Latest Technologies: Wi-Fi Technology

India Latest Technology - NANO

The much awaited Tata small car, which is giving sleepless nights to its rivals, was finally unveiled at the Auto Expo 2008. The small car, which is priced at Rs100, 000 (2,500 dollars), has been named Nano. According to the Tata Motors, the Nano will hit the Indian roads later this year. Ever since the Tatas announced their intention of developing the 1 lakh car (touted as people’s car), the auto industry experts have been raising doubts over the price, features, safety and specifications of Tata Nano. Have a look at specifications and other aspects of the Tata Nano, the four door mini-hatchback.

Looks & Dimensions of Nano: Keeping in mind the young age group, the Tata Motors has strived well to give the Nano a contemporary and stylish look. The snub-nosed small car derives inspiration from Fiat 500 and Nissan Micra. As far as dimensions of the car are concerned, Nano is 3.1 metres (10.23 feet) long, 1.5 metres wide and 1.6 metres high and can accommodate four to five people.

Engine: The small car sports a two cylinder 623 cc, 33 horsepower rear mounted multi-point fuel injection (MPFi) petrol engine. Tata claims that the car can touch the top speed of 105 kms.

Fuel Efficiency: Engineers at Tata Motors have designed an efficient engine that can run 20 Kms on every litre of petrol.

Pollution: Against the criticism and concerns of the environmentalists, Nano surpasses Indian regulatory requirements and Euro IV emission norms. In fact, Tata claims that the small car is less polluting than most of the bikes on Indian roads.

Safety: Tata says that they have tested the small car extensively for front, rear and side collisions and come out with a product that exceeds current regulatory requirements. The safety features of the Nano include a strong passenger compartment, intrusion resistant doors, seat belts, sturdy seats and anchorage.
Price: The base model of the car will sport a price tag of Rs 100,000 (2,500 dollars) which excludes taxes and transport costs. The high end/deluxe models will include air-conditioning and other features to be incorporated based on suggestions of the common people

Sunday, January 6, 2008

Wi-Fi Technology - I

Wi-Fi
Wi-Fi is a technology that allows data transfer over specified radio frequencies; this in turn removes the need for cabled connections making device portability possible. The Wi-Fi revolution has been trumpeted on a number of occasions but has stalled each time on security fears or cost, but as mobile hones have driven the publics understanding of wireless communication the consumer appetite for Wi-Fi products has grown steadily to a point where it became commercially viable.

How does it work?
Moving data using radio frequency is nothing new, in fact the first Morse code radio transmission has a lot in common with today's wifi technology, after sending what is in effect the first binary wireless transmission mankind spent the next 20 years perfecting the reproduction of the human voice in an analogue format.
The telephone while revolutionary did mask the ability of data transmission, this was not left to rot as militaries around the world continued to develop the sending of data via RF transmissions. WIFI of today is a distant cousin of that Morse signal, although instead of a low bandwidth dot and dashes being sent thousands of bits of data are sent every second and we are now measuring in kilobits per second and with newer technologies even megabits.
Wifi as a standard uses the 2.4 GHz range which is largely unused by the European military and other RF users like mobile communications, this frequency band is then broken down into channels which a wireless device can use to transmit data and in order to avoid interference the devices can frequency hop or jump between them mid data stream.
So we have a method of moving data over RF but each device needs to be connected and enabled to work with Wi-Fi, this is in effect like giving each device in your network a handheld radio (except they work at much high frequencies). Over this radio link the binary DataStream carries your data for example a webpage back to the device that requested it. A laptop for example would have a wireless access card or dongle this is both a transmit and receive device, this could connect to another laptop with the same setup and create a point to point connection. It is far more likely that the laptop and any other client device will connect to a router or access point to join a much larger wireless network.
Performance of any wireless link is limited by the same factors that affect your radio or TV signal, weather, distance, power and walls or objects, again an example if you use an indoor aerial for your TV your signal is weaker and therefore the picture quality drops. With a wifi network if the signal strength or quality drops the effective data rate is reduced as more packets are re sent to counteract the errors, so it is important to bear in mind the maximum achievable range of a Wi-Fi enabled device may be at the minimum sustainable speed.

Wi-Fi Variants
The accepted Wi-Fi standards are set by the Institute of Electrical and Electronics Engineers or IEEE, 802.11b was the first to market and is the slowest in terms of raw bandwidth but is also the cheapest to produce equipment for, with speeds up to 11mbits this is the format that is most prevalent in today's electronics marketplace.
Then there is 802.11a which strangely came second, this can handle up to 54mbits and runs in the 5 GHz band, this has until recently been the domain of the corporate network as 802.11a equipment costs more to purchase and gives greater range.
The most recent entry is 802.11g which is back on the 2.4 GHz band but can achieve the 54mbps of 802.11a and brings the benefits of the cost reduction in technology, if you are buying networking equipment 802.11g is the best option today as it is also backwards compatible with 802.11b although your connection will run at the speed of the slowest technology used.