Wireless

How Wireless Carries Data

Wireless is a really cool technology. One way that we can get data from one side to the next is to send a frequency out but vary the amplitude. Depending on what the amplitude is, we can measure whether it's a zero or a one, or whatever data we're trying to transmit.

The other option we have is to vary the frequency. This one is interesting, because we're picking up a frequency and reading that frequency. What we actually have is a really small, minute variation of that frequency, and that variation will tell us whether it's a one or a zero, or whatever data we're transmitting across that line.

So we really have these two methods for sending data over: AM, which is amplitude modulation, and FM, which is frequency modulation. That's how we get data from one location to another.

Advantages of Wireless

One advantage is simply the coverage area. I can stick a couple of wireless access points up and suddenly I've got a really wide range. I don't have to sit at a specific desk or a specific location wherever the network jack is, so I'm free to move around. That mobility is largely why we associate wireless with laptops, though I've also seen PCs with motherboards that have wireless built in.

Another is cost. If I have to wire up a bunch of jacks all over my office to facilitate people's needs and then have all those jacks live, that could cost a lot. If I put up a wireless system instead, it could potentially save me a lot of money, so the cost could be significantly less with wireless.

There's also the ease of installation. For wireless I just need to run a few connections up in my office and put the wireless access points up. I don't have to wire up a huge office with big runs everywhere and all these patch cables, and I don't have to manage all of that. It's really easy to install and manage.

Then there's one I'm going to add that a lot of people will probably disagree with, because I'm also going to add it to the disadvantages: security. With wireless access, it is insecure in nature, and because of that we put a lot of security in to secure our wireless networks. There's a lot of out-of-the-box security that happens when we're talking about wireless connections, things that we could implement when we have a wired network but often don't, because you have to physically connect into that connection. So I'm going to put security into the advantages, but I'm also going to put it into the disadvantages.

Disadvantages of Wireless

For one, security. The communication happens out in the wild where anybody can pick it up and read that traffic, so you have to encrypt that traffic. Security is a concern any time with wireless. We have these wireless standards that encrypt the traffic, but over time those encryption standards get broken and people hack systems. Whatever security we implement now is not good enough for the future, and we're going to have to change it in the future.

Another is that it's a shared medium. And then there's interference. We talked about interference with copper and how other signals can interfere with a copper line, but there are some ways we can combat that. With wireless it's really hard to protect yourself from all of the signals that are coming in, and so any kind of interference that is out there can hinder your communication and hinder your two devices from talking.

A Shared Medium

One of the big disadvantages to wireless networks is the fact that it's shared. We used to have hubs in the middle, which meant that whoever could talk could talk, we would have collisions, there had to be back-off algorithms, and it was not an efficient method. Now most of our networks have gone to switches, where every line to each device out there is a separate line. We can have duplex communication, multiple things can be talking at the same time, and we've got buffers on the switches, so a switch will capture that data and then send it out when it's ready.

We just don't have that with wireless. We go back to the hub method: whatever device talks, any other device can talk at the same time, and we have a collision. That's a problem, and we have to be able to deal with that collision. It's very inefficient.

Not only that, but since it's shared, consider somebody sitting out at the very edge of the network while everybody else has a strong connection and is communicating really fast. A couple of things are going to happen. Number one, that device is going to have to slow down to talk to the access point, and all the other devices are going to have to wait until that communication is done before another device has a chance to talk. Another problem is that when that device on the outskirts is communicating, one of the devices on the other side may not understand that this communication is happening, and in the middle of it all it will ask to speak and cause a collision, forcing the first device to start its communication all over again.

Shared media is not a great way to go. For this and for some other reasons, I find that wireless networks are a little shaky in how they operate. Sometimes they work, sometimes they don't. It all depends on the weather, what kind of devices you have, and what barriers you have in between. There are just so many different variables involved with these wireless networks. They're really cool and really easy to implement when they work, but they cause problems at other times. So it's not always a great way to go, and the cost that you save in setting it up could be a detriment when it comes to productivity, because you're struggling with all of these wireless connections.

It is the day and age we live in, though. We're going to have wireless from here on out, because it's just convenient. In fact, my last network I primarily set up with all wireless, so you could be anywhere in the office and have connectivity. But I also made sure there were some capabilities for people to plug into a port if they needed to, because it can be a little bit unstable at times.

A Note About Equipment

What I see a lot of times is people going out and buying a wireless router, setting it up on their network, and then possibly having problems, or not even realising that they're running inefficiently. A wireless router is not a wireless access point. Those are two different things.

What I'll see is a small business with some sort of wireless router that connects all their devices, and then they want a stronger signal in a section, so they go buy another wireless router. What happens is that a laptop connecting to that second wireless router is now on a separate network from everyone else, so it doesn't have the same communication ability as the rest of the network. You may or may not want that, but probably not; it's probably by accident. So be cognitive of it if you put a wireless router on your network. Maybe what you actually want is a wireless access point instead.

A wireless access point is just a layer 2 device. A wireless router is a layer 3 device, so it actually does some routing and some NATing, whereas the access point just puts the client directly on the network when you connect to it.

The nicer networks I've seen, usually with bigger businesses, have some sort of wireless LAN controller sitting on the network as well. This can work in two different methods. Number one, it could just be a way to program your different wireless access points from one single management console, so that you can manage your wireless access points. But more often than not, what I've seen is that these wireless access points will tunnel the traffic. When I say tunnel, that means the access point will take that data, encapsulate it as if it were its own, send it through the system, and send it back to the wireless controller. The wireless controller will then unpackage it and decide what it needs to do with it, and dump it on the proper network. Possibly that's right there onto this switch, or maybe it's another switch, or maybe it's out to the internet.

This way it can implement some security frameworks. For example, I can have a guest wireless system that never touches the rest of my LAN. There are some other features that are really cool about it as well. So that is a wireless controller: it just helps you manage your wireless LAN.

Wireless Standards

One thing that really pops into our mind when we think about wireless is Wi-Fi. Wi-Fi is defined by IEEE 802.11. There are a lot of different standards underneath there, and we keep adding to it, because we keep coming out with better and faster ways of getting information to people's machines and things that are more stable. We've come a long way with this, but that is one of the standards that's out there.

Another one you're probably familiar with is Bluetooth. That's IEEE 802.15. My mouse is Bluetooth and connects to my laptop, and then there are also things like my Bluetooth speaker. So there are a lot of personal area networks that get created. A PAN is a personal area network between those Bluetooth devices, and it creates some sort of local network between those two.

Then we have something like ZigBee, which is very similar to Bluetooth and is more designed for internet of things or smart home stuff, home automation. It creates a little mesh network and then you can link things together, so it is a network that's created from these smart home devices.

And then you've got something like WiMAX. WiMAX is a metropolitan area network, a MAN. Somewhere within a city they have a mesh network that you can connect to and get internet service providers. So there are lots of different standards out there that allow some of this wireless communication to happen.