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Mobile & Wireless Computing 1© Kemal Akkaya
Department of Computer ScienceSouthern Illinois University Carbondale
CS441 – Mobile & Wireless Computing
Wireless Network ChallengesDr. Kemal AkkayaE-mail: [email protected]
Mobile & Wireless Computing 2© Kemal Akkaya
InstructorDr. Kemal Akkaya, [email protected], Faner 2138Office hours
Monday, Wednesday 1-2pm, Friday 9-9:50am.E-mail is the best way to communicate with me
Class Web Sitehttp://www.cs.siu.edu/~cs441
Teaching assistantMr. Ismail [email protected] hours
T:1:30-3:30pm orBy Appointment
Class Administration: Personnel
Mobile & Wireless Computing 3© Kemal Akkaya
Class AdministrationNo Textbooks
I will provide slides for each chapterThere can be some papers for readingCheck the web site frequently
A reference book“Ad Hoc Wireless Networks, by Murthy and Manoj, 1st Ed., Prentice Hall, 2004. We’ll cover a few chapters from this book
Networking BackgroundNice to have a networking and operating systems background but not mandatory
Rose’s NetworkingTanenbaum’s Networking
We’ll briefly cover them in the class
Mobile & Wireless Computing 4© Kemal Akkaya
What You Need to DoYour prerequisites
Basic concepts of operating systems and networksHighly motivated, critical, dedicated
Your workloadHomework assignments
Reading and summary of some papers/textbook chaptersExplanation for some questions/topics etc.
Hands-on Labs3-4 labs with Sensor motes
Two examsMidterm Final -Comprehensive
Class project (in a small group of around 3 people)Pick a simple protocolExplain and summarize how it worksImplement it in C, C++
Report and presentation on a topic you chooseWe will suggest topics, provide resourcesTopics will be chosen among hot areas in pervasive computing
Mobile & Wireless Computing 5© Kemal Akkaya
Grading Policy and Class SurveyGrading
Please take the class survey
Help me to determine your background
Help me to determine the depth and topics
Suggest topics that you want to be covered
Group project 25%
Midterm Exam 15%
Quizzes 5%
Hands-on Labs 10%
Assignments 10%
Final Exam 20%
Presentation 15%
Mobile & Wireless Computing 6© Kemal Akkaya
Mobile and Wireless Data NetworksExperiencing a tremendous growth over the last decade
Wide deployment of access infrastructureIn-door, out-door, MAN, WAN
Growth of Wireless DataMiniaturization of computing machinery : laptop PDA embedded sensorsIncreasing mobile work forceLuxury of tether less computingInformation on demand anywhere/anyplace
Some Facts:In 2005, more than 1/3rd of internet users had internet connectivity through a wireless enabled device (750 million users)!!! (Source: Intermarket group)In the year 2004 revenue from wireless data was $34B, and by the year 2010 the number of wireless data subscribers will hit 1B!!
What is Mobile and Wireless Computing?Distributed systems with portable computers and wireless communicationsUser can access data anytime, anywhere
Mobile & Wireless Computing 7© Kemal Akkaya
BuzzwordsMobile Computing
Distributed systems with mobile usersIn-door/Out-doorVehicle/human speed
Nomadic ComputingSimilar to Mobile computing
Focuses more on in-door communications
Pervasive Computing : Ubiquitous ComputingMay add some user interface integrationSome says : AI + Mobile Computing stuff
Applications:Military
Border control, target tracking, intrusion detection etc.Civil
Habitat monitoring, search and rescue, meeting rooms etc.
Mobile & Wireless Computing 8© Kemal Akkaya
Wireless Network TypesSatellite networks
Iridium (66 satellites)Qualcomm’s Globalstar (48 satellites)
Wireless WANs/MANsCDPD (Cellular Digital Packet Data )GPRS (General Packet Radio Service)
Wireless LANsIEEE 802.11 : SIU’s LAWN,
Wireless PANse.g. Infrared: Bluetooth
Ad-hoc networkse.g. Emergency relief, military
Sensor networkse.g. Environmental sensing-MICA motes
Wireless WAN Generations:1G (Past)
AMPS, TACS: No data 2G (Past/Present)
IS-136, GSM: <10Kbps circuit switched data
2.5G (Past/Present)GSM-GPRS, GPRS-136: <100Kbps packet switched
3G (Present/Immediate Future)
IMT-2000: <2Mbps packet switched
4G (Future)20-40 Mbps!!
Mobile & Wireless Computing 9© Kemal Akkaya
Examples
PicoNet
Bluetooth
802.11 / WiFi
Wireless LAN
Mobile & Wireless Computing 10© Kemal Akkaya
Applications: Home Networking
Courtesy Dr. Richard Yang, Yale
Mobile & Wireless Computing 11© Kemal Akkaya
Applications: Outdoor Networking
ad ho
cUMTS, WLAN,DAB, GSM, cdma2000, TETRA, ...
Personal Travel Assistant,PDA, laptop, GSM, UMTS, WLAN, Bluetooth, ...
Courtesy Dr. Richard Yang, Yale
Mobile & Wireless Computing 12© Kemal Akkaya
Application: Environmental Monitoring
Wireless Sensor Nodes
monitor an area of interest
Mobile & Wireless Computing 13© Kemal Akkaya
Challenges of Wireless Computing1) Wireless Communication
Implications of using wireless communication for mobile computingThe differences between wireless and wired media
2) MobilityConsequences of mobility on mobile application and system design
3) Poor Resources due to PortabilityPressures that portability places in the design of mobile end-systems
Mobile & Wireless Computing 14© Kemal Akkaya
1) Wireless CommunicationLimited Transmission Range
10m-500m Limited Bandwidth
Wireless networks deliver lower bandwidth than wired networks
1 Mbps Infrared communication11 Mbps wireless local radio communications (shared), IEEE 802.11b9.6 Kbps for wide-area wireless communication
Wired networks10-100 Mbps for Ethernet100 Mbps for FDDI155 Mbps for ATM1 Gbps for Gigabit Ethernet
DisconnectionsNetwork partitionsStall all applications
Uncertainty of PerformanceVariance of bit errorsVariance of delaysVariance of bandwidth
SecurityEasy to intrude in the wireless network
Heterogeneous devices and network connections
Wired links Same characteristics
Outdoor: RadioIndoor: InfraredRural Areas: Satellite
Mobile & Wireless Computing 15© Kemal Akkaya
Heterogeneous Devices
PPerformanceerformance/Weight/Power Consumption/Weight/Power Consumption
Sensors,embeddedcontrollers
Mobile phones• voice, data• simple graphical displays• GSM
PDA• data• simpler graphical displays• 802.11
Laptop• fully functional• standard applications• battery; 802.11
Desktop• fully functional• standard applications• unlimited power supp• Gbps Ethernet
Mobile & Wireless Computing 16© Kemal Akkaya
2) MobilityAbility to change locations while connected to the network
A mobile computer can change its serverDNS server, print server, etc.
Dynamic EnvironmentNetwork Access Point Changes
Address changes: IP addressNetwork Performance Changes
Bandwidth, delay, error rate etc.Available resources change
Depends on the network it connected toData consistency changes
Writing/Reading to/from mobile databasesSecurity changes
Endpoint authentication harder
Mobile & Wireless Computing 17© Kemal Akkaya
3) Poor ResourcesMobile devices are fundamentally different from stationary machines such as desktop computers
Must be designed with variety of constraints in mind, such as size and power consumption – properties much like a wristwatchThey should also be portable
Portability Constraints IncludeLow power consumption
You would not want to carry a battery that is bigger than your computer! Increased risk of data loss
Physical damageUnauthorized accessLoss and Theft
Small user-interfacesRequires a different windowing scheme Buttons versus Recognition
Limited on-board storage, memory, CPU etcPhysical restrictions, power constraints
Mobile & Wireless Computing 18© Kemal Akkaya
SummaryWireless communication brings challenging network conditions
Slow and sometime disconnected communicationMobility causes greater dynamicisim of informationPortability results limited resources to be available on board Mobile computing designers should consider these issues in designing mobile systems, applications and networks that are comparable with the traditional stationary computing and communication in terms of operation, performance, and availabilityVery active research area in the last decade
Many interesting research problems