Saturday, August 26, 2006

What is a Plasma TV?

Plasma TV is the high definition, commonly known as HDTV alternative to the standard cathode ray box like TVs. The primary driver behind a plasma TV is its sharp images and life-like colors. Anyone who has seen a plasma TV must have noticed the difference in shape as compared to the standard TV. Plasma TVs are wider than the standard TV since they are designed in the ratio of 16:9 rather than 4:3 ratio design of standard TVs. The goal of the wide TV screen is to accommodate for wider screen formats which are normally hidden in the standard TV or the screen height is reduced to accommodate the complete image, which in the process further reduces the size of the screen.

The plasma TV also relies on obtaining high quality inputs from broadcasts or DVDs. A plasma TV might need exactly be a cheap or cost-effective device. It may cost in the range of USD 4000 to USD 15000, although prices are falling every day.

Plasma TVs provide another great benefit for people who are running short of living space. The beauty is the plasma TV can be wall mounted. Generally people also like to combine Plasma TVs with a high-end home-theatre system with surround sound effects to create a theatre-like experience at home.

'Plasma' is a scientific term referring to gases like neon and xenon which glow when exposed to an electrical field. Plasma is sometimes called the fourth state of matter, after liquids, solids and gases. Think of a neon sign or fluorescent light bulb to understand plasma as it applies here.

TVs display color images based on thousands of pixels. Pixels are the small elements of pictures. Think of as a picture broken down into multiple pieces. Like any other color display technology, the pixels are made up of 3 basic colors, that is red, green and yellow. The mixture of these colors can create any color in the entire spectrum. Since the viewer is generally far enough from the screen, he cannot make out the individual pixels on the screen and the individual pixels fuse into one to create an illusion of motion as displayed to the viewer. This is true for all display technologies including, TV, computer monitor, the LCD display on the camcorder etc.

In a plasma TV, the individual pixels are made from three tiny containers of an inert gas such as neon or xenon. There are literally hundreds of thousands of these tiny tubes on an average plasma TV screen. All of these individual pixels are sandwiched between two electrically-charged plates. Remember that plasma glows when exposed to an electrical current. A computer processing unit receives signals from a cable or broadcast antenna which tells it how to reassemble the entire picture hundreds of times per second.

The computer controls the electrical field down to individual pixels, allowing different combinations of colors to glow. The viewer is usually not aware of all the changes, because his or her brain is processing all of the information as a continuously moving image. Because a plasma TV screen contains quite a few more pixels than a standard television, the image is noticeably sharper. Each pixel combination can reproduce an exact hue, not a quick approximation. This means the colors are usually deeper and richer.

The main drawback of a plasma TV system is vulnerability to damage. If a hard object strikes the screen, hundreds of individual gas-filled tubes instantly lose their ability to glow. Replacing all of those elements is a time-consuming and expensive process, if it can be done at all. Owners of plasma TV systems should always consider purchasing insurance and extended warranties, since the most common fix appears to be total replacement of the screen. Because the gas forming the plasma can leak or become less reactive to electrical charges, plasma TV systems do have a limited shelf life. It may take several years before a noticeable change in picture quality, but the cumulative effects are similar to what happens in neon and fluorescent lighting-eventually the gas inside the tube will begin to flicker instead of burning steadily.

Thursday, August 24, 2006

What is Bluetooth?

Bluetooth is the wireless technology typically used for connecting devices like mobiles and laptops. It uses the radio frequencies of 2.45 GHz. Using Bluetooth technology, data can be transferred for nearly 10 meters. All it needs to function is a Bluetooth chip and a receiver embedded in the product to carry the signal over the air medium.

Bluetooth makes life really simple for a gizmo geek. Devices like digital cameras, mobile phones, PDAs, iPOD, or other MP3 player has become a part of daily life. Now most of these products may need to transfer data between them, for example, transferring pictures and video from a digital camera to a laptop, or synchronizing data between a PDA and a laptop. This could be a simple enough task if all of the devices use a common standard to inter-connect. Though most of them support USB which is more or less becoming a de-facto standard, there is still a dependency on the cables and different types of pins supported by the device depending on the manufacturer. A common standard like Bluetooth for any data transfer in wireless form comes as a real boon in such scenarios.

One can compare Bluetooth with Infrared technology (iRDA), with a few differences. Unlike Infrared which requires a line of sight connectivity between the 2 devices, Bluetooth simply requires that the distance between the devices should be in the acceptable range. For example, while driving the mobile phone could be on the dashboard and using a Bluetooth headset, a person can talk as he drives. Also most infrared connections can work only between 2 devices. Using Bluetooth many devices can be connected together.

In a small network like home, the Bluetooth devices are always communicating with each other, if they are powered on. This way they create a Bluetooth LAN for a small distance where all Bluetooth enabled devices can communicate with each other. The Bluetooth LAN is called as a Personal Area Network (PAN) or Piconet.

Though other gadgets in the home might utilize the 2.45 GHz range, Bluetooth separates itself from these by using a very weak signal that "flies under the radar." Conversely these other products rarely cause interference with Bluetooth because frequency hopping keeps potential interference negligible.

Bluetooth devices comes in three classes, Class 1, Class 2 and Class 3. Point to note is Class 3 Bluetooth devices can transmit data up to 100 meters as opposed to a maximum 10 meters for the other 2 classes. Class 3 Bluetooth devices are very rare.

Bluetooth is not considered a very secure technology for data transfer, but it was never designed for that purpose as well. The basic objective was to provide a single wireless communication mechanism between multiple devices. Also the maximum distance supported by Bluetooth makes it pretty irrelevant to add the extra overhead of security in data transfer.

Although Bluetooth can be perceived to be a replacement for Wireless LAN or Wi-Fi, the low bandwidth supported by Bluetooth needs to be considered. Most Bluetooth communications happen over 1 Mbps. So, if I have to copy a 500 MB video file from my camcorder to my laptop and I also have the USB cable available, it is a no-brainer on my choice for USB for faster access. On the contrary if, I am moving around the house talking to someone on the mobile phone, and the mobile phone needs to charged at the same time as well, I would prefer using a Bluetooth headset.

Sony Ericsson pioneered this technology before being joined by IBM, Intel, Nokia, and Toshiba in May 1999. Today over 1,000 international electronics manufacturers belong to the Bluetooth Special Interest Group or SIG. Bluetooth is named after King Harald Bluetooth of Denmark, who in the 930s consolidated warring factions of Denmark, Norway and Sweden. This ability to establish peaceful communication between differing peoples is a metaphor for the ability to connect devices from differing technologies.

What is IPTV?

IPTV or Internet Protocol Television, is a service that delivers over internet connection rather than the regular cable connection. It has services integrated like Video on demand, voice over IP (VoIP), and digital phones. There are currently some 1600 free IPTV channels available gloabally.

IPTV connection will need a subscription, a broadband internet connection and a set top box.

Since IPTV will be delivered mostly over existing telephone networks, it will be more cost effective for carriers as well as subscribers. See the image below for more clarity on the technology used.

One of the advantages of IPTV is the ability for digital video recorders (DVRs) to record multiple broadcasts at once. According to Alcatel, one leading provider, it will also be easier to find favorite programs by using "custom view guides." IPTV even allows for picture-in-picture viewing without the need for multiple tuners. You can watch one show, while using picture-in-picture to channel surf!

IPTV viewers will have full control over functionality such as rewind, fast-forward, pause, and so on. Using a cell phone or PDA, a subscriber might even utilize remote programming for IPTV. For example, if a dinner function runs longer than expected, you don't have to miss your favorite program. Just call home and remotely set the IPTV box to record it.

IPTV enables interaction for TV viewers. For example, in a reality show, for the TV audience to give in their vote or opinion, they have to send a SMS or phone. Using IPTV, the communicate mode will be 2-way and the audience will be able to cast their vote or voice their opinion from their TV itself.

One can also receive Web service notifications while watching IPTV for things such as incoming email and instant messages. If you IPTV is packaged with digital phone, Caller ID might pop up on screen as your telephone rings.

IPTV is already growing in the international market, with providers in many countries including Japan, Hong Kong, Italy, France, Spain, Ireland, and the United Kingdom. In the United States SBC, reportedly purchased a software delivery system for IPTV services from Microsoft in 2004 for $400 million dollars. Alcatel is working with Microsoft to develop a "global solution" for IPTV services, and Verizon has also made a deal with Microsoft for IPTV software.