Routing systems

Switching video, audio and data signals is still a major function within a broadcast facility infrastructure. Every situation is somewhat different, and there are routing switchers in a wide array of sizes to fit every situation.

Among this year’s exhibits were switching solutions for every situation.

Routers vary from small analog video and audio 4×4 or 8×1 utility switchers to expandable wideband serial digital routing systems of 512×512 and larger, with an extensive selection of control capabilities and external interfaces. Selecting a new large routing switcher today is more a case of “How do you want to control it?” than “How big a matrix do you need?”

As networking becomes more integral to the broadcast facility's needs, video and audio routing will become less of a central requirement. The use of servers and Ethernet networks to move files around a facility and browse the facility archives is becoming the norm, while conventional video and audio routing may soon become a thing of the past. In the meantime integrating analog and digital, video and audio together will still be important. The question today is often how best to deal with current needs while planning for the future.

Conventional facilities today may still need a mix of analog video and audio in conjunction with newer digital video and AES digital audio. The central nature of a routing matrix, or matrices, requires a great deal of thought about making the transition to a new system. Those lucky enough to be moving to a new building with a large amount of new digital equipment have the advantage of going fully digital in one big step.

Those who must add a digital matrix now and still use some of the existing analog infrastructure have a different dilemma. One solution is the Chyron Sirius series of routing switchers that offer both analog and digital I/O so that signals going in as analog or digital are available on digital and analog outputs simultaneously. This approach allows for a mixture of analog and digital within the same matrix and would be suitable for an analog facility that needs to maintain the mix of signals for a prolonged period.

Adding a digital matrix to an analog facility or extending an existing one requires new hardware often with an associated control system, unless the existing equipment manufacturer offers a control system that can control both the old and the new. At the large end of the range are the Thomson (Grass Valley Group and Philips) systems and the Miranda (Nvision), Leitch, Utah Scientific, Sony and Chyron (Pro-Bel) routers. All of these offer a variety of matrix sizes and control choices.

Systems such as the Grass Valley 7500 WB or 7500 NB series provide a way to integrate a new digital router with existing 7000 series hardware and can even interface with the older Horizon series of routers if needed. The new Encore control system provides a way to control legacy frames and can also control other routing systems such as the Philips Trinix or Venus series. The Trinix system can also be integrated into an existing Jupiter control system. Adding a control system for a new matrix that can control existing hardware certainly has economic advantages and allows new hardware to be added in parallel with on-air operations. The Grass Valley Concerto system allows a mix of video and audio signal types and with built-in A/D and D/A capability can save on external conversion units. Concerto is also expandable within a frame from 32×32 up to 128×128 and can also be controlled by the Encore control system.

The Utah Scientific UTAH-400 router aims at high crosspoint density with a 160×160 switch in just 8RU, or as large as 640×640 in 48RU. The UTAH-400 systems also provide the ability for full output monitoring and the ability to expand to greater than 1000×1000. Leitch offers the Integrator series of routing frames that can be combined to form a distributed routing fabric that provides both control and switching redundancy by distributing the control and switching over a group of smaller matrix frames, rather than housing all of the hardware in a single frame.

Most large routing switcher manufacturers also offer tie line capabilities allowing sources in an analog matrix to be selected and automatically routed to a digital matrix through external A/D converters or vice versa. For facilities that are combining existing analog and digital hardware this too provides an important capability to integrate the old with the new. Automatic tie lines are also capable of connecting individual distributed matrices together to allow routing of sources from one area to another using a single control system. This can reduce the size of a single matrix and allow smaller distributed matrices to be utilized around a facility while still using a single control system that can communicate to the individual matrix frames.

A digital matrix frame today often offers the ability to route a wide range of different serial digital signals within a single matrix. Many systems, like the PESA Cheetah series of digital video routing switchers, are available from 64×64 up to 512×512 and are specified as being able to route signals from 3 Mbits/s to 1.5 Gbits/s. This has the advantage that one frame can be used for routing 3 Mbits/s serial digital AES audio, 19 Mbits/s serial transport streams, all of the different SD video standards from composite video at 143 Mbits/s up to 360 Mbits/s, 540 Mbits/s signals, and uncompressed HD at 1.483 Gbits/s or 1.485 Gbits/s. This advantage is countered by the size requirements and location for a matrix that can do everything vs. the use of smaller distributed routers for a specific type of signal. A universal digital matrix does, however, offer the ability to change the signal type and incorporate HD signals, for example, when they need to be added. Sony offers a router that covers both SD and HD video up to a 1056×1088 matrix size with multiple VI switching points to allow for different timed source material.

Reliability is always an important factor for large routing systems. Most manufacturers offer front-pluggable and hot-swappable modules to reduce signal path downtime. Redundant control and power supplies are a minimum requirement, but the new Miranda Nvision routing systems provide redundancy of both matrix control and signal outputs. A manual changeover switch can be used to switch to a backup control and output module that provides online stand-by capability. Digital video, audio, time code and data matrices up to 256×256 are all available. The audio frames also provide audio processing and utilize a TDM architecture.

When it comes to choosing a router, however, the choice of a control system plays a major role. Usually the choice is between standard control panels with fixed capabilities at relatively low cost against programmable control panels that can be customized for individual control locations' requirements. Customized control panels are often more costly, but the ability to change their operation between shows or from day to day can be a big advantage over a fixed panel. Panels can also be taken off-line as necessary to eliminate control from specific locations.

There is a wide variety of programmable panel styles using an even greater array of button and display choices. Using programmable panels require careful thought about button placement and the functionality required to produce a user-friendly button layout. Buttons should have a positive action and provide instant feedback to the operator. Some buttons are awkward to use and provide poor feedback. The panel display, legend or button readout should be easy to read and the panel operation intuitive to the user. The choice and length of source names can also make a difference in the speed and ease of use of a control panel. Different colors also aid in differentiating between panel functions when used logically to break up control, for example, of source or destination selection.

Most new control systems are Ethernet-based, which makes cabling easier and less costly than some previously used proprietary control systems. Careful network management may be required if panels are to be connected to a facility's internal network infrastructure. Ethernet control also provides for a straightforward connection for external control systems and automation or production switcher interfaces. The control system often keeps the system information on a server database that can be mirrored for online redundancy. Changes to system configuration, capabilities and names can usually be performed online with the ability to implement the changes without affecting the current systems operation. Configuration changes should be within a few seconds following the commitment of the change to the routing system. Minor configuration changes, such as changing a source name, should be immediately visible on all panels and displays where that name shows up. Ethernet control also enables long-distance monitoring and remote control of a matrix (with appropriate security) from the Internet using a browser or PC-based application. This can be used to easily expand router control for temporary or permanent remote applications with a minimum of interface requirements. Internet browser applications or custom PC-based GUIs are now offered by companies such as Grass Valley, PESA and Sierra Video Systems, to provide central routing switcher monitoring and control.

Smaller routing systems are available from a variety of companies, such as the Chyron Pro-Bel Mistral series of small HD and SD serial digital routers with programmable control panels. Extron now offers a Digital XPoint switch for 4×4 or 8×8 serial digital switching for small applications. This unit provides automatic signal selection of SD video inputs and includes Ethernet and serial (RS-422 or RS-232 control). Evertz, Crystal Vision, Network Electronics, Datatek and Ross Video all offer solutions that cater to the low cost, small routing needs for video and audio. The Sierra Video Systems Yosemite router can combine different signal formats by module selection and can be connected to other frames within the same family. Control is via RS-485 panels or a GUI for system configuration.

For computer and monitor switching check out the range of small multimedia switchers from ISIS that provide switching of SVGA signals (R,G,B,H and V). These units are equipped with computer SVGA connectors for I/O instead of the typical BNCs that require adapters for connection of computer equipment. Ensemble Designs also offers an 8×1 and 8×8 range of video utility switches in their Avenue range of products.

Whether your routing need includes a mixture of digital or analog signals, video in SD or HD, audio, data, or something more exotic, the requirement for a stable, flexible control system is as equally important as a reliable router matrix.