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Wireless and Mobile Computing and Networking at the University of Florida Technology, Infrastructure

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Title: A Data Warehousing Approach for Mobile Data Management Last modified by: Dr. Sumi Helal Created Date: 9/30/1996 6:28:10 PM Document presentation format – PowerPoint PPT presentation

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Title: Wireless and Mobile Computing and Networking at the University of Florida Technology, Infrastructure


1
Wireless and Mobile Computing and Networking at
the University of FloridaTechnology,
Infrastructure Research
  • University of Florida
  • http//net-services.ufl.edu/wireless
  • http//www.harris.cise.ufl.edu

2
Talk Overview
  • Technology
  • Mobile Devices
  • Wireless Networks
  • The 802.11b Wireless LAN
  • Infrastructure
  • The Wireless campus project
  • Synergistic Research Activities
  • Helal (CISE) Wireless Mobile Tech for the
    Elders
  • Others ..

3
(Mobile Information Appliances)
Subscriber Identification Module (SIM)
4
Platform Limitations
  • Limited battery power
  • Limited memory capacity
  • Limited processing power (in some devices)
  • Limited I/O modalities (no keyboard)
  • Limited display size, resolution refresh rate
  • Wide variety of devices lacking platform
    standardization (started to change with advent of
    Java 2 Micro-Edition)

5
Wireless Networks
6
Wireless Networks
7
Wireless Data Networks
  • Unlicensed Frequency
  • The 802.11 Wireless LAN
  • Bluetooth
  • Infrared
  • Licensed Frequency
  • 2G-2.5G D-AMPS, CDMA, GSM, iDEN, CDPD
  • 3G CDMA2000, W-CDMA
  • Mobile Networking
  • CDPD Wireless packet data
  • iDEN Wireless packet data Mobile IP
  • GPRS EDGE Wireless packet data other mobile
    networking protocols (competition to Mobile IP)

8
802.11
  • Unlicensed Frequency
  • indoor/outdoor coverage with cell sizes ranging
    from 300 feet (indoor) to 1000 feet (outdoor)
  • Bandwidth
  • 802.11b 11Mb/s
  • 802.11a 100Mb/s
  • 802.11g 54Mb/s
  • Effective bandwidth in presence of multiple users
    is less (for instance 6Mb/s in 803.11b)

9
Network Limitations
  • Low bandwidth
  • Limited spectrum, interference
  • High latency (in 2G and 3G)
  • High Bit Error Rate (BER)
  • bad carrier signal, handoffs
  • Frequent disconnection
  • Heterogeneity of network coverage
  • In many cases, lack of network infrastructure ?
    Ad-hoc Networks
  • Preserving Return on Investment in presence of a
    rapidly evolving technology

10
Challenges
Mobile environment differs greatly from the
traditional fixed-network environment. The
difference is limitations that can be divided
into two categories.
  • Platform diversity and limitations which
    platform to use for a certain application?
  • Network limitations -- which network to support?
    What if the devices use different network
    interfaces?

11
Which Platform?
Mobile User
12
Target Platforms
Platform Mobile Information Device (MID) Palm-sized Devices Jupiter class (HPC) Laptops Tablet PC Desktop
Examples Cell phone PDA Tablets Notebook Fujitsu, ViewSonic, .. Workstation
Screen Size Extremely small Small Small to medium Medium to large Medium to large Large
Location/ Use Extremely small and mobile Small and extremely mobile Fairly small and mobile Fairly powerful devices, mobile Fairly powerful devices, mobile Large devices, fixed location
Input devices / navigation Specialized keys. Limited, small keypad and/or pen-based. Usually pen-based, small keyboard Full-size keyboard, mouse, voice Stylus, wireless KB and Voice Keyboard, mouse, voice, etc.
13
Operating Systems
OS KVM Palm OS Symbian EPOC Windows CE / Pocket PC Windows 98/NT/2000, Unix, Mac OS
Memory footprint Very Small small Small to Medium Small to medium Large
Memory requirements A few 100KB 1MB 4MB 4 MB 32 MB 16 MB 32MB gt 32 MB
Development/debugging tools Some Some Some Some Numerous
14
Implementation Language
Language C/C Java C
Code Native, platform specific Universal, platform independent Platform specific
Development difficulty/speed Fair/medium Moderate/fast fair/fast
Porting to other platforms Difficult Very little or no porting Difficult
Development/Debugging tools Excellent Excellent Excellent
Speed Excellent/platform optimized Poor to good, usually not platform optimized Excellent/platform optimized
15
Wireless Infrastructure at UF
  • Recognizing the importance and impact of using
    wireless and mobile technology in education and
    research, the University Network Services and
    Several University Colleges and Schools have
    committed to provide for the indoor and outdoor
    deployment of the 802.11b wireless LAN
    technology.

16
Short History of Wireless at UF
  • Lombardis initiative -- First Wireless Classroom
    Trial in CSE Building, Spring 1999
  • 20 IBM thinkpads, 20 PC cards, two Bay Network
    access points (2Mbps), Static IP configurations
    no authentication
  • The University IE Proposal to the National
    Science Foundation (even though was not funded,
    it brought together awareness and commitment of
    various University entities)
  • Outdoor campus deployment begun (Jan 2001)
  • CISE deployment (May 2001)
  • Law School deployment (July 2001)
  • College of Engineering all-classroom deployment
    (May 2001 Nov 2001)

17
Blueprints of the Big Picture
  • We envision that many educational activities can
    be taken to a higher level of effectiveness if
    this opportune technology is exploited properly.
    In particular, we identify several undergraduate
    curricula that, for a long time, have been
    deprived from having the appropriate computing
    environments that they needed. Botany, geology,
    animal science, agriculture, anthropology, remote
    sensing, architecture, veterinary medicine, civil
    engineering, exercise physiology, and forestry
    are among the many curricula that would benefit
    significantly from the wireless outdoor
    laboratory, a concept that can be achieved with
    todays technology. By bringing the (wireless)
    network and the (portable) computers much closer
    to the actual subjects of study (plants, humans,
    trees, crops, animals, roads, building, etc.), it
    will be possible to design and develop
    substantially effective curricula for
    undergraduate and graduate education.

18
Goals of the Wireless Campus Project
  • Create a Pervasive Computing environment within
    the University of Florida campus, by exploiting
    wireless, mobile networking technology and
    portable computing appliances.
  • Modify and extend existing curricula in several
    major areas to take advantage of the wireless
    connectivity that will blanket UF campus.
  • Explore research issues in Pervasive Computing
    (e.g. projects undertaken in the Harris Lab by
    Dr. Helal)
  • Potentially, integrate some University services
    into the wireless network.

19
Objectives of the Wireless Campus Project
  • Indoor and outdoor wireless connectivity
  • Ideally Single IP, secure roaming solution
    pending industry adoption of IPv6
  • Support for a variety of devices (notebooks,
    iPAQs, Palms, wearable computers, )
  • Different views of network resources for
    different student groups
  • Anticipated use of thin client technology
  • Innovative solutions for software license
    management (not all mobile users active at once
    licenses will need to be spread over multiple
    network domains (unusual)
  • Challenging requirements security scalability

20
International Center on Pervasive Technology for
Successful Aging
Sample Research Activities on Mobile and Wireless
  • Dr. Bill Mann, Director
  • Dr. Sumi Helal, Director of Technology
    Development
  • Rehabilitation Engineering Research Center on
  • Technology for Successful Aging
  • University of Florida

Funded by National Institute on Disability and
Rehabilitation Research
21
Pervasive Technology for Elders
  • Health care system ( Nurses) will not sustain
    the increasing number of elders
  • Goal how to help elders stay at home and live
    independently
  • Broad center activities
  • Create smart spaces
  • Create magic Wands for interaction with smart
    spaces
  • Create and perform extensive testing of
    applications that use the smart home/phone
    infrastructure

22
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23
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24
Sample Applications
Location Tracker elder finds her whereabouts
Security Alert alerting the elder to security breaches
Unlocking Device lock/unlock doors and windows
Intercom elder talks to person at the door
Emergency Alert phone alerts care giver
Reverse Locator others find elders whereabouts
Mapmaker elder finds directions to destinations
Pager for TV Remote phone pages TV remote
Switch functions turn on/off light, stereo, etc.
25
Sample Applications
Alert/Alarm phone alarms elder to take medications
Weather Info elder queries phone for weather conditions
Mail Notification phone notifies elder of mail arrival
Grocery shopping assistant phone as shopping assistant
Dictation phone takes and organize notes from elder
On demand service ordering elder shops (eg. order a pizza)
Remote monitoring phone shows images of remote places
Bookkeeping of health measurements taking blood pressure
26
ICTAPlannedRenovationRoom 447, CSE Bldg.
Main Entrance to ICTA
Video Tele-conferencing
Meeting Table
Front door
Workstations
Elder Home Mockup
Harris Mobile Computing Laboratory
Servers
Window
Workshop Area
Storage Pins
27
Early Prototyping
Video
28
802.11 Wireless Networking
29
History
  • In 1985, as an attempt to stimulate the
    production and use of wireless network products,
    the FCC modified Part 15 of the radio spectrum
    regulation, which governs unlicensed devices. The
    modification authorized wireless network products
    to operate in the Industrial, Scientific, and
    Medical (ISM) bands using spread spectrum
    modulation.

30
FCC ISM Restrictions
  • Frequency restrictions
  • 902-928 MHz
  • 2.4-2.4835 GHz
  • 5.725-5.850 GHz
  • 1 Watt power restriction
  • 100mW for WLANs
  • Spread Spectrum transmission

31
History
  • The first wireless LAN technologies operated in
    the 900MHz band and were low speed (1-2Mbps),
    proprietary offerings.
  • 1992, wireless LAN makers began developing
    products operating in the unlicensed 2.4 GHz
    frequency band.
  • IEEE approved 802.11 standard in 1997

32
802.11 transmission methods
  • FHSS
  • DSSS
  • IR

33
Frequency Hopping Spread Spectrum (FHSS)
  • minimum 75 non-overlapping channels with a
    maximum 1 MHz bandwidth
  • Three possible hop patterns (22 hops in a given
    pattern)
  • Minimum rate of 2.5 hops/s
  • Maximum dwell time of 400ms

34
Direct Sequence Spread Spectrum (DSSS)
  • Combines a data signal with a higher data rate
    bit sequence (chipping code). Minimum of 10.
  • 14 twenty-two MHz channels

35
Characteristics of FHSS
  • Lower cost
  • Lowest power consumption
  • More tolerant to signal interference
  • Lower potential data rates
  • Less range than direct sequence
  • Less interoperability

36
Characteristics of DHSS
  • Highest cost
  • Highest power consumption
  • Less tolerant to interference
  • Highest potential data rates
  • Better range than frequency hopping
  • Better interoperability

37
802.11 Layers
38
802.11 Data Link LayerMechanisms
  • CSMA/CA
  • RTS/CTS
  • CRC checksum
  • Acknowledgments
  • Fragmentation

39
802.11 Features
  • Beacon frames
  • Authentication
  • Roaming
  • Security
  • Power saving

40
Security Features
  • Service Set Identifier (SSID) (also
    called Network Identifier or Network Name)
  • MAC address filtering
  • Wired Equivalent Privacy (WEP) encryption

41
WEP Encryption
  • Algorithm based on RSA RC4 algorithm
  • 40bit and 128bit keys
  • Security partially relies on maintaining the
    secrecy of the WEP key.
  • Shown to be weak

42
Wireless Access Modes
  • Ad hoc
  • Infrastructure

43
802.11 Future
  • 802.11g
  • 2.4Ghz frequency band, gt20Mbps data rate
  • 802.11a
  • 5.7Ghz supporting data rates up to 54Mbs.

44
UF Wireless Deployment
45
UF Wireless Deployment
  • Cisco Aironet 350 series access points
  • Authenticated via Gatorlink userid
  • Not using WEP encryption
  • No registered MAC address
  • Area VLANs and a common configuration to allow
    roaming

46
Compatibility
  • Wireless Ethernet Compatibility Alliance (WECA)
  • Wireless Fidelity - WiFi

47
Channel Coordination
  • 802.11b DSSS hardware only offers 11 channels.
  • At most, only three non-overlapping channels can
    be used (1,6, and 11).
  • Where common channels overlap there will be
    co-channel interference which will negatively
    impact performance.

48
DSSS Channels
49
Channel Coordination
50
Vertical Channel Coordination
51
Basic Topology
Authentication Gateway
Core POP
Access Point
52
VPN Authentication
Authentication Gateway
CORE POP
VPN Concentrator
Access Point
VPN connection
53
VLAN Trunking
  • VLAN trunking (802.1q) allows the transport of
    multiple 'logical' (Virtual) ethernets over one
    single physical ethernet.
  • This allows the delivery of authentication VLANs
    in parallel with building VLAN(s).
  • This use of VLANs allows roaming through wireless
    areas that share the same VLAN.

54
VLAN Trunking Design
CORE POP
Authentication VLAN passes through CORE POP at
layer 2 only and is not routed. Routing for the
VLAN is performed by the Authentication Gateway.
Routed connection for Authentication Network
Authentication VLAN
Authentication Gateway
802.11q Trunk
Authentication VLAN
Access Point
Building VLAN(s)
Building Network(s)
Authentication VLAN
Access Point
BPOP Switch
55
Area VLAN Implementation
CORE POP
Authentication Gateway
Authentication VLAN
802.11q Trunk
Authentication VLAN
Authentication VLAN
Building Network(s)
Building Network(s)
Access Point
Access Point
56
Problems/Issues
  • Departmental wireless networks
  • Rogue wireless networks
  • Interference from other devices
  • Security
  • Malicious interference
  • Interoperability
  • Competing technology
  • Emerging technology

57
Isolated Deployment
  • If you are deploying wireless service and it can
    not be incorporated into the campus plan the
    following steps are critical
  • Contact Network Services to coordinate frequency
    usage.
  • Change the SSID to a non-default setting (and do
    NOT use ufw).
  • Disable the SSID broadcasting capability.

58
Current Wireless Campus Coverage(Spring 2002)
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