Feature N° 2
This article is the second in a series of four features on the new Global Mobile Communications by Satellite (GMPCS). It has been prepared to coincide with the International Telecommunication Unions forthcoming World Telecommunication Policy Forum, to be held in Geneva on October 2123.
The article gives some background on the proposed new Little LEO systems, what they might offer to users, and how they compare with the other proposed GMPCS offerings.
The Little LEO operators are more retiring; modest even. Perhaps they can afford to be. There seems little doubt that the services planned by these systems will be the first to market and what's more, there seem to be plenty of willing buyers for their product. Some fear that the same may not be able to be said for the Big LEO contenders.
Little LEO satellites are so-called because they are small (measuring around one cubic metre, and weighing in at around 100 kg), and because they occupy what is know as a Low Earth Orbit. In practice, this means they occupy orbital slots between 700 km and 1,500 km from the Earth which is 'low' relative to other satellite systems. LEO systems are non-geostationary systems, which means that, unlike the geostationary satellites which comprise most of the existing communications satellite network, they move in relation to a fixed point on the Earth's surface.
The Little LEO contenders hope to gain a competitive edge by offering fast and inexpensive services, and by getting a foothold in the market well ahead of their big brothers. Some systems are already partially on-line, but most are due to start offering services between 1997 and 1998. The majority of ventures intend to use the satellites as either 'bent pipe' systems, or store-and-forward systems. The bent pipe system relays messages directly between users, while the store-and-forward approach means that a satellite receives information from a ground station, stores it in on-board memory, continues on its orbit, and releases the information to the next appropriate ground station, or user. Users will be able to access the new Little LEO systems using small hand-held messaging units incorporating a low-power omni-directional antenna and weighing less than half a kilogram.
So much for the technical spec. but what exactly makes a Little LEO different? The principle difference between the proposed offerings of Little LEO operators and other Mobile Satellite Systems (MSS) is that they concentrate on providing data services, rather than handling real-time voice traffic. The kinds of services you can expect from a Little LEO provider are messaging (including e-mail and two-way paging), limited Internet access, and fax.
Important niche markets for Little LEOs will include remote data communications, digital tracking (for the transportation management market), environmental monitoring, and SCADA (Supervisory Control and Date Acquisition a system which provides remote monitoring of isolated facilities such as mines, oil refineries etc).
While less 'glamorous' in the public's eye, the Little LEOs may well turn out to be the MSS success stories. The systems themselves are less technically ambitious that their bigger counterparts. For a start, there are generally many fewer satellites in the constellation, alleviating a lot of the complexities inherent in the Big LEO systems. And the process of transferring data is not nearly as demanding as the transfer of voice, because data can be buffered in memory at times when system resources are overloaded. Real-time voice traffic, on the other hand, must be processed almost instantaneously, since buffering the signal causes unacceptable delays and/or fragmentation of the signal, resulting in poor service quality.
The upshot of all this is that the Little LEO operators are able to promise their services at prices well below that of the voice-oriented systems. And while the Big LEOs will have to hawk their product to existing mobile phone users, who may not want to pay the higher charges for the privilege of global interconnection, Little LEO customers will largely comprise companies with a clearly-defined business need. These organizations will be willing to pay for services such as remote monitoring, if they can be shown to have a beneficial result on the quarterly maintenance bill. More importantly, they will have the means to afford for such services. Big LEO providers will also try to target the corporate market, but companies will be wary of increasing their telecommunications bill unless they can be convinced that their employees' new GMPCS phonesets are actually resulting in greater productivity a figure much harder to quantify. If the Big LEO systems are to achieve the volume of users needed to keep call costs down, the ordinary consumer will have to be wooed as well. And while most of us might like the idea of a mobile phone which we could use to call Fred in Freedonia, how many of us would be willing to buy the handset (some priced at US$3,000) and then pay the cost of the call?
All in all, the future looks bright for the Little LEO operators. But one dark cloud on the horizon could be the need for new spectrum allocation for these services. Operators were hopeful that the ITU's two-yearly World Radiocommunication Conference in 1995 would acknowledge the importance of the proposed Little LEO systems by increasing the amount of radio spectrum available to them. But they walked away from the four-week conference almost empty handed, losing out to the Big LEO players, who successfully convinced the conference to increase spectrum allocation in the 2GHz range, to be made available to Big LEOs from the year 2000. Little LEOs need more spectrum in the 1GHz band, but the conference directed that most of their requests be subjected to further study. Operators now have no choice but to wait until the next WRC in 1997.
None of this seems to have dampened the enthusiasm of the Little LEO promoters, though; if anything competition between rival (planned) systems is hotter than ever. How many of these plans are ever fully realized remains to be seen, but it seems certain that the diminutive members of the family of mobile satellite systems will find themselves a comfortable niche in the new Information Age.
| Back to the WTPF Home Page |