Patent Application
20240333399
This application claims the benefit of European Patent Application Number 23165737.0 filed on Mar. 30, 2023, the entire disclosure of which is incorporated herein by way of reference.
The present invention relates to an optical detector, an optical receiver and a corresponding method for quantum communication.
In order to establish long-distance secure communication links, it is expected that in the near future, an important application of quantum communication will be free-space quantum key distribution (QKD) over an air-ground link or a space-ground QKD link.
In these channels, atmospheric turbulences distort the wavefront of optical beams including those used for quantum communication. Since it is not possible to amplify quantum signals, a setup for free-space QKD receiver requires a large telescope for receiving the signal. However, when the diameter of the telescope becomes larger than the coherence length of the wavefront, the so-called Fried parameter, the telescope cannot efficiently focus the received light. Therefore, distortions of the wavefront of a QKD link are even more severe than for a classical communication link, leading to a spatial multi-mode signal at the receiver.
The most sensitive photon detectors, such as a superconducting nanowire single photon detector (SNSPD), however, require spatial single-mode input, preferably delivered by a single-mode fiber or another single-mode waveguide. Furthermore, such detectors require cryogenic temperatures of a few K, which makes it difficult to use phase shifters based on a thermo-electric effect for coupling the multi-mode signal into the single-mode fiber or the detector. Furthermore, typically such a cryogenic detector is not placed in the same chamber or box together with detector optics, since the design of photonic circuitry compatible with temperatures of a few K is too complicated.
There is a need for a quantum optical receiver and detector with improved detection sensitivity.
According to the invention, this problem may be solved by the subject matter of one or more embodiments described herein.
According to a first aspect of the invention, an optical detector for quantum communication is provided. The optical detector comprises a photonic lantern comprising a multi-mode input port configured to receive a spatial multi-mode input signal, and a plurality of single-mode output ports connected to the multi-mode input port by respective light channels, wherein the photonic lantern is configured to split the spatial multi-mode input signal by guiding the spatial multi-mode input signal in the individual light channels into a plurality of mutually orthogonal spatial single-mode output signals and output the plurality of single-mode output signals through the single-mode output ports; a coherent beam combiner configured to coherently combine the plurality of single-mode output signals to form a single-mode combined output signal; and a photodetector assembly comprising one or more single photon counters and arranged and configured to detect the combined output signal to provide a detection signal.
According to a second aspect of the invention, an optical receiver for quantum communication is provided. The optical receiver comprises the inventive optical detector and a telescope configured to guide the multi-mode input signal into a multi-mode waveguide coupled to the multi-mode input port of the optical detector.
According to a third aspect of the invention, a method for quantum communication is provided. The method comprises receiving a multi-mode input signal by a multi-mode input port of a photonic lantern; guiding the multi-mode input signal in a plurality of light channels to respective single-mode output ports of the photonic lantern, thereby splitting the multi-mode input signal to mutually orthogonal single-mode output signals; coherently combining the plurality of single-mode output signals to form a single-mode combined output signal, receiving the combined output signal by a photodetector assembly comprising one or more single photon counters to provide a detection signal.
A fundamental concept of the invention is to provide a multi-mode interface of the optical detector and couple the entire multi-mode input signal into the optical detector before combining the multiple modes into a single-mode combined output signal that is suitable for the photodetector. To achieve this, the invention proposes a photonic lantern, which is used to split the multi-mode input signal into separate single-mode signals that are subsequently coherently combined into the combined output signal. This single-mode combined output signal is suitable for the photoreceiver to achieve a strong electrical detection signal.
A particular advantage of the solution according to an aspect of the invention is that the optical detector has a multi-mode interface. In this way, it is easier to couple the multi-mode input signal into the optical detector and finally achieve a strong detection signal compared to a single-mode fiber interface that attempts to couple the multi-mode input signal directly into a single-mode waveguide. Having experienced atmospheric distortions, such a multi-mode input signal rapidly changes its mode pattern and wavefront due to dynamic atmospheric turbulences. Their dynamics are dependent on the velocity of the wind in the optical channel between the optical transmitter emitting the quantum communication signal and the optical receiver including the optical detector. In the case of receiving quantum communication signals from a satellite, wind velocities in the upper atmosphere, e.g. due to the Jetstream, are very high leading to a rapid mode pattern variation.
The photonic lantern is a component commonly known in the field of optics. The photonic lantern as understood with regard to the present invention is compatible with the common use of the term in the field of optics. It is configured to split a spatial multi-mode signal or beam into a plurality of mutually orthogonal spatial single-mode signals or beams propagating in light channels within the photonic lantern. One example implementation could be on the base of step-index fibers or waveguides providing higher order LPXY-modes that would be separated by spatially separated light channels to a plurality of single-modes, i.e. LP01-modes. In principal, other than LP-optical modes could be implemented, e.g. Gaussian modes, such as a TEMxy-modes. Also other types of waveguide such gradual index waveguides can be used. The photonic lantern can also be implemented by a multi-mode waveguide having a gradual transition to a multi-core waveguide including single-mode cores.
As within this application, the optical detector and the optical receiver are intended to be used for quantum communication using a photon stream including QKD encoded pulses. A QKD encoded pulse is a pulse intended and suitable for quantum communication, typically containing on average less than one photon and carrying information in the form of a quantum state. Classically, such a quantum state may be polarization. In the most common BB84 scheme, polarization states of 0°, 90°, +45° and −45° are used. However, other quantum states such as e.g. the orbital angular momentum, the E91 scheme or decoy states may be applied to the QKD encoded pulses within this invention.
Advantageous embodiments and further developments emerge from the description with reference to the figures.
According to some further aspects of the optical detector according to the invention, the photonic lantern comprises a multi-mode waveguide portion comprising the multi-mode input port and supporting the spatial multi-mode input signal. The a multi-mode waveguide portion thus guides the multi-mode input signal right after coupling into the multi-mode input port. The photonic lantern further comprises a plurality of single-mode waveguide portions, each having one of the plurality of single-mode output ports and supporting the single-mode output signals. The photonic lantern further comprises an intermediate portion arranged between the multi-mode waveguide portion and the plurality of single-mode waveguide portions and configured to gradually split the multi-mode input signal into the plurality of single-mode output signals. The intermediate portion is thus a transition portion in where the multi-mode input signal gradually divides into the mutually orthogonal single-mode output signals. The intermediate portion might also be configured as a waveguide. The light channels are provided through all the three portions. The single-mode waveguide portions thus guide the signal modes split in the intermediate section as single-mode beams. The dimension of the waveguide's core thus depends on the selected wavelength, e.g., 1550 nm, and further parameters, such as e.g. the numerical aperture (NA) of the waveguide.
According to some further aspects of the optical detector according to the invention, the photonic lantern further comprises an adapter portion arranged between the intermediate portion and the single-mode waveguide portion and configured to arrange the light channels of the intermediate waveguide portion according to an arrangement of the single-mode waveguide portions. Such an adapter is necessary e.g., if the multi-mode portion and intermediate portion are formed as a three-dimensional fiber bundle, however, the single-mode output ports of the single-mode waveguide portion are arranged array-like in a plane. Implemented on a chip, an adapter could comprise a three-dimensional waveguide arrangement in order to provide e.g., a plane single-mode waveguide portion. Furthermore, the adapter portion provides a matching function for efficient optical coupling between different photonic integrated platforms. The adapter thus increases the flexibility of the design of the single-mode waveguide portions.
According to some further aspects of the optical detector according to the invention, the photonic lantern is configured to split the spatial multi-mode input signal of a wavelength of about (i.e., +/−10%, or 5%, or 1%, or <1%) 1550 nm into the plurality of mutually orthogonal spatial single-mode output signals. This wavelength is a preferred wavelength since it would be compatible with the widely used terrestrial photonics fiber network, e.g., in undersea cables etc.
According to some further aspects of the optical detector according to the invention, the coherent combiner comprises combiner optics configured to combine the plurality of single-mode output signals exiting the single-mode output ports to a single-mode combined output signal. Such a single-mode combined output signal is easier to apply to a photon counter and can provide a stronger signal. The coherent combiner further comprises a plurality of phase shifters each configured to shift a phase of a respective one of the plurality of single-mode output signals. The phase shifters enable the coherent combination of the single-mode output signals. Furthermore, a control circuit is provided and configured to control the phase shift of each of the phase shifters based on the detection signal provided by the one or more single photon counters. In this way, phase changes of the multi-mode input signal can be quickly adapted so that a stable single-mode combined output signal is achieved.
According to some further aspects of the optical detector according to the invention, the combiner optics are configured as waveguide optics comprising at least one waveguide combiner. Each of the single-mode output ports thus is connected to a respective single-mode waveguide. In this way, the detector is relatively robust against vibrations or mechanical shocks. Furthermore, it provides a small compact optical detector.
According to some further aspects of the optical detector according to the invention, the phase shifters are configured as optomechanical phase shifters. These phase shifters can be implemented to optical waveguides e.g. on-chip optical waveguides. They thus result in a compact and robust optical detector.
According to some further aspects of the optical detector according to the invention, the coherent combiner comprises: a wavefront phase shifter arranged upstream the multi-mode input port, and a wavefront control circuit connected to the one or more single photon counters and the wavefront phase shifter and configured to control the wavefront phase shifter based on the detection signal. The wavefront phase shifter can be implemented as a tunable phase plate or a deformable mirror or any other suitable device. In this way, the setup is facilitated since no individual phase shifters for each light channel are used to adapt the phase of the plurality of single-mode output signals for coherent combining.
According to some further aspects of the optical detector according to the invention, the optical detector further comprises a reference light channel configured to receive a reference quantum signal. The photodetector assembly comprises a reference input port configured to receive the reference quantum signal and combine the reference quantum signal with the combined output signal. In this way, a CV-QKD detector can be implemented without requiring a local oscillator and modulator that is typically used in homodyne CV-QKD detectors. This significantly facilitates the setup of the photodetector assembly.
According to some further aspects of the optical detector according to the invention, at least one of the one or more single photons counter is a superconductive nanowire photon counter (SNSPD). Such a photodetector provides higher sensitivity than for example typical avalanche photodiodes (APDs), in particular in the infrared spectral range, e.g., around a wavelength of 1550 nm.
According to some further aspects of the optical detector according to the invention, the optical detector further comprises a cryogenic chamber comprising the photon assembly and having a temperature of less than 100 K. The temperature of the cryogenic chamber may also be considerably less than 100 K, such as e.g. less than 15 K, 5 K, 4 K or 1 K. In particular, the temperature is below the temperature of liquid Helium, i.e., below about 4.15 K, in order to form a He cryostat. Such a cryogenic chamber allows the use of particular photodetectors, such as the superconductive nanowire photon counter (SNSPD), which provides higher sensitivity than for example typical avalanche photodiodes (APDs), in particular in the infrared spectral range, e.g., around a wavelength of 1550 nm.
According to some further aspects of the optical detector according to the invention, the detector assembly is provided on a photonic chip. Furthermore, the photonic lantern may also be provided on the same photonic chip. In consequence, all kind of possible combiner optics such as waveguide combiners is provided on the same photonic chip. This results in a small, compact and robust optical detector.
According to some further aspects of the optical detector according to the invention, the photonic chip is arranged in the cryogenic chamber. This represents a particularly compact solution for the optical detector, that could be placed in a small He cryostat. In this way, the optical detector also provides superior sensitivity for detecting a quantum communication signal after experiencing wavefront distortions through the atmosphere.
According to some further aspects of the optical receiver according to the invention, the receiver further comprises a pointing system configured to couple the multi-mode input signal into the multi-mode fiber based on the detection signal. A pointing system in combination with a multi-mode fiber is a suitable approach to receive the optical communication signal as a multi-mode input signal.
The above aspects can be combined with each other as desired, if useful. In particular, where appropriate, all features of the optical detector and the optical receiver are transferable to the method for quantum communication, and vice versa. Further possible embodiments, further developments and implementations of the invention also comprise combinations, not explicitly mentioned, of features of the invention described before or below with respect to the embodiments. In particular, the skilled person will thereby also add individual aspects as improvements or additions to the respective basic form of the present invention.
The present invention is explained in more detail below with reference to the embodiments shown in the schematic figures:
In the figures of the drawing, elements, features and components which are identical, functionally identical and of identical action are denoted in each case by the same reference designations unless stated otherwise.
The optical detector 10 for quantum communication shown in
As described above, the photonic lantern 20 understood with regard to the present invention is compatible with the common use of the term in the field of optics as will be explained in detail further below.
The photonic lantern 20 further comprises a plurality of single-mode output ports 22 connected to the multi-mode input port 21 by respective light channels 23. The photonic lantern 20 is configured to split the spatial multi-mode input signal L1 by guiding the spatial multi-mode input signal L1 in the individual light channels 23 into a plurality of mutually orthogonal spatial single-mode output signals L2. The plurality of single-mode output signals L2a-L2d is output through the respective single-mode output port 22. In
As within this embodiment, the photonic lantern 20 is configured to split the spatial multi-mode input signal L1 of a wavelength of about 1550 nm into the plurality of mutually orthogonal spatial single-mode output signals L2. The light channels 23 are thus configured to support only a single optical mode from the multi-mode input port 21 to the respective single-mode output port 22. Splitting the plurality of modes contained in the multi-mode input signal L1 into mutually orthogonal spatial single-modes L2 is thus achieved by spatially separated light channels 23. In some embodiments, this is achieved by a multicore fiber or a multi-core waveguide, wherein the multicore fiber or multi-core waveguide includes a plurality of single-mode fiber or waveguides configured to guide only a single optical mode. As explained above, the optical mode are determined by the photonic lantern and can be, in the case of a step-index structure, of LPxy-type. However, the invention is not limited to these kind of modes. All types of optical modes forming a mutually orthogonal mode system (Gaussian, Laguerre, Bessel, . . . ) can be implemented using suitable waveguides.
The optical detector 10 further comprises a coherent beam combiner 30 configured to coherently combine the plurality of single-mode output signals L2 to form a single-mode combined output signal L3. Due to the coherent coupling, the respective amplitudes of the plurality of single-mode output signals L2 are thus added to form the combined single-mode output signal L2, which provides a strong signal strength.
The optical detector 10 further comprises a photodetector assembly 40 comprising one or more single photon counters 41. The photodetector assembly 40 is arranged and configured to detect the combined output signal L3 to provide a detection signal L4. The single photon counter 41 is thus able to count the received photons of a photon stream as typically used in quantum communication links and convert the signal into the detection signal L4. In this embodiment, the single photon counter 41 is configured as a superconductive nanowire photon counter (SNSPD), which is particularly sensitive in the infrared spectral range, in particular around 1550 nm, compared to other single photon counter technologies. In further embodiments, the single photon counter 41 is configured as an avalanche photodiode (APD) or any other suitable single photon counter 41. The detection signal L4 is thus an electrical signal providing the communicated information by the quantum communication link.
The optical receiver 100 for quantum communication shown in
In further embodiments and not shown in
The optical receiver 100 shown in
The optical receiver 100 comprises a multi-mode waveguide 120 coupled to the multi-mode input port 21 of the photonic lantern 20 of the optical detector 10. The multi-mode input signal L1 coupled to the multi-mode fiber 120 thus propagates from the multi-mode fiber 120 to the multi-mode input port 21 to couple into the photonic lantern 20. This coupling could be achieved using coupling optics, in particular employing aspheric lenses. The coupling could also be achieved by butt-coupling of an and-face 121 of the multi-mode fiber 120 with the multi-mode input port 21. In further embodiments, coupling optics are applied to efficiently couple the multi-mode input signal L1 from the multi-mode fiber 120 to the multi-mode input port 21.
The photonic lantern 20 shown in
The photonic lantern 20 further comprises a plurality of single-mode waveguide portions 25, each having one of the plurality of single-mode output ports 22 and supporting the single-mode output signals L2. Depending on the applied optical modes, the single-mode waveguide portions 25 include single-mode waveguides 28 that have a core of about 10 μm and an NA of about 0.1, e.g. for a wavelength of 1550 nm. In the present embodiment, the plurality of single-mode waveguide portions 25 is implemented by separate single-mode waveguides 28 arranged in a plane configuration. In further embodiments, the plurality of single-mode waveguides 28 are realized by a multi-core fiber. In the present embodiment, four single-mode waveguides 28 are shown. In further embodiments, less than four or five and more single-mode waveguides 28 are applied. In particular, in some embodiments, more than 10, 20, 50 or 100 single-mode waveguides 28 are applied. In particular, in further embodiments, the number of single-mode waveguides 28 is about equal to the number of modes supported by the multi-mode waveguide portion 24. This can be estimated using standard formulas in the art, just as:
wherein N is the number of single-mode waveguides 28, d the diameter of the core of the multi-mode waveguide portion, NA the numerical aperture of the multi-mode waveguide portion 24 and λ the wavelength of the multi-mode input signal L1.
The photonic lantern 20 further comprises an intermediate portion 26 arranged between the multi-mode waveguide portion 24 and the plurality of single-mode waveguide portions 25 and configured to gradually split the multi-mode input signal L1 into the plurality of single-mode output signals L2. Although separate light channels 23 are shown in
The photonic lantern 20 further comprises an adapter portion 27 arranged between the intermediate portion 26 and the single-mode waveguide portion 25 and configured to arrange light channels 23 of the intermediate portion 26 according to an arrangement of the single-mode waveguide portions 25. In the present embodiment, the adapter portion 27 rearranges the light channels 23 of the intermediate portion 26 from an original circular cross-section to a plane arrangement of the plurality of the single-mode waveguide portions 25. The three-dimensional nature of the photonic lantern 20 is only indicated in
Similar to the previous embodiments, the photonic lantern 20 of the present embodiment is configured to split the spatial multi-mode input signal L1 of a wavelength of about 1550 nm into the plurality of mutually orthogonal spatial single-mode output signals L2 to be compatible with the terrestrial photonic network. In further embodiments, other wavelengths are used, such as e.g. 850 nm.
In the embodiment of the optical receiver 100 shown in
The coherent beam combiner 30 further comprises a plurality of phase shifters 32 each configured to shift a phase of a respective one of the plurality of single-mode output signals L2. In the present embodiment, the phase shifters 32 are configured as optomechanical phase shifters. Such phase shifters can be directly applied to the single-mode waveguides 28 as shown in
The optical detector 10 shown in
The optical receiver 100 shown in
In the present embodiment, the single photon counter 41 is implemented as a superconductive nanowire photon counter (SNSPD). Since this type of detector comprising superconductors requires an operation at cryogenic temperatures, the optical detector 10 also comprises a cryogenic chamber 50 comprising the detector assembly 40 including the single photon counter 41. The cryogenic chamber 50 has a temperature of less than about 4 K. In this way, the temperature is below the temperature of liquid Helium, i.e. below about 4.15 K, so that a He cryostat is formed. In further embodiments, the temperature of the cryogenic chamber 50 is higher and may be less than 150 K, 100 K or 10 K, 5K or even lower as for example less than 2 K, or less than 1 K. In the present embodiment, the photonic lantern 20, the combiner optics 31 and the detector assembly 40 are provided in the cryogenic chamber 50. In further embodiments, only the detector assembly 40, or only the detector assembly 40 and the combiner optics 31, are provided in the cryogenic chamber 50.
In this embodiment, the optical detector 10 also comprises a photonic chip 60. The photonic chip 60 may be made of any commonly used technique for photonic integrated circuits, such as indium phosphide or silicone waveguides. The detector assembly 40, the combiner optics 31 and the photonic lantern 20 are provided on the photonic chip 60, i.e. the same photonic chip 60. In further embodiments, only the detector assembly 40, or only the detector assembly 40 and the combiner optics 31, are provided on the photonic chip 60.
In this embodiment, the photonic chip 60 comprising the photonic lantern 20, the combiner optics 31 and the detector assembly 40 is arranged in the cryogenic chamber 50. In this way, a very compact and cryogenic cooled and therefore sensitive optical detector 10 is realized.
The optical receiver 100 shown in
The main difference between the previously described optical receiver 100 and shown in
By propagating through the wavefront phase shifter 36, the multi-mode input signal L1 is thus altered to a spatially modulated modified multi-mode input signal L1′. This modulation effectively takes into account the different lengths of the optical paths of the split single-mode input signals through the photonic lantern 20 and the combiner optics 31. The length of the optical beam path may change due to temperature variations or mechanical stress or other factors.
A corresponding wavefront control circuit 37 is used to control the wavefront modulation. In this embodiment, the wavefront control circuit 37 is connected to the single photon counter 41 of the photodetector assembly 40 and the wavefront phase shifter 36 by electrical lines 39, such as cables. The wavefront control circuit 37 is configured to control the wavefront phase shifter 36 based on the detection signal L4 provided by the one or more single photon counters 41. The control algorithm is based on a maximum signal optimization algorithm, which could e.g., implement deep learning strategies. Therefore, even without any individual phase shifters 32 as described in the previous embodiment shown in
In this example as well, a multi-mode waveguide 120 is used to couple to the multi-mode input port 21 of the optical detector 10 in a similar way as shown in
Similar to the embodiment described in relation to
Similar to the embodiment described in relation to
In this embodiment as well, the photonic chip 60 comprising the photonic lantern 20, the combiner optics 30 and the detector assembly 40 is arranged in the cryogenic chamber 50, which in this embodiment is configured as a He cryostat. In this way, a very compact and cryogenic cooled and therefore sensitive optical detector 10 is realized.
The photodetector assembly 40 shown in
The photodetector assembly 40 comprises a balanced detector 44 including two single photon counters 41. In the present embodiment, the single photon counters 41 are implemented as superconductive nanowire photon counters (SNSPD). As in the previous embodiments of the optical detector 10, a reference light channel R is configured to receive the reference signal R, wherein the photodetector assembly comprises a reference input port 42 configured to receive the reference signal R1 and combine the reference signal R1 with the combined output signal L3 using the waveguide coupler 45. Two single photon counters 41 are arranged downstream each output port 45a, 45b of the waveguide coupler 45 and configured to detect the combined output signal L3 mixed with the reference signal R1. The single photon counters 41 of the balanced detector 44 is configured to measure a quadrature at a time and feed an analog-digital converter 47. The electrical output of the photon counters 41 is amplified by an operational amplifier or transimpedance amplifier 46 to provide a detection signal L4. Compared to a typical homodyne CV-QKD detector, due to the reference light channel R, no local oscillator and modulator is required anymore upstream the waveguide coupler 45. However, in further embodiments, a local oscillator and a modulator is used in place of the reference channel R to form a homodyne CV-QKD detector.
The method for quantum communication depicted in
The systems and devices described herein may include a controller or a computing device comprising a processing and a memory which has stored therein computer-executable instructions for implementing the processes described herein. The processing unit may comprise any suitable devices configured to cause a series of steps to be performed so as to implement the method such that instructions, when executed by the computing device or other programmable apparatus, may cause the functions/acts/steps specified in the methods described herein to be executed. The processing unit may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.
The memory may be any suitable known or other machine-readable storage medium. The memory may comprise non-transitory computer readable storage medium such as, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory may include a suitable combination of any type of computer memory that is located either internally or externally to the device such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. The memory may comprise any storage means (e.g., devices) suitable for retrievably storing the computer-executable instructions executable by processing unit.
The methods and systems described herein may be implemented in a high-level procedural or object-oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of the controller or computing device. Alternatively, the methods and systems described herein may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems described herein may be stored on the storage media or the device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or special-purpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein.
Computer-executable instructions may be in many forms, including modules, executed by one or more computers or other devices. Generally, modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the modules may be combined or distributed as desired in various embodiments.
It will be appreciated that the systems and devices and components thereof may utilize communication through any of various network protocols such as TCP/IP, Ethernet, FTP, HTTP and the like, and/or through various wireless communication technologies such as GSM, CDMA, Wi-Fi, and WiMAX, is and the various computing devices described herein may be configured to communicate using any of these network protocols or technologies.
In the detailed description above, various features have been combined in one or more examples in order to improve the rigorousness of the illustration. However, it should be clear in this case that the above description is of merely illustrative but in no way restrictive nature. It serves to cover all alternatives, modifications and equivalents of the various features and exemplary embodiments. Many other examples will be immediately and directly clear to a person skilled in the art on the basis of his knowledge in the art in consideration of the above description.
The exemplary embodiments have been chosen and described in order to be able to present the principles underlying the invention and their application possibilities in practice in the best possible way. As a result, those skilled in the art can optimally modify and utilize the invention and its various exemplary embodiments with regard to the intended purpose of use. In the claims and the description, the terms “including” and “having” are used as neutral linguistic concepts for the corresponding terms “comprising”. Furthermore, use of the terms “a”, “an” and “one” shall not in principle exclude the plurality of features and components described in this way.
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23165737.0 | Mar 2023 | EP | regional |
