Reflection #7

Wireless Technology


Dr. Dayang has proceeded the topic about wireless technology but unfortunately I couldn't come to class :(


Nevertheless, here is my entry to wrap up about the wireless technology. Well, I did some revision on my own about this topic.


WIRELESS

• Wireless telecommunications networks are a type of information transmission system that uses electromagnetic waves.

BLUETOOTH

The Bluetooth logo

• Bluetooth is an industrial specification for wireless personal area network or PANs.
• Bluetooth is acceptable for situations when two or more devices are in proximity to each other and don't require high bandwidth
• The distance covered only a very short range which is less than 10 meters. 
• Devices involved : mobile phones, laptops, PCs, printers, digitial cameras and video game consoles. 

The devices that use Bluetooth can be connected to the laptop as well.

INFRARED DATA TRANSMISSION

The IrDA logo.

• IrDA (Infrared Data Association) is a technology where we can transfer any files from any devices by using infrared light, the one that is non RF.
• The characteristic of infrared transmissions are: 
• The power to transfer data is not so high.
• Only can transfer in a short range, for example the remote control.
• Mainly attached to mobile phones to transfer the data or files from one to another.
• Nevertheless, many laptops sold today are equipped with an IrDA-compatible transceiver that enables communication with other devices, such as printers, modems, LANs, or other laptops.
• However, the limit of transfer speed ranges from 2400 bps to 4 Mbps.
• Requires line of sight transmission.

The various devices that can transfer files and data by using infrared communication.

BROADBAND TECHNOLOGY

• It refers to a telecommunications signal or device of greater bandwidth with greater the information-carrying capacity.
• Today, broadband is widely use to enable the internet access to laptop and mobile devices.
• The device that is simply used is the broadband stick with different service providers.

The different service providers in Malaysia.

• Mobile broadband allows for mobility so that the user can get internet access where ever there are. However, it depends on the service provider's coverage as well.
• Fixed broadband are mainly used for home or business and more stable because it uses cable and usually runs on fibre.

Router

Reflection #6

UNBOUNDED MEDIA / UNGUIDED MEDIA

• The media transport electromagnetic wave without physical conductor.
• Signal are broadcasting through air which means it is available to anyone who has device that capable of receiving the signal.

TERRESTIAL MICROWAVE

• It requires line of sight transmission and reception equipment.
• The taller the antennas, the longer the sight distance.
• Make tower on the hills or mountain to be higher than the ground.
• The signal transferred one way at a time.

To increase the distance, a system called repeater can be installed with the antenna.

2 TYPES OF ANTENNAS:

1. Parabolic dish
2. Horn

PARABOLIC DISH

• Based on geometry repeater of parabola.
• Works like a funnel (catching a wide range of waves and directing to a common point called focus)
• This is used by line namely maxis celcom and digi to catch the data.

HORN

• Looks like a gigantic scoop
• Outgoing transmission are broadcast up to a stern and deflected outward in a series of narrow parallel beams by the scooped shaped of the horn.
•  

SATELLITE

• Same principal as the terrestrial microwave
• Super tall antenna and repeater
• Single bounce
• Capability = any location on earth no matter how remote
• High quality communication without requiring a huge investment in ground-based infrastructure.

Now let see the equipment used and distance covered of four transmission:

1. RADIO FREQUENCY
2. CELLULAR PHONE
3. WIFI
4. BLUETOOTH

The equipment used and distance covered of four transmission:
 
RADIO FREQUENCY

• The rate of oscillation in the range of about 3 kHz to 300 GHz.
• Corresponds to the frequency of radio waves, and the alternating currents which carry radio signals.
• Antenna must be used to received the signal.
• Usually done via a resonator – a circuit with a capacitor and an inductor forming a tuned circuit.
• Resonator act as amplifier to the oscillations within a particular frequency band
• It also reducing oscillations at other frequencies outside the band.

 
CELLULAR PHONE
Cellular phone is using various transmission
1G  

• 1G is short for first-generation wireless telephone technology.
•  This generation of phones and networks is represented by the brick-sized analog phones introduced in the 1980’s.
•  Subsequent numbers refer to newer and upcoming technology.

2G  

• 2G phones use digital networks.
• 2G networks and their digital nature also made it more difficult to eavesdrop on mobile phone calls.
  

3G 

• 3G networks are an in between standard. 
• 3G is seen more as pre4G instead of a standard of its own. The advantage 3G networks have over 2G networks is speed.  
• 3G networks are built to handle the needs of today’s wireless users.
• This standard of wireless networks increases the speed of internet browsing, picture and video messaging, and handheld GPS use.

4G 

• 4G (AKA Beyond 3G) is like the other generations in that its advantage lies in promised increased speeds in data transmission. There is currently no formal definition for 4G, but there are objectives.  
• One of these objectives is for 4G to become a fully IP-based system, much like modern computer networks.  
• The supposed speeds for 4G will be between 100 Mbit/s and 1 Gbit/s.

WiFi

• WiFi is the original technology of wireless local area network or WLAN.
• It is usually based on IEEE 802.11 specifications.
• uses the same radio frequencies as Bluetooth, but with higher power consumption resulting in a stronger connection.
• The devices that are able to access this type of transmission are mobile computing devices such as laptops.
• With the frequency of 2.4 GHz, WiFi has the range 100-300 feet indoor and 300-900 feet outdoor.

All in all, we already used all these transmission and the evolution of these transmission are still going on today. Maybe in future, we might have a new technology that way more intelligent than today. Who knows?