Digital signage is the use of digital systems and electronic displays to provide promotional and other types of messages to viewers or potential customers. Companies and broadcasters use digital signage systems to effectively, rapidly, and efficiently provide messages to bothpublic and private areas (such as companies, hotels, and sports stadiums).

Traditionally, digital signage vendors have relied on a server client model for content distribution. The server runs the content management and scheduling software and pushes templates and content to "signage players" that are placed in close proximity to the display devices. With the advent of cost effective HD encoding and very low cost compact set top boxes (STBs), the signage environment in many cases can migrate to simple AV over IP (digital television) architectures - HD Signage. Content for the HD signage architecture is encoded as HD video in a content head end with all channels distributed live throughout the network to each endpoint display.

Digital Signage Model

Digital signage systems based on the sever client model encompass an "all PC" architecture. The central servers store and distribute content and templates that run on the digital signage players placed at each display endpoint. The servers comprise two components - 1) a powerful server PC and 2) the signage management system. The digital signage players comprise 2 components - 1) the hardware platform which is almost always a very compact PC platform and 2) the player software on that platform. Digital signage systems may include software that simplifies content creation.

HD Signage Model

Media integrators can take advantage of HD encoding to establish internal broadcast channels for signage. The high definition channels are distributed to very low cost set top box appliances, live, and in real time. This approach provides an independent infrastructure that does not rely on the content system. Any content, live or generated by a content server, can be injected into the agnostic HD distribution

Figure 1.Digital Signage Distribution

Figure 2, HD Signage Distribution

environment for distribution to any endpoint. The infrastructure is 100% industry standard, with encoders and endpoints simply exchanging H.264 live network video. Grouping and distribution is easily accommodated through multicast network technology to an unlimited number of endpoints free from software licensing requirements.

Endpoint Cost

Traditional digital signage endpoints require a digital signage placer (a PC appliance) which ranges in cost from $500 to $2000. Digital signage vendors may also charge a software license for each digital signage player platform that can range from$300 to $500 or more in addition to the player. The average price for an endpoint player/software system is estimated to be approximately $2000 per endpoint.

The cost of a high definition set top box (comparable to a compact version of a home digital cable receiver and pervasive in the hospitality industry for in-room video on demand) can be less than $400 providing a savings of more than $1600 per display endpoint!

Endpoint Longevity

Digital signage players have traditionally been based on personal computers. Owners of these devices are at the mercy of needs for operating system upgrades and signage system upgrades that may require additional graphics power. The useful life of PCs can be relatively short when compared to longevity of television set top boxes. Once a STB is deployed that has high definition capability (H.264), it can perform that task for its entire life without the need for upgrades or additional software updates.

Figure 3, HD Digital Costs

Figure 4, HD Signage Management

Bandwidth Efficiency

The new industry television media standards such as the MPEG-4 H.264 video compression system has replaced less efficient MPEG-2 video compression technology. While the MPEG-4 systems was designed to provide HD signals using 4 to 8 Mbps, it was also efficiently designed to provide other formats of media such as static images and text. The data transfer requirements for text based media are hundreds or thousands of times lower than the data transmission rate for video transmission.

If multicast (one-to-many packet processing) is not available on the target network, or if a multicast CAT5 data network cannot be installed, the number of display endpoints served with real time HD will be limited to the number of streams each encoder can produce or the STBs can include DVR storage systems to operate in a process that is similar to existing digital signage systems (download, store, and play).

Content and the Sales Process

Digital signage systems rely on designers and operators to create scripts (command and control sequences) that are applied to each zone using the signage network managers and broadcast servers.

This can be a complex value chain that requires the use of complex tasks and skill sets. As a result, the sales process for the integrator is content centric, and involves the extensive training of personnel from many different departments.

By adopting the simpler model of distributed AV over IP, this can simplify both the content creation and sales processes. HD Signage integrators can install video broadcast systems to drive the displays and very easily establish channels and groups. Live content from broadcast sources, content internally generated or content from signage servers can easily be fed into the internal channels and endpoint groups. The integrator delivers an end to end distribution system that DOES NOT rely on a customized content system. The sales process is easier; the client has lower costs, increased flexibility, and does not have a system that relies on a single digital signage vendor.

Benefits of the HD Digital Signage Model

Some of the key benefits of using television distribution for the digital signage system include the ability to include live content into the signage displays and simplified signage management processes.

Live Content

Television based digital signage systems are designed to deliver live video content while traditional digital signage systems are not proficient at delivering live content. Integrating any content system to a television signage deployment system is rather simple by configuring the output to be HD resolution and feeding that signal to the HD encoder.

HD Signage Management

Signage management systems identify, organize, and distribute messages to groups of end display endpoints. Traditional signage management systems may offer a limited set of abilities to local channel selection and display endpoint grouping. Certain groups of displays carry the same content channel all of the time. Many set top box manufacturers sell or make available central control software that allows managers to group and manage their STBs. A number of other companies make server based control systems to manage and schedule live network video channels and the STBs that receive them. Such companies offer the ability to schedule, propagate, and apply simple HTML templates over the video and operate serial ports for display control. A unique feature of STBs is that they may be either centrally or locally

controlled via a user remote (when enabled, users can simply change channels as easy as if they were in their living room).

Bringing AV Back to the Enterprise

Digital signage has delivered great technology but has over-complicated some simple facility challenges. HD Signage allows integrators to simply distribute high quality content throughout a facility or campus, without a concern for creating the content, managing complex PC deployments, or incurring substantial endpoint costs for technology that may ultimately have quite a short lifecycle.

HaiVision Systems Inc. is a private company and a world leader in delivering the most advanced video networking technology. HaiVision s products are deployed worldwide within the foremost telepresence suites and boardrooms, in healthcare facilities for video collaboration and training, for continuous presence distance education and remote learning, and within broadcast for remote interviews, IPTV, and content distribution.