WO2024104591A1

WO2024104591A1 - Keeping track of changes in a high-resolution digital map

Info

Publication number: WO2024104591A1
Application number: PCT/EP2022/082332
Authority: WO
Inventors: Volodya Grancharov; Christopher Hollmann
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-11-17
Filing date: 2022-11-17
Publication date: 2024-05-23

Abstract

There is provided techniques for keeping track of changes in a high-resolution digital map of a geographical area. A method is performed by a controller. The method comprises identifying a difference between a first low-resolution digital map of the geographical area and a second, subsequently generated, low-resolution digital map of the geographical area by comparing the second low-resolution digital map to the first low-resolution digital map. The method comprises issuing an indication, responsive to the difference is larger than a threshold difference for at least one subarea of the geographical area, that said at least one subarea of the geographical area in the high-resolution digital map is outdated.

Description

KEEPING TRACK OF CHANGES IN A HIGH-RESOLUTION DIGITAL MAP

TECHNICAL FIELD

Embodiments presented herein relate to methods, a controller, a server, computer programs, and a computer program product for keeping track of changes in a high- resolution digital map of a geographical area.

BACKGROUND

For many devices, such as robots or self-driving cars, it is important to know their exact position and for the devices to have a good knowledge of the surrounding environment. This can be enabled by providing the devices with a sensor to scan their environment and by enabling the devices to access, or create, a digital map of the environment. Non-limiting examples of such sensors are camera units, radar units, lidar units, and other types of sensor units. Using the sensor to obtain an image of the surroundings, the device can deduct from the image where on the map the device is currently positioned. This process is called localization.

In some cases it is also essential to note changes in the digital map. The digital map can be updated with the information from the device. Performing such updating at the same time as the localization is called simultaneous localization and mapping (SLAM). In general terms, SLAM refers to the computational problem of constructing, or updating, a map of an unknown environment whilst simultaneously keeping track of a device’s location within it. By updating the digital map, the device can not only react to unforeseen circumstances, for example a path being blocked by an obstacle, but also inform other devices in the same area that the path is blocked. This allows the other devices to adjust their respective routes based on the new information, without these other devices first having to encounter the blockage themselves. This is an example where devices that move in the same physical environment will benefit from getting access to already pre-built digital map of the physical environment.

As follows from the above, using current technology, the updating of digital maps often requires the devices to be equipped with special hardware, as well as software, to create accurate, and thus high-resolution, digital maps. This makes the devices expensive and bulky (in order to accommodate the special hardware). Further, performing localization and mapping also requires high battery power and high- performing processing circuitry. Therefore, even if a device is equipped with such special hardware and software, the device can decide not to perform update of the external global digital map if not necessary since this would consume both energy and processing resources. This makes the capacity to update digital maps limited in practice.

One consequence of this is that digital maps run the risk of at least occasionally be outdated. Therefore, when, for example a device enters an area, the device does not know if the device can rely on any pre-built digital map for this area, and thus only localize itself without building a digital map, or if the device itself needs to build a new digital map, as the physical reality may have changed since the pre-built digital map of the area was generated.

SUMMARY

An object of embodiments herein is to provide techniques that handle situations where digital maps run the risk of being outdated.

According to a first aspect there is presented a method for keeping track of changes in a high-resolution digital map of a geographical area. The method is performed by a controller. The method comprises identifying a difference between a first low- resolution digital map of the geographical area and a second, subsequently generated, low-resolution digital map of the geographical area by comparing the second low- resolution digital map to the first low-resolution digital map. The method comprises issuing an indication, responsive to the difference is larger than a threshold difference for at least one subarea of the geographical area, that the at least one subarea of the geographical area in the high-resolution digital map is outdated.

According to a second aspect there is presented a controller for keeping track of changes in a high-resolution digital map of a geographical area. The controller comprises processing circuitry. The processing circuitry is configured to cause the controller to identify a difference between a first low-resolution digital map of the geographical area and a second, subsequently generated, low-resolution digital map of the geographical area by comparing the second low-resolution digital map to the first low-resolution digital map. The processing circuitry is configured to cause the controller to issue an indication, responsive to the difference is larger than a threshold difference for at least one subarea of the geographical area, that the at least one subarea of the geographical area in the high-resolution digital map is outdated.

According to a third aspect there is presented a controller for keeping track of changes in a high-resolution digital map of a geographical area. The controller comprises an identify module configured to identify a difference between a first low- resolution digital map of the geographical area and a second, subsequently generated, low-resolution digital map of the geographical area by comparing the second low- resolution digital map to the first low-resolution digital map. The controller comprises an issue module configured to issue an indication, responsive to the difference is larger than a threshold difference for at least one subarea of the geographical area, that the at least one subarea of the geographical area in the high- resolution digital map is outdated.

According to a fourth aspect there is presented a computer program for keeping track of changes in a high-resolution digital map of a geographical area. The computer program comprises computer code which, when run on processing circuitry of a controller, causes the controller to perform actions. One action comprises identifying a difference between a first low-resolution digital map of the geographical area and a second, subsequently generated, low-resolution digital map of the geographical area by comparing the second low-resolution digital map to the first low-resolution digital map. One action comprises issuing an indication, responsive to the difference is larger than a threshold difference for at least one subarea of the geographical area, that the at least one subarea of the geographical area in the high-resolution digital map is outdated.

According to a fifth aspect there is presented a method for keeping track of changes in a high-resolution digital map of a geographical area. The method is performed by a server. The server is configured to manage a database in which the high-resolution digital map is stored. The method comprises obtaining, from a controller, an indication that at least one subarea of the geographical area in the high-resolution digital map of the geographical area is outdated. The method comprises, in response thereto, issuing a notification to devices capable of scanning the geographical area that the at least one subarea of the geographical area in the high-resolution digital map is outdated.

According to a sixth aspect there is presented a server for keeping track of changes in a high-resolution digital map of a geographical area. The server is configured to manage a database in which the high-resolution digital map is stored. The server comprises processing circuitry. The processing circuitry is configured to cause the server to obtain, from a controller, an indication that at least one subarea of the geographical area in the high-resolution digital map of the geographical area is outdated. The processing circuitry is configured to cause the server to, in response thereto, issue a notification to devices capable of scanning the geographical area that the at least one subarea of the geographical area in the high-resolution digital map is outdated.

According to a seventh aspect there is presented a server for keeping track of changes in a high-resolution digital map of a geographical area. The server is configured to manage a database in which the high-resolution digital map is stored. The server comprises an obtain module configured to obtain, from a controller, an indication that at least one subarea of the geographical area in the high-resolution digital map of the geographical area is outdated. The server comprises an issue module configured to, in response thereto, issue a notification to devices capable of scanning the geographical area that the at least one subarea of the geographical area in the high- resolution digital map is outdated.

According to an eighth aspect there is presented a computer program for keeping track of changes in a high-resolution digital map of a geographical area. The computer program comprises computer code which, when run on processing circuitry of a server configured to manage a database in which the high-resolution digital map is stored, causes the server to perform actions. One action comprises obtaining, from a controller, an indication that at least one subarea of the geographical area in the high-resolution digital map of the geographical area is outdated. One action comprises, in response thereto issuing a notification to devices capable of scanning the geographical area that the at least one subarea of the geographical area in the high-resolution digital map is outdated. According to a ninth aspect there is presented a computer program product comprising a computer program according to at least one of the fourth aspect and the eighth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium could be a non-transitory computer readable storage medium.

Advantageously, these aspects enable devices crossing the geographical area to get access to improved localization, as the high-resolution digital map can be updated on a need basis.

Advantageously, these aspects enable devices crossing the geographical area to be redirected to parts of the geographical area where the high-resolution digital map is up to date.

Advantageously, these aspects enable the usage of dedicated scanning devices to be reduced as updates to the high-resolution digital map need to be performed more rarely.

Advantageously, since only the changed parts of the high-resolution digital maps need to be updated, these aspects enable the bandwidth required for updating high- resolution digital maps to be low.

Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram illustrating a communication system according to embodiments;

Fig. 2 is a schematic block diagram of a system for keeping track of changes in a high- resolution digital map 300a of a geographical area according to embodiments;

Fig. 3 shows examples of high-resolution digital maps according to embodiments;

Figs. 4 and 5 are flowcharts of methods according to embodiments;

Fig. 6 is a schematic diagram showing functional units of a controller according to an embodiment;

Fig. 7 is a schematic diagram showing functional modules of a controller according to an embodiment;

Fig. 8 is a schematic diagram showing functional units of a server according to an embodiment;

Fig. 9 is a schematic diagram showing functional modules of a server according to an embodiment; and

Fig. 10 shows one example of a computer program product comprising computer readable means according to an embodiment.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

The embodiments disclosed herein relate to techniques for keeping track of changes in a high-resolution digital map 300a of a geographical area 120. In order to obtain such techniques there is provided a controller 6oo, 700, a method performed by the controller 600, 700, a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the controller 600, 700, causes the controller 600, 700 to perform the method. In order to obtain such techniques there is further provided a server 800, 900, a method performed by the server 800, 900, and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the server 800, 900, causes the server 800, 900 to perform the method.

Fig. 1 is a schematic diagram illustrating a communication system 100. The communication system 100 comprises access nodes no deployed in a geographical area 120. Each access node no could be any of a radio access network node, radio base station, base transceiver station, node B (NB), evolved node B (eNB), gNB, access point, integrated access and backhaul node, transmission and reception point (TRP). In some aspects it is assumed that the access nodes 110 are stationary and thus have fixed positions in relation to the geographical area 120 or some other coordinate system. A subarea in the geographical area 120 is marked at reference numeral 130. In general terms, the access nodes no are configured to perform joint communication and sensing (JSAC) in the geographical area 120.

Aspects of JSAC as applicable to the herein disclosed embodiments, for example how to generate low-resolution digital maps from measurements made by access nodes no or other type of radio equipment, are inter alia disclosed in 3GPP TR 22.837 “Feasibility Study on Integrated Sensing and Communication”, version 0.2.0, in J. Zhang, F. Liu, C. Masouros, R. Heath, Z. Feng, L. Zheng, and A. Petropulu, “An Overview of Signal Processing Techniques for Joint Communication and Radar Sensing,” IEEE Journal of Selected Topics in Signal Processing, Vol. 15, No 6, 2021, and in J. Zhang, M. Rahman, K. Huang, Y. Guo, S. Chen, and J Yuan, “Enabling Joint Communication and Radar Sensing in Mobile Networks - A Survey,” IEEE Communications Surveys & Tutorials, Vol. 24, No. 1, 2022.

In brief, the access nodes no can use the electromagnetic waves they transmit (and receive, possibly after reflection in physical objects, such as buildings, vehicles, trees, etc., located in the geographical area) to create a low-resolution digital map of the geographical area 120. This map can be continuously updated (for example, every minute, every io minutes, every hour, etc.). In some examples the update frequency at which the map is updated is adapted according to some parameters, such as the time of day (e.g., with fewer updates being made during the night, etc.) or the location at which a given access node is placed (e.g., with fewer updates in rural areas than in urban areas, etc.). In the present context, JSAC can thus be utilized to generate a low- resolution digital map of the geographical area 120. As will be further disclosed below, the low-resolution digital map of the geographical area 120 can be used to keep track of changes in a high-resolution digital map of the same geographical area 120.

Fig. 2 is a schematic diagram illustrating a system 200 for keeping track of changes in a high-resolution digital map 300a of a geographical area 120. The system comprises a controller 600, 700 and one or more server 800, 900. The controller 600, 700 is configured to communicate with access nodes no as well as with the one or more server 800, 900. In some examples the controller 600, 700 is part of, integrated with, or collocated with one of the access nodes no. Optionally, the controller 600, 700 is further configured to communicate with devices 240. Each server 800, 900 is configured to communicate with the controller 600, 700 as well as at least some of the devices 240. In this respect, each server 800, 900 might be configured to communicate with its own set of devices 240. The devices 240 are capable of performing localization and mapping, for example using SLAM. Although the devices 240 are illustrated as unmanned aerial vehicles, sometimes referred to as drones, the devices 240 could be other types of devices that are capable of performing localization and mapping. Some non-limiting and illustrative examples of devices 240 are portable wireless devices, user equipment (UEs), smartphones, extended reality (XR) devices, laptop computers, tablet computers, wireless sensor devices, robots, self-driving cars, consumer electronics, and dedicated scanning device. The controller 600, 700 has access to data stored in a database 220. The database 220 at least stores a low-resolution digital map of the geographical area 120. How the low-resolution digital map can be generated will be disclosed below. Each server 800, 900 has access to data stored in a database 230. The database 230 at least stores a high-resolution digital map of the geographical area 120. The high-resolution digital map of the geographical area 120 might have been generated based on data collected by devices 240 scanning the geographical area 120 with a high precision sensor. There can be different examples of low-resolution digital maps and high-resolution digital maps. In some examples, the low-resolution digital map is a three- dimensional (3D) digital map of the geographical area 120. Likewise, in some examples, the high-resolution digital map 300a is a 3D digital map of the geographical area 120. In some examples, the high-resolution digital map 300a is rendered using SLAM or 3D reconstruction techniques. Examples of high-resolution digital maps will be disclosed below with reference to Fig. 3. How the high-resolution digital map can be generated will be disclosed below.

Examples of such high-resolution digital maps are shown in Fig. 3. Fig. 3 shows examples of high-resolution digital maps in terms of an initial high-resolution digital map 300a and an updated high-resolution digital map 300b. As can be seen, high- resolution digital map data 310a in the initial high-resolution digital map 300a has been updated to other high-resolution digital map data 310b in the updated high- resolution digital map 300b. Particularly, in the updated high-resolution digital map 300b, a building represented by the high-resolution digital map data 310a in the initial high-resolution digital map 300a has been removed. For illustrative purposes, the building is assumed to be located in the subarea 130 of the geographical area 120 in Fig. 1. It is here noted that the herein disclosed embodiments are not based on detecting whole buildings that have been removed, but Fig. 3 is merely intended to illustrate the underlying principles of the inventive concepts disclosed herein.

Reference is now made to Fig. 4 illustrating a method for keeping track of changes in a high-resolution digital map 300a of a geographical area 120 as performed by the controller 600, 700 according to an embodiment.

The herein disclosed embodiments are based on having access to an easily updatable low-resolution digital map and a seldomly updatable high-resolution digital map overlaying the same geographical area 120.

Whenever an updated low-resolution digital map of the geographical area 120 is available, this updated low-resolution digital map can be compared to a stored low- resolution digital map of the same geographical area 120 to detect possible changes in the geographical area 120. Hence, the controller 600, 700 is configured to perform step S106. Sio6: The controller 6oo, 700 identifies a difference between a first low-resolution digital map of the geographical area 120 and a second, subsequently generated, low- resolution digital map of the geographical area 120 by comparing the second low- resolution digital map to the first low-resolution digital map.

If the controller 600, 700 cannot detect any such changes by comparing the updated low-resolution digital map with the stored low-resolution digital map, then the controller 600, 700 can discard the updated low-resolution digital map and wait for the next updated low-resolution digital map of the geographical area 120 before a new comparison can be made. In this respect, it is envisioned that there in some scenarios might be some very minor changes to the geographical area 120 that would affect the high-resolution digital map but that are not detectable by comparing the low-resolution digital maps. However, such minor changes will not affect the localization and mapping process carried out by the devices 240 since each device 240 uses a large amount of data points for the localization and mapping, and therefore any minor changes would only affect very few of these data points, and therefore not impact the end result.

However, if the controller 600, 700 detects any change in the geographical area 120, this indicates that the high-resolution digital map 300a might be outdated. Hence, the controller 600, 700 is configured to perform step S108.

S108: The controller 600, 700 issues an indication, responsive to the difference being larger than a threshold difference for at least one subarea 130 of the geographical area 120, that the at least one subarea 130 of the geographical area 120 in the high- resolution digital map 300a is outdated.

The server 800, 900 is thereby made aware of that part of the high-resolution digital map 300a needs to be updated.

Embodiments relating to further details of keeping track of changes in a high- resolution digital map 300a of a geographical area 120 as performed by the controller 600, 700 will now be disclosed with continued reference to Fig. 4. In general terms, the second low-resolution digital map is based on data having been captured later in time than the data which the first low-resolution digital map is based on.

In some aspects, the low-resolution digital maps and the high-resolution digital map 300a are based on different types of data. In particular, in some embodiments, the first and the second low-resolution digital maps are rendered from a first type of data and the high-resolution digital map 300a is rendered from a second type of data, different from the first type of data. In some examples, the first low-resolution digital map is rendered from first measurements obtained during first joint communication and sensing in the geographical area 120 as performed by at least one access node no, and the second low-resolution digital map is rendered from second, subsequently obtained, measurements obtained during second joint communication and sensing in the geographical area 120 as performed by the at least one access node no. In particular, in some embodiments, the controller 600, 700 is configured to perform (optional) steps S102, S104.

S102: The controller 600, 700 generates the first low-resolution digital map from first measurements obtained during first joint communication and sensing in the geographical area 120.

Si 04: The controller 600, 700 generates the second low-resolution digital map from second, subsequently obtained, measurements as obtained during subsequent joint communication and sensing in the geographical area 120.

Filtering can be obtained to avoid having transients in the measurements impacting the generation of the low-resolution digital maps. In this respect, the second low- resolution digital map might be generated from a set of the second measurements as averaged over a time window. Averaging measurements over a time window corresponds to low-pass filtering the measurements.

As disclosed above, the controller 600, 700 in S108 issues an indication that the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a is outdated. There could be different intended recipients of the indication. In some embodiments, the indication is sent to a server 800, 900 managing a database 230 in which the high-resolution digital map 300a is stored. As will be further disclosed below, the server 8oo, 900 might then, in turn, notify the devices 240. In other examples, the controller 600, 700 notifies the devices 240 itself. That is, in some embodiments, the indication is sent to devices 240 capable of scanning the geographical area 120. The controller 600, 700 might then request the devices 240 to scan the outdated subarea 130 of the geographical area 120. That is, the indication might request at least some of the devices 240 to scan the at least one subarea 130 of the geographical area 120.

In some aspects, the controller 600, 700 uses new low-resolution digital map data of the geographical area 120, and in particular of the outdated subarea 130 of the geographical area 120, to update the previously scanned low-resolution digital map of the geographical area 120. Therefore, in some embodiments, the controller 600, 700 is configured to perform (optional) step S110.

S110: The controller 600, 700 replaces the first low-resolution digital map with the second low-resolution digital map responsive to the difference being larger than the threshold difference.

Reference is now made to Fig. 5 illustrating a method for keeping track of changes in a high-resolution digital map 300a of a geographical area 120 as performed by the server 800, 900 according to an embodiment. Further, it is assumed that at least some of the devices 240 have access to the high-resolution digital map 300a via interaction with the server 800, 900. The server 800, 900 is configured to manage a database 230 in which the high-resolution digital map 300a is stored.

As disclosed above, the server 800, 900 is made aware of that part of the high- resolution digital map 300a needs to be updated. In particular, the server 800, 900 is configured to perform step S202.

S202: The server 800, 900 obtains, from the controller 600, 700, an indication that at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a of the geographical area 120 is outdated.

The server 800, 900 then, in turn, makes the devices 240 aware of that part of the high-resolution digital map 300a is outdated. In particular, the server 800, 900 is configured to perform step S206. S206: The server 8oo, 900, in response thereto (i.e., in response to having obtained the indication in S202), issues a notification to devices 240 capable of scanning the geographical area 120 that the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a is outdated.

The devices 240 are thereby made aware of which parts in the high-resolution digital map 300a that are updated and which parts in the high-resolution digital map 300a that are outdated.

Embodiments relating to further details of keeping track of changes in a high- resolution digital map 300a of a geographical area 120 as performed by the server 800, 900 will now be disclosed with continued reference to Fig. 5.

In some aspects, the outdated map area, i.e., the at least one subarea 130 of the geographical area 120, is tagged as outdated. That is, in some embodiments, the server 800, 900 is configured to perform (optional) step S204.

S204: The server 800, 900 tags the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a as outdated.

In some aspects, based on any detected changes, the server 800, 900 can request devices 240 that are inside, or close to, the affected subarea 130 to provide updates so that the high-resolution digital map 300a can be updated. Therefore, in some embodiments, the notification requests at least some of the devices 240 to scan the at least one subarea 130 of the geographical area 120.

There can be different ways for the server 800, 900 to determine which of the devices 240 that are to scan the subarea 130. In some examples, this depends on the capabilities of the devices 240. For example, it might be preferred that devices 240 capable of themselves running SLAM or 3D reconstruction techniques are requested to scan the subarea 130. For example, it might be preferred that the devices 240 in closest proximity to the subarea 130 are requested to scan the subarea 130. The location of the devices 240 within the geographical area 120 can either be determined, and reported back to the server 800, 900, by the devices 120 themselves, or be determined, and reported back to the server 800, 900, by the access nodes no (possibly via the controller 600, 700). Therefore, in some embodiments, which of the devices 240 that are to scan the at least one subarea 130 of the geographical area 120 is decided as a function of proximity of the devices 240 to the at least one subarea 130.

Further in this respect, if there are not any capable devices 240 in the subarea 130, the server 800, 900 might instruct dedicated scanning devices to move to the subarea 130 to perform a scan and report high-resolution digital map data 310b of the subarea 130 back to the server 800, 900 for the high-resolution digital map 300b to be at least partly updated.

The high-resolution digital map 300a might be updated using new high-resolution map data 310b. Particularly, in some embodiments, the server 800, 900 is configured to perform (optional) steps S208, S210.

S208: The server 800, 900 receives, from at least one of the devices 240, high- resolution digital map data 310b of the at least one subarea 130 of the geographical area 120.

S210: The server 800, 900 updates the high-resolution digital map 300a by replacing high-resolution digital map data 310a of the at least one subarea 130 in the high- resolution digital map 300a with the received high-resolution digital map data 310b.

Once the devices 240, or the dedicated scanning devices, have provided enough high- resolution digital map data 310b, and the server 800, 900 has updated the high- resolution digital map 300b as needed, the high-resolution digital map needs no longer to be tagged as outdated. Hence, in some embodiments, the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a is tagged as outdated until the high-resolution digital map 300a has been updated.

The thus updated high-resolution digital map 300b can then be stored in the database 230 and made available to the devices 240.

In some aspects, a previously detected change is reverted. This implies that the original high-resolution digital map 300a becomes valid again. Hence, in some embodiments, the server 800, 900 is configured to perform (optional) step S212. S212: The server 8oo, 900 obtains a further indication that the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a of the geographical area 120 is no longer outdated.

This implies that the high-resolution digital map 300a needs no longer to be tagged as outdated, without any update of the the high-resolution digital map 300a being required. Hence, in some embodiments, the at least one subarea 130 of the geographical area 120 in the high-resolution digital map 300a is tagged as outdated until the further indication is obtained.

Fig. 6 schematically illustrates, in terms of a number of functional units, the components of a controller 600 according to an embodiment. Processing circuitry 610 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1010a (as in Fig. 10), e.g. in the form of a storage medium 630. The processing circuitry 610 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 610 is configured to cause the controller 600 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 630 may store the set of operations, and the processing circuitry 610 maybe configured to retrieve the set of operations from the storage medium 630 to cause the controller 600 to perform the set of operations. The set of operations maybe provided as a set of executable instructions. Thus the processing circuitry 610 is thereby arranged to execute methods as herein disclosed.

The storage medium 630 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

The controller 600 may further comprise a communications (comm.) interface 620 for communications with other entities, functions, nodes, and devices, as in Fig. 2. As such the communications interface 620 may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry 610 controls the general operation of the controller 6oo e.g. by sending data and control signals to the communications interface 620 and the storage medium 630, by receiving data and reports from the communications interface 620, and by retrieving data and instructions from the storage medium 630. Other components, as well as the related functionality, of the controller 600 are omitted in order not to obscure the concepts presented herein.

Fig. 7 schematically illustrates, in terms of a number of functional modules, the components of a controller 700 according to an embodiment. The controller 700 of Fig. 7 comprises a number of functional modules; an identify module 730 configured to perform step S106, and an issue module 740 configured to perform step S108. The controller 600, 700 of Fig. 7 may further comprise a number of optional functional modules, such as any of a generate module 710 configured to perform step S102, a generate module 720 configured to perform step S104, and a replace module 750 configured to perform step S110.

In general terms, each functional module 710:750 maybe implemented in hardware or in software. Preferably, one or more or all functional modules 710:750 maybe implemented by the processing circuitry 610, possibly in cooperation with the communications interface 620 and/or the storage medium 630. The processing circuitry 610 may thus be arranged to from the storage medium 630 fetch instructions as provided by a functional module 710:750 and to execute these instructions, thereby performing any steps of the controller 600, 700 as disclosed herein.

Fig. 8 schematically illustrates, in terms of a number of functional units, the components of a server 800 according to an embodiment. Processing circuitry 810 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1010b (as in Fig. 10), e.g. in the form of a storage medium 830. The processing circuitry 810 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 810 is configured to cause the server 800 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 830 may store the set of operations, and the processing circuitry 810 maybe configured to retrieve the set of operations from the storage medium 830 to cause the server 800 to perform the set of operations. The set of operations maybe provided as a set of executable instructions. Thus the processing circuitry 810 is thereby arranged to execute methods as herein disclosed.

The storage medium 830 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

The server 800 may further comprise a communications interface 820 for communications with other entities, functions, nodes, and devices, as in Fig. 2. As such the communications interface 820 may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry 810 controls the general operation of the server 800 e.g. by sending data and control signals to the communications interface 820 and the storage medium 830, by receiving data and reports from the communications interface 820, and by retrieving data and instructions from the storage medium 830. Other components, as well as the related functionality, of the server 800 are omitted in order not to obscure the concepts presented herein.

Fig. 9 schematically illustrates, in terms of a number of functional modules, the components of a server 900 according to an embodiment. The server 900 of Fig. 9 comprises a number of functional modules; an obtain module 910 configured to perform step S202, and an issue module 930 configured to perform step S206. The server 900 of Fig. 9 may further comprise a number of optional functional modules, such as any of a tag module 920 configured to perform step S204, a receive module 940 configured to perform step S208, an update module 950 configured to perform step S210, and an obtain module 960 configured to perform step S212.

In general terms, each functional module 910:960 maybe implemented in hardware or in software. Preferably, one or more or all functional modules 910:960 maybe implemented by the processing circuitry 810, possibly in cooperation with the communications interface 820 and/or the storage medium 830. The processing circuitry 810 may thus be arranged to from the storage medium 830 fetch instructions as provided by a functional module 910:960 and to execute these instructions, thereby performing any steps of the server 800, 900 as disclosed herein.

The controller 600, 700 and/or the server 800, 900 maybe provided as a standalone device or as a part of at least one further device. Thus, a first portion of the instructions performed by the controller 600, 700 and/or the server 800, 900 maybe executed in a respective first device, and a second portion of the instructions performed by the controller 600, 700 and/or the server 800, 900 maybe executed in a respective second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the controller 600, 700 and/or the server 800, 900 maybe executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a controller 600, 700 and/or a server 800, 900 residing in a cloud computational environment. Therefore, although a single processing circuitry 610, 810 is illustrated in Figs. 6 and 8 the processing circuitry 610, 810 maybe distributed among a plurality of devices, or nodes. The same applies to the functional modules 710:750, 910:960 of Figs. 7 and 9 and the computer programs 1020a, 1020b of Fig. 10.

Fig. 10 shows one example of a computer program product 1010a, 1010b comprising computer readable means 1030. On this computer readable means 1030, a computer program 1020a can be stored, which computer program 1020a can cause the processing circuitry 610 and thereto operatively coupled entities and devices, such as the communications interface 620 and the storage medium 630, to execute methods according to embodiments described herein. The computer program 1020a and/or computer program product 1010a may thus provide means for performing any steps of the controller 600, 700 as herein disclosed. On this computer readable means 1030, a computer program 1020b can be stored, which computer program 1020b can cause the processing circuitry 810 and thereto operatively coupled entities and devices, such as the communications interface 820 and the storage medium 830, to execute methods according to embodiments described herein. The computer program 1020b and/or computer program product 1010b may thus provide means for performing any steps of the server 800, 900 as herein disclosed.

In the example of Fig. 10, the computer program product 1010a, 1010b is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 1010a, 1010b could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial

Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1020a, 1020b is here schematically shown as a track on the depicted optical disk, the computer program 1020a, 1020b can be stored in any way which is suitable for the computer program product 1010a, 1010b. The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

1. A method for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the method being performed by a controller (600, 700), the method comprising: identifying (S106) a difference between a first low-resolution digital map of the geographical area (120) and a second, subsequently generated, low-resolution digital map of the geographical area (120) by comparing the second low-resolution digital map to the first low-resolution digital map; and issuing (S108) an indication, responsive to the difference being larger than a threshold difference for at least one subarea (130) of the geographical area (120), that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

2. The method according to claim 1, wherein the second low-resolution digital map is based on data having been captured later in time than data which the first low- resolution digital map is based on.

3. The method according to claim 1 or 2, wherein the first and the second low- resolution digital maps are rendered from a first type of data and the high-resolution digital map (300a) is rendered from a second type of data, different from the first type of data.

4. The method according to any preceding claim, wherein the first low-resolution digital map is rendered from first measurements obtained during first joint communication and sensing in the geographical area (120) as performed by at least one access node (110), and wherein the second low-resolution digital map is rendered from second, subsequently obtained, measurements obtained during second joint communication and sensing in the geographical area (120) as performed by said at least one access node (110).

5. The method according to any preceding claim, wherein the method further comprises: generating (S102) the first low-resolution digital map from first measurements obtained during first joint communication and sensing in the geographical area (120); and generating (S104) the second low-resolution digital map from second, subsequently obtained, measurements as obtained during subsequent joint communication and sensing in the geographical area (120).

6. The method according to claim 5, wherein the second low-resolution digital map is generated from a set of the second measurements as averaged over a time window.

7. The method according to any preceding claim, wherein the high-resolution digital map (300a) is rendered using simultaneous localization and digital mapping, SLAM.

8. The method according to any preceding claim, wherein the method further comprises: replacing (S110) the first low-resolution digital map with the second low- resolution digital map responsive to the difference being larger than the threshold difference.

9. The method according to any preceding claim, wherein the indication is sent to a server (800, 900) managing a database (230) in which the high-resolution digital map (300a) is stored.

10. The method according to any of claims 1 to 8, wherein the indication is sent to devices (240) capable of scanning the geographical area (120).

11. The method according to claim 10, wherein the indication requests at least some of the devices (240) to scan said at least one subarea (130) of the geographical area (120).

12. A method for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the method being performed by a server (800, 900), the server (800, 900) being configured to manage a database (230) in which the high- resolution digital map (300a) is stored, the method comprising: obtaining (S202), from a controller (600, 700), an indication that at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) of the geographical area (120) is outdated; and in response thereto: issuing (S206) a notification to devices (240) capable of scanning the geographical area (120) that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

13. The method according to claim 12, wherein the high-resolution digital map (300a) is rendered using simultaneous localization and digital mapping, SLAM.

14. The method according to claim 12 or 13, wherein the notification requests at least some of the devices (240) to scan said at least one subarea (130) of the geographical area (120).

15. The method according to claim 14, wherein which of the devices (240) that are to scan said at least one subarea (130) of the geographical area (120) is decided as a function of proximity of the devices (240) to the at least one subarea (130).

16. The method according to any of claims 12 to 15, wherein the method further comprises: tagging (S204) said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) as outdated.

17. The method according to any of claims 12 to 15, wherein the method further comprises: receiving (S208), from at least one of the devices (240), high-resolution digital map data (310b) of said at least one subarea (130) of the geographical area (120); and updating (S210) the high-resolution digital map (300a) by replacing high- resolution digital map data (310a) of said at least one subarea (130) in the high- resolution digital map (300a) with the received high-resolution digital map data (3iob).

18. The method according to claim 16 in combination with claim 18, wherein said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is tagged as outdated until the high-resolution digital map (300a) has been updated.

19. The method according to any of claims 12 to 16, wherein the method further comprises: obtaining (S212) a further indication that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) of the geographical area (120) is no longer outdated.

20. The method according to claim 16 in combination with claim 19, wherein said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is tagged as outdated until the further indication is obtained.

21. The method according to any preceding claim, wherein the high-resolution digital map (300a) is a three-dimensional, 3D, digital map of the geographical area (120).

22. The method according to any preceding claim, wherein each of the low- resolution digital maps is a three-dimensional, 3D, digital map of the geographical area (120).

23. A controller (600) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the controller (600) comprising processing circuitry (610), the processing circuitry being configured to cause the controller (600) to: identify a difference between a first low-resolution digital map of the geographical area (120) and a second, subsequently generated, low-resolution digital map of the geographical area (120) by comparing the second low-resolution digital map to the first low-resolution digital map; and issue an indication, responsive to the difference being larger than a threshold difference for at least one subarea (130) of the geographical area (120), that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

24. A controller (700) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the controller (700) comprising: an identify module (730) configured to identify a difference between a first low- resolution digital map of the geographical area (120) and a second, subsequently generated, low-resolution digital map of the geographical area (120) by comparing the second low-resolution digital map to the first low-resolution digital map; and an issue module (740) configured to issue an indication, responsive to the difference being larger than a threshold difference for at least one subarea (130) of the geographical area (120), that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

25. The controller (600, 700) according to claim 23 or 24, further being configured to perform the method according to any of claims 2 to 11.

26. A server (800) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the server (800, 900) being configured to manage a database (230) in which the high-resolution digital map (300a) is stored, the server (800) comprising processing circuitry (810), the processing circuitry being configured to cause the server (800) to: obtain, from a controller (600, 700), an indication that at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) of the geographical area (120) is outdated; and in response thereto: issue a notification to devices (240) capable of scanning the geographical area (120) that said at least one subarea (130) of the geographical area (120) in the high- resolution digital map (300a) is outdated.

27. A server (900) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the server (800, 900) being configured to manage a database (230) in which the high-resolution digital map (300a) is stored, the server (900) comprising: an obtain module (910) configured to obtain, from a controller (600, 700), an indication that at least one subarea (130) of the geographical area (120) in the high- resolution digital map (300a) of the geographical area (120) is outdated; and in response thereto: an issue module (930) configured to issue a notification to devices (240) capable of scanning the geographical area (120) that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

28. The server (800, 900) according to claim 26 or 27, further being configured to perform the method according to any of claims 13 to 22.

29. A computer program (1020a) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the computer program comprising computer code which, when run on processing circuitry (610) of a controller (600), causes the controller (600) to: identify (S106) a difference between a first low-resolution digital map of the geographical area (120) and a second, subsequently generated, low-resolution digital map of the geographical area (120) by comparing the second low-resolution digital map to the first low-resolution digital map; and issue (S108) an indication, responsive to the difference being larger than a threshold difference for at least one subarea (130) of the geographical area (120), that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

30. A computer program (1020b) for keeping track of changes in a high-resolution digital map (300a) of a geographical area (120), the computer program comprising computer code which, when run on processing circuitry (810) of a server (800) configured to manage a database (230) in which the high-resolution digital map (300a) is stored, causes the server (800) to: obtain (S202), from a controller (600, 700), an indication that at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) of the geographical area (120) is outdated; and in response thereto: issue (S206) a notification to devices (240) capable of scanning the geographical area (120) that said at least one subarea (130) of the geographical area (120) in the high-resolution digital map (300a) is outdated.

31. A computer program product (1010a, 1010b) comprising a computer program (1020a, 1020b) according to at least one of claims 29 and 30, and a computer readable storage medium (1030) on which the computer program is stored.