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SRLMJ23

macrumors 68020
Original poster
Jul 11, 2008
2,307
1,413
Central New York
How does this exactly work? I caught some of it in the keynote but not the entire thing. I'm just looking for details. Thanks in advance!
 

Matthew Yohe

macrumors 68020
Oct 12, 2006
2,200
142
How does this exactly work? I caught some of it in the keynote but not the entire thing. I'm just looking for details. Thanks in advance!

The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

When you enter or leave a certain region that you define, you can have the phone remind you of something. This feature has also been available to developers to implement in their own apps since iOS 4.0.
 

m11rphy

macrumors 6502a
Dec 26, 2009
642
372
The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

When you enter or leave a certain region that you define, you can have the phone remind you of something. This feature has also been available to developers to implement in their own apps since iOS 4.0.

how would i have my phone but a geo-fence around my home or office ?
 

tourada

macrumors regular
Feb 27, 2011
160
0
Idaho
how would i have my phone but a geo-fence around my home or office ?

If you have a 4s, ask Siri to remind you of something when you get to/leave a location (home, office, etc.). You will need to add these addresses in your contact profile of yourself.
If you have a 4, same thing, but all manually in the reminders app.
 

smr

macrumors 6502a
Sep 14, 2007
815
166
Shropshire, UK
You can ask Siri to "Remind me to do x when I leave here", and a reminder saying do x will pop up when you leave.

In practice this happens when I'm a few hundred yards away when driving, so not that practical, but better than forgetting something completely!

This uses the location services, which may use cell tower triangulation and/or GPS. Trying this at work today (where cell tower triangulation is poor due to poor coverage) my battery took quite a hit - I guess it was using GPS then?
 

mackmgg

macrumors 68000
Nov 2, 2007
1,660
572
The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

Are you sure about that? My phone battery went down 15% in under and hour with a geolocation reminder set. I hope Apple fixes that, as it seems useful, but not if it's that taxing on the battery. Maybe it could check once every five minutes or so?
 

JRoDDz

macrumors 68000
Jul 2, 2009
1,927
183
NYC
Are you sure about that? My phone battery went down 15% in under and hour with a geolocation reminder set. I hope Apple fixes that, as it seems useful, but not if it's that taxing on the battery. Maybe it could check once every five minutes or so?

I have noticed when I create a georeminder, my gps arrow stays constantly on. This would put a serious dent in battery life no?
 

smr

macrumors 6502a
Sep 14, 2007
815
166
Shropshire, UK
I have noticed when I create a georeminder, my gps arrow stays constantly on. This would put a serious dent in battery life no?

I think the arrow is a 'location services' arrow, not strictly a GPS arrow. As others have stated, the iPhone uses assisted GPS to determine location, so it uses cell tower triangulation and wi-fi hotspot positioning to help determine position. If these other positioning services (which use less power than GPS) give a good 'quality' position, the iPhone probably relies more on these than GPS, but where these are poor, the GPS will be used. I also suspect the GPS might only be activated every minute or so for reminders, but it still does hit battery life.
 

det2004

macrumors 6502
Aug 20, 2007
357
14
I have noticed when I create a georeminder, my gps arrow stays constantly on. This would put a serious dent in battery life no?

I would think so...I tried the location based reminders on my 4 with one of the betas and the battery life seemed worse, but I have yet to try it on the final build of ios 5.
 

FreeState

macrumors 68000
Jun 24, 2004
1,738
115
San Diego, CA
There is a problem I have been experiencing with this when I turn wifi off. I get the notices as if I have arrived or left the location, even though I am over a mile away. It seems to need some more work.
 

netnothing

macrumors 68040
Mar 13, 2007
3,806
415
NH
No idea exactly how the Geo-fence works, but I did notice that if the address isn't exact, the reminder doesn't go off.

For example, went to my parents house which is in a rural area. There address is 149 Main Street (for example).

My reminder never went off.

When I was there, I noticed the reminders app thought the current location was 66 - 269 Main Street.

So if it's not exact, then it doesn't seem to work.

-Kevin
 

smr

macrumors 6502a
Sep 14, 2007
815
166
Shropshire, UK
No idea exactly how the Geo-fence works, but I did notice that if the address isn't exact, the reminder doesn't go off.

For example, went to my parents house which is in a rural area. There address is 149 Main Street (for example).

My reminder never went off.

When I was there, I noticed the reminders app thought the current location was 66 - 269 Main Street.

So if it's not exact, then it doesn't seem to work.

-Kevin

I have noticed the same problem in the UK. Our post codes (ZIP codes) are georeferenced, but one post code can cover several houses, and the georeference position for our post code is some distance from our house.

It would be better if Apple:

1) let one add the GPS Lat long position of addresses (e.g. Home), and/or
2) let you create an 'event' that signalled leaving a location e.g. the loss of signal from a specific wi-fi station. The signal from our wi-fi router at home is lost half way down our drive, so it would be a very precise reminder location for leaving/arriving at home, and it wouldn't need the power-hungry GPS.
 

walnuts

macrumors 6502a
Nov 8, 2007
591
333
Brooklyn, NY
I noticed a sudden increase in battery usage when using a geofence reminder too- something like a 15% drop over an hour which seems pretty consistent with full use of GPS. Nice feature, but too much battery drain to be useful for me.

Siri, remind me to plug in my phone when I go home or to work because your geofence feature kills my battery!
 

Beeplance

macrumors 68000
Jul 29, 2012
1,564
500
This is what sucks. It uses a bookmark stored in your contacts and NOT maps. Why not maps??

To my knowledge, it uses Maps as well. There is a geofence set up in an area around your current location, and that is done using Maps. Although I have to say I'm not really sure.
 
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