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The "Hidden Node" Problem

Overview    |     Problem    |     Solution

Overview

The "hidden node" problem affects all simplex (transmit and receive on the same frequency) communications, whether voice, data or otherwise. This page describes the problem and suggests some specific steps that can be taken to reduce the effect.

 

Problem

Consider the scenario depicted in the following diagram:

 

 

 

Solution

The designers of stations A and C could help eliminate (or at least greatly reduce the likelihood of) the hidden node problem by building a station that has better RF coverage using the techniques below.

The best solution is to use all of the above techniques. It's also more realistic since there are practical limits to each of the above options. Using all available options maximizes the chance of hearing and being heard by all other stations.

With data radios, another solution is to use a protocol that helps to avoid collisions. Two examples are described below.

 


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This page was last updated on 04-Jan-2018