© Microhard Systems Inc.
Confidential
73
5.0 Installation
The are a number of factors to consider when preparing to deploy a radio network, several of
which have been touched-upon or detailed elsewhere within this manual. Following is a list-
ing of a number of factors, in no particular order:
Network Topology
The P2400 currently operates in the 2.4 GHz ISM FHSS Band and supports various Point-to-
Point and Point-to-Multipoint topologies.
Throughput
The P2400 is capable of up to 345 kbps asynchronous baud rate. The network topology has
an effect on how this available throughput is ‘shared’ between all nodes on the network.
Distance
The physical distance between the modems dictates such things as required antenna per-
formance and heights. When contemplating antenna types, keep in mind the directivity
(omnidirectional or directional) of the antennas being used.
Terrain
Along with distance, the terrain is a very important consideration with respect to antenna
height requirements. The term ‘line-of-sight’ (LOS) refers to being able to ‘see’ one location
from another - a minimum requirement for a radio signal path. In addition to LOS, adequate
clearance must also be provided to satisfy ‘Fresnel Zone’ requirements - an obstruction-free
area much greater than the physical LOS, i.e. LOS is not enough to completely satisfy RF
path requirements for a robust communications link.
Transmit Power
Having read thus far through the factors to be considered, it should be clear that they are all
interrelated. Transmit power should be set for the minimum required to establish a reliable
communications path with adequate fade margin. Required transmit power is dictated primar-
ily by distance, antenna type (specifically the ‘gain’ of the antennas being used), and the re-
ceive sensitivity of the distant modem. Cable and connector losses (the physical path from
the modem’s ‘antenna connector’ to the antenna’s connector) must also be taken into ac-
count.
Receive Sensitivity
The P2400 has exceptional receive sensitivity, which can produce a number of benefits, such
as: added fade margin for a given link, being able to use less expensive coaxial cable or an-
tenna types, being able to operate at greater distances for a given distant transmitter power
(perhaps negating the requirement for a Repeater site!). Distance, antenna gain, transmit
power, and receive sensitivity are critical ‘numbers’ for radio path calculations. Fortunately,
the Pico Series features the maximum available transmit power combined with exceptional
receive sensitivity - two ‘numbers’ which will produce the most favorable path calculation
results.
The installation,
removal, or
maintenance of any
antenna system
components must be
undertaken only by
qualified and
experienced
personnel.
