Latency Performance Evaluation of LEO Starlink and SES-12 GEO HTS Network Under Tropical Rainfall Conditions

Abstract

High Throughput Satellites (HTS) in geostationary Earth orbit (GEO) have been rapidly launched to meet the growing demand for high-speed data. However, the latency of HTS remains the same as that of conventional GEO satellites due to the characteristics of their orbit. Recently, Starlink HTS satellites in low Earth orbit (LEO) mega constellations have been operationalised globally, providing low-latency internet services compared to GEO HTS. Despite their high-speed benefits, Ku-band HTS systems are highly susceptible to rain-induced signal attenuation, particularly in regions with heavy rainfall, such as the tropics and equatorial countries. This phenomenon weakens the radio frequency signals and impacts real-time latency in the communication link. This research aims to determine the latency effect of the HTS satellite in LEO and GEO and evaluate its performance under heavy rainfall conditions. This study utilises real satellite link services from SES-12 GEO HTS and LEO Starlink for performance assessment. Continuous latency measurements are recorded over six months to analyse Ku-band performance in a heavy rainfall region. The results indicate that extreme rainfall in the tropical region significantly affects GEO satellite links, causing prolonged signal degradation due to fixed ground stations. In contrast, Starlink’s LEO network experiences less impact from rain fade, as it dynamically switches between multiple satellites. The results show latency for the GEO terminal link ranges from 600 milliseconds (ms) to 3000 milliseconds (ms), whereas latency for the LEO Starlink terminal ranges from 20 milliseconds (ms) to 100 milliseconds (ms). Starlink provides higher satellite link availability at 99.6% onsite compared to 94% for the tropical region's SES-12 GEO HTS satellite services.

ABSTRAK: Satelit Jalur Lebar Berkapasiti Tinggi (HTS) dalam orbit geostasioner (GEO) berkembang pesat bagi memenuhi permintaan data berkelajuan tinggi. Namun, latensi HTS GEO kekal tinggi seperti satelit GEO tradisional. Sebaliknya, HTS dalam orbit bumi rendah (LEO) seperti Starlink menawarkan internet berlatensi rendah secara global.Walaupun berkelajuan tinggi, sistem HTS menggunakan jalur Ku terdedah kepada pelemahan isyarat hujan, terutamanya di kawasan tropika. Fenomena ini bukan sahaja melemahkan isyarat frekuensi radio tetapi juga menjejaskan latensi komunikasi masa nyata. Penyelidikan ini bertujuan untuk menentukan kesan latensi sistem satelit HTS di orbit LEO dan GEO serta menilai prestasinya dalam keadaan hujan lebat. Pengukuran latensi berterusan direkodkan selama enam bulan bagi menganalisis prestasi jalur Ku di kawasan beriklim hujan lebat.Kajian ini menilai kesan latensi HTS LEO dan GEO dalam keadaan hujan lebat menggunakan perkhidmatan satelit SES-12 GEO HTS dan LEO Starlink di Makmal Komunikasi Satelit IIUM. Keputusan menunjukkan hujan lebat memberi kesan besar kepada sambungan GEO kerana stesen bumi tetap, manakala rangkaian LEO Starlink kurang terjejas kerana boleh beralih antara satelit. Kelewatan GEO ialah 600ms–3000ms, manakala Starlink hanya 20ms–100ms. Starlink juga lebih stabil dengan 99.6% ketersediaan berbanding 94% bagi SES-12 GEO HTS di kawasan tropika menyebabkan degradasi isyarat berpanjangan.