Lighter-than-air Ascent-Assisted Non-Orbiting Nodes for Aerial Mesh Communication Systems

Abstract

The wireless communication system includes a non-recurring aerial node that provides a wireless route between terrestrial nodes. The non-recurring node has a plurality of directional antennas horizontally oriented in a plurality of directions for transmitting wireless signals to and receiving wireless signals from other non-recurring aerial nodes in a first frequency band, and a plurality of directional antennas oriented towards the Earth's surface for transmitting wireless signals to and receiving wireless signals from a plurality of terrestrial nodes in a second different frequency band. The aerial node includes a route creation circuit for creating a wireless route between terrestrial nodes via one or more aerial nodes, and a data transmission circuit for transmitting data via the route. The non-recurring node can be a drone lighter than one piece of air, a two-piece drone with a suspended communication capsule lighter than air, a heavier rotary-wing drone with a suspended communication capsule with or without lift assistance from a gas lighter than air, or a balloon with a suspended communication capsule.

Description

Technical Field

[0001] Cross-reference to related applications This application claims the benefit of U.S. Provisional Application No. 63 / 334,051, filed May 24, 2022.

Background Art

[0002] Issued patents and patent publications of the assignee disclose a variety of space-based systems, methods, and apparatuses for transmitting data via non-terrestrial (aerial) nodes including orbiting nodes (satellites) and non-orbiting nodes (drones and / or balloons). These use novel route creation and data transmission protocols to establish inter-node wireless routes between terrestrial nodes, between non-terrestrial nodes, and between non-terrestrial nodes and terrestrial nodes. The assignee's protocols support the simultaneous transmission of data from multiple source nodes to their respective destination nodes via long-distance routes that may include multiple orbiting satellites and / or other types of aerial nodes. These patents and patent publications include U.S. Pat. Nos. 10,084,536, 10,085,200, 10,291,316, 10,447,381, and 10,979,136, and U.S. Patent Publications 2021 / 0359751, 2022 / 0029699, 2022 / 0173795, and 2022 / 0173796.

[0003] In a typical implementation, a route is created step by step via signals transmitted from a ground node and received by one or more aerial nodes (drones, balloons, or satellites), which then transmit signals received by other aerial nodes or ground nodes. For example, a first aerial node that receives a signal from a transmitting ground node transmits a routing signal that can be received by either another aerial node or another ground node. A ground node or another aerial node that receives the routing signal can then return data to the original transmitting ground node via the aerial node from which the routing signal was received. The route back to the transmitting ground node can include one or more aerial nodes. More advanced versions of this “reverse routing” technique are disclosed in U.S. Patent No. 10,979,136 (“the ’136 patent”) and U.S. Patent Application Publication No. 2022 / 0173796 (“the ’796 publication”). The assignee's protocol can use statistical probabilities to create routes and transmit data via satellites without heavy and expensive thrusters and the fuel to maintain them in a given position. Instead, these can use lightweight and inexpensive satellites that do not need to have their positions controlled and can be deployed in a probability distribution or be allowed to assume a probability distribution. SUMMARY OF THE INVENTION

[0004] The present disclosure relates to various structures of lighter-than-air and heavier-than-air, lift-assisted non-orbiting nodes (drones and balloons) that are particularly useful in systems with or without artificial satellites. That is, the disclosed structures can be used in communication systems that use any type of non-orbiting aircraft as a system node in a wireless route. The disclosed drones can be used in a local system that includes only the drones, as described below with reference to FIGS. 12-14, or in a wide-area system in combination with satellites. In civilian applications, drones are typically deployed at an altitude of at least 10 miles to avoid interference with commercial aviation. Lighter-than-air vehicles can, in essence, occupy higher altitudes, but in preferred embodiments, these are deployed near the lower 10-mile limit to increase the drone-to-ground signal strength. It will also be understood that some applications use drones under the lower 400-foot ceiling permitted by FAA regulations in other non-restricted airspaces (such as near airports). These drones can find use in urban areas or mountainous terrain where ground nodes can see very few (or only a limited number) of high-altitude drones or satellites at all. They can also provide more reliable communication with ground nodes in buildings or other locations where the strength of the wireless link with high-altitude drones can be impaired.

[0005] The non-recirculating nodes of the present disclosure are also useful in certain applications where the 400-foot ceiling is interrupted by emergency government intervention, such as during or after situations where communication over a particular area is endangered or interrupted due to severe weather, earthquakes, or other natural disasters. Airlines may be ordered to cease operations in the disaster zone in order to clear the area, giving priority to non-recirculating low-altitude nodes. In the absence of a low-altitude limit for nodes in such situations, the drones described in the present disclosure can provide rapid communication with personnel on the ground, ideally maintaining communication between command posts and individual emergency workers and law enforcement officers. Drones at 1,000 to 2,000 feet can transmit and receive signals from the ground with sufficient strength to ensure the integrity of data transmission using the drones. Such altitude drones may be vulnerable to severe weather or other hazards, but the drones themselves are inexpensive, easily replaceable, and automatically begin participating in route creation and data transmission as soon as they are deployed.

Brief Description of the Drawings

[0006] When interpreted in conjunction with the accompanying drawings, in which like reference numerals and characters refer to like features throughout, the manner in which the specific objects of the claimed subject matter are achieved by such drones and communication systems will be better understood from the following detailed description of the preferred embodiments. The following is a brief identification of the drawings used in the accompanying detailed description.

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[0021] Those skilled in the art will readily understand that, although the drawings are not to exact scale, the following detailed description of the preferred embodiments will be sufficient for practicing and using the present invention upon reading it.

Best Mode for Carrying Out the Invention

[0022] The following detailed description is intended to provide specific examples of particular embodiments that illustrate various ways of implementing the claimed subject matter. It is written taking into account the level of knowledge of those skilled in the art to which the claimed subject matter pertains. Accordingly, certain details may be omitted as unnecessary for enabling such persons to implement the described embodiments.

[0023] The following detailed description of certain preferred embodiments of the subject matter is configured as follows. I. Definitions II. Embodiments of Non-Orbiting Aerial Nodes (Drones) A. Single Lighter-Than-Air Drone B. Two-Part Lighter-Than-Air Drone C. Two-Part Heavier-Than-Air Rotor Drone with Lift Assist III. Route Creation in Systems with Orbiting / Non-Orbiting Aerial Nodes A. General Description of an Exemplary Satellite Deployment B. Local and Wide Area Routing Systems and Methods 1. Local Area Data Transmission Using Drones 2. Wide Area Data Transmission Using Drones and Satellites 3. Examples of Local and Wide Area Routes IV. Operational Uses of the Disclosed Non-Orbiting Aerial Nodes V. Summary and Conclusion

[0024] I. Definitions

[0025] The detailed description in the following sections uses a number of terms that are intended to have a specific meaning. With respect to satellite deployment, the specific terms relate to options for the systems and methods disclosed below, where a satellite is used either alone or in combination with non-geostationary aerial nodes such as the illustrated LTA and the ascent-assisted drones. In known fixed orbits, or in certain advantageous embodiments where routing is based on the statistical likelihood of creating a link between nodes, a satellite may be deployed in a "probability-distributed" or "unconstrained orbit". Both of these terms are related to the term "random orbit" used in the previously referenced assignee's patents and patent publications. The intended meaning of these terms is that when a satellite is deployed in an orbit, it is allowed to take any orbital path without applying motive power by an on-board propulsion system. However, neither term is intended to exclude the initial deployment of a satellite at a specific orbital inclination, altitude or attitude, or at a specific geographical location relative to another satellite in the system. In other words, a "probability-distributed", "unconstrained" or "random" orbit may be one in which a satellite is initially deployed in a manner designed to provide coverage of a specific observation width of the Earth's surface, but after they are placed in orbit, it means that they are deployed such that their positions relative to other satellites and the Earth are not controlled at any given time. A satellite does not need to be deployed randomly in a mathematical sense, but using mathematical methods to determine the direction, inclination, altitude, speed, etc. of satellite deployment taking into account the geographical areas of the Earth served by a wireless route using one or more satellites is within the scope of these terms. In addition to this, individual satellites may be launched in different orbital directions (eastward or westward around the Earth) in combination with either of the foregoing or other deployment techniques. For example, a satellite may be ejected from a launch vehicle traveling in an orbital direction (i.e., generally eastward or westward) at different speeds and in different directions, such that after a certain time, they will separate themselves into "random" orbits in an essentially unconstrained manner. This presents a constellation of multiple satellites as being probability-distributed in random orbits to an observer on Earth.

[0026] In the system described in this book, the terms "passive attitude control" and related terms such as "without active attitude control" as applied to a satellite mean that the satellite does not have an attitude control mechanism having parts that are moved to different positions by an on-board device that requires a motive power to intentionally change the attitude of the satellite with respect to an external reference system. Examples of active attitude control mechanisms are a propulsion system having thrusters that can impart a moment to the satellite to rotate it, or a mechanical actuator having moving parts used to change the center of gravity or angular momentum of the satellite, or the position and / or orientation of the solar panels of the satellite. These terms do not exclude the use of passive means that change or control the satellite attitude without using moving parts, whereby the satellite may tend to assume a particular attitude over time simply due to its structure and the materials used in its manufacture. In addition to this, these terms do not exclude the use of various approaches such as using electric means to stabilize the satellite attitude within certain limits. This may include techniques such as the selective switching of an array of one or more electromagnets to change the interaction with the Earth's magnetic field in a manner that affects the satellite attitude. The terms "passive attitude control" and "without active attitude control" also cover similar technologies that are currently known or may be developed in the future.

[0027] A "node" or "system node" is a physical object having one or more transceivers for transmitting wireless signals intended to be received by other nodes and receiving wireless signals transmitted from other nodes. The node may be a terrestrial ground station, the example of which is described in the following paragraph, or a transceiver above the surface of the Earth ("air node"). The air node includes, but is not limited to, artificial satellites orbiting the Earth, fixed-wing or rotary-wing aircraft heavier than air, and non-circling drones, rigid airships lighter than air with or without propulsion and steering systems. Non-circling air nodes also include balloons. In this context, "rigid" means an enclosure or casing having a substantially fixed shape and capable of only limited deformation. Similar to satellites, non-circling air nodes do not need to be maintained exactly at a predetermined position to support route creation. However, since they are exposed to atmospheric conditions, they may include sufficient propulsion and guidance systems to limit their range of motion. The present disclosure mainly relates to routes between air nodes of the same type at the same altitude, or between air nodes of the same or different types at multiple altitudes.

[0028] A "ground node" or "terrestrial node" can refer to a fixed-location terrestrial station such as a land cellular telephone switch, or a mobile node that can move between locations under its own power while transmitting and receiving radio signals. The terms "mobile ground node" or "mobile terrestrial node" can also refer to an aircraft in flight that serves as the original originating node from which passengers wish to send data to a destination ground node, including another aircraft in flight, or a destination ground node on the actual surface of the Earth, or it can be the original destination ground node on the surface of the Earth from which a system user wishes to send data to an aircraft in flight or another system ground node on the surface of the Earth. An elevated ground node enables more users to connect to the communication system in areas of low population density. The terms "mobile ground node" or "mobile terrestrial node" further mean a mobile ground vehicle (such as an automobile) that is the original from which crew members wish to send data to a destination ground node, including an aircraft in flight, or a destination node on the actual surface of the Earth, or it can be the original originating node on the surface of the Earth from which a system user wishes to send data to an aircraft in flight or another system node on the surface of the Earth. Examples of other types of mobile ground nodes include, but are not limited to, portable devices such as smartphones and tablet computers, trucks and buses, and marine vessels such as cruise ships, fishing boats (of all sizes), and pleasure boats. Thus, terms such as "mobile ground node" and "mobile terrestrial node" as used in this disclosure are to be understood as being broadly construed to include any node ("originating node") that forms the end of the route from which data is transmitted, or any node ("destination node") that forms the end of the route to which it is received, whether physically on the surface of the Earth, in the air above the surface, or in a body of water.

[0029] In the following description, the terms "routing message" and "data communication" (or "data transmission") are also used. A "routing message" is a wireless signal transmitted from a system node (ground or air) that contains or has characteristics that can be used to determine the suitability of a node for inclusion in a multi-link wireless route. "Data communication" includes, unless explicitly or contextually indicated otherwise, the content (digital or otherwise) transmitted via a wireless link between two orbiting satellites, between two non-orbiting air nodes, or between a satellite or other non-orbiting air node and a ground node. Without being limited to such, the systems and methods described herein are generally applicable to the transmission of data within a packet as defined herein in the sense of being a collection of digital data having a portion representing the content of the transmission (sometimes called the "payload") and a control portion (sometimes called the "header" or "trailer") containing information such as the source and destination addresses, error detection codes, sequence information, and encryption information that enables the payload to be delivered properly. A given wireless signal can include both a routing message and a data communication. Throughout the description of this document, the term "wireless" is not generally limited to references to electromagnetic radiation at frequencies commonly called radio waves. It means encompassing any frequency of electromagnetic radiation capable of transmitting information, including light, microwaves, VHF ("ultra-high frequency"), UHF ("extremely high frequency"), and the like.

[0030] As will be understood by those skilled in the art, in the description of this document, the control circuits and components described and illustrated in the various drawings are meant to be examples of any electronic computer system capable of performing the functions attributed to them. Such a computer system typically includes the necessary input / output interface devices, a central processing unit (CPU) with an appropriate operating system, application software for executing program instructions, and temporary and non-temporary memory modules. In addition to this, terms are used in this document to refer to elements of the system for the sake of simplicity. For example, terms such as "component", "module", "system", "device", "interface", etc. generally intend to refer to any computer-related entity, whether it is hardware, a combination of hardware and software (firmware), software, or software in execution, unless the context clearly indicates otherwise. In addition to this, the terms "module" or "component" do not in themselves mean a self-contained structure, but may include various hardware and firmware combined to perform a specific function. In this regard, a component or module may, but is not limited to, be a process executed on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of example, both an application executed on an electronic computing device and the device itself may be components. One or more components may reside within a process and / or an execution thread, a component may be localized on one computer, and / or may be distributed between two or more computers.

[0031] II. Embodiments of Non-Rotary Aerial Nodes (Drones)

[0032] As already described, communication systems that employ the assignee's methods and protocols can be used with various types of non-orbiting aerial nodes. Various structures of heavier-than-air drones have been proposed, such as the SolarStrato (trademark) High Altitude Platform Station (HAPS) developed by AeroVironment, Inc., described at www.avinc.com / about / HAPS. These so-called "pseudo-satellites" are fixed-wing aircraft with a wingspan of 255 feet (compared to the 211-foot wingspan of a Boeing 747) and carry solar panels and ten propellers. These would be numerous enough to support particularly large amounts of communication and would be costly to build and launch. These sizes would make them particularly vulnerable if used in hostile environments such as combat zones, which are used to support direct communication with combat troops instead of a disrupted local infrastructure. In settings where a large number of SolarStrato (trademark) drones have a high "death" rate, there is a significant cost penalty to replace them.

[0033] The drones described in this document avoid these drawbacks. They are inexpensive to build and launch. They can be deployed in swarms at low altitudes to increase the likelihood of establishing communication with the ground surface, which can be a critical issue in situations where the local infrastructure has been damaged or impaired, such as in war zones or natural disasters. They support the assignee's unique routing protocol, which does not require the drones to be in fixed positions and enables them to self-integrate into the communication system immediately after deployment.

[0034] A. Single Lighter-Than-Air Drone

[0035] Figures 1-3 show one preferred embodiment of an LTA drone comprising a rigid airship designed to operate as a type A node in a system such as that further described below and in the '796 publication. For the purposes of this description, a right-handed coordinate system is superimposed on drone 10, with the positive x-axis (+x) along the centerline of the drone generally defining the forward nose orientation, the positive y-axis (+y) pointing vertically upward in the nominal direction of the drone, and the positive z-axis (+z) pointing left as viewed from the -x direction. In this example, drone 10 has a generally circular cross-section in the yz plane centered on the x-axis (Figure 3) and elliptical cross-sections in the xy and xz planes (Figures 1 and 2), and comprises a regular elliptical casing 100 that is symmetric about all three axes and is geometrically an oblate ellipsoid. (In this and similar contexts, "generally circular" means that the shape may deviate from a perfect circle provided that the drone is still able to perform its intended function.) In the following description, the coordinate system is attached to the drone unless the context indicates otherwise, and the "drone directions" refer to the relationships of the x-, y-, and z-axes with respect to the Earth's surface. (The drawings show the origin of the coordinate system at the center of gravity of the elliptical casing 100 of drone 10 merely to facilitate illustration and explanation.) Figures 1-3 show the drone in its nominal orientation during deployment in a communication system as described below with reference to Figures 12-14 and Figure 12 of the '796 publication, with the +y axis of the drone pointing vertically upward perpendicular to the Earth's surface, the xy plane parallel to the Earth's surface, and the nose orientation in the +x direction. "Upper", "side", and "lower" surfaces are so designated in the context, and "right" and "left" are as viewed from the -x direction.

[0036] The LTA drone 10 includes three arrays of separately operable directional antennas. In this embodiment, the upper antenna array 102 includes a plurality of antennas distributed in the region between the three-dot chain lines in FIGS. 1 and 2, the side antenna array 104 includes a plurality of antennas distributed in the region between the two-dot chain lines (which similarly extends to the right side of the drone) in FIGS. 1 and 2, and the lower antenna array 106 includes a plurality of antennas distributed in the region marked in FIG. 1 by a dashed line (which similarly extends to the right side of the drone as shown in FIG. 3). In one preferred embodiment, the antennas have parabolic reflectors with circular mouths and central feeds, and are mounted to the drone such that these mouths are proximate to the inner surface of the drone 10. In another embodiment, the parabolic antennas can have multiple feeds, as described in the assignee's U.S. Patent No. 10,085,200, to increase the number of beams generated by each, thereby improving the opportunity to pair antennas between different drones. Although the antennas are shown as circles in FIGS. 1 and 2, depending on the manner in which they are mounted in place, they may or may not be actually visible from outside the drone.

[0037] The upper antenna array 102 is designed to make a wireless link with satellites in layers B, C, and D in the system shown in FIG. 14. In this embodiment, it includes a total of 12 antennas. The four central antennas 102a, 102b, 102c, and 102d are equally spaced such that the centers of these ports are on the line where the xy plane intersects the surface of the drone. The four additional upper antennas with lateral left offset antennas 102e, 102f, 102g, and 102h are equally spaced such that the centers of these ports are on a line displaced by a predetermined distance to the left of the line of the central antennas. The four antennas with lateral right offset antennas 102i, 102j, 102k, and 102l are equally spaced such that the centers of these ports are on a line displaced by a predetermined distance to the right of the line of the central antennas. The center - to - center distance between the antennas in each row of the lateral offset antennas is the same as that of the central antennas, and each lateral offset antenna is located at half the distance between adjacent central antennas.

[0038] The circumferential arrangement of the upper array antennas in the yz plane is conceptually shown in FIG. 3, which represents the central antennas 102a, 102b, 102c, and 102d as a single conceptual antenna 102C, the left - offset antennas 102e, 102f, 102g, and 102h as a single conceptual antenna 102L, and the right - offset antennas 102i, 102j, 102k, and 102l as a single conceptual antenna 102R. In this embodiment, the center of the left - offset antenna 102L is circumferentially separated from the center of the line of the center antenna 102C by a distance d TL and the right - offset antenna 102R is circumferentially separated from the line of the center antenna 102C by a distance d TR The LTA drone 10 has an on - board rechargeable battery (see FIGS. 4 and 5 described later) and a plurality of solar cell arrays SP for converting light from the sun into current for charging the battery. In this embodiment, as shown in FIG. 2, the solar cell arrays are arranged in the spaces between the antennas of the upper antenna array.

[0039] Referring to FIG. 3, as the diameter of the drone decreases, the angle α between the y-axis and the center of antenna 102L TL increases along the x-axis (in both directions from the origin where x = 0), and the same applies to the angle α between the y-axis and the center of antenna 102R. For example, the angles α TR associated with antennas 102e and 102i (and antennas 102h and 102l) TL and α TR are greater than the corresponding angles associated with antennas 102f and 102j (and antennas 102g and 102k). Thus, the upper array antennas at the ends of the drone 10 are oriented more laterally (i.e., closer to the xz plane) than the upper array antennas closer to the y-axis. This facilitates the creation of wireless links with satellites in layers B, C, and D located at shallower angles. (See FIG. 14.) The angles α TL and α TR are typically equal and are selected such that the antennas are arranged in the upper array generally upward and away from the Earth's surface to transmit wireless signals to the satellites and receive wireless signals from the satellites. The preferred range of α TL and α TR is 0° to 10° at x = 0. In this embodiment, d TL and d TR are constant along the length of the casing, but in some cases, it may be preferable to maintain α TL and α TR constant along the length of the casing or to vary them according to the operating requirements. Conversely, the upper array antennas closer to the center of the drone (such as antennas 102f, 102g, 102j, and 102g) do not give much opportunity to form wireless links with satellites at such shallower angles. Thus, in an optional configuration, the upper antenna array may include one or more auxiliary antennas 102AX on both sides of the drone in addition to the other antennas shown in FIGS. 1 and 2. The optional nature of these antennas is indicated by the dashed-dotted lines in these depictions in FIGS. 1 - 3.

[0040] The side antenna array 104 shown in FIGS. 1 to 3 is designed to make a wireless link with other drones in layer A of FIG. 14. This includes a total of 12 antennas in 6 two-row arrays, with 6 antennas in each row. The first row of side antennas consists of six horizontal antennas 104a, 104b, 104c, 104d, 104e, and 104f, whose centers are equally spaced around the "equator" of the elliptical drone (i.e., the line along the outer perimeter of the drone in the xz plane). The second row of side antennas consists of six downcast antennas, three of which are located on one side of the drone. The downcast antennas on the left side of the drone are denoted by reference numerals 104g, 104h, and 104j. Each is arranged such that its center is placed on a line offset downward from the line of the horizontal antennas, and the distance between their centers is the same as the distance between antennas 104a, 104b, and 104c, and each downcast antenna is placed at half the distance between antennas 104a, 104b, and 104c. The downcast antennas on the right side of the drone (not shown) are arranged in the same manner with respect to the horizontal antennas 104d, 104e, and 104f on that side.

[0041] The arrangement of the antennas within the side array 104 is shown in FIG. 3, which represents the horizontal antennas as two conceptual antennas 104L and the downcast antennas as two conceptual antennas 104D on both sides of the drone 10. The antennas 104L are oriented approximately parallel to the Earth's surface along the length of the drone. The centers of the downcast antennas 104D are circumferentially spaced by a distance d S from the center of the line of the horizontal antennas 104L. Thus, the angle α S between the z-axis and the center of the antenna 104D increases along the x-axis (i.e., in both directions from the origin) as the diameter of the drone decreases (i.e., the angle α S associated with antennas 104a and 104g (and antennas 104c and 104i) is greater than the corresponding angle associated with antennas 104b and 104h). The angle α Sis preferably selected such that it is 5° to 10° at x = 0, whereby the lateral antenna and the downcast antenna form a side antenna array that is generally parallel and horizontally oriented with respect to the surface of the earth. In this embodiment, d S is constant along the length of the casing, but in some cases it may be preferable to maintain the value of α S constant along the length of the casing or to vary it according to the operating requirements. In a system where all drones are at substantially the same altitude, the side array antenna provides sufficient antenna beam coverage to establish a wireless link between a particular drone and nearby drones via the lateral antenna and between drones near the horizon via the downcast antenna.

[0042] Referring further to FIGS. 1-3, the antennas within the lower antenna array 106 are designed to make a wireless link with the ground nodes "T" shown in FIG. 14 associated with specific local areas such as Hawaii, San Francisco, New York, and London (used as an example in FIG. 14). There are a total of 12 antennas in the lower array, arranged substantially the same as the antennas of the upper array 102. Specifically, the lower array includes a total of 12 antennas. The four central antennas 106a, 106b, 106c, and 106d are equally spaced such that the centers of these ports are on a line where the xy plane intersects the surface of the drone. The four additional lower antennas with lateral left offset antennas 106e, 106f, 106g, and 106h are equally spaced such that the centers of these ports are on a line displaced a predetermined distance to the left of the line of the central antennas. The four antennas with lateral right offset antennas (not visible in the drawing) are equally spaced such that the centers of these ports are on a line displaced a predetermined distance to the right of the line of the central antennas (such as the upper antennas 102i, 102j, 102k, and 102l). The center-to-center distance between the antennas in each row of the lateral offset antennas is the same as that of the central antennas, and each lateral offset antenna is located at half the distance between adjacent central antennas. The circumferential arrangement of the lower array antennas in the yz plane is conceptually shown in FIG. 3, which represents the central antennas 106a, 106b, 106c, and 106d as a single conceptual antenna 106C, the left offset antennas 106e, 106f, 106g, and 106h as a single conceptual antenna 106L, and the right offset antennas as a single conceptual antenna 106R. In this embodiment, the center of the left offset antenna 106L is circumferentially separated from the center of the center antenna 106C by a distance d BL only, and the right offset antenna 106R is circumferentially separated from the line of the center antenna 106C by a distance d BR only.

[0043] Similar to that described in connection with the upper antenna array 102, as the diameter of the drone decreases, the angle α between the y-axis and the center of the antenna 106LBL increases along the x-axis (in both directions from the origin), and the angle α between the y-axis and the center of the antenna 106R BR is the same. Thus, the lower array antenna at the end of the drone 10 is oriented laterally (i.e., closer to the xz plane) than the lower array antenna closer to the y-axis. The angle α BL and α BR are typically equal and are selected such that the antennas are arranged in the lower array generally facing towards the surface of the Earth to transmit wireless signals to ground nodes and receive wireless signals from satellites. The preferred range of α BL and α BR is 0° to 10° at x = 0. In this embodiment, d BL and d BR are constant along the length of the casing. However, in some cases, it may be preferable to maintain α BL and α BR constant along the length of the casing or vary them according to operating requirements. This provides coverage of a sufficiently wide area of the Earth's surface to enable the establishment of wireless links with multiple ground nodes. A supplementary antenna such as 102AX to complement the upper antenna array may be provided at the lower part of the LTA drone 10. However, the proximity of the drone to the Earth's surface (compared to the distance to the satellite node) should obviate the need to increase the surface footprint of the lower array antenna of the drone.

[0044] Figure 4 schematically shows the internal components of the LTA drone 10 including the internal circuit that executes the route creation and data transmission functions described later in Section III. For clarity, Figure 4 schematically represents only the upper antenna array 102, the side antenna array 104, the lower antenna array 106, and the solar panel SP. The electronic control and communication module shown in Figure 4 includes a central processing unit 210 that includes an operating system module 212, a GNSS (Global Navigation Satellite System) module 214, and a motor / steering / attitude (MSA) control module 216. The operating system module 212 provides overall control of the other system components shown in Figure 4, as described in the immediately following paragraph. The GNSS module 214 enables the drone 10 to determine its position relative to the Earth's surface in a manner employed by known global navigation satellite systems such as the United States-based Global Positioning System (GPS), the European Union's Galileo system, Russia's GLONASS system, and China's Beidou system. The GNSS module also functions as a system clock for the routing and data transmission operation phases described further below. The central processing unit 210 also controls the route creation / data transmission circuit 310. In an important aspect of the LTA drone 10, the circuit 310 controls separately operable upper antenna route creation / data transmission circuit 312, side antenna route creation / data transmission circuit 314, and lower antenna route creation / data transmission circuit 316, each of which is dedicated only to controlling route creation and data transmission via its respective associated antenna array, as described in the next paragraph. The rechargeable battery 410 provides operating power to the drone. The MSA module 216 controls the on-board mechanical components already described, which are detailed next.

[0045] Figure 4 shows the electronic control and communication modules that occupy most of the internal volume of the drone 10, but in reality, they actually occupy very little space. Most of the internal volume is occupied by one or more inflatable bladders GB filled with helium or other gases lighter than air (conceptually shown by the long dashed line in Figure 3) to maintain the drone at a predetermined altitude. The bladders are pumped to provide sufficient buoyancy to lift the drone to its operating altitude, where they release an amount of helium lifting gas sufficient to make the upward lift L on the drone equal to its weight W. (See Figure 3.) At the desired altitude, the coordinates x L , y L , z L of the center of lift CL and the coordinates x G , y G , z G of the center of gravity CL are such that x L = x G and z L = z G (In this embodiment, x L = x G = 0 and z = L = z G = 0), and the entire drone, including the casing of the drone itself, the hardware and electronic components shown in Figure 4, and the bladders, is constructed so as to be positioned relative to each other. In the y direction, the center of the upward lift CL is located at +y L , and the center of gravity is located at -y G . When there is no external force on the drone, this encourages it to hover at a constant altitude with the xz plane parallel to the Earth's surface, the y-axis perpendicular to the Earth's surface, and the lower antenna pointing downwards.

[0046] However, in practice, most applications advantageously involve a method of maintaining the drone level (where the xz plane is parallel to the Earth's surface) at the operating altitude and orienting the +x direction towards a specific nose bearing. This embodiment incorporates a plurality of mechanisms for controlling the drone attitude (i.e., pitch, roll, and yaw), for maintaining it in a desired position, or in some applications, for steering it along a predetermined flight path. In this description, "pitch" refers to the angular direction with respect to the z-axis, "roll" refers to the angular direction with respect to the x-axis, and "yaw" refers to the angular direction with respect to the y-axis. "Zero pitch" refers to the attitude where the x-axis is parallel to the ground surface, "zero roll" refers to the attitude where the z-axis is parallel to the ground surface, and "zero yaw" refers to the attitude where the x-axis points in the desired nose bearing direction. As already stated, typical design conditions are zero pitch, roll, and yaw within certain limits that enable the antenna of the drone to make a wireless link with other nodes within the specific communication system in which the drone is deployed.

[0047] An important feature of the LTA drone 10 lies in the various mechanical and electromagnetic components 510 that, together with the GNSS module 214 and the MSA module 216, comprise an induction and propulsion system for controlling the position and orientation of the drone to maintain it in a nominal direction, with pitch, roll, and yaw all being zero, and the drone either hovering at a desired fixed position or following a desired flight path. The route creation and data transmission methods described later in Section III rely heavily on keeping the antenna array in an appropriate direction with respect to the ground surface so that the antenna array can properly form the intended wireless links with other system nodes within various layers. It is also important to control the position and nose orientation of the LTA drone to provide services to ground nodes within any given local area. FIG. 4 identifies these components collectively as a servo motor and transmission 514 connected to the upper fin 518T and the lower fin 518B by means of an electromagnetic array 512 for nose orientation / yaw control, an upper drive shaft 516T, and a lower drive shaft 516B, respectively, and a propeller 520 driven by the servo motor via a shaft 522. The servo motor applies torque to the drive shaft 516 to rotate the fins to a desired angle of attack between +β and -β with respect to the y-axis (see FIG. 2) under the control of the MSA module 216. The transmission enables the fins to be rotated independently throughout their range of motion. The MSA module 216 also controls the rotational speed of the propeller 520.

[0048] A first aspect of maintaining / controlling the attitude of the LTA drone 10 is to construct it and all of its components to have a predetermined weight distribution that tends to maintain it in horizontal flight (pitch = 0°). The pitch angle θ is shown in FIG. 5, which is a side view representing the drone weight distribution that biases the drone to an attitude of θ = 0°. FIG. 5 illustrates how, if the drone pitches in any direction, the resulting displacement of the lift force L and the weight W creates a moment about the center of gravity that tends to return it to horizontal flight (θ = 0°). The drone is constructed to maximize the distance along the y-axis between the center of lift CL and the center of gravity CG in order to maximize the stabilizing moment that occurs if the drone pitches. In addition to this, the present embodiment also distributes the drone weight so as to create an inertial moment that resists the force that pitches its front end 100F up (+θ°) or down (-θ°). To that end, within the possible range, the heavier components of the drone are arranged such that the total weight W of the drone is the center of gravity CG of the front auxiliary device F and the center of gravity CG of the stern auxiliary device A and these are both arranged in the xy plane like the total center of gravity CG and the center of lift CL. Many of the drone components such as the antenna, solar panel, and bladder must be arranged within the drone according to these functions, so the remainder of the weight W is mainly due to the rechargeable battery 410. FIG. 5 reflects the expectation that in most embodiments, the main contributions to the front auxiliary weight w F and the stern auxiliary weight w A are the configurations 412F and 412A consisting mainly of the drone's rechargeable battery respectively. Other components can be arranged to contribute to the auxiliary weights w F and w A , but there may be constraints on where these can be arranged to provide the desired values. Therefore, it may be necessary to add ballast to achieve the desired effect. For example, in a preferred embodiment, the drone has w F equal to w A and their associated auxiliary centers of gravity CG F and CG Aare constructed to be equidistant x in the x - direction from the drone's center of gravity CG Aux Moreover, even if θ is not maintained at 0°, effective route creation and data transmission can be achieved. The preferred range is +10° ≥ θ ≥ -10°, and the more preferred range is +6° ≥ θ ≥ -6°, although a wider range is still operable.

[0049] The next aspect of maintaining / controlling the attitude of the LTA drone 10 is to provide for maintaining its roll angle φ = 0°, as shown in FIG. 3. Similar to the pitch angle θ, the y - alignment of the lift force L and the weight W essentially biases the drone into an attitude of φ = 0°, as shown in FIG. 3, such that the resulting displacement of the lift force L and the weight W creates a moment about the center of gravity that tends to return it to φ = 0°. In addition to this, by incorporating an inclinometer (not shown) into the MSA module 216, more active control of the roll angle is achieved. When the inclinometer detects a non - zero value of φ, the software within the operating system module 212 and the MSA module 216 cooperate to generate a feedback loop that rotates the fins 518T and 518B in opposite directions through appropriate angles +β and -β to the servo motor / transmitter 514 to maintain φ = 0°. Suitable electronic inclinometers are commercially available, and one example is a micro - electro - mechanical system (MEMS) such as the ADIS16201 field - programmable gate array biaxial inclinometer / accelerometer available from Analog Devices, Inc., Wilmington, Massachusetts 01887.

[0050] This method of controlling roll is effective in situations where the +x axis of the drone is oriented in the direction of the dominant wind PW and the LTA drone 10 is held in the desired position by the propulsive force PF generated by the propellers 520, and thus in situations where air flow is created over the fins 518T and 518B. (Position and heading control are described next.) In most situations, the drone is expected to be exposed to the dominant wind, which is an effective way to control roll under all conditions except abnormal atmospheric conditions. Even if the dominant wind is gentle, the inherent tendency of the drone to assume the position of φ = 0° aids in maintaining it in the desired direction with respect to roll. And if the GNSS module 214 does not detect the movement of the drone, especially in the absence of perturbations with other such tendencies, the same tendency should be sufficient to control the amount of roll. Further, even if φ is not maintained at 0°, effective route creation and data transmission can be achieved, with the preferred range being +10° ≥ φ ≥ -10°, and the more preferred range being +6° ≥ φ ≥ -6°, although wider ranges are still operable.

[0051] The final aspect of maintaining / controlling the attitude and direction of the LTA drone 10 is described with reference to FIGS. 6 and 7, where FIG. 6 is a view taken in the direction shown in FIG. 5, and FIG. 7 is a detailed view of the electromagnetic array 512 labeled "Attitude / Steering Magnet" in FIG. 4. For the purposes of this objective, the yaw angle ψ is defined as the amount by which the +x axis of the LTA drone 10 deviates from the desired heading with respect to the Earth's surface. In one implementation, the MSA module 216 includes a suitable device for sensing the direction of the x axis with respect to the Earth, such as an ECC-2D series e-compass from Jewell Instruments, 850 Primet Road, Manchester, New Hampshire 03103, to provide an appropriate signal to the operating system module of the drone heading. FIG. 7 is a detailed view of the electromagnetic array 512 with a passive attitude control mechanism that interacts with the Earth's magnetic field to control the drone heading.

[0052] As seen in FIG. 7, the electromagnetic array 512 is viewed from the -y direction. The array comprises four orthogonal electromagnets 512a, 512b, 512c, and 512d, and their N poles "N" and S poles "S" are oriented as shown when they are activated. The Earth's magnetic field is represented by magnetic flux lines MF. In FIG. 7, the LTA drone 10 is shown together with the magnets 512a and 512c aligned with the Earth's magnetic field by the attraction of these N and S poles to the Earth's north and south magnetic poles. (The Earth's north magnetic pole is actually a south magnetic pole, and vice versa for the Earth's south magnetic pole.) In this orientation, the drone nose bearing, i.e., the direction of the +x axis, is due east. The drone is brought to any desired nose bearing by an appropriate algorithm resident in the operating system module software 212 together with an e-compass (not shown), and a feedback loop can be generated to operate the electromagnets 512a, 512b, 512c, and 512d in a predetermined manner to produce a rotational force about the y axis that tends to change / maintain the drone nose bearing.

[0053] As described above, the LTA drone 10 is typically maintained in a fixed position relative to the Earth when used in the communication system described below with reference to FIGS. 12-14. The preferred deployment altitude is about 10 miles, which is typically above the jet stream at a maximum altitude of 9 miles. However, the drone may be subject to some air currents as described above. The GNSS module 214 obtains periodic readings of the drone's position, which are processed by the operating system module 212 to calculate any initial drift at the drone's position. Appropriate algorithms resident in the operating system module provide appropriate signals based on the direction in which the drone has moved from its desired position and its current nose bearing provided by the on-board e-compass. The operating system module provides appropriate signals to the electromagnets 512a, 512b, 512c, and 512d so that the drone is oriented in the appropriate direction to maintain / return to its desired position via the operation of the servo motor 514 to rotate the shaft 522 and generate the propulsive force PF on the propeller 520. The angle of attack β of the fins 518T and 518B also helps to keep the +x axis of the drone facing the prevailing wind PW at a yaw angle ψ = 0°.

[0054] During operation, the operating system module 212 receives readings from the GNSS module at appropriate intervals according to the angle of the nose azimuth of the x-axis at that time, and controls the angle of attack of the propellers, electromagnets, and fins via a conventional feedback loop so that the +x axis points in the direction of the prevailing wind and the drone remains aligned with it. It is not necessary for the drone to return to the desired position in a straight line for proper operation of the system. For example, in a preferred embodiment, it may "tack" back to the desired position depending on how far it has moved. In this embodiment, when the GNSS module indicates that the drone has not moved from its desired position, it is presumed to be facing the prevailing wind head-on. The oblate ellipsoid shape reduces the drag force and power required to maintain the drone at the desired position. In an alternative configuration, the drone may include a wind direction sensor that directly indicates the direction of the prevailing wind to help maintain the drone at the desired position.

[0055] In another implementation, the LTA drone follows a predetermined flight path designed to increase the number of antenna pairings between them. For example, a circular flight path with a diameter of about 1 to 2 miles will change the angle of the drones relative to each other and subsequently cause these antennas to face each other at slightly different angles. (The flight path may vary slightly from a perfect circle due to atmospheric conditions.) The operating system module 212 steers the drone via serial inputs from the GNSS module 214 indicating the drone position and flight path and from the MEMS tilt sensor, and heading information from the ecompass to control the drone flight path. The MSA control module 216 controls the fins 518T and 518B and the propellers 520, as appropriate, using the selective actuation of the magnets within the electromagnetic array 512 via the servo motor / transmission 514. This implementation can be realized using different flight paths to achieve the same purpose.

[0056] B.2 Part Lighter-than-air Drone

[0057] Figures 8 - 10 show a first alternative embodiment of a two - part LTA drone 1010 that includes an upper vehicle 1020 that is lighter than rigid air and a communication capsule 1030 connected to the vehicle 1020 by a rod 1040. (Features in this embodiment that have counterparts in the embodiment of FIGS. 1 - 7 are similarly indicated with reference numerals in the "1000" series.) In order to enable the communication capsule to rotate about the y - axis with an angular velocity ω with respect to the surface of the Earth, a bearing structure suitable for the purpose attaches the rod 1040 to the upper vehicle and / or the communication capsule. The communication capsule 1030 has an elliptical cross - section (FIGS. 8 and 10) in the xy - and yz - planes and a substantially circular cross - section (FIG. 9) in the xz - plane, providing a constant cross - sectional area against any dominant wind as it rotates, and comprises a rigid casing 1100 of a regular ellipse that is symmetric with respect to all three axes and is geometrically a flattened ellipsoid. The drone 1010 includes all of the components of the air - lighter drone 10 described above in connection with FIGS. 1 - 7. The upper vehicle 1020 has a solar panel SP, a central processing unit 210, a rechargeable battery 410 (including any ballast), mechanical components 510, and a bladder (not shown) for the same purpose as the bladder GB shown in FIG. 3. The lower communication capsule 1030 houses communication components including an antenna and a route creation / data transmission circuit 310. FIGS. 8 - 10 schematically show an upper antenna array 1102, a side antenna array 1104, and a lower antenna array 1106. The rod 1040 includes suitable means for connecting electrical / electronic components within the upper vehicle 1020 to the rotating communication capsule 1030. In an alternative embodiment, the tasks of the CPU can be divided between a power CPU within the upper vehicle 1020 that manages the battery, solar panel, and MSA control module, and a communication CPU within the communication capsule 1030 that manages the route creation / data transmission circuit.

[0058] Both the upper vehicle 1020 and the communication capsule 1030 include an electromagnetic array (not shown) similar to that described above in connection with FIG. 7. The electromagnetic array within the upper vehicle maintains the drone 1010 at a fixed geographical location or steers it along a desired flight path in the same manner and with the same effect as described in connection with the LTA drone 10. In an optional non-rotating embodiment, the upper vehicle 1020 and the lower capsule 1030 are rigidly attached and the control system can maintain the drone at a fixed position or fly it along a predetermined flight path, similar to the drone 10. In this embodiment, the communication capsule 1030 does not include an electromagnetic array and is preferably an oblate ellipsoid with its major axis aligned with the major axis of the vehicle 1020.

[0059] In a rotating embodiment, the electromagnetic array within the communication capsule rotates it at an appropriate speed to increase the probability that a transmitted radio beam is received by another drone, due to the antenna "sweeping" the area as the drone rotates. (See FIGS. 11A - 11C and the accompanying text of U.S. Patent No. 10,979,136.) The actual rotation speed depends on various factors. If it is too fast, the antenna pairing may be too short to support communication, and if it is too slow, the number of antenna pairings during any given time period decreases. The antenna structure also affects the optimal rotation speed in that narrow beam - directed antennas are more efficient at lower rotation speeds and wider beam antennas support higher rotation speeds. A preferred range for ω is considered to be 1 - 3 rotations per minute, although a wider range may still be operable. In addition, a rechargeable battery and any ballast mass are disposed within the communication capsule 1030 in the same manner and with the same effect as the LTA drone 10 described above in connection with FIG. 5.

[0060] C. Two - part heavier - than - air rotary - wing drone with lift assist

[0061] FIG. 11 is a schematic side view of a second alternative embodiment of drone 2010 for use as a type A node in the system described with reference to FIGS. 12-14. Drone 2010 comprises a two-part non-circling aerial node in which a communication capsule from FIGS. 8-10 is suspended from a heavier-than-air rotary wing aircraft (HTA drone) having optional lift assistance provided by a gas lighter than air.

[0062] HTA drone 2010 includes a heavier-than-air rotary wing vehicle 2020, and a communication capsule 2030 having a rigid casing is suspended from the heavier-than-air rotary wing vehicle 2020 by a rod 2040 connecting the vehicle 2020 and the communication capsule 2030. (Features in this embodiment having counterparts in the embodiment of FIGS. 1-10 are similarly denoted by reference numerals in the "2000" series.) As in the second embodiment of FIGS. 8-10, vehicle 2020 has a solar panel SP, a central processing unit 210, a rechargeable battery 410 (including any ballast), and a mechanical component similar to component 510 in the manner described in the next paragraph, and a communication component including an antenna and a route creation / data transmission circuit 310 is housed within communication capsule 2030. FIG. 11 schematically shows an upper antenna array 2102, a side antenna array 2104, and a lower antenna array 2106. As described in connection with drone 1010, the tasks of the CPU can be divided between a power CPU in the upper vehicle 2020 and a communication CPU in the communication capsule 2030.

[0063] The drone 2010 is the same as the lighter-than-air embodiments of FIGS. 8 - 10 in most operational aspects, but structurally, the heavier-than-air rotor vehicle 2020 is replaced by the lighter-than-air upper vehicle 1020. In a preferred implementation, the rotor vehicle comprises four rotors arranged 90° apart when viewed from above, and these electric motors 2510 (two of the motor / rotor units 2510a and 2510b are seen in FIG. 11). The position, altitude, direction, and flight path are controlled by inputs to the rotor / motor units 2510, which are similar to the inputs to the fins 1510a and 1510b and the propellers 1520 on the upper vehicle 1020 by the mechanical components 510 of the embodiments shown in FIGS. 8 - 10.

[0064] In one implementation, the drone 2010 is maintained at a fixed geographical location with the same effect as an LTA drone. In that case, the operating system module detects the movement of the drone 2010 from the desired position and activates the servo motor and transmission module to control the rotor / motor unit and keep the drone essentially stationary in a manner similar to that used to control the fins and propeller motors in the previous embodiments by processing the input from the on-board GNSS circuit and the MSA module. Similarly, the rotors can also be used to steer the drone along a desired flight path. In an embodiment where the upper vehicle and the lower capsule are firmly attached, the rotors can be controlled to rotate the entire drone around its y-axis to obtain the same effect as the embodiments shown in FIGS. 8-10. In yet another configuration, the rod attaches the communication capsule for rotation with respect to the upper vehicle in the same manner as the drone 1010. The rotary-wing upper vehicle provides more operation alternatives than a drone with an upper vehicle lighter than air. For example, in a structure where the upper vehicle and the lower capsule are firmly attached, the control system can maintain the drone at a fixed position or fly it along a predetermined flight path. Alternatively, the rotary-wing vehicle 2020 can be rotated entirely around its y-axis to obtain the same effect as described above, whether it is stationary or moving. In another variant, the upper vehicle and the communication capsule are attached in the same manner as the drone 1010 to enable them to rotate relative to each other. The communication capsule can be rotated by using an electromagnetic array such as in the drone 1020 while the upper vehicle 2020 is maintained in a stationary state or steered along a predetermined flight path. The communication capsule is preferably oblate ellipsoidal in non-rotating applications where the x-axis is maintained in line with the prevailing wind and prolate ellipsoidal in rotating applications.

[0065] An important feature of this embodiment is incorporating an optional inflatable bladder GB2 containing helium or other gas lighter than air into the upper vehicle. The gas provides a given amount of buoyancy to the drone 2010 to reduce the amount of electrical power required to maintain at a desired altitude. In a preferred embodiment, this maintains the drone at a minimum design altitude for a given application, whereby the drone can use more power to raise the drone to higher altitudes if necessary. For example, a given system may be designed for multiple groups of type A nodes at different altitudes (see FIG. 14). If some number of higher altitude drones are lost due to failure, hostile action, or otherwise, these can be replaced by some of the lower altitude drones by applying more power to the rotors / motors. Using a gas lighter than air to provide lift assist to the drone 2010 is optional but reduces the amount of electrical power required by the rotors / motors to perform these functions described above.

[0066] III. Route Creation in Systems with Orbiting / Non-Orbiting Aerial Nodes

[0067] For reference in the following description of the use of drones according to this specification, Table 1 shows the distance to the horizon (DH) and footprint for orbiting and non-orbiting aerial nodes at different altitudes. To avoid interference with commercial aircraft, drones and balloons must be above about 10 miles and, by FAA regulations, drones can also fly below 400 feet unless in otherwise restricted airspace such as near airports. JPEG2025517954000002.jpg85137

[0068] This table explains the trade-offs involved in the design of communications using only orbiting satellites as system nodes. The distance to the horizon and the corresponding footprint increase as the satellite altitude increases, potentially providing wider coverage with fewer satellites, but the strength of the radio signal between the satellite and the ground surface attenuates as these altitudes increase. Below, a method will be described by which the performance of satellite-based long-distance communications can be improved and services can be provided in local areas without relying on satellites, by combining a constellation of orbiting satellites with a plurality of non-orbiting aerial nodes, particularly drones according to this disclosure.

[0069] A. General Description of Exemplary Satellite Deployment

[0070] FIG. 12 shows various forms in which a constellation of satellites such as those described above can be envisioned for implementing such a system. This drawing is based on a standard Mercator projection of the Earth, showing the equator, the Tropic of Cancer, and the Tropic of Capricorn. FIG. 12 illustrates an exemplary system comprising a plurality of satellites at different altitudes and orbital inclinations that can be used in a multi-level orbiting / non-orbiting node communication system described below with reference to FIG. 14, which includes a layer A of non-orbiting nodes and three layers B, C, and D of satellite nodes orbiting at different altitudes within an orbital track at different inclinations. The orbital track OTB shown by the short dashed line represents a satellite SB deployed in a circular orbit at an altitude of 400 miles from a launch point BC at 45° north latitude. X The second orbital track OTC shown by the long dashed line represents a satellite SC deployed in a circular orbit at an altitude of 1000 miles from a launch point CC at 28° north latitude. X The third orbital track OTD shown by the dotted line represents a satellite SD deployed in a circular orbit at an altitude of 2000 miles from a launch point SD at 13° north latitude. X This means that these are examples of the orbital tracks that the satellites within this system can assume, and for example, a particular layer can include satellites within different orbital tracks.

[0071] Satellites within the orbital tracks are processed so as to appear to an observer on the surface of the earth to be randomly (stochastically) distributed in the air after a predetermined time. By carefully synchronizing the timing of deploying satellites to each orbital track, for example by deploying satellites to a particular orbital track at substantially equal intervals, the length of time required to achieve the probability distribution can be reduced. Although it may be theoretically possible to use a sophisticated algorithm that predicts or at least estimates the position of the satellites as a function of time and thus determines the deployment timing in advance, in this system it is not necessary to predict the positions of the satellites relative to each other. This is because, as a probabilistic system, it depends on the probability of establishing a wireless link between different aerial nodes and between an aerial node and a surface node.

[0072] The probabilistic nature of creating a route through one or more satellites through a constellation of satellites in an unconstrained probabilistic orbit depends on the number of satellites that may be within the line of sight of a given point on the surface of the Earth at any given time. To illustrate the statistical principles underlying such a system, consider a constellation of 100 satellites in an orbital path OTB at an altitude of 400 miles. The satellites cover an area of the Earth between 45 degrees north latitude and 45 degrees south latitude. This is approximately 140,000,000 square miles, or about 70% of the Earth's surface of approximately 200,000,000 square miles. The satellites within this orbital track have a footprint of approximately 10,000,000 square miles (the 400-mile altitude orbit in Table 1), represented by the long dashed line in Figure 4. Thus, each satellite within the orbital track OT4 within its observation width "covers" approximately 7.1% (10,000,000 square meters ÷ 140,000,000 square meters) of the observation width, and as a result, any one point on the surface that is approximately 1,800 miles (DH = 1,830 miles in Table 1) from the outer extent of the orbital path will, on average, "see" at least 7 out of 100 satellites (100 × 0.071). (Similarly, a satellite sees 28 other satellites. See Table 1.) Since establishing communication with statistically distributed satellites is probability-based, the system considers that there is a 92.9% probability that a satellite cannot be seen from any point within its area. However, in a constellation of 100 satellites, the probability that any given surface location within that area cannot see at least one satellite is 0.929 100 ≈ 6.3×10 -4 (i.e., about 1 in 1,600). Surface locations near the northern and southern boundaries of the orbital observer (45 degrees north latitude and 45 degrees south latitude in this example) will see fewer satellites, but the probability of connecting to a ground station at such locations is still sufficient to support the immediate creation of multiple satellite-to-surface wireless links to these ground stations. In addition to this, the system is fully scalable by adding satellites to the constellation to increase the probability of the immediate generation of a wireless link between a satellite and any given ground station.

[0073] An important factor in assembling a multi-satellite wireless route is the number of other satellites that any given satellite can "see". Referring to Table 1, a satellite within any orbital path can theoretically see other satellites on the horizon up to a distance of 2×DH. In the example of the previous paragraph, each satellite in a 400-mile orbit can theoretically "see" approximately 3,660 miles (2×1,830 miles) on the horizon, although interference from surface structures at the horizon may reduce that distance, resulting in a more conservative estimate of 3,500 miles. Thus, the first satellite receiving an initial routing signal from a transmitting ground station can, on average, see a very large number of other satellites within the observation width covered by a constellation (extending between 45 degrees north and 45 degrees south latitude) that can potentially receive the routing message from the first satellite, and the satellites receiving these routing messages can further transmit the routing messages to a large number of other satellites within an observation width up to 3,500 miles away, and so on. The purpose of the satellite constellations, routing protocols, ground station configurations, and system architectures described in this document is to utilize this characteristic for the purposes described. Other important features of the disclosed systems and methods include, but are not limited to, the ability to scale up in complexity by incorporating more satellites and other types of aerial nodes at different altitudes, the ability to adapt to a wide variety of aerial node deployment strategies, and the ability to compensate for the reduction of aerial nodes due to orbital decay, node failures, and hostile actions, among others.

[0074] An important feature of the system is the ability to create wireless links via the routing protocol described in the following subsections and assemble them into optimal routes when ground nodes do not know the positions of air nodes (regardless of whether they are circular or non-circular) and air nodes do not know the positions of other air nodes. Due to this property, the system may not always be able to immediately create a route connecting a specific pair of ground nodes. However, a thoughtful selection of the placement and number of directional antennas on air nodes and ground nodes should result in a 90% success probability of creating a route during a given route creation phase.

[0075] B. Local and Wide Area Routing Systems and Methods

[0076] FIG. 13 is used to illustrate one embodiment of a protocol for creating an optimal wireless route through a system that includes only non-circular air nodes ("local area data transmission") and a system that has multi-level circular / non-circular nodes ("wide area data transmission") that will be further described below with reference to FIG. 14.

[0077] 1. Local Area Data Transmission Using Drones

[0078] In one embodiment, route creation is performed separately for a route that includes only drones ("local area routing") and a route that includes drones and one or more layers of satellites ("wide area routing"). FIG. 13 is a schematic diagram showing a local area routing network with wireless links created to transmit data to a ground node in a system having a plurality of non-circular air nodes such as those shown in FIGS. 1-11. The manner in which the routing protocol is adapted to transmit data via a longer route that includes satellites in a constellation such as that in FIG. 12 is described in the following subsections.

[0079] FIG. 13 uses, as an example, five first - layer nodes 1A, 1B, 1C, 1D, and 1E that have received an initial routing message RMI from a ground - based transmitting node TNA. A typical ground - based node has a plurality of antennas for transmitting the initial routing message in a plurality of directions around the surrounding hemispherical space. In the drawing, the initial routing message is referenced by the reference numeral "RMIX", where "X" is the first - layer node that has received the initial routing message. In an actual system, there may be more nodes that receive the initial routing message. The quality Q of each initial routing message, as determined by the receiving first - layer node, is given in parentheses with each routing message. The quality Q is a quantitative parameter that indicates the desirability of a wireless link between two nodes to support data transmission between nodes, as further explained below. In this system, Q is the measured signal strength. Other implementations are possible where the routing message includes error - encoded data and then the degree to which the routing message contains incorrect data is evaluated. However, the measured signal strength is a preferred parameter because it does not require including additional data in the routing message that would increase the bandwidth, power, and time required for their transmission.

[0080] In a subsequent interval, all of the first - level nodes transmit a first - level routing message with all of these antennas. The first - level routing message includes the terrestrial node address information within the received initial routing message and the quality of the received initial routing message. A node that receives the first - level routing message is called a "second - level node". The drawing shows four second - level nodes 2A, 2B, 2C, and 2E. Consistent with the above terms, the first - level routing message is referenced by the reference numeral "RM1X", where "X" is the second - level node that received the first - level routing message. The routing message received by the second - level node is indicated by a dashed - dotted line. Each second - level node records the identification information of the antenna that received the first - level routing message and determines the quality Q of the received first - level routing message.

[0081] Figure 13 shows the routing protocol in the event that a node such as second - level node 2A receives two first - level routing messages that identify the same terrestrial node. Assume that node 2A receives a first - level routing message RM1A at antenna A X and a first - level routing message RM1B at antenna A Y RM1B has a higher quality (Q = 8) than RM1A (Q = 6), but the route to terrestrial node TNA through node 1B includes link RMIB with quality Q = 1. Applying the principle that "a chain is no stronger than its weakest link", although the sum of the qualities of links RMIB (Q = 8) and RM1B (Q = 1) is higher, since the other possible route to terrestrial node TNA includes link RM1B with the lowest quality (Q = 1), node 2A selects the first - level routing message RM1A (Q = 6) received at antenna A XRemember it. That is, node 2A discards (does not remember) the antenna that received the routing message with the lowest quality (lowest signal strength) among the initial first - layer routing messages, and remembers the identification information of the antennas that received other first - layer routing messages. The remembered Q is called "the highest first - layer quality". Figure 13 shows the sub - route selected by the first - layer node by the thick dashed line indicating the link established via the preferred first - layer routing message RM1A. The possible links that are discarded are shown by the non - thick dashed line. The second - layer node stores the identification information of the selected antenna A X the quality Q (Q = 2) of the lowest - quality routing signal (RMIA) received by the antenna, and the address information of the ground node TNA to which the antenna has a route.

[0082] After that, the second - layer node transmits second - layer routing messages with all of these antennas. The second - layer routing message includes the ground node TNA address information and the lower of the quality Qs of the respective initial and first - layer routing messages that link the first and second - layer nodes and the first - layer node and the ground node TNA. In Figure 13, the second - layer routing message is referred to by the reference numeral "RM2X", where "X" identifies the node (the "third - layer node") that received the second - layer routing message.

[0083] The third - layer node that received the second - layer routing message processes them in the manner shown in Figure 13. As a first example, two of the second - layer routing messages transmitted by node 2A are received by two respective third - layer nodes 3A and 3C. Node 3A receives the second - layer routing message RM2A 1 and node 3C receives the second - layer routing message RM2A 2 Node 3A only receives the second - layer routing message RM2A 1 so it is the routing message RM2A1 Store the identification information of the antenna that has received it, and associate the address information of the ground node TNA with the antenna. The possible links established via the second - layer routing message are indicated by a two - dot chain line, and the selected link is shown thickly.

[0084] Node 3B receives a single second - layer routing message RM2B 1 and thus has only one possible route to the ground node TNA. Node 3C receives three second - layer routing messages (from the second - layer node 2C), namely RM2A 2 , RM2B 2 and RM2C 1 . The routing message RM2A 2 contains the quality (Q = 2) of the initial routing message RM1A as described above. The second - layer routing message RM2B from node 2B 2 contains the quality (Q = 3) of the initial routing message RM1C sent from node 1C to node 2B because it is the lower of the qualities Q of RM1C 1 (Q = 4) and RM1C (Q = 3). The routing message RM2C from node 2C 2 contains the quality (Q = 3) of the initial routing message RM1C from node 1C to satellite 2B because it is the lower of the qualities Q of RM1C 2 (Q = 5) and RM1C (Q = 3). Node 3C determines the respective quality of each received second - layer routing message and the quality of the weaker link to the ground station via the second and first - layer nodes. Thus, comparing with Q = 2 for both the routing messages RM2B 2 and RM1A, since the lowest quality of the link back to the first - layer node via that route is Q = 3 (RM1C), node 3C selects the sub - route passing through node 2C established by RM2C 1 . Node 3C stores the antenna that has received the second - layer routing message RM2C and the address information of the ground node TNA.

[0085] The principle underlying the selection of a preferred wireless sub - route returning from the third - layer node to the transmitting base station can be described in general terms through an understanding of the algorithm used by the node's routing circuit to select a preferred third - layer routing message based on the sub - route. The routing circuit of each third - layer node makes two determinations. The first is to determine the quality of each second - layer routing message received from each second - layer node and match it with the low link quality included in the associated second - layer routing message. RM2A 2 (Q = 7) matches RMIA(Q = 2), RM2B 2 (Q = 2) matches RMIC(Q = 3), RM2C 1 (Q = 5) matched RMIC(Q = 3). The second is to identify a preferred second - layer routing message representing a second sub - route from the third - layer node to the terrestrial node TNA via the first - layer node. This second sub - route comprises a third wireless link between the third - layer node and the second - layer node associated with the preferred second - layer routing message. In this example, the preferred third - layer routing message is RM2C 1 because all of its links have a higher quality than any of the first, second, or third wireless links associated with any other received second - layer routing message, i.e., the links within the sub - route through RM2C 1 , RM1C 2 and RMIC all have a higher quality than the lowest - quality link within any other possible sub - route (Q = 3 for RMIC, Q = 2 for RMIA and RM2B 2 ). The node memory stores the identification information of the antenna from which the preferred third - layer routing message was received and associates it with the terrestrial node address information within the third - layer routing message.

[0086] Next, the third - layer node transmits the third - layer routing message on all of these antennas. The third - layer routing message includes the ground - node address information and the lowest quality Q included in the received second - layer routing message associated with the address of the transmitting ground - node TNA.

[0087] Thereafter, all of the ground nodes in the system analyze all of the routing messages they receive. Figure 13 shows a ground node TNB that has received a first - layer routing message RM1D (Q = 2) from node 1D, a second - layer routing message RM2C 2 (Q = 6) from node 2C, and a third - layer routing message RM3E (Q = 5) from node 3E. Since all of the received third - layer routing messages include link qualities and other possible routes that have link qualities lower than the lowest quality among each of these included link qualities (shown by the thin solid lines in Figure 13), using the same algorithm as the node, the receiving ground node TNB selects the antenna on which it received the routing message RM3E. The ground node TNB stores the identification information of the selected antenna (the antenna on which it received the "highest" quality third - layer routing message RM3E) and associates with it the destination of the transmitting ground - node TNA within the third - layer routing message RM3E. The selected link is shown by the thick solid line in Figure 13. In a system with 50 ground nodes, this routing method can result in up to 2,450 routes that connect all ground nodes to another ground node.

[0088] The route thus established enables the data at the receiving ground node TNB, sometimes called the "originating ground node" with reference to its role as the point where data transmission begins, to reach the transmitting ground node TNA, sometimes called the "destination ground node" as it is the destination of the data. Due to the way the quality parameter Q is measured, the route is automatically the best among ground nodes with respect to signal strength. Route creation does not require the nodes to be in an exact orientation (fixed pitch, roll, and yaw), or at the same altitude or known location. This is because the upper, side, and lower antenna arrays can transmit and receive signals over most of the spherical space surrounding the nodes. This supports the probabilistic nature of the routing process where any one node has a high probability of receiving a wireless signal from other nodes even if it does not know the positions of the other nodes. The routing protocol shown in Figure 13 automatically selects the inter-node links that generate the optimal route. As already described, this structure, along with the unique routing method, makes the drone lightweight, inexpensive, and easy to deploy. As will be described later, the same routing protocol is also applied to route creation that includes satellites within the probabilistic orbit.

[0089] This summarizes how data is transmitted from TNB to TNA after antenna selection is performed according to the routing protocol described above in relation to Figure 13. Route creation phase (Read below) 1. Antenna E1 X RMEI with the TNA address recorded in 2. Antenna E2 X RME1 with the TNA address recorded in 3. Antenna E3 X RME2 with the TNA address recorded in 4. Antenna TNB X RME3 with the TNA address recorded in Data transmission (Read above) 4.E1 XData address to the TNA transmitted 3.E2 X Data address to the TNA transmitted 2.E3 X Data address to the TNA transmitted 1.TNB X Data address to the TNA transmitted

[0090] In one implementation, the route creation / data transmission cycle continues for 4 seconds in a 1-second route creation phase. The aerial nodes within the system move, severing the wireless links between some of them, and a particular route is considered to remain long enough and stable enough for a 3-second data transmission phase before a new route creation phase is required. In a variant, the entire cycle takes 1.0 second, the route creation phase lasts 0.33 second, and the data transmission phase lasts 0.33 second. The remaining time is "silent" and no wireless signals are transmitted by any node. This reduces power requirements, increases battery life, and also makes it more difficult to find and destroy aerial nodes. By introducing pauses between consecutive route creation / data transmission cycles, greater weight reduction can be achieved. For example, if a 20 - 30 second silent time is introduced between consecutive cycles, the power required by the drone (or balloon) can be reduced by an order of magnitude or more in some cases, along with a reduction in weight due to the need for fewer solar panels and batteries. Continuous route creation / data transmission may be estimated to require an oblate ellipsoid drone with a length of 20 - 30 feet along the x-axis and a maximum diameter of 5 - 6 feet. Introducing a 20 - 30 second pause between cycles can allow for a major axis of only 3 - 5 feet with a maximum diameter of 2 - 4 feet due to the resulting reduction in bladder size. For embodiments including a flat ellipsoidal communication capsule, a comparable size reduction would be possible.

[0091] 2. Wide Area Data Transmission Using Drones and Satellites

[0092] The routing protocol described above is used in a modified manner to create routes that include non-orbiting nodes and orbiting satellites within a constellation as shown in FIG. 14. A multi-level system having the following architecture is an example of a system that supports local area and wide area data transmission.

[0093] Referring to FIG. 14, the multi-layer system includes aerial nodes within a hierarchical cohort in the following manner. Layer / Cohort A: Drones and / or balloons below an altitude of 400 feet, or balloons and / or drones at an altitude of 10 - 20 miles. In the embodiments herein, the drones are maintained in a fixed position as described above. Layer / Cohort B: Very Low Earth Orbit (「VLEO」) satellites at an altitude of 200 - 400 miles. These satellites see a decaying orbit due to aerodynamic drag, but retain their usefulness in the system until these orbits decay to an altitude of approximately 100 miles. Layer / Cohort C: Low Earth Orbit (「LEO」) satellites at an altitude of 800 - 1000 miles. Layer / Cohort D: Satellites orbiting above 2,000 miles. In some applications, this example may include geostationary satellites.

[0094] The downward antenna 106 of the drone forms a wireless link with ground nodes within its coverage area, the lateral antenna 104 enables routing and data transmission with other drones, and the upward antenna 102 receives and transmits signals to the next higher level, in this case the Layer B satellite. The drone optimizes this inter-node communication paradigm by distributing the computational load involved in route creation and data transmission, and thus enables the system to handle a very large amount of traffic between ground nodes participating in the system at any given time. As more fully described in the '796 publication and summarized below, route creation and data transmission between ground nodes, between nodes within a given layer, and between nodes in different layers are performed by adaptation of the protocol described with reference to FIG. 12. However, the drone processes route creation and data transmission tasks using separate route creation / data transmission modules 312, 314, and 316 according to the nature of the signals received by the antennas within the arrays with which they are associated. This frees the central processing computer 210 within the drone from most of the computational load involved in the complex routing and data transmission protocols described in the '796 publication.

[0095] This routing approach effectively treats users, nodes, route creation, route usage, and route timing as being within different complex frequency bands, different complex altitude ranges, and different complex geographical areas. Below, using these concepts, a system for providing a practical worldwide system for transmitting data or supporting telephone calls over long distances between terrestrial locations around the world will be described. FIG. 13 shows an exemplary system representative example where aerial nodes generally occupy each of the levels "A", "B", "C", and "D" with four or more or less distinct layers at different altitudes. One feature of this type of system is that while using low-altitude non-circling aerial nodes advantageously equipped with the LTA and / or HTA drones described herein to serve local clusters of surface nodes, for multi-layer communication routes over longer distances, it automatically transitions to satellite nodes at higher altitudes at levels B, C, and D. This exemplary system has four layers of aerial nodes, but can be easily implemented using more or less different numbers of layers. In this regard, the number of layers is partially determined by the expected volume of traffic. The ratio of traffic destined for distant locations to local traffic is also important in determining how many layers to utilize for any given route. The routing protocols described in this document and the '796 publication enable satellite cohorts to easily route between them, as in the exemplary implementation described herein, which describes new decision rules and methods where the node itself determines whether the routing message is directed to a node in a different layer (up or down) or to a node in the same layer. Thus, data transmission can also move within a route that can have links between nodes within the same layer or between nodes in different layers.

[0096] Depending on system requirements or local surface topography, drones may all be at substantially the same altitude, as shown in FIG. 8, or may occupy a range of altitudes. This proximity to the ground has two important advantages. First, it is to enhance the signal strength between the drone and the ground in the manner of a cellular base station to consumer device link. This provides sufficient signal strength to penetrate obstacles such as the top of a car or the roof of a building. It also enables the use of highly focused antennas, which allows different antenna beams to cooperate with different users in close proximity. Techniques such as spread spectrum modulation (i.e., code division multiple access) may also be used to minimize crosstalk between individual users.

[0097] In FIG. 14, type A drones are indicated by the letter "A", followed by a letter representing the local area ("H" for Hawaii, "S" for San Francisco, "N" for New York, "L" for London, England), and a numerical indicator showing it as a particular one of the drones in a particular local area. For example, AH2 and AH42 represent drone numbers 2 and 42 within the local area covering Hawaii, AS26 and AS12 represent drone numbers 26 and 12 within the local area covering San Francisco, AN26 and AN40 represent drone numbers 26 and 40 within the local area covering New York, and AL8 and AL38 represent drone numbers 8 and 38 within the local area covering London. For clarity, FIG. 12 shows only a representative number of drones within each local area.

[0098] In a typical implementation, Type B satellites cover a larger area that enables the creation of routes between drones in different local areas. The satellite requires a downward antenna to find Type A nodes (drones), a lateral antenna to link to other Type B satellites, and an upward antenna to receive and transmit routing messages (and data transmissions) to Type C satellites. The satellites are identified by the letter "S" followed by a layer designation ("B", "C", or "D") and the number of the individual satellite. For example, Figure 13 shows satellites SB101, SB82, SB65, SB71, SB156, SB181, and SB92 from left to right. The system includes a sufficient number of satellites in a probabilistic orbit to provide a sufficient probability that links between different levels of nodes can generate the desired routes within a specific allotted time. A constellation of 200 satellites in Coho rt B is expected to support the multi-level routing protocol described in this document. Type B nodes may also include satellites maintained in a pre-planned fixed orbit.

[0099] Type C satellites orbit at an altitude of 800 - 1000 miles. If the satellites are in an uncontrolled probabilistic orbit, they can be deployed at different altitudes within this range. This satellite cohort is useful for mid-range routing to enable route creation between different Layer B satellites. They require a horizontal antenna for routing with other Layer C satellites, an upward antenna to connect to higher-orbit Type D satellites, and a downward antenna to connect to Type B satellites. A constellation of 50 satellites in Cohort C is expected to support the routing protocol described here. The naming convention described above is also used for Layer C satellites, along with satellites SC45, SC26, SC32, SC12, and SC6, which represent five of the satellites in this cohort.

[0100] Type D satellites are limited in number and are useful for creating links between C layer satellites to support long-distance communications such as intercontinental data transmission. Satellites in equidistant polar orbits that form a grid on the Earth's surface, like certain satellite designs currently in mass production, may also be valuable. Most systems require a limited number of Type D satellites, and these designs are preferably determined by the expected traffic load. These require horizontal and downward antennas. The distance between these may be large, but due to their height above the Earth, they will have a very long line of sight across the horizon presented by the Earth's curvature. It is expected that about 10 satellites within cohort D will be sufficient to support this multi-level protocol. Figure 14 shows three of the satellites, SD9, SD2, and SD5.

[0101] To create a route from one specific ground node to another, a postal code paradigm is adopted that uses a five-digit "zone designation" {x1,x2,x3,x4,x5} to identify the zones or areas served by different ground node cohorts. When a routing message is directed to a D layer satellite according to the routing protocol described in this document, the first digit designates the wide area region used in the routing protocol. (This is approximately the same as the regions of the United States identified by the first digit of the postal code.) The following are examples of wide area regions covering the Earth designated by the digit x1. x1 = 1: From Europe including the UK to 60° West longitude (excluding India). x1 = 2: Eastern Eurasia, China, the Pacific Ocean north of the equator. x = 3: North America and the Atlantic Ocean north of the equator. x1 = 4, 5, 6: A roughly equal-area region from the northern tropics to approximately 30° North latitude, including Mexico, northern Africa, India, and Southeast Asia. x1 = 7, 8, 9: A roughly equal-area region including South America, the Atlantic Ocean south of the equator, sub-Saharan Africa, the Indian Ocean, and the Pacific Ocean south of the equator.

[0102] The next digit x2 represents a sub-region within each wide area region participating in the routing protocol. The sub-region is associated with a C-layer satellite, which allows for a maximum of 10 sub-regions (x2 = 0 to 9) for each wide area region. The next digit x3 represents an extended local region within each sub-region. The extended local area is associated with a B-level satellite, which allows for 10 extended local area regions (x3 = 0 to 9) within each sub-region. The last two digits (x4, x5) specify individual drones within the local area, thus allowing for the use of a maximum of 100 drones (x4, x5 = 00 to 99) within the local area. The drones and satellites each store a lookup table with longitude and latitude boundaries for the wide area region, sub-region, and extended local region. Similar to the drones, the satellites also include a GNSS circuit indicating the longitude and latitude of the satellite at any given time, whereby the airship or satellite determines its position as represented by a three-digit zone designation.

[0103] Route creation involving drones and satellites within one or more of Layers B, C, and D involves populating a lookup table with the identification information of the antennas of each airship and satellite for use in transmitting wireless signals to nodes at adjacent levels. That is, each drone stores the identification information of the antenna that provides the best composite quality link to a satellite within Layer B via adaptation of the routing protocol described above with reference to FIG. 13. Conversely, Layer B stores the identification information of its own antenna associated with that link. Similarly, the satellites within Layers C and D also know the antennas associated with the best quality links between each of them within both layers. Thus, each of Layers A, B, and C knows the antenna to be used to transmit data to an adjacent layer. During the route creation period, for example, if the drones in the occupied area are not within the line of sight of the Level B satellites within the local area region, such as within a remote area or an island, a route to the satellite is created directly from any terrestrial node within that area in a manner similar to the method described above for creating a link between the drone and the Level B satellite. The '796 publication describes in more detail in paragraphs 0170 - 0183 the route creation protocol used to create inter-layer links.

[0104] 3. Examples of Local and Wide Area Routes

[0105] FIG. 14 shows some examples of high-capacity local, medium-range, and long-range routes for data transmission that can be quickly created by using drones in a four-tier satellite / drone system. FIG. 14 shows all the drones at the same 10-mile altitude as shown in the drawing. For ease of reference, the satellite altitude and the distance to the horizon ("DTH") are also shown in FIG. 14. For clarity of explanation, the links from the drones within the wide area route to the terrestrial surface nodes are omitted from FIG. 14. 1. Local Area Route within New York City (dash-dotted line) 2-Hop Route - TN29 ⇔ AN26 ⇔ TN49 ("Curved Pipe")[[]] 3-hop route - TN8 ⇔ AN16 ⇔ AN24 ⇔ TN29 2. Wide area route using only Layer B satellites (dashed line circle) Between Hawaii and San Francisco - AH42 ⇔ SB82 ⇔ AS12 Between San Francisco and New York - AS43 ⇔ SB65 ⇔ SB71 ⇔ AN12 3. Wide area route using Layer B and Layer C satellites (double dashed line) Between San Francisco and London - AS43 ⇔ SB65 ⇔ SC32 ⇔ SC12 ⇔ SB92 ⇔ AL6 4. Wide area route using Layer B, Layer C and Layer D satellites (triple dashed line) Between Hawaii and London - AH42 ⇔ SB101 ⇔ SC26 ⇔ SD2 ⇔ SC12 ⇔ SB92 ⇔ AL38 The routes shown in the figure are only examples. Also, routes can be created directly between satellites in non - consecutive layers (e.g., between Layer B and Layer D satellites), or directly between a drone and a satellite in any of Layers B, C, and D.

[0106] IV. Operational uses of the disclosed non - orbiting aerial nodes

[0107] The above embodiments and principles support a wide variety of uses of the non-orbiting aerial nodes that are the subject of this disclosure. The structure and their operations of the non-orbiting aerial nodes can be adjusted to achieve the goals of a particular system. In some systems, the non-orbiting aerial nodes can be balloons as shown in FIGS. 1-11, or a combination of one or more of balloons and drones, or variations thereof. In one embodiment, the balloon node comprises the balloon itself and an operation capsule that has the same function as drone 10 but without a gas bladder GB and is suspended by a wire from the balloon. The balloon embodiment is operable using the MSA control module 216. The operation capsule can also be a flat elliptical communication capsule 1030 having a similar array of antennas, solar panels, and batteries. The balloon node can be deployed at an altitude of 1 to 10 miles. In other embodiments, the balloon node can be moored to the ground surface at a lower height, for example 400 feet, for a stronger link with ground surface users.

[0108] The actual physical size of the antenna depends on how much power is required and the amount of solar power generation required. Furthermore, the number of downward, lateral, and upward antennas on the drone can vary according to different traffic requirements. Separate control of each antenna array by the upper antenna route creation / data transmission circuit 312, the side antenna route creation / data transmission circuit 314, and the lower antenna route creation / data transmission circuit 316 enables a particular system to use different frequencies to create upward links, lateral links, and downward links. This also enables each of the respective arrays 102, 104, and 106 to have antennas of different sizes. In a system where the ground node has more power, the lower antenna array may have less stringent operating requirements. Conversely, in certain locations such as a military theater, the antennas in the lower array must connect to weaker signals from combat troops and may therefore require antennas designed for that purpose and / or a lower array with more antennas. In a system designed to monitor a worldwide oil platform, the downward antenna preferably can pick up signals from multiple oil platforms over a wide area. In a system designed to provide coverage to users on remote islands or a small city in the middle of the desert, all of the users are located in a relatively small area and the antennas are designed accordingly and can be placed on the drone.

[0109] By using different frequencies for different antenna arrays, it is also possible to adapt the drone (or balloon) to a myriad of specific applications. For example, by using different frequencies for the side-facing antenna and the downward-facing antenna, more efficient use of the bandwidth becomes possible. In one application, the side-facing antenna can use a dedicated first frequency band to create a wireless link between drones, and the downward-facing antenna can use a different second frequency band that has already been assigned to local police or fire departments. This can be particularly advantageous during forest fires in remote areas where reliable communication among firefighters is crucial. A variation of this configuration can enhance communication in a combat theater where infantry and tanks need to exchange information in real time. The first frequency band is dedicated to the wireless link between drones, and a selected number of downward-facing antennas use a part of a different second frequency band for the wireless link with tanks, and the remaining downward-facing antennas use a different part of the second frequency band for the wireless link with infantry. By arranging the antennas within the downward array 106, those using the first and second frequencies can be spread along the lower part of the drone. For example, the first frequency band portion can use the lower array antennas 106a and 106c and the antennas 106a and 106c (and their corresponding lateral right offset counterparts), and the second frequency band portion can use the remaining lower array antennas. In a system that includes satellites, the upward-facing antenna can use a third frequency band that is different from the first and second frequency bands.

[0110] The disclosed drones (and balloons) can also be used in cellular phone communication in remote areas without an available base station. The routes created as described above can be used to send cellular phone calls in a manner directly similar to how data is transmitted through the multi-level system shown in FIG. 14. The destination phone number in a particular call can perform the same function as the destination address in data transmission for the aforementioned zip code paradigm. A cellular phone provider can allocate a small percentage (e.g., 10%) of the government-assigned frequency bands to the routing method in this disclosure to provide service in areas where a user's device cannot connect to a base station, enabling implementation of such a system without interrupting normal phone service.

[0111] Other drone / balloon embodiments can include more or fewer sets of antennas that are controlled independently or otherwise. In some systems, downward and lateral antennas can be controlled by the same route creation / data transmission circuit in situations where the expected local traffic is low. This reduces drone costs while still allowing it to appropriately handle local traffic. In another variation, for applications where antennas within a single array use different frequencies, separate route creation / data transmission circuits dedicated to the antenna array can use different microprocessors to control the antennas in different arrays.

[0112] V. Summary and Conclusion

[0113] The drones described in this book provide a powerful way to implement the multi-tier drone / satellite system described in FIG. 14, which can enable both local area and long-distance worldwide wireless communication in one integrated system. Many previous proposals for wireless-capable drones used large solar-powered, heavier-than-air aircraft. Such known drones are very expensive and would require extensive modification to function as drones in a multi-level system such as those described in this book and in the '796 publication. In fact, many of the hardware and software features of the drones described here, as well as the ways to control them, create wireless routes between them, and use orbiting satellites, would have been beyond the understanding of those skilled in the art. The drones described in this book are relatively inexpensive, making it cheaper to manufacture them in sufficient numbers to support a communication system such as those described in this book, and also cheaper to replace them if they are damaged or malfunction during operation. Even without replacement, the routing algorithms described above will automatically recreate routes through the system without the lost drone during the next route creation cycle.

[0114] Those skilled in the art will readily recognize that many other variations of the embodiments selected to illustrate many of the structures and methods, including the disclosed subject matter, are possible. This entire disclosure describes the basic principles and operational characteristics of the systems, methods, and apparatuses that form the subject matter and is presented to enable those skilled in the art to implement them. It is in no way limiting with respect to other embodiments and implementations within its spirit and scope.

Claims

1. A lighter-than-air (LTA) non-circulating aerial node for deployment in a wireless communication system, the wireless communication system comprising at least one ground node and a plurality of the LTA non-circulating aerial nodes capable of providing a radio route including at least one of the LTA non-circulating aerial nodes, wherein the LTA non-circulating aerial node is a rigid casing, An antenna structure for transmitting and receiving wireless signals in multiple directions, Route creation circuit for determining a quality associated with a routing message received from at least one of a ground node and another non-circulating aerial node, which indicates suitability for including the LTA non-circulating aerial node and the ground node or (ii) the LTA non-circulating aerial node and the other non-circulating aerial node as a link in the radio route, the route creation circuit including a memory for storing antenna identification information associated with the received routing message, A data transmission circuit for transmitting data from the LTA non-orbiting aerial node to the ground node or another non-orbiting aerial node using the antenna in which the identification information is stored in the memory, A battery for supplying power to the route creation circuit and the data transmission circuit, An LTA non-circulating aerial node comprising a rigid casing containing a gas lighter than air for providing an upward force to the LTA non-circulating aerial node.

2. An LTA non-orbiting aerial node according to claim 1, wherein the antenna structure includes a plurality of directional antennas oriented generally parallel and horizontal with respect to the Earth's surface in a plurality of directions within the space around the casing for transmitting radio signals to and receiving radio signals from other non-orbiting aerial nodes when the LTA non-orbiting aerial node is deployed in the radio communication system.

3. An LTA non-orbiting aerial node according to claim 2, wherein the antenna structure includes a plurality of directional antennas directed generally toward the surface of the Earth in order to transmit radio signals to a plurality of ground nodes and to receive radio signals from a plurality of ground nodes when the LTA non-orbiting aerial node is deployed in the wireless communication system.

4. An LTA non-orbiting aerial node according to claim 3 for use in a radio communication system further comprising multiple orbiting satellites, wherein the antenna structure includes a plurality of directional antennas directed generally upward away from the Earth's surface to transmit radio signals to and receive radio signals from the satellites when the LTA non-orbiting aerial node is deployed in the radio communication system.

5. An LTA non-orbiting aerial node according to claim 4, wherein the directional antenna includes a parabolic antenna.

6. An LTA non-circulating aerial node according to claim 1, The casing has the shape of an elongated ellipsoid having an x-axis along its principal axis and a z-axis that, together with the x-axis, defines an xz plane oriented parallel to the Earth's surface when the LTA non-orbiting aerial node is deployed in the wireless communication system. The casing includes a bladder for containing a gas lighter than air, and is an LTA non-circulating aerial node.

7. An LTA non-circulating aerial node according to claim 1, wherein the quality includes the signal strength of the received routing message as measured by the route creation circuit.

8. An LTA non-circulating aerial node according to claim 1, wherein the battery is rechargeable, and the casing further includes a guidance and propulsion system powered by the rechargeable battery for controlling the position and orientation of the LTA non-circulating aerial node and a solar panel for recharging the battery.

9. A lighter-than-air (LTA) non-circulating aerial node for use in a wireless communication system, the wireless communication system comprising at least one ground node and a plurality of the LTA non-circulating aerial nodes capable of providing a radio route including at least one of the LTA non-circulating aerial nodes, wherein the LTA non-circulating aerial node comprises a rigid casing and a communication capsule suspended from the rigid casing. The communication capsule is (a) An antenna structure for transmitting and receiving radio signals in multiple directions, (b) A route creation circuit for determining a quality associated with a routing message received from at least one of a ground node and another non-circulating aerial node, which indicates suitability for including the LTA non-circulating aerial node and the ground node or (ii) the LTA non-circulating aerial node and the other non-circulating aerial node as a link in the radio route, the route creation circuit including a memory for storing antenna identification information associated with the received routing message, (c) A data transmission circuit for transmitting data from the LTA non-orbiting aerial node to the ground node or the other non-orbiting aerial node using the antenna in which the identification information is stored in the memory, The aforementioned casing is (a) A guidance and propulsion system for controlling the position and direction of the LTA non-circulating aerial node and a battery for supplying power to the guidance and propulsion system, the route creation circuit and the data transmission circuit, (b) An LTA non-circulating aerial node comprising a gas lighter than air for providing an upward force to the LTA non-circulating aerial node.

10. An LTA non-circulating aerial node according to claim 9, The battery is rechargeable, and the casing includes a solar panel for recharging the battery and a bladder for containing a gas lighter than air. The casing has the shape of an elongated ellipsoid having an x-axis along its principal axis and a z-axis that, together with the x-axis, defines an xz plane oriented parallel to the Earth's surface when the LTA non-orbiting aerial node is deployed in the wireless communication system. The communication capsule is an LTA non-circulating aerial node, having the shape of a flattened ellipsoid attached to the casing for rotation around an axis perpendicular to the xz plane.

11. A lighter-than-air (LTA) non-circulating aerial node for use in a wireless communication system, the wireless communication system comprising at least one ground node and a plurality of the LTA non-circulating aerial nodes capable of providing a radio route including at least one of the LTA non-circulating aerial nodes, wherein the LTA non-circulating aerial node comprises a balloon for holding the LTA non-circulating aerial node against gravity and a communication capsule suspended from the balloon, the communication capsule is An antenna structure for transmitting and receiving wireless signals in multiple directions, Route creation circuit for determining a quality associated with a routing message received from at least one of a ground node and another non-circulating aerial node, which indicates suitability for including the LTA non-circulating aerial node and the ground node or (ii) the LTA non-circulating aerial node and the other non-circulating aerial node as a link in the radio route, the route creation circuit including a memory for storing antenna identification information associated with the received routing message, A data transmission circuit for transmitting data from the LTA non-orbiting aerial node to the ground node or another non-orbiting aerial node using the antenna in which the identification information is stored in the memory, An LTA non-circulating aerial node, including a battery for supplying power to the route creation circuit and the data transmission circuit.

12. The LTA non-circulating aerial node according to claim 11, wherein the antenna structure is When the LTA non-orbiting aerial node is deployed in the wireless communication system, a plurality of directional antennas are provided to be oriented generally parallel and horizontal to the Earth's surface in multiple directions within the space around the casing in order to transmit radio signals to other non-orbiting aerial nodes and to receive radio signals from other non-orbiting aerial nodes, An LTA non-orbiting aerial node, when deployed in the wireless communication system, includes a plurality of directional antennas generally pointed toward the Earth's surface for transmitting radio signals to a plurality of ground nodes and receiving radio signals from a plurality of ground nodes.

13. An LTA non-orbiting aerial node according to claim 12 for use in a radio communication system further comprising a plurality of orbiting satellites, wherein the antenna structure includes a plurality of directional antennas directed generally upward away from the Earth's surface for transmitting radio signals to and receiving radio signals from the satellites when the LTA non-orbiting aerial node is deployed in the radio communication system.

14. An LTA non-circulating aerial node according to claim 12, The communication capsule has the shape of a flattened ellipsoid with a substantially circular cross-section oriented parallel to the Earth's surface when the LTA non-orbiting aerial node is deployed in the wireless communication system. The battery is rechargeable, and the casing includes a solar panel for recharging the battery, in the LTA non-orbiting aerial node.

15. An LTA non-circulating aerial node according to claim 12, wherein the communication capsule further includes a battery-powered guidance and propulsion system for controlling the position and orientation of the LTA non-circulating aerial node.

16. A heavier than air (HTA) non-circulating aerial node for use in a wireless communication system, the wireless communication system comprising at least one ground node and a plurality of the HTA non-circulating aerial nodes capable of providing a radio route including at least one of the HTA non-circulating aerial nodes, the HTA non-circulating aerial node comprising a rotorcraft and a communication capsule suspended from the rotorcraft, The communication capsule is (a) An antenna structure for transmitting and receiving radio signals in multiple directions, (b) A route creation circuit for determining a quality associated with a routing message received from at least one of a ground node and another non-circulating aerial node, which indicates suitability for including the HTA non-circulating aerial node and the ground node or (ii) the HTA non-circulating aerial node and the other non-circulating aerial node as a link in the radio route, the route creation circuit including a memory for storing antenna identification information associated with the received routing message, (c) A data transmission circuit for transmitting data from the HTA non-orbiting aerial node to the ground node or the other non-orbiting aerial node using the antenna in which the identification information is stored in the memory, The aforementioned rotary-wing aircraft is (a) A guidance and propulsion system for controlling the position and orientation of the HTA non-circulating aerial node and a battery for supplying power to the guidance and propulsion system, the route creation circuit and the data transmission circuit, (b) an HTA non-circulating aerial node comprising a gas lighter than air for providing an upward force to the HTA non-circulating aerial node.

17. An HTA non-circulating aerial node according to claim 16, The aforementioned communication capsule has the shape of a flattened ellipsoid and is attached to the rotorcraft for rotation. The battery is rechargeable, and the rotary-wing aircraft includes a solar panel for recharging the battery. The rotary-wing aircraft is an HTA non-orbiting aerial node, which is constructed such that the rotation axis of the flattened ellipsoid operates substantially perpendicular to the Earth's surface when the HTA non-orbiting aerial node is deployed to the radio communication system.

18. A non-circulating aerial node for use in a wireless communication system, wherein the wireless communication system comprises at least one ground node and a plurality of the non-circulating aerial nodes capable of providing a wireless route including at least one of the non-circulating aerial nodes, the non-circulating aerial node is An antenna structure for transmitting and receiving radio signals in multiple directions, the antenna structure comprising: a plurality of directional antennas generally parallel and horizontal to the Earth's surface in multiple directions in the space around the non-orbiting aerial node for transmitting radio signals to and receiving radio signals from other non-orbiting aerial nodes in a first frequency band; and a plurality of directional antennas generally directed toward the Earth's surface for transmitting radio signals to and receiving radio signals from multiple ground nodes in a second frequency band different from the first frequency band; Route creation circuit for determining a quality associated with a routing message received from at least one of a ground node and another non-circulating aerial node, which indicates suitability for including the non-circulating aerial node and the other non-circulating aerial node or (ii) the non-circulating aerial node and the ground node as a link in the radio route, the route creation circuit including a memory for storing antenna identification information associated with the received routing message, A non-orbiting aerial node comprising: a data transmission circuit for transmitting data from the non-orbiting aerial node to the ground node or the other non-orbiting aerial node using the antenna in which the identification information is stored in the memory.

19. A non-orbiting aerial node according to claim 18, comprising a lighter-than-air (LTA) aerial node, wherein the LTA aerial node has a rigid casing including the antenna structure, the route creation circuit, the data transmission circuit, a rechargeable battery for supplying power to the route creation circuit and the data transmission circuit, a solar panel for recharging the battery, and a bladder for housing a lighter-than-air gas to provide an upward force to the LTA aerial node.

20. A non-circulating aerial node according to claim 18, comprising a lighter-than-air (LTA) aerial node having a rigid casing and a communication capsule suspended from the rigid casing, The communication capsule includes the antenna structure, the route creation circuit, and the data transmission circuit. A non-orbiting aerial node, the casing comprising a guidance and propulsion system for controlling the position and orientation of the LTA aerial node; a rechargeable battery for supplying power to the guidance and propulsion system, the route creation circuit and the data transmission circuit; a solar panel for recharging the battery; and a bladder for containing a gas lighter than air to provide lift to the LTA aerial node.

21. A non-circulating aerial node according to claim 19, comprising a heavier than air (HTA) node having a rotary-wing aircraft and a communication capsule suspended from the rotary-wing aircraft, The communication capsule includes the antenna structure, the route creation circuit, and the data transmission circuit. The rotary-wing aircraft is a non-orbiting aerial node, comprising a guidance and propulsion system for controlling the position and orientation of the HTA node, a rechargeable battery for powering the guidance and propulsion system, the route creation circuit and the data transmission circuit, a solar panel for recharging the battery, and a bladder for containing a gas lighter than air to provide lift to the HTA node.

22. A wireless communication system comprising: a plurality of ground nodes, each having a ground node antenna structure for transmitting and receiving radio signals in a plurality of directions around a surrounding hemispherical space; and a plurality of non-circulating aerial nodes, each of which provides a radio route between at least two of the ground nodes via at least one of the non-circulating aerial nodes, wherein each of the plurality of non-circulating aerial nodes includes an aerial node antenna structure, the aerial node antenna structure is To enable the creation of one or more links in the radio route between the non-orbiting aerial nodes, a plurality of directional antennas, which are generally parallel and horizontal with respect to the Earth's surface in multiple directions in the space around the non-orbiting aerial node, for transmitting radio signals to and receiving radio signals from other non-orbiting aerial nodes in a first frequency band, A wireless communication system including a plurality of directional antennas generally oriented toward the Earth's surface for transmitting radio signals to a plurality of ground nodes and receiving radio signals from a plurality of ground nodes in a second frequency band different from the first frequency band, in order to enable the creation of one or more links in the radio route between the ground nodes and the non-orbiting aerial nodes.

23. A wireless communication system according to claim 22, wherein the non-orbiting aerial node is located in a probability-distributed orbit.

24. A wireless communication system according to claim 22, wherein the directional antenna includes a parabolic antenna.

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