data communications and networking by behrouz a forouzan ppt

... means sending a digital or an analog signal without modulation using a low-pass channel Broadband transmission means modulating a digital or an analog signal using a band-pass channel A low-pass ... between each pair of adjacent layers Headers and trailers are control data added at the beginning and the end of each data unit at each layer of the sender and removed at the corresponding layers of ... Communication with user’s application program: application layer b Error correction and retransmission: data link and transport layers c Mechanical, electrical, and functional interface: physical layer

Ngày tải lên: 12/04/2023, 21:01

... communicating at a same layer Headers and trailers are control data added at the beginning and the end of each data unit at each layer of the sender and removed at the corresponding layers of the ... low-pass channel Broadband transmission means modulating a digital or an analog signal using a band-pass channel The Nyquist theorem defines the maximum bit rate of a noiseless channel Optical ... establishment of the security parameters is done via a mechanism called security association (SA) The two protocols defined by IPSec for exchanging datagrams are Authentication Header (AH) and

Ngày tải lên: 16/10/2021, 15:39

... AND CONCEPTS 57 SUMMARY 58 PRACTICE SET 59 Review Questions 59 Multiple Choice 60 Exercises 63 Chapter 4.1 Signals ANALOG AND DIGITAL 65 65 Analog and Digital Data 66 Analog and Digital Signals ... encapsulation of a network-layer packet in a data-link-layer frame The figure also shows how network-layer addresses are unchanged compared to the data-link-layer addresses that change from station ... ■ Apple, AppleTalk, EtherTalk, LocalTalk, TokenTalk, and Macintosh are registered trademarks of Apple Computer, Inc ■ Bell and StarLan are registered trademarks of AT&T FM Page xxxii Wednesday,

Ngày tải lên: 24/10/2017, 13:15

... Chapter 2: Fundamentals of Data and Signals TRUE/FALSE The terms “data” and “signal” mean the same thing ANS: F PTS: REF: 30 By convention, the minimum and maximum values of analog data and ... 18 A(n) converts the analog data to a digital signal by tracking the analog waveform and taking “snapshots” of the analog data at fixed intervals ANS: codec PTS: REF: 48 19 Quantization ... waveforms, rather than continuous waveforms a Analog signals c Digital signals b Analog bauds d Analog data ANS: C PTS: REF: 34 The three basic components of analog and digital signals are: amplitude,

Ngày tải lên: 19/10/2017, 16:27

...  means communication at a  distance.  The  word  data  refers  to  information  presented  in  whatever  form  is  agreed  upon  by  the  parties  creating  and  using  the  data.  Data  communications  are  the  ...  are  the  exchange  of  data  between  two  devices  via  some  form  of  transmission medium such as a wire cable.  Topics discussed in this section: Components Data Representation Data Flow 1.2 ... Figure 1.1  Five components of data communication 1.3 Figure 1.2  Data flow (simplex, half­duplex, and full­duplex) 1.4 1-2 NETWORKS A  network  is a set of devices (often referred to as  nodes)  connected  by  communication 

Ngày tải lên: 23/09/2020, 13:31

... the  International  Standards  Organization  (ISO)  is  a  multinational  body  dedicated  to  worldwide agreement on international standards. An ISO  standard  that  covers  all  aspects  of  ... Topics discussed in this section: Physical and Data Link Layers Network Layer Transport Layer Application Layer 2.28 Figure 2.16  TCP/IP and OSI model 2.29 2-5 ADDRESSING Four levels of addresses are used in an internet employing  ... Physical Layer Data Link Layer Network Layer Transport Layer Session Layer Presentation Layer Application Layer 2.9 Figure 2.5  Physical layer 2.10 2-4 TCP/IP PROTOCOL SUITE The  layers  in 

Ngày tải lên: 23/09/2020, 13:31

... Periodic and Nonperiodic Signals 3.3 Note Data can be analog or digital Analog data are continuous and take continuous values Digital data have discrete states and take discrete values 3.4 Note Signals can be analog ... discrete  states.  Analog  data  take  on  continuous values. Digital data take on discrete values Topics discussed in this section: Analog and Digital Data Analog and Digital Signals Periodic and Nonperiodic Signals ... signals 3.2 3-1 ANALOG AND DIGITAL Data can be  analog  or  digital. The term  analog data  refers  to  information  that  is  continuous;  digital  data  refers  to  information  that  has 

Ngày tải lên: 23/09/2020, 13:32

... 100 kbps, what is the average value of the baud rate if c is  between 0 and 1? Solution We assume that the average value of c is 1/2 The baud rate is then 4.5 Note Although the actual bandwidth of a digital ... Figure 4.27  Components of a PCM decoder 4.58 Example 4.15 We have a low­pass analog signal of 4 kHz. If we send the  analog  signal,  we  need  a  channel  with  a  minimum  bandwidth of 4 kHz. If we digitize the signal and send 8  ... Figure 4.2  Signal element versus data element 4.4 Example 4.1 A  signal  is  carrying  data  in  which  one  data  element  is  encoded  as  one  signal  element  (  r  =  1).  If  the  bit  rate  is 

Ngày tải lên: 23/09/2020, 13:32

... 5-2 ANALOG AND DIGITAL Analog­to­analog  conversion  is  the  representation  of  analog information by an analog signal. One may ask  why  we  need  to  modulate  an  analog  signal;  it  is  already analog. Modulation is needed if the medium is  ... Example 5.2 An analog signal has a bit rate of 8000 bps and a baud  rate  of  1000  baud.  How  many  data  elements  are  carried  by  each  signal  element?  How  many  signal  elements do we need? ... Figure 5.4  Implementation of binary ASK 5.9 Example 5.3 We  have  an  available  bandwidth  of  100  kHz  which  spans  from  200  to  300  kHz.  What  are  the  carrier  frequency and the bit rate if we modulated our data by 

Ngày tải lên: 23/09/2020, 13:32

... use of available bandwidth to achieve specific goals Efficiency can be achieved by multiplexing; privacy and anti-jamming can be achieved by spreading 6.2 6-1 MULTIPLEXING Whenever  the  bandwidth  ... that  allows  the  simultaneous  transmission  of  multiple  signals  across  a  single  data  link. As data and telecommunications use increases, so  does traffic Topics discussed in this section: ... of  100  kbps  and  another with a bit rate of 200 kbps, are to be multiplexed.  How this can be achieved? What is the frame rate? What  is the frame duration? What is the bit rate of the link?

Ngày tải lên: 23/09/2020, 13:32

... communications, such as radio and television, and paging systems 7.28 Figure 7.21  Unidirectional antennas 7.29 Note Microwaves are used for unicast communication such as cellular telephones, satellite networks, ... Figure 7.18  Propagation methods 7.24 Table 7.4  Bands 7.25 Figure 7.19  Wireless transmission waves 7.26 Figure 7.20  Omnidirectional antenna 7.27 Note Radio waves are used for multicast communications, ... Figure 7.2  Classes of transmission media 7.3 7-1 GUIDED MEDIA Guided media, which are those that provide a conduit  from one device to another, include twisted­pair cable,  coaxial cable, and fiber­optic cable

Ngày tải lên: 23/09/2020, 13:33

... reserved during the setup phase; the resources remain dedicated for the entire duration of data transfer until the teardown phase 8.7 Example 8.1 As a trivial example, let us use a circuit­switched network  ... telephones  in  a  small  area.  Communication  is  through  4­kHz  voice  channels.  We  assume that each link uses FDM to connect a maximum  of two voice channels. The bandwidth of each link is then  ... Figure 8.4  Circuit­switched network used in Example 8.1 8.9 Example 8.2 As another example, consider a circuit­switched network  that connects computers in two remote offices of a private  company.  The  offices  are  connected  using  a 

Ngày tải lên: 23/09/2020, 13:33

... Topics discussed in this section: Bandwidth Sharing CM and CMTS Data Transmission Schemes: DOCSIS 9.30 Figure 9.16  Division of coaxial cable band by CATV 9.31 Note Downstream data are modulated using the 64-QAM modulation ... theoretical downstream data rate is 30 Mbps 9.33 Note Upstream data are modulated using the QPSK modulation technique 9.34 Note The theoretical upstream data rate is 12 Mbps 9.35 Figure 9.17  Cable modem (CM) ... networks: data transfer is done by one network, signaling by another 9.7 Figure 9.4  Data transfer and signaling networks 9.8 Figure 9.5  Layers in SS7 9.9 9-2 DIAL-UP MODEMS Traditional  telephone 

Ngày tải lên: 23/09/2020, 13:33

... checksum is considered as one data item and is shown in  color). The result is 36. However, 36 cannot be expressed  in 4 bits. The extra two bits are wrapped and added with  the sum to create the wrapped sum value 6. In the figure,  ... one’s  complement  arithmetic. Figure 10.24 shows the process at the sender  and at the receiver. The sender initializes the checksum  to  0  and  adds  all  data  items  and  the  checksum  ... the sum. Otherwise, there is an error somewhere and the  data are not accepted 10.83 Example 10.19 We can make the job of the receiver easier if we send the  negative  (complement)  of  the  sum,  called  the 

Ngày tải lên: 23/09/2020, 13:33

... clear that ** a y a B a f = if α a >0; 0 otherwise. Similar arguments can be made for variables f ab and f aj . Therefore, we can rewrite [LR 4 (D)] as: \ min max(0, a a a ab aj a a A b A ... a 96.1% classication accuracy rate when only textual and structural content-based analysis are used, and 97.4% clas- sication accuracy rate when skin color-related visual content-based analysis ... resides on the addition of structural and visual content-based analysis to the classical textual content-based analysis along with several major -data mining techniques for learning and classifying....

Ngày tải lên: 01/06/2014, 01:19

... 3 Data and Signals 57 3.1 ANALOG AND DIGITAL 57 Analog and Digital Data 57 Analog and Digital Signals 58 Periodic and Nonperiodic Signals 58 3.2 PERIODIC ANALOG SIGNALS 59 Sine Wave 59 Phase 63 Wavelength ... telephone and cable TV, can be used for data transfer. McGraw-Hill Forouzan Networking Series Titles by Behrouz A. Forouzan: Data Communications and Networking TCPflP Protocol Suite LocalArea Networks Business ... issues: data communications, networks, the Internet, and protocols and standards. First we give a broad definition of data communications. Then we define networks as a highway on which data can travel....

Ngày tải lên: 28/02/2014, 17:08

... < ;data: DataGrid x:Name="grdData" Margin="15" AutoGenerateColumns="False"> < ;data: DataGrid.Columns> < ;data: DataGridTemplateColumn Header="Hand"> ... database at all times. It can create a connection to the database, maintain state with the database, and remain connected. On the other hand, a web application is what is known as a pseudo-conversational ... < /data: DataGrid.Columns> < /data: DataGrid> 11. Save the MainPage.xaml file and navigate to the code behind for the application, located in the MainPage.xaml.cs file. Wire up the Loaded...

Ngày tải lên: 05/10/2013, 03:20

... Special Considerations Pedro Pablo Garc a Lázaro 1 , Gladys Patricia Cannata Arriola 2 , Gloria Soledad Cotrina Romero 3 and Pedro Arauco Nava 3 1 Hospital Nacional Almanzor Aguinaga Asenjo, ... Patients 73 Galilah F. Zaher and Mohamed A. Abdelaal Chapter 5 Thrombosis Associated with Immunomodulatory Agents in Multiple Myeloma 115 Jose Ramon Gonzalez-Porras and Mar a- Victoria Mateos ... Disease – Special Considerations 37 Pedro Pablo Garc a Lázaro, Gladys Patricia Cannata Arriola, Gloria Soledad Cotrina Romero and Pedro Arauco Nava Chapter 4 Venous Thromboembolism in Cancer...

Ngày tải lên: 19/02/2014, 23:20

... run away from an unpleasant reality, maybe back into compulsive spending and debting and away from program, take a breath and instead, run headlong toward recovery. Do your 4th step. Take direction ... courageous manner and facing the inevitable pain of life instead of the taking the path of addiction and avoidance. Step 5. Admitted to God, to ourselves, and to another human being the exact nature ... is at least one 15 minute call TO a sponsor and a 15 minute call FROM each sponsee. So we are now talking about at least half an hour if a sponsor has only one sponsee (and most have more than...

Ngày tải lên: 21/02/2014, 14:20