Is it possible to push data directly from one device to another over the mobile network without using a server and without wifi or Bluetooth?
(Both have the same app installed.)
How? :)
Yes. Android is capable of peer to peer communication over 3G
Google for android 3G peer to peer and you will get many hits. And you'll see that you have some hurdles to overcome:
Identifying own and target Android's internet IP
Configuring the right sockets etc.
Getting past firewalls
And all this is depended on whether or not your telecomm provider allows P2P in the first place.
Related
I can't find any documentation on Android Wear that shows how to create an app that leverages the fact that some watches (like my Samsung Galaxy Gear) can now connect directly to the internet via wi-fi when the phone is not around.
I have a few apps that generate https requests to access a REST service and I would like to know if these can be directly called from a Wear app connected to wi-fi (no phone).
Similar questions don't seem to answer this:
Direct internet connection on Android Wear?
https://stackoverflow.com/questions/26062487/android-wi-fi-direct-persistent-connection
Android: Establish "Wi-Fi Direct" connection with networked devices
My tests on a Wear emulator tethered to an internet enabled Phone emulator show:
java.net.UnknownHostException: Unable to resolve host "api.xxx.com": No address associated with hostname
But of course there's no direct wi-fi connection on the watch emulator so my next step is to try on a real watch and phone.
My suspicion is that Android Wear's data API handles this transparently so direct http requests seem impossible.
Best, thanks in advance for your help.
Even if Android 5.1.1 support Wi-Fi Feature. Android Wear on Wi-Fi: Using a smartwatch without a phone nearby
You should stick to the Data Layer API, you cannot send http request directly from watch. Fetch internet data from the phone, then transfer it to watch with Data Layer API.
You can see this Does Android Wear support directly access the Internet?
And this document Always-on and Wi-Fi with the latest Android Wear update
From the last update its possible to make http requests over wifi using android wear. You can even connect a bluetooth headphone to it to use with some streaming app.
While on wifi, if your mobile phone is connected to the internet too (dont need to be the same wifi, can be even 3g) it will act the same way it would when bluetooth connected yo our phone, but with its own internet access.
This dont mean apps will change their behavior, because most of them are coded to make the requests from your phone, but if you have an app that make direct networks requests, it will send them from your watch without advising or needing your phone.
How to do networks requests on android wear
Just use the same network requests libraries you would use on a normal Android mobile application, like volley, retrofit, okhttp. The code is exactally the same, and by the way, any Android Mobile library works with Android Wear too.
I am writing an Android server app that streams mjepg video using http local connection to a client (Google Glass) under the same network environment.The Glass does not support 802.1X EAP so I choose to host a portable HotSpot (teathering) on the server allowing Glass to join. Doing so gives Glass access to the local ip of the server. At this point neither the server nor Glass have internet connection (since they are connected locally with HotSpot and neither has 3G).
My question is if there is a better way to achieve peer to peer video streaming without having to give up the ability to connect to the internet?
Sorry in advance if what I have said above seems ambiguous. I have very little prior knowledge in networking.
==03-07-14 ==
Thanks #greenapps I have updated the question. I hope this is clearer :)
No, the Android device most probably only contains a single wifi client, and it will be unable to perform both as a teathering hotspot and also being connected to another WiFi infrastructure.
The best way to do this, is to have both you clients connect to the WiFi infrastructure instead. But as you hinted, the infrastructure network uses 802.1X EAP, and Google Glass does not support it.
So you are only left with the solution of using another WiFi infrastructure than the one you are trying to use.
Is it possible to let an Android (>4.0) device establish a WiFi-Direct connection with a Mac OS or Windows device?
According to the Wifi-Direct Docs the protocol allows:
Android 4.0 (API level 14) or later devices with the appropriate hardware to connect directly to each other via Wi-Fi
It doesn't look like Google provides this functionality via the API. Although WiFi-Direct isn't a proprietary protocol and could be implemented for any platform. There are a few posts around the web of people trying to get Wifi-Direct to work under windows:
Broadcast message from Desktop PC to Android Device using WIFI connectivity
https://superuser.com/questions/417888/how-do-i-connect-a-laptop-running-windows-7-to-an-android-phone-using-wifi-direct
http://www.intel.com/content/www/us/en/wireless-products/my-wifi-technology.html
http://androidforums.com/android-lounge/552970-howto-wifi-direct-use-your-laptop-desktop-softap-android-reverse-tethering.html
All you need is to use java.net.Socket. Depends on what do you mean by establish direct connection. TCP connection is established when on destination device (windows or mac) you open listening socket by ServerSocket. On other device you can use Socket with destination address. Of course, windows or mac box will propably have to open that port in firewall.
I guess what you actually need to know is how to get name of target computer or how to discover computers on local network. Unfortunately, it does not depend on android version I think. You should check http://en.wikipedia.org/wiki/Zero_configuration_networking about some hints. I fear there might be problem in need to open privileged port on android, as normally you have to be root for that. And that would require rooted android.
Of course you should specify what do you intend with that direct connection and what software do you need. If both ends have your application, you can just open any not allocated and unpriviledged port on android. Use UDP to broadcast periodically name of android device (propably ask user to enter name of his device). Use multicast to send requests, and receive replies the same way. Multicast sending and receiving would require your application on android and on windows and on mac also. Now you can read from multicast application what type of machine it is, and what local port it left open for your direct connection. From source of udp message you know where to connect.
You may use some framework to speed things up. All this require some knowledge about networking, but I don't know simpler and well working solution. Unless you provide details about what is your direct connection to do.
I want to start a local network connection using the built-in Wi-Fi hotspot on Android devices.
Is there a way to accomplish it?
And how to communicate between two devices?
EDIT:
I want to do it programmatically. Then I can transfer my own data between devices.
I haven't done this before, so my answer is all theoretical.
I think what you need to do is declare one device the server and start its hotspot manually with a known name.
Start / stop built-in Wi-Fi / USB tethering from code? (According to this question, you can't start hotspot programatically).
Once you have the hotspot set up, you start up the server app and wait for incoming connections. The server app can show you the ip address or hostname.
On the clients, you can do a simple check and see if the hotspot name is around and automatically connect to it if you find it. See this link for connecting to a network:
Using WifiManager to connect to a network
As for your second question, how to communicate - you need to establish a connection between the devices. For this, you need the ip address of the server. The simplest thing to do would be to show the ip address on the server UI and then manually enter it on the clients and press connect. It would then establish a connection to the server on a known port and you can send messages between client and server.
For reference, I found NanoHttpd, which is a webserver for Android. It uses ServerSocket to listen for incoming connections.
Possible answers:
Before ICS and non rooted devices
There is no way you can connect to a device over wifi. There is no API to do. Bluetooth is your best option or user interaction.
Before ICS and rooted devices
I am not sure if someone hacked the code, but when I tried to do an automatic connection to a wifi spot I noticed:
The api is hidden inside the SDK.
The method that does the connection checks the thread who ask for it. If it's not the os thread, it throws an exception.
Using ICS
With ICS there is a new way to connect devices through wifi called Wi-Fi Direct.
Here is a link with some demos.
If you are going to develop your own application for each and every individual terminals(devices) then i think for you socket programming will do the trick .
Yes , android supports socket programming in the same was as java socket programming .
1st google java socket programming tutorials and then you can using the same knowledge in android .
Also do remember to include the uses internet permission in the manifest , actually thats something which ate my brains for a long time :)
You mean communication between wifi enabled devices without any server like p2p? if so its wifi direct which is supported in ICS check this out http://developer.android.com/reference/android/net/wifi/p2p/package-summary.html
Before ICS there is no standard android API for wifi direct, though Galaxy S2 has wifi direct it uses proprietary API's which 3rd party devs can't use.
i dont know programmically create wify LAN,but you can create wify LAN manually,then you can do java tcp/udp program as said by brianestey
"As for your second question, how to communicate - you need to establish a connection between the devices. For this, you need the ip address of the server. The simplest thing to do would be to show the ip address on the server UI and then manually enter it on the clients and press connect. It would then establish a connection to the server on a known port and you can send messages between client and server."
for manual connection follow the steps
take settings/wireless&networks/portable wi-fi hotspot settings from any one of the phone
create new hotspot and turn on wi-fi portable hotspot from there
connect all other device to that hotspot including your pc
you will get ip of each device programmically (includig pc,but i dont know)
I'm trying to develop an Android application which have to be able to transfer data/message between two Android mobiles, as a client server connection using their own Wifi, which having no network or routers nearby. I just tried using Tcp program to do this but it fails, its not connecting, I'm getting ConnectException and connection refused.
[Edited] Is it possible to achieve this using Android Portable Hotspot integrated with application? Is there any tutorial regarding this approach?
Any Ideas, how to do this?
Thanks.
You need to get the two devices networked to each other before you can worry about tcp usage of that network connection.
If one device is willing to perform access-point like functionality as part of a portable hotspot, and you select that as a wirelss network on the other, you may achieve a network connection between the two that can be used for custom traffic. Though there are ways the hotspot could be implemented where that would not work. Also of concern, the "client" device will now be sending all of its network traffic through the hotspot device, including not just foreground apps but anything it decides to do in the background.