NO COPYING FROM OTHER STUDENTS Please!
Network Systems Design
Please respond to both of the following questions:
What are the similarities between attacks that can occur against a computer connected to the internet and a smart phone using a cellular network to gain internet access?
What are some of the common attacks hackers can use to attack cellular networks and the devices that are connected to them?
These are discussion questions which require 150 words
Vacca, J. (2014) Network and System Security, 2nd edition. Syngress
ISBN 978 0124166899
- Chapter 11
There are two very broad methods by which we stay connected through the use of physical wires and cables. The other method is through the more mobile method of wireless communication. We are all undoubtedly familiar with both of these technologies and how they shape our lives every day. This lecture is focuses on mobile communication capabilities and what we can achieve through this technology. It wasn’t that long ago that we needed to sit in front of a computer that was physically connected to a network in order to communicate on the Internet. Even our home based systems used modems that connected us to the world through phone lines. That technology hasn’t changed that much, but we are now able to do so much more without the cumbersome cables tying us to a location. Even though our voice and data traffic still end up on a traditional telephone line, the way we do it today is significantly different from how we started out. We’ll cover the different systems that have been developed, the change from analog to digital and the differences between them, and the transitions from 2G to 4G along with the new capabilities each iteration brought about. We won’t get too deep into how these phones communicate on the network, but you will have an understanding of at least the basics of how mobile phones operate and how the signals move through the air, to the wire, and back through the air again. This is an important technology to understand because so many people are using smart phones every day. The networks are saturated with hundreds of millions of users every day, and the people working on the systems that are used must be able to maintain all of the connectivity at a constant rate.
For more information, please read the following articles:
- Edwards, C. (2013). All power to the smartphone. Engineering & Technology, 8(1), 66 69.
- Hao X., Yanyou, Q., Jun J., & Yuanfei, C. (2014). Using smart phone sensors to detect transportation modes. Sensors, 14(11, 20843 20865.
IS696 Week 7 – Cellular Networks
When we think about network connectivity we know that there are two very broad methods by which we stay connected. One is through the use of physical wires and cables and the other is through the more mobile method of wireless communication. We are all undoubtedly familiar with both of these technologies and how they shape our lives every day, especially in a more mobile focused world so this week’s lecture is going to focus on mobile communication capabilities and contrast what we can achieve through each.
It wasn’t that long ago that we needed to sit in front of a computer that was physically connected to a network in order to communicate on the internet. Even our home based systems used modems that connected us to the world through phone lines and that technology hasn’t changed that much since we still use modems in our homes but now most of those are connected through our cable companies and the speeds are infinitely faster than a few decades ago. Of course, wireless communication has taken off and virtually anyone who wants to stay connected can do so from almost anywhere in the world. Smartphones have given us the ability to communicate with almost anyone from one point on the earth to the other. If there’s a wireless access point or a cell phone tower, we can easily reach out and touch someone. We have so much mobile technology today that we can conduct any type of communication that would have previously required a regular telephone line or computer in the past. This mobility has driven many upgrades on telephone networks as they all vie to get our business on what they each declare to be the best network available. So let’s take a look at how we transitioned from traditional telephones to wireless telephony and how that has changed our lives in the past decade. And it wasn’t that long ago that if you wanted to make a phone call you would need to use a phone physically connected to a cord and even with today’s mobile phone networks the majority of capabilities we have access to while on the go still end up travelling on the physical phone lines that run from pole to pole in every city of the country. Wireless signals from our cell phones can only travel so far across the airwaves and once they reach a cell tower the content is transferred to a physical line that allows the communication to travel to other parts of the country and world. So we call it mobile communication but the funny thing is that a portion of it still uses the same communication concepts that were created in the late 1800’s and the signals are still carried on phone lines that were strung onto poles over the past hundred years.
It’s actually quite amazing to think that this is one technology that still heavily relies upon its original framework to continue to work today. The very first cell phone call was placed on April 3rd, 1973 when Martin Cooper placed a call to Dr. Joel Engel. Martin Cooper was a manager for Motorola and Joel Engel worked for AT&T; two companies that are still well known today as communication giants. Of course, none of us probably knew anything about mobile phones at that time and some of us were not even alive. But the technology they displayed on that day eventually led to consumer based capabilities that brought handheld phones into the hands of, first those who could afford the high cost, but eventually to anyone who wanted one. The original generation of mobile phones operated on analog signals but the generation that followed adopted a digital signal. Switching over to digital held several big advantages. First, it provides greater capacity by digitizing and compressing voice signals. Second, it allows voice and control signals to be encrypted which greatly improves security and deters criminal activity against mobile communication. And third, it gave us a brand new service known as text messaging. Many different systems were developed at that time and in the United States we settled on GSM and CDMA with different carriers using different systems. CDMA is used by Sprint and Verizon while GSM is used by the other major carriers including those throughout Europe. Some international phones have the ability to operate on CDMA or GSM automatically which gives business travelers a lot of flexibility. GSM became the dominant service in the United States so let’s quickly cover how it works. GSM, which was initially released in 1990’s retained most of the design elements from earlier systems with some changes to the details. The mobile device is basically divided into two pieces, the phone itself, and the SIM card. If you have a GSM phone you are probably familiar with the little white card that holds some of the basic carrier information. This is the card that allows the phone to operate on the network and switching phones is as easy as removing the card and plugging it into another compatible phone. This card also allows the network to encrypt conversations between the phone and the towers.
We won’t get too deep into the weeds of these phones communicate on the network but you should understand that mobile phones on a GSM network talk to a cell phone tower over the air waves and a base station controller handles handing the call over to other towers as you continue to move. And ultimately your call ends up on the normal physical phone lines. So if you are having a conversation with your mother while you are driving from Florida to Georgia, your phone is dynamically changing from tower to tower and your communication is being sent through the air, to the tower, through a few more devices, and placed on the wire to be moved to whatever location your mom is in. All of this happens seamlessly without us knowing it until a call is dropped. The technology behind how all of this works is quite intricate and we shouldn’t take for granted how much research has gone into bringing this capability, which most of use for the majority part of our day. GSM uses a handful of different frequencies and uses time division multiplexing to share the bandwidth between the millions of users roaming across the country with their phones attached to their ears. This design is known as 2G which stands for 2nd generation and it was replaced by 3G or third generation. 3G added another new previously unavailable capability, the ability to send data over the cell phone networks. And if we look at how the phone networks are being used today we will quickly see that data usage is much higher than voice and that continues to grow exponentially. Many experts actually expect that data will continue to dominate the mobile phone networks as new capabilities are added. We can now surf the internet, pay our bills, have video chats with friends and family, watch movies and TV shows, and even do our college homework assignments on a smart phone. I’m not sure what new technologies await us in this arena but I can be sure that we will continue to see increases in what can be accomplished from a mobile platform. Now, even though 3G brought us data capabilities those capabilities were not very impressive. We were limited to speeds of approximately 3 megabits per second which was great for basic email and web traffic but couldn’t handle the level or type of traffic being pumped across the airwaves today.
It wasn’t until 4G networks were deployed that we were able to push the content we have available to us today. 4G has the potential to give us speeds up to 300 times faster than its predecessor and is often described as lightning fast. Realistically the averages don’t seem to approach speeds greater than 20 megabits but even those speeds allow us to stream popular content from Netflix, Hulu, YouTube, Periscope, and may other video and music applications. The capabilities we have today greatly exceed what we could have done even just a few years ago and it has put the telephone network providers in an interesting position. With today’s strong consumer desire for mobility we have actually reached a point where anyone who wants a mobile phone has one. This has put the cell phone industry into an interesting position because the only way a company can attract new subscribers is to convince them to leave their current provider by offering deep discounts and better service; and this is great for the consumer. This is why there are so many advertisements trying to lure us into leaving our current mobile providers and switch to what another company has to offer. And these same companies are already starting to discuss what the next generation of mobile communication will bring even though no real standards have been developed yet. 5G is expected to have speeds of up to 10 gigabits which could provide even greater bandwidths for moving large amounts of data over the airwaves. One technology that isn’t quite as effective on mobile platforms today is the ability to play the massive multiplayer online games because the bandwidth requirements cannot sustain the needs of those platforms. Another technology that could benefit from 5G speeds is an increase in the video and audio quality of all the online multimedia that is already being streamed today. And so many people are tossing around the internet of things phrase which may end up connecting many more of our household devices to the internet which of course will use up more bandwidth. So it’s good to see that the industry is thinking forward on what may be needed in the next generation of mobile communications but don’t get your hopes up. No one expects 5G to be around before 2020 and even that is just an estimated target date.
So you now that you have an understanding of the history of these networks you may be able to appreciate the capabilities they give to you every day. Most communication technologies were created in a lab and used by just a few people before they were eventually developed into what we have available to us today. And those technologies don’t get developed overnight; they take many years to mature into something consumers can use. I think we all can agree that mobile communication is only going to get bigger as we continue to push more towards an environment where we work away from desks and traditional offices. Mobile communication has really transformed personal lives as well as the business world and I expect it to do so even more over the next decade.