Develop Reference

Diffrence between two android APIs

please someone can explain me what's the different between using android.net.wifi and android.net.wifi.p2p to use a Wireless network in android app developpment, i know that with the second one, we can use a Wifi without access point, but it's working juste with API 14 at least. what about the first ? is this working too without an access point, and does require API 14 at least ?
Thanks in advance.

P2P is the api to connect to devices on an ap without internet connection

Get mobile cell tower timing advance on Android 2.3

I need to get the mobile cell tower timing advance.
Is it possible on Android 2.3+ ?
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It seems that it's not possible to retreive the timing advance...
Is it possible to know the distance between the mobile and the cell and the bearing otherwise ? I suppose I can't use the Google hidden geolocation api in commercial application ;-)
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Thanks

For LTE technology there is already an access to Timing Advance values: see http://developer.android.com/reference/android/telephony/CellSignalStrengthLte.html#getTimingAdvance()

This is currently not implemented, and it will be a hard task because it is device-dependent.
The actual timing advance is only known by the modem, also called the baseband processor (BP). The modem is coded by the device's constructor and thus cannot be modified, and can differ between constructors and devices.
Android runs on the application processor (AP) and uses AT commands to communicate with the BP (modem). For example, Android internally sends AT commands to the modem to send SMS, receive calls, ...
The only way to get the actual timing advance would be to query the BP (with an AT command), but whether the constructors implement a specific AT command to get it is up to them. Unfortunately almost no devices implement it (only very old ones), so there is no way to get this information.

I don't think it's a good idea to use timing advance for geolocation, since it is only relevant on GSM networks. Once the device hands over to UMTS networks, no more timing advance.
Why not use http://developer.android.com/guide/topics/location/obtaining-user-location.html ?

If you need Antenna location you don't need Timing Advance. Then you need LAC, CID etc. which are all part of the public AOS API, and then you can query some public database for the location of these. There are dozens of Android apps that already does this. Perhaps even as an example app for Android developers. Google it.
However, GSM Timing Advance (TA) knowledge is definitely still of interest for several other reasons. So if someone know how to extract this info from the Android vendor RIL, please let us know.

Making android bluetooth app send a warning when out of range

I have a quick question about trying to develop a new app on Android. So as the title says, I'm to use Bluetooth to link up two Bluetooth capable devices and when they are at a specific maximum range (5-20 ft), have the phone play some sort of alarm.
I do not however, own an Android Phone, but I am instead developing it on the Emulator on my computer. Earlier, I discovered that the emu is not Bluetooth capable nor does it have any form of sounds.
Is there any way of continuing on besides getting a real phone? Any helpful workarounds are welcome

regarding the emulator capabilities : you'd better buy a device soon ... duplicate?
And regarding the alarm triggering i'm a bit curious : on what are you relying ? SNR ? is there an easy way to access this kind of data on Android ? (only had a glance at the reference pages)

Sensor simulator on 2.1

I have a specific problem. I need to make openintents sensor simulator work
on 2.1 emulator. Does anyone has an advice on how to pass around deprecated code and make it work on emulator 2.1. Ty in advance for any help or advice you might have.

Most of the sensors are not implemented in the emulator. You need a real device to test code that access sensors within Android.
See the following site about the limitations of the emulator:
http://technotak.blogspot.com/2011/02/what-are-limitations-of-android.html

Measuring "real" phone signal strength on a mobile phone

I want to programmatically measure the phone signal strength in a mobile phone. I don't actually care about the mobile phone or the programming environment: It can be based on android or windows mobile or even J2ME and can be from any manufacturer (please no iPhone). However, it needs to be a real, commercial mobile phone and not a special measurement device.
This problem is not as easy as it seems with a first look. I am aware that there already exist a number of methods that claim to return the phone signal strength. Some of these
are:
SystemState.PhoneSignalStrength for WM6
RIL_GetCellTowerInfo for WinCe (dwRxLevel member of returned RILCELLTOWERINFO struct)
android.telephony.NeighboringCellInfo.getRssi() for android
The problem with the above is that they only return a few (under 10) discrete values, meaning that, for instance, the return values of SystemState.PhoneSignalStrength can only be translated to (for instance) -100 dbm, -90 dbm, -80 dbm, -70 dbm and -60 dbm, something that is not useful for my application, since I'd like to have as much precision as possible.
It doesn't matter if there is an undocumented solution that only works on only one phone, if you can tell me a way I'd be grateful.
Thanks in advance

Please check about JSR-256 Mobile Sensor API for Java ME. Nokia S60 5th edition devices support this API. You can check about network signal intensity by using this API. But, it might be good to ask it's granularity from Nokia Forum first.

Here's a solution I found for people who are still looking for an answer:
Some windows mobile HTC mobile phones have a program called fieldtest.exe which contains the information I need (probably other phones also have that, I've only tested with a specific HTC but from search on google I understand that most HTC WM phones it). The fieldtest program not only has the exact signal strength for the phone, but also a big amount of other very useful telephony information not accessible otherwise.
The only problem is how can you use the data of that program in your process since all the values are stored in a ListView.
Well, that was the point of another question I had posted.
So, the solution is to run the fieldtest program and extract / steal the required values from there !

There is a good tutorial that explains how to get the Real GSM signal measured by your phone
Try this tutorial:
http://www.firstdroid.com/2010/05/12/get-provider-gsm-signal-strength/
Hope it help,
Adrian.

On WindowsCE platforms this might be tough. The last platform I worked on used a Siemens modem which I could directly access and get their own information from. However since their last firmware update they've now closed this off and forced me to go via RIL.
I'm guessing you might have to find a particular unit with a particular modem. However I don't know of any in particular. Sorry. :(