How do uavs communicate

The longer the wavelength, the lower the frequency, and the longer the range. The figure below illustrates the wavelength of each of the four frequencies stated above.

UAV Control. These frequencies have a benefit of long range without any data loss. However, due to the longer wavelengths these systems are unable to transfer large data rates.

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Connect with us today to discover which on our drone detection packages works best for your environment. Data Link. Drone Communication - Data Link How do drones communicate with their operator? What are the range limitations for a drone? Advanced data link system There are various combinations of data link systems available to the consumer that can be used for UAV operation. The three main components data links are used in the operation of the UAV are: UAV Control Video Transmission Telemetry A few things to be mentioned regarding specific radio frequencies commonly used in a data link system.

When the communication is established, an end-to-end tunnel path is generated from a DC device. However, Fig. During this process, communication won't established unless all the MAC authentications are successfully processed. MT 1 sends a Direction request to DC. These keys are generated to communicate with RS. However, in Fig. The process from Direction request to Route direction is performed with one stroke.

If this process does not finish successfully, re-transmission is performed from Direction request process. In Fig. MT 2 encrypts Kmtmt with temporary key i. Tunnel request is encrypted with Ktun, and tunnel response is encrypted by Kmtmt. The sharing process is neglected in this section, because of the same process in the AS and DC key sharing method.

MT 1 requests DC to make a route by Direction request. At this point, RS only knows a common key Ktun. MT 1 generates an end key Kmtmt and encrypts it with Ktmp [i. Decryption is also performed using Ktmp to get Kmtmt. The tunnel response is encrypted using Kmtmt.

RS relays the tunnel response to MT 1 as it is without any decryption. Subsequently, all the communications among MTs are encrypted using Kmtmt key. Even though the communication packet passes through RS, decryption is impossible because RS does not possess Ktmp to decrypt Kmtmt.

NTMobile provides mobility and connectivity at the same time for MTs in different kinds of networks using direct tunnel creation as it has been explained in Sect. This issue has been resolved via implementing autonomous route optimization that has been verified its effectiveness in previous work [ 45 ].

The latency and delays in the network affect the performance of the communication system. NTMobile system runs a lot of authentications and key sharing processes to perform the secure connection between two nodes in a heterogeneous network.

Besides that, the switching process also causes a handover latency in the system. They measured the handover latency caused by the switching of access points during TCP connection between two nodes. The switching process has manually proceeded based in two different case scenarios:. Table 1 shows the results of the experiments of the previous above-mentioned case scenarios. In the network configuration, the authors set the packet length transmitted by IPerf to be bytes.

In this evaluation, the processing time required for packet processing by NTMobile has been measured. Table 2 illustrated the results of the time measurement of the NTMobile networks and in normal communication case where NTMobile has not been used. The experiments revealed that NTMobile can perform Table 5 shows the references of throughput in Skype application.

The conducted experiments also revealed that the throughput of NTMobile is less than normal communication due to the encryption process, MAC process, and encapsulation process refer to Tables 3 , 4.

However, the measured throughput is more than enough for the most applications requirements as shown in Table 2. Therefore, NTMobile works efficiently as a communication medium. First, UAV must have an adaptive network switching feature. To achieve that, the authors integrated UAV into a single board computer please refer to Sect.

This integration helped UAV to switch between different networks when the connected network is not available or does not provide an Internet service. However, these networks must be added networks in the single board computer.

Moreover, IP can be changed through a single board computer. In this configuration, the single board computer works as a gateway. The tested networks are mobile networks where the coverage is offered in the experimental area and a wireless network with multiple access points provided by the authors i.

As has been mentioned in this paper, the communication between two nodes ends when the node switches the network and due to the change of the IP address of the MT. However, NTMobile has a mobility function where it can keep the communication even if the address changes.

Briefly, the encapsulation feature separates the roles of an IP address serves as a location identifier and a communication identifier, and that is the reason why the mobility function is achievable in the NTMobile system, and MTs can change the network access whenever they need during the communication. Theoretically, the proposed work can be also applicable into modern standards and data exchange categories. NTMobile can be used to the transmission of UAV data during the mission in a heterogeneous network environment through various data formats e.

To run NTMobile application on the UAV board, the authors must connect the flight controller to the independent operation system because most of the current flight controllers in the market have insufficient memory to run additional application or external program. Flight controllers execute manual and autopilot tasks with some few basic commands such as running external sensors. Therefore, the authors integrated a single board computer with quad-core cortex 1.

Figure 8 shows the electronic circuit diagram that connects the flight controller to the single board computer. The flight controller supports two serial ports i. These serial ports support autopilot protocols, and the serial port number two communicates with the flight controller through a single board computer. Then, the authors set serial two as a default serial input on baud. Subsequently, the authors configured the single board computer by installing the required packages of the autopilot commands, NTMobile framework, and adapter files.

The power module provides a 5-volt power source and ground inputs on the UAV module. NTMobile application is installed on three separated virtual machines. In the bridged network mode, the guest system receives direct access to the network where the host system is connected to the network. After installing Linux operation on the virtual machines, the authors installed the NTMobile network on the servers.

Each account has an e-mail address and password. Then, FQDN is generated and displayed automatically on the console. The UAV account information is demonstrated in Listing 1.

Also, the ED account information is presented in Listing 2. In this experiment, DC assigned two virtual IPs: This is permanent even if the IP is changed due to vertical handover as explained in Sect. Then, the authors can run the GCS autopilot software in the single board computer to send commands to the flight controller refer to Listing 7.

In this experiment, UAV was assigned to map a crop field according to the waypoints in Table 8. Figure 10 shows the experimental field, whereas Fig. The red areas in the graph pinpoint the lost connection status when the vertical handover occurs or when the IP changes. Network packet analyzer shows the packets per second in Y-axis and time in second X-axis. Also, in Fig. The flight logs of the mapping mission are received through NTMobile refer to Fig. Flight plan design and switching waypoints which designed by the authors before executing the mission.

A sample of the throughput graph of TCP at port 22 of the SSH protocol: encrypted packet in a specific period of time. When network switch, or during the searching process, UAV starts a hovering mode. If there is no communication to ED in a range of 2 min while UAV in hovering mode, the flight controller will send the UAV back to the launch point by executing RTL command on the flight controller, this can be achieved by configuring and programming the signal board computer.

In Figs. The first network switch, UAV hovered for 38 s until it communicated again with ED and 84 s in the second switching waypoint. In the third switching waypoint, UAV was in hovering mode for 22 s and 20 s for switching waypoint number four. In the final switching waypoint, UAV hovered for 85 s till the new connection with ED has been established.

As shown in Fig. The airspeed is demonstrated in Fig. Figure 22 a also presents the status of the UAV in hovering mode, and Fig. These flight logs data can be obtained after fulfilling the mission, and UAV returned to the launch point. The flight logs profile is recorded inside the memory of the flight controller and the GCS application. After switching network and new IP obtained, NTMobile used end-to-end encryption feature, where UDP tunnel is recreated in the same way as at the beginning of the communication [ 48 ].

There were some modifications needed to the software layer of the communication gateway inside the single board computer that connected to the UAV flight controller see Figs.

A program has been designed by authors to help UAV to switch network in specific waypoints in the flight plan design and to change the flight mode accordingly. The time of switching should be less than 2 min long. The employed UAV has 21 min of maximum flight time.

In this experiment, the total flight time of the mission was 15 min. Communication before and after executing the flight mission has also been captured, as shown in Fig. These data are provided by flight logs profile after completing the given mission. The novelty of this study is the introduction of continuous connectivity into the UAV communication control system even if it forced to switch network access. Three systems have been used i. AS, DC, and RS offer consistent communication between two nodes in the network even if one of the MTs is exposed to vertical handover or switch network.

A key sharing mechanism between the nodes and TLS protocol encrypts the keys and all the communication packets in the NTMobile.

The authors used a single board computer, connected to the UAV flight controller to run the NTMobile client application and manage the autopilot mission. A real flight experiment is executed to map a crop field.

A loss of communication is due to a network switch, and it has been measured. During the switching process UAV will be in hovering or stationary mode waiting to connect to the ED again. Also, obtaining a different IPv in a heterogeneous network system is critical for UAV during the mission.

Aljehani M, Inoue M Safe map generation after a disaster, assisted by an unmanned aerial vehicle tracking system. Article Google Scholar. Almalki FA, Angelides MC A machine learning approach to evolving an optimal propagation model for last mile connectivity using low altitude platforms. Comput Commun — By utilizing high-quality, reliable communications links , civilian UAVs are able to relay aerial visuals and data to those on the ground with ease, while still remaining in flight.

However, in defense applications, different types of drones are implemented. Defense drones vary greatly from civilian UAVs, as their missions are frequently longer duration or require striking capabilities in addition to providing aerial visuals of the battlefield below. One concern in the use of drones in defense applications is the occurrence of signal jamming. When signal jamming is used, this cuts the remote pilot and operations base off from visuals of what the drone is seeing.

While it seems like a disastrous scenario, most defense drones are engineered to return to base after a loss of communications contact. By eliminating available GPS data, jamming becomes a infrequent occurrence, allowing defense drones to complete their missions and return to base safely.