Support of E-UTRAN-HRPD Inter-RAT SON as specified in TS 36.413
makes use of the RIM procedures described in clause 5.15 of TS 23.401
. The architecture is depicted in Figure 17.1-1
. The interfaces used are the S1 and the S121 interfaces.
An eNodeB is addressed by the Target eNodeB Identifier. An HRPD Access Network is addressed by HRPD Sector ID as defined in TS 29.276
For messages transferred between E-UTRAN and HRPD Access Network, the source access network node sends a message to its MME including the source and destination addresses. The MME decides, which access network node to send the message to, based on the destination address.
The MME performs relaying between S1 and S121 messages as described in TS 36.413
and TS 29.276
It enables interactions between E-UTRAN and HRPD access network to allow for the transfer of node level SON information.
The S121 interface shall support the following requirements:
SON information transferred between E-UTRAN and HRPD access network shall be transported as transparent containers without modifications by the MME.
The Figure below shows the protocol stack for the S121 interface.
S121 Application Protocol is the Application Layer Protocol between the MME and HRPD AN. S121 Application Protocol (S121-AP) provides application layer reliability for its messages, if required.
User Datagram Protocol transfers messages. UDP is defined in RFC 768 .