My Thought on Chapter 6…

Transmission Systems & Packet Switching

Starting chapter 6, we are given key words (which I will list and define).

  • bandwidth- range of wavelengths, frequencies, or energies in a certain band
  • circuit switching- “when two nodes communicate with each other over a dedicated communication path”
  • dial-up
  • DSL- faster than dial-up, doesn’t require reconnection every time
  • Cable- provides transmission over cable TV technology
  • Fiber Optic- small strands of glass to make data transmission faster

packet switching- when a file is split up and “packaged” into different folders (packets), then each folder then makes its way to its own spot and then unpacks and repacks

the order is: source address -> destination address -> data length -> data -> error check

In class, we were given the example of a jigsaw puzzle to visualize the activities of packet switching. the packets are the puzzle pieces; they are unassembled and then reassembled. I found this especially helpful, being a visual learner.


Here are some review videos I have found helpful in reviewing the basics from Chapter 6:

Packet Switching Basics:

Packet Switching vs. Circuit Switching:

Transmission System Basics:

Field Trip: E-waste Recycling Center

Through the video we watched prior to our field trip, I learned many new things. For instance, I had no idea at what capacity US recycling is shifted to other countries. When we were shown clips of the working conditions of people on recycling plants in Hong Kong, I was very much so saddened. Being exposed to those harmful chemicals and elements without even being warned is a poor business practice as well as poor moral choices for their employers. The employees themselves didn’t know they were being exposed to mercury (from the broken tubes they showed) and the harmful effects of the toner leakage from printers.

However, at Temple, I was pleasantly surprised to learn about how we reduce and reuse BEFORE we recycle. I think the misconception is that recycling will solve all problems, but people often forget that it is the last step after the lifespan of an item. To be proactive, we have to put in the effort to take down the amount of waste we produce before it gets to the recycling phase.

I was surprised to find out that there was no program already before the time when our Recycling Center manager took over. I think it is extremely smart to have this program in a school this size. As he said, many people in the area (staff and students) are making enough just to get by, but not enough to get the technology they may need for their careers and school. The program is also a great way for students to learn skills involved with repair, customer service, and many other tech abilities. I think the way temple is offering the service is more than adequate. They are productive, open-minded, and really looking to help the Temple family. I think that when they obtain the new space, they will have even more room to grow and expand their outreach to more students and community members. I think their publicity will grow when they have a larger space, because they will have a greater sense of establishment. They are doing so much good and deserve better working conditions for their impact on campus.

Here is another video I found on how e-waste is recycled:

Foolish Tech Predictions…

The prediction I have chosen out of “The 7 Worst Tech Predictions of All Time” is #4.

“There is no reason anyone would want a computer in their home.”

I think that this was foolish to think in the first place. A computer is a way to access knowledge. I would not have assumed that no one would want their own personal one, let alone only having 5 in the world. I cannot imagine a life without having access to look up anything from a chicken recipe to a movement that happened before my grandmother was born. I do realize that I take it for granted, but most people take many things for granted every day. The person who made this assumption evidently did not factor this into his future plan.

Here is a video I found about technology predictions for 2018!


My thoughts on week 3…

This week we learned even more about binary encoding and other encoding systems. Some of the systems we learned about were ASCII, Unicode, and UTF-8. Unicode, or UTF-8, is a system which assigns a common code to a binary code. It was a fantastic system to represent computer commands and other various symbols, but ASCII was replaced by another system called Unicode. This system uses the first 128 codes from ASCII, but has also incorporated many more alphabets, languages, and even emojis. Unicode includes almost 140,000 every-expanding symbols, which is quite impressive. Similarly, the only reason we have for using binary encoding and binary numbers is so that there is less ambiguity in signal transmission. This is related to Unicode in that they both are used to sum up many codes into shorter sequences, easier for deciphering and use in the digital world.


Here’s a look at what ASCII, Unicode, and and UTF-8 are all about.

My thoughts on week two…

The big question of this week is why use binary encoding of numbers?

First, let’s clarify what a binary digit, or BIT, even is. A binary digit is defined as a modern communication system based on numbers. Sounds simple enough, right?

To answer our previous question, we use binary encoding because it is easier to clarify if a number is high or low and also because there is less room for questioning/ambiguity.

Converting from decimal to binary to octal and hexadecimal is something I have never done before, and am still trying to get a grip of… So, rather than trying to explain it to you, we’ll watch the following video and improve together. Just remember the bases of your numbers!

My thoughts on week one…

Here are some thoughts I’ve had throughout our first week in Digital World. I found it fascinating to learn about the phonograph and the process of how it later turned into vinyl records. I never would have thought that they came from a button factory. Other than the phonograph, I think all the fundamentals we have learned about this week are 100% essential to understanding how our digital world functions today. Without these bold first advances of the time, we would not be where we are today in this tech-savvy world. So, here are some main ideas I’ve grabbed onto and some examples/thoughts/insights on why they might be so important to understand.

Idea #1: Scientists are different from engineers in that they are the ones who explain how systems work as opposed to engineers who are creators of various new things.

MY TAKE: Although scientists and engineers are often grouped together by people (including myself) who are not fully immersed in the technological and scientific areas of study, I have learned more about their differences this week than I have in the past year. Without both, of their own measure, we wouldn’t have things such as the phonograph or the telephone. These are just two examples of things we have examined in class, how they work, and how they have come to be.

Idea #2: Information vs. Signal vs. Message

Information- knowledge given/taken

Signal- physical thing that transfers from sender to receiver

Message- content of knowledge given/taken

MY TAKE: These concepts are pretty easy to grasp, so let’s go with an example to identify these key terms in an everyday situation. For example, you call a friend and tell her that you got an A on your test today. In this case, the signal is the means of your phones connecting, the information is your friend learning of your A on your test, and the message is your speech and sound and content of telling your friend about your A.


Idea #3: Transducer vs. Transmitter vs. Receiver vs. Transmission Channel

Transducer- device that converts energy from one form to another

Transmitter- device that sends the transducer signal

Receiver- device that recovers transmitted signal from the channel

Transmission Channel- physical medium on which signal is carried

MY TAKE: Without the understanding of the phonograph, people may never understand how important it was to affecting what are now our vinyl records, our CDs, and our DVDs. They operate under the same basic ideas. Bringing back up the phonograph example from earlier, we will now identify the parts of the phonograph that correspond with our Idea #3 key terms. Our transducer is the diaphragm of the phonograph, our transmission channel is the crank arm/wax cylinder, and our transmitter is the stylus (needle).


Idea #4: Frequency and Analog vs. Digital Signals

Frequency- number of complete cycles of a waveform (in Hz)

Analog- infinite number of values in a range, continuous, more difficult to work with

Digital- can have a limited number of values in a range, discrete, easier to work with

MY TAKE: Although the analog system is our older and more difficult system to use, it has taken us up to about the middle of the 20th century. From the phonograph to radios and the volume controls on TVs, analog systems have come in handy for their basic operation. Analog signals provide clearer answers since their numbers are more precise and digital are a tad easier to work with, not giving as much precision as analog. Digital information systems today include our computers and cell phones, but also include morse code as one of its top examples.


Idea #5: Switching System vs. Signaling System

Switching System ex: old fashioned telephone switchboard

Signaling System ex: part of the telephone system that establishes and controls connections

MY TAKE:  The switching system, as you may have guessed, is the older system used by telephone operators and consumers alike well into the 1960s. The signaling system is a more enhanced form of this technology that does the work for us in a sense. I believe it is still important to see how far operators did come in their time using this switching system and to see how difficult it may have been for them to make physical connections while today not a thought it put into it.