KVM enterprise and video matrix switchers in broadcast applications by Steve Montgomery ngineers within the professional broadcast world are comfortably familiar with video routers for the control of uncompressed video and audio signals within live studio and editing locations. However there is less familiarity with the use of KVM enterprise and video matrix switchers to carry out the same function for computer signals. This class of product is, however, becoming more important as an expanding number of content creation, editing and workflow systems used within the broadcast industry migrate to file-based and PC-hosted applications at an ever-increasing rate. Point-to-point KVM extenders have been available for many years; allowing direct interconnection of individual computers with keyboards, video terminals and mice. These have steadily evolved in line with technology and are very widely used, the latest versions being able to cope with the highest video resolutions and highspeed user interface devices over both copper and fibre connections. KVM extenders are frequently deployed within the broadcast industry to provide connectivity between individual computers and user terminals for a variety of applications. The latest generation of KVM equipment has evolved from simple point-to-point connection device into a comprehensive range of matrix switching systems that combine KVM extension with instant routing and signal duplication, essentially performing for computer signals a parallel task to that provided by the video router for video feeds. This type of product is well-established in control room and 60 | TV-BAY MAGAZINE E enterprise computing environments to provide rapid reconfiguration of banks of computers and monitors to control anything from an electricity grid to a military command centre. IHSE's Draco series, Draco Major and the new Draco Tera provides this functionality and are now frequently being deployed within broadcast locations. Both devices enable near-instantaneous (millisecond) switching of single, dual and quad-head digital video up to 1080p to monitors together with analogue and digital audio and transparent, bi-directional USB2.0 data, enabling the connection of HID devices, tablets, jog wheels, memory and webcams. Ray Gordon, managing director of official UK distributor for IHSE points out the benefits: "A key feature of the Draco range lies in its flexibility in interfacing to both copper and fibre cables at the same time. This means that a single switching unit can receive and deliver signals by the most appropriate method for short and long range transmission, without the need for additional interfacing units. Another highly desirable feature is the ease of linking to third party control systems found in the broadcast world and to bespoke applications via IP or RS232 interfaces directly into the switch." "Broadcast studios, post-production houses and edit studios are rapidly building virtual systems where banks of computers and file storage devices are located in dedicated computer rooms. KVM switches provide dynamic and highly flexible connectivity with the ability to instantly reconfigure and personalise interconnections between terminals and processors," explains Mike Whelan, managing director of specialist system and solution provider Digital Garage, "This, in effect, allows any user to arrange terminals to their own preferred configuration, whilst becoming far less reliant upon the actual physical equipment configuration. The advantages to both the user and organisation are massive; in time and efficiency improvement and in maximising the use and flexibility of limited resources." The distinction between real-time switching and packet based systems is important and should be considered in any practical application. Realtime switches act in a similar manner to standard production video routers by setting up electronic paths between input and output. An alternative method using IP routing, often referred to as KVM-over-IP will, of necessity, require that content is packetized and compressed to a far greater level. These devices may also introduce undesirable bit stuffing and bit or frame dropping. In addition, transmission protocols and handshaking procedures will introduce switching and transmission delays, bandwidth and routing constraints; and whilst this may be acceptable for some applications, it is generally held that real-time systems are the most suitable, available at a lower price and are recognised as the preferred option for the broadcast industry. Typical examples of KVM enterprise level and video switchers include their use in post production and editing suites in which the expensive source and editing machines are located remotely and shared between users. Within space-limited studios, not only is the computing equipment physically removed providing a saving of space, but a far greater range of applications can be delivered to fewer consoles. >>