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Broadband speed and the difference in averages
Monday 17 November 2014 07:03:13 by Andrew Ferguson

To start this week off we thought we would show some more detail on the various speeds seen, particularly after some questions have been raised as to why the median speeds we usually show in our speed test summaries can be lower than some other sources.

The main difference is that we quote a median speed when talking about ISP and regional speeds, which means that half the people in an area will get faster than the figure and half slower. The mean which is generally what people mean when they say 'average' tends to be higher in cases where a few connections excel, so may overstate what is generally available

Download Speeds from our speed test for October 2014
  Speed 90% will achieve Median Mean Top 10%
England 1.9 Mbps 12.1 Mbps 22.3 Mbps 54.7 Mbps
Northern Ireland 1.7 Mbps 13.3 Mbps 23.2 Mbps 53.2 Mbps
Scotland 1.8 Mbps 8.8 Mbps 18.4 Mbps 47 Mbps
Wales 1.3 Mbps 6.7 Mbps 16.2 Mbps 40.2 Mbps
ADSL/ADSL2+ 0.9 Mbps 4.2 Mbps 5.5 Mbps 12.1 Mbps
FTTC 10.9 Mbps 32.3 Mbps 33.2 Mbps 62.8 Mbps
Cable 9.3 Mbps 34.5 Mbps 45.4 Mbps 98.4 Mbps
FTTH/FTTP 8.4 Mbps 98.6 Mbps 139 Mbps 255 Mbps

The graphic above that we tweeted over the weekend shows the difference that quoting our usual median speed (left hand image) compared to the mean makes very easily. The degree of difference highlights the need for those promoting broadband and publishing data to make it clear whether discussing median or mean speeds.

For the average consumer us telling you what the average speed in Wales is means very little as what matters to you is what speed you get to your house and what faster speed options you have. Fortunately most broadband providers now provide a speed range when you make an enquiry and/or sign-up and this will often be given as a range of speeds.

Comments

Posted by TheEulerID over 2 years ago
The lower decile measurements look odd, especially cable & fttp which don't suffer distance degradation. As far as I'm aware slowest cable & ftth speeds are 50 & 40mbps respectively so speeds below 10mbps look strange. It might be congestion or poorly conducted tests, but there must be some doubt over what it means.

Even FTTC beat cable and FTTH on that measure, despite distance issues.


Posted by herdwick over 2 years ago
@TheEulerID - FTTC has a guaranteed data rate to the cab per user whereas cable has a big gang sharing a common pipe so I can see how this arises. I think "Bottom 10%" would be a better heading as 90% achieve *more than* the first column.

I do like medians and percentiles, virtually nobody achieves the average in practice (how many people have the average number of legs etc)
Posted by andrew (Favicon staff member) over 2 years ago
FTTH also available at 20 Mbps and 40 Mbps. Also on cable still a good number on older legacy speed packages to account for lower.

Of course I could model and include/exclude good/bad results and come up with a 'perfect' model but then that would not reflect the experience of everyone.

As things stand we have seen the bottom 10% and 25% speeds improvement a lot in the last year or two.
Posted by TheEulerID over 2 years ago
I mentioned the 40mbps FTTH speed, but I didn't know about the 20mbps service.

However, the point isn't so much about correcting for it, but to note that the exceptionally low speeds are less trustworthy as it is open to all sorts of testing environment issues, In contrast, it's not really possible for the upper decile figures to be distorted upwards.

So I'd urge caution in interpreting the lower decile figures.
Posted by andrew (Favicon staff member) over 2 years ago
So would I, but there are those that want people to advertise with the lower decile figures.
Posted by herdwick over 2 years ago
Agreed, but in the vernacular of the whingeing campaigner it's all the fault of the supplier if your set up is broken and results consequently dismal.
Posted by gerarda over 2 years ago
The last decile will be a crucial measure when the Govt/Ofcom/BT fudge the outcome of the BDUK rollout
Posted by TheEulerID over 2 years ago
@gerarda

The lower decile of measurements is not comparable with the political targets. The political targets are about availability, whilst the measurements are also about what people care to pay for. A significant part of the market will go for the cheaper option, which will very often be slow ones.

It's easy to model actual capabilities once there's a statistically significant take-up of FTTC given actual line sync data and the distribution of line lengths. Unfortunately that data isn't generally available, but BDUK auditors will surely have access to it.
Posted by Blackmamba over 2 years ago
Hi TheEuler
I think the result that have been advertised by Thinkbroadband Staff are ok as they are the (average/median) when they are dropping off the lower results at three months aprox 90 days if this is correct. If this is not correct the results are much lower.
Posted by andrew (Favicon staff member) over 2 years ago
@Blackmamba Please stop obsessing about the three months. County Councils and providers are free to contact us for individual runs of statistics and our explanations of the various oddities that do show up.

When we publish Q4 2014 results it will be 1st Oct 2014 to 31st Dec 2014. Monthly results speak for themselves.

The three months on the maps is a rolling 90 day window.
Posted by gerarda over 2 years ago
@TheEulerID

Having had 8 years of universal ADSL availability which has been no where approaching universal any independent stats which would indicate the numbers getting quoted are similarly fabricated is a plus.
Posted by Blackmamba over 2 years ago
Hi Andrew. staff.
I have been checking the results on many post codes and I am finding the window is larger than 90 days. I have also found that an ISP SKY switches the data from one post code to another GU102NZ to GU102NY. The fault on the ZEN lines 20/2 is with Openreach for 1month we have had over 20 staff. In your view could the modem/router trans padding be changing
Gu102NZ. Cab 12. GU102NY Cab 6
Posted by andrew (Favicon staff member) over 2 years ago
@Blackmamba The NZ and NY issue was previously explained before and the few times you've insisted there is a mistake on the removal we have checked and all has been working as planned.

As I've said the map is not intended for ripping to produce statistics by third parties, if people need to do that in official capacity they should talk to us properly.
Posted by TheEulerID over 2 years ago
@gerarda

Ofcom report that broadband availability in the UK is close to 100%. Of course, there are not-spots, and for a significant proportion it's very slow. (Although we certainly haven't had a claim of universal coverage lasting 8 years).

Of course, even a 99.9% coverage would leave approaching 30,000 premises without a service, so there will be plenty of counter-examples for the cynics.
Posted by Blackmamba over 2 years ago
Hi Andrew Staff
Many thanks for your reply.
I am not ripping stats for a third party all I am trying to do get the ZEN line above Surrey 15 meg Target and hold,and also prove the line will surport 40/10 which the customer is paying for. Just think how many more are being ripped off.
Posted by andrew (Favicon staff member) over 2 years ago
And the line length is what?
Posted by Blackmamba over 2 years ago
Hi Andrew Staff.
The cable lenght is 1800 Mtres master socket Cab 12 post code GU102NZ position in road. Hindhead Exchange I think it should be above 15 meg not dropping below 6 meg.
The distance from Cab 6 distance to GU102NY is aprox .5 mile this should give 36 down. Headley Down exchange.
I feel the post code should be split I think there is a feedback .
Posted by gerarda over 2 years ago
I was told in 2006 by a senior govt economic development official that broadband was "a job done". All policy until very very recently as been based on that assumption.
Posted by andrew (Favicon staff member) over 2 years ago
A line at 1800 metres will not support speeds of 40/10 and even 15 Mbps is pushing it. VDSL2 does not always behave to plan once you get to line lengths like that.

We will not be adding the extra zoom level because it involves creating many Gigabytes of further information.
Posted by Blackmamba over 2 years ago
Hi Andrew staff
Maney thanks for your time I will just have to wait three months for SkY to be removed.
Posted by Blackmamba over 2 years ago
Hi Andrews staff
Just checked my data and the SkY should be removed on the 23-24 December many thanks again I have contacted the customer and told him your findings
Posted by gerarda over 2 years ago
&TheEulerID You might care to read the digital britain report of 2009 for the sort of stats on which policy was being made then. - sub 2 mb speeds affecting "more than 1 in 10", 50% NGA coverage, and no mention of notspots at all

On the basis of "more than 1 in 10" being somewhat less than 1 in 8 say, those stats would indicate no improvement over 5 years.
Posted by andrew (Favicon staff member) over 2 years ago
Well our data shows a different picture.

In Wales
Q3 2009 51% of tests under 2 Mbps
Q3 2014 17% of tests under 2 Mbps

40% down to 11% in England
46% down to 13% in Scotland
57% down to 14% in NI
Posted by TheEulerID over 2 years ago
@gerarda
I've just read the relevant part of the "Digital Britain" report, and there is mention of not-spots (on page 52).

It also says that an estimated 11% can't get 2mbps. Whilst this site has a higher proportion of tests below that, it's a self-selecting sample, and therefore far from guaranteed to be representative. Also, slow results can be skewed through poorly conducted tests.

However, as Andrew shows, there's been a big change in test results with sub-2mbps results reduced by approaching over two-thirds.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
Customers on an exchange that has CN21 should be over the 2 meg target if they have taken up the option with their ISP,s
Posted by TheEulerID over 2 years ago
@blackmamba

By CN21, do you mean 21CN? As far as I'm aware, the only way that affects the speed of any particular line is that it utilises ADSL2+, rather than ADSL. There are other things like a fundamental change to the core network, carrying voice over IP and so on. But it doesn't guarantee 2mbps. That is surely where the 2mbps USC is to be implemented under BDUK projects.
Posted by andrew (Favicon staff member) over 2 years ago
@Blackmamba that comment about 21CN is pure disinformation. There is no way that 21CN guarantees the USC will be met, someone syncing at say 384 Kilo bits per second on a 66dB attenuation line might see a jump to 700 Kbps if they are lucky.

Some people have also found that using ADSL2+ and ADSL2 modes means long lines perform worse.

21CN IS NOT the solution to USC issues.
Posted by gerarda over 2 years ago
@the EulerID
Thanks for pointing that page out. The report's use of notspots in quotes defeated the search facility on my browser
However the figures are even more bizarre. For example only 550K (2%) of lines are too long to get 2mbs
Posted by gerarda over 2 years ago
@blackmamba
Our village is served by an exchange with ADSL Max and 21CN, and all the lines are connected to an FTTC enabled cabinet. Yet % of the properties are unable to get any fixed broadband and the other 20% less than 1mb.

I really do not know where you get your information from.
Posted by gerarda over 2 years ago
missed an 80 off in front of %
Posted by Blackmamba over 2 years ago
Hi Gerarda
Many thanks for your reply.
I see you have problems in your village from your remarks on CAB ? Location ?
I have checked many locations in Surrey and found that customers under 2 meg
either had faults or did not order the upgrade.
My son who lives in South Yorkshire on a very long line was under the 2 meg untill we had many visits from Openreach and we demanded to be transfered to CN21 this moved him to 3.5 meg.
I also made this statement at a meeting with SCC and Openreach thus logging the 70 exchanges in Surrey and ticked them of as the exchanges changed over to CN21.
Posted by gerarda over 2 years ago
@blackmamba
As Andrew said what you stated was disinformation.
Your son's line is obviously quite short compared to ours and you can't equate CN21 with ability to over-ride the laws of physics
Posted by Blackmamba over 2 years ago
Hi Gerarda
Many thanks for your reply.
It's seem that you and Andrew think I am incorrect that is OK with me . I have been dealing with this since 2004 in the Ewhurst Area.
Posted by gerarda over 2 years ago
we don't "think". We know from long experience. Andrews much more than mine. You are extrapolating from experience in one small area. if I was to do the same I would say that only 20% of the UK can get broadband.
Posted by Blackmamba over 2 years ago
Hi Gerarda
Thanks again for your reply.
I do no think Surrey is a small area or my son,s line is very short as it is classed over 1200 ohms line resistance. I have had experience from 1957 when I joined BT fist day overhead Long Lines.
Posted by andrew (Favicon staff member) over 2 years ago
1200 ohms resistance, but what is the attenuation for the line as reported by the modem?

http://www.coolwebhome.co.uk/calc will do the line stats based speed estimate for you

You are aware that probably most of those 70 Surrey exchanges already had ADSL2+ available via TalkTalk?
Posted by Blackmamba over 2 years ago
Hi Andrew Staff
I am refering to three years ago when most of the exchanges were not on CN21 eg Hindhead and many others. Once Hindhead CN21 was provided this switched from -2 to plus + 2 on most BT lines if they were changed over the other ISP,s had to request it and pay.
The 1200 ohms resistance leval was when small exchanges were absorbed into the larger exchanges some were spreed out over three exchange areas
Posted by andrew (Favicon staff member) over 2 years ago
And have you bothered to check when ADSL2+ arrived from Sky and TalkTalk who offer that from Hindhead exchange?

ADSL2+ is NOT JUST A 21CN tech.

So answer the question about the actual attenuation of the line? Sounds like your 1200 ohms was not an actual measurement. dB attenuation at 300kHz is the key measurement for ADSL/ADSL2+ speeds.
Posted by Blackmamba over 2 years ago
Hi Andrew Staff
The customer that was receiving 1.8 down was with ZEN on ADSl and did not want to go to Talk/Talk or SKY so he waited untill Hindhead went CN21 then applied for ADSL2+ he then received aprox 3.25 down at 4201 m getting him over the 2 meg target.
Posted by andrew (Favicon staff member) over 2 years ago
1.8 is cunningly close to the old limit for Home 2000, so may have been on the very old fixed speed services, rather than IPStream Max.

If you are running aome investigation or campaign, best to actually get the highly useful data like this along with attenuation figures.
Posted by gerarda over 2 years ago
@blackmamba 4.2km is a not a long line by rural standard, many are off the end of this chart
http://www.thinkbroadband.com/images/guides/broadband-speed/adsl-adsl2-distance-graph.jpg
Posted by Blackmamba over 2 years ago
Hi Gerarda.
This customers line was transfer in Jan to FTTC at a range of 1800m on post code GU102NZ it was banded to 20/2 thus having a problem of getting above the 15 meg (Surrey target) it has dropped to 6 meg. There is work over the week end using traffic lights Sat//Sun where I think the problem is ( E sides) the problem has effected another CAB 6.
Posted by andrew (Favicon staff member) over 2 years ago
As I have pointed out 1800m is pushing it for 15m, let alone Superfast.

Spending as much as they are on this one property is obscene when there are others in the county suffering the same or slower.

The 15 Meg Surrey target does it say everyone on a cabinet has to be above 15 Meg?

Posted by Blackmamba over 2 years ago
Hi Andrew Staff
The Surrey 15 Meg target is to the Post Code GU102HZ
Posted by andrew (Favicon staff member) over 2 years ago
So Surrey only has a target speed of 15 Mbps for this one postcode, very strange.

Really worried about how the County Council is running the project if spending so much time and money on a single postcode.
Posted by Blackmamba over 2 years ago
Hi Andrew Staff
SCC is not spending any money on this Post Code it's the ISP,s ZEN,and Titan the cost is running at aprox £3k not BT.
Posted by andrew (Favicon staff member) over 2 years ago
So why have Zen and Titan splurged £3000 on this one customer then?

ISP would take ten years at £25 to pay off this cost.

At 1800m it is well know to those who understand VDSL2 performance that small variations in local conditions can swing the speed drastically. Only way to improve speeds is more fibre or new thicker copper if sticking to fixed line tech.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
Costs are rising no traffic lights at 1200 hours Sunday.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers
ZEN is still holding the fault Referance open for the above Gu102NY traffic Lights not used over the weekend reason unknown.
Posted by Blackmamba over 2 years ago
Hi Broadband Watcher.
No new information Openreach is stalling so it must be something with ZEN ISP being on this CAB or they are unable to clear the problem.
Posted by Blackmamba over 2 years ago
Hi Broadband Watcher.
I have seen report that the DLM has been switched off could this be the problem all the time on this post code area GU102NZ,GU102NY.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers
The above speeds on the post codes still the same not dropping off hope to hear from ZEN on Monday.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
If the rumours are correct over this Cab plus the stalling by all sides this installation is modified to vectoring we will have to wait and see if I am correct, this will be better than the groundnut scheme of Africa.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
Both Openreach and ZEN are still stalling it is know that a pole is a D pole causing the drop in speed after the DP blocked has been changed the cost is still rising. I still think it is tied to the post codes.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
New update pole to be changed out on Wednesday with pole erection and traffic lights. The costs are rising
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
Openreach did not change out Pole on Thursday no traffic lights. The costs are rising.
Posted by Blackmamba over 2 years ago
Hi Broadband Watchers.
Openreach pole not changed out but had a rest on Gu102NZ FRIDAY advised profile on 40/10 from a line engineer. I think Openreachand and ZEN are stalling untill the end of the year reason ??.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
ZEN line running at 12-13 meg down up 1.6 up.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers
ZEN line running and holding but still on the incorrect post code.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers
ZEN line dropping under 10 meg ( (basic window) and returning to 12-13 still on incorrect post code.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
ZEN line still holding but post codes are not dropping off at the three month window 90 Days.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
ZEN is checking for a common fault on the network because the speed drops below 10 meg.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers
The Zen line still on the incorrect post code must be very close to the 90 day cut off on the SKY line which is controlling the situation.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
The ZEN line average is improving as the old results are starting to be dropped off but still showing on the incorrect post code.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
ZEN line window been extended by SKY yesterday one new test been made.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers
ZEN line still being checked by ISP and Openreach SF,s team and Rein team will be working on the 5/01/14. On this post code a BT line is showing over the 15 meg target location unknown.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
Update on the ZEN line faults still outstanding as the speed up and down still dropping fault has been passed further up the tree yesterday.
Posted by Blackmamba about 1 year ago
Hi Broadband Watchers.
ZEN line holding at 13.7 meg today after Openreach has changed out line cards over the weekend.
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