ühekanalilise simpleksside variant, mille korral andmeside kahe jaama vahel toimib kummaski suunas erinevat, kuid etteantud spektriosa piires püsivat sagedust kasutades, a variation of single channel simplex wherein telecommunication between two stations is effected by using in each direction frequencies that are intentionally slightly different but contained within a portion of the spectrum allotted for the operation