Malaysia DVB-T2 Trial
Hock Leong Tan, Rohde & Schwarz
As part of this year’s Asia-Pacific Broadcasting Union’s Digital Broadcasting Symposium in Kuala Lumpur, an important 4-day DVB-T2 field trial took place to showcase the technology and its superior capabilities. The field measurements and results of the field trial were subsequently presented later in the week at the Symposium Conference.
The field trial was conducted by ABU, DVB, Rohde & Schwarz and Radio Television Malaysia with the support of Media Broadcast, TeamCast and S & T in Kuala Lumpur from 4-7 March 2011. Attended by over 120 participants representing 16 countries from the region, the event aimed to provide firsthand information on DVB-T2 and the expertise in setting up, as well as operating such transmissions in their own countries.
The four-day event was comprised of a two-day workshop followed by a two-day field measurement exercise in and around the city of Kuala Lumpur. The workshop featured DVB-T2 technology, its implementation, advanced features and benefits as compared with the first generation DVB-T.
For the field trial, the R&S SCX8000 transmitter was configured to transmit 600 watts from the Kuala Lumpur Tower. DVB-T2 modes such as 256QAM and 16QAM were selected for comparison with DVB-T. The purpose was to demonstrate the differences in spectral efficiency and the resulting increase in coverage by using DVB-T2. The measurements were conducted using an R&S ETL TV analyzer.
Several sites in and around Kuala Lumpur were carefully selected for coverage comparisons. This was done with the help of the engineering team from Media Broadcast, Germany. Among the sites selected, the inner city site allowed reception evaluations under a severe multipath environment. Whilst an urban edge site, which was located about 30 km from the KL Tower, allowed reception comparisons for low field strengths.
During the field measurements, a step attenuator was used as shown in Figure 2. At each site, the incoming DVB-T signals were attenuated using the step attenuator to identify the points of failure where the video could no longer be observed on the R&S ETL TV analyzer. This was repeated with DVB-T2 signals. With this the margins for DVB-T as compared to DVB-T2 were identified for each of the selected locations.
Two test vehicles with close to 100 participants took part in the field trials. This allowed the participants to witness the actual measurements and comparisons on site.
A brief summary of the measurement results is shown in Table 1. In this configuration, it is noticed that for similar C/N conditions the data rate can be increased from 24.8 Mbps to 40.2 Mbps by using DVB-T2 instead of DVB-T. This is a significant improvement and clearly demonstrates the superior performance of the DVB second generation DTT standard.