As the mobile radio communication needs of uniformed and emergency services soared, two way land mobile radio communication systems are evolved from analog to digital. Although digital radios have better communication range, noise performance and provide superior voice quality in most cases compared to analog counterparts, they have hard time to maintain good voice quality in particular conditions like high frame error rate conditions. In this work, ETSI Digital Mobile Radio standard is assessed and proposed an optimization to improve its voice quality for particular conditions when voice quality deteriorated. Proposed improvement consists of a better forward error correction coding compared to already in use to improve the overall frame error rate performance. By utilizing proposed forward error correction, we achieved 3.35 dB improvements at high signal-to-noise region. As a result, the overall voice quality and communication range of Digital Mobile Radio system are enhanced without intervening Digital Mobile Radio air protocol.