3.4.8 Discuss the need for speed in data transmission, and how speed can
be enhanced.
Teaching Note:
Students must know that documents and graphics files can be sent in
different formats and the format affects the speed of transmission.
Common formats such as JPEG and BMP should be known. The
principles of data compression should be considered but details of
methods are not required.
JSR Notes:
The San Andreas assessment statement. And this is one of those ones that is pretty obvious, but still, you need to have a way to address it prepared; it would be a silly question to find yourself wasting time scratching your head trying to come up with a way of stating the obvious. We need speed in transmission for all the same reasons we need reliable systems. All of our transmissions have a reason, and the sooner that reason is met, the better. And in fact, network transmission can often be the one most irksome bottleneck in a computer system. Everything else you do on a computer whizzes right along until you start downloading something, so the faster the better.
And in terms of the teaching note, compression generally serves two purposes, firstly, it saves storage and primary memory space, but now-a-days neither is much limited. But when it comes to the second purpose, transmission, compression really does help. Often times you can compress various media files to anywhere from half to one-tenth their original size, which reduces the time it takes to transfer that file from half to one-tenth the time.
Note that often times quality is visible/auditorially reduced, but often times not, while still yielding substantial gains in size reduction. Furthermore there are many "loss-less" compression technologies that limit the compression algorithms to things that take away none of the original data.
In fact, both of the examples worked out in detail in the text book would be considered loss-less compression. So you get increased speed in transmission, and absolutely no loss in data quality. Nice.
Note that whenever there is something in the text book that either explicitly or obviously is not related to the syllabus assessment statements, you really shouldn't spend too much time with. Personally I love the concept of vector graphics in relation to the need for speed, but you've got enough to occupy yourself with that is required.