In a nutshell Fast Dormancy allows the RRC state machine to go to IDLE(CELL_PCH) from CELL_DCH without waiting for the timer to expire. Is there any OS (Android, Windows Phone, iOS etc) which exposes APIs using which we can invoke fast dormancy on 3G devices? Any pointers appreciated.
EDIT: Does any OS expose API's to
switch off 3G radio or switch radio
states(DCH,FACH,IDLE etc.)
I'm not sure if I understood your question correctly (I'm not familiar with the actual 3G-technology), but at least BlackBerry API (since 4.2.1) does have the following method:
Requests that the radios belonging to
the provided Wireless Access Families
be powered off.
http://www.blackberry.com/developers/docs/6.0.0api/net/rim/device/api/system/Radio.html#deactivateWAFs(int)
Constants used with the above:
http://www.blackberry.com/developers/docs/6.0.0api/net/rim/device/api/system/RadioInfo.html#WAF_3GPP
Not sure if this is what you actually meant.
It seems that Blackberry also expose fast dormancy since API 4.0.0
http://www.blackberry.com/developers/docs/5.0.0api/net/rim/device/api/io/IOProperties.html#CDMA_SET_FAST_DORMANCY_FLAG
and
http://www.blackberry.com/developers/docs/4.0.2api/net/rim/device/api/io/IOProperties.html
The OFono stack used by MeeGo seems to have Fast Dormancy settings (and radio toggling) in the radio settings api, but I can't really see at which level those would be available to users. The API doc is in their git repo:
http://meego.gitorious.org/meego-cellular/ofono/blobs/5639c653979e324e0b3a195ec3fab07fc2bd3a05/doc/radio-settings-api.txt
I've read NCFD has been blamed for spotty 3G performance on iOS devices in some cases, so I'm not sure programmatically playing with at an application level is such a good idea, especially since you'd be making assumptions about the entire platform's network stack requirements.
Related
I am looking for a wireless communication technology for exchanging data between devices via sound in ultrasonic frequencies.It is possible to communicate with two mobile devices.I want to communicate a mobile and an embedded device.Is it possible?Any device is working with this protocol?
Of course it is possible. Back in the 1970's my TV remote control used ultrasound to change the channel and turn the TV off. The control was somewhat rudimentary IIRC a short press changed the channel up and a long press turned the TV off. It worked quite reliably for these functions.
Providing more functionality would require a more complicated modulation scheme which, as has been said in another answer, would be prone to interference from other sound sources. This probably explains why infra-red communucation signals are used in more modern remote control systems.
It is possible - why shouldn't it be? Smartphones are just embedded computers too. I imagine getting CE/FCC/etc certifications with such an embedded device will not be so easy. And production testing ...
But is it feasible? Probably not. Power consumption is a lot higher than with any RF-link, it's more susceptible to noise (quite literally) and the required components (microphone+speaker) are bigger than RF-components (antenna).
And then there's a whole bunch of other things you need to keep in mind when working with ultrasound, starting with the plastic design of the embedded device. But also things like the effect of ultrasound on people and their pets etc.
I know this is not directly programming related, but is there a way to purposely limit the signal strength on a testing mobile device to determine how your app performs under weak signal conditions?
I have an app that streams video and audio to a server, and need to test how it performs in low signal areas.. Any suggestions please?
One realistic way to do it is put it in a weak Faraday cage. You can make one or buy a bag or other pre-manufactured cage that protects against radio transmissions. As long as it's not too strong, it should weaken but not completely block the signal.
you can use a software like network link conditioner on OSX and netlimiter on windows, they have options for bandwidth limiting and even packet loss and presets for different typical situations plus the ability to create some yourself, you can just create a wifi network on your machine and connect to it from the device you want to test
please not that iOS has network link conditioner built-in (you can find it under the developer menu in settings), while android may have something on a rooted device (never tried anything though)
If run run your app in a simulator, many have options for emulating poor signal conditions.
There is at least one open source project whose aim is to simulate different network conditions for exactly the type of testing you are describing:
https://github.com/facebook/augmented-traffic-control
This can work in a cellular network but in this would most likely require your own base stations etc. This is possible via other open source projects (e.g. http://openbsc.osmocom.org/trac/), but is likely not necessary as you can probably simulate the same affect with the WiFi test set up.
I have developed many apps on Android, and I have tried using Broadcast Receiver concept in many of them such as knowing when the battery is low or such.
I would like to use the same concept in developing on Windows phone, but I could not find Broadcast Receiver in it.
I want my application to know whenever the user took a new photo by camera. In addition, keep tracking of it.
What do you suggest?
There’s no broadcast receiver concept in Windows Phone.
IMO, this is by design.
I know two good reasons why I wouldn’t want that on my phone: privacy (almost no one reads list while installing apps) and battery life.
You can read those photos while your app is running (caching file list+modified times for faster updates).
And/or, you might want to create a lens extension, here’s a link for WP8.
I want to read how much data from 3G every app uses. Is this is possible in iOS 5.x ? And in iOS 4.x? My goal is for example:
Maps consumed 3 MB from your data plan
Mail consumed 420 kB from your data plan
etc, etc. Is this possible?
EDIT:
I just found app doing that: Data Man Pro
EDIT 2:
I'm starting a bounty. Extra points goes to the answer that make this clear. I know it is possible (screen from Data Man Pro) and i'm sure the solution is limited. But what is the solution and how to implement this.
These are just hints not a solution. I thought about this many times, but never really started implementing the whole thing.
first of all, you can calculate transferred bytes querying network interfaces, take a look to this SO answer for code and a nice explanation about network interfaces on iOS;
use sysctl or similar system functions to detect which apps are currently running (and for running I mean the process state is set to RUNNING, like the ps or top commands do on OSX. Never tried I just suppose this to be possible on iOS, hoping there are no problems with app running as unprivileged user) so you can deduce which apps are running and save the traffic stats for those apps. Obviously, given the possibility to have applications runnning in background it is hard to determine which app is transferring data.
It also could be possible to retrieve informations about network activity per process/app like nettop does on OSX Lion, unfortunately nettop uses the private framework NetworkStatistics.framework so you can't dig something out it's implementation;
take into account time;
My 2 cents
No, all applications in iOS are sandboxed, meaning you cannot access anything outside of the application. I do not believe this is possible. Neither do I believe data-traffic is saved on this level on the device, hence apple would have implemented it in either the network page or the usage page in Settings.app.
Besides that, not everybody has a "data-plan". E.g. in Sweden its common that data-traffic is free of charge without limit in either size or speed.
I'm building a small controller device that I'd like to partner with a computer. I've settled on using OSC out from my custom built hardware and am pretty satisfied with what I can get from WOscLib. Two goals I'd like to achieve are portability and a very nice ratio between battery:computing power, and this has lured me towards using iPhoneOS to accomplish my goals.
I think the iPad would suit my needs perfectly, except that using wifi to broadcast OSC out from my device requires that device to be connected to a third device with a wifi chip, and this would destroy the goal of portability, whilst also introducing potential latency and stability headaches. My question is pretty simple: Can I push OSC commands FROM my controller TO an iPad via USB and the Camera Connection Kit? If I could accomplish this, the two major goals of my project would be fulfilled very nicely.
This seems like it should be a simple little question, but researching this obsessively over the past few weeks has left me more almost more uncertain than if I had done no research at all. I'd really like some more confidence before I go down this route, and it seems like it should be possible. Any insight would be very, very appreciated.
The simple answer is that you can't :-(
In order to interface your custom hw you'll have to
obtain a license from apple.
no third device is required. you can click "create network" on your wifi menu in osx and then you ipad can connect directly to that. many apps now use osc over wifi on the ipad. some are done in java. im not sure about objective c.
You could connect a USB ethernet device to the iPad Camera Connection Kit and send OSC over ethernet from your custom controller.
Somewhere along the line since this question was asked, USB ethernet devices became officially supported over the CCK.