User's Manual

EX7100 Technical Manual - Introduction
©1999 Exicom Technologies (1996) Ltd 1-7 Issue 2 - February 2001
1.6 System Planning
Digital Radio link planning is a complex procedure requiring a study of each site and the
path between each site. Exicom Technologies is able to assist in system planning if this is
required.
Specialist software packages are used by Radio System Engineers to determine path
losses and sources of interfering signals that may affect the reliability of the radio link.
(Unlike an FM signal, a digital radio signal is susceptible to interference and fades, similar
to those found on television broadcast systems)
The EX7100 is capable, under ideal circumstances, of providing communications over
paths of more than 50 kilometres.
However, the following considerations must be taken into account, which will assist in
determining the maximum link distance and system reliability:
> Operating frequencies
> Free Space loss
> Terrain effects: Absorption and Reflection losses
> Antenna gain and position
> Cable losses
> Transmit power
> Receiver sensitivity
> Required fade margin
Further to these considerations, the system designer must be aware of factors at each
site, which may affect the reliability of the radio link. These factors include:
> Access to a reliable power source.
> Antenna height.
> Access to a suitable grounding system.
> Lightning and surge protection
> Other radiating and receiving systems using the site