C-V2X or DSRC? At this time, neither regulators nor car manufacturers know the answer, but Harman believes it may have a solution
Here at Connected Car we recently received an announcement from Harman’s Telematics Business Unit, which is a part of Harman Connected Car division. Harman’s telematics product line spans top to bottom, including connectivity components – telecommunications control units, antennas and other kinds of accessories and functionality including V2X systems.
The release told us that Harman is supporting a dual-mode V2X solution, which means the system speaks two languages – legacy 802.11p (also known as DSRC mode) and alternatively it can speak C-V2X which is a part of the 5G standard as published by the 3GPP group – it uses the same spectrum but differs in terms of signalling and security. Harman’s system can apparently operate in eitherDSRC or C-V2X, but not both simultaneously. Harman feels that this dual methodology is important as there is no accepted standard in most countries except for China, the decision in most territories having mainly been left to the market. Most recently, the EU has reversed its own policy, which was initially to go with 802.11p. Now EU policymakers will leave the market to decide which technology is most important.
Different automotive companies are making different bets as to which technology will prevail. Of the big players, GM, VW and Toyota voted early for 802.11p/DSRC and both GM and VW have begun to produce cars with DSRC capability. After firmly standing behind DSRC in the early days, Toyota has now back-tracked and is now taking a ‘wait and see’ approach. Ford, a very large player in the market, has been actively promoting the C-V2X standard and is working closely with the standards bodies including the 5G Automotive Alliance (5GAA) to develop new use cases that use C-V2X to provide positional awareness in vehicles and other kinds of functionality.
With all of these auto makers making different bets there is a lot of risk in the market. What Harman says it intends to do is to enable auto makers to switch on the fly.
This dual system seems like an interesting solution and would appear to allow manufacturers to hedge their bets. Having said that, could putting both systems into the car increase costs, we wondered? To learn the answers to this question and more, Vince Holton talked with Roger Jollis, Harman’s Director of Product Management, Telematics
VH: Let’s start with the background first. Harman’s press release announcing Dual-Mode V2X says that you are offering this solution in order to address network concerns. What are these concerns and how widespread are they?
RJ: Personally I don’t think that that is an accurate assessment of what we are trying to do with V2X. V2X is principally about peer-to-peer (P2P) communications capability. There is a vehicle to network capability on C-V2X, but primarily, P2P will deliver the most value for vehicle-to-vehicle communications. A network is not necessary in the picture. This is important for a number of reasons: first, as you imply in the question, if network coverage isn’t available, not having a P2P connection introduces a lapse in the safety capabilities of the vehicle. It is important to be able to communicate without the network. The second important reason you don’t put a network into the equation is latency. If a network is involved then information will be delayed in flowing between the members of the network and that delayed receipt of time-related messages could cause safety issues. In the case of P2P communications you are able to cut latencies down – in the case of C-V2X to less than 5 milliseconds between vehicles. So we are not dealing with network problems, we’re dealing with the need to be able to provide P2P capability.
It is true that as 5G is rolled out there are going to be areas where network connectivity is not quite as effective as it could be and that’s where P2P will be essential.
What network capability will deliver that P2P won’t is road network information – cautions, instructions for detours, possibly load balancing, construction information – these types of instructions. These are not as time- or latency-critical as a warning that there might be a traffic conflict at an intersection, or a pedestrian that is crossing between cars and in a blind spot.
Moving forward, the other thing that is going to be important with 5G ……