The irony of NBN’s satellite numbers

After spending millions on consultants to criticise past decisions in the 2013 NBN Strategic Review, the company responsible for building the National Broadband Network, NBN Co, has repeated supposed past mistakes in a metric definition.

The review was highly critical of the former management of NBN Co when it stated that its Interim Satellite Service (ISS) had passed 250,000 premises when the satellites only had capacity to service 48,000 premises:

NBN Co has previously reported Satellite premises covered as 250,000, however the Independent Assessment considers that it is more appropriate to report 48,000 Premises Passed given the contractually limited capacity of the ISS.

NBN Co Strategic Review, Page 50

Consequently, the review revised the company’s performance figure down in the review — stating the former management had missed the target of 250k premises by 80% (page 40) by reclassifying the meaning of the metric.

Strategic Review says that NBN Co has missed their Corporate Plan target by 80% by "reclassifying" the meaning of Satellite Premises Passed
Strategic Review says that NBN Co has missed their Corporate Plan target by 80% by “reclassifying” the meaning of Satellite Premises Passed

Yet, three years later — here we are again with the company using the total satellite footprint as their headline “Premises Passed and Ready for Service” figure.

NBN Co’s weekly progress report, which provides a high-level summary of premises passed across Australia, says 404,064 premises have been “covered” by the Long Term Satellite service. Yet, in the 2016 corporate plan, the company states that satellites only has the capacity to service 250,000 premises at a time.

Following the footsteps of the Strategic Review, NBN Co will technically miss its corporate plan satellite target by around 50%.

NBN Co reports 404,064 premises covered by satellite as at 16th June 2016, yet the satellites can only handle 250,000 premises.
NBN Co reports 404,064 premises covered by satellite as at 16th June 2016, yet the satellites can only handle 250,000 premises.

The hilarity of it all

What can I say? Metrics are arbitrarily defined by those who want to portray a specific outcome. Criticism of metric definition is moot, and really occurs only when trying to pursue a line of argument intended by those writing it. The Strategic Review is an excellent example of this.

Perhaps unnoticed by many at the time, the numbers in the review favoured the Multi-Technology Mix even though there was no increase in capacity for the satellite.

The review considered only 206,000 premises passed by FY16 in the “revised outlook” — however, it magically jumped up to 340,000 premises passed in the adopted “multi-technology” case without any physical changes to the satellites.

NBN's satellite apparently passes 340k by FY16 premises in the MTM model
NBN’s satellite apparently passes 340k by FY16 premises in the MTM model
... yet in the revised outlook, only 206k premises are passed with satellite even though there are no changes to the satellite
… yet in the revised outlook, only 206k premises are passed with satellite even though there are no changes to the satellite

Remarkable isn’t it? Just goes to show how a metric can be reclassified to portray missed targets, then rapidly reclassified again to make your own rollout model look better 😉

Just how fair is nbn’s proposed Satellite Fair Use Policy?

Simple maths shows 2x more per-user capacity compared with interim satellite, but only 0.7x more data allowance is proposed.

After revealing the proposed restrictions and fair use policies to help manage traffic and congestion on nbn Satellite service, some residents have taken to Whirlpool Broadband Forums to express their concerns.  The primary concern being that a 75 GB 4-week rolling average limit doesn’t translate to 75 GB of “anytime data”.

According to the draft Fair Use Policy, nbn will — in addition to limiting the maximum usage per service to 75 GB on the standard CVC Class 0 — also limits the ISP-wide 4 week rolling average download and upload during peak periods (from 7am to 1am the following day, local time).  Currently, the base CVC Class 0 is proposed to be 15 GB download and 3 GB upload.

This means, if the Fair Use Policy isn’t altered before the final satellite product release, a service provider would have to either carefully balance a number of lower capacity plans with higher capacity plans to maintain an average of 15GB, or offer one plan that provides close to 15GB with around 40GB of off-peak data up for grabs for all users.

CVC Class AVC+CVC Fee
(25/5 Mbps)*
User data cap
(4-week rolling avg)
Peak Period Download
(ISP 4-wk average)
Peak Period Upload
(ISP 4-wk average)
0 $27.00 75 GB 15 GB 3 GB
1 $45.00 100 GB 20 GB 4 GB
2 $67.00 150 GB 25 GB 5 GB

Realistically, however, we can expect RSPs to oversell slightly given the 15 GB limit is averaged across the ISP using the assumption that a portion of their users will not reach the 15 GB limit.


Comparing increased capacity with Fair Use Policy

But just how fair is this 15 GB / 3 GB averaged limit being proposed by nbn?  Let’s see how it compares with the current nbn Interim Satellite Service and nbn Fixed Wireless network.

Per-user allocated capacity

Firstly, let’s check how much satellite capacity is expected to be assigned to an end user.  Since nbn imposes minimum customers-to-CVC (AVC-to-CVC) ratio (so RSPs can’t hog virtual capacity), we can calculate these numbers by dividing the CVC capacity by the maximum and minimum customers.

Estimating the per-user allocated capacity on the draft NBN satellite service FUP
Estimating the per-user allocated capacity on the draft NBN satellite service FUP

As seen above, this averages out to be around 125 kbps per user on CVC Class 0, 145 kbps per user on CVC Class 1 and 190 kbps per user on CVC Class 1.

CVC Class Maximum CVC (Mbps) Average per-user capacity allocation (kbps)
0 475 125
1 550 145
2 735 190

In comparison, the dimensioning of nbn‘s Fixed Wireless network allocates roughly 500 kbps per-user and 40 kbps on the current nbn Interim Satellite Service (ISS).  In light of this, let’s compare the percentage difference in capacity on the various CVC Classes compared to Fixed Wireless and ISS:

CVC Class Per-user capacity (kbps) % of ISS capacity (40 kbps) % of FW capacity (500 kbps)
0 125 313% 25%
1 145 363% 29%
2 190 475% 38%

So, the standard CVC Class 0 product has roughly 2 times (or is 313% of) per-user allocated capacity on the Interim Satellite Service.  It is also roughly a quarter of the capacity on the NBN Fixed Wireless network.  How do the Fair Use Policies for the ISS and Fixed Wireless compare numerically to the proposed Long Term Satellite?

Fair use policies

Interim Satellite Service: nbn‘s fair use policy for the Interim Satellite Service is structured similarly to the proposed Long Term Satellite policy.  Currently, the cap at a per-AVC (or customer) basis is 50GB.  313% of that would bring it to ~150GB, rather than the 75GB proposed.

But as we have said, this limit means little given the bulk of downloads generally occur during peak time.  While nbn doesn’t have a peak time average limit on the ISS, the company has mandated an ISP-wide averaged 9.7 GB download limit on a 4-week rolling average basis.  For this model, let’s assume that ~90% of traffic occurs during peak time — coming to an estimated ISP-wide averaged 8.7 GB download limit on a 4-week rolling average basis.  313% of that would bring us to ~27.6 GB, compared to the 15 GB proposed.

In summary, while per-user assigned capacity has increased by around 2x compared with the ISS — data limits in the fair use policy have only increased by a mere 0.72x.

Fixed Wireless: nbn‘s fair use policy for the Fixed Wireless network is straightforward.  RSPs must maintain, on average across their user base, less than 200GB download (let’s consider download only).  Like the ISS, there are no limits on peak/off-peak usage… but let’s assume that 90% of traffic is carried during peak time (meaning ~180 GB download).  If we take 25% of the Fixed Wireless fair use policy, we get 45 GB per month of peak time data per month.

Having calculated that, however, it’s important to remember that Fixed Wireless is a fundamentally different product.  Given it has far more capacity compared with any satellite product, there is more room to wriggle when it comes to the fair use policy limits.  However, for completeness sake, while the per-user capacity on the LTS is around 25% of Fixed Wireless — the data limits in the fair use policy are a mere 8.3%.

CVC Class % of ISS capacity % of ISS FUP (1) % of ISS FUP (2) % of FW capacity % of FW FUP (1)
0 313% 172% 150% 25% 8%
1 363% 230% 200% 29% 11%
2 475% 245% 300% 38% 17%

Table: % of per-user allocated capacity when compared with ISS capacity and FW capacity, and compares this with the % of the various data allowances set in proposed Fair Use Policy
(1) refers to the ISP-wide 4-week rolling average, (2) refers to the per-AVC cap (50 GB on ISS, not applicable for FW)

The summary

nbn appears to be very conservative when it comes to allocating data allowances on the Fair Use Policy.  Comparing to the Interim Satellite Service, per-user capacity has increased by between 2x to ~3x (depending on which CVC Class you choose).  However, ISP-wide peak-time data allowance only increases by between ~0.72x to ~2.5x (again, depending on CVC Class being compared).

As the writer doing the analysis, I believe there is scope for nbn to increase limits currently proposed in the draft Fair Use Policy.  Ideally, if service providers can buy two times more CVC capacity compared with what they can do on the ISS — they should be able to offer customers around the same amount more data… but I’m not going to sit here and pretend that using capacity can be calculated using simple maths.

Real networks are far more complex beasts, and simple calculations do not necessarily reflect how real networks behave.  But I believe a simple scale projection, as I’ve done above, would aid the public gaining some perspective on how little data caps have increased in comparison to the new satellite’s extra capacity.

All is not lost:

Some service providers who are helping nbn test their satellite systems before the Q2 2016 launch are actively working with nbn to get the best Fair Use Policy possible.  In the words of Paul Rees, the managing director at SkyMesh:

“We’re doing all we can to get the best FUP for customers that provides decent Data Allowances that don’t wreck LTSS performance at peak times.”

“The FUP hasn’t been set in stone yet, those numbers are just part of a draft document. So let’s have some calm, and save the ‘going nuts’ until the FUP has been formally decided.”

Wise words, Paul.  We wish you all the best in your pursuit.

NBN Long Term Satellite restrictions: revealed

nbn proposes standard 75GB data cap per month with 100GB and 150GB premium options to ensure satellites aren’t congested.

On Friday, nbn, the company responsible for building the National Broadband Network, released draft documents relating to the NBN Co Satellite Network set to launch in the second quarter of next year as part of the Satellite Trial Product Agreement.  The documents (see bottom of page) reveal a number of measures and restrictions expected to be taken by the company to prevent excessive use of data by end users.

CVC Classes

nbn will be introducing a concept called CVC Classes, which are essentially different levels of service on the NBN Co Satellite Network.  There are three classes, starting with the standard CVC Class 0, plus two additional premium CVC Classes — 1 and 2.  These classes are costed differently, have a different maximum contention ratio and have a different maximum data usage cap.

Cost

Cost-wise, the company will charge service providers an extra $18.00 and $40.00 ex. GST per Access Virtual Circuit (essentially, per end-user) for CVC Class 1 and 2 respectively on top of the existing AVC and CVC costs.  CVC Class 0 will have no additional charge.

The following table shows the AVC + CVC Class Fee. (Note: this is not representative of the cost of NBN Satellite plans.  Actual costs are likely to be higher as this excludes any CVC, NNI, network transit and peering costs incurred by Service Providers).

CVC Class CVC Class Fee AVC TC-4
12/1 Mbps
AVC+CVC Fee
(12/1 Mbps)
AVC TC-4
25/5 Mbps
AVC+CVC Fee
(25/5 Mbps)
0 $0.00 $24.00 $24.00 $27.00 $27.00
1 $18.00 $24.00 $42.00 $27.00 $45.00
2 $40.00 $24.00 $64.00 $27.00 $67.00

Data usage caps

On the data usage cap side, the company is two key enforcement metrics across all classes.  As part of the Fair Use Policy, nbn will introduce a per-AVC (essentially, per end-user) cap calculated on a rolling 4 week average basis.  The maximum usage over the four weeks are 75 GB, 100 GB and 150 GB for CVC Class 0, 1 and 2 respectively.  This is compared to 50 GB currently being enforced on the nbn Interim Satellite Service.

A second data usage enforcement metric is the “Peak Period” usage, which is calculated as an average across the Service Provider’s CVC Class user base.  During this peak period, defined as being between 7:00 am to 1:00 am (the following day) in the local timezone of the premises — the average upload/download data usage across all the ISP’s CVC Class users is 15/3GB, 20/4GB and 25/5GB for CVC Class 0, 1 and 2 respectively.

CVC Class AVC+CVC Fee
(25/5 Mbps)*
User data cap
(4-week rolling avg)
Peak Period Download
(ISP 4-wk average)
Peak Period Upload
(ISP 4-wk average)
0 $27.00 75 GB 15 GB 3 GB
1 $45.00 100 GB 20 GB 4 GB
2 $67.00 150 GB 25 GB 5 GB

* this is not representative of the cost of NBN Satellite plans.  Actual costs are likely to be higher as this excludes any CVC, NNI, network transit and peering costs incurred by Service Providers.

Failure for the service provider to comply with the data usage caps could result in data deprioritisation by nbn and/or shaping upload and download speeds to 256/256kbps until the issue is resolved.

Contention ratios

nbn will also place restrictions on the CVC-to-AVC contention ratio, enforcing a minimum number of end users a service provider must have on a particular CVC before allowing them to step up to the next tier.

On a CVC Class 0 CVC, the CVC capacity can range from the initial 100 Mbps up to 475 Mbps in 25 Mbps intervals.  The service provider must have at least 890 AVCs (equivalent to users) in that CVC Class in order to increase their CVC capacity beyond the initial 100 Mbps. A minimum of 210 additional AVCs are required for each 25 Mbps capacity increase.

For CVC Class 1, the maximum CVC capacity is 550 Mbps.  To move beyond the initial 100 Mbps CVC, the service provider must have at least 680 AVCs and can increase in 25 Mbps intervals for every 195 AVCs.

CVC Class 2 CVCs have a maximum CVC capacity is 725 Mbps.  Moving beyond the initial 100 Mbps CVC would require 548 AVCs and 25 Mbps increases for every 142 AVCs.

CVC Class Maximum CVC (Mbps) Minimum AVCs
(end-users) required
to move beyond
initial 100 Mbps
AVCs (end-users)
required for each
25 Mbps interval
beyond 100 Mbps
0 475 890 210
1 550 680 195
2 735 548 142

For assuming the 12/1 Mbps tier across all users: CVC class 0 provides a minimum contention ratio of ~1:106 with CVC class 1 and CVC Class 2 requiring a minimum contention of ~1:81 and ~1:68 respectively.

thoughts & analysis

Managing satellite network traffic has always been a tricky issue.  One one hand, the company doesn’t want to be perceived as disadvantaging rural and regional areas.  On the other hand, it is a necessity to make sure the service isn’t so heavily congested that no-one can use it.

The Interim Satellite Service was a good learning experience for nbn.  Service providers wanted to offer their users “unlimited” or high quota plans, thinking it could be offset by many more low-usage users.  They soon realised that the providers were unable to manage their own capacity well enough and soon, implemented traffic management policies to help manage the overly congested 48,000 users on the limited existing capacity of Optus and IPStar.

The limitations set by nbn are complex, there’s no doubt about that.  There are more intricacies that are omitted in this post — simply because they are too hard to explain simply.  These complexities means that small RSPs may struggle with implementing the traffic limiters and monitoring tools required to meet nbn‘s strict policies.  This could result in reduced competition in the long run.

On the quota…


Read updated analysis

Note from the writer: Please take this section with a grain of salt.  My views have changed substantially since this section was written because I had assumed that an end user could actually access all of the 75GB, 100GB and 150GB of data on CVC Class 0, 1 and 2 respectively.  However, it is now evident to me that the Fair Use Policy has implications on time of use and doesn’t account for data incurred during shaped data usage.  Please read the updated analysis for more information.

So, will 75 GB on a rolling 4-week average be enough? As a standard quota, I think it will fit within most people’s needs.

Currently, NBN offers 50 GB on a 4-week rolling average to their Interim Satellite Service.  So, 75 GB may seem like a small bump — but it’s 50% more nonetheless.

To keep things in perspective, statistics released by ABS show the average data consumption across all fixed-line technologies (end of 2014) is around 60 GB.  Further to that, the statistics released by nbn in their end of FY14/15 shows average data consumption on the NBN has steadily risen from 80 GB in September 2014 to 109 GB in June 2015.  So on an average consumption basis, I think the 75 GB monthly quota would fit the bill for most people.

So while nbn would expect most customers who take up a standard-tier 75 GB plan, the option is there to bump it up to 150 GB which is technically above the 109 GB average for current fixed-line/fixed-wireless nbn end users.

We also need to consider the demographic of the majority of these users: they live in very rural or remote communities.  Most regional centres are serviced by NBN Fixed Wireless and some form of NBN Fixed-line technology.  The remaining of these customers would have previously had very limited Internet connectivity, if any.

The standard 75 GB, plus the option of the more expensive 100 and 150 GB tiers will provide these rural communities with more than just a taste of online connectivity.  It will give users access to services like email and YouTube, and perhaps even more revolutionary — access to video conferencing through the likes of Skype or access to massive libraries of online TV content on Netflix, Presto or Stan.  All this will be possible within the confines of 75 GB, provided image quality is throttled accordingly.

Ideally, of course, each user should be given more capacity.  Hopefully, with the launch of the second satellite, nbn is able to augment some of the redundancy capacity on that satellite to use as more bandwidth for each user.

Relevant documents

[Source: nbn Testing Arrangements, Satellite Trial Product Terms supporting documentation]

NBN Long Term Satellite beams

NBN to cease Interim Satellite orders mid-November

Remote customers advised to wait until Long Term Satellite launch in the second quarter of 2016.

The company responsible for building the National Broadband Network, nbn, has updated their public website this afternoon — informing customers wishing to connect to their current Interim Satellite Solution (ISS) and the nbn™ Satellite Support Scheme (NSS) that it will cease accepting new orders for both services on November 15th, 2015.  nbn will also cease installation of new equipment from December 15th, 2015.

This comes as the first NBN satellite, Sky Muster, successfully launched at the start of this month and is expected to commence commercial services in the second quarter of 2016.

The company has advised would-be customers of the ISS and NSS that after the cease-sale dates for both services:

[…] you will need to wait for the launch of our Long Term Satellite services expected in the second quarter of 2016 and then connect your retail service provider.

The Interim Satellite Solution (ISS) was a temporary service set-up to replace the existing Australian Broadband Guarantee (ABG) while the new NBN satellites were being designed and launched.  The service, which uses existing satellite capacity on Optus and IPStar satellites, reached its maximum capacity of 48,000 customers in mid-December 2013 when it saw higher-than-anticipated take-up and use — leading to a serious congestion during peak periods.  The company had since implemented a number of changes, including enforced data caps, to prevent service abuse.  The service was opened up to an additional 9,000 activations in April 2014.

The new Long Term Satellite (LTS) significantly upgrades the existing satellite services on both the ISS and NSS, and is designed to deliver speeds of up to 25 Mbps download and up to 5 Mbps upload to customers in remote and regional Australia.

[nbn™ Satellite Support Scheme]

NSW Bogan to benefit from NBN satellite launch

Bogan rejoices over 25/5Mbps speeds in 2016

Residents in the settlement of Bogan near Nyngan, NSW will soon benefit from the launch of the nbn’s first long term satellite called “Sky Muster”.  This is a big win for the community, whose broadband quality rating was determined to be “E” (the lowest band) by the Department of Communication’s MyBroadband analysis.

The satellite, expected to launch on the first day of October, will bring a massive network capacity boost over the current NBN Interim Satellite Service.  The company building the NBN says the satellites are expected to enter into commercial service some time in 2016 and will deliver speeds of up to 25 Mbps download and 5 Mbps upload to rural communities – such as Bogan, NSW.

According to nbn’s rollout map, there are three premises in the Bogan township:

  • 2403 Bogan Road, Bogan
  • 2835 Bogan Road, Bogan
  • 3185 Cathundral Bogan Road, Bogan

However, the accuracy of addressing information especially in rural areas may be patchy due to incomplete or out of date data in the GNAF database (Australia’s authoritative Geocoded National Address File).

opinion/analysis

This really isn’t news. The writer of this piece is aware of how many satire pieces out there poke fun at Bogan, NSW.  He simply wanted to add to this – while featuring the National Broadband Network.

He also apologises in advance for the bad pun.