Match List-I with List-II:

List-I		List-II
a)	Baudot code	i)	Permits the correction of errors by receiver without retransmission
b)	Hamming code	ii)	Provides no error detection at all
c)	Error detecting code	iii)	Permits the detection of two errors or correction of only one error
d)	Forward error-correcting code	iv)	Uses an extra parity bit at the end of each word to detect errors in received data

Choose the correct option from those given below:

Baudot Code:

• Baudot is a five-bit binary code that uses crosses and dots.
• Originally used in wireless telegraphy as a replacement for Morse Code.
• Binary code which uses crosses and dots.
• Used for teleprinter message and allowed to encode 25 = 32 characters.
• The Baudot code includes two 30-symbol character sets, and two Shift symbols, the shift symbols are used to shift between the two character sets, thereby allowing for 60 different 
• It provides no error detection at all

​​Hamming code:

Hamming codes are linear block codes. The family of (n, k) hamming codes for q ≥ 3 is defined by the following expressions:

1. Number of Block diagrams (n) = 2q – 1

2. Number of message bits (k) = 2q – q – 1

3. Number of Parity bits (q) = (n – k)

Hamming code is a set of error-correction codes that can be used to detect and correct '1' bit errors that can occur when bit stream are sent through channel. It can be employed in both burst and signal error correction

Error detecting code:

• An error occurs when, it is altered between transmission and reception (1 is transmitted and 0 is received, and vice versa)
• For reliable communication, errors must be detected and corrected.
• Error detection means deciding whether the received data is correct or not without having a copy of the original message.
• Error detection and correction uses the concept of redundancy, which means adding extra bits for detecting errors at the destination.
• These redundant bits are added by the sender and removed by the receiver.

• The error detection methods include:

1). VRC (Vertical Redundancy Check): It is an error-detecting code commonly used in digital networks and storage devices to detect an error in data sent by the sender.

2). LRC (Longitudinal Redundancy Check): It is an error-checking method used on an eight-bit ASCII character

3). CRC (Cyclic Redundancy Check)

4). Checksum