"This standard provides the specification for the Interfaces which coincides with the Reference Point ""A""@ ""Ater"" and ""Aquater"" defined in the TR45 Network Reference Model shown in TSB-100. The scope of this standard includes the following topics: ?MSC-BS and BS-BS interfaces: ?Descriptions of the specified functional capabilities that provide wireless telecommunications services across the MSC-BS and BS-BS Interface as defined in the TR45 Network Reference Model; ? Descriptions of the division of responsibility of the functions provided between the BS and the MSC@ and between the source BS and the target BS@ without prescribing specific implementations; ?Descriptions of the MSC-BS Interface and the BS-BS interface standards that support the functional capabilities of the following air interface signaling protocols: ?ANSI/EIA/TIA-553 (only to support hard handoffs to AMPS) ?TIA/EIA IS-2000 ?TIA/EIA IS-637-A; ?PCF-PDSN interfaces: ?Descriptions of the specified functional capabilities that provide packet data services across the PCF-PDSN interface; ?Descriptions of the division of responsibility of the functions provided between the PCF and the PDSN without prescribing specific implementations. The interfaces defined in this standard are specified by a set of characteristics@ including: ? Physical and electromagnetic parameters. ?Channel structures. ?Message types and contents. ?Network operating procedures. ?User data framing and transport."