Japan Cablenet Swims Upstream

2:45 PM -- The speed craze in Japan has prompted what looks to be the first announced deployment of Docsis-based upstream channel bonding.

Japan Cablenet Ltd., the second largest MSO there, will bond both upstream and downstream channels when it debuts a new tier called "Speed Star 160" later this month.

The MSO, which operates 17 systems in the Tokyo metro region, did not disclose pricing or speeds, but the name of the product implies that at least the downstream will bond four 6 MHz channels and provide a shared pipe of 160 Mbit/s. If Cablenet does the same in the upstream, bursts could reach 120 Mbit/s.

Fellow MSO Jupiter Telecommunications Co. Ltd. (J:COM) has a 160 Mbit/s (downstream) Docsis 3.0 service deployed across the board, but has not yet indicated plans to introduce upstream channel bonding. (See J:COM Does Docsis 3.0 All Over.)

Cablenet is fueling the new service with Arris Group Inc. (Nasdaq: ARRS)'s C4 cable modem termination system (CMTS) and WBM760C wideband modems. (See Cablenet Bonds With the Docsis Upstream.)

Cablenet's deployment of upstream channel bonding indicates that Arris may soon try to obtain Silver or Full Docsis 3.0 qualification at CableLabs . Arris's flagship CMTS has obtained only Bronze qualification, a tiered level that supports downstream channel bonding and IPv6, but does not include upstream channel bonding. (See CableLabs Accelerates Docsis 3.0 Testing .)

So far, only one CMTS vendor -- Casa Systems Inc. -- has won Silver and/or Full Docsis 3.0 qualification. (See CableLabs Cheers Casa Chassis, Cisco, Arris & Casa Make the CableLabs Grade, and A Decade of Docsis .)

— Jeff Baumgartner, Site Editor, Cable Digital News

Jeff Baumgartner 12/5/2012 | 4:08:27 PM
re: Japan Cablenet Swims Upstream

Yes, I will be interested to know that too....considering they are putting "160" in the product name, it appears that they'll advertise the shared, downstream burst rate of 160 Mbit/s, which is how J:COM advertises its high-end product.-á-áI will be keeping an eye on how they advertise the upstream rate...but I'll be surprised if they tout anything above-á20 Mbit/s.-á -áThen again, they may surprise me.

Michael Harris 12/5/2012 | 4:08:28 PM
re: Japan Cablenet Swims Upstream

Given the big shared bi-directional pipe, it will be interesting to see what downstream and upstream speeds they advertise. In any case, a faster upstream may mean a faster downstream for users given TCP "ack" issues.

Jeff Baumgartner 12/5/2012 | 4:08:29 PM
re: Japan Cablenet Swims Upstream

Hans Plug, the senior director of C4 product line management at Arris, told us that Japan Cablenet is starting off by bonding two upstream channels. However, a new software release will allow the MSO to bond four.

He also says Arris hasn't solidified any plans to submit the C4 for "Silver" or "Full" Docsis 3.0 qualification, but evidently some MSOs want to start deploying the upstream channel bonding feature before that happens.

Plug says Arris is sparking that feature in its already-deployed CMTSs by updating the software on the gear's field-programmable gate arrays (FPGAs).

"It's really a field upgrade," he says, pointing out that some other CMTS vendors that rely on Broadcom will need that vendor's new D3 chipset to incorporate upstream channel bonding.

Of course, all of this won't matter too much if MSOs don't plan to do upstream channel bonding right away. Plug points out that boosting upstream speeds is of big importance for cable MSOs in Asia, but evidently fiber competition in the U.S. and Europe are giving operators there reason to give upstream channel bonding a closer look.

-áSo we'll have to see if Cablenet's decision-áto incorporate upstream channel bonding is a rare exception or indicitive of a wider trend.
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