Geographic Scale

Networks come in different geographical scales

We have networking protocols that establish this communication between devices that are very small. And when I say small, I mean literally this small. We have ones that are quite a bit larger than that. We have ones that are very large, and we have ones that span the globe. We have different geographical scales when it comes to this networking, and we call it by different names, and there are different protocols that fall under those different scales.

Let's say this is our network and we have two LANs, local area networks. Local area networks are just locally connected devices. But here in between, we have what's known as a WAN, a wide area network, that spans a much greater size, a much greater area. Now, that area could be across the globe. It could be across the country, or it could be across the city, or it could be across the campus, or it could be that we're not exactly sure what this WAN looks like. And so we have different names depending on what this geographical scale looks like.

Here are some of the names that we may encounter: a near field communication, a personal area network, a local area network, a campus area network, a metropolitan area network, a wide area network. So we see WAN, MAN, CAN, LAN, PAN. These are different area networks.

Protocols versus concepts

Let me give you an example of this. There is a defined set of protocols that define how a LAN is going to operate. So that is a LAN. Those are protocols right there. Same thing: there are some protocols that are more loosely defined as being WAN type of protocols, so this is a little more on the concept side.

And there are times when we have WAN connections that actually use LAN technologies. We would call that a WAN connection even though they're using a technology that specifies that it's a LAN. As an example, this could go clear across the country between this router and this router. We would call that a WAN right there from a concept level, even though maybe one of these lines is using Ethernet, and that is a LAN. We would consider it a WAN link because of the geographical aspect of it, but it's using LAN protocols on there.

So just know that there's a difference between these protocols and concepts. Generally speaking, the local area network, personal area network and near field communication are more closely associated with protocols, versus a campus area network, a metropolitan area network and a wide area network, which are more associated with those concepts. But whether it's a protocol or a concept, what is clear is that there are specific geographical areas that each one of these really represents.

We start out with near field communication, which is the smallest. We go up through PAN, LAN, CAN, MAN and WAN, where we get to bigger and bigger and bigger networks, or at least geographically they're more spread apart.

Near field communication

An example of a near field communication is between two phones. You take two phones and you bump them together. Maybe they exchange some sort of information. Maybe it's a business card. Maybe it's some sort of photos. Whatever the case may be, it's really close. You pretty much have to have these right next to each other, within like an inch and a half, in order for it to start communicating back and forth. So it's a really small area there. We call them near field communication, or NFC.

Personal area network

A personal area network is quite a bit bigger. It's everything within maybe 30 ft from wherever your device is at. Think something like Bluetooth. With this, you have your phone and it's connected to speakers or some sort of earbuds or some other device that's really close. You get too far away and it disconnects, because it's a pretty short range that this type of network has.

Local area network

Then there is a local area network, and we've talked a lot about local area networks. It's usually connected with a switch or a hub, and it's all the devices that can communicate across here. We also call it a broadcast domain. You can broadcast across this network right here. So this is a local area network where all the local devices can talk with each other.

Campus area network

Next up, we have a campus area network. You can think of a literal college campus, or even a business campus. I know we have several large businesses just south of here, like Nike and Intel, that have large campuses for the business.

But here what I'm showing right here is actually Clark College, which I am a professor at. What we see here is all of the buildings that we have as part of this campus: the Barrett administration building, the diesel technology building. So all of these buildings need to be interconnected. We can see it's much larger than what maybe a LAN would have. This is probably made up of several LANs here. So maybe there's a LAN in this building, or I can tell you that's not actually how it's broken up, but the idea behind this is that there's several LANs that are interconnected across this campus, and there's even some buildings across the street that are associated with this college right here. So this would be a campus area network.

Metropolitan area network

Then we have a metropolitan area network, or a MAN. This is actually maybe not a metropolitan area, this is just a small city right here, but it's an example that I specifically know of, which is Insichu. Insichu has these buildings right here, so we've got this little campus right here. They were a company, a small company, that kept growing, and they outgrew this little area right here. So what they had to do is start getting different buildings in this small little town. Well, those need to be interconnected. So now what they're doing is they're extending across the city. They're interconnecting all of these different buildings. So it's just one example of a metropolitan area network.

Here's another example of a metropolitan area network, and that's Intel. You can see that Intel has all of these locations. In fact, here's the Intel Aloa campus, which you see down here. You have the Hawthorne Farm campus. So there are these different campuses that need to be interconnected. This is a great example of how we have campus area networks that are interconnecting these campuses, but the campuses are all spread out, and so we have a metropolitan area network interconnecting all of these different campuses.

Wide area network

Let's take a look at Intel again for wide area networks. Here in Hillsboro, they have local area networks that are all interconnected to create campus area networks, and all those campuses are connected to create metropolitan area networks. But that's just for servicing there in Oregon. Let's say they have spots all around the world, and I'm not sure where all the spots are at, but they need a connection that goes beyond that metropolitan area network. And now we have a WAN connection, a wide area network, all set up.

Other area networks

There are other types of area networks, such as radio area network, body area network, storage area network, wireless local area network or wireless LAN, a virtual area network, a home area network. These are not really all that important, or they don't quite fit into the same concepts that we're talking about, so I'm not going to talk too much about that. Just know that there are these others that exist out there.

The ones that I want you to be most familiar with at this point in time are the near field communications, the personal area network or PAN, the local area network or LAN, campus area network or CAN, metropolitan area network or MAN.