WO2023052260A1

WO2023052260A1 - Outdoor luminaire with interior reorientable antenna

Info

Publication number: WO2023052260A1
Application number: PCT/EP2022/076510
Authority: WO
Inventors: Nicolaas Antonie VAN RIJSWIJK; René Cornelis REUSER; Ronald Johannes Gelten
Original assignee: Signify Holding B.V.
Priority date: 2021-09-30
Filing date: 2022-09-23
Publication date: 2023-04-06

Abstract

An outdoor luminaire (10) is provided for mounting on or attaching to a lighting fixture, the luminaire (10) comprising a housing (30), a first modulation unit (45), internal to the housing, for use as a communication node in a wireless data network connected to a first antenna unit (50) internal to the housing, the first modulation unit configured to generate a first signal (46) for transmission using the first antenna unit; the first antenna unit (50) having a plurality of antennas each having a directional radiation pattern (55) facing in a different direction, the plurality of antennas mounted on the first antenna unit (50) in a fixed manner and the respective antenna directions re-orientable by rotating the first antenna unit around or on a vertical axis (101) through the center of the first antenna unit.

Description

OUTDOOR LUMINAIRE WITH INTERIOR REORIENT ABLE ANTENNA

FIELD OF THE INVENTION

The invention relates to the field of outdoor lighting and communication networks. More particularly, various outdoor luminaires, lighting fixture and outdoor lighting systems are disclosed herein wherein the luminaires have reorientable antenna mounted therein.

BACKGROUND OF THE INVENTION

Outdoor lighting systems have been designed and deployed to provide illumination to improve visibility in the absence of natural daylight throughout the outdoor environment, such as on streets, in parks, at airports, and other public and/or private outdoor venues. However, over the last two decades outdoor lighting systems have been evolving in part as a result of the proliferation of networked technology.

More recently omnidirectional radios were added to streetlights in outdoor lighting systems, such as disclosed in United States Patent Application US 2007/0252528 AL These radios enable remote control of the lighting infrastructure using a wireless lighting control network. Radios, such as those based on IEEE802.15.4 and 6L0WPAN, allow the individual streetlights or lighting fixtures to operate as a wireless mesh network which when combined with a central controller allow a more versatile and flexible operation of the streetlights.

Over the last decade, there is a growing need for network connectivity, in particular in the smart city context. By deploying audio, video and environmental sensors municipalities want to better monitor and interact with the outdoor environment, this in combination with data collection and artificial intelligence allows for a better understanding and control of the urban environment. In addition, there is also a need for deploying a denser end-user communication service infrastructure, to enable new and/or higher quality services to users within the urban environment.

International patent application WO2014/141312 Al discloses a street type LED lighting body integrated with a telecommunications device having mounted therein a number of antennas pointing in a fixed direction. Chinese Utility Model CN205069845 U relates to an elongated communication antenna for use in a street lamp, wherein the elongated antenna shape is to enable use in an elongated street lamp and wherein the a motor is provided attached to the elongated antenna base for rotation of the antenna and thereby the antenna emission.

United States patent 8,564,497 Bl discloses a cylindrical-shaped enclosure having tapered ends that can be mounted on a light post. The enclosure on the interior houses a module having a radio disposed on a printed circuit board (PCB) and an antenna connected to the PCB. The antenna may be rotated about an axis that extends along a longest dimension of the enclosure, where the top or lower piece of the housing can house a lighting system.

SUMMARY OF THE INVENTION

Although outdoor lighting systems are good candidates for providing services beyond lighting, the uptake of connected lighting services does not appear to be in line with the need for such services. Several obstacles may be identified. Cost is an important obstacle for municipalities, although power generally is available at the location of legacy lighting fixtures, the communication infrastructure generally is not. Installing a wired data communication network to support the deployment of a data communication network within an outdoor lighting system can be very costly, as it requires closing and repairing postinstallation the streets and/or sidewalks where such wired communication links are installed.

Use of a wireless data communication network on the other hand will require mounting of additional wireless radio communication devices to the lighting fixtures which results usually rather unsightly pods or modules being mounted on lighting fixtures. Instead, the inventors propose to install a high-capacity data communication network in the outdoor lighting systems themselves, by embedding directional Radio Frequency, RF, communication equipment within the luminaires of the streetlights. Directional radio communication links here are beneficial in that they can reduce interference amongst adjacent devices. However, when integrating directional radios within luminaires, this also brings about a need to be able to properly orient the antennas of the radios.

In view of the above, the present disclosure is directed to outdoor luminaires, lighting fixtures and outdoor lighting systems that aim to ameliorate at least one of the problems discussed above. More particularly, the goal of this invention is achieved by an outdoor luminaire as claimed in claim 1, a lighting fixture as claimed in claim 10 and an outdoor lighting system as claimed in claim 12. In accordance with a first aspect of the invention an outdoor luminaire is provided for mounting on a light pole or structure, the luminaire comprising: a power connector for powering a lighting unit and a first modulation unit; a housing having a first exit window for egress of illumination light and a second exit window for ingress and egress of radio communication signals. The luminaire further comprising a mounting point attached to or integrally formed by the housing, the mounting point configured to mount the luminaire on the light pole or structure, the first modulation unit, internal to the housing, for use as a communication node in a wireless data network connected to a first antenna unit internal to the housing, the modulation radio unit configured to generate a first signal for transmission using the first antenna unit. The luminaire further comprises the first antenna unit, having at least one antenna having a directional radiation pattern facing a first direction, the first direction being mechanically re-orientable within a plane orthogonal to a vertical axis when the luminaire is mounted and the lighting unit comprising a light source for providing illumination light.

As a result of an independently re-orientable directional antenna, it is possible to mount/attach the luminaire to the lighting fixture/streetlight or other structure at an optimum orientation that allows the illumination output of the luminaire emitted through the first exit window to be directed in a preferred direction while at the same time enabling antenna re-orientation for tweaking the wireless links.

The modulation unit may operate as a node in a point-to-point link or as a leaf node in a point-to multi-point radio communication system. The operating frequency for the first modulation unit is at least above 6 GHz, and preferably in the mmWave frequency range, ranging from 30 GHz to 300 GHz, more preferably in the 60 GHz band which spans roughly 51-71 GHz. The first modulation unit is preferably a MU-MUMO radio supporting directional links that use electronic beamforming, such known from IEEE 802.1 lay -2021 style radios and/or Terragraph radios.

The first modulation unit may, for example, comprise a base-band unit and an RF unit configured for driving a transmit signal over a feedline towards the first antenna unit comprising the at least one antenna. In case of bi-directional communication, the feedline is used alternatively to transport a received signal to the receiver.

The directional antenna may be a passive directional antenna or an active directional array antenna. For the sake of brevity, the transmit signal here is referred to in singular, as it relates to the transmit signal for a single antenna. However as will be clear to those skilled in the art, when using electronic beamforming, the transmit signal comprises separate signals for the separate elements of the active array antenna.

When using bi-directional communication different methods may be used to implement bi-directional operation. For example, the first modulation unit, may utilize Time Division Duplexing (TDD), in which the first antenna unit is alternatively operated in a transmission or reception mode. Other time-division approaches are also feasible where radios coordinate accesses, allowing a more flexible time-slot allocation for transmission or reception. When simultaneous transmission and reception is required, alternative methods of operation are envisaged which may include Frequency Division Duplexing, or FDD. In this case different frequencies are used for the transmission and reception, thereby allowing simultaneous transmission and reception using the first antenna unit.

Preferably, the first antenna unit further comprises further antennas, each of the further antennas having a respective directional radiation pattern facing a respective different direction and each of the further antennas configured to receive a respective further signal for transmission from the first modulation unit and wherein the first and further antennas are mounted on the first antenna unit in a fixed manner and the respective antenna directions are mechanically re-orientable within the plane by rotating the first antenna unit around or on a second vertical axis through the center of the first antenna unit.

Advantageously, the above allows to re-orient the antennas in unison, thereby reducing the complexity of the redirection and simplifying the installation of the luminaires. Thereby even when as a result of the attachment of the luminaire to the pole and or mounting point, the communication quality resulting from the orientation of the antennas is compromised, the rotational freedom on the first antenna unit within the housing provides the flexibility to improve communication. Preferably, the respective antenna directions are offset with a 90 degree offset, ideal for Manhattan style street layouts.

The first antenna unit, may further be enhanced, by the addition of a member, for example in the form of a rod or pin, attached to the first antenna unit in a fixed manner and protruding through an opening in the housing. The member may be used to allow angular rotation of the first antenna unit without the need to open up the housing. Optionally the member may include fastening means for detachable fastening of the member in a position after alignment. To this end, the member may be fitted with a clamp, a clasp, or bolt that allows fixation of the member, and thereby angular orientation of the first antenna unit. The fastening means may attach to the exterior of the housing or a purpose built fixation member on the housing exterior, such as a rim or flange to which the clamp, clasp, or bolt can be attached. By using a known relation between the antenna orientation and the member and installer can install and align the luminaire in a simple manner, relying on beamforming for any fine-tuning.

Alternatively, instead of a pin/rod, a ring-shaped segment of the housing may be rotatable and attached in a fixed manner to the first antenna unit. In this manner the rotatable ring-shared segment may be used to manipulate the first antenna unit orientation. The advantage of this way of working is that in this manner, no apparent hole is visible Again some sort of fastening means, like a clamp or bolt may be used to fixate the rotatable housing segment to the rest of the housing once aligned. Decorative or abstract markers may be provided on the rotatable housing exterior to facilitate antenna alignment for the installer.

As a result of the use of multiple antenna’s the required angular rotational freedom can be limited without detracting from the full 360 degree coverage. The latter in turn may benefit structural integrity of the housing and facilitate weather proofing.

In a first option of the first aspect the power connector is a Power-over- Ethemet, PoE, connector and the PoE connector is arranged to provide power to the luminaire and at the same time to provide at least one of: 1) network connectivity that allows the first modulation unit to retrieve data via the PoE connector network for transmission over the wireless data network and 2) network connectivity that allows the first modulation unit to transmit data received over the wireless data network via the PoE connector.

Advantageously this first option allows the PoE connector to provide power to both the radio and the luminaire. In this configuration, the Power-Sourcing Equipment, PSE, is placed outside the luminaire, e.g. within the pole. This effectively distributes the power dissipation and space requirements over the PSE and Powered Device, PD, (here the luminaire). By doing so the thermal and space requirements for the luminaire are reduced. This, given the integration of the first modulation unit and first antenna unit within the housing is particularly advantageous/desirable.

The PoE connector may be used to communicate data destined for a Local Area Network, LAN, at the location where the luminaire is mounted. The luminaire thus relays data from the wireless data network destined to the LAN, to the LAN. This may for example be beneficial in applications where a command for a local sensor at the pole or luminaire needs to be sent to the luminaire, or where output data for output by a user interface mounted on the luminaire pole is needs to be sent to the luminaire.

Alternatively or additionally, the PoE connector may be used to communicate data originating from the LAN towards a remote destination reachable through the wireless data network. This may for example be beneficial in applications where sensor output is to be transmitted to a remote receiver in response to abovementioned sensor command, or for relaying user input in response to the output data provided on the user interface as discussed hereinabove.

Alternatively or additionally, the PoE connector may be connected to a local wireline bridge/gateway device that is used to relay traffic to and/or from the wireless data network to and/or from a wireline network (e.g. a high-bandwidth copper, or optical fiber network). In this manner the luminaire is part of a bridge/gateway function between the wireline and wireless data network.

Alternatively or additionally, the PoE connector may be connected to a local wireless bridge/gateway device that is used to relay traffic to and/or from the wireless data network to and/or from a further wireless data network, such as a 4G, 5G, or Wi-Fi network. In this manner the luminaire is part of a bridge/gateway function between the two wireless data networks.

In a second option of the first aspect the first the first antenna unit further comprises further antennas, each of the further antennas having a respective directional radiation pattern facing a respective direction, the respective directions being mechanically re-orientable within the plane and wherein each of the further antennas is configured to receive a respective further signal for transmission from the first modulation unit and each of the at least one antenna and the further antennas re-orientable in a different direction.

When a luminaire in accordance with the first aspect includes only a single antenna it may be re-oriented during installation, such a luminaire is best suited as a leaf node in a mesh network, as it will be difficult to support point-to-multi-point links (although technically this may still be possible when using beamforming - provided the targets are in the same general direction). The second option of the first aspect adds further antennas each re-orientable in a different respective direction, thereby allowing for better point-to-multi- point coverage.

Preferably, the first modulation unit comprises a single baseband unit providing an output signal to the RF unit for up-conversion and driving an antenna in case of transmission, in case of bi-directional communication the RF unit also performs the downconversion. The advantage of using a single base band unit, is that may fulfil a bridge function for the RF units/antennas attached thereto. However, it will be clear to those skilled in the art that alternatively, the first modulation unit may comprise multiple baseband units, for example one for each antenna direction, where each base band unit has an RF unit for driving an (array) antenna. In this case a bridge is required if one wants to relay signals from one baseband unit to the next. However, similar functionality may be realized using either approach.

The RF units may be located with the baseband unit in the first modulation unit, however, alternatively the RF units may be located in the first antenna unit instead.

In a third option building on the first or second option, the first and further antennas are mounted in a fixed orientation on the first antenna unit and the respective directions are re-orientable by rotating the first antenna unit around a second vertical axis through the center of the first antenna unit. In this manner, the antennas mounted on the antenna unit may be re-oriented in unison.

In a fourth option building on the third option, the first antenna unit of the luminaire comprises a total of three antennas, wherein two of the antennas of the first antenna unit face opposite directions and the third antenna of the antennas of the first antenna unit faces a direction orthogonal to the other antennas of the first antenna unit.

Using the above antenna configuration, it is possible to create a mesh network using the radio nodes in luminaires located along a street. Utilizing three antennas per luminaire a mesh network may be implemented having a network topology resembling a ladder structure, thereby offering redundancy and graceful degradation for connections along streets tolerant to obstructions such as trees, etc. Alternatively in more open area deployments the use of three antennas per luminaire may also allow a hexagonal deployment.

In a fifth option building on the third option, the first antenna unit comprises a total of four antennas, the four antennas forming two pairs of two antennas each, the antennas of each antenna pair facing in opposite directions and the two pairs of two antennas facing in orthogonal directions.

A luminaire using this orthogonal antenna configuration is useful in a setting where streets have a Manhattan style routing, i.e. are either parallel or orthogonal. By allowing two opposing antennas to be directed in unison it is possible to address such street layouts. When using active antennas, the mechanical re-orientation may be further complemented by electronic beamforming.

In addition, this type of luminaire when used in a ladder topology allows one of the high-speed directional links to be used to provide connectivity directly to locations (premises or other venues), adjacent to the roadside.

In a sixth option which builds on each of the options of the first aspect, the first modulation unit is mechanically attached to the first antenna unit. In this manner the baseband unit, the RF units and the antenna units may co-located from and to the radio unit and antenna unit, in addition the wiring such as the feedlines between the RF units and the antennas need not be flexible.

In a seventh option that builds on the first aspect, the first antenna unit consists of a first antenna, the luminaire comprising further antenna units identical to the first antenna unit, each of the first antenna unit and the further antenna units is arranged to be re-orientable in a different direction and wherein each antenna of the further antenna units receives a respective signal from the first modulation unit and each antenna of the first antenna unit and the further antenna units is individually re-orientable around a respective vertical axis within the plane orthogonal to the first vertical.

Using the abovementioned antenna configuration, the antennas can be oriented in a more flexible manner, thereby preserving the flexibility to direct the illumination exit window independent from the RF signals, yet further improving the ability to properly align the directional antennas, thereby improving the link quality of narrow beam signals.

Similar to the situation described for the second option of the first aspect, also the seventh option of the first aspect may make use of one or more baseband units in the first modulation unit for driving directional active array antennas. Likewise, the base-band unit will provide outgoing baseband signals to an RF unit associated with an (array) antenna and in case of bi-directional operation, will receive incoming baseband signals from the RF unit associated with the (array) antenna. The active phased array antenna may be provided with a number of array elements, also referred to as tiles, where preferably the number of tiles in the horizontal direction is larger than in the vertical directions, so as to enable a wider scan range in the horizontal direction than in the vertical direction.

In an eighth option that builds on the sixth option, each antenna unit is mounted on a rotatable bracket inside the housing, and the respective brackets can be rotated at a pivot and fixed in position.

Using the above antenna configuration, the antennas can be aligned by pivoting the bracket and subsequently fixed in position, by fixation of the brackets that they are mounted on.

In a nineth option of the first aspect that builds on the first aspect or any of the other options, the antennas are active array antennas, and the luminaire is arranged to use beam forming for each of the active array antennas, using electronic beamforming techniques to fine-tune the direction of the radiation pattern. When using active array antenna(s), the RF unit(s), which may be either located within the first modulation unit or in the first antenna unit (and further antenna units in case of the seventh option of the first aspect), will need to provide support for up- conversion and beamforming to generate phase shifted output signals for each of the active antenna array elements. In case of bi-directional operation, the RF units will conversely also need to provide phase-shifting and combining of the received signals as well as downconversion.

To prevent interference of beamforming with the antenna alignment process, the beamforming procedures may temporarily be disabled and re-enabled once the rough antenna alignment has been completed. As indicated before the antenna alignment tends to improve the channel transfer matrix conditioning and thereby when beamforming is enabled may be further optimized.

In a tenth option which builds on the first option and all abovementioned options, the first modulation unit and antennas are arranged for bi-directional communication.

In an eleventh option of the first aspect, which builds on the nineth option, the lighting unit includes a first lighting controller, and the first lighting controller is coupled to the first modulation unit and configured to receive lighting control information from the first modulation unit.

In the above manner the lighting control network function may be merged with the higher speed data communication network but utilizing the network connectivity in a time- division multiplexed fashion.

In a twelfth option of the first aspect, the luminaire of the first aspect or any one of the options, further comprises a second radio unit for use as a communication node in a wireless lighting control network connected to a second antenna unit, and wherein the lighting unit includes a second lighting controller, and the second lighting controller is connected to the second radio unit and configured to receive lighting control information from the second radio unit.

The additional radio unit allows the luminaire of the twelve option to be seamlessly integrated in existing wireless lighting control networks, that make use of established lighting control systems using Nema/Zhaga control nodes.

In accordance with a second aspect of the invention a lighting fixture is provided comprising: a light pole, a luminaire in accordance with the first aspect or an option thereof mounted there on or thereto, and a first peripheral requiring network connectivity, a mains connection for providing power to the luminaire and the first peripheral, and wherein the luminaire is arranged to receive power from the light pole and the luminaire is arranged to provide network connectivity to the first peripheral.

The lighting fixture in accordance with the second aspect may be a street light or another outdoor lighting fixture for providing illumination, that provides network connectivity to one or more peripherals, such as an environmental sensor with network connectivity, a camera with network connectivity, a cellular base station, a WiFi access point or hotspot, a kiosk for providing a user interface, comprising a display, such as a touch screen, for users to access informational services.

In accordance with a third aspect of the invention an outdoor lighting system is provided comprising a plurality of lighting fixtures in accordance with the second aspect, wherein the respective antennas of the luminaires of the plurality of street lights are aligned in order to enable the luminaires to provide a wireless data network by means of their respective radio units, and wherein the wireless data network is connected to at least one of: a wireline link at least one of the plurality of lighting fixtures and/or a wireless gateway providing a data network by means of at least one of the first modulation units of the luminaires of the plurality of lighting fixtures.

It is noted that the above apparatuses may be implemented based on discrete hardware circuitries with discrete hardware components, integrated chips, or arrangements of chip modules, or based on signal processing devices or chips controlled by software routines or programs stored in memories, written on a computer readable media, or downloaded from a network, such as the Internet.

It shall be understood that the outdoor luminaire of claim 1, the lighting fixture of claim 10 and the outdoor lighting system of claim 12 may have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims.

It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different figures. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

FIG. 1 A and IB each depict a lighting fixture with an outdoor luminaire;

FIG. 2 depicts a block diagram of an outdoor luminaire;

FIG. 3 depicts a perspective view of an antenna unit comprising a plurality of reorientable antennas;

FIG. 4A and 4B illustrate antenna configurations for an antenna unit having three and four fixed antennas respectively;

FIG. 5A and 5B illustrate a problem encountered with luminaires having an antenna unit having fixed antennas;

FIG. 6A, 6B and 6C depict a top view of a luminaire having multiple reorientable antenna units each having a single antenna;

FIG. 7 depicts an artist impression of a luminaire with a detachable housing component removed and;

FIG. 8 depicts an exemplary directional radio emission pattern; and

FIG. 9A and 9B depict a lighting fixture comprising a luminaire and two peripherals.

DETAILED DESCRIPTION OF EMBODIMENTS

The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments.

Within outdoor lighting networks there is an increased need for connectivity. Connectivity in the past was provided by means of wireline networks which often were combined with the power infrastructure, or alternatively using separate power and wireless lighting control networks. Lighting control networks, on account of the modest bandwidth requirements of lighting control applications, generally made use of techniques such as IEEE 802.15.4, which typically were complemented by higher layer protocols such as 6L0WPAN.

Because of the very nature of lighting networks, providing illumination for the benefit of people roaming through its footprint, as well as their spatial deployment throughout urban areas and/or venues, outdoor lighting networks are promising candidates for also providing other networked services. Such networked services may range from (environmental) sensor-networks to wireless connectivity services for end-users, and/or providing other services as commonly found in smart cities. Outdoor luminaires may have a role in providing a high-bandwidth wireless backbone that can enable many of these services. Such luminaires would include a radio, preferably built-in the luminaire, for esthetical, but also practical reasons (exposure to the elements). The radios in turn are building blocks that allow creation of a data communication network, preferably a mesh network, where all or select luminaires out of the lighting network are communication nodes that may provide network connectivity, up to Gbit speeds, for deploying services and/or network connectivity at nearby premises.

The wireless backbone is preferably connected at one or more locations to a wireline network, such as a fiber optics network. Using the wireless Gbit mesh network, the need to deploy cables, which often causes great inconvenience can be reduced. In doing so a layered structure is created where on the bottom we see the wireline layer, such as a singlemode fiber network. Such a fiber network may be a host fiber (i.e. optical fiber on which capacity is rented out to multiple tenants) or can be proprietary fiber (e.g. optical fiber put in place for dedicated application such as a telecom provider putting in their own fiber for a telecom site, or a dedicated optical fiber to a security camera).

On the top we see the “access layer”, which has the typical equipment that is accessed through the fiber layer. This may include security cameras, loT devices, WiFi access points (for example WiFi-5 and/or WiFi-6) providing network access to the public (either free-of-charge, or pay-for-use WiFi, private WiFi). Optionally the same infrastructure may also be used to provide network connectivity to private or commercial applications, thereby at least partially replacing fiber-to-the-home style deployments. More optionally the network connectivity may also serve as a backbone for small-cell cellular base-stations for telecom operators.

A wireless mesh network that uses the outdoor lighting infrastructure as envisioned by the present invention can thus provide “last-mile” connectivity using luminaires with embedded radios. An additional advantage is that installation is very simple because on the one hand all equipment is integrated in the luminaires and installation work is as simple as a luminaire replacement, and on the other hand, the wireless network can be made to be a self-organizing network, thereby reducing the need for elaborate manual commissioning.

To limit the amount of radio signal interference, the inventors consider the use of directional radio signals. Such signals may be generated using a passive directional antenna or alternatively using an active array antenna. Fig. 8, shows a top view of an exemplary radio emission pattern for a directional antenna. Directional antennas may be used to target the emissions from a particular antenna in a pre-determined direction. As a result, a point-to-point connection with a good signal to noise ratio can be established, that in comparison with omnidirectional transmitters reduce the interference in particular in dense networks.

Although it is possible to use an active array antenna to implement a directional link, alignment of the active array antenna remains beneficial, when using MU- MIMO techniques alignment of the array antennas in a link, generally improves the channel transfer matrix as antenna alignment may result in a better conditioned channel transfer matrix, that in turn improves the achievable throughput.

When using a directional antenna integrated in a luminaire at a fixed orientation, an issue may arise. Outdoor lighting luminaires generally are designed to have a light exit window for output of illumination light. In order to provide proper illumination in the luminaire coverage area, the luminaire needs to be oriented correctly. When the illumination exit window is aligned, this may cause a directional antenna having a fixed orientation to be poorly oriented. Poor alignment of the radio antennas amongst different communication nodes in turn may result in sub-optimal performance. When the luminaires are designed for road-side deployment, this phenomenon will typically materialize in curves, but could also materialize elsewhere.

The present invention is aimed at a luminaire for mounting on or attachment to a light pole or structure (e.g. a building or stationary object), where the luminaire is designed to allow adjustment of the radio antennas mounted within the luminaire, in a manner that allow adjustment of the emission direction of the respective radiation patterns independently from the orientation of the illumination light beam, thereby enabling independent alignment of the illumination and luminaire RF radiation patterns. To this end the luminaire includes an adjustment mechanism inside the luminaire that allows re-orientation of the antennas and thereby radio beam(s) independently from the luminaire orientation.

Fig. 1 A and IB each depict a light pole 15 with an outdoor luminaire 10. Fig. 1A depicts a light pole having mounted a luminaire on top thereof, whereas Fig. IB depicts a light pole, where the luminaire is attached to an arm of the pole. The figure further elucidates the effect of reorientation of a single antenna 13 mounted in the luminaire 10. Once the luminaire 10 is mounted on the pole 15 and the illumination exit window is aligned (which may be by orienting the luminaire on the pole, or a light directing means, such as a lens, collimator or other means for reorienting the light output), it is still possible to adjust the orientation of an antenna 13, mounted inside the luminaire 10 within a (horizontal) plane orthogonal to the (vertical) axis 17 through the luminaire 10. The axis 17 is parallel to the vertical axis 16 through the light pole 15 upright. In the above manner the main lobe of an antenna output may be reoriented. It will be clear to those skilled in the art that the main concept of the invention may also be deployed in luminaires mounted on poles that have a design other than those shown in Fig. 1 A and IB.

Fig. 2 depicts an exemplary block diagram of an outdoor luminaire 10. The luminaire in question may be mounted on or attached to a pole 15 as discussed above. The luminaire comprises a power connector 20 for receiving power from the pole. This connector preferably is integrated in the house, such that when the luminaire is mounted on the light pole the connector engages with a power connector or power cable 25 provided by the pole. Alternatively, a cable may be provided on the luminaire with a connector to connect to the pole, or a cable connector on the luminaire may be provided for receiving power from the pole. The power received from the pole is used to power a lighting unit 60 and a first modulation unit 45.

The housing 30, comprises a first exit window 40 for egress of illumination light and a second exit window 35 for ingress and egress of a radio communication signals. The first exit window 40 for egress of the illumination light is transparent to the illumination light and may for example be clear, frosted or fitted with other means to provide homogeneous illumination. The second exit window 35 needs to be transparent for radio frequency waves and may for example be manufactured from a non-transparent plastic which shields the internals of the luminaire 10 from view. Optionally the luminaire housing may comprise a detachable member that can be fixed into place, by clasp, clamps, screws, or may be self-clamping and that may be removed to provide access to the luminaire internals.

Preferably, such a removable member may be detached from the luminaire after the luminaire is mounted on/attached to the light pole or structure thereby providing access to the antenna orientation mechanism after luminaire mounting. The detachable member may be attached to a further part of the housing, this further part of the house, preferably includes the mounting point for attaching the luminaire to the light post.

The housing is used to house the first modulation unit 45, internal to the housing, for use as a communication node in a wireless data network connected to a first antenna unit 50 also internal to the housing. The first modulation unit comprises at least one baseband unit configured to generate a first signal 46 for transmission using the first antenna unit. The housing also houses the first antenna unit 50 having at least one antenna 100 having a directional radiation pattern 55 facing a first direction, the first direction being mechanically re-orientable within a plane orthogonal to an axis through a vertical member of the light post when the luminaire is mounted thereon or attached thereto.

As indicated the directional antenna may be a static antenna or an active antenna. In case of an active antenna, the mechanical antenna reorientation may, be complemented by beamforming using an active array antenna. Although at a higher level of abstraction the operation of these alternatives is similar for the first modulation unit 45 and the first antenna unit 50, but there are subtle differences.

In order to implement beamforming, the first modulation unit 45 will typically comprise one (or more) baseband unit(s) as discussed above, that modulate MAC layer data packets into baseband signals for transmission. After digital-to-analog conversion by the baseband unit, the modulated signals are sent to an RF unit where the modulated signals are typically low-pass filtered prior to being passed on to an IQ mixer for up-conversion. In case of the active antenna array this is followed by a power-distributor and phase-shifters. The phase-shifted antenna signals are subsequently passed to line amplifiers prior to being passed on to the feedlines feeding the respective array antenna elements.

Conversely, when the first antenna unit (50) and the first modulation unit (45) are used for receiving a signal, the signals received by the respective array antenna elements of the array antenna of the first antenna unit will be passed to the respective low-noise amplifiers for amplification. Prior to being passed on to the phase-shifters. The received phase-shifted signals will then be combined by a combiner and passed on to the IQ mixer for down-conversion. There after the IQ branches will, generally after low-pass filtering be passed onto a baseband unit, where the branch signals are analog-to-digital converted and demodulated. Depending on the implementation, the RF units may be co-located with the baseband unit or alternatively co-located with the active array antennas. Returning to Fig. 2, the luminaire further also includes the lighting unit 60 comprising a light source, for example in the form of a plurality of Light Emitting Diode, LEDs, for providing illumination light 65. Apart from the light source the lighting unit 60 may also include a light source driver and a controller for controlling lighting unit operation.

The luminaire 10, comprises a at least one first directional antenna, however preferably the luminaire comprises multiple further directional antennas. The further antennas in turn having a respective directional radiation pattern facing a respective direction, the respective directions being mechanically re-orientable within the plane. Each of the further antennas is configured to receive a respective further signal for transmission from the first modulation unit and may be reoriented to face a different direction. By using multiple directional antennas, the luminaire may wirelessly communicate with multiple nodes. A variety of different multi-antenna configurations are envisaged, and two preferred varieties will be discussed here in below:

A luminaire that comprises an antenna unit that in turn comprises multiple antennas and

A luminaire that comprises multiple antenna units each having a single antenna.

Where the antennas may be static directional antennas or active directional (array) antennas, both solutions will be discussed next.

Multiple antennas in the antenna unit

Fig. 3 depicts a perspective view of an antenna unit 50 comprising a plurality of reorientable antennas 100, 100’, the underlying idea being that the antenna units, although mounted in a fixed manner onto the antenna unit 50, are reorientable by rotating the antenna unit 50 around the vertical axis 101. The first axis runs through the center of the first antenna unit, which when the luminaire containing the antenna unit is mounted on the light pole, will be parallel to the axis through the upright member 15 of the light pole.

As depicted in Fig. 4A the number of antennas mounted on the antenna unit (including the first antenna unit), may have a total of three antennas, wherein two of the antennas of the antenna unit face in opposite directions 105, 106. The third antenna in turn faces in a direction 107 orthogonal to the other antennas. This type of configuration may be beneficial for connecting nodes not only along one side of the street, but also across the street. A more fault tolerant network may be created that from a topological viewpoint resembles a ladder. Preferably, the installer, prior to installation, creates and installation plan wherein the installer can plan the desired orientation, to be later on realized in the field.

As depicted in Fig. 4B, the same principle can be extended to a larger number of antennas, in this figure four. The antennas here comprise two antenna pairs 111 and 112, wherein the two antennas of each pair face in opposite directions and the two antenna pairs face in orthogonal directions. This particular configuration in turn may be used when deployed roadside, to provide network connectivity also to premises adjacent to the road.

Preferably, as shown in Fig. 3, the first modulation unit 45 is attached to the first antenna unit 50. In this manner aligning of the radio signals will be simplified. For example, the radio signals can be routed on one and the same printed circuit board towards the antennas as the radio unit rotates with the antennas in unison. Alternatively, the radio signal could be provided from the radio unit to the respective antenna using a flexible link, such as a (shielded) coaxial cable and/or a twisted pair cable.

Fig. 5A and 5B illustrate how two luminaires, each having an antenna unit having four antennas mounted with a fixed orientation may be used to allow communication between the two nodes when there is a bend in the road.

As can be seen in Fig 5A, when luminaires have fixed directional antenna orientations and the luminaires are oriented so as to properly illuminate an adjacent road 140, the antenna orientations may be oriented in a suboptimal direction. Fig. 5B shows how the first two antenna pairs 120 and the second two antenna pairs 130 can be re-oriented independent from the target illumination area of the luminaires. As a result, the antenna directions can be aligned such that the two luminaires have a better line-of-sight.

As a result of this re-orientation the next node over (not shown) may not have optimal connectivity. Depending on the directionality of the antennas, in particular the beamwidth of the radiation pattern of the transmitter and the type of radio used (MIMO, or MU-MIMO), it may be possible to partially align the antennas and already achieve an improved transmit quality.

Multiple antenna units

However, at times a better alignment, or close to optimal alignment may be required in all directions and hence one, multiple or all antennas may be re-orientable individually. Fig. 6A and 6B, depict a top-view of luminaire 30 having multiple re-orientable antenna units 50’ each having a single antenna located at a pivot point pl, p2, p3, p4.

Fig. 6B shows how one of the antenna units 50’ is rotated around the pivot point p2 so as to redirect the main lobe of the antenna in the direction d2.

Preferably, each of the antenna units 50’ can be reoriented by rotating them around the respective pivot points as indicated. In such embodiments, preferably the antenna units combined cover a 360-degree range in the horizontal plane orthogonal to the upright of the light pole. It may be beneficial for each antenna unit 50’ to be able to span a range of more than 90-degrees, however typically, for a four-antenna unit luminaire it will be sufficient for at least one antenna unit to cover one of the quadrants. For the four-antenna luminaire depicted in Fig. 6A, this may imply that each antenna unit can rotate so as to cover a 90-degree angle, wherein the depicted directions dl, d2, d3 and d4 are the center directions. It will be clear to those skilled in the art that luminaires with larger numbers of antenna units may be implemented.

Fig. 6C, shows how two of the antenna units 50’ can be reoriented in a similar direction, in this manner the system may leverage the MU-MIMO modem to provide a higher data capacity in said direction. In this case the two adjacent antenna units are rotated by -45 and +45 degrees respectively, relative to 6A. To further increase the flexibility in providing coverage, it may be desirable to allow the antenna units to rotate over a range of more than 90 degrees. However, when the antenna units are mounted at the same height as indicated in Fig. 6A-6C, neighboring antenna units may start obstructing the transmit beam at some point. This in turn may be addressed, by placing the antenna units at different vertical offsets.

It is further noted that it may further be possible to also implement combinations of the above. It may be possible to use a single rotating antenna unit, as depicted in Fig. 3 where the individual antenna’s 100 and 100’ are mounted not rigidly to the antenna unit, but rather are also individually reorientable, thereby providing more flexibility, in particular when the rotational range of the individual antennas is limited.

Fig. 7 provides an artist impression of an opened-up luminaire 10 for mounting to an arm of a light pole as depicted in Fig. IB. The luminaire in Fig. 7 has a housing comprising two-parts, one detachable housing member (not shown) and a fixed housing member (shown). The fixed housing member comprises a mounting point 405 to mount the luminaire 10 to the arm of the light pole. In addition, the luminaire comprises a antenna unit 420 comprising four antenna units 100 (two shown). Once the luminaire is mounted to the light pole, the antenna unit may be rotated thereby reorienting the antennas of the luminaire in unison.

The alignment of the antenna units may be done in a phased approach, where the initial alignment is done by the installer by directing the antennas to closely match the line-of-sight from one luminaire to the next, once a radio link is obtained with the neighbor node, a fine alignment may be done using feedback from the radio regarding, for example in the form of a measured signal -to-noise ratio and/or other link quality metric. Once the desired orientation is achieved, the antenna unit may be fixated, using the screws 410 and 411 highlighted by the dashed circles.

In case of the luminaire design depicted in Fig. 7, the rotational freedom of the antenna unit, is in the range of -10 to 10 degrees, which is sufficient for most roads, but larger degrees of rotational freedom may be implemented without departing from the general concept presented. Once the antenna unit is fixated, the detachable housing member, which may take the form of a cover, may again be attached to the luminaire and fixed thereto, for example using clamps, clasps or screws. In case of the luminaire depicted in Fig. 7 the detachable housing member is preferably manufactured from a plastic, such that it may also double as the second exit window for ingress and egress of the radio communication signals. Preferably the internal components or modules, such as the radio unit, the antenna units and the lighting unit of the luminaire are weatherproofed, such as in accordance with IP65, such that the housing does not require to be weatherproofed.

Weatherproofed components inside the housing also enable alternative luminaire designs in a manner that does not require a detachable housing member. The housing may for example include a hinged section or may be fitted with openings and/or apertures that allow access to the re-orientation and fixation mechanisms of the antennas without having to fully remove part of the housing. More optionally the housing instead includes openings and/or apertures that grant access to the orientation and fixation mechanisms, which openings and/or apertures, may be sealed using plugs or lids, that prevent excessive ingress of dirt and/or moisture.

The luminaire depicted in the figure further comprises a lighting unit 430 mounted below the antenna unit.

Fig. 8 depicts an exemplary directional radio emission pattern of a directional antenna. As can be seen in the figure, the main lobe indicated by the dashed line extends from the emission source location S in the direction ML to the target node T. The narrow beam shape although directional, is not smooth, as can be seen in Fig. 8 and will typically include multiple side lobes in the off-angle directions. In practice the ideal symmetrical radiation pattern may be further influenced by the presence of the luminaire housing, and/or other nearby objects.

When using an active array antenna, the active array antenna design, including the phase shifters in the absence of external influences determines the main lobe beamwidth, here indicated by a. The beamwidth may be designed using known techniques and can be customized for the actual installation. Considerations here involve for example, the total coverage area required, the number of active array antennas, the scan-range of each of the respective active antennas and/or whether overlap between adjacent antennas is desirable or not.

Generally, a narrower beamwidth will result in an ability to achieve a higher signal to noise ratio at the target for a set amount of transmission energy, this in return may allow for modulation schemes with more complex constellations that allow higher throughput. However, a tighter beamwidth will also require a more accurate alignment of the installation. The design of the (array) antenna may thus be a trade-off between link quality and alignment sensitivity.

Active array antennas in turn allow electronic beamforming, whereby a narrow beam may be scanned in horizontal and/or vertical direction. As in case of outdoor lighting networks, the network extends primarily in the horizontal direction, it is preferable to have a wider scan range in the horizontal plane. In a practical system, with four active antennas, it may be beneficial to design the system to design the electronic beamforming with freedom to scan in the horizontal direction in the range of [-45,45] degrees and in a vertical direction within a range of [-10,10] degrees.

However as in general misalignment of an array antenna may still result in a suboptimal channel transfer matrix. As a result, even when using beamforming, it remains beneficial to re-orient the array antennas in an appropriate manner that improves the channel transfer matrix conditioning and hence the (MU-)MIMO performance.

Although the focus up to this point was primarily on the transmission of radio signals, it will be understood by those skilled in the art of radio communication, that RF communication in wireless mesh networks customarily is bi-directional, accordingly the antenna arrangements as discussed herein may and can be used for both data transmission and reception.

Antenna arrangements discussed, may be used for deploying high speed wireless Gbit mesh data communication networks in luminaires in outdoor lighting installations. However, luminaires in conventional outdoor lighting installations are often part of wireless lighting control networks themselves and utilize bi-directional communication, for exchanging control information and reporting status. To allow backwards compatibility with such installations, luminaires in accordance with the present invention may also be equipped with a legacy radio function implemented using a second radio unit, thereby creating two fully independent wireless networks, one being a wireless lighting network (e.g. based on IEEE 802.15.4 network technology, and/or in addition, or alternatively, on cellular network technology, such as 3G, 4G or 5G). The second radio unit may for example be particularly relevant when a municipality already has a wireless lighting control network deployed using radio modules connectable using Zhaga/Nema connectors.

More optionally, all luminaires are fitted with such a second radio unit providing the conventional wireless lighting control function and only select ones of the luminaires are also fitted with a high-speed data communication network link as described herein. In this manner the select nodes may function as bridge(s) that provide backhaul link(s) for the wireless lighting control network. The latter may be particularly useful when the lighting control network utilizes IPv6.

When legacy compatibility is not required, it may be possible to completely abandon the conventional wireless lighting control network technology and deploy both the traffic of the conventional wireless lighting control network and the traffic of the higher speed wireless data communication network, on the high-speed data communication network. In such networks, luminaires might be fitted with multiple IPv6 addresses, one corresponding to the luminaire’s lighting node, for the lighting control data, and one corresponding to the luminaire’s data communication node.

FIG. 9A and 9B depict a lighting fixture comprising a luminaire and two peripherals. Fig. 9A shows the lighting fixture of Fig. 1A, with an additional first peripheral in the form of a sensor SI and a second peripheral device in the form of WiFi-6 transceiver XCV1. Fig. 9B shows how the lighting fixture powers the first and second peripheral as well as the luminaire by means of the power line connection, here the dashed line from the mains- connection of the lighting fixture. The luminaire 10 in turn provides network connectivity to the lighting fixture, for example by means of an ethemet link, here indicated by means of the dotted line. An ethemet cable may couple the luminaire with a peripheral if there is only one, or more preferably with a network switch mounted inside the light pole 15. The switch in turn may be connected with the first and second peripheral, but alternatively larger number of peripherals may be provided and each of the peripherals may be individually addressable from the remote network.

Although power and connectivity may utilize separate networks, advantageously, the lighting pole comprises a Power-over-Ethemet (IEEE 802.3al) power sourcing device that provides both power and (bi-directional) ethemet connectivity to all nodes in the lighting fixture.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In 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 processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in the text, the invention may be practiced in many ways, and is therefore not limited to the embodiments disclosed.

Claims

23 CLAIMS:

1. An outdoor luminaire (10) for mounting on a light pole (15) or structure, the luminaire comprising: a power connector (20) for powering a lighting unit (60) and a first modulation unit (45); a housing (30) having a first exit window (35) for egress of illumination light and a second exit window (40) for ingress and egress of radio communication signals; a mounting point attached to or integrally formed by the housing, the mounting point configured to mount the luminaire on the light pole or structure; the first modulation unit (45), internal to the housing, for use as a communication node in a wireless data network connected to a first antenna unit (50) internal to the housing, the first modulation unit configured to generate a first signal (46) for transmission using the first antenna unit; the first antenna unit (50) having at least one antenna (100) having a directional radiation pattern (13, 55) facing a first direction (14), the first direction being mechanically re-orientable within a plane orthogonal (12) to a first vertical axis (16) when the luminaire is mounted and the lighting unit (60) comprising a light source for providing illumination light (65); the outdoor luminaire characterized in that: the first antenna unit (50) further comprises further antennas (100’), each of the further antennas having a respective directional radiation pattern facing a respective different direction (14’) and each of the further antennas (100’) configured to receive a respective further signal for transmission from the first modulation unit and wherein the first and further antennas are mounted on the first antenna unit (50) in a fixed manner and the respective antenna directions are mechanically re-orientable within the plane by rotating the first antenna unit around or on a second vertical axis (101) through the center of the first antenna unit.

2. The luminaire (10) of claim 1, wherein the power connector (20) is a Power- over-Ethemet, PoE, connector, the PoE connector arranged to provide power to the luminaire and to provide at least one of: network connectivity that allows the first modulation unit to retrieve data via the PoE connector network for transmission over the wireless data network and network connectivity that allows the first modulation unit to transmit data received over the wireless data network via the PoE connector.

3. The luminaire (10) of claim 1, wherein the first antenna unit (50) comprises a total of three antennas, and wherein two of the antennas of the first antenna unit face opposite directions (105, 106) and the third antenna of the antennas of the first antenna unit faces a direction (107) orthogonal to the other antennas of the first antenna unit.

4. The luminaire (10) of claim 1, wherein the first antenna unit (50) comprises a total of four antennas, the four antennas forming two pairs (111,112) of two antennas each, the antennas of each antenna pair facing in opposite directions (115 ; 116, 117; 118) and the two pairs (111,112) of two antennas facing in orthogonal directions.

5. The luminaire of any one of claims 1 to 4, wherein the first modulation unit (45) is mechanically attached to the first antenna unit (50).

6. The luminaire (10) of any one of claims 1 to 4 wherein the antennas are active array antennas and the luminaire is arranged to use beamforming for each of the array antennas to fine-tune the direction of the radiation pattern.

7. The luminaire (10) of any one of claims 1 to 4, wherein the first modulation unit and antennas are arranged for bi-directional communication.

8. The luminaire (10) of claim 7, wherein the lighting unit includes a first lighting controller, and the first lighting controller is coupled to the first modulation unit and configured to receive lighting control information from the first modulation unit.

9. The luminaire (10) of any one of the claims 1 to 4, comprising: a second radio unit for use as a communication node in a wireless lighting control network connected to a second antenna unit, and wherein the lighting unit includes a second lighting controller and the second lighting controller is connected to the second radio unit and configured to receive lighting control information from the second radio unit.

10. A lighting fixture (900) comprising: a light pole (15), a luminaire (10) according to any one of claims 1 to 4 mounted there on or thereto, and a first peripheral (SI, XCV 1 ) requiring network connectivity, a mains connection (PW) for providing power to the luminaire and the first peripheral, and wherein the luminaire is arranged to receive power from the light pole and the luminaire is arranged to provide network connectivity (CN) to the first peripheral.

11. Lighting fixture (900) of claim 10, wherein, the first peripheral is one of: an environmental sensor (SI) with network connectivity, a camera with network connectivity, a cellular base station, a WiFi hotspot (XCV1) and a kiosk for providing a user interface for users to access informational services.

12. Outdoor lighting system comprising a plurality of lighting fixtures (900) according to claim 10, wherein the respective antennas of the luminaires (10) of the plurality of lighting fixtures are aligned in order to enable the luminaires to provide a wireless data network by means of their respective radio units, and wherein the wireless data network is connected to at least one of: a wireline link provided at at least one of the plurality of lighting fixtures and/or a wireless gateway providing a data network by means of at least one of the first modulation units of the luminaires of the plurality of lighting fixtures.