"This standard defines the PCS 1900 requirements needed to support Short Message Service and other Services in a Number Portability environment. In this document@ the phrase ""Number Portability environment"" refers to an environment where Service Provider Number Portability is active in the PCS 1900 networks. The phrase ""Number Portability"" and ""Service Provider Number Portability"" is used interchangeably throughout this document. This standard ensures that Short Message Service Point-to-Point (SMS-PP) works for all subscribers in a PCS 1900 Number Portability environment regardless of whether the subscriber has ported or not. The impact of Number Portability on Customized Applications for Mobile network Enhanced Logic (CAMEL)@ General Packet Radio Service (GPRS)@ number pooling@ optimal routing@ and roaming is outside the scope of this document. In addition@ interworking with equivalent services in non-PCS 1900 networks is also outside the scope of this document."