Teco company has developed a wireless communications system for data exchange in the band 868.3 +-50kHz. This is the range of radio frequencies in the bands identified as intended for industrial, scientific and medical (ISM - Industrial, Scientific, Medical) usage. Selected range is characterized by good resistance to interference in the range sufficient to achieve connections at distances up to 50 mb in built-up area and even to 150 m.b. in open air area.