CS 6910 Pervasive Computing Spring 2007 Section 1

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CS 6910 – Pervasive Computing Spring 2007 Section 1 (Ch. 1): Introduction to Wireless

CS 6910 – Pervasive Computing Spring 2007 Section 1 (Ch. 1): Introduction to Wireless and Mobile Systems Prof. Leszek Lilien Department of Computer Science Western Michigan University Slides based on publisher’s slides for 1 st and 2 nd edition of: Introduction to Wireless and Mobile Systems by Agrawal & Zeng © 2003, 2006, Dharma P. Agrawal and Qing-An Zeng. All rights reserved. Some original slides were modified by L. Lilien, who strived to make such modifications clearly visible. Some slides were added by L. Lilien, and are © 2006 -2007 by Leszek T. Lilien. Requests to use L. Lilien’s slides for non-profit purposes will be gladly granted upon a written request.

Chapter 1 INTRODUCTION [Image of 2 nd ed. cover added by L. Lilien. ]

Chapter 1 INTRODUCTION [Image of 2 nd ed. cover added by L. Lilien. ] Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 2

Pervasive vs. Wireless & Mobile Systems n Evolution n Distributed Computing (DIST) n n

Pervasive vs. Wireless & Mobile Systems n Evolution n Distributed Computing (DIST) n n Wireless Computing n n Really: Wireless & Mobile Computing Pervasive Computing (PERV) Note: Textbook uses “wireless” and “mobile” as synonyms n n Originally non-mobile wireless only Mobile Computing (MOBI) n n Originally wireline only Not precise: e. g. , can have wireless but not mobile Q: Why to study Wireless & Mobile Computing? A: It is foundation for PERV, its critical technology & building block Some other technologies for Pervasive Computing: n n n Embedded computing Sensornets Opportunistic networks (oppnets) and systems n See Lecture Section 0. B Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 3

1. 1. The History of Mobile Radio Communication (1/3) Emphasis (underlines) on this and

1. 1. The History of Mobile Radio Communication (1/3) Emphasis (underlines) on this and next 2 slides added by LTL n n n n 1880: Hertz – Initial demonstration of practical radio communication 1897: Marconi – Radio transmission to a tugboat over an 18 mi path 1921: Detroit Police Department: -- Police car radio dispatch (2 MHz frequency band) 1933: FCC (Federal Communications Commission) – Authorized four channels in the 30 to 40 MHz range 1938: FCC – Ruled for regular service 1946: Bell Telephone Laboratories – 152 MHz (Simplex) 1956: FCC – 450 MHz (Simplex) 1959: Bell Telephone Laboratories – Suggested 32 MHz band for high capacity mobile radio communication 1964: FCC – 152 MHz (Full Duplex) 1964: Bell Telephone Laboratories – Active research at 800 MHz 1969: FCC – 450 MHz (Full Duplex) 1974: FCC – 40 MHz bandwidth allocation in the 800 to 900 MHz range 1981: FCC – Release of cellular land mobile phone service in the 40 MHz bandwidth in the 800 to 900 MHz range for commercial operation Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 4

The History of Mobile Radio Communication (2/3) n n n n n 1981: AT&T

The History of Mobile Radio Communication (2/3) n n n n n 1981: AT&T and RCC (Radio Common Carrier) reach an agreement to split 40 MHz spectrum into two 20 MHz bands. Band A belongs to nonwireline operators (RCC), and B belongs to wireline operators (telephone companies). Each market has two operators. 1982: AT&T is divested, and seven RBOCs (Regional Bell Operating Companies) are formed to manage the cellular operations 1982: MFJ (Modified Final Judgment) is issued by the government DOJ [LTL: Dept of Justice]. All the operators [LTL: RBOCs] were prohibited to (1) operate long-distance business, (2) provide information services, and (3) do manufacturing business 1983: Ameritech system in operation in Chicago 1984: Most RBOC markets in operation 1986: FCC allocates 5 MHz in extended band 1987: FCC makes lottery on the small MSA [LTL: Metropolitan Statistical Area] and all RSA [LTL: Rural Service Area] licenses 1988: TDMA (Time Division Multiple Access) voted as a digital cellular standard in North America 1992: GSM (Groupe Speciale Mobile) operable in Germany D 2 system Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 5

The History of Mobile Radio Communication (3/3) n n n n 1993: CDMA (Code

The History of Mobile Radio Communication (3/3) n n n n 1993: CDMA (Code Division Multiple Access) voted as another digital cellular standard in North America 1994: American TDMA operable in Seattle, Washington 1994: PDC (Personal Digital Cellular) operable in Tokyo, Japan 1994: Two of six broadband PCS (Personal Communication Service) license bands in auction 1995: CDMA operable in Hong Kong 1996: US Congress passes Telecommunication Reform Act Bill 1996: The auction money for six broadband PCS licensed bands (120 MHz) almost reaches 20 billion US dollars 1997: Broadband CDMA considered as one of the third generation mobile communication technologies for UMTS (Universal Mobile Telecommunication Systems) n n During the UMTS workshop conference held in Korea 1999: ITU (International Telecommunication Union) decides the next generation mobile communication systems (e. g. , W-CDMA, cdma 2000, etc. ) 2001: W-CDMA commercial service beginning from October in Japan 2002: FCC approves additional frequency band for Ultra-Wideband (UWB) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 6

[LTL: ] RF = radio frequency Copyright © 2003, Dharma P. Agrawal and Qing-An

[LTL: ] RF = radio frequency Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 7

Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 8

Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 8

Applications [LTL: ] Wireless Telephone Washington, DC Cincinnati, OH [LTL: ] User moves but

Applications [LTL: ] Wireless Telephone Washington, DC Cincinnati, OH [LTL: ] User moves but phone # unchanged Maintaining the telephone number across geographical areas in a wireless and mobile system Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 9

Generations of Wireless Systems & Services n 1 G - First Generation n 2

Generations of Wireless Systems & Services n 1 G - First Generation n 2 G - Second Generation n n Primarily for voice communication Using FDM (frequency division multiplexing) Emphasis still on voice communication but allows for… … Data communication Using TDM (time division multiplexing) Indoor/outdoor and vehicular environment 3 G - Third Generation n n Integrated voice, data, and multimedia communication Need for: n High volume of traffic / Real time data communication n Flexibility, incl. n n Frequent Internet access Multimedia data transfer Compatibility with 2 G Using compression n Without compromising quality n n Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 10

First Generation Wireless Systems and Services Emphasis (underlines) and text in square brackets on

First Generation Wireless Systems and Services Emphasis (underlines) and text in square brackets on this and next slide added by LTL Note: “Cellular systems” called “mobile systems” outside North America. 1970 s Developments of radio and computer technologies for 800/900 MHz mobile communications [1 st mobile band] 1976 WARC (World Administrative Radio Conference) allocates spectrum for cellular radio 1979 NTT (Nippon Telephone & Telegraph) introduces the first cellular system in Japan 1981 NMT (Nordic Mobile Telephone) 900 system introduced by Ericsson Radio System AB and deployed in Scandinavia 1984 AMPS (Advanced Mobile Phone Service) [cellular] introduced by AT&T in North America Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 11

Second Generation Wireless Systems and Services 1982 CEPT (Conference Europeenne des Post et Telecommunications)

Second Generation Wireless Systems and Services 1982 CEPT (Conference Europeenne des Post et Telecommunications) established GSM [global special mobile] to define future Pan-European Cellular Radio Standards 1990 Interim Standard IS-54 (USDC [US digital cellular]) adopted by TIA (Telecommunications Industry Association) 1990 Interim Std IS-19 B (NAMPS [narrowband AMPS]) adopted by TIA 1991 Japanese PDC (Personal Digital Cellular) system standardized by the MPT (Ministry of Posts and Telecommunications) 1992 Phase I GSM system is operational 1993 Interim Standard IS-95 (CDMA) adopted by TIA 1994 Interim Standard IS-136 adopted by TIA 1995 PCS Licenses [added 2 nd band (1900 MHz)] issued in North America 1996 Phase II GSM operational 1997 North American PCS deploys GSM, IS-54, IS-95 1999 IS-54: in North America IS-95: in North America, Hong Kong, Israel, Japan, China, etc GSM: in 110 countries Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 12

Two Basic Technology Choices for 3 G n n n Basic technology in the

Two Basic Technology Choices for 3 G n n n Basic technology in the U. S. n cdma 2000 Basic technology in Europe & Japan n W-CDMA Similar but design & implementation differences Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 13

Third Generation Wireless Systems and Services (1/2) n n IMT-2000 (International Mobile Telecommunications-2000): -

Third Generation Wireless Systems and Services (1/2) n n IMT-2000 (International Mobile Telecommunications-2000): - Fulfill one's dream of anywhere, anytime communications a reality. Key Features of IMT-2000 include: - High degree of commonality of design worldwide; - Compatibility of services within IMT-2000 and with the fixed networks; - High quality; - Small terminal for worldwide use; - Worldwide roaming capability; - Capability for multimedia applications, and a wide range of services and terminals. Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 14

Third Generation Wireless Systems and Services (2/2) n n n Important Component of IMT-2000

Third Generation Wireless Systems and Services (2/2) n n n Important Component of IMT-2000 is ability to provide high bearer rate capabilities: - 2 Mbps for fixed environment; - 384 Kbps for indoor/outdoor and pedestrian environments; - 144 Kbps for vehicular environment. Standardization Work: - Release 1999 specifications - In processing Scheduled Service: - Started in October 2001 in Japan (W-CDMA) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 15

Future: 4 G n n n Expected to implement all standards from 2 G

Future: 4 G n n n Expected to implement all standards from 2 G & 3 G Infrastructure only packet-based, all-IP Some of the standards paving the way for 4 G: n Wi. Max n Wi. Bro (Korean) n 3 GPP Long Term Evolution n n To improves the UMTS mobile phone standard Work-in-progress technologies n E. g. , HSOPA, a part of 3 GPP Long Term Evolutionon Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 16

Subscriber Growth for Wireless Phones Subscribers 3 G Subscribers 2 G Digital-only Subscribers 1

Subscriber Growth for Wireless Phones Subscribers 3 G Subscribers 2 G Digital-only Subscribers 1 G Analog-only Subscribers 90 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 9 1 1 1 1 1 2 2 2 Year Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 17

China Leads World in Mobile Phone Users n n n Total [World] Mobile Users

China Leads World in Mobile Phone Users n n n Total [World] Mobile Users Total [World] Analogue Users > 800 million > 70 million [2003] ZDNet UK reports that the number of mobile phone users in China reached 167 million in April, 2002, a rise of 6 million subscribers on March, 2002. The US, which is the second biggest market, has 136 million subscribers. Mobile phones are the preferred mode of communication in Japan, with 56. 8 million subscribers as of the end of March, 2003. Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 18

Flexibility & Versatility of 3 G n Many diverse subsystems n n Different requirements

Flexibility & Versatility of 3 G n Many diverse subsystems n n Different requirements for different needs Different characteristics n Corresponding to the requirements Different coverage areas Cell = area that can be covered by a single transmitting station (usually called base station) n Picocells, microcells, macrocells & global “cell” n n Figure – next slide Why different cell sizes? n Limited nr of channels per cell n Smaller cells can serve more users n E. g. 2 x smaller => can serve 2 x more users on the same band (with smaller range) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 19

Coverage Aspect of Next Generation Mobile Communication Systems Satellite In-Building Urban Suburban Global Picocell

Coverage Aspect of Next Generation Mobile Communication Systems Satellite In-Building Urban Suburban Global Picocell Microcell Macrocell Global Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 20

Transmission Capacity Global System for Mobile Communications as a Function of Mobility Vehicular Pedestrian

Transmission Capacity Global System for Mobile Communications as a Function of Mobility Vehicular Pedestrian Stationary 0. 01 Universal Mobile Broadband radio Telecommunica tions System Mobile Broadband System Local Multipoint Distribution System Satellite Universal Mobile Telecommunica- tions System 0. 1 Broadband Satellite Multimedia 1 10 100 Data Rate (Mb/s) Transmission capacity as a function of mobility in some radio access systems Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 21

1. 2. Characteristics of Cellular Systems Wireless Technology & Associated Characteristics [From 1 st

1. 2. Characteristics of Cellular Systems Wireless Technology & Associated Characteristics [From 1 st ed. slides – Slightly modified by LTL] n n Wireless Technologies n Cellular n WLAN (Wireless LAN) n GPS n Satellite Based PCS n Campus network (e. g. , Ricochet, Carnegie Mellon U. ) n Home Networking n Ad Hoc Networks n WPAN (Wireless PAN = [personal area network]) n Incl. Bluetooth n Sensor Networks Different technologies needed for different applications -- Details on the next slide – Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 22

[LTL: Yellow and red highlights added] (phone calls) (CMU campus) (also oppnets, IANs) (WPAN

[LTL: Yellow and red highlights added] (phone calls) (CMU campus) (also oppnets, IANs) (WPAN = wireless personal area network) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 23

Wireless Technologies for Application Classes [LTL: Yellow and red highlights added] n Notice the

Wireless Technologies for Application Classes [LTL: Yellow and red highlights added] n Notice the following: n Infrastructure-based networks vs. ad hoc networks (p. 11/2) n Terms & acronyms: n Access point – AP (p. 8/-1, 10/2) n Mobile station – MS (p. 11/2) n Handoff and switching radio resources (p. 11/3) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 24

Application Example: Medical Application ATM backbone network Remote databases In hospital physician ATM switch

Application Example: Medical Application ATM backbone network Remote databases In hospital physician ATM switch Wireless remote consultation Ambulance Possibility for remote consulting (including audio visual communication) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 25

Wireless Features & Their Potential Apps [LTL: ] n Notice the following (p. 11/-1):

Wireless Features & Their Potential Apps [LTL: ] n Notice the following (p. 11/-1): n “Anytime anywhere” not always required n Often “many time” or “many where” is adeqate n n Permanent connectivity not necessary MS can: n Start transaction at AP 1, then move away (loosing connection to it) n Get close to AP 99 & complete transaction at AP 99 Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 26

1. 3. Fundamentals of Cellular Systems Ideal cell area (2 -10 km radius) (circle)

1. 3. Fundamentals of Cellular Systems Ideal cell area (2 -10 km radius) (circle) Cell Alterative shape of a cell (square) BS MS MS Hexagonal cell area used in most models Illustration of a cell with a mobile station (MS) and a base station (BS) [LTL: ] n n n Cell shapes (above) Actually, cell may have a zigzag shape Hexagon is a good approximation in practice n Also, gives non-overlapping cells n (used by clever bees for beehives) E. g. , circles would either overlap, or would have gaps in between Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 27

Cell Bandwidth Limitations & Multiplexing n n n Single BS per cell => limited

Cell Bandwidth Limitations & Multiplexing n n n Single BS per cell => limited bandwidth per cell Increase bandwidth use efficiency by multiplexing MS MS B S Service area (Zone) 4 +1 basic multiplexing techniques n n n FDMA – frequency division multiple access TDMA – time division multiple access CDMA – code division multiple access OFDM – orthogonal frequency division multiplexing New: SDMA – space division multiple access n Specialized for microwave antennas Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 28

FDMA (Frequency Division Multiple Access) [LTL: ] n n Used in all 1 G

FDMA (Frequency Division Multiple Access) [LTL: ] n n Used in all 1 G cellular systems BS allocates to each of n users a channel (a frequency subband) for time the user needs it Frequency User n … User 2 User 1 Time Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 29

FDMA Bandwidth Structure 1 2 3 4 … n Frequency Total bandwidth [LTL: ]

FDMA Bandwidth Structure 1 2 3 4 … n Frequency Total bandwidth [LTL: ] Divided into n channels (frequency subbands) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 30

FDMA Channel Allocation Channel 1 User 1 User 2 … User n Channel 2

FDMA Channel Allocation Channel 1 User 1 User 2 … User n Channel 2 … Channel n Mobile Stations Base Station Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 31

TDMA (Time Division Multiple Access) [LTL: ] time slot … User n Frequency User

TDMA (Time Division Multiple Access) [LTL: ] time slot … User n Frequency User 2 n Used in most 2 G cellular systems BS allocates to each user full bandwidth for duration of a User 1 n Time Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 32

TDMA Frame Structure 1 2 3 4 … n Time Frame Divided into n

TDMA Frame Structure 1 2 3 4 … n Time Frame Divided into n time slots (by a round-robin method) [LTL: ] Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 33

TDMA Frame Illustration for Multiple Users [LTL: ] Note: Non-overlapping time slices “Time 2”

TDMA Frame Illustration for Multiple Users [LTL: ] Note: Non-overlapping time slices “Time 2” slot starts after “Time 1” slot is over, etc. User 1 Time 1 User 2 User n n Mobile Stations Time 2 … n … Time n Base Station Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 34

CDMA (Code Division Multiple Access) n CDMA a. k. a. spread spectrum technique n

CDMA (Code Division Multiple Access) n CDMA a. k. a. spread spectrum technique n Used in some 2 G and most 3 G cellular systems n Simultaneous transmission of data from multiple users on full frequency band n Figure shows all users using: Same range of frequencies n Same time range But n Different codes n n CDMA is enabled by orthogonal codes (= keys) n One distinct code assigned by BS to each user Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 35

CDMA (Code Division Multiple Access) – cont. n CDMA transmission n Transmitter: n n

CDMA (Code Division Multiple Access) – cont. n CDMA transmission n Transmitter: n n Codes (using the key) each user’s data “stream” Puts all coded individual data “streams” on data link n n Receiver: n n Creates a common “mixed” data stream Gets common “mixed” data stream from data link Uses keys to decode (“unmix”) individual data stream from the “mixed” data stream # of simultaneous users limited by # of possible orthogonal codes Complex but robust technique Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 36

[SKIP: ] Transmitted & Received Signals in a CDMA System [LTL: ] 10 -bit

[SKIP: ] Transmitted & Received Signals in a CDMA System [LTL: ] 10 -bit codewords Information bits Code at transmitting end Transmitted signal Received signal Code at receiving end Decoded signal at the receiver Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 37

Frequency Ranges used for FDMA, TDMA & CDMA Copyright © 2003, Dharma P. Agrawal

Frequency Ranges used for FDMA, TDMA & CDMA Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 38

OFDM (Orthogonal Frequency Division Multiplexing) n n OFDM idea – to reduce interference n

OFDM (Orthogonal Frequency Division Multiplexing) n n OFDM idea – to reduce interference n Convert single high-speed data stream to multiple lowspeed data streams n Low-speed data streams sent in parallel using (sub)channels working on multiple-frequencies Frequencies of subchannels in FDMA vs. OFDM n FDMA – non-overlapping frequencies of subchannels n n Figure: Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved Even with gaps between subchannel bands to reduce interference OFDM - overlapping frequencies of subchannels Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 39

Variants & Combinations of FDMA, TDMA & CDMA n n Many variants & combinations

Variants & Combinations of FDMA, TDMA & CDMA n n Many variants & combinations of FDMA, TDMA & CDMA beyond the scope of this discussion Frequency hopping – combines FDMA & TDMA n n Idea: One user uses one channel for a time slot, then changes to another channel for another time slot n See the next slide n Receiver needs to know frequency hopping sequence Main advantage (e. g. , in defense applications): Message gets through even if one frequency band jammed Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 40

Frequency Hopping Each user gets one time slot per frame, on a different frequency

Frequency Hopping Each user gets one time slot per frame, on a different frequency (round-robin used for frequency selection) [LTL: ] Frequency Frame Slot f 1 f 2 f 3 f 4 f 5 Time Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 41

1. 4. Cellular System Infrastructure BS Service area (Zone) Early wireless system: Large zone

1. 4. Cellular System Infrastructure BS Service area (Zone) Early wireless system: Large zone [LTL: ] n n Large zone requires a high-power BS Better: replace large zone with smaller hexagonal zones (next slide) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 42

Cellular System: Small Zone BS BS Service area BS BS BS [LTL: ] n

Cellular System: Small Zone BS BS Service area BS BS BS [LTL: ] n BS covers much smaller area now n Requires much less power (for a given area) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 43

Cellular System Infrastructure n Various kinds of Mobile Stations (MSs) a. k. a. wireless

Cellular System Infrastructure n Various kinds of Mobile Stations (MSs) a. k. a. wireless devices n n Cellphone, PDA, Palm. Pilot, laptop with Wi. Fi card, … MSs need connectivity on the move n E. g. , connectivity from BSs in the cells they visit n n BS is a gateway to wired infrastructure Typical support for MSs: Cellular infrastructure n See next slide Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 44

MS, BSC, MSC, and PSTN wired link PSTN Home phone … MSC BSC …

MS, BSC, MSC, and PSTN wired link PSTN Home phone … MSC BSC … … BS MS BS MS … BSC … BS MS [LTL: ] n n n Several BSs connected via wireline links to one BSC (BS controller) Several BSCs connected via wireline links to one MSC (Mobile Switching Center) Several MSCs interconnected via wireline links to PSTN (Public Switched Telephone Network) and the ATM backbone Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 45

BS Structure n BS consists of n Base Tranceiver System (BTS) n Includes tower

BS Structure n BS consists of n Base Tranceiver System (BTS) n Includes tower & antenna n BSC n Contains all associated electronics Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 46

MSC Database Supporting MS Mobility & Incoming Call Scenario n MSC database for supporting

MSC Database Supporting MS Mobility & Incoming Call Scenario n MSC database for supporting MS mobility 1) Home location register (HLR) for MS n n Located at the “home MSC” for MS n Where MS is registered, billed, etc. Indicates current location of MS n Could be within home MSC’s area OR n Could be in the area of any MSC in the world 2) Visitor location register (VLR) on each MSC n n Contains info on all MSs visiting area of this MSC Incoming call scenario n Based on the called #, incoming call for an MS is directed to the HLR of the “home MSC” for this MS n HLR redirects the call to MSC/BS where the MS is now n VLR of the “current MSC” has info on MS (one of visiting MSs) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 47

Control and Traffic Channels l c o r nt e nn ha o c

Control and Traffic Channels l c o r nt e nn ha o c k) h n Note: Forward/reverse in the U. S. , downlink/uplink elsewhere li n ow (d rd n pli u F ( e s er v Re ( d r a rw Fo Mobile Station nt o ) c k a orw c l o r nli w o h c c i f f n el n an a tr k) d e s r e n an l el el n an ch c ffi a tr k) n li p u ( v Re Base Station [LTL: ] n 4 simplex channels needed for control & traffic n 2 control channels n n n Exchange control msgs Forward channel & reverse channel 2 traffic channels n n For data Forward channel & reverse channel Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 48

More on Control and Traffic Channels [LTL: ] n n n Traffic channels used

More on Control and Traffic Channels [LTL: ] n n n Traffic channels used for call duration => Large # of traffic channels on each BS Handshake steps for call setup use control channels Control channels used for short duration => Small # of control channels on each BS n MSs compete for these few control channels n For call setup, etc. Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 49

Steps for a Call Setup from MS to BS [LTL: ] Steps for a

Steps for a Call Setup from MS to BS [LTL: ] Steps for a call setup from MS to BS n When MS initiates a call BS MS 1. Need to establish path 2. Frequency/time slot/code assigned (FDMA/TDMA/CDMA) Time n 3. Control information acknowledgement 4. Start communic. on assigned traffic channel Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 50

Steps for a Call Setup from BS to MS [LTL: ] Steps for a

Steps for a Call Setup from BS to MS [LTL: ] Steps for a call setup from BS to MS: n When MS responds to a call (somebody calls MS) BS MS 1. Call for MS # pending 2. Ready to establish a path 3. Use frequency / time slot / code (FDMA/TDMA/CDMA) Time n 4. Ready for communication 5. Start communic on assigned traffic channel Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 51

A Simplified Wireless Communication System Representation [LTL: ] n n n The figure shows

A Simplified Wireless Communication System Representation [LTL: ] n n n The figure shows major steps in wireless communications Signal processing operations – beyond the lecture scope Lecture will concentrate on system aspects of wireless data communication Antenna Information to be transmitted (Voice/Data) Coding Modulator Transmitter Carrier Information received (Voice/Data) Decoding Demodulator Antenna Receiver Carrier Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 52

1. 5. Satellite Systems n Application areas of satellite systems n Traditional Applications n

1. 5. Satellite Systems n Application areas of satellite systems n Traditional Applications n Weather satellite n Radio and TV broadcasting n Military satellites n Navigation and localization (e. g. , GPS) n Telecommunication Applications n Global telephone connections n Backbone for global network n Connections for communication in remote places or underdeveloped areas n Global mobile communications Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 53

Basic Concepts & Terminology n Only LOS communication is possible n n n LOS

Basic Concepts & Terminology n Only LOS communication is possible n n n LOS = line of sight Satellites further away from earth cover a wider area Satelites can emit one or more satellite beams Satellites w. r. t. position over earth n Geostationary n Rotating around the earth ES – earth station Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 54

History of Satellite Systems 50 th anniversary of the space age on October 4,

History of Satellite Systems 50 th anniversary of the space age on October 4, 2007 Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 55

1. 6. Network Architectures and Protocols n n [LTL: ] Protocol = basic set

1. 6. Network Architectures and Protocols n n [LTL: ] Protocol = basic set of rules followed to provide systematic signaling steps for information exchange n Other protocols: Diplomatic protocols, protocol to login, … [LTL: ] We will cover later following protocol reference models and protocols: n Open Systems Interconnections (OSI) reference model n Transmission Control Protocol (TCP) (on top of IP) n Internet Protocol (IP) n Internet Protocol Version 4 (IPv 4) n Internet Protocol Version 6 (IPv 6) – work in progress n Mobile IP (MIP) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 56

1. 7. Ad Hoc Network n n [LTL: ] Ad hoc network (AHN) Def

1. 7. Ad Hoc Network n n [LTL: ] Ad hoc network (AHN) Def 1: AHN is a local network with wireless connections or temporary plug-in connections, in which mobile or portable device are a part of the network only while they are in close proximity Def 2: AHN is a collection of wireless MHs forming a temporary network without the aid of any centralized administration or standard support services regularly available on the wide area network (WAN) to which the hosts may normally be connected Examples: n n AHN 1: Instructor’s and students’ computers can create an AHN during lectures AHN 2: Oppnet used after an earthquake Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved © 2007 by Leszek T. Lilien 57

1. 7. MANET n n [LTL: ] MANET = mobile ad hoc network -

1. 7. MANET n n [LTL: ] MANET = mobile ad hoc network - an autonomous system of mobile nodes, mobile hosts (MHs), or mobile stations (MSs) connected by wireless links MSs of a MANET also serve as routers n These routers are mobile n Route messages from SRC to DEST - see Figure n Multihop routing n Store-and-forward passing of info in P 2 P (peer-to-peer) way Source Destination Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 58

MANETs – cont. 1 n n MANETs are highly dynamic n All nodes, incl.

MANETs – cont. 1 n n MANETs are highly dynamic n All nodes, incl. routers, are mobile => topology highly dynamic, unpredictable n Topology change due to MSs mobility made known to (some) other nodes Types w. r. t. infrastructure support n Stand alone - no infrastructure support n Limited infrastructure support n Some routers have access to a fixed infrastructure n n E. g. , access to Internet – like in oppnets E. g. , stub network (SN) – n Stub network = a single LAN which never carries packets between two remote hosts; all traffic is to and/or from local hosts n Multiple routers on SN don't route to one another, they will only route a packet into SN (if it's destined for SN), and out from SN (if it originated on SN) [cf. “stub network“ in Wikipedia] Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 59

MANETs – cont. 2 n n Location of MSs in a MANET: within buildings,

MANETs – cont. 2 n n Location of MSs in a MANET: within buildings, highways, vehicles, on and within human bodies MANET nodes equipped with a “radio” “Radio” = wireless transmitter & receiver (or: wireless transceiver) n With antenna n Types of antennas: n n n Omnidirectional Directional Steerable Any combination of these Xmit/rcv parameters affect MANET topology at any given moment Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 60

Wireless Sensor Networks n (Ad Hoc) Wireless Sensor Networks (WSNs) – a specialized subclass

Wireless Sensor Networks n (Ad Hoc) Wireless Sensor Networks (WSNs) – a specialized subclass of AHNs n Sensor(s) in each node in addition to processor and radio n Sensors sense/measure some physical characteristcs [LTL: ] n n Can be planted at random n n Base Station Even thrown out of a speeding vehicle, even from a plane n n Temperature, humidity, acceleration, pressure, toxicity, … Note: The plane in the Figure is BS & collects data. Another one could have dropped sensor nodes earlier BS collects & aggregates sensed info Example 1 (Fig): Sensing enemy’s moves Antenna Target Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved Sensor 61

Example 2: Sensing a Cloud of Smoke Copyright © 2003, Dharma P. Agrawal and

Example 2: Sensing a Cloud of Smoke Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 62

1. 8. Wireless LAN and PAN n n n IEEE 802. 11 = Wireless

1. 8. Wireless LAN and PAN n n n IEEE 802. 11 = Wireless Local Area Network (WLAN) using the IEEE 802. 11 Hiper. LAN is a European Standard Bluetooth nets are examples of Wireless Personal Area Networks (WPAN) Copyright © 2003, Dharma P. Agrawal and Qing-An Zeng. All rights reserved 63

End of Section 1 (Ch. 1)

End of Section 1 (Ch. 1)