Hacker News Reader

Comment by chambo622 | Hacker News Reader

This is very accurate. I've gotten in the habit of manually killing my phone's WiFi as I leave my apartment and start walking down the hall calling a Lyft/Uber, and the same when outside my office. This remains an unsolved problem.

View on HN

It really isn't. It'd be trivial to allow mobile data to always supplement wifi data. There are apps that do this already ([1] and [2]), and some phones have the option as well (either stock or as a ROM). The problem are cellular data caps, nobody wants to blow their caps by using cellular when they could be using wifi only. There is no way for wifi to know when you're about to lose coverage, or have spotty coverage; the only way around it is to always have the mobile antenna connected to towers so it can take over. But that costs money, many mobile phone companies even disable these options on their phones to reduce congestion in their towers ([3], though it may be out of date now).

One day we might solve this problem, if we're ever able to pressure phone companies into reinvesting into their infrastructure instead of their investors.

[1]: http://speedify.com/mobile-vpn

[2]: https://play.google.com/store/apps/details?id=it.opbyte.supe...

[3]: http://forums.androidcentral.com/samsung-galaxy-s5/402722-ho...

You can enable Wifi Assist on your iPhone to automatically switch to Cellular data when Wifi is weak.

I get that this exists, but it literally never seems to trigger for me. The situation GP brings up happens constantly despite this feature being enabled.

I think the problem is that by the time your phone knows WiFi is non-viable (e.g. it's sent, retried, timed out), you've probably screwed whatever connection you were hoping to make.

Short of hammering the AP with test transmissions (oh no, battery life) when the connection starts to get below a certain level, not sure how it could solve this before the user attempts to do something.

I think the onus is on devs to implement it. So far, the only app I've found with robust reconnect is XiiaLive Pro (a music-streaming app). I use it daily for streaming radio stations and I often forget to disable WIFI when I leave the house, so by the time I'm down the block, the music usually cuts off for 1-2 seconds before the app realizes WIFI is gone. Amazingly, it auto-retries using the 3g/4g connection. I've used 10s of music streaming apps, and ALL of them required a manual stop/start after WIFI signal is gone.

For those looking for it, go to Settings > Cellular. Then scroll down and tap the slider for Wi-Fi Assist.

https://support.apple.com/en-us/HT205296

I have that enabled and the setting states that ~70MB have been downloaded in this way, but I don't know over which period and it also never does "feel" like it's working.

Watch some Netflix over semi-reliable WiFi and I assure you will feel it working when you get dinged for a data plan overage. True story.

IIRC it's only used for certain system services like Siri etc.

I've heard too many horror stories of people blowing through their data caps because Wifi Assist was too aggressive.

I disabled it after my phone freaked out one day and kept re-downloading the same few hundred iTunes songs over and over, blowing past my data cap and costing me $30 in overages, all while it was asleep on my desk (albeit mysteriously very warm).

I disabled it for this exact reason. On the other hand, if it were not this aggressive it would probably not be useful.

There are also consequences to your battery for utilizing cellular data instead of/in addition to WiFi. I'm an atypical user in that I don't really care about cellular data costs, but it annoys me when my battery begins dropping at a visible rate and my phone becomes toasty warm.

I considered that, but thought the impact would be inconsequential. If you want to save battery life you'd turn one or both antennas off (or GPS, vibrations, screen brightness, etc.). Maybe running both would be too much for the battery though, I don't know.

My phone lasts nearly 24 hours on a charge, I wouldn't mind it last considerably less (18 hours for example) if I used both antennas though.

I don't know how regular web-browsing / app use from the phone with two antennas would affect it, but I frequently use my phone as a WiFi hotspot for a laptop, and that's rather battery intensive.

You are only scratching the surface. The real problem is not for mobile to take over, we can do it, but when to consider wifi down. It is all fun and games if your wireless network is connected to good fiber, but it is not always the case. Internet uplink may be high RTT or flaky itself, it may be low speed and someone started torrent client and video call, it may as well be the very same mobile broadband with "unlimited throttled home" plan, wifi AP can be connected to gateway over multiple wireless hops, etc.. Platform always has to question "is it problem with remote end or uplink? is uplink 2 better than uplink 1?"

Network switch comes with non-zero cost that all connections must be treated reset and have to be reestablished, so even if the platform monitors quality of all uplinks, we still need some uplink stickiness to avoid constant switching between uplinks in places with spotty coverage or flaky uplinks. I'm not saying current status quo is the best, but currently we cannot have it work perfectly.

It's be good if at the TCP level you could send multiple request packets across different connections on mobile and have whoever got back first was chosen for a while as the default. You have to admit currently this is very clunky.

I would also add that specifically for things like Uber it'd be good to set very low network timeouts for Wifi and allow certain apps to suggest to the device they'd like to switch.

https://en.wikipedia.org/wiki/Multipath_TCP

True, however when you're leaving the building, the most common case ought to be that you stop being able to ping the upstream router. Easy for the phone to find out, since single-hop ICMP doesn't need a long timeout.

There are other possible failure modes, of course, but fixing the common case has value.

Now I'm not too experienced, so correct me if I'm wrong, but isn't a signal strength reading part of the wireless protocol? If your signal strength takes a consistent dive over a small period of time (as you walk out of the building) you could engage the cellular connection to at least supplement the pope wireless connection.

Or how about if some x% of packets were lost/failed checksum you revert to cellular?

Both of these would likely require changes to the wireless drivers but they don't seem too unachievable.

Sure, but that's assuming you can detect the weak signal, boot up the cellular antenna, negotiate a new connection to the nearest towers (after discovering them) and connect to the internet.

I'm making a bit of an assumption here, but I think if Apple or Google could detect spotty wifi quickly enough to boot up the cellular antenna, they would be. I think the issue is more that by the time the phone can tell there is a problem there isn't enough time to bring up the cellular antenna and connect before service is interrupted.

I can't say I know much about cellular networks either, but in my opinion having the cellular antenna connected to the network at all times would greatly simplify the handoff when wifi gets spotty. The ability to use both to download/upload is just icing on the proverbial cake.

I'm not sure how it works exactly, but Google's own cellular company, Google Fi, promotes the fact that they use WiFi when available, even for phone calls, but can switch quickly to cell when needed. Phone calls are not interrupted when switching. I especially like this setup because my cellular reception is poor at work, but I can use my employer's WiFi to receive calls and data. Phone call clarity is better on WiFi than cellular but sometimes there is a bit of lag that reminds me of calling overseas using geosynchronous satellite connections in the 90's.

Great prices also. Since I'm almost always using WiFi, the $20 a month for global unlimited text and phone calls with a $10/gig data rate means I only spend about $25 a month for my smartphone service. You can only use a subset of Google phones, but I find my Nexus 5x fits my needs. I also always get Android updates right away, if I want to install them.

Google's Project Fi wireless service prefers WiFi whenever it can right out of the box. That coupled with rock bottom prices & the ability to hop onto whichever network you like make it the best mobile provider around imo [just a user, no affiliation]

The prices per gb, while initially ground breaking, are now some of the highest in the industry. Look around.

Can you elaborate? I just did a cursory Google and it's not clear to me why this is true.

They're $10/gb flat with refunds for unused GB. At what usage levels do you think they're 'some of the highest rates in the industry?'

I use <3 gb/MO, mainly because the mobile <-> WiFi switching is so seamless, and I've never paid more than $50/mo off contract. The UX is also top tier, which i couldn't say about Straight Talk (my last provider).

I'll buy that they're not the cheapest, but which plan offers substantially cheaper?

Can you really hop onto whichever network you like? I thought they made that decision for you.

Yeah, Google made the decision at activation I think, but the helpful authors of this app helped me un-make it

https://play.google.com/store/apps/details?id=com.cheekydevs...

My LTE is so good I frankly don't let my iPhone have my work wifi credentials.

Also helps me avoid worrying about spying... work has a right to monitor (blue coat) all comms so better to keep work and home stuff separate.

They can monitor all the encrypted traffic I send to my VPN to their hearts' content.

My problem is that without WiFi the iPhone won't do certain things - sync iCloud Photos, download apps over a certain size, etc.

Your battery life must take a pretty big hit though.

I pretty much don't turn on WiFi unless I'm doing streaming audio or video.

Having wifi on is pretty bad for my battery life in general, because I'm moving around a dense city and my phone constantly is trying to connect to open wifi hotspots that are going in and out of range. Keeping it on only extends battery life if my phone is staying in one place with good wifi.

As a general rule, I always turn off the prompt to join open networks. At best, it's annoying as you move around; at worst, you accidentally join a malicious open network.

Settings > Wi-Fi > Ask to Join Networks (at the bottom of that screen)

Here are the options:

Airplane mode, Wifi only, Mobile data (LTE) only, Wifi + Mobile data (LTE). This listing is in order of battery consumption AFAIK.

The user I responded to uses only Mobile data (LTE). His Wifi is never on, but his Mobile data always is. I suggested that since he uses mobile data instead of wifi, he would be using more battery.

When using WiFi your cell radio is still on. The only time having wifi off has been a detriment to my battery is in crappy cell coverage.

Your cell radio is only still on if you leave it on. I've spent plenty of time in airplane mode with wifi enabled for battery reasons.

Windows Phone has a nice manual workaround to this. When you disable WiFi, you can say for just 30m or an hour or four. Excellent because I never remember I've disabled WiFi until I've eaten a ton of mobile data. Of course, it's still a poor substitute for not having proper switching.

Ah the joys of unlimited data. If it really is an issue though try llama which will turn WiFi on or off as you arrive or leave home.

It's not an unsolved problem, it's exactly what the iPhone's Wi-Fi Assist is for.

The problem is that Apple botched the roll out and everybody freaked out and complained about their iPhone eating their data plan and driving their phone bill to $2000.

Did they nerf it? I deal with this problem every day and I have Wifi assist enabled.

It's a solved problem.

On Android, if you unlock the hidden Developer Options, there is a toggle for "Aggressive WiFi to mobile handover".

But I wonder why the setting is hidden and not a default.

because it can potentially cost a lot of money if you turn this on accidentally and have an "aggressive" data plan

There's an app that's basically IFTTT for phones. Let's you set your phone to do things like silence itself or disengage wifi based on location. For the life of me I can't remember the name but it's out there and hopefully someone replies with it.

I think you're talking g about Tasker

Also an old classic that does this is Llama. E.g. you can use it to change ring/silent based on time and location, turn on/off wifi etc.

Yeah that's the one.

I really thought it was just me and my network. I disable my wifi daily starting my commute as Spotify chokes on loading songs as I walk away and lose the connection. I've been searching for a way to make it drop faster but no dice yet.

While driving for Lyft, dropping someone a good ways up Beechwood Canyon, I received a text message "You've fallen off the Lyft network, please drive to where you have better data coverage"

I'm mystified that my iPhone cannot figure out that it's not getting anything (or enough) through Wifi and should switch to cellular.

Reply on news.ycombinator.com