Cmartin73 Wireless Networking Ch 1

The 802.11-2007 standard was created by which organization?

IEEE

modulation

The method of adjusting a signal to create the carrier signal. (p14)

keying method

The method of manipulating a signal so that it can represent multiple pieces of data. (p16, definition 665) aka modulation techniques

carrier signal

a signal modified to be able to distinguish between 0s and 1s. (p14)

distribution layer

routes traffic between virtual LANs and subnets (p12) (like state and county roads that provide medium travel speeds and distribute the traffic within the city or metro area)

The IEEE 802.11-2007 standard defines communication mechanisms at which layers of the OSI model?

physical and data-link layers

High Throughput (HT)

provides PHY and MAC enhancements to support wireless throughput of 100 Mbps and greater. Defined as 802.11n draft amendment for clause 20 radios. (p9, definition 662)

lightweight access points

used in a centralized WLAN archtecture together with WLAN controllers. Minimal intelligence and is functionally just a radio and antenna (p 12, definition 666)

state transition technique

uses the change (transition) of the signal to distinguish between 0s and 1s. (p16)

current state technique

uses the current value (current state) of the signal to distinguish between 0s and 1s. (p16)

amplitude-shift keying (ask)

varies the amplitude, or height, of a signal to represent the binary data (p17) Current state technique where one level can represent 0 and anther can represent 1 bit.

frequency-shift keying (FSK)

varies the frequency of a signal to represent the binary data (p17) Current state technique where one frequency can represent 0 and anther can represent 1 bit.

phase-shift keying (PSK)

varies the phase of a signal to represent the binary data (p18) State transition technique where one phase can represent 0 and anther can represent 1 bit.(p18) used extensively for radio transmissions as defined by the 802.11-2007 standard

What are the two components of a wave?

wavelength and amplitude (p14)

How many degrees make up a complete wave?

360

The OSI model consists of how many layers? Name them, in order.

7 physical, data-link, network, transport, session, presentation, application

Which keying method is most susceptible to interference from noise?

Amplitude-Shift Keying (ASK)

Where are redundant solutions usually designed?

At the core layer to ensure the fast and reliable delivery of packets. (p12)

Global spectrum management is tasked to what organization?

International Telecommunication Union Radiocommunication Sector (ITU-R)

What dos the distribution layer of the network do?

It routes or directs traffic toward the smaller clusters of nodes or neighborhoods of the network. (p12)

What does the access layer of the network do?

It's responsible for slower delivery of the traffic directly to the end user or end node. (p12)

What is the goal of the core?

To carry large amounts of information between key data centers or distribution areas. (p12)

The Wi-Fi Alliance is responsible for which certification programs?

WPA2, defines Wi-Fi security mechanisms and WMM, which enables Wi-Fi networks to prioritize traffic generated by different applications.

What organization ensures interoperability of WLAN products?

Wi-Fi Alliance

What type of signal is required to carry data?

a carrier signal

802.11 technology is typically deployed at which fundamental layer of network architecture?

access layer 802.11 wireless networking is typically used to connect client stations to the network via an access point. Autonomous and lightweight APs are deployed at the access layer, not the core or distribution layer. The physical layer is a layer of the OSI model, not a network architecture layer

The height or power of a wave is known as what?

amplitude

Which wave properties can be modulated to encode data?

amplitude, frequency, and phase

What are the three components of a wave that can fluctuate or be modified to create a carrier signal?

amplitude, frequency, and phase (p14)

Name the two ways a wireless network may be implemented.

as point-to-point or point-to-multipoint solutions. (p12)

A modulated signal capable of carrying data is known as what?

carrier signal

autonomous access points

contain at least two physical interfaces, usually an RF radio card and a 10/100Base T port. All configuration settings exist in the AP itself. Management and configuration occurs at the access layer. encryption & decryption mechanisms and MAC layer mechanisms operate with in the AP. (p 12, definition 650)

WLAN controllers

contains all the intelligence and distributes the AP settings to the RAM on the lightweight APs (definition 687)

802.11 wireless bridge links are typically associated with which network architecture layer?

distribution layer Core layer devices are usually much faster than 802.11 wireless devices, and bridges are not used to provide access layer services. The network layer is a layer of the OSI model, not a network architecture layer

How is a wavelength typically measured?

from the peak of a wave to the peak of the next wave. (p15)

Which sublayer of the OSI model's data-link layer is used for communication between 802.11 radios?

the MAC layer. IEEE 802.11-2007 standard defines communications mechanisms at only the physical layer and MAC sublayer of the data-link layer of the OSI model.

frequency

the behavior of waves (p15) (if you were sitting on a pier counting waves coming to shore, you could tell how frequently they were coming)

wavelength

the distance between similar points on two back-to-back waves. (p15)

amplitude

the height or power of a wave (p14) (if you were standing in the ocean, you feel the force of larger waves more than that of smaller waves)

core

the high-speed backbone or superhighway of the network. It does not route traffic nor manipulate packets, but performs high-speed switching. (p12)

phase

the relationship between two waves with the same frequency. (p15) a wavelength is divided into 360 degrees which refer to starting times

spread spectrum

transmission that uses more bandwidth than is necessary to carry its data. Spread spectrum technology takes the data that is to be transmitted and spreads it across the frequencies that it's using. (2, definition 680)

wireless bridge link

typically used to provide connectivity between buildings; wireless connectivity of two separate, wired networks. (in the same way that county or state roads provide distribution of traffic between neighborhoods) (p13)