Nottingham College has a variety of digital signage screens across many of its campuses, but we acknowledge the impact they can have on energy usage.
Did you know: Darker colours such as black, dark red or green require less energy to be displayed compared to ligher colours such as white when used on certain types of screen like LCD (with multiple backlit zones) or OLED screens?
Digital signage is great for communicating a variety of information including important messages (such as alerts, planned events), latest college news and events, travel information and lots of other use cases. Digital signage allows for more interactive and engaging content as well as being dynamic, reducing the need for printed posters or worrying about out of date posters for date specific events but we are mindful of the electricity consumption of always on displays and the impact they can have.
Implementing Tripleplay
The digital signage solution implemented by Nottingham College uses set-top boxes from a vendor called Tripleplay (owned by Uniguest). These set-top boxes are powered through Power over Ethernet (PoE) which means they require no additional external power source and are directly powered from existing ethernet infrastructure in each of our campuses. Each set-top box is connected to a digital signage screen through HDMI.
The Tripleplay deployment Nottingham College has chosen to implement is a cloud and hybrid sync model. Using the cloud platform means we do not host any additional infrastructure within our own data centre to run the digital signage screens in our campuses, other than the Tripleplay set-top boxes themselves that connect to the cloud management server hosted by Uniguest/Tripleplay. The delivery of content to each different set-top box uses a hybrid sync approach where content is uploaded to a management server and then is synchronised locally to one or more set-top box. This approach locally stores content on flash storage, rather than constantly streaming content from a cloud server to playback content, reducing both network traffic and bandwidth requirements. This helps save the amount of data needed to playback bandwidth heavy content such as 4K video, particularly when this content regularly repeats on a recurring playlist cycle. Just a single data transfer is needed before the playback of content is handled entirely from local flash storage, until an update of the content is required.
Phase one of our digital signage project has seen us deploy 36 digital screens across 7 campuses. Future phases will see a further deployment of additional set-top boxes and digital screens while constantly evaluating the sustainability impact. Procurement of any new digital sigange screens will factor in energy efficiency and our sustainability objectives.
Our current digital signage
We currently have a mixture of digital signage screens from different manufacturers installed in our different campuses from brands like ViewSonic, Philips, Samsung, LG and others. These vary in age and hence some are more modern than others in relation to energy rating. Over the next few years, we intend to standardise existing digital signage screens in order to help unify digital signage hardware for both management and our sustainability objectives.
Because of the mixture of different manufacturers currently, we face some challenges in implementing a reliable college wide solution to having control of the power on/off state of digital signage screens when not in use e.g. outside of open hours/weekends. For our initial first step regarding sustainability, leveraging the Tripleplay management software, we trigger an event across all screens on a schedule to override the default playlist content for any digital signage display with a sustainable holding screen which uses minimal elements and dark colours (black solid background, with grey text).
Implementing this helps reduce unnecessary network traffic/bandwidth when these screens are not in use by replacing all screens with this holding screen which is a static image and overrides the normal playlist content that would be active as part of the normal playlist schedule. In addition, this can also reduce the amount of energy used out of hours for certain screen types like OLED. This mode is automatically enabled 9:00 PM every weekday (5:30 PM on Friday), before ending at 7:00 AM the following morning. At the weekend this sustainability mode is active throughout this period until Monday morning.
We are working towards implementing a standardised solution where by we can automatically turn the screen of any digital signage on/off on-demand or through automatic scheduling to further reduce energy, in conjunction with limiting network/bandwidth data outside of normal hours in the future.
Power management control
For power management control we are currently investigating a number of solutions including:
- TV controllers (using RS-232).
- Power on/off scheduling for TVs which feature their own operating system and/or management system.
- IP/network controllers.
- Wake-on-LAN (WOL)
- HDMI CEC (Consumer Electronics Control)
From testing and evaluation so far we have found the following:
- RS-232 is supported on nearly all the digital signage screens we have currently and Tripleplay set-top box devices all support an RS-232 serial connection, however Tripleplay does not provide TV controller profiles for most of the existing hardware we currently have.
- ViewSonic commercial displays feature a customised version of Android as well as power on/off scheduling capabilities, the management software myViewBoard Manager allows for control of power states and other settings through an ethernet or WiFi connection. Thanks to our modern smartboard project, we have several hundred ViewSonic smarboards deployed which also use this software and our ViewSonic commercial displays can leverage this as well.
- Nearly all current TV models support power on/off scheduling with multiple schedules possible, but not all TV devices can be connected to a network source for syncing to a network time. In most cases this would also need to be set manually on each individual screen which may be an issue for time changes like daylight savings.
- WOL is not approved by our IT infrastructure due to security considerations and filtered out on our network.
- HDMI CEC is implemented on most TV displays, but its reliability is not consistent for wider usage from testing on different devices.
This evaluation has identified that there is likely no single solution possible given the mixture of hardware and a combination of options may need to be used for different campuses to achieve reduce power consumption reliabily.
In combination with standardisation and further investment into our digital signage project, we aim to have full control of the physical digital signage screens in relation to power management functionality in the future alongside existing content management controls to help meet our sustainability objectives.
