• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15

Theory of data communication

Extracts from this document...


Btec National Unit 8 - Communications Technologies Hand-in date Return date Assessment No: 8.1 Assessment Title: The theory of data communications This assessment has been internally verified by: Edexcel Hand out date: 21/10/10 Hand in date: 21/11/10 On going assignment used as a delivery tool This assessment provides the opportunity to meet the grading criteria for the unit as indicated in the grid below. Student Name: Learner Authentication Statement If you copy from someone else or allow another candidate to copy from you, or if you cheat in any way you may be disqualified from at least the assignment concerned. Any help or information you have received from people other than your subject teacher must be clearly identified in the work itself Any books, information leaflets or other material (eg videos, software packages or information from the internet) which you have used to help you complete this work must be clearly acknowledged in the work itself. To present material copied from books or other sources without acknowledgement will be regarded as deliberate deception. Declaration by learner I have read and understood the above statements. I have produced the work without help except for help from my subject lecturer and the help which I have declared in the work itself. I have acknowledged all source material in the work itself. Signed __________________________(Learner) Date ____________________ Criterion Description Page Reference Assessors Signature/Date Comments P1 Identify and explain types of communication devices 4 P2 Explain the principles of signal theory 5 P3 Describe communication protocols used and explain why they are important 7 M1 Explain techniques that can be used to reduce errors in transmissions 6 D1 Critically compare the OSI seven layer model and the TCP/IP model 10 To be read in conjunction with the Grading Criteria Grid for the unit and the Assignment General Instructions in the Student Handbook.- The theory of data communications WHAT YOU WILL LEARN IN THIS ASSIGNMENT * types of communication devices, signal theory, error reduction techniques, protocols, OSI and TCP/IP ...read more.


With this I will now do 2 to the power of X, X being 0,1,2,3,4,5,6 etc. 25 24 23 22 21 20 - This is the 2x 1 0 0 1 0 1 - This is the binary for 37 32 16 8 4 2 1 - This is the base 2 rule Now to check that the binary is correct I will take the base 2 numbers where the binary is a 1 and add them together. I should get the denary number: 32+4+1=37 This is how denary is converted to binary. Data Packets In networking, data must be formed in a package to be able to be transported over a network. Package formats vary for different types of networks. However the term data packet is always used to describe a package. A packet will contain a minimum of the foundation address, the destination address, data and error control. The foundation address is sent so the destination knows who sent the data. The destination address is used to find the right destination. Data is the actual information being sent. Error control is sent to help identify problems with the data once it has arrived at its destination (see chapter 1b for error detection techniques). Asynchronous and Synchronous Transmissions Asynchronous transmission means that the receiving device must accept the receipt of data before the source device will send more data. In synchronous transmission, both devices will synchronise with each other before any data is sent. Bandwidth (Analogue) Analogue signals are sine waves which look like the waveform in image 1. Sine waves are known as analogue signals is because they are an analogy of sound waves which travel in the same way. Analogue bandwidth is the number is cycles that occurs with the sine wave over a period of time, for example in image 1, the wave is 1Hz and occurred within 20ms so the bandwidth is 1Hzpms (1 Hertz per millisecond). ...read more.


Most of these processes build upon what it needs and assumes that only an underlying transport method (such as a datagram or connection) will be provided. Transport Layer (OSI) In OSI, the Transport layer takes the data that is going to be sent and breaks it down into individual packets that are sent and then reassembled by the Transport layer at the destination. It also provides a signalling service which tells the sender that the destination had received the data has been successfully received. Transport Layer (TCP/IP) In TCP/IP, the Transport layer introduces two transport protocols, TCP and UDP. TCP implements reliable transportation of data whereas UDP doesn't. The reason this is, is because TCP required acknowledgement to ensure that data is sent correctly and successfully. If an error is detected, the packet can be resent. UDP just broadcasts the data without any need for a reply from the destination therefore data transportation will be faster but will be less reliable as errors can occur. Comparing Transport for both Models Transport for both models is very similar as they both contain transfer protocols that required acknowledgement that data has been received by the destination. While this would be slower, this is more effective as data will always end up being sent correctly. Network Vs. Internet. Both OSI and TCP/IP support a connectionless network service. OSI's CLNP is practically identical to the Internet's IP. Both are best-effort-delivery protocols. They are virtually identical but the one major difference that sets them apart is that CLNP supports variable length addresses whereas IP supports fixed, 32-bit addresses. Data Link/Physical Vs. Subnet In OSI, the Data Link and Physical layers resemble directly to the Subnet layer of TCP/IP. Most of the time, the lower layers below the Network layer of TCP/IP is rarely discussed. During the creation of both OSI and TCP/IP, it was decided that the Network layer for TCP/IP would match the Data Link layer of OSI. ?? ?? ?? ?? BTEC IT Practitioners Unit 8 Communication Technologies Olateju Famuyiwa ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Information Systems and Communication section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Information Systems and Communication essays

  1. Marked by a teacher

    Database Coursework on a Vehicle Rental System: Analysis

    5 star(s)

    it is first located by the staff member, withdrawn from the file and placed in the bin. In the proposed system, the record is located in the computerised database and the user clicks a "Delete" button, which removes that record from the system.

  2. The Impact of Mobile Phones on social Interaction

    major role in this growth and in helping to increase interaction is summed up very well by senior analyst Charles Golvin (cited in (2) ) of Forrester research who comments "people can be in touch anytime and anywhere they want to".

  1. Threats to Data

    Many things can happen to data from accidentally deleting it to a hacker signing on to your machine and deliberately deleting or changing something. Add to this the possibility of machine failure or fire then there must be a way of reloading data if the worst happens.

  2. Strand Two ITGS Assignment - Standards and Protocols allow different rules and settings to ...

    to Standards and Protocols since these digital nomads depend on Internet Protocols and Communication Protocols in order for them to be able to roam around the world, while working. http://www.sciencedaily.com/releases/2008/10/081027174646.htm * In this article, a man named Jerome P. McDonough, feared that people today are using technology to store files,

  1. Using ICT to communicate

    this booklet is written to try and inform students of what the year 10 lessons will consist of, so the booklet has to be strait forward and to the point so that year nines wont think that there going to choose a lesson because they think it will be easy,

  2. ict as level coursework

    If there are outlining problems with the system then it is not fit for its purpose as one of the user requirements state that it should be easy to use and understand. Testing Strategy Now I will go over my user requirements and explain how I will test them.

  1. Communication & Employability Skills for IT. OCR Cambridge Technicals Unit 1 LO1-P1

    wrong hands, so the teacher would have to password protect the USB so that no one can gain access to it, even if it was the teacher?s family members. Other protection businesses need to take is the proper disposal of paperwork.

  2. Discuss the Causes and Effects of the Digital Divide

    The more wealthy people do not directly benefit form the divide but they benefit from other things such as the information age where more newer technology can help make their lives easier than it already is. Countries have varied amount of technology in them for example countries in Africa will

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work