Communications system having an underwater transmitter
Patent Information
- Application Number
- PCT/EP2026/054103
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-27
- Filing Date
- 2026-02-16
- Publication Date
- 2026-09-03
Smart Images
Figure EP2026054103_03092026_PF_FP_ABST
Abstract
Description
[0001] Communication system with an underwater transmitter
[0002] Description
[0003] The invention relates to communication between communication partners in a maritime environment. That is, at least one communication partner is located underwater and wishes to send data from there.
[0004] Establishing robust communication networks is of paramount importance for comprehensive maritime domain awareness (MDA) in remote marine areas, particularly regions lacking conventional infrastructure. Disruption of these networks can have significant repercussions for social and economic stability. The emergence of mobile ad-hoc networks (MANETS) utilizing radio waves and the nascent underwater Internet of Things (UW-IoT), which uses acoustic signals, represent a significant advancement in underwater technology. These adaptive and scalable networks expand the capabilities of the Internet of Things (IoT) underwater, enabling enhanced data collection and real-time monitoring. The combination of these adaptive and scalable networks can also function in locations where traditional infrastructure has failed.However, since the technology is still in its infancy, there is still potential for development.
[0005] The object of the present invention is therefore to create an improved communication concept.
[0006] The problem is solved by the subject matter of the independent patent claims. Further advantageous embodiments are the subject matter of the dependent patent claims.
[0007] A communication system with multiple communication partners is revealed. These partners include an underwater transmitter, multiple converters, and a receiver. The converters can transform underwater communication into surface communication and vice versa. A converter can therefore also be called a gateway. The receiver can be located either above or below water. The underwater transmitter can be, for example, an unmanned underwater vehicle (UUV), such as a remotely operated underwater vehicle (ROV) or an autonomous underwater vehicle (AUV), or a manned underwater vehicle such as a submarine. The converters can be any type of water platform, located both above and below water.Examples include drilling platforms, wind farms, unmanned surface vessels (UPS), manned ships, and also helicopters and aircraft equipped with so-called dipping sonar. Underwater communication is wireless, primarily using sound waves.
[0008] The underwater transmitter now sends a route request via underwater communication to the communication partners of the multitude of communication partners. The route request can also be referred to as a route request. The route request can be broadcast to all communication partners within range of the underwater transmitter. However, the route request is not forwarded by the communication partners. Rather, only the repeaters that receive the route request send an acknowledgment back to the underwater transmitter. The acknowledgment can contain an Internet Protocol (IP) header, e.g., IPv4 or IPv6. Furthermore, the acknowledgment can contain a truncated AODV (Ad-hoc On-Demand Distance Vector) header, which includes the destination and receiving addresses. This means that an AODV message, specifically an empty one, can be sent from the repeater to the underwater transmitter via Internet Protocol.Alternative protocols can also be used. The repeater can copy the sender ID of the route request and use it as the receiver ID. An IP address is particularly suitable as the ID. This allows the underwater transmitter to build a table of reachable repeaters. Based on the received acknowledgments, the underwater transmitter then selects a repeater and sends it a search query to locate the receiver. Specifically, the repeater whose acknowledgment reaches the underwater transmitter first can be selected. This allows for a simple and efficient way to find the repeater with the best underwater data connection to the underwater transmitter at any given time. Often, this is the repeater located closest to the underwater transmitter.
[0009] Specifically, the underwater transmitter waits a predetermined period of time to receive acknowledgments. During this time, the underwater transmitter stores the incoming acknowledgments in the order they were received. After the predetermined period has elapsed, the underwater transmitter sends a request to the selected repeater if the receiver has not received an acknowledgment within this time. The receiver can send the acknowledgment if it receives the route request immediately, i.e., directly without any further hop (i.e., forwarding the route request through another node). In principle, waiting for the predetermined period can also be omitted.
[0010] However, waiting the specified time period has the advantage that a communication partner who is the recipient and receives the route request directly can immediately send a route response, thus avoiding routing via other communication partners.
[0011] This means that, optionally, all communication partners receiving the route request can verify that they are the intended recipient and, if successful, send an acknowledgment (i.e., a route reply) to the underwater transmitter. The underwater transmitter can then send a data packet directly to the recipient (i.e., without routing through other communication partners) once the recipient's acknowledgment is received. Thus, the underwater transmitter can wait for the recipient's acknowledgment during the specified time period and refrain from sending a route search to the recipient if the acknowledgment is received within that timeframe. The AODV protocol can be used for establishing the connection over water, optionally without modifications.
[0012] The selected repeater searches for a route to the receiver above water and sends an acknowledgment to the underwater transmitter when the route to the receiver is known. If the route to the receiver is known, but the receiver is not directly reachable, the underwater transmitter sends the data packet to the selected repeater for forwarding to the receiver. In other words, the data packet is only sent underwater to the receiver if the receiver can access it directly, i.e., without the route request being forwarded by other communication partners. Otherwise, the data packet is sent to the nearest repeater. If the receiver is underwater and not directly reachable, the data packet is sent above water by the repeater to another repeater, which then forwards the data packet to the receiver. Therefore, the underwater transmitter does not know the route to the receiver.An exception exists if the receiver is directly reachable from the underwater transmitter. If the AODV protocol is used to establish the connection above water, the repeater request and repeater response can be selected according to the route request and route response, respectively. However, repeater requests are only answered by repeaters with the corresponding repeater response. The data packet is advantageously payload data. This payload data can include, for example, sensor data, either direct or processed, such as a situational awareness map.
[0013] The repeaters know at least an approximate position of the underwater communication partners they can reach. To determine the positional information of these underwater communication partners, they can send out informational messages, either randomly within a predetermined time window or, alternatively, regularly. Based on these messages, the receiving repeaters can calculate a predefined metric and transmit it in their response to the selected repeater. This metric could be, for example, the signal-to-noise ratio of the last received message from the underwater receiver. While this doesn't allow for the determination of the receiver's absolute position, it does provide information about which repeater has the best position relative to the receiver. However, it is, for example,It is also possible that the approximate position of the receiver, particularly the transmitters, is taken from a mission plan or estimated otherwise underwater. The information message can also be referred to as a ping, although a response from the transmitter is not necessarily required.
[0014] The communication participants located above water can each establish radio data links 38', 38" to each other, thus creating a communication network 38. Information can be exchanged via broadcast, multicast, or unicast over the radio data link. A broadcast radio data link is suitable for establishing a routing table, while a multicast or unicast radio data link, using a routing table, can transmit the (payload) data. The entirety of the radio data links can also be referred to as a network. A network that is only established when data is to be sent, for example, because the network nodes are moving and not fixed in place, is called a reactive ad-hoc network. This means that the route for the data packet is only determined when the data packet is to be sent. In particular, the route is determined decentrally at each node.Reactive ad-hoc networks have the advantage over proactive ad-hoc networks of generating less data traffic. This is particularly useful in the military sector.
[0015] One idea is therefore to forgo underwater data routing altogether, meaning that underwater communication is conducted directly from a single sender (underwater transmitter or repeater) to the receiver. This avoids long transmission paths underwater. Underwater channels have lower bandwidth and significantly longer transmission times, which leads to more frequent packet collisions underwater, potentially rendering both data packets unusable. This means the data packets would have to be retransmitted underwater, which in turn increases the likelihood of collisions with other underwater data packets. While traditional routing is often faster underwater than the proposed approach of eliminating underwater routing, the number of transmitted and often redundant packets is significantly reduced by foregoing underwater routing.This also reduces the risk of data packets being intercepted and read by unauthorized third parties. This is particularly important in military environments.
[0016] In exemplary implementations, the selected repeater sends a surface route request after receiving the query. The communication partners of the multitude of communication partners located above water respond to the surface route request with a surface route reply if they are the recipient of the request, or alternatively, forward the submarine route request. The repeater route request and the repeater reply can correspond to the Route Request and Route Reply of the AODV protocol.
[0017] If, in exemplary embodiments, no above-water route response is received by the selected repeater within a specified time period, the selected repeater sends an above-water repeater request to find a repeater that can reach the underwater receiver. The repeater can respond to the above-water repeater request with an above-water repeater response if the corresponding repeater can establish underwater communication with the receiver. Advantageously, the above-water repeater response includes information regarding the underwater position of the receiver. This information can be used to check the suitability of the repeaters for establishing a route to the receiver if more than one repeater can reach the underwater receiver.
[0018] The selected repeater, i.e., the repeater that initiated the surface route request, can now send an acknowledgment to the underwater transmitter. Advantageously, the acknowledgment includes the receiver's ID. This allows a connection to be established simultaneously with two receivers. The underwater transmitter can then send the data packet to the selected repeater for forwarding to the receiver. The data packet can be sent via unicast. Advantageously, the communication system uses a mobile ad-hoc network for communication between the communication partners. The use of unmanned vehicles, including unmanned surface vehicles (USVs), unmanned underwater vehicles (UUVs), and unmanned aerial vehicles (UAVs), has the potential to significantly improve mobile ad-hoc networks (MANETs) in various application areas.In maritime environments, unmanned surface and underwater vehicles (UPSs and UUVs) enable robust communication through surface or underwater nodes, preferably using technologies optimized for the respective medium.
[0019] Unmanned aerial vehicles (UAVs) in flying ad-hoc networks (FANETs) provide vital aerial connectivity in areas inaccessible to conventional networks. The aforementioned technologies illustrate the potential of dynamic ad-hoc communication in vehicle-based (VANETs) and sensor-actuator networks (SANETs). These networks are crucial for real-time data exchange and operational efficiency in autonomous navigation and environmental monitoring.
[0020] For the integration of gateway nodes (converters) into ad-hoc networks with multiple domains, robust synchronization and efficient data routing between these media are advantageous. This is particularly beneficial given the mobility of UPS systems and the varying environmental conditions that can complicate the maintenance of stable connections. Suitable protocols such as GUWMANET (underwater) and AODV (above water) provide a solution to ensure stable data transmission.
[0021] The Ad-hoc On-Demand Distance Vector (AODV) protocol plays a central role in managing data packets and determining their routes. When a node needs to determine a route to a destination, it sends a Route Request (RREQ) message. Incoming messages first undergo a verification process where their content is compared to the contents of the message cache. This ensures that the messages are not duplicates. If the message is new and has been added to the cache, it is checked whether the current node is the intended destination. If the node is the destination, the message has been successfully delivered, a Route Reply (RREP) is sent back to the source, and the message is processed. If the node is not the intended destination, the node forwards the message to the next hop, as specified in the routing table entries.This method ensures the efficient and reliable delivery of messages within the network. The AODV protocol operates at the network layer of the ISO-OSI model.
[0022] Mobile ad-hoc networks (MANETs) are self-configuring networks consisting of wirelessly connected mobile devices that form the communication system. Each node (communication partner) in a MANET is capable of acting as a router, thereby facilitating the forwarding of data to other nodes that are not within direct transmission range.
[0023] In a preferred embodiment, an improved ad-hoc on-demand distance vector (AODV) protocol for multi-domain ad-hoc networks is disclosed, integrating communication domains above and below water. This integration utilizes, for example, unmanned surface vehicles (USVs) or sonar buoys as gateways between surface and underwater communication in conjunction with unmanned underwater vehicles (UUVs) and unmanned aerial vehicles (UAVs), thus ensuring robust communication in challenging maritime environments.
[0024] Analogously, a method for communication between a plurality of communication partners is disclosed, wherein the communication partners include a) an underwater transmitter; b) a plurality of converters trained to convert underwater communication into surface communication and surface communication into underwater communication; and c) a receiver, wherein the method comprises the following steps:
[0025] 1) Sending a route request to the communication partners of the multitude of communication partners from an underwater transmitter;
[0026] 2) Returning an acknowledgment to the underwater transmitter from the repeaters of the majority of repeaters receiving the route request; 3) Selection of a repeater by the underwater transmitter based on the received acknowledgments;
[0027] 4) Sending a search request to the selected converter by the underwater transmitter to locate the receiver;
[0028] 5) Finding a route to the receiver across water using the selected converter;
[0029] 6) Sending a confirmation to the underwater transmitter when the route to the receiver is known;
[0030] 7) Sending a data packet to the selected converter for forwarding to the recipient.
[0031] Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. These show:
[0032] Fig. 1: in conjunction with Fig. 2 and Fig. 3, a schematic representation of a communication system for route planning from an underwater vehicle to a surface vehicle, and in conjunction with Fig. 4 and Fig. 5, a schematic representation of a communication system for route planning from one underwater vehicle to another underwater vehicle.
[0033] Before exemplary embodiments of the present invention are explained in detail below with reference to the drawings, it should be noted that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.
[0034] Fig. 1, in conjunction with Figs. 2 and 3, shows a route setup for sending a data packet 10 from an underwater transmitter 35 to a receiver 34 located above water, and, in conjunction with Figs. 4 and 5, a route setup for sending a data packet 10 from an underwater transmitter 35 to a receiver 34 located underwater. The receiver is, by way of example, an underwater-to-surface communication partner, in particular a manned or unmanned underwater vehicle, which can communicate both by radio on the surface and, in principle, also by underwater communication. The reference numerals are used throughout for the same features. Unless explicitly stated otherwise, the description of the features applies to both embodiments, i.e., all figures.
[0035] The figures thus show a schematic representation of a communication system 20. The communication system 20 comprises a plurality of above-water communication partners 22, 24, 26, 28, 30, a plurality of converters 32, 32', an underwater-to-above-water communication partner 34 as a receiver, and an underwater transmitter 35, which constitute the communication partners. The aforementioned communication partners 22, 24, 26, 28, 30, 32, 34, 35 of the communication system 20 can also be referred to as participants or nodes. The converters 32, 32' can convert underwater communication into above-water communication and above-water communication into underwater communication. The converters 32, 32' therefore include a radio module 48, 48' and an underwater transducer 49, 49'. A data processing unit (not shown) can convert data received via radio into an (acoustic) underwater communication message, and vice versa.The underwater-above-water communication partner 34 can be located above water (see Fig. 1, Fig. 2 and Fig. 3) or below water (see Fig. 4 and Fig. 5), as indicated by arrow 36. The number of knots is purely exemplary and can be any number.
[0036] Now the nodes located above water can each establish radio data links 38', 38" to each other and thus create a communication network 38.
[0037] Fig. 1 now shows that the underwater transmitter 35 sends a route request 40 to the reachable communication partners.
[0038] The two transmitters 32, 32' are reachable in the diagram, but not the underwater-surface communication partner 34. The transmitters 32, 32', which receive the route request, now send an acknowledgment 42, 42' of the route request 40 back to the underwater transmitter 35.
[0039] Figures 2 and 4 show that the underwater transmitter, based on the received acknowledgments 42, 42', selects the repeater 32' and sends a search query 44 to the repeater 32' to locate the receiver 34. The selected repeater 32' then searches for the receiver 34, preferably by means of a route request transmitted via broadcast (see dashed lines), using the radio data links 38 above water. In the embodiment shown in Figure 2, the receiver 34 can be reached above water. After receiving the route request 38', the receiver 34 sends a route response 38" (see solid line) to the selected repeater 32'. The selected repeater 32' sends an acknowledgment 46 to the underwater transmitter 35, since the route to the receiver 34 is now known.
[0040] Figure 3 shows that the underwater transmitter 35 sends the data packet 10 intended for the receiver 34 by means of underwater communication to the selected converter 32' for forwarding by means of above-water communication to the receiver 34.
[0041] The embodiment in Fig. 4 differs from the embodiment in Fig. 2 in that the receiver 34 is located underwater. Therefore, the selected converter 32' does not receive a route response from the receiver within a predetermined time period. This signals the selected converter 32' to send a converter request 38'" (see dashed line), preferably via broadcast. All converters 32, 32' that can establish an underwater data connection to the receiver 34 now respond to the converter request with a converter response 38"" (see solid line). This is the case for converter 32. The selected converter 32' sends the acknowledgment 46 to the underwater transmitter 35, since the route to the receiver 34 is now known in this case as well. With the received acknowledgment 46, the route to the receiver 34 is known, and the underwater transmitter 35 can send the data packet 10 to the receiver (see Fig. 2).5).
[0042] Although some aspects have been described in connection with a device, it is understood that these aspects also constitute a description of the corresponding process, so that a block or component of a device can also be understood as a corresponding process step or as a feature of a process step. Similarly, aspects described in connection with or as a process step also constitute a description of a corresponding block, detail, or feature of a corresponding device.
[0043] The embodiments described above merely illustrate the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be obvious to other people skilled in the art. Therefore, it is intended that the invention be limited only by the scope of protection set forth in the following claims and not by the specific details presented herein by way of description and explanation of the embodiments. Reference numerals:
[0044] 10 data packets
[0045] 20 Communication system
[0046] 22 above-water communication partners
[0047] 24 above-water communication partners
[0048] 26 above-water communication partners
[0049] 28 above-water communication partners
[0050] 30 above-water communication partners
[0051] 32 converters
[0052] 32' converter
[0053] 34 Underwater-abovewater communication partners 36 Arrow
[0054] 38 radio connections
[0055] 38' Route request (radio link)
[0056] 38" Route response
[0057] 38'“ Converter request
[0058] 38"" Converter response
[0059] 40 (Underwater) route request
[0060] 42 Acknowledgement of receipt
[0061] 44 search queries
[0062] 46 Confirmation
[0063] 48 radio modules
[0064] 49 underwater transducers
Claims
Patent claims 1. Communication system (20) with the following features: - encompassing a large number of communication partners (22, 24, 26, 28, 30, 32, 32', 34, 35) a) an underwater transmitter (35); b) a plurality of converters (32, 32') trained to convert underwater communication to surface communication and surface communication to underwater communication; c) a recipient (34); - wherein the underwater transmitter (35) is trained to send a route request (40) to the communication partners (22, 24, 26, 28, 30, 32, 32', 34, 35) of the multitude of communication partners; - wherein the repeaters (32, 32') of the majority of repeaters receiving the route request (40) are trained to send an acknowledgment (42) back to the underwater transmitter (35); - wherein the underwater transmitter (35) is trained to select a repeater (32') based on the received acknowledgments (42) and to send a search request (44) to this repeater (32') in order to locate the receiver (34); - wherein the selected converter (32') is trained to search for a route over water to the receiver (34) and to send an acknowledgment (46) to the underwater transmitter (35) when the route to the receiver (34) is known; - wherein the underwater transmitter (35) is configured to send a data packet (10) to the selected converter (32') for forwarding to the receiver (34).
2. Communication system (20) according to claim 1, - wherein the communication partners (22, 24, 26, 28, 30, 32, 32', 34, 35) of the multitude of communication partners who receive the route request directly from the underwater transmitter (35), check after receiving the route request (40) whether they are the receiver and, if the check is successful, send an acknowledgment (46) to the underwater transmitter (35);- wherein the underwater transmitter (35) is configured to send the data packet (10) to the receiver (34) when the receiver's acknowledgment (46) has been received.
3. Communication system (20) according to one of the preceding claims, wherein the underwater transmitter (35) is configured to wait for a predetermined period of time and during this period store the incoming acknowledgments (42) in the order of their receipt and send the search request to the converter (32, 32') whose acknowledgment (46) arrived first, provided that no acknowledgment from the receiver (34) has been received within the predetermined period of time.
4. Communication system (20) according to claims 2 and 3, wherein the underwater transmitter (35) waits for the acknowledgment (46) of the receiver (34) during the specified time period and refrains from sending the search request (44) if the acknowledgment is received within the specified time period.
5. Communication system (20) according to one of the preceding claims, - wherein the selected converter (32') is trained to send an overwater route request (38'); - wherein the communication partners (22, 24, 26, 28, 30, 32, 32') of the multitude of communication partners located above water are trained to respond to the overwater route request (38') with an overwater route response (38") if they are the recipient of the overwater route request (38') or alternatively, to forward the overwater route request (38').
6. Communication system (20) according to claim 5, wherein the selected transmitter (32') is configured to send a surface transmitter request (38"') if no surface route response (38") has been received within a predetermined time period, in order to find a transmitter (32, 32') that can reach the receiver (34) underwater.
7. Communication system (20) according to claim 6, wherein the transmitters (32, 32') are configured to reply to the surface transmitter request (38"') with a surface transmitter response (38"") if the corresponding transmitter (32, 32') can establish underwater communication with the receiver.
8. Communication system (20) according to claim 7, wherein the converters (32, 32') are configured to transmit information regarding the position of the receiver (34) underwater in the abovewater converter response (38““).
9. Communication system (20) according to claim 7 or 8, wherein the selected converter (32') is configured to send an acknowledgment (46) to the underwater transmitter (35).
10. Communication system (20) according to claim 9, wherein the selected converter (32') is configured to send the data packet (10) to the selected converter (32') for forwarding to the receiver (34).
11. Communication system (20) according to one of the preceding claims, wherein the communication partners (22, 24, 26, 28, 30, 32, 32', 34, 35) are trained to establish a mobile ad-hoc network for communication.
12. Communication system (20) according to one of the preceding claims, wherein the data packet comprises user data, in particular sensor data.
13. Method for communication between a plurality of communication partners (22, 24, 26, 28, 30, 32, 32', 34, 35), wherein the communication partners comprise a) an underwater transmitter (34); b) a plurality of converters (32, 32') configured to convert underwater communication into surface communication and surface communication into underwater communication; and c) a receiver (34), wherein the method comprises the following steps: 1) Sending a route request (40) to the communication partners of the multitude of communication partners from an underwater transmitter (35); 162) Sending back an acknowledgment of receipt (42) to the underwater transmitter (35) from the repeaters (32, 32') of the majority of repeaters receiving the route request (38'); 3) Selection of a converter (32'), based on the received acknowledgments, by the underwater transmitter (35); 4) Sending a search request (44) to the selected converter (32') by the underwater transmitter (35) to locate the receiver (34); 5) Searching for a route to the receiver (34) over water through the selected converter (32'); 6) Sending an acknowledgment (46) to the underwater transmitter (35) when the route to the receiver (34) is known; 7) Sending a data packet (10) to the selected converter (32') for forwarding to the receiver (34). 17