3 Definitions, symbols and abbreviations

36.4593GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)Release 17SLm interface Application Protocol (SLmAP)TS

3.1 Definitions

For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].

Elementary Procedure: SLmAP consists of Elementary Procedures (EPs). An Elementary Procedure is a unit of interaction between LMUs in the E-UTRAN and E-SMLCs in the EPC. These Elementary Procedures are defined separately and are intended to be used to build up complete sequences in a flexible manner. If the independence between some EPs is restricted, it is described under the relevant EP description. Unless otherwise stated by the restrictions, the EPs may be invoked independently of each other as standalone procedures, which can be active in parallel. The usage of several SLmAP EPs together or together with EPs from other interfaces is specified in stage 2 specifications (e.g., TS 23.305 [2]).

An EP consists of an initiating message and possibly a response message. Two kinds of EPs are used:

– Class 1: Elementary Procedures with response (success and/or failure).

– Class 2: Elementary Procedures without response.

For Class 1 EPs, the types of responses can be as follows:

Successful:

– A signalling message explicitly indicates that the elementary procedure successfully completed with the receipt of the response.

Unsuccessful:

– A signalling message explicitly indicates that the EP failed.

– On time supervision expiry (i.e., absence of expected response).

Successful and Unsuccessful:

– One signalling message reports both successful and unsuccessful outcome for the different included requests. The response message used is the one defined for successful outcome.

Class 2 EPs are considered always successful.

3.2 Symbols

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3.3 Abbreviations

For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 [1].

LMU Location Measurement Unit

SLmAP SLm Interface Application Protocol

SRS Sounding Reference Signal

TNL Transport Network Layer

UL RTOA Uplink Relative Time of Arrival

UTDOA Uplink Time Difference of Arrival