  Short-range wireless technologies will enable vehicles to communicate and
coordinate their actions, thus improving people's safety and traffic
efficiency. Whereas IEEE 802.11p (and related standards) had been the only
practical solution for years, in 2016 a new option was introduced with Release
14 of long term evolution (LTE), which includes new features to enable direct
vehicle-to-vehicle (V2V) communications. LTE-V2V promises a more efficient use
of the channel compared to IEEE 802.11p thanks to an improved PHY layer and the
use of orthogonal resources at the MAC layer. In LTE-V2V, a key role is played
by the resource allocation algorithm and increasing efforts are being made to
design new solutions to optimize the spatial reuse.In this context, an
important aspect still little studied, is therefore that of identifying
references that allow: 1) to have a perception of the space in which the
resource allocation algorithms move; and 2) to verify the performance of new
proposals. In this work, we focus on a highway scenario and identify two
algorithms to be used as a minimum and maximum reference in terms of the packet
reception probability (PRP). The PRP is derived as a function of various
parameters that describe the scenario and settings, from the application to the
physical layer. Results, obtained both in a simplified Poisson point process
scenario and with realistic traffic traces, show that the PRP varies
considerably with different algorithms and that there is room for the
improvement of current solutions.
