Monthly Archives: August 2011

What is 1G or First generation of wireless telecommunication technology?

The First generation of wireless telecommunication technology is known as 1G was introduced in 1980. The main difference between then existing systems and 1G was invent of cellular technology and hence it is also known as First generation of analog cellular telephone. In 1G or First generation of wireless telecommunication technology the network contains  many cells (Land area was divided into small sectors, each sector is known as cell, a cell is covered by a radio network with one transceiver) and so same frequency can be reused many times which results in great spectrum usage and thus increased the system capacity i.e. large number of users could be accommodated easily.

Use of cellular system in 1G or First generation of wireless telecommunication technology resulted in great spectrum usage.  The First generation of wireless telecommunication technology used analog transmission techniques which were basically used for transmitting voice signals. 1G or  first generation of wireless telecommunication technology also consist of various standards among which most popular were Advance Mobile Phone Service (AMPS), Nordic Mobile Telephone (NMT), Total Access Communication System (TACS). All of the standards in 1G use frequency modulation techniques for voice signals and all the handover decisions were taken at the Base Stations (BS). The spectrum within cell was divided into number of channels and every call is allotted a dedicated pair of channels. Data transmission between the wire part of connection and PSTN (Packet Switched Telephone Network) was done using packet-switched network.

Different standards of 1G were used worldwide like:

In 1982 Advance Mobile Phone Service (AMPS) was employed in United States and later it was used in Canada, Central America, South America, Australia,  Argentina, Brazil, Burma, Brunei, Bangladesh, China ,Cambodia, Georgia, Hong Kong, Indonesia, Malaysia, Kazakhstan, Mexico, Mongolia, Nauru, New Zealand, Pakistan, Guinea, Philippines, Russia, Singapore, South Korea, Sri lanka, Tajikistan, Taiwan, Thailand, Vietnam, Western Samoa.

Total Access Communication System (TACS) / Extended Total Access Communication System (ETACS) was employed in United Kingdom, United Arab Emirates, Kuwait, Macao, Bahrain, Malta, Singapore.

Nordic Mobile Telephone-450 (NMT-450) was employed in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Hungary, Poland, Russia, Spain, Sweden, Thailand, turkey and Ukraine.

Nordic Mobile Telephone-900 (NMT-900) was employed in Cyprus, Denmark, Finland, France, Greenland, Netherlands, Norway, Switzerland and Thailand.

C-NETZ (C-NETZ in German refers to C Network which was the first cellular wireless telephone network in Germany) was employed in Germany, Portugal and South Africa.

Radiocom2000 was employed in France.

Radio Telephone Mobile System (RTMS) was employed in Italy

Nippon Telephone and Telegraph (NTT) was first employed in Japan and later NTACS (Narrowband Total Access Communications System) and JTACS (Japanese Total Access Communication System) were also employed.

Use of Analog signals for data (in this case voice) transmission led to many problems those are:
1. Analog Signals does not allow advance encryption methods hence there is no security of data i.e. anybody could listen to the conversion easily by simple techniques. The user identification number could be stolen easily and which could be used to make any call and the user whose identification number was stolen had to pay the call charges.

2. Analog signals can easily be affected by interference and the call quality decreases.

References
1. For C-NETZ Reference taken from the book Der Telefon-Ratgeber (The Phone Guide )- Page 124 written by Fritz Jörn
2. Introduction to 3G mobile communications By Juha Korhonen
3. Wireless networks By P. Nicopolitidis

How to install WordPress?

WordPress the worlds most used blogging tool used for making millions of websites is famous for its easy usability and wide range of customizations.  WordPress installation is not at all a tedious job it’s very simple and hardly takes any time. Various web hosts are now offering tools for automatic  WordPress installation for their users. Yet if you want to install WordPress manually , we are there to guide you.

How to install WordPress?
Installing WordPress is easy if you do it step by step. There are two ways to install WordPress
1) Automatic One Click Installation.
2) Famous 5 Minute Installation (Manual Installation)

Before we begin with installation process we need to take care of few points.
1) We need to own a domain name (Unique name that can be used to identify your website on internet) and a hosting account (Space on server allocated to you to stores all the information and data of your website and provides internet connectivity to makes your data available on the internet). While selecting a Web Hosting Company for Hosting account we should think about few points those are :
a) The plan we are taking for hosting an account should have secure socket layer support.
b) It should support streaming media.
c) It should allow shell access, FTP access and logs and statistics access, it supports making of sub-domains.

2) Check that your web host and your machine (Computer) must satisfy the minimum requirements to run WordPress.

Let’s Start the Installation Process by Automatic One Click Installation
Step 1:
Login your hosting account and go to Control Panel (CP).

Step 2: Select “One Click Installations” or click on WordPress installation. (Option may differ from host to host so you need to find where in hosting account is it located).

Step 3: On a new page Click on WordPress which is located in the left side Navigation Bar (Under Blogs). Then Click on “Install” which is located in the top Navigation Menu and then customize your WordPress settings according to your choice and click on “Install”.

Now you will have the entire login information at your given email address.
Hurray!!! Your WordPress has been setup.

Let’s Start the Installation Process by Famous 5 Minutes Installation.
Step 1: Download the latest version of WordPress and unzip it at a folder on hard disk of your Computer.

Step 2: Sign up for your hosting account and Check your FTP Account Information.
a) You will get an email titled “Hosting Account Setup” on your given email address.
b) Find your “FTP Account Information” in the email.

Step 3:Now create a MySQL database for WordPress on web server and also a MySQL user having all the privileges to  access and modify the database.
Creating MySQL database
a) Press “Databases”, select MySQL and press “Create Database”.
b) Write description, Select username and password for accessing Database.
c) Press “OK” and wait until your MySQL is setup
d) Select pencil option to “Edit/view details” and save the changes.

Step 4: Change the name of wp-config-sample.php file to wp-config.php.

Step5: Now open wp-config.php file in Text Editor (like notepad) and enter your database details.

// ** MySQL settings – You can get this info from your web host ** //
/** The name of the database */
define(‘DB_NAME’, ‘putyourdbnamehere‘);
/** MySQL database username */
define(‘DB_USER’, ‘usernamehere‘);
/** MySQL database password */
define(‘DB_PASSWORD’, ‘yourpasswordhere‘);
/** MySQL hostname */
define(‘DB_HOST’, ‘localhost‘);

Fill in the following information:
MySQL Database Name
Name of the MYSQL database created by you on web server which can be used by WordPress.
MySQL Database Username
Name of the user you created to access database on web server.
MySQL Database Password
Enter the password which is required to access database.
MySQL Database Host
Enter the hostname of your Database Server
Now find following in your wp-config.php:
define(‘AUTH_KEY’, ‘put your unique phrase here’); define(‘SECURE_AUTH_KEY’, ‘put your unique phrase here’); define(‘LOGGED_IN_KEY’, ‘put your unique phrase here’); define(‘NONCE_KEY’, ‘put your unique phrase here’);
And Save your wp-config.php file.

Step 6: Now upload the WordPress files on the web server at any location you want.
i) If you wish to add WordPress in root of your domain then upload all the unzipped files of WordPress directory (leaving the directly itself) in  root directory of web server.
ii) If you wish to add WordPress  in a subdirectory at your web site then change the directory name from “WordPress” to the required subdirectory name  and upload it to the root directory of web server.
For example if you wish to add WordPress in subdirectory with the required name as “nay”, you should change the directory named “wordpress” to “nay” and upload it to the root directory of your web server.

Step7: Go to http://www.yourdomain.com/wp-admin/install.php

i)If your WordPress is installed in root directory, go to http://www.yourdomain.com/wp-admin/install.php

ii)If your WordPress is installed in subdirectory called nay. for example,  got to http://www.yourdomain.com/nay/wp-admin/install.php

Congrats!!! You have successfully installed WordPress.

Minimum Requirements for Different versions of WordPress

The minimum requirements for different version of WordPress are different

The minimum requirements for WordPress 3.2 are:

  • PHP version 5.2.4 or higher version.
  • MySQL version 5.0 or higher version.
  • Apache mod rewrite module (If you want Permalinks) (optional) (Mostly used for MultiSite)

The minimum requirements for WordPress 3.1, 3.0, 2.9 are:

  • PHP version 4.3 or higher version
  • MySQL version 4.1.2. or higher version
  • Apache mod rewrite module (If you want Permalinks) (optional) (Mostly used for MultiSite)

The minimum requirements for WordPress 2.8, 2.7, 2.6, 2.5 are:

  • PHP version 4.3 or higher version
  • MySQL version 4.0 or higher version
  • Apache mod rewrite module (If you want Permalinks) (optional) (Mostly used for MultiSite)

The minimum requirements for WordPress 2.3, 2.2, 2.1 are:

  • PHP version 4.2 or higher version
  • MySQL version 4.0 or higher version
  • Apache mod rewrite module (If you want Permalinks) (optional) (Mostly used for MultiSite)

The minimum requirements for WordPress 2.0 are:

  • PHP version 4.0 or higher version
  • MySQL version 3.23.23 or higher version
  • Apache mod rewrite module (If you want Permalinks) (optional) (Mostly used for MultiSite)

For a better efficiency use platform containing Linux Operating System, a NGINX web server or an Apache web server. WordPress will work swiftly on any server that supports MYSQL, PHP and mod rewrite module. Many features of WordPress need remote connection so it is necessary that your host should grant permissions for remote connections. WordPress will not function properly if your HTTP connections are blocked.

For best security purposes you should ask the host to run suPHP or equivalent on web server to make it more secure.

Tricks for using Google Plus

Hot Keys to use Google Plus more comfortably.

a)      Using the “j” key or “k” key we can move from one post to other post  where “ j” key is for moving to a forward post and “k” key is for moving to a  back post.

b)      Use the “j” and “k” keys in dropdowns like notification dropdown where  “j” is for moving up and “k” is for moving down.

c)      Press “q” key we can jump to Google+ chat box.

d)      Press “q” key twice in the home page allows us to find people and add them in chat list.

e)      Press Esc key to close notification window.

f)       Press Tab moves through the users and comments in a post.

g)      Press Enter/Return to start a comment.

h)      Press Tab and Enter/return to submit comment.

i)       Press Tab twice and then Enter will delete comment.

j)       Press Space Bar to scroll down.

k)      Press Shift and Space Bar to scroll up.

l)     We can tag anyone in post by adding “@” or “+” in front of their name. This will create a notification in their profile that they were added (tagged) and will create a link to their profile. Adding name in Enclosing brackets will provide exact search for the person.  For example: +”David”.

m) Press “+” instead of “+1” button on a post.

n) Press “-” for removing your “+1” from a post.

o) Press “s” for sharing a post.

p) Press “e” for expanding the older comments on a post.

q) Press “p” for toggle (hide / show) “+1” on your post.

Hot keys for Navigation.

i)          Press “g” and “h” for redirecting to Home page.

ii)         Press “g” and “p” for redirecting to Profile.

iii)         Press “i” and “i” for going to photos.

iv)        Press “i” and “p” for going to photos from phone.

v)         Press “i” and “m” for going to photos of me.

vi)        Press “i” and “a” for going to photo album.

vii)       Press “g” and “i” for incoming**

viii)       Press “g” and “n” for notifications

Incoming = People who have added you but are not added in your circle.

Hot keys for Edit Settings.

i)      Press “e” and “e” for Edit settings.

ii)     Press “e” and “l” for Edit Languages.

iii)    Press “e” and “d” for Edit data

iv)    Press “e” and “a” for linked accounts

v)     Press “e” and “p” for edit privacy.

vi)    Press “e” and “g” for edit general.

1) Have you ever used the formatting commands in Google talk? If yes then here is good news for you.

Formatting commands in Google+ is same as that of Google talk.

a)  For Italic

_italic text_    =    italic text

b)  For Bold

*bold text*   =   bold text

c) For Strike through

-strikethrough text-    =    strikethrough text

d) For Italic and Bold text

_*italic bold text*_  =     italic bold text

We can also use Unicode characters in comments or post:  Ήΐ!!! ħоŵ ѓ ự?

2)      “+1” Button in Google Plus is like a voting counter. If you appreciate a post click the “+1” button and that makes the post recommendable to others and also gets added in “+1” Tab on your profile so that you can read it at any moment. In a Post the “+1” button acts same as the “like” in Facebook. If you appreciate the post press “+1” and if you want to remove your “+1” from the post click the “+1” button again. Pressing “+1” button again will delete your “+1” vote from that post.

3)      “+1” Button is an easy way to set your favorites and manage the never ending list of your favorites on web. You can also set the viewing (want to share with friends, or everyone on web or private) of your “+1”Tab on your profile.

4)      Bored of notification? Google Plus has a solution. Now you can mute your notification too.Click on notification select the notification you want to mute and press “mute this post” option on    the right end of the cascaded window.

5)      Google Plus arranges the post on top of your stream whenever there is a new comment or “+1”. If you are tired of this here’s the solution select that post and click on the small arrow on top of that post a cascade window will open and then select “Mute this post option”.

6)      You can also receive notification on your mobile in SMS form. All you have to do is Click the “gear” icon which is at the right of the screen in Google+ then select Google+ settings. Click the “Google+” tab and click “Add phone number” under that Enter your mobile number, Select Country press “Send verification code” button. Google will send a verification code at your mobile number. Enter that code in Verification Code box.

7)      You can manage the viewing of your post. If you don’t want to share your post click the small arrow at top right of that post. A cascade window will appear and click “Disable reshare”.

8)      We can share our post with everyone even if they are not signed in to Google+ just by Clicking on timestamp, we will get a permanent link to that post which can be share by everyone.

9)   We can search all the post written or shared by us on Google+ from Google by using  “site:plus.google.com/(your unique Google+ ID)”Google ID is the series of number that can be seen in the URL when you are on your profile.

10)  We can also enjoy private conversation with a friend or group of friends by sharing an post like always just  remove “public” and other circles from the share box of  the  post do disable “resharing” and tag the friends using “@” or “+” before their names. Tagged friends will get notifications and you can communicate with them via comments in that post.

11)  Circle: You can add friends in groups known as circle and set their visibility. All people in a circle can view other added persons in the same circle. You can set circle settings by making it public so that everyone can see who all are added in a circle. In short you can make many circles according to your choice like family, school friends, college friends etc. And if you want to keep your circle private that means no one can know that who is added in that circle this is visible only to you and the added persons. You can do this by clicking “Private” in circle settings.

12)If we want  some circle to be on top of other circle start name them with a dot or period (“.imp”) asterisk will be the next in queue (“*good”) i.e. the one which starts with asterisk will appear after dot.

13) To copy all the persons in a circle into other circle click “view circle in tab” select “More actions” and “Select all” and now you can drag all selected person to other circle. To select more than one person press ctrl or shift or make a selection box by dragging from one point to other.

14) On a circle page if you want to view many people on the circles press ctrl and minus (-). To view everything in normal size press ctrl and plus (+). We can view the profile of a person just by Double click on that person name at circle page.

15)To get a graphical effect to see who is inside the circle hover your mouse on a circle that contain minimum 30 persons in it and then scroll with your mouse wheel , the persons face in a circle will rotate like merry-go-round.

16) Photo Editing is easy just open image from “photo” tab click “Action” and select “Edit Photo”. We will get various color and special effects. We can also view and share our photos stored on picasa through Google’s Picasa Web Albums site.

17)If  you want to view how your profile looks to others just go to “Profile and privacy” option of Google plus settings and type anybody’s name in the box named as “See how your profile appears to other users” and press “Preview” .

18) If we want to check who all can see the post just go to top of the post you will see “Public” or “limited”, click on “limited”. “Limited” is a link to check all those who can view the post. We can’t share Limited posts publicly but can share it with other individuals and circles.

19) There is a triangle and circle menu at the top of each post this menu allows us to delete, edit post disable commenting and resharing for the post written by us whereas it allows to report abuse, mute, post, or block the person for the post written by others.

20) Tagged photos are public because we can’t disable resharing for the photos which are tagged. Tagged person can view the entire album in which he has been tag and further they can also tag anyone.

Technologies used in 0G (Zero Generation) or Mobile Radio Telephone System

Which technologies were used in 0G or Mobile Radio Telephone system ?

The following technologies were used in 0G or Mobile Radio Telephone System 1) Push to talk 2) Mobile Telephone System (MTS)  3)Improved Mobile Telephone Service (IMTS) 4) Advanced Mobile Telephone System (AMTS) systems 5) MTD (Mobile telephony system D) 6) OLT (Offentlig Landmobile Telefoni or Public Land Mobile Telephony).

Push-to-talk (PTT) also referred as Press-to-Transmit provides half duplex communications to the two way radio i.e. only one person will speak at a time and other should hear. Here a button was used to switch different operations i.e. when a person wants to speak the button should be pressed; this enabled the transmitter and the receiver gets disabled automatically. Button should be released when they are done. Similarly the listener presses the button to reply; hence it was named as push to talk. Push-to-talk (PTT) also supports group calling i.e. one person can speak with many other persons of the same group. In this system only one large transmitter with single channel was used for both sending and receiving.

Example: At the airport, the air traffic controller uses one radio frequency to speak to all the pilots under him, in such a way all other pilots are aware of all the aircrafts position at that moment.

Mobile telephone system (MTS) was introduced in United States in 1946. Mobile telephone system used transceivers, these transceivers were too large to carry, so they were placed in vehicles .Mobile telephone system (MTS) was an analog system using half duplex mode of communication (voice signals can either be transmitted or received at an instance of time).In MTS system the entire land was divided into sections where each section had a Base station with a single high power transmitter which controls all the operations of that section. All the base stations in every section used the same frequency, so in order to avoid radio interference the base stations needed to be far away from each other. MTS used Push To Talk (PPT) technique. It used a PPT switch to turn on/off the transceiver. Pressing the PPT switch would turned on the transmitter and releasing the switch would turn on the receiver and the transmitter would automatically get off. When the user needs to make a call the callers need to make a call to the MTS operator where the operator would ask for the Mobile subscriber number and would find an idle channel for transmitting the call to the mobile terminal. The calls in MTS were switched manually. The major drawback of MTS was congestion as only three channels were provided that means only three voice calls would be made at a time in a specific sector.

Improved Mobile Telephone Service (IMTS) was an advance version of MTS (Mobile telephone service). IMTS was the first full duplex system (voice signals can be transmitted and received at the same time), two way communications were supported. Push to talk system was eradicated which was the prime factor of MTS. The main advantage of IMTS was that it supports direct dialing i.e. the user can directly call PSTN (Public switched telephone network) rather than calling operator. IMTS used transmitter of 200 watt, this high powered transmitter was placed on a hill top to cover the entire town or city (covered area is referred as cell).In IMTS Bandwidth was narrowed to attain more number of frequencies. Using IMTS each call needed two radio channels one channel to transmit and one of receive. Only 33 channels were available with operating frequencies Roaming was not support due to lack in number of channels. As the high powered transmitters and same frequency were used neighboring cell had to be far away from each other in order to avoid interference. Fading is one of the major problems of Improved Mobile Telephone Service (IMTS).

Mobile telephone System A: Mobile telephone System A was the first telephone system in Sweden which was developed by Sture Lauhren and Ragnar Berglund at Swedish Telecom. In 1956 MTA started of with its commercial services. It was the first automatic mobile telephone system in the world which provides direct calling i.e. the user can dial and get a call from the other telephone user without the telephone operator’s support. This system had 125 subscribers; this system was mostly used by banks, industries, government offices, various agencies and transport companies etc. The drawback of this system were the telephone size was bulky , call setting time was more , the system was bit complex so using the system was difficult. With these limitation this system was demolish in 1969.

Mobile telephone System B: Mobile telephone System B was the modified version of Mobile telephone System A developed by Berglund. In 1965 MTB started of with its commercial services in Stockholm. The Swedish Telecom company gave the mobile telephones on rent to the subscribers. The call could only be made up to three minutes, after three minutes the call becomes noisy and had to be disconnected. This system had 600 subscribers. MTB was demolished in 1983.

Mobile telephone System D: Mobile telephone System D also known as   Mobiltelefonisystem D in Swedish was introduced in 1971 in Sweden.  This system worked on the frequency band of 450 MHz. This system had 80 radio channels and 110 radio base stations. More than 700 operators were used in this system. To make a call the user need to know the location of the other end user i.e. the other subscriber (to whom the call was to be received) so that the operator could transfer the call to the nearest radio base station. This network had 20,000 subscribers. MTD was also used in Denmark and in Norway and allowed roaming facility within the Scandinavian countries. This System was demolished in 1987.

OLT (Offentlig Landmobile Telefoni or Public Land Mobile Telephony):Public terrestrial mobile telephone service also known as Norwegian for Offentlig Landmobil Telefoni (OLT) was the first manual mobile telephone system. OLT was launched by Televerket in 1966. The OLT network works on VHF band 160MHz where Frequency modulation technique is used on 160 -162 MHz (Mobile Unit) and 168-170 MHz (Base Station). The Major parts of country didnot have coverage but in 1981 it had 30,000 subscribers which made it the world’s largest network of that time. Each user was allotted  five digit number. Mobile used for this network were mostly Half duplex (voice signals can either be transmitted or received at a time) except few expensive mobiles. These Expensive mobiles were full duplex (voice signals can be transmitted and received at the same time).The main drawback of OLT system was anybody could hear the conversation and with the increase in number of subscribers the service went short of capacity.