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Contributor
blondcb
Posts: 30
Registered: ‎02-04-2011

Re: Location Accuracy

Thanks.

 

Now NAT online is showing me where I actually am, at my home!

Trojan Terminator
Andmike
Posts: 3,860
Registered: ‎03-23-2011

Re: Location Accuracy

Glad you got home safely blondcb.  ;-)

 

Just a further comment about location and Norton Anti-Theft.

 

I have just asked the website to find my phone and it comes back with a location about 4.5 miles away although I have GPS enabled.  However it is reporting me being offline and says that this fix was 1 hr 30 mins ago.  I assume that as I currently don't have internet access on my phone and so it is deemed "offline", then Norton Anti-Theft can't ask the GPS system to give it a fix and it goes back to some phone related data (not sure where it got this from) to offer a location.

 

Obvious really....until I connect my phone to the internet and Norton Anti-Theft notes that I have come online.  So I ask it to locate my phone and I still get the same answer - 4.5 miles away and it tells me that it last knew of my location 1 hr 39 mins ago.  So even telling it to locate me when it sees me as online it does not seem to be able to update or use GPS.  Now perhaps you can see why I have said elsewhere that I remain puzzled as to exactly how Norton Anti-theft is calculating location. 

 

P.S, there it also no indication on the phone that there has been any attempt to kick start the GPS functionality despite my asking the website to find me at least 5 times.  I do know however that sometimes it can find me accurately as it has found you.

smithy
Posts: 1,830
Registered: ‎02-07-2011

Re: Location Accuracy

[ Edited ]

Hi

With my Samsung Galaxy S 2 i find the location feature very interesting in Norton Anti-theft as i have tried it a couple of times now and it is very accurate, considering i am just using the Wireless Networks in Android location settings.

 

It would be interesting as mentioned to know how this technology works? as i have only used it once before with another Security app on the Market and the accuracy for wireless networks with that paticular app mentioned in a previous post in this forum was terrible It gave a circled area with a diameter of about 2 kilometers and basically said pin the tail on the donkey with your blind fold off.:smileyvery-happy: what a joke, so if the lost or stolen device was under some structure you could kiss your little baby goodbye.

 

As for NAT i find the wireless system can get a accuracy ranging from 50-100 meters from my location using either the text message feature or the Anti-theft website method, both giving a identical location from the test i just ran while typing this post.

 

So i am yet to have a good play with GPS side of things as i will in the coming days.

 

Otherwise this looks very promising for all Android NAT and NMS users and can only get better and better. keep up the good work JoeK and the Symantec Norton Team.:smileywink:

 

Cheers

smithy
Posts: 1,830
Registered: ‎02-07-2011

Re: Location Accuracy

hi

 

just did a bit more testing and went for a walk to get a better idea of the accuracy of the wireless network usage of the NAT plugin and the locate feature.

 

The results show i am 100 to 150 meters (330 to 500 feet) from location point on the Google map.

 

Which is still a good effort without the use of GPS tracking and pin pointing, but i also live within a kilometer or two of a couple of  (.07 to 1.3 miles) transmitting mobile network  towers.

 

I will keep testing and posting results. :)

 

Cheers

smithy
Posts: 1,830
Registered: ‎02-07-2011

Re: Location Accuracy


Andmike wrote:

 Just a further comment about location and Norton Anti-Theft.

I have just asked the website to find my phone and it comes back with a location about 4.5 miles away although I have GPS enabled.  However it is reporting me being offline and says that this fix was 1 hr 30 mins ago.  I assume that as I currently don't have internet access on my phone and so it is deemed "offline", then Norton Anti-Theft can't ask the GPS system to give it a fix and it goes back to some phone related data (not sure where it got this from) to offer a location.

 

Obvious really....until I connect my phone to the internet and Norton Anti-Theft notes that I have come online.  So I ask it to locate my phone and I still get the same answer - 4.5 miles away and it tells me that it last knew of my location 1 hr 39 mins ago.  So even telling it to locate me when it sees me as online it does not seem to be able to update or use GPS. 


Hi

perhaps the update frequency has to be changed to allow more frequent refresh cycles, as i am sure we do not always stay in one location for a hour.

 

In the real world i guess the ideal frequency would be about  every 5 minutes .

 

And perhaps the inconsistent online and offline status may have something to do with the method of loation. If they are using the triangulation method from the network towers, maybe not enough signals were available to triangulate when the 1 hour  fequency check of your location took place.???

 

I guess i am doing a little bit of guess work as we do not know the method of location.

 

As for the GPS  maybe there were not enough sattelites locked at the time of the 1 hour frequency update.????

 

So more frequent updates of the location i think would be the perfect fix for the issue, one hour seems way too long for me.

 

Cheers

Symantec Employee
erik_carlstrom
Posts: 4,409
Registered: ‎04-10-2008

Re: Location Accuracy

I'm not sure frequency would make a difference.  I know that tower triangulation is the least accurate method, even there are a couple local.  Distance is highly dependant on signal strength by distance as well as the environment.  I've usually seen "accurate within X kilometers" from triangulation.  

 

For location services, do you only have GPS enabled or Assisted GPS as well?  You could try playing around with these settings.  

Erik
Product Manager
Symantec Corporation
Contributor
blondcb
Posts: 30
Registered: ‎02-04-2011

Re: Location Accuracy

Erik, I'm still not clear on what is being used to establish location for each of the products, NAT & NMS.  If using multiple sources, e.g., GPS, Wi-Fi, Web, Triangulation, what is the priority for them being used?

 

Thanks

Symantec Employee
erik_carlstrom
Posts: 4,409
Registered: ‎04-10-2008

Re: Location Accuracy

For the mobile client it starts with GPS, then AGPS, and then triangulation. It all depends on signal strength for each one, so "results may vary" depending on your environment. GPS is a wonderful technology, but as with most electromagnetic signals what they pass through, reflect off of, etc will impact their path and amplitude.
Erik
Product Manager
Symantec Corporation
smithy
Posts: 1,830
Registered: ‎02-07-2011

Re: Location Accuracy

Hi

 

I found this info to be very interesting it really is worth a read

 

A-GPS

 

"Standalone" or "Autonomous" GPS operation uses radio signals from satellites alone. A-GPS additionally uses network resources to locate and utilize the satellites in poor signal conditions. In very poor signal conditions, for example in a city, these signals may suffer multipath propagation where signals bounce off buildings, or be weakened by passing through atmospheric conditions, walls or tree cover. When first turned on in these conditions, some standalone GPS navigation devices may not be able to work out a position due to the fragmentary signal, rendering them unable to function until a clear signal can be received continuously for up to 12.5 minutes (the time needed to download the GPS almanac and ephemeris

An Assisted GPS system can address these problems by using data available from a network. For billing purposes, network providers often count this as a data access, which can cost money depending on the plan

 

GPS-

 

Due in part to regulations encouraging mobile phone tracking, including E911, the majority of GPS receivers are built into mobile telephones, with varying degrees of coverage and user accessibility. Commercial navigation software is available for most 21st century smartphones as well as some Java-enabled phones that allows them to use an internal or external GPS receiver (in the latter case, connecting via serial or Bluetooth). Some phones with GPS capability work by assisted GPS (A-GPS) only,[dubious ] and do not function when out of range of their carrier's cell towers. Others can navigate worldwide with satellite GPS signals as a dedicated portable GPS receiver does, upgrading their operation to A-GPS mode when in range. Still others have a hybrid positioning system that can use other signals when GPS signals are inadequate.

 

Mobile Signal Tower Triangulation-

 

Mobile phone tracking refers to the attaining of the current position of a mobile phone, stationary or moving. Localization may occur either via multilateration of radio signals between (several) radio towers of the network and the phone, or simply via GPS. To locate the phone using multilateration of radio signals, it must emit at least the roaming signal to contact the next nearby antenna tower, but the process does not require an active call. GSM is based on the signal strength to nearby antenna masts.[1]

Mobile positioning, which includes location based service that discloses the actual coordinates of a mobile phone bearer, is a technology used by telecommunication companies to approximate where a mobile phone, and thereby also its user (bearer), temporarily resides. The more properly applied term locating refers to the purpose rather than a positioning process. Such service is offered as an option of the class of location-based services

 

Further links and info-

 

A-GPS

http://en.wikipedia.org/wiki/Assisted_GPS

 

Mobile GPS

http://en.wikipedia.org/wiki/Mobile_GPS_navigation

 

Mobile Signal Tower Triangulation-

http://en.wikipedia.org/wiki/GSM_localization


i hope that helps to clarify a few things i know it did for me.

 

Cheers

Trojan Terminator
Andmike
Posts: 3,860
Registered: ‎03-23-2011

Re: Location Accuracy

Good bit of background smithy,

 

I would make the following comment on A-GPS, which I hope is a little easier to understand than the undoubtedly accurate Wikipedia entry.  

 

As I understand it a pure GPS device has to check and cross check a lot of satellite data to work out where it is.  This can take a long time if it has no idea where it is to start with.  With A-GPS a phone can use basic network data to give the GPS a fair idea of where it should start from, thus speeding up the GPS's ability to get a good fix.

 

Not sure if that helped at all.  ;-)