Chapter 4 Transmission of Digital Data / Media & Service BY Dr.Sukchatri Prasomsuk

Contents : 4.1 Digital Data Transmission 4.2 DTE-DCE Interface 4.3 Modems 4.4 Type of Transmission Media 2/63

4.1 Digital Data Transmission Communication Mode : 3/63

4.1 Digital Data Transmission Data Transmission 4/63 Data Transmission Parallel Serial SynchronousAsynchronous

4.1 Digital Data Transmission Parallel vs Serial line 5/63

4.1 Digital Data Transmission Parallel Transmission : Transmission in which bits in a group are sent simultaneously, each using a separate link. 6/63 Sender ; Computer LPT1, LPT2, LPT3, etc. Receiver ; Printer, Plotter, Circuit, etc, 8 bits

4.1 Digital Data Transmission Serial Transmission : Transmission of data one bit at a time using only one single link. 7/63 Sender (RS232) Receiver (RS232) Parallel/Serial Converter bits are sent

4.1 Digital Data Transmission Asynchronous Transmission : Transfer of data with start and stop bit(s) and a variable time interval between data units. We send one start bit (0) at the beginning and one or more stop bits (1s) at the end of each byte. There may be a gap between each byte. Asynchronous here means “asynchronous at the byte level” but the bits are still synchronized; their durations are the same. 8/63

4.1 Digital Data Transmission Asynchronous Transmission : Clock independent 9/63 Sender Receiver Start bitStop bit Gaps Data Direction of flow

4.1 Digital Data Transmission Asynchronous Transmission : 10/63

4.1 Digital Data Transmission Synchronous Transmission : A transmission method that requires a constant timing relationship between the sender and the receiver. We send bits one after another without start/stop bits or gaps. It is the responsibility of the receiver to group the bits. 11/63

4.1 Digital Data Transmission Synchronous Transmission : Clock dependent 12/63 Sender Receiver Data Direction of flow

4.1 Digital Data Transmission Bit Oriented synchronization : 13/63

4.1 Digital Data Transmission Character Oriented synchronization : BiSync 14/63

4.2 DTE-DCE Interface Data Terminal Equipment (DTE) : A device that is an information source or an information sink. It is connected to a network through a DCE. Data Circuit-Terminal Equipment (DCE) : A device used as an interface between a DTE and a network. 15/63

4.2 DTE-DCE Interface Data Terminal Equipment (DTE) : is any device that is a source of or destination for binary digital data. Data Circuit-Terminal Equipment (DCE) : is any device that transmits or receives data in the from of an analog or digital signal through a network. Interface : the electrical specification of EIA-232 defines that signals other than data must be sent using OFF -> lessthan -3 Volts and ON -> greater than +3 Volts 16/63

4.2 DTE-DCE Interface 17/63 DTE DCE DTE DCE Interface; ~ 15 m. EIA-232, EIA-442, EIA-449 Interface EIA-232, EIA-442, EIA-449

Data Terminal Equipment End of the user’s device on the WAN link Data Communications Equipment End of the WAN provider’s side of the communication facility DCE is responsible for clocking DCE DTE Modem CSU/DSU DTE DCE 4.2 DTE-DCE Interface Serial Implementation of DTE vs DCE Internet

19/63 CSU/ DSU End user device Service Provider DTE DCE 4.2 DTE-DCE Interface 4.2 DTE-DCE Interface Serial Point-to-Point Connections

20/ DTE-DCE Interface 4.2 DTE-DCE Interface Fixed Interfaces Router—rear view Serial WAN ports can be fixed

4.2 DTE-DCE Interface Modular Interfaces 21/63 Console Router—rear view Ethernet AUIEthernet 10BaseTISDN BRI S/T Serial WAN ports can be modular Module WAN Interface Card

4.3 Modems Modem stands for MOdulator/DEModulator. Modem is a communication device that converts binary signal into analog acoustics signal for transmission over telephone lines and converts these acoustics signals back into binary form at the receiving end. A Modulator converts a digital signal into an analog signal using ASK, FSK, PSK or QAM. (Digital-to-Analog) A Demodulator converts an analog signal into a digital signal. (Analog-to-Digital) 22/63

4.3 Modems 23/63

4.3 Modems Modem Type :Modem Type : 1. Asynchronous : for Low speed communication 2. Synchronous : for High speed communication 3. Half-Duplex : must alternately send and received signals. 4. Full-Duplex : can simultaneously handle two signals using two carriers to transmit and receive data. 24/63

4.3 Modems Signal Constellation 25/63

4.3 Modems Constellation Samples : 26/63

4.3 Modems Some Standard : V29: -Transmission rate up to 9600 bps V.32bis : -2-dimensional TCM with 128 points -Transmission rate up to 14,400 bps V.32ter : -2-dimensional TCM with 512 points -Transmission rate up to 19,200 bps V.34 : -2-dimensional TCM with 768 points -Transmission rate up to 28,800 bps 27/63

4.3 Modems Error Correcting : LAPD (Link Access Protocol D) : based on HDLC synchronous protocol. MNP (Microcom Networking Protocol) : trademark of Microcom TCM : modulation with error detecting code V.42 : CRC error correcting standard 28/63

4.3 Modems Fallback : 29/63

4.3 Modems Intelligent Modems : contain software to support a number of additional functions, such automatic answering and dialing. The AT command format is : AT command [parameter] command [parameter] command [parameter]... 30/63

4.3 Modems Hayes Commands set : 31/63

4.3 Modems Hayes Response Code : 32/63

4.4 Type of Transmission Media Transmission media can be divided into two broad categories: 33/63 Transmission Media Guided UnGuided Twisted-pair cable Coaxial cable F/O cable MicrowaveSatelliteCellular - Radio wave (Wireless)

4.4 Type of Transmission Media Twisted-pair cable: UTP (100 Hz - 5 MHz) 34/63

4.4 Type of Transmission Media Twisted-pair cable : STP (100 Hz - 5 MHz) 35/63

4.4 Type of Transmission Media UTP CategoryUTP Category (CAT): Category 1 : for telephone systems, low speed. Category 2 : for voice and data transmission of up to 4 Mbps. Category 3 : transmission of up to 10 Mbps. (Standard cable for telephone system) Category 4 : transmission of up to 16 Mbps. Category 5 : transmission of up to 100 Mbps. Category 6 : transmission of up to 250 Mbps. 36/63

Differentiating between Connections 37/63 AUI connectors are DB15 ISO 8877 (RJ-45) connectors and jacks are slightly larger than RJ-11 phone connectors and jacks Fiber Connector Port

UTP Device 38/63 The RJ-45 Connector 1 8 8Pair 4 R Wire Pair T is Tip R is Ring Pair 2 T2 Pair 2 R2 Pair 3 T3 Pair 1 R1 Pair 1 T1 Pair 3 R3 Pair 4 T4 Pin

UTP Implementation Straight- through 39/63 Wires on cable ends are in same order Pin Label 1RD+ 2RD- 3TD+ 4NC 5NC 6TD- 7NC 8NC Cable 10BaseT/ 100BaseT Straight-through Pin Label 1TD+ 2TD- 3RD+ 4NC 5NC 6RD- 7NC 8NC Server/Router Straight-through Cable 8 1 Hub/Switch 8 1 o

UTP Implementation Crossover 40/63 Some wires on cable ends are crossed 8 1 og Cable 10BaseT/ 100BaseT Crossover Pin Label 1RD+ 2RD- 3TD+ 4NC 5NC 6TD- 7NC 8NC Pin Label 1RD+ 2RD- 3TD+ 4NC 5NC 6TD- 7NC 8NC Crossover Cable br Hub/Switch

4.4 Type of Transmission Media Coaxial Cable : (100 KHz MHz) RG-8, RG-9, RG-11 used in thick Ethernet, Radio RG-58 used in thick Ethernet, Radio Transmitter RG-59 used for TV 41/63

4.4 Type of Transmission Media Fiber Optic Cable : Typical 42/63

4.4 Type of Transmission Media Fiber Optic Cable : Cable Structures 43/63

4.4 Type of Transmission Media Fiber Optic Cable : Optical Comparison 44/63

4.4 Type of Transmission Media Fiber Optic Cable : Light Source 45/63

4.4 Type of Transmission Media Fiber Optic Cable : Transmission Mode 46/63

4.4 Type of Transmission Media Telephone system : 47/63

4.4 Type of Transmission Media Intra-Office cable : 48/63

49/63 Comparing Ethernet Media Requirements 10Base5 100BaseTX 10BaseT 100BaseFX Media Maximum Segment Length Topology Connector 50-ohm coax (thick) 500 meters Bus 100 meters Star Point-to-Point EIA/TIA Cat 3, 4, 5 UTP 2 pair EIA/TIA Cat 5 UTP 2 pair 62.5/125 micron multi- modeF/O AUI ISO 8877 (RJ-45) Duplex media- interface connector (MIC) ST ISO 8877 (RJ-45) 400 meters100 meters

4.4 Type of Transmission Media UnGuided Media :UnGuided Media : Unguided media or wireless communication, transport electromagnetic waves without using a physical conductor. Instead, signals are broadcast through air. VLF : Very low frequency (3KHz-30KHz)--Suface LF : Low frequency (30KHz-300KHz)--Suface MF : Middle frequency (300KHz-3MHz)--Tropospheric HF : High frequency (3MHz-30MHz) --Ionospheric VHF:Very high frequency (30MHz-300MHz)-Space & line of sight UHF : Ultra high frequency (300MHz-3GHz) --Space SHF : Super high frequency (3GHz-30GHz) --Space EHF : Extremely high frequency (30GHz-300GHz) --Space 50/63

4.4 Type of Transmission Media Wireless Communication : 51/63

4.4 Type of Transmission Media UnGuided Media : MicrowaveUnGuided Media : Microwave 52/63

4.4 Type of Transmission Media Diagram of a microwave repeater 53/63

4.4 Type of Transmission Media  Typical repeaters required of a 20 GHz System 54/63

4.4 Type of Transmission Media UnGuided Media : SatelliteUnGuided Media : Satellite 55/63

4.4 Type of Transmission Media UnGuided MediaUnGuided Media : Satellite Band  C-Band : 4-6 GHz ; GHz Uplink, HGz Downlink  X-Band : 7-8 GHz  Ku-Band : GHz ; GHz Uplink, GHz Downlink  K-Band: GHz  Ka-Band: GHz 56/63

4.4 Type of Transmission Media UnGuided MediaUnGuided Media : Geostationary Satellite 57/63

4.4 Type of Transmission Media UnGuided Media :UnGuided Media : Cellular Telephony 58/63

4.4 Type of Transmission Media UnGuided Media :UnGuided Media : Frequency band 900 MHz 59/63

4.4 Type of Transmission Media Comparison of Media :Comparison of Media : 60/63

4.4 Type of Transmission Media Ex.Ex. VSAT design for bank system 61/63

4.4 Type of Transmission Media Factor to select media :Factor to select media : Cost Data rate and Bandwidth Distance 62/63

Q/A Thank you 63/63