Does Android support near real time push notification?



Answers

XMPP is a good solution. I have used it for a push enabled, realtime, Android application. XMPP is powerful, highly extensible and easy to integrate and use.

There are loads of free XMPP servers (though out of courtesy you shouldn't abuse them) and there are open source servers you can run on one of your own boxes. OpenFire is an excellent choice.

The library you want isn't Smack as noted above, it's aSmack. But note, this is a build environment - you will have to build the library.

This is a calculation I did on battery life impact of an XMPP solution:

The Android client must maintain a persistent TCP connection by waking up periodically to send a heartbeat to the XMPP server.
This clearly imposes a cost in terms of power usage. An estimate of this cost is provided below:

  • Using a 1400mAh battery (as supplied in the Nexus One and HTC Desire)
  • An idle device, connected to an 3G network, uses approximately 5mA
  • The wake-up, heartbeat, sleep cycle occurs every 5 minutes, takes three seconds to complete and uses 300mA
  • The cost in battery usage per hour is therefore:
    • 36 seconds 300mA = 3mAh sending heartbeat
    • 3600 seconds 5mA = 5mAh at idle
    • 4:95 + 3 = 7:95mAh combined
  • A 1400mAh battery lasts approximately 11.6 days at idle and 7.3 days when running the application, which represents an approximate 37% reduction in battery life.
  • However, a reduction in battery life of 37% represents the absolute worst case in practice given that devices are rarely completely idle.
Question

I recently learned about the ability of iPhone apps to receive nearly instantaneous notifications to apps notifications to apps.

This is provided in the form of push notifications, a bespoke protocol which keeps an always on data connection to the iPhone and messages binary packets to the app, which pops up alerts incredibly quickly, between 0.5 - 5 seconds from server app send to phone app response time. This is sent as data - rather than SMS - in very very small packets charged as part of the data plan not as incoming messages.

I would like to know if, using Android, there is either a similar facility, or whether it's possible to implement something close to this using Android APIs. To clarify, I define similar as:

  • Not an SMS message, but some data driven solution
  • As real time as is possible
  • Is scalable, i.e., as the server part of a mobile app, I could notify thousands of app instances in seconds

I appreciate the app could be pull based, HTTP request/response style, but ideally I don't want to be polling that heavily just to check for notification; besides which it's like drip draining the data plan.




As GTalk is gone from the SDK, it might be a good idea to make a 'standard' push messaging system. That way, only one service has to run, only one extra tcp connection needs to be open. Applications should talk to this service using Intents and should first request permission to send and receive notification from the service. The service should then notify the user a new application wants to send and receive messages. The user will then grant or deny permission, so he stays in control. The application will then register an action + category to the service, so the service knows how to deliver the pushed message.

Would the a good idea or not?




Have a look at the Xtify platform. Looks like this is what they are doing,




There is a new open-source effort to develop a Java library for push notifications on Android, using the Meteor comet server as a backend. You can check it out at the Deacon Project Blog. We need developers, so please spread the word!




If you can depend on the Google libraries being there for you target market, then you may want to piggy back on GTalk functionality (registering a resource on the existing username - the intercepting it the messages as they come in with a BroadcastReceiver).

If not, and I expect you can't, then you're into bundling your own versions of XMPP. This is a pain, but may be made easier if XMPP is bundled separately as a standalone library.

You may also consider PubSubHubub, but I have no idea the network usage of it. I believe it is built atop of XMPP.




I have recently developed http://pushdroid.org its a single application that should be installed on the phone just like google has implemented it in 2.2 this works from 1.5 and is broadcasting via intent.




They have their listeners which has to be used by you by using their library classes in your code. You need not to bother about pushing. You have to send the message to server server will push the message to the device. They use OAuth. Regarding Protocols, there are two methods using CCS and XMPP. CCS just uses XMPP as an authenticated transport layer, so you can use most XMPP libraries to manage the connection. To send notifications to device you can write code in android app to send as well as your server code. the message sending will be done only by your code. Rest will be taken care by Google Server in GCM case. You can check detail at this link

http://developer.android.com/google/gcm/server.html

Also, for security issues

google cloud messaging security https://groups.google.com/forum/#!topic/android-gcm/M-EevBitbhQ

In case your app is not running then also devices can recieve notification because you have to write code for broadcast listeners. In background it will be listening to server and whenever any message packet will be there it will recieve the message as notification. Android has service you need to not to bother about it. You have only to use those resources using the library class that makes your work easier and let them write if your app is not running then also it recieve notification. Obviously, there would be some listener whick make the app to recieve.Check "Recieve the message" section in this link

http://developer.android.com/google/gcm/client.html

It will acccept request from users also. For GCM it will do. Please check "Send a message"

http://developer.android.com/google/gcm/client.html




The problem with GCM is that there is a lot of configuration involved in the process:

  • You have to add a lot of boilerplate to you Android app
  • You need to configure an external server to comunicate with the GCM server
  • You will have to write tests

If you like simple things (like me) you should try UrbanAirship. It is (IMHO) the easiest way to use GCM in your app without doing a lot of configuration. It also gives you a pretty GUI to test that your GCM messages are being delivered correctly.

  • You can find the docs and getting started guide here
  • You can find a sample application here

Note: I am not afiliated with UrbanAirship in any way




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