Bent-Pipe Satellite Without On-board Regenerative Payload
The Thaicom-4 (IPSTAR) broadband satellite is a bent-pipe satellite with unprecedented capacity and functionality, and with no on-board regenerative payload. All intelligence, switching and routing capability is based on-ground, permitting future upgrades of the system platform's electronics and software.
Advanced Error Correction Coding for High Speed Uplinks with Small Antennas
Thaicom-4 (IPSTAR) utilizes proprietary waveforms for the air interface between the IPSTAR user terminal and gateway. The forward link to the terminal is TDM overlaying OFDM that incorporates system enhancements to efficiently maximize spectrum utilization. The return link from the user terminal is based on Multimode Multiple Access MF-TDMA for flexible gateway access, enabling Network Management Systems (NMS) to match application bit rates and traffic density requirements, including TDMA-DAMA for voice applications, and Slotted Aloha for web browsing and other bursty traffic.
Every mode employs advanced error correction coding, which allows the uplink to use small antennas and power amplifiers even for high speed data rates.
Adaptive Coding & Modulation (ACM) and Diverse Site Switching (DSS) Against Rain-Fade
IPSTAR's Adaptive Coding & Modulation (ACM) feature mitigates the effects of rain-fade which allows automatic adjusting of modulation, coding and gain on a per User Terminal basis, thus maintaining high levels of Quality of Service (QoS) and overall link availability. In addition, IPSTAR Diverse Site Switching (DSS) management monitors the beacon signal level and control site switching between a primary and diverse site during heavy rain in order to maintain high system availability.
Narrow Spot Beam Technology and Frequency Reuse
While conventional satellite technology utilizes a broad single beam to cover continents and regions, Thaicom-4 (IPSTAR) maximizes the available transmission frequency with the introduction of multiple spot beams and frequency reuse, resulting to 25 times higher bandwidth capacity than conventional Ku-band satellites. Despite the higher costs associated with spot beam technology, the overall cost per circuit is considerably lower than the existing shaped beam satellites.