A centralized charging system based on cutting time slot
pan yong jun 1; li fang qin 1; guo shou feng 2 (1.dept. of computer eng.; changchun post and telecommun. inst.; changchun 130012; china; 2.co. of telecommun.; er longshan farm; wudalianchi 164550; china)
Discussion about J city user-line project ratio
li bao yan; lin jia yun; yuan jin fu (changchun telecommunication engineering design institute; changchun post and telecommun.inst.; changchun 130012; china)
Radio paging fault detection system
li shu qiu; tian zhi zhong; wang shi gang; wang xue jun (dept. of computer eng.; changchun post and telecommun.inst.; changchun 130012; china)