The diversity of Trace requirements makes it difficult to identify and anticipate all the operator's specific needs. Thus, the objective of this TS is not to list an exhaustive set of information to meet all the requirements. Rather, Trace data is defined without any limitation on the 2 following dimensions:

• Trace scope: NEs and signalling interfaces to Trace.
• Trace depth: level of details of Trace data.

In order not to have any limitation of Trace data, there are six levels of details defined: Maximum, Minimum, Medium, MaximumWithoutVendorSpecificExtension, MinimumWithoutVendorSpecificExtension and MediumWithoutVendorSpecificExtension. The first three levels allow for vendor specific information to be traced and sent in the trace report file. The Maximum (or MaximumWithoutVendorSpecificExtension) Levels allow all Trace data to be recorded. The other Levels provide a decoded subset of the data in the Maximum Level and allow an operator the flexibility in selecting the appropriate Trace data to record. The Trace Depth, specified at the Trace Session activation, is used to choose the level of detail of information to be retrieved. The Maximum (or MaximumWithoutVendorSpecificExtension) Levels of detail allow for retrieval of signalling interface messages within the Trace Scope in encoded format (see Figure 4.1.1).

The Minimum (or MinimumWithoutVendorSpecificExtension) Levels of detail allow for retrieval of a decoded subset of the IEs contained in the signalling interface messages (see Figure 4.1.2).

The Medium (or MediumWithoutVendorSpecificExtension) Levels of detail allow for retrieval of the decoded subset of the IEs contained in the signalling interface messages in the Minimum Level plus a selected set of decoded radio measurement IEs. The Trace data recorded at each Level is defined in TS 32.423.