ENT 219 Wireless Local Area Networks (WLAN)

Weekly Schedule 

Main Textbook:   Designing and Implementing Wireless LANs, Mark Ciampa, Course

     Technology, 2001, ISBN 0619034947.

Supplemental Required Textbook:  CWNA Official Study Guide, Planet3 Wireless, 2002, 

                                                          ISBN  0971605726

Teaching Tools and Resources on CD:

Instructor’s Resource contains slides, lecture notes, exams (Exam-View Pro) - Course Technologies 

CWNA Official Study Guide (PDF file)- Only for Instructor’s use.  

Cisco Access Point Software Configuration Guide (AP) CD

Cisco Wireless Network Interface Card Software Configuration Guide (WNIC) CD 

Cisco Wireless Bridge Software Configuration Guide (WGB) CD

WEEK 1 Discussion      Wireless Computer Network- Introduction

Application of wireless technology at home, car, office, and field environments

·         Wireless Devices

·         SWAP protocol

·         IEEE standards (802.11, 802.11b, 802.11a, 802.11g)

·         WLAN organizations

·         Review of number systems- binary, hexadecimal.

·         Bluetooth, PAN protocols

·         WAP, WML, WAP proxy, WAP communications

·         WLAN, Access Point (AP), Wireless Bridge, Wireless Network Interface Card (WNIC)

·         PDA, PCS, and circuit switching

·         CDPD and packet switching

·         WLAN applications in manufacturing, health care, and on campus

·         WLAN advantages/disadvantages over traditional wired networks

1.      Mobility

2.      Ease of installation

3.      Reliability

4.      Disaster recovery

5.      Potential for EM interference

6.      Security issues

7.      Wi Fi and compatibility issues between vendors

 

Hands-on lab: Fabricate communication media required to provide initial communication with AP, router/switch and with a wireless Bridge (Week 1 into Week 2). LAB 1.

Assigned reading: Chapter 1 main textbook, chapters 1, 6 supplemental textbook.

Supplements: Lecture notes, Lab 1, slide presentation (MS Power Point presentation) on CD

Written AssignmentEnd of chapter questions. Student to re-organize their class notes after each class session.

 

WEEK 2 and WEEK 3

           Wireless LAN Fundamentals

Light-based WLANs

·         Infrared emission, detection, devices, IrDA specifications

·         Directed and Diffused infrared, installation, transmission rates

·         Advantages and disadvantages

RF Transmission Review

·         EM spectrum

·         FCC allocations

·         Transmission/reception of RF signals and antennas (RFLOS, Fresnel zone)

·         Gain, losses, decibels (dB, dBm, dBi)

·         IRP, EIRP

·         Modulation schemes (Frequency, Phase)

·         Spread spectrum

1.      FHSS- hopping code, transmission, error correction, orthogonal FHSS

2.      DSS- Barker “chipping” coding. Exclusive OR operation of data and code

3.      BW requirements, channel and frequency assignments

Handout matrix of standards.

Physical view of WLAN devices (show samples and describe interface port connections)

·         WNIC- PCI, ISA bus-based, PC Card

·         Access Points as wireless “smart hubs”. AP functions and modes (repeater, bridge).

·         Wireless Bridge (WGB) functions and modes (root, non-root, AP, repeater).

·         WGBs used for bridging wired networks wirelessly.

 

Radio- based WLAN

·         Peer-to-peer WLAN = “Ad Hoc” = Cisco Home” = IBSS WLAN mode

·         Infrastructure WLAN. Present implementation of each mode. VITAL INFORMATION.

1.      BSS

2.      ESS

 

Hands-on lab activities:

1.   Finish the Lab 1 fabrication of the communication media required to provide initial communication with AP, and with a wireless Bridge.

2.      Review MS Windows (98SE, 2000, XP) configurations to establish wired Peer-to-Peer networking. Infrastructure “core” wired network should already be working in advance of this class session. Students must have knowledge of cabled ethernet network hardware (equivalent to Cisco Academy Sem1) prior to conducting this experiment.

3.      Lab 2

 

Answer questions from prior assignment. Have selected students present their solutions.

Assigned reading: Chapter 2 main textbook, Chapters 2, 4, 8 (pages 214 and 215) of the supplemental textbook.

Supplements: Lecture notes, slide presentation (MS Power Point presentation), “show-and-tell”

Written Assignment: End of chapter questions.

QUIZ #1: Chapters 1, 6 of supplemental text.

 

WEEK 4

 

IEEE 802.11 Physical Layer Standards

 

            Wireless Standards

·         Justification for wireless communication standards and need for standards Bodies

·         Dejure and de facto standards

·         IEEE 802 series standards (802.3, 802.5, 802.11b/a)

 

802.11 Physical Layer

·         Physical Layer Convergence Procedure (PLCP) sub layer “frame” and associated bit fields

·         Physical Medium Dependent (PMD) sub layer

 

 

Spread Spectrum Physical Layer Specifications

·         ISM frequency allocation (FCC)

·         FHSS and GFSK (4 level) PLCP frame

·         FHSS Medium Dependent Standards

·         FHSS signal data-rate field values (bit pattern vs. transmission speed)

·         FHSS start frame delimiter

·         DSSS DBPSK and DQPSK PLCP frame

·         DQPSK bit pattern to phase value correlation

·         DSSS Medium Dependent Standards     

·         DSSS Transmissions

·         DSSS Channels (channel number vs. frequency)

 

Diffused Infrared Physical Layer Specifications

·         Diffused Infrared PLCP Standards

·         Diffused Infrared PLCP frame and frame fields

·         Diffused Infrared PMD Standards

·         16-pulse position modulation (16-PPM)

 

Review of 7-layer OSI and 4-layer DOD TCP/IP network Models

·         Review of network hardware associated with each layer of both network Models

  

Student activities:

  1. Compare/contrast PLCP sub layer frames for FHSS and DSSS transmissions
  2. Specify how ASCII data would be processed using GFSK, 4-level GFSK, DBSK, and DQPSK transmission methods. For example, use the ASCII for the letter “A” (01000001) and predict the transmitted waveforms.
  3. Supplemental Lab.

 

Answer questions from prior weeks assignment. Have selected students present their solutions.

Assigned reading: Chapter 3 main and supplemental textbooks

Supplements: Lecture notes, slide presentation (MS Power Point presentation). Show hardware devices.

Written Assignment: Selected questions and projects chosen from the textbooks- Chapter 3 of both textbooks

 

QUIZ #2: Chapters 2, 4 of the supplemental textbook
 

WEEK 5

IEEE 802.11 Layer 2 MAC and Layer 3 Network Layers

802.11 Medium Access Control Layer

·         Accessing a wireless medium

·         WLAN topologies

·         Channel access methods including contention

·         CSMA/CD and wireless CSMA/CA protocols (compare and contrast the two)

·         Slot time

1.      Frame acknowledgement (ACK)

2.      Interference spaces: IFS, SIFS, PIFS, DIFS

3.      “Hidden” node problem

4.      Virtual carrier sensing (RTS/CTS)

5.      Net allocation vectoring (NAV)

·         Point coordination function (PCF)

1.      Polling

2.      Beaconing, beacon frame, null data frame

3.      DCF contention

·         Fragmentation to reduce collisions (at MAC sublayer)

1.      Fragmentation frame sizing

2.      Fragmentation with RTS/CTS

·         Associating to a WLAN

1.      IBSS WLAN mode association procedure

2.      BSS WLAN mode association procedure

3.      ESS WLAN mode association procedure

·         Access Point Scanning

1.      Passive scanning

2.      Active scanning

3.      Probe frame

4.      Probe response

5.      Service set identification (SSID)

6.      Associate request frame

7.      Associate response frame

·         Authentication of a node to a WLAN

1.      Extended SSID

2.      Manual assignment of MAC addresses into AP table

3.      Access Control Lists (ACLs)- AP ethernet interface

·         Privacy

1.      Wired Equivalent Privacy (WEP), and EAP, VPN

2.      WEP 40, 128 bit

3.      Public, shared “keys”

4.      Authentication frame

     

      Hands-on-Lab activity: Lab3- Wireless IBSS “Ad Hoc” mode.

 

Assigned reading: Chapter 4 main textbook pages (91- 114), Ch 7, 8 supplemental textbook

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

 

Written Assignment: Problems from Chapter 4 main textbook, and Ch 7, 8 supplemental textbook

 

QUIZ # 3: Chapter 3 of the supplemental textbook

 

WEEK 6 (Continuation of Week 5)

ESS Cell- to- Cell Roaming- Chapter 4 (continued)

·         Re-association protocol

·         Re-association request frame

·         Re-association response frame

·         Disassociation from an ESS at AP

Synchronization

·         Node PC to an AP using PCF

·         Beaconing using time stamps

Power Management and Power Save Polling (PSP)

·         Portable PC (laptop) sleep mode interference with WLAN communication at AP

·         802.11 PMF in ESS and extended ESS modes.

·         Buffering at AP

·         Traffic indication map (TIM)

·         Forwarding

MAC Frame Formats

·         Management frames- setup initial communication PC node to AP

·         Control frame – assist delivery of data. Include RTS frame.

·         Data frame

IEEE 802.11 Network Layer

·         TCP/IP wireless implementation

·         Mobile IP

1.      Home IP address

2.      Home agent

3.      Foreign network

4.      Foreign agent

5.      Care-of IP address

6.      Encapsulated mobile IP frame

 

Hands-on Lab activity: Lab 4- IBSS Catchment Zone

Assigned reading: Chapter 4 (pages 115- end of chapter)

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

 

Written Assignment: Main textbook Chapter 4, and Ch 7, 8 supplemental textbook

QUIZ # 4: Questions from supplemental textbook Ch 7, 8.         

Review for EXAM #1.
 

 WEEK 7

 

EXAM #1

Exam to cover course material covered during the first 6 weeks.  The exam should include some questions about the network devices (connector types, interface cabling, power requirements, antenna orientation, which OSI layer supports a particular device, etc). Exam should allow sufficient time so that the students do not feel time-pressured. A combination of multiple choice, short answer, and show-work calculations should be utilized in the construction of the exam questions (50 questions total). A practical “hands-on” test element should also be considered (time permitting). The exam should be structured with the following distributed weighting: 15% Ch1, 15% Ch2, 30% Ch3, and 40% Ch4.

 Optional Research paper assignment (use Internet and other sources).  Suggested topics:

1.      Wireless channel access methodologies: token passing and demand priority.

2.      Mobile IP protocol description and mechanics

3.      Public vs. shared key cartography methods

4.      Association and re-association of stations to wireless cell(s). Are there open standards applicable to “roaming” from AP to AP

 

WEEK 8

Building a Wireless Local Area Network

Assessment of WLAN Requirements

WLAN planning

1.      Costs

2.      Needs

3.      Organizational requirements

4.      Documentation of existing infrastructure

5.      Compatibility and interoperability

6.      Radio-based WLAN vs. Infrared

7.      RFP

 

Designing WLAN Layout

·         IBSS, BSS, or ESS  layout?

·         Coverage areas (cells)

·         Bandwidth vs. distance considerations (dynamic rate shifting)

·         Determining number and placement of Access Points

·         Powered vs. un-powered media connection to backbone

·         SNR of RF transmissions

·         Site survey for best location of APs and wireless bridges (WGBs)

·         Discrete BSS cells vs. a distributed linked ESS architecture

·         Channel assignments

·         Mobility of nodes and “roaming” considerations

·         DHCP vs. static IP allocations (nodes, APs, WGBs)

·         Security issues

·         Network support issues

 Hands-on lab activity: Lab 5- Wireless IBSS upgrade to BSS mode

 Review results of EXAM # 1.  Setup individualized appointments to assist students having difficulty.

Assigned reading: Chapter 5 of main textbook

Supplements: Lecture notes, slide presentation (MS Power Point presentation).

Written Assignment: Selected questions and projects chosen from the main textbook- Chapter 5

Begin class review of the supplemental Cisco documentation (on CD) for the WNIC, AP

 

WEEK  9 and WEEK 10

Access Point Applications (Repeater, Root, Multi-cell operation)

NOTE:  The last eight weeks have lead up to this time when the student will finally be able to fully utilize a wireless Access Point (AP), setup multiple APs, and see the WLAN come together and operate. Needless to say, the instructor must make sure that the backbone wired LAN is operational and that the wireless AP and WNIC (s) are operational and ready for the students use. Students should have read over all documentation regarding the WNIC and AP in advance of the actual installations (Cisco CD Software Guides and Help Q&A files, and Cisco website). It is suggested that this information be posted on a website hosted by your college so that access is fast.

 

Discuss 802.11b Standard metrics (data rates vs. distance, transmission types, etc). Reference the “Wireless LAN technologies Standards Matrix”.

Hands-on-activity: Lab 6- Using AP as a Repeater.

 

Create an Networked WLAN- Multiple Cells: ESS mode

Infrastructure LAN: Connect the AP to your preexisting backbone-wired LAN (use the Linksys BEFSR41 router/switch) via the RJ 45 connector on the rear of the AP. WARNING: The Cisco 350 series AP uses a powered CAT5 connection- make sure you correctly connect your wired LAN into the AP’s port or you could damage all of your network!!

Next setup and configure the wireless laptop(s) to associate with the AP.

Now ALL THE PCs SHOULD BE ABLE TO COMMUNICATE with each other and to the WLAN portion of your extended network. All of the student PCs can now access the browser AP interface. Be careful that mischievous or “malicious” students don’t add their own secret passwords or disturb your intended AP configuration without your consent. If this happens you will have to re-flash the entire configuration and start all over (i.e. you don’t want this to happen).

Now you add the second AP. 

Hands-on activities: Lab 7- ESS mode (multi-cell operation with ROAMING capability). This Lab puts all prior theory and application together. This Lab will require several hours (students need the practice with configurations of PCs, laptops, and APs). Some troubleshooting is likely.

 Assigned reading: Chapter 6 of main textbook, and excerpts from the Cisco Software Configuration Guides

Supplements: Lecture notes, slide presentation (MS Power Point presentation).

Written Assignment: Selected questions and projects chosen from the main textbook- Chapter 6

Continue class review of the supplemental Cisco documentation (on CD) for the WNIC, AP

 

Assign the WLAN DESIGN PROJECT (Lab 11). This project will involve the design and implementation of a real-life hybrid network including IP addressing and SN mask. There will be a mix of network devices: ethernet wired-PCs (some connected to a WGB, and others connected to the router/switch), a router/switch (provides connectivity and DHCP services), a wireless Bridge (WGB), WNIC laptops, and AP(s). All procedures to setup and fully configure the WNICS, and AP(s) will be required as well as an explanation as to how the student decided upon their particular design.

 

WEEK  11

Configuring the WLAN

Refer to the Cisco Aironet 350 Access Point Software Configuration Guide (APSCG is on CD) for specifics.

To communicate with the Access Point (AP)

·         Use of Hyperterminal Windows utility

·         Use of Telnet Windows utility

·         Browser utility- preferred method. A Cisco administrative GUI AP interface will appear when you direct the browser of a station (connected to the same subnet as the AP) to the IP address of the AP. You must beforehand setup the initial AP configuration (IP address, SSID, profile, etc- see the APSCG) in order to communicate with the AP. Refer also to Week 10 material.

 Security Measure (minimal) Configurations to safeguard the AP

·         Browse to the AP security menu (GUI)

·         User account setup: Write, SNMP, Ident, Firmware, and Admin account types

·         Restriction of station access to WLAN through AP

1.      Use of Access Control Lists (ACLs): MAC address filtering, Protocol filtering

2.      Service Set IDs (SSID)

3.      Scanning prohibitions: active, passive

·         Wired Equivalent Privacy (WEP) configuration (40, 128 bit)

1.      WEP keys: temporary, permanent

2.      Encryption

       Site Survey Active Mode Setup

·         Settings: Destination MAC, Continuous Link, No. of packets, Packet size, Data retries, Data rate, Delay between packets, Packet Tx type, Percent Success Threshold

·         Program attributes

·         Passive mode or passive scanning with beaconing

·         Active mode or active scanning

 Power Management

·         Constant awake mode (CAM)

·         Maximum Power Save Mode (Max PSP)

·         Fast Power Save Mode (Fast PSP)

 Hands-on Activities:

1.                  Allow the students controlled access of AP via their station’s Browser. Have the students document current settings in all menus of the GUI. Have the students write down (on paper) the required changes to configure the AP: IBSS, BSS, ESS modes.  Use two or more wireless stations as nodes in the WLAN. The students will be connected to the WLAN on their cabled PC through a wireless bridge(s) or the router/switch.

2.                  Lab 8. Conduct a WEP key setup on WNIC and AP (if a WGB is used it will also need to be WEP enabled to match the WNIC and AP settings chosen). How difficult would it be to “hack” into the WLAN using 40 bit WEP, 128 bit WEP?

3.                  Have the students remotely monitor station associations to the AP using the ACU utility at their station. Have a student take a portable wireless station and roam in and out of RF range of the AP. What happens?

4.                  Demonstrate prohibition of active scanning requests to minimize unauthorized access of AP. Enable the prohibition in the Security menu of the AP GUI. Take a portable wireless PC and remove the SSID label using the ACU. Roam out of RF coverage of the AP, then return to within range. Was an association made to the AP?

 

Review for EXAM #2 (next week)

Assigned reading: Chapter 8 of main textbook, and Ch 10 of the supplemental textbook. 

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

Written Assignment: Main textbook- Chapter 8, and Ch 10 of supplemental textbook

Continue class review of the supplemental Cisco documentation (on CD) for the WNIC, AP

 

 WEEK 12

EXAM #2

Exam #2 to cover course material covered during the last 5 weeks.  The exam should include some practical questions about the network devices (configuration settings, AP modes, initial setup of WNIC and AP). Exam should allow sufficient time so that the students do not feel time-pressured. A combination of multiple choice, short answer, and show-work calculations should be utilized in the construction of the exam questions (50 questions total). The exam should be structured with the following distributed weighting: Ch 5 25%, Ch 6 50%, Ch 8 25%.

 

Finish Hands-on activities (Lab 8) from Week 11.

Have students turn-in a basic network diagram of their WLAN DESIGN PROJECT. The final report is due by week 15 (after wireless bridges are covered). At this point all of the WLAN device configuration settings are due as well as a written procedure for implementation.

Assign additional homework problems from Chapters, 5, 6, 8 and require re-reading of Chapters 1-4 of the main textbook.

  

WEEK 13

Managing the Cisco Aironet WLAN

·         SNMP

1.      Software agents

2.      MIB

3.      Management station

4.      Alarms

5.      Traps 

·         RMON management

1.      Event alarms

2.      WAN connection 

·         Station Utilities

1.      Statistics

2.      Link status meter

3.      Link test utility indicators 

·         AP Utility Menus (includes multiple submenus)

1.      Map

2.      Network

3.      Associations

4.      Setup

5.      Logs

6.      Home 

·         Upgrading the WLAN

1.      System upgrade

2.      Webpage upgrade

3.      Radio firmware upgrade

 

·         Modification of the AP Radio Settings

1.      SSID

2.      Data Rate

3.      Transmit power level

4.      Fragmentation threshold

5.      RTS

Hands-on Activities:

1.      Have students run the Cisco Aironet 350 Statistics to analyze frames (PLCP, etc) sent/received, and errors.

2.      Lab 9- Introduction to AP Access Control (Filtering)

 

Assigned reading: Chapter 9 of the main textbook, and excerpts from the Cisco Software Configuration Guides 

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

Written Assignment: Selected questions and projects chosen from the main textbook- Chapter 9

Continue class review of the supplemental Cisco documentation (on CD) for the WNIC, AP and introduce the WGB Cisco documentation (on CD).

Quiz: Chapter 10 of the supplemental textbook

 

WEEK 14

Wireless Network Settings and Troubleshooting the WLAN

 

·         Ethernet Parameters- WLAN

1.      Primary access point configuration

2.      ID assignments on port: MAC, IP, Subnet

3.      DHCP and Static IP

4.      Ethernet advanced settings: packet forwarding sequence- blocking-listening-learning-forwarding-disabled. Similar to switch technology STP.

 ·         Other Cisco WLAN Settings

1.      DNS server

2.      Routing setup: destination network, gateway, subnet mask 

·         Access Point Filtering (Demonstrate using a computer projector overhead unit)

1.      By MAC address

2.      By protocol 

Troubleshooting Scenarios (class participation). Present class with each problem and have them troubleshoot and make suggestions. Students should be very familiar with all configuration settings by now and should only have to refer to notes occasionally to answer configuration-specific questions.

Main Textbook contains some excellent problem scenarios:

1.      Driver problems for AP, WNIC, Wireless Bridge- causes, symptoms, solutions.

2.      Folder, file, drive sharing difficulties.

3.      Incorrect IP addressing. Incorrect MAC assignments.

4.      Ad Hoc mode but no stations appear in ACU

5.      CAM difficulties with portable PCs in “sleep” mode

6.      Slow WLAN throughput- causes and remedies

7.      WLAN doesn’t function- SSID, profile, client name. How to tell if WLAN is working correctly using ACU, the AP GUI, and using the PING command

 Students should complete their WLAN Design Project  this week. The complete Project Final Report is due week 15.

 Hands-on-activity: Lab 10 – Wireless Bridge (WGB)

 Assigned reading: Chapter 10 of the main textbook and Ch 9 of the supplemental textbook 

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

 Written Assignment: The main textbook- Chapter 10, and Ch 9 of the supplemental textbook.

 Continue class review of the supplemental Cisco documentation (on CD) for the WNIC, AP and WGB.

  

WEEK 15

Wireless Bridge Technology

 

Installing the Cisco Aironet 350 Wireless Workgroup Bridge (WGB)

·         Refer to Cisco WGB documentation on CD

·         Using the configuration console menu

·         Using station browser to access the WGB GUI

·         Establishing an SSID on the WGB

·         Selecting proper data rate

·         World mode

·         RTS/CTS parameters to prevent collisions

·         Encryption, EAP setup

·         Configuring Radio Link tests

1.      Signal strength

2.      Antenna alignment

3.      Specification of “target” address

4.      Packet size

5.      Packet errors

6.      Link test

7.      Diversity

8.      Power level setting

9.      Fragment size 

·         Configuring the ethernet port

1.      Set active port

2.      Set maximum frame size

3.      Add MAC addresses 

·         Configuring WLAN Ids

1.      Node name

2.      DHCP

3.      IP address

4.      Subnet mask

5.      DNS server    

Monitoring Workgroup Bridge Performance

·         WGB GUI Statistics menu

1.      Throughput

2.      Errors

3.      Status

4.      Network maps

5.      History

6.      ARP table 

·         Association table: Node addressing (Niddisp)

·         Using WGB Filters (ACLs)

1.      MAC addressing

2.      Protocols 

·         Event logs

·         Diagnostics

1.      Diagnostics menu

2.      Escape sequencing

3.      Link test

4.      Loading firmware updates

 

Hands-on Activities:

1.      Have class decide the best location for the wireless bridge(s) in the existing WLAN. Should you use hubs or switches to connect stations to the WGB? How does the AP associate to the WGB and individual stations attached to the WGB?

2.      Finish Lab 10 (WGB Testing portion)

3.      Have class set SSID, client name, mode, IP address to minimally setup the WGB. Can are these settings the same, different, to those of the AP and WNICs? Can subnets be spanned?

4.      Have the class direct their individual browser to the IP address of the WGB (they already know the WGB IP address) and access the configuration GUI. Document all settings for future reference. Which settings are mandatory/optional?

 

QUIZ: Chapter 9 of the supplemental textbook

Review for FINAL EXAM: to mostly cover week 13- week 15 material including Ch 9, 10, and WGB

        Guide but will also be comprehensive (Ch1 onwards).

Assigned reading: Re-read Chapters 9, 10 of the main textbook 

Supplements: Lecture notes, slide presentation (MS Power Point presentation) on CD.

Written Assignment: Main textbook- Chapter 9, 10

Finish class review of the supplemental Cisco documentation (on CD) for the WNIC, AP and WGB.

 

WEEK 16

 

Review homework and activities from week 15

.

Final Exam: Weighting: Chapter 9 -  25%, Chapter 10 -  25%, WGB - 15%. Remaining 35% of exam is

                      comprehensive in nature drawing from Chapters 1 – 6, and Ch 8 .

  

Course Grading:

Three major Examinations:               40% of course grade

Hands-on Activities:                          25%

Pop Weekly Quizzes                        15%

Homework weekly assignments         5%

WLAN Design Project                        10%

Class participation                              5%