The solution presented here is now operated by TDF following the acquisition of ItasTim in 2016.

TDF Télédiffusion de France

ItasTim and the monitoring of its terrestrial TV broadcasting network

The ITASTIM company is a Digital Terrestrial TV and radio broadcasting operator. It manages a park of 400 broadcasting sites in France, each one delivers one or more DTT Multiplex and one or more Radio.

The 24/24 supervision of the functioning state of the national broadcasting infrastructure requires powerful and user-friendly management tools. The French software LoriotPro Broadcast Edition edited by LUTEUS company was chosen for this task.  

We should rather say a double task. First, to supply to the ItasTim operators a tool alerting them of any problems that may arise in the broadcasting network. Secondly, to provide to the customers of ItasTim, a view on the current status of their sites and the quality of service delivered. For example, the transmitter status is indicated as well as more technical parameters such as emission levels, BER, MER, etc.

In date of this document and in few key figures, LoriotPro realized the daily network monitoring of about 400 broadcasting sites incorporating an average of 10 broadcast and network devices, more than 9,000 indicators of real-time managed states, mostly they indicate a correlated state from the treatment of a collection of several SNMP objects. The result is a collection of about 20000 SNMP objects made in a average time of 1 minute, some critical values related to the diffusion being collected every 15 seconds other less critical  such as UPS statuses every 5 minutes .

To achieve this, the broadcast network monitoring software has to face many technical constraints. The first is mainly due to the geographical isolation of the sites. The data links required by the supervision tool to periodically collect equipment status, are based on low speed technologies and with slow transit time, satellite, GPRS. It is therefore important to consider these constraints and not to overload these links by aggressive and too frequent collections. Nevertheless some status indicators such as the presence of signal transmitters and the emission level is critical, frequent collection is necessary in these cases to promptly notify the operators of possible failure. To this reality, must be added the necessary time for polling such large number of equipments and for such variety of models.  Indeed, the collection of operating data on equipment is provided by the standard SNMP protocol but manufacturers in the world of digital terrestrial television have not defined standards for the definition of monitoring objects. This result in many variations reported in the MIB file which imposes to have many different polling programs for each device model. 

The LoriotPro Broadcast Edition has helped address these needs and technical constraints due to the features that we list below:

  • A multitasking SNMP collection engine able to make recurring queries and massively parallel on all sites with time constraints of the order of one second.
  • An embedded scripting language (LUA) for the development of customized applications based on the C ++ native functions LoriotPro
  • An internal database in memory for easy management of hundreds of indicators (Global Object) reflecting the state of SNMP values or correlation result
  • Very dynamic visuals in Windows environment (ActiveView dashboards) that can contain several thousand status indicators refreshed every second
  • A Web server exposing the collected values, statutes, correlations, to custom developed and dedicated graphical interfaces available for the common WEB browsers.
  • Logging of all events occurring within the network for analysis a posteriori.
  •  Generating alarms in different formats toward operators (visual, sound, email and SMS)

We will now scan these points to see how they are covered by the implemented solution. Let's start with the WEB Server and the client application. As set out above, ItasTim customers have access to a Web site that allows them to check the status and quality of the service provided. This web application was custom developed to meet the following needs:

  • Have a summary view of the overall state of the broadcasting network
  • Have a dashboards showing the map of France and all transmitter sites with their current operating status
  • Have synoptics showing the main functional blocks and their current operating status
  • Access to each functional block (receiver, amplifier, modulator, etc.) and to their technical measured values
  • Access to the historical status of the equipment by multi selections (date / time, site, equipment, alarm severity)
  • Provide contextual information to sites, coverage maps, GPS location, site photos, etc

The WEB interface is modular and allows the ItasTim operators to access dashboard with information common to all customers.
As any web application, it has "Server Side" code and "client side" code. On the server-side the embedded LUA language is used while on the client-side standard HTML5, CSS, JQUERY and AJAX are at work. Below are some screenshots of the web application in the administrator mode:
Broadcast network WEB monitoring
On the server, the need of the operators, LoriotPro updates many dashboards with fresh data. These are based on a unique concept to the LoriotPro product that is called Active View. Active Views are custom built for the needs of the operators and end users. In the context of ItasTim, Active Views provide access to summary views, detailed site views, or geographical views or synoptic views. The alarm acknowledgements are possible in contextual menus at different levels (multiplex, site equipment). Graphic objects are dynamic, more than 3000 in one Active View, and by color change indicates the current status of sites, multiplex equipment. They are updated every 5 seconds. Below are some screenshots of the Windows interface of the LoriotPro server:

LoriotPeo Broadcast windows interface

Now let us see the internal principles of operation of the solution. As we have already said LoriotPro is a multitasking SNMP polling engine able to make recurring and massively parallel queries on all broadcast sites with time constraints of the order of one second. For a better understanding, we have positioned the functional blocks in the schema below:
Broadcast network real time monitoring principles

On the left, a broadcast site is represented with some of its broadcast equipments. In the center, the database of  Global Object and their associated SNMP polling and correlation agents. Global Object are structures in memory which stores the data collected and / or correlated. Agents are LUA codes that are executed at regular intervals by the audit modules (Audit Plugin). A reserved set of threads of the Windows operating system is dedicated to running agents codes by audit modules, ensuring multitasking. On the right a dashboard of Active View type, takes in the database of Global Object those relating to update its graphical objects status.

Polling and correlation agents are coded in LUA scripting language within a single library. The embedded language LUA within LoriotPro enhanced of  hundreds of functions dedicated to SNMP enabled the rapid development of the associated SNMP polling and correlation agents, it offers a unique modification flexibility and optimal execution speed, the code behind the script functions being in compiled C language.

Behind these complex operations, the issue that might arise is a heavy work of configuration management and change management. The broadcast network extends regularly and the process for adding new sites must be "taylorized". To achieve this goal, the configuration of the whole relies on descriptive files, one file per site, of the equipment settings. In these files in text format are present all the information necessary for performing the data collection and data visualization. It therefore contains information as diverse as the site name, the site GPS location, synoptic template to apply , IP addresses of devices, the names of polling agents, the emission threshold levels, etc.

When adding a new site by creating its configuration file, the operator can update the current active configuration  in minutes by calling dedicated programs support to enrich the data of  Global Object 'LoriotPro directory, to set up collection audits and changing visuals (ActiveView).

As you have noticed, the software provides the functionality and power needed to fulfill the implementation of an active monitroing of a terrestrial TV broadcasting network. Expansion possibilities through integrated services based on the LUA language development tools allow a limitless customization of operational GUIs to the needs of our customers. We hope that this case study will have brought you a clear view of the capabilities of the monitoring software, LoriotPro Broadcast Edition.