Patent Description:
<CIT> relates to a method and an electronic device for transmitting and receiving data via an ultrawideband in a wireless communication system.

According to claim <NUM> of the present disclosure there is provided an infrastructure-controller for an infrastructure, the infrastructure-controller configured to:.

Advantageously, such an infrastructure-controller can reduce power consumption at the infrastructure because the length of time that the ranging nodes are activated for receiving the key-ranging-signal can be reduced. Additionally, ranging operations with a plurality of keys can be scheduled such that the key-ranging-signals signals for the individual keys do not clash with each other.

In one or more embodiments the ranging-scheduling-signal is a BLE signal; and / or the key-ranging-signal is UWB signal.

In one or more embodiments, each of the ranging nodes comprises a ranging antenna.

In one or more embodiments the infrastructure-controller is further configured to, for each of one or more second keys:.

The second-infrastructure-node-start-ranging-time may be set such that the ranging nodes are activated for the second key at a time that does not overlap with when the ranging nodes are activated for the first key and any other second keys if there are any. The second-ranging-scheduling-signal can have a frequency in the first RF frequency range. The second-key-ranging-signal can have a frequency in the second RF frequency range.

In one or more embodiments the infrastructure-controller is configured to set one or more of: an infrastructure-node-start-ranging-time; an infrastructure-node-stop-ranging-time; an infrastructure-node-ranging-duration; a second-infrastructure-node-start-ranging-time; a second- infrastructure-node-stop-ranging-time; and a second-infrastructure-node-ranging-duration such that the ranging nodes are activated for the one or more second keys at a time that does not overlap with when the ranging nodes are activated for the first key or any other second keys if there are any.

In one or more embodiments the infrastructure-controller is configured to:
activate the one or more ranging nodes associated with the infrastructure by sending a node-activation-signal to the one or more ranging nodes over a Controller Area Network, "CAN", bus.

In one or more embodiments the infrastructure-node-start-ranging-time equals the timing-information.

In one or more embodiments the timing-information comprises an infrastructure-delay-period. The infrastructure-controller may be configured to determine the infrastructure-node-start-ranging-time by adding the infrastructure-delay-period to a clock-signal.

In one or more embodiments the infrastructure-controller is configured to:
deactivate the one or more ranging nodes associated with the infrastructure at an infrastructure-node-stop-ranging-time based on the timing-information.

In one or more embodiments the infrastructure-controller is configured to determine the infrastructure-node-stop-ranging-time by adding a predetermined infrastructure-node-ranging-duration to the infrastructure-node-start-ranging-time. The timing-information may comprise the infrastructure-node-stop-ranging-time.

In one or more embodiments the infrastructure is a vehicle or a building.

In one or more embodiments the infrastructure-controller is configured to send an infrastructure-connection-signal to the key, to maintain a connection with the key. The infrastructure-connection-signal may have a frequency in the first RF frequency range.

In one or more embodiments the infrastructure-controller is further configured to:.

In one or more embodiments the infrastructure-controller is further configured to:
determine a ranging result based on the received key-ranging-signal.

In one or more embodiments the infrastructure-controller is configured to:.

In one or more embodiments the infrastructure-controller is configured to:
provide a control-signal to an actuator associated with the infrastructure based on the ranging result.

According to claim <NUM> of the present disclosure, there is provided a key-controller configured to:.

In one or more embodiments the key-controller is further configured to send a key-connection-signal to the infrastructure, to maintain a connection with the infrastructure. The key-connection-signal may have a frequency in the first RF frequency range.

In one or more embodiments the key-ranging-time equals the timing-information.

In one or more embodiments the timing-information comprises a key-delay-period. The key-controller may be configured to determine the key-ranging-time by adding the key-delay-period to a clock-signal.

In one or more embodiments the key-controller is associated with a key fob. In one or more embodiments the functionality of the key-controller is provided by a mobile communications device (such as a smartphone).

According to claim <NUM> of the present disclosure there is provided a computer-implemented method for an infrastructure, the method comprising:.

According to claim <NUM> of the present disclosure there is provided a computer-implemented method for a key, the method comprising:.

There is also provided an infrastructure, including a vehicle, comprising any infrastructure-controller disclosed herein.

There is also provided a key, including a key fob or a mobile communications device, comprising any key-controller disclosed herein.

It should be understood, however, that the present invention is limited only by the appended claims <NUM>-<NUM>.

The figures and Detailed Description that follow also exemplify various example embodiments. Various example embodiments may be more completely understood in consideration of the following Detailed Description in connection with the accompanying Drawings.

Ranging services can be used to determine the distance between an infrastructure (such as a building or a vehicle) and a key that is used to obtain access to the infrastructure. The functionality of the key can be provided by a key fob or by a portable communications device such as a smartphone. When the key is sufficiently close to the infrastructure, access can be granted by unlocking a door for example.

Such ranging services can result in a high burden of power consumption at the infrastructure in the way that a ranging operation can be initiated by the key. In some examples, before the ranging is started, communication over a radio frequency (such as Bluetooth Low Energy (BLE)) is used to connect the infrastructure to the key. Then the ranging can be performed over a different radio frequency (such as ultra-wideband (UWB)). The initial communication event (e.g. a BLE radio packet on the air) can be the only synchronization event that the infrastructure and the key can use to start the ranging service in a synchronized way.

<FIG> shows an example embodiment of the present disclosure that includes an infrastructure <NUM> and a key <NUM>. The infrastructure <NUM> includes an infrastructure-controller <NUM>. The key <NUM> includes a key-controller <NUM>. As indicated above, the infrastructure could be a car, a building, a room, public transport (such as handsfree public transport) or any other environment including those mentioned in all applications discussed in CCC (car connectivity consortium) and the FiRa consortium. The key <NUM> can be a key fob, such that the key-controller <NUM> is associated with the key fob. Alternatively, the functionality of the key-controller <NUM> is provided by a mobile communications device such as a smartphone.

The infrastructure <NUM> has one or more ranging nodes, and each ranging node can have a ranging antenna <NUM>. In this example there are three ranging nodes / antennas <NUM>. In the following description, each mention of a ranging antenna <NUM> can also be construed as applying to a corresponding ranging node. For example, any activation or deactivation of a ranging antenna can be considered as functionally equivalent to the activation or deactivation of a ranging node.

If there are a plurality of ranging nodes <NUM>, then they can be located at different locations on, or associated with, the infrastructure <NUM>. The ranging nodes / antennas <NUM> are for receiving ranging signals from the key <NUM>, such that the infrastructure-controller <NUM> can determine the distance between the infrastructure <NUM> and the key <NUM>.

The infrastructure-controller <NUM> is configured to send a ranging-scheduling-signal <NUM> to the key <NUM>. The ranging-scheduling-signal <NUM> includes timing-information for a subsequent ranging operation. As will be discussed below, use of this timing-information to schedule the subsequent ranging operation can greatly reduce power consumption of the infrastructure <NUM>.

The infrastructure-controller <NUM> can then activate the one or more ranging antennas <NUM>, for receiving a key-ranging-signal <NUM> from the key <NUM>, at an infrastructure-antenna-start-ranging-time (or equivalently an infrastructure-node-start-ranging-time) based on the timing-information. A ranging antenna <NUM> can be activated in any one of a number of ways. For instance, the ranging antenna <NUM>, or a processor / module associated with it, can be activated by a microcontroller unit (MCU) sending an out-of-band control signal to the ranging antenna <NUM>. Such an out-of-band control signal can be sent over a Controller Area Network (CAN) bus, for example.

The ranging-scheduling-signal <NUM> has a frequency in a first RF frequency range, and in this example is a BLE signal with a frequency of <NUM>. This can represent a low power way of initiating the communication with the key <NUM>. The key-ranging-signal <NUM> is in a second RF frequency range, which is different to the first RF frequency range. That is, the second RF frequency range can be considered as an out-of-band signal when compared with the first RF frequency range. In this example, the key-ranging-signal <NUM> is an ultra-wideband (UWB) signal with a frequency in the range of <NUM> to <NUM>.

Having a ranging antenna <NUM> at the infrastructure <NUM> that is enabled to receive the key-ranging-signal <NUM> can consume a relatively high amount of power, which can be especially problematic when the infrastructure <NUM> is battery powered (such as when the infrastructure <NUM> is a vehicle). Such high power consumption can also cause problems with excess heat generation.

Turning now to the key-controller <NUM>, it receives the ranging-scheduling-signal <NUM> from the infrastructure <NUM>. As described above, the ranging-scheduling-signal <NUM> includes timing-information for a subsequent ranging operation. The key-controller <NUM> causes the key <NUM> to send a key-ranging-signal <NUM> to the infrastructure <NUM>, at a key-ranging-time based on the timing-information. As will be described in detail below, the key-ranging-time (at which the key-controller <NUM> sends the key-ranging-signal <NUM>) and the infrastructure-antenna-start-ranging-time (at which time the one or more ranging antennas <NUM> at the infrastructure <NUM> are activated) can be set based on the timing-information such that the ranging antennas <NUM> can reliably receive the key-ranging-signal <NUM> without being enabled for an unduly long time, thereby not consuming an unduly high amount of power.

In the example of <FIG>, the infrastructure-controller <NUM> also sends an infrastructure-connection-signal <NUM> to the key <NUM> to maintain a connection with the key <NUM>. Similarly, the key-controller <NUM> sends a key-connection-signal <NUM> to the infrastructure <NUM> to maintain a connection with the infrastructure <NUM>. Such signals can be sent periodically, in accordance with a communications protocol that is being used. The infrastructure-connection-signal <NUM> and the key-connection-signal <NUM> have a frequency in the first RF frequency range, which in this example means that they are both BLE signals.

As will be discussed in detail below, the infrastructure-controller <NUM> can then determine a ranging result based on the received key-ranging-signal <NUM>. Optionally, the infrastructure-controller <NUM> can then provide a control-signal to an actuator (not shown) based on the ranging result. For instance, to grant access to the infrastructure <NUM> by unlocking a door. In the example of <FIG>, where there is a plurality of ranging antennas <NUM>, the infrastructure-controller <NUM> can determine the ranging result based on a plurality of received key-ranging-signals <NUM>.

The example of <FIG> can therefore provide scheduling of a ranging service / ranging operations, which are performed at the infrastructure <NUM>. This can provide one or more of the following advantages:.

<FIG> shows schematically an example embodiment of a method for a key <NUM> to communicate with an infrastructure (in this example a car <NUM>) to perform a ranging operation. Steps to the left of the vertical dashed line in <FIG> are associated with the key <NUM>. Steps to the right of the vertical dashed line in <FIG> are associated with the car <NUM>. As it is shown in <FIG>, time increases in a vertically down direction.

The key <NUM> is shown as having two columns in which method steps can occur. The first column relates to ranging operations performed by the key <NUM>, which involves sending and receiving UWB signals in this example. Such UWB signals are shown with dotted lines (as shown in the legend in the top-right corner of the drawing) and also with boxes that are filled with a dotted pattern (as shown in the legend in the bottom-left corner of the drawing). The second column relates to communication operations performed by the key <NUM>, which involves sending and receiving BLE signals in this example. Such BLE signals are shown with dashed lines (as shown in the legend in the top-right corner of the drawing).

The car <NUM> is shown as having five columns in which method steps can occur. The first column relates to communication operations performed by the car <NUM>, which involves sending and receiving BLE signals in this example. Such BLE signals are shown with dashed lines (again as shown in the legend in the top-right corner of the drawing). The second column relates to steps that are performed by an electronic control unit (ECU) of the car <NUM>. The third to fifth columns relate to ranging operations that are performed by respective first to third ranging antennas associated with the car <NUM>, and involve sending and receiving UWB signals in this example. Such UWB signals are again shown with dotted lines (as shown in the legend in the top-right corner of the drawing) and also with boxes that are filled with a dotted pattern (again as shown in the legend in the bottom-left corner of the drawing).

A ranging operation is started by the car <NUM> at step <NUM>. In response, the ECU of the car <NUM> determines timing-information for the subsequent ranging operation. The timing-information may comprise an absolute time that the key <NUM> should send a key-ranging-signal <NUM> to the car <NUM> - for instance at <NUM>:<NUM>:<NUM> using the <NUM>-hour clock. Alternatively, the timing-information may include a key-delay-period (which may also be referred to as a delta-t) that should be waited before the key <NUM> sends the key-ranging-signal <NUM> to the car <NUM>. Either way, the timing-information can be set such that the car <NUM> has sufficient time to enable its ranging antennas, and also such that the key <NUM> has sufficient time to receive an instruction from the car <NUM> and begin transmitting the key-ranging-signal <NUM> to the car <NUM>.

The car <NUM> can then send a ranging-scheduling-signal <NUM> to the key <NUM>, wherein the ranging-scheduling-signal <NUM> comprises the timing-information. In some examples, the ranging-scheduling-signal <NUM> can be provided as part of a periodic car-connection-signal <NUM> that the car <NUM> sends to the key <NUM> to maintain a BLE connection between the car <NUM> and the key <NUM>.

The key <NUM> receives the ranging-scheduling-signal <NUM> from the car <NUM> and causes the key <NUM> to send the key-ranging-signal <NUM> to the car <NUM> at a key-ranging-time based on the timing-information. In this example, this is achieved by a BLE module in the key <NUM> sending a serial peripheral interface (SPI) message <NUM> to a UWB module in the key <NUM>. This SPI message <NUM> is shown with a dot-dashed line in <FIG> (as shown in the legend in the top-right corner of the drawing). As discussed above, the key-ranging-time may equal the timing-information (i.e. the timing-information is an absolute time). Alternatively, the timing-information may comprise a key-delay-period, and the key <NUM> determines the key-ranging-time by adding the key-delay-period to a clock-signal.

The key-ranging-time is illustrated schematically in <FIG> with reference <NUM>, as the instant in time that the key <NUM> sends the key-ranging-signal <NUM> to the car <NUM>.

The key <NUM> can also send a key-connection-signal <NUM> to the car <NUM> to maintain the BLE connection with the car <NUM>.

Returning to the processing that is performed at the car <NUM>. In response to the ranging operation being started by the car <NUM> at step <NUM> and the determination of the timing-information, the car <NUM> activates the three ranging antennas that are shown in <FIG>, at a car-antenna-start-ranging-time based on the timing-information. As discussed above, the ranging antennas are represented by the third to fifth columns of the car <NUM> in <FIG>, and are for receiving instances of the key-ranging-signal <NUM> from the key <NUM>.

In this example, the ECU of the car <NUM> sends an antenna-activation-signal <NUM> to each of the ranging antennas over a Controller Area Network (CAN) bus. The ECU can provide at least some of the functionality of the infrastructure-controller of <FIG>. Signals sent over the CAN bus are shown as thick lines in <FIG> (as shown in the legend in the top-right corner of the drawing). The antenna-activation-signal <NUM> instructs each ranging antenna to prepare for ranging (step <NUM>) and then activate the ranging antenna at the car-antenna-start-ranging-time, which is shown schematically in <FIG> with reference <NUM>.

In a similar way to that described above with reference to the key-ranging-time <NUM> at the key <NUM>, the car <NUM> can set the car-antenna-start-ranging-time <NUM> such that it equals the timing-information (i.e. the timing-information is an absolute time). The car-antenna-start-ranging-time <NUM> can be set such that it has an absolute time that matches the key-ranging-time <NUM>, or the car-antenna-start-ranging-time <NUM> can be set such that it has an absolute time that is offset from (and later than) the key-ranging-time <NUM>. In this way, a time buffer <NUM> can be provided between the key <NUM> sending the key-ranging-signal <NUM> and the ranging antennas being activated for receiving the key-ranging-signal <NUM>.

Alternatively, the timing-information can include a car-delay-period, and the car <NUM> can determine the car-antenna-start-ranging-time by adding the car-delay-period to a clock-signal. The car-delay-period may the same as, or different to, the key-delay-period.

In some examples, the car <NUM> can deactivate the one or more ranging antennas at a car-antenna-stop-ranging-time <NUM> (or equivalently an infrastructure-node-stop-ranging-time) based on the timing-information. For instance, the car <NUM> can determine the car-antenna-stop-ranging-time <NUM> by adding a predetermined car-antenna-ranging-duration (or equivalently an infrastructure-node-ranging-duration) to the car-antenna-start-ranging-time <NUM>. In other examples, the timing-information comprises the car-antenna-stop-ranging-time <NUM>.

The length of time that the ranging antenna is activated is represented by the height of the box labelled as <NUM> in <FIG>. This can also be referred to as a car-antenna-ranging-duration <NUM>, and is the length of time between the car-antenna-start-ranging-time <NUM> and car-antenna-stop-ranging-time <NUM>. At least the car-antenna-start-ranging-time <NUM> is set based on timing-information that is also used to set the key-ranging-time <NUM>.

In response to receiving the key-ranging-signal <NUM> from the key <NUM>, the car <NUM> responds <NUM> to the key-ranging-signal <NUM> by sending a car-response-ranging signal <NUM> to the key <NUM>. The car-response-ranging signal <NUM> is a UWB signal in this example.

Also in response to receiving the key-ranging-signal <NUM> from the key <NUM>, optionally the car <NUM> can deactivate the ranging antennas (i.e. the car does not need to wait for a predetermined antenna-stop-ranging-time <NUM> before deactivating the ranging antennas). Then, in response to sending the car-response-ranging signal <NUM>, the car <NUM> can reactivate the ranging antennas for receiving a key-response-ranging-signal <NUM> from the key <NUM>. This reactivation of the ranging antennas is shown schematically in <FIG> with boxes <NUM>.

Turning back to the processing that is performed at the key <NUM>, the key <NUM> waits for the car-response-ranging signal <NUM> from the car <NUM> (the waiting is shown schematically as box <NUM> in <FIG>), and when it receives the one or more car-response-ranging signals <NUM> the key <NUM> responds with the key-response-ranging-signal <NUM>. The key-response-ranging-signal <NUM> is also a UWB signal in this example. This exchange of UWB signals to complete the ranging operation is well-known in the art.

Turning again to the processing that is performed at the car <NUM>, the car <NUM> can determine a ranging result based on: (i) one or more instances of the received key-ranging-signal <NUM>; and (ii) one or more instances of the received key-response-ranging-signal <NUM>. The ranging result may be a distance between the key <NUM> and the car <NUM>, as is known in the art. The car can then provide a control-signal (not shown) to an actuator associated with the car based on the ranging result (e.g. to unlock the car).

<FIG> shows schematically a method of a key <NUM> communicating with a car <NUM> to perform a ranging operation, in which timing-information is not exchanged in order to schedule the ranging operation.

As shown in <FIG>, the length of time <NUM> that the ranging antenna is activated is much longer than the equivalent duration in <FIG>. This is because in <FIG> the ranging antennas are activated immediately in response to the initiation of the ranging operation. In practice this can result in the ranging antenna being activated for <NUM> seconds if the key <NUM> does not come within range of the car <NUM> to start exchanging UWB signals. For instance, if a user holding their key <NUM> is close enough to the car <NUM> for BLE communication to commence, but not close enough for UWB signals to be successfully exchanged, then the car can consume a significant amount of power in listening for UWB signals. In addition to the undesirable power consumption, this can also result in components associated with the ranging antennas overheating.

<FIG> shows an example of a timing diagram that illustrates BLE signals that can be sent from a car to schedule ranging operations with a first key and a second key, wherein the ranging operations include exchanging UWB signals. Advantageously, the ranging operations with the first key and the second key can be scheduled such that the UWB signals for the individual keys do not clash with each other. It will be appreciated that the functionality that will be described with reference to <FIG> can be extended to a system that includes more than one second key (and therefore more than two keys in total).

A BLE connection between the car and the first key (key <NUM>) is shown with reference <NUM> in <FIG>. This connection has periodic BLE connection events, which include at least a car-connection-signal <NUM>'. In this example the BLE connection events occur every <NUM>.

A BLE connection between the car and the second key (key <NUM>) is shown with reference <NUM> in <FIG>. This connection also has periodic BLE connection events, which include at least a second-car-connection-signal <NUM>" to maintain a connection with key <NUM>. In this example the BLE connection events occur every <NUM>.

As shown in <FIG> a ranging operation with key <NUM> is initiated, which causes the BLE connection with key <NUM> to also include a ranging-scheduling-signal <NUM>'. The ranging-scheduling-signal <NUM>' includes timing-information that will be used by key <NUM> to set a key-ranging-time, at which time key <NUM> will send a key-ranging-signal to the car.

The car also uses the timing-information to set a car-antenna-start-ranging-time <NUM>', at which time one or more ranging antennas associated with the car are activated for receiving the key-ranging-signal from key <NUM> and a ranging round is started. In this example, a car-delay-period (delta T1) is used to set the car-antenna-start-ranging-time <NUM>'. In this way the ranging antenna is scheduled to be activated at the car-antenna-start-ranging-time <NUM>' relative to the ranging-scheduling-signal <NUM>'. The ranging rounds for key <NUM> are shown in <FIG> as having the car-antenna-start-ranging-time <NUM>', a car-antenna-stop-ranging-time <NUM>' and a car-antenna-ranging-duration <NUM>'. In this example, the UWB ranging rounds for key <NUM> are periodic, occurring every <NUM>. The car-antenna-ranging-duration <NUM>' is set such that there is sufficient time for a ranging round with multiple anchors / ranging antennas. For instance, there may be <NUM> anchors / ranging antennas on the car in one example.

<FIG> also shows that a ranging operation with key <NUM> is initiated, which causes the BLE connection with key <NUM> to also include a second-ranging-scheduling-signal <NUM>". The second-ranging-scheduling-signal <NUM>" includes second-timing-information that will be used by key <NUM> to set a second key-ranging-time, at which time key <NUM> will send a second-key-ranging-signal to the car.

The car also uses the second-timing-information to set a second-car-antenna-start-ranging-time <NUM>", at which time the one or more ranging antennas associated with the car are activated for receiving the second-key-ranging-signal from key <NUM> and a ranging round is started. In this example, a second-car-delay-period (delta T2) is used to set the second-car-antenna-start-ranging-time <NUM>". In this way the ranging antenna is scheduled to be activated at the second car-antenna-start-ranging-time <NUM>" relative to the second-ranging-scheduling-signal <NUM>". The ranging rounds for key <NUM> are shown in <FIG> as having the second-car-antenna-start-ranging-time <NUM>", a second-car-antenna-stop-ranging-time <NUM>" and a car-antenna-ranging-duration <NUM>". In this example, the UWB ranging rounds for key <NUM> are also periodic, occurring every <NUM>.

Advantageously, the car (for example a car-controller associated with the car) can set the second-car-antenna-start-ranging-time such that the ranging antennas are activated for the second key at a time that does not overlap with when the ranging antennas are activated for the first key. In this way, the likelihood of any clashes between the ranging operations can be reduced or avoided.

In some examples, a car-controller associated with the car can negotiate delta T1 and delta T2 using BLE signals (i.e. out-of-band signals when compared with the UWB ranging signals) before any UWB ranging signals are exchanged.

That is, a car-controller can set one or more of: a car-antenna-start-ranging-time, a car-antenna-stop-ranging-time, a car-antenna-ranging-duration, a second-car-antenna-start-ranging-time, a second-car-antenna-stop-ranging-time and a car-antenna-ranging-duration; such that the ranging antennas are activated for the second key at a time that does not overlap with when the ranging antennas are activated for the first key and any other second keys if there are any.

One or more of the examples disclosed herein propose as a first step (one portable device is doing the ranging service) that via a connectivity radio a payload is sent out in order to propose a time value, which can be a delay between the out of band connectivity radio packet and the time when a portable device will send out its first ranging radio packet. This delay can be matched to the internal capabilities of the infrastructure and the delays in this distributed network.

For instance, in a car there can be several BLE anchors connected via CAN to a central microcontroller. This microcontroller can control distributed UWB anchors via the same CAN bus or over different gateways. The car can have access to predetermined values for the internal delays that occur when switching on the UWB receivers, and on this basis it can send out a proposed time window for the portable device (all of that relative to a radio connection event on the air (e.g. a BLE connection between car and key)).

In the case of a further portable device appearing at the same time and being connected to the same infrastructure / car, this portable device may not be synchronized at all to the other portable device. However, the infrastructure / car can have access to the timings of the communications between the two portable devices. Examples disclosed herein can schedule the second portable device relative to the first running ranging service with the first portable device. because the car knows the connectivity to portable device <NUM> and <NUM>. An example disclosed herein can propose another slot (by sending out another delay to the portable device <NUM>). In this way, the different ranging sessions (session <NUM> and <NUM>) are scheduled to avoid collisions. If a third device is found and connected, then this procedure can of course be extended such that the ranging sessions of all three devices do not collide.

As will be appreciated from the above discussion, examples disclosed herein can be especially useful in a car access system. This includes a car access system with many UWB receivers for localisation and BLE nodes for communication, and several authorized keys that can legitimately approach the car (this can be considered as a private fleet). Communication can start with low power BLE radio and after some time UWB ranging starts for localisation. The car first enables its own UWB receivers and then requests the key device to initiate ranging. The car should enable UWB receivers early enough in order not to miss incoming UWB messages. Here, the receive windows should be large enough since BLE communication delay and uncertainty may not be known - for instance they can variable based on the environment. However, advantageously this window can be reduced or minimized by executing both initiate and respond commands at known synchronized times. Thus, saving power on UWB nodes which are waiting for the incoming initiation message.

The car does not a priori need to know which of a plurality of keys is the preferred key and has to try (range) all devices that are detected. This method can avoid unnecessary collisions with a retry method (hopping sequence) that is currently proposed by the Car Connectivity Consortium (CCC) because it can actively schedule the ranging activities leading to a defined and optimized system performance.

This, examples disclosed herein can relate to active scheduling instead of hopping in time slots when collisions are detected. The scheduling can relate to scheduling ranging rounds to various keys / devices / tags.

Claim 1:
An infrastructure-controller (<NUM>) for an infrastructure (<NUM>), the infrastructure-controller configured to:
send a ranging-scheduling-signal (<NUM>) to a key (<NUM>), wherein the ranging-scheduling-signal comprises timing-information for a subsequent ranging operation; and
activate one or more ranging nodes (<NUM>) associated with the infrastructure, for receiving a key-ranging-signal (<NUM>) from the key, at an infrastructure-node-start-ranging-time based on the timing-information;
wherein:
the ranging-scheduling-signal has a frequency in a first RF frequency range;
the key-ranging-signal has a frequency in a second RF frequency range; and
second RF frequency range is different to the first RF frequency range.