SatLink's Open Hub Architecture

The Open Hub architecture specifies a completely open, standards-based TDM/TDMA Hub architecture at both the software and hardware level for IP networking over satellite.

This allows for Hubs and complete satellite networks that integrate easily into existing network environments and which will evolve with the needs of the hub owner. This allows easy upgrades to support more VSATs and/or more carriers. This allows for fast swap-outs using industry standard equipment like Cisco and networking interfaces like Ethernet. This also allows for sharing the hub with other organizations on a controlled access basis and allows for the optional integration of third party hardware modules for value-added functions.

Example third party equipment includes: application-level traffic shapers, application-level accelerators, multicast IP and IPTV servers, advanced network security devices, VoIP gateways and SIP servers, beacon receivers, and L-Band or optical RF switches.

At the software level, the SatLink NMS (Network Management System) has a built-in web-server with HTTPS support to provide easy, but secure, access to authorized operators. They can use almost any type of device (e.g., smart phone) to perform tasks from anywhere, anytime, via its graphical user interface.

Hub owners can easily create and authorize Virtual Network Operators (VNOs) to access the NMS only to monitor or fully manage their own VSATs, or have other degrees of limited control, as if they had their own private Hub. VNOs are organizations with their own skilled operational staff (or moderate technical expertise). No dedicated hardware or carriers are required to add VNOs to a SatLink Hub.

Also supported is integration with the customer’s Operational Support Systems (OSS) and/or Business Support Systems (BSS) through a "North-Bound" Application Programming Interface (API), ideal for this purpose, based on the widely-used SOAP standard for this type of application-level integration.

All SatLink Hubs are designed to support the well-established, open standards of DVB-RCS and DVB-RCS2 for TDM/TDMA networks. These standards, published by the European Technical Standards Institute (ETSI) are the only open, fully documented standards for TDM/TDMA technology. See DVB-RCS & DVB-RCS2 for more information on these standards.


Schematic Diagram of a SatLink Hub

OpenHub Architecture


Due to its open architecture, easy scalability is achieved for up to ten (10) forward links and 50,000 VSATs simply by adding FLS modules to standard racks. The addition of more TDMA carrier capacity is obtained by adding more RLS modules, one per FLS, or multiple per FLS if needed. Each RLS can manage one or more different TDMA Carrier Groups. One Network Accelerator (NetAcc) can serve multiple FLS modules (and their associated RLS modules) as may be desired depending on traffic loads. More NCC modules can be added if TDMA Carrier Group throughput requirements (and therefore timeslot assignment rates) grow excessively.

Further scaling beyond 10 Forward links (or 50,000 VSATs) is accomplished by adding another NMS.

The Hub can be configured for any desired forward to return traffic ratio, even for networks with more Return (and/or Mesh) capacity than forward capacity.

Redundancy ratios can vary from 1:1, 2:1, etc., up to 5:1 for the FLS, RLS, NetAcc, and NCC, depending on the desired cost and availability targets. Even the LAN switching and IP routing are given full redundancy with automatic failover for carrier-class Hubs with availability that must exceed 99.999%.

The standards-based API for integrating the SatLink NMS with the customer’s OSS and BSS enables smooth work-flow processes for VSAT installations & moves, assignment of service plans to subscribers, managing alarms and accounting data, and enforcement of Fair Use Policies, among many other important operations and business functions.

In addition, all these OSS functions, as well as detailed Hub and VSAT configurations, monitoring, and performance analysis, can be performed directly in the SatLink NMS.

The SatLink Open Hub architecture stands in sharp contrast to the proprietary TDM/TDMA technologies and closed backplane, chassis-based Hub systems used by competitors.

Proprietary technologies have short lifetimes and do not evolve to their next generation reliably. Also, they more easily lock-in customers to a network that cannot be upgraded without full replacement.

Closed chassis-based Hubs have a single point of failure, in the backplane, typically, or due to a common control processor, power source, or single critical physical interface. They also have fixed or limited configuration ratios which force early obsolescence of the chassis as the network grows.

For introductory information on TDM/TDMA see Satellite Technology for IP.