Satellites connect the world, but they generally neither connect to each other nor connect users to each other without some ground-based hub application, which adds time, complexity and cost at various levels. Every satellite link requires at least one spacecraft and two ground terminals. Some use more of one or the other but, until very recently, the only way to interconnect multiple end-users was to route signals through a complex ground network. Satellites have merely been “bent pipes” modulating and amplifying signals but not acting on the signals with any intelligence. While Iridium created a highly intelligent network ten years ago, with satellites switching signals and communicating with each other, intelligent broadband satellites, with processing, switching and routing capabilities on-board, are just coming into service, at the same time as IP-based services are becoming ubiquitous. This combination has the potential to dramatically change the way content is delivered, shared and stored adding user options and value for a range of key markets.

Despite the early demonstrations on NASA’s Advanced Communications Technology Satellite (ACTS) satellite starting in the 1970’s it is only with the recent start of service of Hughes’ SPACEWAY 3 satellite that commercial broadband users have benefited from onboard digital processing and packet switching combined with spot-beam technology for direct site-to-site high-speed connectivity. At about the same time, U.S. defense users also started receiving the same benefits on the WGS satellite network.

Looking forward, other alternatives being developed to move the intelligence into the sky include the ESA-funded ULtra fast Internet Satellite Switching (ULISS) demonstration program for Ka-band multimedia distribution using Radio Burst Switching, and the Internet Router In Space (IRIS) demonstration by Cisco, hosted by Intelsat General for the DoD. But what are the advantages of having switching or routing systems on-board the satellite, vs. on the ground? Most importantly, such on-board capabilities provide technical and cost advantages to organizations operating mesh networks among widely dispersed and possibly mobile terminals for whom the key benefit is the ability to have a virtual hub in space rather than tied to a specific node on the terrestrial network. This is particularly important when the terrestrial network may be at risk of being compromised, which is the case for disaster recovery, emergency, military and extraction industry operations.

Such systems also have the potential for storing large amounts of HD content and/or varying content by region without duplicating capacity. This is a great benefit for media applications that use IP as a transport medium, including streaming of video and entertainment content, corporate data and satellite news gathering applications. IPTV in particular may be significantly enhanced by the ability to provide different content by region with a simpler, more direct delivery model that provides economic value, specifically through benefits such as reduction of capacity needed, and the potential elimination of double hops.

How Do Individual User Groups Benefit?
On-board switching/routing benefits any vertical market that requires mesh capability added to a star network or having a hub anywhere in the network. On-orbit intelligence enables the user to eliminate the need to go through central point on ground - hub or data center or gateway — and supports the desire for point-to-point interconnectivity.

On the government side military goals of achieving the net-centric “Everything Over IP” service is clearly dependant on this type of advanced satellite processing. In addition, in the civil government arena, first responder command and control/tactical users benefit, because for them response time is critical, thus they value the ability to bypass double-hops for routing traffic. On the enterprise side the benefits are most obvious for large networks with thousands of sites (e.g., oil & gas; credit card verification), although small enterprises benefit from the reduction in backhaul links to a datacenter due to direct connections without the need for routing through a hub facility.

These mesh advantages particularly benefit broadcasters needing to get varying content to different market regions. For these users, on-board switching and/or routing can facilitate video on demand and other time-shifting applications. With the expansion of HD content offerings, broadcasters can provide more content choices and options as well as better capacity utilization at same or lower cost. This “selective connectivity” for video multicast facilitates individualized broadcasting to selected groups and sub-groups. This benefits not only broadcasters, but those corporate networks with remote teleworkers or consumers, such as small companies in remote locations. In addition, on-board routing or switching enhances a range of applications such as remote monitoring, maintenance and control systems including video that need the ability to increase feed or bandwidth size on demand to investigate issues at remote facilities in industries such as extraction or construction.

Mobility applications are especially well-suited to having intelligence in the sky. In this case, an advanced satellite with directive beams can support applications such as mobile IPTV, enabling both the mobile and on-demand access to interactive video for delivery of content to the truly moving edge. Other edge content applications include point-to-multipoint, such as satellite caching of data, imagery or other media for transport to different destinations and download as needed. These applications have value to a range of corporate and government users, such as military or first-responders needing ad-hoc visual communications, mapping, and headquarters coordination.

So Why Doesn’t Everyone Do This?
While most of the technology already exists, manufacturers will need to redesign some equipment for specific purposes, in particular the ground equipment. This poses difficulties for applications with a lot of ground terminals, since the cost savings from eliminating duplicate capacity or hub networking are offset by the risks. If there’s a problem with the satellite and a need to repoint to get switching through another bird; this also leads to questions about the availability and costs of backup options. There is also a need to drive power consumption down and right-size power for individual applications to keep the on-orbit technology cost-competitive with terrestrial options.

An additional requirement is for strengthened QoS to separate out video, data, voice for shared networks, and to establish or modify priorities among them, depending on the specific user requirements. This requires the network and its components be able to support customer-specified throughput consistently for a particular application, such as a business video session.

What Will Move This Forward?
As IP platforms, mobile applications and enhanced video services expand and integrate, so too will the advantages of having more intelligence on-board satellites rather than on the ground. At the same time, costs will be driven down by the continued cross-over of technology from military to commercial, broadcast to enterprise, supporting the business case for moving more investment in space to help move content closer to the edge.