icting market interests. 15.18 LTE TV This brings us to LTE TV. As documented earlier in this chapter, considerable time, money and effort has been spent on mobile TV standardisation and network and handset development with to date no commen- surate fiscal return. It has been difficult to realise a return on investment partly due to competing standards, (DVB H, Media FLO, ISDBT, DMB DAB and MBMS, mobile broadcast and multicast service) and partly due to network and handset development limitations and performance constraints compounded by regional and national differences in mobile-TV frequency-band allocation and incompatible standards. Although mobile TV has been successful in some markets, for example Japan, it has failed to achieve global scale and in most markets there has been a marked reluctance by consumers to pay for mobile TV content. The longer-term economics and effectiveness of hybrid satellite and cellular networks such as DVB SH in Europe or ATC (ancillary terrestrial component) hybrid satellite and terrestrial networks in the US also remain unproven, a topic addressed in the following chapter. This might lead one to question the merit of introducing yet another mobile TV standard to service a global market that is presently nonexistent. However, the inclusion of multicast broadcast single-frequency networks, MBSFN, as a work item in present and future LTE releases suggests that there is still a measure of vendor and operator confidence that mobile TV remains a worthwhile investment opportunity. Remarkably, it may be and MBSFN could be used to realise additional revenue and im- prove returns on existing spectral and network investment both for the cellular and broadcast community. 15.18.1 The Difference Between Standard LTE and MBSFN - The Technical Detail MBSFN is based on 7.5-kHz subcarrier spacing rather than the 15-kHz used in standard LTE. This doubles the symbol length from 66.7 microseconds to 133.4 microseconds and allows the cyclic prefix to be increased from 4.69 microseconds to 33.33 micr