4ETSI. Terrestrial trunked radio (TETRA) voice plus data part 2: air interface, ETSI EN 300 392-2 V3.2.0 [S/OL]. [2011-05- 04]. http ://www.etsi.org.
5BAKARIC S, BORZIC M, BRATKOVIC D, et al. TETRA: technical features and applicationof professional communication technologiesin mobile digital radio networksfor special purpose service [C]// ELMAR 2005 47th International Symposium. Za- dar: European Telecommunication Standards Institute, 2005: 307-310.
