HY 532 Sst ata s at p pst aat E-mail: traganicsd.uoc.gr . : 0810 393553 tta 1 S ese st: csd.uoc.gr

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HY 5 32 Συστήματα Ασύρματων Επικοινωνιών Απόστολος Τραγανίτης E-mail: tragani@csd.uoc.gr Τηλ. : 0810 393553 Ενότητα 1 Σημειώσεις στο : www.csd.uoc.gr/~hy 5 32

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Στοχοι του μαθηματος Κατανοηση των θεμελιωδων αρχων που διεπουν τις ασυρματες/κινητες επικοινωνιες και δικτυα Γνωριμια με τα guidelines και τα συστηματα των ασυρματων/κινητων επικοινωνιων Ενημερωση για τις συγχρονες τασεις στην ερευνα και στην τεχνολογία των ασυρματων τηλεπικοι - νωνιων

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Exciting Developments Internet and portable PC & PDA utilize detonating 2G/3G cell correspondence frameworks and Wireless LANs (WLANs) becoming quickly Huge PDA prevalence overall Systems, for example, Bluetooth, UWB, WUSB, Zigbee, WiMAX and so forth opening new entryways Military and security remote needs Important interdisciplinary applications

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Εφαρμογες των ασυρματων επικοινωνιων… Ασύρματες πολυμεσικες επικοινωνίες οπουδήποτε, οποτεδήποτε και για οποιονδηποτε Εφαρμογές : Ασύρματες συσκευές υπολογισμων Ασυρματα τοπικα δικτυα (WLANs) Ασυρματο Video/μουσικη Οικιακα δικτυα πολυμεσων Εξυπνα σπιτια/περιβαλλοντα Μαθηση εξ αποστασεως Τηλειατρικη Συναλλαγες εν κινησει Δικτυα αισθητηρων Ad-Hoc Δικτυα Αυτονομα οχηματα/ρομποτ Περιορισμοι: Στην καθυστερηση Στην ενεργεια Στο φασμα

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Always on Anytime, anyplace and in any shape Voice and interactive media Self administration, natural Simple for the end client Secure, trusted and solid Επιθυμητα χαρακτηριστικα των ασυρματων επικοινωνιων…

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NEAR FUTURE Consumer Entertainment GII Telecommunications AIM Consumer Entertainment Computer data GII Telecommunications Computer data Συγκλιση υπηρεσιων και δικτυων Internet, Broadcasting, Telephony, ... TODAY Consumer Entertainment GII Telecommunications Computer data GII=Gigabit Information Infrastucture

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Design Challenges Wireless stations are a troublesome and limit restricted communicate interchanges medium Traffic designs, client areas, and system conditions are continually changing Traffic is nonstationary, both in space and in time Energy and postpone imperatives change outline standards over all layers of the convention stack

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Evolution of Current Systems Wireless frameworks yesterday 2G Cellular: ~30-70 Kbps. WLANs: ~10 Mbps. Remote frameworks today 3G Cellular: ~300-3600 Kbps. WLANs: ~70 Mbps. Cutting edge 4G IP based Cellular => WLANs Mesh Networks Technology Enhancements Hardware: Better batteries. Better circuits/processors. Interface: Antennas, regulation, coding, adaptivity, DSP, BW. Organize: Dynamic asset allotment. Portability bolster.

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Migration to 3G

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

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4G 3G 2G Future Generations Other Tradeoffs: Rate versus Scope Rate versus Defer Rate versus Taken a toll Rate versus Vitality Rate 802.11b WLAN 2G Cellular Mobility Fundamental Design Breakthroughs Needed

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Current Wireless Systems Cellular Systems Wireless LANs Satellite Systems LMDS WiMAX Paging Systems Bluetooth Ultrawideband radios Zigbee radios

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Συγχρονα συστηματα ασυρματων επικοινωνιων Ασυρματες ζευξεις απο σημειο-σε-σημειο. Κυψελοειδή συστήματα (GSM, CDMA, UMTS… ) Ασύρματα τοπικά δίκτυα ( WLANs π.χ. Wifi) Ασύρματα δίκτυα ευρείας περιοχής (W Μ ANs π.χ. WiMax) Ασυρματα προσωπικά δικτυα ( W Ρ ANs, π.χ. WUSB ) Ασυρματα δικτυα αυθαιρετης δομης ( Ad-Hoc ) Δορυφορικα Συστηματα HomeRF, Bluetooth,UWB… Ασυρματα δικτυα αισθητηρων ( Sensor systems) Δικτυα work, autonomic,… .

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Wireless Local Area Networks (WLANs) 1011 0101 01011011 Internet Access Point WLANs interface "nearby" PCs (100m territory) Breaks information into parcels Channel get to is shared (arbitrary get to) Backbone Internet gives best-exertion benefit Poor execution in some applications (e.g. video)

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Today all WLAN cards have every one of the 3 norms Wireless LAN Standards 802.11b Standard for 2.4GHz ISM band (80 MHz) Direct Sequence Spread Spectrum (DSSS) 1.6-10 Mbps, 500 ft go 802.11a Standard for 5GHz NII band (300 MHz) OFDM with time division 20-70 Mbps, variable range Similar to HiperLAN in Europe 802.11g Standard in 2.4 GHz and 5 GHz groups OFDM Speeds up to 54 Mbps

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Satellite Systems Cover expansive territories Different circle statures GEOs (39000 Km) versus LEOs (2000 Km) Optimized for one-way transmission Radio (XM, DAB) and motion picture (SatTV) broadcasting Most two-way frameworks battling or bankrupt Expensive contrasting option to earthbound framework A couple of aspiring frameworks not too far off

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Paging Systems Broad scope for short informing Message communicate from every base station Simple terminals Optimized for 1-way transmission Answer-back hard Overtaken by cell

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Bluetooth Cable substitution RF innovation (minimal effort) Short range (10m, extendable to 100m) 2.4 GHz band (swarmed) 1 Data (700 Kbps) and 3 voice stations Widely upheld by media communications, PC, and customer gadgets organizations Few applications past link substitution 8C32810.61-Cimini-7/98

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Ultrawideband Radio (UWB) UWB is a drive radio: sends beats of several picoseconds(10 - 12 ) to nanoseconds (10 - 9 ) Duty cycle of just a small amount of a percent A bearer is not really required Uses a considerable measure of transfer speed (GHz) Low likelihood of location Excellent running capacity Multipath exceptionally resolvable: great and awful Can utilize OFDM to get around multipath issue.

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Why is UWB Interesting? Novel Location and Positioning properties 1 cm exactness conceivable Low Power CMOS transmitters 100 times lower than Bluetooth for same range/information rate Very high information rates conceivable 500 Mbps at ~10 feet under current directions 7.5 Ghz of "free range" in the U.S. FCC as of late authorized UWB for business utilize Spectrum allotment overlays existing clients, however its permitted control level is low to minimize impedance "Moore's Law Radio" Data rate scales with the shorter heartbeat widths made conceivable with ever speedier CMOS circuits

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IEEE 802.15.4/ZigBee Radios Low-Rate WPAN Data rates of 20, 40, 250 kbps Star groups or shared operation Support for low inactivity gadgets CSMA-CA channel get to Very low power utilization Frequency of operation in ISM groups Focus is principally on radio and get to methods

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Data rate 100 Mbit/sec UWB 802.11g 802.11a 802.11b 10 Mbit/sec 1 Mbit/sec 3G Bluetooth 100 kbits/sec ZigBee 10 kbits/sec UWB 0 GHz 1GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

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Range 10 km 3G 1 km 100 m 802.11b,g 802.11a Bluetooth 10 m ZigBee UWB 1 m 0 GHz 1GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

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Power Transmission 10 W 3G 1 W 100 mW 802.11bg 802.11a Bluetooth 10 mW ZigBee UWB ZigBee UWB 1 mW 0 GHz 1GHz 2 GHz 3 GHz 4 GHz 5 GHz 6 GHz

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Emerging Systems Ad hoc remote systems Sensor systems Distributed control systems

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Ad-Hoc Networks Peer-to-associate correspondences. No spine foundation. Steering can be multihop. Topology is progressive. Completely associated with various connection SINRs

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Design Issues Ad-hoc arranges give an adaptable system foundation to numerous developing applications. The limit of such systems is for the most part obscure. Transmission, get to, and steering methodologies for impromptu systems are by and large specially appointed. Crosslayer plan basic and exceptionally difficult. Vitality requirements force intriguing outline tradeoffs for correspondence and systems administration.

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Nodes fueled by nonrechargeable batteries Data streams to incorporated area. Low per-hub rates however up to 100,000 hubs. Information profoundly related in time and space. Hubs can collaborate in transmission, gathering, pressure, and flag handling. Sensor Networks Energy is the driving imperative

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Energy-Constrained Nodes Each hub can just send a limited number of bits. Transmit control minimized by amplifying bit time Circuit vitality utilization increments with bit time Introduces a postponement versus vitality tradeoff for every piece Short-extend systems must consider transmit, circuit, and preparing vitality. Modern strategies not really vitality productive. Rest modes spare vitality however confuse organizing. Changes everything about the system plan: Bit portion must be upgraded over all conventions. Postpone versus throughput versus hub/arrange lifetime tradeoffs. Advancement of hub participation.

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Spectrum Regulation Spectral Allocation in US controlled by FCC (business) or O ffice S pectrum M gmnt (resistance) FCC barters ghastly pieces for set applications. Some range put aside for general utilize Worldwide range controlled by ITU-R Regulation can stunt advancement, cause financial fiascos, and defer framework rollout

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