Smart antenna for optical network terminal and indoor optical network

Abstract

The present disclosure relates to an optical network terminal (ONT) for an indoor optical network, in particular an optical network terminal providing Wi-Fi services at an indoor service location. The master access device in the present disclosure is provided for an indoor optical network, whereby the indoor optical network includes one or more slave access devices optically coupled to the master access device. Each slave access device includes at least one transceiver and at least two antenna elements operably coupled to the at least one transceiver in a switchable manner. In this regard, the master access device is configured to evaluate one or more parameters of a radio frequency (RF) signal radiated or received by each slave access device, and switch at least two antenna elements of the slave access device based on the one or more parameters.

Description

Technical Field

[0001] The present disclosure relates to an optical network terminal (ONT) for an indoor optical network such as a local passive optical network (PON) based on fiber-to-the-room (FTTR) networking technology, or to an optical network terminal that provides Wi-Fi services at an indoor service location. Background Art

[0002] Typically, FTTR networking technology is based on fiber optic communications and is therefore able to provide high bandwidth and reliable transmission. The topology and functionality of FTTR technology depends on its implementation, for example, implementations based on the fifth generation fixed network (F5G) can include services to consumers and businesses with the help of wireless technologies based on Wi-Fi, and focus on fiber optic elements extending to connection service locations such as individual users, homes, offices, etc.

[0003] In a local PON, Wi-Fi connectivity can be provided through a home-area architecture based on fiber point-to-multipoint and using backhaul from a central office and / or optical line terminal (OLT), thereby forming a FTTR to home (FTTR-2H) scenario. In general scenarios, especially those that allow fiber connectivity and backhaul to achieve access networks, FTTR can connect primary ONTs to several secondary ONTs or edge ONTs via fiber. Compared to the main access point (AP) of traditional Wi-Fi scenarios, FTTR-based solutions specifically improve Wi-Fi coverage in locations far away from the main AP.

[0004] Typically, desktop edge ONTs are implemented as wall-mounted products that are to be mounted on a wall or used in place of a power socket in a room. Therefore, the positioning, topology, and performance of these edge ONTs may vary depending on uncertain factors such as fiber cabling (e.g., from a master ONT to a corresponding edge ONT), static objects and / or reflective surfaces (e.g., walls and furniture), non-ideal positioning (e.g., caused by installation diversity and constraints), and infrastructure at the installation location (e.g., building conditions and local building regulations). Summary of the invention

[0005] In view of the above, the present disclosure aims to provide an improved master access device, an improved indoor optical network and a method, which aims to facilitate beam switching in the slave access device to perform high-performance radiation in the front hemisphere, thereby particularly used to solve the above-mentioned limitations.

[0006] These and other objects are achieved by the embodiments of the present disclosure as described in the independent claims. Advantageous implementations are further defined in the dependent claims.

[0007] According to a first aspect of the present disclosure, a master access device for an indoor optical network is provided. The indoor optical network includes one or more slave access devices optically coupled to the master access device. Each slave access device includes at least one transceiver and at least two antenna elements operably coupled to at least one transceiver in a switchable manner. The master access device is configured to evaluate one or more parameters of a radio frequency (RF) signal radiated or received by each slave access device, and to switch at least two antenna elements of the slave access device based on the one or more parameters.

[0008] One or more parameters of the radiated or received radio frequency signal may include at least one of radio transmit power, effective isotropic radiated power (EIRP), received signal strength indicator (RSSI), signal to noise ratio (SNR), and front to back ratio (FBR), wherein the front to back ratio is, for example, the ratio of the power or signal strength radiated in the front radiation lobe or main radiation lobe to the power or signal strength radiated in the opposite direction (e.g., 180 degrees from the main lobe).

[0009] Therefore, the present disclosure proposes a smart antenna solution to adjust the coverage direction and signal strength of the slave access device according to the environment to achieve robust performance, such as robust Wi-Fi performance, thereby facilitating accurate and stable service coverage with less dependence on the installation location of the slave access device. In addition, since the radiation direction of the antenna element is switched specifically by switching the antenna element of the slave access device for a given RF stream, the effective radiation coverage of the slave access device at the service location can be advantageously maximized.

[0010] In an implementation manner of the first aspect, the primary access device is configured to sequentially switch at least two antenna elements at regular intervals.

[0011] Thus, the coverage of each slave access device can be advantageously increased. For example, if one or more parameters of the radiated or received signal in the corresponding radiation direction corresponding to the antenna element are within acceptable limits, the slave access device can be configured to radiate or receive signals in all acceptable directions for a given RF stream by sequentially switching the antenna element.

[0012] In an implementation of the first aspect, each slave access device includes at least one further transceiver and at least two further antenna elements switchably operably coupled to the at least one further transceiver.

[0013] In this regard, the master access device is configured to evaluate one or more parameters of the radio frequency signal radiated or received by each slave access device, and switch at least two antenna elements and at least two other antenna elements in the slave access device based on the one or more parameters.

[0014] Advantageously, the primary access device may implement beam switching in a Multiple-Input-Multiple-Output (MIMO) configuration (eg, a 2×2 MIMO configuration).

[0015] In an implementation of the first aspect, the master access device is configured to simultaneously switch at least two antenna elements and at least two other antenna elements of each slave access device.

[0016] Alternatively, the master access device may be configured to sequentially switch the at least two antenna elements and the at least two further antenna elements of each slave access device at regular intervals.

[0017] Advantageously, the coverage range of each slave access device may be further increased by configuring the slave access device to radiate or receive signals in all acceptable directions for the corresponding RF stream by switching the corresponding antenna element for each corresponding RF stream simultaneously or sequentially.

[0018] According to a second aspect of the present disclosure, an indoor optical network is provided, comprising a master access device according to the first aspect of the present disclosure and one or more slave access devices, wherein the one or more slave access devices are optically coupled to the master access device.

[0019] Therefore, an improved indoor optical network is provided, which can be implemented to enhance FTTR-2H technology by deploying smart antenna solutions for slave access devices to achieve a location-independent installation solution for the slave access devices.

[0020] In an implementation manner of the second aspect, each slave access device further includes a phase shifter coupled between one antenna element of the at least two antenna elements and the at least one transceiver.

[0021] In this regard, the phase shifter may be a passive or active phase shifter. Additionally, the phase shifter is configured to apply a predefined amount of phase shift. Thus, at least two antenna elements may be configured to have a predefined amount of phase shift so as to tilt the beam by a predefined amount in the front hemisphere, e.g., for an implementation with two beams per RF stream, the predefined tilted radiation beams may be oriented toward theta or similar angles equal to +30 degrees and –30 degrees, respectively.

[0022] Advantageously, the selection of a tilted beam for a given RF stream by a slave access device reduces interference that may be caused between two adjacent slave access devices and / or from another source of electromagnetic interference.

[0023] In an implementation manner of the second aspect, at least two antenna elements of each slave access device are microstrip antennas or patch antennas.

[0024] Advantageously, the slave access device may be implemented in a compact and economical manner.

[0025] In an implementation of the second aspect, each slave access device includes at least one further transceiver and at least two further antenna elements switchably operably coupled to the at least one further transceiver.

[0026] In this regard, the at least two further antenna elements of each slave access device may be microstrip antennas or patch antennas. In addition, each slave access device comprises a further phase shifter coupled between one of the at least two further antenna elements and at least one further transceiver.

[0027] In this respect, the further phase shifter is a passive phase shifter.Furthermore, the further phase shifter is configured to apply a phase shift of a predefined amount, for example a phase shift equal to the phase shift applied by said phase shifter.

[0028] Advantageously, the antenna element may be configured with a passive phase shift to tilt the beam in the front hemisphere, thereby facilitating selection of the tilted beam for a corresponding RF stream from an access device.

[0029] In an implementation of the second aspect, the at least two antenna elements of each slave access device and the at least two further antenna elements are configured to radiate signals having mutually orthogonal polarizations.

[0030] In addition, each of the at least two antenna elements and the at least two other antenna elements of each slave access device can be configured to radiate signals to cover a corresponding portion of the front hemisphere. For example, in an implementation with four antenna elements, each beam corresponding to the antenna element can cover one-fourth / quarter of the front hemisphere, i.e., a quarter hemisphere beam.

[0031] Advantageously, high isolation between the respective RF streams and high radiation diversity can be achieved. Furthermore, spatial distribution of the main beams corresponding to the RF streams can be achieved with minimal overlap, which may result in minimizing the combined gain and maximizing the gain of the individual antenna elements to limit the EIRP, for example, according to band-specific EIRP regulations.

[0032] In an implementation of the second aspect, each slave access device includes a first printed circuit board layer and a second printed circuit board layer, the first printed circuit board layer including at least two antenna elements and / or at least two additional antenna elements, and the second printed circuit board layer including at least one transceiver and a phase shifter and / or at least one additional transceiver and an additional phase shifter.

[0033] In this regard, the first printed circuit board layer may be assembled over the second printed circuit board layer via one or more connectors (eg, one or more RF spring contacts, such as an antenna clip).

[0034] Advantageously, for example, the slave access device may be implemented in a simplified manner.

[0035] In an implementation of the second aspect, a package size of at least one of the slave access devices is approximately 86 mm×86 mm.

[0036] Advantageously, for example, the slave access device may be mounted on or in place of a conventional power socket.

[0037] In an implementation manner of the second aspect, the indoor optical network includes two or more slave access devices.

[0038] In this regard, at least two of the slave access devices can be optically coupled to the master access device via a splitter. For example, the splitter can include or be a fused biconical taper (FBT) splitter, a planar lightwave circuit (PLC) splitter, an arrayed waveguide grating (AWG), etc.

[0039] According to a third aspect of the present disclosure, a method for operating one or more slave access devices in an indoor optical network is provided, each slave access device comprising at least one transceiver and at least two antenna elements operably coupled to the at least one transceiver in a switchable manner. The method comprises the following steps: evaluating, by a master access device, one or more parameters of a radio frequency signal radiated or received by each slave access device; and switching, by the master access device, at least two antenna elements in the slave access device based on the one or more parameters.

[0040] According to a fourth aspect of the present disclosure, a computer program comprising instructions is provided, which, when the program is executed by a processor of a primary access device according to the first aspect of the present disclosure, causes the processor to execute a method according to the third aspect of the present disclosure or any implementation thereof.

[0041] It should be noted that the method according to the third aspect corresponds to the main access device according to the first aspect and the indoor optical network according to the second aspect and their implementations. Accordingly, the method in the third aspect may have a corresponding implementation. In addition, the method in the third aspect achieves the same advantages and effects as the main access device in the first aspect and the indoor optical network in the second aspect and their corresponding implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above-mentioned various aspects and implementations will be explained in the following description of specific embodiments in conjunction with the accompanying drawings, in which:

[0043] Figure 1 A first exemplary embodiment of an indoor optical network, an exemplary embodiment of a master access device, and a first exemplary embodiment of a slave access device are shown;

[0044] Figure 2 A second exemplary embodiment of a slave access device is shown;

[0045] Figure 3 A third exemplary embodiment of a slave access device is shown;

[0046] Figure 4 A fourth exemplary embodiment of a slave access device is shown;

[0047] Figure 5 The simulation results of the normalized far-field directivity from the access device are shown in polar coordinate form;

[0048] FIG. 6A to FIG. 6D Four exemplary beam directions from an access device are shown;

[0049] Figure 7 shows exemplary return loss and port isolation from access equipment;

[0050] Figure 8 A second exemplary embodiment of an indoor optical network is shown;

[0051] Fig. 9 An exemplary implementation of an indoor optical network for different indoor service locations is shown; and

[0052] Fig.10 An exemplary flow chart of a method according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0053] Reference will now be made in detail to the exemplary embodiments of the present disclosure shown in the accompanying drawings. However, the following embodiments of the present disclosure may be variously modified, and the scope of the present disclosure is not limited by the following embodiments. The reference numerals of similar entities in different embodiments are partially omitted.

[0054] exist Figure 1 , a first exemplary embodiment of an indoor optical network 100 is shown, particularly including an exemplary embodiment of a master access device or master optical network terminal (ONT) 110 and a first exemplary embodiment of a slave access device or slave or edge optical network terminal (ONT) 130. The slave access device 130 is optically coupled to the master access device 110 via a hybrid optical fiber 120 having an electrical link and an optical link.

[0055] The master access device 110 may include a processing and control unit (CPU) 111, a transceiver 112, and a switch control signal generating circuit (SWC) 113. The SWC 113 may be implemented as a separate entity, or may be implemented integrally within the CPU 111. The transceiver 112 is primarily configured to send one or more radio frequency streams RF to the slave access device 130 via the hybrid optical fiber link 120.

[0056] The transceiver 112 is also configured to receive a signal corresponding to the received radio frequency signal from the access device 130, for example, and transmit the received signal to the CPU 111 for further processing. The CPU 111 can process the received signal, in particular to analyze or evaluate one or more parameters, including but not limited to transmit power or receive power, EIRP, RSSI, SNR and FBR. Based on the evaluation, the CPU 111 is configured to generate a switch control signal SC, in particular with the aid of the SWC 113.

[0057] The slave access device 130 may include a transceiver 131 (particularly an optical transceiver), which is configured to receive at least one radio frequency stream RF from the transceiver 112 of the master access device 110 via the optical fiber link 120. The transceiver 131 is also configured to receive a switch control signal SC from the master access device 110 via the optical fiber link 120. The slave access device 130 may also include a switch (SW) 132, followed by two antenna feed paths or feed sections 133, 134.

[0058] The two antenna feeds 133, 134 may be coupled to an antenna array (ANT) 136 having two antenna elements AE1, AE2, respectively, and in particular to respective antenna elements AE1, AE2. In this regard, the antenna elements AE1, AE2 are configured to radiate or receive signals having polarizations orthogonal to each other, for example by means of orthogonal current flows. In this illustration, the antenna feed 133 is coupled to the antenna element AE1, while the antenna feed 134 is coupled to the antenna element AE2 via a passive phase shifter (PS) 135. The passive phase shifter 135 may be configured to apply a defined amount of phase shift so that the antenna feeds 133, 134 (respective antenna elements AE1, AE2) have a defined amount of passive phase shift.

[0059] The switch 132 may be implemented as a single-pole-double-through (SPDT) switch and is configured to receive the radio frequency stream RF from the transceiver 131 and switch between the two antenna feeds 133, 134, for example to switch the transmission of the radio frequency stream RF between the two antenna feeds 133, 134. In this regard, the state of the switch 132 may be controlled or switched by means of a switch control signal SC. The switch 132 may be implemented as a cascade entity between the TRX 131 and the antenna, or may alternatively be implemented as a parallel entity that controls the TRX 131 without transmitting RF signals to the antenna.

[0060] For example, the master access device 110 may initiate a calibration scheme to calibrate the indoor optical network 100. In this regard, the master access device 110 may receive a signal or stream corresponding to a radio frequency signal received through the antenna element AE1 and the antenna feed 133 and another signal or stream corresponding to another radio frequency signal received through the antenna element AE2 and the antenna feed 134, for example, by alternately switching the antenna feeds 133, 134 via the switch 132.

[0061] The master access device 110 (particularly the CPU 111 of the master access device 110) can evaluate one or more signal parameters of the signal or stream and one or more signal parameters of the other signal or stream to specifically identify which of the two polarizations corresponding to the antenna elements AE1 and AE2 is advantageous, and can switch the switch 132 accordingly to maintain communication only via the antenna element with the advantageous polarization. In addition, if both antenna elements AE1 and AE2 produce advantageous polarizations, the master access device 110 can switch the antenna elements AE1 and AE2 at regular intervals, for example, by switching the switch 132 at regular intervals, thereby maintaining communication via the two antenna elements AE1 and AE2.

[0062] exist Figure 2 , a second exemplary embodiment of the slave access device 230 is shown. The slave access device 230 is different from the slave access device 130 in that the slave access device 230 may include a single-pole-multiple-through (SPNT) switch 232 with N antenna feeds and N antenna elements AE1 to AE2. N The N antenna feeds may include corresponding passive phase shifters PS1 to PS N , whereby each passive phase shifter PS1 to PS N can be configured to apply a defined amount of phase shift so that the N antenna feeds (corresponding to the N antenna elements AE1 to AE N ) has a limited amount of passive phase shift. In addition, for example, the N antenna elements AE1 to AE N It may be configured to radiate signals or beams with minimal overlap at corresponding portions of the front hemisphere of the antenna array 236. The spatial division of the front hemisphere of the antenna array 236 may be any spatial division or equal spatial division of the front hemisphere.

[0063] The master access device 110 may initiate a calibration scheme to calibrate the indoor optical network 100. In this regard, the master access device 110 may receive and transmit signals transmitted through the corresponding antenna elements AE1 to AE2 by, for example, alternately switching the N antenna feeds via the switch 232. N The master access device 110 (particularly the CPU 111 of the master access device 110) may evaluate one or more signal parameters of the N signals or streams to specifically identify the N signals or streams corresponding to the antenna elements AE1 to AE2. N The corresponding portion of the front hemisphere of the antenna array 236 is dominant, and the switch 232 can be switched accordingly to maintain communication only via the dominant antenna element.

[0064] exist Figure 3, a third exemplary embodiment of a slave access device 330 is shown. The slave access device 330 may include a first transceiver (TRX1) 131 corresponding to the transceiver of the slave access device 130, and the first transceiver 131 is configured to receive a first radio frequency stream RF1 from the transceiver 112 of the master access device 110 via the optical fiber link 120. The first transceiver 131 is also configured to receive a first switch control signal SC1 from the master access device 110 via the optical fiber link 120.

[0065] In addition, the slave access device 330 may include a second transceiver (TRX2) 331 (particularly an optical transceiver), which is configured to receive a second radio frequency stream RF2 from the transceiver 112 of the master access device 110 via the optical fiber link 120. The second transceiver 331 is also configured to receive a second switch control signal SC2 from the master access device 110 via the optical fiber link 120.

[0066] The slave access device 330 may further include a first switch (SW1) 132 corresponding to the switch of the slave access device 130, and the first switch 132 is configured to switch between the first antenna feed 133 and the second antenna feed 134. The first antenna feed 133 and the second antenna feed 134 may be coupled to a first antenna array (ANT1) 136 including a first antenna element AE1 and a second antenna element AE2, respectively, and in particular, to the first antenna element AE1 and the second antenna element AE2, respectively.

[0067] For example, the first antenna feed 133 is coupled to the first antenna element AE1, and the second antenna feed 134 is coupled to the second antenna element AE2 via the first passive phase shifter (PS1) 135. The first passive phase shifter 135 may be configured to apply a defined amount of phase shift so that the first antenna element AE1 and the second antenna element AE2 have a defined amount of passive phase shift.

[0068] In addition, the slave access device 330 may further include a second switch (SW2) 332, which is configured to switch between the third antenna feed 333 and the fourth antenna feed 334. The third antenna feed 333 and the fourth antenna feed 334 may be coupled to a second antenna array (ANT2) 336 including a third antenna element AE3 and a fourth antenna element AE4, respectively, and in particular, to the third antenna element AE3 and the fourth antenna element AE4, respectively.

[0069] For example, the third antenna feed 333 is coupled to the third antenna element AE3, and the fourth antenna feed 334 is coupled to the fourth antenna element AE4 via the second passive phase shifter (PS2) 335. The second passive phase shifter 135 may be configured to apply a defined amount of phase shift so that the third antenna element AE3 and the fourth antenna element AE4 have a defined amount of passive phase shift.

[0070] In this regard, the first antenna element AE1 and the second antenna element AE2 are configured to radiate or receive signals with mutually orthogonal polarizations, for example by means of orthogonal current flows. In addition, the third antenna element AE3 and the fourth antenna element AE4 are configured to radiate or receive signals with mutually orthogonal polarizations, for example by means of orthogonal current flows.

[0071] Additionally or alternatively, the first antenna element AE1, the second antenna element AE2, the third antenna element AE3 and the fourth antenna element AE4 are configured such that the first antenna array 136 and the second antenna array 336 radiate or receive signals having mutually orthogonal polarizations.

[0072] The first switch 132 may be implemented as a single-pole-double-through (SPDT) switch and is configured to receive the first RF stream RF1 from the first transceiver 131 and switch between the first antenna feed 133 and the second antenna feed 134, for example, to switch transmission of the first RF stream RF1 between the first antenna feed 133 and the second antenna feed 134. In this regard, the state of the first switch 132 may be controlled or switched by means of a first switch control signal SC1.

[0073] Additionally, the second switch 332 may also be implemented as a single-pole-double-through (SPDT) switch and configured to receive the second RF stream RF2 from the second transceiver 331 and switch between the third antenna feed 333 and the fourth antenna feed 334, for example, to switch the transmission of the second RF stream RF2 between the third antenna feed 333 and the fourth antenna feed 334. In this regard, the state of the second switch 332 may be controlled or switched by means of a second switch control signal SC2.

[0074] For example, the first passive phase shifter 135 can provide a 100-degree phase difference between the first antenna element AE1 and the second antenna element AE2, which may cause the first antenna element AE1 and the second antenna element AE2 to tilt the corresponding beams to theta + 30 degrees and theta -30 degrees in the front hemisphere. In addition, the second passive phase shifter 335 can provide a 100-degree phase difference between the third antenna element AE3 and the fourth antenna element AE4, which may cause the third antenna element AE3 and the fourth antenna element AE4 to tilt the corresponding beams to theta + 30 degrees and theta -30 degrees in the front hemisphere.

[0075] In addition, the first antenna element AE1, the second antenna element AE2, the third antenna element AE3 and the fourth antenna element AE4 can be arranged to have an orthogonal radiation polarization of 45 degrees, that is, each antenna element can emit a quarter hemispherical beam, which may cause high isolation between the first radio frequency stream RF1 and the second radio frequency stream RF2 and have high radiation diversity of +45 degrees and -45 degrees polarization. Therefore, the front hemisphere can be spatially divided into four highly directional parts or sectors, and correspondingly, at least two or more sectors can be used, for example, simultaneously to perform positioning in four spatial sectors within the front hemisphere.

[0076] For example, the main access device 110 can receive a first signal or stream corresponding to a first RF signal received through the first antenna element AE1 accompanied by a first antenna feed part 133 and a second signal or stream corresponding to a second RF signal received through the second antenna element AE2 accompanied by a second antenna feed part 134 from the slave access device 330, for example, by alternately switching the first antenna element AE1 and the second antenna element AE2 via the first switch 132.

[0077] In addition, the main access device 110 can receive a third signal or stream corresponding to a third RF signal received through the third antenna element AE3 accompanied by a third antenna feed part 333 and a fourth signal or stream corresponding to a fourth RF signal received through the fourth antenna element AE4 accompanied by a fourth antenna feed part 334 from the slave access device 330, for example, by alternately switching the third antenna element AE3 and the fourth antenna element AE4 via the second switch 332.

[0078] The master access device 110 (particularly the CPU 111 of the master access device 110) can evaluate one or more signal parameters of the first signal or stream and / or one or more signal parameters of the second signal or stream to specifically identify which of the two polarizations corresponding to the first antenna element AE1 and the second antenna element AE2 is advantageous, and can switch the first switch 132 accordingly to maintain communication only via the antenna element having the advantageous polarization.

[0079] Additionally or alternatively, if both the first antenna element AE1 and the second antenna element AE2 produce a dominant polarization, the main access device 110 may switch the first antenna element AE1 and the second antenna element AE2 at regular intervals, for example by switching the first switch 132 at regular intervals, thereby maintaining communication via both the first antenna element AE1 and the second antenna element AE2.

[0080] Additionally, the master access device 110 (particularly the CPU 111 of the master access device 110) can evaluate one or more signal parameters of the third signal or stream and / or one or more signal parameters of the fourth signal or stream to specifically identify which of the two polarizations corresponding to the third antenna element AE3 and the fourth antenna element AE4 is advantageous, and can switch the second switch 332 accordingly to maintain communication only via the antenna element having the advantageous polarization.

[0081] Additionally or alternatively, if both the third antenna element AE3 and the fourth antenna element AE4 produce a dominant polarization, the main access device 110 may switch the third antenna element AE3 and the fourth antenna element AE4 at regular intervals, for example by switching the second switch 332 at regular intervals, thereby maintaining communication via both the third antenna element AE3 and the fourth antenna element AE4.

[0082] It should be noted that the slave access device 330 may include more than two transceivers - ie, the slave access device 330 may operate for more than two radio frequency streams, and its corresponding antenna feeding schemes to additional antenna arrays, which may be similarly implemented in the exemplary manner.

[0083] exist Figure 4 In FIG. 4 , a fourth exemplary implementation of the slave access device 330 is shown. Specifically, in Figure 4 4, an exemplary PCB implementation of the slave access device 330 is shown along the xy axis. The PCB implementation can be implemented by stacking a first PCB 401 on top of a second PCB 402. The first PCB 401 can include a first antenna array 136 and a second antenna array 336, specifically including a first antenna element AE1, a second antenna element AE2, a third antenna element AE3, and a fourth antenna element AE4, each of which can be arranged to have an orthogonal radiation polarization of 45 degrees.

[0084] The second PCB 402 may include a first switch 132, a first antenna feed 133, a second antenna feed 134, and a first phase shifter 135, as well as a second switch 332, a third antenna feed 333, a fourth antenna feed 334, and a second phase shifter 335. For example, the first switch 132 and the second switch 332 may be implemented as RF MEMS or stripline switches. The first antenna feed 133, the second antenna feed 134, the third antenna feed 333, and the fourth antenna feed 334 may be implemented as stripline transmission lines.

[0085] In this regard, the first phase shifter 135 may be implemented, for example, as a stripline phase shifter together with the stripline transmission line according to the second antenna feed 134 by an additional transmission line section having a finite amount of phase length. Similarly, the second phase shifter 335 may be implemented, for example, as a stripline phase shifter together with the stripline transmission line according to the fourth antenna feed 334 by an additional transmission line section having a finite amount of phase length that is the same as or different from the first phase shifter 135.

[0086] In this regard, the first antenna feed 133 may be coupled to the first antenna element AE1 of the first antenna array 136 via the first connector 403. Additionally, the second antenna feed 134 may be coupled to the second antenna element AE2 of the first antenna array 136 via the second connector 404. Furthermore, the third antenna feed 333 may be coupled to the third antenna element AE3 of the second antenna array 336 via the third connector 405. Furthermore, the fourth antenna feed 334 may be coupled to the fourth antenna element AE4 of the second antenna array 336 via the fourth connector 406. The first connector 403, the second connector 404, the third connector 405, and the fourth connector 406 may be RF connectors, such as spring contacts.

[0087] Although not shown, the second PCB 402 may include the first transceiver 131 and the second transceiver 331 as well as additional circuits and / or elements that may be required for normal operation of the slave access device 330 , such as a power harvesting circuit.

[0088] It should be noted that some components in the second PCB 402 (for example, the first switch 132, the first antenna feed 133, the second antenna feed 134, the first phase shifter 135, the second switch 332, the third antenna feed 333, the fourth antenna feed 334 and / or the second phase shifter 335) can be arranged in the first PCB 401 together with the first antenna array 136 and the second antenna array 336.

[0089] exist Figure 4At the bottom of FIG. 4 , a PCB implementation of the slave access device 330 is shown along the xz axis. The first antenna array 136 and the second antenna array 336 may be implemented in the first PCB 401 , which may have a thickness t of 2 mm. 401 , ie the base material thickness. Therefore, the total thickness t may be limited to about 4.5 mm, which depends in particular on the type of RF connector employed between the first PCB 401 and the second PCB 402 .

[0090] exist Figure 5 , simulation results of normalized far-field directivity from access devices 130, 230, 330 are shown in polar coordinate form. For example, curve 501 may correspond to the first antenna element AE1, and curve 502 may correspond to the second antenna element AE2.

[0091] It can be seen that a defined amount of passive phase shift (particularly a phase shift of 100 degrees) between the first antenna element AE1 and the second antenna element AE2 can tilt the corresponding beams approximately to theta + 30 degrees and theta - 30 degrees, respectively. For example, curve 502 shows a main lobe amplitude of 8.27 dBi, where, at an operating frequency of 5.5 GHz, the main lobe direction is 32 degrees, the side lobe level is -4.8 dB, and the angular width is 58.6 degrees.

[0092] Follow FIG. 6A to FIG. 6D , four exemplary beam directions from the access device 330 are shown. Specifically, FIG. 6A to FIG. 6D Four highly directive beams in four different and / or orthogonal directions, ie four quarter hemisphere beams, are shown, generated in particular by four switch combinations of the first switch 132 and the second switch 332 .

[0093] For example, Fig. 6A A first highly directive beam or first quarter hemisphere beam is shown corresponding to a first radio frequency stream RF1 radiated from the first antenna element AE1, in particular by switching the first switch 132 to connect the first radio frequency stream RF1 to the first antenna element AE1 through the first antenna feed 133. The directivity of the radiated beam is exemplarily shown by a white arrow along the upper left, with a gain rating of 6.34 dBi.

[0094] in addition, Figure 6B A second highly directive beam or a second quarter hemisphere beam is shown corresponding to the second RF stream RF2 radiated from the third antenna element AE3, in particular by switching the second switch 332 to connect the second RF stream RF2 to the third antenna element AE3 through the third antenna feed 333. The directivity of the radiated beam is exemplarily shown by the white arrow along the upper right, with a gain rating of 6.27 dBi.

[0095] also, Figure 6C A third highly directive beam or third quarter hemisphere beam corresponding to the second RF stream RF2 radiated from the fourth antenna element AE4, in particular by switching the second switch 332 to connect the second RF stream RF2 to the fourth antenna element AE4 through the fourth antenna feed 334, is shown. The directivity of the radiated beam is exemplarily shown by the white arrow along the lower left, with a gain rating of 6.49 dBi.

[0096] Furthermore, Fig.6D A fourth highly directive beam or fourth quarter hemisphere beam is shown corresponding to the first RF stream RF1 radiated from the second antenna element AE2, in particular by switching the first switch 132 to connect the first RF stream RF1 to the second antenna element AE2 through the second antenna feed 134. The directivity of the radiated beam is exemplarily shown by the white arrow along the lower right, with a gain rating of 6.45 dBi.

[0097] exist Figure 7 , the simulation results of the return loss and port isolation from the access device 330 are shown. In the graph, the x-axis represents the frequency in GHz, and the y-axis represents the amplitude of the scattering parameter in dB. In this article, curve 701 represents the return loss corresponding to the radio frequency stream (for example, corresponding to the second radio frequency stream RF2). It can be seen that in the 5.2 GHz to 5.8 GHz frequency band (particularly suitable for the wireless LAN standard IEEE 802.11.a / n / ac / ax), a return loss of more than -10 dB can be achieved, which can again ensure a high overall antenna efficiency.

[0098] In addition, curve 702 represents the port isolation between two RF streams, for example, the port isolation between the first RF stream RF1 and the second RF stream RF2. It can be seen that in the 5.2 GHz to 5.8 GHz frequency band, more than 30 dB of port isolation can be achieved, which can again ensure high MIMO diversity.

[0099] exist Figure 8 , a second exemplary embodiment of an indoor optical network 800 is shown. The indoor optical network may include a primary access device or a primary optical network terminal (P-ONT) and N slave access devices or edge optical network terminals E-ONT1 to E-ONT N The master access device P-ONT may correspond to the master access device 110 of the indoor optical network 100, and the N slave access devices E-ONT1 to E-ONT NEach slave access device in may correspond to the slave access device 130, the slave access device 230, or the slave access device 330. In this regard, the N slave access devices E-ONT1 to E-ONT N It is optically coupled to the primary access device P-ONT through an optical splitter (SPL) 801 .

[0100] In this regard, the primary access device P-ONT can be coupled to the optical splitter 801 via the input optical fiber link 120 of the optical splitter, and the optical splitter 801 can be connected to the optical splitter 801 through N parallel optical fiber links 8021 to 802 N The input is split. N from access device E-ONT1 to E-ONT N Each slave access device can be connected via N parallel optical fiber links 8021 to 802 N Coupled to the optical splitter 801.

[0101] The optical splitter 801 may be a passive optical splitter. For example, the optical splitter 801 may be a PLC splitter, such as a 1×N PLC splitter, which may split an input (i.e., an incident optical signal) into N parallel outputs. Alternatively, the optical splitter 801 may be a FBT splitter, such as a 1×N FBT splitter, which may include N welded or fused optical fibers.

[0102] exist Fig. 9 , an exemplary implementation of an indoor optical network 800 is shown for different indoor service locations. In this example, a first slave access device 901, a second slave access device 902, and a third slave access device 903 are installed (e.g., wall-mounted) at their respective locations and are coupled to the master access device 110 through an optical splitter 801. The first slave access device 901, the second slave access device 902, and the third slave access device 903 may correspond to any one of the slave access devices 130, 230, and 330. For example, the first slave access device 901, the second slave access device 902, and the third slave access device 903 may correspond to the slave access device 330.

[0103] The first slave access device 901 is shown with its four exemplary quarter hemisphere beams 9011 to 9014, the second slave access device 902 is shown with its four exemplary quarter hemisphere beams 9021 to 9024, and the third slave access device 903 is shown with its four exemplary quarter hemisphere beams 9031 to 9034. In this regard, the first quarter hemisphere beams 9011, 9021, and 9031 may correspond to Fig. 6A The first quarter hemisphere beam 9012, the second quarter hemisphere beam 9022 and the second quarter hemisphere beam 9032 may correspond to Figure 6BThe third quarter hemisphere beams 9013, 9023 and 9033 may correspond to the quarter hemisphere beams shown. Figure 6C The quarter hemisphere beam shown, and the fourth quarter hemisphere beams 9014, 9024 and 9034 may correspond to Fig.6D A quarter hemisphere beam is shown.

[0104] In this example, it can be seen that due to the obstruction caused by the wall and furniture and the floor, the first quarter hemisphere beam 9011, the third quarter hemisphere beam 9013 and the fourth quarter hemisphere beam 9014 of the first slave access device 901 may not have an advantage. Therefore, the master access device 110 can configure the first slave access device 901 to maintain its primary communication in the direction of the second quarter hemisphere beam 9012, for example, via the antenna switching technology described above.

[0105] It can also be seen that, due to the positioning of the second slave access device 902, it can be considered that the first quarter hemisphere beam 9021, the second quarter hemisphere beam 9022, the third quarter hemisphere beam 9023 and the fourth quarter hemisphere beam 9024 of the second slave access device 902 have advantages, that is, there is no line of sight blocking. Therefore, the master access device 110 can configure the second slave access device 902 to maintain its communication in all directions according to its four quarter hemisphere beams 9021 to 9024.

[0106] In addition, it can be seen that since the third slave access device 903 is positioned near a window such as a noise source and / or EMI, the second quarter hemisphere beam 9032 and the fourth quarter hemisphere beam 9034 of the third slave access device 903 may not have an advantage. Therefore, the master access device 110 can configure the third slave access device 903 to maintain its communication only in the direction of the first quarter hemisphere beam 9031 and the third quarter hemisphere beam 9033.

[0107] exist Fig.10 , an exemplary implementation of a method 1000 according to the third aspect of the present disclosure is shown. In a first step 1001, one or more slave access devices are provided, wherein each slave access device includes at least one transceiver and at least two antenna elements operably coupled to the at least one transceiver in a switchable manner. In a second step 1002, one or more parameters of a radio frequency signal radiated or received by each slave access device are evaluated by a master access device. In a third step 1003, at least two antenna elements of the slave access device are switched by the master access device based on the one or more parameters.

[0108] Conventional antenna systems for edge ONTs deployed in FTTR-2H networks may include low and / or high gain antennas with fixed beams to achieve high quality Wi-Fi services. For example, a conventional edge ONT with a 5GHz Wi-Fi band may include a compact antenna with an omnidirectional radiation pattern, or a mixture of an omnidirectional antenna and a high gain antenna. A high gain antenna may generate a focused beam toward the center of each service location without sufficient radiation to the tangential angle. In contrast, a low gain antenna with a quasi-omnidirectional radiation pattern may again ensure radiation to any possible angle, but the disadvantage is high interference between adjacent edge ONTs. For example, two edge ONTs located on both sides of a thin wall may experience huge EMI while having strong backward radiation, for example, radiation from a backup omnidirectional antenna.

[0109] More complex antenna systems such as phased array antennas, meta-surfaces, or meta-volume antennas may not be a viable solution for edge ONTs, especially in terms of cost and complexity, as it requires a complex phased array feeding system and a large number of antenna elements.

[0110] The present disclosure proposes a smart antenna solution for edge ONTs to radiate high performance towards users within the front hemisphere while maintaining minimal dependence on the installation location of the edge ONT, which is achieved in particular by dividing the front hemisphere into several areas and selecting some or all areas based on the usefulness of the areas, and only establishing channels for each of the RF streams in these areas. This advantageously solves the limited coverage of fixed beam antennas and the dependence of their performance on the installation location.

[0111] It is worth noting that in the specification and the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit can satisfy the functions of several entities or items recorded in the claims. In addition, the word "coupled" means that the elements can be directly connected together or can be coupled through one or more intermediate elements. In addition, the disclosure about any aspect is also related to other aspects of the present disclosure.

[0112] Although the present disclosure has been illustrated and described for one or more implementations, equivalent changes and modifications may be made by those skilled in the art after reading and understanding this specification and the accompanying drawings. In addition, although a particular feature of the present disclosure may be disclosed for only one of several implementations, such a feature may be combined with one or more other features in other implementations as may be necessary and advantageous for any given or specific application.

Claims

1. A main access device (110) for an indoor optical network (100, 800), in, The indoor optical network includes one or more slave access devices (130, 230, 330) optically coupled to the master access device (110); Each slave access device (130, 230, 330) includes at least one transceiver (131) and at least two antenna elements (AE1, AE2) operably coupled to the at least one transceiver (131) in a switchable manner; The master access device (110) is configured to evaluate one or more parameters of the radio frequency (RF) signal radiated or received by each slave access device (130, 230, 330), and to switch the at least two antenna elements (AE1, AE2) of the slave access device (130, 230, 330) based on the one or more parameters.

2. The master access device according to claim 1, wherein: The one or more parameters of the radiated or received radio frequency (RF) signal include at least one of radio transmission power, effective isotropic radiated power, received signal strength indication, signal-to-noise ratio and front-to-back ratio.

3. The master access device according to claim 1 or 2, wherein: The master access device (110) is also configured to sequentially switch the at least two antenna elements (AE1, AE2) at regular intervals.

4. The master access device according to any one of claims 1 to 3, in, Each slave access device (130, 230, 330) comprises at least one further transceiver (331) and at least two further antenna elements (AE3, AE4) switchably operatively coupled to the at least one further transceiver (331); The master access device (110) is configured to evaluate the one or more parameters of the radio frequency (RF) signal radiated or received by each slave access device (130, 230, 330), and to switch the at least two antenna elements (AE1, AE2) and the at least two other antenna elements (AE3, AE4) of the slave access device (130, 230, 330) based on the one or more parameters.

5. The master access device according to claim 4, wherein: The master access device (110) is configured to simultaneously switch the at least two antenna elements (AE1, AE2) and the at least two other antenna elements (AE3, AE4) of each slave access device (130, 230, 330); or The master access device (110) is configured to sequentially switch the at least two antenna elements (AE1, AE2) and the at least two additional antenna elements (AE3, AE4) of each slave access device (130, 230, 330) at regular intervals.

6. An indoor optical network (100, 800), comprising: The master access device (110) according to any one of claims 1 to 5; as well as The one or more slave access devices (130, 230, 330) are optically coupled to the master access device (110).

7. The indoor optical network according to claim 6, in, Each slave access device (130, 230, 330) further includes a phase shifter (135) coupled between one of the at least two antenna elements (AE1, AE2) and the at least one transceiver (131).

8. The indoor optical network according to claim 7, wherein: The phase shifter (135) is a passive phase shifter; and The phase shifter (135) is configured to apply a predefined amount of phase shift.

9. The indoor optical network according to one of claims 6 to 8, wherein: The at least two antenna elements (AE1, AE2) of each slave access device (130, 230, 330) are microstrip antennas or patch antennas.

10. The indoor optical network according to any one of claims 7 to 9, wherein: Each slave access device (130, 230, 330) comprises at least one further transceiver (331) and at least two further antenna elements (AE3, AE4) switchably operatively coupled to the at least one further transceiver (331); Each slave access device (130, 230, 330) comprises a further phase shifter (335) coupled between one of the at least two further antenna elements (AE3, AE4) and the at least one further transceiver (331).

11. The indoor optical network according to claim 10, wherein: The at least two antenna elements (AE1, AE2) and the at least two further antenna elements (AE3, AE4) of each slave access device (130, 230, 330) are configured to radiate signals having mutually orthogonal polarizations; Each of the at least two antenna elements (AE1, AE2) and the at least two further antenna elements (AE3, AE4) of each slave access device (130, 230, 330) is configured to radiate signals to cover a corresponding portion of a front hemisphere.

12. The indoor optical network according to claim 10 or 11, wherein: The further phase shifter (335) is a passive phase shifter; and The further phase shifter (335) is configured to apply a predefined amount of phase shift, preferably a phase shift equal to the phase shift applied by the phase shifter (135).

13. The indoor optical network according to any one of claims 7 to 12, wherein: Each slave access device (130, 230, 330) comprises a first printed circuit board layer (401) and a second printed circuit board layer (402), the first printed circuit board layer (401) comprising the at least two antenna elements (AE1, AE2) and / or the at least two other antenna elements (AE3, AE4), the second printed circuit board layer (402) comprising the at least one transceiver (131) and the phase shifter (135) and / or the at least one other transceiver (331) and the other phase shifter (335); and The first printed circuit board layer (401) is assembled on top of the second printed circuit board layer (402) via one or more connectors (403, 404, 405, 406).

14. The indoor optical network according to any one of claims 6 to 12, wherein: The package size of at least one of the slave access devices (130, 230, 330) is about 86 mm×86 mm.

15. The indoor optical network according to any one of claims 6 to 14, wherein: The indoor optical network (100, 800) includes two or more slave access devices (130, 230, 330); and At least two of the slave access devices (130, 230, 330) are optically coupled to the master access device (110) via an optical splitter (801).

16. A method (1000) for operating one or more slave access devices (130, 230, 330) in an indoor optical network (100, 800), each slave access device comprising at least one transceiver (131) and at least two antenna elements (AE1, AE2) operably coupled to the at least one transceiver (131) in a switchable manner, wherein: The method comprises: The master access device (110) evaluates (1002) one or more parameters of the radio frequency (RF) signal radiated or received by each slave access device (130, 230, 330); and The at least two antenna elements (AE1, AE2) of the slave access device (130, 230, 330) are switched (1003) by the master access device (110) based on the one or more parameters.

17. A computer program comprising instructions which, when said program is executed by a processor of said master access device (110), cause said processor to perform the method (1000) according to claim 16.

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