Database Develop

What does A-GPS cost?

I have got the A-GPS option enabled through KaiserTweak and it does make a big difference on Google Maps. My only concern is- what does it cost? Where is it connecting to to get a fix?
I am on T-Mobile UK Web n Walk (unlimited data plan) so if it is connecting through that then there is no issue. I am just always a bit wary about things that I don't understand (quite a lot to be wary about then!) and couldn't find a straight answer anywhere.
Thanks to anyone who can enlighten me!

THe GPS itself is free, the google maps you pay for the data as it downloads the map info. if you use tomtom then you dont pay for anything other than the initial cost of the maps and software if the software didnt already come with the phone

The GPS signal is courtesy of the huge sums spent on military defense over the past couple decades
For real, there is no charge for the GPS tracking proper. What does not come for free are the maps. so Google maps come over the air, meaning you pay via a data plan. If you purchase navigation software, you will pay for maps as well, but you can load them onto a storage card so there would then be no data charges. so esentially a Nav program like Tom Tom/ Garmin/ iGo, once you pay upfront, it is free thereafter (relatively speaking as you will still need to pay for the cost of charging your device battery)

Thanks for your reply. i understand that the GPS itself is free as it is just receiving satellite signals, however the Kaiser also has assisted GPS as an option in KaiserTweaks. From what I understand, this uses info from network masts to give an approximation of where you are. My question is how does this work, or more precisely are there any cost implications that should make me disable the A-GPS option?

A-GPS in terms of the updates that occur from the network are short bursts of data about every 6 days (or almost never if you use active sync regularly as the updates will occur thru the PC's internet connection). If you have any sort of data plan this is a non issue.
The phone just gets some sattellite data to speed up the startup fix when using the built-in GPS.

RemE said:
A-GPS in terms of the updates that occur from the network are short bursts of data about every 6 days (or almost never if you use active sync regularly as the updates will occur thru the PC's internet connection). If you have any sort of data plan this is a non issue.
The phone just gets some sattellite data to speed up the startup fix when using the built-in GPS.
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You are confusing A-GPS with QuickGPS. QuickGPS simply downloads satellite location data via the internet as opposed to getting it directly from the satellites. It's faster to get it from the internet. A-GPS uses cell tower triangulation, though I'm not sure how (or even if) that integrates with the satellite based triangulation when that feature is enabled. Regardless, I wouldn't think A-GPS would cost anything... it doesn't use data, and doesn't use talk time.

No, A-GPS = Assisted GPS = QuickGPS. It's free if you connects by active synch or a wifi connection. It downloads ephemerides of satellites for next 7 days (position of satellites for 6 days and 23 hours exactly) which helps your GPS for the first fix (or cold fix). So with QuickGPS (or A-GPS) you can do the fix in 15-30 seconds max instead of 2-3 minutes without . It's just an help for your GPS ( more informations on http://www.gpspassion.com)

Or you could say that QuickGPS uses A-GPS technology to assist in obtaining quicker GPS fixes. Either way mickey is right.
If you don't use Active Sync or WiFi very much you will use a small amount of data but it is a negligible amount.

mickeydeplage said:
No, A-GPS = Assisted GPS = QuickGPS. It's free if you connects by active synch or a wifi connection. It downloads ephemerides of satellites for next 7 days (position of satellites for 6 days and 23 hours exactly) which helps your GPS for the first fix (or cold fix). So with QuickGPS (or A-GPS) you can do the fix in 15-30 seconds max instead of 2-3 minutes without . It's just an help for your GPS ( more informations on http://www.gpspassion.com)
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Pretty close: The diffference in layman terms: The A-GPS allows your device to remember the last location when you hit a dead spot. This allows the selected GPS program to continue an estimated tracking based on the last recieved location, direction & speed data.
A(ssited) GPS uses no internet data. So there is no charge period. It just uses satelite data.

mickeydeplage said:
No, A-GPS = Assisted GPS = QuickGPS.
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Ok what is the system used by the latest Googlemaps application, and no doubt others, which gives a rough location purely on cell tower data? I understood this to be AGPS.
Shamelessly ripped from Wikipedia...
Assisted GPS
GPS is a satellite based positioning system. Assisted GPS, or A-GPS was introduced to enhance performance. The development of A-GPS was accelerated by the U.S. FCC's E911 mandate requiring the position of a cell phone to be available to emergency call dispatchers. [1]
Conventional GPS then had difficulty providing reliable positions in poor signal conditions. For example when surrounded by tall buildings (as a result of multipath), or when the satellite signals are weakened by being indoors or under trees. Some newer receivers fare better.
In addition, when first turned on in these conditions, some non-A-GPS units may not be able to download the almanac and ephemeris information from the GPS satellites, rendering them unable to function until a clear signal can be received continuously for up to one minute.
An A-GPS receiver can address these problems in several ways, using an Assistance Server:
The Assistance Server can locate the phone roughly by what cell site it is connected to on the cellular network.
The Assistance Server has a good satellite signal, and lots of computation power, so it can compare fragmentary signals relayed to it by cell phones, with the satellite signal it receives directly, and then inform the cell phone or emergency services of the cell phone's position.
It can supply orbital data for the GPS satellites to the cell phone, enabling the cell phone to lock to the satellites when it otherwise could not, and autonomously calculate its position.
It can have better knowledge of ionospheric conditions and other errors affecting the GPS signal than the cell phone alone, enabling more precise calculation of position. (See also Wide Area Augmentation System)
Some A-GPS solutions require an active connection to a cell phone (or other data) network to function, in others [2] [3] it simply makes positioning faster and more accurate, but is not required.
As an additional benefit, it can reduce both the amount of CPU and programming required for a GPS Phone by offloading most of the work onto the assistance server. (This is not a large amount for a basic GPS - many early GPSs ran on 386/16 or similar hardware).
High Sensitivity GPS is an allied technology, that addresses some of the same issues in a way that does not require additional infrastructure. It notably cannot provide instant fixes when the phone has been off for some time, that some forms of A-GPS can.

Coorect. There are several types of Assisted GPS. The native A-GPS on the Kaiser is only for using the data recieved before hitting a dead spot, so your track can continue as estimated.
The recent cell tower & CID assisted GPS programs can take that a step further & in stead of guessing your track based on last known heading & coordinates can also use information from cell towers. Some process this data through servers which keep track of cell tower locations & then provide an estimated fix based on tower triangulation.

GSLEON3 said:
Pretty close: The diffference in layman terms: The A-GPS allows your device to remember the last location when you hit a dead spot. This allows the selected GPS program to continue an estimated tracking based on the last recieved location, direction & speed data.
A(ssited) GPS uses no internet data. So there is no charge period. It just uses satelite data.
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Yep, correct! A-GPS is only a vector forwarding, short intergration of previous data. Only works whilst GPS gives out 'No Sat Data'
It also depends on if you unit is in mode 1 or mode 2 (only ref'd to WM6 GPSmode reg key as it has the handler)...
DTR Control Flow Values.
GPS_NMEA_0183 = 1
GPS_RTCM_104 = 2
Mode 2 (which is default) processes all data through the WM6 handler, Mode 1 will give you RAW data (which should solve the Navigon 'Destination Reached' problem!!!)
A-GPS costs nothing as it is only a calculation, QuickGPS costs only your Internet acces time for its own download and if you have it setup for Activesync, will only use your comps link....

Wow! glad im not the only one who is confused! I get what you're saying about it just calculating position based on last available data, but that doesn't fit with my experience with googlemaps after a hard reset where it came up with a circle of my location despite no gps fix being available.
Thanks to everyone for their help!

The excellent test of the Kaiser here : http://www.gpspassion.com/fr/articles.asp?id=237&page=1 gives a link for the QuickGPS of the Kaiser here : http://www.cdmatech.com/download_library/pdf/gpsonextra_assistance.pdf

mickeydeplage said:
The excellent test of the Kaiser here : http://www.gpspassion.com/fr/articles.asp?id=237&page=1 gives a link for the QuickGPS of the Kaiser here : http://www.cdmatech.com/download_library/pdf/gpsonextra_assistance.pdf
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Brilliant! Thanks for clearing that one up!

mickeydeplage said:
The excellent test of the Kaiser here : http://www.gpspassion.com/fr/articles.asp?id=237&page=1 gives a link for the QuickGPS of the Kaiser here : http://www.cdmatech.com/download_library/pdf/gpsonextra_assistance.pdf
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Now come on!! Where were you hiding when we needed you for reference many threads back??
Good info input...

Assisted GPS or A-GPS uses the mobile phone network to assist the GPS receiver in the mobile phone to overcome the problems associated with TTFF (time to first fix) and the low signal levels that are encountered under some situations.
For A-GPS, the network provides the Ephemeris data to the cell phone GPS receiver and this improves the TTFF. This can be achieved by incorporating a GPS receiver into the base station itself, and as this is sufficiently close in position to the mobile the data received by the base station is sufficiently accurate to be transmitted on to the mobiles. The base station receiver is obviously on all the time, and will be located in a position where it can "see" the satellites.
The information provided can be either the Ephemeris data for visible satellites or, more helpfully the code phase and Doppler ranges over which the mobile has to search, i.e. 'acquisition data'. These ranges can be estimated as the position of the mobile is bounded because it must be within the cell served by the particular base station. This technique is able to improve the TTFF by many orders of magnitude.
Assisted GPS or A-GPS is also used to improve the performance within buildings where the GPS signals are by 20 dB or possibly more. Again by providing information to the GPS receiver in the mobile it is able to better correlate the signal being received from the satellite when the signal is low in strength. Using this technique it is possible to gain considerable increases in sensitivity and some manufacturers have claimed it is possible to receive signals down to power levels of around -159dBm. The base station supplies the receiver with navigation message bits - 'sensitivity data'.
Summary: A-GPS is designed to help get the first fix, but does not improve GPS accuracy; Therefore QuickGPS is a form of A-GPS
To improve the accuracy of the GPS fix, you need Differential GPS (DGPS) - see below
There are many sources of possible errors that will degrade the accuracy of positions computed by a GPS receiver. The travel time of GPS satellite signals can be altered by atmospheric effects; when a GPS signal passes through the ionosphere and troposphere it is refracted, causing the speed of the signal to be different from the speed of a GPS signal in space. Sunspot activity also causes interference with GPS signals. Another source of error is measurement noise, or distortion of the signal caused by electrical interference or errors inherent in the GPS receiver itself. Errors in the ephemeris data (the information about satellite orbits) will also cause errors in computed positions, because the satellites weren't really where the GPS receiver "thought" they were (based on the information it received) when it computed the positions. Small variations in the atomic clocks (clock drift) on board the satellites can translate to large position errors; a clock error of 1 nanosecond translates to 1 foot or .3 meters user error on the ground. Multipath effects arise when signals transmitted from the satellites bounce off a reflective surface before getting to the receiver antenna. When this happens, the receiver gets the signal in straight line path as well as delayed path (multiple paths). The effect is similar to a ghost or double image on a TV set.
Satellite geometry can also affect the accuracy of GPS positioning. This effect is called Geometric Dilution of Precision (GDOP). GDOP refers to where the satellites are in relation to one another, and is a measure of the quality of the satellite configuration. It can magnify or lessen other GPS errors. In general, the wider the angle between satellites, the better the measurement (see GPS Basics slide show for an illustration). Most GPS receivers select the satellite constellation that will give the least uncertainty, the best satellite geometry.
GPS receivers usually report the quality of satellite geometry in terms of Position Dilution of Precision, or PDOP. PDOP refers to horizontal (HDOP) and vertical (VDOP) measurements (latitude, longitude and altitude). You can check the quality of the satellite configuration your receiver is currently using by looking at the PDOP value. A low DOP indicates a higher probability of accuracy, and a high DOP indicates a lower probability of accuracy. A PDOP of 4 or less is excellent, a PDOP between 5 AND 8 is acceptable, and a PDOP of 9 or greater is poor. Another term you may encounter is TDOP, or Time Dilution of Precision. TDOP refers to satellite clock offset. On a GPS receiver you can set a parameter known as the PDOP mask. This will cause the receiver to ignore satellite configurations that have a PDOP higher than the limit you specify.
The nett result of all these error can amount to 10 metres. To provide corrections, Assisted GPS uses data taken from a series on "Known" fixed locations to provide some estimation of the GPS error at a particular location and thus correct it. How this error correction data gets to your PDA depends on the hardware and software involved. Some GPS hardware vendors offer a web/GPRS based service. Differential GPS (DGPS) uses long-wave radio, requiring an additional radio receiver & many transmitting beacons.
WAAS (Wide Area Augmentation System) is a satellite based differential GPS system (DGPS ). A set of satellites constantly transmit correction data for s et of known points. The simplicity of the system is the error correction data is transmitted in the sand frequency spectrum as the GPS data, so not extra radio gear is needed. http://www8.garmin.com/aboutGPS/waas.html gives a reasonable overview of how WAAS works
WAAS is a US based system first tested in 1999; Europe has an equivalent system called EGNOS (European Geostationary Navigation Overlay Service ) operational since July 2005
PS: the Kaiser's GPS receiver has no DGPS functions

EDGE/GPRS/3G Questions/Issues/Info

This might be a silly question, but does anyone know if the G1 will be able to access the web if you live in an area where 3G is not available yet? I live north of Los Angeles (who has 3G) in Bakersfield and we don't have it yet. I am hoping that I was not an idiot to preorder the phone and then not be able to use all the cool web features.
Thanks in advance,
Jamie

it should still work on the EDGE network

From my understanding it will work with GPRS, Edge, and 3g so you shouldn't have any problems bro by the way I understand the concern.

With a 1150ma battery, GPS, "big" screen etc, 3G will just drain the battery even quicker.
I will not worry about 3G until an extended battery is released- and the fact that 3G will not be in my market for a year of so.

aad4321 said:
Hey guys i have a htc wing now, and it does not have a gps. It looks like the gps for this phone is one of the main highlights, because it uses it for a lot of applications. Does anyone know what the gps strength will be like? Will it work will in a building, it do i have the be in direct light for like ten minuites to get a signal?
Anyone with a htc device with a gps already, does it work well?
I hear the android is a-gps, so mabye it will have the ability to somewhat work well when in a pocket, or building.....
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Time for a lesson on GPS... It uses satellites in the sky, and you need a view of a certain amount of satellites to find your location (4 will find you but not very accurately, the more the better). If you're in a building, and not right next to a window, no GPS will ever find your location, ever. That's like asking if your internet will work if the ethernet cable is unplugged from the back of your computer and you don't have wifi, it goes against the entire idea of how it functions.
Now, as for the quality of the HTC GPS receiver... People have complained about GPS lag, but I maintain my opinion that it's completely software related, my Fuze had none whatsoever. You don't need to be in sunlight, just have enough clear sky that it can get a reading from the satellites. I've taken trips with the Fuze even on very cloudy days and it took a little longer to get a lock (5-10 mins, it locks in like 30 seconds to a minute with clear skies) but once it had my position, it stayed true. All of the upcoming HTC devices use A-GPS, by the way. Diamond, Touch Pro, Xperia, G1...

aad4321 said:
WHAAAT? you dont want to use 3g? lol in my opinion thats 50 percent of the phones features.
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He's using the battery draining as an excuse, something to keep him from pulling his hair out because he won't have 3G for another year. Anyone who's used a phone for data features on both networks knows EDGE doesn't hold a candle to 3G.
As for the original post, yes, it will give you all of the same data features on EDGE as on 3G.

The big thing with A-GPS is that it's mainly used to increase the startup speed of your GPS. Instead of waiting 10 minutes to download the almanac of the satellites in the sky from the GPS sats, it downloads the data over your data connection, using the basis of which cell site you're connected to for determining your rough location. This way it only takes about 30 seconds to get a fix instead of much longer.
The sensitivity of the GPS on phones has been fairly good as far as i've seen on devices like the Tilt and such, so I don't see why a phone with such a heavy emphasis on location-based apps would have a sub-par GPS setup. Here's hoping things work well.

Black93300ZX said:
He's using the battery draining as an excuse, something to keep him from pulling his hair out because he won't have 3G for another year. Anyone who's used a phone for data features on both networks knows EDGE doesn't hold a candle to 3G.
As for the original post, yes, it will give you all of the same data features on EDGE as on 3G.
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Thanks to one and all!!! I am looking forward to my G1 and retiring my Wing.

Black93300ZX said:
He's using the battery draining as an excuse, something to keep him from pulling his hair out because he won't have 3G for another year. Anyone who's used a phone for data features on both networks knows EDGE doesn't hold a candle to 3G.
As for the original post, yes, it will give you all of the same data features on EDGE as on 3G.
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3g doesnt burn that much battery unless your using it constantly like as a primary internet for your computer. also when you put your phone in sleep mode it isnt runnig in the background

haitiankid4lyf said:
3g doesnt burn that much battery unless your using it constantly like as a primary internet for your computer. also when you put your phone in sleep mode it isnt runnig in the background
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Exactly... But when you're without 3G, I guess you try to justify why it's not as good, and that's what he came up with. It's like everything though, people on here try to justify why the iPhone isn't as good as the Diamond/Touch Pro, truth be told it's better in many aspects but comes short in many as well.

3g data transfer?
ok i currently have the tmo wing.. and i can connect my lappy to the tmo data network via usb port.. will i be able to do this with the g1?yes/no maybe?

iife_aint_easy said:
ok i currently have the tmo wing.. and i can connect my lappy to the tmo data network via usb port.. will i be able to do this with the g1?yes/no maybe?
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I choose D... all of the above
No... it will not work out of the box.
Yes/maybe... it should work someday soon unless HTC/T-Mobile have somehow disabled that ability in hardware.
As soon as I get the phone I will be working on it on the Linux side (not an actual internet sharing app... more of a route/iptables script) and I am sure someone will work on a java solution (although a kernel solution would be faster). There was an application for the iPhone that provided internet sharing but it was banned from apple store and Google has said they won't do that so I think it should be here soon.

problems with Wireless (3g and wifi)
does anybody else have problems with the 3g?
i have tmobile and i didnt select the option for only 2g but my 3g keeps going in and out even when im in the same spot it'll go from 3g to Edge for no reason.
also does anybody have problem conecting to wifi?
i have a linksys wireless n (WRT300N) router, the ssid is visible and uts using wep security but when ever i try to connect to it it says out of range or it just stops trying to connect Please Help

haitiankid4lyf said:
does anybody else have problems with the 3g?
i have tmobile and i didnt select the option for only 2g but my 3g keeps going in and out even when im in the same spot it'll go from 3g to Edge for no reason.
also does anybody have problem conecting to wifi?
i have a linksys wireless n (WRT300N) router, the ssid is visible and uts using wep security but when ever i try to connect to it it says out of range or it just stops trying to connect Please Help
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I have an issue with my G1 WIFI connection. If i broadcast my SSID I connect with no problems. but if i disable the broadcast it will not connect, and this is with me manually putting in the connections into the phone.
I called TMobile but they said i needed to call HTC. they didn't have a solution.
BTW, I have no WEP enabled. I just disable the SSID broadcast.

I just connected to my Linksys router with WPA2 and had 3G running, connected no problem.

Haitiankid: try entering the details of your network manually and seeing if it will connect then. Also, as for the 3G fading in and out, are you in a week signal area for 3G?

wifi working
I got my wifi to work. It was my routers fault. What I did was in went into my routers settings by typing 192.168.1.1 and entered 'admin' (no quotes) and no password. Once in my settings I changed my brocasting type from b&g mixed to all mixed changed frequency to auto, changed network key from shared to open and wifi started working. I don't know if all those steps were neccesary but it worked for me. Hope it works for some else.
As for the 3g it seems to be getting better

for those of you with the 3g/edge switching problem...
Hey, if uve got the 3g switching to edge back and forth continuously, its likely because you didnt get a new SIM card when u got the g1. It simply means you have an old SIM card that doesnt support 3g well, call tmobile up tell them your situation, theyve given most people a free new SIM card thats more compatible.

drewernxc said:
Hey, if uve got the 3g switching to edge back and forth continuously, its likely because you didnt get a new SIM card when u got the g1. It simply means you have an old SIM card that doesnt support 3g well, call tmobile up tell them your situation, theyve given most people a free new SIM card thats more compatible.
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I don't think that's the case. I've had the same SIM card since 2000, no problems like this. If any SIM is too old to support 3G, I'd think one made 8 years ago would definitely be the case.
It sounds like he's in a bad coverage area, which could be lots of things. There is a coverage map on the T-Mo website, don't know if it shows 3G. Or it could be the building he's in. My phones have never worked at my grandmother's house. I get full bars on the front porch, and full bars the second I get out the back door, but no signal in the house itself. Even relatives on other networks get little to no coverage inside the house. Probably the really really old insulation and building materials are blocking the signal. At my last apartment I only had a good signal on the corner of my bed, and that disappeared when new neighbors moved in upstairs.
These are radio waves, which aren't foolproof or perfect, they encounter all kinds of interference. Nothings going to be as secure and consistant as a wired connection. Nature of the beast, unfortunately.

haitiankid4lyf said:
I got my wifi to work. It was my routers fault. What I did was in went into my routers settings by typing 192.168.1.1 and entered 'admin' (no quotes) and no password. Once in my settings I changed my brocasting type from b&g mixed to all mixed changed frequency to auto, changed network key from shared to open and wifi started working. I don't know if all those steps were neccesary but it worked for me. Hope it works for some else.
As for the 3g it seems to be getting better
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Careful dude, with the security set to open anyone within range (neighbors, wardrivers, etc.) can use your wifi to get on the internet. Try using WPA or WPA2 security, but leaving it all mixed and frequency at auto.

hsdpa and gprs

Hello,
Whe i am connected to internet, my touch mostly goes to GPRS, bus i want to connect bij hsdpa. how can i change that? It is switching automatic now...

Data connections...
Switching is automatic. Your device will connect to whatever is available in your location at that time.
I'm quite amazed at how irregular the HSDPA signal is where I live. I can walk down the street a hundred yards and get it. Walk to work half a mile away and it goes off again... until I get inside, then it's back on again! Modern technology - great isn't it?

Does 3G, HSDPA, Edge each affect the GPS in anyway?

Me and my friend were arguing whether or not theres a difference between searching for satellites on a 3G/HSDPA and an edge connection.
Is it faster or do they have no correlation at all?

3G/HSDPA/Edge is not necessary at all for gps
gps is a 1 way communication between a passive receiver in a device and a geostationary satellite out in space
3G/HSDPA/Edge is a 2 way communication between a device and a ground based transceiver and antenna setup
in theory you can pull out your sim and throw it in a well
and gps still works
but with assisted gps which x1 support one can get a faster pos by the device getting a rough position from the 3G/HSDPA/Edge connection because they know their own location

[Q] Wireless Network Location Accuracy?

Is there a way to better my location accuracy with ONLY the wireless network? I dont want to use my GPS for things like BeautifulWidgets and FourSquare.. but i would deffinetly like more accuracy as far as my location.. There are alot of times BW says I am about 20 miles away from where i really am, when at home.
This issue is not a lack of signal, i retain HSPA+ everywhere i am in the Kansas City metro area, but there are a few places it occasionally is off/wrong. Doing a refresh will often fix it, but there are times when it moves only a few miles closer to another location.
If you can suggest anything, that would be great.
I have BusyBox fully installed & RootExplorer, so please dont hesitate with any advanced ideas.

Ph0z3 said:
Is there a way to better my location accuracy with ONLY the wireless network?
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Click to collapse
when you write wireless network , you mean mobile GSM? right?
its all about how many cell locations and how close they are..

yeah i mean the towers pinging me & determining my position via tower relay signal.