CS5530 Mobile/Wireless Systems Introduction

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1 Mbile/Wireless Systems Intrductin Yanyan Zhuang Department f Cmputer Science UC. Clrad Springs

2 Intr f Intr Yanyan Zhuang PhD in netwrk systems yzhuang@uccs.edu Office hurs M/W: an hur after class F: 11am 12pm Blackbard: annuncement, schedules 2

3 Outline Why study mbile/wireless systems? What will yu learn? Lectures, Assignments, Prjects, Exams Curse plicy Overview 3

4 Why study mbile/wireless systems? Where des Internet cme frm? Cmputer center à Cmputer netwrks à Internet Wireless Mbility, flexibility 4

5 What will yu learn? Hw d wireless netwrks wrk? WiFi, cellular, Bluetth, etc. N heavy math! Hw t prgram n end-user devices? ios Andrid 5

6 Lectures, Assignments, Prject, Exams Lectures Mnday and Wednesday 4:45PM 6:00 PM ENGR 138 Assignments (individual) ios/andrid prgramming assignments Research prject (individual r in grups) Chse a tpic that interests yu, talk t me befre yu start Midterm and Final (nline, pen-bk, limited time) Midterm TBD, mid/late March (take hme) Final: 5:20 7:20 pm, May 10 (in class) hedule.pdf 6

7 Curse Plicy Grading scale Percentage Grade A A B B C C D D Belw 60 F 7

8 Curse Plicy (cnt.) Grading percentage Assignments: 40% Research prject: 20% Midterm: 20% Final exam: 20% 8

9 Where t get help? Q&A in class Office hurs M/W ne hur after class 6-7pm F: 11:00am -- 12:00pm By appintment ENGR 184 9

10 Overview 10

11 What is a Wireless Netwrk First, what is a netwrk? Cmputer netwrks } A large number f separate but intercnnected cmputers } The cnnectin: via a cpper wire, fiber ptics, micrwaves, infrared, satellites, and s n Internet } The mst well-knwn netwrk f netwrks 11

12 Where did Internet cme frm? ARPANET ( ): Advanced Research Prjects Agency Netwrk Funded by Advanced Research Prjects Agency (ARPA) f United States Department f Defense Gal: netwrk academic cmputers (UCLA, SRI, UCSB, Utah -- first ndes in 1969) 1971: ~20 ARPANET ndes 12

13 Where did Internet cme frm? Rugh sketch: late 1960s 13

14 1970s CS4500/5500 t 1980s: ARPANET UC. Clrad transitined Springs Ref. MOS4E, t TCP/IP OS@Austin, Clumbia, UWisc

15 Grwth f Internet Hsts 15

16 What is a Wireless Netwrk (cnt.) Use f netwrks Business, hme use Mbile users } Peple n the g want t d all things they d at hme and in ffice } Mbile cnnectivity } Cellular, WiFi (IEEE ) Different mbile systems Smartphnes/tablets/smart watch GPS RFID (Radi-Frequency IDentificatin) 16

relay infrmatin they sense abut the state f the physical wrld } The ndes may be cars r

17 What is a Wireless Netwrk (cnt.) Sme ther wireless netwrks Sensr netwrks } Made up f ndes that gather and wirelessly relay infrmatin they sense abut the state f the physical wrld } The ndes may be cars r phnes, r may be separate devices Car s OBD sensrs Separate devices accelermeters, barmeters, cean bttm seismmeters, pressure recrders and hydrphne 17

18 Netwrk Reference Mdel A fur layer mdel based n experience 4 Applicatin Prgrams that use netwrk service 3 Transprt Prvides end-t-end data delivery 2 Internet Send packets ver multiple netwrks 1 Link Send frames ver a link 18

19 Netwrk Reference Mdel (cnt.) A fur layer mdel based n experience Every Internet device must speak! 4 Applicatin 3 Transprt 2 Internet 1 Link SMTP HTTP RTP DNS TCP IP Ethernet Cable DSL UDP 3G netwrk layer 19

20 LAN and WLAN Wireless ruter / Base statin The standard fr wireless LANs is called IEEE , ppularly knwn as WiFi 20

21 Wireless vs. Wired Link layer 4 Applicatin 3 Transprt 2 Internet SMTP HTTP RTP DNS TCP IP UDP Medium: pen air N wiring required Less secure than wired netwrks 1 Link Ethernet Cable DSL 3G It s a lt mre difficult fr unauthrized eavesdrppers and ther snps t mnitr data in a wired netwrk 21

22 Wireless vs. Wired Advantage Allws mbility Much cheaper and easier t deply, change, and upgrade Disadvantage Expsed (unshielded) medium } Susceptible t physical phenmena (interference) } Mre errrs Slwer data rates fr lnger distances Security: anyne in range hears transmissin 22

23 Wireless Standards Cellular 2G: GSM, CDMA 3G: CDMA2000, WCDMA, TD-SCDMA 4G/5G/LTE IEEE a: 5.0Ghz band, 54Mbps (25 Mbps perating rate) b: 2.4Ghz band, 11Mbps (4.5 Mbps perating rate) g: 2.4Ghz, 54Mbps (19 Mbps perating rate) Other versins (802.11n, p, etc.) IEEE : lw pwered wireless : 2.4Ghz, 2.1 Mbps (Bluetth) : 2.4Ghz, 250 Kbps (Sensr Netwrks) 23

24 Wireless Link Characteristics 24

25 Wireless Transmissin Range The range that the receiver is just able t receive/decde the signal 1. Transmissin pwer 2. Signal-t-nise rati 25

26 A Wireless Link? 26

27 A Wireless Link! 27

28 Sme ther issues Hidden terminals A B C A and C can bth send t B but can t hear each ther A is a hidden terminal fr C and vice versa 28

29 Sme ther issues (cnt.) Expsed terminals A B C D Expsed nde: B sends a packet t A; C hears this and decides nt t send a packet t D (despite that this will nt cause interference) 29

30 Summary What is a netwrk Different kinds f wireless netwrks Wireless standards Issues with wireless netwrks 30

CS4500/5500 Operating Systems Introduction

CS4500/5500 Operating Systems Introduction Operating Systems Intrductin Yanyan Zhuang Department f Cmputer Science http://www.cs.uccs.edu/~yzhuang UC. Clrad Springs Ref. MOS4E, OS@Austin, Clumbia, UWisc Intr f Intr Yanyan Zhuang PhD in netwrk systems