Section: D.3.7 E-UTRAN to GERAN A/Gb mode Inter RAT handover D.3.7.1 General
Content: The interoperation procedures describe information flows for Gn/Gp SGSNs and other EPS network elements. All messages between SGSN and MME, between SGSN and BSS, between SGSN and HSS and between SGSN and P-GW (GGSN in TS 43.129[ None ]  [8]) as well as the therein contained information elements are the same as specified for the adequate TS 43.129[ None ]  [8] procedures. These messages and procedure step descriptions are taken from TS 43.129[ None ]  [8] for explanatory purposes only. These descriptions are in italic text and shall not be modified by the interoperation procedures. It cannot be assumed that the messages and procedure step descriptions that are taken from TS 43.129[ None ]  [8] will be updated when modifications or corrections are performed for TS 43.129[ None ]  [8]. If there are any discrepancies for these messages and procedure step descriptions TS 43.129[ None ]  [8] takes precedence. The messages between the MME and any other node than the Gn/Gp SGSN as well as the therein contained information elements are the same as specified in the main body of this technical specification for the IRAT handover E-UTRAN to/from GERAN A/Gb mode procedure (clauses 5.5.2.3 and 5.5.2.4). These descriptions are in bold italic text and should be modified simultaneously when clauses 5.5.2.3 or 5.5.2.4 are updated. If there are any discrepancies, the procedure step descriptions in clauses 5.5.2.3 or 5.5.2.4 take precedence.