necessary for the entire measurement Summary period. A connection is briefly required More information and data sheet at only when defining measurement tasks By developing the R&S ® UMS100 mon- www.rohde-schwarz.com (search term: UMS100) and when checking the results. This itoring systems, Rohde & Schwarz now REFERENCES keeps both network infrastructure and provides a fundamentally new solu- [*] Spectrum Monitoring Software overhead costs low. If an alarm is trig- tion. The systems are compact, cost-effi- R&S ® ARGUS: The successful “classic” gered, the R&S ® UMS100 automatically cient, exceptionally powerful, and also now available as version 5. News from Rohde & Schwarz (2003) No. 177, sets up a connection to the control cen- extremely versatile. Owing to their inte- pp 46–50 ter, transmits all required data, and then grated sophisticated measurement and disconnects. analysis functions, the monitoring sys- tems are an excellent tool for handling The equipment supplied includes the the difficult measurement requirements complete measurement system with encountered in today’s communications antenna(s), a solid metal tripod, and scenarios. material for mounting the system on Thomas Krenz a mast, wall, or ceiling. You merely need to provide a suitable location, the Ukrastotnaglyad (UCRF), the Ukrainian frequency authority, subjected the power supply, and a network connec- R&S ® UMS100 radiomonitoring system to tion via a LAN or GSM network. The comprehensive testing – with the results R&S ® UMS100 will then be ready for use being resoundingly positive (for details, see within a very short period of time. Newsgrams on page 59).

Digital Radio Mondiale (DRM) is the R&S ® ARGUS Spectrum Monitoring Software

new digital broadcasting standard ITU-compliant measurements

for frequencies below 30 MHz. The for Digital Radio Mondiale

current version of the R&S ® ARGUS DRM – a new broadcasting Like all other broadcasting transmitters, standard DRM transmitters must be planned and spectrum monitoring software now licensed. As soon as broadcasting starts, Digitization of broadcasting worldwide the individual national regulatory author- also provides a decoder for ITU- has not slowed down. A successful ities are responsible for verifying that the standard in the frequency range up to licensing conditions are complied with; compliant DRM measurements. 30 MHz is Digital Radio Mondiale (DRM). moreover, they have to locate and elim- DRM primarily offers sound broadcast- inate interference where required. The ing applications, but can also be used new DRM module for R&S ® ARGUS was for data services (for details, see box on specifically developed to handle these page 51). tasks.

49 News from Rohde & Schwarz Number 191 (2006/III) RADIOMONITORING Monitoring systems

R&S ®ARGUS ready for DRM are measured and displayed in realtime. Another advantage provided by the All these values can be stored so that automated measurements is the inte- R&S ®ARGUS is the standard software they will be available for subsequent grated alarm mechanism. The user can from Rohde & Schwarz for ITU-compliant offline analysis or documentation. The define a specific upper and lower limit measurement and evaluation tasks; the software also displays numerous param- for each measurement parameter and software is successfully deployed around eters graphically – for example, delay, for each frequency. While the measure- the world and continuously developed Doppler shift or sample rate history, the ment is running, the software compares and updated. The current version 5.2.2 SNR spectrum, and the constellation dia- the results with the reference values. If can now be equipped with a special gram (FIG 2). the limits are violated (overshoot/under- module for measuring and analyzing shoot), an alarm is triggered. This may DRM signals. In addition to the audio signal, DRM can be an entry in a log file, or an acous- transmit auxiliary information such as tic signal. The measurement can also The digital, I/Q-demodulated data simple text messages as well as multi- be started fully automatically to thor- stream of the receiver, e. g. of the media content, for example NewsService oughly analyze the signal that triggered R&S ® ESMB or R&S ® EM510 from Journaline ® (FIG 3), or images in mul- the alarm. Rohde & Schwarz, is used as an input timedia object transfer (MOT) protocol signal. As these instruments are already format. All this information can be dis- installed in many monitoring stations, played directly by the software, stored, DRM up to 120 MHz in the there are usually no additional pur- and displayed again when needed. future chasing costs for hardware; only the R&S ®ARGUS software module needs to Like all other measurement parame- At present, DRM transmitters broad- be added. ters, demodulated audio signals can be cast approximately 800 hours of pro- stored and replayed when needed. The gramming each day worldwide, with The software features a well-structured signals are replayed in sync with the the trend increasing. The DRM con- user interface, conveniently present- measurement results. Thus, variations in sortium has decided to expand the fre- ing all measurement values and further audio quality can be directly correlated quency range up to 120 MHz in the next information at a glance (FIG 1). The user with changes in technical parameters, few years. This means a lot of work merely selects the DRM transmitter fre- for example. for the regulatory authorities. But with quency; all other settings are handled by R&S ®ARGUS, they can easily step up to R&S ®ARGUS. With DRM, as is common the plate. with digital modulation methods, mul- Automatic measurement mode Thomas Krenz tiple services can transmit on the same frequency; in the next step, users can In addition to these interactive actions, select which of the maximally four ser- all measurements can run automatically vices is to be analyzed. during user-definable periods. Especially during the setup phase, many DRM The software displays the most impor- transmitters do not yet broadcast around tant data such as name and ID of the the clock but only a few hours per day. current service, language, and type of In this case, the automatic measure- program, as well as data rates and alter- ment mode (AMM) of R&S ®ARGUS is the native frequencies. The receive level as ideal solution. The measurements can well as the signal-to-noise ratio and var- be adapted to the current transmission ious synchronization and checksum sta- plan as needed. If a transmitter is not in tus displays provide information about operation at the moment, the monitoring the quality of the received signal. system can perform other tasks. When broadcasting does start, R&S ®ARGUS The key technical parameters that promptly triggers the predefined mea- describe a DRM signal – such as DRM surements fully automatically – no user mode and bandwidth, interleaver depth, assistance required. More information and data sheet at www.rohde-schwarz.com error correction, DC offset, sample fre- (search term: ARGUS) quency offset, Doppler shift, and delay –

50 News from Rohde & Schwarz Number 191 (2006/III) Digital Radio Mondiale

DRM is a new standard for digital broadcasting below 30 MHz. A major advantage over analog broadcast transmitters in this frequency range is the outstanding quality of the audio signal, which is virtually equal to FM quality. As with other digital transmission methods, a wide vari- ety of additional information can be transmitted in addition to the audio signal. For example, it is possible to display the title and artist of the song currently being played. Moreover, news, weather forecasts, and traffic information as well as images and even web pages can be transmitted.

Since existing AM frequency bands can be used and since AM transmitters require only minor modifications to be DRM-compatible, the use of the DRM standard is set to expand. The DRM signal is defined in such a way that it fits into existing AM frequency plans with 9 kHz or 10 kHz FIG 1 Key parameters at a glance: the R&S ®ARGUS software user interface. bandwidth. There are also other modes that use only 4.5 kHz or 5 kHz bandwidth. To achieve good audio quality despite these comparatively narrow bandwidths, highly efficient audio compression methods such as MPEG-4 AAC, MPEG-4 CELP, and HVXC are used.

The coded orthogonal frequency division multi- plex (COFDM) method is used for transmission. This method allows, for example, the number of carriers to be varied in order to flexibly respond to requirements such as coverage, quality, and bandwidth.

FIG 2 Constellation diagram.

FIG 3 R&S ®ARGUS also displays the multimedia content of DRM transmissions, such as NewsService Journaline ®.

51 News from Rohde & Schwarz Number 191 (2006/III)