Blind Spot Cameras

[NigelM]

Posts on Connectivity/4G etc went here: Model-S-connectivity-(service-plan-upgradability-speed)

 

[metafor]

Obviously the baseband and all the RF have to be in one place, but there's no reason the AP couldn't be 100m away on the end of a piece of ethernet if you wanted to (USB is rather more plausible in this case. Local comms latency is trivial in comparison to the cellular link.

Yes and no. On a PC system and software, the communications latency is irrelevant. AP's and platform software for mobile don't always work well with connectivity-through-USB or distantly-removed links due to the requirements for connected-stand-by. Granted, I don't know the Model S's software; perhaps they just shelved connected-stand-by and other nice mobile-system features and are running it like a standard PC. In which case they could very well have the RF module in a separate place connected via SDIO or USB.

The proposition here was swapping it with whatever Tesla pick for Model S 2.0 - though actually the original proposition was swapping just the modem rather than the Tegra since my suspicion was/is that they are separate. And certainly swapping Tegra modules will only be feasible as an upgrade offered by Tesla, not an aftermarket upgrade - but a relatively likely one for them to offer in the long term, as against trying to keep the software competitive running on the existing hardware.

That depends. Very few next-gen AP's in either the mobile or PC world will be automotive-grade. Tegra 3 just happened to be as TSMC's 40LP happens to fit in that temperature and voltage curve. Most next-gen AP's will be 28nm or below and I don't believe the models have it working well in automotive-grade temperatures. I'd anticipate the computer to be the last thing they'd think of upgrading.

Any reason to assume that they are using a phone-style close-coupled baseband rather than operating the Tegra standalone (like a WiFi-only tablet) and having the cellular modem separate (like plugging a USB modem into said WiFi-only tablet)?

How many tablets do you know that actually work with USB plugin modems? Few have the host-mode necessary (purely a software limitation) to do that anyway. There are certain plugin modules for GPS, but not for 3G/4G connectivity; those are done generally via hotspotting.

This is all speculation, but there's a number of reasons for thinking they might have a separate modem:

- The Tegra modules don't appear to contain one (based on Nvidia info)
- Tesla is a small customer by Nvidia standards (albeit a prestigious one). Getting development support for these parts is generally much easier if you just want then as a generic AP rather than with
the close-coupled cellular support where you normally need orders for millions of units to get people to talk to you.
- Cellular modems are an off-the-shelf item
- Approvals and carrier support for different markets is easier with a separate module.

I agree with all of that. But getting an AP to work with off-the-shelf modems with something other than wifi hotspotting isn't trivial; I can't recall one commercial tablet that you can do it with.