Comtech EF Data’s Advanced VSAT Series products offer industry-leading solutions for cellular backhaul, Universal Service Obligation (USO) networks, corporate networks, Internet Service Providers and other applications requiring high-performance IP transport in a hub-spoke network environment. Incorporating advanced technologies developed by Comtech EF Data, Comtech AHA and Memotec, these products are specifically designed to provide unmatched performance at an attractive price for a wide range of applications in a hub-spoke environment.
The Advanced VSAT Series includes the CDM-800 Gateway Router, the CDM-840 Remote Router, the CDD-880 Multi-Receiver Router and the CXU-810 RAN Optimizer. The products incorporate industry-leading WAN bandwidth optimization to provide the most efficient:
Physical layer transport without compromising latency
The Advanced VSAT Series supports the most advanced FECs available today:
DVB-S2 for the high-speed shared outbound traffic
VersaFEC (Low-latency LDPC) for return traffic
DVB-S2 delivers unmatched bandwidth efficiency for high-speed traffic.
VersaFEC is a patented (covered by U.S. patents 7,353,444 and 7,415,659; other patents pending) system of high-performance, short-block, low-latency LDPC codes designed to support latency-sensitive applications, such as cellular backhaul over satellite. VersaFEC provides excellent coding gain with lowest possible latency. VersaFEC’s coding performance is similar to that of DVB-S2 (short block) with 70-90% lower latency.
The combination of DVB-S2 for the outbound traffic and VersaFEC for the return traffic provides maximum spectral efficiency with minimal latency.
Adaptive Coding & Modulation (ACM) Capable
Satellite users have traditionally relied on worst-case link margin to overcome rain fade and other impairments, which leads to significant inefficiencies. ACM converts the available link margin into increased throughput - a gain of 100% or more is possible.
With the ability to maximize throughput under all conditions - rain fade, inclined orbit satellite operation, interference or other impairments - ACM allows each remote to achieve maximum throughput thereby maximizing network efficiency and availability.
RAN Optimization can significantly reduce the satellite bandwidth required for cellular backhaul. The RAN Optimization capability of the Advanced VSAT Series gives users the ultimate control by allowing them to select the level of RAN optimization to achieve desired link quality and bandwidth savings. The pre-emptive bandwidth management maintains superior voice and service quality even under wide area network (WAN) congestion. Supporting E1 RAN and IP RAN, the Advanced VSAT Series provides a seamless migration from a legacy E1 RAN to an all IP RAN with no change in satellite equipment.
Detailed usage statistics are also provided to assist with link monitoring and fine tuning.
Seamless E1 and IP/Ethernet Operation
The Advanced VSAT Series allows simultaneous E1 and IP/Ethernet operation in a hub-spoke topology, while supporting advanced capabilities including RAN optimization, header compression, payload compression, Quality of Service and ACM.
In addition to supporting hybrid networks, the products allow for seamless migration from an E1 RAN to an all IP RAN.
For efficient IP networking and transport over satellite, the Advanced VSAT Series features integrated routing capability with very low overhead encapsulation, header compression, payload compression and Quality of Service. The advanced QoS combined with header and payload compression ensures the highest quality of service with minimal jitter and latency for real-time traffic, priority treatment of mission critical applications and maximum bandwidth efficiency.
Header Compression - The Advanced VSAT Series supports industry-leading header compression for IP traffic. Header compression can reduce the 40 byte IP/UDP/RTP header to as little as 1 byte. For TCP/IP, the 40 byte header is reduced to as little as 3 bytes. For applications such as VoIP, header compression can provide bandwidth savings exceeding 60%. E.g. 8 kbps G.729 voice codec requires 24 kbps of IP bandwidth once encapsulated into an IP/UDP/RTP datagram. With header compression, the same voice call needs about 8.5 kbps - a saving of almost 65%. And, bandwidth requirements for typical Web/HTTP traffic can be reduced by 10% or more with TCP/IP header compression.
Payload Compression - The Advanced VSAT Series supports industry-leading payload compression for IP traffic. Implemented in the hardware for maximum throughput and efficiency, payload compression can reduce the required satellite bandwidth by as much as 40-50%.
Low Overhead Encapsulation - The Advanced VSAT Series supports low overhead encapsulation for transmit and receive. Comtech EF Data’s patent-pending Streamline Encapsulation (SLE) is used for the return channel encapsulation while Enhanced GSE is used for encapsulating the outbound traffic.
SLE can reduce the encapsulation overhead by as much as:
65% compared to HDLC
90% compared to AAL5 used in DVB-RCS
90% compared to proprietary framing used by other VSAT solutions
And, Enhanced GSE is typically 15-20% more efficient compared to standard GSE.
Quality of Service (QoS) - The Advanced VSAT Series supports multi-level QoS to ensure the highest quality service with minimal jitter and latency for real-time traffic, priority treatment of mission critical applications and maximum bandwidth efficiency.
Supported modes are:
DiffServ - Industry-standard method of providing QoS enabling seamless co-existence in networks that implement DiffServ
Max/Priority - Provides multi-level traffic prioritization with the ability to limit maximum traffic per priority class
Min/Max - Provides a Committed Information Rate (CIR) to each user defined class of traffic with the ability to allow a higher burstable rate depending on availability
G.703 Clock Extension
Cellular networks require precise synchronization of base stations, which is a challenge when using IP backhaul. Most operators are forced to use GPS-based external equipment for site synchronization. The Advanced VSAT Series’ G.703 clock extension capability propagates a high stability G.703 reference from Hub to the Remote. This process does not require additional bandwidth.