Читать книгу Mobile Communications Systems Development - Rajib Taid - Страница 76

In the previous sections, several logical interfaces between the concerned network elements of mobile communications networks were described and illustrated. Different functions and procedures are performed over the respective logical interfaces. Some logical interfaces do not become ready for exchanges of information between the concerned network elements. Also, following the occurrence of an erroneous event, a logical interface may become unusable. In such scenarios, a logical interface between two network elements requires to be initialized and configured or reinitialized/reconfigured, with protocol layer‐specific data, to make it ready for exchanges of information over it. The procedure for initialization and configuration with protocol layer‐specific data differs from one logical interface to another one.

Example 3.10 illustrates the typical messages flows for initialization of the S1 logical interface, which is used between the LTE/eNodeB and its MME.

Similarly, the Gb‐interface which is used in the GPRS system is also required to be initialized. The NS protocol layer of the Gb‐interface in the BSC/PCU end initializes and sends the configuration data to the peer layer on the SGSN side of the Gb‐interface.