TRAI Assesses Mobile Network Quality 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.

Information Note to the Press (Press Release No. 88/2026) TELECOM REGULATORY AUTHORITY OF INDIA www.trai.gov.in New Delhi, 03 July2026 For Immediate Release TRAI Assesses Mobile Network Quality 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. 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. 2. 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. 3. 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 8th May’ 2026 to 9th 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. 4. 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: - 15. Key Parameters Assessed a) Coverage Gap: Percentage of samples, for which signal strength observed less than the minimum prescribed signal strength for respective technology (2G/ 3G/ 4G/ 5G). b) Voice Services: Call Setup Success Rate (CSSR), Drop Call Rate (DCR), Call Setup Time, Call Silence Rate, Speech Quality (MOS). c) Call Silence Instance: Number of call silence instance occurred during the calls. d) Data Servies: Download/ Upload Throughput, Latency, Jitter, Packet Drop Rate 6. 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. 2Annexure 1. Gangtok and Pakyong Districts (City drive) Coverage Gap – The coverage distribution found less than the minimum specified signal strength for the drive test route in auto-selection mode (5G/4G/3G/2G) during voice testing, is as below: Parameter AIRTEL BSNL RJIL VIL Total Number of Samples captured on Drive test 18887 16333 18790 18653 route Number of Samples having poor signal strength 1348 6388 476 3504 Number of Samples having no coverage 0 1531 0 0 Note: Signal strength has been considered poor if it falls below −110 dBm for 5G & 4G, −90 dBm for 3G, and −85 dBm for 2G. Coverage Gap observed (City drive) AIRTEL BSNL RJIL VIL Note: Plot is based on Dynamic Drive Test results only. 4b) Dropped Calls - The TSP-wise details of dropped calls in auto-selection mode (5G/ 4G/ 3G/ 2G) are as below: Parameter AIRTEL BSNL RJIL VIL Number of successful Calls Established 131 117 134 130 Number of dropped Calls 0 18 3 0 Locations of Dropped Calls (City drive) BSNL RJIL Note: Dropped calls locations are shown in red colour and which can be clicked to know the exact location (latitude and longitude) on the map. 5c) Call Silence Instance - The TSP-wise details of Call silence instance in Auto-selection mode (5G/4G) are as below: Parameter AIRTEL BSNL RJIL VIL Call Established 129 104 125 122 (within service provider network) Number of silences calls for >3 Sec 8 5 4 7 Total number of silence instances for >3 Sec 17 5 5 17 Locations of Call Silence Instance (City drive) AIRTEL BSNL RJIL VIL Note: Call silence instances are shown in red colour and which can be clicked to know the exact location (latitude and longitude) on the map. 6d) Data Download and Upload throughput: The TSP-wise details of Average Download (DL) and Upload (UL) throughput against declared typical DL/UL Throughput for month, in Auto- selection mode (5G/4G/3G/2G) are as below: (i) Download Throughput RJIL Measured AIRTEL BSNL VIL Parameter (upto 5G) in (upto 5G) (upto 4G) (upto 5G) Typical Download throughput (Mbits/s) 5.04 5.00 15.00 15.00 declared by TSP Average Download Throughput measured during (Mbits/s) 50.93 10.88 63.89 22.12 IDT AIRTEL BSNL RJIL VIL Note: Plot is based on Dynamic Drive Test results only. 7(ii) Upload Throughput RJIL Measured AIRTEL BSNL VIL Parameter (upto 5G) in (upto 5G) (upto 4G) (upto 5G) Typical upload throughput (Mbits/s) 3.77 3.00 7.00 8.00 declared by TSP Average Upload Throughput measured during IDT (Mbits/s) 13.29 4.10 13.80 10.47 AIRTEL BSN L RJIL VIL Note: Plot is based on Dynamic Drive Test results only. 82. Deorali Bazar, Gangtok to Nathu La Pass via NH 310: - a) Coverage Gap – The coverage distribution found less than the minimum specified signal strength for the drive test route in auto-selection mode (5G/4G/3G/2G) during voice testing, is as below: Parameter AIRTEL BSNL RJIL VIL Total Number of Samples captured on Drive test route 13089 14797 8802 7563 Number of Samples having poor signal strength 4584 6087 1711 3597 Note: Signal strength has been considered poor if it falls below −110 dBm for 5G & 4G, −90 dBm for 3G, and −85 dBm for 2G. Coverage Gap observed (Highway drive) AIRTEL BSNL RJIL 9VIL Note: Plot is based on Dynamic Drive Test results only. 10b) Dropped Calls - The TSP-wise details of dropped calls in auto-selection mode (5G/ 4G/ 3G/ 2G) are as below: Parameter AIRTEL BSNL RJIL VIL Number of successful Calls Established 66 72 49 36 Number of dropped Calls 3 14 11 4 Locations of Dropped Calls (Highway drive) AIRTEL BSNL RJIL VIL Note: Dropped calls locations are shown in red colour and which can be clicked to know the exact location (latitude and longitude) on the map. 11c) Call Silence Instance - The TSP-wise details of Call silence instance in Auto-selection mode (5G/4G) are as below: Parameter AIRTEL BSNL RJIL VIL Call Established 48 63 36 31 (within service provider network) Number of silences calls for >3 Sec 9 7 5 7 Total number of silence instances for >3 Sec 17 14 10 13 Locations of Call Silence Instance (Highway drive) AIRTEL BSNL RJIL VIL Note: Call silence instances are shown in red colour and which can be clicked to know the exact location (latitude and longitude) on the map. 12d) Data Download and Upload throughput: The TSP-wise details of Average Download (DL) and Upload (UL) throughput against declared typical DL/UL Throughput for month, in Auto- selection mode (5G/4G/3G/2G) are as below: (i) Download Throughput (Highway drive) RJIL Measured AIRTEL BSNL VIL Parameter (upto 5G) in (upto 5G) (upto 4G) (upto 5G) Typical Download throughput (Mbits/s) 5.04 5.00 15.00 15.00 declared by TSP Average Download Throughput measured during (Mbits/s) 41.60 6.68 60.26 13.79 IDT AIRTEL BSNL 13RJIL VIL Note: Plot is based on Dynamic Drive Test results only. 14(ii) Upload Throughput (Highway drive) RJIL Measured AIRTEL BSNL VIL Parameter (upto 5G) in (upto 5G) (upto 4G) (upto 5G) Typical upload throughput (Mbits/s) 3.77 3.00 7.00 8.00 declared by TSP Average Upload Throughput measured during IDT (Mbits/s) 7.51 3.34 7.50 4.86 AIRTEL BSNL RJIL 15VIL Note: Plot is based on Dynamic Drive Test results only. 16