TIA-1138

This specification applies to High Rate Packet Data Revision A and Revision B compliant access terminals and access networks which are enhanced to support the E-UTRAN and HRPD interworking. 

These requirements ensure that a compliant access terminal can obtain interworking service through any access network conforming to this standard. These requirements do not address the quality or reliability of that service, nor do they cover equipment performance or measurement procedures. 

This specification is primarily oriented toward requirements necessary for the design and implementation of access terminals. As a result, detailed procedures are specified for access terminals to ensure a uniform response to all access networks. Access network procedures, however, are specified only to the extent necessary for compatibility with those specified for the access terminal. 

This specification includes provisions for future service additions and expansion of system capabilities. The architecture defined by this specification permits such expansion without the loss of backward compatibility to older access terminals.