For many years, television stations have been searching for a system that permits them to use mobile phones to contribute live images and audio. Why mobile phones? Because they are lightweight, everyday devices that nearly everybody carries. In case of breaking news, this would allow journalists to get earlier images of an unexpected event, without the delay of waiting for an additional kit to arrive.
Up to now, the best that could be achieved was to store the images and then forward them to the TV station in order to air them. Thanks to the advent of UMTS technology (also known as 3GSM), it is now possible to send videos captured by handsets.
The third generation of mobile phones was developed to add multimedia features to what had been basically a voice device with limited data capacity. A 3G device supports circuit-switched connections for conventional phone calls and packet switching for data interchange. One of the goals of the technology was to offer videophone capabilities.
The 3G standard used in Europe is UMTS, which uses wideband code division multiple access (WCDMA) standard for transmissions. Each 5MHz channel can support data rates of 384kb/s to a handheld phone, with the possibility of downloads up to 3.6Mb/s.
The 3G phone offers basic services such as voice, e-mail and SMS, but the higher data capacity of the network adds multimedia applications such as multimedia messaging service (MMS).
The devices support video downloads and have integral cameras. All the necessary tolls are present in a 3G system to use the device as a remote video camera. Aside from the device and radio systems, what is needed for newsgathering is an underlying core to bring together the technologies.
IP multimedia subsystem
The IP Multimedia Subsystem (IMS) allows users to deliver multimedia data across a common core across fixed, cellular or wireless broadband networks. One of the best-known features of IMS is push to talk. Users can move sessions seamlessly between a fixed office phone and a mobile phone. In an IMS session, video and audio can use different carriers, so the voice can use a public switched telephone network (PSTN) and the video can be transmitted via UMTS. That way, the entire UMTS bandwidth can be dedicated to video, achieving a higher picture quality. It is this feature that is used to backhaul video and audio from the phone.
One example of a mobile device with this capability enables a 3G handset to deliver live video and audio inserts. The technology used in the mobile device was developed by Motorola using IMS.
The broadcaster routes incoming feeds from the 3G devices to a special server, which saves all of them to hard disk for possible to use afterwards. It then converts the selected feed to a standard video signal (SDI, PAL, NTSC, etc.) in real time for live insertion into a television program.
With this software, traditional equipment (satellite links, cameras and vans) is not necessary to obtain the first images of an event. Using an everyday device — the mobile phone — is sufficient. And with only 64kb/s, the quality is more than acceptable, and as the quality will improve as carriers deploy higher bandwidths.
It is necessary to point out that this system also works with videocall and with the coming mobile technologies, such as high-speed downlink packet access (HSDPA) and high-speed uplink packet access (HSUPA).
The mobile device is made up of two parts: the phone, which sends the video and audio, and the server, which receives them and converts them into a video signal in real time. For a reporter to use this system, the handset must be in a UMTS coverage zone, and the server must be connected to the Internet using a public/fixed IP.
The phone uses IMS to send the video at the same time the audio is sent through the PSTN. This allows the full available uplink bandwidth is used to send the video, and therefore receiving a higher quality. The signal reaches the server via the Internet.
The base-station server has a capacity to record six calls, but it can queue additional calls, waiting to be accepted. An operator can switch around the six calls and then take one to air.
This combination of 3G/UMTS and IMS technology means that television stations now have a powerful system to help them get breaking news to air quickly simply by using a mobile phone.
José María Carrera Mestas is sales manager for Createcna.