INITIATIVES FOR IMPROVEMENT OF HF COMMUNICATION IN INDIAN AIRSPACE (Presented by India)

Transcription

1 12 th Meeting of Arabian Sea-Indian Ocean ATS Coordination Group ASIOACG/12) & 8 th Meeting of Indian Ocean Strategic Partnership to Reduce Emissions (INSPIRE/8) New Delhi, India, September 2017 AGENDA ITEM 6: Communication/Navigation/Surveillance Issues INITIATIVES FOR IMPROVEMENT OF HF COMMUNICATION IN INDIAN AIRSPACE (Presented by India) SUMMARY This paper presents Indian initiatives for improving HF communication in the oceanic airspace through space diversity technique and by replacing the existing HF transmitters & receivers in Mumbai, Chennai, Kolkata and Delhi with state of art equipment. 1. INTRODUCTION 1.1 Mumbai Oceanic Control Centre uses High Frequency Radiotelephony (HFRT) extensively for maintaining two-way communication with aircraft. This mode of communication assumes significance considering the fact that only 60% of aircraft operating in Arabian Sea / Indian Ocean airspace are using ADS-C/ CPDLC. Legacy aircraft which are not capable of satisfactory datalink communication rely solely on HFRT to remain in contact with Mumbai Oceanic Control (OCC). 1.2 Performance of HFRT in Mumbai oceanic airspace has been reported unsatisfactory by airline operators. The reason for this degraded performance may be attributed to inherent performance issues in tropical region and also to old generation equipment. 1.3 AAI is in the process of revamping the HF operations in Indian airspace by augmenting the HF reception through space diversity technique in Mumbai FIR. The roadmap includes replacement of existing HF Transmitters and Receivers with state-of-the-art equipment for increased level of redundancy and reliability. 2. DISCUSSION 2.1 Enhancing HF Reception in Mumbai FIR: In order to mitigate the issue of degraded performance of HF receivers during adverse propagation conditions, AAI is strengthening the HF infrastructure at airports on priority. This includes establishment of Network Assisting Stations employing Best Signal Selection (BSS) technique along the western coast of India with the objective of augmenting Mumbai HF. Two remote locations geographically separated, one each at Trivandrum and Chennai, were identified to install HF receivers thereby mitigating unsatisfactory local HF reception due fading of signals. These remote locations will be interconnected through terrestrial media which will introduce space diversity to reduce fading effect and selecting the best signal through Signal-to Noise ratio (SNR) voting. Page 1 of 5

2 2.1.1 The schematic diagram of Augmentation of Mumbai HF Reception with remote receivers located at Chennai, Trivandrum and Mumbai is attached as Annexure-I and II Four HF receivers each will be installed at Mumbai, Chennai and Trivandrum airports. Voice received at these locations will be converted to IP and the data will then be transmitted through the Multi Protocol Label Switching(MPLS) links to Mumbai, where the Signal to Noise Ratio will be compared to select the best audio, which will be routed to the HF operator for the frequency selected in the Remote Controller Unit This project is being carried out as SITC (Supply, Installation, Testing & Commissioning) project by M/s Rhodes and Schwarz and M/s Alps Techno Systems India with cost of INR 110 million and the installation is expected to be completed by December 2017.After the final implementation, the coverage of HF reception in the western coast of India is expected to improve. Significant improvement in HF coverage in the southern portion of Mumbai FIR is expected as shown in Annexure-III. 2.2 Introduction of State-of-The-Art HF transmitters and Receivers: Most of the HF transmitters which are currently being used at Mumbai, Delhi, Chennai and Kolkata have already completed specified service life. The occasional failure of equipment and degradation of equipment performance may be causing adverse effect on the HF communication especially in oceanic region. 2.3 AAI is in the process of replacing HF Transmitters and Receivers which has outlived its life span. A total quantity of 46 HF Receivers with estimate cost of INR 740 million and 29 HF Transmitters with estimate cost of INR 1240 million in Mumbai, Chennai, Delhi and Kolkata. (Refer Table-1). The project is planned to be completed by March EQUIPMENT MUMBAI DELHI CHENNAI KOLKATA TOTAL HF Receivers with accessories HF Receiver Antennas HF Transmitters with accessories Table A dedicated Specialized Maintenance Unit (SMU) shall be established at Hyderabad for maintaining the system with minimum downtime throughout life span. 2.4 It is expected that with the complete revamping of HF Systems, the performance of HFRT in India will significantly improve in regard to redundancy, range, availability and reliability. 3. ACTION BY THE MEETING 3.1 The meeting is invited to: a) Note the contents of this paper, and b) Discuss any related matter, as appropriate Page 2 of 5

3 SPACE DIVERSITY BETWEEN MUMBAI, CHENNAI AND TRIVANDRUM Pilot flies over Mumbai & Chennai FIR & sends frequency F1.All stations listens this frequency. Annexure - I Mumbai not receiving frequency F1 Due fading MUMBAI Chennai and Trivandrum receiving signals in frequency F1 CHENNAI IP RADIO GATEWAY TRIVANDRUM IP Radio VCX-IP Router For Best Signal Selection & Voice activity IP Radio Gateway VOTED AUUIO BEST BSS VCS System Existing Page 3 of 5

4 Annexure-II SCHEME FOR AUGMENTATION OF MUMBAI HF RECEPTION WITH REMOTE RECEIVERS Page 4 of 5

5 ASIOACG12 & INSPIRE8 IP05 Annexure-III GEOGRAPHICAL EXPANSE EXPECTED TO BE BENEFITTED Page 5 of 5