Israeli telco Bezeq said this week it will work with chip firm Sckipio, testing its latest G.fast chipset the SCK 23000 in 1 Gbps configurations. Sckipio said that its 23000 chipset can support speeds up to 2Gbps over short distances.This is a bit of a step up for Bezeq, which so far has 1.59 million broadband lines, out of the 2.1 million homes where it has a phone line installed. Those lines have yet to have vectoring switched on, even with VDSL and the fastest service it markets today is 100 Mbps, and its average broadband speed is 47 Mbps.
Bezeq has previously had a strategy of pushing for fiber to the home, and already has fiber at the curb with the last mile (quite a bit less than a mile) carried on copper. Precisely a year ago it agreed to take Adtran G.fast first generation devices to lift its performance to 300 Mbps. This suggests that the Bezeq loop was around 300 meters long at its longest.
So this announcement is a substantial upgrade, which means that a full 1 Gbps service can be announced, and this may still be using Adtran equipment, but usually Adtran is agnostic as far as the chip is concerned and usually uses both Sckipio and Broadcom chips.
Bezeq has clearly been looking for a way to avoid drilling into Israeli buildings some of which are made of concrete, driving up the price of fiber to the home installations.
The Sckipio release talks about fiber now going to within 100 meters of Bezeq served homes, but this doesn’t ring true to us, as if that was the case, then first generation G.fast chips would have delivered a lot more than 300 Mbps.
One clue in the press release is the fact that the operator is planning to work with Sckipio on its cross-DPU vectoring. We have been told in the past by Sckipio that each group of 24 lines has its own vectoring, but that 4 of these can be configured to talk to one another if more lines, (up to 96) are in one bundle and all need crosstalk cancellation.
Sckipio was first in the market to come out with first generation of G.fast chips and Broadcom beat it to a second generation chip and only one other Chinese supplier Metanoia is known to have a G.fast chip at all.
Sckipio then came out with this distributed vectoring system, which it says can only be reverse powered up to 24 lines. Which is why it has distributed its crosstalk cancellation in groups of 24 lines.
The other feature Sckipio added is bonding for the new chips so that it can deliver up to a 3 Gbps PHY rate over two twisted pair lines.
Sckipio is widely rumored to have all or part of the defining AT&T contract, which is known to be connecting its fiber directly to the coax which DirecTV customers in MDUs use to take DirecTV – usually known as the coax connecting the channel stacking switch. This means it has to get its fiber backhaul up the side of buildings to the roof above apartments, and not to the basement.
Recently the Broadband Forum did device certification on products from Adtran, Exfo and Viavi, to go with Arris, Calix, Huawei, Metanoia, Nokia and Technicolor, who had already passed certification. The chips are all from either Broadcom, Metanoia or Sckipio.
The other feature that Sckipio has been tantalizing telcos with has been cDTA. The key to cDTA is two-fold. First, it uses the fact that G.fast uses Time Division instead of Frequency Division, to allow a different ratio of upstream to downstream. Because this is dynamically switchable, it can be allocated on the fly using policy algorithms to adapt to changing combinations of upstream and downstream traffic.
This can mean that operators can reach longer distances for G.fast by allocating more or all of the capacity at any point in time, in one direction to pass a service level test.