By far the biggest impact on operational expenditure is energy. Again, while the transmitters themselves are the leading power draw, it is very important to consider everything in the transmitter station, including cooling and management, as part of the energy audit.
Legacy transmitter sites in operation today have an efficiency of around 20%. That is to say, for every kilowatt of radiated RF power, it needs 5kW of AC input. Clearly, improving efficiency will have a big impact on this key operational cost. It is also important to remember that power consumption is directly correlated to carbon footprint, so increasing efficiency not only reduces costs, it reduces the carbon footprint.
The new TH1 transmitter from Rohde & Schwarz is designed for efficiency. On average it provides 44% energy efficiency, taking all transmitter costs into consideration. The actual efficiency is dependent upon factors like frequency of operation, but at any frequency the total power conversion factor will be 42% or better.
With the R&S®TH1, for every kilowatt of radiated RF power, we now only need around 2.3kW of AC input. Energy costs would be cut by 50% or more compared to the installed base of transmitters. And even compared to any other transmitter currently on the market, the R&S®TH1 reduces energy costs by at least 15%. That is a real, very tangible benefit for any user.
Those numbers are the headline good news for operational efficiency, and are easy to incorporate into any business case. There are other measures though, which also contribute to the overall efficient operation of transmitters. These are centred on the amount of management and engineering time required to keep the network running effectively.
The first and most obvious step is to employ robust system design to ensure the transmitters are fundamentally extremely reliable. With the R&S®TH1 this includes careful selection of every single component for a lifespan beyond the typical service use of the transmitter. The circuit boards, power amplifier stages and modular construction are then designed to ensure even cooling of any component and to ensure that there are no hotspots, no thermal stresses and no risks from temperature gradients.
Previous generations of Rohde & Schwarz transmitters have a proven reputation for reliability, and that will be further improved with the latest designs in the R&S®TH1. More reliable electronics make for more reliable transmitters, which means a much reduced requirement for engineers to travel to site to effect emergency repairs.
Another crucial aspect is the integrated transmitter control layer, which enables self-monitoring and self-adaptation of key parameters in order to allow the transmitter to continuously work in the optimal working point - not only on the day of commissioning, but also 10 years after the start of transmission. The control system monitors KPIs like signal power, signal quality and power consumption and makes the necessary adjustments to ensure that these key parameters are always in the optimum. That is of critical importance, for instance if the actual efficiency of a transmitter deviates from the initially set value over time and nobody notices, that may result in a significantly higher energy bill than expected and may even take the business model at risk if energy costs become uncontrolled. The R&S®TH1 transmitter is minimizing that risk with its state-of-the-art technology and functionalities.
Moreover, the intelligent control layer allows transmitter operators to implement automation mechanisms by defining operational limits, which the transmitter system uses for self-adaptation and for a more efficient communication to the network operations staff. When the management system senses that any metric is approaching one of the defined limits, it proactively starts to interact with the operator, e.g. via an SNMP trap. Again, costs are reduced by eliminating the need to continually monitor the network by human or by a network management system, which natively does not have the intelligence to tell the difference between a normal status information and one which shows critical values.
In even the best of systems there will inevitably be the occasional failure, and under these circumstances it is important that the repair be completed as swiftly and simply as possible. The web interface shows precisely where the problem is, and which module needs replacing in the field to rectify the issue. It also shows whether the repair is urgent, sending an engineer immediately, or whether it is a regular maintenance task which can be carried out at a later, more convenient time.
Ultimately, the intelligent support continues beyond this. Recognising where the fault is, the intelligence in the control layer then knows that the board or module is about to be replaced. When the physical exchange takes place, the software then automatically and instantly loads the appropriate configurations and transfers the licences, so the system is immediately up and running again with no need for set-up.
By using intelligence in the transmitter control layer, a transmitter operator is enabled for managing engineering and supervisory resources to best effect, minimizing the need for highly trained staff and emergency callouts. This is another valuable step in operational efficiency which, combined with the greatly reduced overall power consumption, allows the network operator to face its budgetary challenges.
