Monday, October 5, 2015

NBN Data Drought

ABC TV's Landline program featured "Data Drought" (Pip Courtney, 4/10/2015 1:22:26 PM). This concerned problems with the NBN Interim Satellite service. Internet speeds in rural and regional Australia were reported to be "... so slow it's impossible to do online banking or email a small photograph". One example cited was five students of the School of the Air who have to share 20 GB per month. The report appears to have been prompted by a recent meeting of the Isolated Children's Parents' Association. Also mentioned in the program is the Better Internet for Rural, Regional and Remote Australia Facebook page started by Kristy Sparrow.

One claim in the ABC program is that the NBN service has been sized for 48,000 customers, not the 200,000 it has. As a result there is only capacity for 10 gigabytes a month, not even the 20 GB currently allocated.

The NBN interim satellite users are now limited to 20 GB a a month, after which the service is shaped to 128 kbps, then further reduced by an unspecified amount for an unspecified level of use:
"If you exceed your Normal Data Allowance during a Billing Period, your Peak Information Rate will be reduced to 128/128 kbps for the remainder of that Billing Period. If you then increase your Excess Data Usage by placing a continuous load on the service, your Peak Information Rate will be progressively reduced. " From "SkyMesh NBN Interim Satellite Plans
But what is not clear is why this is effecting users in the ways described in the ABC program. The speed of 128 kbps should be more than enough for on-line banking, emailing photos and for e-learning (half that, 64 kbps, should be sufficient).

I use a wireless modem with a 10GB a month allocation, which then gets "shaped". This is fine for on-line banking, email, podcasts and low resolution video (as well as for tutoring and being a student of on-line university courses using Moodle).

E-learning should work well at 64 kbps. This should be more than enough for downloading documents, engaging in on-line text based discussion forums and uploading assignments. It should also be sufficient for limited podcasts and low resolution video. It also should be enough for webinars using audio and limited video (I have successfully used Blackboard Collaborate for webinars at 32 kbps). Applications which assume low latency and high bandwidth will not work well, but then these should not being used in this application.

Unfortunately the ABC TV program does not provide technical details of exactly what speeds remote NBn users are experiencing. However, "The shape of bush disconnection…" (Amanda, July 29, 2015) provides no only a first hand personal account of the problems, but also speed test results. These indicate speeds of 50, 65, 72, 95 kbps which Amanda describes as "Unrelentingly awful.". Then the unshaped speed of 2.16 Mbps as "our internet returned".

The problem may be that users who exceed the 20 GB limit and are then reduced to 128 kbps then attempt to squeeze the maximum amount of data from this and are then penalized with a further reduction in speed. The solution might be to reduce the data allocation further (for example to 10 GB) and reduce the speed after this to 128 kbps, but then not reduce it further. This should be sufficient for e-learning.

Also the applications used for e-learning may need to be checked to see if they are designed and configured for e-learning. As an example, webinar software is normally configured assuming a high speed link. The settings can be changed to suit a slower line. I generally set the system to 64kbps and for 8khz sound, even when I am using a high speed link. This gives slower video and sound like a telephone, rather than a hi-fi, but it works more reliably. Also some software works better than others (and some can;t be configured at all). I have sound Blackboard collaborate works well.

However, this is also a matter of perception. Someone used to 2.16 Mbps will find 95 kbps to be slow. The perception that city users are receiving much more data will decrease satisfaction with the remote service. There is no technical means to correct the relative imbalance between city and remote users, the remote Internet service will be tens or hundreds of times slower, even with new satellites, due to physics and geography.

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