There has been a lot of hype lately about fifth generation (5G) mobile network technology. Compared to 4G, this modern method of connecting wireless devices to cellular networks offers higher data rates, ultra-low latency, improved reliability, expanded configurability, increased network capacity and availability, and numerous It is designed to provide connectivity between users.
The U.S. Department of Defense (DoD) wants to leverage these commercial advances in its communications systems, but 5G, like its predecessors, does not have sufficiently robust security features. For military applications, wireless connectivity protects communications from unwanted detection (identifying the presence of a signal), unwarranted geolocation (identifying the source of the signal), and intentional jamming (interfering with the transmission and reception of the signal). and become vulnerable. Before the Department of Defense can fully take advantage of his 5G technology, network vulnerabilities must be identified, quantified, and mitigated.
“For commercial communications, you might worry a little bit about interference, but you don’t have to worry about someone intentionally trying to find you and jam your communications, as you would in the military.” explains tactical network researcher Nicholas Smith. A group that is part of the Communications Systems Research and Development Area at MIT Lincoln Laboratory. “Militaries also have to deal with more difficult travel scenarios than just people traveling on foot or in cars, such as planes traveling at Mach speeds.”
Smith is part of a team at Lincoln Laboratory that is assessing 5G vulnerabilities and developing potential solutions to make this latest generation of technology resilient enough for military use.
mountain of data
In April 2022, with funding from the Department of Defense FutureG and 5G Directorate, Lincoln Laboratory’s 5G Vulnerability Assessment Team headed to Hill Air Force Base (AFB) near Salt Lake City, Utah, to conduct an over-the-air testing campaign. It was conducted. Newly opened 5G network test bed designed and installed by Nokia Corporation. The team was one of the first to use the testbed at Hill Air Force Base. The testbed is one of five Department of Defense FutureG and 5G Office testbeds located at U.S. military installations as locations to evaluate 5G network capabilities and functionality. Although 5G vulnerabilities have been modeled for some time, this test campaign marks one of his first red team campaigns against 5G in this area.
Over two weeks, the team deployed a GPS-equipped antenna array connected to a software defined radio to collect network signals, which were analyzed on a standalone computer server. Each day, the team drives his three trucks, each loaded with one of these sensor systems, to various locations around the base and asks Hill Air Force Base contact personnel to adjust parameters for specific networks. I requested that. For example, turning a particular base station on or off, increasing or decreasing traffic, etc. You can adjust the base station power and adjust the beam steering direction. With each adjustment, the team collected data to determine how difficult 5G signals are to detect, locate, and jam. The mountainous terrain allowed the team to obtain results from a variety of altitudes.
Before heading to the field, the team performed modeling and simulations to prepare the experimental setup, determining how far the signal can be detected from 5G base stations, where to place the sensors to minimize geolocation errors, and We took into consideration factors such as: The optimal sensor shapes are: We also verified the algorithms used for detection and geolocation.
At the Hill Air Force Base field, the team will detect 5G signals through several types of detection algorithms, ranging from general energy detectors (which measure the energy or power of the received signal) to more specialized matched filter detectors (which compare energy). were consistently detected. conversion of the unknown received signal into the energy of the known signal). They detected signals as far as the horizon (about 20 kilometers away, and verified even greater distances through simulations), especially for a particular type of signal called a signal synchronization block (SSB), which is very far away. Signal detected in range. SSB is detectable by design. Mobile devices must detect SSB to synchronize to the wireless network’s time and frequency and ultimately access the network. However, this detectability means that SSB has a significant vulnerability.
“Detection makes it easier to jam,” Smith said. “Once an attacker detects the signal, they can jam it. SSB is periodic in time and frequency, so it’s very easy to detect and jam it.”
To determine the geographic location of the signal, the team performed angle-of-arrival estimation using the MUltiple SIGNAL CLASSIFICATION (MUSIC) algorithm, which estimates the direction of arrival of the signal received by the antenna array. As Smith explained, if you have two sensors spaced apart on opposite sides of the map, and you know the angle of the signal from both sensors, you can draw intersecting straight lines. can. Where they intersect is a geolocation point.
“One of our objectives was to see how cheap and easy it is to detect, locate, and jam 5G signals,” explains Smith. “Our results show that it doesn’t need to be highly sophisticated; off-the-shelf, low-cost hardware setups and open-source algorithms can be effective.”
This 5G vulnerability assessment is an extension of a previous 4G vulnerability assessment conducted by the institute.
generational progress
A new generation of wireless communication technology typically emerges once every 10 years. His 1G, the first generation focused on voice, paved the way for the first mobile phones in the 1980s. The second generation, 2G, allowed for less static noise, more secure voice transmission, and introduced Short Message Service (SMS) or text messaging. The introduction of 3G in the early 2000s provided the core network speeds needed to launch the first smartphones, providing internet to smartphones and supporting mobile applications such as maps and video calling. And with 4G offering even higher data transfer speeds, high-definition video streaming, improved quality of voice calls (due to long-term evolution, i.e. LTE technology), and his IoT devices such as smart watches and digital home assistants. It’s now possible.
The rollout of 5G, which began in earnest in 2019 and continues to evolve, has brought orders of magnitude improvements in several areas, including speed, latency, connectivity, and flexibility. For example, 4G data speeds theoretically top out at 1 Gbit/s, while 5G tops out at 20 Gbit/s, making it 20 times faster. In addition to operating on low-band frequencies (below 6 GHz), 5G can also operate on less congested mmWave frequencies (above 24 GHz). The abundant spectrum available at these high frequencies enables ultra-high capacity, ultra-high throughput, and ultra-low latency. However, high-frequency signals are subject to scattering as they travel through the atmosphere, so their range is limited. To address this limitation, researchers are looking to complement the currently large cell phone towers (macrocells), which are located several miles apart, by creating smaller towers that are more closely spaced, especially in dense urban areas. (microcells, picocells, or femtocells). These small cells allow high data rates to be delivered to many users without the need for radio frequencies to travel as far.
Large-scale multiple-input multiple-output (MIMO) antenna arrays provide another means of serving concurrent users. Having a large number of antennas on a 5G base station means that instead of the radio signal being spread out in all directions, it is tightly focused in the direction of the target toward the intended receiving device, such as a cell phone, laptop, or self-driving car. It means you can. This focusing technique, called beamforming, helps users achieve more accurate and reliable wireless connections with faster data transfer, and prevents data from being sent to unintended recipients.
“5G provides an opportunity for communications to become more based on beamforming and massive MIMO,” Smith says. “Using these technologies, 5G has the potential to be more undetectable, more geolocatable, and more anti-jamming than all previous generations. However, 5G is not inherently secure. , so you need information on how to configure your network that way.”
Improved resilience
Over the past year, the team has applied insights from field testing campaigns to strengthen the resiliency of standard 5G components and processes.
“Our goal is to make resiliency enhancements as simple and cost-effective as possible for the Department of Defense to implement, leveraging existing 5G technology and requiring no changes to 5G hardware, at least on the cell phone side. Make it expensive,” Smith says.
Going forward, Smith is excited to design more complex algorithms, especially those that use machine learning to detect and locate 5G signals. He also expressed the team’s interest in the possibility of using 5G for drone swarms, which Smith said is “one of the most difficult problems as far as communications go,” due to factors such as mobility complexity and power limitations. “One.”
If the 10-year technology cycle holds, 6G could launch around 2030. New capabilities may include the application of artificial intelligence to manage network resources. Extending frequencies to even higher (terahertz) ranges. Integrate communications across land, air, sea, and space into an integrated ecosystem.
“Our current program is actually called 5G-to-nG [next generation]“We are already looking at 6G and the vulnerabilities it could pose to the Department of Defense,” Smith said.
