Method for resource reservation in a private wireless network and corresponding network for carrying out this method - Patents.com

Abstract

A method for resource reservation in a private wireless communication network comprises obtaining trajectories, velocities and radio ranges of each terminal, determining from the obtained data whether there is a spatial area and corresponding time interval in which at least two radio ranges are about to intersect, and if so, determining whether there is a risk of collision in said time interval between packets transmitted or received by the terminals whose radio ranges intersect, and if a risk of collision is determined, generating assistance data in the form of preferred and / or non-preferred radio resources from metric values ​​stored in a database and transmitting the generated assistance data to at least one terminal, and using by the at least one terminal the generated assistance data transmitted by the application server for adapting radio resource reservation.

Description

[Technical field]

[0001] At least one of the embodiments generally relates to a method for resource reservation, and also to a device configured to implement the method. [Background technology]

[0002] In a vehicle-to-everything (V2X) communication system, information can be exchanged between a vehicle and any entity, e.g., another vehicle, a pedestrian, an infrastructure entity such as a roadside unit (RSU), etc. Previous versions of V2X communication, designated as LTE C-V2X, were built on LTE cellular networks, whereas recent versions of V2X communication, designated as NR (New Radio) V2X in the 3rd Generation Partnership Project (3GPP)™, are built on 5G cellular networks. In NR V2X, communication can take place between two user equipments (UEs) through a side link (SL). Two side link communication modes are defined here: In SL mode 1, the base station (BS) controls the SL transmission. In SL mode 2, the UE performs sensing and autonomously, i.e. without the assistance of the base station, selects radio resources from a pool of radio resource candidates for direct communication with another UE over the so-called PC5 interface. Radio resources, or more simply resources, are defined by time-frequency slots. A UE performing radio resource reservation as specified in 3GPP NR V2X SL Mode 2 is configured to perform three steps.

[0003] In a first step, the UE tries to receive other UEs on local radio resources within a sensing window [t0;t1], typically 1 second, where t0 and t1 are time instants. In this way, the UE obtains a map of resources reserved by other UEs and free resources, i.e. resources not used by any other UE. In a second step, the UE randomly selects a radio resource to use for its transmission among the free resources identified by sensing. In a third step, the UE uses the selected resource for its transmission within a so-called reservation window [t1;t2], typically 1 ms to 500 ms, where t2 is time instant.

[0004] In NR V2X SL mode 2, semi-persistent scheduling (SPS) of periodic traffic is further considered. Once one or more resources are selected, the UE repeats the resource reservation N times, where N is an integer, without repeating either the resource detection or the resource selection steps. In other words, the UE uses the same resource periodically within a reservation window [t1;N*t2], which is typically between 1 ms and 15 s. Since an SPS reservation may last for several seconds, any sensing made more than 1 second before the resource selection will quickly expire. As propagation conditions change, the sensing information used for reservation may become obsolete and collisions may occur.

[0005] In [1], a new feature called "InterUE-coordination" is considered to avoid the hidden node problem and thus improve the reliability of resource reservation by limiting collisions. It allows a first UE to provide assistance to a second UE, which is monitoring the same channel but is located spatially distant. More precisely, the first UE is configured to share its sensing results with the second UE, which benefits from the extended sensing. Thanks to this new feature, the second UE can recognize UEs located outside its communication range but inside the communication range of the first UE. This feature provides extended sensing in space but not in time, and thus cannot solve the problem of out-of-date sensing.

[0006] Moreover, due to the limited sensing capability of the UE in time and space, such as the communication range R and the sensing window [t0;t1], the UE often faces the problem of hidden destination nodes, where a node is, for example, a UE or more generally a terminal. This problem is illustrated in Figure 1. Two user equipments U1 and U2 move along a path, for example a railway track. Their communication ranges, shown as circles, are distributed over a spatial area [s i ;s f ] corresponds to the time window [t i ;t f ] at time t1 <t i Now, U1 (or U2) cannot detect U2 (or U1) because U1 is outside the communication range of U2 and U2 is outside the communication range of U1. i At a time before , both U1 and U2 have a resource reservation in which at least one common specific time-frequency resource is used and continues for a sufficient amount of time (more likely in SPS) that is [s i ;s f ], [t i ;t f], if U1 and U2 are within communication range of the other UE due to the reservation, there is a high collision risk on the common reserved resource. Both UEs will experience packet collisions until at least one SPS session is terminated or the physical encounter of the UEs is terminated. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] 3GPP NR V2X Release 17 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, it is desirable to find a resource reservation method that avoids the sensing deadline and hidden destination node problems and limits the risk of packet collisions. [Means for solving the problem]

[0009] At least one of the embodiments relates generally to a method for resource reservation in a private wireless communication network comprising a set of terminals moving along a route, a set of roadside units located along the route in wireless communication with the terminals and an application server, and an application server connected to a database associating each configuration of terminals in a given spatial area with a metric value representative of how wireless resources are used in the given spatial area, the method comprising: The application server obtains the trajectory, speed and wireless communication range of each terminal; The application server determines whether there is a space area and a corresponding time interval where at least two wireless communication ranges are about to intersect from the acquired trajectory, velocity and wireless communication range; if an intersection is identified, the application server determines whether there is a risk of collision in the time interval between packets transmitted or received by the terminals whose wireless coverage areas intersect; if a collision risk is identified, the application server generates assistance data in the form of preferred and / or non-preferred radio resources from the metric values ​​stored in the database and transmits the generated assistance data to the at least one terminal; The at least one terminal adapts radio resource reservation using the generated assistance data sent by the application server; Includes.

[0010] The disclosed method limits the risk of packet collisions by providing assistance data to the terminals, which is used to adapt their radio resource reservations to make them better orthogonal.

[0011] In one embodiment, the application server determining whether there is a risk of collision between packets transmitted or received by terminals with intersecting wireless communication ranges includes determining that there is a risk of collision if the terminals with intersecting wireless communication ranges have at least one identical reserved wireless resource.

[0012] In one embodiment, each configuration of the terminal in the database is associated with a tag indicating whether the configuration is associated with difficult radio conditions, and the application server is adapted to determine whether there is a risk of collision between packets transmitted or received by terminals with intersecting radio ranges, the method comprising: Identifying a device configuration in the database that most closely resembles the current device configuration; Identifying a risk of collision if the identified configuration is associated with a tag indicating that the configuration is associated with a difficult radio condition; Includes.

[0013] In one embodiment, the application server generating assistance data in the form of non-prioritized radio resources comprises: Identifying a device configuration in the database that most closely resembles the current device configuration; estimating a collision rate for each wireless resource from sensing data associated in a database with the identified terminal configuration; determining a set of prioritized and / or non-prioritized radio resources from the collision rate; Includes.

[0014] In one embodiment, determining the set of preferred and / or non-preferred radio resources from the collision rate includes determining the radio resources as non-preferred radio resources if the collision rate exceeds a threshold, and as preferred resources otherwise.

[0015] In one embodiment, the application server generating assistance data in the form of preferred and / or non-preferred radio resources comprises: Identifying a device configuration in the database that most closely resembles the current device configuration; estimating an interference probability for each wireless resource from sensing data associated in a database with the identified terminal configuration; determining a set of preferred and / or non-preferred radio resources from the interference probability; Includes.

[0016] In one embodiment, determining the set of preferred and / or non-preferred radio resources from the interference probability includes determining the radio resources as non-preferred radio resources if the interference probability exceeds a threshold, and as preferred resources otherwise.

[0017] In one embodiment, the application server generating assistance data in the form of preferred and / or non-preferred radio resources comprises: Identifying a device configuration in the database that most closely resembles the current device configuration; estimating a value of degradation of transmission performance of each wireless resource from sensing data associated in a database with the identified terminal configuration; determining a set of prioritized and / or non-prioritized radio resources from a value of the degradation of transmission performance; Includes.

[0018] In one embodiment, determining the set of preferred and / or non-preferred radio resources from the value of the transmission performance degradation comprises determining the radio resources as non-preferred radio resources if the value of the transmission performance degradation exceeds a threshold and as preferred resources otherwise.

[0019] In one embodiment, using by the at least one terminal the generated assistance data sent by the application server for adapting the radio resource reservation comprises selecting for the final radio resource candidate pool those radio resources identified as preferred resources in both the initial radio resource candidate pool and in the assistance data.

[0020] In one embodiment, using by the at least one terminal the generated assistance data sent by the application server for adapting the radio resource reservation comprises removing radio resources identified in the assistance data as non-preferred resources from the initial radio resource candidate pool.

[0021] A private wireless communication network is also disclosed, comprising a set of terminals moving along a route, a set of roadside units located along the route in wireless communication with the terminals and an application server, and an application server connected to a database associating with each configuration of terminals in a given spatial area a metric value representative of how radio resources are used in the given spatial area, the application server and the terminals being configured to implement a resource reservation method according to any one of the disclosed embodiments.

[0022] A computer program product is disclosed that includes program code instructions that can be loaded into a programmable device, which when executed by the programmable device cause the program code instructions to perform a resource reservation method according to any one of the disclosed embodiments.

[0023] Disclosed is a storage medium storing a computer program including program code instructions, which when read from the storage medium and executed by a programmable device cause a resource reservation method according to any one of the disclosed embodiments to be performed.

[0024] The characteristics of the invention will emerge more clearly on reading the following description of at least one example of embodiment, the said description being produced with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 illustrates the hidden destination node problem. [Diagram 2] FIG. 1 illustrates a private wireless communications network (PNW) in which the present embodiments may be implemented. [Diagram 3] 1A-1C show several configurations of terminals with associated metrics. [Figure 4] 4 is a flowchart of a resource reservation method according to certain embodiments; [Diagram 5] 1 is a table showing prioritized and non-prioritized radio resources; [Figure 6] FIG. 2 illustrates in detail the steps of a resource reservation method according to a particular embodiment. [Figure 7] FIG. 2 illustrates a schematic diagram of an example of a hardware architecture of an application server configured to generate resource reservation assistance data according to certain embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Fig. 2 represents a private wireless communication network (PNW) in which the present embodiment can be implemented. As an example, the PNW is a 5G private network for trains. In such a PNW, all terminals, e.g. user equipment according to 3GPP terminology, have a fully specified and predictable trajectory. Each terminal is associated with a static wireless communication range, e.g. 300 m around the terminal. The packet traffic at the application layer may be known statistically, e.g. as an average period, or may be known precisely, e.g. as an exact time separation between any two consecutive application packets. The wireless traffic is not known in advance and depends on 3GPP NR V2X SL mode 2. The wireless communication network PNW comprises roadside units (RSUs) 110, 111 arranged along a route, i.e. a railroad track 170 along which the train 130 runs. Each terminal is within the communication range of at least one RSU.

[0027] The RSUs 110, 111 provide the services of the wireless communication network to the UEs. A train 130 or a terminal 131 located in the train 130 that receives / transmits data related to the control of its track are examples of such UEs. The terminal 131 is, for example, a mobile terminal or a relay station that allows a mobile terminal located in the train to access the services of the wireless communication network through the RSU. Each RSU is a fixed wireless terminal and can transmit / receive control and data information with nearby equipment, for example, another RSU or a vehicle (for example, a train). Each RSU is provided with some application layer features such as encapsulation and decapsulation to read (or transmit) data from the access layer to the application layer or from the application layer to the access layer, so that it can exchange information with any application server SRV.

[0028] The wireless communication network PNW further comprises at least one application server SRV configured to obtain information, e.g., local channel environment, from each RSU. The server SRV may be an independent physical entity or an extended software entity distributed to all RSUs. The SRV is further configured to calculate radio-based metrics, e.g., channel busy ratio (CBR) or channel occupancy ratio (CR). In addition, the SRV knows all terminals in the private network, i.e., it knows their physical location and mobility, e.g., their spatial location, velocity, trajectory. These latter data may be known by the SRV with a certain time granularity, e.g., every second, in which case the SRV can interpolate between sampled data to extrapolate a continuous prediction of the terminal's trajectory. The SRV may further associate a spatial location and a time period with any identified application packet associated with the terminal. The SRV represents the application layer group of all RSUs. Although RSUs are separate physical entities, given their connections with the SRV, any terminal in the PNW targets the best RSU to reach the SRV, and the SRV targets the best RSU to reach any terminal in the PNW. The best RSU is, for example, the RSU with the most reliable channel or the RSU that is physically closest to the terminal. The wireless communication network PNW further comprises a database DB. Database aiding is routinely used in navigation and wireless communication services. DB aided services usually rely on statistical data related to the user's experience in space and time. Therefore, the DB is filled with several metrics by considering a large number of terminals crossing a given spatial area at different times, for example during a week. These metrics represent the radio situation from the terminal's point of view, showing how radio resources are used in a given spatial area. Therefore, the metrics can be calculated from the RSU sensing and / or the terminal sensing. Thus, for each terminal configuration (TC) during this time frame, a specific radio situation is stored.The metric may correspond to a model of the wireless communication channel such as a channel power delay profile, fading levels at different radio frequency resources, interference levels at different radio frequency resources, power levels at different radio frequency resources, CBR, previous estimates of one or more of the instantaneous wireless communication. More generally, the metric may correspond to any type of data related to the wireless communication channel experienced in a given spatial area that is useful for a terminal to adjust its communication settings in that area.

[0029] A configuration TC of terminals is defined as a spatial configuration of a set of terminals (defined by the spatial location of each terminal) having a certain speed in a given spatial area. An example of Nb such terminal configurations, e.g., Nb=10, is shown in FIG. 3. Each dot represents a terminal in a given spatial area bounded by a rectangle. In each configuration, each terminal is associated with a given speed. Thus, in the DB, each TC is associated with a metric value representative of the radio conditions, e.g., a CBR value representative of the radio conditions measured by RSUs located on the border of the given spatial area.

[0030] In order to limit the number of TCs, an averaging process can be performed so that the DB obtains an average radio condition for similar TCs, so that the average radio condition is stored in the DB for each registered TC.

[0031] In one variant, no averaging is performed: the DB only keeps the last metric values ​​measured. This is a special case where only one time instant is taken into account. The radio situation is thus recent and does not represent the past.

[0032] In another variant, the DB is a collection of instantaneous conditions over time and space, where a particular TC means a particular radio condition.

[0033] The current configuration TC is selected from the stored configurations associated with the metrics that represent the wireless status.curr The current configuration TC is predicted by selecting the metric value associated in the DB with the TC that is closest to the curr It is possible to predict the wireless conditions.

[0034] Fig. 4 shows a flow chart of a resource reservation method according to a particular embodiment. The method is implemented, for example, in an application server SRV. For each terminal, resource reservation (Sensing, Selection, Resource Reservation for [t0;t1]) (SPS) is performed at time t0, applied during [t1;t2], and repeated N times. There may be a certain time between the end of sensing and the start of reservation. This time can be ignored, so there is no need to take this time into account.

[0035] In step S300, the SRV obtains the physical trajectory, velocity, and communication range of each terminal. For example, the SRV obtains the trajectory, velocity, and communication range from the memory in which they are stored.

[0036] In step S302, the SRV determines, from the trajectory obtained in S300, the speed of the terminals and also the communication ranges known by the SRV, a spatial area [s i ;s f ] and the corresponding time interval [t i ;t f ]>t0. If no such intersection exists, i.e., the spatial area [s i ;s f ] does not exist, the method ends for the at least two terminals UE1 and UE2.

[0037] In step S304, [t i ;t f], it is detected whether there is a risk of collision between packets transmitted / received by at least two terminals UE1 and UE2. More precisely, if the respective wireless communication ranges of at least two terminals intersect, it is determined that there is a risk of collision if some of the reserved wireless resources of the terminals are identical. If a risk of collision is detected, the method continues to S306. If a risk of collision is not detected, for example because there are no common resources in the resource reservations of the terminals, the method ends.

[0038] Although the wireless coverage areas intersect, it may be determined that there is no risk of collision because the reserved wireless resources are orthogonal. i ;t f The risk of radio collisions in ] is detected from the reserved radio resources determined at time t0 and the periodicity of the SPS. Indeed, as soon as the terminal has used the resources it has selected, it transmits in part of a packet the details of the reservation, for example the time-frequency location of its next reservations and a Sidelink Control Information (SCI) indicating the periodicity, if any, of these reservations.

[0039] In a second embodiment, the RSU collects radio measurements, e.g. sensing reports, from nearby terminals. The SRV aggregates information from the RSUs, including each RSU's internal data, such as the location, speed, density of the associated terminals, as well as the terminal's sensing. The SRV can then build, through a learning process, a space-time map of radio resources that is used to associate the interference status as a function of space and time with any configuration (TC) of terminals. As a result, once the state of interference as a function of space and time is known, the TC associated with the difficult radio condition can be tagged as such in the database. In step S304, the SRV determines which TC the terminal belongs to, or determines the nearest TC to which the terminal belongs. If this TC is associated with a difficult radio condition, a collision risk is detected as described above, and the method continues with step S306.

[0040] In step S306, the assistance data is extracted from the database DB and is divided into t1 and t i The assistance data is generated by the SRV between the UE and the UE. The assistance data may be in the form of, for example, non-prioritized and / or preferred radio resources. In one example, the assistance data is provided as a table as shown in FIG. 5. The table in FIG. 5 includes the following: i ;t f For each radio resource in t , it is indicated whether the resource is a non-prioritized radio resource or a preferred radio resource. In Fig. 5, non-prioritized radio resources are indicated by a cross, whereas preferred radio resources are left blank. These assistance data are then used to limit the risk of packet collisions. i At least one terminal is sent before [t i ;t f ], for example by changing the frequency of the reserved resources or, in case of a self-reassessment of the terminal's resource reservation as provided by the standard 3GPP NR V2X SL Mode 2, by considering the assistance data as the sensing result of the terminal's selection. At least one terminal uses the transmitted assistance data to adapt its radio resource candidate pool to [t i ;t f More precisely, the assistance data is adapted to at least one terminal in step S308 by [t i ;t f ] to better orthogonalize radio resource reservations in

[10] and thus avoid collisions. According to 3GPP NR V2X SL Mode 2, the initial radio resource candidate pool for a given terminal is obtained by excluding any resources whose SCI is decoded by this terminal and whose Reference Signal Received Power (RSRP) measured by this terminal exceeds a preconfigured threshold.

[0041] For this purpose, the InterUE-coordination mechanism of 3GPP TS 21.2006.02.02 can be used. This mechanism allows the first terminal to share its sensing results with the second terminal, so that the second terminal benefits from the enhanced sensing. To this end, the first terminal informs the second terminal of its set of preferred and / or non-preferred resources determined based on its sensing results. In one embodiment, the second terminal selects for its final radio resource candidate pool the resources identified as preferred resources in both its initial radio resource candidate pool and in the set of preferred resources transmitted by the first terminal. In another embodiment, the second terminal removes the set of non-preferred resources transmitted by the first terminal from its initial radio resource candidate pool to obtain its final radio resource candidate pool.

[0042] The same principle is used here, with the SRV determining a set of preferred and / or non-preferred radio resources and transmitting this set of preferred and / or non-preferred resources as assistance data to UE1 and / or UE2. In one embodiment, at least one of the two terminals selects for its final radio resource candidate pool the resources identified as preferred resources in both its initial resource candidate pool and in the assistance data transmitted by the SRV. In a variant, at least one of the two terminals removes from its initial radio resource candidate pool the set of non-preferred resources identified as non-preferred resources in the assistance data to obtain its final radio resource candidate pool.

[0043] According to the specification of the standard 3GPP TR 37.985 v17.0.0(2021-12) “Overall description of Radio Access Network (RAN) aspects for Vehicle-to-everything (V2X) based on LTE and NR (Release 17)”, section 6.3.2.2, the first terminal provided with the final resource candidate pool selects a given number N rRandomly select resources, where N r Depends on the terminal requirements and needs. For example, N r is equal to 3, which allows for a single initial transmission and two retransmissions of a packet. The size of the final resource candidate pool should be equal to or greater than x% of the preconfigured resource pool shared by the first terminal and the other terminals, where x is set to, for example, 20, 35 or 50 depending on the traffic priority of the first terminal. The N selected by the first terminal r The resources are then effectively used by the first terminal according to their time-frequency locations for packet transmission and retransmission. A packet transmitted or retransmitted on a resource by the first terminal includes at least data and includes the SCI so that the second terminal can sense the resource used by the first terminal by attempting to decode the SCI and measuring the associated RSRP. When the SCI is decoded by the second terminal and the associated RSRP exceeds a preconfigured threshold of the second terminal, the resource and possibly the next resource indicated in the SCI are said to be occupied or reserved by the first terminal and the second terminal does not include these resources in its initial resource candidate pool.

[0044] FIG. 6 illustrates an exemplary embodiment of step S306 of the resource reservation method.

[0045] In step S306-1, the current terminal configuration (TC curr ) is required. TC curr The TC in the database closest to the TC is identified. The radio conditions associated with the identified TC are then used as a prediction of the radio conditions of the current terminal configuration. For each spatial location of a TC close to a single registered TC, the DB curr TC vs. radio conditions may be used as a prediction of the radio conditions associated with TC. This information (TC vs. radio conditions) may optionally be used in step S306-2.

[0046] In step S306-2, the data is stored in the DB, and in step S306-1, the data is stored in the TC curr From the sensing reports associated with the TC identified as the closest to , SRV estimates the future status of each resource r, e.g., the number of terminals that can use resource r, which sums up to the number of collisions for r. By dividing this number by the number of resource reservations, SRV estimates the collision rate λ r By comparing the collision rates of all resources, the SRV can extract resources that are more likely to host serious collisions. In step S306-3, the collision rate λ r is compared to a preconfigured threshold to determine the set of non-prioritized and / or prioritized resources. r is a preconfigured threshold λ TH If so, the associated resource is tagged as a non-preferred resource, otherwise it is tagged as a preferred resource. The set of non-preferred and / or preferred resources is then transmitted to the terminal.

[0047] In the first variant, the collision rate λ for each resource r is r is combined with the power level. In fact, resource collisions result in interference if the associated signals physically collide, which means that a terminal can sense other terminals. curr From the reports associated with the TCs identified in S306-1 as the closest to , the SRV calculates the number of interferences or the interference probability for each terminal's associated power. More precisely, the SRV, given the transmission powers of each terminal, calculates the number of interferences or the interference probability for each of the aforementioned resources, i.e., λ, that will host collisions in the near future. r >λ THFor each resource, where SIR is a signal to interference ratio (SIR), it can be predicted. By comparing this SIR to a first preconfigured threshold, the SRV can define an interference probability, for example using the relative difference between the first threshold and the predicted SIR. If the interference probability is greater than a second preconfigured threshold, the associated resource is tagged as a non-preferred resource in S306-3, otherwise it is tagged as a preferred resource. The set of non-preferred and / or preferred resources is then transmitted to the terminal.

[0048] In a second variant, link level parameters can be associated with each TC in a database. In this case, in step S306-1, curr The link level parameters associated with the TC identified as the closest to are used to predict the transmission performance, e.g., packet reception rate (PRR), frame error rate (FER). Indeed, according to the terminal's link level parameters, interference may affect the transmission performance, e.g., packet reception rate (PRR), frame error rate (FER). Given the noise figure and the aforementioned SIR, the SRV can estimate the SINR (signal to interference plus noise ratio). Provided with the modulation and coding scheme used by the terminal, the SRV can predict the frame error rate and / or packet reception rate, which are used as typical performance metrics in such scenarios. If the performance degradation, e.g., FER, is greater than a preconfigured threshold, the associated resource is tagged as a non-preferred resource in step S306-3, otherwise it is tagged as a preferred resource. The set of non-preferred and / or preferred resources is then transmitted to the terminal.

[0049] The set of transmitted non-preferred and / or preferred resources to be used by the terminal as assistance data in step S308 may also be generated in S306 according to various embodiments disclosed below.

[0050] In the first embodiment, SRV allows one terminal U1 to freely select its resources. Then, when resource selection for U2 is required, U2 is provided with a set of non-preferred resources, which are the resources reserved by U1. In general, U n>1 When resource selection is required, n is {U k<n} k in E Each terminal is provided with a set of non-prioritized resources, which are resources reserved by E, where E represents the potentially interfering terminal.

[0051] In the second embodiment, TC curr From the TC identified in step S306-1 as the closest to, the SRV predicts which resource any terminal will select. According to the TC, the SRV extracts assistance data that has resulted in good radio conditions in the past. Therefore, before any resource reservation, the SRV transmits the assistance data to the terminal.

[0052] In a third variant, if the SRV predicts too much interference such that a distributed approach would be too detrimental to performance, it decides to schedule the terminals. Mimicking a base station, the SRV calculates the exact set of preferred resources for each terminal such that no set conflicts with any other set.

[0053] FIG. 7 illustrates, in schematic form, an example of a hardware architecture of an application server 10 configured to generate assistance data for resource reservation according to a particular embodiment.

[0054] The server 10 comprises at least one set of a processor or CPU (Central Processing Unit) 101, a random access memory RAM 102, a read-only memory ROM 103, a storage unit such as a hard disk or a storage media reader, e.g. a SD (Secure Digital) card reader, STCK 104, connected by a communication bus 106, and a communication interface COM 105 that allows the server 10 to send and receive data.

[0055] The processor 101 is capable of executing instructions loaded into the RAM 102 from the ROM 103, from an external memory (such as an SD card), from a storage medium (such as an HDD), or from a communication network. When the server 10 is powered on, the processor 101 is capable of reading and executing instructions from the RAM 102. These instructions form a computer program that causes the processor 101 to perform the methods described with respect to Figures 4 and 6.

[0056] The methods described with respect to Figures 4A and 6 can be implemented in the form of software by execution of a set of instructions by a programmable machine, such as a DSP (digital signal processor), a microcontroller or a GPU (graphics processing unit), or in the form of hardware by a machine or dedicated components (chips or chipsets), such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). In general, the server 10 includes electronic circuitry adapted and configured to implement the methods described with respect to Figures 4A-6.

Claims

1. A method for resource reservation in a private wireless communication network comprising a set of terminals moving along a path and an application server connected to a database that associates a metric value representing how wireless resources are used in a given spatial area with each configuration of the terminals in the given spatial area, the method comprising: the application server obtaining the trajectory, speed and wireless communication range of each of the terminals; the application server identifying from the obtained trajectory, speed and wireless communication range whether there is a spatial area where at least two wireless communication ranges are about to intersect and a corresponding time interval; if the intersection is identified, the application server identifying whether there is a risk of collision during the time interval between packets transmitted or received by the terminals whose wireless communication ranges intersect; if the risk of collision is identified, the application server generating support data in the form of suitable and / or unsuitable wireless resources from the metric values stored in the database and transmitting the generated support data to at least one terminal, the metric value being any type of data related to the wireless communication channel experienced in a given spatial area and corresponding to data useful for a terminal to adjust its communication settings in that area; the at least one terminal adapting the wireless resource reservation using the generated support data transmitted by the application server, the support data having the form of suitable and / or unsuitable wireless resources; comprising: the application server identifying whether there is a risk of collision between packets transmitted or received by the terminals whose wireless communication ranges intersect includes identifying that there is a risk of collision if the terminals whose wireless communication ranges intersect have at least one identical reserved wireless resource; the application server generating support data in the form of suitable and / or unsuitable wireless resources comprises: Identifying, in the database, the configuration of the terminal that is closest to the configuration of the current terminal, where the configuration of the terminal is defined as the spatial configuration of a set of terminals having a certain speed in a given spatial area, and the spatial configuration of the set of terminals is defined by the spatial positions of each terminal included in the set of terminals; Estimating the interference probability of each radio resource from the sensing data associated in the database with the identified terminal configuration; Determining a set of suitable and / or unsuitable radio resources from the interference probability, where the determining includes determining a radio resource as an unsuitable radio resource if the interference probability exceeds a threshold, and determining it as a suitable resource otherwise; The use by the at least one terminal of the generated assistance data transmitted by the application server to adapt radio resource reservation includes selecting, for the final radio resource candidate pool, the radio resources identified as suitable resources in the initial radio resource candidate pool, or the use by the at least one terminal of the generated assistance data transmitted by the application server to adapt radio resource reservation includes removing from the initial radio resource candidate pool the radio resources identified as unsuitable resources. A method. Claim 2 The generation by the application server of assistance data in the form of suitable and / or unsuitable radio resources includes: Identifying, in the database, the configuration of the terminal that is closest to the configuration of the current terminal; Estimating the collision rate of each radio resource from the sensing data associated in the database with the identified terminal configuration; Determining a set of suitable and / or unsuitable radio resources from the collision rate; The method according to claim 1, comprising: Claim 3 The determination of a set of suitable and / or unsuitable radio resources from the collision rate includes determining a radio resource as an unsuitable radio resource if the collision rate exceeds a threshold, and determining it as a suitable resource otherwise, as claimed in claim 2. The method described. Claim 4 The generation of assistance data on the form of suitable and / or unsuitable radio resources by the application server comprises: identifying, in the database, the configuration of the terminal that is closest to the current configuration of the terminal; estimating, from the sensing data associated in the database with the identified terminal configuration, the value of the degradation of the transmission performance of each radio resource; determining a set of suitable and / or unsuitable radio resources from the value of the degradation of the transmission performance; The method according to claim 1, comprising the above steps.

5. Determining a set of suitable and / or unsuitable radio resources from the value of the degradation of the transmission performance includes determining a radio resource as an unsuitable radio resource if the value of the degradation of the transmission performance exceeds a threshold, and determining it as a suitable resource otherwise. The method according to claim 4.

6. A private wireless communication network comprising: a set of terminals moving along a path; a set of roadside units arranged along the path for wireless communication with the terminals and the application server; and an application server connected to a database that associates a metric value representing how radio resources are used in a given spatial area with each configuration of the terminals in the given spatial area, wherein the application server and the terminals are configured to implement the method according to any one of claims 1 to 5.

7. A computer program comprising program code instructions loadable onto a programmable device, which, when executed by the programmable device, cause the programmable device to implement the method according to any one of claims 1 to 5.

8. A storage medium storing a computer program comprising program code instructions, which, when read from the storage medium and executed by a programmable device, cause the programmable device to implement the method according to any one of claims 1 to 5.

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