When you have both fully turned on how does the phone know which one to use
in any given situation?

John <john@nospam.invalid> wrote:

> When you have both fully turned on how does the phone know which one
> to use in any given situation?

It's decided by the app getting the Internet connection. Look in
whatever is that secret app to see if it has a data option to prefer one
connection over another. You didn't bother to mention the app(s).

VanguardLH wrote:

> John wrote:
>
>> When you have both fully turned on how does the phone know which one
>> to use in any given situation?
>
> It's decided by the app

Is it?

There are some settings (e.g. not to do updates unless a wifi connection
is available, so not to run up a 3G/4G bill) but that doesn't mean the
app can force a given type of connection, it simply chooses whether or
not to use whatever happens to be available at any given time.

Am 28.08.21 um 09:23 schrieb Andy Burns:

> There are some settings (e.g. not to do updates unless a wifi connection
> is available, so not to run up a 3G/4G bill) but that doesn't mean the
> app can force a given type of connection, it simply chooses whether or
> not to use whatever happens to be available at any given time.

Exactly.

The decision, which network is actually used, will be solely made by
Android itself. And unfortunately, it's rule is as simple as "if WiFi is
available, prefer it". The only ways to get your trusty 3G/4G/5G back
over an unreliable or slow WiFi are to remove that WiFi SSID from the
list of known networks or turn off WiFi completely.

On Sat, 28 Aug 2021 10:17:25 +0200, Hergen Lehmann wrote:

> Am 28.08.21 um 09:23 schrieb Andy Burns:
>
>> There are some settings (e.g. not to do updates unless a wifi connection
>> is available, so not to run up a 3G/4G bill) but that doesn't mean the
>> app can force a given type of connection, it simply chooses whether or
>> not to use whatever happens to be available at any given time.
>
> Exactly.
>
> The decision, which network is actually used, will be solely made by
> Android itself. And unfortunately, it's rule is as simple as "if WiFi is
> available, prefer it". The only ways to get your trusty 3G/4G/5G back
> over an unreliable or slow WiFi are to remove that WiFi SSID from the
> list of known networks or turn off WiFi completely.

I find this sometimes in cafes and such places. The in-house wi-fi is not
accepted. The only way is to turn your own wi-fi off. Then you forget to
turn it back on :o?
--
Jim S

On Sat, 28 Aug 2021 10:17:25 +0200, Hergen Lehmann wrote:
Hergen Lehmann <hlehmann.expires.5-11@snafu.de> asked
>>>>> When you have both fully turned on how does the phone know which one
>>>>> to use in any given situation?
>>> It's decided by the app getting the Internet connection. Look in
>>> whatever is that secret app to see if it has a data option to prefer one
>>> connection over another. You didn't bother to mention the app(s).
>> There are some settings (e.g. not to do updates unless a wifi connection
>> is available, so not to run up a 3G/4G bill) but that doesn't mean the
>> app can force a given type of connection, it simply chooses whether or
>> not to use whatever happens to be available at any given time.
> The decision, which network is actually used, will be solely made by
> Android itself. And unfortunately, it's rule is as simple as "if WiFi is
> available, prefer it". The only ways to get your trusty 3G/4G/5G back
> over an unreliable or slow WiFi are to remove that WiFi SSID from the
> list of known networks or turn off WiFi completely.

The actual app I was using which got me wondering was the speedtest app.
https://play.google.com/store/apps/details?id=org.zwanoo.android.speedtest

But the question is more generic in that I don't know how Android 11 knows
when to use the Wi-Fi versus when to use Cellular Data when both are on.

If both Wi-Fi and Cellular Data are fully turned on, which does it use?
By fully turned on I mean none are explicitly disabled in Android settings.

If you need to know my settings, I don't know them all, but here are some:
[Settings][Connections][Wi-Fi]=on
[Settings][Connections][Wi-Fi Calling]=on
[Settings][Connections][Mobile networks][Data roaming]=on
[Settings][Connections][Mobile networks][Network mode]=5G/LTE/3G/2G(auto connect)
[Settings][Connections][Data usage][Data saver]=off
[Settings][Connections][Data usage][Mobile data]=on
[Settings][Connections][Data usage][Mobile data only apps]=off

What other settings are needed for both types to be "fully turned on?"

"John" <john@nospam.invalid> wrote in message
news:sgbs86$1rqj$1@gioia.aioe.org...
> When you have both fully turned on how does the phone know which one to
> use
> in any given situation?

On my Android phone (Samsung) the rule is very simple: if it has a wifi
connection it will use that one; if it hasn't, it will try the mobile
internet connection instead. This means I can leave mobile internet turned
on permanently, and regulate whether to use wifi or mobile by turning wifi
on or off. The algorithm is fairly primitive: if wifi is turned on but the
router has no WAN connection to the internet, it will not try mobile :-(

There may be some apps which allow you to choose which connection they will
use, but mostly (as for Windows and Linux) the choice is taken automatically
at OS level.

Am 28.08.21 um 11:24 schrieb John:

> The actual app I was using which got me wondering was the speedtest app.
> https://play.google.com/store/apps/details?id=org.zwanoo.android.speedtest

Most speedtest apps explicitly prompt you to turn off WiFi before
measuring cellular speed. Some may also do it automatically, after
requesting the permission to do so. In any case, the switch is global
and affects the whole phone.

> But the question is more generic in that I don't know how Android 11 knows
> when to use the Wi-Fi versus when to use Cellular Data when both are on.

If WiFi is turned on and successfully connected, it will be used.

Andy Burns <usenet@andyburns.uk> wrote:

> VanguardLH wrote:
>
>> John wrote:
>>
>>> When you have both fully turned on how does the phone know which one
>>> to use in any given situation?
>>
>> It's decided by the app
>
> Is it?
>
> There are some settings (e.g. not to do updates unless a wifi connection
> is available, so not to run up a 3G/4G bill) but that doesn't mean the
> app can force a given type of connection, it simply chooses whether or
> not to use whatever happens to be available at any given time.

As mentioned, it is a preference often configured in the app. I don't
how the phone makers handle OS updates, but aren't the app updates
handled by the Play Store app (well, for those apps you get from there)?

In the Play Store's config, there is an auto-update setting. I have
mine set to:

Auto-Update apps
- Over any network
- Over wi-fi only <--- I chose this
- Don't auto-update apps

As for other apps, you set their preference, if they have one, over
which hardware to get an Internet connection for updates. For Google
Maps:

settings -> wi-fi only <--- I have that off

For its offline maps:

settings -> Offline maps settings -> Download preferences -> wifi only

I did not find a similar wi-fi/cellular option in Firefox Mobile. I
suspect that since you chose to load the web browser that you want an
Internet connection, and hopefully the app first picks wi-fi, if
available, and then falls back to cellular (data). I don't much web
browsing on my smartphone to generate enough traffic to check data
volume; however, I'd have to disable wi-fi for a while to force the web
browser to use cellular data, and then reenable wi-fi to generate the
same web traffic to see if data usage diminished with the availability
of wi-fi. From some users, they noted that Firefox would use wi-fi, if
available, but the users wanted to force Firefox to use data despite a
wi-fi connection was available.

I can't see why not to use wi-fi, if available. Typically it is much
faster than data. To only way I know of to force use of data and ignore
any wi-fi hotspots would be to disable wi-fi (settings -> Network ->
Wi-Fi -> Off.

For apps that do give a choice, and could eat up your data quota without
you realizing, you can force them to use wi-fi. My aunt went on
vacation, and did not realize her web cam app (to let her monitor while
away her sister who had poor health) ate up all her data quota when she
didn't have a wi-fi connection. For me, and to block an app from using
my limited data quota, I went to settings -> Network -> Data Manager.
Whether viewing the Mobile or Wi-Fi panel, I can select and app to
enable/disable the "Enable usage of cellular data in the background".
That's why the web cam app (Amcrest View Pro) shows "restricted" when
looking at data usage.

VanguardLH <V@nguard.LH> asked
> I did not find a similar wi-fi/cellular option in Firefox Mobile.

Try NetGuard https://github.com/M66B/NetGuard/releases

It's not only for blocking ads.
It also acts as a firewall.

For _any_ app, NG can block its access to wi-fi or to cellular or both.

VanguardLH used his or her keyboard to write :
> For apps that do give a choice, and could eat up your data quota without
> you realizing, you can force them to use wi-fi.

Didn't most USA carriers switch to unlimited cellulardata for free recently?

On 8/28/2021 4:26 AM, NY wrote:
> There may be some apps which allow you to choose which connection they will
> use, but mostly (as for Windows and Linux) the choice is taken automatically
> at OS level.

Windows router tables have a metric, don't they?
Isn't it the metric which determines which choice is taken?

Maybe Android router tables also have a metric?
TERMUX: /system/bin/ip route show table 0 | grep metric

On 8/28/2021 5:58 AM, Hergen Lehmann wrote:
> If WiFi is turned on and successfully connected, it will be used.

https://stackoverflow.com/questions/6940973/can-i-get-the-routing-table-entry-in-android/6941126

Shows routes of all tables
/system/bin/ip route show table 0

Shows route table which used when rmnet0 is active interface (mobile data).
/system/bin/ip route show table rmnet0

Shows route table which used when wlan0 is active.
/system/bin/ip route show table wlan0

In "Developers options" it is possible to keep rmnet0 active,
even while wlan0 is active. But only one interface will be used
at the same time (and one route table).

When WiFi connected to the network, but has no internet link,
interface rmnet0 will be selected as main and route table
will be used from rmnet0 table.

When WiFi has internet link, wlan0 will be used as main interface
and "ip route show table wlan0" as current route table.

you can add or delete route from/to any route table as usual
with ip command by adding "table xxx" to route string.

For example:
/system/bin/ip route delete table wlan0 default via 192.168.7.1 dev wlan0 proto static
/system/bin/ip route add table wlan0 192.168.7.0/24 dev wlan0 proto kernel scope link src 192.168.7.10 metric 327

All route tables will be overwritten every time interface
goes on/off, lease renewed, etc...

On 28/08/2021 11.26, NY wrote:
> "John" <john@nospam.invalid> wrote in message
> news:sgbs86$1rqj$1@gioia.aioe.org...
>> When you have both fully turned on how does the phone know which one
>> to use
>> in any given situation?
>
> On my Android phone (Samsung) the rule is very simple: if it has a wifi
> connection it will use that one; if it hasn't, it will try the mobile
> internet connection instead. This means I can leave mobile internet
> turned on permanently, and regulate whether to use wifi or mobile by
> turning wifi on or off. The algorithm is fairly primitive: if wifi is
> turned on but the router has no WAN connection to the internet, it will
> not try mobile :-(

Huh, no. Mine, if the WiFi has no internet, doesn't use it, unless I insist.

I simply have both enabled and leave it all to automatics. I have
disabled the use of free wifis. I very seldom have to check.

There is another setting which is configure a particular WiFi connection
as metered, expensive; thus it will not use that connection to download
updates or maps, say. I use it when the WiFi comes from another phone,
via tethering.

>
> There may be some apps which allow you to choose which connection they
> will use, but mostly (as for Windows and Linux) the choice is taken
> automatically at OS level.

I have not seen any. Only some that will not use the connection unless
it is WiFi, but it does not influence which one to activate.

--
Cheers,
Carlos E.R.

On 28/08/2021 12.45, knuttle wrote:
> On 8/28/2021 5:58 AM, Hergen Lehmann wrote:
>> If WiFi is turned on and successfully connected, it will be used.
>
> https://stackoverflow.com/questions/6940973/can-i-get-the-routing-table-entry-in-android/6941126
>
>
> Shows routes of all tables
> /system/bin/ip route show table 0
>
> Shows route table which used when rmnet0 is active interface (mobile data).
> /system/bin/ip route show table rmnet0
>
> Shows route table which used when wlan0 is active.
> /system/bin/ip route show table wlan0
>
> In "Developers options" it is possible to keep rmnet0 active, even while
> wlan0 is active. But only one interface will be used at the same time
> (and one route table).

There is a normal setting that keeps the data connection active but
disabled when WiFi is active, in order to switch back to it. For
example, when the phone is left on a table, screen off, it may be
listening using the cellular data and switch to WiFi when you pick it up
or when it actually has to download something - to preserve battery.

--
Cheers,
Carlos E.R.

Here are all my wifi/cellular data settings that I know of.
[Settings][Connections][Wi-Fi]=on
[Settings][Connections][Wi-Fi Calling]=on
[Settings][Connections][Mobile networks][Data roaming]=on
[Settings][Connections][Mobile networks][Network mode]=5G/LTE/3G/2G(auto connect)
[Settings][Connections][Data usage][Data saver]=off
[Settings][Connections][Data usage][Mobile data]=on
[Settings][Connections][Data usage][Mobile data only apps]=off

I just found out I also have Developer Options "Mobile data always active."
[Settings][Developer options]=on
[Settings][Developer options][Networking][Wi-Fi scan throttling]=on
[Settings][Developer options][Networking][Mobile data always active]=on

I don't know what they really do but here's what they say they do.
Wi-Fi scan throttling
[Saves battery and improves network performance.]

Mobile data always active
[Always keep mobile data active, even when Wi-Fi is active
(for fast network switching).]

Both seemed like good things so that's why both are on.
(improves network performance)
(fast network switching)

What else do I need to set in the Android 11 settings menus?
And how do I know for sure which is being used at any given time?

On 8/28/2021 12:56 PM, Carlos E. R. wrote:
> Mine, if the WiFi has no internet, doesn't use it, unless I insist.

Samsung download booster utilizes Wi-Fi and LTE networks simultaneously.
https://www.verizon.com/support/knowledge-base-211186/

I don't know which Samsungs have it but it's been there a while.
https://visihow.com/Simultaneously_Use_Wi-Fi_and_LTE_on_Your_Galaxy_S5_to_Boost_Download_Speed
https://www.samsung.com/za/support/mobile-devices/what-is-the-download-booster-and-how-do-i-enable-it-on-my-samsung-galaxy-note4/

Is it only Samsungs that can use both wifi and celldata at the same time?
--
Ken Hart
kwhart1@frontier.com

John <john@nospam.invalid> wrote:
> Here are all my wifi/cellular data settings that I know of.
> [Settings][Connections][Wi-Fi]=on
> [Settings][Connections][Wi-Fi Calling]=on
> [Settings][Connections][Mobile networks][Data roaming]=on
> [Settings][Connections][Mobile networks][Network mode]=5G/LTE/3G/2G(auto connect)
> [Settings][Connections][Data usage][Data saver]=off
> [Settings][Connections][Data usage][Mobile data]=on
> [Settings][Connections][Data usage][Mobile data only apps]=off
>
> I just found out I also have Developer Options "Mobile data always active."
> [Settings][Developer options]=on
> [Settings][Developer options][Networking][Wi-Fi scan throttling]=on
> [Settings][Developer options][Networking][Mobile data always active]=on
>
> I don't know what they really do but here's what they say they do.
> Wi-Fi scan throttling
> [Saves battery and improves network performance.]
>
> Mobile data always active
> [Always keep mobile data active, even when Wi-Fi is active
> (for fast network switching).]
>
> Both seemed like good things so that's why both are on.
> (improves network performance)
> (fast network switching)
>
> What else do I need to set in the Android 11 settings menus?
> And how do I know for sure which is being used at any given time?

As described by others, by default, Wifi is always preferred when both are
available. The reason being that wifi almost never incurs additional costs
whereas mobile data often does.

On 8/28/2021 6:18 AM, Chris wrote:

<snip>

> As described by others, by default, Wifi is always preferred when both are
> available. The reason being that wifi almost never incurs additional costs
> whereas mobile data often does.

One exception is if you're using public Wi-Fi. In that case, if you're
doing anything private (banking, shopping, e-mail, etc.), you should
either use a VPN or turn off Wi-Fi so the phone has to use cellular data.

In article <sgdobf$dh2$2@dont-email.me>, sms
<scharf.steven@geemail.com> wrote:

> One exception is if you're using public Wi-Fi. In that case, if you're
> doing anything private (banking, shopping, e-mail, etc.), you should
> either use a VPN or turn off Wi-Fi so the phone has to use cellular data.

false.

banking, shopping and webmail all use https, so no issues with anyone
snooping on the details.

imap should be configured to be encrypted but it often isn't, however,
that's a very easy fix.

thus, there is no vpn needed for the scenario you describe.

a vpn might be useful for *other* reasons, however.

Hergen Lehmann <hlehmann.expires.5-11@snafu.de> wrote:
> Am 28.08.21 um 09:23 schrieb Andy Burns:
>
> > There are some settings (e.g. not to do updates unless a wifi connection
> > is available, so not to run up a 3G/4G bill) but that doesn't mean the
> > app can force a given type of connection, it simply chooses whether or
> > not to use whatever happens to be available at any given time.
>
> Exactly.
>
> The decision, which network is actually used, will be solely made by
> Android itself. And unfortunately, it's rule is as simple as "if WiFi is
> available, prefer it". The only ways to get your trusty 3G/4G/5G back
> over an unreliable or slow WiFi are to remove that WiFi SSID from the
> list of known networks or turn off WiFi completely.

My Samsung (A51) has an (Wi-Fi) 'Advanced' setting 'Switch to mobile
data' (on/off switch) which says 'Use mobile data whenever your Wi-Fi
internet connection is slow or unstable', so in the scenario you
describe, there would be no need to turn off Wi-Fi.

Carlos E. R. <robin_listas@es.invalid> wrote:
> On 28/08/2021 11.26, NY wrote:
> > "John" <john@nospam.invalid> wrote in message
> > news:sgbs86$1rqj$1@gioia.aioe.org...
> >> When you have both fully turned on how does the phone know which one
> >> to use
> >> in any given situation?
> >
> > On my Android phone (Samsung) the rule is very simple: if it has a wifi
> > connection it will use that one; if it hasn't, it will try the mobile
> > internet connection instead. This means I can leave mobile internet
> > turned on permanently, and regulate whether to use wifi or mobile by
> > turning wifi on or off. The algorithm is fairly primitive: if wifi is
> > turned on but the router has no WAN connection to the internet, it will
> > not try mobile :-(
>
> Huh, no. Mine, if the WiFi has no internet, doesn't use it, unless I insist.
>
> I simply have both enabled and leave it all to automatics. I have
> disabled the use of free wifis. I very seldom have to check.

NY describes Samsung's 'Intelligent Wi-Fi' feature (earlier know by
other names.

That feature 'learns' the locations of networks (SSIDs) you use
regularly. When you're in/near those locations, Wi-Fi will be turned on,
when your elsewhere, Wi-Fi will be turned off. I.e. both a battery-
saving and security/privacy feature.

If *such* a special network has no WAN connection - i.e. router is up,
but WAN is down - it will not try mobile. I.e. when I'm home and my
cable ISP is down, my phone will not try to use mobile data. That
feature is normally an advantage and in the exceptional case when it's
not, it's easy to turn off Wi-Fi completely and the phone will use
mobile data.

> There is another setting which is configure a particular WiFi connection
> as metered, expensive; thus it will not use that connection to download
> updates or maps, say. I use it when the WiFi comes from another phone,
> via tethering.

Hmmm! Interesting. I'll look if our phones have a similar setting for
use in similar situations. (For example on our last holiday, my phone
had a cheap data bundle, but my wife's phone had not. I didn't want to
risk tethering her's to mine, because something might decide to download
100's of MB thinking it's a cheap Wi-Fi connection.)

> > There may be some apps which allow you to choose which connection they
> > will use, but mostly (as for Windows and Linux) the choice is taken
> > automatically at OS level.
>
> I have not seen any. Only some that will not use the connection unless
> it is WiFi, but it does not influence which one to activate.

FWIW, I've seen some, but indeed not many.

Robin Goodfellow <Ancient-of-Days@Heaven.Net> wrote:

> VanguardLH <V@nguard.LH> asked
>> I did not find a similar wi-fi/cellular option in Firefox Mobile.
>
> Try NetGuard https://github.com/M66B/NetGuard/releases
>
> It's not only for blocking ads.
> It also acts as a firewall.
>
> For _any_ app, NG can block its access to wi-fi or to cellular or both.

I don't want to block wi-fi or cellular data access to Firefox Mobile.
I want it to get an Internet connect using whatever access method
available. I would /prefer/ it first use wi-fi, if available. If wi-fi
was not available, then fallback to cellular data. I want to grant BOTH
access methods to the app. I just want it to use wi-fi over data. It
is a preference (or priority).

While some apps lets you configure a preference, Firefox Mobile does
not. From what I've read in forums from users that want the app to
prefer data over wi-fi, they didn't have a choice. They could disable
wi-fi to force the app (and all other apps) to use cellular data, but
they would prefer a preference/priority setting in the app. The only
reason I saw for those users wanting data to have higher priority over
wi-fi was that the phone was reconnecting to a wifi SSID successfully
but the wifi hotspot was unreliable or Internet-dead, so the app getting
wifi wouldn't work, but it would work via data. Without a preference
settings, the apps get wi-fi over data, and they wanted a switch to
reverse that to the apps getting data over wi-fi. They still wanted
both connection methods, but wanted to decide the priority order.

Maybe NetGuard lets you select which access method to allow for an app,
but that would block access using the other methods. Users want to
prioritize which access method an app gets, like wi-fi over data, or
data over wi-fi. They want both access methods to provide a fallback to
one that does work should the higher priority method fail. They may
want wi-fi to get higher priority than cellular data, but they don't
want to restrict the app to just wi-fi access.

FromTheRafters <erratic@nomail.afraid.org> wrote:

> VanguardLH used his or her keyboard to write :
>
>> For apps that do give a choice, and could eat up your data quota without
>> you realizing, you can force them to use wi-fi.
>
> Didn't most USA carriers switch to unlimited cellular data for free
> recently?

You need to check your service contract with whomever is your cellular
provider. MNVOs can do whatever they want independently of whatever the
primary carriers are doing that the MVNOs are using. I doubt all
primary cellular carriers went to unlimited data. They may have gone to
unlimited text, but it's damn easy to consume all bandwidth across all
customers if there were no restrictions. Considering calls and texts
are low bandwidth, having unlimited data bandwidth means the service
effectively has no quotas on any type of traffic, and I doubt all
primary or MVNO providers have to to unlimited everything. They
couldn't handle that load.

I suspect you confused unlimited text with unlimited data. Text doesn't
give you Internet access, and is low bandwidth. Data gives you Internet
access, and is high bandwidth.

VanguardLH used his or her keyboard to write :
> I suspect you confused unlimited text with unlimited data.

My carrier gave everyone postpaid in the usa free unlimited everything.