“How
Ethernet Works”: Useful terms
This
article by Nick Pidgeon (2000) was the best overview for the basic terminology,
as below:
o
Local
Area (LAN) usually within a building
o
Wide
Area (WAN) think two local libraries, for example
§
Fiber
optic connections are blurring distinctions between two because of increases in
speed, efficiency
o
Protocol—set
of rules governing connections, must be shared by devices on networks; establish
rules for constructing frames
§
Maximum/minimum
lengths, required information (such as destination & source addresses),
§
No
two devices have same addresses
o
“Broadcast
address” causes all devices in network to receive; otherwise, devices discard
messages not intended for them (though they do “see” such messages if connected
to medium)
o
Medium—cable,
whether coaxial copper or fiber optic
o
Segment—contains
a single shared medium (i.e. cable)
o
Node—devices
that attach to a segment
o
Frame—chunks
of information communicated between nodes
Tone
of techno-topia: “How Home Networking Works” and “How Wireless Mesh Networks
Work”
The
first article are I read was Wilson & Fuller’s 2001 article on home
networking. It was pretty
straightforward. Most of the terms and concepts were not particularly new for
me. I did, however, find the discussion of advancements in the technology for
healthcare and housing to be interesting. Although some of the affordances that the
technology offers for healthcare providers to monitor patients at home and for
homeowners to control climate and security options for their homes while they
are away were really interesting, the slightly overawed tone put me off a
little. In fact, I also found the same
tone in Roos’ article, “How Wireless Mesh Networks Work” (2007). To be fair, he was talking about some of the
ways that wiring things that I’d never imagined wiring offers new opportunities,
it reminds me a little of the how-we-are-all-going-to-be-living-in-the-future
children’s books that I remember seeing when I was a child. I don’t think that sort of techno-topia is
quite as common now, but new and cool stuff still does have a tendency to make
people gush a little.
Maximizing
interactivy: “How Wireless Mesh Networks Work”
I
do want to summarize a few points in Roos’ 2007 article on wireless mesh
networks, though, because these were new to me.
The main thing that struck me was that by using the presence of proximate
devices and by populating the space with a number of small wi-fi transmitters
that wireless capability surprisingly can offer more efficient transmission than
dedicated cables. This made sense when I
thought about it, but it wasn’t something that would have automatically
occurred to me.
I
was impressed with the many benefits that wireless mesh networks can provide,
for example:
o
Works
with all types of devices. I’d always
thought of network nodes being primarily desktop work stations, but here
printers and smart phones and scanners and what-have-you can not only receive
but also pass on information.
o
For
urban areas, mesh nodes on street lights and stop lights can be used by
emergency workers when phone or cell service is down.
o
Can
also be used for diagnostics on power, water supplies without the need to dig
and run lines.
o
Can
be used in developing countries as alternative to physical phone system;
solar-powered nodes can obviate need for electricity and connect to satellite
or cellular system.
o
Good
for colleges because require fewer wired locations and improves bandwidth for
sharing larger files (i.e. apparently can break up packets and send multiple
directions to reunite later (if I understand correctly)).
o
Also
good for densely populated buildings, institutions like hospitals, hotels,
etc., where dense mesh connections can be built up instead of wiring everything.
o
Good
for temporary and outdoor venues.
o
Good
for keeping inventory with scanning devices in large warehouses.
o
There
are probably future military uses for battlefield surveillance networks (i.e. devices
dropped into various battlefield locations)
Maximizing
the interactivity does seem to have a downside in my opinion. Surveillance devices in this type of a
setting kill two birds with one stone.
They can service as additional network devices, increasing transmission
options. Of course, they also do their
normal surveillance job. Surely this
will increase the likelihood of making public spaces even more capable of
tracking us than they already are. Most
of us—I am not an exception—love the idea of maximizing connectivity and all
the conveniences of a fully-wired space.
On the other hand, I do feel a sense of disquiet about the electronic
eyes watching me.
Topologies:
“How Hybrid Networks Work”
Several
articles discussed topologies, such as the star topology and the token ring,
but this one was particularly helpful in clarifying these concepts for me. I found the pros and cons of the different
arrangements interesting, for example, the central hub of the star topology
allows for certain efficiencies of centralization, but the one-way traffic of the
token ring prevents collisions on the same segment. I think the topologies probably can be
leveraged into productive metaphors, but I don’t yet know what these might be.
Emerging
concepts: What I’m noticing so far
First,
I have noticed two opposing principles, somewhat ironic in their opposition,
the principle of materiality and the principle of invisibility. First, networks—computer, water, electric,
social—all have actual physical nodes even as the conduits may be less
obviously physical (wi-fi). Second, the
material aspects are largely invisible.
The cables are in the walls, underground, out of sight. Reductions in size also allows network
connections to weave themselves more firmly into the fabric of our lives while
becoming less and less visible. I was
reminded of a book that I bought quite a while ago, Beneath the Metropolis, describing underground conduits, ancient
and modern, that run under world cities such as New York, Mexico City, Paris, Cairo,
Tokyo and others (Marshall & Emblidge, 2006). The book describes subway tunnels, aqueducts,
underground shopping centers, escape tunnels, sewers, even tectonic
plates. Although the book doesn’t
particularly go into fiber-optic cables and things like that, clearly these are
also similarly invisible and equally important.
I
had a personal experience that illustrated the principle of materiality, at
least in relation to submarine communication cables. I was visiting Vietnam for 10 days over Christmas in 2006, and I ran out
of money. Frustratingly, my credit card stopped working. The reason, I was
told, is that there had been an earthquake in Taiwan. The irony is that I lived and worked in
Taiwan, but the earthquake affected me more than it did my friends back in
Taiwan because it had snapped the submarine cable that Vietnam depended on for
the internet and rendered my credit card unusable. In the end, I had to call my
boss in Taiwan and have him wire money to a bank in Vietnam, and I had to take
a motorcycle taxi to another city to pick it up. I’m not sure exactly how wiring money got
around the issues with the cables, but at any rate, my plan B worked, and I was
able to finance the rest of my trip.
Networks represented? Art connections
For
some reason, this initial discussion of computer networking also got me
thinking of art, I’m not sure why. I
thought of Kandinsky because the style of his art reminded me of
networks.
Wikimedia commons image: Vassily Kandinsky, 1923 - Composition 8, huile sur toile, 140 cm x 201 cm, Musée Guggenheim, New York.jpg
Searching out Kandinksy I
found a fascinating article from MOMA with a network showing the genealogical
relationship between Kandinsky and many of the other abstract artists who
influenced him or that he influenced. I also went searching for and found a
contemporary artist doing what is described as new media art. Deborah Aschheim does mixed media networks using digital
devices and sculpture, all in an attempt to represent memory as a neural networks.
References
Marshall, A., & Emblidge, D. (2006). Beneath the
metropolis: The secret lives of cities. New York: Caroll & Graf.
Roos, D. (2008, March 11). How hybrid networks work.
HowStuffWorks.com. Retrieved from
http://computer.howstuffworks.com/hybrid-networks.htm
Roos, D. (2007, June 20). How wireless mesh networks work.
HowStuffWorks.com. Retrieved from
http://computer.howstuffworks.com/how-wireless-mesh-networks-work.htm
