Navori's Blog

How Digital Signage Systems Work

30 November 2016

In this article we will discuss the various components that make up a typical digital signage system, and look at how each component interacts with each other.  It’s important to note that we will be reviewing various methodologies and point out which ones are better than the others.

So let’s dive in and see what makes digital signage “tick”!


Stand-Alone vs Networked Solutions

There are two main types of digital signage systems: stand-alone and networked.


Stand-Alone Digital Signage

Believe it or not, there are still some digital signage products that operate in complete isolation.  These are products that include the core components you find in most digital signage systems (scheduler and player) into a single software product.  Both modules are installed on the playback PC so you perform all programming tasks, then switch the computer to playback mode until you need to make any changes.

Since it was difficult to find local and reliable internet access at each end-point, stand-alone software was quite common in the early days of digital signage.  Today, there are less reasons to use this type of system because high-speed internet access is available pretty well everywhere.

These solutions are much less popular unless you are installing digital signage displays in a very remote location, or in a location where internet access is very expensive (take trade shows, for example).


Networked Digital Signage

Most networked digital signage solutions require three components: a back-end content management server (CMS), a user interface (UI) and a player software.

Networked digital signage also comes in two “flavors”: on premise and cloud (also known as “software as a service” or SaaS).

Here are the main differences:

On Premise Digital Signage Solutions

On premise digital signage CMS servers are purchased and installed on the end-user’s hardware, whether this is a physical PC server at their business location or on a remote, hosted server.  On premise solutions are purchased and there is no recurrent monthly fee (other than if the owner decides to host the software elsewhere).  The software owner must cover all the operating costs, such as equipment maintenance, security, backups, etc.

This option is very attractive for large corporations who want to be in total control of their IT environment since there are often network firewalls and proxy servers to deal with.  These companies have the staff and expertise required to ensure their digital signage network is secure, and operates reliably.  This is why on premise digital signage solutions make a lot of sense for them.

Cloud Digital Signage Solutions

Cloud based digital signage solutions remove the server from the equation.  With this option, the digital signage CMS server is essentially leased, not bought.  There is no CMS server to install, maintain or secure as these tasks are all performed by the Cloud service provider.  The other components of any typical digitals signage system are all there.  Cloud customers are provided with a front-end “dashboard” user interface and they deploy player software to show their programs on each networked display.

This option is very attractive for small and medium sized businesses that don’t have the resources necessary to handle the CMS server maintenance tasks and other aspects of operating a server environment (security, backups, etc.)

Cloud based systems require little upfront investment as there is no software to purchase.  Instead, customers pay a monthly, per player fee.  The more players they deploy, the higher the monthly cost.

There are some disadvantages, though.   Monthly fees are ongoing for as long as the customer subscribes to the service, and in many cases you can’t convert a Cloud plan to an On Premise ownership.  So it pays to shop around, in case your business takes off and you decide to bring the technology in-house.


Other considerations

Both types of solution will offer a user dashboard and player software.  Here we break down how these modules work.


The CMS Server Dashboard – Locally Installed vs Web-Based

The CMS Server is the back-end software that runs the show.  Most CMS Servers use some type of database to store information.  They also require a web or FTP server to communicate with their assigned players.  The CMS Server dashboard is the interface that is used to log in and access the system.  Some products require end-users to install a local software app to communicate with the server.  Other solutions are web-based, and don’t require any locally installed software.  Instead, these products let end-users log in using the web browser of their choice.  Web based dashboards are more popular because there is no local software to buy, install and maintain.  These type of software products are usually easier to learn, and use.

It’s important to understand the difference between locally installed software and web-based systems.  Locally installed software needs to be updated periodically as new versions are released.  With web based software, end-users receive updates as soon as they are installed on the CMS Server.  The end-user has nothing else to do, in order to take advantage of the software’s new features.

Also, locally installed software may need to be installed on multiple devices.  For example, a person may have an office PC and a laptop so they would need to install two copies of the software.  This can have many implications such as the need to keep track of multiple licence numbers.  With web-based software, there are no limits to the number of devices that the end-user can login from.  Web-based software delivered in HTML5 can also be accessed by tablets and smartphones, regardless of the manufacturer, make or model.  This is why web-based software dashboards have become so popular.


Networking considerations

Most networked Digital Signage Systems can communicate via the internet through wired or wireless connections.  Wireless networking includes WiFi and 4G/LTE cellular data as well.  In a typical networked system, the CMS Server will receive connections from users accessing the system and send/receive data from each player.  Here again we have different options to choose from: streaming or forward and store.


Streaming Digital Signage Systems

These systems are based on video streaming technologies.  Any non-video content is converted to a video format, on-the-fly and streamed to each digital signage player deployed on the network or over the internet.  The better streaming based solutions offer some type of local buffer so players can continue to play content if the device or PC loses its network connection.  The CMS needs a streaming server to prepare, encode and deliver the content.  Current generation codecs ensure the content is played at a respectable quality.  Streaming servers come in two types of configuration: unicast and multicast.  Multicast video streaming is preferable, especially if you need to push content to large numbers of playback devices.


Forward and Store Digital Signage Systems

This is a more common methodology.  In this case, all required content stored on the CMS Server is sent to each playback device and store on each device’s onboard memory or hard drive.  If the player loses connection to the network, content will continue to play for as long as it’s scheduled to do so.

This approach is more resilient as there is less dependence on players receiving a steady stream of data.  This also saves a lot of bandwidth because only the required content is sent to each player.  It’s interesting to note that some digital signage systems are also compatible with web pages and streaming video.  These products can play a mix of local and remote content so when connectivity is lost, only locally stored content will continue to be shown.  It lets the player “fail elegantly” and in many cases, the audience won’t even know anything’s happened.


Digital Signage Player Software

This is the last piece of the puzzle.  The digital signage player software receives instructions and content from the CMS server, then executes the schedules and programming.  Digital signage player software comes in two types: interpreted and native.

Interpreted digital signage player software uses a programming technique that is easier to code and develop.  However, these player software programs tend to be less stable and reliable than player software that uses native code.

There are as many digital signage player software versions as there is media player hardware.  In the early days of digital signage, people used mostly PC hardware running on Windows, Linux or MacOS.  Now there are many other hardware platforms to support, such as: Android media player devices / tablets and System on Chip (SoC) equipped flat panel displays.  Digital signage media player hardware comes in several form factors, from small PC cases to “stick” shaped units that plug right into a display’s HDMI port.  Then you have SoC displays where the player hardware is contained inside the display itself.  Interestingly, some display hardware manufacturer also developed a standard for purpose-built computers that can be inserted in a slot on the side of the display.

The digital signage player is the software that enables all these devices to play the content scheduled in the CMS Server.


Yet another Option: Disconnected Players

In some cases, networked players can be used in a non-networked environment.  In order to receive updates these players must be compatible with external devices such as USB memory sticks or SD cards.  When the USB stick is inserted, the player retrieves its update as if it came from the network.  This digital signage feature is only found in high-end software products.


The road ahead

Digital signage systems continue to evolve.  Hardware becomes smaller and more powerful over time.  Networks are getting faster, and software is getting smarter.  This will lead to ongoing improvements for future digital signage systems.