hat
Relay ki emèt nan oswa trè pre zòn pwoteksyon estasyon paran an (yon "ranpli-nan") sou menm kanal la oswa frekans yo rele estasyon rapèl nan peyi Etazini an. Sepandan, sa a ka difisil paske li posib yo gen toude estasyon entèfere ak chak. lòt sof si yo ak anpil atansyon ki fèt. Ka entèferans radyo evite lè l sèvi avèk egzat tan atomik jwenn nan GPS satelit parfe senkronize estasyon ko-chanèl, tankou nan yon rezo sèl-frekans (SFN).
eng
Relays which broadcast within or very near the parent station's coverage area (a "fill-in") on the same channel or frequency are called booster stations in the U.S. However, this can be tricky because it is possible to have both stations interfering with each other unless they are carefully designed. Radio interference can be avoided by using exact atomic time obtained from GPS satellites to perfectly synchronise co-channel stations, as in a single-frequency network (SFN).