Digital Cellular Telecommunications System (Phase 2); Unstructured Supplementary Service Data (USSD) - Stage 2 (GSM 03.90; Second Edition; Version 4.1.1)
英文名称:Digital Cellular Telecommunications System (Phase 2); Unstructured Supplementary Service Data (USSD) - Stage 2 (GSM 03.90; Second Edition; Version 4.1.1)