Terminologies in Telecommunication Oum Saokosal
Terminologies in Telecom <ul><li>What is digital? </li></ul><ul><li>Source coding for communication? </li></ul><ul><li>Cha...
What is digital? (1) <ul><li>Analog  is one in which a base carrier’s alternating current frequency is modified in some wa...
What is digital? (2) <ul><li>Digital : Electronic technology that processes data in: positive (1) and non-positive (0). Th...
Source Coding for communication <ul><li>Source coding , also known as  quantization  or  signal formatting , is a way of p...
Channel Coding? (1) <ul><li>Channel coding  refers to the forward error correction (FEC) 1  code and ”bit interleaving” 2 ...
Channel Coding? (2) <ul><li>Forward error correction  (FEC): is a system of error control for data transmission, whereby t...
Channel Coding? (3) <ul><li>Bit interleaving  is a technique to keep track of the number and sequence of bits which are br...
Modulation <ul><li>Modulation  is the process where a Radio Frequency or Light Wave's amplitude, frequency, or phase is ch...
Multiplexing (1) <ul><li>Multiplexing  is a process where multiple analog message signals or digital data streams are comb...
Multiplexing (2) <ul><li>Frequency Division Multiplexing (FDM)   :  each  signal is assigned a different frequency.  </li>...
CDM <ul><li>Code Division Multiplexing (CDM) is a  technique in which each channel transmits its bits as a coded channel-s...
CDMA (1) <ul><li>Basic Idea:  An analogy to the problem of multiple access is a room (channel) in which people wish to com...
CDMA (2) <ul><li>Code Division Multiple Access (CDMA) is a &quot;spread spectrum&quot; technology, allowing many users to ...
TDM <ul><li>Time-Division Multiplexing  ( TDM ) is a type of digital or analog multiplexing in which two or more signals o...
GSM (1) <ul><li>GSM uses narrowband TDMA, which allows eight  simultaneous calls on the same radio frequency. </li></ul><u...
GSM (2) <ul><li>GSM is the most popular standard for mobile phones in the world.  </li></ul><ul><li>GSM also pioneered a l...
FDM (1) <ul><li>Frequency-division multiplexing (FDM) is a scheme in which numerous signals are  combined for transmission...
FDM (2) <ul><li>When FDM is used in a communications network, each input signal is sent and received at  maximum speed at ...
Thanks
Upcoming SlideShare
Loading in...5
×

Terminology In Telecommunication

5,034
-1

Published on

Terminology In Telecommunication

Published in: Technology, Education, Business
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
5,034
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
132
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide
  • In telecommunications, a carrier wave, or carrier is a waveform (usually sinusoidal) that is modulated (modified) with an input signal for the purpose of conveying information. This carrier wave is usually of much higher frequency than the input signal.
  • a   channel access method   or   multiple access method   allows several   terminals   connected to the same multi-point   physical medium   to transmit over it and to share its capacity. Examples of shared physical media are   wireless networks , bus networks ,   ring networks ,   hub networks   and   half-duplex   point-to-point links.
  • Spread-spectrum   techniques are methods by which   electromagnetic energy   generated in a particular bandwidth   is deliberately spread in the   frequency domain, resulting in a   signal   with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural   interference   and   jamming, and to prevent detection.
  • Terminology In Telecommunication

    1. 1. Terminologies in Telecommunication Oum Saokosal
    2. 2. Terminologies in Telecom <ul><li>What is digital? </li></ul><ul><li>Source coding for communication? </li></ul><ul><li>Channel coding? </li></ul><ul><li>Modulation </li></ul><ul><li>Multiplexing </li></ul><ul><ul><li>CDM -> CDMA </li></ul></ul><ul><ul><li>TDM -> GSM </li></ul></ul><ul><ul><li>FDM </li></ul></ul>
    3. 3. What is digital? (1) <ul><li>Analog is one in which a base carrier’s alternating current frequency is modified in some way, such as by amplifying the strength of the signal or varying the frequency, in order to add information to the signal. </li></ul>
    4. 4. What is digital? (2) <ul><li>Digital : Electronic technology that processes data in: positive (1) and non-positive (0). Thus, data transmitted or stored with digital technology is expressed as a string of 0's and 1's. Each of these state digits is referred to as a bit.  </li></ul>
    5. 5. Source Coding for communication <ul><li>Source coding , also known as  quantization  or  signal formatting , is a way of processing data in order to reduce redundancy or prepare it for later processing. Analog-to-digital conversion and data compression are two categories of source coding. </li></ul>
    6. 6. Channel Coding? (1) <ul><li>Channel coding  refers to the forward error correction (FEC) 1  code and ”bit interleaving” 2  in communication and storage where the communication media or storage media is viewed as a channel. </li></ul><ul><li>The channel code is used to protect data sent over it for storage or retrieval even in the presence of noise (errors). </li></ul>
    7. 7. Channel Coding? (2) <ul><li>Forward error correction (FEC): is a system of error control for data transmission, whereby the sender adds redundant data to its messages. This allows the receiver to detect and correct errors without asking the sender for additional data. </li></ul>
    8. 8. Channel Coding? (3) <ul><li>Bit interleaving is a technique to keep track of the number and sequence of bits which are broken by time division multiplexing and sent across one communications channel simultaneously so that they can be quickly and efficiently reassembled into their original form upon receipt. </li></ul>
    9. 9. Modulation <ul><li>Modulation is the process where a Radio Frequency or Light Wave's amplitude, frequency, or phase is changed in order to transmit intelligence. The characteristics of the carrier wave are instantaneously varied by another &quot;modulating&quot; waveform. Common Methods: </li></ul><ul><ul><li>Amplitude Modulation </li></ul></ul><ul><ul><li>Frequency Modulation </li></ul></ul><ul><ul><li>Phase Modulation </li></ul></ul><ul><ul><li>Pulse Modulation </li></ul></ul>
    10. 10. Multiplexing (1) <ul><li>Multiplexing  is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. </li></ul><ul><li>Demultiplexing is a reverse process which can extract the original channels on the receiver side. </li></ul>
    11. 11. Multiplexing (2) <ul><li>Frequency Division Multiplexing (FDM) : each signal is assigned a different frequency. </li></ul><ul><li>Time Division Multiplexing (TDM) : each signal is assigned a fixed time slot in a fixed rotation. </li></ul><ul><li>Statistical Time Division Multiplexing (STDM): time slots are assigned to signals dynamically to make better use of bandwidth. </li></ul><ul><li>Wavelength Division Multiplexing (WDM) : each signal is assigned a particular wavelength; used on optical fiber. </li></ul>
    12. 12. CDM <ul><li>Code Division Multiplexing (CDM) is a technique in which each channel transmits its bits as a coded channel-specific sequence of pulses. </li></ul><ul><li>Code-division multiplexing (CDM) is a technique that enables digital bit streams be transferred over an analog channel. </li></ul>
    13. 13. CDMA (1) <ul><li>Basic Idea: An analogy to the problem of multiple access is a room (channel) in which people wish to communicate with each other. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different languages (code division). </li></ul>
    14. 14. CDMA (2) <ul><li>Code Division Multiple Access (CDMA) is a &quot;spread spectrum&quot; technology, allowing many users to occupy the same time and frequency allocations in a given band/space. </li></ul><ul><li>CDMA assigns unique codes to each communication to differentiate it from others in the same spectrum. </li></ul>
    15. 15. TDM <ul><li>Time-Division Multiplexing  ( TDM ) is a type of digital or analog multiplexing in which two or more signals or bit streams are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. </li></ul><ul><li>The GSM telephone system is an application examples of TDM. </li></ul>
    16. 16. GSM (1) <ul><li>GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency. </li></ul><ul><li>GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1,800 MHz frequency band. </li></ul>
    17. 17. GSM (2) <ul><li>GSM is the most popular standard for mobile phones in the world. </li></ul><ul><li>GSM also pioneered a low-cost (to the network carrier) alternative to voice calls, the Short message service which is now supported on other mobile standards as well. </li></ul>
    18. 18. FDM (1) <ul><li>Frequency-division multiplexing (FDM) is a scheme in which numerous signals are combined for transmission on a single communications line or channel. Each signal is assigned a different frequency (subchannel) within the main channel. </li></ul>
    19. 19. FDM (2) <ul><li>When FDM is used in a communications network, each input signal is sent and received at maximum speed at all times. </li></ul><ul><li>However, if many signals must be sent along a single long-distance line, the necessary bandwidth is large, and careful engineering is required to ensure that the system will perform properly. </li></ul><ul><li>In some systems, time-division multiplexing is used instead. </li></ul>
    20. 20. Thanks
    1. A particular slide catching your eye?

      Clipping is a handy way to collect important slides you want to go back to later.

    ×