By Rich Nesin, General Manager and Resident Philosopher, HomePNA
Have you noticed the press coverage that high performance home networking over existing wires is getting? It makes me nostalgic for the days when analysts dismissed us with a quick ‘the world is going wireless”. It probably is, but installations in millions of IPTV homes over the last couple years say that it isn’t always the best solution. Last week’s ITU announcement about completing the first G.hn standard seems to have gotten the most coverage yet (possibly due to how extraordinarily rare it is for a standards group to deliver a standard on time). So you may be wondering what actually happened and how?
If you have been following my ramblings about home networking standardization in the IEEE P1901; and ITU Q4/15 you may already have a good idea of what happened. If you’re not familiar with the ITU, standards can only be approved during special ITU “plenary” meetings. A plenary is a formal two week meeting of the entire SG 15 (not just the Q4/15 group that is part of SG 15 or the even smaller G.hn group that is part of Q4/15 and has been meeting every couple weeks for the last year to get the work done on time). Like the other meetings, the plenary was very technical with lots of informal working meetings during the evenings to refine the contributions and achieve consensus on the contributions (or in the words of one engineer, “lots of real work was done”). This is the “how”. This and a lot of hands-on direction from some of the world’s largest telcos. Being the customer has its advantages and these customers see the advantages of a single open world-wide existing-wire home networking standard.
So what happened? I wrote a little about MACs and PHYs back in a June post about HomePNA's guaranteed QoS. Like most other home networking technologies, G.hn is built of two components; a MAC and a PHY. The MAC part, short for medium access control, manages the communication between devices on the home network. The PHY part, short for physical interface, encodes and decodes the data from the MAC – encoding it so that it can be carried efficiently over the media (which in the case of G.hn can be powerlines, phone wires or coax) and decoding the data that is received from the media so it can be processed by the MAC. Every product featuring a G.hn interface will have a MAC and PHY. So what is G.hn’s new G.9960 standard? It’s the new G.hn PHY. The companion G.hn MAC spec is scheduled to be completed in September.
More soon …