Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Pages: [1] 2

Author Topic: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE  (Read 3332 times)

Bowdon

  • Content Team
  • Kitizen
  • *
  • Posts: 2395

https://www.ispreview.co.uk/index.php/2018/04/openreach-to-test-sra-on-uk-fttc-superfast-broadband-lines-again.html

Quote
Openreach (BT) has announced that they intend to conduct a new Proof of Concept (PoC) to test the impact of applying Seamless Rate Adaption (SRA) to their 40-80Mbps capable VDSL2 based Fibre-to-the-Cabinet (FTTC) broadband lines, which could help to keep such lines stable.

At this point anybody familiar with SRA will possibly raise a wry smile, after all it’s not the first time that Openreach have tried to adopt it and indeed it’s already been implemented on their new hybrid-fibre G.fast service. The operator also tried to adopt it as part of their Long Reach VDSL (LR-VDSL) trial but that has now been shelved.

Prior to that the last time that we saw SRA being attempted on Openreach’s hybrid fibre VDSL2 tech was as part of their Vectoring trials between 2014 and 2015 (vectoring is designed to remove crosstalk interference and thus improve performance), which ran into a fair few development challenges and only ever resulted in a highly targeted deployment of Vectoring (the SRA component of that trial was not a big problem).

Quote
UPDATE 5:19pm

We understand from ISPs that the trial will take place on just 200 lines via Huawei cabinets, which will start around mid-May and run until the end of June 2018. Apparently the trial will mostly involve Openreach’s own employees and their Network Operations Centre will then apply SRA line by line (Dynamic Line Management (DLM) will also be disabled).

Assuming all goes well then the prospect exists for a larger trial of around 100,000 lines, which could begin around September and run until the end of this year.

I had to post this here as I couldn't find the original news story.
Logged
BT Full Fibre 500 - Smart Hub 2

Ronski

  • Helpful
  • Kitizen
  • *
  • Posts: 4300
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #1 on: April 16, 2018, 06:19:06 PM »

I notice it says Huawei cabinets, no surprise there. Can ECI actually support SRA?
Logged
Formerly restrained by ECI and ali,  now surfing along at 390/36  ;D

ktz392837

  • Reg Member
  • ***
  • Posts: 559
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #2 on: April 16, 2018, 09:41:36 PM »

If the ECI do not support SRA they need to rip them all out and put in Huawei.

What an absolute kick in the teeth that yet again the ECI cabs are ignored. 

How about testing/trialing on ECI first?  Especially as ECI can't get Ginp, vectoring or 3db or anything else?

They really are utter sh*t and should be returned to ECI for a full refund and appropriate compensation.

FFS instead of Gfast replace the ECI cabinets with Huawei with everything turned on.   It will be cheaper, and give more benefit to a greater number of people. 

Oh I forgot they can charge twice as much for Gfast and hopefully force users on ECI to upgrade as they as so cr*p compared to Huawei.

Rant over.
« Last Edit: April 16, 2018, 09:47:29 PM by ktz392837 »
Logged

Ixel

  • Kitizen
  • ****
  • Posts: 1282
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #3 on: April 16, 2018, 11:11:01 PM »

I guess we know where the 'continued effort on resolving the G.INP issues with ECI' is currently going, to this new trial for Huawei only.
Logged

kitz

  • Administrator
  • Senior Kitizen
  • *
  • Posts: 33879
  • Trinity: Most guys do.
    • http://www.kitz.co.uk
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #4 on: April 17, 2018, 01:31:34 AM »

I saw that this morning on the Openreach site.   I didn't know it was just Huaweis though. :(

pffffft the divide just gets bigger.  :'(
I don't see any way out of this for those on ECI cabs.  G.fast wont do anything for me and any others who are too far from the cab to benefit.
Logged
Please do not PM me with queries for broadband help as I may not be able to respond.
-----
How to get your router line stats :: ADSL Exchange Checker

kitz

  • Administrator
  • Senior Kitizen
  • *
  • Posts: 33879
  • Trinity: Most guys do.
    • http://www.kitz.co.uk
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #5 on: April 17, 2018, 01:35:23 AM »

They really are utter sh*t and should be returned to ECI for a full refund and appropriate compensation.

As an aside do people realise that ECI and the V41 goes down in history as the first ever system based vectoring DSLAM in the world -linky

Although the theory of vectoring had been around for a while, it was all done on the linecard, which wasn't always popular because of the in-efficiency of wastage of ports.
From what I can gather the V41 didn't become commercially available until either very late 2011/early 2012. 


So when BT/Openreach sat down in ~2010 and started designing their network there was no such thing as vectored DSLAMs.   By the time the V41's came out then Openreach would have already had on order several hundred M41s.

Although I have mentioned this in the past about how close timescales were with the new V41's, I more recently forgot about problems of lead in time until reading an NBN article about broadband trends in Australia and the difficulties of planning a network during a time of emerging new technologies.   NBN started planning in 2010 for initial rolloug of 2012-2014 (just slightly later than Openreach).  Those difficulties are :-
1) Time to Market
2) Quote "at the time of the initial planning for NBN – technologies such as DOCSIS 3.1, VDSL2 Vectoring and G.fast did not exist" 


So here we are in 2018 saying why didn't Openreach buy V-41's when placing their orders in 2011.   Perhaps they may have done if there was such a thing as system level vectoring and V-41's actually available when they started designing their network.  It explains why Deutsch Telekom and France also rolled out FTTC with M-41's.  I guess you can't plan and order something which isn't yet available.  :'(
Logged
Please do not PM me with queries for broadband help as I may not be able to respond.
-----
How to get your router line stats :: ADSL Exchange Checker

re0

  • Reg Member
  • ***
  • Posts: 840
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #6 on: April 17, 2018, 05:55:30 AM »

It will be intersting to see the results of this trial, who will benefit from it most and whether it will actually make it out of the trial and into a nationwide rollout. I imagine it could benefit almost everyone, but especially those that see huge variations in background conditions. Though it is certainly a shame that there is not much hope for people on ECI kit.

SRA has been virtually absent in xDSL products rolled out by BT/Openreach (except for some trials which have existed in more recent years), though some LLU providers back on ADSL2+ did activate SRA on their services. If I recall correctly ADSL24 LLU had SRA, along with some pointers that would imply that O2/Be trialled the capabilities on their own LLU hardware. Back during the rollout of BT's 21CN WBC services to exchanges, it seems that BT chose not to implement SRA as they confirmed so during the later stage of the rollout in 2011 (https://www.ispreview.co.uk/story/2011/09/22/bt-not-implementing-adsl2-broadband-seamless-rate-adaptation-technology.html). So this could be the firist emergence of SRA on Openreach's network with availability to all ISPs on the platform if the trial is successful.
Logged
ISP: Gigaclear - Hyperfast 900 (up to 940 Mbps symmetrical)

andyfitter

  • Reg Member
  • ***
  • Posts: 172
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #7 on: April 17, 2018, 08:02:29 AM »

Would SRA significantly affect the need for DLM and all of its complexities/foibles? Your line gets worse... SRA drops the speed. Your line gets better and SRA increases it again? No more capping/banding?
Logged

re0

  • Reg Member
  • ***
  • Posts: 840
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #8 on: April 17, 2018, 08:17:33 AM »

Would SRA significantly affect the need for DLM and all of its complexities/foibles? Your line gets worse... SRA drops the speed. Your line gets better and SRA increases it again? No more capping/banding?

According to the information in the main article linked in this topic, G.fast has SRA. However, according to https://www.btplc.com/SINet/sins/pdf/STIN520v2p0.pdf it still also uses DLM. I cannot say this will be representive of whether it will impact the need for it in VDSL (FTTC) connections. But I would imagine that there will always be an underlying DLM that caps those extremely problematic lines, and paremeters such as the SNRM and retransmission will continue to be adjusted as per the line's performance since SRA can be a good combat against slowly changing line conditions (steady increase of errors, more intererence) but immediate changes may probably still cause drops.
Logged
ISP: Gigaclear - Hyperfast 900 (up to 940 Mbps symmetrical)

Ixel

  • Kitizen
  • ****
  • Posts: 1282
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #9 on: April 17, 2018, 11:18:22 AM »

I suspect that the reason DLM has been turned off for the lines on the trial (if I read it correctly) is because DLM might see fluctuating sync rates as a sign of instability and therefore band a line (like my first line is currently banded). It's possible that if SRA was rolled out that banding may no longer be used for such a situation, but remain for issues such as rapid re-syncs.
Logged

PhilipD

  • Reg Member
  • ***
  • Posts: 591
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #10 on: April 17, 2018, 11:38:12 AM »

Hi

Here we go again, another trial of a technology that Openreach should have deployed and tested with at the very start, seamless rate adaption (SRA) raises it's head again this time on VDSL.  :lol:  A small trial involving staff to start with, news posted at ISPreview.

No surprise this looks like a Huawei only trial, likely never to come to an ECI cabinet.

Regards

Phil

Logged

re0

  • Reg Member
  • ***
  • Posts: 840
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #11 on: April 17, 2018, 11:44:43 AM »

There's already a topic for it in "News Articles" at http://forum.kitz.co.uk/index.php/topic,21373.0.html.

Though I do truly feel sorry for those on ECI cabinets.  :lol:
Logged
ISP: Gigaclear - Hyperfast 900 (up to 940 Mbps symmetrical)

PhilipD

  • Reg Member
  • ***
  • Posts: 591
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #12 on: April 17, 2018, 12:57:47 PM »

Hi

I had SRA for short time whilst on a LLU ADSL line.

I did work, with the sync speed fluctuating quite often without a full resync and the SNR staying pretty constant, however it didn't make the line any more stable overall or more more immune from resyncs.  I guess the problem with some lines is there are times where there is more noise than a 6db margin can cope with, so it makes no difference if SRA is keeping that margin constant or not, it's going to get knocked out regardless.  It was more annoying really as sync speed would drop at night, so it was trading a fluctuating SNR margin for a fluctuating sync speed, but providing no more immunity to resyncs, i.e, not providing a benefit.

G.Fast is suppose to sync back up very quickly, so SRA may be even less of a benefit.

BeThere did trial it on ADSL2+ and found nothing but problems, it never went live. 

The trouble with introducing things like SRA, G.INP and vectoring after the fact, is that the horse has bolted, by that I mean there is a very broad range of modems out there, all of which have been sold not requiring to support whatever UK/Openreach flavour of these technologies they trial, so it's almost impossible to introduce changes without breaking far more than it fixes.

Regards

Phil









Logged

Bowdon

  • Content Team
  • Kitizen
  • *
  • Posts: 2395
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #13 on: April 17, 2018, 01:10:47 PM »

I think the only way out for us on ECI cabinets is hoping that OR start pushing G.fast pods on poles and manholes etc. That would solve the inequality of service we're getting as we would be all on the same pods, and if they were pushed closer to our houses we would get a genuine speed boost and be just like everyone else.

I wish OR would comment about the state of ECI cabinets.

I noticed in my area all except 1 are ECI cabinets and they became available in April, May, July, August and October in 2012.
Logged
BT Full Fibre 500 - Smart Hub 2

re0

  • Reg Member
  • ***
  • Posts: 840
Re: Openreach Trial SRA On UK FTTC Superfast Broadband Lines Again UPDATE
« Reply #14 on: April 17, 2018, 01:42:48 PM »

I guess the problem with some lines is there are times where there is more noise than a 6db margin can cope with, so it makes no difference if SRA is keeping that margin constant or not, it's going to get knocked out regardless.
That's why the DLM will almost certainly remain on VDSL (FTTC) since SRA is probably not going to suffice alone in cases where the line is unable to sustain after a sudden onset of interference that causes it to drop. After the trial, I would imagine that the DLM would be set the SNR as a "target" and that SRA would just work to get the SNR as low as that target if permitted depending on error ratess. But I could be completely wrong. I only speculate at this point.

G.Fast is suppose to sync back up very quickly, so SRA may be even less of a benefit.
Indeed. Apparently only a few seconds compared to the couple of minutes required for VDSL.

The trouble with introducing things like SRA, G.INP and vectoring after the fact, is that the horse has bolted, by that I mean there is a very broad range of modems out there, all of which have been sold not requiring to support whatever UK/Openreach flavour of these technologies they trial, so it's almost impossible to introduce changes without breaking far more than it fixes.
Very true. I remember the issues that were present with the good ol' BT Home Hub 5A/Plusnet Hub One and G.INP on the upstream. Of course, quite a lot of us know about this ... and these were modem-router combos handed out by some of the largest ISPs (or at least combined, as both are under the BT group)!

I noticed in my area all except 1 are ECI cabinets and they became available in April, May, July, August and October in 2012.
I am guessing that the ECI cabinets were probably part of the commercial rollout? And the one that is not was either part of the BDUK scheme or was put in place some time after the others to boost capacity?
Logged
ISP: Gigaclear - Hyperfast 900 (up to 940 Mbps symmetrical)
Pages: [1] 2