Investigation Report: Routers Work

How Routers Work?

---

Fujitsu GeoStream R980 industrial strength router. 

The Internet is one of the 20th century's greatest communications developments. It allows people around the world to send e-mail to one another in a matter of seconds, and it lets you read, among other things, the articles on tecinvestigation.blogspot.com.

We're all used to seeing the various parts of the Internet that come into our homes and offices -- the Web pages, e-mail messages and downloaded files that make the Internet a dynamic and valuable medium. But none of these parts would ever make it to your computer without a piece of the Internet that you've probably never seen. In fact, most people have never stood "face to machine" with the technology most responsible for allowing the Internet to exist at all: the router.

Keeping the Messages Moving

When you send e-mail to a friend on the other side of the country, how does the message know to end up on your friend's computer, rather than on one of the millions of other computers in the world? Much of the work to get a message from one computer to another is done by routers, because they're the crucial devices that let messages flow between networks, rather than within networks.

Let's look at what a very simple router might do. Imagine a small company that makes animated 3-D graphics for local television stations. There are 10 employees of the company, each with a computer. Four of the employees are animators, while the rest are in sales, accounting and management. The animators will need to send lots of very large files back and forth to one another as they work on projects. To do this, they'll use a network.

When one animator sends a file to another, the very large file will use up most of the network's capacity, making the network run very slowly for other users. One of the reasons that a single intensive user can affect the entire network stems from the way that Ethernet works. Each information packet sent from a computer is seen by all the other computers on the local network. Each computer then examines the packet and decides whether it was meant for its address. This keeps the basic plan of the network simple, but has performance consequences as the size of the network or level of network activity increases. To keep the animators' work from interfering with that of the folks in the front office, the company sets up two separate networks, one for the animators and one for the rest of the company. A router links the two networks and connects both networks to the Internet.

Directing Traffic:

The router is the only device that sees every message sent by any computer on either of the company's networks. When the animator in our example sends a huge file to another animator, the router looks at the recipient's address and keeps the traffic on the animator's network. When an animator, on the other hand, sends a message to the bookkeeper asking about an expense-account check, then the router sees the recipient's address and forwards the message between the two networks.

One of the tools a router uses to decide where a packet should go is a configuration table. A configuration table is a collection of information, including:

• Information on which connections lead to particular groups of addresses
• Priorities for connections to be used
• Rules for handling both routine and special cases of traffic

A configuration table can be as simple as a half-dozen lines in the smallest routers, but can grow to massive size and complexity in the very large routers that handle the bulk of Internet messages.
A router, then, has two separate but related jobs:

• The router ensures that information doesn't go where it's not needed. This is crucial for keeping large volumes of data from clogging the connections of "innocent bystanders."
• The router makes sure that information does make it to the intended destination.

In performing these two jobs, a router is extremely useful in dealing with two separate computer networks. It joins the two networks, passing information from one to the other and, in some cases, performing translations of various protocols between the two networks. It also protects the networks from one another, preventing the traffic on one from unnecessarily spilling over to the other. As the number of networks attached to one another grows, the configuration table for handling traffic among them grows, and the processing power of the router is increased. Regardless of how many networks are attached, though, the basic operation and function of the router remains the same. Since the Internet is one huge network made up of tens of thousands of smaller networks, its use of routers is an absolute necessity.

Transmitting Packets:

When you make a telephone call to someone on the other side of the country, the telephone system establishes a stable circuit between your telephone and the telephone you're calling. The circuit might involve a half dozen or more steps through copper cables, switches, fiber optics, microwaves and satellites, but those steps are established and remain constant for the duration of the call. This circuit approach means that the quality of the line between you and the person you're calling is consistent throughout the call, but a problem with any portion of the circuit -- maybe a tree falls across one of the lines used, or there's a power problem with a switch -- brings your call to an early and abrupt end. When you send an e-mail message with an attachment to the other side of the country, a very different process is used.

Internet data, whether in the form of a Web page, a downloaded file or an e-mail message, travels over a system known as a packet-switching network. In this system, the data in a message or file is broken up into packages about 1,500 bytes long. Each of these packages gets a wrapper that includes information on the sender's address, the receiver's address, the package's place in the entire message, and how the receiving computer can be sure that the package arrived intact. Each data package, called a packet, is then sent off to its destination via the best available route -- a route that might be taken by all the other packets in the message or by none of the other packets in the message. This might seem very complicated compared to the circuit approach used by the telephone system, but in a network designed for data there are two huge advantages to the packet-switching plan.

• The network can balance the load across various pieces of equipment on a millisecond-by-millisecond basis.
• If there is a problem with one piece of equipment in the network while a message is being transferred, packets can be routed around the problem, ensuring the delivery of the entire message.

The Path of a Packet:

The routers that make up the main part of the Internet can reconfigure the paths that packets take because they look at the information surrounding the data packet, and they tell each other about line conditions, such as delays in receiving and sending data and traffic on various pieces of the network. Not all routers do so many jobs, however. Routers come in different sizes. For example:

• If you have enabled Internet connection sharing between two Windows 98-based computers, you're using one of the computers (the computer with the Internet connection) as a simple router. In this instance, the router does so little -- simply looking at data to see whether it's intended for one computer or the other -- that it can operate in the background of the system without significantly affecting the other programs you might be running.
• Slightly larger routers, the sort used to connect a small office network to the Internet, will do a bit more. These routers frequently enforce rules concerning security for the office network (trying to secure the network from certain attacks). They handle enough traffic that they're generally stand-alone devices rather than software running on a server.
• The largest routers, those used to handle data at the major traffic points on the Internet, handle millions of data packets every second and work to configure the network most efficiently. These routers are large stand-alone systems that have far more in common with supercomputers than with your office server.

Routing Packets: An Example

Let's take a look at a medium-sized router -- the router we use in the Techinvestigation office. In our case, the router only has two networks to worry about: The office network, with about 50 computers and devices, and the Internet. The office network connects to the router through an Ethernet connection, specifically a 100 base-T connection (100 base-T means that the connection is 100 megabits per second, and uses a twisted-pair cable like an 8-wire version of the cable that connects your telephone to the wall jack). There are two connections between the router and our ISP (Internet service provider). One is a T-1 connection that supports 1.5 megabits per second. The other is an ISDN line that supports 128 kilobits per second. The configuration table in the router tells it that all out-bound packets are to use the T-1 line, unless it's unavailable for some reason (perhaps a backhoe digs up the cable). If it can't be used, then outbound traffic goes on the ISDN line. This way, the ISDN line is held as "insurance" against a problem with the faster T-1 connection, and no action by a staff member is required to make the switch in case of trouble. The router's configuration table knows what to do.

In addition to routing packets from one point to another, the HowWorks router has rules limiting how computers from outside the network can connect to computers inside the network, how the HowStuffWorks network appears to the outside world, and other security functions. While most companies also have a special piece of hardware or software called a firewall to enforce security, the rules in a router's configuration table are important to keeping a company's (or family's) network secure.

One of the crucial tasks for any router is knowing when a packet of information stays on its local network. For this, it uses a mechanism called a subnet mask. The subnet mask looks like an IP address and usually reads "255.255.255.0." This tells the router that all messages with the sender and receiver having an address sharing the first three groups of numbers are on the same network, and shouldn't be sent out to another network. Here's an example: The computer at address 15.57.31.40 sends a request to the computer at 15.57.31.52. The router, which sees all the packets, matches the first three groups in the address of both sender and receiver (15.57.31), and keeps the packet on the local network. (You'll learn more about how the addresses work in the next section.)

Between the time these words left the Howworks.com server and the time they showed up on your monitor, they passed through several routers (it's impossible to know ahead of time exactly how many "several" might be) that helped them along the way. It's very similar to the process that gets a postal letter from your mailbox to the mailbox of a friend, with routers taking the place of the mail sorters and handlers along the way.

Knowing Where to Send Data:

Routers are one of several types of devices that make up the "plumbing" of a computer network. Hubs, switches and routers all take signals from computers or networks and pass them along to other computers and networks, but a router is the only one of these devices that examines each bundle of data as it passes and makes a decision about exactly where it should go. To make these decisions, routers must first know about two kinds of information: addresses and network structure.

When a friend mails a birthday card to be delivered to you at your house, he probably uses an address that looks something like this:

Joe Smith 123 Maple Street Smalltown, FL 45678

The address has several pieces, each of which helps the people in the postal service move the letter along to your house. The ZIP code can speed the process up; but even without the ZIP code, the card will get to your house as long as your friend includes your state, city and street address. You can think of this address as a logical address because it describes a way someone can get a message to you. This logical address is connected to a physical address that you generally only see when you're buying or selling a piece of property. The survey plot of the land and house, with latitude, longitude or section bearings, gives the legal description, or address, of the property.

Logical Addresses

Every piece of equipment that connects to a network, whether an office network or the Internet, has a physical address. This is an address that's unique to the piece of equipment that's actually attached to the network cable. For example, if your desktop computer has a network interface card (NIC) in it, the NIC has a physical address permanently stored in a special memory location. This physical address, which is also called the MAC address (for Media Access Control) has two parts, each 3 bytes long. The first 3 bytes identify the company that made the NIC. The second 3 bytes are the serial number of the NIC itself.
The interesting thing is that your computer can have several logical addresses at the same time. Of course, you're used to having several "logical addresses" bring messages to one physical address. Your mailing address, telephone number (or numbers) and home e-mail address all work to bring messages to you when you're in your house. They are simply used for different types of messages -- different networks, so to speak.

Logical addresses for computer networks work in exactly the same way. You may be using the addressing schemes, or protocols, from several different types of networks simultaneously. If you're connected to the Internet (and if you're reading this, you probably are), then you have an address that's part of the TCP/IP network protocol. If you also have a small network set up to exchange files between several family computers, then you may also be using the Microsoft NetBEUI protocol. If you connect to your company's network from home, then your computer may have an address that follows Novell's IPX/SPX protocol. All of these can coexist on your computer. Since the driver software that allows your computer to communicate with each network uses resources like memory and CPU time, you don't want to load protocols you won't need, but there's no problem with having all the protocols your work requires running at the same time.
On the next page, you’ll learn how to find your computer’s MAC address.

MAC Addresses:

The chances are very good that you'll never see the MAC address for any of your equipment because the software that helps your computer communicate with a network takes care of matching the MAC address to a logical address. The logical address is what the network uses to pass information along to your computer.
If you'd like to see the MAC address and logical address used by the Internet Protocol (IP) for your Windows computer, you can run a small program that Microsoft provides. Go to the "Start" menu, click on "Run," and in the window that appears, type WINIPCFG (IPCONFIG/ALL for Windows 2000/XP). When the gray window appears, click on "More Info" and you'll get this sort of information:

Windows 98 IP Configuration:

Host Name: NAMEHOWSTUFFWORKS
DNS Servers: 208.153.64.20
&nbsp208.153.0.5
Node Type: Broadcast
NetBIOS Scope ID:
IP Routing Enabled: Yes
WINS Proxy Enabled: No
NetBIOS Resolution Uses DNS: No

Ethernet adapter:

Description: PPP Adapter
Physical Address: 44-45-53-54-12-34
DHCP Enabled: Yes
IP Address: 227.78.86.288
Subnet Mask: 255.255.255.0
Default Gateway: 227.78.86.288
DHCP Server: 255.255.255.255
Primary WINS Server:
Secondary WINS Server: Lease Obtained: 01 01 80 12:00:00 AM
Lease Expires: 01 01 80 12:00:00 AM

There's a lot of information here that will vary depending on exactly how your connection to the Internet is established, but the physical address is the MAC address of the adapter queried by the program. The IP address is the logical address assigned to your connection by your ISP or network administrator. You'll see the addresses of other servers, including the DNS servers that keep track of all the names of Internet sites (so you can type "www.howstuffworks.com" rather than "216.27.61.189") and the gateway server that you connect to in order to reach the Internet. When you've finished looking at the information, click OK. (Note: For security reasons, some of the information about this connection to the Internet has been changed. You should be very careful about giving your computer's information to other people -- with your address and the right tools, an unscrupulous person could, in some circumstances, gain access to your personal information and control your system through a "Trojan Horse" program.

Understanding the Protocols:

The first and most basic job of the router is to know where to send information addressed to your computer. Just as the mail handler on the other side of the country knows enough to keep a birthday card coming toward you without knowing where your house is, most of the routers that forward an e-mail message to you don't know your computer's MAC address, but they know enough to keep the message flowing.
Routers are programmed to understand the most common network protocols. That means they know the format of the addresses, how many bytes are in the basic package of data sent out over the network, and how to make sure all the packages reach their destination and get reassembled. For the routers that are part of the Internet's main "backbone," this means looking at, and moving on, millions of information packages every second. And simply moving the package along to its destination isn't all that a router will do. It's just as important, in today's computerized world, that they keep the message flowing by the best possible route.
In a modern network, every e-mail message is broken up into small pieces. The pieces are sent individually and reassembled when they're received at their final destination. Because the individual pieces of information are called packets and each packet can be sent along a different path, like a train going through a set of switches, this kind of network is called a packet-switched network. It means that you don't have to build a dedicated network between you and your friend on the other side of the country. Your e-mail flows over any one of thousands of different routes to get from one computer to the other.

Depending on the time of day and day of the week, some parts of the huge public packet-switched network may be busier than others. When this happens, the routers that make up this system will communicate with one another so that traffic not bound for the crowded area can be sent by less congested network routes. This lets the network function at full capacity without excessively burdening already-busy areas. You can see, though, how Denial of Service attacks (described in the next section), in which people send millions and millions of messages to a particular server, will affect that server and the routers forwarding message to it. As the messages pile up and pieces of the network become congested, more and more routers send out the message that they're busy, and the entire network with all its users can be affected.

Tracing a Message

If you're using a Microsoft Windows-based system, you can see just how many routers are involved in your Internet traffic by using a program you have on your computer. The program is called Traceroute, and that describes what it does -- it traces the route that a packet of information takes to get from your computer to another computer connected to the Internet. To run this program, click on the "MS-DOS Prompt" icon on the "Start" menu. Then, at the "C:\WINDOWS>" prompt, type "tracert www.tecinvestigation.blogspot.com". When I did this from my office in Florida, the results looked like this:

The first number shows how many routers are between your computer and the router shown. In this instance, there were a total of 14 routers involved in the process (number 15 is the Howstuffworks.com Web server). The next three numbers show how long it takes a packet of information to move from your computer to the router shown and back again. Next, in this example, starting with step six, comes the "name" of the router or server. This is something that helps people looking at the list but is of no importance to the routers and computers as they move traffic along the Internet. Finally, you see the Internet Protocol (IP) address of each computer or router. The final picture of this trace route shows that there were 14 routers between the Web server and me and that it took, on average, a little more than 2.5 seconds for information to get from my computer to the server and back again.

You can use Traceroute to see how many routers are between you and any other computer you can name or know the IP address for. It can be interesting to see how many steps are required to get to computers outside your nation. Since I live in the United States, I decided to see how many routers were between my computer and the Web server for the British Broadcasting Corporation. At the C:\WINDOWS> prompt, I typed tracert www.bbc.com. The result was this:

You can see that it took only one more step to reach a Web server on the other side of the Atlantic Ocean than it did to reach a server two states away!

On the next page, we'll go into detail about Denial of Service attacks.

Denial of Service Attacks:

In the first quarter of 2000, there were several attacks on very popular Web sites. Most of these were "Denial of Service" attacks -- attacks that served to prevent regular readers and customers of the sites from getting a response to their requests. How did someone manage to do this? They did it by flooding the servers, and their attached routers, with requests for information at a rate far too great for the system to handle.

Most routers have rules in the configuration table that won't allow millions of requests from the same sending address. If too many requests from one address are received in a short period of time, the router simply discards them without forwarding. The people responsible for the attacks knew this, so they illicitly planted programs on many different computers. These programs, when triggered, began sending thousands of requests a minute to one or more Web sites. The programs "spoofed" the IP address of the sender, placing a different false IP address on each packet so that the routers' security rules wouldn't be triggered.
When the packet floods were triggered, millions of requests for information began to hit the targeted Web sites. While the servers were being heavily taxed by the requests, the real impact was to the routers just "upstream" from the servers. Suddenly these routers, which were robust but of a size appropriate for normal traffic, were getting the levels of requests normally associated with Internet backbone routers. They couldn't handle the massive number of packets, and began discarding packets and sending status messages to other routers stating that the connection was full. As these messages cascaded through the routers leading to attacked servers, all paths to the servers were clogged, legitimate traffic couldn't get through the logjam, and the attackers' goals were accomplished.

Web content providers and router companies have placed new rules designed to prevent such an attack in the configuration tables, and the companies and universities whose computers were used to launch the attacks have worked to prevent their systems being used maliciously. Whether their defenses, or the new attacks designed by criminals, will prevail remains to be seen.

Backbone of the Internet:

In order to handle all the users of even a large private network, millions and millions of traffic packets must be sent at the same time. Some of the largest routers are made by Cisco Systems, Inc., a company that specializes in networking hardware. Cisco's Gigabit Switch Router 12000 series of routers is the sort of equipment that is used on the backbone of the Internet. These routers use the same sort of design as some of the most powerful supercomputers in the world, a design that ties many different processors together with a series of extremely fast switches. The 12000 series uses 200-MHz MIPS R5000 processors, the same type of processor used in the workstations that generate much of the computer animation and special effects used in movies. The largest model in the 12000 series, the 12016, uses a series of switches that can handle up to 320 billion bits of information per second and, when fully loaded with boards, move as many as 60 million packets of data every second. Beyond the computing power of the processors, these routers can handle so much information because they are very highly specialized. Relieved of the burden of displaying 3-D graphics and waiting for mouse input, modern processors and software can cope with amazing amounts of information.

Even with the computing power available in a very large router, how does it know which of the many possibilities for outbound connection a particular packet should take? The answer lies back in the configuration table. The router will scan the destination address and match that IP address against rules in the configuration table. The rules will say that packets in a particular group of addresses (a group that may be large or small, depending on precisely where the router is) should go in a specific direction. Next the router will check the performance of the primary connection in that direction against another set of rules. If the performance of the connection is good enough, the packet is sent, and the next packet handled. If the connection is not performing up to expected parameters, then an alternate is chosen and checked. Finally, a connection will be found with the best performance at a given moment, and the packet will be sent on its way. All of this happens in a tiny fraction of a second, and this activity goes on millions of times a second, around the world, 24 hours every day.

Knowing where and how to send a message is the most important job of a router. Some simple routers do this and nothing more. Other routers add additional functions to the jobs they perform. Rules about where messages from inside a company may be sent and from which companies messages are accepted can be applied to some routers. Others may have rules that help minimize the damage from "denial of service" attacks. The one constant is that modern networks, including the Internet, could not exist without the router.

Investigation Report: How Drones work?

How Drones Work!

---

In this brave new digital world, the word "drone" has taken on some seriously ominous overtones. Mass media portrays drones as cold-blooded mechanizations silently soaring the skies in search of unsuspecting human targets. The general public sees surveillance drones as creepy reminders that someone, somewhere is watching every little thing you do. Drones are indeed powerful weapons and spy tools. But they're also much more.
Although "drone" is the most common term, these flying machines are also often called UAVs (unmanned aerial vehicles). Although government and military agencies were among the first to explore drones for their warfare capabilities, these winged devices are now also marketed to kids, teenagers, RC plane hobbyists, photographers, videographers, farmers and just about anyone who can benefit from a viewpoint in the skies around them.

Military-grade drones may fit in a backpack, or they may be nearly as big as a full-size plane and loaded with death-dealing armaments. These drones can cost tens of millions of dollars and have wingspans of more than 100 feet (30 meters).

Although military drones are promoted to the public as bloodless and precise types of war machines, they can be disturbingly deadly. The Bureau of Investigative Journalism estimates that in Pakistan alone, the United States executed more than 400 drone attacks that killed as many as 4,000 people, of which perhaps 1,000 were civilians and 200 were children.

Consumer and commercial drones offer a happier spin on automated flight. They may actually fit in your palm and run you less than $100. Sturdier, more advanced models can cost thousands and scream high into the sky (and possibly onto local radar), which may very well land you in trouble with the Federal Aviation Administration (FAA).

Small drones operated by commercial enterprises are growing in number. Those businesses will benefit in amazing and as-of-yet unforeseen ways, using drones to boost revenue and help economies all over the globe.

Fire departments, police units and disaster responders all use drones to some degree, assessing harrowing situations, finding missing people and helping fellow humans. Drones are handy for construction, mapping, wildlife conservation, pipeline inspection and much more.

Drones are also just plain fun. We humans can't sprout wings and fly, but we can do a little vicarious living through our winged friends, lofting cameras for amazing images or just zooming around the heavens for the joy of it.

The Drone Backstory:

A 1934 Lowe Wilde Drone aircraft painted by the artist William Heath Robinson 

 

There was no history-rattling moment when the first drone went airborne. That's in large part because it's a matter of semantics when trying to determine exactly which historical device qualified as a drone. Was it one of the explosives-laden balloons used in the 1800s? Was it the initial V-1 rockets that the Germans deployed during WWII?

In the early 1900s, military groups used drones, including radio-controlled versions, for target practice. Engineers also developed unmanned aircraft loaded with munitions. These weren't really drones. They were the first cruise missiles, sometimes called flying torpedoes, and not meant to return to base.
During the Cold War, the U.S. ramped up research on drones, hoping to use them as substitutes for manned spy planes. As the Vietnam War dragged on, drones flew thousands of high-risk reconnaissance missions and were destroyed by enemy fire, but in the process saved the lives of pilots who otherwise would have perished.

At about the same time, engineers began equipping drones with real-time surveillance capabilities. With their onboard cameras and unlimited courage, drones could approach enemy lines and document troop movements and strategies without risking human lives.

In 2002, the CIA first used a Predator drone to kill an enemy combatant in Afghanistan. The Predator (more precisely, the MQ-1 Predator), with its spine-chilling name, was one of the first military drones to see widespread action. It was unveiled in 1995 and has since zoomed all over the world — but it's used mostly in the Middle East. It can fly more than 500 miles (805 kilometers) on single mission and circle targets for hours; armed versions can fire sophisticated missiles.

The Predator is one of the best-known military drones, but now it's just one of many. Those first strikes in Afghanistan were, as they say, just the beginning.

More Military Might:

Military UAV pilots get extensive training, but many burn out early on. 

 

As the digital revolution has unfolded with its tiny microprocessors and long-distance communications abilities, drones have become more and more useful for military operations. By one estimate, the U.S. military has roughly 11,000 manned airplanes and perhaps 8,000 drones, meaning that a third of the air force is unmanned. For anyone who feared the coming age of automated, sci-fi-type warfare ... well, those days are already here.

The U.S. military has three categories for drones: mini, tactical and strategic. Mini drones are small and mostly used for short-range surveillance. Tactical drones can fly for several hours and as far as 200 miles (322 kilometers) and are used to assess enemy targets. Strategic drones can fly for days and carry weapons.
Some drones use battery power to turn propellers. Newer and pricier versions have full-blown jet engines and can fly more than 500 miles (805 kilometers) per hour, soaring to 50,000 feet (15,240 meters) or even higher.

Some drones are autonomous, following preprogrammed routines. Many others require pilots. Those pilots may be on the ground near the operation, or they may sit in control rooms, thousands of miles away, guiding their minions by high-speed wireless networking links.

In part because there's a delay of a couple of seconds from the control room to the drone, crashes do happen. Sometimes pilots push the wrong buttons. Sometimes they misread the flight data they see on their workstation monitors; cameras on the drones simply aren't a substitute for a pilot's real vision and other senses. More than 400 large drones have crashed since 2001, but many disasters have been averted, too. If a communications link is cut, advanced drones are programmed to fly in circles or even to return to the nearest base without human guidance.

Like air traffic controllers, drone pilots have high-stress yet often dull and repetitive jobs, mostly surveilling areas for intelligence and potential targets. Because of burnout, they quit three times as often as regular pilots, and the U.S. military recently doubled drone pilot salaries to stop them from running for the exits.
Those who stay receive extensive training in a traditional classroom setting, as well as hands-on training at their computers. They execute endless practice runs and then review their in-flight decisions, attempting to hone their minds to select the best approach to any given scenario, particularly those that involve the use of deadly force.

When they score an important victory, these pilots receive medals just like any others, and in spite of the geographical disconnect from their targets, many suffer emotional trauma from the damage their strikes cause.

Not all drones inflict suffering and mayhem. There is an entire range of drones for commercial and private use.

Drones in Your Homes:

Drones are used in agriculture all the time. This drone is sweeping a winery’s grapes so the winemaker can assess the maturity of the fruit.

 

In many places, including the U.S., civilian and commercial drone use is severely restricted by aviation administration regulations, primarily in the name of safety. That does not, however, stop thousands of people from using drones for a plethora of purposes, including videography, sheep herding, product delivery and crop surveying.

If you perform a quick search through your favorite online megastore you'll see that dozens of drones are available. Some are less than $100. Other costs thousands. There are two broad drone categories: fixed wing and rotary. Each type has its strengths and weaknesses.

Fixed-wing drones can be hand-launched, but often they require a runway or even an unwieldy catapult. But they're generally faster and can fly much longer than their rotary brethren.

One option is the eBee senseFly, a fixed-wing drone designed specifically for mapping purposes. Toss it into the air and it follows a preprogrammed route, snapping high-resolution images that are then integrated into maps and 3-D models. It can cover more than 4 square miles (10.4 square kilometers) on a single flight. Farmers are the primary customers, as they can use the drone to optimize their agricultural practices and increase their yields. The eBee retails for more than $10,000.

The Agribotix Hornet LR is another fixed-wing drone, and like the eBee, it's intended largely for agricultural use. It has a 6.4-foot (2-meter) wingspan and a cruising speed of more than 30 miles (48 kilometers) per hour. It can fly for nearly an hour and a half before it must descend for recharging. Rather than only offering purchase options, Agribotix leases units to customers for less than $2,000.

Fixed-wing drones are just a teensy sliver of the commercial and hobbyist drone market.

The Most Common UAVs

A DJI Innovations DJI Phantom 2 Vision aerial system drone was demonstrated during a media preview for International CES 2014.

 

Fixed-wing drones are fast and fly far, but rotary models are much more common, in part because they're easier to fly and more stable for purposes like photography. If you want a rotary drone, you'll have dozens of options from which to choose.

On the cheap side, for instance, there's the Hubsan Mini RTF quadcopter, which sells for less than $60. It's so tiny that it will fit in the palm of your hand. After a 40-minute charging session, you'll get about seven minutes of flight time during which you can make the drone do four-way flips and other stunts. You can also capture pictures on a miniscule 0.3-megapixel camera.

The Parrot AR.Drone 2.0 Power Edition is a quadcopter that sells for around $400 online. This drone features upgraded batteries that offer about 36 minutes of flight time. It comes with a free flight control app that you can load to your WiFi-enabled device, such as a tablet or smartphone, letting you control the drone to range of 165 feet (50 meters). It also has a 720p HD video camera that streams video live to your device, giving you a bird's-eye view literally on the fly.

One of the better-known drone manufacturers is DJI, which makes the DJ Phantom series. These drones aren't just for fun — they're intended to give blossoming cinematographers a way to catch amazing high angles without the need for more expensive gear. Some models come with GoPro camera mounts, while others are equipped with onboard cameras of their own.

The FC40 Phantom 2 Vision+ quadcopter weighs in at just under $1,000. It can fly to more than 2,600 feet (792 meters), with a flight time of roughly 25 minutes. A controller helps you manage the drone's flight, while the app that you load on your phone or tablet manipulates the video and camera capabilities.

With all of these flying contraptions zipping around, it's hard to deny that they seem awfully reminiscent of regular old remote-control helicopters and planes. So what's the difference between those traditional radio-controlled machines and new-age drones?

It has a lot to do with automation and advanced digital features. Whereas traditional remote-controlled devices require constant attention, drones can do amazing things on their own. Program in a GPS location, for example, and a drone can automatically fly itself to that point and then hold its position. Or you can run a so-called "follow me" mode, and the drone will follow you around, tracking you by sensing the signals from your phone.

Modern drones are equipped with a whole slate of similar fun and useful features. Of course, none of those capabilities are worth much if the thing can't get off of the ground.

Aerial Acrobatics:

If you want to spend an afternoon flying your drone, you’ll need to have fresh batteries at the ready. 

 

Even casual observers realize one striking thing about drones — they often have four propellers (but can have anywhere from three to eight) unlike traditional RC helicopters, which have only one main rotor. Drones need extra rotors because they need more stability to pull off their automated functions.
More rotors also means more lift. Lift, of course, is the push that spinning propellers create beneath a flying machine. The more lift a device has, the higher and faster it can go, and the more weight it can carry. That last part is vital for anyone who wants to attach a camera to a drone. Too little lift means a drone will moan and groan and crash, or maybe never get airborne at all.

There's a reason that most consumer drones don't get much more than 15 to 20 minutes of flight time, and that reason is related to power. Drones need batteries to power their props. A couple of lightweight rechargeable batteries suffice for a short amount of time in the air. Adding more (or more powerful) batteries is a great idea ... until you realize the extra weight they add actually reduces overall flight time.

As power flows from the batteries to the rotor motors, the propellers begin to spin, and it's the spin of each prop relative to the others that changes altitude and direction. Rev up the rotors and they'll generate enough lift to overcome the force of gravity, zipping the drone higher and higher.

If you want the drone to tilt on one side, two of the rotors will begin spinning faster on one side, creating more lift. In doing so, some of the upward lift becomes more of a sideways force, causing the drone to move forward or backwards. In the same manner, different prop speeds will spin the drone.

Obviously, you don't have to think through these processes as you're flying your drone, otherwise you'd probably crash it every 10 seconds. Drones are loaded with accelerometers and gyroscopes that help them maintain their orientation in space. These instruments detect linear acceleration, tilt and other directional cues to keep them from dive-bombing the ground or, worse, unsuspecting bystanders.

Many drones also have integrated GPS so the machine "knows" where it is. Command the drone to hover in one small space and it will do so, fighting a breeze if necessary.

To input your commands, you need a controller, typically one that uses 2.4 gigahertz radio waves. Many drone controllers look just like RC controllers of yore; that is, a boxy unit with two thumb joysticks and a collapsible antenna. Others rely on a combination of 2.4 gigahertz signals and WiFi, and they may pass on an old-school controller for one that looks more like a gamepad, or they may rely on a control app on your smartphone or tablet.

The act of flying consumer drones ranges from pretty easy to fiendishly difficult. Cheaper drones are budget friendly but may be so difficult to fly (and so delicate) that they're broken before you can figure out how to make them travel in a straight line. Pricier drones often have some automatic functions, like landing assistance, that help simplify some of the harder and riskier portions of flights, easing you into your new role as pilot.

Drones: Dystopia or Dream?

Whether you’re a drone enthusiast or you fear their hovering presence, it’s a certainty that you’ll see more of them in the near future. 

 

Drones are the stuff of dystopian nightmares. They're used for surveillance at home and abroad, raising privacy issues everywhere. They can carry weapons and can kill people from thousands of miles away while the operator sips coffee in a temperature-controlled office.

Yet drones are a dream come true for many commercial enterprises. Farmers can better monitor fields and livestock. Construction engineers can much more easily see their projects from every angle. Drones can offer new perspectives on real estate, move cargo and deliver packages.

By one estimate, drone technology could create more than 100,000 jobs in the next decade. And they could boost the economy by billions and billions of dollars as they spill into sectors of engineering, computer science, commercial contracting, videography, forestry and, of course, the military [source: Whitlock]. All of these disciplines will require experts in fabricating and flying drones — and commercial drone pilots could start with an annual salary of $50,000 to more than $100,000, working for manufacturers, surveyors, law enforcement or any number of other organizations.

Colleges, such as the University of North Dakota, are increasingly offering degrees for piloting drones in anticipation of the drone explosion. Students train on simulators as they build up their flight hours, but in many cases they can't fly actual drones as part of their coursework. That's because before drones can truly take flight, they'll have to surmount legal and regulatory hurdles. At present, the FAA limits what drones can do in American airspace, even if you're practicing through a college program.

Hobbyists must keep their machines flying lower than 400 feet (122 meters) and at least 5 miles (8 kilometers) from airports to prevent conflicts with manned aircraft. In spite of those rules, the FAA has documented dozens of near misses from people who violate regulations, and any of those instances could have potentially caused serious damage to an airplane and endangered lived. Those kinds of problems complicate the government's ability to integrate commercial drone usage on a larger scale.

Still, Congress has directed the FAA to find ways to regulate drones, particularly commercial drones, in ways that will help harness these technologies for the economy. Because of the large scale of drones' likely impact on our society (and because we're talking about a federal bureaucracy) you can bet that it will be a few years before drones really take off commercially across the country.

In the meantime, drone technology continues to evolve much more quickly than any single organization can track. Hobbyist drones are getting cheaper and more capable by the month, and more and more manned military craft are being replaced by enormous, powerful and deadly drones that can scour the skies far longer than any traditional craft.

If you were waiting for the day of the drones to arrive, realize this — that day has already come. Drones, for good or bad, will be a part of our culture for many years to come.

Author's Note: How Drones Work

Just like that, the drones are everywhere. I was running down a remote rural path a few weeks ago when I met a bicyclist heading the opposite direction. He'd strapped a controller to his handlebars and was guiding a quadcopter 20 feet (6 meters) above and ahead of him. I don't know whether he was recording a video or just flying for fun, but it was proof that no matter where we go, these small flying machines are with us, too. Let's hope that in the long run, that's a good thing.

Careers: Drone Pilots

How Drone Pilots Work ?

---

Elmer Sperry, inventor of the gyroscope, was tasked with creating an unmanned aerial vehicle that could deliver and detonate a warhead. 

In 1898 the second version of Madison Square Garden was only 8 years old. There, on the shore of an indoor pond custom built for his purposes, the eccentric, brilliant inventor Nikola Tesla released a weird, metal boat and proceeded to make it zip around over the surface of the water. But how? Many of the stunned onlookers wondered if he was able to control the vehicle with his mind. In fact, Tesla was using radio waves to guide his invention, U.S. patent number 613,809 — arguably the world's first robot. Tesla's innovative use of radio waves to achieve remote control of a craft may legitimately be called the dawn of drone piloting [source: PBS].

The next step, of course, was to get that craft airborne.

The origins of drone piloting date back to the origin of airplanes themselves. The common denominator has been the military. The risks associated with surveillance, reconnaissance, bombing and fighting are so high that from the earliest days of air warfare, military strategists have been thinking of ways to get pilots out of the craft and safely on the ground.

During World War I, the inventor of the gyroscope, Elmer Ambrose Sperry, was contracted to develop a drone biplane for the Navy. Sperry and his son Lawrence assembled a team and began research and development on Long Island, New York. Their idea was to launch the unmanned aircraft with a catapult, pilot it remotely for 1,000 yards (914 meters) and then make the aircraft dive and detonate a warhead. Crash after crash followed as every attempt ended in failure. Finally, in March 1918, one of their planes flew the 1,000 yards (914 meters), dove on the selected target, recovered and landed. It was the first true drone. Or, as the experts like to say, it was the beginning of unmanned aerial systems [source: Barnhart].

The problem with early drones, like the one developed by Sperry, was that they were too unreliable for combat. While the U.S. Navy did evolve an attack drone that they deployed in the Pacific theater during World War II, most drones used by the military in the first half of the 20th century served as target practice for pilots-in-training [source: Barnhart].
During the Cold War era, more sophisticated drones began to be used for reconnaissance and surveillance. Today, more than 90 percent of extant drones are used for data gathering, whether by military, law enforcement or environmental monitoring agencies [source: Barnhart].

The Drone Pilot Spectrum:

Hobbyist and commercial drone pilots can catch amazing images with their unmanned craft. 

The U.S. military's use of drones to strike targets abroad has become highly controversial. Air Force drone pilots have been called "armchair killers," and the fact that a pilot can be sitting at a console in Nevada while pulling a trigger that kills people in Pakistan is found, by many people, to be unsettlingly remote and cold. But many, if not most, drone pilots are not actually directly engaged in making kill shots. Their job is to fly surveillance missions that gather data about potential threats all over the world.

One way or another, there's no getting around the fact that many of these soldiers wake up at home, drive a few minutes to their job site and then pilot expensive flying machines all over the world before going home for dinner. The job of the modern military drone pilot is a far cry from what we think of when we picture fighter pilots.

On the other end of the spectrum is the hobbyist drone pilot. Often self-taught, the hobbyist might even have built her own drone and taught herself to use it. Or, at least, that's the way it used to work. People have been making and flying model airplanes by remote control for many years, but with the advent of smartphone technology and cheap, off-the-shelf quadcopters equipped with cameras, the hobby of drone piloting has really taken off. Built-in drone cameras are motivating their pilots to take risks for great footage that the old-fashioned model airplane pilots rarely took.

The current rules are incomplete and in flux, but in general terms, you're not allowed to fly your drone above 400 feet (120 meters), you've got to be able to see it at all times and you have to keep it 5 miles (8 kilometers) away from local airports. Until February 2015, law enforcement officials had been issuing steep fines to hobbyist pilots who disobeyed these rules [source: Fitzpatrick].

Somewhere between the soldier and the hobbyist are the commercial pilots, many of whom have made businesses out of aerial photography and cinematography. The world of commercial drone piloting is rapidly growing, despite the fact that the new Federal Aviation Administration (FAA) guidelines concerning commercial drones won't come into effect until 2017. We'll discuss this in more depth on the next page.

Finally, there's a potential fourth category of drone pilot — drones themselves. In theory it's possible to plot GPS coordinates and simply send a drone off to pilot itself to a destination. The major obstacle to this is, well, obstacles. You need pilots to man the monitor and keep a sharp eye out for impediments such as trees, power lines, tall buildings and other drones. But new miniature 3-D camera technology is already making it possible for drones to "see" obstacles in their path and take evasive action [source: Finley]. A future in which drones pilot themselves may not be far off.

Military Drone Pilots:

U.S. military pilots in Las Vegas steer high-tech Predator drones -- complete with infrared camera, still camera and two missiles -- above Afghanistan. 

Two young men sit in a dark, smelly room in the Nevada desert. They're looking at the image of a mud hut somewhere in Afghanistan. At their fingertips are the controls to a powerful, unmanned aerial vehicle (UAV) that's hovering unseen in the skies high above the hut. They've been looking at this little house for hours, and nothing has moved except for a few goats. Finally, they're told that an intelligence source has determined there's an insurgent inside and they need to destroy the place. Placing a laser on the corner of the hut, they release a Hellfire missile from the UAV. A split second later they see something dart out of the house. Is it a kid? A dog? Then it's gone. The house is rubble, and whoever or whatever they saw is gone too. There's no mention of this darting figure in the official report, but the incident still haunts Senior Airman Brandon Bryant, one of the two men at the controls that day [source: Power].

In lightless, windowless boxes on Air Force bases around the country, people sit on chairs in regulation one-piece flight uniforms watching bright screen images transmitted from the other side of the world. These pilots control UAVs that patrol the skies over Syria, Iraq, Pakistan and other hot spots across the globe. More often than not the pilots are gathering data, but sometimes they're firing missiles at military targets. And they're at their posts for as long as 13 to 14 hours a day, six days in a row. On average, drone pilots fly their craft three times longer than conventional Air Force pilots spend aloft in their cockpits [source: Terkel].

Long hours, together with the strange disconnect between their immediate surroundings and the real-world consequences of their work, leads to a deadly combination of boredom and stress. And to top it all off, they get no respect. Teased by their peers for playing video games rather than flying, drone pilots are increasingly burnt out.

Recently, the Air Force has been having trouble recruiting new drone pilots to replace those who are retiring or quitting. The problem has reached such crisis proportions that Air Force Secretary Debra Lee James has publicly announced they are more than doubling incentive pay (to $1,500 per month). The Air Force needs more than 1,200 drone pilots, but as of January 2015 they had only 988 [source: Terkel].

Increasing the pay may not be enough. After six years of working as a drone warrior, Senior Airman Bryant left the Air Force, turning down a $109,000 bonus to keep flying [source: Power].

Drone Pilot Schooling:

More than 300 U.S. institutions now have permits from the Federal Aviation Administration to fly UAVs for teaching and reseach purposes. Students might accumulate some debt in school, but they're likely to land high-paying jobs as soon as they get out.  

Pick a disaster, any disaster. 9/11? Katrina? Fukushima? As rescue crews struggle through the rubble, miniature helicopters equipped with cameras zip up and down ruined buildings and in and out of wreckage too dangerous or difficult for humans to reach quickly. Use of robots like these has resulted in a nine-fold improvement in the performance of rescue teams at disaster sites. And the person you will often find at the controls for one of those helicopters is Dr. Robin Murphy. Founder of the Center for Robot-Assisted Search and Rescue (CRASAR) at Texas A&M University, Murphy is one of the leaders in the field of disaster relief robotics. Her CRASAR center has been directly involved in numerous disaster relief operations since its founding [source: CRASAR].

Murphy is also a teacher at A&M where she mentors graduate students through the school's computer science program. A&M is one of 358 U.S. public institutions, including 14 universities and colleges, that have an FAA permit to fly UAVs for the purposes of teaching and research. Some of them, including several community colleges, have drone pilot training programs, but only three schools offer degrees in the field: Kansas State University, the University of North Dakota and Embry-Riddle Aeronautical University. The programs don't just feature extensive flight simulation — at Embry-Riddle, for instance, students must also accumulate 13 credits in engineering to ensure they understand the drone system inside out [source: Raftery].

One recent graduate from the Kansas State program racked up $60,000 in student loans, but then immediately walked into a six-figure job with the military [source: Raftery]. While this graduate said he hopes to find work in the civilian market eventually, for now, the jobs are all with the military; there isn't really an official civilian drone pilot market yet.

Universities and other institutions are starting to offer training programs because they're expecting a massive boom in the use of commercial drones. In fact, everybody who knows anything about drones is anticipating this boom. They're just waiting for the FAA to make it legal.

The Future of Drone Pilots:

Google and Amazon foresee a future that includes package-delivering drones. 

At the end of February 2015, the Federal Aviation Administration (FAA) lost a court battle that has important implications for commercial drone pilots. The judge in the case said the FAA could not yet regulate the use of drones without allowing the general public to have a comment period. This means that many of the $10,000 fines for operating without a permit have been reversed. Drone entrepreneurs can get back to business with pursuits like aerial photography for real estate companies and advertising firms [source: Kravets].

But they're still operating in a gray zone. The FAA has been working toward creating new regulations to govern drone technology, but their work isn't yet complete. On Feb. 15, 2015, the agency issued a proposal to let commercial drones under 55 pounds (25 kilograms) fly at will [source: Levin].

The proposal also dials back the anticipated requirements for drone pilots, who won't be forced to get a license. Instead, operators will have to pass a written test that demonstrates they have a basic understanding of aeronautical information, including airspace classifications, radio communication and emergency procedures [source: Fung].

But the actual regulations might not go into effect for another few years.

In the absence of official regulation, insurance companies have been drawing up their own rules to create policies that cover the proliferating use of commercial drones. Entrepreneurs who buy the insurance are operating on the time-honored assumption that you can't break rules that don't exist yet. Many are contracting themselves out for aerial photography, mapping and surveying. But people involved in drone flight anticipate a vast array of other applications from agricultural spraying to firefighting to ambulance services to parcel delivery [source: Levin].

Famously, online retail giant Amazon has already declared its intention of creating a drone delivery system that could see packages arriving on your doorstep within minutes of placing an order. Google has also jumped into the fray and is actively experimenting with a drone delivery system. The company anticipates a single pilot handling the flights of multiple drones at once. A European organization called Platform Unmanned Cargo Aircraft (PUCA) shares this vision and is working toward the deployment of large, slow-moving cargo drones that would deliver goods to isolated communities. PUCA proposes a single pilot controlling as many as 30 planes at a time [source: Madrigal].

In the meantime, a U.S. company called Skycatch, which uses drones to map sites for mining and construction companies, is building a list of pilots for its clients to hire. Called Workmode, the list already has 3,000 names on it, 1,000 of them in the U.S. Eventually, Skycatch wants to automate Workmode so it operates like an aerial version of Uber, allowing people to hire drone pilots for their various needs with their smartphones [source: Levin]. After all, it's unlikely that most people would need to actually own a personal UAV. But it seems like drones could fit quite naturally into the sharing economy.

Author's Note: How Drone Pilots Work:

When I was a kid I was convinced that by the time I grew up everybody would be driving hovercrafts. I never would have guessed that when we finally got around to creating working hovercrafts, drivers would be passé. As I see it, the basic problem is that we're too heavy to zip around in drones. The solution is obvious, we need to be lighter. Some futurists predict that we'll be able to download our consciousnesses into computer chips — why not just download to a drone? Maybe a transformer drone would be best — one that could reassemble itself into an ambulatory robot upon reaching its destination. Being a quadcopter could get old pretty quickly.

Investigation Report: Hack a Drone !

Can you hack a drone?

---

A drone is essentially a flying computer, and is as hackable as any other laptop or desktop device. 

We live in an age of hackers. Whether it's yanking payment and credit card information from large retailers, pilfering personnel information from the U.S. government or snatching a treasure trove of juicy emails, salary information and unreleased films from Sony Pictures, the black hats are out there and they're trying to get in. Everything is a potential target, and that includes drones. Hackers have developed malware designed to infiltrate and overtake the small quadcopters that you might find hovering around your local park or eventually dropping off your Amazon packages. They've also come up with a way to bring down the high-powered unmanned aerial vehicles (UAVs) increasingly employed by military forces [sources: de Looper, Sternstein].

Maldrone is a type of malware specifically aimed at UAVs and intended to hack into drones via Internet connections. Drones, after all, are essentially flying computers. As such, they're susceptible to the same type of hacks as a laptop or smartphone. Drone hacking technology can be used to either swipe the data that the machines collect or even take over their physical control [sources: de Looper, Sternstein, Moskovitch].

SkyJack, for example, looks like a run of the mill drone, but is designed to hunt down other UAVs, hack into them and control them. In other words, it could potentially be used to amass a fleet of zombie drones. Samy Kamkar, the hacker behind the Internet worm that crippled MySpace in 2005, has publicly released the specs for the SkyJack drone, giving hackers all the info they need to build their own versions. The machine runs on software that directs it to locate other drones within a certain area and take over their control by severing the drones' Internet connection with its rightful owner [source: Crook].

Meanwhile, military drone hackers look to bring down UAVs by confusing them. Iranian officials, for example, say that they were able to ground a U.S. Air Force drone flying along the country's border with Afghanistan in late 2011 by manipulating its global positioning system (GPS). It's believed that the hackers first jammed the drone's communication links, leaving it unable to send and receive information and controls to and from operators on the ground. The move also disconnected the drone from the GPS system that it used to coordinate its path. As the drone switched to autopilot control, it also went looking for unencrypted GPS frequencies. The hackers sent the drone "spoof" coordinates that led the machine to believe that it was close to its home base in Afghanistan. Instead, the machine landed in Iran [sources: Moskvitch, Sternstein].

The spoofing attack has led to an arms race of sorts, with military drone outfits scrambling to beef up their protections against hackers. Among other moves, experts recommend hiding the exact positions of GPS receivers to make them more difficult to locate. The U.S. military is currently working with Boeing to develop a "hacker-proof" drone which would shield its onboard communications system from potential attacks. The computers operate on a new programming language that creators say is less vulnerable to hacks. At least for the time being [source: Sternstein, Sternstein].