IPStar |
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IPSTAR-1 Satellite is a Geostationary orbit satellite utilizing Ku-band spectrum for user applications. Ku-band spectrum provides the optimal solution for services in the Asia-Pacific region with a high Link-Availability (Margin) for user applications using a small user antenna size.
Proprietary waveforms are used for air interface between a user terminal and IPSTAR gateway. The downlink (Forward Link) to the Terminal will be TDM overlaying OFDM with patent pending enhancement to maximize the efficiency of spectrum utilization. The uplink channels (Return Link) from the user terminal will be based on Multimode Multiple Access MF-TDMA. The access methods can be selected by gateway Network Management System (NMS) to match application bit rate and traffic density requirement, including TDMA-DAMA for voice, and Slotted Aloha for web browsing and other bursty traffic. Every mode will employ advanced error correction coding, which will allow the uplink to use small antennas and power amplifiers even for high-speed uplink data rates. Future generation may employ spread spectrum CDMA technology to further enhance system capability. Optionally, there will be one-way version using telephone line as the Return Link, providing a cheaper alternative to a full two-way version.
The Satellite is a bent-pipe satellite achieving unprecedented capacity and functionality with no on-board regenerative payload. This eliminates the need for low reliability, heavy and power consuming on-board processor. Therefore, the Satellite will be as reliable as any conventional communications satellites and will certainly be more reliable than any broadband satellite that employs on-board processor. All intelligence, switching and routing capability will be put on the ground at gateway and network control centers. This will allow future upgrade of all electronics and software, which have been evolving with more capability and cost effectiveness at a very rapid pace.
The Satellite will have the capability to allocate its precious on-board resources (Dynamic Power Management and Dynamic Bandwidth Management) appropriately according to the actual need to maintain communication links at the highest level possible Quality of Service (QoS). This allocation is monitored and controlled on a dynamic basis through Satellite Payload Operation Center (SPOC) with the link quality information processed on-line by Gateway and Network Management Centers (GNCs).
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Key Technology Features
- Spot Beam Coverage: Traditional satellite technology utilizes a broad single beam to cover entire continents and regions. With the introduction of multiple narrowly focused spot beams and frequency reuse, IPSTAR is now capable of maximizing the available frequency for transmissions. Increasing bandwidth 20 times more than traditional Ku-band satellites translates into a more efficient satellite for SSA. Despite the higher costs associated with spot beam technology, the overall cost per circuit will be much lower than existing shaped beam satellites.
- Dynamic Power Allocation: This new technology optimizes the use of power among beams and allocates a power reserve of 20% to be allocated to beams that may be affected by rain fade, thus maintaining the link. Given the vast geographical coverage of the Satellite, it is unlikely that rain would fall simultaneously across the entire region; therefore this dynamic allocation of power only to beams in need is a very effective way to increase IPSTAR System's overall high link availability and reliability.
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| IPSTAR Technical Information
Spacecraft Configuration |
Description and Approximate Capacity |
Spacecraft |
- Geo-stationary satellite with Bent Pipe payload configuration (no on-board processing to avoid the obsolescence of processing technology which develops at a remarkable speed, no inter-satellite link)
- 12 years life
- 15 kW power
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Orbital Slot |
- Located at 120° East
- Additional satellite for co-location or different slot in the future
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Total Digital Bandwidth Capacity |
- 45 Gbps of Spot Beam aggregate capacity at 75-120 cm. Dish
- Equivalent to 1,000+ Transponders of 36 MHz of conventional coding and modulation
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Ku Beams
Ka Beams |
- 84 Spot beams, 3 Shaped beams, 7 Regional Broadcast beams
- 18 Feeder beams and Gateways
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Beam Configuration |
Description and Approximate Capacity |
Ku Spot Beams |
- For highly populated areas
- 20+ Gbps uplink (Return Link) capacity
- 20+ Gbps downlink (Forward Link) capacity (excluding broadcast capacity)
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Ku Shaped Beams |
- For less populated areas
- 0.5+ Gbps uplink capacity
- 0.5+ Gbps downlink capacity
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Frequency and Access |
Description and Approximate Capacity |
Uplink (Return Link)
(A narrow band data link from a consumer Terminal to the Gateway) |
- 14.000-14.375 GHz (Spot Beam)
- 14.375-14.500 GHz (Shaped/Spot Beam)
- 13.775-13.975 GHz (Broadcast beam)
- Multi-mode Multiple Access
- Slotted AlohaTDMA Aloha Return Link – STAR (IPSTAR Proprietary)
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Downlink (Forward Link)
(A wide band data link from a Gateway to the consumer Terminal) |
- 11.500– 11.700GHz (Broadcast Beam)
- 12.200 – 12.750 GHz (Spot Beam)
- 10.950 – 11.200 GHz (Shaped/Spot Beam)
- Turbo product code orthogonal frequency division multiplex L-code Link – TOLL (IPSTAR Proprietary)
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Terminal, Gateway, and Network Configurations
| IPSTAR user terminal will be a low-cost, flexible and high performance two-way satellite terminal that works in conjunction with the Satellite and the Gateway. Air interface employing advanced waveforms on forward and return channels are optimized for the overall system efficiency.
The waveform for forward channel is based on TDM-OFDM technology that utilizes bandwidth and power more efficiently.
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The forward channel is optimized to accommodate multiple data rates, a variable number of users of different modulation formats and forward error correction coding.
On the other hand, for the return channel is based on MF-TDMA technology for bursty traffic and dedicated allocation for high data rate applications.
The waveform is fixed to a more robust modulation to ensure link-availability at low transmission power. However, if higher transmission bit rates are required, the return channel can be configured to dedicated allocation behaving like a SCPC-Like (pre-assigned TDMA) channel that can support higher transmit data rates up to 4.0 Mbps at the expense of required additional transmit power from the user terminal. |
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Key Technology Features
- Dynamic Bandwidth Management: Because satellite links will always have less theoretical bandwidth than optical fibre links, efficient bandwidth management techniques are required to maintain the competitiveness of broadband satellite systems. A network control center will be used to allocate bandwidth capacity to each connection according to current traffic characteristics, network congestion, link conditions and user requirements. This technology will adjust bandwidth dynamically (modulation and coding) to suit changes in weather conditions, thus maintaining very high link availability. Since it will be used on the ground, it is upgradeable in the future if required.
- New Coding and Modulation Technique: IPSTAR's modulation and coding technologies provide for efficient use of radio frequency bandwidth which allows for high and flexible digital transmission rates. This system allows for the use of small antennas and transmitters suitable for home and corporate use and can maintain up to 99.6% link-availability rate. The Modulation and Coding (link parameters) can be adjusted dynamically, resulting in dynamic bandwidth capacity to optimize the trade-off between bit-rate and sudden changes in weather condition (such as rain).
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