General Radio Overview SECTION 2 - Radio Technology Overview Explain that this is just a brief overview of radio tech.

History of Wireless Wireless Has Come a Very Long Way ESTeem has been wireless over 30 years Patent on first wireless modem in 1984 Wireless Has Come a Very Long Way Lower data rates 2,400 bps Latest hardware 19,200 bps First Generation for Serial Networks Higher data rates in wideband channels Spread Spectrum Latest generations closing in on wired speeds Open protocol standards Wireless Ethernet (WLAN)

Primary Uses of Wireless Moving Hardware Maintenance Vehicles Factory Floor Machines Overhead Cranes Public Safety Mobile Applications

Primary Uses of Wireless Difficult or Too Costly to Run Cable Across waterways Communication across roadways Airfield lighting “Inaccessible” Areas

Primary Uses of Wireless City or County Coverage Impracticable to Cable Water Distribution Wastewater Systems Long Distance Communication

Spread Spectrum Advances Wireless Originally a military communication technique used for anti-jamming Allowed for civilian use by FCC in early 1990’s Wide-band transmissions used for much higher data rates than narrow band Used in many applications from cordless phones to wireless networks

Spread Spectrum Modulation Data broken into small packets transmitted on moving frequencies Very resilient to noise Frequency Hopping Combines data with spreading signal Very efficient when signal strength greater than noise Direct Sequence Latest modulation technique Efficiency (54 Mbps) and high noise immunity Designed for non-line of sight urban operation OFDM (Orthogonal Frequency Division Multiplex)

Line of Sight No Line Of Sight Repeater Remote Master SECTION 2 - Radio Technology Overview Repeater No Line Of Sight This is a classic example of an application that needs a repeater because there is no line of sight between the remote and the master. The repeater is set up so it can relay the message from the master to the remote site. Master Remote

Radio Characteristics SECTION 2 - Radio Technology Overview Transmission Speed Turn-On time Bandwidth Transmitter Characteristics Receiver Sensitivity Receiver Squelch Receiver Characteristics The one thing inherent to all transmitters is the turn on time. This is the amount of time it takes for a transmitter to turn on to be able to transmit the out going message. Bandwidth- is the width of the frequency that the radio is transmitting on. transmission speed is dependant on the turn on time and the band width that the transmitter is transmitting Receiver sensitivity and squelch are inversely proportional to each other. The higher the sensitivity the lower the squelch and vise versa

Bandwidth 20 MHz The Bandwidth Directly Controls Data Rate 10 MHz SECTION 2 - Radio Technology Overview The Bandwidth Directly Controls Data Rate 5, 10 ,20 MHz Bandwidth selections 20 MHz 10 MHz VHF and UHF both have advantages and disadvantages, usually the advantages for one is the disadvantage for the other and vise versa. 11 Mbps 1 Mbps 5 MHz 54 Mbps

Spread Spectrum Most Spread Spectrum Radio Use Unlicensed Bands Industrial Scientific & Medical (ISM) 900 MHz and 2.4 GHz Unlicensed National Information Infrastructure (U-NII) 5.15 to 5.825 GHz Manufacturer Gets FCC Approval - Not User Most Spread Spectrum Radio Use Unlicensed Bands Frequency propagation has less loss than higher frequencies Narrower bandwidth for fewer side by side channel operation 900 MHz Frequency Band Greater bandwidths available for more frequency channels Most common band for wireless Ethernet hardware 2.4 GHz Frequency Band Very low noise floor and fewer users Licensed for public safety/municipal applications 4.9 GHz Frequency Bands Proprietary and 802.11a channels 5.8 GHz Frequency Band

Frequency Hopping Breaks Information Signal (Data) Into Smaller, Moving Narrow Band Signals Complexity Does Not Lie In The Spreading and De-Spreading Of the Data Signal but In Synchronization of Narrow Data Signal Uses Spreading Signal to Change Frequency of Carrier (Hop) Across Band Hopping in Patterns Greater Than 100 times/sec Interference Handled by Moving Hopping Patterns

Frequency Hopping Diagram Signal Strength RFI Frequency Data Data Data Bit Hopping Data Frequency Hopping Synthesizer Frequency Hopping Synthesizer Hop code generator Hop code generator Transmitter Receiver

Direct Sequence Combines Information Signal with Spreading Signal to Produce Wide-Band Transmission Pieces of Each Bit Are Send Across Whole Band Receiver Then Adds Back Up - Process Gain If Some Pieces Are Lost They Don’t Add to the Overall Gain of Receiver, but Data is Not Lost Any Interfering Signal Not In Original Spreading Code Signal is Then “Spread” Itself and Filtered Out in Receiver

Direct Sequence Diagram Spread RFI Signal Signal Strength RFI Frequency Data Data Spread Data Carrier Filter PN Sequence generator Spreading Signal Spreading Signal PN sequence generator Transmitter Receiver

OFDM Latest Generation of Spread Spectrum Available bandwidth divided into multiple data subcarriers (52) 300kHz-Wide Subchannels 48 used for data and 4 used for error correction All channels evenly spaced (Orthogonal) All subcarriers transmit simultaneously for high spectral efficiency Parallel data transmission paths Resilient to RF interference Low Mutipath distortion

OFDM Diagram Result After RFI RFI/Mutipath Data Data Data Stream Evenly Spaced Subcarriers Result After RFI Evenly Spaced Subcarriers Signal Strength RFI/Mutipath Frequency Data Data Data Stream Simultaneously Transmitted Data OFDM Subcarrier Generator OFDM Demodulator Transmitter Receiver

Antenna Fundamentals SECTION 2 - Radio Technology Overview

Decibels (dB) Used for all mathematical calculations in the radio world. dB is a logarithmic number dB =10 log (linear number) A gain of 2 = 10 log (2) = 3 dB A gain of 4 = 10 log (4) = 6 dB When a number doubles it goes up 3 dB When a number reduces by 1/2, it goes down -3 dB To multiply linear numbers you add logarithms To divide linear numbers you subtract logarithms

Antenna Gain SECTION 2 - Radio Technology Overview Antenna Gain measure in decibels (dB) Doubles every 3 dB Effective Radiated Power (ERP) = Tx Power + Antenna Gain - Feedline Losses Received Signal = Rx Power + Antenna Gain - Feedline losses As Antenna Gain increases Antenna Pattern becomes more directional Antenna gain is a logarithmic equation, gain doubles for every 3db increase, but is cut in half for every 3db decrease. High Gain antennas become more directional. This slide give an example of a High Gain UHF antenna. Erp is the rf power plus or minus the gain or loss of the antenna. The loss that is incurred at the transmit site can quite possibly be made up at the receive site, through the same practice.

Radiation Patterns RF Energy Antenna Top View Omni-Directional Antenna Radiates RF energy in all directions from antenna RF Energy Antenna Top View

RF Basics - Omni-Directional Antennas Radiates RF energy in all directions from antenna Usually used at the Master and Repeater Nodes 360 degrees Omni-directional Antenna Vertical Polarized Top View Radiation Pattern Vertical Polarization Side View Radiation Pattern Vertical Polarization

RF Basics - Antenna Gain As Antenna Gain increases the Antenna Pattern becomes more directional Omni- Directional Antenna Shown Below 3 dB Points 360 degrees Remains Unchanged Vertical Beam Width (degrees) Top View Radiation Pattern Vertical Polarization Side View Radiation Pattern Vertical Polarization

Radiation Patterns RF Energy Antenna Top View Directional Antenna Compresses RF Energy in one direction RF Energy Antenna Top View

RF Basics - Directional Antennas Radiates RF energy in one direction Usually used at Remote Nodes in a Point to Multi-point system or Point to Point Site Side View Radiation Pattern Vertically Polarized Vertical Beam Width (degrees) Back Lobe 3 dB Points Horizontal Beam Width (degrees) Back Lobe Top View Radiation Pattern Vertically Polarized 3 dB Points

RF Basics - Antenna Gain SECTION 2 - Radio Technology Overview As Antenna Gain increases the Antenna Pattern becomes more directional Directional Antenna Shown Below 3 dB Points 3 dB Points Horizontal Beam Width (degrees) Vertical Beam Width (degrees) Antenna gain is a logarithmic equation, gain doubles for every 3db increase, but is cut in half for every 3db decrease. High Gain antennas become more directional. This slide give an example of a High Gain UHF antenna. Erp is the rf power plus or minus the gain or loss of the antenna. The loss that is incurred at the transmit site can quite possibly be made up at the receive site, through the same practice. Back Lobe Back Lobe Top View Radiation Pattern Vertically Polarized Side View Radiation Pattern Vertically Polarized

Directional Antenna Vertical Polarized SECTION 2 - Radio Technology Overview Antenna Polarization Vertical Or Horizontal Polarization Polarization is the radiating element referenced to earth All nodes must be the same polarization Cancellation of signal if mismatched Vertical Polarization for Most Radio Applications Mixture of Omni and Directional Antennas No Horizontal Polarization of Omni-Directional There are two types of polarization for antennas, they are vertical and horizontal. You must always place the antennas in the same polarization. If you do not theoretically they will never see each other. Thus they will effectively cancel each other out. Normally all antennas for SCADA applications the antennas are vertically polarized. Directional Antenna Vertical Polarized Omni-directional Antenna Vertical Polarized

RF Basics - Feedlines Feedline Pipeline for RF Energy From Radio to/from Antenna Different Cable Types Have Different Losses The lower the loss the more expensive the cable Losses Based Upon Length & Frequency Expressed in dB/100 ft. by the manufacturer The higher the frequency, the more attenuation in cables, connectors, etc. All feedlines and connectors induce losses to RF energy

RF Basics - Feedline Attenuation Table Feedline Attenuation (- dB/100 ft.)

Standing Wave Ratio (SWR) Ratio of Maximum to Minimum Values in Standing Wave Pattern Voltage (VSWR) or Current Mismatch in Impedance (Antenna or Cable) Will Induce Standing Waves Measurement of Forward and Reflected Power Most Field Expedient Wattmeter ( i.e. Bird Model 43)

SWR Measurement To Antenna Transceiver Directional Watt Meter Maximum = 10% Reflected Power ESTeem commands to initialize transmitter Radio ON command for serial Advanced Menu 195E and 210 To Antenna Transceiver Directional Watt Meter

Typical Outdoor Antenna Block Diagram Interface Cable Feedline User’s Device Lightning Arrestor 12 VDC Power Supply

Typical Indoor/Mobile Antenna Diagram Interface Cable Feedline User’s Device 12 VDC Power Supply

Typical Model 195E Mounting Model 195E Outdoor Fixed Base Hardware Diagram External Antennas Directional Antennas Omni-Directional Antenna Antenna Feedline Weather Proof Boot Direct Pole Mount Pole Mounting Kit EST P/N AA195PM Unit Shown With Rubber Duct Antennas Weather Proof Front Cover Weather Proof Boot Direct Mount Antennas Power Over Ethernet Cable Ethernet Surge Protection EST P/N AA166 PoE Power Supply EST P/N AA175 Ethernet CAT-5e Cable 300 ft. maximum Ethernet CAT 5e Cable EST P/N: AA09.2 To LAN Interface

Antenna Spacing Odd Multiples of 1/4 Wavelength Antenna Spacing Spacing Odd multiple of 1/4 wave lengths Measure from base of one antenna to tip of other 1/4 wave (in.) = 2952/freq. (MHz) 922 MHz = 3.20 inches Odd Multiples of 1/4 Wavelength