The video refereeing system is an important component of modern sports, providing the opportunity to make correct decisions based on factual circumstances that may not be detected with the naked eye.
Video refereeing systems require extensive management: human resources, technical resources, administrative resources, regulations, interaction between teams and referees, operators of the video systems, and many more.
Challenges associated with different setups of VAR systems
Based on our experience, the current significant challenge is the lack of sufficiently qualified personnel, which affects everything. By utilizing local systems situated at the stadium or match venue, the issue is that the working staff are effectively unavailable for a specific duration, being dedicated solely to one match, which additionally includes travel to and from the event. The complication is that personnel assigned to one match cannot be utilized for other events for a significant time.
Alternatively, the fact that the entire system can be located in a single location is one of the reasons why organizing a VAR center is popular among many leagues and federations. If the competition regulations allow it, this also facilitates collective decision-making, allowing more qualified colleagues from the league to get involved and aid. Referees and replay operators are situated in one location, they are readily available, and they can manage several matches in a single day if the schedule permits. Moreover, they avoid the stress of travel, which makes it more convenient for the staff and cost-effective, as it allows for significant savings in transportation expenses and reduces the need for personnel.
The limitation of VAR center solutions lies in their dependence on a single location for all of the equipment and the server that oversees refereeing. Delivering video signals from all cameras to this server can be a demanding task. Cost-effective solutions based on H.264/HEVC transmission do not carry synchronization signals and are hard to align. Furthermore, they often do not provide the necessary picture quality.
Another drawback of this solution is that if the communication channel is lost, the server may continue processing without receiving video signals. Meanwhile, the game at the venue continues, and it may happen that video from a crucial moment is not recorded, making it difficult to make a judgment. Overcoming these issues requires reliable channels, preferably with duplication. The channels for high-quality transmission, with low latency ensuring synchronization of video streams with the scoreboard controller data are quite expensive.
Hybrid video refereeing solution
Drawing on solutions refined through more than 15 years of experience, SLOMO.TV offers a hybrid video refereeing system: the VAR servers are situated at the match venue, whereas the workstations and the VAR team are located in the remote VAR center. In this scenario, a lot of issues, including the synchronization of video streams with each other and their alignment with scoreboard controller data, are resolved automatically.
The VAR center has the following equipment: a Multiviewer for monitoring of all channels, and a refereeing monitor displaying the actual analysis of the moment. In football, an additional third monitor is used to view the delayed video signal according to the regulations.
All incoming video signals are recorded on a local server. Even if there is a brief interruption in the communication channel, it does not cause any issues. The delay between the control panel operation and the response on the monitor is minimal and corresponds to the internet latency.
With only three video signals being transmitted — the referee's monitor, the Multiviewer monitor, and, if required, the delay monitor — it is possible to operate with minimal speeds of 12 to 25 Mbps, which can be supported even by mobile internet connections. There is no need to use expensive video signal delivery systems.
Furthermore, the hybrid VAR system incorporates intercom audio transmission, ensuring that referees on the field can communicate seamlessly with the VAR center and receive a return signal for making refereeing decisions without delay.
The system can also be used to arrange a video wall, showing selected frames to monitor information on all screens and transmit referee information.
At SLOMO.TV, we are convinced that the optimal solution for tackling modern challenges in video refereeing lies in the implementation of a hybrid VAR system.
