With the right expertise, these existing distribution systems can often be re-engineered on a case-by-case basis to support mobile TV. Much depends on the age, specification and configuration of the existing system. Other major considerations will include cost of work, rollout time and electromagnetic compatibility with co-networked radio services.
It is also worth noting that, unlike mobile phone calls, it is likely that mobile TV viewing will take place at a user-determined time and place. This could lead to the deployment of simpler, dedicated mobile TV hot spots. Accurately identifying the key indoor areas to be covered will contribute to the commercial success of a mobile TV service.
Mobile TV networks - both outdoor and indoor - will invariably operate in single-frequency network (SFN) mode, owing to limited spectrum availability and handset operation. Network fine-tuning will be essential to ensure synchronisation between the micro indoor cells and the macro outdoor broadcast network. SFNs demand the tightest control of signal levels and timing to minimize interference and to optimize network coverage.
It is clear that the mobile TV network environment will be complex and dynamic, requiring a unique breed of engineering solution. It will be important to balance the demands of the macro network as a whole, with the precise confined-coverage requirements of individual locations on a micro scale.
Chris Jaeger is managing director of Broadcast Australia International Business Group
Paul Chan is engineering director of Hong Kong-based Radio Frequency Engineering