The concept of distributing linear broadcast content via cellular mobile broadband networks has been discussed for several years, originally with a unicast mode of operation. The introduction of a broadcast mode in LTE - variously known as eMBMS or MBSFN - has opened the door for more promising approaches. Roland Brugger and Alexander Schertz, both from the IRT in Germany, have analysed recent studies done by the mobile broadband community on the delivery of TV programmes by means of cellular LTE networks in MBSFN mode.The comparison is broadly that of High-Tower-High-Power (HTHP) and Low-Power-Low-Tower (LTLP) network topologies.
In the first part of their article they use the findings of these studies to evaluate the spectral consumption of these approaches for different reception scenarios and compare them with classical broadcast approaches using DVB-T2. The second part of their article looks into the implementation and running costs of the different transmission systems and network topologies involved and uses the public broadcaster's TV offering in Germany as a practical example for this cost comparison.
Too costly and not spectrum efficient
The major conclusion of the article is that, at least for today’s cellular network infrastructure, and even with new state-of-the-art mobile technology, it is not reasonable to use cellular networks for the provision of linear TV content over large areas for reasons of cost and of spectrum resource usage.
To achieve a significantly better spectrum usage, for cellular networks with nation- or region-wide coverage, much higher base station densities would be needed; such base station densities would currently be available only in metropolitan areas. The costs of very dense cellular networks which have significantly lower spectrum consumption are by a factor of 25 to 30 higher than the costs of present broadcast networks.