BSNL Indigenous 4G Built With TCS and Tejas Faces Call Drops, Connectivity Issues: Report

Why It Matters

Voice reliability is critical for telecom operators; persistent drops threaten BSNL’s market share and the credibility of India’s Made‑in‑India 4G ambition. The situation also tests the viability of domestically sourced network equipment against established global vendors.

Key Takeaways

• Indigenous 4G rollout causing voice call drops
• TCS, Tejas, C‑DOT built the 4G stack
• Data remains stable while voice suffers
• Subscriber churn rising in Kerala
• TRAI reports net subscriber decline in December

Pulse Analysis

India’s push for telecom self‑reliance reached a visible milestone when BSNL launched its fully indigenous 4G network in September 2025. The stack, assembled by Tata Consultancy Services, Tejas Networks and C‑DOT, promised a home‑grown alternative to foreign equipment and was hailed as a strategic win for national security and cost control. By leveraging domestic R&D, the consortium aimed to reduce dependence on legacy vendors and create a scalable platform for future upgrades such as 5G. However, the transition from legacy 2G/3G infrastructure to a new stack inevitably introduces integration challenges that can surface only under real‑world traffic.

Early field trials have revealed a stark contrast between data and voice performance. While broadband speeds meet expectations, voice calls suffer from frequent drops, one‑way audio, and erroneous “number switched off” prompts, even in areas with strong signal strength. These symptoms point to potential issues in the radio access network’s signaling protocols or the core network’s session management, areas that are notoriously complex when migrating to a new vendor‑agnostic stack. For subscribers accustomed to reliable voice service, such glitches erode trust and accelerate migration to private operators that already operate mature, globally sourced LTE solutions.

The commercial fallout is already evident. BSNL’s subscriber additions in September‑November 2025 were modest, and December data showed a net loss of over 200,000 users, a trend amplified in its Kerala stronghold where complaints are most vocal. Competitors are likely to capitalize on this weakness, offering bundled data‑voice packages and leveraging their established network stability. Regulators, meanwhile, will monitor the rollout closely, balancing the strategic goal of indigenization with consumer protection mandates. BSNL must accelerate remediation, possibly by hybridizing with proven foreign modules, to restore voice reliability and safeguard its market position while preserving the broader vision of a domestically sourced telecom ecosystem.