Multiplexing and Data Rate Essay Example

Multiplexing and Data Rate Essay Multiplexing CHAPTER 4 Outline * Frequency Division Multiplexing(FDM) * Synchronous Time Division Multiplexing * Statistical Time Division Multiplexing * Asymmetric Digital Subscriber Line(ADSL) Multiplexing * Set of methods that permits the concurrent transmission of different signs over a solitary connection * permits a few transmission sources to share a bigger transmission limit Link = physical way Channel = segment of a connection that conveys a transmission between a given sets of lines 2 CATEGORY OF MULTIPLEXING WDM FDM TDM ADSL Frequency Division Multiplexing * FDM †various signs are joined for ransmission on a solitary correspondences line or channel. Each sign is doled out an alternate recurrence (subchannel) inside the primary channel. * Useful data transmission of medium surpasses required transfer speed of channel * e. g. communicate radio and digital TV * Channel apportioned regardless of whether no information Frequency Division Multiplexing Diagram * Each sign is adjusted to an alternate bearer recurrence * Carrier frequencies isolated by monitor groups (unused transfer speed) †to forestall obstruction so flags don't cover. 3 FDM System FDM is a simple multiplexing method that consolidates signals. FDM process FDM Demultiplexing Example 1 Assume that a voice channel involves a transmission capacity of 4 KHz. We have to join three voice channels into a connection with a data transfer capacity of 12 KHz, from 20 to 32 KHz. Show the arrangement utilizing the recurrence space without the utilization of watchman groups. Arrangement Shift (tweak) every one of the three voice channels to an alternate data transmission, as appeared in next figure Example 2 Five channels, each with a 100-KHz transfer speed, are to be multiplexed together. What is the base data transmission of the connection if there is a requirement for a watchman band of 10 KHz between the channels to forestall obstruction? Arrangement We will compose a custom exposition test on Multiplexing and Data Rate explicitly for you for just $16.38 $13.9/page Request now We will compose a custom exposition test on Multiplexing and Data Rate explicitly for you FOR ONLY $16.38 $13.9/page Recruit Writer We will compose a custom exposition test on Multiplexing and Data Rate explicitly for you FOR ONLY $16.38 $13.9/page Recruit Writer For five channels, we need at any rate four gatekeeper groups. This implies the necessary transmission capacity is at any rate 5 x 100 + 4 x 10 = 540 KHz, as appeared in next Figure. Model 3 Four information stations (computerized), each transmitting at 1 Mbps, utilize a satellite station of 1 MHz. Structure a suitable arrangement utilizing FDM Solution The satellite station is simple. We isolate it into four channels, each channel having a 250-KHz transmission capacity. Each computerized channel of 1 Mbps is adjusted with the end goal that every 4 bits are regulated to 1 Hz. One arrangement is 16-QAM regulation. Figure 6. 8 gives one potential arrangement. Simple Carrier Systems ATT (USA) * Hierarchy of FDM plans * Group 1. 12 voice channels (4kHz each) = 48kHz 2. Range 60kHz to 108kHz * Supergroup 1. 60 channel 2. FDM of 5 gathering signals on transporters somewhere in the range of 420kHz and 612 kHz * Mastergroup 1. 10 supergroups Analog Hierarchy To boost the effectiveness founda tion, multiplexed signals from lower transmission capacity lines onto higher-transfer speed signals FDM of Three Voiceband Signals FDM Applications 1. Regular utilized radio telecom AM and FM * AM (530 †1700KHz) †imparted to every single radio broadcast * FM utilizes a more extensive band (88 †108MHz) †each station needs more transmission capacity, 200KHz 2. TV Broadcasting * Each TV channel has own data transfer capacity of 6 Mhz 3. first Generation of Cellular phones * Voice signal 3KHz (300 †3300Hz) channels * Bt = 10 x Bm , in this manner each channel has 30KHz channels * every client has been distributed two 30KHz channel, along these lines 60KHz. Model 4 The Advanced Mobile Phone System (AMPS) utilizes two groups. The principal band, 824 to 849 MHz, is utilized for sending; and 869 to 894 MHz is utilized for getting. Every client has a data transmission of 30 KHz toward every path. The 3-KHz voice is adjusted utilizing FM, making 30 KHz of regulated sign. What number of individuals can utilize their ellular telephones all the while? Arrangement Each band is 25 MHz. In the event that we separate 25 MHz into 30 KHz, we get 833. 33. As a general rule, the band is isolated into 832 channels. Frequency Division Multiplexing * Multiple light emissions at various recurrence * Carried by optical fiber * A type of FDM (same idea) * Eac h shade of light (frequency) conveys separate information channel * 1997 Bell Labs * 100 bars * Each at 10 Gbps * Giving 1 terabit for each second (Tbps) * Commercial frameworks of 160 channels of 10 Gbps now accessible * Lab frameworks (Alcatel) 256 channels at 39. 8 Gbps each * 10. 1 Tbps * Over 100km WDM Operation Same general engineering as other FDM * Number of sources creating laser pillars at various frequencies * Multiplexer merges hotspots for transmission over single fiber * Optical enhancers intensify all frequencies * Typically many km separated * Demux isolates channels at the goal * Mostly 1550nm frequency run * Was 200MHz per channel * Now 50GHz Dense Wavelength Division Multiplexing * DWDM * No official or standard definition * Implies more channels all the more firmly divided that WDM * 200GHz or less TDM advanced procedure that permits a few associations with share the high transfer speed of a connection ach association involves a part of time in the connection TDM is a computerized multiplexing method to join information. TDM : Time Slots and Frames In a TDM, the information pace of the connection is n times quicker, and the unit span is n times shorter. Time Division Multiplexing Example 5 Four 1-Kbps associations are multiplexed together. A unit is 1 piece. Find : (1) the term of 1 piece before multiplexing, (2) the transmission pace of the connection, (3) the length of a schedule opening, and (4) the span of an edge? Arrangement We can address the inquiries as follows: 1. The term of 1 piece is 1/1 Kbps, or 0. 001 s (1 ms). 2. The pace of the connection is 4 Kbps. 3. The term of each schedule opening 1/4 ms or 250 ms. 4. The term of an edge 1 ms. Interleaving †¢ switches are synchronized and turn at a similar speed however inverse bearing †¢process of sending a unit information onto the way when the association on the multiplexing and de-multiplexing is open Example 6 Four channels are multiplexed utilizing TDM. In the event that each channel sends 100 bytes/s and we multiplex 1 byte for every channel, show the casing going on the connection, the size of the edge, the term of a casing, the edge rate, and the bit rate for the connection. Arrangement The multiplexer is appeared in Figure 6 Model 7 A multiplexer joins four 100-Kbps channels utilizing a time allotment of 2 bits. Show the yield with four self-assertive data sources. What is the edge rate? What is the casing term? What is the bit rate? What is the bit term? Arrangement Figure 7 shows the yield for four subjective sources of info. Coordinated Time Division Multiplexing * Possible when information pace of medium surpasses information pace of advanced sign to be transmitted * Multiple computerized signals interleaved of each sign in time during transmission * Interleaving can be at bit level of squares * Time spaces preassigned to sources and fixed Time openings assigned regardless of whether no information * Time spaces don't need to be equally conveyed among sources Synchronous TDM System TDM Link Control * No headers and trailers * Data interface control conventions not required * Flow control * Data pace of multiplexed line is fixed * If one channel beneficiary can not get information, the * others must c arry on * The comparing source must be extinguished * This leaves void spaces * Error control Errors are recognized and taken care of by singular channel frameworks Data Link Control on TDM Framing †¢Time space length = transmitter cradle length †¢Each outline contains a pattern of time allotment Framing bits follow an example to guarantee approaching stream synchronized with demux to isolate time allotments precisely * No banner or SYNC characters organizing TDM casings to deal with the general TDM connect * Must give synchronizing component * Added digit confining * One control bit added to each TDM outline * Looks like another channel â€Å"control channel† * Identifiable piece design utilized on control channel * e. g. substituting bit design 01010101†¦unlikely to be supported on an information channel * Can look at approaching piece designs on each * channel with sync design * If design not coordinate, progressive piece position re search until persevere o ver various edge * When build up, recipient keep checking the encircling piece channel * If the example break, the collector should again enter a confining inquiry mode Example 8 We have four sources, each making 250 characters for every second. On the off chance that the interleaved unit is a character and 1 synchronizing bit is added to each edge, discover (1) the information pace of each source, (2) the length of each character in each source, (3) the edge rate, (4) the span of each edge, (5) the quantity of bits in each casing, and (6) the information pace of the connection. Arrangement Answer as follows: 1. The information pace of each source is 250 x 8 = 2000 bps = 2 Kbps. 2. The term of a character is 1/250 s = 4 ms. 3. The connection needs to send 250 casings for every second. 4. The length of each edge is 1/250 = 4 ms. 5. Each edge is 4 x 8 + 1 = 33 bits. 6. The information pace of the connection is 250 x 33 = 8250 bps. Model 9 Two channels, one with a piece pace of 100 Kbps and another with a piece pace of 200 Kbps, are to be multiplexed. How this can be accomplished? What is the edge rate? What is the casing term? What is the bit pace of the connection? Arrangement We can distribute one space to the primary channel and two openings to the subsequent channel. Each edge conveys 3 bits. The casing rate is 100,000 edges for each second since it conveys 1 piece from the main channel. The casing term is 1/100,000 = 10 ms. The bit rate is 100,000 edges/s x 3 bits/outline = 300 Kbps. Heartbeat Stuffing * Problem Synchronizing different information sources * Each source has separate clock, variety among clock cause misfortune