Microwave Backhaul Link Deployment Between Mt. Phulchowki and Tribhuvan International Airport for Aeronautical Surveillance

Overview

A 13GHz microwave backhaul communication link was supplied, installed, tested, and commissioned between Mt. Phulchowki and the rooftop of the Operations/Administration Building at Tribhuvan International Airport (TIA), Kathmandu, for the Civil Aviation Authority of Nepal (CAAN). The work was carried out under contract reference NCB-02/CNS/2022 (2078/79) and completed in 2023. The link spans a 15.3 km aerial distance, with Phulchowki located at an altitude of 9000 feet AMSL.

Scope & Deliverables

• Trango Systems equipment deployed: GigaOrion-IDU-1 (Single) indoor unit, HP4-13-0266-1A/1B high-power outdoor units, AD13G-3-S2 13GHz 0.9m antennas, OMC-13-HP-S2-V2 orthomode combiner, and PS-1U-TB-48revB power supply.
• Antenna structures mounted on 2m and 1.5m GI poles with L-shaped concrete foundations; weatherproofing applied using coax seal, PVC, and rubber tapes.
• Layer-2 managed switch installed for VLAN-based data segregation, supporting separate AOCC, ADSB, and Management networks.
• Link configured for 60 MHz bandwidth and 1 Gbps data speed, operating at 12814 MHz (TX) and 13080 MHz (RX), with Adaptive Coding & Modulation (ACM) and Automatic Transmit Power Control (ATPC).

Outcome

The link was commissioned with RSSI maintained at -39 dBm and reported stable operation under all weather conditions. It provides CAAN with a microwave backhaul path between Mt. Phulchowki and TIA carrying AOCC and ADSB traffic segregated by VLAN, supporting real-time aeronautical data transmission and air traffic communication.