Connecting Blackberry Devices - sockets

I need to create a blackberry application that connects two phones for information exchange. One of these phones should support several incoming connections at the same time and serve them all. The other phones should not see any other phones except the central one.
What would be the best way to achieve this? Connecting through sockets? Data Services? Internet? What would be the advantages/disadvantages of each?

To asses the advantages and disavantages of each method one would really need to know the full requirments of you project. That said though, I would suggest you look at the BlackBerry Messenger SDK. The SDK nicely abstracts away all the issues with mobile-to-mobile communications.

Related

Peer-to-peer communication between iOS devices

I am trying to prototype a solution to a problem and am currently exploring multiple routes I could try. Is it possible for one iOS device, running a certain app, to communicate directly with another iOS device, running the same application - without the need to be on the same LAN?
Solutions I am currently investigating are using Bluetooth and ad-hoc wireless connections.
Ideally, the application when installed would ask the user for the required permissions, and then would accept and/or send data to/from another client after a handshake had happened.
My concern with Bluetooth is that 'pairing' would need to happen with every device, rather than happen in the background once the user has installed the app. I have a feeling what I am talking about isn't possible from what I've been reading elsewhere on Stackoverflow.
Take a look at Bluetooth Low Energy.
https://developer.apple.com/library/ios/#samplecode/BTLE_Transfer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012927
Here is another example,
https://github.com/KhaosT/CBPeripheralManager-Demo
You might also want to look into GameKit and peer-to-peer connectivity there.
I can't tell you anything about it, but you might try looking at iOS 7. If that's an option, I'd take a look. Can't talk about what it is because of NDA though.
Depending on what you need to communicate, you could try checking out this project, which lets you share arrays of strings between iOS devices over Bluetooth LE.
You don't need to "pair" the devices and it can still communicate while the app is in the background. SimpleShare
Hope it helps!
From the documentation of MultipeerGroupChat:
MultipeerGroupChat sample application utilizes the Multipeer Connectivity framework to enable nearby users to discover, connected, and send data between each other. This sample simulates a simple chat interface where up to 8 devices can connect with each other and send text messages or images to each other. Here you will learn how to bring up framework UI for discovery and connections and also how to monitor session state, listen for incoming data and resources, and send data and resources.
This is an excellent example at developer.apple.com here is the link
https://developer.apple.com/library/ios/samplecode/MultipeerGroupChat/Introduction/Intro.html
Also this tutorial from Ralf Ebert demonstrates how to use Multipeer Connectivity framework for peer communication should help you.
https://www.ralfebert.de/tutorials/ios-swift-multipeer-connectivity/

Share text between iPhone and other phones using wifi

Is it possible to send and receive data between iPhone and other phones such as blackberry or android over wifi. I am on the move it to create an iPhone app with the above functionality. Can any one has previous experience in this, or any sample codes to do this. I have searched a lot but couldn't find anything relevant.
you can do this by using a server application. So the iphone pushes the data to the server and the other devices are either getting push notifications or something similar or simply poll for the data.
Without a server, you have the trouble of finding the other devices. If its safe to assume they are all on the same subnet, then you could use a UDP broadcast to do this.
There's many ways of doing this, every one with its own pitfalls. So there's no generic answer to this question without knowing in more detail what's the purpose of it.

App communication in nearby devices without user intervention

Is it possible to communicate two instances of an app:
In nearby devices (Android or iPhone)
Without user intervention (aside from starting the app once)
Without internet (but not network) connection?
How?
Android to Android?
iPhone to iPhone?
Android to iPhone and vice-versa?
Let us ignore the issues associated with implementing the network communication at the application level and focus on the system design problem your question raises.
You want an application on one device to connect to another associated application on another device without any user intervention/interaction beyond launching the device. In order for this to work your system is going to need a 3rd party separate from the two devices/applications that provides a lookup service.
What will need to happen is each application will need to communicate with this service, ask for the data regarding other device it should connect to, if it exists, and then attempt that connection. This is basically how a bittorrent tracker works.
Keep in mind that there's quite a bit more involved in the implementation than that simple scenario suggests. For example, the proper registering/unregistering of devices, registration timeouts, security, etc.
Unless I misunderstand your question, you should be able to just use standard sockets (TCP or UDP depending on your needs) for communication between any/all devices. For iPhone, you could probably use the NSStream classes and for Android you'd use the Socket classes.
Can the new NFC feature be an answer to this?

How to do peer-to-peer communication in an iPhone app?

I'm trying to write a simple chat application for the iPhone (as an experiment). Is there a simple way for two devices to discover each others' IP addresses, and given the addresses is there a simple API or protocol that would let me send text messages back and forth?
I've investigated SIP (specifically Sofia and eXosip), but these tools exist as C libraries and are beyond my current ability to port them to the iPhone.
Update: I'm trying to connect two devices over the Internet (i.e. not over Bluetooth or a local wireless network, which is what GameKit does).
You're going to need a server that provides the match making service. Game Center makes this pretty easy, but your users will have to have Game Center accounts.
Alternatively, you can set up an XMPP (formerly Jabber, it's what powers Google Chat) server (I've never done this, but there are several available) and use the XMPP Framework for Cocoa. There are instructions for using it in iPhone apps here.
I'm sure there are other chat servers and client source also available. IRC and Mobile Colloquy come to mind.
Finally, you could write your own server using your favorite server language / framework. This isn't too hard (I've done it myself), but it's far from what I'd call simple, and I wouldn't use it for a production system.
There is support for exactly this kind of ad-hoc peer-to-peer networking in GameKit. Have a look at the second half of the GameKit documentation for details:
http://developer.apple.com/library/ios/#documentation/...
NSNetService is a good option.
Take a look at WebRTC Datachannels. WebRTC is a newer option with native iOS support a standard that is still being finalized, but it is more flexible should the iOS app need to communicate with browser or even android peers

Finding the systems connected in local network from iPhone?

I am developing an application which identifies(find) all the systems connected in same network/LAN to share the data.
could please share with me how to identify(find) the systems which are connected in same network/LAN.
thanks in advance.
When you say all systems, I assume you mean all instances of your application? If so then the correct solution is to use Bonjour. Documentation on how to use it can be found here. Note that your app needs to be actively running on all the devices that you are trying to discover, since the iPhone does not support background apps.
If you are just talking about finding all other devices in the area then you need to resort to techniques like port scanning.