Computer Networks Assignment-MAH021214_22532_45222


Computer Networks










Question 1: 3

Part A.. 3

Part B.. 4

Part C.. 5

Part D.. 5

Part E.. 6

Part F. 6

Part G.. 6

Part H.. 7

Question 2. 7

Question 3. 8

Question 4. 9

Question 5. 10

Question 6. 10

References. 12

Question 1:

Part A

Robotic Controls:  Mechanical technology was commanded at an early stage by the machine apparatus industry. In that capacity, the early theory in the outline of robots was to plan systems to be as hardened as could be expected under the circumstances with every hub (joint) controlled freely as a single-input/single-output (SISO) direct framework. Point-to-point control empowered basic undertakings, for example, materials exchange and spot welding. Nonstop way following empowered more complex errands, for example, circular segment welding and shower painting. Sensing of the outside environment was constrained on the other hand nonexistent. Robot control is the study of controlling robots (Mansfield & Antonakos, 2002). The most widely recognized sort of robot disappointment is not mechanical or electronic disappointment yet rather disappointment of the product that controls the robot. Case in point, if a robot were to run into a divider, and its front touch sensor did not trigger, the robot would get to be stuck (unless the robot is a tank), attempting to drive through the divider. This robot is not physically stuck, however it is “rationally stuck”: its control program does not represent this circumstance and does not give a path to the robot to get free. Numerous robots fall flat thusly. This part will examine a portion of the issues ordinarily experienced when utilizing robot sensors, and present a skeleton for contemplating control that may help in avoiding control disappointment of ELEC 201 robots. There are three types of control method mentioned below.

Feedback Control: In input control, the variable being controlled is measured and contrasted and a target esteem. This contrast between the real and wanted quality is known as the mistake. Criticism control controls info to the framework to minimize this blunder.

Feed Forward Control: Feed forward control portraying a component or pathway inside a control framework which passes a controlling sign from a source in its outside surroundings, frequently an order signal from an outer administrator, to a heap somewhere else in its outer surroundings (Li & Chen, 2012). A control framework which has just bolster forward conduct reacts to its control motion in a predefined manner without reacting to how the heap responds; it is interestingly with a framework that likewise has criticism, which conforms the yield to make note of how it influences the heap, and how the heap itself may fluctuate eccentrically; the heap is considered to fit in with the outside environment of the framework or system.

Open Loop: An open-circle/ loop controller is frequently utilized as a part of basic methodologies due to its effortlessness and ease, particularly in frameworks where input is not discriminating. A common case would be an ordinary clothes washer, for which the length of machine wash time is totally reliant on the judgment and estimation of the human administrator. By and large, to acquire a more precise or more versatile control, it is important to sustain the yield of the framework once again to the inputs of the controller. This sort of framework is known as a shut circle framework or system.

Part B

Asynchronous Transfer Mode (ATM) is, as per the ATM Discussion, “an information transfer’s idea characterized by ANSI and ITU (previously CCITT) principles for carriage of a complete scope of client movement, including voice, information, and feature signals”. ATM was created to address the needs of the Broadband Coordinated Administrations Advanced System, as characterized in the late 1980s and intended to bring together telecom and machine systems (Bates, 2000). It was intended for a system that must handle both conventional high-throughput information activity (e.g., document exchanges), and continuous, low-idleness substance, for example, voice and feature.  Asynchronous Transfer Mode (ATM) is a high velocity organizing/network standard intended to help both voice and information correspondences. Asynchronous Transfer Mode (ATM) is ordinarily used by Web access suppliers on their private long-separation systems. Asynchronous Transfer Mode (ATM) works at the information connection (Layer 2 in the OSI model) over either fiber or contorted pair link.

Asynchronous Transfer Mode (ATM) varies from more basic information join advances like Ethernet in a few ways. For instance, Asynchronous Transfer Mode (ATM) uses no steering. Equipment gadgets known as Asynchronous Transfer Mode (ATM) switches make point-to-point associations in the middle of endpoints and information streams specifically from source to terminus. Moreover, as opposed to utilizing variable-length bundles as Ethernet does, Asynchronous Transfer Mode (ATM) uses settled measured cells (Jacobs & Posluns, 2003). Asynchronous Transfer Mode (ATM) cells are 53 bytes long that incorporates 48 bytes of information and five (5) bytes of header data. Short for Asynchronous Transfer Mode (ATM) is a system innovation focused around moving information in cells or bundles of an altered size. The cell utilized with ATM is moderately little contrasted with units utilized with more seasoned advances. The little, steady cell size permits ATM gear to transmit feature, sound, and machine information over the same system, and guarantee that no single sort of information hoards the line. Some individuals surmise that ATM holds the response to the Web data transfer capacity issue, yet others are suspicious. ATM makes an altered channel, or course, between two focuses at whatever point information exchange starts. This varies from TCP/IP, in which messages are partitioned into parcels and every parcel can take an alternate course from source to goal. This distinction makes it less demanding to track and bill information use over an ATM system, however it makes it less versatile to sudden surges in system activity. At the point when obtaining ATM administration, you for the most part have a decision of four separate sorts of administration.

Part C

A cyclic redundancy check (CRC) is a blunder locating code usually utilized as a part of computerized systems and capacity gadgets to identify unintentional changes to crude information. Pieces of information entering these frameworks get a short check worth appended, in light of the rest of a polynomial division of their substance; on recovery the computation is rehashed, and restorative move can be made against assumed information debasement if the check qualities don’t match (Paret, 2012). CRCs are supposed in light of the fact that the check (information confirmation) worth is an excess (it grows the message without including data) and the calculation is focused around cyclic codes. CRCs are well known on the grounds that they are easy to execute in twofold fittings, simple to examine numerically, and especially great at recognizing basic blunders brought about by commotion in transmission channels. Since the check esteem has an altered length, the capacity that produces it is incidentally utilized as an issue capacity. The CRC was concocted by W. Wesley Peterson in 1961; the 32-bit CRC capacity of Ethernet and numerous different guidelines is the work of a few scientists and was distributed in 1975.

Part D

FDDI (Fiber Distributed Data Interface) is a situated of ANSI and ISO norms for information transmission on fiber optic lines in a local area network (LAN) that can stretch out in reach up to 200 km (124 miles). The FDDI convention is focused around the token ring convention. Notwithstanding being expansive topographically, a FDDI neighborhood can help a large number of clients (Shinder, 2001). FDDI is much of the time utilized on the spine for a wide zone system (WAN). FDDI (Fiber Distributed Data Interface) is a situated of ANSI and ISO norms for information transmission on fiber optic lines in a neighborhood (LAN) that can stretch out in extent up to 200 km (124 miles). The FDDI convention is focused around the token ring convention. Notwithstanding being substantial topographically, a FDDI neighborhood can help a great many clients. FDDI is much of the time utilized on the spine for a wide area network (WAN).

Part E

A CSU/DSU CSU/DSU (Channel Service Unit/Data Service Unit) is an equipment gadget about the measure of an outside modem that changes over a computerized information outline from the interchanges innovation utilized on a local area network (LAN) into a casing fitting to a wide area network (WAN) and the other way around. A CSU/DSU CSU/DSU (Channel Service Unit/Data Service Unit)  is a fittings gadget about the measure of an outer modem that changes over an advanced information outline from the correspondences engineering utilized on a local area network (LAN) into a casing suitable to a wide area network (WAN) and the other way around (Saltzer & Kaashoek, 2009). Case in point, on the off chance that you have a Web business from your home and have rented an advanced line (maybe a T-1 or partial T-1 line) to a telephone organization or a door at a Web access supplier, you have a CSU/DSU (Channel Service Unit/Data Service Unit) at your end and the telephone organization or entryway host has a CSU/DSU at its end.

Part F

Short for Appeal for Remarks, an arrangement of notes about the Web, began in 1969 (when the Web was the ARPANET). A Web Record can be submitted to the IETF by anybody, yet the IETF chooses if the archive turns into a RFC (Minoli, 2005). In the long run, in the event that it picks up enough investment, it may advance into a Web standard. Every RFC is assigned by a RFC number. Once distributed, a RFC never shows signs of change. Alterations to a unique RFC are allotted another RFC number.

Part G

Multiplexing is sending numerous flags or streams of data on a transporter in the meantime as a solitary, complex sign and after that recouping the different signs at the less than desirable end. Multiplexing is sending numerous flags or streams of data on a bearer in the meantime as a solitary, complex sign and afterward recouping the different signs at the less than desirable end (Mansfield & Antonakos, 2002). In simple transmission, signs are normally multiplexed utilizing frequency-division multiplexing (FDM) in which the transporter data transfer capacity is separated into sub channels of distinctive recurrence widths, each one convey a sign in the meantime in parallel. In computerized transmission, signs are regularly multiplexed utilizing time-division multiplexing (TDM), in which the various signs are persisted the same direct in substituting time openings. In some optical fiber systems, numerous signs are conveyed together as particular wavelengths of light in a multiplexed sign utilizing thick wavelength division multiplexing (DWDM).

Part H

Metro Ethernet is the utilization of Transporter Ethernet innovation in metropolitan area network (Mans). Since it is ordinarily a gathering try with various monetary patrons, Metro Ethernet offers cost-viability, unwavering quality, adaptability and transmission capacity administration better than most restrictive systems. Metro Ethernet can associate business local area netwrok (LANs) and individual end clients to a wide area network (WAN) or to the Web. Companies, scholastic organizations and government offices in substantial urban communities can utilize Metro Ethernet to unite extension yards or work places to an intranet. An ordinary Metro Ethernet framework has a star system or cross section system topology with individual switches or servers interconnected through link or fiber optic media (Du, 2013). “Immaculate” Ethernet engineering in the MAN environment is generally economical contrasted and Synchronous Digital Hierarchy (SDH) or Multiprotocol Label Switching (MPLS) frameworks or systems  of a like transmission capacity. Notwithstanding, the recent advances can be connected to Metro Ethernet in urban regions eager to dedicate the essential monetary assets to the assignment.

Question 2

Initially, E-NRZ gives a most extreme move rate that lessens dc part. Second, under most detrimental possibility, E-NZR gives at least one move for each 14 bits, lessening the synchronization issue. Third, the equality bit gives a mistake check. The inconveniences of E-NZR are included unpredictability and the overhead of the additional equality bit.

In Nonreturn to Zero level (NRZ-l) encoding technique bit esteem 1 is spoken to by zero voltage and bit esteem 0 is spoken to by positive voltage. This is straightforward and monetary system to execute however there are a few issues of this sort of encoding which can be highlighted as takes after:-

  • At the point when there is long example of 0s in information it will deliver a flag that never shows signs of change which is known as dc part.
  • There is synchronization issue when the voltage level doesn’t change for long because of long 0s or 1s example. Gadgets having diverse clock rates can’t impart.
  • There is no instrument to check the accuracy of the information got.

Improving this encoding to enhanced NRZ (E-NRZ) by dividing information stream into 7 bit words; transforming bits 2, 3, 6, and 7; and including one odd equality bit will make taking after favorable circumstances over the issues of NRZ-L recorded underneath:-

Upsetting the chose bits will make a base move rate which helps decreasing the dc part.

  • Presenting odd equality most pessimistic scenario move is each 14 bits. This improvement decreases the synchronization issue.
  • Equality bit is helpful for blunder recognition. For this situation wherever the equality bit is 1 the framework will acknowledge the information if aggregate number of 1s is odd and wherever the equality bit is 0 the framework will acknowledge the information if aggregate number of 1s is even or zero.
  • There is disservice of E-NRZ in the execution stage on the grounds that it presents intricacy and overhead of additional equality bit.

Question 3

There are seven requested layers in OSI model. Albeit physical layer of sender have physical association with the physical layer of beneficiary this model is considered as sensibly having shared association with the comparing coherent layers as indicated in figure 1. At the point when sender begins sending procedure from Application layer, most importantly information is sent to its own particular lower layer. Getting information from above layer own data is likewise added to the message and passes the consolidated bundle to the layer just beneath it. At last the entire bundle is sent to collector end through physical layer. At the less than desirable end the bundle is perused layer by layer. Here each one layer gets and uproots the data implied for it and the remaining bundle is sent to the upper layer.

Layer 7 Application ———————— Layer 7 Application
Layer 6 Presentation ———————— Layer 6 Presentation
Layer 5 Session ———————— Layer 5 Session
Layer 4 Transport ———————— Layer 4 Transport
Layer 3 Network ———————— Layer 3 Network
Layer 2 Data link ———————— Layer 2 Data link
Layer 1 Physical _______________ Layer 1 Physical
Sender Dotted lines : Logical Connection

Solid lines : Physical connection


Figure 1 OSI Model sender and beneficiary/ receiver

In the situation inquired as to whether we consider President as a physical layer, lawful group as the higher layer and the quantity of center directors more higher layer; the physical correspondence continue through the physical layer (Chief) simply because the data is not sent through legitimate group and center administrators. Thusly this situation do _not_ take after the OSI model.

Question 4

SNRdB = 3 = 10logSNR, SNR = 100.3 = 1.995

C = B*log2(1+SNR)= 474.76 bit/s

Question 5

Accepting that each one sign is running at the same rate, each one specimen is changed over into a 8 bit esteem. The quantity of examples = 2^8 = 256 Synchronous time division takes a byte from sign for preparing (Jacobs & Posluns, 2003). Twenty voice signs transmitted over a curved pair at an 8 bit quality would be spoken to thusly. 202562=10240 bps .The data transfer capacity needed is 10240 bps which can be obliged with a Cat1 line.

Question 6

Z-Band’s RF broadband dissemination frameworks or shystem emphasize the most recent in feature over curved pair link engineering. Z-Band frameworks commonly incorporate one bit of organized UTP Feline 5e or CAT 6 cabling (Furnell, 2005). The link houses four sets of bent copper wires for an aggregate of eight “pins,” offering an extensive variety of feature and information transmission usefulness. The adaptability offered by circulating feature over bent pair offers a few favorable circumstances over other basic television/ cable sorts, for example, coax.

Video signal can be transmitted over wound or twisted pair wire. However there are different variables which impact the execution and nature of the signal. As per the observed data or information is delineated in figure 2 the weakening pointedly increments with frequencies over 105HZ.

Figure 2 Lessening of wound pair media

Because of this lessening even fantastic feature signals which oblige high transmission rate can be exceptionally fluffy and twisted when the link length is high. There are CAT 5, CAT5e, CAT6 and CAT7 kind of links produced where accelerate system is actualized to get the transmission rate up to or more 100 Mbps however their execution length is constrained to just 100 meters.

After every 100 meters enhancer can be utilized to increase the constricted sign. Despite the fact that this thought determines the lessening issue however including additional intensifier each certain compass is lavish. Now and again this can be unrealistic as well.


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