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 present embodiments generally relates to a method for resource reservation, and also to a device configured to implement the method. [Background technology]

[0002] Vehicle-to-everything (V2X) communication systems enable the exchange of information between vehicles and any entity, such as another vehicle, a pedestrian, or an infrastructure entity, such as a roadside unit (RSU). While earlier versions of V2X communication, designated as LTE C-V2X, were built on LTE cellular networks, more recent versions of V2X communication, designated as 3GPP (3rd Generation Partnership Project) (trademark) New Radio (NR) V2X, are built on 5G cellular networks. NR V2X allows communication between two user equipments (UEs) via sidelink (SL). Two sidelink communication modes are defined: In SL mode 1, the base station (BS) controls SL transmission; and in SL mode 2, the UE performs sensing and autonomously selects radio resources from a pool of candidate radio resources for direct communication with another UE over the so-called PC5 interface, without the assistance of a base station. 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 attempts 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 own transmission from among the free resources identified by sensing. In a third step, the UE uses the selected resource for its own transmission within a so-called reservation window [t1;t2], typically 1 ms to 500 ms, where t2 is time instant.

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

[0005] In Non-Patent Document 1, a new feature called "Inter-UE-coordination" is considered to avoid the hidden node problem and thus improve the reliability of resource reservation by limiting collisions. This allows a first UE to provide assistance to a second UE, which is a UE monitoring the same channel but located spatially distant. More precisely, the first UE is configured to share its sensing results with the second UE, so that the second UE benefits from 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 therefore cannot solve the problem of outdated sensing.

[0006] Moreover, due to the limited sensing capabilities 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 the node may be a UE or more generally a terminal. This problem is illustrated in Figure 1. Two user equipments U1 and U2 move along a path, e.g., a railway track. Their communication ranges, shown as circles, are hidden within a spatial area [s i ;s f ] corresponds to the time window [t i ;t f ] at time t1 <t i Then 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 [s], both U1 and U2 have a resource reservation in which at least one common specific time-frequency resource is used and which lasts for a sufficient amount of time (more likely in SPS) and which is [s i ;s f ], [t i ;t f], if U1 and U2 are within communication range of each other due to the reservation, there is a high risk of collision on the common reserved resource. Both UEs will experience packet collisions until at least one SPS session ends or until the physical encounter between the UEs ends. [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 problems of sensing expiration and hidden destination nodes and limits the risk of packet collisions. [Means for solving the problem]

[0009] At least one of the present embodiments generally relates to a resource reservation method in a private wireless communication network comprising: a set of terminals moving along a route; a set of roadside units located along the route that wirelessly communicate with the terminals and an application server; and an application server connected to a database that associates metric values ​​representing how wireless resources are used in a given spatial area with each configuration of terminals in the given spatial area, the method comprising: The application server acquires the trajectory, velocity 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 risk of collision is identified, the application server will use the metric values ​​stored in the database to Suitable and / or non Suitable generating assistance data in the form of radio resources and transmitting the generated assistance data to at least one terminal; at least one terminal adapting 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 the terminals' radio resource reservations to make them better orthogonal.

[0011] In one embodiment, the application server's 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 identifying whether there is a risk of collision between packets transmitted or received by terminals whose radio communication ranges intersect includes: 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 difficult radio conditions; Includes:

[0013] In one embodiment, the application server is Suitable Generating assistance data in the form of radio resources includes: 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; From collision rate Suitable and / or non Suitable determining a set of radio resources; Includes:

[0014] In one embodiment, the collision rate Suitable and / or non Suitable Determining the set of radio resources involves determining whether to deactivate radio resources if the collision rate exceeds a threshold. Suitable radio resource, otherwise Suitable This includes determining resources.

[0015] In one embodiment, the application server Suitable and / or non Suitable Generating assistance data in the form of radio resources includes: 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; From the interference probability Suitable and / or non Suitable determining a set of radio resources; Includes:

[0016] In one embodiment, the interference probability Suitable and / or non Suitable Determining the set of radio resources includes determining whether to deactivate radio resources when the interference probability exceeds a threshold. Suitable radio resource, otherwise Suitable This includes determining resources.

[0017] In one embodiment, the application server Suitable and / or non Suitable Generating assistance data in the form of radio resources includes: 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; From the value of degradation of transmission performance Suitable and / or non Suitable determining a set of radio resources; Includes:

[0018] In one embodiment, the value of the degradation of the transmission performance is Suitable and / or non Suitable The determination of the set of radio resources includes determining whether to deactivate the radio resources when the value of the degradation of the transmission performance exceeds a threshold. Suitable radio resource, otherwise Suitable This includes determining resources.

[0019] In one embodiment, the at least one terminal uses the generated assistance data sent by the application server to adapt the radio resource reservation, both in the initial radio resource candidate pool and in the assistance data. Suitable Selecting the identified radio resources as resources for a final radio resource candidate pool.

[0020] In one embodiment, the at least one terminal uses the generated assistance data sent by the application server to adapt the radio resource reservation, the assistance data being non-transitory. Suitable The method includes removing the radio resource identified as the resource 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 indicative of how radio resources are used in the given spatial area, the application server and the terminals 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, and that when the program code instructions are 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 from a reading of the following description of at least one example of embodiment, the said description being made with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 illustrates the hidden destination node problem. [Figure 2] 1 illustrates a private wireless communications network (PNW) in which the present embodiments may be implemented. [Figure 3] 1A-1C illustrate several configurations of terminals with associated metrics. [Figure 4] 1 is a flowchart of a resource reservation method according to certain embodiments; [Figure 5] 1 is a table illustrating preferred and non-preferred radio resources. [Figure 6] 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 hardware architecture of an application server configured to generate assistance data for resource reservation according to certain embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 2 illustrates 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 (UE) in 3GPP terminology, have fully specified and predictable trajectories. Each terminal is associated with a static wireless communication range, e.g., 300 m around the terminal. Packet traffic at the application layer can be known statistically, e.g., as an average duration, or precisely, e.g., as the exact time separation between any two consecutive application packets. The wireless traffic is not known in advance and relies on 3GPP NR V2X SL Mode 2. The wireless communication network PNW includes roadside units (RSUs) 110, 111 located along a route, i.e., a railroad track 170 on which a train 130 travels. Each terminal is within the communication range of at least one RSU.

[0027] The RSUs 110 and 111 provide services of a wireless communication network to UEs. A train 130 or a terminal 131 located within the train 130 that receives / transmits data related to the control of its track is an example of such a UE. The terminal 131 is, for example, a mobile terminal or a relay station that enables a mobile terminal located within the train to access services of the wireless communication network via the RSU. Each RSU is a fixed wireless terminal that can transmit / receive control and data information to / from nearby devices, such as another RSU or a vehicle (e.g., a train). Each RSU is provided with some application layer features, such as encapsulation and decapsulation, for retrieving (or transmitting) 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 includes at least one application server SRV configured to obtain information, such as 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, such as channel busy ratio (CBR) or channel occupancy ratio (CR). In addition, the SRV knows all terminals in the private network, i.e., their physical locations and mobility, such as their spatial locations, velocities, and trajectories. These latter data may be known to the SRV at 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 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 typically rely on statistical data related to users' experiences 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 various times, for example, during a week. These metrics represent the radio situation from the terminal's perspective, indicating how radio resources are used in a given spatial area. Therefore, the metrics can be calculated from RSU sensing and / or terminal sensing. Therefore, 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, a fading level at different radio frequency resources, an interference level at different radio frequency resources, a power level at different radio frequency resources, a CBR, a previous estimate 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 terminals to adjust their communication settings in that area.

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

[0030] To limit the number of TCs, an averaging process can be performed to allow the DB to obtain 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 value 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 situations over time and space, where a particular TC denotes a particular radio situation.

[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 radio conditions.

[0034] 4 shows a flowchart 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 consideration.

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

[0036] In step S302, the SRV determines, from the trajectories obtained in S300, the speeds of the terminals, and the communication ranges known by the SRV, a spatial area [s i ;s f ] and consequently 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 radio ranges intersect, it may be determined that there is no risk of collision because the reserved radio resources are orthogonal. i ;t f ] is detected from the reserved radio resources determined at time t0 and the periodicity of the SPS. Indeed, as soon as the terminal uses the resources it has selected, it transmits in part of a packet Sidelink Control Information (SCI) indicating the reservation details, for example the time-frequency position of the next reservation and the periodicity of these reservations, if any.

[0039] In a second embodiment, an 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, velocity, and density of associated terminals, as well as terminal sensing. The SRV can then, through a learning process, build a spatiotemporal 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 interference status as a function of space and time is known, TCs associated with difficult radio conditions can be tagged as such in a 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 difficult radio conditions, a collision risk is detected as described above, and the method continues at step S306.

[0040] In step S306, the assistance data is extracted from the database DB and then calculated based on t1 and t i The assistance data is generated by the SRV between the Suitable and / or Suitable In one example, the assistance data is provided as a table as shown in Figure 5. The table in Figure 5 includes the following: [t i ;t f For each radio resource in Suitable Is it a radio resource, or Suitable In Figure 5, the radio resources are shown. Suitable Radio resources are indicated by crosses, Suitable The radio resources are left blank. These assistance data are then used to limit the risk of packet collisions. i is sent to at least one terminal before [t i ;t f ], for example by changing the frequency of the reserved resources or, in the 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

[0014] 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 for which the SCI is decoded by this terminal and for which the Reference Signal Received Power (RSRP) measured by this terminal exceeds a preconfigured threshold.

[0041] For this purpose, the InterUE-coordination mechanism of Non-Patent Document 1 can be used. This mechanism allows a first terminal to share its sensing results with a second terminal, so that the second terminal benefits from enhanced sensing. For this purpose, the first terminal can share its UE-specific information determined based on its sensing results. Suitable and / or non Suitable In one embodiment, the second terminal uses its initial radio resource candidate pool and the set of resources transmitted by the first terminal for its final radio resource candidate pool. Suitable Both in terms of a set of resources Suitable In another embodiment, the second terminal selects the identified resource as the resource. Suitable A set of resources is removed from the initial radio resource candidate pool to obtain the final radio resource candidate pool.

[0042] The same principle is used here, SRV Suitable and / or non Suitable Determine a set of radio resources and Suitable and / or non Suitable In one embodiment, at least one of the two terminals determines the set of resources for its final radio resource candidate pool in both its initial resource candidate pool and the assistance data sent by SRV. Suitable In one variant, at least one of the two terminals selects a resource that is identified as a non-resource in the assistance data. Suitable Non-identified resources Suitable A set of resources is removed from the initial radio resource candidate pool to obtain the final radio resource candidate pool.

[0043] According to the specification in section 6.3.2.2 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)”, a first terminal provided with the final resource candidate pool selects a given number N from the pool. r Randomly select N resources, where N r depends on the terminal requirements and needs. For example, N r is equal to 3, which allows for the initial transmission of a single packet and two retransmissions. The size of the final resource candidate pool should be equal to or greater than x% of the pre-configured resource pool shared by the first terminal and 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 an SCI such that a 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 currThe 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 will curr , and obtains radio conditions that are used as a prediction of the radio conditions associated with . This information (TC vs. radio conditions) can 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 closest to , SRV estimates the future status of each resource r, e.g., the number of terminals that can use resource r, which sum 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 and Suitable and / or Suitable The set of resources is determined. The collision rate λ r is the preconfigured threshold λ TH If the associated resource is greater than Suitable tagged as a resource, otherwise Suitable Tagged as a resource. Suitable and / or Suitable The set of 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. currFrom the reports associated with the TCs identified in S306-1 as closest to , the SRV calculates the number of interferences or interference probability for each terminal's associated power. More precisely, given the transmit power of each terminal, the SRV determines the number of interferences or interference probability for each resource mentioned above as hosting a collision in the near future, i.e., λ r >λ TH For each resource, S306-3, a signal-to-interference ratio (SIR) can be predicted. By comparing this SIR to a first preconfigured threshold, the SRV can define an interference probability using, for example, 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 marked as non-interference in S306-3. Suitable tagged as a resource, otherwise Suitable Tagged as a resource. Suitable and / or Suitable The set of 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, the TC curr The link level parameters associated with the TC identified as the closest to are used to predict transmission performance, e.g., packet reception rate (PRR), frame error rate (FER). Indeed, according to the terminal's link level parameters, interference may affect transmission performance, e.g., packet reception rate (PRR), frame error rate (FER). Given the noise figure and the aforementioned SIR, SRV can estimate the SINR (signal to interference and noise ratio). Provided with the modulation and coding scheme used by the terminal, 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 resources are deactivated in step S306-3. Suitable tagged as a resource, otherwise SuitableTagged as a resource. Suitable and / or Suitable The set of resources is then transmitted to the terminal.

[0049] The transmitted non-transmitted data is used as assistance data by the terminal in step S308. Suitable and / or Suitable A set of resources 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 selects the non-resources reserved by U1. Suitable A set of resources is provided. n>1 When resource selection is required, U n is {U k<n} k in E Non-reserved resources are reserved by Suitable A set of resources is provided: 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 resource, the SRV predicts which resource any terminal will select. According to the TC, the SRV extracts assistance data that has provided 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, the SRV decides to schedule the terminals. Mimicking a base station, the SRV determines the exact set for each terminal so that no set collides with any other set. Suitable Compute a set of resources.

[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 reservations according to certain embodiments.

[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., an SD (Secure Digital) card reader, STCK 104, and a communication interface COM 105 that allows the server 10 to send and receive data, all connected by a communication bus 106.

[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 a 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 component (chip or chipset), such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Generally, the server 10 includes electronic circuitry adapted and configured to perform the methods described with respect to Figures 4A-6.

Claims

1. 1. A method of resource reservation in a private wireless communications network comprising: a set of terminals moving along a route; 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 said given spatial area, said method comprising: The application server acquires the trajectory, velocity, and wireless communication range of each of the terminals; 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 the intersection is identified, the application server determining 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 said risk of collision is identified, said application server generating assistance data in the form of preferred and / or non-preferred radio resources from said metric values ​​stored in said database and transmitting said generated assistance data to at least one terminal, said metric values ​​corresponding to any type of data related to wireless communication channels experienced in a given spatial area and useful for a terminal to adjust its communication settings in that area; - adapting, by the at least one terminal, radio resource reservation using the generated assistance data sent by the application server, the assistance data having the form of preferred and / or non-preferred radio resources; Including, The application server's determining whether there is a risk of collision between packets transmitted or received by the terminals whose wireless communication ranges intersect includes determining that there is a risk of collision if the terminals whose wireless communication ranges intersect have at least one identical reserved wireless resource; generating assistance data in the form of preferred and / or non-preferred radio resources by the application server, Identifying in the database a configuration of terminals that is closest to a current configuration of terminals, the configuration of terminals being defined as a spatial configuration of a set of terminals that have a certain velocity in a given spatial area, and the spatial configuration of the set of terminals being defined by the spatial position of each terminal included in the set of terminals; estimating an interference probability of each wireless resource from sensing data associated in the database with the configuration of the identified terminal; determining a set of preferred and / or non-preferred radio resources from the interference probability, wherein determining includes determining radio resources as non-preferred radio resources if the interference probability exceeds a threshold, and as preferred resources otherwise; wherein using by the at least one terminal the generated assistance data sent by the application server to adapt radio resource reservation comprises selecting radio resources identified as suitable resources in an initial radio resource candidate pool for a final radio resource candidate pool, or wherein using by the at least one terminal the generated assistance data sent by the application server to adapt radio resource reservation comprises removing the radio resources identified as non-suitable resources from an initial radio resource candidate pool.

2. generating assistance data in the form of preferred and / or non-preferred radio resources by the application server, Identifying a terminal configuration in said database that is closest to the current terminal configuration; estimating a collision rate for each wireless resource from sensing data associated in the database with the identified terminal configuration; determining a set of preferred and / or non-preferred radio resources from the collision rate; The method of claim 1 , comprising:

3. 3. The method of claim 2, wherein determining a set of preferred and / or non-preferred radio resources from the collision rate comprises determining a radio resource as a non-preferred radio resource if the collision rate exceeds a threshold, and as a preferred resource otherwise.

4. generating assistance data in the form of preferred and / or non-preferred radio resources by the application server, Identifying a terminal configuration in said database that is closest to the current terminal configuration; estimating a value of degradation of transmission performance of each wireless resource from sensing data associated in the database with the identified configuration of the terminal; determining a set of preferred and / or non-preferred radio resources from a value of the degradation of transmission performance; The method of claim 1 , comprising:

5. 5. The method of claim 4, wherein determining a set of preferred and / or non-preferred radio resources from the value of the degradation in transmission performance comprises determining radio resources as non-preferred radio resources if the value of the degradation in transmission performance exceeds a threshold, and as preferred resources otherwise.

6. 6. A private wireless communications 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, the application server connected to a database associating with each configuration of terminals in a given spatial area a metric value indicative of how radio resources are used in the given spatial area, the application server and the terminals being configured to implement a method according to any one of claims 1 to 5.

7. A computer program comprising program code instructions that can be loaded into a programmable device, said program code instructions causing the programmable device to perform a method according to any one of claims 1 to 5 when said program code instructions are executed by said programmable device.

8. 10. A storage medium storing a computer program including program code instructions, the program code instructions causing a method according to any one of claims 1 to 5 to be performed when the program code instructions are read from the storage medium and executed by a programmable device.

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