TRAI drive test finds mobile network gaps on key Sikkim highways, tourist destinations

Gangtok / New Delhi: The Telecom Regulatory Authority of India (TRAI) has identified significant mobile network coverage gaps and uneven service quality across parts of Sikkim, with a recent independent drive test showing that connectivity deteriorates sharply along the highway linking Gangtok to Nathu La Pass.

The Independent Drive Test (IDT), conducted in May 2026, assessed the performance of four telecom service providers across Gangtok and Pakyong districts. The exercise covered 102.8 kilometers of city roads, 66.5 kilometers of the NH 310 corridor from Deorali Bazar to Nathu La Pass, and five key stationary locations frequented by residents and tourists.

Reliance Jio recorded the highest average download speeds among all operators, delivering 63.89 Mbps in urban areas and 60.26 Mbps on the highway. Airtel followed with average download speeds of 50.93 Mbps in city areas and 41.60 Mbps along the highway. Vodafone Idea posted average download speeds of 22.12 Mbps in cities and 13.79 Mbps on highway stretches, while state-run BSNL recorded the lowest performance at 6.68 Mbps on the highway.

Upload speed results showed a similar pattern, with Reliance Jio and Airtel leading the rankings and BSNL trailing the other operators.

The regulator also found that network reliability declined significantly in mountainous terrain. While urban areas generally maintained stable connectivity, highway routes experienced frequent coverage gaps, call drops and periods of call silence lasting more than three seconds.

BSNL recorded the highest number of poor signal samples, with 6,388 out of 16,333 samples in city areas and 6,087 out of 14,797 samples on the highway indicating weak coverage. The operator also registered the highest number of dropped calls in urban areas, with 18 call drops out of 117 successfully established calls.

Airtel and Vodafone Idea completed the city drive test without recording any call drops. However, all four operators experienced degraded performance on the NH 310 route toward Nathu La Pass, highlighting the challenges of maintaining reliable mobile connectivity in the Himalayan terrain.

TRAI also evaluated network quality at five high-footfall locations: the District Court near Suhim Colony in Gangtok, Nathu La Pass View Point at Kupup, the Sub-Divisional Magistrate’s Office in Pakyong, STNM Hospital in Sochakgang, and Tsomgo Lake View Point on Jawaharlal Nehru Road.

The regulator said its Regional Office in Kolkata has shared the findings with the telecom service providers and directed them to take corrective measures to improve network coverage, speech quality and overall service reliability, particularly along strategically important highway corridors and major tourist destinations.