Part 1: General Review of Signalling
a.) Explain the fundamental differences of analog and digital signalling.
Baher (2001, p. 2) states that the natural world we live in, as well as most artificial sources, produce signals which we have grown accustomed to consider mainly of the analog type. This means that the signal f (t) is defined, somehow, for all values of the continuous variable t, and its amplitude can assume any value of a continuous range. Such a signal is referred to as an analog signal. In contrast to analog signals, other signals are defined only for discrete values of t. Thus, the independent variable t assumes discrete values.
Goleniewski (2006, p. 18) pointed out that when the signal being a continuously variable along amplitude and frequency, it is recognized as analog waveform.
The digital signal is different from the analog waveform by having a series of discrete pluses which represent one and zero bits.
b.) What is the major disadvantage of analog signal? Describe.
When comes to analog signal, the main disadvantages are recognized as limited accuracy because of limited tolerances of transistors and limited flexibility for adaption.
Goleniewski (2006, p. 19) says through the transmitting of analog signalling, noise is always negletable. For example, random unwanted variation. When analog signal is copied and re-copied, or transmitted over long distances, these apparently random variations become dominant. However, in order to elimate these losses, we can use shield, good connections, and several cable types such as coaxial or twisted pair. Another limitation of analog signal is about bandwidth because they cannot support high-speed data.
c.) Explain why analog signals cannot be recovered af...
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...ection, the bandwidth is used full for data transmission.
c.) Explain the relationship between the data rates of the inputs to a Time Division Multiplexing (TDM) and the data rate of the output.
We can use Public Switched Telephone Network (PSTN) as an example to explain the relationship between the data rates of the inputs and output of a TDM. Hanrahan (2005) indicates that there exists the need to transmit multiple subscribers’ calls along the same transmission medium. To meet the requirement, TDM is used because TDM allows switches to create channels within a transmission stream. If an input is a standard DS0 voice signal has a data bit rate of 64 Kbit/s, TDM takes frames of the voice signals and multiplexes them into a TDM frame which runs at a higher bandwidth. In other words, if the TDM frame consists of n voice frames, the bandwidth will be n*64 Kbit/s.
8. Computers are said to process data digitally because the data is processed in binary bits.
The pre-recorded video of the subject (measurement data) is saved NI - TDMS file format. TDMS - Technical Data Management Streaming is a file format from National Instruments to save well- documented measurement data. Data from TDMS are read frame by frame in Read Frame VI. The TDM...
There have been many new improvements in TRS in the last several years. These improvements give users choices that make TRS calls more natural and “functionally equivalent” to voice telephone communications.
Recording technology wasn’t always a digital process. Before the 1970s, all recordings depended on capturing a physical analogue sound with microphones. This was done on either tape or disk. Analogue recordings lacked the sonic integrity that the 21st century demanded; it was becoming increasingly problematic and expensive in reducing noise and distortion that plagued analogue recordings. As a result, audio researchers began to study digital conversion techniques. They discovered that digitizing an electrical audio signal consisted of sampling the audio wave thousands of times a second, measuring the peak amplitude of each sample, and then assigning one of a limited number of binary values to each.
They understand more prominent effectiveness were given when the legacy range TDMA is emphasized to the UMTS, GPRS data spaces modified to EDGE data spaces. Operational strategy: AT&T has added to a MSOC (Management System Operational Control) procedure to guarantee productive response times to client service and the requests of the system execution AT&T will move towards operational excellence as its legacy TDMA hardware, billings systems and transport base are shut down. The clients at present on this system are for the most part organizations that will move up to the more proficient information solutions of EDGE or HSPDA. Therefore this pattern supports in developing in data ARPU. People
This book is a classic: everybody knows it, and everything has been written about it. Let me write some more. Postman's book caused a lot of public discussion in the mid-eighties, but it is now as relevant as ever, possibly more so. Today, it has almost become an axiom of our society that the answer to the questions raised by our technological advances lie in the application of further technology, some of it undeveloped and possibly speculative as of now. In the field of media, this has led to the hypothesis that the messages we want to communicate, and the media we choose to communicate them, are largely orthogonal issues, which is why we can analyze and quantify media, talk about the 'bandwidth' (in bits/second) of, say, a computer animation, or television viewing, or reading a book. Does it not make sense, then, to pick the medium with the highest bandwidth, and to develop media with better bandwidth, shorter access time etc.?
Detection of weak stimulus e.g. Faint sounds can't be explained on the basis of laws of thresholds.This thing lead the signal detection theory to develop.
as Hertz (Hz). The sounds of speech are in the range of 250 Hz to 4000
Digital signals convert regular signals into strings of ones and zeros, which is much more efficient than analog signals. Broadcasters can maximize their use of channel space because digital signals carry significantly more information than analog signals. Several digital programs and services can be sent in the space occupied by a single analog channel. The result of this is that the consumer is provided with more channel choices(FCC).
The difference between wave (sinusoids) and wavelet is shown in figure 3.1. Waves are smooth, predictable and everlasting, whereas wavelets are of limited duration, irregular and may be asymmetric. Waves are used as deterministic basis functions in Fourier analysis for the expansion of functions (signals), which are time-invariant, or stationary. The important characteristic of wavelets is that they can serve as deterministic or non-deterministic basis for generation and analysis of the most natural signals to provide better time-frequency representation, which is not possible with waves using conventional Fourier analysis.
b) It is not fully reliable as internet glitches of signals can hinder communication effectively.
Making a telephone call no longer should conjure up visions of operators connecting cables by hand or even of electrical signals causing relays to click into place and effect connections during dialing. The telephone system now is just a multilevel computer network with software switches in the network nodes to route calls get through much more quickly and reliably than they did in the past. A disadvantage is the potential for dramatic and widespread failures; for as has happened.
The information can be expressed through words, numbers, sounds, and images. By better understanding digital technology, we improve our control over such information.