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Wireless Networking Technologies

Lecture based on Comer's Ch. 16

Morgan Vigil

on 27 September 2012

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Transcript of Wireless Networking Technologies

Presented by Morgan Vigil
Westmont College
CS140: Networks
September 27, 2012 Wireless Networking
Technologies Taxonomy of Wireless Networks Wireless Networks Local Area Networks Metro Area Networks Wide Area Networks Personal Area Networks Personal Area Networks
(PAN) Categories Bluetooth
ISM Wireless What are the purposes for each of the three basic types of PAN technologies? 902
MHz 928
MHz 2.4
GHz 2.48
GHz 5.725
GHz 5.850
GHz 26 MHz
bandwidth 83.6 MHz
bandwidth 125 MHz
bandwidth Technologies and Standards 802.15.1a - Bluetooth
802.15.2 - Coexistance among PANs
802.15.3 - High Rate PAN
802.15.3a - Ultra Wideband High Rate PAN
802.15.4 - Zigbee technology
802.15.4 - Alternative low data rate PAN (low power) Bluetooth Wireless replacement for cables
Uses 2.4 GHz frequency band
Short range (up to 5m)
Device is master or slave
Master grants permission to slave
Data rate up to 721 Kbps Ultra Wideband Uses wide spectrum of frequencies
Consumes very low power
Short distance
Signal permeates obstacles
Data rate up to 500 Mbps at 2 m
IEEE has not formed single standard Zigbee For remote control (not data)
For industry and home automation
Data rate of 20, 40, or 250 Kbps
Low power
3 levels of security being defined Other Short-distance Communication Technologies InfraRED (IrDA) Family of standards for various purposes
Range of one to several meters
Directional transmission with cone covering 30 degrees
Data rates between 2.4 Kbps (control) and 16 Mbps (data)
Signal may reflect from surfaces, cannot penetrate solid objects Radio Frequency Identification (RFID) Over 410 RFID standards
Passive RFIDs
Active RFIDs
Limited distance (active > passive)
Frequencies > 100 MHz to 868-954 MHz
Inventory, sensors, passports, etc. Local Area Networks (LAN) Standards 802.11
802.11g 802.11e - improved quality of service, such as guarantee of low jitter
802.11h - like 802.11a but adds control of spectrum and power
802.11i - enhanced security (full version WPA2)
802.11k - provides radio resource management
802.11n - data rate over Mbps to handle multimedia apps
802.11p - Dedicated short-Range Communication (DSRC) among vehicles on a highway and vehicle-to-roadside
802.11r - improved ability to roam access points without losing connectivity
802.11s - mesh networks see Comer 269 Spread Spectrum Technologies Wireless LAN Architecture Access points/base stations
Interconnection mechanisms
wireless hosts/nodes/stations Building blocks of wireless LAN Types of wireless LAN Ad hoc
Infrastructure Infrastructure Complications dead zone
overlap see Comer 273 Coordination Coordination among Access Points Contention and Contention-Free Access Why does 802.11 need to use the CSMA/CA technique? What are the tradeoffs between complex access points and lower cost access points? Metropolitan Area Networks (MAN) WiMAX
(World-wide Interoperability for Microwave Access) Fixed WiMAX
Mobile WiMAX Access Last-mile alternative DSL or cable modems
High-speed interconnection for nomadic users
Unified data and telecommunications access
As a backup for a site's Internet connection Interconnect Backhaul from Wi-Fi access points to a provider
Private connections among sites
Connection between small and large ISPs see Comer 277 uses licensed spectrum
each cell covers 3-10 Km
used scalabe orthogonal FDM
guarantees quality of services
transport 70 Mbps in each direction at short distances
provides 10 Mbps over a long distance What is the difference between WiMAX (802.16) and WiFi (802.11)?
Why do we need WiMAX technology?
What are the uses for WiMAX? WAN (Wide Area Network) Cellular Communication systems Satellite communications systems cell density
various cell size
interference Why does the actual cellular coverage look like the second figure? What strategies help to make it function better in the real world? Very Small Aperture Terminal
(VSAT) Global Positioning System (GPS) Distance calculated in relation to time Future of Wireless Software Radio Frequency
Signal Direction
MAC protocol Multiple-Input Multiple-Output (MIMO)
Separate Radio Antennae As new software radio technologies emerge, why is channel management important? Analog to Digital Wireless Research VillageNet Digital Divide "inequalities between groups in terms of access to, knowledge of, or use of information and communication technologies . . . " Wikipedia, Digital divide global national VillageCell VillageLink VillageShare wireless backhaul using 50-700MHz
frequency bands low-cost alternative to high end cell phone networks relies on software defined radios* and open source software move away from analog television leaves bands open channel bonding protects gateway connection

intelligently schedules uploads
using a proxy server RemoteMath Application to test and demonstrate the effectiveness of VillageCell.

Sits on Dr. Math
- VoIP Local Application FCC Connect America http://www.broadbandmap.gov/technology/terrestrial-fixed-wireless-unlicensed/terrestrial-fixed-wireless-licensed/terrestrial-mobile-wireless American Indian reservations are some of the least connected areas Example: Ute Mountain Reservation 97% of this population only has access to 3 or fewer wireless providers (87% of the national population has access to 4 or more)
13.3% has access to DSL connection (compared to national 88.9%)
98.5% has access to wireless
85.1% of this population is Native American
Median income is ~ $22,200 (national median income is ~$54,900) How is wireless access relevant to preserving culture?
How can increased wireless access in rural areas relieve conditions of poverty? As a personal challenge, name 2-3 technologies associated with each type of wireless network... Overview What are some of the limitations to IrDA technologies? RFID?

Name examples of applications for each technology What are some near future uses you can think of as applications for PAN technology? Main Points What are the different types of wireless technologies (smallest to largest)?

What problems do wireless technologies address (opposed to wired technologies)?

What are techniques used to avoid interference?

What are common tradeoff patterns you see in wireless technologies?

Give 1-2 examples of each type of wireless technology.

How can wireless technologies be used in a redemptive manner?
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