Re: [802.3_NGEPON] 802.3ca (100G-EPON) bi-weekly consensus

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Jorge wrote: > The answer is not going to be to deploy more 25 Gbps wavelengths and equipment whereby any one ONU can only peak at 25 Gbps. This is what you get with tunable optics in NG-PON2, for example.

Let’s keep in mind that ITU SG-15 has begun investigation of both 25 Gbps per channel in NG-PON2 as well as ‘Bonding’ of several NG-PON2 channels to create aggregates of 50, or 100 Gbps. Since NG-PON2 already allows for up to 8 channels, it is not hard to imagine that a bonding of 8 channels could allow for a MAC rate of 200 Gbps and a ‘billboard’ speed of 100 Gbps to use the same terminology as you are.

However, it would be true that an ONU having 8 tunable Tx and 8 Tunable Rx would cost significantly more than an ONU with a single Tunable Tx and a Single Tunable Rx and a 25 Gbps MAC rate. Insofar as whether the costs of an ONU with a single Tunable Tx and a single Tunable Rx would be more expensive than the costs of an ONU with four fixed Tx, four fixed Rx, and muxes on the Tx as well as Demuxes on the Rx, this remains to be validated. I would argue that the current market pressure to achieve a low cost single channel Tunable Tx / Tunable Rx will certainly have an impact on the decision made to accept or reject tunability outright in NG-EPON. I would just caution that it would be too early and imprudent to make such a decision before having all facts at hand.

> When we add a second wavelength and corresponding equipment we can have an aggregate network capacity of 50 Gbps, and thus be able to support a flagship speed tier of 15 Gbps (~1/3 of 50 Gbps) and a billboard speed tier of 25 Gbps (~1/2 of 50 Gbps. Similarly, when we add a 3rd and 4th wavelengths and corresponding equipment we can have an aggregate network capacity of 100 Gbps, and thus be able to support a flagship speed tier of 30 Gbps and a billboard speed tier of 50 Gbps.

I understand the marketing pressure of being obligated to demonstrate temporary peak throughput for a single user rather than sustained throughput for all users. This is the same reason that you can’t be effective when selling 1 Gbps FTTH service unless the ONU has 802.11 AC Wifi inside and the customer has an 802.11 AC WiFi on his computer. Users call in and say ‘Why can’t I see 1000 Gbps on my Speed Test’. To this end, providing Gigabit services on GPON, even with a low split ratio of 1:16, is certainly good marketing. All I know is when I did it once myself in my past life as an operator, with a GPON system, I could not convince myself to put more than 12 business customers behind a single power splitter when I had to sign SLA’s for 100 Mbps business services.

This mean that even an eventual NG-PON2++ system with 8 channels of 25 Gbps, supporting 200 Gbps of aggregated throughput for all users on a PON, could never be advertised as a service faster than 25 Gbps for an end-user unless its NG-PON2 ONU would include more than 1 Tunable-Tx/Tunable Rx channel pair. However, it is definite that the average sustained quality of service for all users on the PON would be greater with a single Tunable Tx / Tunable Rx @ 25 Gbps which can roam across 8 channels than for 32 users sharing a 50 Gbps ‘NG-EPON Gen 2’ pool of bandwidth.

There must be use cases, and with business services & mobile fronthaul on the same PON being certainly good examples, where an ‘average sustained throughput for all users’ must become more important than ‘temporary peak throughput’ for a single user. I fear that NG-EPON without support for Tunable Tx / Tunable Rx would only become a ‘Residential’ service standard.

Furthermore, I think there should be hooks in NG-EPON for support for more than 4 channels, as there is already support for 8 wavelength pairs in NG-PON2. Perhaps it would be two instances of NG-EPON on the same PON, a first one on a first set of four wavelength pairs, and a second one a second instance of four wavelength pairs.

I remain very much convinced that for as long as the tuning range is kept below 10 nm, there will be no significant cost disparity between tunable and fixed systems.

From: Liudekun <liudekun@xxxxxxxxxx>
Reply-To: Liudekun <liudekun@xxxxxxxxxx>
Date: Wednesday, February 17, 2016 at 4:20 AM
To: STDS-802-3-NGEPON <STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx>
Subject: Re: [802.3_NGEPON] 802.3ca (100G-EPON) bi-weekly consensus - call for agenda items

Hi Glen and All:

I quite agree with Glen that “If 100G-EPON technology fails, It will be because of high cost”.

Let’s consider that why we choose the PON as the final access technology in the past. It’s due to that it’s a point to multi-point system,   32/64/128 users can share one fiber , one OLT, that’s the reason PON is a low cost system.

When we consider 1G EPON, its’ 32/64/128 users sharing 1G bandwidth ,not a dedicating 1G bandwidth. So it’s same for 100G EPON. 100G EPON should be 32/64/128 users sharing 100G bandwidth. But the absolute majority 100G ONUs don’t need to support 100G peak rate.

That’s the difference between a single wavelength TDM system and a multiple wavelength system. For a single wavelength TDM system, the peak rate of ONUs is always equal to the total system capacity .   But for a multiple wavelength system, the peak rate of the ONUs is not necessary equal to the total system ! (The peak rate of a 100G EPON ONU can be only 25Gb/s)

The cost of ONUs are the majority cost of the total PON system,   if we want to make a real low cost 100G EPON system, from me, we should focus on how multiple ONUs with 25Gb/s peak rate to achieve a 100G EPON system.

By the way, I don’t mean I exclude the 100Gb/s peak rate ONUs, it can be applied for some very high-end users,    but a 100G EPON ONU with only 25Gb/s peak rate should be able to satisfy the major scenario in 100G EPON   , from the cost effective consideration .

For page 7, I didn’t understand very well about what “100G ONU” really means, if all the 100G ONUs means a 100Gb/s peak rate ONU in the slides(as they are shown in the figure), I need to differ with this.

Best regards

Dekun Liu

____________________________________________________

Advanced Access Technologies Dept. 网络研究接入技术部

Huawei Technologies Co., Ltd. 华为技术有限公司
Phone: +86 027-59267217 Email: liudekun@xxxxxxxxxx

From: Glen Kramer [mailto:glen.kramer@xxxxxxxxxxxx]
Sent: Wednesday, February 17, 2016 3:05 AM
To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_NGEPON] 802.3ca (100G-EPON) bi-weekly consensus - call for agenda items

Curtis,

I'd like to discuss the general architecture approach. We had a number of presentations in Dallas leading towards this approach, but since the Dallas meeting was per-TF, we didn't make any formal decisions. In Atlanta, we started looking into various low-level details, but the big picture is left undefined. My slides are attached. All feedback is welcome.

Thanks,

Glen

On Mon, Feb 15, 2016 at 10:49 AM, Curtis Knittle <C.Knittle@xxxxxxxxxxxxx> wrote:

Dear Colleagues,

This coming Thursday, February 18, 11:30-1:00 Mountain Time, we will hold an IEEE 802.3ca 100G-EPON consensus building meeting. Please let me know by Wednesday noon (Mountain Time) whether you have requests for agenda time.

If I do not receive agenda requests by noon Wednesday, I will cancel the meeting.

Thank you!

Curtis

Curtis Knittle

VP Wired Technologies – R&D

CableLabs

desk: +1-303-661-3851

mobile: +1-303-589-6869

c.knittle@xxxxxxxxxxxxx

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Broadband Technology Group

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