Wednesday, February 16

GATE 2011 Answer Key

GATE 2011 logo Answer Key IN EE EC CS ME CE PI

GATE 2011 answer key is available for

Click the above link to download the answer key in pdf format.

Hacking iPhone (iOS): Jailbreak and Unlock

Hacking iOS installed on an iPhone is easier done than said.

iPhone iOS Jailbreak Unlock

These are two different things:

  • Jailbreak: Jailbreaking is done to install apps from non-Apple source (itunes App store) also called third-party apps.
  • Unlock: Unlocking is done to remove any operator lock that has been installed. So an AT&T locked iPhone sold in USA can be operated anywhere in the world on any operator network.

Jailbreaking an iPhone does not unlock it. But before Unlocking an iPhone, it needs to be Jailbroken.

  • Jailbreaking installs an App 'Cydia' on the iPhone. Cydia is used to add many features to iPhone.
  • Use the search feature of this app to install 'Ultrasnow'. Installing Utrasnow Unlocks the iPhone

Following both steps above makes an iPhone usable on any operator around the world.

Step-by-step tutorials for all versions of iOS  are available here.

Latest hacks for iPhone and other devices can be found on Dev-Team blog.

Saturday, February 12

Exynos processor: Samsung Orion

Samsung Exynos aka Orion processor logoOrion is just a codename of Samsung's ARM architecture based processor Exynos.  The name is a combination of two Greek words Exypnos meaning smart and Prasinos meaning Green.

First model is the Exynos 4210, which is a dual-core 1GHz processor. It will be fabricated from March 2011 using 45 nm LP process of chip manufacture.

The SoC has quad-core Mali 400 GPU. It is capable of 1080p video decode, and also support DDR3 RAM.

It will interesting to devices, especially tablets based on this application processor.

Facebook Live Commenting [New Features]

Facebook live commentingWe spend time on Facebook to check out what our friends are doing. Watching photos and commenting on them. Things get interesting when people suddenly start commenting in large group, but what the hell, I need to refresh my page to see what the new comment is and wait for page reloads.

A terrible mess!

Facebook Engineering team is rolling out a new feature called Live Commenting It's like chatting on your instant messenger, no more page reloads. Just comment auto-loads behind the scenes.

When someone comments on your post or photo, the comments start loading automatically, without any page refresh! This is the magic of Javascript technology AJAX.

To achieve this the facebook team has tested, many  technology approaches like:

  • Pushing vs. Polling Data
  • Write Locally, Read Globally

To understand the details of these processes, you can visit Facebook's Engineering team page.

Tuesday, February 8

Mobile Number Portability (MNP): Behind the scenes

Mobile Number Portability allows swithcing between mobile phone operators without changing the mobile number. Sounds simple, but there are loads of tasks performed behind the scene at the operator end.

Few terms used:

  • SIM (Subscriber Identity Module):
    • Securely stores IMSI number used to identify a mobile device.
  • IMSI (International mobile subscriber Identity):
    • A 14-digit number that uniquely identifies for your sim card in entire world. It is used for routing calls to the user.
  • MSISDN (Mobile Subscriber Integrated Services Digital Network):
    • Identifies the SIM card inserted in to the mobile phone
    • MSISDN is mapped against the IMSI and the map is known by the SIM issuing network operator.
  • ICC-ID (Integrated Circuit Card ID):
    • Every SIM is internationally identified by an unique ICC-ID. It is a 19-digit number printed behind the sim.

When you lose your SIM the operator demaps the MSISDN off the lost SIM's IMSI and maps it against a new IMSI.  But the same thing can't be done for number portability as IMSI and MSISDN are network dependent and cross-mapping is not allowed.

When you port your number:

  • The new operator selects an unregistered MSISDN with its own network code.
  • This information is stored on MNP server along with new IMSI and ICC-ID.
  • This database is accessible by all networks.
  • On dialling a number, operator from which call originates queries the MNP server (centralized database) to get routing information for the call.  The call is then completed with the new routing information.


The call routing can be illustrated as below:

mobile number portability

  • For a number ported from mobile operator B to operator C.
  • If user from operator A calls, operator A seeks the routing information from MNP server.
  • If information is received, the call is routed according to new information, If no information is received, the call is routed as per the routing information of original operator.

Sunday, February 6

Remove Facebook apps and/or enhancing your privacy settings

I used about 135 apps some time in past. Currently I use only 15 of those apps. That translates to free access to my private data (photos etc) for 120 unnecessary apps! Mind you some of these apps were also spammy.

Some applications on Facebook platform have access to your private data when you are logged out.

There is a way to remove these apps from your profile. Else you might end up seeing your profile on a dating website some day.

The steps are as follows:

  • Click on Accounts -> Privacy Settings at top right corner 

open facebook privacy settings

  • On following page, click on 'Edit your settings' under Apps and Settings at the bottom left corner

o-pen website and app settings

  • The following page will display the number of Apps you use. Click 'Remove' unwanted and spammy apps

remove apps

  • The following page shows all the apps that have access to your personal information.
  • To remove an app directly click the 'x' in front of that application

remove particular app

  • To tweak privacy settings for a particular application, click on 'Edit Settings' in front of the application.

tweak application setting

  • The interface will expand as shown below and you can tweak access as necessary.

tweak application privacy setting

 

Congrats you have just avoided misuse of your facebook account.

Android 3.0, Honeycomb- Awesome Tablet OS

Android 3.0 is a new version of the Android platform optimized for tablets.

The video below tells more than words can express.





The improvements include:

  • Users can switch between text/voice input modes from a button in the System Bar
  • Users can also connect full keyboards over either USB or Bluetooth, for a familiar text-input environment
  • Built-in support for Media/Photo Transfer Protocol lets users instantly sync media files with a USB-connected camera or desktop computer
  • New multitouch support is now available to JavaScript and plugins
  • Redesigned Camera application to take advantage of a larger screen for quick access to exposure, focus, flash, zoom, front-facing camera
  • Multiple tabs replace browser windows and a new “incognito” mode allows anonymous browsing