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Ch 1 Introduction to Wireless Communications & Networks Reading materials: [1]Overview of wireless communications Ch 1 Introduction to Wireless Communications & Networks Reading materials: [1]Overview of wireless communications [2]移动通讯词汇(中英)

Outline FPart 1 Introduction to Wireless Communication & Networks FPart 2 Applications of Wireless Outline FPart 1 Introduction to Wireless Communication & Networks FPart 2 Applications of Wireless Networks

Part 1 Introduction to Wireless Communication & Networks l The Wireless Vision l Technical Part 1 Introduction to Wireless Communication & Networks l The Wireless Vision l Technical Challenges l Current Wireless Systems l Emerging Wireless Systems l Spectrum Regulation l Standards

Wireless History First Mobile Radio Telephone 1924 Wireless History First Mobile Radio Telephone 1924

Pre-Cellular Wireless l One highly-elevated antenna in a large service area l Small number Pre-Cellular Wireless l One highly-elevated antenna in a large service area l Small number of channels l Very low capacity l Examples: MJ and MK systems in the United States

The Cellular Concept l Basic Principles Frequency Reuse Cell Splitting First proposed by D. The Cellular Concept l Basic Principles Frequency Reuse Cell Splitting First proposed by D. H. Ring at Bell Laboratories in 1947

Cellular - Implementation Cellular - Implementation

Cellular - Implementation Cellular - Implementation

Cellular Systems: Reuse channels to maximize capacity l l l Geographic region divided into Cellular Systems: Reuse channels to maximize capacity l l l Geographic region divided into cells Frequencies/timeslots/codes reused at spatially-separated locations. Co-channel interference between same color cells. Base stations/MTSOs coordinate handoff and control functions Shrinking cell size increases capacity, as well as networking burden BASE STATION MTSO

GSM System Architecture GSM System Architecture

Cellular Phone Networks San Francisco BS BS Internet MTSO PSTN New York MTSO BS Cellular Phone Networks San Francisco BS BS Internet MTSO PSTN New York MTSO BS

The Wireless Revolution l Cellular is the fastest growing sector of communication industry (exponential The Wireless Revolution l Cellular is the fastest growing sector of communication industry (exponential growth since 1982, with over 2 billion users worldwide today) l Three generations of wireless l l l First Generation (1 G): Analog 25 or 30 KHz FM, voice only, mostly vehicular communication Second Generation (2 G): Narrowband TDMA and CDMA, voice and low bit-rate data, portable units. 2. 5 G increased data transmission capabilities Third Generation (3 G): Wideband TDMA and CDMA, voice and high bit-rate data, portable units

World Telecom Statistics Crossover has happened in May 2002! World Telecom Statistics Crossover has happened in May 2002!

Cellular Subscribers by Technology as of Jun 2. 41 Billion Cellular Customers Worldwide GSM/UMTS Cellular Subscribers by Technology as of Jun 2. 41 Billion Cellular Customers Worldwide GSM/UMTS Totals 82. 3%

World Cellular Subscriber Distribution as of June 2006 World Cellular Subscriber Distribution as of June 2006

GSM Growth - 1993 to June 2006 GSM Growth - 1993 to June 2006

Exciting Developments l Internet and laptop use exploding l 2 G/3 G wireless LANs Exciting Developments l Internet and laptop use exploding l 2 G/3 G wireless LANs growing rapidly l Huge cell phone popularity worldwide l Emerging systems such as Bluetooth, UWB, Zigbee, and Wi. MAX opening new doors l Military and security wireless needs l Important interdisciplinary applications

Future Wireless Networks Ubiquitous Communication Among People and Devices Wireless Internet access Nth generation Future Wireless Networks Ubiquitous Communication Among People and Devices Wireless Internet access Nth generation Cellular Wireless Ad Hoc Networks Sensor Networks Wireless Entertainment Smart Homes/Spaces Automated Highways All this and more… • Hard Delay Constraints • Hard Energy Constraints

Design Challenges l Wireless channels are a difficult and capacitylimited broadcast communications medium l Design Challenges l Wireless channels are a difficult and capacitylimited broadcast communications medium l Traffic patterns, user locations, and network conditions are constantly changing l Traffic is nonstationary, both in space and in time l Energy and delay constraints change design principles across all layers of the protocol stack

Evolution of Current Systems l Wireless systems today l l l Next Generation l Evolution of Current Systems l Wireless systems today l l l Next Generation l l l 2 G Cellular: ~30 -70 Kbps. WLANs: ~10 Mbps. 3 G Cellular: ~300 Kbps. WLANs: ~70 Mbps. Technology Enhancements l l l Hardware: Better batteries. Better circuits/processors. Link: Antennas, modulation, coding, adaptivity, DSP, BW. Network: Dynamic resource allocation. Mobility support.

Migration to 3 G Migration to 3 G

3 G: ITU-Developed IMT-2000 Global Satellite Suburban Macrocell Urban Microcell Basic Terminal PDA Terminal 3 G: ITU-Developed IMT-2000 Global Satellite Suburban Macrocell Urban Microcell Basic Terminal PDA Terminal Audio/Visual Terminal In-Building Picocell

Future Generations Rate 4 G 802. 11 b WLAN 3 G Other Tradeoffs: Rate Future Generations Rate 4 G 802. 11 b WLAN 3 G Other Tradeoffs: Rate vs. Coverage Rate vs. Delay Rate vs. Cost Rate vs. Energy 2 G 2 G Cellular Mobility Fundamental Design Breakthroughs Needed

Current Wireless Systems l Cellular Systems l l Wireless LANs Satellite Systems l Paging Current Wireless Systems l Cellular Systems l l Wireless LANs Satellite Systems l Paging Systems l Bluetooth l Ultrawideband radios l Zigbee radios

Cellular Systems -1 G Cellular Systems -1 G

Cellular Systems -2 G Cellular Systems -2 G

Cellular Systems 2 G-D-AMPS Cellular Systems 2 G-D-AMPS

Cellular Systems 2 G-GSM Cellular Systems 2 G-GSM

Cellular Systems 2 G-CDMA Cellular Systems 2 G-CDMA

Cellular Systems--2. 5 G Cellular Systems--2. 5 G

Cellular Systems--3 G Cellular Systems--3 G

Cellular Systems 3 G—IMT-2000 Cellular Systems 3 G—IMT-2000

Cellular Systems 3 G—UMTS Cellular Systems 3 G—UMTS

Cellular Systems--4 G Cellular Systems--4 G

Cellular Systems--4 G(续) Cellular Systems--4 G(续)

WLAN WLAN

Wireless Local Area Networks (WLANs) 01011011 0101 1011 Internet Access Point l l WLANs Wireless Local Area Networks (WLANs) 01011011 0101 1011 Internet Access Point l l WLANs connect “local” computers (100 m range) Breaks data into packets Channel access is shared (random access) Backbone Internet provides best-effort service l Poor performance in some apps (e. g. video)

Wireless LAN Standards l 802. 11 b (Current Generation) l l 802. 11 a Wireless LAN Standards l 802. 11 b (Current Generation) l l 802. 11 a (Emerging Generation) l l l Standard for 2. 4 GHz ISM band (80 MHz) Frequency hopped spread spectrum 1. 6 -10 Mbps, 500 ft range Standard for 5 GHz NII band (300 MHz) OFDM with time division 20 -70 Mbps, variable range Similar to Hiper. LAN in Europe 802. 11 g (New Standard) l l l Standard in 2. 4 GHz and 5 GHz bands OFDM Speeds up to 54 Mbps In 200? , all WLAN cards will have all 3 standards

WPAN WPAN

Satellite Systems l Cover very large areas l Different orbit heights l l Optimized Satellite Systems l Cover very large areas l Different orbit heights l l Optimized for one-way transmission l l GEOs (39000 Km) versus LEOs (2000 Km) Radio (XM, DAB) and movie (Sat. TV) broadcasting Most two-way systems struggling or bankrupt Expensive alternative to terrestrial system l A few ambitious systems on the horizon l

Inmarsat System (海事卫星) Inmarsat Satellite Inmarsat NCS NOC OCC AERO TT&C SCC RESCUE COORDINATION Inmarsat System (海事卫星) Inmarsat Satellite Inmarsat NCS NOC OCC AERO TT&C SCC RESCUE COORDINATION CENTRE LES MARITIME National & International Telecom Network fax voice telex data LAND

Inmarsat 卫星覆盖图 Inmarsat 卫星覆盖图

车载卫星导航系统 车载卫星导航系统

军 用 卫 星 指 挥 系 统 军 用 卫 星 指 挥 系 统

中国卫星概况 l l l 1970年 4月24日,第一颗人造卫星“东方红一号” 发射成功,使中国成为世界上第五个独立研制 和发射人造地球卫星的国家 1975年 11月26日,首次发射回收了返回式遥感卫 星 使中国成为世界上第三个掌握卫星返回技术 的国家 1984年 中国卫星概况 l l l 1970年 4月24日,第一颗人造卫星“东方红一号” 发射成功,使中国成为世界上第五个独立研制 和发射人造地球卫星的国家 1975年 11月26日,首次发射回收了返回式遥感卫 星 使中国成为世界上第三个掌握卫星返回技术 的国家 1984年 4月8日发射成功第一颗“东方红二号”地 球静止轨道通信卫星 4月16日定点于东经 125赤 道上空,使中国成为世界上第五个独立研制和 发射静止轨道卫星的国家

中国卫星系列 l 返回式遥感卫星系列 l “东方红”通信广播卫星系列 l “风云”气象卫星系列 l “实践”科学探测与技术试验卫星系列 l “资源”地球资源卫星系列 l “北斗”导航定位卫星系列 中国卫星系列 l 返回式遥感卫星系列 l “东方红”通信广播卫星系列 l “风云”气象卫星系列 l “实践”科学探测与技术试验卫星系列 l “资源”地球资源卫星系列 l “北斗”导航定位卫星系列

Paging Systems l Broad coverage for short messaging l Message broadcast from all base Paging Systems l Broad coverage for short messaging l Message broadcast from all base stations l Simple terminals l Optimized for 1 -way transmission l Answer-back hard l Overtaken by cellular

Bluetooth l Cable replacement RF technology (low cost) l Short range (10 m, extendable Bluetooth l Cable replacement RF technology (low cost) l Short range (10 m, extendable to 100 m) l 2. 4 GHz band (crowded) l 1 Data (700 Kbps) and 3 voice channels l Widely supported by telecommunications, PC, and consumer electronics companies l Few applications beyond cable replacement 8 C 32810. 61 -Cimini-7/98

Ultrawideband Radio (UWB) l UWB is an impulse radio: sends pulses of tens of Ultrawideband Radio (UWB) l UWB is an impulse radio: sends pulses of tens of picoseconds(10 -12) to nanoseconds (10 -9) l Duty cycle of only a fraction of a percent l A carrier is not necessarily needed l Uses a lot of bandwidth (GHz) l Low probability of detection l Excellent ranging capability l Multipath highly resolvable: good and bad l Can use OFDM to get around multipath problem.

Why is UWB Interesting? l Unique Location and Positioning properties l Low Power CMOS Why is UWB Interesting? l Unique Location and Positioning properties l Low Power CMOS transmitters l Very high data rates possible l 7. 5 Ghz of “free spectrum” in the U. S. l 1 cm accuracy possible l 100 l 500 times lower than Bluetooth for same range/data rate Mbps at ~10 feet under current regulations l FCC recently legalized UWB for commercial use l Spectrum allocation overlays existing users, but its power level is very low to minimize interference l “Moore’s Law Radio” l Data allowed rate scales with the shorter pulse widths made possible with ever faster CMOS circuits

IEEE 802. 15. 4 / Zig. Bee Radios l Low-Rate WPAN l Data rates IEEE 802. 15. 4 / Zig. Bee Radios l Low-Rate WPAN l Data rates of 20, 40, 250 kbps l Star clusters or peer-to-peer operation l Support for low latency devices l CSMA-CA channel access l Very low power consumption l Frequency of operation in ISM bands Focus is primarily on radio and access techniques

Data rate 100 Mbit/sec 100 kbits/sec UWB 802. 11 g 802. 11 b 3 Data rate 100 Mbit/sec 100 kbits/sec UWB 802. 11 g 802. 11 b 3 G 802. 11 a Bluetooth Zig. Bee 10 kbits/sec UWB 0 GHz 1 GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

Range 10 km 3 G 1 km 100 m 10 m 802. 11 a Range 10 km 3 G 1 km 100 m 10 m 802. 11 a 802. 11 b, g Zig. Bee UWB Bluetooth Zig. Bee UWB 1 m 0 GHz 1 GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

Power Dissipation 10 W 3 G 1 W 100 m. W 802. 11 bg Power Dissipation 10 W 3 G 1 W 100 m. W 802. 11 bg Bluetooth 10 m. W Zig. Bee UWB Zig. Bee 802. 11 a UWB 1 m. W 0 GHz 1 GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

Emerging Systems l Ad hoc wireless networks l Sensor networks l Distributed control networks Emerging Systems l Ad hoc wireless networks l Sensor networks l Distributed control networks

Ad-Hoc Networks l l l Peer-to-peer communications. No backbone infrastructure. Routing can be multihop. Ad-Hoc Networks l l l Peer-to-peer communications. No backbone infrastructure. Routing can be multihop. Topology is dynamic. Fully connected with different link SINRs

Design Issues l Ad-hoc networks provide a flexible network infrastructure for many emerging applications. Design Issues l Ad-hoc networks provide a flexible network infrastructure for many emerging applications. l The capacity of such networks is generally unknown. l Transmission, access, and routing strategies for ad -hoc networks are generally ad-hoc. l Crosslayer design critical and very challenging. l Energy constraints impose interesting design tradeoffs for communication and networking.

Sensor Networks Energy is the driving constraint l Nodes powered by nonrechargeable batteries l Sensor Networks Energy is the driving constraint l Nodes powered by nonrechargeable batteries l Data flows to centralized location. l Low per-node rates but up to 100, 000 nodes. l Data highly correlated in time and space. l Nodes can cooperate in transmission, reception, compression, and signal processing.

Energy-Constrained Nodes l Each node can only send a finite number of bits. l Energy-Constrained Nodes l Each node can only send a finite number of bits. l l Transmit energy minimized by maximizing bit time Circuit energy consumption increases with bit time Introduces a delay versus energy tradeoff for each bit Short-range networks must consider transmit, circuit, and processing energy. Sophisticated techniques not necessarily energy-efficient. l Sleep modes save energy but complicate networking. l l Changes everything about the network design: l l l Bit allocation must be optimized across all protocols. Delay vs. throughput vs. node/network lifetime tradeoffs. Optimization of node cooperation.

Spectrum Regulation l Spectral Allocation in US controlled by FCC (commercial) or OSM (defense) Spectrum Regulation l Spectral Allocation in US controlled by FCC (commercial) or OSM (defense) l FCC auctions spectral blocks for set applications. l Some spectrum set aside for universal use l Worldwide spectrum controlled by ITU-R Regulation can stunt innovation, cause economic disasters, and delay system rollout

Standards l Interacting systems require standardization l Companies want their systems adopted as standard Standards l Interacting systems require standardization l Companies want their systems adopted as standard l Alternatively try for de-facto standards l Standards determined by TIA/CTIA in US l IEEE standards often adopted l Process fraught with inefficiencies and conflicts l Worldwide standards determined by ITU-T l In Europe, ETSI is equivalent of IEEE

Main Points l The wireless vision encompasses many exciting systems and applications l Technical Main Points l The wireless vision encompasses many exciting systems and applications l Technical challenges transcend across all layers of the system design. l Cross-layer design emerging as a key theme in wireless. l Existing and emerging systems provide excellent quality for certain applications but poor interoperability. l Standards and spectral allocation heavily impact the evolution of wireless technology

Some Acronyms in this lecture l l l l OFDM: Orthogonal Frequency Division Multiplexing Some Acronyms in this lecture l l l l OFDM: Orthogonal Frequency Division Multiplexing DAB: Digital Audio Broadcasting UAV: Unmanned Aerial Vehicle OSM: Office of Spectrum Management FCC: Federal Communications Commission TIA: Telecommunications Industry Association CTIA: Cellular Telecommunications Industry Association ISM: Industrial, Scientific, and Medical ETSI: European Telecommunications Standards Institute EDGE: Enhanced Data services for GSM Evolution HDR: High Data Rate DSP: Digital Signal Processing SINR: Signal-to-Interference-plus-Noise Ratio

Part 2 Applications of Wireless Networks l 概况 l 美国 l 欧洲 l 亚洲 Part 2 Applications of Wireless Networks l 概况 l 美国 l 欧洲 l 亚洲 l 重要厂商

概况--无线通信网络的发展 概况--无线通信网络的发展

概况--无线网络应用 概况--无线网络应用

概况--无线网络应用现状 概况--无线网络应用现状

概况--无线热点 概况--无线热点

美国现状 美国现状

美国星巴克 美国星巴克

欧洲现状 欧洲现状

欧洲—“The Cloud” 欧洲—“The Cloud”

欧洲—“MAGNET” 欧洲—“MAGNET”

亚洲现状 亚洲现状

亚洲现状 亚洲现状

亚洲现状 亚洲现状

重要厂商-Cisco 重要厂商-Cisco

重要厂商-Intel 重要厂商-Intel

重要厂商-Intel(续) 重要厂商-Intel(续)

重要厂商-Microsoft 重要厂商-Microsoft

重要厂商-IBM 重要厂商-IBM

重要厂商-手机厂商 重要厂商-手机厂商

重要厂商-宠物服务(1) 重要厂商-宠物服务(1)

重要厂商-宠物服务(2) 重要厂商-宠物服务(2)

重要厂商-宠物服务(3) l “Pets. Cell”,兼容现有的蜂窝网络和卫星GPS技 术。 l 能够让宠物的主人与他们的宠物讲话,以及在 必要时请求别人提供帮助。 l 如果宠物走失,有人发现这个宠物在大街上徘 徊,按一下宠物身上佩带的设备,自动拨号功 能就可以把电话打到宠物主人的家里,让主人 找回宠物。 重要厂商-宠物服务(3) l “Pets. Cell”,兼容现有的蜂窝网络和卫星GPS技 术。 l 能够让宠物的主人与他们的宠物讲话,以及在 必要时请求别人提供帮助。 l 如果宠物走失,有人发现这个宠物在大街上徘 徊,按一下宠物身上佩带的设备,自动拨号功 能就可以把电话打到宠物主人的家里,让主人 找回宠物。

09年上半年无线网卡市场概况 l l http: //www. chinamobile. com/focus/3 g/zx/200908/t 20 090829_12612. htm 华为、网讯、中兴通讯占据了71%的市场份额,而半年 前这一数字仅为 40%。 09年上半年无线网卡市场概况 l l http: //www. chinamobile. com/focus/3 g/zx/200908/t 20 090829_12612. htm 华为、网讯、中兴通讯占据了71%的市场份额,而半年 前这一数字仅为 40%。 市场均价为 512元。 在USB、PCM-CIA和Express. Card三种主流接口中, USB的消费需求比例最高,达到了68. 2%的关注度,而 PCMCIA和Express. Card接口的关注度分别为 19. 4%和 12. 2%。接口类型正由PCMCIA向USB、Express过渡。