06-03-2012, 02:47 PM
TRANSMISSION MEDIA , ANALOG VS DIGITAL DATA TRANSMISSION
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INTRODUCTION
The transmission medium is the physical path between the transmitter and receiver in a data transmission system.
Transmission media is divided into two types: Guided(wired) or Unguided(Wireless).
Wired Media is the most common and is further divided into three different types of cabling: Coaxial, Twisted Pair, and Fiber Optic Cables
Wireless media, which is, in a sense, no media at all, is also gained popularity. Wireless transmissions use radio waves or infrared light to transmit data.
CHARACTERISTICS OF TRANSMISSION MEDIA
Each type of transmission media has special DESIGN FACTORS as follows:
COST: It is defined as the price of the materials used in constructing and designing a certain media.
INSTALLATION REQUIREMETS : Installation requirements are the factors needed to establish a system of media to be used.
BANDWIDTH: The term Bandwidth refers to the measure of the capacity of a medium to transmit data.
BAND USAGE: Band Usage is the allocation of the capacity of transmission media .
GUIDED TRANSMISSION MEDIA(CABLE)
Guided Transmission Media uses a cabling system that guides the data signals along a specific path. Guided Media is also known as Bounded Media, since the data signals are a bounded system.
Cabling technology is not limited to copper wire only. Cables can be any physical or conductive media like wires, coaxial cables or optical fiber.
TWISTED PAIR CABLE
Physical description
Two insulated copper wires arranged in regular spiral pattern.
Number of pairs are bundled together in a cable.
Twisting decreases the crosstalk interference between adjacent pairs in the cable, by using different twist length for neighbouring pairs.
Applications
Most common transmission media for both digital and analog signals.
Less expensive compared to coaxial cable or optic fibre.
Limited in terms of data rate and distance.
Telephone network
Individual units (residence lines) to local exchange (end office)
Subscriber loops
Supports voice track using analog signalling.
May handle digital data at modest rates using modems.
Allows data rate of 64 kbps.
TWISTED PAIR CABLE
Two types of twisted-pair cable are used: shielded and unshielded.
Shielded twisted pair (STP)
Shielded with a metallic braid or sheath.
Reduces interference.
Better performance at higher data rates.
More expensive and difficult to work compared to unshielded twisted pair(UTP).
[attachment=18022]
INTRODUCTION
The transmission medium is the physical path between the transmitter and receiver in a data transmission system.
Transmission media is divided into two types: Guided(wired) or Unguided(Wireless).
Wired Media is the most common and is further divided into three different types of cabling: Coaxial, Twisted Pair, and Fiber Optic Cables
Wireless media, which is, in a sense, no media at all, is also gained popularity. Wireless transmissions use radio waves or infrared light to transmit data.
CHARACTERISTICS OF TRANSMISSION MEDIA
Each type of transmission media has special DESIGN FACTORS as follows:
COST: It is defined as the price of the materials used in constructing and designing a certain media.
INSTALLATION REQUIREMETS : Installation requirements are the factors needed to establish a system of media to be used.
BANDWIDTH: The term Bandwidth refers to the measure of the capacity of a medium to transmit data.
BAND USAGE: Band Usage is the allocation of the capacity of transmission media .
GUIDED TRANSMISSION MEDIA(CABLE)
Guided Transmission Media uses a cabling system that guides the data signals along a specific path. Guided Media is also known as Bounded Media, since the data signals are a bounded system.
Cabling technology is not limited to copper wire only. Cables can be any physical or conductive media like wires, coaxial cables or optical fiber.
TWISTED PAIR CABLE
Physical description
Two insulated copper wires arranged in regular spiral pattern.
Number of pairs are bundled together in a cable.
Twisting decreases the crosstalk interference between adjacent pairs in the cable, by using different twist length for neighbouring pairs.
Applications
Most common transmission media for both digital and analog signals.
Less expensive compared to coaxial cable or optic fibre.
Limited in terms of data rate and distance.
Telephone network
Individual units (residence lines) to local exchange (end office)
Subscriber loops
Supports voice track using analog signalling.
May handle digital data at modest rates using modems.
Allows data rate of 64 kbps.
TWISTED PAIR CABLE
Two types of twisted-pair cable are used: shielded and unshielded.
Shielded twisted pair (STP)
Shielded with a metallic braid or sheath.
Reduces interference.
Better performance at higher data rates.
More expensive and difficult to work compared to unshielded twisted pair(UTP).