PHYSICAL LAYER + WIRELESS TECHNOLOGIES

physical layer

Provides the means to transport the bits that make up
a data link layer frame across the network media

physical layer

The encoded bits that comprise a frame are received by either an end device (host) or an intermediate device (router/switch)

physical layer

This layer accepts a complete frame from the data link layer and encodes it as a series of signals that are transmitted onto the local media

Network Interface Cards

____ connect a device to a network.

Network Interface Cards

Used for a wired connection

Wireless Local Area Network (WLAN)

___________ NICs are used for wireless connections

copper cable, fiber optic cable, wireless

There are three basic forms of network media:

copper cable

The signals are patterns of electrical pulses

fiber optic cable

The signals are patterns of light

wireless

The signals are patterns of microwave transmissions

physical components

Electronic hardware devices, media, and other connectors that transmit and carry

the signals to represent the bits

physical components

Network adapters (NICs), interfaces and connectors, cable materials, and cable

designs

encoding

Method of converting a stream of data bits into a predefined "code”

encoding

Codes are groupings of bits used to provide a predictable pattern that can be recognized by both the sender and the receiver

signalling

Method of representing the bits

signalling

The physical layer standards must define what type of signal represents a "1" and

what type of signal represents a "0"

bandwidth

The capacity of a medium to carry data

kilobits per second (kb/s) or megabits per second (Mb/s)

Bandwidth is typically measured in

throughput

Measure of the transfer of bits across the media over a given period

True

True or False: Due to a few factors, throughput usually does not match the specified bandwidth in physical layer implementations.

attenuation

In copper media, this says that the longer the signal travels the more it deteriorates

Electromagnetic interference (EMI) or radio frequency interference (RFI)

distorts and corrupts the data signals being carried by copper media

crosstalk

disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire

fiber optic cable

Transmits data over longer distances and at higher bandwidths

fiber optic cable

Transmit signals with less attenuation and is completely immune to EMI and RFI

fiber optic cable

Bits are encoded on the fiber as light pulses

wireless media

carry electromagnetic signals that represent the binary digits of data communications using radio or microwave frequencies

wifi

Standard IEEE 802.11

bluetooth

IEEE 802.15

802.11 channels

Spectrum divided into channels at different frequencies

personal area networks

bluetooth is a type of