Give selection procedure of compensation.

1) In general there are two situation in which compensation is required.

2) In 1st case, the system is absolutely unstable & the compensation is required to stabilize, if as well as to achieve a specified performance.

3) In 2nd case the system is stable, but the compensation is required to obtain the desired performance.

4) The system which are type 2 or higher are usually absolutely unstable, for these type of system clearly load compensator increase the margin of stability.

5) In type 0, type 1 system stable operation is always possible, if the gain if sufficiently reduced. In Such cases any of the 3 compensator lead, lag and Lead lag may be used to obtained the desired performance.

Compare lead and lag compensator

 Lead compensator   

1) Introduce lead phase shift in the system

2) Improve transient response

3) Decrease rise time 

4) Decrease settling time 

5) Increase Bandwidth

6) Faster response

7) less overshoot

8) Increasing damping

Lag compensator 

1) Introduce lag phase shift in the system

2) Improve steady state response

3) Increase rise time. 

4) Increase settling time.

5) Decrease Bandwidth 

6) Slow response 

7) Increase overshoot.

8) Decrease damping

State function of switches in optical fiber link.

  

1) An optical switch is a device that selectively switches optical signals from one channel to another.

2) In commercial terms it refer to any piece of circuit switching equipment between fibers.

3) The switches are used to switch the traffic stream from primary fiber into another fiber in case the primary fiber fails.

What is the function of OTDR

 i) OTDR detects faults going in the optical fiber       link.

 ii) Fast automatic testing.

 iii) Troubleshoot the faults in optical fiber                   communication.

iv) Maintain optical telecommunication network.

Requirements of rectifiers

Rectifier is a electronic circuit or a device which is used for converting AC voltage/current to DC voltage/current.

Requirements of rectifiers:- i) Rectifier is able to convert two directional Alternate Current (AC) to unidirectional pulsating Direct Current (DC).

ii) Rectifier removes, the negative part from Alternate Current (AC).

iii) By using Rectifier and step-down transformer we get desired DC voltage.

iv) Rectifier divided into two types:-  a) Half wave rectifier

                                                    b) Full wave rectifier

State concept of GPON

 

GPON or Gigabit passive optical network is a point to multipoint access mechanism.

The main characteristics of GPON is the use of passive splitters, which enable a single feeding fiber from the networks provider's central location to serve multiple users with their homes and small business. 

GPON uses the advanced Encryption standard (AES) for security purpose, which was designed to be efficient in both hardware and software and support a block length of 128 bits and key length 128, 192 and 256 bits.

GPON also support all types of Ethernet protocol.

Describe DWDM development of multiple wavelength with the help of a neat diagram. State its advantages also

Fig shows DWDM deployment on an OC-192 trunk ring for wavelength.

DWDM is a technology that puts together multiplexes data signals from different sources so, they can share a single optical fiber pair while maintaining complete partition of the data stream.

Individual signal is carried on a separate light wavelength. The dense part of DWDM refers to the fact that more than 80 separate wavelength, each about 0.8 of a nano-meter (nm) wide can short a single optical fiber.

DWDM allows enormous amount of data to traverse a single network link. Because they are

carried an clear wavelength, the streams also called channel do not interfere with each other.

Consequently data integrity if maintained of well as any security related positioning is also maintained.

Advantage:-

i) Improve scalability

ii) Provide extra resilience

iii) Maximum Capacity system available.

iv) Greater fiber capacity

v) Easier network expansion

vi) Can conserve switched bandwidth

vii) DWDM System Capable of longer span length

True or False in maths

1)  If A = {1,2,3} then {2,3} is proper subset of A.

True

False

Ans:- True

2) If A = {1, 2}, B = { 2, 3, 5 } and C = { 1, 2, 5 } then find A intersection B intersection C.

{2}

{1}

{3}

Ans:- {2}

What is the difference between potentiometer as an error detector and synchro as an error detector

 1) Potentiometer →  Two pots connected in uniform.

2) Synchro → Interconnection of a synchro transmitter and synchro control transformer.

3) Potentiometer → Potentiometer as an error detector associated with angular as well as linear position control system.

4) Synchro → Synchro as an error detector associated with only angular position control.