1.2 Protocols, Standards, Standard organizations, Bandwidth, Data Transmission rate and Bits per Second

PROTOCOL

  • A Protocol is defined as a set of rules that governs data communications.
  • A protocol defines what is to be communicated , how it is to be communicated and when it is to be communicated.
  • For successful communication to occur, the sender and receiver must agree upon certain rules called protocol.

ELEMENTS OF PROTOCOL

A. Syntax
It means the structure or format of the data. It is the arrangement of data in a particular order.
B. Semantics
It tells the meaning of each section of bits and indicates the interpretation of each section.
It also tells what action/decision is to be taken based on the interpretation
C. Timing
It tells the sender about the readiness of the receiver to receive the data.
It tells the sender at what rate the data should be sent to the receiver to avoid overwhelming the receiver.

STANDARDS: 

Standards are the set of rules  for data communication that are needed for  exchange of information among devices. It is important to follow Standards which are created by various  Standard Organization like IEEE , ISO , ANSI etc.


Types of Standards :

Standards are of two types :

  • De Facto Standard.
  • De Jure  Standard.

De Facto Standard :  The meaning of the work ” De Facto ”  is ” By Fact ”  or “By Convention”.
These are the standard s that have not been approved by any Organization , but have been adopted as  Standards  because of it’s widespread use. Also , sometimes these standards are often established by Manufacturers.

For example :   Apple  and Google are two companies which established their own rules on their products which are different . Also they use some same standard rules for manufacturing for their products.

De Jure Standard :  The meaning of the word “De Jure”  is  “By Law” or “By  Regulations” . 
Thus , these are the  standards that have been approved by officially recognized body like ANSI , ISO , IEEE etc. These are the standard which are important to follow if it is required or needed.


 STANDARD ORGANIZATIONS 

  • Data Communication refer as the exchange of  data between two devices via some form of Transmission media such as cable ,wire or it can be air or vacuum.

Standard Organizations for Data Communication :

1) International Standard Organization (ISO) – 
ISO is the International Organization for Standardization. It creates set of rules and standards for graphics , document exchange , data communication etc.

2) Consultative Committee for International Telephony and Telegraphy (CCITT) –
CCITT is now standard organization for the United States. CCITT developer’s recommended set of rules and standards for telephone and telegraph communication.

It has developed 3 set of specifications :

  • V Series for Modern Interfacing.
  • X series for Data Communication.
  • Q series for Integrated Services Digital Network(ISDN).

3) American National Standard Institute (ANSI) – 
ANSI is primary organization for fostering the development of technology standards in the United States and providing various set of rules and standard for  Data Communication.

4) Institute of Electrical and Electronic Engineering (IEEE) –
It is US based professional organization of electronic , computer and communication engineering. It provides various set of rules and standard in communication and networking field.

5) Electronic Industries Association(EIA) –  
This organization establish and recommends industrial standards. EIA has developed the RS(Recommended Standards) series of Standards for data and telecommunication.

6) Standard Council of Canada (SCC) –
It is an official Standard Agency for Canada . It has Similar responsibilities as ANSI has. 


BANDWIDTH:  
  
Bandwidth is measured as the amount of data that can be transferred from one point to another within a network in a specific amount of time. Typically, bandwidth is expressed as a bitrate and measured in bits per second (bps).
The term bandwidth refers to the transmission capacity of a connection and is an important factor when determining the quality and speed of a network or the internet connection. 

There are several different ways to measure bandwidth. Some measurements are used to calculate current data flow, while others measure maximum flow, typical flow, or what is considered to be good flow.
Bandwidth is also a key concept in several other technological fields. In signal processing, for example, it is used to describe the difference between the upper and lower frequencies in a transmission such as a radio signal and is typically measured in hertz (Hz).

Bandwidth can be compared to water flowing through a pipe. Bandwidth would be the rate at which water (data) flows through the pipe (connection) under various circumstances. Instead of bits per second, we might measure gallons per minute. The amount of water that possibly can flow through the pipe represents the maximum bandwidth, while the amount of water that is currently flowing through the pipe represents the current bandwidth.

Bandwidth was originally measured in bits per second and expressed as bps. However, today’s networks typically have much higher bandwidth than can be comfortably expressed by using such small units. Now it is common to see higher numbers that are denoted with metric prefixes, such as Mbps, (megabits per second), Gbps (gigabits per second), or Tbps (terabits per second).

K = kilo = 1,000 bits
M = mega = 1,000 kilo = 1,000,000 bits
G = giga = 1,000 mega = 1,000,000,000 bits
T = tera = 1,000 giga = 1,000,000,000,000 bits
 

After terabit, there are petabit, exabit, zettabit, and yottabit, each representing an additional power of 10.
Bandwidth can also be expressed as bytes per second. This is commonly denoted with a capital B. For example, 10 megabytes per second would be expressed as 10 MB/s or 10 MBps.
One byte is eight bits.
Thus, 10 MB/s = 80 Mb/s.
The same metric prefixes can be used with bytes as with bits. Thus, 1 TB/s is one terabyte per second.

Data Transmission Rate

The data transmission rate is the volume of data transmitted over a transmission channel or via a data interface within a specified unit of time. The units used for this are baud or bits/s.

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