http://www.ericsson.com/res/thecompany/docs/journal_conference_papers/wireless_access/p22-huschke.pdf This article from 2011 was written for the IEEE symposium on dynamic spectrum access nets. I may have discussed it previously, but not in this same context. Here is its premise: ------------------------------- As it stands, it is expected that the mobile phone will be used to access a significant amount of video content from the Internet. As a part of this convergence, it is therefore reasonable to expect that every personal device with capabilities equivalent to and exceeding a modern smartphone will be able to provide access to TV in addition to its capability to access Internet video. Furthermore, the user experience will be greatly improved with the provision of a return channel to the network, allowing operators and broadcasters to benefit from knowledge of user behaviour, and for advertisers to gain direct access to viewers. Lastly, it is desirable that the signal format that is received by a mobile device be compatible with the signal format used predominantly for broadband access. These reasons make LTE especially suitable for a broadcast service, beyond what has been possible with other attempts in the space such as ATSC-M/H, DVB-H or Media-FLO, which are the currently available alternatives capable of offering access to mobile TV. A further benefit is that LTE network infrastructures are currently being rolled out by several mobile network operators. A reuse of deployed infrastructure can be envisioned which enables a cost-effective transition into a novel TV broadcast network deployment. ------------------------------- We can go around and around on this, but the salient points (IMO) are: 1. "Furthermore, the user experience will be greatly improved with the provision of a return channel to the network, allowing operators and broadcasters to benefit from knowledge of user behaviour, and for advertisers to gain direct access to viewers." This sentence implies the LTE infrastructure is two-way. I know one could weasel this into saying, "But the 'return channel' could be on another LTE network from the one used by TV broadcasters," but that just weaseling. The same could be said for using any other broadcast standard for the TV itself. For example, an ATSC/MH, DVB-H, or MediaFLO device, can *also* be provided with cellular service, to create narrowband two-way channels back to the broadcaster, to taddle on user behavior. 2. "A further benefit is that LTE network infrastructures are currently being rolled out by several mobile network operators. A reuse of deployed infrastructure can be envisioned which enables a cost-effective transition into a novel TV broadcast network deployment." Aha. Sure, as long as the LTE network is being run by the cell operator and not the US-style "TV broadcasters." Remember that the European definition of "TV broadcaster" is MUCH more comparable to what in the US is called "TV network." Like NBC, CBS, etc. Not your local ABC affiliate, in other words. 3. With #2 firmly in mind, i.e. that what they really mean is how much spectrum a cell operator would set aside for TV broadcast, "Our simulations show that MBMS has a spectral efficiency of 3.1b/s/Hz up to a cellular inter-site-distance of 2km. With this, 85MHz of spectrum are sufficient to provide the desired aggregate service rate. Comparing this to the in total 300MHz used by TV services, the potential savings in spectrum are significant." Leaving aside the overt attempt at hyperbole, TV in the not-so-tiny DC market has 12 multiplexes, or 72 MHz of spectrum. (And 3.3 b/s/Hz without having to rely on 2 Km spacing of towers.) Let's not get back into why US-style broadcast stations want plenty of overlap into adjacent markets, in closely spaced markets. 4. More importantly, concerning WHO is going to provide that 85 MHz channel, their reasoning is: "The cellular inter-site-distances we have considered are typically achieved by one cellular network alone. In principle it is possible that several cellular networks that are present in the same market provide MBMS services jointly, at least in geographical areas where cellular sites are sparsely deployed, in order to further enhance the service availability in these areas." So, one broadcaster, for a market the size of DC or even NYC. Possibly a second LTE network, but only if the AREA covered by the first doesn't span the entire market. Now you might say, what about local news crews? Sure, whatever that one broadcaster thinks he needs to keep. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.