Friday, 11 May 2012

Seventh Footmark on 10th May

Introduction to Wireless Technology

                                                                   RELAX CORNER                                                                

* Fun *

 * Good Picture *

  * Enjoy it *

Meteor Blaze... awesome!!!

Footage from Leonid Meteor Shower November 17th, 2009!!!


                                                   ...How Do I Feel....                                             

After this lesson, undoubtedly, I learned new knowledge from Dr. Dayang...

The lesson I attended making me more understand about telecommunication in particular blue tooth... so that I can wisely use it in my daily life....

Besides that, my group was the last group to do presentation....that was a good experience because the topic we did was forum and chatting...we have deeper understand about this chapter during prepare the presentation....

  *   A computer would deserve to be called intelligent if it could    
              deceive a human into believing that it was human.  *         

The lesson I learnt today....

ü  Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras and video game consoles over a secure, globally unlicensed short-range radio frequency. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group.

ü  Wireless technology
ü  Is referred to worldwide standard for the wireless exchange of data between electronic devices
ü  Created basically to solve simple problem: replacing the cables used on mobile devices with radio frequency wave
ü  This technology includes a simple low-cost and low-power global radio system
ü  IEEE develop standard 802.15 – focus on segment known as Wireless Personal Area Networks (WPAN) = based on the Bluetooth tech

ü  Bluetooth works everywhere as long as it has the hardware that compiles with Bluetooth wireless specification to ensure communication compatible worldwide.
ü  This tech allows users bring connectivity with them anywhere they go….Europe, Asia, America or other parts of the world
ü  Utilizes a radio-based =  it does not require a line of sight connection in order to communicate

ü  To establish a connection, 2 bluetooth equipped devices simply have to come within 10 meter range of each other.
ü  Before communication can happen = a device must request a connection either to accept/reject
ü  The sending device = client while the receiving devices is the server.
ü  All Bluetooth devices can operate as both client and server

ü  Concept: focused on point-to-point and point-to-multiple connection with small network called piconets.
ü  Each piconets hold up 8 active units
ü  When multiple network exist within the same room they become known as a scatternet
ü  Allows 3 types of data links between any 2 nodes:
ü  An asynchronous data channel
ü  Simultaneous voice channels
ü  Asynchronous data channels 

ü  In order to resist interference bluetooth employs spread-spectrum technique called
 frequency hopping
ü  This frequency is also used by the wireless networking standard IEEE 802.11 but operates with shorter data packets
ü  To avoid interfering with other system is by sending out very weak signal of 1 milliwatt (if u compare with the most powerful cell phone = can transmit signal of 3 watts)

ü  Low power limits the range of a Bluetooth device to about 10 meters (cutting the chances of interference between any computer system & portable telephone/tv
ü  Low power = the walls in a house would not stop a Bluetooth signal
ü  If many different Bluetooth in the room = one might think that they would interfere with one another….
ü  Several devices will be ON the same frequency at the same time = technique called spread-spectrum frequency hopping

ü  The transmitter change frequencies 1,600 times every sec = more device can make full use of the radio spectrum 

Pros & Cons of Bluetooth
          Cost of the manufacturers : components
          Too technologically advanced
          Ease of use
          Communication increase
          Support half and full duplex communication
          Low power consumption (no batteries use)
          Spread spectrum frequency hopping

Advantages and weakness of Bluetooth
Piconet & Scatternet

 Bluetooth and the future
            Bluetooth is a short range wireless technology that will be replacing cables and enabling multiple devices to connect in the near future. It acts as a bridge between obsolete and new technologies. This technology is an enabler of a range of applications at home and in the office. By using Bluetooth for connecting people, isolated microprocessors within devices and increasing programming logic, the way in which people interact with their homes and their workplaces could change drastically and dynamically.

Broadband & Infra red

-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).

-Broadband signaling method is one that includes or handles a relatively wide range (or band) of frequencies. Broadband is always a relative term, understood according to its context. The wider (or broader) the bandwidth of a channel, the greater the information-carrying capacity, given the same channel quality.

-Many computer networks use a simple line code to transmit one type of signal using a medium's full bandwidth using its baseband (from zero through the highest frequency needed). Most versions of the popular Ethernet family are given names such as the original 1980s 10BASE5 to indicate this. Networks that use cable modems on standard cable television infrastructure are called broadband to indicate the wide range of frequencies that can include multiple data users as well as traditional television channels on the same cable. Broadband systems usually use a different radio frequency modulated by the data signal for each band.[6] The total bandwidth of the medium is larger than the bandwidth of any channel 

-Definition: Infrared technology allows computing devices to communicate via short-range wireless signals. With infrared, computers can transfer files and other digital data bidirectionally. The infrared transmission technology used in computers is similar to that used in consumer product remote control units.

-Installation and Usage - Computer infrared network adapters both transmit and receive data through ports on the rear or side of a device. Infrared adapters are installed in many laptops and handheld personal devices. In Microsoft Windows, infrared connections can be created through the same method as other local area network connections. Infrared networks were designed to suppport direct two-computer connections only, created temporarily as the need arises. However, extensions to infrared technology also support more than two computers and semi-permanent networks.

-Range - Infrared communications span very short distances. Place two infrared devices within a few feet (no more than 5 meters) of each other when networking them. Unlike Wi-Fi and Bluetooth technologies, infrared network signals cannot penetrate walls or other obstructions and work only in the direct "line of sight."

-Performance - Infrared technology used in local networks exists in three different forms:
  • IrDA-SIR (slow speed) infrared supporting data rates up to 115 Kbps
  • IrDA-MIR (medium speed) infrared supporting data rates up to 1.15 Mbps
  • IrDA-FIR (fast speed) infrared supporting data rates up to 4 Mbps  

Bluetooth internet

Broadband Internet 

*All intelligent thoughts have already been thought; what is necessary is only to try to think them again.*

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