Bharti Airtel Builds South Asia’s First Commercial TD-LTE Network

India-based Bharti Airtel is a leading multinational telecommunication company with more than 200 million users across 20 countries in Asia and Africa. It is the biggest mobile operator in India. In June 2010, with a bid of 33.14 billion rupees ($US655.6 million), the company obtained a 2.3 GHz broadband spectrum license. In the same year, Bharti Airtel chose to use TD-LTE technology in the construction of its 4G network. According to an estimate by well-known consulting company Informa, the number of LTE users in India will reach 18.83 million by 2016, and  revenue from data will reach $US11.446 billion by 2016. This represents a huge opportunity for the mobile market and is an incentive for Bharti Airtel to invest in a TD-LTE network.

In November 2010, several telecom equipment manufacturers were invited to conduct TD-LTE tests over a six month period. The tests items covered basic functionality, reliability, network coverage, and performance. ZTE passed more tests than any other company and had the best technology. In August 2011, ZTE signed a contract with Bharti Airtel to build a commercial TD-LTE network for Kolkata, India’s third-largest city. Of Bharti Airtel’s TD-LTE network construction projects, the Kolkata project is the only one in a type-1 city.

2G Site Sharing Saves Installation Costs 

 To save installation costs, ZTE thought carefully about site design and equipment installation. Existing 2G sites were used, and TD-LTE distributed baseband modules were positioned on the same racks as 2G equipment so that power supply and 2G transmission could be shared. To guarantee reliable power supply and reduce power costs, ZTE used DPD + Doherty technology to achieve a power amplifier efficiency of 30–40%. This greatly reduced the system’s power consumption.

In India, the base station antenna is usually installed on an iron tower; however, the cost to build an iron tower is five to ten times the cost in China under the same conditions. Also, land is very expensive in India, and towers are built very slim to accommodate three antennas only. This meets the minimal requirement of three sectors for a base station. There is no other choice but to build new iron towers for the antennas of a new network.

ZTE solved this problem by providing broadband multiport antennas that support both 2G and TD-LTE. These antennas replace the existing 2G antennas. A broadband multiport antenna has two ports for 2G RF modules, and the remaining ports are for TD-LTE RF modules. The ingenious structure of the multiport antenna saves the cost of building new iron towers and is an excellent example of how to use site space efficiently during multinetwork construction. The replaced 2G antennas can even be reused to further save costs. 

Exclusive Cell Splitting Technology Saves Equipment Costs

During the network construction for Bharti Airtel, ZTE used universal distributed macro base stations with four-channel RF modules. Generally speaking, one RF module can only support one sector; however, the four-channel RF module from ZTE supports cell splitting. By configuring backstage network management software, a four-channel RF module can be split into two two-channel RF modules to support two sectors. Compared with a two-channel RF module, a four-channel RF module increases the average capacity by 20% to accommodate more network users.

In the early stage of network construction, data services are developed differently in different regions. For example, residential areas demand more data services and suburbs demand fewer. If all regions use two-channel base stations, network congestion may occur in busy regions. If all regions use four-channel base stations, equipment installation and maintenance costs would be high, and power would be wasted in idle regions with fewer users.

 In India, ZTE combined two-channel and four-channel base stations according to user demands in different regions. A four-channel RF module was used to support one sector in high-capacity regions, and a four-channel RF module was split into two two-channel RF modules to support two sectors in low-capacity regions. A base station has three sectors, so it only needs two four-channel RF modules for full network coverage. This saves 30% of equipment purchase, construction, and maintenance costs. When low-capacity regions become high-capacity regions, network capacity can be expanded by combining cells and increasing the number of RF modules.

Diverse Terminals for Commercialization

As a multinetwork operator, Bharti Airtel has always used different companies to supply equipment and construct networks. This means that equipment of different suppliers needs to be connectable with base stations. There are also numerous TD-LTE terminal manufacturers, and connectivity between different terminals is a test of the maturity of base station equipment. ZTE’s open and standard base station port design ensures that different equipment can be connected. The diversity of terminals is a prerequisite for successful network commercialization. During the process of building the network for Bharti Airtel, ZTE conducted connectivity tests with devices from more than 40 manufacturers and laid a good foundation for network commercialization. ZTE has five terminals that can be used on Bharti Airtel’s commercial TD-LTE network, including TD-LTE single-mode data card, TD-LTE/FDD-LTE/UMTS/GSM multimode data card, indoor CPE, outdoor multimode CPE, and TD-LTE/UMTS/GSM multimode uFi that supports Wi-Fi signal conversion.

Highly Efficient Network Delivery 

During the Bharti Airtel’s TD-LTE project, ZTE strictly monitored shipment, installation, network optimization, and debugging. ZTE provided professional project management teams throughout the entire project, from site selection to construction and installation. On September 28, 2011, ZTE transported the equipment to the site in Kolkata and began installation. On October 28, 2011, the first call was made. On March 1, 2012, the first 500 sites were installed. On April 10, 2012, South Asia’s first TD-LTE network was commercialized in Kolkata.

On April 10, 2012, Bharti Airtel launched the TD-LTE network and demonstrated it to the media, government officials, and users. The high download speed and HD video streaming provided by TD-LTE was impressive. Kapil Sibal, minister of human resource development and minister of communications and information technology of India, was present and addressed the ceremony. Bharti Airtel President and CEO Sunil Mittal said, “I would like to thank ZTE who has built this network for Bharti Airtel here in Kolkata. It is actually the first relationship that we have set up with ZTE who are one of the leading providers of broadband services and mobile network, and I would like to express my thanks to ZTE for having put up this wonderful network in a very short time expectation.”

Bharti Airtel recognized the quick delivery, outstanding performance, and perfect end-to-end solution demonstrated by ZTE in the Kolkata TD-LTE project. On November 2012, ZTE secured another two contracts to build TD-LTE networks in Punjab and Haryana, becoming Bharti Airtel’s biggest TD-LTE equipment supplier. In the future, ZTE will work closely with Bharti Airtel to bring better and faster mobile internet to Indian users.

Bharti Airtel President and CEO Sunil Mittal said, “I would like to thank ZTE who has built this network for Bharti Airtel here in Kolkata. It is actually the first relationship that we have set up with ZTE who are one of the leading providers of broadband services and mobile network, and I would like to express my thanks to ZTE for having put up this wonderful network in a very short time expectation."