Thursday 12 October 2017

3GPP Sidelink and its proposed extensions

In an earlier post I discussed briefly about the sidelink: V2V communications are based on D2D communications defined as part of ProSe services in Release 12 and Release 13 of the specification. As part of ProSe services, a new D2D interface (designated as PC5, also known as sidelink at the physical layer) was introduced and now as part of the V2V WI it has been enhanced for vehicular use cases, specifically addressing high speed (up to 250Kph) and high density (thousands of nodes).

Before going further, lets just quickly recap the different V2x abbreviations:

  • V2X = Vehicle-to-Everything
  • V2V = Vehicle-to-Vehicle
  • V2I = Vehicle-to-Infrastructure 
  • V2P = Vehicle-to-Pedestrian 
  • V2H = Vehicle-to-Home
  • eV2X = enhanced Vehicle-to-Everything

I came across this interesting presentation from ITRI that provides lot more details on sidelink and its proposed extension to other topics including eV2X and FeD2D (Further enhanced Device-to-Device).

There are quite a few references in the document that provides more details on sidelink and its operation and extension to other devices like wearables.

There are also details on synchronization and eV2X services.

There is also a very nice D2D overview presentation by Orange that I am embedding below (download from slideshare)


Kit Kilgour (via Linkedin) said...

Nice overview of the theory. The business case currently seems underwhelming given the lack of enthusiasm that chipset vendors have for implementing Sidelink. From a public safety perspective, the current very low power and higher frequencies make it unattractive as a proper coverage extension/P2P solution. V2X pull might make it more credible - but there are other alternatives.

For Public Safety, natural areas being looked at a architectures that maintain the LMR Direct Mode capabilities combined with cellular for macro coverage - a 1.8W terminal in the 400MHz band has a signal that will travel a long way, even in city propagation at 1.5m elevation. V2X is a different use case because you are primarily interested in a low range but low latency solutions that can tie in to cellular macro coverage. rather than mimicing trunk radio - potentially DSRC as an alternative in those circumstances

Eiko Seidel (via LinkedIn) said...

I see many things (Public safety, V2x and FeD2D) mixed up here. All of the use cases and eventually also the implementations are completely different things and have very little in common with each other, except that the interface is commonly called PC5. QCOM announced first V2X chipsets with the autonomous mode. Nothing to do with public safety or ProSe proximity detection etc.