Prologue to Wireless Systems and History

Introduction to wireless systems and history l.jpg
1 / 45
1412 days ago, 528 views
PowerPoint PPT Presentation

Presentation Transcript

Slide 1

Prologue to Wireless Systems and History CS 515 Mobile and Wireless Networking I brahim Korpe oğ lu Computer Engineering Department Bilkent University, Ankara Ibrahim Korpeoglu

Slide 2

Objectives and Compromises in Designing Cellular Systems Objectives Maximize clients per MHz Maximize clients per cell refer to Base stations are too expensive Compromises made for these destinations High power transmitters at base stations to build the range High power transmitters for client sets High client set intricacy High power utilization because of complex computerized flag handling High system multifaceted nature Ibrahim Korpeoglu

Slide 3

Features of Cellular Systems Low piece rate discourse coding: <= 13 Kb/s Increases the quantity of clients per MHz and cell-website Decreases the voice quality Some frameworks (like CDMA) make utilization of discourse inertia High Transmission Delay 200 ms round-excursion time High-many-sided quality DSP (advanced dignal preparing) For discourse coding and de-modulatioin Ibrahim Korpeoglu

Slide 4

Features of Cellular Systems Fixed Channel Allocation Channel are designated to cell-locales statically Dynamic assignment is mind boggling to work likewise with handoffs Frequency Division Duplex Network and framework unpredictability for giving synchronization between system components is mitigated TDD requires synchronized time at both closures Mobile handset control control Decreases the co-channel impedance Hence expands the framework limit Implemented in CDMA frameworks Ibrahim Korpeoglu

Slide 5

System Capacity System Capacity is the number all clients that can impart (utilize the framework) in the meantime A base station (cell) has an altered number of channels accessible, thus at a given time a settled number of clients can talk all the while Ibrahim Korpeoglu

Slide 6

System Capacity(C) and Coverage Area(d 2 ) System 1 System 2 d Low cost base-stations covering a little zone High cost base-stations covering a vast zone Each base station has a settled number of channels for both frameworks All diverts in System1 = 9 x All directs in System2 C1/C2 = (d2/d1) 2 Ibrahim Korpeoglu

Slide 7

System Capacity/Coverage Area/Economics Compare high-level and low-level PCS frameworks Assume chann el s/MHz are the same for both frameworks High-level System Cell-webpage dividing: 20,000 ft (6km), cost = $ 1M Low-level System Cell-webpage dispersing: 1,000 ft (300m) Low-level System Capacity = (20000/1000) 2 = 400xHigh-level Capacity Then, to have both framework costs a similar Base station costs in low-level frameworks ought to be $ 1M/400 = $ 2500 Ibrahim Korpeoglu

Slide 8

Wide Area Data Systems Characterized by Providing high versatility Wide-extend Low information rate 9.2 Kbps, 19.2 Kbps Digital information correspondence Deployed in a few urban communities and areas in USA Some Systems like CDPD are overlayed over existing cell framework (AMPS) CDPD: Cellular Digital Packet Data CDPD utilizes the unused voice channels as a part of AMPS framework for information transmission Ibrahim Korpeoglu

Slide 9

Wide Area Wireless Packet Data Systems Ibrahim Korpeoglu

Slide 10

Example: Metricom Provides remote Internet access for desktop, tablet and palmtop PCs A Metricom modem can interface with the serial/USB port or can associate as a PCMCIA card to the primary transport. A metricom modem has around 1 mile run Uses a Microcellular Packet Radio Network Frequency band: ISM band at 902-928 MHz (915 MHz center freq.) Power control is utilized to minimize impedance and amplify battery lifetime Systems Shoe-box sizes base station Mobile terminal remote connectors Deployed in Bay Area, San Francisco. Ibrahim Korpeoglu

Slide 11

Metricom - How it works Computers utilize Metricom modems that send information by means of radio signs to construct stations situated with respect to utility shafts The post - best radios send the information by means of radio flag to wired recieving wires The radio signs are changed over to wire-based signs at the reception apparatus and sent to the metricom arrange interface over fast system Metricom organize interface associates straightforwardly to the web and private systems Ibrahim Korpeoglu

Slide 12

Metricom Coverage - Bay Area, San Francisco Ibrahim Korpeoglu

Slide 13

High-Speed Wireless LANs (WLAN) Characterized by Low portability (not for vehicular utilize) High speed information transmission Confined districts – structures and grounds Coverage: 100m – 300m for every base station Speed: 2-11Mbps, 20Mbps Uses ISM groups 902-928 MHz 2400-2483.5 MHz 5725-5850 MHz Uses FHSS or DSSS range use strategies Ibrahim Korpeoglu

Slide 14

WLAN Standards Ibrahim Korpeoglu

Slide 15

Personal Area Networks (PANs) Bluetooth 2.5GHz ISM band 10m territory, 1mW transmit control 100m territory, requires increment in transmit control 1 Mbps information rate shared between 7 gadgets FHSS spread range utilize TDD duplex plan Polling based numerous get to Retricted begin topology 1 ace associates with 7 slaves Ibrahim Korpeoglu

Slide 16

Paging Systems Categorized as One-way informing (uneven correspondence) Wide-region scope Low multifaceted nature, low-control pager ( beneficiary ) gadgets Ibrahim Korpeoglu

Slide 17

Wide-Area Paging System City 1 Terrestrial Link Paging Terminal City 2 Paging Terminal Terrestrial Link Paging Control Center City N Paging Terminal Satellite Link Ibrahim Korpeoglu

Slide 18

Satellite Based Mobile Systems Categorized as Two-way (or one-way) restricted quality voice or information transmission Very wide range and scope Large locales Sometimes worldwide scope Very helpful in meagerly populated territories: country regions, ocean, mountains, and so on. Target: Vehicles and/or other stationary/portable uses Expensive base station (satellites) frameworks Ibrahim Korpeoglu

Slide 19

Satellite based frameworks Very extensive scope Low general framework limit Expensive administration Proposed Satellite Systems LEOS: Low-earth circle satellite frameworks 10-100 satellites/framework High general framework limit, low defer Many yet equivalently less costly satellites MEOS: Medium-earth satellite frameworks GEOS: Geostationary or Geosynchronous Orbit Systems Fewer than 10 satell ites/framework Low general framework limit, top of the line to-end delay (~0.5sec) Very costly satellites Iridium, Globalstar, Teledesic, Inmarsat are some illustration frameworks Ibrahim Korpeoglu

Slide 20

History of Wireless and Mobile Communication Ibrahim Korpeoglu

Slide 21

History 1831: Faraday had initially begun trying different things with electromagnetic waves. Electromagnetic wave : one of the waves that are proliferated by synchronous occasional varieties of electric and attractive field power and that incorporate radio waves infrared obvious light bright, X beams Gamma beams Ibrahim Korpeoglu

Slide 22

History – Mathematics and EM 1864: Maxwell who had been chipping away at a scientific model for electromagnetic waves at long last distributed his paper on the subject. One of the outcomes of his hypotheses was that E.M. waves would go at close to the speed of light. This had additionally been tentatively controlled by others at the time. Ibrahim Korpeoglu

Slide 23

History At the time not very many individuals completely comprehended Maxwell's condition. Three researchers who have been called Maxwellians considered his conditions encourage: Lodge, Hertz, Tesla. Oliver Lodge understood that the conditions not just inferred the way of light and warmth, additionally that there was an entire range of radiation with wavelengths both above and beneath those of unmistakable light. He was most likely one of the first to understand this could be delivered electrically . Ibrahim Korpeoglu

Slide 24

History – Existence of EM Waves while Lodge was completing his analyses, Heinrich Hertz in Germany was likewise doing some of his own concerning Maxwell's conditions. Hertz's examinations concerning Maxwell's conditions included era, discovery, and estimation of waves in free space, as opposed to along wires. 1887: Hertz demonstrates presence of EM waves; first start transmitter creates a start in a beneficiary a few meters away The units of recurrence waves is named after him, 1 cycle/second equivalents a Hertz. Ibrahim Korpeoglu

Slide 25

History – Wireless Telegraph 1896: Guglielmo Marconi shows remote broadcast to English transmit office 1897: ``The Birth of Radio'' - Marconi granted patent for remote transmit 1897: First ``Marconi station'' built up on Needles island to speak with English drift 1898: Marconi granted English patent no. 7777 for tuned correspondence 1898: Wireless transmitted association amongst England and France built up Ibrahim Korpeoglu

Slide 26

History – Frequency Tuning In 1898: Tesla gave one of the principal remote exhibits with a what we would call a remote control vessel. He understood that things of this nature would need to just react to their own recurrence, and stay dormant something else. This was Tesla's key radio tuning creation, which he had initially depicted quite a while before. Ibrahim Korpeoglu

Slide 27

History – Transoceanic Communication 1901: Marconi effectively transmits radio flag crosswise over Atlantic Ocean from Cornwall to Newfoundland 1902: First bidirectional correspondence crosswise over Atlantic 1909: Marconi granted Nobel prize for material science Ibrahim Korpeoglu

Slide 28

History – Voice over Radio 1914: First voice over radio transmission 1920s: Mobile recipients introduced in squad cars in Detroit 1930s: Mobile transmitters created; radio gear possessed the majority of squad car trunk by 1934: Amplitude Modulation (AM) frameworks utilized by squad cars and stations 1935: Edwin Armstrong showed recurrence balance (FM) interestingly. Larger part of police frameworks changed over to FM Ibrahim Korpeoglu

Slide 29

History – Mobile Telephony 1946: First open cell phone administration was presented. In the first place interconnection of versatile clients to open exchanged phone arrange (PSTN) 1949: FCC (Federal Communications Commission) of US perceives portable radio as new class of administration 1950-1960: AT&T Be