What Is Global Positioning System in Computer Hardware?
Also known as: GPS, Global Positioning System, A+ hardware, satellite navigation, IT glossary
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Quick Definition
The Global Positioning System (GPS) is a network of satellites that constantly send signals down to Earth. A GPS receiver, like the one in your phone or car, catches these signals and calculates exactly where you are. It uses the time it takes for the signals to travel from several satellites to figure out your latitude, longitude, and even your altitude. This works anywhere in the world, 24 hours a day, as long as the receiver can see the sky.
Must Know for Exams
In the CompTIA A+ certification exams, GPS appears primarily as a hardware technology under Mobile Devices and Hardware topics. The exam objectives ask candidates to identify GPS as a standard feature of laptops, tablets, and smartphones. You should know that GPS is a satellite-based system and does not rely on cellular towers or Wi-Fi for location, although assisted GPS (A-GPS) can use those networks to speed up the initial location fix.
The A+ exam may present a scenario where a user cannot get a GPS lock on their smartphone. You need to troubleshoot by checking if the device is in airplane mode, if it has a clear view of the sky, if location services are enabled, and if the GPS antenna (which is inside the device) might be damaged. Another common exam scenario involves a laptop that has a GPS receiver built in, and you need to enable it in the operating system or configure the appropriate driver.
The CompTIA Network+ exam touches on GPS in the context of timing and synchronization, particularly for NTP. You may be asked about how a Stratum 1 NTP server uses GPS as a primary time reference. In the Security+ exam, GPS location data is discussed in relation to geolocation policies and mobile device security.
You might see a question about using GPS to enforce a location-based access policy or to remotely wipe a device that leaves a certain geographic area. For the CompTIA IT Fundamentals (ITF+) exam, GPS is a simple recognition item. You should know it stands for Global Positioning System, that it uses satellites, and that it is used for navigation and location services.
Across all these exams, the key is to understand GPS as a hardware component, its dependency on satellite signals, and its role in providing location and time data in IT systems.
Simple Meaning
Think of the Global Positioning System as a giant, invisible map that covers the whole planet. Instead of using roads or landmarks, this map is made of signals coming from a fleet of satellites orbiting high above us. Your phone or a car GPS unit is like a small receiver that listens to these signals.
Each satellite constantly sends out a message that says, I am here, and the time is exactly this. When your receiver picks up this message, it knows how far away that satellite is based on how long the signal took to arrive. To figure out your exact location, your receiver needs to hear from at least four satellites at the same time.
This is similar to how you might figure out where you are in a large room by listening to the echoes of your voice from the walls. If you know the distance to each wall, you can pinpoint your spot. GPS works the same way, but the walls are satellites moving at 14,000 kilometers per hour.
The system was originally built by the United States Department of Defense for military use, but it was opened to civilians in the 1980s. Today, almost every smartphone has a GPS chip. The system is incredibly accurate, often pinpointing your location within a few meters.
It does not require you to send any signals back, so it is completely free to use and private. The satellites carry very precise atomic clocks to keep the timing accurate. Without GPS, many modern technologies would not work the way they do, from finding the nearest coffee shop to guiding airplanes to the runway.
Even your internet banking and stock trading depend on GPS for precise time synchronization. In simple terms, GPS is the Earths global address system, telling every device exactly where it is at any moment.
Full Technical Definition
The Global Positioning System is a space-based radio-navigation system owned by the United States government and operated by the United States Space Force. It provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. System Overview The GPS system is divided into three segments.
The space segment consists of a constellation of at least 24 operational satellites (plus spares) in medium Earth orbit at an altitude of approximately 20,200 kilometers. These satellites are arranged in six orbital planes, each inclined at 55 degrees to the equator. This configuration ensures that a receiver anywhere on Earth always has at least four satellites in view.
The control segment includes a network of ground stations spread around the world, including a master control station at Schriever Air Force Base in Colorado. These stations track the satellites, monitor their health, and upload navigational data, including almanac and ephemeris information. The user segment refers to the GPS receivers and the software that processes the satellite signals.
How It Works Each satellite continuously broadcasts a radio signal containing a pseudorandom noise (PRN) code and a navigation message. The PRN code allows the receiver to identify which satellite is transmitting. The navigation message contains the satellites precise orbital data (ephemeris), the approximate orbital data for all satellites (almanac), and the satellite clock correction information.
A GPS receiver calculates its position by measuring the time delay between when the satellite transmitted the signal and when the receiver received it. This time delay, multiplied by the speed of light, gives the distance to the satellite. This process is called trilateration.
With signals from at least three satellites, the receiver can compute a two-dimensional position (latitude and longitude). With a fourth satellite signal, the receiver can calculate its altitude (three-dimensional position) and correct for clock errors between the receivers internal clock and the satellites atomic clocks. Accuracy and Error Sources Typical civilian GPS accuracy is around 5 to 10 meters under open sky.
Several factors can degrade accuracy. Atmospheric effects, especially in the ionosphere and troposphere, can slow the radio signals slightly. Multipath interference occurs when signals bounce off buildings or terrain before reaching the receiver.
Satellite geometry (Dilution of Precision or DOP) affects accuracy when satellites are clustered closely together. Selective Availability, a deliberate degradation of civilian signals, was turned off in 2000. Differential GPS (DGPS) and Real-Time Kinematic (RTK) techniques can achieve centimeter-level accuracy by using a fixed ground station to correct errors.
In IT Environments GPS is implemented in hardware as a dedicated GPS chipset, often integrated into system boards or connected via USB, serial, or I2C interfaces. In enterprise and cloud infrastructure, GPS is critical for Network Time Protocol (NTP) servers that require precise time synchronization. Many servers use GPS receivers as a primary time source for Stratum 1 NTP servers.
Additionally, location-based services in mobile device management and asset tracking rely on GPS hardware and APIs.
Real-Life Example
Imagine you are at a very large, completely dark sports stadium at night. You have a friend standing on the top row of the east side, another friend on the top row of the west side, and a third friend on the top row of the north side. Each friend has a powerful flashlight and a stopwatch.
You want to figure out exactly where you are standing on the field. You ask each friend to flash their light at exactly the same moment. Because you are standing at a certain distance from each friend, you see the flashes at slightly different times.
By looking at your own stopwatch and measuring the time difference between seeing each flash, you can calculate how far you are from each friend. If you know you are 30 meters from the east friend, 40 meters from the west friend, and 50 meters from the north friend, you can draw three imaginary circles on the ground. Your location is the single point where all three circles overlap.
This is exactly how GPS works. The satellites are your friends in the sky, but instead of flashlights, they send radio signals. Your GPS receiver is you on the field. The satellites all transmit at the same time, but the signals arrive at your receiver at different times depending on your distance to each satellite.
The receiver measures these tiny time differences and calculates your position. In the stadium analogy, the friends must have perfectly synchronized stopwatches, just as GPS satellites use atomic clocks. Also, a fourth friend would be needed to tell you your height above the ground, which is why GPS needs four satellites for a full 3D location.
This simple method of measuring distances from known points is the foundation of all GPS technology.
Why This Term Matters
GPS matters deeply in real IT work because it provides two essential services that are foundational to many technologies: precise location and exact time. For system administrators, GPS is a critical component of Network Time Protocol (NTP) infrastructure. Enterprise networks and data centers require extremely accurate time synchronization for logging, authentication, and transaction ordering.
A Stratum 1 NTP server typically uses a GPS receiver as its reference clock, ensuring that all servers on the network agree on the time within a few microseconds. Without GPS, systems would drift apart in time, causing issues with email timestamps, security certificates, and database replication. In networking and cybersecurity, GPS location data is used for geofencing and access control.
A company might enforce a policy that allows VPN connections only from within a specific geographic area. GPS coordinates from a mobile device can be used as part of a multifactor authentication flow. In cloud infrastructure, GPS is less directly used, but the services that depend on GPS are everywhere.
Content delivery networks (CDNs) route traffic based on the geographic location of users, often determined by an IP address database that is itself built using GPS-correlated location data. Mobile device management (MDM) systems rely on GPS to locate lost or stolen laptops and phones. Asset tracking tags in data centers use GPS to log the precise location of equipment during transport and installation.
For IT professionals supporting field technicians, GPS is essential for dispatch and job assignment. Even something as simple as a car service schedule or a delivery route optimization relies on GPS data. In short, GPS is not just a consumer convenience.
It is an infrastructure technology that underpins time synchronization, location services, security policies, and operational logistics in modern IT environments.
How It Appears in Exam Questions
In CompTIA A+ exams, GPS appears in multiple choice questions and performance-based scenarios. A typical multiple choice question might ask: Which of the following technologies allows a smartphone to determine its geographic location without using cellular towers? The correct answer is GPS.
Another question may ask: A users smartphone is unable to acquire a GPS signal. Which of the following is the MOST likely cause? The answer could be that the device is in airplane mode or that the user is inside a building with no windows.
Scenario questions are very common. For example, the exam presents a situation where a field technician needs to use a tablet to navigate to a remote job site. The tablet cannot get a GPS lock.
You must select the correct troubleshooting steps, such as verifying that location services are turned on, moving the tablet to an open area, or checking for a hardware switch that disables wireless radios. In Network+, GPS appears in questions about NTP configuration. A question might ask: What external time source is commonly used by a Stratum 1 NTP server to ensure high accuracy?
The answer is a GPS receiver. Another question could ask you to identify the required hardware for a time server that must synchronize to within 1 millisecond of UTC. In Security+, GPS appears in questions about mobile device management policies.
For instance: A company wants to ensure that company-issued tablets can only access corporate email when they are within the city limits. Which feature would an administrator configure? The answer is geofencing, which relies on GPS.
You may also see questions about remote wipe triggers based on GPS location. In performance-based questions, you might be asked to configure location settings on a mobile device or to interpret a log file showing GPS coordinates. The exam expects you to know that GPS is independent of cellular networks and that it requires a sky view.
Knowing these patterns helps you prepare for the kinds of traps exam writers set.
Practise Global Positioning System Questions
Test your understanding with exam-style practice questions.
Example Scenario
A company owns a fleet of delivery vans used for transporting sensitive medical equipment. Each van is equipped with a ruggedized tablet computer mounted in the dashboard. The tablet has a built-in GPS receiver.
One morning, a driver reports that the navigation app on the tablet is not working. It keeps saying Searching for GPS and never finds a location. You are the IT support technician.
You ask the driver if the van is parked in the garage. The driver says yes. You explain that GPS signals cannot pass through thick concrete and metal. You instruct the driver to drive the van out of the garage and into the open parking lot.
After a few minutes of driving outside, the navigation app locks onto the GPS signal and displays the current location. The issue is resolved. In this scenario, the GPS receiver in the tablet needs a clear line of sight to the sky to receive the weak radio signals from satellites.
The concrete and steel structure of the garage blocks those signals entirely. This is a classic example of how environmental factors directly impact GPS functionality. The fix is simply to move the device to an open area.
This scenario illustrates why IT technicians need to understand the physical limitations of GPS hardware, not just the software settings.
Common Mistakes
Thinking GPS uses cellular towers or Wi-Fi hotspots to determine location.
GPS is a satellite-based system and operates independently of cellular networks or Wi-Fi. It receives signals directly from satellites orbiting Earth. While Assisted GPS (A-GPS) can use cellular networks to speed up the initial fix, the actual positioning is still done via satellite signals.
Remember that GPS stands for Global Positioning System and uses satellites. Cellular towers and Wi-Fi are used for network-based location, which is a different technology often called A-GPS or just location services, but pure GPS does not need them.
Believing GPS works perfectly indoors or underground.
GPS signals are very weak radio waves that can be blocked by roofs, walls, concrete, and metal. Indoors, especially in basements or buildings with metal roofs, the signal strength is usually too low for a receiver to lock onto enough satellites.
Always assume GPS requires a clear view of the sky. If a device needs location indoors, it likely relies on Wi-Fi positioning or cellular triangulation, not pure GPS.
Confusing GPS with the Global Navigation Satellite System (GNSS) as a whole.
GPS is just one specific satellite navigation system, owned by the United States. There are other systems like GLONASS (Russia), Galileo (European Union), and BeiDou (China). Many modern devices use GNSS receivers that can listen to multiple systems for better accuracy.
Use GPS when referring specifically to the US system. Use GNSS when talking about the broader collection of satellite navigation systems. For CompTIA exams, GPS is the term used, but knowing GNSS is helpful for real-world understanding.
Assuming GPS receivers are external devices that must be plugged in.
GPS receivers are often built directly into the motherboard or system board of laptops, tablets, and smartphones. They are tiny chips that are always present in modern mobile devices. An external USB GPS receiver is an accessory, not the standard.
For exam purposes, treat GPS as a standard built-in hardware component of any mobile device. You enable it through software settings, not by plugging in hardware.
Thinking GPS requires an internet connection to work.
GPS receivers only receive signals. They do not transmit data. The satellite signals are free and available without any internet connection. However, many navigation apps download maps over the internet, and A-GPS uses the internet to get satellite almanac data faster.
The GPS hardware itself works offline. The need for an internet connection comes from the application software using GPS data, not from the GPS system itself.
Exam Trap — Don't Get Fooled
The exam question describes a situation where a user's smartphone cannot get a GPS lock while they are in a moving car. The answer choices include turning on Wi-Fi, disabling Bluetooth, or switching to airplane mode. A learner might choose turning on Wi-Fi because they think it helps location.
Understand that GPS is a separate, independent hardware system. Wi-Fi and cellular networks assist with location by providing rough position data, but they do not help the GPS chip lock onto satellites. If the problem is no GPS lock, the fix is to ensure a clear view of the sky, enable location services in the OS, and check for a hardware switch or airplane mode.
Turning on Wi-Fi will not help the GPS chip acquire satellite signals.
Commonly Confused With
GPS uses satellites to determine location, while Wi-Fi positioning uses the known locations of nearby Wi-Fi access points to estimate a device's location. Wi-Fi positioning works indoors and can be faster, but it is less accurate and depends on a database of Wi-Fi network locations.
Indoors at a mall, your phone might use Wi-Fi positioning to show you are near a specific store, but when you step outside, GPS takes over to give you turn-by-turn directions on the road.
Cellular triangulation uses the signal strength from multiple cell towers to estimate a phone's location. It is less accurate than GPS, often within hundreds of meters. GPS provides much more precise coordinates down to a few meters. Cellular triangulation works where there is cell service, while GPS requires a satellite view.
When you call 911 from a cell phone, emergency services use cellular triangulation to find your general area, but if your phone has GPS and sends those coordinates, they can find your exact location on a hiking trail.
A-GPS is a hybrid system that uses cellular or Wi-Fi networks to download satellite orbital data (almanac) to speed up the initial GPS lock. The actual location calculation is still done using satellite signals. A-GPS does not replace GPS, it just helps it start faster.
When you first turn on your phone in a new city, A-GPS uses the cellular network to quickly tell the GPS chip which satellites are overhead, so the phone finds your location in seconds instead of minutes.
Step-by-Step Breakdown
Satellites Transmit Signals
Each GPS satellite continuously broadcasts a radio signal that contains its exact position in space and the precise time the signal was transmitted. This signal is sent on specific frequencies, including L1 (1575.42 MHz) for civilian use. The satellites use onboard atomic clocks to keep time accurate to within a few nanoseconds.
Receiver Captures the Signal
The GPS receiver, such as a chip inside a smartphone, listens for these signals from any satellites in its line of sight. It identifies each satellite by its unique pseudorandom noise (PRN) code and begins decoding the navigation message that contains the satellite's orbital data and clock corrections.
Time Delay Measurement
The receiver calculates the time it took for the signal to travel from the satellite to the device. This is done by comparing the timestamp in the signal with the receivers own internal clock. The time difference, though very tiny, is measured with high precision. This time delay is the core measurement needed for distance calculation.
Distance Calculation
The receiver multiplies the time delay by the speed of light, which is approximately 299,792,458 meters per second. This gives the distance from the receiver to the satellite. This distance is not perfectly accurate due to clock errors and atmospheric effects, so it is called a pseudorange.
Trilateration
Using the known positions of at least three satellites (from their orbital data) and the calculated distances to each, the receiver performs trilateration. It determines that it is located at the intersection point of imaginary spheres centered on each satellite. With three satellites, it gets a 2D position (latitude and longitude).
Four Satellite Fix for 3D and Clock Correction
With a fourth satellite signal, the receiver can solve for altitude (3D position) and also correct for the error between its own internal clock and the satellites atomic clocks. This is why GPS receivers need at least four satellites in view for the most accurate, three-dimensional position fix.
Output Position and Time
The GPS receiver outputs standard data formats, typically NMEA 0183 sentences, over a serial interface. This data includes latitude, longitude, altitude, speed, heading, and precise UTC time. The operating system or application software then uses this data for navigation, mapping, time synchronization, or other location-based services.
Practical Mini-Lesson
In a practical IT context, understanding GPS goes beyond knowing it finds your location. For professionals, the most common interaction with GPS is in the management of mobile devices and the configuration of time services. First, lets talk about mobile device management (MDM).
As an administrator, you might need to enforce a policy that requires a company laptop or tablet to have its GPS enabled at all times. On Windows devices, GPS settings are found under Settings Privacy Location. You must ensure that the Location Service is turned on and that the specific application has permission to access location.
On macOS, the setting is in System Preferences Security Privacy Privacy Location Services. On mobile devices running Android or iOS, location services are a system-wide toggle. A critical point for exams is that GPS hardware can be disabled by a physical switch on some laptops, a feature sometimes called wireless kill switch or airplane mode.
Always check that first during troubleshooting. Second, consider GPS as a time source. Many enterprise data centers use dedicated network time servers that connect to a GPS antenna mounted on the roof.
The server receives the GPS signal, extracts the precise UTC time, and distributes it to all network devices via NTP. As an IT professional, you may be tasked with installing and configuring such a time server. You would need to ensure the GPS antenna has a clear view of the sky, that the coaxial cable is properly shielded, and that the server software is configured to use the GPS time source.
The configuration might involve setting the server as a Stratum 1 NTP server and specifying the GPS device as the reference clock, often using a PPS (Pulse Per Second) signal for microsecond accuracy. Third, GPS accuracy can be affected by environmental and hardware factors. As a technician, if a user reports that their device shows the wrong location, you should check for a clear sky view, check for interference from metal objects or electronic devices, and verify that the GPS driver is installed and up to date.
You should also understand that GPS is a receive-only technology, so it does not consume cellular data. However, applications that use GPS data, like mapping apps, do consume data for map tiles and updates. Finally, GPS connects to broader IT concepts like geofencing in cybersecurity, where you can define a virtual boundary, and any device that exits that boundary triggers an alert or a remote wipe.
This is a standard feature in enterprise MDM solutions. Understanding these practical aspects ensures you can support GPS-dependent systems in the real world and pass certification exams that test this knowledge.
Memory Tip
Four satellites for a four-dimensional fix: time plus three space dimensions.
Covered in These Exams
Current Exam Context
Current exam versions that test this topic — use these objectives when studying.
220-1101CompTIA A+ Core 1 →N10-009CompTIA Network+ →220-1101CompTIA A+ Core 1 →220-1102CompTIA A+ Core 2 →Related Glossary Terms
An A record is a DNS record that maps a domain name to the IPv4 address of the server hosting that domain.
5G is the fifth generation of cellular network technology, designed to deliver faster speeds, lower latency, and support for many more connected devices than previous generations.
802.1X is a network access control standard that authenticates devices before they are allowed to connect to a wired or wireless network.
Two-factor authentication (2FA) is a security method that requires two different types of proof before granting access to an account or system.
Frequently Asked Questions
Does GPS work on an airplane?
Yes, GPS works on an airplane as long as the GPS receiver has a clear view of the sky through a window. However, some airlines ask passengers to turn off wireless devices during takeoff and landing, which would include GPS functionality.
Do I need a data plan for GPS to work on my phone?
No, the GPS chip itself does not need a data plan. It receives free satellite signals. However, to see a map or get directions, you need map data, which typically requires an internet connection unless you download offline maps beforehand.
Can GPS be used to track stolen laptops?
Some laptops have built-in GPS, but many do not. Tracking a stolen laptop often relies on Wi-Fi positioning or IP address geolocation. However, specialized asset tracking tags with GPS can be placed in laptops for tracking purposes.
What is the difference between GPS and A-GPS?
GPS is the satellite system itself. A-GPS (Assisted GPS) uses cellular or Wi-Fi networks to help the GPS receiver get a faster initial lock by providing satellite orbital data. Once locked, A-GPS works just like regular GPS.
Why does my GPS lose signal in tunnels?
Tunnels block the radio signals from GPS satellites because the signals cannot penetrate through thick layers of rock, concrete, and metal. The receiver cannot hear any satellites, so it loses the location fix until it exits the tunnel.
How accurate is civilian GPS?
Civilian GPS is typically accurate to within 5 to 10 meters under open sky. With differential GPS (DGPS) or Real-Time Kinematic (RTK) corrections, accuracy can be improved to within a few centimeters.
Is GPS the same on all devices?
The basic GPS technology is the same, but the quality of the GPS chip and antenna can vary between devices. Higher-end devices often have more sensitive receivers that can lock onto satellites faster and maintain a fix in more challenging conditions.
Summary
The Global Positioning System is a critical hardware technology that provides location and time data to billions of devices worldwide. For IT professionals, understanding GPS means recognizing it as a built-in component of mobile devices, knowing that it relies on satellite signals for accuracy, and being able to troubleshoot issues like a lost lock due to environmental obstructions. In certification exams such as CompTIA A+, Network+, and Security+, GPS appears in questions about mobile device hardware, NTP time synchronization, and geolocation security policies.
The key points to remember are that GPS requires at least four satellites for a full 3D fix, that it works independently of cellular and Wi-Fi networks, and that its effectiveness depends on a clear view of the sky. Mastering these fundamentals will help you handle real-world IT tasks and exam questions confidently. GPS is a foundational technology that connects the physical world to digital systems, and a solid grasp of it is essential for any IT support or infrastructure role.