Tuesday, March 27, 2007

GSM frequency bands, 3G and IMEI

GSM frequency bands used around the world are:
850 MHz (In America)
900 MHz (In Europe)
1800 MHz (In Europe and Asia)
1900 MHz (In America)


In mobile phones, dual band refers to functionality that allows a mobile phone to support two frequency bands out of the four major GSM bands. A cellphone with dual band 850/1800 MHz, for example, will work in both the United States (850 MHz) and India (1800 MHz).

Various countries use different frequency bands for their mobile networks, and a triband phone can be used on three of these bands.Generally these tri band mobile are manufactured to support two home countrys networks and one for roaming.

Triband phones are mobile phones that support the GSM 900/1800/1900 MHz bands (commonly sold in Europe, Asia, and Africa), or alternatively the 850/1800/1900 bands (commonly sold in the Americas).

Literally speaking quad band mobile phones means the phones which support all the GSM frequency bands. These are only known as world phones.

When gifting mobile phones..
Make sure that the mobile you are presenting is world phone.
When bringing mobiles to India(from abroad) make sure that their IMEI No starts with 3, so that its compatible with the networks Indian networks.


3G is short for third-generation technology. The services associated with 3G provide the ability to transfer simultaneously both voice data (a telephone call) and non-voice data (such as downloading information, exchanging email, and instant messaging). In marketing 3G services, video telephony has often been used as the killer application for 3G.
The first country which introduced 3G on a large commercial scale was Japan. In 2005, about 40% of subscribers used 3G networks only, with 2G being on the way out. It was expected that the transition from 2G to 3G would be largely completed during 2006, and upgrades to the next 3.5G stage with 3 Mbit/s data rates were under way.

Usage of 3G networks in India is yet to be approved by government.

International Mobile Equipment Identity

The International Mobile Equipment Identity is a number unique to every GSM. It is printed on the phone underneath the battery and can also be found by dialing the sequence *#06# into the phone. The IMEI (14 digits plus check digit) or IMEISV (16 digits) includes information on the origin, model, and serial number of the device.

The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop a stolen phone from accessing the network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "ban" the phone using its IMEI number. This renders the phone useless, regardless of whether the phone's SIM is changed.

Record the serial number (IMEI) of the handset in a safe place (enter *#06# on most GSM handsets to receive a 15 digit serial number).

IMEI information from a GSM
On many devices the IMEI number can be retrieved by entering *#06#.
Retrieving from nokia mobile phones by pressing *#92702689# (*#WAR0ANTY#), this opens the warranty menu in which the first item is the serial number (the IMEI).

IMEI numbers of cellular phones connected to a GSM network are stored in a database (EIR - Equipment Identity Register) containing all valid mobile phone equipment.
When a phone is reported stolen or is not type approved, the number is marked invalid.

Central Equipment Identity Register (CEIR)
If a mobile handset is lost or stolen, as the owner or operator of the device, you can contact the CEIR which will blacklist the device in all currently operating switches. This makes the lost or stolen handset unusable. The action of blacklisting stolen mobile handsets is seen as a deterrent to crime, however, it is possible to change an IMEI with special tools and there are certain mobile networks that do not automatically blacklist handsets registered with the CEIR. Current statistics state that about 10 % of current IMEI's in use today are not unique or have been reprogrammed (hacked).

International Mobile Equipment Identity Software Version (IMEISV)
For example the IMEI code 35-209900-176148-1 or IMEISV code 35-209900-176148-23 tells us the following:
TAC(Type Allocation Code): 352099 so it was issued by the BABT and has the allocation number 2099
FAC(Final Assembly Code): 00 so it was numbered during the transition phase from the old format to the new format (described below)
SNR: 176148 - uniquely identifying a unit of this model
CD: 1 so it is a GSM Phase 2 or higher
SVN: 23 - The 'software version number' identifying the revision of the software installed on the phone. 99 is reserved

"New IMEIs can be programmed into stolen handsets and 10% of IMEIs are not unique." According to a BT-Cellnet spokesman quoted by the BBC.

In many countries changing the IMEI or IMEISV is considered as a crime.

Comments and suggestions are welcome about the content!!

Manoranjan Reddy Mandadi

Friday, March 23, 2007

Google Inc,

The one that comes into our mind when one says Google is Google's search engine. There are many other products which are owned by Google Inc. Off course their claim to fame is Search Engine. Google maintains an estimated 450,000 servers. Google don’t reveal the hardware they use. Google was co-founded by Larry Page and Sergey Brin while they were students at Stanford University.

Google Search Engine
Google is a search engine owned by Google Inc, Whose mission statement is to "organize the world's information and make it universally accessible and useful".If we like to know about any thing, we just Google it. The largest search engine on the web. Microsoft, others suffer as Google's web search share grows.

Google Mail
Google mail known as Gmail for short is a free Web mail and POP3 e-mail service provided by Google. This service offers over 2.8 GB of file storage, a search-oriented interface and a unique 'conversation view'. Gmail is well-known for the use of Asynchronous Java Script And XML (AJAX) programming in its design. Instead of downloading or refreshing the whole page Gmail downloads in small parts, which makes it very fast compared to others. Gmail is integrated with Gtalk. GMail is the only service provider which offers POP3 e-mail service for free

Google orkut
Orkut is an Internet social network service run by Google. It claims to be designed to help users meet new friends and maintain existing relationships. Orkut goes a step further by permitting the creation of easy-to-setup simple forums (called "communities") of users.

Google Blogger
Blogger is a web log publishing system. Now a day’s blogs are very crazy as you all know. Google provides free blogging. A blog is a user-generated website where entries are made in journal style and displayed in a reverse chronological order.

Google Picasa Web Albums
Picasa is a computer application for organizing and editing digital photos. There is native support for Windows XP and Windows Vista, as well as a beta Linux version, available through Google Labs.

Google Talk
Google Talk is a computer application for Voice over IP and instant messaging, offered by Google. All messages are archived to the Chats mailbox in Gmail, unless 'Off the Record' is enabled in Google Talk. We can access contacts of orkut also in Gtalk .It also notifies us if a new mail arrives to our Gmail or a new scrap into our orkut account.

Google AlertsGoogle Alerts is a service offered by search engine company Google which notifies you (by email) about the latest web and news pages of your choice.

Google Docs and Spreadsheets
Google Docs & Spreadsheets, sometimes simply called Google Docs, is a Web-based word processor and spreadsheet application offered by Google. It allows users to create and edit documents and spreadsheets online while collaborating in real-time with other users.

Google Froogle Shopping List
Froogle is a price comparison service launched by Google Inc. It is currently in beta test stage. A user can type product queries to return lists of vendors selling a particular product, as well as pricing information.

Google Maps
Google Maps is a free web map server application and technology provided by Google that powers many map-based services including the Google Maps website. It offers street maps, a route planner, and an urban business locator for numerous countries around the world.

Google Base
Google Base is an online database provided by Google into which any user can add almost any type of content. If any body searches for a product, and if it’s in our Google base list, it will be displayed. Google will not be involving in any transactions of this kind.

Google AdSense
AdSense is an ad serving program run by Google. Google will publish their ads on our sites/blogs. These ads are administered by Google and generate revenue on either a per-click or per-thousand-impressions basis.If any body viewing our blog/site clicks an ad we will be paid for it.

Google Adwords
Google Adwords is a service run by Google, using which you can place you ads in web pages or displaying your ads when a search is made on keywords relating to that ad. Most of Google’s revenue is from Adwords.

Google Analytics
Google Analytics is a free service offered by Google that generates detailed statistics about the visitors to a website. Google Analytics is integrated with AdWords in order to use at an ease.

Google Webmaster Tools
Google Webmaster Tools is a service offered by Google to help website owners with indexing and ranking on Google search. Graphs and diagnostics are also given to let the user analyze Google traffic.

There are many other Google’s products.
These are a few to name.

Do sending your coments.
Manoranjan Reddy Mandadi

Wednesday, March 21, 2007

Thermal Cameras and Thermography

You people might be quite familiar with digital cameras and analog cameras.
Have you any time heard about thermal cameras.

These are the cameras which play a significant role in surveillance and security.

A thermographic camera, sometimes called a Forward Looking InfraRed(FLIR),is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light.

All the living organisms as well as non living objects will emit infra-red energy and we exploit this using our longwave IR imaging systems with a view to identifying objects.These cameras are used in many R&D Departments like aviation,electronics,electricals,etc...

Thermography is now the leading non-intrusive, non-invasive and non-destructive tool used in an ever widening range of areas. All objects emit infra-red energy and we exploit this using our longwave IR imaging systems with a view to identifying previously unidentifiable faults which would often result in costly repercussions.

Infrared cameras, active and passive infrared camera systems can be used for security surveillance and nondestructive testing.

SARS (Avian Flu/Bird Flu) screening cameras have been installed in many airports around world.

The side by you see a domed camera.
These type of cameras are mainly used in banks,domestic purposes,etc.
These cameras are capable of
->Auto switching from daytime (color) to infrared sensitive nighttime (B&W).
->Indoor,weatherproof outdoor models for any application.
->Auto turn-over feature enables the dome to rotate 180 degrees and reposition itself for uninterrupted viewing of any subject that passes directly under the dome.
->23X Optical Zoom

Here you can see a picture of dog taken using an infrared camera.
Different colors in the picture implies temperatures that are different from area to area.

Thursday, March 15, 2007

POP e-mail

In computers POP stands for Post Office Protocol.

POP is an application layer protocol used to retrieve e-mail from a remote server over a TCP/IP connection.

By using POP service you can retrieve e-mails from remote server using Microsoft's OUTLOOK,Opera Mail, Netscape Mail,Eudora,etc.

These services use POP for incoming mail and Simple Mail Transfer Protocol (SMTP) for out going mails

The version which is being used now in POP3.
POP4 is now in R & D. Not yet officially standardized...

Gmail is the only mail service which offers POP e-mail for free.

You can configure your POP mail service settings(GMail) by visiting

Thursday, March 8, 2007

Macintosh and PCs

You know that there only two types of computers on earth.

* Macintosh
* PCs

1.Macintosh are developed by Sun Microsystems and also known as Mac for short.The Mac run only on MacOS developed by Sun Microsystems and MacOS cannot be installed on others.Mac systems are considered as the robust.Complete print media uses Mac.It was one of the first commercially successful personal computers to use a graphical user interface (GUI) and mouse instead of the then-standard command line interface.Here is picture of the Macintosh 128K, the first Macintosh computer, introduced in 1984, upgraded to a 512K "Fat Mac"

2.The others i.e PCs,Desktops,Laptops fall under the category of PCs and are all considered as IBM clones.Here is snapshot of the original IBM PC (ca. 1981)These can use any Operating System.

Thursday, March 1, 2007

Visual Programming

Most of people are tending towards Java, .net , asp.net,etc which are common and mundane...

Let's try Visual Programming(VC++)
This is also known as "Systems Programming".
Here we mainly deal with Windows and there is no dearth of jobs in this.
This is a little bit tough
though very intresting and "Jeeth pakki hai" because there is no huge competition