Presentation Title Subhead Date

Transcription

1 Wireless 2013 Best Practices: Spectrum, Hardware, Software Presentation Title Subhead Date Tim Vear Dave Mendez Systems Support

2 The Wisdom of Dilbert

3 Program! 9:00 10:00 Spectrum Update! 10:00 10:15 Break! 10:15 11:15 Principles of Radio Transmission! 11:15 11:30 Break! 11:30 12:30 Effective Antenna Setup! 12:30 1:30 Lunch! 1:30 2:30 Frequency Compatibility and Coordination! 2:30 2:45 Break! 2:45 3:45 Using Shure Wireless Workbench!

4 Spectrum Update

5

6 Popular Bands For Wireless Mics UHF TV VHF TV GHz User License Required User License Not Required

7 Broadcast vs. Broadband! 10% Watch TV antenna 53% Own a Smartphone

8 300 MHz 3 GHz

9 Wireless Mic Spectrum: United States Wireless System Bands (broadcast) : 278MHz Wireless System Bands (consumer) : 115MHz DECT ( ) MHz) Traveling frequencies STL, ICR frequencies ( MHz) High-band VHF UHF ( MHz) ALS 2.4GHz ( MHz) ( MHz) (72-76MHz) ( MHz) 49MHz (43-50MHz) TV 7-13 ( MHz) ALS ( MHz) TV ( MHz) 900MHz ( MHz) Frequency in MHz 2400

10 More UHF Changes Coming! 470 MHz! 698 MHz! 806 MHz! Analog DTV! TV! Radio Astronomy??? DTV! Analog New TV! Services! S A F E T Y! S A F E T Y! FCC plans to auction more TV band to carriers! TV stations that move share auction $! Congressional approval received March 2012! Auction must occur by 2022!

11 700 MHz Band Closed June 12, 2010! Core TV Band! 700 MHz Band! 470 MHz! 698 MHz! 806 MHz! Analog DTV! TV! Radio Astronomy DTV! New! Analog TV! Services! S A F E T Y! S A F E T Y!

12 TV Band Devices!

13 TV Band Devices! Now authorized nationwide! Only Fixed devices so far!

14 Active White Space Networks! Wilmington, NC! TV Band Device! KTS Wireless Agility Data Radio! Database! Spectrum Bridge! Nottoway, VA! TV Band Device! Adaptrum ACRS 1.0! Database! Telcordia TV!

15 Where TV Band Devices Operate! Permitted Users! Wireless Mics! Fixed TVBD s! Wireless Mics! Fixed & Portable TVBD s! Local Assignments SAFETY SAFETY TV TV TV TV TV TV TV TV TV TV TV TV RESERVED TV Radio Astronomy TV TV TV TV RESERVED TV TV TV TV TV TV TV TV Channel Frequency Range (MHz)

16 13 Markets Where Public Safety Uses TV Channels Market Channels Market Channels Boston 14, 16 Miami 14 Chicago 14, 15 New York 14, 15, 16 Cleveland 14, 15 Philadelphia 19, 20 Dallas 16 Pittsburgh 14, 18 Detroit 15, 16 San Francisco 16, 17 Houston 17 Washington DC 17, 18 Los Angeles 14, 15, 16, 20

17 Geo-location Database! Database shows with TV channels are reserved for wireless mics! Registering event protects you from interference on non-reserved channels! Licensed users get quick access! Unlicensed users need FCC approval first! 30-day advance notice required! Expect them to be very selective!

18 Register for Additional Protected Channels! 6 mics per channel Unlicensed! Users! FCC! 30 days! Database! Licensed! Users! 1-2 days

19 Database Registration! Database now available nationwide! Steps to register:! Determine if you qualify! File a Request to Register Unlicensed LPADs! Wait for FCC approval! Use File Number to register in database!

20 Geo-location Database! SpectrumBridge, Telcordia databases active! Google & Keybridge databases in testing phase!

21 Telcordia says!

22 Telcordia WSD TV Database

23 Telcordia WSD TV Database

24 Telcordia WSD TV Database

25 Incentive Auction!

26 Incentive Auction! Reverse Auction! TV stations bid to change/share channel OR go dark for $! Forward Auction! Carriers bid $ on open spectrum! Repacking! Stations are moved to new channels! How much spectrum? Which spectrum? When?

27 How much spectrum?! Depends on how many TV stations volunteer! 40 MHz? 60 MHz? 80 MHz?! Could vary in different cities!

28 Which spectrum?!

29 The Most Likely Scenario! ACTUAL SIZE DEPENDS ON TV STATION PARTICIPATION TV TV TV TV TV TV TV TV TV TV RESERVED TV MED / ASTRO GUARD BAND! RESERVED AUCTION TV TV TV GUARD BAND! TV TV AUCTION TV Freq Range (MHz)

30 Auction Timeline! FCC wants to start auction in 2014! Repacking process could take several years!

31 Other Issues! Should Reserved TV channels for wireless mics be eliminated?! Should license eligibility be expanded?!

32 Licensing - The New Hierarchy!! TV! Stations! Licensed Wireless Mics! Unlicensed Wireless Mics & TV Band Devices! Temporary Licensing Scheme for Wireless Audio Systems: No license required for power output < 50mW

33 Wireless Mic Licenses! ELIGIBLE NOW! Broadcasters! Educ TV networks! Cable networks! TV & film prod co s! NOT ELIGIBLE NOW! Theaters, venues! Hotels/convention ctrs! Theme parks! AV rental/prod co s! Churches! Schools!

34 What Shure is Advocating! Preserve reserved channels exclusively for wireless microphones! Expand license eligibility for easier database access!

35 Summary! Spectrum will become more crowded! Some users will have to move to new frequencies! License will be valuable!

36 Choosing Frequencies in the New Era Today No need to do anything different Some fixed TVBDs No portable TVBDs on the horizon Choose systems with widest tuning range and best channel-to-channel spacing Future Choose frequency ranges that overlap reserved channels Assign frequencies according to need: Primary: Reserved Channels 1 TV channel can support 6 14 wireless mics, depends on receiver selectivity Secondary: Adjacent channels to DTV Tertiary: Any other open UHF channels For large installations, reserve additional channels in the database

37 Principles of Radio Transmission

38 Radio Frequency Transmission Radio Waves: Series of electro-magnetic field variations in space. Travel a significant distance from their source. Radio Signals: Radio waves modulated to carry information. May be modulated in amplitude, frequency, and/or phase y-axis x-axis Electric field Magnetic field Direction of propagation

39 Radio Wave Properties Speed: 3x10 8 meters per second in vacuum, same as the speed of light. Speed is constant in a given medium. Medium: Unlike sound, radio waves do not need physical substance to propagate. Radio waves move most efficiently in a vacuum. Polarization: Electric field component is perpendicular to magnetic field component. Radio wave is polarized in direction of its electric field component. Usually parallel to the axis of the transmitting antenna.

40 The Wave Equation C = L x F where C=speed of light, L=wavelength, F=frequency C=3x10 8 meters/second (186,000 miles/second) L=300/f meters, where f=frequency in MHz VHF UHF MHz Meters

41 Radio Spectrum Frequency in Hz AM radio FM radio Visible light X-rays Gamma rays, Cosmic rays HF VHF UHF SHF EHF VLF LF MF Television, Wireless Systems Radar, Microwave Infrared Ultra violet Wavelength in meters

42 Propagation: Wavelength vs. Obstacle Wavelength Metal Obstacle Wavelength much SMALLER than obstacle: WAVE IS REFLECTED

43 Propagation: Wavelength vs. Obstacle Wavelength Metal Obstacle Wavelength much LARGER than obstacle: WAVE PASSES BY

44 Propagation: Wavelength vs. Opening Metal Obstacle Wavelength Opening Wavelength much SMALLER than opening: WAVE PASSES THROUGH

45 Propagation: Wavelength vs. Opening Metal Obstacle Wavelength Opening Wavelength much LARGER than opening: WAVE IS REFLECTED

46 Analog FM Radio Frequency Signal Deviation = change (modulation) of radio frequency Un-Modulated Modulated Amplitude Amplitude Frequency f 0 Frequency Rate of modulation = audio frequency Width of modulation = audio amplitude (f 0 - deviation) f 0 (f 0 + deviation) FM audio quality is not directly dependent on radio signal strength!

47 UHF Wireless Regulatory and Technical Limits MHz (TV 14 51) 250 mw max power (licensed users) 50 mw max power (unlicensed users) 100 khz max deviation (15 to 45 khz generally used) Secondary licensed users under Part 74 (Low Power Auxiliary Service) Eligible licensed users Radio or television broadcast license holders Broadcast networks Some cable television operators Motion picture and television program producers Broadband Radio and Educational Broadcast Service licensees Unlicensed users under Part 15 Must not interfere with licensed users Not entitled to interference protection

48 Transmitter and Receiver Essential Elements

49 Audio Processing for Radio Noise reduction Pre-emphasis and de-emphasis Dynamic range improvement Companding systems Analog or digital processing possible Audio Process Transmit Receive Audio process

50 Pre-emphasis equalization 24dB 20dB 16dB 12dB 8dB 4dB Amplitude 0dB -4dB 10 Hz 30 Hz 100 Hz 300 Hz 1 KHz 3 KHz 10 KHz 30 KHz Frequency

51 De-emphasis equalization +4dB 0dB -4dB -8dB -12dB -16dB Amplitude -20dB -24dB 10 Hz 30 Hz 100 Hz 300 Hz 1 KHz 3 KHz 10 KHz 30 KHz Frequency

52 Compander (2:1, fixed rate) +20 db +10 db (Audio clipping) +10 db (Over-modulation) (Audio clipping) +20 db +10 db 0 db -10 db -20 db -30 db -40 db -50 db -60 db Transmitter: 100 db Dynamic Range Radio Link: 50 db Dynamic Range -40 db (Radio link noise floor) Receiver: 100 db Dynamic Range 0 db -10 db -20 db -30 db -40 db -50 db -60 db -70 db -70 db -80 db (Audio noise floor) (Audio noise floor) -80 db Higher compression rates possible Variable compression rates possible

53 Compander (variable) +20 db +10 db (Audio clipping) +10 db (Over-modulation) (Audio clipping) +20 db +10 db 0 db -10 db -20 db -30 db -40 db -50 db -60 db Transmitter: 100 db Dynamic Range Radio Link: 50 db Dynamic Range -40 db (Radio link noise floor) Receiver: 100 db Dynamic Range 0 db -10 db -20 db -30 db -40 db -50 db -60 db -70 db -70 db -80 db (Audio noise floor) (Audio noise floor) -80 db Variable compression rate, variable threshold Variable expansion rate, variable threshold

54 Radio Frequency Processing RF signal basic process Modulation and demodulation RF signal improvement Frequency multiplying and downconversion Signal may be analog or digital Analog or digital processing possible Audio Process RF Process RF Process Audio process

55 Crystal-controlled Analog Transmitter Quartz crystal Preamp Pre-emphasis Compressor Voltage- Controlled- Oscillator (VCO) Multipliers RF Amp AF RF

56 Frequency-synthesized Analog Transmitter Preamp Pre-emphasis Compressor Synthesized VCO RF Amp Programmable Frequency Divider and PLL Controller AF RF

57 Crystal-controlled Analog Receiver Front End Mixer Deemphasis Intermediate Frequency (IF) Filter IF Amp FM Demodulator Expander Audio Amp Quartz crystal Local Oscillator RF IF AF (10.7 MHz typical) Single Conversion Crystal Receiver

58 Frequency-synthesized Analog Receiver Front End Mixer Intermediate Frequency (IF) Filter IF Amp FM Demodulator Expander Deemphasis Audio Amp Programmable Frequency Divider and PLL Controller Local Oscillator RF IF AF (10.7 MHz typical) Single Conversion Crystal Receiver

59 Digital Wireless Transmission

60 Digital Wireless Transmission Use of digital technologies in wireless systems Analog Analog audio and radio signals Analog signal processing Digital control and/or display Hybrid Analog audio and radio signals Digital audio signal processing Digital control and/or display Digital Digital audio and radio signals Digital signal processing Digital control and/or display

61 Tradeoffs of Digital Wireless Transmission Pro s Greater RF spectral efficiency More simultaneous systems Better audio fidelity Wider, flatter frequency response Increased dynamic range and signal-to-noise ratio Less audible artifacts Improved RF performance Reduced Intermodulation products Better resistance to multipath and interference Leverages advances in digital audio and radio technology Encryption Con s Increased cost and complexity Latency

62 Digital Modulation Methods Transmitter must be modulated in discrete steps Change transmitter parameter in fixed amounts Represent specific bits by specific values of parameter Transmitter parameters are Frequency, Amplitude, Phase FSK (Frequency Shift Keying) Each discrete frequency shift represents a specific bit ASK (Amplitude Shift Keying) Each discrete amplitude shift represents a specific bit PSK (Phase Shift Keying) Each discrete phase shift represents a specific bit QAM (Quadrature Amplitude Modulation) Combination of PSK and ASK

63 Typical Digital Modulation Spectra 2FSK (Two Frequency Shift Keying) 8PSK (Eight Phase Shift Keying)

64 Basic Digital Transmission Scheme ADC converts analog audio input signal to digital audio data DSP prepares digital data for transmission Compress digital audio data Add error correction and timing data Frame complete data into digital word stream DAC converts digital data stream to analog data stream DAC may be integrated with DSP or with Transmitter Necessary because transmitter is actually an analog device Transmitter converts analog data stream to RF output Modulation may be AM, FM, or PM as required Tunable by frequency-synthesized VCO RF amplifier provides required output power

65 Frequency-Synthesized Digital Transmitter Preamp Analog to Digital Converter Data Control Digital Signal Processor Data Control Digital to Analog Converter RF Transmitter RF Amp Programmable Frequency Divider and PLL Controller Analog Digital RF

66 Basic Digital Reception Scheme Analog front-end filter removes out-of-band interference Analog single down-conversion stage Tunable by frequency-synthesized Local Oscillator Intermediate Frequency: similar to analog receiver High-precision IF filter and amplifier ADC converts analog IF data to digital data word stream DSP reconstructs original digital audio data Extract timing data Decompress digital audio data Apply error correction DAC converts processed digital audio data to analog audio Audio amplifier provides required analog output signal

67 Frequency-Synthesized Digital Receiver Front End Filter Mixer Intermediate Frequency (IF) Filter IF Amp Analog to Digital Converter Data Control Digital Signal Processor Data Control Digital to Analog Converter Audio Amp Programmable Frequency Divider and PLL Controller Local Oscillator RF IF Digital Analog

68 Bandwidth vs. Bit Rate Calculation of bit rate (data rate) Resolution (bits-per-sample): 16-bit or 24-bit typical One bit has two possible values: 0 or 1 (2 1 = 2) 16 bit has about 64,000 possible values: 2 16 = 65, bit has about 16 million values: 2 24 = 16,777,216 Sample rate (samples-per-second): 44.1 khz or 48 khz typical Bit rate = Resolution x Sample rate = bps (bits-per-second) 16 bit x 44.1 khz = kbps (CD-quality bit rate) 24 bit x 48 khz = 1152 kbps (High-performance rate) Required RF bandwidth = bit rate for uncompressed data khz for CD-quality audio 1152 khz for High-performance audio Not possible (or legal) to transmit such a wideband signal

69 Typical Digital Modulation Coding Symbol coding: transmit more than one bit per cycle Required bandwidth = bit rate bits-per-symbol 2-FSK: Two Frequency Shift Keying Two frequency values, bandwidth = bit rate 1 bit-per-symbol (values: 0, 1) QPSK: Quadrature Phase Shift Keying Four phase values, bandwidth = bit rate 2 2 bits-per-symbol (values: 00, 01, 10, 11) 8-PSK: Eight Phase Shift Keying Eight phase values, bandwidth = bit rate 3 3 bits-per-symbol (values: 000, 001, 010, 100, 011, 101, 110, 111) 16-QAM: 16 values, 4 bits-per-symbol, bandwidth = bit rate 4 More bits-per-symbol = less required bandwidth

70 2-PSK Symbol Coding: 1 bit/symbol Q 180 = 0 I 0 = 1

71 4-PSK Symbol Coding: 2 bits/symbol Q 90 = = 0 0 I 0 = 1 1 (with Gray Coding) 270 = 1 0

72 8-PSK Symbol Coding: 3 bits/symbol Q 90 = = = = I 0 = = (with Gray Coding) 270 = = 1 0 1

73 8-PSK Symbol Coding: with errors Q I

74 Transmission Error Bit Error Rate (BER): number of data errors over time Actual BER increases with: RF noise Multipath Fading Non-linearity of RF circuits Low RF power Predicted BER increases with higher symbol coding 8PSK requires moderate RF noise floor 16QAM requires very low RF noise floor Minimum acceptable BER determines squelch

75 Data Compression Lossless compression: original data integrity is maintained Effective on redundant data: text, spreadsheets, etc. Not effective on most audio data Lossy compression: data is selectively removed Most significant data is maintained Least significant data is removed Selection is based on perceptual measurement Limitations of human hearing Validated by listening tests Compression ratio vs. quality High compression may reduce perceived audio quality High audio quality may require lower compression ratio Goal: highest quality audio with required compression ratio

76 Compression Algorithms Codec: mathematical compression scheme (Code-Decode) Digital recording Codecs MP3, AAC, WMA, etc. Lossy compression High latency (up to 100 ms) Less sound quality at high compression ratios: 128 kbps = 11/1 ratio Not suitable for real-time wireless audio Specialized low-latency audio Codecs Philips SBC: 5 ms Fraunhofer ULD: 6 ms Shure proprietary: 2.9ms

77 Latency Latency = delay in digital signal path Added by components: ADC, DAC, DSP Due to processing time within or between digital components Does not generally occur in analog signal path Effects of Latency 0-3 ms, usually negligible 3-5 ms, noticeable but not irritating 5-10 ms, somewhat irritating especially for vocal in-ear monitor users ms, irritating for many users 20+ ms, affects musical timing Overall latency should be kept as short as possible Ideally, less than 5 ms. Cumulative: digital wireless + digital mixer + digital processor, etc.

78 Receiver IF Filter Selectivity: Minimum frequency separation Each system must operate on a unique frequency Frequencies must be at least 0.3 to 1.5 MHz apart Minimum spacing = receiver selectivity (IF Filter) Amplitude Frequency

79 Track Tuning Front End Filter Advanced RF filtering technology for the receiver Filter moves with selected frequency maximizing isolation of signal from interference Selected frequency Effective front-end bandwidth ~ 20MHz filter 60 MHz

80 Track Tuning Increases receiver selectivity Enhances the use of Wide Band antenna accessories Removes previous bandwidth limitations Selected frequency filter Effective front-end bandwidth ~ 20MHz 60 MHz

81 UHF-R Receiver

82 Multipath Interference Metal reflecting surface (larger than wavelength) Transmitter Receiver Direct path Indirect path (multipath)

83 Diversity Systems 1 Antenna A Antenna B Passive combiner Receiver Passive antenna combining (not true diversity)

84 Diversity Systems 2 Antenna A Antenna B Phase switch Receiver Controller Phase switching diversity

85 Diversity Systems 3 Antenna A Antenna B Antenna Switch Receiver Comparator Antenna switching diversity

86 Diversity Systems 4 Antenna A Antenna B Antenna Switch Receiver Predictive comparator Predictive antenna switching diversity

87 Diversity Systems 5 Antenna A Antenna B Receiver 1 Receiver 2 Comparator/ Audio switch Receiver switching diversity Audio Output

88 Diversity Systems 6 Antenna A Antenna B Receiver 1 Receiver 2 Comparator/ Audio mixer Receiver combining diversity Audio Output

89 Squelch Circuits AMPLITUDE SQUELCH based on RF signal strength NOISE SENSITIVE SQUELCH based on audio signal quality, looks for high frequency noise characteristic of RF signal TONE KEY SQUELCH a super-audible tone is sent with carrier receiver gate will not open if tone is not present A-B LEDs indicate squelch status

90 Tone Key Squelch Tone Key off Tone Key on Additional Tone Key Functions (ASK coding) Battery level Transmitter power level Transmitter audio gain settings Transmitter lock settings

91 Shure UHF Wireless What Is The Range? Let s define Range Distance between the receiver and where the first drop-out occurs The range of most PRO UHF systems is approx. 500 ft. under ideal conditions Minus: 95% (outdoor) if the selected frequency overlaps with a TV channel 65% (indoor) if the selected frequency overlaps with a TV channel 50% if the frequencies are not compatible (multiple systems) 50% if the antennas are not properly setup 50% if used inside of a building 40% if the receive antennas are very close to other electronic equipment

92 UHF Wireless Systems What Is The Range? MHz MHz MHz RF Noise Floor Channel 66 Channel 67 Channel 68 Channel 69 Operating Range: 500 ft. 100 ft. 10 ft.

93 Effective Antenna Setup

94 Antenna Types Omnidirectional ½ wave or ¼ wave dipole type Vertical polarization Uniform sensitivity in plane perpendicular to axis 2.14dBi gain (relative to theoretical isotropic antenna) Directional Log periodic or helical type Vertical or circular polarization Increased sensitivity on-axis Decreased sensitivity off-axis Up to 13dBi gain (up to 11dB relative to ½ wave)

95 Omnidirectional 1/2 Wave (Dipole) Omnidirectional Antennas Whip, telescoping, or cable types Wideband types available Independent of ground plane ½ L (Min) Current (Max) 1/4 Wave Whip type Narrow band Must be attached to a ground plane! Ground plane ¼ L Current

96 Wideband Omnidirectional Antenna Element A Element B Horizontal Pattern (viewed from above) Vertical Pattern (viewed from side)

97 Directional Antennas Directional Log periodic (wide band) Helical (wide band) Good for increased range or pattern control Log periodic (with amplifier) Helical (courtesy of Professional Wireless Systems)

98 Log Periodic Antenna Near cardioid pattern MHz band 120 deg. beamwidth 5-7dBi forward gain Vertical polarization Vertical Polarization Horizontal Polarization Vertical Polarization Horizontal Polarization Log periodic pattern from above (antenna pointing right) 270 Vertical Polarization Horizontal Polarization

99 Active Directional Antenna 120 Allows pickup of RF signal from longer distance ( >500 feet) Internal amplifier (+3dB, +10dB) to compensate for long antenna cables Usually require DC voltage to operate

100 Helical Antenna Ultra-directional pattern MHz band 60 deg. beamwidth 9-11dBi forward gain Circular polarization

101 Distance: Microphone to Antennas (Closer is Better) RF Path Loss (Signal Source: ULX1-J1 and M1 Transmitters, ~13-14 dbm Output, Mounted on Microphone Stand ~5' Above Ground) (UA860WB Antenna, 6' RG58 Coax, Rhode & Schwarz FSH3 Spectrum Analyzer, Data Taken Outdoors in Parking Lot) Horizontal Scale Changes Signal Strength (dbm) DTotel:Shure Applications Engineering Distance (feet) UHF MHz UHF MHz Inverse Square Law

102 Antenna Placement Proper orientation Non-diversity receiver: vertical Diversity receiver: 90 apart 90

103 Antenna Placement Adequate spacing Minimum: > ¼ wavelength Best: > 1 wavelength VHF: 15 UHF: 4

104 Antenna Placement Antenna height should be above audience or other obstructions Altitude is your friend! >> 6 ft

105 Body Attenuation vs. Direction Receiver Bodypack transmitter on performer s back

106 Antenna Placement: Wireless Mic Transmit > Wireless Mic receive Minimum distance from transmit antenna to receive antenna should be at least 10 ft. >10 ft.

107 Antenna Placement: In-ear Transmit > Wireless Mic Receive Minimum distance: In-ear transmit > Wireless mic receive At least 10 ft. with low-power, omni antennas Farther with high-power and/or high-gain antennas May be closer with parallel directional antennas >10 ft.

108 Antenna Placement Minimum distance from transmit or receive antenna to any parallel metal structure should be at least ¼- wavelength (4-5 in. in the UHF range).

109 Antennas inside steel enclosure Antenna Placement?

110 Antenna Placement? Antennas inside steel enclosure

111 Antenna Placement? Antennas in metal cage

112 Antenna Placement? Antennas too close together

113 Comparison of Coaxial Cable Types

114 Coaxial Cable Losses 50 Ω coaxial cable should be used (robust, consistent) Less recommended: RG59, RG6, RG11 (75 Ω) Typical Cable Loss for 50 Ohm Cable Type Of Cable RG58C/U SHURE PA MHz (100 ft) 9dB 650MHz (100 ft) 19 db RG8X/U SHURE UA dB 10.3 db RG213/U SHURE UA db 6.03 db RG8/U Belden db 3.1 db

115 Antenna Amplifiers B antenna A antenna B amplifier A amplifier (Cable loss >5 db)

116 Antenna System Configuration +3 to +10dB 4dB Approx -7dB Approx -7dB +3 to +10dB Antenna System Gain: (Ant Gain) + (total booster/amp gain) (cable loss) (split loss) Total gain for 500 ft range = -3 to +6 db (fewer compatible systems) Total gain for 20 to 200 ft range = -12 to -3dB (more compatible systems) Total acceptable gain varies with system and manufacturer

117 Remote Antenna Best Practices Use ½ wave omni or wideband directional antennas Position for best line-of-sight Maintain adequate diversity separation Net loss < 5dB Use minimum cable length Use lowest loss cable Use amplifier(s) when necessary Net gain < 5dB Use minimum gain Separate wireless mic receive antennas from in-ear monitor and intercom transmit antennas!

118 Antenna System Configuration NO requirement for symmetry in antenna configuration: Antennas do NOT have to be the same type: Omni with uni OK! Different types of omni OK! Different types of uni OK! Antenna cables do NOT have to be the same length: Short cables with long cables OK! Cable with direct connection on receiver or distribution amp OK!

119 Antenna System Configuration More than 3 systems? Antenna distribution Hidden receivers? Remote antennas Long range operation? Directional antennas

120 Antenna Distribution Prevents closely-spaced receiver antennas from interfering with each other Passive splitter feeds one pair of antennas to 2 diversity receivers ~3dB loss per split Active splitter feeds one pair of antennas to 4-5 diversity receivers no loss! Multiple active splitters can be linked to feed a large number of receivers RF Cascade Only available on some receivers Eliminates need for external splitter No loss, but limited cascade depth

121 Passive Antenna Distribution Passive splitter B Passive splitter A B antenna A antenna

122 Active Antenna Distribution (one level) B antenna A antenna

123 Active Antenna Distribution (two level) B antenna A antenna

124 Active Distribution (>2 distros) B antenna A antenna

125 RF Cascade Distribution B antenna A antenna

126 RF Cascade Distribution UR4+ Maximum 10 units 20 dual channel RX All RX must be in same band! All RX must be powered on!

127 Lectrosonics PF25 Bandpass Filters

128 Distributed Antenna Systems For Large Venues

129 Distance: Microphone to Antennas RF Path Loss (Signal Source: ULX1-J1 and M1 Transmitters, ~13-14 dbm Output, Mounted on Microphone Stand ~5' Above Ground) (UA860WB Antenna, 6' RG58 Coax, Rhode & Schwarz FSH3 Spectrum Analyzer, Data Taken Outdoors in Parking Lot) Horizontal Scale Changes Signal Strength (dbm) DTotel:Shure Applications Engineering Distance (feet) UHF MHz UHF MHz Inverse Square Law

130 Distributed Antenna Systems Depending on the environment, useful coverage areas when using a handheld transmitter: Omni-directional half wave antennas - up to 150 feet Directional antennas - up to 250 feet Match antenna to coverage area: omni vs directional Position for best line-of-sight Maintain adequate diversity separation Utilize high quality low loss coaxial cable Keep coaxial cable runs as short as practical Maximum of two RF amplifiers in-line (i.e. UA830USTV)

131 Distributed Antenna Systems Net loss < 5dB Install low loss cable with the minimum length Use amplifier(s) when necessary Net gain < 5dB Use minimum gain Use as few antennas as practical Specify quality wireless systems i.e. UHF-R for receiver RF performance Calculate the gain structure of the network RF amplifiers Coaxial cable loss Combiner/splitters

132 Multi-room Antenna Distribution B antenna A antenna B antenna A antenna Passive combiner B Room 1 Room 2 Passive combiner A

133 Multi-room Antenna Distribution Room C Room B Room A B B B Equipment Rack A A A B A = UA830USTV = UA221

134 Multi-room Antenna Distribution What s Wrong with this Picture? Room C Room B Room A Too Many RF Amplifiers! B B B Equipment Rack A A A B A = UA830USTV = UA221 = bias T (necessary for more than two amplifiers per line) DC supply

135 Multi-room Antenna Distribution Room 1 Room 2 B A Equipment Rack B A A B DC supply B A B A Room 3 Room 4 = UA830WB = UA221 (modified for DC to both legs) = bias T (necessary for more two amplifiers per line)

136 Large Area Antenna Coverage B

137 Large Area Antenna Coverage

138 Distributed Antenna System Schematic

139 Distributed Antenna System Notes

140 Gain Structure Analysis

141 Antenna Combiner High End PA821/PA821A Transmitter Combiner Will Combine Multiple Antennas into One Output Close to Unity Gain/Loss Signal Combining Two Required for Diversity DC Bias for Active Devices Needs to be Added PA421A 4-Port Combiner Also Applicable

142 2.4 GHz Spectrum

143 2.4GHz Wireless Band Regulatory and Technical Limits (US) MHz ISM Band (Industrial Scientific Medical) Wavelength = inches 1mW single frequency, continuous 100mW single frequency, pulsed average 1W frequency hopping, <75 channels (15 minimum) 4W frequency hopping, >75 channels 4W direct sequence spread spectrum (DSSS) Average dwell time at any frequency: < 0.4 seconds within a time period of 0.4 sec. X number of channels Many users: Computer devices: Wi-Fi, Bluetooth, ZigBee Consumer devices: cordless telephones, microwave ovens, remote controls Commercial devices: RFID, motion sensors, railway applications Unlicensed users under FCC Part 15

144 Wi-Fi Channels Worldwide

145 Wi-Fi Non-Overlapping Channels

146 ZigBee Spectrum

147 Wireless Audio Techniques for 2.4GHz Goals: Find clear channels Co-exist with other users Fixed frequency Frequency hopping Redundant frequency hopping Summary: Only good for low channel counts!

148 DECT Spectrum

149 1.9 GHz DECT/UPCD Band 1920MHz 1930MHz (unlicensed) DECT bands can differ by country Europe is MHz Examples of DECT devices Plantronics headsets CT14, CS55PLT Cordless phones (labeled DECT v6.0)

150 Multiple Carrier (DECT/UPCS) Mics shares multiple frequencies UPCS/DECT = 5 useable carrier frequencies Mics can use any of these if interfered with Each carrier freq = pool of available channels Adjacent bands will not interfere Guard Bands exist between these 1.40 MHz MHz GHz GHz GHz GHz GHz GHz GHz Shure Incorporated Confidential

151 Time Division Multiple Access Characteristics Typical UHF Mic Activity: Single freq, on-air 100%, Transmit only DECT Activity: Multi-Carrier TDMA Shared freqs, mics transmit & receive 8.33% of the time Pack 5 ms of audio into small (417 µs) time-slots 5 ms 5 ms Mic 1-4 Audio Return (5 ms) Mic 1-4 Audio Rtn (5 ms) Freq. 1 (of 5) Mic 1 Audio Tx (5 ms) Mic 1 Audio Tx (5 ms)

152 TDMA Clock Sync ing Synchronization highly recommended Unsync d systems => overlapped timeslots One timeslot from one system can occupy two from another Sync d Systems => Enables maximum channel count Shure Incorporated Confidential

153 Frequency Compatibility & Coordination

154 System-to-System Interference Primary Compatibility issues: Minimum frequency separation (selectivity) Transmitter IMD products (intermodulation)

155 Frequency Compatibility: Minimum frequency separation Each system must operate on a unique frequency Frequencies must be at least MHz apart Minimum spacing a function of receiver selectivity Amplitude Frequency

156 Linear vs. Non-linear Circuits Linear Circuit (Audio) Freq 1 Freq 2 Non-Linear Circuit (Radio) Freq 1 Freq 2 Freq 1 Freq 2 MHz

157 Frequency Compatibility: Intermodulation (IMD) Inherent non-linearities of wireless circuitry Occurs with 2 or more transmitters Generated in transmitters and/or receivers IMD product strength Proportional to square of transmitter power Inversely proportional to square of transmitter separation

158 2 Transmitter IMD

159 3 Transmitter IMD

160 2 Transmitter IMD

161 2 & 3 Transmitter IMD

162 Example: Improved Transmitter Linearity UR1 10 mw P9T 10 mw

163 Microwave Isolator in Transmitter Antenna Circuit Before After

164 Typical UHF Pre- selected Compa6ble Groups Pre-selected compatible groups All channels within a preset group are compatible

165 Shure Frequency Bands (U.S.) Wireless Microphone Systems UR G1 H4 J5 L3 X1 ULXD G50 J50 L50 U J4 M4 UB UA UC UB UA ULX G3 J1 M1 SLX G4 G5 H5 J3 L4 PGX H6 J6 L5 PG H7 K7 M7 Personal Monitor Systems PSM1000 G10 J8 L8 PSM900 G6 G7 K1 L6 PSM700 H3 L2 HF HA, HB HC PSM600 HD HE PSM400 HF X1 PSM200 H2 Radio Astronomy & Medical Telemetry Primary Users Public Safety DTV STATIONS New Services PS New Svcs PS TV Chan MHz Current Discontinued

166 Shure Frequency Bands (U.S.)

167 Insuring System-to-System Compatibility Choose pre-selected compatible frequency set: A Group is a programmed set of frequencies A Channel is one frequency in a group All Channels in a Group are compatible -or- Calculate a custom compatible frequency set: Observe minimum channel-to-channel spacing Observe minimum channel-to-intermod spacing Must be done with a computer program (i.e. WWB)

168 Advanced Frequency Selection Criteria RF Zones Isolated rooms or venues in the same facility Can ignore intermodulation calculations Can relax spacing Band Planning Separate wireless classes (mics, ears, intercoms) into separate slices of the spectrum Take advantage of receiver RF front end filtering

169 Frequency Coordination Steps Gather Data Site Information and Location Existing Wireless Systems Planned New Wireless Equipment Analyze RF Spectrum (on paper) Conduct Site Survey Evaluation of Facility and Structure On-site Spectrum Analysis Perform Frequency Coordination Calculations

170 Wireless Workbench 5 Wireless Workbench 6 Select Coordination Tools IAS Intermodulation Analysis System (Professional Wireless) RF Spectrum Scanning Tools AXT600 Spectrum Manager WinRadio WR-G305WSM Wireless Receivers (AXT400, UR4D+, ULXD4) Other Devices: TTI, Spectrum Analyzers, Wideband Antennas recommend Shure UA860SWB

171 Tool Comparisons

172 Site Evaluation Data Collection Location of Installation Facility Address, City, State, ZIP Code Inventory of Existing Wireless Equipment Make, Model, Frequency Band, Frequency, RF Power Level, Room Create List of Equipment Being Added Make, Model, Frequency Band, Frequency, RF Power Level, Room Site and Floor Plan with Dimensions Indoors or Outdoors Multiple Rooms or Venues? Show Coverage Requirements Distance from Stage to Antennas Equipment Room Locations and Cable Runs Identify any Interior Decorating Structures or Obstructions example: divisible walls

173 Site Evaluation Data Collection (con d) Determine Spectrum Availability Conduct RF Spectrum Scan - On-site Outdoor and Indoor Scans for Comparison Look For and Ask About Any Other Radio Transmitters at the Site: Look for Any On-Premises and Nearby Antennas or Towers Out-of-Band Commercial Radio (i.e. Public Safety Transmitters, Paging Transmitters, Cell Sites, Two-Way Radio Systems, etc.) Digital Equipment (DSPs, Digital Video, Video Displays, etc.) Computers and Computer Controlled Systems (i.e. Lighting, etc.)

174 Sample Inventory What s Missing Stevenson High School Wireless Frequencies Key: New Channel Wanted Channel working - Leave where it is Would like some channel suggestions Compiled 1/7/2013 Location Brand Band Location Grp-Chnl Brand Band Location Grp-Chnl Brand Band Performing Arts Ctr. Stadium Bus Page Forum Sennheiser Shure J Shure J Sennheiser Sennheiser Location Grp-Chnl Brand Band Location Grp-Chnl Brand Band Sennheiser Point Bus Page Cardio Sennheiser shure J Sennheiser Sennheiser Sennheiser Sennheiser Location Grp-Chnl Brand Band Sennheiser Stadium Location Grp-Chnl Brand Band Sennheiser 4-2 Shure J1 M-P room Sennheiser Sennheiser Location Grp-Chnl Brand Band Sennheiser Aerobics Location Grp-Chnl Brand Band Sennheiser Sennheiser E- Commons Sennheiser Sennheiser Location Grp-Chnl Brand Band Sports Sennheiser Center Location Grp-Chnl Brand Band Sennheiser F-H Bus Page 1-21 Shure J1 Location Grp-Chnl Brand Band Portables MHz Sennheiser EW Sennheiser EW500 Location Grp-Chnl Brand Band Portables B-Band Sennheiser EW100 Gen Sennheiser EW100 Gen2 Location Grp-Chnl Brand Band Portable Band-A Sennheiser EW100

175 Sample Inventory Spreadsheet Colonial Heights Christian Church Wireless Inventory Revision 2 12/4/2012 LOCATION MAKE MODEL BAND GROUP CHANNEL FREQUENCY (MHz) TV Channel Sanctuary Shure SLX H (Master list freq) Sanctuary Shure SLX H Sanctuary Shure SLX H Sanctuary Shure SLX H Sanctuary Shure SLX H Sanctuary Shure SLX H Sanctuary Shure SLX H Sanctuary Shure SLX L Sanctuary Shure SLX L Sanctuary Shure SLX L Sanctuary Shure SLX L Sanctuary Shure SLX L Comments Gym (Family Life Ctr) Shure SLX G Gym (Family Life Ctr) Shure SLX G Gym (Family Life Ctr) Shure SLX G Gym (Family Life Ctr) Shure SLX G Gym (Family Life Ctr) Shure SLX G Gym (Family Life Ctr) Shure SLX H Gym (Family Life Ctr) Shure SLX L Gym (Family Life Ctr) Shure SLX L Gym (Family Life Ctr) Shure SLX L Gym (Family Life Ctr) Shure SLX L Gym (Family Life Ctr) Shure SLX L Gym (Family Life Ctr) Shure SLX L

176 Spectrum Analysis Database Searches FCC: Cavell & Mertz: Telcordia: Spectrum Bridge: IAS Software from Professional Wireless Identify Public Safety Reserved Frequencies 13 Cities New York City TV Channel Licensed to Trunked 2- Way Radio Commercial Provider Create TV Broadcast Summary see examples

177 Spectrum Analysis (con d) Interpreting TV Broadcast Signal Strength from Databases Distance from TV Transmitter/Antenna/Tower Transmitting Power Level Low-power Stations 15 kw ERP max Major stations 1000 kw ERP max (18 db difference) Propagation Considerations Directional TV Transmitting Antennas Cross-border Stations Mexico and Canada Obstructions (Buildings, Mountains, etc.) Curvature of Earth (Tower Height, Site Elevation, etc.) Tropospheric Ducting (Temperature Inversions, etc.) unusual enhanced propagation (

178 Telcordia WSD TV Database

179 Telcordia WSD TV Database

180 Telcordia WSD TV Database

181 Cavell-Mertz TV Database

182 FCC TV Database

183 Strengths of TV Databases Telcordia Visual Maps with Contours Accurate for Active Stations FCC-INFO/Cavell & Mertz Source for Proposed New Broadcast Operations Search for Applications, Construction Permits FCC Database Source of All Knowledge Research Individual Station Status

184 FCC TV Database

185 FCC TV Database

186 FCC TV Database

187 RF Spectrum Scan Scottsdale, AZ Essentially Line-of-Sight (Pima Rd and McDonald Dr: ~16 miles)

188 RF Spectrum Scan North Phoenix, AZ Signals Reduced Shadowing from Mountains (32 nd St and Union Hills Rd: ~22 miles)

189 RF Spectrum Scan Deloitte University, Westlake, TX Outdoors December 3, 2012 Westlake is ~32 miles from Dallas/Ft Worth TV Broadcast farm. Scans courtesy of Clayton Mills, Highway Marketing

190 RF Spectrum Scan Deloitte University, Westlake, TX Indoors December 3, 2012 Westlake is ~32 miles from Dallas/Ft Worth TV broadcast farm. Scans courtesy of Clayton Mills, Highway Marketing

191 Other Interference Sources Unknown radio transmitters Wireless in-ear monitor systems Wireless intercom systems Portable Studio Transmitter Links (STL) Out-of-band transmitters (CB, Business, Public Safety) GSM devices: mobile phones, pda s Hi-capacity power equipment Motors, HVAC, Lighting Nearby digital equipment Audio DSP (CD players, DAT, FX) Computers, computer-controlled devices (Lighting, etc)

192 LED Video Wall: off

193 LED Video Wall: On, No Image

194 LED Video Wall: On with Image

195 Stones Brooklyn Video Wall: 10 behind

196 Compatibility Tools Shure AXT600 Spectrum Manager Shure networked receivers Win Radio WR-G305e or WR-G33WSM TTI Spectrum Analyzer Shure Wireless Work Bench 6 Shure Wireless Work Bench 5 PWS Intermod Analysis Software

197 Using Shure Wireless Workbench

198 Wireless Workbench Software Operational functions: Remote monitoring of wireless systems Remote control of wireless systems Fast setup of multiple wireless systems Spectrum scanning Analytical functions: Frequency compatibility analysis Frequency coordination and synthesis

199 Contact Info: Shure Support Systems Support Ph: Product Technical Support Ph: Knowledge base: Shure Service Department (Repair and Parts) Ph:

200 Point-to-Point Wireless

201 What is Point-to-Point Wireless? Audio transmission from fixed transmitter to fixed receiver (or multiple receivers). Applications Delay towers Parade routes Cry rooms

202 Example System Self-powered loudspeakers Mono mix from console P9T Set for PTP Mode UR4 Receivers set to Line Out

203 Blonder- Tongue BTY- UHF- BB Antennas (One for Transmit) Coaxial Cable to Antenna Point-to-Point Example Radio Signal Shure P9T Personal Monitor TransmiQer B SLX4 Diversity Receiver (or UR4) A A Blonder- Tongue BTY- UHF- BB Antennas (Two for Diversity Receive) B Coaxial Cable from Antennas Microphone Mixer/Preamp (Shure SCM262 Shown) Microphone Mixer/Preamp Audio Power Amplifier Loudspeakers Paging Microphone (Shure model 522 shown) Refer to the Shure s Frequently Asked Questions Database answer ID and for additional implementation details.

204 Point-to-Point Equipment Example

205 Point-to-Point RF Planning Determine Link Distance (in feet) Evaluate Radio Path Obstructions (Clear Line-of-Sight Important) Potential Antenna Locations and Heights Identify Clear Frequencies Select Candidate Transmitters and Receivers (i.e. P9T, UR4) Identify Transmitter RF Power and Required Received Signal Level Determine Radio Path Loss Analyze RF Link Gain Structure Finalize Antenna Selection Based on RF Link Analysis

206 Point-to-Point RF Planning RF Path Loss (Signal Source: ULX1-J1 and M1 Transmitters, ~13-14 dbm Output, Mounted on Microphone Stand ~5' Above Ground) (UA860WB Antenna, 6' RG58 Coax, Rhode & Schwarz FSH3 Spectrum Analyzer, Data Taken Outdoors in Parking Lot) Horizontal Scale Changes Signal Strength (dbm) DTotel:Shure Applications Engineering Distance (feet) UHF MHz UHF MHz Inverse Square Law

207 Point-to-Point RF Planning Path Loss Calculations There s an App for That! islipstick RF (available from Apple itunes) Select RF Menu Select RF Path Loss For Path Loss value only, set TX Out, TX Line, TX Ant, RX Ant, RX Line, and Fade parameters to zero

208 Point-to-Point RF Planning

209 Special Considerations for PTP Transmitter and receiver must be in same frequency range Tone key frequencies must match Or (less preferred) tone key circuit must be defeatable on receiver Audio processing (companding, pre-emphasis) must be similar Stereo requires two transmitters/receivers on different frequencies Unless using IEM bodypack receiver for output! High power operation and directional antennas can achieve range over ½ mile!* * Operating at power levels greater than 50 mw requires FCC license.

210 Receiver Signal Strength Interpretation

211 UR4 Receiver - RF Signal Strength Meter

212 ULXP4 Receiver RF Signal Strength Meter

213 ULXD4 Receiver - RF Signal Strength Meter

214 Shure Online Antenna Calculator

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216

217

218 Batteries

219 9V Batteries: Primary vs. Rechargeable Life of Different Battery Types :00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 Voltage Alkaline NiMH 8.4V NiCd 7.2V Time (Hours) Wireless Battery Life Volts Frequency Synthesized Crystal Controlled 0:00 0:57 1:54 2:51 3:48 4:45 5:42 6:39 7:36 8:33 9:30 10:2 11:2 Time (Hours)

220 Rechargeable Battery Issues New chemistries Lithium Polymer: now suitable for 9V applications High capacity NiMH suitable for AA applications Must have multiple batteries for rechargeable operation One in unit One ready to go Possibly one in charger Battery meter accuracy is dependent on battery chemistry!

221 Wireless System Audio Gain Structure

222 Wireless System Gain Structure Gain setting points: 1. Transmitter gain setting 2. Receiver output setting 3. Mixer input setting Symptoms: Distortion or Clipping Transmitter gain set too high Mixer input gain set too high Receiver output set too high Poor signal-to-noise ratio (usually hiss ) Transmitter gain set too low Receiver output set too low Mixer input gain set too low Solution: Set Transmitter to highest gain without clipping receiver audio indicators Set Receiver to maximum output level Observe mic/line settings on Receiver output and Mixer input Mic level Receiver output is usually best match to Mic level Mixer input Most Receiver Line level outputs are not actually +4dBu nominal level