Satellites and IT – Myths and Realities

Bruce Elbert

President,

Application Technology Strategy, Inc.

The connection between satellite communications and Information Technology (IT) was established some 20 years ago when the Very Small Aperture Terminal (VSAT) first appeared, but the debate as to its validity still rages. That major corporations like Wal-Mart and Chevron as well as several US government agencies including the US Postal Service and FEMA would adopt VSAT networks for data is clear proof. However, obstacles remain to satellites being a more common tool for overcoming the limitations of terrestrial services like T1s, Frame Relay and DSL. It is perhaps a contradiction that even in corporations that rely on private satellite TV for training and employee communications, the IT connection for data is lacking. I believe that greater confidence results when users understand that (1) satellite data communications is practical and affordable, and (2) the adoption of this approach is achievable with a reasonable amount of effort.

Satellites and Data

Satellite communication of data is merely a part of the overall telecommunications picture and thus has a natural connection to IT. This is because information resources that comprise IT are really embedded within a network, and that network employs telecommunications. Organizations with lots of employees at a single location, as well as at other locations, rely on Local Area Network (LAN) and Wide Area Network (WAN) facilities that they construct within and between buildings and that are obtained from service providers, notably telephone companies. All of this is expensive and demands attention to detail since every IT application is dependent on the availability and performance of these resources.

The good news is that the aforementioned front-line users of VSATs have demanded the same capabilities and service guarantees from leaders in the satellite industry as they do from other IT and telecommunications providers. Our industry is therefore prepared to respond to IT requirements for extended broadband connectivity. The Army discovered this – their “Network Centric” style of battle relies on commercial satellite links and ground equipment.

Why don’t most IT managers “think” in terms of satellites when an appropriate requirement comes up? I believe this is because satellites are appropriate in certain special cases, and these cases are exceptions to what normally arises for most enterprises or even individuals. Examples of these exceptions include:

1. High-speed access from remote places not adequately served
2. Extending service over a wide region such as a large country, continent or ocean
3. A necessity to deliver identical technical characteristics in areas with incompatible services
4. Extending across borders to achieve a trans-national network
5. Multicast of digital content on a point-to-multipoint basis
6. Distributing high-quality real-time video and audio

The key point is that when one such demand arises, an adept IT manager or network engineer will include potential satellite data solutions among the alternatives considered for extending the overall network. Experience shows that managers who do this will get results when and where they need them.

Dispelling Myths

Several of these exceptions involve service to remote or extensive areas where terrestrial networks either don’t exist or are very difficult to employ on a seamless basis. Thanks to the success of DBS and Satellite Radio, most IT managers and network engineers are well aware of what a satellite can physically do. However, that little piece of knowledge can be a dangerous thing because of a variety of myths that seem to prevail. Here is my summary of these doubt-creators:

Myth 1 - Satellite technology is for space cadets who were raised at a launch site. While it is true that some satellite knowledge is helpful, a depth of understanding of these systems is not required.

Myth 2 - Satellites are unreliable and fall from the sky. In fact, end-to-end reliability is better than cable and telephone for the end user. Parenthetically, GEO satellites cannot re-enter the atmosphere due to their altitude; old ones that reach end-of-life are simply raised to a higher altitude and turned off.

Myth 3 - It’s a big investment. This will not be the case if you work with a service provider who invested the capital and provides the hands-on expertise.

Myth 4 - Latency will kill the application. Latency only affects some applications and can usually be addressed with a combination of satellite network “tuning” and possibly application modification.

Myth 5 - Satellite broadcasts are insecure because anyone can listen to them. Information security of satellite transmissions is achieved with the same technology that addresses this issue with regard to the open Internet.

Some of these myths are based in technical issues that require careful attention. For example, Myth 4 regarding latency is an inherent concern because of the propagation delay of one quarter second between ground sender and ground receiver. This, of course, adds to the delay caused by other IT resources, particularly client/server processing and IP switching and routing. Data application users generally do not notice response times less than two seconds, so propagation delay is certainly manageable. However, if the computers, servers and digital processing elements add substantial delay, the service quality may suffer.

This issue can be overcome by identifying the time-sensitive application and configuring it appropriately. In one such difficult but soluble case, an inventory management application was designed to run on a PDA via a wireless LAN. The designer, assuming very short transmission delay, coded the application so that the data was sent piece by piece, requiring confirmation at every step. When a long distance connection over a satellite hop was inserted between the PDA and the server, the application slowed down to a crawl. The solution was to modify the application to forward its data in blocks rather than short queries. Once the user hits the return key, the accelerated application connects to a local VSAT and directly uploads the entire block over the satellite. Due to a high-degree of error correction, there is minimal retransmission delay because block delivery is so reliable.

A requirement for secure data delivery (Myth 5) can be addressed with confidence thanks to encryption and authentication technology. The Secure Sockets Layer (SSL) protocol used to assure privacy of on-line transactions is very effective for securing end-to-end satellite data transfers. Also, the popular Digital Encryption Standard (DES) can be used to secure all data that is transmitted to the satellite and thus relayed to all points within the footprint. Even stronger encryption technologies are available. One very popular IT networking approach on terrestrial networks is the Virtual Private Network (VPN) using a standard called IPsec. This approach, like DES, secures all information that leaves the point of origination (typically a firewall) until it is deciphered at the distant server. Putting a VPN over a satellite is potentially effective, but requires the same kind of care as I discussed with regard to application acceleration.

How to Proceed?

Say that you’re convinced that there is a role for a satellite-IT connection; how much, then, do you need to understand about getting such a network into existence? My recommendation is that you first understand your telecommunications requirements, and then determine what expertise you and your organization require with regard to alternative satellite solutions. Then, be sure to allocate the time and money to do it right.

Here is a suggested check list of success factors:

1. Understand what you’re trying to do – basic requirements and desired outcomes
2. Survey what’s out there – attend conferences and visit vendors
3. Get internal buy-in – find allies who would benefit as well
4. Run demos and pilots – see how this works in your real-world situation
5. Choose the right supplier partner(s)
6. Stick to your idea and plan – don’t get sidetracked
7. Get your technical people into satellite training – dispel the myths

I’ve covered what I believe are primary inhibitors and enhancers for those needing to connect IT to satellites for the first time. This is basic IT planning and design, not rocket science. Take this list and adapt it to your needs. Bounce ideas off others and get comfortable with the thinking and players in the industry. It would be very effective to meet with other users who have gone before you to learn how best to establish your connection between satellites and IT.