DOCSIS (Data Over Cable Service Interface Specification)

DOCSIS is the physical layer and format protocols for cable modems in the USA and seems likely to be adopted in many countries helped, it must be said, by Microsoft's investment in cable companies in many territories. Unfortunately the DVB have their own standard just coming to fruition and it seems likely that both standards will be rolled out over the next few years. The American standard was, in fact, submitted to the DVB for consideration earlier this year but the Technical Module was by then well advanced with its own, so DOCSIS did not find favour. So resolution of the problem passed upward to ETSI and the ITU. But really it was too late to look for a single standard with cable companies already implementing digital cable. Now higher authorities have a problem with schizophrenia. On the one hand, they, of course, want to see a single standard in place to benefit the industry and the consumer. On the other hand, they are all for competition and would seriously undermine their credibility if they took a partisan approach. So it is strongly rumoured that the ITU will adopt a standard which refers to physical and low level transport protocols layers as alternative appendices. It then will come back to the DVB to accommodate DOCSIS modems within the DVB framework. Microsoft's bottomless piggybank is, of course, tipping the balance a tad, and the UK cable companies will go with MCNS / DOCSIS. But DVB modems are strongly supported elsewhere in Europe and there are likely to be half a million of them in circulation by the end of 1999. It only goes to prove the importance of getting technical standards in place ahead of the commercial need.