NBN Rollout Scrapped

[NBNMyths]

Syd any idea what the temperature rating would be of the gear required in a FTTN cabinet?

50 degrees c max?

I posted a link a while back to a VDSL2 DSLAM, and yes the max operating temp was 50 ºC. No way will that be achieved without active cooling for the cabinets. I'm already shuddering at the power bill for air-conditioning ~60,000 roadside cabinets.

EDIT: Here's an example: ftp://ftp.zyxel.com/VES-1602FE-57/datasheet/VES-1602FE-57_2.pdf

0-50 ºC, and 10-95% humidity. So they'll need reverse-cycle AC to cool, heat and dehumidify depending on the time of year and geographic location.

 

[sydboy007]

I posted a link a while back to a VDSL2 DSLAM, and yes the max operating temp was 50 ºC. No way will that be achieved without active cooling for the cabinets. I'm already shuddering at the power bill for air-conditioning ~60,000 roadside cabinets.

EDIT: Here's an example: ftp://ftp.zyxel.com/VES-1602FE-57/datasheet/VES-1602FE-57_2.pdf

0-50 ºC, and 10-95% humidity. So they'll need reverse-cycle AC to cool, heat and dehumidify depending on the time of year and geographic location.

Huawei seem to have from -40 to +65 operational temperature, but like all electronics the more time you spend at the upper limits, the faster the equipment will break down. Still, it doesn't take too much over say 30 degrees to get into the upper ranges of operational temperatures inside a sealed box.

It might be possible to use mil-spec equipment - no idea if they do that for VDSL technology - to withstand higher operating temperatures, but either way you will be paying a lot of additional cost over the standard technology.

If they can get away with non active cooling, they will also see much higher temperature swings inside the node, which causes other issues too, as the circuit boards and other components expand and contract with the temperature swings. That's why most electronic equipment like a nice data centre with aircon that keeps things at a relatively constant temperature.

I'm just looking forward to the first nodes in a leafy Sydney North Shore suburb being installed, when Mrs Marsh is standing with her placard out front the white picket fence demanding the eyesore be moved. Between the shading of her petunias and the graffiti magnet it will be, she doesn't see why they can't be underground.

*NB - the current Government has kept the ban on Huawei so not too relevant, but doubt other vendors have much better high temperature tolerances.

 

[DB008]

I'm just looking forward to the first nodes in a leafy Sydney North Shore suburb being installed, when Mrs Marsh is standing with her placard out front the white picket fence demanding the eyesore be moved. Between the shading of her petunias and the graffiti magnet it will be, she doesn't see why they can't be underground.

So....
Who is at fault? Libs or ALP?
Who started this project?

 

[Smurf1976]

Huawei seem to have from -40 to +65 operational temperature, but like all electronics the more time you spend at the upper limits, the faster the equipment will break down. Still, it doesn't take too much over say 30 degrees to get into the upper ranges of operational temperatures inside a sealed box.

It might be possible to use mil-spec equipment - no idea if they do that for VDSL technology - to withstand higher operating temperatures, but either way you will be paying a lot of additional cost over the standard technology.

If they can get away with non active cooling, they will also see much higher temperature swings inside the node, which causes other issues too, as the circuit boards and other components expand and contract with the temperature swings. That's why most electronic equipment like a nice data centre with aircon that keeps things at a relatively constant temperature.

I've worked servicing and installing electronic equipment outdoors in metal boxes. Nothing to do with the NBN, but electronics nonetheless. Noting that this was professional grade equipment built to a strict standard, not consumer electronics built down to a price, comments as follows.

Temperature - On a hot day (high 30's is about as high as it gets down here) everything inside the box is too hot to touch if it's in full sun. You'd be looking at temperatures around 15 - 20 degrees higher than ambient due to the direct heating from the sun plus internal heat generation (anything that uses electricity produces at least some heat in operation). So in Hobart you'd expect the temperature inside to range from about 0 to about 60 degrees. Somewhere like Perth or Adelaide it would get into the mid 60's I'd expect. Inland parts of mainland Australia it could approach 70.

A complication in that is the surrounding ground surface. If it's natural bush or something like an asphalt road or a water reservoir then it doesn't reflect a lot of heat back onto the cabinet and so it's only heated on the side the sun is actually coming from. But if it's concrete or something like a light coloured fence then that would reflect more heat, thus heating the cabinet from both sides and raising the temperature further.

You can keep the temperature down a bit using simple mechanical ventilation. Exhaust fan blows air out the top and sucks it in the bottom. But unless you're in an incredibly clean environment (eg natural bushland not beside a road) then you'll end up with a box full of dust rather quickly unless you use a filter on the air inlet. And if you use a filter then it needs replacement every 3 - 6 months depending on location and how dusty it is. And if it was somewhere really dusty, like near a beach (sand blowing around) or heavy industry (coal dust etc) then it's going to be blocked in no time. If you're in a city then just take a look at things in the CBD which aren't cleaned too often and you'll see that they're covered in a film of black muck (presumably from vehicle exhausts, tyres wearing away, general contamination of the air due to the sheer volume of activity - even the rubber on your shoe soles wears away and ends up in the air or down the drain).

The other option for cooling is to air-condition the box. It works but now you've got a need for a more substantial supply of electricity, the issue being finding somewhere to get that from close by rather than the cost of power as such, and you've also got an air-conditioner which will inevitably fail at some point too. Not to mention that any external condenser is prone to vandalism.

So how long do electronics actually last outside in a metal box? Here's some real data.

In inland parts of Tasmania, including Hobart (not really inland but close enough) and Launceston it's around 30 years lifespan. But go to a coastal location and salt spray becomes a major issue, corroding the cabinet itself (unless it's stainless steel which is expensive) rather quickly. Steel rusts once the paint goes, aluminium also falls apart due to corrosion. And if it's somewhere near an industry emitting sulphur fumes then it's a nightmare with corrosion - you can easily spot a vehicle (for example) that has been routinely parked in such a place as it looks "old" alarmingly quickly. Sulphur leads to corrosion to the point that there's a true story at a certain factory down here of a company vehicle (ute) literally snapping in half due to the extent of corrosion. Needless to say, cabinets fall apart pretty quickly too - realistic lifespan is 2 years.

How many places are subject the salt spray issue? Pretty much anywhere on the coast where the wind blows from the sea to inland - that's most places on the coast.

How many places have sulphur pollution? It's emitted in potentially problematic quantities by places that process metallic ores (smelters), anything which burns coal or fuel oil and in some cases by gas processing plants may also emit sulphur. Whilst most coal used in Australia is low in sulphur (mostly around 0.3 - 0.5%), there are instances where much higher sulphur content coal (approaching 4%) is used and it does cause pollution issues at times. So whilst it's not a mainstream issue, there would be at least a few places where cabinets will rust due to pollution from sulphur.

But what about that heat? The same electronics that last 30 years in Tas (removed due to being obsolete) fail after 20 years in Adelaide. Whilst Tas does get the occasional very hot day (record for Hobart is 41.8), they are relatively infrequent compared to the heatwaves which occur quite routinely in SA. I don't have data for more inland regions, but I'd guess that they would have an even shorter lifespan for the equipment.

Cold is also a potential issue, albeit one easily resolved by heating the cabinet with an internal resistive (electric) heater. But it's certainly quite possible to end up with a box dripping wet on the inside due to condensation in some locations if it's not heated or ventilated adequately (but ventilation means dust).

Another issue is graffiti. Roadside cabinets are a magnet for it and attitudes vary across the country. Some councils ignore it, others see it as an emergency and require removal within 24 hours (including weekends and public holidays). If the asset owner doesn't remove it then the council does - sending the owner a bill for an after hours call out and the cost of the paint (which will be whatever colour the council happens to think looks nice, typically ends up being a dark colour which causes more problems when the sun comes out as it gets hotter than a light colour would).

Now, if they build the cabinets from stainless steel, keep them regularly painted in a light colour (which will be anything from once a decade to once a day repainting depending on graffiti), only put them in places near existing power infrastructure that's readily accessible and don't expect the electronics to last more than 15 or so years then it's all going to be just fine. A lot of ifs and buts there though.

 

[sydboy007]

http://www.telepower.com.au/INT94b.PDF

From the mouth of Telstra back in 1994

In Australia air temperatures in excess of 45 °C are not uncommon. Dense packaging of the electronics within the housings results in areas of relatively concentrated heat generation which must be dissipated. Power conversion equipment can be a significant source of the heat energy. Telstra's experience shows the temperature in presently used housings can vary from 40 °C to 60 °C daily. Reduction of heat using an active cooling system raises system costs and fan-forced air circulation does not always provide significant cooling. Elevated temperatures have an adverse affect on the reliability of electronics. Dry-out of electrolytic capacitors might be expected to threaten the reliability of power conversion equipment. Similarly, the service-life degradation of batteries as a function of operating temperature is well known.

I wonder how many of these unforeseeable issues will plague the MTM rollout?

 

[drsmith]

I posted a link a while back to a VDSL2 DSLAM, and yes the max operating temp was 50 ºC. No way will that be achieved without active cooling for the cabinets. I'm already shuddering at the power bill for air-conditioning ~60,000 roadside cabinets.

EDIT: Here's an example: ftp://ftp.zyxel.com/VES-1602FE-57/datasheet/VES-1602FE-57_2.pdf

0-50 ºC, and 10-95% humidity. So they'll need reverse-cycle AC to cool, heat and dehumidify depending on the time of year and geographic location.

Myths,

Take a closer look at the application diagram in the above link and you'll see the obvious error in your post.

 

[Garpal Gumnut]

The whole NBN Rollout is a shambles, and as is usual with ALP ideas, the Coalition have to try and make it pay for itself.

Such a massive waste.

gg

 

[NBNMyths]

Myths,

Take a closer look at the application diagram in the above link and you'll see the obvious error in your post.

That link is to an FTTB version, but the street cabinet version isn't much different. -10 to 60 º, and still 10-95% RH.
http://www.zyxel.com/au/en/products_services/ves_1624ft_55a.shtml?t=p

 

[NBNMyths]

So....
Who is at fault? Libs or ALP?
Who started this project?

The libs, because it's their FTTN system that requires the huge (fridge-size) powered street cabinets every ~400m along every street:

…and the pictured FTTN cabinet isn't actively cooled. How big will it be in hotter areas of Australia, where AC is required?


The ALP's NBN requires much smaller cabinets, and only a few per suburb:

 

[drsmith]

That link is to an FTTB version, but the street cabinet version isn't much different. -10 to 60 º, and still 10-95% RH.
http://www.zyxel.com/au/en/products_services/ves_1624ft_55a.shtml?t=p

Not 0-50 ºC as you so boldly claimed.

It's your problem that you struggle so much with acknowledging when you're wrong.

 

[NBNMyths]

It's your problem that can't acknowledge when you're wrong.

I'm not sure what your point is.

I quickly posted a link to what turned out to be FTTB version. Does the 10 º extra street cabinet version make any difference to whether they'll need active cooling or not? Not in most parts of Australia it doesn't, so the point stands.

Tasmania and (close)east-coat mainland aside, 40+ degree days are common, which would easily lead to >60 º in an uncooled cabinet full of heat-generating active electronics. So either you cool them (adding cost, size and power consumption), or you don't and expect no communications in hot weather and regular replacements due to failure. Which option wood you pick?

EDIT: While I couldn't find any testing of cabinets, I did find a test of car interior temperatures by the RACQ. It found the peak air temp inside a car parked in full sun on a 32.5 º day reached 75.1 º after two hours. Doesn't bode well for a cabinet full of heat-gereating equipment sitting in the sun all day, does it?

There's a reason why even Telstra's baby rural exchanges are made of insulated sandwich panel and have redundant AC units.

 

[H C]

So....
Who is at fault? Libs or ALP?

The "Libs" are at fault. They are insisting on changing the original NBN plan to something that requires littering Australia with many ugly inefficient nodes. Think about what they are doing here. They are essentially taking an exchange and the technology required to make one operate, splitting it up and then placing those chunks out in the streets. It's not just inefficient, it's a sloppy solution.

 

[IFocus]

The libs, because it's their FTTN system that requires the huge (fridge-size) powered street cabinets every ~400m along every street:
View attachment 56269
…and the pictured FTTN cabinet isn't actively cooled. How big will it be in hotter areas of Australia, where AC is required?


The ALP's NBN requires much smaller cabinets, and only a few per suburb:

View attachment 56270

Is the cabinet just a termination point or are there active components?

 

[NBNMyths]

Is the cabinet just a termination point or are there active components?

In FTTN cabinets there are active components. It's where the fibre finishes and the copper starts. So you have VDSL2 DSLAMs (which are powered), plus AC-DC converters to send the DC voltage down the copper, and backup batteries.

In FTTP cabinets, there are no active components and no electricity. They contain the GPON (Gigabit Passive Optical Network) splitters. There is one cabinet for every ~288 premises. Those cabinets then link to the area's FAN (Fibre Access Node), which is active (powered), and typically housed in a telephone exchange.

 

[drsmith]

I'm not sure what your point is.

I quickly posted a link to what turned out to be FTTB version. Does the 10 º extra street cabinet version make any difference to whether they'll need active cooling or not? Not in most parts of Australia it doesn't, so the point stands.

and emphasised a max operating temp of 50 ºC, twice.

I posted a link a while back to a VDSL2 DSLAM, and yes the max operating temp was 50 ºC. No way will that be achieved without active cooling for the cabinets. I'm already shuddering at the power bill for air-conditioning ~60,000 roadside cabinets.

EDIT: Here's an example: ftp://ftp.zyxel.com/VES-1602FE-57/datasheet/VES-1602FE-57_2.pdf

0-50 ºC, and 10-95% humidity. So they'll need reverse-cycle AC to cool, heat and dehumidify depending on the time of year and geographic location.

You obviously don't want to acknowledge you're wrong and by subsequently attempting to discount the 10 º extra in the street cabinet version, you demonstrate a further ignorance in terms of the flexibility that provides in terms of both passive and active ventilation.

 

[NBNMyths]

and emphasised a max operating temp of 50 ºC, twice.



You obviously don't want to acknowledge you're wrong and by subsequently attempting to discount the 10 º extra in the street cabinet version, you demonstrate a further ignorance in terms of the flexibility that provides in terms of both passive and active ventilation.

I did acknowledge I was wrong re the 50 v 60 º.

I then wrote that the 10 º makes little difference for most parts of Australia. For reliable operation, the cabinets are going to need active cooling and/or humidity control. Do you dispute this?

 

[IFocus]

and emphasised a max operating temp of 50 ºC, twice.



You obviously don't want to acknowledge you're wrong and by subsequently attempting to discount the 10 º extra in the street cabinet version, you demonstrate a further ignorance in terms of the flexibility that provides in terms of both passive and active ventilation.

LOL you are starting to struggle if this is all you have to dispute.

Note that 60 degrees C max is a limit but equipment ages and performance degrades exponentially at the top end of the range. I would expect some sort of powered cooling och.

 

[drsmith]

LOL you are starting to struggle if this is all you have to dispute.

Have you considered how the internal components inside the typical desktop computer case are kept cool ?

You should stick to squawking in the asylum seeker thread. That way you'll only be losing one argument at a time.

 

[H C]

Have you considered how the internal components inside the typical desktop computer case are kept cool ?

Have you considered that we dont place "typical desktop computers" out in the street exposed to the elements 365 days of the year? They usually have a great big brick shell around them called a house. Those components in desktop computers are not going to be running at 100% or near 100% utilisation 24/7 either.

 

[sptrawler]

Regional Power Stations through out W.A, have tin sheds full of high speed turbo diesel engines running at 3000rpm. These engines and the alternators are controlled by electronic control modules, including plc's and avr's. The sheds aren't air conditioned, nor the electrical control panels (when I worked on them) and electronics failure was extremely rare.
I'm talking about Power Stations in Marble Bar, Nullagine, Halls Creek, Wiluna etc, where temps inside the stations can hit 60c, no problems.
The amount of heat you are talking about in a low current system, like the NBN electronics, is far less than the heat stress your underbonnet car computer is subjected to.
I think you need to get a grip on reality.

If your so $hit scared of the heat related problems in an optical fibre node cabinet, best you don't drive your car.

How many of you have A/C units outside in direct sunlight, OMG you must be worrying endlessly.lol
The A/C unit electronics not only has to put up with ambient temps but also the heat generated by the compressor and and condenser.