CS431 Assignment 1 Solution and Discussion
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Assignment No. 01
Semester: Fall 2019
Wireless Communications – CS431
Total Marks: 20
Due Date: Nov 15, 2019Objectives of this assignment are:
• To understand how to overcome a signal attenuation problem.
• To understand the method with minimum code to make error free wireless communication.Instructions:
Please read the following instructions carefully before solving & submitting the assignment:- The assignment will not be accepted after due date.
- Zero marks will be awarded if the assignment does not open or the file is corrupt.
- The assignment file must be an MS Word (.doc/.docx) file format; Assignment will not be accepted in any other format.
- Zero marks will be awarded if assignment is copied (from other student or copied from handouts or internet).
- Zero marks will be awarded if Student ID is not mentioned in the assignment file.
This assignment covers week 1 to week 3 lectures.
For any query about the assignment, contact at [email protected]
Assignment Questions
Question#1 (10 Marks)
An organization has its satellite based network that it provides direct broadcast services. This organization comes across signal attenuation problem due to the long distance communication links which results in the poor service.
As a network engineer, what you will advise to that organization to compensate this attenuation?Question#2 (10 Marks)
A wide area network based organization wants to make error free communication by using CRC error detection technique. In addition the organization wants to keep the transmission code in minimum of its length.Being a networking engineer, which one of the following would you suggest to the organization to achieve its goal?
- Polynomials
- Error Correction
- Hamming Code
Support your answer with atleast one valid example.
Best of Luck
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Answer to Q#1
A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal.
Transponders are microwave repeaters located at intermediate points in a communications link, which are used to compensate for the signal attenuation along the route to extend the range of the link. They receive the very weak signals from a sender at one end of the link, amplify them, and re-transmit them at much higher power to the receiver at the other end of the link. The whole purpose of a communications satellite system is to place a transponder in position, to keep it there and to keep it powered up. Because of the very high launch costs, for satellite systems to be economically justified, the transponder should be able to carry high traffic volumes including television channels as well as dozens of multiplexed voice communications and other data links. It should also be small and light.Questions: Marks 10
Question # 1 Marks 10
An organization has its satellite-based network that it provides direct broadcast services. This organization comes across signal attenuation problem due to the long distance communication links, which results in the poor service.
As a network engineer, what you will advise to that organization to compensate this attenuation?Answer to Q#1
A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal.
Transponders are microwave repeaters located at intermediate points in a communications link, which are used to compensate for the signal attenuation along the route to extend the range of the link. They receive the very weak signals from a sender at one end of the link, amplify them, and re-transmit them at much higher power to the receiver at the other end of the link. The whole purpose of a communications satellite system is to place a transponder in position, to keep it there and to keep it powered up. Because of the very high launch costs, for satellite systems to be economically justified, the transponder should be able to carry high traffic volumes including television channels as well as dozens of multiplexed voice communications and other data links. It should also be small and light.Answer to Q#2
Being a networking engineer, he should suggest the use of polynomial codes to the organization for desired objective.
The benefits of using polynomial codes is that it produces short codes. For example, here a 6-bit pattern is replaced by 3 terms.
In polynomial codes, the degree is 1 less than the number of bits in the binary pattern. The degree of polynomial is the highest power in polynomial. For example as shown in fig degree of polynomial x5 +x2 + 1 are 5. The bit pattern in this case is 6.
A pattern of Os and 1s can be represented as a polynomial with coefficient of o and 1.
Here, the power of each term shows the position of the bit and the coefficient shows the values of the bit.
For example, if binary pattern is 100101, its corresponding polynomial representation is x5 + x2 + 1. Figure shows the polynomial where all the terms with zero coefficient are removed and x J is replaced by x and XO by 1.