Newbie - Questions on GPS functioning - Help!

glennc

Hello,
Never used a car or any gps before. Going to N.C. Last three times got lost and stopping at gas stations is not alway clear and accurate for directions. Cell phone reception in many areas is non-existent. So decided to get a Magellan 2136T -LM. Am having problems with these units and am going to return the second one today since I bought the first IIRC last Saturday.
I am trying to confirm the true and inaccurate information one receieves from store employees. I have been advised that on a GPS without blue tooth, that all the communications, the lists of points of interest is all done over the satellite network and the GPS unit's servers. Is this true?
What happen with the live traffic signal that requires an antenna adapter power supply. Is that receiving the speed limits and traffic problems via the GPS satellites or a cellular phone network?
What occurs if you have a unit with bluetooth, can you make calls through the GPS satellite network or is that still cellular tower?
I have been informed that there are dead spots for GPS reception in North Carolina. I don't mean in an underground parking lot but in and around say west of Asheville and the Great Smoky National Park.
One google I can view my friend's home and him standing in it practically, yet the Magellan couldn't find the road that he lives on. The road has probably been there since before they invented telephones. Is this a common GPS problem?
Thanks for any assistance, I am overwhelmed with features, models and requirements and varying advice.
Sincerely,
Glenn

sussamb

There's a lot of mis-truths in there :wink:

Bluetooth on your GPS generally just allows you to use your cell phone 'hands free' via your GPS. It's still using the cell signal.

Your GPS contains all the map and POI data, it doesn't come down the satellite network, but updating the map and POI data is usually done via your PC.

Traffic generally comes via a FM radio signal received by your GPS, speed limits are part of the map data.

It's true there can be dead spots for GPS, but it would normally be in very constricted spaces without a clear view to the sky, I wouldn't have thought that applies to your national parks, although signals in canyons can be tricky.

While maps are kept as up to date as possible there is no guarantee that every road will be there, so it's quite possible that your friends road may not be on the map.

glennc

There's a lot of mis-truths in there :wink:

Bluetooth on your GPS generally just allows you to use your cell phone 'hands free' via your GPS. It's still using the cell signal.

Your GPS contains all the map and POI data, it doesn't come down the satellite network, but updating the map and POI data is usually done via your PC.

Traffic generally comes via a FM radio signal received by your GPS, speed limits are part of the map data.

It's true there can be dead spots for GPS, but it would normally be in very constricted spaces without a clear view to the sky, I wouldn't have thought that applies to your national parks, although signals in canyons can be tricky.

While maps are kept as up to date as possible there is no guarantee that every road will be there, so it's quite possible that your friends road may not be on the map.

Hello suusamb,
Thanks for the response and I expected almost total mistruths, so glad for your assistance. So to make sure I have this correctly, The GPS Unit holds the points of interest, hospitals and current roads. All the calculation for routing a trip, returning from a wrong turn and locating the nearest hospital or restaurant is all done by the GPS Unit. It is only receiving current locations data from the Satellites? This will give me a much better understanding of what the hey is going on. Much appreciated.
Is it normal for a latest update to be a year old? A problem I have is that the features and display of the Magellan 2136T-LM I like better than Garmin and Tom Tom videos of comparable units. But I have had two bad units and I am afraid of that brand.
Thank you again for the clarification!!
Cheers
Glenn

sussamb

Yep, you've got it, although to be accurate it's not receiving its location from the satellites, but information from them that enables the GPS to display what it believes is your position on the screen :)

Maps are as up to date as they are. There seems to be no real logic as to when new roads make it onto the maps, I was directed once onto a road that was still under construction ... but that's rare :wink:

Tiger-Heli

The GPS Unit holds the points of interest, hospitals and current roads. All the calculation for routing a trip, returning from a wrong turn and locating the nearest hospital or restaurant is all done by the GPS Unit. It is only receiving current locations data from the Satellites?

You've almost got it.

It receives both current location and velocity data from the satellites - I'm pretty sure it will also interpolate if the signal is briefly lost (last known point was here, vehicle was traveling northeast at 60 mph, signal was lost for 1 minute, so current position should be a mile NE of last known position. (I could be wrong about this).

Also, I'm not sure if routing and re-routing is technically done to the map POI data or to converted GPS co-ordinates, but it is all done internally by the GPS independent of the satellite connection.

Hospital info would be stored in the POI from the map data so if the unit doesn't know there's a hospital nearby it won't show that (or it might show an older hospital 5 miles away rather than a new one a block west).

Also on some phone GPS software (not sure if mainstream car ones support this), you can select a navigation point using the map itself. If not, you can select a nearby adddress. For example, let's say your friend lives at 1234 Mulberry street and you can find this on Google Maps, but the GPS doesn't even list Mulberry Street. Even if you can't select the location on the GPS, you could check Google Maps and find the next intersection from your friend's house is 987 CandyApple Lane and navigate to that on the GPS. (Of course, this assumes that SOME road in the town will be in the GPS and that you have access to the Internet via computer or smartphone - i.e. it's good if you are planning a trip from home, not great if you are on the road and decide to change destinations).

Is it normal for a latest update to be a year old? A problem I have is that the features and display of the Magellan 2136T-LM I like better than Garmin and Tom Tom videos of comparable units.

I can't say for Magellan. I've always used Garmin and they update maps typically 4 times a year. Basically, Garmin and TomTom have basically been front tier, with Magellan and Navigon (before I think they were bought by Garmin) as second-tier, so I would expect Garmin and TomTom to have more frequent updates.

It might or might not be a huge issue to you, though - we have Garmin units that don't include map updates and are three or four years old and still work fine for locating and navigating to a street address. Where they typically don't work so well is if you want to find a nearby restaurant and it will show one that closed a year ago.

Tiger-Heli

Maps are as up to date as they are. There seems to be no real logic as to when new roads make it onto the maps, I was directed once onto a road that was still under construction ... but that's rare :wink:

Yes - there are really two similar but not identical issues here. One is how often the GPS manufacturer issues updates (either map data or firmware) - in the case of Garmin, 4 times a year for map updates (or at least you can update the unit that often). Second is how often the updated maps add useful info - i.e. the detail maps for San Francisco get completely changed in the latest map update, but Chicago is not changed at all and that is where you live. (Extreme example, but you get the idea.)

glennc

Yep, you've got it, although to be accurate it's not receiving its location from the satellites, but information from them that enables the GPS to display what it believes is your position on the screen :)

Maps are as up to date as they are. There seems to be no real logic as to when new roads make it onto the maps, I was directed once onto a road that was still under construction ... but that's rare :wink:

Much appreciated. I have spent three days of continuous research and time to try go get a GPS that works and the misinformation is astounding!
Regards,
Glenn

glennc

The GPS Unit holds the points of interest, hospitals and current roads. All the calculation for routing a trip, returning from a wrong turn and locating the nearest hospital or restaurant is all done by the GPS Unit. It is only receiving current locations data from the Satellites?

You've almost got it.

It receives both current location and velocity data from the satellites - I'm pretty sure it will also interpolate if the signal is briefly lost (last known point was here, vehicle was traveling northeast at 60 mph, signal was lost for 1 minute, so current position should be a mile NE of last known position. (I could be wrong about this).

Also, I'm not sure if routing and re-routing is technically done to the map POI data or to converted GPS co-ordinates, but it is all done internally by the GPS independent of the satellite connection.

Hospital info would be stored in the POI from the map data so if the unit doesn't know there's a hospital nearby it won't show that (or it might show an older hospital 5 miles away rather than a new one a block west).

Also on some phone GPS software (not sure if mainstream car ones support this), you can select a navigation point using the map itself. If not, you can select a nearby adddress. For example, let's say your friend lives at 1234 Mulberry street and you can find this on Google Maps, but the GPS doesn't even list Mulberry Street. Even if you can't select the location on the GPS, you could check Google Maps and find the next intersection from your friend's house is 987 CandyApple Lane and navigate to that on the GPS. (Of course, this assumes that SOME road in the town will be in the GPS and that you have access to the Internet via computer or smartphone - i.e. it's good if you are planning a trip from home, not great if you are on the road and decide to change destinations).

Is it normal for a latest update to be a year old? A problem I have is that the features and display of the Magellan 2136T-LM I like better than Garmin and Tom Tom videos of comparable units.

I can't say for Magellan. I've always used Garmin and they update maps typically 4 times a year. Basically, Garmin and TomTom have basically been front tier, with Magellan and Navigon (before I think they were bought by Garmin) as second-tier, so I would expect Garmin and TomTom to have more frequent updates.

It might or might not be a huge issue to you, though - we have Garmin units that don't include map updates and are three or four years old and still work fine for locating and navigating to a street address. Where they typically don't work so well is if you want to find a nearby restaurant and it will show one that closed a year ago.

Truly appreciate your time and response. The help I am getting and the understanding is extremely valuable. Just got off the phone with Magellan Tech and this one completely contradicted the one I talked to yesterday.
Solely from watching youtube videos of the Garmin 145LMT and the Tom Tom VIA 1505 LMT, I must say purely from a display with sidestreets names, I like the Tom Tom. They have to be better than the Magellan I got, and I believe they are both of high quality. So my fingers are crossed. I am going to return my unit today and get a Tom Tom. I need time to learn it and I am technically savy on many things but GPS's I have no experience. Thanks
Glenn

glennc

Maps are as up to date as they are. There seems to be no real logic as to when new roads make it onto the maps, I was directed once onto a road that was still under construction ... but that's rare :wink:

Yes - there are really two similar but not identical issues here. One is how often the GPS manufacturer issues updates (either map data or firmware) - in the case of Garmin, 4 times a year for map updates (or at least you can update the unit that often). Second is how often the updated maps add useful info - i.e. the detail maps for San Francisco get completely changed in the latest map update, but Chicago is not changed at all and that is where you live. (Extreme example, but you get the idea.)

Thanks again for clarifying. Got to be better than a year old and it also trashes the unit........ {:-))!
Glenn

Tiger-Heli

It's going to be personal opinion between Garmin and TomTom.

I have only personally used Garmin.

I liked the "Looks" of TomTom and read a great review of the two a week or so ago, but can't find it now and don't remember what site it was on.

I remember the review was something along the lines of "Garmin says Turn right on Highway 452 in 300 yards" while "TomTom says take the next right on St. Louis Freeway" - it had other key differences in philosophy between the units that confirmed for ME that Garmin was correct for ME - but like I said, I can't find it. This is SIMILAR, but I don't think it was the page I am thinking of:
http://forums.gpsreview.net/discussion/14386/x/p1/

Not sure if these are okay with the forum, but this has good basic info:
http://gpstracklog.com/buyers-guides/auto-gps-buyers-guide

This seems fairly unbiased and helpful, but note that I think Junction View was just coming out when this was written (note that it doesn't show the split-screen views on the Garmin). I think Garmin has improved and expanded this a lot since this review, but I don't know that they are better than TomTom yet):
http://www.gpspassion.com/fr/articles.asp?id=279

This is fairly unbiased, but it is also 4-years old and I think a lot has changed since then:
http://www.gpsmagazine.com/2007/06
/garmin_vs_magellan_vs_tomtom_which_gps_picks_the_best_routes.php

This has fairly good info from a Garmin bias:
http://www.poi-factory.com/node/35530

This has fairly good info from a TomTom bias:
http://discussions.tomtom.com/t5/GO-800-1000-2000-Via-Start-20-40/TomTom-vs-Garmin-in-regards-to-features/td-p/70603

Fairly unbiased here:
http://www.tomtomforums.com/t18893-advantages-over-garmin.html

Five pages of info here (I didn't read all of it):
http://www.amazon.com/forum/gps/Tx2QYVHNNABWUFG?_encoding=UTF8&cdForum=Fx1ZP396JKI1BQ4

Again - I really wish I could find the link that more clearly showed the philosophy differences, if anyone else knows ...

glennc

It's going to be personal opinion between Garmin and TomTom.

I have only personally used Garmin.

I liked the "Looks" of TomTom and read a great review of the two a week or so ago, but can't find it now and don't remember what site it was on.

I remember the review was something along the lines of "Garmin says Turn right on Highway 452 in 300 yards" while "TomTom says take the next right on St. Louis Freeway" - it had other key differences in philosophy between the units that confirmed for ME that Garmin was correct for ME - but like I said, I can't find it. This is SIMILAR, but I don't think it was the page I am thinking of:
http://forums.gpsreview.net/discussion/14386/x/p1/

Thanks you Sir! But time is running so I ran out and got a Tom Tom and it is updating and charging as I type. I sure hope it functions properly. No one tells people that they need to start researching a GPS unit long before one needs to leave on a trip.......
Glenn
Not sure if these are okay with the forum, but this has good basic info:
http://gpstracklog.com/buyers-guides/auto-gps-buyers-guide

This seems fairly unbiased and helpful, but note that I think Junction View was just coming out when this was written (note that it doesn't show the split-screen views on the Garmin). I think Garmin has improved and expanded this a lot since this review, but I don't know that they are better than TomTom yet):
http://www.gpspassion.com/fr/articles.asp?id=279

This is fairly unbiased, but it is also 4-years old and I think a lot has changed since then:
http://www.gpsmagazine.com/2007/06
/garmin_vs_magellan_vs_tomtom_which_gps_picks_the_best_routes.php

This has fairly good info from a Garmin bias:
http://www.poi-factory.com/node/35530

This has fairly good info from a TomTom bias:
http://discussions.tomtom.com/t5/GO-800-1000-2000-Via-Start-20-40/TomTom-vs-Garmin-in-regards-to-features/td-p/70603

Fairly unbiased here:
http://www.tomtomforums.com/t18893-advantages-over-garmin.html

Five pages of info here (I didn't read all of it):
http://www.amazon.com/forum/gps/Tx2QYVHNNABWUFG?_encoding=UTF8&cdForum=Fx1ZP396JKI1BQ4

Again - I really wish I could find the link that more clearly showed the philosophy differences, if anyone else knows ...

Tiger-Heli

??? - I just saw my previous comments quoted, did I miss any replies in the comments?

Boyd

Glenn, please try not to use the "quote" button unless it is really needed for context. And if you do use it, please edit out everything except the most important part. It makes threads difficult to read when you quote full posts from other users, and it really adds nothing. Most of the time you should just use the post reply button instead.

Thanks. :)

glennc

Glenn, please try not to use the "quote" button unless it is really needed for context. And if you do use it, please edit out everything except the most important part. It makes threads difficult to read when you quote full posts from other users, and it really adds nothing. Most of the time you should just use the post reply button instead.

Thanks. :)

Sorry, my fault. Will remember that for the future.
Glenn

Boyd

You just did it again. :lol:

Tiger-Heli

Yep - LOL - he did!!! :lol:

Different forums have different opinions on this. Personally, I tend to abuse the quote function a bit b/c sometimes I will be replying to what one user said and someone else types a comment in the mean time and it looks like I replied to them instead of the person I intended.

But there is no reason to quote comments that you aren't responding to in any case ...

glennc

Dang!
Glenn

Tiger-Heli

Again - I really wish I could find the link that more clearly showed the philosophy differences, if anyone else knows ...

Finally found it: http://www.amazon.com/review/R1E0W8H8S7E762/ref=cm_cr_dp_title?ie=UTF8&ASIN=B004MYFTEC&nodeID=172526&store=gps