One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol • Hacker News Board

Re: One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol

#41

Post by balladeer » Mon, Oct 01, 2018, 6:12 AM UTC

ReverseCold wrote: post #3

Still waiting on an AirDrop client for non-Apple products. It works really well and is pretty convenient. Maybe this paper will help.

And I am waiting for iMessage to come to other platforms just like Apple Music on Android [1].

Even a basic Android app would do and I think it's perfectly fine if one can have an iMessage account on other platforms iff they have at least one Apple product with "Messages" app on it - an iPad, a Mac, or an iPhone etc.

It's a pretty good messaging service but almost useless to me (and I am sure to a lot of people) because very few among my friends have iPhones but a hell lot of them have Macs - like really a lot!

[1] https://play.google.com/store/apps/details?id=com.apple.andr...

Re: One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol

#42

Post by balladeer » Mon, Oct 01, 2018, 6:19 AM UTC

natvert wrote: post #39

natvert wrote: post #16

Earlier quoted context omitted.

Or lack of real software ownership e.g. no root allowed!)

Wow. No love. Isn't lack of root like buying a house but the builder refusing to give you a master key or permission to change the locks?

I would say it's more like seller not allowing you to dig the whole house inside out and build one from scratch by choosing the size of brick, how much they were baked, brand of cement used and all that. Like they do not allow something like this in gated communities/apartments.

Re: One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol

#43

Post by PaulHoule » Mon, Oct 01, 2018, 9:06 AM UTC

matthewmacleod wrote: post #30

PaulHoule wrote: post #22

Earlier quoted context omitted.

For that matter I don't like interference on the crowded WiFi bands. It seems some creep uses AirDrop to send some lewds to somebody else on a plane every other week. I want to know my mac is using my wired and wireless network the way I intend rather than degrading the performance of WiFi, Bluetooth, ZigBee, Z-Wave, and other protocols that keep piling into unlicensed airspace.

To be clear, this feature is standards-compliant WiFi. It uses standard 802.11 frames and leverages the vendor-specific features to allow custom payloads. It’s not “degrading the performance” of WiFi - it is WiFi.

Unlicensed spectrum is limited. There are just three channels in the 2.4 GHz, and not really more than in the 5 GHz band because most of the 5 GHz band is occupied by weather radar and you can only use that spectrum if you pay the patent trolls for the coexistence technology specified by law.

When you turn on a WiFi analyzer program and see many WiFi networks using the same spectrum, there is interference. It isn't that it "stops working" but you will get packet loss, reduced data transfer, etc. Every printer that sets up its own AP, every phone that is a hotspot, is interference.

If you want and really use these services that is one thing, but it is insane that people use WiFi to print at a mall store when they could hook up the printer to the register with a 6 foot cable.

The article itself shows a substantial degrade of WiFi performance on the Mac itself because the mac is momentarily disconnecting from the real network to stay synchronized with the lewds network.

Re: One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol

#44

Post by mstute » Wed, Oct 03, 2018, 12:30 PM UTC

PaulHoule wrote: post #43

matthewmacleod wrote: post #30

Earlier quoted context omitted.

To be clear, this feature is standards-compliant WiFi. It uses standard 802.11 frames and leverages the vendor-specific features to allow custom payloads. It’s not “degrading the performance” of WiFi - it is WiFi.

Unlicensed spectrum is limited. There are just three channels in the 2.4 GHz, and not really more than in the 5 GHz band because most of the 5 GHz band is occupied by weather radar and you can only use that spectrum if you pay the patent trolls for the coexistence technology specified by law. When you turn on a WiFi analyzer program and see many WiFi networks using the same spectrum, there is interference. It isn't t…

The degradation happens only when you explicitly start using a service (such as AirDrop) that uses AWDL. The AWDL interface becomes inactive once there is no more traffic on the interface. In the measurements, we show the performance when both infrastructure and AWDL traffic is present (i.e., the Wi-Fi radio needs to switch channels in between).

In fact one could argue that AWDL actually reduces "interference" because two neighboring devices can communicate directly and do not need to go an additional one-hop detour over an access point.

Re: One Billion Apples’ Secret Sauce: Recipe for Apple Wireless Direct Link Protocol

#45

Post by mstute » Wed, Oct 03, 2018, 12:34 PM UTC

solarkraft wrote: post #20

userbinator wrote: post #14

Earlier quoted context omitted.

I do wonder if there are patents on this, and if that has prevented other devices from adopting this kind of protocol? WiFi has always had AdHoc mode which enables two devices to directly communicate like they were on the same Ethernet link, and I've used it a few times for a similar use-case to yours. It seems AirDrop is just a layer on top of that which facilitates the configuration required, but otherwise it would…

Doesn't Ad hoc force you to disconnect from your current Access Point? I'm under the impression that this is not the case with Air Drop.

Yes, unless your AP and ad hoc networks are on the same channel, you need two Wi-Fi radios to support this. AWDL "solves" this problem by quickly switching between these channels and schedules frame transmissions when the radio is tuned to the correct channel so the operation is (almost) transparent for the user (obviously, you loose some airtime for channel switching and your average latency increases).