Tuesday 8 May 2012

Wireless technology


It's another brand new week!!!!
A new day brings new hope. So live the day to the fullest and hope to God that there's another day awaiting you. J
The topic for today was wireless technology. In this context, Dr Dayang taught us what is  the real definition for bluetooth.
Bluetooth
Bluetooth has becomes a part of our life now. However, all of you may wonder how exactly it works….So, here you go…. XD



How bluetooth work:
It utilizes a radio based, that means it does not require a line of sight connection in order to communicate.
2 bluetooth equipped devices simply have to come within 10 meter range of each other.
A device must request a connection either to accept or reject.
Concept:
Point to point and point to multiple connection with small network called piconets.
Each piconets hold up 8 active units.
When multiple network exist within the same room they become known as scatternet.
 To resist interference bluetooth employs spread-spectrum technique called frequency hoping.
Frequency hoping means several devices will be ON the same frequency at the same time.
Bluetooth and the future
The future of Bluetooth looks strong, with initiatives underway for higher throughput, more ubiquitous usage and links with Wifi and Ultra Wideband (UWB) broadcast technology.
Operating systems such as the Mac OS and Windows continue to have native support for Bluetooth.
The Bluetooth SIG partners are working on enabling Bluetooth information points, to enable advertising models based around users pulling information from ‘information points’, rather than having to ‘push’ information out.
Other emerging features include Bluetooth in cars; automatic configuration of piconets; and quality of service (QoS) improvements, for example enabling audio and video data to be transmitted at a higher quality.

Broadband
The term broadband refers to a telecommunications signal or device of greater bandwidth, in some sense, than another standard or usual signal or device (and the broader the band, the greater the capacity for traffic).

How is broadband different from dial-up service?
·         Broadband service provides higher-speed of data transmission. It allows more content to be carried through the transmission “pipeline.”
·         Broadband provides access to the highest quality Internet services—streaming media, VoIP (Internet phone), gaming, and interactive services. Many of these current and newly-developing services require the transfer of large amounts of data that may not be technically feasible with dial-up service. Therefore, broadband service may be increasingly necessary to access the full range of services and opportunities that the Internet can offer.
·         Broadband is always on. It does not block phone lines and there is no need to reconnect to network after logging off.
·         Less delay in transmission of content when using broadband.

Infrared
Infrared is a energy radiation with a frequency below our eyes sensitivity, so we cannot see it. Even that we cannot "see" sound frequencies, we know that it exist, we can listen them.
Infra-Red is interesting, because it is easily generated and doesn't suffer electromagnetic interference, so it is nicely used to communication and control, but it is not perfect, some other light emissions could contains infrared as well, and that can interfere in this communication. The sun is an example, since it emits a wide spectrum or radiation.
Infrared keyboard

The adventure of using lots of infra-red in TV/VCR remote controls and other applications, brought infra-red diodes (emitter and receivers) at very low cost at the market.
From now on you should think as infrared as just a "red" light.
This light can means something to the receiver, the "on or off" radiation can transmit different meanings.
Lots of things can generate infrared, anything that radiate heat do it, including out body, lamps, stove, oven, friction your hands together, even the hot water at the faucet. 
To allow a good communication using infra-red, and avoid those "fake" signals, it is imperative to use a "key" that can tell the receiver what is the real data transmitted and what is fake.  As an analogy, looking eye naked to the night sky you can see hundreds of stars, but you can spot easily a far away airplane just by its flashing strobe light.  That strobe light is the "key", the "coding" element that alerts us.


Before the end of our class, our classmates showed us how to use forum and chatting corner. They had provide us a lot of info about MSN,SKYPE and Yahoo Messenger. Thanks for their efforts!!! I had learnt a lot…..XD

MSN Messenger
Here's a video regarding the usage of infrared telescope to uncover hidden cosmic creatures, including the coolest stars, dark asteroids and the most luminous galaxies!!!