The Middle East saw a major first in broadcasting during the Doha Asian Games in December 2006. 1500 VIPs and VIP visitors could view the Games as well as other TV programmes from broadcasters such as the BBC and Al Jazeera on Samsung and Nokia DVB-H phones thanks to a new technology that was implemented in time for the event. Rohde and Schwarz worked hand in hand with Qtel, Qatar’s national telecommunications company, to put in place the Qtel DVB-H pilot network in the country.
“Rohde and Schwarz undertook the entire project including hardware production, delivery and services,” says Eashwarahally Vikas, who is responsible for Rohde and Schwarz’s broadcast operations in the Middle East and Africa. “We were responsible for the manufacture of the electronics equipment, which was at the heart of the installation. We partnered primarily with T-Systems who took the primary responsibility of planning the network as well as implementation of the headends for this,” he adds.
The supply included Rohde and Schwarz’s R&S AVE264 series Of H.264/AAC video/audio encoders, its Flute server, its R&S DIP010 series of IP encapsulators, the R&S NV8200 series of medium power transmitters as well as the R&S XV8000 series of on-channel repeaters. In addition to supplying its own hardware, the German manufacturer undertook the responsibility for the entire system including integration of complete head-end with ESG, antennas, network and coverage planning as well as the installation and commissioning of the entire network.
The headend contains encoders and encapsulators. If, for instance, the user feeds in 15 programmes, an analogue feed when converted to digital will take about 270 Mbps per programme. As this cannot be transmitted, the encoder’s job is to reduce this to 500kpbs or less depending of the network configuration and screen size the operator intends to support in the market. These inputs are sent via an IP switch to an encapsulator. The job of the encapsulator is to do time slicing of information and provide additional forward error correction (FEC). Time slicing, means that the encapsulator helps reduce mobile phone battery usage by providing bursts of information rather than continuously. “These bursts are received within mili seconds. In principle, your viewing is not disturbed in any way because the playback is continuous as each burst of information is stored in the phone’s memory buffer and plays while the next burst comes through,” explains Vikas.
The head end is also capable of statistical multiplexing, thereby, providing almost 30% additional capacity for future needs. Additionally, this is an open platform thereby allowing for integration with future encryption systems. “The whole network currently operates on an open platform, so, in principle, all fully compliant DVB-H phones can work in this network,” explains Vikas. “Currently Samsung and Nokia mobiles are in use. The network has been planned for 20-25 DVB-H channels (Video & Audio) for indoor and mobile coverage.”
Discussion for the project began as early as the end of 2005 because this was clearly a new technology that Qtel was seeking to demonstrate in time for the Asian Games. “They floated the global tender and the criteria was that they needed a reliable supplier who could also do good planning. Planning was essential. While most mobile phone operators would seek lower power, our planning was based on higher power because of the indoor and mobile range of coverage Qtel required. This meant that the equipment would be more expensive and was not the cheapest solution but we were able to offer the best price versus performance ratio and Qtel was able to appreciate this,” explains Vikas.
Likewise, being a German manufacturer with more than 50 years of experience in this business, Vikas claims that Rohde & Schwarz offers greater reliability and redundancy. “If any product is manufactured well, the likelihood of inherent fault occurring will be low. We take care of this in our manufacturing and our design process. We are well known for this as we make equipment for mission critical applications such as the defence sector and on-air sectors,” he says.
R&S conducted a site survey in August 2006, to check which areas were appropriate for mobile transmission and if existing masts were high enough to support certain coverage and whether they could carry certain antennas. Based on this survey, the team identified which sites were ideal for coverage. “We then submitted our coverage planning for approval. Such planning needs a lot of competence because the whole network is synchronised on the same frequency. The benefits of doing this are huge in terms of efficient spectrum usage, continuous reception of programmes and additional network gain, which is available due to the SFN which, in turn, also reflects favourably in terms of financial savings,” explains Vikas.
Production of the equipment began at the end of August and was delivered by mid September 2006. “As time was limited, everything had to be air freighted. By October, we switched on the network and handed it over to Qtel. We also kept two staff members for support during the Asian Games because this is very new technology and everything had to be right,” adds Vikas.
One of the advantages of broadcasting programmes into mobile phones was that these signals could be received anywhere. “Unlike TV signals, which force you to be in an area such as your home, you can watch TV anywhere on your mobile phone – in your car, while shopping – shopping malls are not great areas for TV signals. This meant that the TV network had to be integrated differently with higher powers and on channel repeaters than as in case of the mobile phone network for this project,” explains Vikas.
Qtel, in the meantime, had already negotiated contracts with content providers and fed these programmes to the network implemented by R&S. These programmes were encoded as well as multiplexed together. This included time slicing and transmission using terrestrial network as per the DVB-H standard. As a result, the mobile phones with built in DVB-H receivers could receive these programmes and the viewer could select over the programme guide the channel they wished to watch.
One of the biggest challenges was to complete the entire project within three months, says R&S. The rest of the time was spent in paper work.
Additionally, logistics was a significant challenge. “During the Asian Games, a lot of equipment was being brought into the country and it was a significant challenge to get so many containers out of the port on time. Logistics was a problem. The technical challenge was not that much,” he says.
Likewise, as Qatar has good infrastructure, implementing the technology was not as tough as getting space on a high-rise building.
“Qatar is full of high rise buildings. This meant that to ensure that everything went well, we also needed to be in a high-rise building. Technically, we had the know-how in terms of synchronising the network and on-channel repeaters. The coverage of the network has, in fact, been better than predicted and the total coverage requirement was met. The whole network has been established in a single frequency network (SFN) including the usage of on-channel repeaters, which repeat the same frequency in the network with almost no signal delay in order to maintain the synchronisation. These repeaters have been specifically used as gap fillers to cover the stadiums and shopping malls,” explains Vikas.
While using an SFN, the on-channel repeaters play a very important role since they provide extension of coverage from the main station without disturbing the synchronisation of the network.
“This also means they do not require additional signal feeds as the repeaters pick up the signals off air. If, for any reason, the synchronisation in the network is lost, then instead of adding the signals, the different transmission sites cancel each others’ signals,” explains Vikas.
Training for the Qtel people was done on-site during network implementation. However, more training is scheduled at the company’s headquarters in Germany this year.
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