There are a number of different ways that you could connect your wide area network. And in this video, we’ll look at some of the most popular WAN transmission mediums. Satellite communication is communication to space. You’re sending information to a satellite that is then directing that traffic back down to a ground station. This is obviously going to be slightly more expensive than a traditional terrestrial connection but you are able to get throughputs of 50 megabits per second down and three megabits per second up. You would commonly install satellite network for your wide area network in locations that might be difficult to network or you might not have access to a cable modem or a DSL connection.
Because you do have to send signals up to a satellite and then back down to Earth again, you’ll find the latencies will be much larger than what you would find for terrestrial networking. For example, some of the best response times you might see is 250 milliseconds up and 250 milliseconds down which is a big difference over a connection that might remain here on Earth. This also commonly uses higher frequencies to communicate, usually in the 2 gigahertz range. This is a line of sight communication and it requires that nothing is in the way between you and the satellite. It’s common when the rain clouds come in that you get rain fade. The connection between you and the satellite is disrupted by all of this water that’s in between and the clouds. And you have to wait for the clouds to go away to be able to receive a network communication again.
A large percentage of our wide area networks use copper as the communications medium. It’s very inexpensive to install and it’s very easy to maintain. Although copper is less expensive, it does come with a bandwidth limitation when you compare it to fiber. But many wide area networks such as cable modems, DSL, a T1, and a T-3 all use copper for that local loop or final mile to the user. And for most wide area network connections it’s a combination of fiber and copper. It may be copper provided to you as the end user but there may be fiber communication within the backbone of the network provider.
With fiber we’re using light to send digital signals instead of an electrical signal over copper. This would have a higher installation cost than putting in a copper connection, and the equipment is certainly more costly to purchase and to maintain, but you can communicate over very long distances using fiber connectivity. It’s common to see fiber used in the core of our provider networks. They can put many customers over a single strand of fiber and they usually support SONET and wavelength division multiplexing using optic fiber. As our bandwidth requirements have been increasing we’re starting to see more fiber make its way to the premise itself. So we’re seeing fiber installations in businesses and even fiber installations that are going through our neighborhoods and to our homes.
There’s also wide use of wireless wide area networks. This is being used over a mobile provider’s network. And we can now have our mobile phone or external hotspot provide wireless connectivity for all the devices that we happen to use every day. We commonly see these wireless WAN’s used for very specific purposes such as security systems or point-of-sale reporting. But you also see wireless used for travel or field service operations where you don’t have a way to plug-in to a physical network connection. This is, of course, limited by the coverage for that wide area network provider. And there are differences in speed depending on where you may be and how far you may be away from the provider’s antenna.
Category: CompTIA Network+ N10-007