Considerations in Deploying a Digital Signage Solution
Whenever most people think of a digital signage solution, they think of a multitude of displays in an airport or stadium. This is accurate in describing a large scale digital signage solution. However, digital signage solutions are being used in a wide variety of applications including small scale applications in sports bars, salons, small retail establishments, etc. These small scale applications may have as few as two displays. A digital signage solution boils down to three basic components: a content player, a distribution method, and a display device. The scale of the digital signage solution will mandate the type of content player, the method of distribution, and the number of displays required.
A digital signage player may be any type of device that is capable of producing a video signal that can be distributed to displays. The most common device used to generate digital signage content is a computer or dedicated server. Some digital signage solutions use an on-board player that is mounted to, or contained within the display. An important consideration when selecting the digital content player how the content will be generated and maintained. For some situations use of a Microsoft® Office program such as PowerPoint® is more than sufficient to generate and maintain the content. For situations where this type of program is not sufficient there are many different options. Some may choose to purchase packaged software or use a Software as a Service (SaaS) vendor that is specific to creating and maintaining digital signage content. Still others may choose to outsource the generation and maintenance of their digital signage content to a vendor who specializes in digital signage content. There are pros and cons to each of these options, but the decision will ultimately be based upon the requirements of the digital signage solution as well as the resources and creative bandwidth of the company purchasing the solution.
The distribution method used for the digital signage solution will be determined by many different factors as well as the requirements of the solution. The main determining factor in which type of solution should be used is the distance between the player and the display. For short runs of cable it is typically best to use the native cabling of the signal, i.e. if the content player is generating a VGA signal, then a VGA distribution amplifier and VGA cabling should be used. For short to medium runs of cable it is typically best to use a video balun, or over UTP video extender. These devices act as balanced/unbalanced signal converter and extend video signals over twisted pair cabling such as Cat5e or Cat6. It is possible to use existing cabling infrastructure with these devices. Using the existing infrastructure can save both time and money on materials and installation cost. For medium to long runs of cable it is typically best to use an IP addressable solution. This solution will allow the video signal to be sent over either a parallel network, or the existing network. An important consideration when choosing the distribution method is the type of video signal that will be distributed, either analog or digital.
Digital signals, such as HDMI, DVI-D and DisplayPort, carry Transition Minimized Differential Signaling (TMDS) which is a technology for transmitting high-speed serial data. In digital signage applications this technology is critical for supporting multi-panel video walls. A multi-panel video wall is when a number of displays are used to create a single image. Another important consideration when choosing the distribution method is the possibility of using existing cabling infrastructure. As discussed previously, video baluns and IP addressable solutions are both capable of using the unshielded twisted pair (UTP) Cat5e or Cat6 cabling.
However, in many situations, especially in schools, there will be an existing master antenna television (MATV) coaxial cable network. It is possible to tap into this network by using a signal modulator. A signal modulation device will take an input from a content player and broadcast the signal over the coaxial cable where the TVs will be able to tune to a specific channel and receive the signal. The benefits of using the existing MATV network are the time and money saved on materials and installation cost, as well as the fact that coaxial cable provides from 370 to 1,000 times more capacity than twisted pair. This capacity allows for the delivery of either static content or full motion high definition video to the displays.
Choosing the right display for a digital signage solution is very important. While the price and availability of consumer television make them an attractive choice, it is important to first consider the total cost. For most manufacturers, using a consumer display in a digital signage application will void the manufacturer's warranty. This means that if there are any problems with the display, the manufacturer will not offer any support. If the display is irreparably damaged, then it must be replaced. In addition the power supply for a consumer display is not designed to run the TV for the number of hours that are required in a digital signage application. This will also lead to the shortened life of a consumer display in a digital signage application. Commercial grade displays are specifically designed for use in a digital signage environment. The manufacturer's warranty covers this type of use and the power supply is designed to power the display for extended periods. Though the cost of the commercial displays is initially higher, using a commercial grade display in a digital signage application is likely to reduce the overall total cost.
Another consideration on the topic of displays is the type of display that will be used, plasma, LCD, or LED. Plasma displays are capable of generating the highest picture quality of the display types used. However, plasma displays are susceptible to "burn-in", which may result in a ghosted or blurry image, as well as glare in bright light conditions. This combination of factors means that plasma displays are not ideal for digital signage applications. LCD displays are by far the most popular in digital signage applications. LCD displays are not as susceptible to burn-in, or glare as plasma displays. LED displays carry a higher initial cost than LCD display, but have a lower overall operating cost. The operating cost is lower because the LED displays use less power and last longer than LCD displays.
A final consideration in a digital signage solution is the availability of a network connection. A network connection allows for many additional features and control options. With a network connection it is possible to easily distribute content to on-board players that are connected to the display. A network connection also allows for IP control of hardware and software from local or remote locations. This will allow the manager of the digital signage solution to completely control the system from anywhere that has an available Internet connection. A final benefit of a digital signal solution with a network connection is the ability to determine regional distribution of the content to the displays. This feature breaks the digital signage solution into "zones" that are able to simultaneously display different content. A good example of where this would be useful would be a retail store. With zoned content the digital signage system would be able to either play a single message to all zones announcing the store closing, special sales, etc., or each different zone displaying content that is specific to each department.