big challenges which telcos will face in their transition to a HetNet. Small cells can be linked by technologies such as microwave, fiber, wireless connectivity or in some areas copper. Telcos can either use existing infrastructure or go for a backhaul transmission which will positively impact the network performance.

Small cell solutions are self configuring and self optimizing which require very limited configuration changes in macro network so interworking is definitely not a major challenge. In India the main challenge would be to provide the backhaul to small cells but there are innovative solutions like millimeter wave and unlicensed band radios which can solve this problem as well, says Surojeet Roy, Lead - Wireless Solutions, Alcatel-Lucent India.

While there is no one-size-fits-all kind of a solution, there are certain things which an operator can do before deciding on its HetNet strategy. Since a small cell radius is significantly small, it is critical to decide where to deploy them. Depending on the technology chosen, one would have to take a decision on where to locate the hotspots for offloading the traffic while not disregarding the limiting factors such as friendly locations, backhaul etc, says Nokia Siemens Networks spokesperson.

Further an important part of the equation is the interworking between hetnet and macrocells. There are many considerations around that. One has to account for optimization of the multiple layers - take the most and the best out of them - while keeping the customer experience. Another thread of this is the integration to non 3GPP technologies such as WiFi. Then provisioning and setup for the user must be made seamless while making no impact on the experience, adds the NSN spokesperson.

The telcos would need to do extensive work in their movement towards heterogenous networks. However, it is clear that the telcos would need to move towards integrating small cells and WiFi in their network. In the end, the approach they take would depend on the market and their own economic and spectral considerations.

Gagandeep Kaur and Rimit Singh, Light Reading India