Communications with vehicles has come a long way since 1979, when drivers made ‘check calls’ from roadside telephone boxes. With the advent of mobile phones, fleet managers were able to contact their drivers, whenever they wanted – well almost. But talking requires two people to be available at the same time. Usually the driver does not concentrate, because he is driving, and has to call back – more charges, and when did you last record a phone conversation? Now, satellite communication allows transmission of vehicle position and data. Messages sent to vehicles are stored in the vehicle (and by the sender). Messages sent to the office are stored at the office. Neither messages or positions can be intercepted. The purpose of this paper is to illustrate why the ‘key to better fleet management’ is in integrating data from messages with other systems. Pre-formed messages requiring only the ‘blanks’ to be filled bring standardisation to the system. Message fields can be formatted so that specific data may be collected and posted to other software packages. Users of such systems report savings in manpower by reducing duplication of work e.g.: a message confirming the delivery of a consignment, sent by the driver, is posted to the accounts system and an invoice raised automatically. The future includes transmission of bar codes, signatures on PODs (proof of delivery notes) and viewing of consignment positions, by customers, on the Internet. The conclusion must be that – in the battle for survival, where making profit can sometimes depend on saving costs – it will be those companies that embrace technology to link all their systems so as to exchange data, who will win out.

Cellnet/British Telecom (BT) has been active in the area of GPS/GSM location and application research for over five years. Cellnet/BT have undertaken considerable development and field trials of various GSM methods for location positioning, which have resulted in several patent registrations. Recent R&D projects undertaken by the Mobility engineering team at BT Labs. include MOSA (Mobile Social Alarm) and City Guide using GPS positioning data to deliver value-added applications and services for both the general public and business users. A critical factor to the successful development of innovative value-added services is co-operation with partners, to promote and evolve open standards for GSM location.

Self-organising radio systems have been proposed for aeronautical and maritime communication, navigation and surveillance applications. In aviation, the introduction of the VHF Data Link (VDL) Mode 4 is currently being discussed, while the implementation of Automatic Identification Systems (AIS) is planned in the maritime domain. Operating in an autonomous mode, a self-organising radio system employing Time Division Multiple Access (TDMA) does not require a terrestrial infrastructure, such as base stations. The concept of self-organisation is based on the cooperative behaviour of a large number of users sharing a common VHF radio channel. Analyses have shown that uncoordinated stations, so-called hidden users, can cause interference in self-organising radio systems. This paper presents two different approaches to autonomous self-organisation together with the results of investigations of intra-system interference. Such analyses may help to introduce potential improvements to the system performance, which reduce the effect of hidden users in this very promising GNSS-based technology.

Digital Selective Calling (DSC) is causing serious problems for Search and Rescue (SAR) providers. Administrations must seriously consider the humanitarian and legal implications of continuing the implementation of DSC. They may be in violation of the Safety of Life at Sea Convention, the International Convention on Maritime Search and Rescue, 1979, and the United Nations Convention on the Law of the Sea, 1982, by knowingly implementing communications technology that may jeopardize lives at sea even though the primary intent of DSC is to establish a suitable distress alerting method. States may very well open themselves to legal liability if loss of life or environmental damage can be linked in any way to the known faults of DSC.

Projected requirements for automatic dependent surveillance (ADS) include the downlinking of certain aircraft flight parameters periodically and upon command from the ground. This will require a primary source of the data such as a flight management system (FMS) and, of course, a radio datalink. This paper provides a description of an existing system that could fulfil much of the interim airborne ADS equipment requirements by using GPS/OMEGA/INS/ACARS for existing aircraft which are not equipped with, or envisioned to be equipped with, SATCOM, FMS or IRS.

This paper was presented at the Institutes NAV90 Conference but was received too late for inclusion in the Proceedings. Copies of the Proceedings are available on application to the Director.