How real simultaneous dual band Wi-Fi enables next-gen in-vehicle connectivity
embedded.com
embedded.com
Throughput, there is not that much data, unless you encapsulate it in some verbose format.
You could do efficient ingress and egress routing if adjacent cars had the means to communicate their destinations, rather than using 100-year-old technology like blinking lights.
The latency of a 4G network cannot meet this requirement. With the latency of 4G network, a car driving at 100 km/h still moves 1.4 m from the time it finds a obstacle to the time when the braking command is executed.
Under the same condition, with the latency on a 5G network, the car will move just 2.8 cm, and this performance is comparable with the standard of an anti-lock braking system (ABS).'
From: https://www.huawei.com/minisite/5g/en/defining-5g.html
> With the latency of 4G network, a car driving at 100 km/h still moves 1.4 m from the time it finds a obstacle to the time when the braking command is executed.
I'm a fan of self-driving cars, but I would never buy one that depends on an external network to know when to brake.
Unfortunately there's also still no agreement on what 5G will actually be, what technologies it will entail, or how it will be deployed. Of course, since none of this is defined yet, there are also no guarantees on what performance will be achievable in practice.
The industry will need to solve this issue long before 5G is widespread. The solution will likely involve DSRC, C-V2X, or LTE-V/LTE Direct, which are tailored for the vehicular communication use case (involving both vehicle-to-vehicle [V2V] and vehicle-to-infrastructure [V2I]). It's unlikely a single technology will be able to handle all the challenges of a V2X scenario (highly mobile nodes, congestion, low SNR, requirements for sub-millisecond connection times), and so a second connection management layer will have to be built on top of multiple existing PHYs to enable simultaneous low-latency, high-throughput, and secure communications.
(Note that the linked article is actually about in-vehicle communication, however.)
For one, autonomous vehicles (the ones most people care about anyway - Waymo et al) are not widely using connectivity between vehicles - who wants an autonomous vehicle that will only stop for other compatible vehicles? Instead they are almost entirely reliant on visual sensors etc.
What has changed between 4G and 5G is the device to device protocol (which is not widely used and is completely incompatible with normal mobile signals) has been improved to support vehicles travelling at high speeds. But the thing is, there was already a protocol to enable that kind of communication and 5G does little if anything to improve on it.
Autonomous vehicles are probably never going to rely on network connectivity to work properly - the risk of losing your connectivity is too great.
Without fail my 2 meter radio keys up in about 70% of the drivethroughs I go through. Some of them are probably due to overloading the front end, some of them probably aren't filtered well enough.
Had a microwave that would take out WiFi in a ~200ft radius when it was running.
Etc.
Additionally the risk of benign or malicious interference is too great. We can't live in a world where a 14-year old with a soldering iron and $20 in parts can jam 12 lanes of traffic at rush hour. Or where a solar wind or foreign enemy can cause mass casualty events such as disconnecting all autonomous vehicles simultaneously.
I wonder if a low bandwidth directional link might be best. Where all cars in a "pack" agree they have the same firmware. Then do each others calculations and then confirm whether they agree by only checking a hash of the calculation. This would be a much smaller payload and could be transmitted on redundant channels on different bands. It would at least be harder to jam.
Well... not to be argumentative or anything, but a 14-year-old with a smaller budget could easily cause similar chaos on a busy highway by, say, rolling a heavy object down a hill onto it or throwing some spiked gardening tools onto the road at night. Although they don't generally do that, protesters do pretty much the same thing (that's how we all first started hearing about BLM, recall).
Doing that puts them at severe risk of detection and capture, doesn't scale well, is pretty easy to remedy, and dealing with foreign objects on roadways is pretty easy (people drive around them, and maintenance personnel and/or police move them off the road) and needs to be because it happens all the time without any malicious actors involved.
Consider:
> “The big difference with 5G is that when you start to talk about “autonomy” and factories, cars and hospitals thinking for themselves, they will rely on split-second connectivity to do so – with no room for error,” said Aicha Evans is senior vice president and general manager of the Communication and Devices Group at Intel Corporation, in February just ahead of Mobile World Congress.
(https://iq.intel.com/5g-communications-key-autonomous-drivin...)
A wireless network containing safety critical devices written with no room for error. Alrighty then.
Also V2V is vaporware that isn’t actually needed for safe self-driving cars, because the cars have to safely interact with human-driven vehicles (the majority of cars on the road for the next 10 years).
Is there some purely technical reason why this is the case, or is it mostly that nobody has bothered to make this efficient/fast?