MICROWAVE LINK EVOLUTION May 1, 2015 Alan Nichols, RF Engineer
Converting Microwave to HD Four Microwave Dish locations, The Studio and three towers. Two towers are on Slide and one tower is on Mc Cleland Peak. Alan Nichols RF Design 2012
From SD Analog to HD Digital ASI & I/P The three CBS Affiliate ENG vans transmit HD H.264 QPSK to the SLIDE Mountain receive site, the Studio receive site and the Mc Clellan Peak receive site. Each of the ENG van radios have been changed to NewStream MRC digital radios and the encoder is the Microwave Video Systems HD that accepts the HD/SDI signal and converts it to ASI to enter the NewStream radio. Mc Clellan Peak and Slide ENG receive the 2 GH radios TX from the ENG Vans with an MRC 4100 receiver that outputs ASI to the MVS Mux. At the CBS Affiliate Studio the G-Line analog radios output ASI to the MVS Decoder that will output HD/SDI to the Video Frame Synchronizer and Embedded Audio to Analog Audio converter to restore the transport stream audio to Analog Stereo to enter the Wheatstone Production Audio console. Lip Sync adjustment is made with the audio delay adjustment and used by the CBS Affiliate studio for live HD News Production. The way I accomplished the conversion of the Analog radios to Digital was by using the ASI input on the ENG van radios and using the G-Line base band input for ASI from a MUX. Adding a MUX to the G-Line radios permitted two HD signals from two HD Encoders to enter the MUX and be decoded at the receive site with HD IRD s for the Live ENG Vans and the HD Tahoe Camera on Slide mountain.
I/P Bullets for control of the receive sites I used a Spread Spectrum Bullet radio to pass I/P from the Studio to each ENG mountain site to create the full duplex I/P link. The I/P Bullet also controls the Tahoe Camera and Lamar pan & tilt. The bandwidth of the Bullet is 10 base T. I reversed the old Mc Clellan Peak STL link and used the two 7 GHz radios to make this a digital HD link to return ENG to the studio after submitting a 601 Application to the FCC for channel change and TX-RX swap. We would like to increase the STL link bandwidth and have full duplex to permit live transfers and also have full I/P control of the Tower site with I/P security cameras.
Performance of the HD Digital ASI & I/P links The Nissan Xterra has a Horn antenna and it has the best receive gain of all the ENG vehicles. The Tahoe HD Camera is Multiplexed with the ENG signal on Slide Mountain at 9,750 feet is passed in that ENG Digital I/P link to the Studio in Reno. Control of the Pan & Tilt and the HD camera funtions is with the Duplex I/P Bullet in that link.
Microwave link of the future is ASI & I/P Telco quality Radios that have: Flexible Modular Design Additional Power output (+35 dbm) for 16-64QAM (+38 dbm) for QPSK Modulation for longer link distances Redundant Power for DC and AC sites Internal and External Radio configurations with power inside the building or an HPS on the Antenna Remote access over I/P to configure radios SNMP traps to see alarms Redundant Radio Design to fail over without loss of data Duplex I/P and HD Video Channels on the same link
GL Link What is it used for? GL Links are designed to transport program material and data between two sites separated up to 50 miles apart Typical applications include connecting a broadcast studio to a remote transmitter site, or bringing the output of an ENG receiver back to the studio Designed for continuous 24/7 operation Building large multiple hop networks that are hundreds of miles long Connecting remote areas where there is no fiber Alternate routes for fiber networks prone to backhoe fades
How are Point to Point Radios Different? Most equipment that we manufacture is designed for ad hoc operation over relatively short hops. Propagation characteristics are not known in advance Long term reliability of microwave paths is not a big factor in wireless camera or ENG operations. The circuit only has to work for a brief amount of time. Some breakup may be acceptable Multipath is common with ad hoc operation. Modulations such as DVB-T work well with multipath, but are not as spectrally efficient as other waveforms Wireless camera operation usually involves transporting only a single video stream
How are Point to Point Radios Different? Point to point radios must provide highly reliable circuits The gold standard for STL reliability is 99.999%, meaning < 4 minutes of outage per year. Telecoms use 99.9999% Point to point radios often transport multiple video streams. Spectrally efficient modulations such as DVB-S are commonly used Engineering studies are done in advance to determine propagation characteristics, taking weather history, path length, antenna gains, etc. into account Hot standby systems are used to minimize hardware outages
How are Point to Point Radios Different? Point to point radios usually use large, highly directional, high gain antennas, often fed through long waveguide runs Split systems with a separate base station and Out Door Unit (ODU) are also common Where a great deal of traffic needs to go between two points, multiple links may share the same set of antennas Duplex operation through the same set of antennas is popular The most common frequency bands for point to point links in the US are 6, 7, 13, 18 and 24 GHz operating in 20, 25, or 30 MHz wide channels
Point to Point Link Antennas Parabolic antennas with diameters 6 10 are required by the FCC Very high gain An 8 antenna at 13 GHz has a gain of ~47 dbi Extremely narrow beam width, typically < 2 Knowing predicted signal level is essential for proper alignment
Path Study and Link Budget Designing a GL systems starts with a path study All parameters affecting link reliability, including the weather are taken into account Received signal level is accurately predicted Annual minutes of outage are predicted
Univision Sinwest Project > 500 mile long backbone running along the West Coast 19 Nodes and growing Most traffic is IP Operational since 2012 GL link is Univision s radio of choice for all stations
What is a GL Link? The RF Central GL link is a highly versatile modular point to point link system that is continuously evolving. Each year, new modules are added to the system, providing new capabilities and preventing obsolescence. GL supports both ASI and IP transmission using any Part 74 or Part 101 point to point microwave band. It is most commonly used by broadcasters to connect studio and transmitter sites, but there are a variety of other applications as well
GL Link - Highlights Designed from the ground up for broadcast Future proof design supports both ASI and IP transport Redundant power supplies for high reliability Modular design meets any point to point link need Split or all indoor systems Supports up to 4 ASI streams Built-in encoders available Quick repair and diagnosis by exchanging modules The Most Versatile Point to Point Link System Ever GL Link
GL Link - Highlights Extensive logging and analysis tools allows for easy fault location in large networks NTP Time synchronization of mainframes unifies logging Full SNMP management The Most Versatile Point to Point Link System Ever GL Link Duplex in a single mainframe Three transmitter power options Built-in encoders and decoders are available
GL Link Architecture
GL Link A modular system to meet every need
GL Series Radios Indoor Systems Verses Outdoor System Indoor Systems (IDU) All active parts are in the mainframe Easier to service Link budget must support waveguide loss and remain reliable Many radios can be diplexed on one antenna Use MFR/2B mainframe Outdoor System (ODU) All non-rf components are in the mainframe RF components are located at the antenna eliminating waveguide loss and expense Does not support complex systems on one antenna Mandatory at frequencies > 13 GHz Use MFR/2A
GL Series Radios Indoor Systems Verses Outdoor System Indoor Systems (IDU) Outdoor System (ODU) In all candor, the outdoor system also has a mainframe that looks exactly like the one above. I just couldn t think of a way to show that in an attractive looking slide
7 GHz Duplex Indoor System
Duplex 12 GHz ODU System
MFR/2 Functions Power distribution to all modules System management and configuration Configuration storage Front panel user interface System logging and alarms Supports six modules in slots 0-5 All slots are electrically equivalent with one exception Modules cannot be damaged by plugging them into the wrong slot Modules are not hot swappable
The MST Software Suite A complete set of tools for GL Link configuration, monitoring and logging. It is not a fancy web browser Specialized SNMP manager for configuration and monitoring Software update tool Log viewing tool Bit rate calculator ASI routing configuration tool Telnet Client Connects to mainframe via Ethernet Provides graphic representation of the network
MST Alarm Viewer Tool
MST Bitrate Calculator The MST bitrate calculator simplifies choosing the correct constellation and symbol rate
MFR/2 Mainframe Front Panel Display & Keyboard Linux CPU Supports Redundant Supplies & Frame I/O
MFR/2 Functions MFR/2A Internal IF wiring for use with outdoor units MFR/2B Internal IF wiring for use with indoor configurations 70 MHz IF Routing makes the difference!
MFR/2 MST GUI
Meet the Modules Standard Power Supplies Supplies power to run entire frame PWS/13 85-264 VAC PWS/11 85-264 VAC &18-36Vdc PWS/12 85-264 VAC & 36-72Vdc Except for the input voltages all supplies are functionally the same All supplies feature automatic line voltage switching
Meet the Modules New Redundant Power Supplies First shipments were in 2013 Due to conflicts with older hardware, we did not adopt until late 2014 One supply comfortably runs entire mainframe PWS/A 85-264 VAC PWS/D 18 75 VDC Requires use of PSI/1 Interface module All supplies feature automatic line voltage switching Hot Swappable Mix and Match AC & DC Supplies
Meet the Modules -- DCM/x Down Converter Converts received signal down to from carrier frequency to 70 MHz Linear Internal RX down converter Dual conversion design eliminates image problems Available in microwave bands from 1.9 GHz to 14.5 GHz SMA RF input & BNC IF output Green status light illuminates when unit is operational with no alarms
Meet the Modules -- DCM/x Down Converter
Meet the Modules UCM/x Up Converters Converts signal from 70 MHz to carrier frequency Dual conversion design eliminates images Typical power output +24 dbm @ 16-64 QAM Sufficient power output for many link applications Bands available from 1.9 GHz to 14.5 GHz SMA RF out & monitor port (-30dBm) simplifies testing BNC IF input available
Meet the Modules UCM/x Up Converters
Meet the Modules AMP/x Standard Power Amplifier Module Amplifies output of up converter from milliwatts to watts Available in all bands from 2-13 GHz ~ +31.5 dbm power output with QPSK modulation Slightly lower power output 10 GHz and above - 30 db SMA monitor port simplifies testing
Meet the Modules AMP/x Standard Power Amplifier Module
Meet the Modules The UNM/3 Duplex Modem Modulates/demodulates ASI to/from 70 MHz The heart of the system Fully duplex Symmetric and asymmetric data rates Transports two ASI streams and a single Ethernet stream Transparent MUX with 8 virtual channels Replaces the UNM/2 single ASI modem with no Ethernet Uses a variant of DVB-S modulation and DVB-T Constellations from QPSK to 256 QAM
Meet the Modules -- UNM/3 Control Panel
Meet the Modules UNM/3 Graphic Interface
Meet the Modules AMH/x High Power Amplifier Module Available in Part 74 and Part 101 6 GHz bands only ~ +38 dbm power output with QPSK modulation ~ +35 dbm power output with 16-64 QAM modulation Requires the full output of the power supply Must be the only module in the mainframe SMA monitor port simplifies testing
Meet the Modules AMH/x High Power Amplifier Module
Meet the Modules SFP/4 The Swiss Army Machete of ASI Boards 4-Way transparent ASI multiplexer 4-Way transparent ASI demultiplexer Hitless ASI switch SMPTE-310 to ASI converter Does all of the above simultaneously, as well as providing other functionality too esoteric to mention Uses ASI SFP s for I/O
Meet the Modules SFP/4 The Swiss Army Machete of ASI Boards
Meet the Modules SFP/4 The Swiss Army Machete of ASI Boards
Meet the Modules MPA/4 & DMA/4 Transparent Mux MPA/4 multiplexes up to four ASI Streams into a single stream DMA/4 demultiplexes the single steam back into four streams Completely transparent No PID remapping needed
Meet the Modules MPA/4
Meet the Modules DMA/4
Meet the Modules CDP/2 ODU Interface Card Powers and controls one transmitter and one receiver head through a length of LMR400-75 75 Ohm Cable. Supports full duplex operation Requires MFR/2A mainframe, not the MFR/2B Provides power, telemetry and IF signal to ODU Short circuit to head will not damage module
Meet the Modules CDP/2 ODU Interface Card
Meet the Modules Honorable Mentions ASW/6 Hitless switch for up to six ASI inputs SWO/5, SWO/6 RF switches for hot standby systems SFN/1 Single frequency network adapter TAD/1 T1/E1 adapter card ENS/1, ENS/2, CDC/1, CDC/2 SD encoder/decoder cards DCD/1, DCD/2, DCD/3 SD decoder cards ENR/1, ENR/2 HD encoder/decoder cards DCA/1, DCA/2 HD Decoder cards There are even more cards and applications, but you probably heard enough already!
How does one antenna feed several radios? By properly using channel filters and circulators, a single antenna may be shared among multiple radios Channel filters pass signals within their passband and reflect out of band energy back towards the source Circulators are three port devices that allow energy flow in a single direction. Often, one of the ports connects to a terminating load Each radio requires its own circulators and filter
BNTA-1 Branching Tray The number of frequencies and configurations makes each branching network a custom assembly
BEXT/x Branching Network for ODU s The BEXT/x external diplexer for ODU system provides duplex operation with one antenna
We re not done!!! GL links continue to evolve New modules were introduced at NAB 2015 that combined up converter, down converter and amplifier into one module IP only version in development Many accessories and applications were not shown here Portable configurations are available using most of the gear shown here Over the past five years millions of dollars worth of GL equipment was deployed to RF Central customers Now we are done. Thank you for listening!