Vietnamese GPS FAQs (frequently-asked questions)

The Global Positioning System, usually called GPS, is the only fully-functional satellite navigation system. A constellation of more than two dozen GPS satellites broadcasts precise timing signals by radio to GPS receivers, allowing them to accurately determine their location (longitude, latitude, and altitude) in any weather, day or night, anywhere on Earth.

VGPS is Vietnamese GPS application. VGPS is The World's First and Only GPS application that runs on any mobile phone.

VGPS can run on any color phone that has at least 500KB memory.

Minimum Requirements:

Color phone
Screen size (Width x Height): 176x182
Total memory >= 500KB

Recommended Requirements:
Color phone
Screen size (Width x Height): 240x320
Touch Screen
Total memory >= 1024KB

Your phone need to meet the minimun requirements in order to run VGPS. You can check whether your phone meets minimun requirements or not by using PhoneTest application. Download PhoneTest application in Downloads section. Install it on your phone and run to test the phone's screen size and memory.

Contact us to understand more about VGPS, and to discuss your requirement for making VGPS work with your city maps.

If you just want to test or experience VGPS, you can download VGPS demo version from download section to test on your phone.

Please be noted that even the map and VGPS are free but there is a service charge ($20) for making VGPS work with your city map because we need to spend time to work on each individual requirement.

We will assist you to make VGPS run on your phone by doing the following steps:
1. Check your phone model and configurations.
2. Introduce where to buy/get Garmin map in your home city.
3. Compile VGPS version for your map.
4. Test VGPS demo version before final version.
5. Send you VGPS final version.

You can find your home city map from Free Garmin Map Downloads. If your city map does not exist in Free Garmin map Downloads, you can search for your city map by typing "City name garmin map" in google search. For example: If you want to search for paris garmin map, type paris garmin map in google search at bottom of this page.

You can also contact us, we may suggest you where to find your city map.

It is not necessary to have Assisted-GPS (AGPS) mobile phone to install VGPS.

Any normal phone which has at least 500 KB memory can run VGPS. VGPS can run on Symbian phones, Windows Mobile phones, Linux phones, or even on a phone without OS at all.

Yes, you can run VGPS without full GPS module inside or outside (bluetooth GPS) the mobile phone.

VGPS is a real-time tracking GPS application that run on any phone. When VGPS is used with a bluetooth GPS receiver (GlobalSat BT 338) in a car travelling at 80km/h, VGPS moved the map at the same speed of the car.

VGPS has 3 versions: VGPS, VGPS179 and VGPSBlue

1.Version VGPS does not require internal or external GPS receiver. This version is used for phone that does not have internal and external GPS receiver.

2. Version VGPS179 supports Standard Location API JSR179. This version is used for phone that has internal GPS receiver.

3. Version VGPSBlue supports bluetooth GPS receiver and Standard NMEA Sentence. This version is used for phone that has bluetooth connection and external bluetooth GPS receiver.

If you do not have internal or external GPS receiver, you can download VGPS.zip from download section to test with your phone.

If you have a phone with internal GPS receiver, you can download VGPS179.zip from download section to test with your phone.

If you have external bluetooth GPS receiver, you can download VGPSBlue.zip from download section to test with your phone and a bluetooth GPS receiver.

Conclusion:

Regardless whether you have bluetooth GPS receiver or not, you still can enjoy GPS map on your mobile phone.

VGPS can calculate a shortest route between two given points on the map and automatic guide you along the route (AutoRouting).

When VGPS guide you, it will show the road name on the screen so you will know which road you need to take in order to reach your destination.

To use AutoRouting function, you need to define a waypoint start and a waypoint end, then you select AutoRouting from main menu.

VGPS is using A* algorithm for autorouting. A* is known as one of the best algorithms for routing.

To answer the question how long does it take for VGPS to calculate a route, we need to consider the amount of memory that VGPS can use for routing.

Because the memory of the phone is very limit ((some phone has only 500KB memory) and routing node data is quite huge (about 154KB for 18,888 routing nodes), we introduce an option for you to choose whether you want to load all routing nodes information into memory or not. If your phone have enough memory, VGPS can load all routing nodes into memory otherwise, it will keep routing nodes in memory card.

For a graph that has 18,888 routing nodes, VGPS need only 16ms (16 miliseconds. 1 second = 1,000ms) to find a route if all routing nodes have been loaded into memory. If you choose not to load all the routing nodes into memory (i.e keep all the routing nodes in memory card and VGPS will read memory card when it examines a node), VGPS will need about 200ms to find a route among 18,888 nodes.

For your information:

• 1 second = 1,000 miliseconds
• 1 millisecond (1 ms): cycle time for frequency 1 kHz
• 1 millisecond: duration of light for typical photo flash strobe
• 1 millisecond: repetition interval of GPS C/A PN code
• 1.000692286 milliseconds: time taken for light to travel 300 km in a vacuum
• 2 milliseconds: half life of hassium-265
• 2.27 milliseconds: cycle time for the A above middle C in music (440 Hz); if a tuning device for musical instruments generates just one tone, it is probably this tone
• 3 milliseconds: a housefly’s wing flap
• 3.4 milliseconds: half life of meitnerium-266
• 5 milliseconds: a honeybee’s wing flap
• 8 milliseconds: camera shutter speed at setting 125
• 9 milliseconds: typical maximum seek time for a 7200rpm hard disk
• 10 milliseconds (10 ms): cycle time for frequency 100 Hz (also known as a "jiffy")
• 16.7 milliseconds: cycle time for American 60 Hz AC mains grid
• 20 milliseconds: cycle time for European 50 Hz AC mains grid
• 33.3 milliseconds: the amount of time one frame lasts in 30fps video
• 50 milliseconds: cycle time for the lowest audible tone, 20 Hz
• 60 milliseconds: cycle time for European 16.7 Hz AC electrified railroad power grid
• 30 to 100 milliseconds: typical minimum latency for a broadband internet connection (important for online gaming)
• 100 to 150 milliseconds: typical time for a human blink
• 16 miliseconds: typical time for VGPS to find a shortest route within 18,888 routing nodes. (6 times faster than a human blink!)

VGPS support displaying/searching of all languages in Unicode UTF-8 format. Therefore displaying of German, Cyrillic, Chinese and Japanese characters (and of course Vietnamese characters) on the phone shouldn't be a problem provide that your phone also has Unicode font of these languages. You can download VGPSBlueRussia.rar which is a VGPS's showcase of displaying Non English Unicode Characters on a phone to try it on your phone.

VGPS support following map format:

ALAN (map, waypoints, tracks)
Holux (map, waypoints, tracks)
RUSSA map
GPS Exchange format
PCX5 (waypoints, routes, tracks)
Magellan (waypoints, tracks)
OziExplorer (waypoints, routes, tracks)
Garmin MapSource format
Polish format

You can convert Open Street Map format to Polish format or Garmin format to use with VGPS.

Steps to clip and convert OSM to Polish format:

1. If you don't have JDK 5.0 in your PC, you can get it from the Sun Java site. Download "JDK 5.0 Update 12" from here
Download JDK 5.0 Update 12

install JDK 5.0 to c:\program files\java\jdk1.5.0_12 folder in your PC

2. Create a folder osm in your PC c:\osm

3. Download planet.osm from here
Download planet.osm

unzip it to c:\osm folder
(To unpack the file on Windows use 7-zip uncompression tool. On Linux use bzip2)

4. Download osm2vgps.rar from here
Download osm2vgps.rar

unzip it to c:\osm folder

5. Open file bounds.txt in c:\osm folder, change minLat, minLon, maxLat, maxLon to your city's bounds. Save the bounds.txt file.

6. Open file osm2vgps.bat in c:\osm folder, change the parameter planet-070725.osm to your new planet.osm file download from step 3. Save the osm2vgps.bat file

7. Open command prompt window and change directory to c:\osm folder

8. Run osm2vgps.bat c:\osm\osm2vgps.bat

9. osm2vgps will take about < 8 minutes to run. It will generate 2 following files:
data.osm
data.mp

data.osm is clipped map data in osm format. It contains only map data (nodes/segments/ways) within bounds.

data.mp is map data in polish format. You can use GPSMapEdit to view this file however do not edit/save it because GPSMapEdit can not save point names and street names in unicode UTF8 format.

10. zip data.mp and send to us. We will assist you to make VGPS work with your city map.

Note: OpenStreetMap has changed their data structure recently, so you may need to modify osmclip.java a bit to work with new data format. And if you modified osmclip.java please send it back to us so that we can publish it here.


Steps to clip and convert OSM to Garmin format:


You can follow Stevez's guide to convert OSM to garmin format, replace australian's lat/lon with your city's lat/lon:

To create these garmin img files, I first download an extract of the OSM data that includes the Australian landmass.

This is done using the OSM XAPI using the command :-

wget --timeout=0 "http://www.informationfreeway.org/api/0.5/*[bbox=110,-44,156,-9]" -O australia.osm

Once I have the Australian data, I then use a perl script to extract the different states.

planetosm-excerpt-area.pl -bbox -37,140.971,-28,154.500 australia.osm > NSW.osm

planetosm-excerpt-area.pl -bbox -39.4,140.2,-33.7,151.5 australia.osm > VIC.osm

planetosm-excerpt-area.pl -bbox -29.3,137.5,-10,155.5 australia.osm > QLD.osm

planetosm-excerpt-area.pl -bbox -44.16,142.47,-39.16,149.706 australia.osm > TAS.osm

planetosm-excerpt-area.pl -bbox -39.5,127.35,-25.62,141.965 australia.osm > SA.osm

planetosm-excerpt-area.pl -bbox -36.180,111.03,-13.138,130.04 australia.osm > WA.osm

planetosm-excerpt-area.pl -bbox -26.39,128.44,-10,139 australia.osm > NT.osm

This perl script is written by Nick Burch and can be found at planetosm-excerpt-area.pl

This creates individual OSM files for each state, which are then converted to Garmin .img files using Steve Ratcliffe's excellent mkgmap software. mkgmap is written in Java.

java -jar mkgmap.jar --mapname=63240001 --description=OSM_NSW NSW.osm

java -jar mkgmap.jar --mapname=63240002 --description=OSM_VIC VIC.osm

java -jar mkgmap.jar --mapname=63240003 --description=OSM_QLD QLD.osm

java -jar mkgmap.jar --mapname=63240004 --description=OSM_NT NT.osm

java -jar mkgmap.jar --mapname=63240005 --description=OSM_SA SA.osm

java -jar mkgmap.jar --mapname=63240006 --description=OSM_WA WA.osm

java -jar mkgmap.jar --mapname=63240007 --description=OSM_TAS TAS.osm

You can go to download section to download GPSMapedit. This software is used to edit/modify Garmin map in PC.

GPSMapedit supports following format:

ALAN (map, waypoints, tracks)
Holux (map, waypoints, tracks)
RUSSA map
GPS Exchange format
PCX5 (waypoints, routes, tracks)
Magellan (waypoints, tracks)
OziExplorer (waypoints, routes, tracks)
Garmin MapSource format
Polish format

If GPSMapedit can not understand your GPS data, you can use GPSBabel application in download section to convert GPS data from other format to GPS Exchange format or Polish format.

VGPS can only automatic determine your current position on the map with an internal or external bluetooth GPS receiver.

If you do not have GPS receiver you need to determine your current position on the map manually by searching for the street name around your current position.

After you identified your position on the map, you can use Waypoints function to mark your position.

Let we clarify the process of making VGPS work with your garmin map.

1. Java application can not access file system on your memory card (unless your phone is smart phone and supports PDA feature)

2. Java application can only access resources from within application .jar file. This is to prevent java application from accessing sensitive information from your memory card. (some user put their credit card, bank account or user and password in their memory card)

3. VGPS is a java application so it can not read garmin map directly from your memory card. garmin map need to put inside VGPS.jar file so that VGPS can read the data within the .jar file

4. To put garmin map inside VGPS.jar file, we need to compile VGPS with your garmin map.

5. After compilation, the size of VGPS.jar will equal to the size of your garmin map file because the map data has been integrated into VGPS.jar file.

6. It is possible to have more than one VGPS in your phone. Each VGPS will correspondence with one garmin map file.

7. Because of all the labour hard work and time spend to make VGPS work with your garmin map, there is a service charge of $20 to compile VGPS for the first garmin map. If you have more than one garmin map, each additional garmin map will be $5. You can use paypal to support our hard work.

8. You can send your garmin map (.img) to j2megps @ yahoo.com (no space before and after @).

9. When you send your garmin map to us, please mention your phone model and/or your bluetooth GPS receiver model (if you have one).

10. If you don't have garmin map for your city, click on Free Garmin Map Downloads. You may find your city map there. Or you can search the internet to find your garmin map in the search box below.

11. It is possible to use OpenStreetMap data with VGPS so if you can not find garmin map for your city, you can read step by step tutorial for Making routable map from OSM data to use with VGPS here

VGPS is not an open source project. If we publish the source, map company will modify it and sell it. So currently, we have to compiled the map manually. As it take our time to attend each individual requirement, we are unable to provide free service. However, for open source project, we can provide VGPS with group discount service.

If you are looking for free solution to use gps map on mobile phone, you can try the following applications: