7.27 Test method for Device-to-Device Proximity Services

36.523-33GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 3: Test suitesRelease 17TSUser Equipment (UE) conformance specification

7.27.1 Direct Discovery test method

SS-UE is configured in coverage, i.e. it is associated with a EUTRA-cell (as specified in clause 7.27.2.1).

SS-UE can be configured for sidelink data transmission and/or reception:

– When UE under test is configured in sidelink discovery type 1 (i.e. ue-Selected), the SS-UE is configured in reception with the same pool(s) of resource.

– When UE under test is configured in sidelink discovery type 2B (i.e. scheduled), the SS-UE is configured in reception with the same pool of resource and same indexes.

– For transmission, TTCN configures the SS-UE with a pool of resources and provides the SL_DATA_REQ ASP including:

– the SL-DCH message to be transmitted,

– the timing info indicating the SFN/Subframe of the first discovery period,

– the number of discovery periods in which the message shall be transmitted,

– the selected PSDCH resource value (n_PSDCH), this value is incremented by TTCN after each transmission cycle. To avoid clashes when multiple PC5_DISCOVERY messages are transmitted within the same discovery period, TTCN will provide different n_PSDCH values.

7.27.2 Direct Communication test method

7.27.2.1 Synchronisation and SBCCH transmission

When configured in coverage, the SS-UE is associated with a EUTRA-cell, it is configured with the same configuration parameters i.e. Band, Bandwidth, UL frequency, Cell timing, Frame structure of the associated EUTRA cell.

When out of coverage, SS-UE is configured explicitly by TTCN, e.g. Band, Bandwidth, Frame structure. For timing synchronisation SS-UE can be configured either:

– To synchronise from UE under test transmitted SLSS/MIB-SL: UE under test is the synchronisation source. The SS-UE shall use the received SLSS and MIB-SL including the DirectFrameNumber/DirectSubframeNumber as synchronisation source as specified in TS 36.331 [19], clause 5.10.9.2

– To be the synchronisation source: SS-UE shall initiate autonomously the DirectFrameNumber/DirectSubframeNumber and transmit SLSS/MIB-SL.

When the SS-UE is configured by TTCN over sidelink system control port to receive/transmit SLSS and MIB-SL, the following rules apply:

– For transmission, the complete MIB-SL message is provided to SS-UE. SS-UE shall set the DirectFrameNumber and DirectSubframeNumber in the MIB-SL, a dummy value is provided by TTCN.

– The MIB-SL is sent to SS-UE using asn.1 types. The rules for encoding and transmission of SBCCH messages (MIB-SL) are specified in TS 36.331 [19].

– For reception, SS-UE shall report SLSS or MIB-SL over the sidelink system indication port.

7.27.2.2 Sidelink data transmission/reception

When UE is in coverage and configured in transmission mode 1 (i.e. scheduled), the sidelink Scheduling Grant is configured in SS by TTCN over system control port. On PDCCH, the SS informs the UE under test if it is allowed to make sidelink data transmission by transmitting ‘DCI format 5’ including ‘SCI format 0’ with the CRC scrambled by SL-RNTI (acc. to TS 36.213 [30] clause 14.2). The UE under test will transmit on PSCCH/PSSCH as specified in the received DCI format 5 and ‘SCI format 0’. SS shall only react on reception of SR and grant allocation configured from the TTCN. The following sidelink grant allocation is configured:

– SS is configured to maintain PUCCH Synch.

– SS is configured to send automatically a ‘configured Grant’ (in terms of NPSCCH, ITRP and NPRB) to the UE on every reception of a Scheduling Request, within 10 subframes.

– The default resource for PSCCH is NPSCCH = 11,

– The default configured grant for PSSCH in SCI format 0 is ITRP = 36 and NPRB = 25. The SS shall allocate resource allocation RBs corresponding to PRB indices 0..(NPRB-1).

– SS-UE is configured with the same pool(s) of resources as UE under test.

When UE is out of coverage or configured in transmission mode 2 (i.e. ue-Selected), UE selects autonomously the resources on PSCCH/PSSCH. SS-UE is configured with the same pool(s) of resources as UE under test.

The SS-UE, when triggered to transmit data, is configured with IMCS=0 and the same NPSCCH , ITRP and NPRB as specified above.

SS-UE is configured with a ProSe layer 2 identity and with the UE ProSe layer 2 identity. When configured in transmission, the SS-UE shall construct the MAC packets using these identities. In reception, SS-UE shall send to TTCN only the PDCP data packets received with the correct layer 2 identities in PSCCH and in MAC headers.