Proponents of wired home networks say that no wireless networking such as Wi-Fi will ever have the features that are needed for videos, chief among them protection for their copyrighted content and guaranteed quality of service for flicker-free viewing.
Of the three possible wireline media, coax is rated as the best, especially for speed (bandwidth) and interference-free operations. Powerline is considered second with the phone wires are the most limited.
The G.hn triple wire initiative, started by some of the world’s largest telcos with Intel climbing aboard, set higher bandwidth standards for coax than for Powerline or phone wires. The speed target for G.hn is a theoretical 1 Gbps for a “clean” line. The real bandwidth is likely to be upwards of 500 Mbps for coax and in the neighborhood of 250 Mbps for Powerline. Both of those are higher than the 100 Mbps to 200 Mbps speeds of existing home networking technologies.
The goal of G.hn is to develop one chip that can be used in devices that’ll network over any of the home’s wires. Service providers want to reduce the time and cost of installations.
The specifications for G.hn are expected to be completed by year-end.
Many feel that’s an overly optimistic goal and that 2010 is the earliest that G.hn specs could be integrated into the gear that broadband service providers ship. ABI Research is optimistic about G.hn and expects that by 2013 some 42 million G.hn-compliant boxes will ship including set-top boxes, residential gateways and other consumer premises equipment (CPE) hardware.
HomeGrid, the Intel-backed G.hn public facing alliance, includes in its members a number of chipmakers for existing wireline technologies such as Coppergate. It’s no surprise then that HomeGrid is pushing the ITU (International Telecommunications Union) to provide backward compatibility with existing Powerline communications home networking standards such as the market leading HomePlug Powerline Alliance, the HD-PLC Alliance and the Universal Powerline Association (UPA).
HomeGrid also wants compatibility with the coax-based MoCA (Multimedia over Coax Alliance), and the coax- and phone line-capable HPNA (HomePNA). MoCA is the most widely deployed wireline network because Verizon has standardized on it for its FiOS broadband and pay-TV. AT&T is using HPNA networking for its Uverse broadband and pay-TV service.
The driving force for more bandwidth in home networks is the world’s telcos drive to sell pay-TV in competition with the cable and satellite TV services – mostly the cable TV operators, which are taking away their traditional telephone and broadband customers. Comcast alone added 639,000 new phone subscribers in the first quarter of 2008.
The goal of the ITU group that’s developing the G.hn specification is that G.hn will work at a target rate of 1 Gbps over any of the home’s three wires. Actual throughput will be dependent on the wire. The goal is 400 Mbps for 99% of coaxial connections and 250 Mbps in 98% of Powerline connections.
Because they work over wires that were intended for data transmission, HPNA and MoCA are considered clean-line technologies. The home, however, has many fewer coax and telephone jacks than AC outlets. Estimates are that the average American residence has 43 AC outlets. The number of coax and phone jacks is much fewer in Europe and Asia than in the US.
What makes G.hn attractive to digital service providers (DSPs), telcos and cablecos, is that one device, a router, set-top box or network outlet can be plugged into any coax connector or AC outlet or telephone jack and work with all the other devices that have G.hn in the same house.
DSPs see the triple play of G.hn reducing their installation time and costs by making possible more “ship and plug and play situations,” fewer “truck rolls” in industry parlance.
There are now five different network “standards” for wireline home networks:
– MoCA for coax
– HomePlug (HPNA) for coax and phone wires
And three incompatible “standards for electrical wires:
– HomePlug
– UPA
– HD-PLC
None of the five are compatible. In fact, the three Powerline network schemes are not even compatible with each other.
Oddly, it’s two of the Powerline network standards that are available at retail – HomePlug and UPA. Gear with MoCA or HomePNA are not available at retail although D-Link has promised a consumer version of MoCA compatible gear this fall.
There are four different versions of Wi-Fi on the market – “g,” “b,” “a” and “n,” the newest. Wi-Fi partisans have made sure that each new version is backwards compatible with prior versions, eliminating consumer confusion.