WO2019086098A1

WO2019086098A1 - Network access node and methods thereof

Info

Publication number: WO2019086098A1
Application number: PCT/EP2017/077765
Authority: WO
Inventors: George Koudouridis; Johan Christer QVARFORDT
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2017-10-30
Filing date: 2017-10-30
Publication date: 2019-05-09

Abstract

The invention relates to a first network access node (100) for a wireless communication system (500), which obtains a set of first position information (402a, 402b,..., 402n) for a first service area (502). Each first position information of the set of first position information (402a, 402b,..., 402n) comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined. The first network access node (100) further receives a first control message (602) from a second network access node (300). The first control message (602) comprises a set of second position information (404a, 404b,..., 404n) for a second service area (504), wherein each second position information of the set of second position information (404a, 404b,..., 404n) comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined. The first network access node (100) further generates a set of combined position information for the first service area (502) and the second service area (504) based on the set of first position information (402a, 402b,..., 402n) and the set of second position information (404a, 404b,..., 404n). Furthermore, the invention also relates to corresponding methods and a computer program product.

Description

NETWORK ACCESS NODE AND METHODS THEREOF

Technical Field

The invention relates to a network access node. Furthermore, the invention also relates to corresponding methods and a computer program.

Background

Two of the objectives with the specification of 4G in the 3GPP standardization work were to achieve management simplicity and operational cost efficiency. These objectives have been defined in terms of requirements on Self-Organizing Networks (SON) as specified in a number of use cases. 3GPP specifies the operation of a number of SON use cases, and the first one to become well-defined is the automation of neighbour relations. The concept of neighbours and neighbour cells implies that every access node (in a radio access network) maintains an entry in a neighbour relation table for each one cell of its neighbour access nodes. Broadly, SON comprises a framework for all self-configuration, self-optimization, and self-healing processes consisting of several different functions from evolved nodeB (eNB) activation to radio parameter tuning.

A self-configuration process is defined as the process where newly deployed nodes are configured by automatic installation procedures to get the necessary basic configuration for system operation. This process works in pre-operational state. Pre-operational state is understood as the state from when the eNB is powered up and has backbone connectivity until the radio frequency (RF) transmitter is switched on. One of the key functions of the self- configuration process handled in the pre-operational state is the initial radio configuration of an access node.

Self-optimization process is defined as the process where user equipment (UE) and eNB measurements and performance measurements are used to auto-tune the network. This process works in operational state which is the state where the RF interface is additionally switched on. The functions of the self-optimization process, which are handled in the operational state, aims at optimizing and/or adapting to the radio environment.

Summary

An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions. The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the present invention can be found in the dependent claims. According to a first aspect of the invention, the above mentioned and other objectives are achieved with a first network access node for a wireless communication system, the first network access node being configured to

obtain a set of first position information for a first service area, wherein each first position information of the set of first position information comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined;

receive a first control message from a second network access node, wherein the first control message comprises a set of second position information for a second service area, wherein each second position information of the set of second position information comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined;

generate a set of combined position information for the first service area and the second service area based on the set of first position information and the set of second position information. Position information in this disclosure should be understood to be/mean a representation of a physical spatial location where a client device, such as a first client device and/or a second client device, may (be expected to) appear in a service area.

Service area in this disclosure can be understood to mean a defined space wherein a network access node is expecting to provide connection coverage to client devices.

A first network access node according to the first aspect provides a number of advantages over conventional solutions. An advantage of the first network access node is that it enables the first network access node to obtain information from a neighbouring (second) access node about positions where client devices have been discovered increasing the knowledge of the service area where radio resources might be demanded. By means of the first and second determination types the first network access node can determine at least one of:

regions of the service area where no client devices have been detected by any network access node,

regions of the service area that are covered by the first network access node but not covered by other network access nodes, regions of the service area that are covered by other network access nodes but not covered by the first network access node, and

regions of the service area that are covered by other network access nodes and covered by the first network access node.

Furthermore, the first network access node according to the first aspect allows each network access node of the wireless communication system to autonomously build a radio service map with optimal resolution and for position information of different accuracies and share the position information with other network access nodes in the wireless communications system, allowing a distributed radio service map construction with no performance degradation compared to a centralized radio service map.

The determination of the regions will in the following disclosure be denoted region determination.

In an implementation form of a first network access node according to the first aspect, the first network access node is further configured to

generate the set of combined position information for the first service area and the second service area based on a union operation of the set of first position information and the set of second position information.

An advantage with this implementation form is that it enables the first network access node to incorporate received position information in its first service area and to derive an updated service area based on the comparison of the first and second determination types, the comparison resulting in an updated region determination as previously mentioned.

In an implementation form of a first network access node according to the first aspect, the first determination type indicates at least one of:

a) determined by the first network access node or by a first client device,

b) determined by a network access node other than the first network access node or by a client device other than a first client device, and

c) predicted by the first network access node based on the first spatial indication and on a first resolution granularity. An advantage with this implementation form is that it enables the first network access node to exchange information about the determination of each position of its service area which in a subsequent step enables region determination as previously mentioned. In an implementation form of a first network access node according to the first aspect, the second determination type indicates at least one of:

d) determined by the second network access node or by a second client device, e) determined by a network access node other than the second network access node or a client device other than a second client device, and

f) predicted by the second network access node based on the second spatial indication and on a second resolution granularity. An advantage with this implementation form is that it enables the first network access node to receive information about the determination of each position of other network access nodes' service areas which in a subsequent step enables the determination of regions.

determine a set of updated second position information by

setting the second determination type to b) if the second determination type indicates d);

setting the second determination type to b) if the second determination type indicates e).

setting the second determination type to c) if the second determination type indicates f).

An advantage with this implementation form is that it enables the first network access node to process and share information with other network access node about positions covered by the second network access nodes. This allows position information to be propagated throughout the network.

determine a set of updated first position information based on the set of combined position information.

An advantage with this implementation form is that it enables the first network access node to maintain an up to date position information.

In an implementation form of a first network access node according to the first aspect, each first position information further comprises a first resolution granularity for the first spatial indication;

each second position information further comprises a second resolution granularity for the second spatial indication.

The first resolution granularity and the second resolution granularity can be the granularities in c) indicated by the first determination type and f) indicated by the second determination type, respectively. An advantage with this implementation form is that it enables the first network access node to determine an optimal resolution granularity for each position information based on the number of detected client devices. It also allows the first network access node to share the position information with its optimal resolution with other network access nodes. Having resolution granularity in the second position information allows the first network access node to determine how to process the second position information by comparing the received second resolution granularity with the first resolution granularity.

In an implementation form of a first network access node according to the first aspect,

each first position information further comprises a first accuracy for the first spatial indication;

each second position information further comprises a second accuracy for the second spatial indication.

An advantage with this implementation form is that it enables the first network access node to determine an accuracy for each position information based on the accuracy in the determination process of the physical spatial location of the client devices. It also allows the first network access node to share the position information with its determined accuracy with other network access nodes. Having accuracy in the second position information allows the first network access node to determine how to process the second position information by comparing with the first position information based on the received second accuracy.

each first position information further comprises a first timestamp;

each second position information further comprises a second timestamp.

The first and second timestamps can define one or more time periods, respectively. An advantage with this implementation form is that it enables the first network access node to determine the distribution of the client devices over the positions at different time periods throughout a day. The first timestamp indicates the time periods for position information where client devices have been detected by the first network access node in its service area. The time periods can be determined by the first network access node based on a classification of cluster density of client devices over time. The second timestamp indicates time periods for position information where client devices have been detected by the second network access node in its service area. The time periods can be determined by the second network access node based on a classification of cluster density of client devices over time. This allows for the maintenance of different instances of position information to be shared with other network access nodes and compared for different time periods.

the first spatial indication indicates an expected position of a first client device in the first service area;

the second spatial indication indicates an expected position of a second client device in the second service area.

An advantage with this implementation form is that it enables the first network access node to: determine the physical spatial location of the detected client devices, receive the physical spatial location from the detected client devices, or determine the physical spatial location by means of prediction based on a resolution granularity. It also allows network access nodes to share the spatial indication with each other. In an implementation form of a first network access node according to the first aspect,

each first position information further comprises a first coordinate type for the first spatial indication;

each second position information further comprises a second coordinate type for the second spatial indication

wherein the first coordinate type and the second coordinate type indicates at least one of: Cartesian coordinates, spherical coordinates, geographical coordinates, GPS coordinates, interstellar coordinates, direction information, cell portion, serving beam information, sector information, reference point relative information, and location index. An advantage with this implementation form is that it enables different network access nodes to maintain its own spatial indication coordinate type and share it with other network access nodes. This allows for a flexible and feasible implementation of position information. In an implementation form of a first network access node according to the first aspect, the first network access node is further configured to

generate a second control message comprising a request for the set of second position information;

transmit the second control message to the second network access node;

receive the first control message in response to the transmission of the second control message. An advantage with this implementation form is that it allows the first network access node to request position information for a second service area. In one example, this is beneficial when a new network access node requests position information from an existing network access node. In an implementation form of a first network access node according to the first aspect, the first network access node is further configured to

receive a third control message from the second network access node; wherein the third control message comprises a request for the set of first position information;

generate a fourth control message comprising the set of first position information;

transmit the fourth control message to the second network access node in response to the reception of the third control message.

An advantage with this implementation form is that it allows the first network access node to share position information for a first service area with another network access node. In one example, this is beneficial when a new network access node issues the request.

receive a set of first radio signal information from a set of first client devices in the first service area;

obtain a set of first path-loss estimations based on the set of first radio signal information and the set of combined position information;

obtain a set of first interpolation based estimations based on the set of first radio signal information and the set of combined position information;

determine a set of first estimated radio signal information based on a weighted aggregation of the set of first path-loss estimations, the set of first interpolation based estimations, and the set of combined position information; generate a radio service map based on the set of first radio signal information, the set of combined position information, and the set of first estimated radio signal information, wherein the radio service map associates the set of combined position information to the set of first estimated radio signal information.

An advantage with this implementation form is that it enables the first network access node to determine the radio signal in the set of positions in the service area by combining different estimation methods. The weighted combination of different methods is used to improve the estimation of the radio signal information by diminishing the effect of the bias of each method proportionally to the weights.

obtain the set of first position information based on the received set of first radio signal information.

An advantage with this implementation form is that it enables the first network access node to determine the position information based on the radio signal information from client device. The benefit of doing this is to eliminate the signalling of position information from the client devices to the first network access node. Another benefit is that it reduces the signalling of radio signal measurements from the client devices for a position if radio signal information for this position has been already derived.

restrict the set of combined position information based on a threshold value associated with the set of first estimated radio signal information.

An advantage with this implementation form is that it enables the first network access node to limit the storage size and memory consumption for storing position information which is limited to position information of the service area, and the exchange of information between network access nodes as a response to the request about the entire set of position information maintained by a network access node. In an implementation form of a first network access node according to the first aspect, the first network access node is further configured to allocate radio resources to the set of first client devices in the first service area based on the generated radio service map.

An advantage with this implementation form is that it enables the first network access node to determine the potential coverage map of a service given the obtained radio signal information in each position of the service area. This implies the determination of the set of client device positions where client devices are covered by the first network access node. The generated radio service map further allows for estimating the radio resources required for the each position in the service area.

According to a second aspect of the invention, the above mentioned and other objectives are achieved with a method for a first network access node, the method comprises

obtaining a set of first position information for a first service area, wherein each first position information of the set of first position information comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined;

receiving a first control message from a second network access node, wherein the first control message comprises a set of second position information for a second service area, wherein each second position information of the set of second position information comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined;

generating a set of combined position information for the first service area and the second service area based on the set of first position information and the set of second position information. The method according to the second aspect can be extended into implementation forms corresponding to the implementation forms of the first network access node according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the first network access node. The advantages of the methods according to the second aspect are the same as those for the corresponding implementation forms of the network node according to the first aspect.

The invention also relates to a computer program, characterized in code means, which when run by processing means causes said processing means to execute any method according to the present invention. Further, the invention also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.

Further applications and advantages of the present invention will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the present invention, in which:

- Fig. 1 shows a first network access node according to an embodiment of the invention;

- Fig. 2 shows a method according to an embodiment of the invention;

- Fig. 3 shows a wireless communication system according to an embodiment of the invention;

- Fig. 4 shows signalling between a first network access node and a second network access node according to an embodiment of the invention;

- Fig. 5 shows information elements of position information according to an embodiment of the invention;

- Fig. 6 shows signalling between a first network access node and a second network access node according to an embodiment of the invention;

Detailed Description

Fig. 1 shows a first network access node 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1 , the first network access node 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The first network access node 100 may be configured for both wireless and wired communications in wireless and wired communication systems, respectively. The wireless communication capability is provided with an antenna 1 10 coupled to the transceiver 104, while the wired communication capability is provided with a wired communication interface 1 12 coupled to the transceiver 104.

That the first network access node 100 is configured to perform certain actions should in this disclosure be understood to mean that the first network node 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions. The first network access node 100 is configured to obtain a set of first position information 402a, 402b,..., 402n for a first service area 502 (shown in Fig. 3). Each first position information of the set of first position information 402a, 402b,..., 402n comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined. The first network access node 100 is further configured to receive a first control message 602 (shown in Fig. 4) from a second network access node 300 (shown in Fig. 3). The first control message 602 comprises a set of second position information 404a, 404b,..., 404n for a second service area 504 (shown in Fig. 3). Each second position information of the set of second position information 404a, 404b,..., 404n comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined. Furthermore, the first network access node 100 is configured to generate a set of combined position information for the first service area 502 and the second service area 504 based on the set of first position information 402a, 402b,..., 402n and the set of second position information 404a, 404b,..., 404n.

Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a first network access node 100, such as the one shown in Fig. 1 . The method 200 comprises obtaining 202 a set of first position information 402a, 402b,..., 402n for a first service area 502. Each first position information of the set of first position information 402a, 402b,..., 402n comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined. The method 200 further comprises receiving 204 a first control message 602 from a second network access node 300. The first control message 602 comprises a set of second position information 404a, 404b,..., 404n for a second service area 504. Each second position information of the set of second position information 404a, 404b, 404n comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined. Furthermore, the method 200 comprises generating 206 a set of combined position information for the first service area 502 and the second service area 504 based on the set of first position information 402a, 402b,..., 402n and the set of second position information 404a, 404b,..., 404n.

In an embodiment of the invention the first network access node has the capability to combine different estimation methods so as to obtain a refined estimation. Especially, a weighted aggregation of path-loss estimations and interpolation based estimations is herein disclosed. The first network access node is therefore further configured to

obtain a set of first interpolation based estimations based on the set of first radio signal information and the set of combined position information; determine a set of first estimated radio signal information based on a weighted aggregation of the set of first path-loss estimations, the set of first interpolation based estimations, and the set of combined position information. The weighted aggregation for the set of first estimated radio signal information for each position information may be performed according to at least one of the following methods:

• A weighted sum of the set of first path-loss estimates and the set of first interpolation based estimates wherein weights are determined based on the priority of the path-loss estimation and interpolation based estimation methods;

· A weighted sum of the set of first path-loss estimates and the set of first interpolation based estimates wherein weights are determined based on the position distance between the first network access node and each position information in the set of combined position information and its associated priority to the path-loss estimation and interpolation based estimation methods;

· A weighted sum of the set of first path-loss estimates and the set of first interpolation based estimates wherein weights are determined based on the determination type of each position information in the set of combined position information and its associated priority to the path-loss estimation and interpolation based estimation methods;

• A weighted sum of the set of first path-loss estimates and the set of first interpolation based estimates wherein weights are determined based on the position accuracy each position information in the set of combined position information and its associated priority to the path-loss estimation and interpolation based estimation methods;

• A priority aggregation of the set of first path-loss estimates and the set of first interpolation based estimates based on priorities associated to line of sight (LOS) or no line of sight (NLOS) ;

• A maximum aggregation of the set of first path-loss estimates and the set of first interpolation based estimates; and

• A minimum aggregation of the set of first path-loss estimates and the set of first interpolation based estimates.

For example, the following combined approaches can be envisaged for deriving an estimation of the received signal strength P for a position (x, y, z) (in this example given in Cartesian coordinates):

weighted-sum given by P = w_PLP_PL + w_mP_m, with w_PL and w_m fixed for all positions, weighted-sum given by the distance of a position (x,y, z) from the position of the first network access node (x₀,y_Q, z₀) given by d = j {x - x₀)² + (y - y₀)² + (z - z₀)² , for instance in one example more distant positions that a distance of d₀ may weight interpolation- based estimate higher than path-loss estimate as follows:

p ₌ (WpLoPpL + w_IM0P_IM if d≤ d₀

[w_PL1P_pL + w_lM1P_m if d > d₀

weighted-sum given by the determination type, for instance in one example for predicted position the pathloss weight w_PL = w_predl could be higher than the interpolation weight w_m = w_unpredl i.e., w_predl > w_unpredl while the pathloss weight w_PL = w_pred2 could be higher than the interpolation weight w_IM = w_unpred2\.e., w_pred2 < w_unpred2 in all other cases, i.e. p _ (WprediPpL + w_unpredlP_IM if type = predicted

X VpredlPpL + ^wunpredlPlM Otherwise

weighted-sum given by the position accuracy, for instance in one example a position accuracy a that is lower than a reference position accuracy of a₀weight interpolation-based estimate may weight higher than path-loss estimate as follows:

p₌ (WpLoPpL + w_IM0P_IM if a≤ a₀

[wpLiPpL + w_miP_m if a > a₀

LOS and/or NLOS priority aggregation where,

PPL if{^x _> y) ^z) is LOS position,

{P_IM otherwise.

maximum aggregation given by P = max(P_PL, P_IM),

minimum aggregation given by P = vnm.(P_PL, P_IM),

position information related weight where different weights may apply on different positions as a function of different determination types (see below for the different definitions of the first determination type and second determination types, respectively) and/or different position accuracies.

It should be noted that also any aggregation combination of the above aggregation approaches can be employed according to embodiments of the invention. Furthermore, the combination of the path-loss and the interpolation estimates may be reduced to include only the interpolation estimate for certain radio service information such as BLER/BER, RSRQ, CSI, etc. For such a service information the path-loss estimate is omitted and the weight of the interpolation estimate is set to 1 , i.e., w_IM = 1, while the weight of the path-loss estimate is set to 0, i.e. w_PL = 0 , in the weighted combination = w_PLP_PL + w_mP_m .

In one example embodiment, the first network access node 100 performs the following steps:

(1 ) Obtain first position information as determined by a client device or a neighbour network access node based on client device radio signal measurements at a number of different positions and for each position information estimate a determination type is assigned; (2) Receive second position information from a neighbour network access node, e.g. a second network access node 300.

(3) Combine the obtained first position information in step 1 ) with the received second position information in step 2) to derive a map of a service area of interest. For each position in the map of the service area derive a radio service information in the following way:

Estimate a value of the radio service information based on a path-loss model, if the radio service is radio signal related, such as RSS, RSRP, etc. The path- loss model can be derived from radio measurements of client devices at positions being in LOS. The transmit power and estimate a path-loss exponent factor in the path-loss model are derived based on radio signals from the client devices;

Estimate a value of the radio service information based on an interpolation method by using radio measurements of client devices at positions being in LOS and/or NLOS;

- Combine the two radio service values derived by the path-loss model and the interpolation methods above to derive an aggregated initial RSS map. For the combination any function can be used such as weighted-aggregation, maximum-aggregation, position information-related weighting, such as determination type, accuracy, LOS/NLOS aggregation, etc;

(4) Compare the values of the radio service at each position information against a threshold value so as to restrict the map to the service area of interest.

Fig. 3 shows a wireless communication system 500 according to an embodiment. The wireless communication system 500 comprises a first network access node 100 and second network access node 300 configured to operate in the wireless communication system 500 and connected to each other with a link 506. For simplicity, the wireless communication system 500 shown in Fig. 3 only comprises one first network access node 100 and one second network access node 300. However, the wireless communication system 500 may comprise any number of first network access nodes 100 and any number of second network access node 300 without deviating from the scope of the invention.

The wireless communication system 500 shown in Fig. 3 further comprises a number of client devices. A set of first client devices 412a, 412b,..., 412n are located in a first service area 502, where the first service area 502 is under the coverage of the first network access node 100. A set of second client devices 414a, 414b,..., 414n are located in a second service area 504, where the second service area 504 is under the coverage of the second network access node 300. The first service area 502 corresponds to the set of first position information defining a three-dimensional region wherein the first network access node 100 is expecting to provide connection coverage. However, the first service area is not limited thereto and can define an area larger or smaller than the connection coverage region. In the same way, the second service area 504 corresponds to the set of second position information defining a three- dimensional region wherein the second network access node 300 is expecting to provide connection coverage. Also the second service area can define an area larger or smaller than the connection coverage region. Furthermore, the first service area 502 and the second service area 504 may be neighbouring areas, as shown in Fig. 3. However, the first service area 502 and the second service area 504 may in some cases be overlapping or positioned further away from each other.

The first network access node 100 obtains position information associated with the set of first client devices 412a, 412b,..., 412n, while the second network access node 300 obtains position information associated with the set of second client devices 414a, 414b,..., 414n. Said position information may be exchanged between the first network access node 100 and the second network access node 300 as will now be described with reference to Fig. 4.

Fig. 4 shows the steps performed by the first network access node 100, as well as the signalling received from the second network access node 300, according to an embodiment of the invention. In step I in Fig. 4, the first network access node 100 obtains a set of first position information 402a, 402b,..., 402n for a first service area 502. As previously described, each first position information comprises a first spatial indication and a first determination type. Further information about the first position information will be given below with reference to Fig. 5. The set of first position information 402a, 402b,..., 402n may e.g. be obtained from position information, either measured or calculated by the first network access node 100 itself or measured and reported by a first client device 412n. The first network access node 100 can determine the position information of a client device based on angle-of-arrival of a received signal and an estimation of the path-loss between the first network access node and the client device. The first network access node 100 can further combine time of arrival and/or of the angle of arrival of the received signal by different antenna elements belonging to the first network access node 100 and/or the first network access node 100 and other network access nodes. The first client device 412n may determine its position information based on time difference of arrival of signals received from different antenna elements belonging to one or multiple network access nodes. The first client device 412n can further report position information based on its GPS-coordinates to the first network access node 100. In step II in Fig. 4, the first network access node 100 receives a first control message 602, comprising a set of second position information 404a, 404b,..., 404n for a second service area 504, from a second network access node 300. The second network access node 300 may transmit the first control message 602 to the first network access node 100 due to different reasons. For example, the first control message 602 may be transmitted periodically or be triggered by an event. In the latter case, the second network access node 300 may transmit a first control message 602 e.g. when the second network access node 300 has been reconfigured, new second position information is available to the second network access node 300, or more information has made an existing second position information more accurate. In addition, the second network access node 300 may transmit the first control message 602 upon a request from the first network access node 100, as will be described below with reference to Fig. 6. As previously described, each second position information comprises a second spatial indication and a second determination type. Further information about the second position information will be given below with reference to Fig. 5

In step III in Fig. 4, the first network access node 100 uses the obtained set of first position information 402a, 402b,..., 402n and the received set of second position information 404a, 404b,..., 404n to generate a set of combined position information for the first service area 502 and the second service area 504. The first network access node 100 may generate the set of combined position information for the first service area 502 and the second service area 504 based on a union operation of the set of first position information 402a, 402b,..., 402n and the set of second position information 404a, 404b,..., 404n.

The union operation may performed in a number of different ways. At least one of the following methods can be used:

• Concatenate the set of first position information with the set of second position information;

• Concatenate the set of first position information with a processed set of second position information, wherein each position information comprises the second spatial indication, and the second determination type is set to b) if e), b) if d), and c) if f) (see below for the different definitions of the first determination type and second determination types, respectively);

• Concatenate the set of first position information with a processed set of second position information wherein the spatial indication of the second position information being of different coordinate type is converted in the processed second position information to spatial indication of the first coordinate type; • Concatenate the set of first position information with a processed set of second position information wherein the resolution granularity of the processed second position information is adopted to the resolution granularity of the first position information. A processed set of second position information can herein mean an updated set of second position information where updated second spatial indication, updated second determination type, updated second resolution granularity and/or updated second position accuracy are derived based on the first position information and the second position information. By combining the set of first position information 402a, 402b,..., 402n and the set of second position information 404a, 404b,..., 404n the first network access node 100 may increase the accuracy and resolution of the position information available to the first network access node 100. The generated set of combined position information may further be used to update the set of first position information 402a, 402b,..., 402n, i.e. the first network access node 100 may determine a set of updated first position information based on the set of combined position information. In addition, the set of first position information 402a, 402b,..., 402n may be updated e.g. when new first position information is obtained or an existing first position information has become more accurate. In a similar way, the set of second position information 404a, 404b,..., 404n may be updated as new or modified second position information is made available to the second network access node 300. Any time updates have been made to the set of first position information 402a, 402b,..., 402n and/or the set of second position information 404a, 404b,..., 404n an updated set of combined position information may be generated by the first network access node 100. The updated set of combined position information may hence be generated based on the updated set of first position information 402a, 402b,..., 402n and/or the updated set of second position information 404a, 404b,..., 404n, and the previously generated set of combined position information.

In embodiments described so far, the first network access node 100 has received position information from one second network access node 300 only. However, the first network access node 100 may exchange positioning information with more than one network access node to further increase the accuracy and resolution of the position information available to the first network access node 100. Hence, in embodiments of the invention the first network access node 100 may receive a set of second position information 404a, 404b,..., 404n from several second network access nodes 300 and generate the set of combined position information based on all the received sets of second position information 404a, 404b,..., 404n. Fig. 5 a) and b) shows information elements comprised in a first positioning information and a second positioning information, respectively, according to embodiments of the invention. Each first position information comprises two mandatory information elements, a first spatial indication and a first determination type, as shown in Fig. 5 a). The first spatial indication comprised in the first position information may indicate an expected position of a first client device 412n in the first service area 502 and may comprises at least one of: Cartesian coordinates, spherical coordinates, geographical coordinates, GPS coordinates, interstellar coordinates, direction information, cell portion, serving beam information, sector information, reference point relative information, and location index. Furthermore, the first determination type, which indicates how the first spatial indication was determined, may indicate at least one of:

a) determined by the first network access node 100 or by a first client device 412n, b) determined by a network access node other than the first network access node 100 or by a client device other than a first client device 412n, and

c) predicted by the first network access node 100 based on the first spatial indication and on a first resolution granularity.

The first resolution granularity defines the resolution of the positions along the x-, y- and z- dimensions which determines the number positions per unit area. The first resolution granularity corresponds to a vector and can be expressed in terms of the inter-position distance between the in the x-, y- and z-axis. In embodiments of the invention, the first resolution granularity may be comprised in the first positioning information. Hence, each first position information may further comprise a first resolution granularity for the first spatial indication, as shown in Fig. 5 a).

In a similar way as for the first position information, each second position information comprises two mandatory information elements, a second spatial indication and a second determination type, as shown in Fig. 5 b). The second spatial indication may indicate an expected position of a second client device 414n in the second service area 504 and may comprises at least one of: Cartesian coordinates, spherical coordinates, geographical coordinates, GPS coordinates, interstellar coordinates, direction information, cell portion, serving beam information, sector information, reference point relative information, and location index. Furthermore, the second determination type, which indicates how the second spatial indication was determined, may indicate at least one of:

d) determined by the second network access node 300 or by a second client device, e) determined by a network access node other than the second network access node 300 or a client device other than a second client device 414n, and f) predicted by the second network access node 300 based on the second spatial indication and on a second resolution granularity.

The second resolution granularity defines the resolution of the positions along the x-, y- and z- dimensions which determines the number positions per unit area. The second resolution granularity corresponds to a vector and can be expressed in terms of the inter-position distance between the in the x-, y- and z-axis. In embodiments of the invention, the second resolution granularity may be comprised in the second positioning information. Hence, each second position information may further comprise a second resolution granularity for the second spatial indication, as shown in Fig. 5 b).

The first determination type and the second determination type may be set by the first network access node 100 directly when the first determination type is obtained and the second determination type is received, respectively. However, the first determination type and the second determination type may in some cases be set by the first network access node 100 after having generated the combined position information. Moreover, the second determination type may be updated before the set of second position information 404a, 404b,..., 404n is used to generate the set of combined position information in the first network access node 100. Hence, in embodiments the first network access node 100 may determine a set of updated second position information by setting the second determination type to b) if the second determination type indicates d), or setting the second determination type to b) if the second determination type indicates e).

In embodiments when sets of second position information 404a, 404b,..., 404n is received from several second network access nodes 300 the second determination type for the same spatial indication may be combined and used by the first network access node 100 to increase the understanding of the probability for the spatial indication to be correct. The accuracy and resolution for the same spatial indication from several second network access nodes 300 can also further be used to increase the accuracy of the spatial indication in the set of combined position information in the first network access nodes 100.

To further increase the accuracy of the set of combined position information additional information may be comprised in the first position information and the second position information. For example, each first position information may further comprise a first accuracy for the first spatial indication, and each second position information may further comprise a second accuracy for the second spatial indication, as shown in Fig. 5 a) and b). The first and second accuracies refer to how close the first and second spatial indications, respectively, are to true position of the first client device 412n and the second client device 414n, respectively. The first and second accuracies may be expressed as a radius. Moreover, the first and second accuracies may be derived as the statistical difference between position measurements and is associated with the positioning method used to estimate the position. The first and second accuracies may correspond to a vector of non-zero length consisting of an inaccuracy indication in horizontal and/or vertical dimensions along with confidence intervals. For example, the horizontal position accuracy of GPS is within 7.8 meters with a 95% confidence interval. As shown in Fig. 5 a) and b) the first position information and the second position information may further comprise information about time. Thus, each first position information may further comprise a first timestamp, and each second position information may further comprise a second timestamp. A first timestamp enables the first network access node 100 to determine the distribution of the client devices over the positions at different time periods throughout a day. The first timestamp indicates the time periods for position information where client devices have been detected by the first network access node 100 in its service area. The time periods can be determined by the first network access node 100 based on a classification of cluster density of client devices over time. The second timestamp indicates time periods for position information where client devices have been detected by the second network access node 300 in its service area. The time periods can be determined by the second network access node 300 based on a classification of cluster density of client devices over time. This allows for the maintenance of different instances of position information to be shared with other network access nodes and compared for different time periods. Moreover, the time aspect of the invention as explained here may also disclose user and traffic information. It is possible that the accuracy of the position information varies over time. In a broader sense, except from spatial indication, all other position information elements, including accuracy, resolution granularity and determination type, may vary over time. Position accuracy may vary over time due to obstacles that prohibit signal reception (different in summer and winter) or due to busy hour traffic when the density of scatterers increase thereby introducing more noise to the signals.

Fig. 6 shows signaling between the first network access node 100 and the second network access node 300 according to an embodiment of the invention. In step I in Fig. 6, the first network access node 100 obtains a set of first position information 402a, 402b,..., 402n for a first service area 502, as previously described with reference to Fig. 4. The first network access node 100 may further receive position information from the second network access node 300, comprised in a first control message 602, as shown in step III in Fig. 6. In the embodiment shown in Fig. 6, the second network access node 300 transmits the first control message 602 upon a request from the first network access node 100. Hence, the first network access node 100 generates a second control message 604 comprising a request for a set of second position information 404a, 404b,..., 404n. In step II in Fig. 6, the first network access node 100 transmits the second control message 604 to the second network access node 300. In response to the transmission of the second control message 604, the first network access node 100 receives the first control message 602 in step III in Fig. 6. However, the second network access node 300 may in embodiments instead transmit position information without a request from the first network access node 100, as previously described with reference to Fig. 4. In such embodiments, the first network access node 100 receives a first control message 602 without transmitting a second control message 604, as shown in Fig. 4.

Moreover, the second network access node 300 may request and receive positioning information from the first network access node 100, as shown in step IV-VI in Fig. 6. In step IV in Fig. 6, the first network access node 100 receives a third control message 606 from the second network access node 300. The third control message 606 comprises a request for the set of first position information 402a, 402b,..., 402n. Hence, the first network access node 100 generates a fourth control message 608 comprising the set of first position information 402a, 402b,..., 402n in step V in Fig. 6. In step VI in Fig. 6, the first network access node 100 transmits the fourth control message 608 to the second network access node 300 in response to the reception of the third control message 606.

In one example embodiment the second control message 604 is sent by the first network access node 100 to request position information for a selected region. As a consequence, this reduces the position information exchanged between network access nodes. This is especially useful for subsequent continuous updates of position information between existing network access nodes. Similarly, the third control message 606 received by the first network access node 100 can be requesting position information for a selected region, which reduces the position information exchanged between network access nodes.

According to embodiments of the invention the set of combined position information generated by the first network access node 100 may be used by the first network access node 100 to generate or derive a radio service map. The radio service map may represent (i) positions and (ii) radio signal information associated with said positions, including accuracy indication for both the positions and the radio signal information. According to embodiments of the invention, the radio signal information may be represented by radio service indicators such as RSS, RSRP, RSRQ, SNR, BLER/BER, CSI, CQI, or any other service related indicator characterizing the service performance. Thus, the radio signal information for a position may be derived based on radio signal measurement of the above mentioned radio service indicators by a client device at that position. The radio service map may e.g. be used to assist in the allocation of radio resources.

The generation of a radio service map based on the generated set of combined position information will now be described. Firstly, the first network access node 100 receives a set of first radio signal information from a set of first client devices 412a, 412b,..., 412n in the first service area 502. The set of first radio signal information may be based on radio signal measurement by the set of first client devices 412a, 412b,..., 412n, such as e.g. radio signal measurements of downlink reference pilot signals from the first network access node 100.

The first network access node 100 further obtains a set of first path-loss estimations based on the set of first radio signal information and the set of combined position information. The set of first path-loss estimations may e.g. be obtained by using known path-loss estimation methods. For example, using measurements of the positions of the set of first client devices 412a, 412b,..., 412n being in line-of-sight to derive the transmit power of the set of first client devices 412a, 412b,..., 412n and the path-loss exponent factor, and then calculate radio signal values of each none line-of-sight and line-of-sight position.

Furthermore, the first network access node 100 obtains a set of first interpolation based estimations based on the set of first radio signal information and the set of combined position information. The set of first interpolation based estimations may e.g. be obtained by using known interpolation methods based on measurements of the set of first client devices 412a, 412b,..., 412n to estimate radio signal values of each none line-of-sight and line-of-sight position.

The obtaining of the set of first path-loss estimations and the obtaining of the set of first interpolation based estimations may be performed either in sequence or in parallel. Either way, once the set of first path-loss estimations and the set of first interpolation based estimations are available to the first network access node 100, the first network access node 100 may determine a set of first estimated radio signal information based on a weighted aggregation of the set of first path-loss estimations, the set of first interpolation based estimations, and the set of combined position information. The weighted aggregation may be performed e.g. by combining the two radio signal values derived by the path-loss and the interpolation methods to derive an aggregated initial radio signal strength map comprising the set of first estimated radio signal information. For the combination any function can be used such as weighted- aggregation, maximum-aggregation, position information-related weighting, such as determination type, accuracy, LOS/NLOS, etc.

Based on the obtained set of first estimated radio signal information, together with the previously obtained set of first radio signal information and the set of combined position information, the first network access node 100 generates a radio service map. The radio service map associates the set of combined position information to the set of first estimated radio signal information and provides the first network access node 100 with information that may be used to improve the radio resources allocation. Hence, in embodiments the first network access node 100 may allocate radio resources to the set of first client devices 412a, 412b,..., 412n in the first service area 502 based on the generated radio service map.

In embodiments of the invention, the first network access node 100 may restrict the set of combined position information based on a threshold value associated with the set of first estimated radio signal information. The threshold value may e.g. be a radio signal strength value or any equivalent measure. In this way, the threshold value may be used by the first network access node 100 to divide the set of combined position information into a coverage class and out-of-coverage class. When the first network access node 100 generates a radio service map based on the restrict set of combined position information, the generated restricted radio service map will only including the positions with e.g. a radio signal strength value which is higher than the radio signal strength threshold value.

The client device 412n, 414n herein, may be denoted as a user device, a User Equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and/or a mobile terminal, is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. The UE can be a Station (STA), which is any device that contains an IEEE 802.1 1 - conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as New Radio. The network access node 100, 300 herein may also be denoted as a radio network access node, an access network access node, an access point, or a base station, e.g. a Radio Base Station (RBS), which in some networks may be referred to as transmitter, "eNB", "eNodeB", "NodeB" or "B node", depending on the technology and terminology used. The radio network access nodes may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The radio network access node can be a Station (STA), which is any device that contains an IEEE 802.1 1 - conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The radio network access node may also be a base station corresponding to the fifth generation (5G) wireless systems.

Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. Moreover, it is realized by the skilled person that embodiments of the client device 412n, 414n and the network access node 100, 300 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the present solution. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the present solution.

Especially, the processor(s) of the client device 412n, 414n and the network access node 100, 300 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression "processor" may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

1 . A first network access node (100) for a wireless communication system (500), the first network access node (100) being configured to

obtain a set of first position information (402a, 402b,..., 402n) for a first service area

(502), wherein each first position information of the set of first position information (402a, 402b, ... , 402n) comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined;

receive a first control message (602) from a second network access node (300), wherein the first control message (602) comprises a set of second position information (404a, 404b, 404n) for a second service area (504), wherein each second position information of the set of second position information (404a, 404b,..., 404n) comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined; generate a set of combined position information for the first service area (502) and the second service area (504) based on the set of first position information (402a, 402b,..., 402n) and the set of second position information (404a, 404b,..., 404n).

2. The first network access node (100) according to claim 1 , configured to

generate the set of combined position information for the first service area (502) and the second service area (504) based on a union operation of the set of first position information (402a, 402b,..., 402n) and the set of second position information (404a, 404b,..., 404n).

3. The first network access node (100) according to claim 1 or 2, wherein the first determination type indicates at least one of:

a) determined by the first network access node (100) or by a first client device (412n), b) determined by a network access node other than the first network access node (100) or by a client device other than a first client device (412n), and

c) predicted by the first network access node (100) based on the first spatial indication and on a first resolution granularity.

4. The first network access node (100) according to claim 3, wherein the second determination type indicates at least one of:

d) determined by the second network access node (300) or by a second client device (414n),

e) determined by a network access node other than the second network access node

(300) or a client device other than a second client device (414n), and f) predicted by the second network access node (300) based on the second spatial indication and on a second resolution granularity.

5. The first network access node (100) according to claim 3 and claim 4, configured to determine a set of updated second position information by

setting the second determination type to b) if the second determination type indicates d); setting the second determination type to b) if the second determination type indicates e). setting the second determination type to c) if the second determination type indicates f). 6. The first network access node (100) according to any of the preceding claims, configured to determine a set of updated first position information based on the set of combined position information.

7. The first network access node (100) according to any of the preceding claims, wherein each first position information further comprises a first resolution granularity for the first spatial indication;

each second position information further comprises a second resolution granularity for the second spatial indication. 8. The first network access node (100) according to any of the preceding claims, wherein each first position information further comprises a first accuracy for the first spatial indication;

9. The first network access node (100) according to any of the preceding claims, wherein each first position information further comprises a first timestamp;

each second position information further comprises a second timestamp. 10. The first network access node (100) according to any of the preceding claims, wherein the first spatial indication indicates an expected position of a first client device (412n) in the first service area (502);

the second spatial indication indicates an expected position of a second client device

(414n) in the second service area (504).

1 1 . The first network access node (100) according to any of the preceding claims, configured to generate a second control message (604) comprising a request for the set of second position information (404a, 404b,..., 404n);

transmit the second control message (604) to the second network access node (300); receive the first control message (602) in response to the transmission of the second control message (604).

12. The first network access node (100) according to any of the preceding claims, configured to

receive a third control message (606) from the second network access node (300); wherein the third control message (606) comprises a request for the set of first position information (402a, 402b,..., 402n);

generate a fourth control message (608) comprising the set of first position information (402a, 402b,..., 402n);

transmit the fourth control message (608) to the second network access node (300) in response to the reception of the third control message (606).

13. The first network access node (100) according to any of the preceding claims, configured to

receive a set of first radio signal information from a set of first client devices (412a, 412b,..., 412n) in the first service area (502);

determine a set of first estimated radio signal information based on a weighted aggregation of the set of first path-loss estimations, the set of first interpolation based estimations, and the set of combined position information;

generate a radio service map based on the set of first radio signal information, the set of combined position information, and the set of first estimated radio signal information, wherein the radio service map associates the set of combined position information to the set of first estimated radio signal information.

14. The first network access node (100) according to claim 12, configured to

obtain the set of first position information (402a, 402b,..., 402n) based on the received set of first radio signal information.

15. The first network access node (100) according to claim 12 or 13, configured to restrict the set of combined position information based on a threshold value associated with the set of first estimated radio signal information.

16. The first network access node (100) according to any of claims 13 to 15, configured to allocate radio resources to the set of first client devices (412a, 412b,..., 412n) in the first service area (502) based on the generated radio service map.

17. A method (200) for a first network access node (100), the method (200) comprising

obtaining (202) a set of first position information (402a, 402b,..., 402n) for a first service area (502), wherein each first position information of the set of first position information (402a,

402b, ... , 402n) comprises a first spatial indication and a first determination type indicating how the first spatial indication was determined;

receiving (204) a first control message (602) from a second network access node (300), wherein the first control message (602) comprises a set of second position information (404a, 404b,..., 404n) for a second service area (504), wherein each second position information of the set of second position information (404a, 404b,..., 404n) comprises a second spatial indication and a second determination type indicating how the second spatial indication was determined;

generating (206) a set of combined position information for the first service area (502) and the second service area (504) based on the set of first position information (402a, 402b, 402n) and the set of second position information (404a, 404b,..., 404n).

18. A computer program with a program code for performing a method according to claim 17 when the computer program runs on a computer.