Summary of Features

	Optimised for data dominant radio channels
	ETS-300.230 protocol operating at 1200/2400bps FFSK or 4800bps GMSK
	MPT1379 channel access protocol
	Transfer status (1-16), extended status (0-65535) and long data (ASCII or Binary up to 1024 bytes/characters)
	Forward Error Correction (FEC) and Automatic Retransmission (ARQ) combined for high reliability
	Up to 4000 addressable mobile units on the system
	Infrastructure based systems support "registration" and "network time" Diversity reception and transmission, which allows partial messages to be built up from many hilltops and/or retries.
	Optional AVL sub-system (requires RLC292 modem instead of RLC220)

MDS700 is a wide area radio data and vehicle location network operating on conventional PMR using "data dominant" PMR channels.

The MDS700 system is a wide area radio data and vehicle location network operating on conventional PMR using "data dominant" PMR channels.MDS700 systems consist of mobile radio/data units, hilltop sited based stations and a centralised Gateway/Router computer (communications processor).The MDS700 system uses FFSK or GMSK radio modem technology operating at 1200/2400/4800 bits per second and utilises the European ETS-300.230 air interface protocol. Channel contention is managed using MPT1379 or ETS-300.471 channel sharing algorithms for wide area PMR operation.

The Mobile Locator Unit (MLU) is a combined radio-modem and GPS receiver which connects to a conventional PMR radio transceiver (such as Tait T2000 series, Simoco PRM80 series or Motorola GM350/950) through the "facilities/expansion" connector. The following transceivers are commonly used in MDS700 mobile kits:

	Team Simoco SRM9000 series and earlier models
	Tait TM8000 series and earlier models
	Motorola GM600 and GM1200 series and earlier models

The Mobile Locator Unit (MLU) is a combined radio modem and GPS receiver which connects to a conventional PMR radio transceiver through the "facilities/expansion" connector. The following transceivers are commonly used in MDS700 mobile kits:

The Hilltop modems communicate with the Gateway computer system using dedicated Kilostream or Kilostream(n) lines. They can also operate over an partial kilostream line using a suitable MUX.

The Hilltop modems communicate with the Gateway computer system using a fixed bearer. Commonly, these bearers are Kilostream lines or a partial kilostream line using a suitable MUX. Other links technologies have also been used, such as analogue microwave with a suitable muxA Hilltop Modem can operate at either 1200/2400 baud FFSK or 4800 baud GMSK, which is field selectable. It can also provide up to four alarm outputs to the Gateway computer; these are conventionally used to indicate alarms like "battery fail" or "excess reflected power" etc.

The Gateway Computer is a Unix(tm) based high performance PC which processes data from up to 64 remote hilltop sites to provide a wide area, seamless, mobile data network.

The Gateway provides vehicle location data in Simple Vehicle Location Protocol (SVLP) format to one or more hosts connected by RS232 serial or TCP/IP LAN connection. This data includes the mobile callsign, date/time, position, speed, bearing and status information for each of the vehicles in the fleet. The SVLP standard is an "open standard" and can be used to input data in to a wide range of GIS/mapping systems including Thorcom's Traksys2000 mapping packages for WindowsXP. The Gateway communicates with the host system via binary protocol called RMIP (Radio Modem Interface Protocol) using either serial or TCP/IP LAN connections. There can be more than one port. This allows a host command and control system to send and receive messages directed at one, some or all mobiles. The Gateway provides a number of 'volt free contact' alarm outputs which can be triggered by alarm events from hilltops and the router program or other system failures. The Gateway also acts as a host for a number of other services such as the Thorcom GPS Clock ( which can emulate a ‘Rugby Clock’ and the internet time standard ‘xntp’.

The Gateway tracks each mobile utilising the diversity receiving capabilities built in to the system in such a way as to make sure that only the best three hilltops are used when transmitting data back to the mobiles. Incoming data is accepted from any hilltop and can be used to build up a message where different fragments are received from many hilltops simultaneously. If necessary, retries from the mobile can build up a message further until it is finally complete, thence passed onto the host system for action. This is particularly useful in a mobile environment because it mitigates the Guassian, multipath and other effects normally associated with mobile data.