A Small Attempt to Make You Look Into the Future: 4G

The vision of mankind is always beyond the future. The communication technology has developed very rapidly since last few decades. The mobile phone has became the window to the world of information. While 3G is revolutionary thing that man has achieved. The attempts are being made to develop 4G that is the fourth generation communication technology. Very soon within a year the 4G will be ready for deployment. I explained you briefly about 1G, 2G & 3G. This post is targeted towards all the technical predications about 4G.

Although 3G was revolution and just like extension to existing 2G services, 4G is a evolution. 4G is entirely new thing distinct from 2G and 3G telephony. 4G is chiefly aimed to enable users to have uninturruptible and and amazingly high-speed internet access which is give rise to several new features, for example real-time HD video conferencing, streaming, live TV, online gaming, telepresence etc. The whole mobile network architecture is redesigned to achieve high-speed connectivity.

The air interface used in 4G, as explained before is LTE (Long Term Evolution). Just like 2G uses TDMA, 3G uses WCDMA, 4G uses a new technology known as OFDMA (Orthogonal Frequency Division Multiple Access). The core network of 3G is WCDMA. Similarly the core network in 4G is referred as SAE (System Architectural Evolution). This core network is flat all IP network. The major advantage of SAE is that it is designed in such a way to accommodate all networks such as GSM, CDMA, Wi-fi (IEEE 802.11) , Wimax (IEEE 802.16) . That is the device supported with Wi-fi, Wimax etc. can be also supported by SAE. 4G uses MIMO (multiple-input and multiple-output) technique to achieve this much data rate. MIMO is the use of multiple antennas at both transmitter and receiver to improve communication performance and efficiency.

The 4G is totally devoted to data communication and there is no support for traditional voice calls. You cannot dial a phone number directly. Thus, all voice calls are VoIP calls. Your voice after dialing any number gets routed towards the IP network and not PSTN network. By the way, there is also support for IP video calls with much higher quality and less image and voice distortion as compared to 3G video call.

Considering speeds, there is peak download speed upto 1 Gbps and upload speed upto 0.5 Gbps in 4G SAE if the operator has reserved spectrum of 20 MHz.

That's all! Verizon in USA and Vodafone in Germany have successfully launched 4G services. Probably in India the, 4G will arrive after 2015 considering the interest of operators and people. I think my small attempt to make you look into the future will be indeedly successful!

Thanks and regards,
Nitish R. Muley

Media Codecs, Containers and Formats: A Ready Reference

Digital Media is a revolutionary thing all over the world and is the cheapest source of entertainment as well as infotainment for a common person. In the last decade, the availability and emulation of digital media is so much increased. We can't stay away from our MP3 players, iPods and cellphones. MP3 music is the greatest invention for music industry and is very much easily available anywhere. The popularity of MP3 is mainly due to its flexibility, platform independence and its fine compression which can produce better quality audio at lower bitrates (usually 128 kbps is preferred). But still, there is somewhat confusion among people about the media formats, codecs and containers. Today, I am going to tell you everything about these things. Usually, the common audio formats that we use are .wav, .mp3, .aac, .amr, .wma, .m4a etc. On the other hand, the video formats are .mpg, .avi, .mp4, .3gp, .mkv, .wmv etc. Every format is developed for a particular purpose and is emulated on particular platform.
In the sense, digital media (audio or video) is compressed into relatively small files by a software known as ‘coder’ and is again reproduced into original media by the software called as ‘decoder’. The word ‘codec’ refers to the amalgamation of coder (co) and decoder (dec). We have to install a particular codec on our system to emulate or play particular format of media. Three type of codecs are 1. Image codecs, 2. Audio codes and 3. Video codecs.
MPEG (Moving Pictures Experts Group) is the standardization group of experts of ISO which develops and sets standards for video and audio compression and transmission. Another group of this standardization is VCEG (Video Coding Experts Group) which is formed by ITU (International Telecommunication Union).

Audio Codecs:
The consumer audio comes from music industry originally in ‘compact discs’ (CDs). This audio is in uncompressed format which provides very much good and surround quality of sound. A CD contains 80 minutes of this uncompressed audio. It doesn’t require any codec software for playback or emulation. This uncompressed audio requires a lot of space on disc. This space is not available on many systems. So, this uncompressed audio is ‘ripped’ on hard disc and compressed into small files by the ‘codec’ that we manually choose. These codecs compress the audio into very small-sized files (of few MBs) which are easier and better for playback. Let me summarize some of the main audio codecs:

1. PCM (Pulse Code Modulation): This is very basic method to represent analog voice signals digitally. It was invented in 1937. But, it is still the standard form of digital audio in computers, telephones and other systems. This is the lossless codec implies audio is not compressed in this format. Its filename extension is .wav.
2. MP3 (MPEG-1 Audio Layer-3): This codec was designed by MPEG and is patented by USA in 1993. It is the lossy method of audio compression implies during compression there is some loss. It reduces the amount of data required to represent an audio signal. Thus, gives the same quality of sound as that of CD. The MP3 file created is about 11 times smaller than original CD at bitrates of 128 kbps. Thus it is very efficient codec. Its filename extension is .mp3.
3. AMR (Adaptive Multi-rate Audio): This is audio compression codec designed especially for human speech recording. This is adapted by GSM and UMTS as their standard audio codec. Usually, digitally recorded audio is compressed using AMR which vomits the streams other than human speech resulting many hours of recorded speech compressed into few MBs. This was invented in 1999. Two forms of AMR are NB (Narrowband) WB (Wideband). This is used in real-time audio streaming on web due to its small size. Its filename extension is .amr.
4. MIDI (Musical Instruments Digital Interface): This is actually not a codec but is the method optimized for storing and reproducing instrumental music streams. This stream doesn’t contain actual audio signal but contains codes of particular instrument at a particular frequency. So, the whole music stream is stored in few KBs saving disc space. Its filename extension is .mid.
5. MP2 (MPEG-1 Audio Layer-2): This was developed by MPEG is now replaced by MP3 but remains dominant for audio broadcasting and is used on Video CDs. Its filename extension is .mp2.
6. AAC (Advanced Audio Coding): This format is successor to MP3. This is the lossy compression codec for storing digital audio and is now standardized by ISO. It achieves better audio quality than that of MP3 at similar bitrates. It is the default audio codec for Apple Inc. products. Apple Lossless format is the implementation of AAC. It is also adopted as the audio part of MPEG-4. Its filename extension is .aac or .m4a. .m4a refers to MPEG-4 audio stream.
7. WMA (Window Media ™ Audio): This was created by Microsoft Corporation and is the default audio codec for Microsoft Windows and their products.

Video Codecs:
The playback of digital video on computer system is not very simple because if video is uncompressed, it consumes a lot of GBs of hard disc and also volatile memory. So, video often comes in compressed form. Following are the most common video codecs:
1. Motion JPEG: This is the most basic video codec where each video frame is compressed as a stream of JPEG images. It is the lossy video codec. It is common in video-cameras.
2. MPEG-1: It is the lossy codec for video compression developed by MPEG. It is now a widely compatible video codec. This codec is used in Video CDs, digital cable/satellite broadcasting.
3. MPEG-2: This codec is successor to MPEG-1. It was primarily developed for ‘Digital Television Broadcasting’, cable and satellite TV. The first version of technology for DTH, DVB -1(Digital Video Broadcasting) uses MPEG-2 codec. MPEG-2 is the default video codec in DVDs. Its main feature is that it transports higher resolution and higher bitrate video much efficiently and provides very much better quality.
4. MPEG-4: This is the successor to both MPEG-1 and MPEG-2. This is referred commonly as ‘MP4’. It is the multipurpose version of MPEG having many applications regarding the needs of cellphones, pocket players, videoconferencing, broadcasting etc. There are again two parts of MPEG-4. These parts are 1. MPEG-4 Visual and 2. MPEG-4 AVC.
1. MPEG-4 Visual: This part has major two profiles namely, Simple Profile (SP) and Advanced Simple Profile (ASP). Simple Profile is used in situations where the low bitrate and low resolution is mandatory e.g. cellphone, pocket player, low videoconferencing etc. Advanced Simple Profile is commonly used on PCs or higher resolution systems. The video running on cellphone is usually MPEG-4 Visual Simple Profile. MPEG-4 Visual is similar to H.263 codec developed by VCEG of ITU. Streaming videos on YouTube mobile use this codec.
2. MPEG-4 AVC (Advanced Video Coding): I highlight this part because it is today becoming the widely compatible video codec having very high efficiency and compression capability. It delivers the high-quality of video at relatively lower bitrates. It saves upto 50% bitrates during compression resulting into smaller size of video file. As per my observation, a complete rip of movie is compressed in 750 MB in AVC format. It is mainly aimed at the distribution of high-definition (HD) video. Almost every HD video comes in this format. It is the official video codec on Blu-ray disc. The second version of technology used for DTH, which is DVB-2 uses MPEG-4 AVC. This is codec also aimed real-time high-quality video-streaming as well as videoconferencing. The streaming videos on YouTube and other websites use this video codec.
Actually, development of this video codec was the joint project of MPEG and VCEG. Thus, MPEG-4 AVC is also called as H.264 referring to successor of H.263.

5. H.263: This is a video codec originally designed for low-bitrate systems such as cellphones. The videocalls on UMTS or 3G network use this codec. This is also used on streaming videos on Internet. It was used on YouTube. But, with the arrival of H.264 or MPEG-4 AVC, many of the websites including YouTube have discarded this codec. The alternative to this codec is MPEG-4 Visual Simple Profile which is already explained.
6. H.264: This is same as MPEG-4 AVC. Literally, H.264 is another name for MPEG-4 AVC.

7. DivX (Digital Video Express): It is the most popular private video codec which is developed by DivX Networks Inc. Its main feature is to compress lengthy video segments into small-sized files at higher visual quality. It is supported on many DVD players. It actually implements both profiles of MPEG-4 Visual (SP and ASP). It is the video codec commonly associated with ‘ripping’ of DVDs.

8. Xvid: It is the competitor to DivX. It implements MPEG-4 Visual ASP. It is similar to DivX, also compresses lengthy video segments into small-sized files and associated with ‘ripping’ of DVDs. It is also supported on many DVD players. It is not a separate video format but is a ‘program’ to decode and encode MPEG-4 ASP videos.

9. WMV (Window Media ™ Video): This was created by Microsoft Corporation and is the default video codec for Microsoft Windows and their products. It is also adopted on Blu-ray discs.

10. HEVC (High-Efficiency Video Coding): Also referred as H.265, HEVC is emerging video codec having amazing efficiency of compression. This will be the successor to MPEG-4 AVC or H.264. The final drafting work on this will complete in 2012.

Containers:
Media container is the particular ‘file’ which bounds video and audio together using specified codecs. You can refer video container as video format. Every container has its own filename extension and can support many codecs at a time. Following table summarizes some of the popular video containers or formats.

Sr. No.	Container	Developed by	Filename Extension	Supported Codecs	Notes
1.	MPEG-TS	MPEG	.mpg	MPEG-1, MPEG-2	Widely Compatible
2.	AVI (Audio Video Interleave)	Microsoft	.avi	Motion JPEG, DivX, Xvid, AVC	Widely Compatible
3.	MPEG-4	MPEG	.mp4	MPEG-4 Visual, MPEG-4 AVC	Becoming Widely Compatible
4.	3GPP (3rd Generation Partnership Project)	3GPP	.3gp	H.263, MPEG-4 Visual Simple Profile	Developed specially for mobiles
5.	FLV Flash Video	Macromedia Flash	.flv	H.263	For video streaming on web
6.	Matroska	Matroska.org	.mkv	MPEG-4 Visual, MPEG-4 AVC/H.264	Stores number of subtitles, audio and video streams into single file. This format is getting very popular due to this unique feature. One can switch between audio and subtitles during runtime. Commonly used for storage of full-length movies and TV shows.
7.	QuickTime Movie	Apple Inc.	.mov	MPEG-4 Visual ASP, AVC	Developed for Apple products
8.	DAT	Video CD	.dat	MPEG-1	Container format for video on VCD
9.	DVD-Video Object	DVD	.vob	MPEG-1, MPEG-2	Container format for video on DVD

And this was the sufficient information which may be required by you anytime. I think MP3 from audio and MP4 from video should the standard formats as they are widely compatible as compared to others.
I will always provide you updated information about this subject. Be in touch…

Thanks and Regards,

Nitish R. Muley

Ubuntu: Linux for Human Beings

Operating system or simply OS is essential and indivisible software in computer systems. We have been using Microsoft Windows as OS from a long ago. We are very much familiar with Windows XP and Windows 7, the recent release. After all, Windows is commercial OS. In this article, we will go through ‘Ubuntu’, a Linux-based operating system.

Ubuntu is a free and OpenSource operating system. Before we proceed towards Ubuntu, let’s have a short idea about Linux kernel. Linux kernel was written in 1991 by Linus Torwald, a Finnish software developer. Kernel is actually a heart of any operating system because it is the communication bridge between the hardware and actual data processing in the applications at runtime. Linus Torwald developed this Linux kernel in such a manner that anyone can use, modify, extend or redistribute its source code under a license called as GNU General Public License (GPL). The development of any operating system is very much complicated process because the development of kernel takes much time. The operating systems developed as extensions of a kernel are known as derivatives of that kernel. As Linux kernel is OpenSource, many operating systems have been arrived as its derivatives or redistributions. Ubuntu is also one of them. Three of the most popular Linux derivatives are Fedora, Debian and OpenSUSE. Ubuntu is a debian derivative.
The first release of Ubuntu was in 2004. Ubuntu team releases its new version after every 6 months. The recent release of Ubuntu is 11.04 that is, April 2011. The main and striking feature of Ubuntu is that it is targeted towards users rather than towards programmers. Right now, Ubuntu is sponsored by Canonical Ltd in US.
Let us know about some best features of Ubuntu. Ubuntu differs from Windows in every sense. It has a well designed graphical user interface from GNOME (pronounced as g-nome), an OpenSource GUI which is also a part of GNU project. Ubuntu has a graphical desktop environment from Unity GUI, a version of GNOME interface. Ubuntu comes with many in-built daily applications such as OpenOffice.org, VLC Media Player, Mozilla Firefox as web browser. Ubuntu support UTF-8 that is, latest version of Unicode. Thus, it has support for almost all languages in the world.
OpenOffice.org provides a free word processor, spreadsheet and presentation software. Many Windows-based programs can be ran on Ubuntu using the emulator softwares or Virtual Machines such as Wine or VirtualBOX.

Here are some snapshots of Ubuntu:

Ubuntu 10.04 LTS

Ubuntu 11.04

The minimum hardware requirements for Ubuntu 11.04 are:
1. x86 family processors with minimum 1 GHz speed.
2. 128 MB RAM
3. Minimum 5GB of free space on hard drive
4. Minimum 1024 x 768 pixel monitor resolution

Almost every PC nowadays satisfies these requirements. Thus, Ubuntu is free to install on any desktop or laptop computer. Considering speed, Ubuntu is much fast to load as compared to Windows. As per my experience, Ubuntu starts in just 10 seconds and shuts down in just 3 seconds. It has better security against viruses and malicious softwares over Windows.

Ubuntu Workspaces:
The ‘multiple workspaces’ is the most significant feature of Ubuntu. Workspaces are the groupings of multiple windows in Ubuntu. These workspaces make the desktop easier to browse and reduce the clutter in tasks. These are arranged in multiple rows and columns. You can use workspaces to organize your work. As an example, you can have all your communication windows, such as email, browser and chat apps on one workspace and the work you are doing on a second workspace Your music or media player could be on a third workspace.
Ubuntu has two editions namely, desktop and server. Both are available as OpenSource and free softwares.
Similar to command prompt in Windows, Ubuntu has ‘terminal’ as command line interface. This terminal is especially in the point of view of programmers.

How to get Ubuntu?
You can easily download a CD image (.iso) of Ubuntu from its official website, www.ubuntu.com . This CD image is of 700 MB. If it is not possible to you to download this heavy file because of slow internet connection, you can also ship its free CD directly to your home. This shipping is totally free and is also available in India.
After getting the CD, just start your PC and run it. You will have two options to install Ubuntu namely, “bootable operating system” and “install as application”. For installing it as a bootable operating, it needs to make free a partition of your hard drive to install the OS. After doing this, you can choice menu of OS after startup. But I will strongly recommend you to choose the second option that is, “install as application”. This option doesn’t need to dedicate a separate partition for Ubuntu. It can be installed and uninstalled just like any application. Also this doesn’t disturb your current file system.

Many third-party applications for Ubuntu are available on web on its free app store. You can easily download them. The only problem with Ubuntu is that, it needs to download ‘updates’ after installation to extend the functionality of the OS. Even common audio and video codecs are not included in the installation CD. But everything is fine excluding this drawback.
Ubuntu will bring you a hatke desktop experience which has never been on Windows. After all, Ubuntu is “Linux for Human Beings”. It doesn’t matter whether you are programmer or user. No problem to use it once!

Thanks and regards,
Nitish R. Muley

Enhance Your Capabilities with Bluetooth: Connect Wirelessly

As the popularity gadgets like cellphones and players increased, it was a demand among people that these devices should transfer data easily. At the beginning, there was the facility of 'infrared' in these gadgets. Infrared can easily transfer data between two devices within short distance provided that they are in line of sight of each other. Infrared had somewhat slow data transfer rate and so many other drawbacks. So, with the arrival of new technologies. Infrared quit from this industry permanently. Some of the new advanced technologies invented were Bluetooth and WLAN. We will discuss about WLAN later on. Let's turn towards our main subject, Bluetooth. We are using Bluetooth from last few years with the arrival of multimedia smartphones. We always use it for transferring files from one phone to another or to play music with wireless headphone. But right now, I am going to tell you about new interesting advantages of this technology.

Bluetooth is an open wireless technology for exchange or streaming of data over short distances (usually upto 100 metres) with fixed devices like cellphone, PC, laptop etc. Bluetooth creates Personal Area Connection with these devices. Bluetooth is a very secure technology. Bluetooth was invented by Ericsson in 1994. There is misunderstanding among people with word 'Blue' that the radio technology uses waves of wavelength nearer to 'Blue'. But, actually the name 'Bluetooth' is related with 'Halard Bluetooth' who was the name of son of King 'Gorm the Old' of Denmark in A. D. 935. Currently, Bluetooth is managed by 'Bluetooth SIG' (Bluetooth Special Interest Group).

Let me tell you some technical specifications about Bluetooth. Bluetooth is a packet-based protocol. Bluetooth implements a separate radio technology called as FHSS (Frequency Hopping Spread Spectrum) which is a rapid method of transmitting radio signals among many frequency channels. In FHSS, the data being sent to other device is 'chopped' into small pieces and these pieces are transmitted upto about 80 bands each of bandwidth 1 MHz. Bluetooth has frequency range from 2400 MHz to 2483 MHz. This frequency range is reserved from Bluetooth or Wi-fi like technologies. The data rate possible is Bluetooth system is 1 Mbps. Bluetooth uses master-slave structure for communication. Bluetooth has range upto 100 metres.

There are three versions of Bluetooth which are most common in use. Bandwidth is enhanced in every upgrade. Version 1.2 has data transfer rate of 1 Mbps. 2.0 has 3 Mbps. Bluetooth 2.0 is currently very common in use in almost all devices. The most recent version Bluetooth 3.0 has highest bandwidth of 24 Mbps. The following picture shows a handy 'Bluetooth Dongle' connected in PCs or laptops via USB port which have no in-built Bluetooth reciever.

In order to implement this technology, that particular device must be compatible with Bluetooth Profiles for the use of desired services. So, Let us discuss about some of these profiles which is the main purpose of today's article.

A2DP (Advanced Audio Distribution Profile): This profile allows a stream of high bitrate audio to transfer over a Bluetooth connection from source device to handy wireless headset. The device like cellphone encodes the stream of audio into Bluetooth-friendly format and this signal is transferred wirelessly to wireless headset which recieves these signal and again decodes them into original audio. Today, almost all cellphones support A2DP. The audio codecs allowed are- MPEG-1 Audio Layer 3 (MP3) and AAC.



File Transfer Profile (FTP): This profile allows to transfer files within two devices in range. This profile is most commonly used in cellphones and is well known to all of us. It also allows one device to browse file system in other device.

Basic Printing Profile (BPP): This profile allows to send text and images to Bluetooth supported printer wirelessly for easier printing jobs.

Cordless Telephony Profile (CTP): This profile allows cordless phones to work using Bluetooth which increases efficiency of signal and audio quality.

Dial-up Networking Profile (DUP): It is one of the most important profiles of Bluetooth. It allows the Internet access over a Bluetooth connection. It is most common in cellphones. A laptop can easily access Internet by creating a regular GPRS connection using cellphone.

Remote Control Profile (RCP): Most TV remote controllers work with infrared and suffer many drawbacks like 'line of sight'. The remote control profile of Bluetooth allows TV remote controllers to work with Bluetooth. It covers almost all functions of TV.

Basic Imaging Profile (BIP): The profile allows to send images within devices. This profile is most common in digital cameras.

Human Interface Device Profile (HID): This profile allows devices like mouse, keyboard, joystick to work wirelessly using Bluetooth. For this purpose, a small device called 'Bluetooth HID' is inserted in USB port of personal computer which decodes these signals and sends to PC.

Hands-free Profile (HFP): There are many car accidents due to mobile phone. This profile of Bluetooth will save several lives avoiding this danger without rejecting the incoming call. A 'Bluetooth Hands-free kit' is installed withing car. If phone notices any incoming call, it routs this call to Hands-free via Bluetooth. Hands-free is connected to main speaker of car, so that one can talk without disturbing hands from driving.

Phonebook Access Profile (PBA): This profile allows to exchange 'phonebook' within devices. This is often used in 'Hands-free' kit of car to display the name of incoming caller.

SIM Access Profile (SAP): Many cars have in-built GSM receivers so that a car itself can act as a phone. This profile allows these receivers to access a SIM card within a phone via Bluetooth. Thus, car doesn't require separate SIM.

Video Distribution Profile (VDP): This profile allows to transfer a 'streaming' video (recorded or live) from one device to another. This profile also has application in 'videoconferencing'. This profile supports any of these two mandatory codecs- H.263 or MPEG-4 Visual Simple Profile. I think this profile will have better work in version 3.0

Bluetooth also uses a process called as 'pairing'. The two Bluetooth supported devices can be 'paired' so that they can remember each other and can transfer data without the permission.
The Bluetooth technology is leading day by day with increasing its application. I hope with the use of this information you will really try to get best of this technology.

Thanks and regards,
Nitish R. Muley