[binand]

Originally Posted by T1000

If you have the interest, time and energy you can try this experiment.

Not an experiment, but I have done two simultaneous calls (one on Skype which uses data and one regular voice call); both parties could hear me quite clearly. This on a Samsung S2.

Originally Posted by swami.n

The only drawback of the maps IMO is that, when we do out of state trips, the data may be charged in roaming which may be quite expensive

There are no roaming data charges if you roam on the same network (Airtel in your case).

[T1000]

Originally Posted by swami.n

Let me put my experience last month when we were to a lot of temples in and around Mayiladuthurai in TN.

I have the Note2 and a 3G connection with Airtel and a mere 300mb monthly data pack which already had 200+ mb used and the trip actually started on the last 4-5 days of my billing cycle. I did not download the maps into cache at my home and dint have the option to do it while on the travel as well.

So the odds are heavily stacked against me right? But that is where the reality differs.

The only drawback of the maps IMO is that, when we do of state trips, the data may be charged in roaming which may be quite expensive

Thanks swami for quoting a real life example.i appreciate it.

Well, When people say google maps is free, i would like to highlight that they ignore the fact that they indirectly pay for data usage, which is still high in india.

1. Lets calculate the data usage for 2 years on account of google maps usage. I have no idea how much it will be. but just do the math you will realise you are not using google maps for free.

Well i have had nightmares using both google maps and gps devices.

There were couple of situations where we relied on google maps(on a blackberry) to goto a resort at koyna near pune and were stranded because there were no telcom signals.
google map was working for 20 odd kms after we lost the signals. we didnt realise the map data was being fed from the cache.
we drove back 20kms to get full map details again and noted in a piece of paper and continued driving.
The place was remote and it was night time.

Another experience with GPS device was a trip from mumbai to goa, it was sad to know a route to a place like goa was not mapped properly..We were stranded in the night with no help, we kept driving up and down for 60kms to find our way.
Mumbai to goa is 600 odd kms. At the start of the trip my gps device showed 498kms. I was too happy thinking im going to save fuel for 100kms, little did i know that im going to get stuck and spend extra time and fuel to reach goa

After this experience i always cross check the routes with multiple sources. :-)

I travel a lot, ive been using gps device and google for almost 3 years now. im just sharing my experience here.

[T1000]

Originally Posted by invidious

you will invariably lose the signal in tunnels or areas with thick tree or forest cover. Modern cell phones have the option of A-GPS - which is Assisted GPS which uses Mobile Towers which assist the GPS sats in determining your position. So you are better off with a 10,000 rupee Nokia Lumia than with a Map my India.
.

Hi invidious, its nice to bring out A-GPS in the discussion.
What i have heard about A-GPS is, ( im not sure of the facts)
1. A-GPS predicts a satilites postion briefly, for example, for whatever reason a device sees only 2 satellites , A-GPS helps in predicting the position of a 3rd satellite to fix a position.
2. A-GPS also uses mobile towers to fix up a position.
3. A-GPS works better in cities where overlapping of signals from multiple towers are common.
4. The limitation with mobile tower is, it needs signals from more than 1 tower to fix a position.
5. Most of the remote areas operate with only one tower
6. A-GPS fails when it sees signals from repeaters. It interprets signals from repeates as signals from towers and miscalculates the position.
7. Signals bounching of building can misguide A-GPS.

[abhijitvp]

Originally Posted by T1000

Thanks swami for quoting a real life example.i appreciate it.

Another experience with GPS device was a trip from mumbai to goa, it was sad to know a route to a place like goa was not mapped properly..We were stranded in the night with no help, we kept driving up and down for 60kms to find our way.
Mumbai to goa is 600 odd kms. At the start of the trip my gps device showed 498kms. I was too happy thinking im going to save fuel for 100kms, little did i know that im going to get stuck and spend extra time and fuel to reach goa

That’s why I said in my post, don’t rely on GPS for navigation (routing) purpose at least in India. Plan your route, cache the required area of map before you leave and follow the waypoints. I know it’s not possible every time. As far as routing is concerned, Team-Bhp is a great source of information to plan your route to the T.

[T1000]

Originally Posted by abhijitvp

That’s why I said in my post, don’t rely on GPS for navigation (routing) purpose at least in India. Plan your route, cache the required area of map before you leave and follow the waypoints. I know it’s not possible every time. As far as routing is concerned, Team-Bhp is a great source of information to plan your route to the T.

Very true, teambhp travelogue is a treasure!!! i get latest updates on the best route and any road work in progress, road conditions, cost of tolls enroute, availability of quality fuel, good places to eat.. etc from here :-)

[tsk1979]

Originally Posted by T1000

Hi invidious, its nice to bring out A-GPS in the discussion.
What i have heard about A-GPS is, ( im not sure of the facts)
1. A-GPS predicts a satilites postion briefly, for example, for whatever reason a device sees only 2 satellites , A-GPS helps in predicting the position of a 3rd satellite to fix a position.
2. A-GPS also uses mobile towers to fix up a position.
3. A-GPS works better in cities where overlapping of signals from multiple towers are common.
4. The limitation with mobile tower is, it needs signals from more than 1 tower to fix a position.
5. Most of the remote areas operate with only one tower
6. A-GPS fails when it sees signals from repeaters. It interprets signals from repeates as signals from towers and miscalculates the position.
7. Signals bounching of building can misguide A-GPS.

Most of what you have heard is wrong.
AGPS simply downloads the
http://en.wikipedia.org/wiki/Ephemeris for satellites

[binand]

Originally Posted by T1000

Well, When people say google maps is free, i would like to highlight that they ignore the fact that they indirectly pay for data usage, which is still high in india.

I pay Rs. 300 a month for 1GB data. Bulk of it is used for tethering though. I don't find that very high (it is only about 10% of my monthly mobile bill).

On the other hand, with MMI you have to purchase updates. Cost is here.

[T1000]

Originally Posted by tsk1979

Most of what you have heard is wrong.
AGPS simply downloads the
http://en.wikipedia.org/wiki/Ephemeris for satellites

Well, I beg to differ.
http://en.wikipedia.org/wiki/Assisted_GPS
http://tech2.in.com/features/all/wha...it-work/115142
http://gps.about.com/od/glossary/g/A-GPS.htm
http://www.wpcentral.com/gps-vs-agps-quick-tutorial

[dutta_d1]

I think people are missing a point with Google Maps here. Let me state the cons of Google Maps that I have got-

1. Navigation doesn't work offline. Now there's a difference between pointing your location in a cached map and navigation (routing). Google Maps uses it's servers for routing. Hence, even if you cache your entire journey worth of maps and then there is no data connection, it can still point you where you are, but it cannot route you from point A to point B.

2. Size of offline maps is limited. I guess you can save only 10 offline maps or so. Even then, the size of a map is limited to around 90 MB. Hence, it is not possible to cache the whole of India.

3. Google Maps are more or less crowdsourcing effort. Hence, in some unpopular places, the quality of data is not at par.


Hence, I carry both MMI and Google Maps (No need to carry as it comes pre-installed in any smartphone ) during a long car trip.

[T1000]

Originally Posted by dutta_d1

I think people are missing a point with Google Maps here. Let me state the cons of Google Maps that I have got-

1. Navigation doesn't work offline. Now there's a difference between pointing your location in a cached map and navigation (routing). Google Maps uses it's servers for routing. Hence, even if you cache your entire journey worth of maps and then there is no data connection, it can still point you where you are, but it cannot route you from point A to point B.

2. Size of offline maps is limited. I guess you can save only 10 offline maps or so. Even then, the size of a map is limited to around 90 MB. Hence, it is not possible to cache the whole of India.

3. Google Maps are more or less crowdsourcing effort. Hence, in some unpopular places, the quality of data is not at par.


Hence, I carry both MMI and Google Maps (No need to carry as it comes pre-installed in any smartphone ) during a long car trip.

Well said, As of now i use combination of both google maps and gps device.

Google's "cached map" doesnt work if there is a change in plan and if there is no network

Google Offline maps explained: https://support.google.com/gmm/bin/t...6955&ctx=topic

Full Offline map download is not available for india - https://support.google.com/gmm/bin/a...9131&ctx=topic

Google's biggest strength is the huge information it has collected and it gets updated on a daily basis. If you download it for once, then it defeats the main purpose of providing up to date information.

[tsk1979]

Originally Posted by T1000

Well, I beg to differ.
http://en.wikipedia.org/wiki/Assisted_GPS
http://tech2.in.com/features/all/wha...it-work/115142
http://gps.about.com/od/glossary/g/A-GPS.htm
http://www.wpcentral.com/gps-vs-agps-quick-tutorial

You have said exactly the same thing as what I said. Ephemeris data
See from the link you posted(Assisted_GPS)

Assistance falls into two categories:

1. Information used to acquire satellites more quickly [Mobile Station Based(MSB)]
   • It can supply orbital data or almanac for the GPS satellites to the GPS receiver, enabling the GPS receiver to lock to the satellites more rapidly in some cases.
   • The network can provide precise time.
2. Calculation of position by the server using information from the GPS receiver [Mobile Station Assisted(MSA)]
   • The device captures a snapshot of the GPS signal, with approximate time, for the server to later process into a position.
   • The assistance server has a good satellite signal, and plentiful computation power, so it can compare fragmentary signals relayed to it.
   • Accurate, surveyed coordinates for the cell site towers allow better knowledge of local ionospheric conditions and other conditions affecting the GPS signal than the GPS receiver alone, enabling more precise calculation of position.

MSA's do not exist in India. So you have category 1.
This is the Orbital data or Ephemeris data which I mentioned

[binand]

Er... something's wrong. You say:

Originally Posted by T1000

Google's "cached map" doesnt work if there is a change in plan and if there is no network

Google says: "Offline maps lets you select and download certain areas in your Google Maps for Android app, so that you can view that area even when you aren’t connected to the Internet or a mobile network."

You say:

Originally Posted by T1000

Full Offline map download is not available for india - https://support.google.com/gmm/bin/a...9131&ctx=topic

That link lists India under Availability > "Maps for the following countries and regions can be downloaded".

And finally:

Originally Posted by T1000

Google's biggest strength is the huge information it has collected and it gets updated on a daily basis. If you download it for once, then it defeats the main purpose of providing up to date information.

I was under the impression that Google downloaded version updates itself as and when required. Is that not the case?

Last month I went from Bangalore to Calicut. I picked the best of Team-BHP's advice in the relevant thread, and then created a "My Map" in the PC version of Google Maps - including all the intricacies of passing through all the towns in between. My Android phone showed that map in the "My Maps" section (obviously, since it is linked to my Google account) and used it to guide me throughout the trip. Never once did it misbehave. In fact, it was working perfectly fine in the middle of the forest (between Gundlupet - Sultan Bathery) where there is no mobile signal at all. Obviously there are no junctions/turnouts in the middle of the forest for it to voice-guide me, but it was showing my position just fine.

[T1000]

Originally Posted by binand

Er... something's wrong. You say:

That link lists India under Availability > "Maps for the following countries and regions can be downloaded".
.

My mistake, sorry.. yes it allows download of certain areas of india...I was referring too many links today :-)

Im not sure if you can download the full map and get routes

[DriveTrain]

I have used Locus Pro on my Android Smartphone extensively. It is a GPS tool and can use a huge source of Online maps that includes Google , Nokia OVI and a whole host of open source maps (OSM, Freemap, SHOCart, SmartMaps, MapQuest, etc). Most of them can be cached for offline use in areas without mobile coverage. You can also use personal or offline map databases that you might have downloaded earlier in your PC/Laptop.

Even though MOBAC (Mobile Atlas Creator) does not support Google Maps any more , you can still tweak the appropriate xml to point it to Google and download at the required zoom levels. You would be limited to the daily tile download limit and the Atlas size limit. So if you plan to download a significant area in higher zoom levels , you need to plan several days in advance so that you are within the appropriate download limits. You can do all of this in your laptop/PC. Once the download is saved as say a RMaps SQLite database and transferred to your smart phone , Locus Pro can use this as your offline map. You can create a complete route using My Places in Google Maps ( online ) and export the KML. This KML can be imported into Locus Pro and works wonders with the saved offline database. If you want, Locus can do the routing for you as well, however using the option above you can exactly route the way you want it to be and then use the same.

In my last drive to Bhutan and back I relied on this completely and never had to go online .

[.anshuman]

Apart from regular GPS satellites, most newer phones including my Galaxy Note also use GLONASS: http://en.wikipedia.org/wiki/GLONASS to determine location.