1. CWNA Guide to Wireless LANs, Second Edition
Chapter Twelve
Personal, Metropolitan, and Wide Area Wireless Networks

2. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
Wireless Networks
Wireless networks classified into four broad categories:
Wireless personal area network (WPAN): Hand-held and portable devices; slow to moderate transmission speeds
Wireless local area network (WLAN): i.e., IEEE a/b/g
Wireless metropolitan area network (WMAN): Range up to 50 kilometers
Wireless wide area network (WWAN): Connects networks in different geographical areas
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

3. Wireless Networks Coverage
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

4. Point-to-point and Point-to-multipoint Networks
Point-Point
Point-to-multipoint
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

5. Wireless Personal Area Networks-WPAN
WPANs encompass technology designed for portable devices
PDAs, cell phones, tablet or laptop computers
Low transmission speeds
Three main categories:
IEEE standards (Bluetooth)
Radio frequency ID (RFID)
IrDA
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

6. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE (Bluetooth)
Bluetooth uses short-range RF transmissions
Users can connect wirelessly to wide range of computing and telecommunications devices
Rapid and ad hoc connections between devices
adapted and expanded from Bluetooth
Designed for area of about 10 meters
Rate of transmission below 1 Mbps
Up to 1 mw power consumption
Two types of network topologies
Piconet
Scatternet
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

7. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
Piconet: IEEE
Piconet: When two devices come within range, automatically connect
Master: Controls wireless traffic
Slave: Takes commands from master
Piconet has one master and at least one slave
Active slave: Connected to piconet and sending transmissions
Parked slave: Connected but not actively participating
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

8. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
Scatternet IEEE Modes
Devices in piconet can be in one of five modes:
Standby: Waiting to join a piconet
Inquire: Device looking for devices to connect to
Page: Master device asking to connect to specific slave
Connected: Active slave or master
Park/Hold: Part of piconet but in low-power state
Scatternet: Group of piconets in which connections exist between different piconets
uses FHSS
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

9. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE speed Comparison
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

10. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE
Created in response to limitations of
High-rate WPANs
Two main applications:
Video and audio distribution for home entertainment systems
High-speed digital video transfer
High-density MPEG2 transfer between video players/gateways and multiple HD displays
Home theater
PC to LCD projector
Interactive video gaming
High speed data transfer
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

11. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE Modes
Differences between and
Quality of Service (QoS)
Security
High data rates
Spectrum utilization
Coexistence
Table 12-2: IEEE security modes
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

12. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE a, b ,c
a: Will support data transfers up to 110 Mbps between max of 245 devices at 10 meters
Ultrawideband (UWB)
Intended to compete with USB 2.0 and FireWire
IEEE b task group working on improving implementation and interoperability of
IEEE c task group developing alternative physical layer standard that could increase speeds up to 2 Gbps
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

13. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE
Sometimes preferable to have low-speed, low-power wireless devices
Size can be dramatically reduced
IEEE standard addresses requirements for RF transmissions requiring low power consumption and cost
Table 12-3: IEEE data rates and frequencies
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

14. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE ZigBee
ZigBee Alliance: Industry consortium that promotes standard
Figure 12-7: ZigBee and IEEE
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

15. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
Radio Frequency ID
Passive RFID tags: No power supply
Can be very small
Limited amount of information transmitted
Active RFID tags: Must have power source
Longer ranges/larger memories than passive tags
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

16. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IrDA
Infrared Data Association
IrDA specifications include standards for physical devices and network protocols they use to communicate
Devices communicate using infrared light-emitting diodes
Recessed into device
Many design considerations affect IrDA performance
IrDA diodes in device
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

17. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IrDA Drawbacks
IrDA drawbacks:
Designed to work like standard serial port on a personal computer, which is seldom used today
Cannot send and receive simultaneously
Strong ambient light can negatively impact transmissions
Angle and distance limitation between communicating devices
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

18. Wireless Metropolitan Area Networks
Cover an area of up to 50 kilometers (31 miles)
Used for two primary reasons:
Alternative to an organization’s wired backhaul connection
i.e., T1, T3, T4 lines
Fiber Optics
Very expensive to install backhaul connections
Often less expensive to use a WMAN to link remote sites
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

19. Wireless Metropolitan Area Networks - WMAN
Used for two primary reasons
Used to cover area of 50km (31 miles)
Used to replace leased lines, T1 and T3
Use to replace typical fiber ($200,000/mile)
Use to replace city fiber (up to $3M/mile)
Overcome last mile connection
Connection that begins at a fast Internet service provider, goes through local neighborhood, and ends at the home or office
Slower-speed connection is a bottleneck for users
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

20. Wireless Metropolitan Area Networks: Free Space Optics
Optical, wireless, point-to-point, line-of-sight wireless technology
Able to transmit at speed comparable to Fiber Optics
Transmissions sent by low-powered IR beams
Advantages compared to fiber optic and RF:
Lower installation costs
Faster installation
Scaling transmission speed
Good security
Atmospheric conditions can affect transmission
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

21. Local Multipoint Distribution Service (LMDS)
LMDS provides wide variety of wireless services
High-frequency, low-powered RF waves have limited range
Point-to-multipoint signal transmission
Signals transmitted back are point-to-point
Voice, data, Internet, and video traffic
Local carrier determines services offered
Support up to 16,000 telephone calls
For 51 to 155 Mbps over 8km(5miles)
LMDS network is composed of cells
Cell size affected by line of site,
antenna height
overlapping cells,
and rainfall
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

22. Multichannel Multipoint Distribution Service (MMDS)
Many similarities to LMDS
Longer range than LMDS
Lower vulnerability to weather than LMDS
Lower cost than LMDS
Requires line of sight
Normally not encrypted
1.5 Mbps downstream transmission, 300Kbps upstream transmission, up to 56km (35 miles)
Receiving end uses pizza box antenna
In homes, alternative to cable modems and DSL service
For businesses, alternative to T1 or fiber optic connections
MMDS hub typically located at a very high point
On top of building, towers, mountains
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

23. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE (WiMAX)
WiMAX –Worldwide Interoperability for Microwave Access
Highest potential of all WMAN technology
Can connect IEEE hotspots to Internet
Can provide alternative to cable and DSL for last mile connection
Up to 50 kilometers of linear service area range
Does not require direct line of sight
Shared data rates up to 70 Mbps (T1 for up to 60 businesses)
Longer range than IEEE a/b/g
Uses scheduling system
Device competes once for initial network entry (unlike CDMA/CD and CDMA/CA)
A dynamic time slot is assigned to a device
All other devices must wait their turn
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

24. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
IEEE and
IEEE currently only devices addresses in fixed positions
802.16e will add mobile devices to the standard
IEEE standard: Sets standards for mobility over large areas (will permit 75 to 93 mph roaming)
DEPLOYMENT
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

25. Wireless Wide Area Networks (WWANS)
Wireless networks extending beyond 50 kilometers (31 miles)
Two primary technologies:
Digital cellular telephony
Satellites
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

26. Digital Cellular Telephony
Two keys to cellular telephone networks:
Coverage area divided into cells
Cell transmitter at center
Mobile devices communicate with cell center via RF
Transmitters connected to base station,
Each base station connected to a Mobile Telecommunications Switching Office (MTSO)
Link between cellular and wired telephone network
All transmitters and cell phones operate at low power
Enables frequency reuse
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

27. Digital Cellular Telephony
Frequency reuse
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

28. Digital Cellular Telephony
Has evolved since 1980 (analog)
Now uses digital packet-switch technologies
Reuses frequency channels- up to 416 channels
2G –packet switch -GSM
2.5 G - CDMA and GPRS networks
3.0 G -data rate of above 144 kbit/s –EDGE, CDMA200, 1x-RTT
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

29. CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini
Satellites
Satellite use falls into three broad categories:
Acquire scientific data, perform research
Examine Earth
Military and weather satellites
“Reflectors”
Relay signals
Communications, navigation, broadcast
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

30. Satellites –Three Categories
Satellite systems classified by type of orbit:
Low earth orbiting (LEO): Small area of earth coverage
Up to 225 satellites needed for total coverage of earth
Must travel very fast
Medium earth orbiting (MEO): Larger area of coverage than LEO
Do not need to travel as fast
Geosynchronous earth orbiting (GEO): orbit matches earth’s rotation
“Fixed” position
Very large coverage area
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

31. Satellite –Low earth orbiting - LEO
Orbit Altitude to 1,448 km (200 to 900 miles)
Orbit Speed -- 27,359 kph (17,000 mph)
Orbit Time minutes
Round trip time delay– 20 to 40 milliseconds
Total earth coverage –50 to 225 satellites
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

32. Satellite –Medium earth orbiting - MEO
Orbit Altitude – 2,413 to16,090 km (1,500 to 10,000 miles)
Orbit Speed --
Orbit Time – 12 hours
Round trip time delay – 50 to 150 milliseconds
Total earth coverage –10 to 20 satellites
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

33. Satellite –Geosynchronous earth orbiting - GEO
Orbit Altitude – 35,860 km(22,282 miles)
Orbit Speed – fixed over a point
Orbit Time – fixed
Round trip time delay – 250 milliseconds
Total earth coverage –three satellites (less polar regions)
Life – 12 to 15 years
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini

34. The Future of Wireless Networks
IEEE subcommittees currently at work:
802.11d: Supplementary to MAC layer
Promote worldwide use of WLANs
802.11f: Inter-Access Point Protocol (IAPP)
Will assist with faster handoff from one AP to another
802.11h: Supplement to MAC layer to comply with European regulations for 5 GHz WLANs
802.11j: Incorporates Japanese regulatory extensions to a standard
802.11n: WLAN in 2008?
802.11s: Defines a mesh wireless network
Devices configure themselves and are intelligent
CWNA Guide to Wireless LANs, Second EditionCCRI J. Bernardini