Vijaya Cherian looks at why Dubai Media Inc. deployed VISLINK’s Cellular Diversity technology and how it will benefit the broadcaster.
Dubai Media Incorporated (DMI) has invested in an advanced RF network for its wireless camera operations, which is enabled by VISLINK’s Cellular diversity technology in the Gulf region. The deployment brings immediate cost savings to the state-backed broadcaster, which is responsible for the live broadcast of several events in Dubai.
The city-wide wireless camera solution was installed by VISLINK and comprises a wireless camera system that transmits low power signals to a portable repeater system. This two-inch antenna can be rigged onto a building, a car, a boat or a helicopter as required. This then re-transmits the signal at high power to the diversity receive system that is located at the Dubai World Trade Centre and from here, back to the DMI studios. Dubai World Trade Centre is linked by fibre to DMI’s studios.
DMI can use any standard professional broadcast camera fitted with the LINK L1500 transmitter operating at 7GHz to make use of this solution.
“DMI is the first broadcaster in the Middle East to benefit from this technology,” says Mather Al Ali, Vislink’s general manager for the Middle East and North Africa.
“The other alternative is to rent an SNG vehicle for each newsgathering operation. Deploying a satellite truck requires more planning time, and it also needs a team of engineers to go with the vehicle. By doing this, you often tie up a lot of resources, manpower and capital equipment. Besides, you also tie down your satellite space segment, which can be quite expensive depending on how much you are leasing per year.
“This technology eliminates the need for any satellite space segment. You will get the same result; you will get a live, broadcast-quality signal without using any satellite equipment,” he adds.
According to Vislink, the traditional way of setting up such a broadcast requires several engineers to operate antennas and dishes, and carries the risk of losing the video signal because of human error. By comparison, the Cellular Diversity solution is easy to use.
The receiver covers an area within a certain radius of the antenna. Within this area, a camera operator can move around freely with the camera and the signal will be received at the centre. The concept uses a feature of COFDM wireless technology that enables digital signals to bounce off the surfaces of tall buildings in the city centre, and reach the receiver even if there is no direct line of sight.
Al Ali says that some people use traditional microwave links as well to undertake the same operation. However, this technology again demands that both the transmit and the receive stay within line of sight to be operational.
“This again is a very engineering intensive exercise that is cumbersome because it ties up a lot of human resources and obviously, capital equipment. Additionally, it is not mobile so you cannot move easily from one location to another. The Link Research Cellular Diversity system gives us the best of all worlds. It operates on a cellular level and it doesn’t have to be one cell. You can use multiple cells like you would in a GSM network, thereby, allowing the cameraman to move freely between the cells and enabling the signal to go back to the studio without interruption from one cell to another,” he explains.
Hassan Chahine, chief technology officer at DMI was the key person behind the choice of the solution.
“We acquired the system because we could see that it would enable us to capture live events — which is what we do 95% of the time — directly from the streets of Dubai without using much effort or resources to set up prior to going live. For broadcasting live, you require SNG or microwave and for cost reasons, we used to go with microwave technology. Unfortunately, with so many high-rise buildings and cranes, microwave became a nightmare. That’s when I spotted this application in action for the first in London,” he says.
“We have begun to test this application with one cell. What’s great is that it does not require any technical skills and does not work on the line of sight principle. We find this technology to be very useful so eventually, we hope to switch all our OB vans and mobile units to have this kind of wireless application,” he adds.
DMI presently operates with one single cell that covers virtually all of the areas that it requires, all the way from the Dubai Airport terminal to Burj Khalifa, Madinat Jumeirah, Burj Al Arab and so on. A fixed receive site is installed at the World Trade Centre tower. Four antennae have been deployed at the tower to provide 360-degree coverage. This location, in turn, is connected to Dubai TV via fibre.
“We have tested it all the way to Jumeirah Beach arena, which is 21.5kms away and it worked. We have also tested it all the way to the airport, which is 10.5 kms, Mamzar Beach, which is 12.5 kms and Madinat Jumeirah, which is 14.2 kms,” explains Al Ali.
“It’s based on a cellular system so if the broadcaster finds it is not getting the range it would like, it could very easily add a second and a third cell which will more than compensate and give it the additional range it requires. You can, of course, have literally as many cameras as you want. However, for each cell, you will require to have a corresponding diversity receiver and more portable repeater systems,” he adds.
With this solution, the creative people and the journalists will no longer be dependent on the engineering teams’ availability and resources, explains DMI’s Chahine.
“The cameraman and the reporter can go up by themselves to the field. They just need to take the portable receive case and transmit case with them, place the magnetic transmit antenna on the top of the car and they’re good to go. In addition, this technology will help us to shoot from a moving car. This immediately opens up a lot of programming opportunities for DMI, where we can take the car and go to several different locations and shoot and go live without depending on an SNG application. This system is not cheap but I believe that in the long run, this will be very cost effective for us,” concludes Chahine.