Acknowledgement. Wireless History

Transcription

1 Acknowedgement Sides derived from cass materia posted by Dr. A. Godsmith ectures.htm See aso: A. Godsmith, Wireess Communications, Cambridge Press Wireess History Ancient Systems: Smoke Signas, Carrier Pigeons, Radio invented in the 1880s by Marconi Many sophisticated miitary radio systems were deveoped during and after WW2 Exponentia growth in ceuar use since 1988: approx. 8B wordwide users today Ignited the wireess revoution Voice, data, and mutimedia ubiquitous Use in 3 rd word countries growing rapidy Wifi aso enjoying tremendous success and growth Buetooth pervasive, sateites aso widespread 1

2 Future Wireess Networks Ubiquitous Communication Among Peope and Devices Next-Gen Ceuar/WiFi Smart Homes/Spaces Autonomous Cars Smart Cities Body-Area Networks Internet of Things A this and more Chaenges Network/Radio Chaenges Gbps data rates with no errors Energy efficiency Scarce/bifurcated spectrum Reiabiity and coverage Heterogeneous networks Seamess internetwork handoff Device/SoC Chaenges Performance Compexity Size, Power, Cost High frequencies/mmwave Mutipe Antennas Mutiradio Integration Coexistance 5 G Short-Range BT Ceuar Mem CPU Radio GPS Cog WiFi mmw AdHoc 2

3 What is the Internet of Things: Enabing every eectronic device to be connected to each other and the Internet Incudes smartphones, consumer eectronics, cars, ights, cothes, sensors, medica devices, Vaue in IoT is data processing in the coud Different requirements than smartphones: ow rates/energy consumption Are we at the Shannon imit of the Physica Layer? We are at the Shannon Limit The wireess industry has reached the theoretica imit of how fast networks can go K. Fitcher, Connected Panet We re 99% of the way to the barrier known as Shannon s imit, D. Warren, GSM Association Sr. Dir. of Tech. Shannon was wrong, there is no imit There is no theoretica maximum to the amount of data that can be carried by a radio channe M. Gass, Wireess Networks: The Definitive Guide Effectivey unimited capacity possibe via persona ces (pces). S. Perman, Artemis. 3

4 What woud Shannon say? We don t know the Shannon capacity of most wireess channes Time-varying channes. Channes with interference or reays. Ceuar systems Ad-hoc and sensor networks Channes with deay/energy/$$$ constraints. Shannon theory provides design insights and system performance upper bounds Current/Next-Gen Wireess Systems Current: 4G Ceuar Systems (LTE-Advanced) 4G Wireess LANs/WiFi (802.11ac) mmwave massive MIMO systems Sateite Systems Buetooth Zigbee WiGig Emerging 5G Ceuar and WiFi Systems Ad/hoc and Cognitive Radio Networks Energy-Harvesting Systems Chemica/Moecuar Much room For innovation 4

5 Spectra Reuse Due to its scarcity, spectrum is reused In icensed bands and unicensed bands BS Ceuar Reuse introduces interference Wifi, BT, UWB, Ceuar Systems: Reuse channes to maximize capacity Geographic region divided into ces Freq./timesots/codes/space reused in different ces (reuse 1 common). Interference between ces using same channe: interference mitigation key Base stations/mtsos coordinate handoff and contro functions Shrinking ce size increases capacity, as we as compexity, handoff, BASE STATION MTSO 5

6 4G/LTE Ceuar Much higher data rates than 3G ( Mbps) 3G systems has 384 Kbps peak rates Greater spectra efficiency (bits/s/hz) More bandwidth, adaptive OFDM-MIMO, reduced interference Fexibe use of up to 100 MHz of spectrum MHz spectrum aocation common Low packet atency (<5ms). Reduced cost-per-bit (not cear to customers) A IP network 5G Upgrades from 4G 6

7 Future Ceuar Phones Burden Everything for this wireess performance in one device is on the backbone network San Francisco BS N th -Gen Ceuar BS Internet Phone System LTE backbone is the Internet N th -Gen Ceuar Paris BS Much better performance and reiabiity than today - Gbps rates, ow atency, 99% coverage, energy efficiency Wifi Networks Mutimedia Everywhere, Without Wires ac Streaming video Gbps data rates High reiabiity Coverage inside and out Wireess HDTV and Gaming 7

8 Wireess LAN Standards b (Od 1990s) Standard for 2.4GHz ISM band (80 MHz) Direct sequence spread spectrum (DSSS) Speeds of 11 Mbps, approx. 500 ft range a/g (Midde Age mid-ate 1990s) Standard for 5GHz band (300 MHz)/aso 2.4GHz OFDM in 20 MHz with adaptive rate/codes Speeds of 54 Mbps, approx ft range Many WLAN cards have (a/b/g/n) n/ac/ax (current/next gen) Standard in 2.4 GHz and 5 GHz band Adaptive OFDM /MIMO in 20/40/80/160 MHz Antennas: 2-4, up to 8 Speeds up to 1 Gbps (10 Gbps for ax), approx. 200 ft range Other advances in packetization, antenna use, mutiuser MIMO Sateite Systems Cover very arge areas Different orbit heights GEOs (39000 Km) versus LEOs (2000 Km) Optimized for one-way transmission Radio (XM, Sirius) and movie (SatTV, DVB/S) broadcasts Most two-way systems went bankrupt Goba Positioning System (GPS) ubiquitous Sateite signas used to pinpoint ocation Popuar in ce phones, PDAs, and navigation devices 8

9 Buetooth Cabe repacement RF technoogy (ow cost) Short range (10m, extendabe to 100m) 2.4 GHz band (crowded) 1 Data (700 Kbps) and 3 voice channes, up to 3 Mbps Widey supported by teecommunications, PC, and consumer eectronics companies Few appications beyond cabe repacement 8C Cimini-7/98 IEEE /ZigBee Radios Low-rate ow-power ow-cost secure radio Compementary to WiFi and Buetooth Frequency bands: 784, 868, 915 MHz, 2.4 GHz Data rates: 20Kbps, 40Kbps, 250 Kbps Range: m ine-of-sight Support for arge mesh networking or star custers Support for ow atency devices CSMA-CA channe access Appications: ight switches, eectricity meters, traffic management, and other ow-power sensors. 9

10 Spectrum Reguation Spectrum a scarce pubic resource, hence aocated Spectra aocation in US controed by FCC (commercia) or OSM (defense) FCC auctions spectra bocks for set appications. Some spectrum set aside for universa use Wordwide spectrum controed by ITU-R Reguation is a necessary evi. Innovations in reguation being considered wordwide in mutipe cognitive radio paradigms Emerging Systems Advanced Topics Lecture New ceuar system architectures mmwave/massive MIMO communications Software-defined network architectures Ad hoc/mesh wireess networks Cognitive radio networks Wireess sensor networks Energy-constrained radios Distributed contro networks Chemica Communications Appications of Communications in Heath, Biomedicine, and Neuroscience 10

11 Rethinking Ces in Ceuar Coop MIMO Reay DAS Sma Ce How shoud ceuar systems be designed for - Capacity - Coverage - Energy efficiency - Low atency Traditiona ceuar design interference-imited MIMO/mutiuser detection can remove interference Cooperating BSs form a MIMO array: what is a ce? Reays change ce shape and boundaries Distributed antennas move BS towards ce boundary Sma ces create a ce within a ce Mobie cooperation via reays, virtua MIMO, network coding. mmwave Massive MIMO ç10s of GHz of Spectrumè Dozens of devices Hundreds of antennas mmwaves have arge non-monotonic path oss Channe mode poory understood For asymptoticay arge arrays with channe state information, no attenuation, fading, interference or noise mmwave antennas are sma: perfect for massive MIMO Bottenecks: channe estimation and system compexity Non-coherent design hods significant promise 11

12 Software-Defined Network Architectures Video Vehicuar SecurityCoud Networks Computing M2M App ayer Heath Freq. Aocation Power Contro Sef Heaing ICIC QoS Opt. CS Threshod Network Optimization UNIFIED CONTROL PLANE HW ayer Distributed Antennas WiFi Ceuar mmwave Ad-Hoc Networks Ad-Hoc Networks Peer-to-peer communications No backbone infrastructure or centraized contro Routing can be mutihop. Topoogy is dynamic. Fuy connected with different ink SINRs Open questions Fundamenta capacity region Resource aocation (power, rate, spectrum, etc.) Routing 12

13 Cognitive Radios I P CRTx CRRx NCR NCR CR MIMO Cognitive Underay Cognitive radios support new users in existing crowded spectrum without degrading icensed users Utiize advanced communication and DSP techniques Couped with nove spectrum aocation poicies Mutipe paradigms (MIMO) Underay (interference beow a threshod) Interweave finds/uses unused time/freq/space sots Overay (overhears/reays primary message whie canceing interference it causes to cognitive receiver) CR NCRTx Cognitive Overay NCRRx Distributed Contro over Wireess Automated Vehices - Cars - Airpanes/UAVs - Insect fyers Interdiscipinary design approach Contro requires fast, accurate, and reiabe feedback. Wireess networks introduce deay and oss Need reiabe networks and robust controers Mosty open probems : Many design chaenges 13