The Telecom Regulatory Authority of India (TRAI) has released findings of Independent Drive Test (IDT) conducted across Gangtok and Pakyong Districts and from Deorali Bazar, Gangtok to Nathu La Pass along NH 310 in the State of Sikkim under West Bengal LSA, during the month of May- 2026, for information of general telecom consumers. The purpose of this drive test is to assess and verify real time quality of mobile network services (both voice & data) provided by Telecom Service Providers (TSPs). During the IDT, TRAI captures performance of TSPs for key Quality of Service (QoS) parameters like Coverage, Call Drop Rate (CDR), Call Setup Success Rate (CSSR), data Download (DL) and Upload (UL) throughput etc., which are then published to inform Consumers and encourage TSPs to improve their services.

These IDTs have been designed to capture on ground mobile network performance of all TSPs across diverse usages environment like cities, hotspots, public transport hubs, etc. In this type of drive testing, live data and voice sessions are established using SIM cards from all TSPs over 2G, 3G, 4G, and 5G networks. Multiple advanced test handsets are used, and the sessions are monitored and analysed in real-time using advanced Software Systems.

TRAI, through its appointed agency, conducted drive tests across City drive – 102.8 KMs, Highway drive- 66.5 KMs, Hotspot locations - 5, in Sikkim State during 8^th May’ 2026 to 9^th May’ 2026 in West Bengal LSA. These tests were conducted under the supervision of the TRAI Regional Office Kolkata. The observations presented in drive test reports represent the performance of the TSPs on the area/ route under test on the day/ time of conducting the drive test.

Drive Test Route Map: The following map provides overview of drive test routes indicating City drive, Inter-operator calling, Hotspots and Walk tests, as per the legends shown on the map: -

Key Parameters Assessed

1. Coverage Gap: Percentage of samples, for which signal strength observed less than the minimum prescribed signal strength for respective technology (2G/ 3G/ 4G/ 5G).
2. Voice Services: Call Setup Success Rate (CSSR), Drop Call Rate (DCR), Call Setup Time, Call Silence Rate, Speech Quality (MOS).
3. Call Silence Instance: Number of call silence instance occurred during the calls.
4. Data Servies: Download/ Upload Throughput, Latency, Jitter, Packet Drop Rate

           

The overall mobile network performance in Gangtok and Pakyong Districts and from Deorali Bazar, Gangtok to Nathu La Pass along NH 310 for the key parameters has been summarised below: -

a)    Coverage Gap - The signal strength observed during voice testing on the city drive test route and highway drive test route in auto-selection mode (5G/4G/3G/2G), measured as the number of samples having poor signal strength out of the total samples collected, was 1348/ 18887 for Airtel, 6388/ 16333 for BSNL, 476/ 18790 for RJIL and 3504/ 18653 for VIL in the City drive test and was 4584/ 13089 for Airtel, 6087/ 14797 for BSNL, 1711/ 8802 for RJIL and 3597/ 7563 for VIL in Highway drive test. Details of the coverage gaps have been provided in the map Annexed.

 

b)    Dropped Calls - Dropped calls, measured as the number of dropped calls out of the number of successfully established calls, were 0/ 131 for Airtel, 18/ 117 for BSNL, 3/ 134 for RJIL and 0/ 130 for VIL in City drive test and was 3/ 66 for Airtel, 14/ 72 for BSNL, 11/ 49 for RJIL and 4/ 36 for VIL in Highway drive test. Details of the dropped call locations have been provided in the map Annexed.

 

c)    Call Silence Instance - Call silence instances, measured as the total number of silence instances observed for > 3 seconds out of the total calls established, were 8/ 129 for Airtel, 5/ 104 for BSNL, 4/ 125 for RJIL and 7/ 122 for VIL in City drive test and were 9/ 48 for Airtel, 7/ 63 for BSNL, 5/ 36for RJIL and 7/ 31 for VIL in Highway drive test. Details of the dropped call locations have been provided in the map Annexed.

 

d)    Data Download and Upload Throughput:

 

i)   Data Download performance (Overall): Average download speed was observed as 50.93 Mbps for Airtel (5G/4G), 10.88 Mbps for BSNL (2G/4G), 63.89 Mbps for RJIL (5G/4G) and 22.12 Mbps for VIL (5G/4G/2G) in the City drive test and 41.60 Mbps for Airtel (5G/4G), 6.68 Mbps for BSNL (2G/4G), 60.26 Mbps for RJIL (5G/4G) and 13.79 Mbps for VIL (5G/4G/2G) in the Highway drive test. Detail of Download throughput has been provided in the map Annexed.

 

ii)  Data Upload performance (Overall): Average upload speed was observed as 13.29 Mbps for Airtel (5G/4G), 4.10 Mbps for BSNL (2G/4G), 13.80 Mbps for RJIL (5G/4G) and 10.47 Mbps for VIL (5G/4G/2G) in the City drive test and 7.51 Mbps for Airtel (5G/4G), 3.34 Mbps for BSNL (2G/4G), 7.50 Mbps for RJIL (5G/4G) and 4.86 Mbps for VIL (5G/4G/2G) in the Highway drive test. Detail of Upload throughput has been provided in the map Annexed.

 

Locations of Dropped Calls and Call Silence instances can be seen by clicking red dot on the map Annexed.

 

Details of drive test route and area covered during the IDT is as under: -

a)    City - The areas covered in the city drive are Gangtok, Ranipool, Pakyong, Rorathang, Kumrek, Rangpo, Majitar, Singtam, and Mangthang etc etc.

 

b)    Highway- The areas covered in the HW drive are Deorali Bazar to Nathula Pass via NH 310 passing through Gangtok, Tathangchen, Hanuman Tok, Rongyek, Tsomgo Lake and Sherathang etc.

 

c)   Hotspot - The hot spot locations, capturing stationary user experience, are (i) District Court  

      Near Suhim Colony District Court Gangtok Sikkim; (ii) Nathula Pass View Point Kupup  

      Sikkim; (iii) SDM Office Pakyong East Sikkim; (iv) STNM Hospital Sochakgang Sichey  

      Gangtok Sikkim; (v) TSOMGO Lake View Point Jawaharlal Nehru Rd. Sikkim

 

The findings of this IDT report have been shared with respective TSPs for taking further necessary action at their end. Detailed reports of IDT are made available on the TRAI website at www.trai.gov.in. For any clarification or additional information, an email can be sent to adv.kolkata@trai.gov.in or Regional Office of TRAI at Kolkata RO can be contacted on telephone no.  +91-33-22361401.

Click here to see Annexure

****

NJ/ARJ

(रिलीज़ आईडी: 2280639) आगंतुक पटल : 206