|HX50L Broadband Satellite Router|
LDPC return channel for exceptional performance
The HX50L is the cost effective and highly scalable HX terminal which also features support for LDPC coding (same as used in the DVB-S2 standard) on the return channel as well as support for C-band operations. With Quality of Service (QoS) features such as Min CIR with Max Rate together with dynamic allocation of bandwidth the HX50L delivers the QoS demanded by the most rigorous end users. With integrated IP features including NAT/NAPT, DHCP, RIPV1, RIPV2, BGP, and DNS server/relay functionality, together with TCP acceleration and a high-performance satellite modem, the HX50L is the ideal platform to enable broadband IP connectivity for a variety of applications including Internet access, MPLS extension services, virtual leased-line services, and other high-bandwidth solutions.
- C-band network
- Internet services
- SCPC/MCPC replacement links
- MPLS extension services
- Embassy and government networks
- Private leased-line services
- Education services
HX System Architecture
The HX System provides true IP broadband connectivity via satellite. The HX System is based on a “star” network topology where the outbound channel is DVB-S2 with Adaptive Coding and Modulation (ACM). The return channel of the HX System is multi-frequency FDMA/TDMA using the IPoS standard for broadband over satellite. With a DVB-S/DVB-S2 outbound carrier and transmit rates up to 3.6 Mbps, the HX50L provides a cost effective and highly scaleable solution for satellite broadband networks.
Efficiency and flexibility in utilizing satellite bandwidth are at the core of the HX50L design. Each link can be configured to provide a QoS tailored to the requirements of the remote site. This includes adaptive Committed Information Rate (CIR) and Constant Bit Rate (CBR) services that provide guaranteed bandwidth though optimizing use of the bandwidth during periods of idle or light traffic. Remote sites with less stringent bandwidth requirements or service level agreements can be configured for best effort service, thereby allowing service providers to develop a service tailored to their customers’ specific requirements. In addition, the HX System bandwidth allocation scheme uses Aloha channels for initial bandwidth assignment which results in very efficient use of space segment. This frees up unused bandwidth and allows an operator to make more efficient use of space segment resources.
Optimizing the Return Channel with LDPC
OQPSK with LDPC coding provides exceptional performance:
- Spectral efficiency is similar when comparing Rate 9/10 versus 8PSK Rate 2/3;
- OQPSK is less susceptible to noise;
- Lower power BUC requirements;
- 8PSK requires larger burst size for coding gain.
Overall, LDPC provides superior performance.
The Hughes Outdoor Unit
The HX50L is supplied with the Hughes manufactured outdoor unit (ODU). Available in either C-band or Ku-band the Hughes ODU utilizes a constant envelope modulated carrier output that results in exceptional performance and reliability while offering over 9 dB of dynamic range for uplink power control. The ODU includes an LNB and is available in 1 and 2 watt versions for Ku-band and 2 watt for C-band.
- Quality of Service features include:
- Constant Bit Rate (CBR) services
- Adaptive CBR. Minimum and maximum rates are configurable, as is step size.
- Committed Information Rate (CIR) with minimum, guaranteed, and maximum rates
- Best effort with weighted fair queuing
- Class-based weighted prioritization
- Multicast data delivery
- Four levels of IP traffic prioritization
- Bandwidth management
- Supports both preassigned (static) traffic assignment and dynamic traffic assignment
- Idle remotes can be configured to release all network resources
- Acts as a local router providing:
- Static and dynamic addressing
- DHCP server or relay
- DNS caching
- RIPV1, RIPV2, BGP routing support
- Multicasts to and from the LAN by using IGMP
- VLAN tagging
- Firewall capability with integrated access control lists
- Supports unicast and multicast IP traffic
- Software and configuration updates via download from the HX Gateway
- Implements dynamic, self-tuning Performance Enhancement Proxy (PEP) software to accelerate the throughput performance by optimizing the TCP transmission over the satellite, delivering superior user experience and link efficiency
- Bidirectional data compression
- IPSec encryption (optional)
- Configuration, status monitoring, and commissioning via the HX ExpertNMS™
- Embedded Web interface for local status and troubleshooting
- User-friendly LED display indicating terminal operational status
- Closed loop control between hub and remote
- Dynamic outbound coding and modulation changes based on received signal
- Dynamic inbound coding changes based on received signal
- Dynamic remote uplink power control
- IPV6 ready