ee542_452_class1.ppt
TRANSCRIPT
EE 552/452, Spring, 2008
Wireless Communications(and Networks)
Zhu Han
Department of Electrical and Computer Engineering
Class 1
Jan. 22th, 2008
EE 542/452 Spring 2008
OutlineOutline
Instructor information Motivation to study wireless communications and networks Course descriptions and textbooks What you will study from this course
Objectives Coverage and schedule Homework, projects, and exams
Other policies Reasons to be my students Chapter 1
EE 542/452 Spring 2008
Instructor InformationInstructor Information
Office location: MEC 202B Office hours: Mon. Wed. 1:30pm -4:00pm Email: [email protected] Phone: 208-426-4059(o) /301-996-2011(c) Course website: http://coen.boisestate.edu/zhuhan/ Research interests:
Wireless Networking and Resource Allocation No Chinese in class and office hour
EE 542/452 Spring 2008
MotivationsMotivations
Recent Development– Cellular system: 3G, 4G, video, game,
– WIFI everywhere
– WIMAX, next generation metropolitan web for business
– UWB, no cables
– Bluetooth, small devices connections
Job Market – Probably one of most easy and high paid majors recently
– Intel changes to wireless, Micron will follow? Cypress
Research Potential – One-to-one communication has less room to go, but
multiuser communication is still an open issue.
EE 542/452 Spring 2008
Course DescriptionsCourse Descriptions
What is the wireless communication system? What are the wireless channels? What are the theorems? What are the major components and techniques? How is the information transmitted? What are the current industrial standards? What are the state-of-art research? Can I find a job by studying this course? Can I find research topics?
EE 542/452 Spring 2008
Textbook and SoftwareTextbook and Software
Require textbook:
Wireless Communications: Principles and Practice, 2nd Edition, Theodore S. Rappaport, Prentice Hall, 2001.
Require Software: MATLAB; TI C language Recommended readings
Digital communications: J. Proakis, Digital Communications Random process: G.R. Grimmett and D.R. Stirzaker, Probability and
Random Processes Estimation and detection: H.V. Poor, An introduction to Signal
Detection and Estimation Information theory: T. M. Cover and J. A. Thomas, Elements of
Information Theory Error correct coding: P.Sweeney, Error Control Coding Computer Networks: A. S. Tanenbaum, Computer Networks
EE 542/452 Spring 2008
ScheduleSchedule
Cellular concept and network concept Chapter 2
Wireless Channel Large scale loss: chapter 3 Small scale loss, Fading: chapter 4 Midterm1
Wireless communications technique, slight overlap with 451/551 Modulation, chapter 5 Equalization, diversity and channel coding, chapter 6 Speech coding, optional, chapter 7 Midterm2
Wireless Networks and Standards chapter 8,9,10, other materials. Final and final presentation
EE 542/452 Spring 2008
Homework, Project, and ExamHomework, Project, and Exam
Homework 3~4 questions per week Rules: 50% off if late. 0% is 2 week late
Projects: Wireless Channel Simulation: simple MATLAB programs TI DSP C language for wireless modulations and coding, TBD Term presentation
Exams Three exams for each chunk of the book. Votes for the percentages for homework, projects, and exams
Participations Attendance and Feedback
EE 542/452 Spring 2008
Teaching StylesTeaching Styles
Slides plus black board Slides can convey more information in an organized way Blackboard is better for equations and prevents you from not coming. A lesson from last semester: math
Course Website Print handouts with 3 slides per page before you come Homework assignment and solutions Project descriptions and preliminary codes
Feedback Too fast, too slow, small class advantages. Presentation, English, …
EE 542/452 Spring 2008
Other PoliciesOther Policies
Any violation of academic integrity will receive academic and possibly disciplinary sanctions, including the possible awarding of an XF grade which is recorded on the transcript and states that failure of the course was due to an act of academic dishonesty. All acts of academic dishonesty are recorded so repeat offenders can be sanctioned accordingly.• CHEATING• COPYING ON A TEST• PLAGIARISM • ACTS OF AIDING OR ABETTING • UNAUTHORIZED POSSESSION • SUBMITTING PREVIOUS WORK • TAMPERING WITH WORK • GHOSTING or MISREPRESENTATION • ALTERING EXAMS• COMPUTER THEFT
EE 542/452 Spring 2008
Reasons to be my studentsReasons to be my students
Wireless Communication and Networking have great market Usually highly paid and have potential to retire overnight Highly interdisciplinary Do not need to find research topics which are the most
difficult part. Research Assistant, Stipend Free trips to conferences in Alaska, Hawaii, Europe, Asia… A kind of nice (at least looks like) Work with hope and happiness Graduate fast
EE 542/452 Spring 2008
Questions?Questions?
EE 542/452 Spring 2008
Wireless CommunicationsWireless Communications Chapter 1 in the book
– Satellite – TV– Cordless phone– Cellular phone– Wireless LAN, WIFI– Wireless MAN, WIMAX– Bluetooth– Ultra Wide Band– Wireless Laser– Microwave– GPS– Ad hoc/Sensor Networks
EE 542/452 Spring 2008
The electronics boomThe electronics boom
World changes fast
EE 542/452 Spring 2008
Channel, Bandwidth, SpectrumChannel, Bandwidth, Spectrum Bandwidth: the number of bits per second is proportional to B
http://www.ntia.doc.gov/osmhome/allochrt.pdf
EE 542/452 Spring 2008
Mobile Radio telephoneMobile Radio telephone
AMPS:
advanced
mobile phone
system
EE 542/452 Spring 2008
North American Major StandardsNorth American Major Standards PCS GSM Coreless FDMA TDMA CDMA Modulation
– FM– QPSK– GMSK– BPSK– QAM
EE 542/452 Spring 2008
Europe StandardsEurope Standards GSM
CT2
Dect
EE 542/452 Spring 2008
Japan StandardsJapan Standards
EE 542/452 Spring 2008
Basic conceptsBasic concepts Simplex, half-duplex, and full duplex
Frequency division duplexing, FDD– Most of system because of simplicity
Time division duplexing, TDD: – indoor system only, because of delay
Different from FDMA and TDMA
EE 542/452 Spring 2008
Basic concepts (cont.)Basic concepts (cont.)
EE 542/452 Spring 2008
Base StationBase Station
Cheaper, denser, smaller
EE 542/452 Spring 2008
Mobile StationMobile Station
MP3, GPS, vending machine UMPC
EE 542/452 Spring 2008
Pager SystemPager System
EE 542/452 Spring 2008
Cordless phoneCordless phone Virtually all telephones now sold in the US use the 900 MHz, 2.4 GHz, or 5.8 GHz
bands. There is no specific requirement for any particular transmission mode on 900, 2.4, and 5.8, but in practice virtually all 900 MHz phones are inexpensive, bare-bones analog models; digital features such as DSSS and FHSS are generally only available on the higher frequencies.
The recently allocated 1.9 GHz band is used by the popular DECT phone standard from Europe
EE 542/452 Spring 2008
Cellular systemCellular system Mobile identification number (MIN) electronic serial number (ESN)
Chapter 2
EE 542/452 Spring 2008
Land phone calls cellular phoneLand phone calls cellular phone
EE 542/452 Spring 2008
Cellular phone calls land phoneCellular phone calls land phone
EE 542/452 Spring 2008
Mobile Mobile
EE 542/452 Spring 2008
Base StationBase Station
EE 542/452 Spring 2008
OutlineOutline Wireless Network Tutorial.
– First Chapter of my book, in print by Cambridge University Press
– Cellular networks
– Wireless Metropolitan Area Network (WMAN): WIMAX
– Wireless Local Area Network (WLAN): WIFI
– Wireless Personal Area Network (WPAN) Bluetooth Ultra Wide Band (UWB)
– Ad Hoc Networks
– Sensor Networks
– Cognitive Radio Networks
EE 542/452 Spring 2008
Wireless TechnologiesWireless Technologies
PAN(Personal Area
Network)
LAN(Local Area Network)
WAN(Wide Area Network)
MAN(Metropolitan Area Network)
PAN LAN MAN WAN
Standards Bluetooth/UWB802.15.3
802.11802.11802.16802.20
GSM, CDMA, Satellite
Speed Bluetooth < 1 Mbps UWB <480Mbps
b: 11 to g: 54 Mbps 10-100+ Mbps 10 Kbps–2 Mbps
Range Short Medium Medium-Long Long
Applications Peer-to-PeerDevice-to-Device
Enterprise Networks
Last Mile AccessMobile Data
Devices
EE 542/452 Spring 2008
Cellular Networks Road MapCellular Networks Road Map HSCSD: high speed circuit switched data: multiple time slots, realtime 57.6 kbps GPRS: general packet radio service: non-realtime, 171.2 kbps EDGE: Enhanced Data
Rates for GSM Evolution
Multiple modulation and
coding schemes (MCS)
New hardware 384kbps IS-95B: multiple code
Medium data rate (MDR)
Up to 8 codes, 64kbps
Easy to update 3G: WCDMA(UMTS)
CDMA2000, TD-SCDMA– DV, DO
EE 542/452 Spring 2008
3G Standards Comparison3G Standards Comparison 3GPP and 3GPP2
CDMA2000: easy to upgrade. WCDMA: compatible with GSM
EE 542/452 Spring 2008
WMAN/WiMax StructureWMAN/WiMax Structure Replace cable or low speed fiber in the last mile
EE 542/452 Spring 2008
WiMax protocol StacksWiMax protocol Stacks
EE 542/452 Spring 2008
Comparison of 802.11 StandardsComparison of 802.11 Standards g is back compatible with b. but b is supported by Intel
CDMA vs. OFDM
Free WIFI only in Boise airport.
Contention based multiple access
EE 542/452 Spring 2008
Personal Area NetworksPersonal Area Networks 802.15: 4m-10m
– Master-slave piconets
– Capable of connecting a mix of multiple piconets into “scatternet”
– Service discovery protocol allows invisible interaction of various “trusted” devices
– Less susceptible to interference
EE 542/452 Spring 2008
BluetoothBluetooth Wireless PAN 2.4GHz band with 1Mbps speed Spread spectrum frequency-hopping “always on” user-transparent cable-replacement Combination of packet-switching & circuit-switching (good for
data & voice) 3 voice channels - 64Kbps each Low power, low cost Transparently connects “office” devices
– Laptop, Desktop, PDA, Phone, printer
Bridging capability: network-pda-phone Zigbee: low power devices
EE 542/452 Spring 2008
Ultra Wide BandUltra Wide Band High speed at short range:
– 480 Mb/s at ~3m. Does not penetrate walls
Bandwidth
>500MHz
Very low power
density
Wireless USB
HDTV connection
CDMA vs. OFDM
EE 542/452 Spring 2008
SummarySummary Trend
– 802.11 - 802.15 - cellular wireless technologies all competing for customers
– 802.11 WLANs offer “hotspots” at nominal cost (sometimes “free”)
– Cellular services used worldwide
– 802.15 offers bridging options for WLAN and cellular services
– Vertical handoff
Alliances, Partnerships, Coalitions,…– AT&T, Intel, IBM (and investors) form “Cometa”, a company to provide
wireless hot spots across the country
– Motorola, Proxim and Avaya form partnership to provide seamless roaming between WiFi and cellular networks
– HP and Transat Technologies collaborating on project to link 2G/3G to WiFi “hotspots”
EE 542/452 Spring 2008
ComparisonComparison Speed and Range
EE 542/452 Spring 2008
Ad Hoc NetworkAd Hoc Network Mobile Ad Hoc Networks (MANETs)
– An autonomous collection of mobile users that communicate over relatively bandwidth constrained wireless links.
– Since the nodes are mobile, the network topology may change rapidly and unpredictably over time.
– The network is decentralized, where all network activity including discovering the topology and delivering messages must be executed by the nodes themselves. MANETs need efficient distributed algorithms to determine network organization, link scheduling, and routing.
– The set of applications for MANETs is heterogeneous, ranging from small, static networks that are constrained by power sources, to large-scale, mobile, highly dynamic networks
– In a military environment, preservation of security, latency, reliability, intentional jamming, and recovery from failure are significant concerns
EE 542/452 Spring 2008
MANET ExamplesMANET Examples Ad hoc mode of WIFI
Military
Infrastructure-less
EE 542/452 Spring 2008
Wireless Sensor NetworkWireless Sensor Network Consists of a number of sensors spread across a geographical area. Each
sensor has wireless communication capability and some level of intelligence for signal processing and networking of the data. – Military sensor networks to detect and gain as much information as
possible about enemy movements, explosions, and other phenomena of interest.
– Sensor networks to detect and characterize Chemical, Biological, Radiological, Nuclear, and Explosive (CBRNE) attacks and material.
– Sensor networks to detect and monitor environmental changes in plains, forests, oceans, etc.
– Wireless traffic sensor networks to monitor vehicle traffic on highways or in congested parts of a city.
– Wireless surveillance sensor networks for providing security in shopping malls, parking garages, and other facilities.
– Wireless parking lot sensor networks to determine which spots are occupied and which are free.
EE 542/452 Spring 2008
Wireless Sensor NetworksWireless Sensor Networks
EE 542/452 Spring 2008
WSN RequirementWSN Requirement Large number of (mostly stationary) sensors: Aside from the deployment of sensors on the
ocean surface or the use of mobile, unmanned, robotic sensors in military operations, most nodes in a smart sensor network are stationary. Networks of 10,000 or even 100,000 nodes are envisioned, so scalability is a major issue.
Low energy use: Since in many applications the sensor nodes will be placed in a remote area, service of a node may not be possible. In this case, the lifetime of a node may be determined by the battery life, thereby requiring the minimization of energy expenditure.
Network self-organization: Given the large number of nodes and their potential placement in hostile locations, it is essential that the network be able to self-organize; manual configuration is not feasible. Moreover, nodes may fail (either from lack of energy or from physical destruction), and new nodes may join the network. Therefore, the network must be able to periodically reconfigure itself so that it can continue to function. Individual nodes may become disconnected from the rest of the network, but a high degree of connectivity must be maintained.
Collaborative signal processing: Yet another factor that distinguishes these networks from MANETs is that the end goal is detection/estimation of some events of interest, and not just communications. To improve the detection/estimation performance, it is often quite useful to fuse data from multiple sensors. This data fusion requires the transmission of data and control messages, and so it may put constraints on the network architecture.
Querying ability: A user may want to query an individual node or a group of nodes for information collected in the region. Depending on the amount of data fusion performed, it may not be feasible to transmit a large amount of the data across the network. Instead, various local sink nodes will collect the data from a given area and create summary messages. A query may be directed to the sink node nearest to the desired location.
EE 542/452 Spring 2008
Spectrum Hole Spectrum Hole Inefficient usage and over crowded of some spectrums
EE 542/452 Spring 2008
Cognitive RadioCognitive Radio Software radio
– Can change modulation
carrier frequency to
different service
providers
Cognitive radio
with cognitive
ability
EE 542/452 Spring 2008
HomeworkHomework Read Chapter 1 of Rappaport book
Read the handout
EE 542/452 Spring 2008
Questions?Questions?