R1-133518 Principles of broadcast D2D communication for public safety
This contribution suggests some general principles to be used for D2D broadcast communications such as modulation, re-use of existing LTE channels and synchronization.
R1-134543 Synchronization principles for broadcast D2D communication for public safety
This contribution further details the synchronization principles described in R1-133518. The principles of the synchronization within a group are described. It also addresses the “group merging” scenario by describing how the UEs can perform a scanning in the time domain to detect a synchronization signal transmitted by a UE not belonging to the group.
R1-135402 Public safety usage and impacts on synchronization
In this contribution, the synchronization preferences for public safety applications were described: it was recommended to keep the synchronization source within the group for both in-coverage and out-of-coverage scenarios. In case two groups are collocated, it is suggested that some means to exchange synchronization information between the users of different group shall be defined so that the radio resources can be efficiently shared between groups.
R1-140516 Radio resource sharing between Public Safety groups using D2D
As a follow-up of the contribution R1-135402, this contribution describes some possible portioning of the radio resources dedicated to D2D communication: it is proposed to have some resources reserved for the inter-group communication (which can be used to exchange synchronization information for instance), some resources with an exclusive use for a given group (to support emergency calls for instance) and some resources that can be dynamically split between groups that are co-located.
R1-142295 D2D physical channels and signals
This contribution discusses signaling messages for D2D discovery and resource allocation in 3GPP RAN1 Study on LTE D2D Proximity Services . It considers D2D scenario 1C where UEs are in coverage of a single cell and are served by the same eNB. For this LTE controlled D2D mode, the network/eNB can assist users to enable D2D discovery procedure, exploiting thus specific signaling and LTE existing exchanged messages between UEs and the network during the conventional communication. In such case, the discovery procedure and the direct communication is a matter of signaling procedure for D2D resource allocation managed at the eNB. The contribution proposed new Downlink Control Information (DCI) format that can be carried by the Physical Downlink Control Channel (PDCCH) signaling. The new DCI format includes UL scheduling assignments for the receiving D2D UEs.