• C-DOT says 175,000 4G base stations across 100,000 sites are serving about 22–23 million BSNL 4G subscribers
  • HD voice is running in seven telecom circles, while C-DOT's 5G radio remains under live testing on BSNL's network in Ambala

The fact

BSNL's 4G network is now carrying close to 6 petabytes of data each day and serving about 22–23 million subscribers, according to Rajkumar Upadhyay, chief executive of India's Centre for Development of Telematics (C-DOT). He said the network has 175,000 4G base stations spread across roughly 100,000 sites.

The rollout uses technology developed and supplied by an Indian consortium led by Tata Consultancy Services. Tejas Networks provides the radio equipment that links customers' phones to the network, while C-DOT supplies the core technology that routes traffic and supports services. BSNL is still expanding the network, having ordered more than 26,300 additional 4G sites in August.

C-DOT is also extending the services running on top of that infrastructure. Its platform for HD voice calls over 4G is live in seven telecom circles, India's regional service areas, with a wider rollout planned. Separately, the company is testing its 5G radio technology on BSNL's network in Ambala. Upadhyay said a nationwide commercial 5G deployment would require a separate tender.

The assessment

The important change is that BSNL's 4G network is no longer being judged mainly by how many sites it has built. With 22–23 million subscribers now using the network and around 6 petabytes of data moving through it each day, the harder question is whether BSNL can keep service reliable as usage grows.

That cannot be answered by the 6PB figure alone. A network can carry a large amount of traffic and still perform poorly in crowded areas or at the busiest times of day. What matters now is whether customers continue to get stable speeds, reliable calls and consistent service as more people move onto 4G and BSNL adds new sites.

For BTW readers, this shifts the focus from rollout to operation. Site numbers show how far BSNL has built its network; performance data will show how well that network actually works. That operating record will also matter as C-DOT tests 5G, because a larger technology upgrade is more credible if the existing 4G network can handle growing traffic reliably.

What to watch

Watch for BSNL or C-DOT to publish busy-hour speeds, availability, dropped-call rates or congestion data alongside daily traffic. Expansion of HD voice beyond seven circles will provide another operating test. C-DOT's Ambala 5G trial is expected to conclude within about a month, with any subsequent tender representing the next commercial step.