Outdoor lighting fixtures, street lighting fixtures and outdoor lighting systems

Abstract

The outdoor lighting fixture (100) includes a housing (130) having a light exit window (150), a mounting element (120), and a lighting unit (160) having a light source (170) housed in the housing and emitting light (180) through the light exit window. The housing further houses four antennas (210, 220, 230, 240) having respective directional radiation patterns (212, 222, 232, 242) and respective lines of sight (214, 224, 234, 244). The respective lines of sight are oriented with respect to each other in the same manner as the four cardinal directions of a compass perpendicular to the direction of gravity when the lighting fixture is mounted. When the mounting element is surrounded by all four antennas, the lines of sight of all antennas point away from the mounting element, or when the mounting element is not surrounded by all four antennas, the mounting element is positioned outside the lines of sight of the antennas pointing towards the mounting element.

Description

[Technical field]

[0001] The present invention relates to an outdoor luminaire suitable for a communications network, a street light fixture comprising said outdoor luminaire, and an outdoor lighting system comprising a plurality of said outdoor street light fixtures, the luminaire being fitted with a plurality of antennas. [Background technology]

[0002] Outdoor lighting systems have been designed and deployed to provide lighting to improve visibility in the absence of natural daylight throughout outdoor environments, such as streets, parks, airports, and other public and / or private outdoor venues. However, over the past two decades, outdoor lighting systems have continued to evolve, in part as a result of the proliferation of networked technologies.

[0003] More recently, omni-directional radios have been added to street lights in outdoor lighting systems, such as those disclosed in U.S. Patent Application US2007 / 0252528A1. These radios enable remote control of the lighting infrastructure using wireless lighting control networks, allowing individual street lights or lighting fixtures to operate as a wireless mesh network, which when combined with a central controller allows for more versatile and flexible operation of the street lights.

[0004] Over the last decade, there has been an increasing need for network connectivity, especially in the context of smart cities. By deploying audio, video and environmental sensors, municipalities want to better monitor and interact with the outdoor environment, which, combined with data collection and artificial intelligence, allows for better understanding and control of the urban environment. In addition, there is also a need to deploy a denser end-user communication service infrastructure to enable new and / or better quality services to users within the urban environment.

[0005] WO2014141312A1 discloses a street-type LED luminaire integrated with a communication device. Summary of the Invention [Problem to be solved by the invention]

[0006] Although outdoor lighting systems are good candidates for providing services beyond lighting, the uptake of connected lighting services does not seem to be in line with the need for such services. Several obstacles can be identified: Cost is a significant obstacle for municipalities, and while power is generally available at traditional lighting fixture locations, communications infrastructure generally is not. Installing wired data communications networks to support the deployment of data communications networks within outdoor lighting systems can be very costly, as roads and / or sidewalks along which such wired communications links are installed must be closed and rehabilitated after installation.

[0007] On the other hand, the use of wireless data communication networks requires the installation of additional wireless radio communication devices in the lighting fixtures, which usually results in rather unsightly pods or modules being installed in the lighting fixtures. Instead, the inventors propose to install a high-capacity data communication network in the outdoor lighting system itself by embedding directional radio frequency (RF) communication equipment in the streetlight luminaires. The directional wireless communication link here is beneficial in that it can reduce interference between neighboring devices. However, when incorporating directional radios in the luminaires, this also brings the need to have reliable performance and / or functionality of communication between the luminaires.

[0008] In view of the above, the present disclosure is directed to an outdoor lighting fixture, a lighting fixture and an outdoor lighting system that aims to ameliorate at least one of the above-mentioned problems. In particular, the object of the present invention is achieved by an outdoor lighting fixture, a streetlight fixture and an outdoor lighting system as set forth in the appended claims. [Means for solving the problem]

[0009] According to a first aspect of the invention, there is provided an outdoor luminaire comprising a housing having a centre and including a light exit window. A mounting element is attached to or integrally formed with the housing and configured to mount the luminaire to a (pole) structure, a luminaire axis extending through said centre and said mounting element. A lighting unit including a light source is accommodated in the housing, the light source emitting an illumination light beam through the light exit window in operation. The outdoor lighting fixture further includes at least a first antenna, a second antenna, a third antenna, and a fourth antenna, each of the first antenna, the second antenna, the third antenna, and the fourth antenna having a first directional radiation pattern, a second directional radiation pattern, a third directional radiation pattern, and a fourth directional radiation pattern, respectively, and a first line of sight, a second line of sight, a third line of sight, and a fourth line of sight as a first main direction, a second main direction, a third main direction, and a fourth main direction, respectively, of each of the first directional radiation pattern, the second directional radiation pattern, the third directional radiation pattern, and the fourth directional radiation pattern, respectively. The line of sight is perpendicular to a first vertical axis along the direction of gravity, and the antennas together cover a range of at least 300 degrees (preferably a range of 360 degrees) in a horizontal plane when the luminaire is mounted, and the mounting element is positioned outside the line of sight of the antennas.

[0010] A first alternative expressing the invention is: 1. An outdoor luminaire comprising: a housing having a center, the housing including a substantially planar light exit window; a mounting element attached to or integrally formed with the housing, the mounting element configured to mount the luminaire to a structure; a luminaire axis extending through the center and the mounting element; a lighting unit including a light source, the lighting unit being accommodated in the housing, the light source emitting an illumination light beam through the light exit window in a mean beam direction at an angle Φ between 70 and 110 degrees with a plane P; and a plurality of light sources arranged substantially in the plane P in a stacked position, each aligned along the light exit window and the mean beam direction. and at least a first antenna, a second antenna, a third antenna, and a fourth antenna disposed in a first position (P), the first antenna, the second antenna, the third antenna, and the fourth antenna having a first directional radiation pattern, a second directional radiation pattern, a third directional radiation pattern, and a fourth directional radiation pattern, respectively, each having a first line of sight, a second line of sight, a third line of sight, and a fourth line of sight as a first main direction, a second main direction, a third main direction, and a fourth main direction of each of the first directional radiation pattern, the second directional radiation pattern, the third directional radiation pattern, and the fourth directional radiation pattern, respectively, the lines of sight extending (substantially) in the plane P, the antennas together covering a range of at least 300 degrees in the plane P, and a mounting element positioned essentially outside the lines of sight of the antennas in the plane P.

[0011] In the context of the present invention, the expression "substantially flat" here is to be understood as a plate-like or slightly curved plate over an angle of up to 20°. In the context of the present invention, the expression "essentially" here means coinciding with or extending / adjacent to the plane P or crossing the plane P at an acute angle of less than or equal to 5°.

[0012] A second alternative expressing the invention is: An outdoor lighting fixture comprising: a housing having a center, the housing including a light exit window; a mounting element attached to or integrally formed with the housing, the mounting element configured to mount the lighting fixture to a (pole) structure; a lighting fixture axis extending through the center and the mounting element; a lighting unit including a light source, the lighting unit being accommodated in the housing, the light source emitting an illumination light beam through the light exit window in operation; and a first antenna unit including at least one first antenna having a first directional radiation pattern facing in a first direction towards the mounting element and a first line of sight as a main direction of the first directional radiation pattern when the lighting fixture comprises a single lighting fixture head, the mounting element being positioned outside the first line of sight.

[0013] A third alternative expressing the invention is: 1. An outdoor luminaire comprising: a housing having a center, the housing including a light exit window; a mounting element attached to or integrally formed with the housing, the mounting element configured to mount the luminaire to a (pole) structure, a luminaire axis extending through the center and the mounting element; a lighting unit including a light source, the lighting unit being accommodated in the housing, the light source emitting an illumination light beam through the light exit window in operation; and a first antenna unit having at least one first antenna having a first directional radiation pattern and a first line of sight along the luminaire axis, the first line of sight being: i) in the case where the luminaire comprises a single luminaire head; ii) in the case where the luminaire comprises two oppositely arranged luminaire heads, a first antenna unit facing in a first direction towards the mounting element, or ii) in the case where the luminaire comprises two oppositely arranged luminaire heads, facing in a direction along the luminaire axis, away from the mounting element, and at least one further antenna, included in the at least first antenna unit, having a further directional radiation pattern and a further line of sight facing in a further direction, wherein the first line of sight and the further line of sight lie in a plane orthogonal to a first vertical axis along the direction of gravity when the luminaire is mounted, and wherein the further direction forms an angle β with the first direction, 70°≦β≦290°, and the mounting element is positioned outside the first line of sight and the further line of sight of the antenna.

[0014] A fourth alternative expressing the invention is: An outdoor lighting fixture comprising: a housing having a center, the housing including a light exit window; a mounting element attached to or integrally formed with the housing, the mounting element configured to mount the lighting fixture to a (pole) structure, the lighting fixture axis extending through the center and the mounting element; a lighting unit including a light source, the lighting unit being housed in the housing, the light source emitting an illumination light beam through the light exit window in operation; and a first antenna unit having at least one first antenna having a first directional radiation pattern and a first line of sight along the lighting fixture axis. The lighting fixture further comprises second, third and fourth antennas. The second antenna has a second directional radiation pattern and a second line of sight that faces a second direction perpendicular to the first direction when the lighting fixture is mounted. The third antenna has a third directional radiation pattern and a third line of sight that faces in a third direction opposite to, away from, and perpendicular to the second direction when the luminaire is mounted. The fourth antenna has a fourth directional radiation pattern and a fourth line of sight that faces in a fourth direction opposite to, away from, and perpendicular to the second direction when the luminaire is mounted. The first, second, third and fourth lines of sight lie in a plane P that is orthogonal to a first normal axis that is aligned with the direction of gravity when the luminaire is mounted. The mounting element is positioned outside the first, second, third and fourth lines of sight of all four antennas such that i) when the mounting element is positioned in an area bounded by all four antennas, the lines of sight of all antennas point away from the mounting element, or ii) when the mounting element is positioned outside the area bounded by all four antennas, the line of sight of the first antenna points in a first direction toward the mounting element.

[0015] The present invention relates to two basic configurations of outdoor luminaires in which this blocking effect by the mounting element (and carrier) is counteracted: a first configuration relates to an outdoor luminaire with a single luminaire head housing all antennas, and a second configuration relates to an outdoor luminaire with two luminaire heads arranged opposite each other and facing away from each other, with the housing of the antennas being distributed over the two heads.

[0016] In order to cover a range of at least 300 degrees in the horizontal plane for communication, for example 320 degrees or preferably 360 degrees, the single head or two heads of the outdoor lighting fixture together include multiple antennas, namely at least a first antenna (also called South or Back antenna), a third antenna (also called North or Front antenna) arranged oppositely facing away from the first antenna, a second antenna (also called East antenna) and a fourth antenna (also called West antenna). The second and fourth antennas are also called two side antennas, which are arranged oppositely, facing away from each other and oriented in a transverse orientation with respect to the first and third antennas. The antennas typically have a radiation pattern with a transmission and / or reception angle θ in the horizontal plane (when the lighting fixture is mounted) of less than or equal to 90 degrees, such as 60 degrees, 75 degrees or 80 degrees. Typically, 45°≦θ≦90°. Thus, if θ is 90 degrees and the luminaire includes four antennas, and the antennas are mutually oriented similarly to the four cardinal directions of a compass, each antenna covers a different quadrant of a circle in the horizontal plane, and thus a complete circle is covered by the four antennas. However, antennas with angles smaller than 90 degrees may be used. Typically, to cover the entire range of 360 degrees in the horizontal plane, an outdoor luminaire may include more than four antennas, for example, 5, 6, 8, 12, or even up to 24 antennas. It has been found that for known outdoor luminaires, the performance of the antenna (herein referred to as the first antenna) facing the mounting element in the luminaire head is relatively poor. The reason is that in these known outdoor luminaires, antennas with directional radiation patterns are used. Typically, this radiation pattern and line of sight of the first antenna facing the mounting element (when all antennas are located in a single luminaire head) is (partially) blocked by the mounting element (and carrier, e.g., pole) for positioning and mounting the outdoor luminaire.

[0017] In the case of a single head configuration, the proposed arrangement of (at least) the first antenna in a single head, e.g. in the canopy of the luminaire head, achieves that (partial) blocking of the line of sight of the first antenna by mounting elements (and / or poles) is prevented or reduced. This can be achieved by asymmetrically arranging the first antenna with respect to the two side antennas. More preferably, the back antenna is also arranged asymmetrically with respect to the front antenna. Despite the fact that symmetric positioning of antennas in the luminaire head is desirable from the viewpoint of aesthetics and available space in the canopy, it is clear that a symmetric arrangement is not the best solution to achieve a 360° range in the horizontal plane for communication. Alternatively, the four antennas are arranged symmetrically with respect to each other, but rotated as a single unit by a small angle α on a vertical axis with respect to the housing of the luminaire head.

[0018] In the case of a two-head configuration, the four antennas may be arranged in two mutually oppositely arranged (i.e. rotated 180° relative to each other on a vertical axis) heads of the outdoor luminaire, said two heads being preferably identical to simplify the assembly of the complete outdoor luminaire and / or to keep the number of different outdoor parts relatively low. Each luminaire head includes a respective housing having a respective center C and including a respective light exit window. By respective mounting elements of the respective luminaire heads, the housings of the luminaire heads are mounted to a shared / common carrier, e.g. a light pole. Each housing houses a respective antenna unit having two respective antennas. The two antennas in the first luminaire head are considered as the first and second antennas, and the two antennas in the second luminaire head are considered as the third and fourth antennas. Each of the first, second, third and fourth antennas has a respective line of sight. The first, second, third and fourth lines of sight lie in a plane P perpendicular to a vertical direction Vd, which is the direction of gravity in the mounted outdoor luminaire. The four antennas surround an enclosed area EA, and the mounting element is arranged within the enclosed area EA. In this way it can be achieved that none of the four antennas points towards the mounting element, i.e. all the lines of sight of the antennas point away from the mounting element, and that (partial) blocking of the line of sight of the first antenna by the mounting element (and / or pole) is prevented or reduced.

[0019] As mentioned above, the light source emits a light beam through the light exit window. When the outdoor luminaire is a street lamp and its intended use is to illuminate a length of a road, typically such light beam is elongated, e.g. a batwing-shaped beam with lobes. The batwing-shaped beam is oriented such that its lobes and / or its elongated dimension are perpendicular to the luminaire axis La and in the same direction as the second and fourth lines of sight of the side antennas. In this case, the elongated light beam not only forms a (continuous) light line along the length of the road, but also the communication between adjacent outdoor luminaires is well aligned, enhancing relatively reliable and / or efficient communication along the length of the road. Typically, the lobes of the batwing beam are distributed according to the course of the road, and (most obviously) the second and fourth antennas have lines of sight distributed towards the luminaires of the adjacent street lamps on their respective sides.

[0020] The (pole) structure to which the outdoor lighting fixture is to be mounted must be strong enough to support the weight of the outdoor lighting fixture. When the outdoor lighting fixture is placed along the roadside, such structure is most likely a solid (light) pole structure or mast, e.g. made of metal, with internal electrical wiring to power the outdoor lighting fixture. However, other structures are possible, such as a brick wall, fence, or frame. The mounting element by which the outdoor lighting fixture is attached to the carrier is typically at least one of a clamping bracket, a screw, a bolt and nut combination, a manchette, a tubular-shaped element, a hose clamp, tie-raps, and the like.

[0021] In the context of the present invention, the expression "along" is to be understood as an angle with respect to the luminaire axis in the range of -20° to +20°, in particular in the range of -15° to +15°.

[0022] The orientation of the four antennas can also be expressed in the following terms: the respective lines of sight are mutually oriented similarly to the four cardinals of a compass. In the context of the present invention, the expression "similar to the four cardinals of a compass" should be understood to mean two pairs of oppositely oriented antennas facing away from each other, i.e., the antennas of a single pair are oriented at a mutual angle of 180° and the two pairs are oriented perpendicular to each other. In yet another way, the antenna configuration may be expressed in terms that the four antennas each form two pairs of two antennas, with the antennas of each antenna pair facing in opposite directions and the two pairs of two antennas facing in orthogonal directions.

[0023] The outdoor luminaire may be characterized in that (the outdoor luminaire includes only a single luminaire head) the first radiation pattern is directed towards the mounting element and the first line of sight has an angle α with respect to the luminaire axis, α being in the range of 3 to 20 degrees, preferably in the range of 5 to 15 degrees. This may be the case only for the first antenna, but also for some or all of the antennas. The outdoor luminaire may be characterized in that the four antennas form a single unit rotated by an angle α on an axis A that is essentially perpendicular to the vertical gravity direction or to a horizontal plane P (when mounted), α being selected such that the line of sight of the first antenna directed towards the mounting element has a line of sight just along the mounting element. The degree of rotation may depend on the size of the mounting element in the plane P and the distance between the first antenna and the mounting element in the plane P. To that end, preferably α is at least 3°, more preferably α is at least 5°, however, for other practical reasons α should be kept as small as possible, e.g. in that the second and fourth lines of sight are oriented in a direction substantially along the two lobes of the illumination light beam of a batwing shaped beam emitted by the light source, and therefore preferably α is at most 25°, more preferably α is at most 20°, and most preferably α is at most 15°.

[0024] The outdoor luminaire may be characterized in that (wherein the outdoor luminaire includes only a single luminaire head) the first radiation pattern is directed towards a mounting element and the first line of sight is located at a distance δ from the luminaire axis (La), δ being at least half the width (W) of the mounting element in a direction in the plane P transverse to the luminaire axis. The outdoor luminaire may be characterized in that the first antenna is in a shifted position relative to the mounting element in the plane P such that the mounting element is positioned outside the line of sight of the first antenna. Typically, the distance δ is preferably at least 5 cm, more preferably at least 8 cm, most preferably at least 10 cm, preferably 30 cm or less, more preferably 25 cm or less, most preferably 20 cm or less. The shifting of the first antenna relative to the mounting element may achieve a single unit shift of the first, second, third and fourth antennas, where the first antenna remains symmetrically positioned relative to the other (i.e., second, third and fourth) antennas. However, in a first alternative of such a shift, the shift of the first antenna relative to the mounting element can also be achieved by asymmetrical placement of the first and third antennas relative to the second and fourth antennas. In a second alternative of such a shift, the shift of the first antenna relative to the mounting element can also be achieved by asymmetrical placement of the first antenna relative to the second, third and fourth antennas. However, the outdoor luminaire may have the feature that the first direction is opposite to the third direction and the first line of sight is anti-parallel (i.e. parallel but in the opposite direction, i.e. about 180 degrees) to the third line of sight. In this case, the outdoor luminaire may have the first antenna asymmetrically placed relative to the third antenna and the mounting element. In one embodiment, the (centre of) the (said) third antenna unit is located on the luminaire axis.

[0025] The outdoor lighting fixture may also include a combination of rotation through the angle α and shifting of the first and / or more antennas through the distance δ, provided that this results in the mounting element being positioned outside the line of sight of the antennas.

[0026] The outdoor luminaire may be characterized in that the second direction is perpendicular to the first direction and / or the second line of sight is perpendicular to the first line of sight, the fourth direction is opposite to the second direction and / or the fourth line of sight is anti-parallel to the second line of sight, and in a direction perpendicular to the luminaire axis, a distance D1 between the at least one first antenna and the at least one second antenna is less than a distance D2 between the at least one first antenna and the at least one fourth antenna, 0.5*D2≦D1≦0.9*D2. Thus, a first (south) antenna is asymmetrically positioned with respect to the second and fourth antennas.

[0027] The outdoor lighting fixture may be characterized in that a virtual first line between the second antenna and the fourth antenna and a virtual second line between the third antenna and the mounting element virtually cross each other to form a virtual cross shape, and the first antenna is arranged asymmetrically with respect to the virtual cross shape. In such a cross-shaped arrangement, the angle between the line of sight of the first antenna and the second antenna, the second antenna and the third antenna, the third antenna and the fourth antenna, and the fourth antenna and the first antenna is 90° (i.e., β=90°). Also, in this case, the direction of the radiation pattern of the four antennas is essentially optimal to cover a range of 360° in the horizontal plane for communication purposes. Moreover, such a cross shape is a relatively simple configuration.

[0028] The outdoor lighting fixture may be characterized in that (in operation) the light beam is an elongated beam having a beam length direction, and the second and fourth directions are substantially along the beam length direction. Typically, such elongated light beams have an anisotropic light distribution having a first axis and a second axis perpendicular to the first axis. The first axis corresponds to a largest spatial light distribution of the light beam along which the second and fourth directions extend. In a similar aspect, the outdoor lighting fixture may be characterized in that the light beam is a batwing beam having two lobes extending in respective first and second lobe directions, and the second and fourth directions are substantially along the respective first and second lobe directions. Typically, the elongated direction of the beam and / or the lobes of the batwing beam are distributed according to the course of the road and (most obviously) the second and fourth antennas have a line of sight distributed towards the adjacent street light luminaires on each side, thus achieving improved communication between adjacent street light fixtures.

[0029] The outdoor luminaire may have the feature that the number of antennas in the luminaire is four and the number of luminaire heads is two, the two luminaire heads essentially facing in opposite directions from each other, the four antennas being distributed as two antenna units on the two luminaire heads such that their respective lines of sight are oriented with respect to each other similarly to the four cardinal points of a compass, and all antennas point away from the mounting element such that the mounting element is outside the lines of sight of all four antennas. Preferably, to simplify assembly and / or installation and / or to reduce the number of different inventory parts, the outdoor luminaire has two identical luminaire heads, i.e. each of the two luminaire heads includes an antenna unit including an east antenna and a north antenna and not including a west antenna and a south antenna, or an antenna unit including a west antenna and a north antenna and not including an east antenna and a south antenna.

[0030] The outdoor luminaire may have the feature that each antenna is at least partially enclosed in a housing, for example covered by a canopy. The housing provides protection against mechanical and / or environmental impacts from outside the housing. On the other hand, the housing may block the radiation pattern and / or line of sight of the antenna, with the risk of (partial) blocking effects of the radiation pattern and / or line of sight. Partially enclosing the antenna in the housing is a good compromise to counteract said blocking effects and to obtain said protection.

[0031] The outdoor luminaire may further comprise a modulation unit inside the housing for use as a communication node in a wireless data network connected to the first antenna, the second antenna, the third antenna and the fourth antenna. The modulation unit is configured to generate one or more signals for transmission using the first antenna, the second antenna, the third antenna and the fourth antenna. If the outdoor luminaire includes two luminaire heads, it is efficient and cost-interesting to provide a modulation unit in only one of the two luminaire heads. The modulation unit may operate as a node in a point-to-point link or as a leaf node in a point-to-multipoint wireless communication system. The operating frequency of the first modulation unit is at least 6 GHz or higher, preferably in the millimeter wave frequency band in the range of 30 GHz to 300 GHz, more preferably in the 60 GHz band spanning approximately 51 to 71 GHz. The first modulation unit is preferably a MU-MUMO radio supporting a directional link using electronic beamforming, as known from IEEE 802.11ay-2021 style radios and / or Terragraph radios. The first modulation unit includes, for example, a baseband unit and an RF unit configured to drive a transmit signal via a feed line towards a first antenna unit including at least one antenna. In case of bidirectional communication, the feed line is alternately used to transmit a receive signal to a receiver. The directional antenna may be a passive directional antenna or an active directional array antenna. For simplicity, the transmit signal is referred to in the singular form here as it relates to the transmit signal of a single antenna. However, as will be clear to those skilled in the art, when using electronic beamforming, the transmit signal includes separate signals for separate elements of an active array antenna.

[0032] The invention further relates to a streetlight fixture comprising an outdoor lighting device according to the invention. The streetlight fixture further comprises a (light) pole or mast as a carrier.

[0033] The present invention further relates to an outdoor lighting system comprising a plurality (at least two) of street light fixtures according to the present invention, wherein the plurality (at least two) street light fixtures are in line-of-sight of and / or in communication with each other.

[0034] The plurality of streetlight fixtures may be at least 10, 1,000, or 10,000, or even more than 100,000 for very wide communication networks covering entire cities, countries, and / or continents. Using such antenna configurations for outdoor lighting system fixtures, a mesh network can be created with wireless nodes at luminaires located along the street. Using at least three antennas per luminaire, a mesh network with a ladder-like network topology, or using four antennas per luminaire, a matrix-like network topology can be realized, providing redundancy and graceful degradation for connections along the street that are resistant to obstacles such as trees and / or that follow the street layout, etc. [Brief description of the drawings]

[0035] In the schematic drawings, like reference characters generally refer to the same parts throughout the different views and the drawings are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the invention. [Figure 1] 1A and 1B show a first embodiment of a lighting fixture comprising an outdoor lighting apparatus according to the present invention. [Diagram 2] FIG. 2 shows a second embodiment of an outdoor luminaire according to the present invention. [Diagram 3] 3A and 3B show a third embodiment of a lighting fixture comprising an outdoor lighting device according to the present invention. [Figure 4]FIG. 4 shows a fourth embodiment of an outdoor luminaire according to the present invention. [Diagram 5] FIG. 5 shows a fifth embodiment of an outdoor luminaire according to the present invention. [Figure 6] FIG. 6 shows a bird's-eye view of an example of an intersection in which an embodiment of an outdoor lighting system according to the present invention is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] 1A shows a first embodiment of a streetlighting fixture 10 comprising an attached outdoor luminaire 100 in accordance with the present invention. The luminaire 100 has a single luminaire head 110 and is attached to a pole 12 of the fixture 10 by a mounting element 120.

[0037] FIG 1B shows a detailed top view of the luminaire 100 of FIG 1A. The outdoor luminaire 100 comprises a housing 130 having a center C and including a light exit window 150 (as shown in FIG 1A). A mounting element 120 is integrally formed by the housing 130. A luminaire axis La extends through said center C and said mounting element 120. A lighting unit 160 comprises a light source 170 and is accommodated in the housing 130, said light source 170 being configured to emit an illumination light beam 180 in operation through a light exit window (not shown in FIG 1B). A mean beam direction Ba makes an angle Φ of about 80 degrees with the plane P. The housing further accommodates a modulation unit 190, a first antenna 210, as well as further antennas, a second antenna 220, a third antenna 230 and a fourth antenna 240, which are essentially lying in the plane P and are in a stacked position with the light exit window 150 when viewed along the average beam direction Ba.

[0038] The first antenna 210 is configured to emit a first directional radiation pattern 212, during operation, and has a first line of sight 214 as a first main direction (216) of the first directional radiation pattern (212), oriented in a first direction 216 toward the mounting element 120. The further antennas, i.e., second antenna 220, third antenna 230, and fourth antenna 240, are configured in operation to emit further radiation patterns, i.e., second radiation pattern 222, third radiation pattern 232, and fourth radiation pattern 242, and have further lines of sight, i.e., second line of sight 224, third line of sight 234, and fourth line of sight 244, as second main direction (226), third main direction (236), and fourth main direction (246) of the second directional radiation pattern (222), third directional radiation pattern (232), and fourth directional radiation pattern (242), respectively, pointing in further directions, i.e., second direction 226, third direction 236, and fourth direction 246. Each of the four radiation patterns 212, 222, 232, 242 has a transmission and / or reception angle θ of 90 degrees, and due to the mutual orientation of the four antennas, a 360 degree covering in the horizontal plane is achieved. The first line of sight 214, the second line of sight 224, the third line of sight 234 and the fourth line of sight 244 are preferably, but not necessarily, in a plane P, which is perpendicular to the vertical direction Vd, which is the direction of gravity, in the mounted luminaire. As shown in FIG. 1B, the first antenna 210 is asymmetrically arranged in the housing 130 with respect to the further antennas 220, 230, 240, such that the mounting element 120 is arranged in the plane P, but in a shifted position with respect to the mounting element 120, i.e., shifted over a shift δ in the horizontal plane P, so that the mounting element 120 is located outside the first line of sight 214 of the first antenna 210.

[0039] The four directions 216, 226, 236, 246 or lines of sight 214, 224, 234, 244 of the four antennas 210, 220, 230, 240 can also be expressed in terms in which the respective lines of sight are oriented with respect to one another in the same manner as the four cardinal directions of a compass, i.e., the first direction 216 forms an angle β of essentially 90° with the second direction 226, an angle β of essentially 180° with the third direction 236, and an angle β of essentially 270° with the fourth direction 246. In other words, the housing 130 accommodates two pairs of oppositely oriented antennas, i.e., a first pair formed by a first antenna 210 and a third antenna 230 facing away from each other, and a second pair formed by a second antenna 220 and a fourth antenna 240 in an opposing arrangement facing away from each other, the first pair and the second pair being oriented perpendicular to each other.

[0040] The modulation unit 190 is configured for use as a communication node in a wireless data network connected to the first antenna and the further antenna, and is configured to generate first and further signals for transmission using the first and further antennas.

[0041] 1A-B, the light source emits a batwing-shaped light beam 180 having lobes 182, 184. The batwing-shaped beam is oriented such that its lobes 182, 184 are perpendicular to the luminaire axis La and in the same direction as the second line of sight 224 and the fourth line of sight 244.

[0042] FIG. 2 shows a top view of a second embodiment of an outdoor luminaire 100 according to the invention. The luminaire 100 has a single luminaire head 110 and includes an attached mounting element 120 for mounting to a pole 12 of an outdoor fixture. The outdoor luminaire 100 includes a housing 130 having a center C and including a light exit window (not shown). The housing 130 is attached to the mounting element 120. A luminaire axis La extends through said center C and said mounting element 120. A lighting unit 160 includes a light source 170 and is housed in the housing 130, said light source 170 being configured to emit an illumination light beam 180 through the light exit window in operation. The illumination light beam 180 includes two lobes 182, 184. The housing further houses a modulation unit 190, a first antenna 210, and further antennas, a second antenna 220, a third antenna 230, and a fourth antenna 240.

[0043] The first antenna 210 has a first line of sight 214 pointing in a first direction 216 towards the mounting element 120. The further antennas, i.e. the second antenna 220, the third antenna 230 and the fourth antenna 240, have further lines of sight, i.e. the second line of sight 224, the third line of sight 234 and the fourth line of sight 244 pointing in further directions, i.e. the second direction 226, the third direction 236 and the fourth direction 246. The first line of sight 214, the second line of sight 224, the third line of sight 234 and the fourth line of sight 244 lie in a plane P that is orthogonal to a vertical direction Vd, which is the direction of gravity in the mounted luminaire. The four antennas 210, 220, 230, 240 are oriented relative to one another similar to the cardinal points of a compass, and so are the four lines of sight 214, 224, 234, 244, as described with respect to FIG. 1B.

[0044] As shown in FIG. 2, the mounting element is disposed outside the enclosed area EA surrounded by the four antennas 210, 220, 230, 240, with the first antenna 210 pointing towards the mounting element 120. As further shown in FIG. 2, at least the first antenna 210 is disposed asymmetrically in the housing 130, but symmetrically with respect to the further antennas, namely the second antenna 220, the third antenna 230 and the fourth antenna 240. Notably, in this embodiment, all four antennas 210, 220, 230, 240 are rotated as a single unit of antennas on an axis A with respect to the luminaire axis La by an angle α. Said axis A runs essentially through the center C and essentially perpendicular to the plane P. The angle α is such that the first antenna 210 pointing towards the mounting element 120 has a first line of sight 214 that passes just along the mounting element. In FIG. 2, α is about 8°. As a result of this slight rotation, the second line of sight 224 and the fourth line of sight 244 are oriented substantially along the two lobes 182 , 184 of the batwing-shaped illumination light beam 180 emitted by the light source 170 .

[0045] 3A shows a third embodiment of a street lighting fixture 10 comprising an attached outdoor luminaire 100 according to the present invention. The luminaire 100 has a first luminaire head 110 positioned opposite a second luminaire head 140. Each luminaire head is attached to the same, single pole 12 of the fixture 10 by a respective mounting element 120.

[0046] FIG. 3B shows a detailed top view of the luminaire 100 of FIG. 3A. The first luminaire head 110 and the second luminaire head 140 of the outdoor luminaire 100 are identical to each other, but are arranged opposite each other so as to be rotated through 180° to each other on a vertical axis A. Each luminaire head 110, 140 includes a respective housing 130 having a respective center C and including a respective light exit window 150 (as shown in FIG. 3A). The respective mounting element 120 is integrally formed by the respective housing 130 of the respective luminaire head 110, 140. A luminaire axis La extends through said respective center C and said respective mounting element 120. Each lighting unit 160 includes a respective light source 170, housed in the respective housing 130, and said respective light source 170 is configured to emit a respective illumination light beam 180 through a respective light exit window (not shown in FIG. 3B) in operation.

[0047] Each housing 130 further houses a respective modulation unit 190 and a respective antenna unit including two respective antennas. The two antennas in the first luminaire head 110 are considered as a first antenna 210 and a second antenna 220, and the two antennas in the second luminaire head 140 are considered as a third antenna 230 and a fourth antenna 240. The first antenna 210 is configured to emit a first directional radiation pattern 212 in operation and has a first line of sight 214 pointing in a first direction 216. The second antenna is configured to emit a second radiation pattern 222 in operation and has a second line of sight 224 pointing in a second direction. The third antenna 230 is configured to emit a third directional radiation pattern 232 in operation and has a third line of sight 234 pointing in a third direction 236. The fourth antenna 240 is configured to emit a fourth radiation pattern 242 in operation and has a fourth line of sight 244 pointing in a fourth direction 246. The first line of sight 214, the second line of sight 224, the third line of sight 234, and the fourth line of sight 244 lie in a plane P perpendicular to a vertical direction Vd, which is the direction of gravity at the mounted outdoor lighting fixture. As shown in FIG. 3B, the four antennas 210, 220, 230, 240 surround an enclosed area EA, and the mounting element 120 is disposed within the enclosed area EA. As further shown, all lines of sight 214, 224, 234, 244 of the antennas 210, 220, 230, 240 point away from the mounting element 120.

[0048] Each modulation unit 190 is configured for use as a communication node in a wireless data network connected to the first antenna 210 and the further antennas 220, 230, 240 and configured to generate first and further signals for transmission using the first antenna 210 and the further antennas 220, 230, 240. Although each illustrated luminaire head 110, 140 includes a respective modulation unit 190, it is also possible that only either the first luminaire head 110 or the second luminaire head 140 includes a modulation unit 190, which is shared by both luminaire heads 110, 140.

[0049] 3A-B, the light source of each luminaire head 110, 140 emits a respective elongated shaped light beam 180. Both elongated shaped beams are oriented perpendicular to the luminaire axis La and in the same direction as the second line of sight 224 and / or the fourth line of sight 244.

[0050] 4 shows a top view of a fourth embodiment of an outdoor luminaire 100 according to the invention. The luminaire 100 has a single luminaire head 110 and includes an attached mounting element 120 for mounting to a pole 12 of an outdoor fixture. The outdoor luminaire 100 includes a housing 130 having a center C and including a light exit window (not shown). The housing 130 is attached to the mounting element 120. A luminaire axis La extends through said center C and said mounting element 120. A lighting unit, an illumination light beam and a modulation unit are present in the luminaire but are not shown for clarity. The luminaire 100 includes a first antenna 210, a second antenna 220, a third antenna 230, a fourth antenna 240 and four further antennas 250.

[0051] The first antenna 210 has a first line of sight 214 pointing in a first direction 216 towards the mounting element 120. The further antennas, i.e. the second antenna 220, the third antenna 230 and the fourth antenna 240, have further lines of sight, i.e. the second line of sight 224, the third line of sight 234 and the fourth line of sight 244 pointing in further directions, i.e. the second direction 226, the third direction 236 and the fourth direction 246. The first line of sight 214, the second line of sight 224, the third line of sight 234 and the fourth line of sight 244 lie in a plane P that is orthogonal to a vertical direction Vd, which is the direction of gravity in the mounted luminaire. The four antennas 210, 220, 230, 240 are mutually oriented in the same manner as the cardinal directions of a compass, and thus the four lines of sight 214, 224, 234, 244, as described with reference to FIG. 1B. In a direction perpendicular to the luminaire axis La, the distance D1 between the at least one first antenna 210 and the at least one second antenna 220 is smaller than the distance D2 between the at least one first antenna and the at least one fourth antenna, 0.7*D2≈D1. The further antennas 250 are arranged similarly to the first antenna 210, the second antenna 220, the third antenna 230 and the fourth antenna 240, but rotated by 45 degrees on the vertical axis A in the direction of gravity (in the mounted configuration of the luminaire) and have their further radiation pattern 252 and their further lines of sight 254 in further directions 256.

[0052] 5 shows a schematic top view of the antenna arrangement of a fifth embodiment of an outdoor luminaire 100 according to the invention. The outdoor luminaire 100 has a group of six antennas 200 arranged according to six-rotational symmetry around the center C of the hexagonal regular polygon housing 130, with the antennas in slightly shifted positions along each side of the polygon such that the mounting elements 120 and poles 12 are outside the line of sight of the antennas.

[0053] FIG. 6 shows a bird's-eye view of an example of an intersection 1000 in which an embodiment of an outdoor lighting system 1 according to the present invention is provided, seen from a vertical direction Vd. The outdoor lighting system 1 includes a number of street light fixtures 10 arranged along the intersection 1000 according to a road layout. Seven street light fixtures 10 are shown in FIG. 6 to be included in a communication network enabling mutual communication. Each street light fixture 10 includes a lighting fixture 100 according to the present invention. As indicatively shown, each lighting fixture 100 includes at least one antenna unit including four antennas, emits four radiation patterns and has four lines of sight, each of which is oriented in the same way as the cardinal directions of a compass with respect to each other, as described with respect to FIG. 1B. As shown diagrammatically for a first street light fixture 10a, radiation patterns 212, 242 are emitted in the direction of the neighboring street light fixtures 10b, 10c, 10d. Said street light fixtures 10b, 10c and 10d have respective lines of sight that overlap with (at least one of) the radiation patterns 212, 242 emitted by the first street light fixture 10a, thus enabling communication, e.g. data transfer, from the first street light fixture 10a to the further street light fixtures 10b-d. Figure 6 further shows that the line of sight 244 of the first street light fixture 10a overlaps with the radiation pattern 222 emitted from the neighbouring further street light fixture 10b towards the first street light fixture 10a, thus enabling hence and forth communication between the first street light fixture 10a and the further street light fixture 10b. Analogously, back and forth communication between more other neighbouring street light fixtures 10 is likewise possible, thus forming a communication network.

Claims

1. 1. An outdoor lighting fixture, comprising: a housing having a center, the housing including a substantially flat light exit window; a mounting element attached to or integrally formed with the housing, the mounting element configured to mount the lighting fixture to a structure; a luminaire axis extending through said center and said mounting element; an illumination unit including a light source, the illumination unit being accommodated in the housing, the light source emitting an illumination light beam through the light exit window in an average beam direction at an angle between 70 and 110 degrees with a plane P in operation; at least a first antenna, a second antenna, a third antenna and a fourth antenna arranged essentially in said plane P and each arranged in a stacked position along said light exit window and said average beam direction; Including, the first antenna, the second antenna, the third antenna, and the fourth antenna have a first directional radiation pattern, a second directional radiation pattern, a third directional radiation pattern, and a fourth directional radiation pattern, respectively, each having a first line of sight, a second line of sight, a third line of sight, and a fourth line of sight as a first main direction, a second main direction, a third main direction, and a fourth main direction of the first directional radiation pattern, the second directional radiation pattern, the third directional radiation pattern, and the fourth directional radiation pattern, respectively; the line of sight extends substantially in the plane P, and the antennas together cover a range of at least 300 degrees in the plane P; The mounting element is positioned essentially outside the line of sight of the antenna in the plane P.

2. 10. The outdoor lighting fixture of claim 1, wherein the outdoor lighting fixture includes only a single lighting fixture head, the first radiation pattern is directed toward the mounting element, and the first line of sight has an angle α with respect to the lighting fixture axis, where α is in the range of 3 to 20 degrees.

3. 2. The outdoor lighting fixture of claim 1, wherein the outdoor lighting fixture includes only a single lighting fixture head, the first radiation pattern is directed toward the mounting element, and the first line of sight is located at a distance δ from the lighting fixture axis, where δ is at least half a width of the mounting element in a direction in the plane P that is transverse to the lighting fixture axis.

4. 4. The outdoor lighting fixture of claim 1, wherein the first direction is opposite to the third direction and the first line of sight is anti-parallel to the third line of sight.

5. the second direction and the second line of sight are perpendicular to the first line of sight; the fourth direction is opposite to the second direction, and the fourth line of sight is anti-parallel to the second line of sight; 5. The outdoor luminaire of claim 1, wherein a distance D1 between the at least one first antenna and the at least one second antenna in a direction perpendicular to the luminaire axis is smaller than a distance D2 between the at least one first antenna and the at least one fourth antenna, such that 0.5*D2≦D1≦0.9*D2.

6. 6. The outdoor lighting fixture of claim 4 or 5, wherein an imaginary first line between the second antenna and the fourth antenna and an imaginary second line between the third antenna and the mounting element virtually intersect each other to form an imaginary cross shape, and the first antenna is positioned asymmetrically with respect to the imaginary cross shape.

7. 7. The outdoor lighting fixture of claim 1, wherein the light beam is an elongated beam having a beam length direction, and the second direction and the fourth direction are along the beam length direction.

8. 7. The outdoor lighting fixture of claim 1, wherein the light beam is a batwing beam having two lobes extending in respective first and second lobe directions, and the second direction and the fourth direction are aligned with the respective first and second lobe directions.

9. 9. An outdoor luminaire according to any one of claims 1 to 8, wherein the number of antennas in the luminaire is four and the number of luminaire heads is two, the two luminaire heads point essentially in opposite directions, the four antennas being distributed as two antenna units on the two luminaire heads such that their respective lines of sight are oriented with respect to each other similar to the four cardinal points of a compass, and such that all antennas point away from the mounting element such that the mounting element is outside the line of sight of all four antennas.

10. 10. The outdoor lighting fixture of claim 9, wherein each of the two lighting fixture heads includes an antenna unit including an east antenna and a north antenna or an antenna unit including a west antenna and a north antenna.

11. 11. The outdoor lighting fixture of claim 1, wherein each antenna is at least partially contained within the housing.

12. 12. The outdoor lighting fixture of claim 1, further comprising a modulation unit within the housing for use as a communication node in a wireless data network connected to the first antenna, the second antenna, the third antenna, and the fourth antenna, the modulation unit configured to generate one or more signals for transmission using the first antenna, the second antenna, the third antenna, and the fourth antenna.

13. 13. The outdoor lighting fixture of claim 12, wherein the modulation unit is provided in only one of the two heads.

14. A street light fixture comprising the outdoor lighting device according to any one of claims 1 to 13, further comprising a pole as the structure.

15. 15. An outdoor lighting system comprising at least two street light fixtures according to claim 14, said at least two street light fixtures being in respective line-of-sight and / or in communication with each other.

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