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1Q-In general we can say parity bit consist of 7-bit binary code is to finderrors. In Parity bit a single bit is added to extreme to binary data carrying so, the parity bit operation is to check whether it is even parity bit otherwise it is called as odd parity bit.
parity bits are of two types:
a) Even parity bit
b) Odd parity bit
a) Even parity bit: In even parity bit if transmitter transmits the 7-bit binary code as odd parity bit (1101011) parity bit ensure to check error it adds one to received data so to make it as even parity bit.
Example: 1011101(odd parity bit)
+1
11011101(even parity bit)
b) Odd parity bit: odd parity bit is alike of even parity bit if data is accepted by the sender as even parity bit add one to that data to make it as a odd parity bit.
Example:0101101(even parity bit)
+1
10101101(odd parity bit)
2Q-Internet checksum Number: 0A BC 78 9F 85 7E 5D BC
Sender’s checksum calculation:
Partial sum, 0ABC
+789F
-------------
835B
Partial sum, 835B
+857E
-------------
= 108D9
Carry, 08D9
+0001
------------
=08DA
Partial sum, 08DA
+5DBC
------------
=6696
1’s compliment of 6696 = 9969
Hence , transmitted data is 0A BC 78 9F 85 7E 5D BC 99 69
Receiver’s checksum calculation
Partial sum, 0ABC
+789F
------------
= 835B
Partial sum, 835B
+857E
--------------
= 108D9
Carry, 08D9
+0001
-------------
=08DA
Partial sum, 08DA
+5DBC
------------
=6696
Partial sum, 6696
+9969
-----------
=FF
Therefore, result is 1111 and 1’s compliment of that is 0000 which determines that there are no problems.
3Q- Message D= 1011(4 bits)
Pattern P=101 (3 bits)
FCS = 2 bits
Using the values above we can say k = 4
Since P = n-k+1
3 = n-4+1
n = 6
and (n-k) = 2
Information is multiplied by 22 (0100)
D = 1011
*100
---------
101100
So, D = 101100
Then, product is divided by pattern P = 101
1 0 1)1 0 1 1 0 0(1 0 0 1
1 0 1
0 0 0 1 0 0
1 0 1
0 0 1
Remainder = 001
Output is then added to 22 *D (1 0 1 1 0 0) which gives T = 1 0 1 1 0 1. Receiver accept T complete if there are no faults. Therefore, receiver frame is then dived by Pattern P (1 0 1).
4Q-Time division multiplexing:
TDM is plan of transmitting separate signals and receivingseparate signals which can be passes through a single channel.Each and every signal appears on a fraction of time to the alternate side. In TDM time is into small portions as a slot from that slots we can transmit the signals. In TDM we separate different N channels were signals are passes for short time from analog data to digital data. Unlike FDM in TDM bandwidth do not exceeds the medium. In TDM signals is passes to channels in exact clock period if data is transfer over the clock period the data may collapsed it get distorted. overall all we can say that signals should transmitted in allocated bandwidth in give period so that it’s give systematic configuration at end of the operation.
Frequency division multiplexing:
It is divided into multiple logical channels into different range of six frequencies (min-max) bandwidth different user signals can transmitthrough these channel and user signals are switches into different carrier frequency and unique bandwidth in between these signals users prepared distance called gaps to nullified distortion. capacity of the user signal and range of frequency bandwidth must outreach the required bandwidth of all signals. In FDM analog signals are used rather than digital signals to transmission of signals were as digital signals make noise while transmitting the signal through medium.
The two main differences in Frequency division duplex and Frequency division multiplexing. In frequency division duplex to make a movement control of distortion two different frequencies are used for sending data and accepting data, where as in Frequency division multiplexing one through one medium channel transmission of data take place in short time.
5Q- cable modems are of two types,
1.External cable modems
2.Internal cable modems
It is used to send the data and also receive the data from the source and destination.
An external cable is used for the purpose of accessing data and also have connection to the computer devices
An internal cable modem is used within the logical circuits to transmit the data and also receive the data, mainly these are used in computers.
Network traffic can be classified into two types
1.upstream traffic
2. downstream traffic.
When sending the data from source to destination in a network is called as upstream data traffic. For example, sending the data from one point of source to another point of destination by the source of medium like Wide Area Network or Local Area Network is a data upstream.
Getting or retrieving the data from the source to the current machine like PC or laptop by downloading the files.
6Q-TDMA
It is a design consist of two types:
1.base station
2.supporter stations.
TDMA uses single interface line to transfer signals to separated time portions .In TDMA different time space has been created to do chain like sub two channels i.e.; uplink and downlink ,in uplink channel channels merged into 3time slots so that to get equal amount of capacity which are mapped to uplink station known as base station were as at supporter channel downlink is similar to uplink channel equally divided time gaps each slots ae equalized by guard times .guard times are need to have between time space to lack of synchronization between the donors stations .