Home Schooling ICT, part 3: E-mail.

The focus for the next few lessons will be to look at the common office software. I think this next part of the home schooling course is DD1’s favourite. She really enjoys messing around with fonts and sizes in power point presentations. Perhaps it’s because that’s what she sees Mummy and Daddy doing most frequently.

Lesson 3: Keyboard and email

Objectives:

•       Keyboard skills: letters, numbers and symbols

•       Sending emails

•       Difference between letters and emails

1.     http://e-learningforkids.org/Courses/EN/Advanced_Keyboarding/module1/start.htm

2.     Log into gmail

3.     Write an email to Mummy telling her about what we’ve learnt

4.     Read F. Scott Fitzgerald’s letter to his daughter (#2) http://flavorwire.com/363537/adorable-letters-from-famous-authors-to-their-children

5.     Critical evaluation - How are letters different to emails? Why?

The main conclusion I’m aiming for in this section of the course is that each method of communication has its own characteristics, and therefore one should use them with their strengths and limitations in mind. To me, because letters take longer to write and to read, they should be crafted; they should have a beginning, a middle, an end, and a narrative to link the three. Emails are much more immediate, and should be used to precisely and concisely convey meaning; they need to be clearly set out to be easily read, intent to be explicitly and unambiguously set out, and they need to be short enough to be absorbed without effort.

Using the online materials gave mixed results this week. The online keyboard course is quite good, nice “gameplay” and characters, but it’s a bit long. She happily spent 15min working on the first module, until I asked her to exit the module. I think a full 40min of typing wouldn’t keep her attention.

The reason I chose F. Scott Fitzgerald’s letter is because of the positive message he gives to his daughter, that she should worry about the things she can control and not the opinions of others. It shows that peer pressure has always been acutely felt. He’s very grown-up in his use of language to his young daughter, and we learn a little about his relationship with his daughter through the letter. However, I think this was a bit too nuanced for DD1 in the context of the ICT course. Maybe DD1 will come across him again when later on in life.

More in this series: part 2, part 4.

Multicasting the Future of Cable

There’s a fundamental bottleneck in the delivery of bandwidth over cable (HFC) networks: the coax cable itself. As far as bottlenecks go, it’s actually quite large; under commonly deployed technology standards, there could be 100 Mb/s uncontended bandwidth available per person. However, when you consider that the future holds 4k TV (~40Mb/s), 3D (~15Mb/s), HD (~10Mb/s) as well as 300+ channels of SD (~600Mb/s), the bandwidth starts to look quite small, especially if all of this content needs to be broadcast. Fortunately, it doesn’t.

(For those interested, my maths is as follows: Let’s say there are ~30x 8MHz channels in the available frequency spectrum, and each channel can carry ~50 Mb/s under QAM 256, giving total downstream bit rate of 1.5 Gb/s. With a segmentation of 15 homes passed, that gives 100 Mb/s uncontended. The more of that bandwidth that can be reused by more than one consumer, the more services in total that can be carried.)

Currently, the bulk of that bandwidth is to deliver video (TV and VOD) broadcast, i.e. everyone can receive same traffic. This technology platform has enabled a business model for Cable that has existed for the last 25 years. However, the new (at least for Cable) technology model of delivery of Video over IP gives the opportunity to significantly improve the efficiency of bandwidth utilisation. Fundamentally, the opportunity is this: if only one channel is being displayed on the TV, why are we bothering to broadcast all the possible channels? Why not just deliver the channel that’s actually being watched? This 1:1 mapping of content to consumer is inherently possible with Video over IP.

In a previous post I talked about how the Cable industry seemed unfazed by the OTT models that were taking root, and potentially siphoning off some revenue. Regardless of the denial against the competition model, the change of technology is undeniable: the Cable industry is clearly moving away from DVB standards towards delivery of Video over IP.

It actually seems quite a logical move. The Cable industry generally doesn’t like being a technology pioneer, because being first means taking big risks of failure, and Cable investors like the guarantee of revenue and avoid any risk to this revenue. Thankfuly, Video over IP has had over 10 years of testing on the wilder Internet, and robust standards have emerged, standards that Cable is comfortable in adopting.  Standards that cover all areas except one: how to deliver content efficiently and reliably to a large group of consumers.

(The Internet is wild, and for a good reason. Guaranteeing a quality of service costs big money, so by doing away with trifles like efficiency and reliability, the Internet becomes a cheaper place to do business. However, retrofitting efficiency and reliability becomes an expensive and challenging proposition.)

A Multicasting protocol has been developed as a way of delivering content efficiently to a large group of consumers, and does work pretty well. Not only does it allow the same traffic to go to multiple recipients, but the traffic doesn’t flow at all if nobody requests it. That’s an improvement on current DVB. However, multicast currently works on UDP, and UDP is connectionless and therefore unreliable; there is no way in UDP to check that the traffic packet sent actually reached any recipient. And with the heavy video compression techniques in use, a dropped packet could result in a break in viewing of 1s or more, enough to rile the most placid of TV viewer.

A reliable multicasting protocol is needed to make this technology work for Cable. This problem has been tackled by engineering groups, and groups such as Cisco with PGM (Pragmatic General Multicast, RFC3208) and IETF with NORM (NACK Oriented Reliable Multicast, RFC5740) have submitted experimental standards. However, they have yet to be deployed at any scale, so stop short of being a solution. The industry needs a pioneer to develop a scaleable solution, and it need not be from the Cable industry. The ongoing trials at the BBC look very interesting, so perhaps it’s the Content industry that will lead the way.

Home Schooling ICT, part 2: Copyright.

The focus of this week’s lesson was to look at the privacy and legal issues of online behaviours. I wanted to introduce the idea that web sites (and therefore other people) know more about her that she explicitly gives permission, and that even though digital piracy is easy, digital commerce is easier.

Lesson 2: Staying safe and legal with other digital media

Objectives:

·       Identifying types of digital media

·       Understanding ownership of digital media

·       Understanding comparative value of digital versus physical media

1.     Write a list of all digital media types

2.     Look at a [school] photo posted. Did all the children want to be posted online? What happens if they decide when they’re grown up that they don’t like their picture?

3.     Go to bbc.co.uk/privacy/cookies/ and learn about cookies and what they are used for. Think about why cookies may not be a good idea. Write a list of good and bad things about cookies.

4.     Draw a flow of money in a physical media transaction, and then of a digital media transaction. How does this flow change if media is shared?

5.     Find examples of things that have a copyright disclaimer.

6.     Buy some digital content legally: decide whether to download new DM album from 7digital, amazon or iTunes.

7.     Critical evaluation - How many different ways can one pay for content? Why is it important to pay for content? Why might people not pay for content?

The conclusions I was aiming at were that: she needs to be critical in how she shares information online; that there is a whole value chain that relies on consumer purchases; and that there’s more than one value chain.  I don’t think I succeeded in the last point, because we didn’t have time to discuss advertisements properly. We also didn’t really examine the grey area of copyright: fair use. These last two points get quite sophisticated quickly, and I think are above KS2 ability level. However, it’s because they are still areas of debate for even knowledgeable commentators, that they are still important concepts to introduce.

More in this series: part 1, part 3.

Home Schooling ICT, part 1: e-Safety.

My eldest aske me to give her lessons about ICT (Information, Computing and Technology) because she wanted to take her school lessons further. So I developed a 10 week course that covered the topics that she wanted, and the topics that I thought were important: e-Safety, Office Apps, Researching on the Internet, and using her Raspberry Pi. It’s been a really interesting learning experience for me: which topics to choose, how to pitch the topics to the right age and ability, how to deliver the topics to be engaging. I’m going to post how each lesson went.

Lesson 1: Staying safe on the Internet

Objectives:

·       Identifying safe and unsafe behaviours

·       Playing nicely online

·       Understand what to do if unsure

1.     List of 5 favourite online activities

2.     http://www.thinkuknow.co.uk/5_7/

3.     Follow links, read and discuss

4.     Watch a cartoon from Hector’s World

5.     Search for <me> online. Follow the links, and write down all that you can find out about me.

6.     Critical evaluation - have I been safe online?

My approach was to highlight how her online behavoiurs could be easily misinterpreted because there are no contextual cues. And these contextual cues help to identify undesirable people and their undesirable behaviours. The analogy I used was the school playground – a behaviour that would be mean in the playground would also be mean online.

My eldest told me that her school had already played some of the “Hector’s World” videos, so these topics were familiar to her. The task to search for me online was quite surprising – apparently I may have a criminal record in the US! But it nicely highlighted that relying on the Internet was itself an unsafe behaviour (more on that in a subsequent lesson).

She was more engaged when the activity needed her to click or type or write, rather than reading  or watching or listening. Her attention span also dropped to almost completely distracted just before the hour mark – must make sure I pace the lessons carefully.

I think she enjoyed the lesson, and I certainly enjoyed giving it. We’re both looking forward to next week.

More in this series: part 2.