Abstract: A new short message service (SMS) control function proposed by europe telecommunication standardization institute (ETSI) in customized application for mobile nework enhanced logic (CAMEL) Phase 3 and CAMEL Phase 4 helps to solve the service trigger problems of the short message peer to peer (SMPP) based SMS control function solution used now. The design and implementation of the whole solution, SMS SCF call control model (SCSM) automaton, and new service independent block (SIBs) are presented in detail as the extension of service control point (SCP) funtions. The service capability of CAMEL based solution is explained by SMS prepaid service as example.

Key words: customized applications for mobile network enhanced logic, short message peer to peer, short message service, service control point