What is G Fast?

So G Fast is like FTTC but uses a different frequency to 'transmit' over copper from the "pod" to the premises? If you're very close to the pod you can have faster than FTTC broadband. Otherwise I'm not sure what the point is. Are the pods just like mini fibre cabinets so more can be placed nearer to homes? But its just to get faster speeds over copper, not increase the fibre footprint?

Sum up G Fast in a short paragraph!

You've hit the nail on the head with one exception.

The pods can't (easily or cheaply) be put close to homes. They take power and fibre from the existing FTTC cabinet and because they bolt onto the PCP they require no digging or civil works, which makes it a very cheap, and quick solotuipn to provide faster speeds to those within ~350m of the cabinet. With future amendments to the technology this will increase to around 500m.

Last evening at 6pm, a engineer from BNE (Barden Network Engineering) a sub contractor for Carillion was fixing a G Fast pod to my cabinet.

Ah, I thought I had read that G Fast pods could be placed in pavement chambers and therefore be closer to homes. Maybe that was for FTTP? <Goes to search for that article>

Here https://www.thinkbroadband.com/how-broadband-works but I misread or misunderstood the pavement pods are for the future.

The future post 2020 may see smaller G.fast pods being stuck into pavement chambers or on poles, but a lot depends on how popular the faster speeds are.

They can be, but it's considerably more expensive to run fibre to the ~4million DP's that Openreach have.

However by far, powering the nodes is the most difficult/costly part.

Openreach are working on reverse power nodes which basically means each of the customers connected to the nodes each contribute a share of the power to the node over their copper line when using the service.

Openreach has done both the cabinets and pavement pods in its trials, and the costs of getting power and fibre to the pods in pavement chambers close to homes means that for the first 10 million premises the large pods will be placed at the PCP

After that roll-out there may be more roll-out and that would most likely be a mixture of large pods and the waterproof bricks http://blog.thinkbroadband.com/2015/09/g-fast-and-fo... and its first picture is a chamber based G.fast node.

NOTE: These metal cases may be on some poles in Northern Ireland and North Yorkshire already as they've existed for a while buy only delivering VDSL2.

I believe they have also looked at using reverse power - taking a feed from the consumer premises to power the pods. But, I believe it is pretty complex taking power feeds from a number of households and you would need to ensure a single property could power the entire pod just in case only one has a running system at a point in time.

Yes, I mentioned that?

They also looked at powering nodes over copper pairs from the existing power feed the VDSL2 cabinet has, and with multiple pairs could power a 16 line node at up to 1 km. Huntingdon has some using this arrangement.

Yeah, that's called forward powering I believe.

Sorry, somehow missed that part of your post, must have been sleep-reading...

In reply to a post by Woolwich:

So G Fast is like FTTC but uses a different frequency to 'transmit' over copper from the "pod" to the premises? If you're very close to the pod you can have faster than FTTC broadband. Otherwise I'm not sure what the point is. Are the pods just like mini fibre cabinets so more can be placed nearer to homes? But its just to get faster speeds over copper, not increase the fibre footprint?

Sum up G Fast in a short paragraph!

Yet another xDSL-type technology using higher frequencies along with some very clever signal processing to deliver higher speeds, albeit with more distance limitations, over existing copper wires.

In reply to a post by ian72:

I believe they have also looked at using reverse power - taking a feed from the consumer premises to power the pods. But, I believe it is pretty complex taking power feeds from a number of households and you would need to ensure a single property could power the entire pod just in case only one has a running system at a point in time.

Maybe I've misunderstood, but given electricity prices I'm not sure some of us would agree to subsidise our ISP's power requirements.

I read somewhere it was estimated to cost around £50-80 per year, based on 4 houses connected to one DP node.

You're not subsidising their requirements, it would be for yours, as you'd be using the service if you chose to take it out.

You wouldn't be forced to.

Just like you have to pay the electric that is used to power the ADSL/VDSL modem or /fibre ONT in the home now

Edited by MrSaffron (Wed 16-Aug-17 13:29:58)

Then if it becomes available as an option don't sign up for it... Those that want faster speeds when and if this happens may be willing to pay (and if it wasn't done this way then the solution would likely be more expensive so the consumer would just end up paying more for the rental anyway).

Not quite, we don't currently supply electric for the FTTC cabinets, or ADSL hardware in exchanges, but we do have the modem which is in our own property, so it would be an additional cost. If that cost was small I wouldn't be fussed though.

But you do pay for BT getting the power to the cabs and would pay for BT getting the power to the nodes - within your broadband bills. If it was cheaper to run that power back from the consumer and therefore reduced the overall cost then that ought to be a better option. One thing is certain - BT don't pay for the electricity out of the kindness of their hearts.

Was that cost split between four properties, so a max of £20 a year, if so I would be ok with that, but not sure about £80 of electricity. Suppose it would depend on the cost of the service as well.

Per home but I think based on 4. If there were 16 port nodes then I suspect the cost would drop to only a few quid a month.

For £6.50 a month, if it was the difference between 2meg or 200meg, I'm sure most would see it worth it.

Alternatively, Openreach pay for the power, and charge an extra £6.50 a month for the rental. Eithrr way, you pay for the service and everything that goes with it.

You could always get some solar panels with some storage batteties to power your modem and reverse power unit

Edited by deleted (Wed 16-Aug-17 13:54:46)

So if G Fast has a limited range what's it for, who's it aimed at? Do BT think fibre punters like me will upgrade their speed? I'm more interested in the higher upload speed than the download TBH as I have a lot of large files to send to off-site backup.

(I'll look but I bet there's a handy chart with expected G Fast speed based on current FTTC delivery somewhere in Think Broadband?)

So if its just for speed what about all those who still don't have fibre or only have slow fibre connections. There's a street nearby which has just had a fibre cabinet installed on the pavement (not yet live). You'd think sticking a G Fast pod on the cabinet would have been a better idea. Or is it the case that G Fast wouldn't reach all the lines on the PCP as some may be too far away?

G.fast is all about getting to 10 million premises with access to an ultrafast broadband option as soon as possible.

G.fast is NOT about bringing faster broadband to those who have slow speeds now, why? Because people have lobbied for higher speeds and this is the response, a little like why does Virgin Media keep offering higher speeds on its network...

Politically getting the UK to an ultrafast footprint in line or better than other major economies is something politicians want.

Those that don't have fibre or slow fibre now, depends on where you live, and g.fast is paid for by Openreach money alone so they can deploy where they like. For those with no fibre, some inner city areas are due to be covered by the 2 million FTTP premises roll-out, and this may also cover some on cabinets where the g.fast has not reached. Then there are the BDUK projects still delivering and then there is the USO which is under discussion.

Or alternatively as in common in the UK we can all just sit and complain

It is a cheap upgrade for some.

It does not help many at all, but for some it will bring improvement to the current VDSL speed without FTTP work, which OR is currently very reluctant to do as no one is currently interested in funding it. It will allow them to compete with Virgin in many areas.

This will not help those who need a faster uplink it can offer. Nor does it help those who are far away from cabinets or on EO lines. It is just one technology to extend the life of the copper network without excessive investment.

Even if they started digging in fibre to every home now, it would be ten years before completion. Technologies like this will basically help bridging this gap.

In reply to a post by MrSaffron:

Because people have lobbied for higher speeds and this is the response

So those on the very fast end of superfast are getting faster, while those on the slow end of superfast, or ADSL2+, or even slower are getting nowt?

Way to go UK...hide the slower areas' and slow-spots' problems by pushing the national average speeds up for those already on very fast lines.

As MrS says they are looking to get 10 million premises at ultrafast speeds using G.Fast. If that is "not many" then how many do you think they have to support to be worthwhile?

Did you miss this part of MrS's post?

For those with no fibre, some inner city areas are due to be covered by the 2 million FTTP premises roll-out, and this may also cover some on cabinets where the g.fast has not reached. Then there are the BDUK projects still delivering and then there is the USO which is under discussion.

This is a no win scenario - lots of people complain we are behind because we can't offer super fast speeds so BT look to do something about it. Then people complain that some can't get fast speeds (which BT have and are working on, some of which using government funding). No matter what BT do they cannot please everyone (unless of course there was an enormous pot of cash and human resources sitting around somewhere to do all the work).

You'll find those on left with ADSL are not economically viable hence Openreach are waiting for someone else to pay for it.

Anyone know if BDUK funded cabs are getting G-Fast - If so what makes them economically viable now?

In reply to a post by lee111s:

You could always get some solar panels with some storage batteties to power your modem and reverse power unit

I do have solar panels, but batteries are not economically viable, but that's a different topic.

I would guess it depends on takeup of VDSL and, number of properties close enough to the cab to benefit.

Openreach will likely have calculations for the various possibilities.

I would imagine though that they'll be just as eligible as a commercial FTTC cab if the meet the criteria.

Openreach aren't always right on what is and isn't a good commercial investments. A number of BDUK cabs have far surpassed expectations - my cab alone is a BDUK cab and all 128 ports were gone within 24 hours of them being made available.

https://www.thinkbroadband.com/how-broadband-works

For those who are interested one of our guides has a G.fast range table in it.

And to add the G.INP roll-outs, and less successfully vectoring, but these have seen Huawei cabinets doing better on average than ECI by a few Meg now.

Also LR-VDSL but needs ADSL/ADSL2+ turned off.

People don't want a BT Group monopoly, but they also want someone to do a standard service everywhere, perhaps the answer is Government buys all commercial operators and does a NBN ala Australia, but then they are spending a lot more money than the UK government has done.

Estimate is across all cabinets 64% are in range for a minimum connection speed of 100 Mbps

As infill continues this number may flex around a little.

In reply to a post by MrSaffron:

and less successfully vectoring, but these have seen Huawei cabinets doing better on average than ECI by a few Meg now.

A side-note that virtually all of BDUK deployment has been done with Huawei cabinets. Addition of vectoring and/or LR-VDSL is thus feasible to most of these areas.

In reply to a post by MrSaffron:

https://www.thinkbroadband.com/how-broadband-works

For those who are interested one of our guides has a G.fast range table in it.

Those seem quite optimistic speeds!

Aside:
Can I point out that, at some point in the future, it will become important to label these estimates by the version of G.Fast that is in use.

When FTTC came out here, we suffered from re-posts of old graphs, where it became unclear that some data related to 7MHz estimates, some 8MHz, and some 17MHz.

Just trying to preempt the arguments in 3 years time...

In reply to a post by kebabselector:

You'll find those on left with ADSL are not economically viable hence Openreach are waiting for someone else to pay for it.

Anyone know if BDUK funded cabs are getting G-Fast - If so what makes them economically viable now?

General answer:

There are different reasons for "not economically viable" in each case...

Exchanges might not be viable for ADSL2+ because there is no physical space.

PCPs might not be viable for FTTC because of a difficult and costly distance for power.

PCPs might not be viable for G.Fast because of the density of housing within 300m (though the density within 1km is fine for VDSL2).

So ... it is plausible for a PCP cabinet to have needed BDUK funds to get the power issue addressed. But now power (and fibre) is there, that BDUK cabinet is no more costly to upgrade to G.Fast than any other in the country.

Meanwhile, the best economically-viable PCP might not be able to get a G.Fast upgrade because the PCP is physically sited too close to an obstruction, that is too costly to move/remove. No room for a pod.

Specific answer:
BT reported they were including the "Allhallows" exchange in Kent in the trial. Every single PCP on that exchange that has been upgraded was done with a BDUK subsidy.

It will be interesting to see how accurate it is.

The VDSL2 table is possibly way out ... several lines I know of are at about 400-450m from the cabinet and have attenuations of about 16dB ±1 with speeds well into the 70s and potentially just over 80 compared to your predicted 9dBand42 Mbps.

My line, is 440m, by road and I know here most of the ducts are - it cannot be shorter unless it went through a Church and graveyard! The single attenuation figure for downstream is 16.7 dB (the D1, D2 , D3 Line/Signal figures are 11.6/14.8, 28.0/27.7, 43.8/42.9) and I am currently sync'd at 80000kbps.

In reply to a post by MrSaffron:

https://www.thinkbroadband.com/how-broadband-works

For those who are interested one of our guides has a G.fast range table in it.

Thanks, that was what I was thinking of.

But - natch - more questions are raised. I kinda thought I could look at these tables and work out what speed G Fast might bring my line based on my FTTC speed. I appear to be 200m from the cabinet but I think my line takes a scenic route and could be longer. My router says I have 60481 kbps down and 20000 up with aa attenuation of 17db on the down side and 20 up.

The tables say - or suggest ? - 17db mean I must have an 800m line length and my speeds would be 28 down and 10 up.

I must be reading this all wrong or making assumptions...

It certainly needs to be remembered that everyone pays for the power consumption of the port at the DSLAM today; it is just hidden away within the money you pay your ISP, and they pay on to BT.

For reverse-powered G.Fast, it becomes an explicit issue that might have to be separated out...

In reply to a post by R0NSKI:

Was that cost split between four properties, so a max of £20 a year, if so I would be ok with that, but not sure about £80 of electricity. Suppose it would depend on the cost of the service as well.

The standards that have been written to provide reverse power generally allow for up to around 15W to be used, but examples I've seen suggest nearer 10W being used. Per port.

Over a year, 10W maps to 90kWh. At 12p per unit, that's roughly £11. About £1 per month.

Could this be handled by BT offering two wholesale prices that differ by £1 per month?

For comparison: In today's FTTC DSLAMs, a fully-populated 288-port Huawei consumes 600W, or approx 2W per port. About 20p per month of today's bills.

Note:
As chipsets take advantage of better manufacturing capability, power requirements generally drop ... so there is merit in waiting for later iterations of the hardware before plumping for a design that is to be reverse-powered.

They are amendment 2 i.e. what is being deployed

I expect most people to say the VDSL2 figures are pessimistic, they are meant to be, to thus ensure we are not overstating coverage, and this is important as take-up increases and cross-talk increases.

I also know from looking at speed test results visitors to thinkbroadband get higher speeds than others generally, suggesting that others are more likely to be on the impacted type figures, and when I manually double check samples we aim to be at the low end of impacted.

Without knowing where you actually are hard to say much beyond a pessimistic view on crosstalk and assumption of high take-up means the majority should easily do better than the chart suggests

This also makes the average higher on Huawei more impressive as early commercial ECI type areas were the dense urban ones where a lot of the time everyone was in a superfast distance.

In reply to a post by MrSaffron:

They are amendment 2 i.e. what is being deployed

Have BT actually said they are using amendment 2?

All the trial results seem to pre-date the power increases (ie amendment 2), and seem consistent with amendment 1 instead.

Granted the publicly-available speed results are relatively old; BT will have newer figures that they don't seem to want to make public.

In reply to a post by MrSaffron:

Without knowing where you actually are hard to say much beyond a pessimistic view on crosstalk and assumption of high take-up means the majority should easily do better than the chart suggests

Fair enough. Do you think the 17db = 800m is a nearly accurate figure? Just out of interest.

In reply to a post by Woolwich:

The tables say - or suggest ? - 17db mean I must have an 800m line length and my speeds would be 28 down and 10 up.

I don't know about @MrSaffron's tables, but I've had a few lines, with different modems.

A 650m line that would have reached around 55-60Mbps. Unfortunately, the firmware didn't report the attenuation.

A 375m line which dropped from 90/25 to 78/24 over 3 years. Attenuation was 16.5dB. There is a chance it was thicker copper and would have relatively lower attenuation, acting like 300m of standard copper.

A 100m line which has been anywhere from 95/30-107/35 over 3 years. Attenuation is 8.5dB, but this is likely to be thinner copper, so behaving more like a 150m line.

But ... some modems seem to choose different ways of reporting attenuation.

I would suggest over-pessimistic.

I have seen my speeds drop quite a bit over time as more residents come on line, however, I would guess that of the properties served by the multi-pair cable from the cabinet there is a 90% take-up so very little chance of much more cross talk.

Would need to sit down and do lots more checking if I was to use the word accurate, and busy with other daily stuff that keeps me going for a few hours

I've seen tests on lines and as sample increases will tweak accordingly, so its based on what we've seen in the last few months rather than say 2015 presentations

the original intention of g.fast was supposed to be nodes installed closer to the home so rolled out "alongside" more fibre, but BT have turned this on its head and are now using it akin to what adsl2+ was vs adsl, currently aft the FTTC cabinet locations so it boosts the shortest lines only.

When BT have saturated this method of deployment its possible they will start using remote nodes or they may use an alternative tech such as FTTP for the longer lines.

Pilot has been extended.

500,000 passed now, increasing to 1m by the end of 2017.

FWIW these this is my line taken from DSLstats 600m from the cabinet. I know I'm 600m away because it was measured by a BTO engineer with his test equipment a few months ago:

Downstream Upstream
Line attenuation (dB): 15.1 6.1
Signal attenuation (dB): Not monitored
Connection speed (kbps): 40000 9999
SNR margin (dB): 3.8 6.7
Power (dBm): 13.8 7.4
Interleave depth: 16 0
INP: 47.00 0
G.INP: Enabled
Vectoring status: Unknown


EDIT: I was also told that in his well informed opinion that my line had aluminium in it somewhere, which he says is everywhere. That is the reason I couldn't get a sync above 40/10. There is an interesting general tale he told me about the high prevalence of aluminium that is in the loop, but that is another story.

Edited by TygerTyger2010 (Thu 17-Aug-17 14:13:48)

I know was a bit slow getting it up today, as sifting through code

Please can those of you who understand G.fast better than I do advise me.
I currently receive 45Mbps down on BT Infinity 1. I was told by a BT engineer that I wouldn't achieve better speeds than that on Infinity 2 or any FTTC service because when our 1960's housing development was built it was wired with cheap and readily available aluminium rather than copper wiring.
Will G.fast be available to homes like mine or does it rely on copper wiring all the way from Cabinet to Master Socket?

It won't be available to you while it's deployed from the cabinet as it's going to be for the next few years.

Having aluminium doesn't disqualify you from G.Fast, but it does mean you would need to have a line shorter than people supplied by copper.

A 45Mbps speed suggests you aren't likely to benefit from G.Fast from the cabinet, and will need a node to be installed closer to you.

But that's a guess. We (the public) don't really know yet.

I've found some recently-allocated charge codes that Openreach are using for unmetered electricity supplies for G.Fast:

1 line card: 124 watts
2 line cards: 173 watts
3 line cards: 221 watts
4 line cards: 267 watts

If these DSLAMs can only handle 48 ports in total, then that's 12 ports per card, and roughly 4 watts per port, and 75 watts on non-port tasks.

The code allocation doesn't mention the vendor of the DPU, but it suggests that only one is being rolled out at the moment.

ali can actually match or beat copper. For some reason there is an assumption on here that BT use good quality copper when its used but in various areas thats not the case.

In my area the copper is really thin, but the ali is about 2-3x the thickness.

my attainable is currently around 80mbit even tho the last 50m or so is ali.

Your most likely barrier to g.fast is line length rather than cable type, a copper line even with good copper wouldnt boost you from 45meg to the specs needed for good g.fast.

Whereas I would agree that a short to short-ish run of Aluminium of decent guage won't stop an 80/20 sync, what kind of total line length are you talking about here ?

I had a long and informative lecture from a friendly BT engineer including the fact that Aluminium is a big issue that they often had to deal with.

He himself wanted 80/20 and could only get 40/10 because of Aluminium in his home line.

I can get a pretty much optimum 40/10 sync with Aluminium present @ 600m . I can't get anything above that.

from the cabinet is about 370m

The issue with ali as I understand it is 2 issues.

1 - it corrodes on joints.
2 - compared to same thickness of copper it has higher attenuation, however not all copper matches the thickness of ali deployed, so e.g. 0.6mm ali should beat say 0.1mm copper.

Some more info on my current pair.

I had a recent fault at the cabinet, and there was short periods of time I had less crosstalk and my attainable increased as a result, it was at times over 100mbit. I dont know if this was with no crosstalk at all, but certainly less crosstalk
Before the fault however my attainable was less than 70 (6db snrm), interestingly after some discussions with openreach I know only the tie pair ordering got changed not the D side, so I heave learnt the tie pairs themselves can have a huge affect on crosstalk, and those are brand new copper.

Lots of faults due to incorrect and poor tie pair terminations. Probably the single largest fault issue with FTTC.

In reply to a post by Chrysalis:

from the cabinet is about 370m

The issue with ali as I understand it is 2 issues.

1 - it corrodes on joints.
2 - compared to same thickness of copper it has higher attenuation, however not all copper matches the thickness of ali deployed, so e.g. 0.6mm ali should beat say 0.1mm copper.

Some more info on my current pair.

I had a recent fault at the cabinet, and there was short periods of time I had less crosstalk and my attainable increased as a result, it was at times over 100mbit. I dont know if this was with no crosstalk at all, but certainly less crosstalk
Before the fault however my attainable was less than 70 (6db snrm), interestingly after some discussions with openreach I know only the tie pair ordering got changed not the D side, so I heave learnt the tie pairs themselves can have a huge affect on crosstalk, and those are brand new copper.

I think we tend to generalise about aluminium in the network. And that�s because most of it on the network is the really thin stuff. Very, very thin. We see a disproportionately high about of faults in the underground network where you can basically pull apart the join between two bits of aluminium or aluminium and copper.

There�s some of the nice thick stuff around but you still get the problem with the poor joints between wires which just doesn�t happen much with copper. I can only put it down to the aluminium going brittle somehow as most of the time there�s no water involved and the joints are dry. It just isn�t good for a telecoms network.

When I had my long conversation with the BTO engineer a couple of months ago that was effectively the point he emphasised. The problem with aluminium was at the joints.

Brittleness, cracks and corrosion being the biggest issues concerning aluminium.

His statement to me was that aluminium joint issues were very common and problematic.

Elements of the BT/BTO management seem to consider this a non-existant or minimal problem (by area at least) according to an interesting story he told me.

In reply to a post by TygerTyger2010:

When I had my long conversation with the BTO engineer a couple of months ago that was effectively the point he emphasised. The problem with aluminium was at the joints.

Brittleness, cracks and corrosion being the biggest issues concerning aluminium.

His statement to me was that aluminium joint issues were very common and problematic.

Elements of the BT/BTO management seem to consider this a non-existant or minimal problem (by area at least) according to an interesting story he told me.

It�s increasingly getting changed for copper in some areas now. Areas where there�s small lengths of a few hundred metres here and there. But yeah, it�s all about the joints.

Unfortunately in others there�s so much of the stuff that it would be prohibitively expensive to replace.

I am not saying ali cannot be to blame, however I think the danger is when it exists its automatically assumed to be the problem and it prevents an investigation, engineers have a motivation to close jobs quickly, and having ali on the cable gives a convenient excuse to pass on to the end user.

My E side has thicker copper than my D side but has no relevance on FTTC.

On the D side info I was given a couple of years back had it at 0.2mm copper and 0.7mm (last 50m) ali.

The best copper seems to be mainly used for long runs in rural areas, alot of city areas seem to have thinner copper.

Edited by Chrysalis (Fri 18-Aug-17 11:03:32)

That was the case, longer rural runs would get the really thick copper. However when cables are renewed nowadays they only seem to use one gauge of copper.

yes but most of the network isnt getting renewed. They will only swap out cable if there is a reason to. Someone not happy with their sync speed typically wont qualify.

Edited by Chrysalis (Fri 18-Aug-17 11:10:43)

>>The best copper seems to be mainly used for long runs in rural areas

A phone line would be planned to be well under 500ohm single wire resistance when the network was built so wire poundage will reflect this.

Smaller gauge wires in main side cables are often smaller gauge because high pair count cables have to be able to fit in the ducts!

Original aluminum cables from the fifties were specced at 0.8mm as it has about the same resistance as 0.5mm copper. These were often directly buried alongside ducts to save duct space!

Hi there,

can someone please see this pic and tell me if this is a gpod cabinet and not just a fibre extention ?

is this a gpod

That indeed is G.fast.

In reply to a post by lee111s:

That indeed is G.fast.

thank you,
any idea if it will be any good to me ?

my connection stats

Connecting at 80meg I'd expect something

Use https://www.dslchecker.bt.com as this will show what speeds are available when it goes live.

With it having that silver lock on it, it may be live now so pop your number into the dsl checker

Edited by deleted (Fri 18-Aug-17 20:01:33)

i did and its not showing live yet, will keep an eye on it

A press release from the GPO suggests aluminium was first used in 1969...

http://forum.kitz.co.uk/index.php?topic=14615.0

In reply to a post by Chrysalis:

yes but most of the network isnt getting renewed. They will only swap out cable if there is a reason to. Someone not happy with their sync speed typically wont qualify.

Tell me about it.

However, I can tell you in my area in areas where many people have complained about sync speed we are swapping aluminium lengths out for copper. It depends on how much local managers want to engage with the local community I suppose.

In reply to a post by WWWombat:

A press release from the GPO suggests aluminium was first used in 1969...

http://forum.kitz.co.uk/index.php?topic=14615.0

I had completely forgotten about that!

The moral of the story is that if someone is from an area with lots of Al the story is that the UK has masses of it in the local loop.

In reply to a post by burakkucat:

I had completely forgotten about that!

My memory seems to have hit the point that I could remember half the content, but I couldn't remember where I saw it. It took judicious re-googling with a variety of keywords to find again.

I did find references to the same changes in house electrical wiring - also requiring different types of fixtures.

In reply to a post by MrSaffron:

The moral of the story is that if someone is from an area with lots of Al the story is that the UK has masses of it in the local loop.

Yes, and I suspect most areas have some ali, in my experience that�s been the case. I also imagine some towns would have loads, depends when the network was built.

In reply to a post by WWWombat:

A press release from the GPO suggests aluminium was first used in 1969...

http://forum.kitz.co.uk/index.php?topic=14615.0

Really interesting link. Someone has put in the comments that it�s a good job they didn�t achieve their objectives. Well they did as far as I can see. For a good while aluminium was the only type of cable laid in the D-side network. That�s why we see it seemingly randomly mixed in with copper cables, as if a copper cable went faulty in the 70s or 80s it would have been replaced with an aluminium one. Presumably that was all that was available from stores to engineers. I bet you would have to make a special case to your manager to obtain some copper cable at that time.

Edited by deleted (Sat 19-Aug-17 13:09:51)

Also in housing areas that were built up in the 70s.

I think the estate across the road from me was built in the 70s.

We all know ali exists in various parts of the network, but I was trying to correct the assumption the copper in the network is consistently decent grade when its not. As such ali is not always the cause of poor speeds or instability.

>>A press release from the GPO suggests aluminium was first used in 1969...

Thanks for the confirmation, the press release clearly mentions, as I reported, aluminium cables were first used in the 50s. Where the boffins of the time specced 0.8mm conductors. This release is mainly about the release of 'connector wire insulated 1' crimps to mitigate the cutting back to the 0.5mm gauge against the advice of the original research.

Today CWI1 crimps are probably worse for broadband than the ali cable! They certainly are being replaced on sight.

But money talks and if you can maintain a 500ohm single wire resistance with a cheaper roll out, why wouldn't you? It was all about a loop seizing a dial tone in them days. In 1965 the PO were projecting telephone ownership could reach 50% by 1980! They had a lot of expansion work to do.

Today Virgin and OLOs are putting tubes straight in the ground with no ducts. Crazy short term thinking at 100mm below the tarmac. It will cost them in the long term.as they get regularly damaged. It's already happening.

I was wrestling with a 800pr 0.9mm copper cable the other day. 1937 vintage. In them days the exchange was a lot further away so heavier poundage was essential. Monster cable, duct filler, larger than a modern 4800. Cut into the 'new' 60s exchange later in it's life and probably giving todays broadband subscriber who declines to move to FTTC top service. Sometimes old stuff is better!

Edited by deleted (Sat 19-Aug-17 22:25:44)

In reply to a post by partial:

>>A press release from the GPO suggests aluminium was first used in 1969...

Thanks for the confirmation, the press release clearly mentions, as I reported, aluminium cables were first used in the 50s.

It does indeed confirm that, but also confirms they were only experiments that far back. "Patient research" continued until a "breakthrough in the mid 60s". Will any of that experimental stuff still exist in the network?

I found an article in the New Scientist 1964 that maybe describes that patient research: the use of aluminium in an "8 year experiment". https://goo.gl/LMHja9

That was a 54-pair line between Dover and Deal; it describes the polythene sheath as less resistant to water than lead, and looks like it took part in experiments for cable pressurisation (becoming standard from 1963?). The distance (8 miles) also suggests it wasn't access network, but perhaps a junction cable.

The 1969 press release says that "changeover happened eight months ago" - in early 1969 - but without stating exactly what changed over. The context of the release relates to the access network specifically. The only realistic way to interpret *what* changed over is the use of aluminium in the live access network.

Perhaps, though, trunk and junction cables started to use aluminium at an earlier date.

Is the CWI1 anything like today's jelly crimps? The NS's article describes something rather strange-sounding.

In reply to a post by partial:

In 1965 the PO were projecting telephone ownership could reach 50% by 1980! They had a lot of expansion work to do.

They did better than that!

In 1965, it seems that there were only 400,000 homes with phones (though there were a lot more businesses, and a lot more phones); that's 2% of the 17m homes of the day.

By 1980, they'd reached 14.3m homes out of the 20m that then existed. Something like 72%.

By 1995, they'd reached 21m homes out of the 23m that then existed. Something like 90%.

In reply to a post by partial:

Today Virgin and OLOs are putting tubes straight in the ground with no ducts. Crazy short term thinking at 100mm below the tarmac. It will cost them in the long term.as they get regularly damaged. It's already happening.

Especially when you watch the behaviour of existing utility companies, and what they do. When you see the water and gas companies choosing to re-use old pipes by lining them on the inside with new plastic pipes, it has to tell you something.

In reply to a post by partial:

I was wrestling with a 800pr 0.9mm copper cable the other day. 1937 vintage. ... Sometimes old stuff is better!

If you're lucky, you're lucky!

In reply to a post by partial:

>>A press release from the GPO suggests aluminium was first used in 1969...

That press release was suggesting that all cables could be aluminium by the end of 1969, but it patently didn't happen to that extent

The reason why could be related to one other point made in the article: Aluminium cables were only 10% cheaper than copper.

Yes, copper prices reached peaks in 1968, 1970 and 1974. Aluminium hit peaks at the same time too, but then stood relatively steady in the rest of the seventies. However, copper prices fell back much more, and then kept falling in the rest of the seventies. More than enough to account for the 10%.

Perhaps, then, the savings turned out to be fleeting.

Thanks. Interesting article. 54pr is pretty much always going to be a junction. I have never seen an aluminium junction. Doesn't mean they never existed. Just means I never saw one.

Prior to mid 90s the various 'districts' were run as pretty much self contained independent businesses and had their own ideas. I would expect coax junctions came along and put pay to them.

CWI1s were phosphor bronze compression crimps, ali friendly. Known as Blue Beans nowadays, although they were also purple and ungrease filled white originally.

Rather than previously twisted and sleeved joints, really bad for ali, they used a calibrated tool to compress and puncture insulation, really good for ali.

Jointers tools became uncalibrated and old school would strip, twist and then crimp. Or perhaps they would twist and crimp with the back of their cutters. Really bad for broadband. Removed on sight nowadays. Stopped using them late eighties.

Similar compression connectors 'MJ4s' used on main side into the mid nineties. same problem, much more difficult to get rid of on a cable with thousands of pairs and no slack!

State of the nation 1965 for telecom saddos! www.samhallas.co.uk/repository/documents/local_lines.pdf

In reply to a post by partial:

State of the nation 1965 for telecom saddos! www.samhallas.co.uk/repository/documents/local_lines.pdf

Fascinating! A great addition to the stats collection. Most information I had tended to peter out prior to 1970.

Unfortunately, it means a bit of my earlier data is rather incorrect, but armed with this (and further searching), I'll go back and fix that.

Elsewhere in this thread, there is a set of statistics available. From this (and other sources), I've been able to determine that my first statistic below is incorrect:

In reply to a post by WWWombat:

In 1965, it seems that there were only 400,000 homes with phones (though there were a lot more businesses, and a lot more phones); that's 2% of the 17m homes of the day.

By 1980, they'd reached 14.3m homes out of the 20m that then existed. Something like 72%.

By 1995, they'd reached 21m homes out of the 23m that then existed. Something like 90%.

Better data shows:
- 1958, 16% of 16m homes had telephone = 2.6m
- 1965, 21% of 17.4m homes had telephone = 3.7m
- 1970, 35% of 18.3m = 6.4m
- Figures for 1980 and 1995 remain correct

So, In 1965, it appears (from various sources), there were
- 3.7m residential connections
- 6.2m exchange connections
- 8.8m pairs in the access network (30% spare)
- 10 million telephones

That�s a great read! I particularly liked the section �A New Cabinet� which describes what we now know as shelf cabinets. An ingenious invention apparently! We all despise them now as although they put the D-sides through numbered holes no one thought it a good idea to also do the same for the E-sides! So they just come up in the middle in a complete mess! There�s still plenty of shelf cabinets about too.