Overview of Radio Communication
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This document provides an overview of radio communication. It covers topics such as radio and microwave communication, spectrum management, digital microwave systems, fading countermeasures, modulation methods, broadband wireless access, radio frequency identification, intelligent transportation systems, and amateur radio. The key points covered include definitions of radio frequency bands, common applications that use radio frequencies, and concepts related to radio wave propagation, spectrum allocation, and digital microwave link performance.
Overview of Radio Communication
- 1. Overview of Radio Communication OVERVIEW OF RADIO COMMUNICATION NTIPRIT National Telecommunication Institute for Policy Research, Innovation and Training Ghaziabad – 201002. www.ntiprit.gov.in Naveen Jakhar, ITS 1
- 2. Overview of Radio Communication Topics covered in this Presentation: 1. Radio & Microwave Communication. 2. Spectrum Management. 3. Digital Microwave Systems. 4. Fading and measures to counter Fading effect. 5. Digital Microwave link – Performance Objectives. 6. Modulation Methods. 7. A word about BWA 8. Other wireless communication Applications Overview of Radio Communication 2
- 3. Overview of Radio Communication PHz = petahertz Ehz = exahertz 3
- 4. Overview of Radio Communication + Satellite TV+ WiFi, Bluetooth Cellphones + + Satellite TVGPS + Short-Wave Broadcast 4
- 5. Overview of Radio Communication Radio Waves Propagation • Ground Waves - < 30 MHZ (Tropospherically Reflected) • Sky Waves – reflected by ionosphere. Short Waves 30MHz – 40 MHz ( Ionospherically Reflected) • Space Wave- > 40 MHZ ( >1000 MHZ also know as LOS ) Ground Waves - suitable for frequencies < 30 M Hz. Waves travel in troposphere. • Direct Wave. • Ground Reflected Wave. • Tropospherically Reflected Wave. 5
- 6. Overview of Radio Communication Propagation Modes Ground-Wave 6
- 7. Overview of Radio Communication Propagation Modes Direct-Wave All Frequencies 7
- 8. Overview of Radio Communication SATELLITE REPEATER 10000 KM 1500 KM 750 KM LOS MAXIMUM COVERAGE EARTH TROPOSPHERIC SCATTER IONOSPHERIC REFLECTION (HF RADIO) FIG. : MODES OF COMMUNICATION 8
- 9. Overview of Radio Communication UHF = Ultra-High Frequency applications 1000 m 3 GH300 MHz 10 Km FREQUENCY WAVELENGTH 2 GHz UHF TV 1000 MHz Keyless Entry 315 MHz Analog Cell Phone WiFi etc. 2.4 GHz Digital Cellphone GPS 1.575 GHz 9
- 10. Overview of Radio Communication BLUETOOTH- 2.4 - 2.485 GHZ WI-FI- 2.4-5.0 GHZ GPS-: L1 (1575.42 MHz) and L2 (1227.60 MHz) KEYLESS SYSTEMS-315 MHZ 10
- 11. Overview of Radio Communication 11 Basic mechanisms that impact propagation • Reflection: electromagnetic wave impinges upon an object which has very large dimensions when compared to the wavelength of the propagation wave. – Occurs from the surface of the earth, building and walls. • Diffraction: occurs when the radio path is obstructed by a surface that has sharp irregularities (edges). – Secondary waves present throughout the space and even behind the obstacles, giving rise to a bending of waves around the obstacles. • Scattering: occurs when the medium through which the wave travel consists of objects with dimensions that are small compared to the wavelength, and where the number to obstacles per unit volume is large. foliage, atmospheric impurities.
- 12. Overview of Radio Communication 2.Spectrum Management 12
- 13. Overview of Radio Communication At national level, each administration has its own regulating agency like NTIA/FCC in USA, Ofcom in UK and WPC Wing in India. WPC- Wireless Planning and Coordination Wing, under DOT,MOC &IT HQ at Sanchar Bhawan New Delhi. Radio spectrum is divided into spectrum bands that are allocated to specific services, such as mobile, fixed, broadcast, fixed satellite and mobile satellite services on exclusive basis. Spectrum Management 13
- 14. Overview of Radio Communication In India the Wireless Planning & Coordination (WPC) Wing of the Ministry of Communications & IT, is the National Radio Regulatory Authority responsible for Frequency Spectrum Management, including licensing and caters for the needs of all wireless users (Government and Private) in the country. The WPC Wing performs its functions through various divisions / groups. The wireless services is based on National Frequency Allocation Plan (NFAP) which was made effective from 01.01.2000. The latest one is Draft NFAP 2011. NFAP is the basis for development, manufacturing and spectrum utilization activities in the country. Spectrum Management in IndiaSpectrum Management in India 15
- 15. Overview of Radio Communication Transmission Systems Bounded media (Optical Fiber, coaxial cable) •Bounded media require a physical connection between two points to guide current, electromagnetic wave or light. Unbounded media (UHF, VHF, Microwave and Satellite) Unbounded media needs no such physical connection . 16
- 16. Overview of Radio Communication OF Vs MW Systems OF Systems • Very High Bandwidth • up-to 40 GBps with DWDM • High Reliability • OF cable susceptible to cuts etc. MW Systems • Limited Bandwidth due to Radio. • Max up-to STM-1 systems. • Less Reliable. • Quick Deployment • Suitable for Hilly, inaccessible and difficult terrain areas. • Mobile End links 17
- 17. Overview of Radio Communication Microwave Systems 1. Unlike Cellular Systems, Microwave systems work on Line of Sight (LOS) principle. 3. Wideband Microwave Systems operate between stations that are hundreds of Kms apart with number of Repeaters in between. • Station A, Station B. • Tx and Rx Antenna. • Hop Distance. 2. Microwave Systems are point to point systems. 18
- 18. Overview of Radio Communication Radio Frequency Bands(ITU Designations) VHF band 30 – 300 MHz UHF 300 – 3000 MHz beyond 1000 MHz LOS communication SHF 3GHz to 30 GHz EHF 30 GHz to 300 GHz VHF-Very High Frequency. UHF-Ultra high freq. SHF- super high freq. EHF-Extremely High Freq. 19
- 19. Overview of Radio Communication L 1-2 GHz S 2-4 GHz C 4-8 GHz X 8-12 GHz Ku 12-18 GHz K 18-27 GHz Ka 27-40 GHz V 40-75 GHz M/W Frequency Bands W 75-110 GHz 20
- 20. Overview of Radio Communication Frequency Usage Some commonly used MW Bands are: • Police Radios: Country dependent. • FM Radio: 100 MHz Approx. • Television: 300 MHz Approx. • Mobile networks: 450-2000 MHz Approx. • Trunk Routes 2-100GHz. The frequencies used by mobile networks varies according to the standard being used. 21
- 21. Overview of Radio Communication 23 Spectrum Bands Identified for various wireless telecom services (INDIA) Band Technology 450MHz 2G & 3G 700 MHz Digital Mobile TV 800 MHz 2G & 3G 900MHz 2G 1800MHz 2G 1900MHz 2G & 3G 2010-2025 MHz BWA 2.1 GHz 3G 2.3 GHz BWA 2.5 GHz BWA 3.3 GHz BWA 3.4GHz BWA 2.4-2.4835, 5.15-5.35 & 5.725-5.875 GHz are de-licensed spectrum bands. 23
- 22. Overview of Radio Communication Fading - Occurs due to multi-path signals. Challenges of Radio Transmission 24
- 23. Overview of Radio Communication Counter Measures For Fading • Diversity Techniques • Space Diversity. • Frequency Diversity. • Power Control • ATPC- Automatic Transmit Power Control • RTPC-Remote Transmit Power Control 25
- 24. Overview of Radio Communication Classification of Radio Transmission Equipment • Low Capacity • 2 Mbps • 8 Mbps UHF(400-700MHz) 2Ghz • Medium Capacity • 34 Mbps 7 & 13 GHz. • Large Capacity • 140 Mbps 4,6 & 11 GHz. • Mini- Links • up-to 16 E1’s (34 Mbps) 15 & 18 GHz,. 26
- 25. Overview of Radio Communication Commonly Used Digital MW Systems Long Haul Systems Make i) High Capacity 6 Ghz 140 Mb/s Systems Fujitsu, NEC, BEL, ITI (carrying 1920 voice channels ) Used in Main Trunk Routes ii) Medium Capacity 7Ghz, 34 Mb/s Fujitsu, NEC, BEL, ITI Used in thin Routes Short Haul Systems 11 Ghz, 140 Mb/s Used for satellite End Links NEC & Others 13 Ghz, 34 Mb/s Used for junction Networking 27
- 26. Overview of Radio Communication Microwave System configuration Radio equipment required at the terminal : 1. Base Band (BB) Processing equipment. 2. I.F modulation equipment/ De-MOD equipment 3. UP converter/ Down Converter. 4. Power Amplifier 5 Antenna Sub. System. 6 Equalizer 28
- 27. Overview of Radio Communication ( Base Band Processing ) B.P.F. P.A. (FET) RF Combiner Antenna RF (6GHz) 140 Mbps MOD 140 Mbps IF RF (6GHz) DEMOD EQUALIZER D / C B.P.F. Amplifier BLOCK SCHEMATC OF A 6-GHZ DIGITAL M/W SYSTEM IF ( 70MHz) U / C ( 70MHz) IF 29
- 28. Overview of Radio Communication Lower Band Fr in M Hz Upper Band Fr in M Hz 1,1x 6460 1’,1’x 6800 2,2x 6500 2’.2’x 6840 3,3x 6540 3’,3’x 6880 4,4x 6580 4’,4’x 6920 5,5x 6620 5’,5’x 6960 6, 6x 6660 6’,6’x 7000 7,7x 6700 7’,7’x 7040 8,8x 6740 8’,8’x 7080 Frequency Plan for 6 G Hz Digital M/W Systems ( 6425-7110 M Hz ) 30
- 29. Overview of Radio Communication Mini-Link Medium Capacity point to point Microwave link of capacity 4-16 E1 links operating in 15, 18, 23 and 38 G Hz bands. Small radio unit together with an integrated compact antenna forms ODU. 35
- 30. Overview of Radio Communication Digital ModulationDigital Modulation Carrier signal: Ac cos (2πfct + φ) Modulation: m(t) Modulated signal: Ac (t) cos (2πfc(t) t + φ(t)) Vary Vary Vary amplitude frequency phase Variations are discrete!!!!! ∝ m(t); discrete 37
- 31. Overview of Radio Communication Digital Modulation Types 1. AMPLITUDE MODULATION (ASK or OOK) ( Amplitude Shift Keying or On off Keying) 2. FREQUENCY MODULATION (FREQUENCY SHIFT KEYING- FSK) 3. PHASE MODULATION (PHASE SHIFT KEYING -PSK) 4 QUADRATURE AMPLITUDE MODULATION (QAM) 38
- 32. Overview of Radio Communication Required RF Bandwidth: RF BW = Rs/Rc*(1+α ) Rs = Symbol Rate. Rc= coding rate. α = cosine roll-off factor of RRC filter. Free Space Path Loss: FSL = 32.2 + 20 log (f) + 20 log (d) in db. f = frequency in MHz. d = distance in kms. Some Fundamental Formulae 39
- 33. Overview of Radio Communication What is the Required RF Bandwidth to carry 64kbps of data stream, which is ½ Rate coded and BPSK modulation is used ? Assume RRC filters with α = 0.25. Some Fundamental Formulae What is the change in RF Bandwidth requirement if QPSK modulation is used instead of BPSK modulation ? 40
- 34. Overview of Radio Communication What is ? • WiMAX or “Worldwide Interoperability for Microwave Access” had its origins in backhaul connectivity using microwave access. • WiMAX has become a “hot topic” in the wireless industry, with visible and aggressive backing from INTEL, among others. • WiMAX is designed to provide “last-mile” or “backhaul” connectivity using wireless – “Last-mile” refers to a wireless connection from a major trunk line to a business or residential user – Using IEEE 802.16 Broadband Wireless Access (BWA) standard, approved in January 2003, to provide operations in the <11GHz spectrum range 41
- 35. Overview of Radio Communication WiMAX Vision: Broadband Everywhere BWA Operator Network Backbone INTERNET BACKBONE Mobile Backhaul 3 RESIDENTIAL & SoHo DSL LEVEL SERVICE 1 802.16d FRACTIONAL E1 for SMALL BUSINESS E1+ LEVEL SERVICE ENTERPRISE BACKHAUL for HOTSPOTS 2 802.16d H H HH H H H H H WMAN Nomadic Coverage --> handoff from HOT SPOTS 4 = wide area coverage outside of Hot Spots Mobility 5802.16e 42
- 36. Overview of Radio Communication Other Applications • RFID • Intelligent Transport System(ITS) • Amateur radio (HAM) 43
- 37. Overview of Radio Communication RFID OperationsRFID Operations 45
- 38. Overview of Radio Communication Technical Parameter Active RFID Passive RID Tag Power Source Internal to Tag Energy transferred from Reader via RF Tag Battery Yes No Availability of Tag Power Continuous Only within the range of Reader field Requirement of Signal Strength from Reader to Tag Low High Available Signal Strength from Tag to Reader High Low Active and Passive TagsActive and Passive Tags 46
- 39. Overview of Radio Communication Radio Frequency Identification Devices (Exemption from Licensing Requirement) Rules, 2005 • “Use of low power Equipment in the frequency band 865 – 867 MHz for (RFID) Radio Frequency Identification Devices (Exemption from Licensing Requirement) Rules, 2005 -rules were published in the Gazette of India, Part II, Section 3, Sub-Section (i), dated the 11th March, 2005, vide notification No.168 (E), dated the 11th March, 2005. • Rule 3. Use of wireless equipment in the band 865 – 867 MHz.- Notwithstanding anything contained in any law for the time being in force, no licence shall be required by any person to establish, maintain, work, possess or deal in Radio Frequency Identification Devices (RFID), on non-interference, non-protection and non-exclusive basis, in the frequency band 865 – 867 MHz with maximum 1 Watt transmitter power, 4 Watts Effective Radiated Power and 200 kHz carrier bandwidth. • Rule 4. In case where any person to whom a licence has been issued under section 4 of the Act, informs that his licensed system is getting harmful interference from any other radio communication system exempted under these rules, the use of such unlicensed Wireless equipment shall be discontinued forthwith. 49
- 40. Overview of Radio Communication Intelligent Transport System(ITS) • Intelligent transport systems (ITS) are advanced applications which aim to provide innovative services relating to different modes of transport and traffic management and enable various users to be better informed and make safer, more coordinated, and 'smarter' use of transport networks. • ITS are systems in which information and communication technologies are applied in the field of road transport, including infrastructure, vehicles and users, and in traffic management and mobility management, as well as for interfaces with other modes of transport. 50
- 41. Overview of Radio Communication Amateur radio (HAM) Amateur radio (also called "ham" radio) is the use of designated radio frequency spectra • for purposes of private recreation, • Non commercial exchange of messages, • Wireless experimentation, self-training, and emergency communication. The term "amateur" is used to specify "a duly authorised person interested in radio-electric practice with a purely personal aim and without pecuniary interest, and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). 53
- 42. Overview of Radio Communication Amateur radio (HAM) The WPC—regulates amateur radio in India. The WPC assigns call signs, issues amateur radio licences, conducts exams, allots frequency spectrum, and monitors the radio waves. In India, the Amateur radio Society of India (ARSI) represents amateur radio interests at various forums. 54
- 43. Overview of Radio Communication Thank You !! 55