Unfortunately, HAN Fan has been told that the powerline part of the spec has been gutted of anything new, resulting in a me too technology--three years after HomePlug was standardized and chips available.
G.hn is talked of as a Gigabit technology. This was never the case on powerline. And the last minute gutting finalized it. So what was removed and what are the implications?
Most high-speed powerline communications technology on the market today use frequency band between 2-30Mhz. G.hn's "innovation" was to add widen the band and add additional bands.
- G.hn removed their 100-200Mhz band as nobody seemed to believe in it (i.e. nobody worked on finishing it)
- G.hn reduced their 2-100Mhz band to 2-80Mhz due to ITU-R complaining about interference to license radio users above 80Mhz.
- G.hn has one mandatory band of 2-50Mhz. This is identical to the IEEE 1901 second band.
Both the 2-50Mhz and 2-80Mhz bands are problematical due to EMI regulations--you have 30dB less power after 30Mhz. This step makes the analog front ends complex and expensive. Also you don't get much more performance due to the reduced power. This is why IEEE 1901 (aka HomePlug AV) made using above 30Mhz optional.
Bottom line. The United Nations now has an new powerline communications recommendation which will not have much, if any, performance gain, likely cost more, and is trying to compete with an already dominate standard, HomePlug AV with multiple chip vendors.
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30 dB power reduction causing AFE to be complex and expensive is bull crap. There are already products/ announced products that will go beyond 30 MhZ.
ReplyDeleteSmart silicon mfrs can design the chipsets to work on any frequency range and any power limits. However if silicon mfr is dumb to not handle the above 30 Mhz range, they should not be in the business of making chipsets