A method for random access resources management in NTN network and a system thereof

Abstract

A method for managing radio resources suitable for a system in a non-terrestrial network (NTN) comprising at least a NTN satellite (100) and plurality of user equipment (200) that are configured to transmit data to NTN satellite (100) through random access. It is characterized by comprising following steps realized by the NTN satellite (100); assigning resource units (RU) from a resource pool to a first user equipment group as a first priority random access (RA) resource and to a second user equipment group as a second priority RA resource (420) for a next random access period where said first group of user equipment (310) have higher priority than second group of user equipment (320) for data transmission through random access, determining a first transmission probability for said first user equipment group and a second transmission probability for said second user equipment group where first transmission probability is higher than second transmission probability, broadcasting transmission probabilities to first group of user equipment (310) and second group of user equipment (320).

Description

[0001] DESCRIPTION

[0002] A METHOD FOR RANDOM ACCESS RESOURCES MANAGEMENT IN NTN NETWORK AND A SYSTEM THEREOF

[0003] TECHNICAL FIELD

[0004] Invention relates to a method for managing radio resources suitable for a system in a nonterrestrial network (NTN) comprising at least a NTN satellite and plurality of user equipment that are configured to transmit data to NTN satellite through random access and a system thereof.

[0005] PRIOR ART

[0006] The random access procedure is a fundamental aspect of network communication, enabling devices to initiate communication with a network without a prior scheduling arrangement. In the context of non-terrestrial networks, such as those utilizing LEO satellites, this procedure faces unique challenges. The primary issue stems from the high propagation delays between the loT device and the LEO satellite. These delays are significantly longer than those encountered in terrestrial networks, primarily due to the greater distances involved in satellite communication.

[0007] When loT devices attempt to transmit critical information using random access, these high propagation delays can lead to a series of complications. After repeated random access failures, due to propagation delay, devices are effectively unable to establish a connection for prolonged periods. This condition is particularly problematic for critical loT applications where timely data transmission is imperative.

[0008] In the existing art, one solution to circumvent these challenges has been the implementation of scheduled transmission for devices. Scheduled transmission involves pre-allocating transmission slots to loT devices, thus avoiding the need for the random access procedure. While this approach does mitigate the issue, it introduces another significant challenge, particularly in the context of large-scale loT deployments. The massive overhead associated with scheduling transmissions for a large number of loT devices becomes a substantial bottleneck. This overhead is not just limited to the computational and resource allocation aspects on the network side but also includes the management and maintenance of the schedule, which becomes increasingly complex as the number of devices scales up.

[0009] Moreover, scheduled transmission lacks the flexibility of random access. In scenarios where loT devices need to transmit data sporadically or in response to unforeseen events, a rigid schedule is not optimal. This rigidity can result in inefficient utilization of network resources, as transmission slots may be allocated to devices that have no data to send, while others with urgent data are unable to transmit until their scheduled time.

[0010] Furthermore, the management of such scheduled transmissions in a non-terrestrial network involving LEO satellites adds an additional layer of complexity. The dynamic nature of satellite orbits, coupled with the variable propagation conditions in the satellite communication environment, necessitates frequent reconfiguration of the schedule, adding to the administrative overhead.

[0011] In summary, the current state of the art, while providing solutions like scheduled transmissions to address the prolonged random access deprivation experienced by loT devices in nonterrestrial networks, particularly with LEO satellites, introduces significant challenges in terms of overhead and inflexibility, particularly in large-scale deployments.

[0012] All the problems mentioned above have made it necessary to make an innovation in the relevant technical field as a result.

[0013] BRIEF DESCRIPTION OF THE INVENTION

[0014] The present invention relates to a method to eliminate the above-mentioned disadvantages and bring new advantages to the relevant technical field.

[0015] An object of the invention is to increase successful random access attempts of user equipment having critical data to be transmitted.

[0016] Another object of the invention is to increase the efficiency of resource allocation.

[0017] To achieve all the objects mentioned above and that will emerge from the following detailed description, the present invention relates to a method for managing radio resources suitable for a system in a non-terrestrial network (NTN) comprising at least a NTN satellite and plurality of user equipment that are configured to transmit data to NTN satellite through random access. Accordingly, it comprises the following steps realized by the NTN satellite;

[0018] - assigning resource units (RU) from a resource pool to a first user equipment group as a first priority random access (RA) resource and to a second user equipment group as a second priority RA resource for a next random access period where said first group of user equipment have higher priority than second group of user equipment for data transmission through random access,

[0019] - determining a first transmission probability for said first user equipment group and a second transmission probability for said second user equipment group where first transmission probability is higher than second transmission probability,

[0020] - broadcasting transmission probabilities to first group of user equipment and second group of user equipment. Dynamic resource allocation for high priority and low priority devices is realized together with dynamic probability allocation. Thus, devices having critical data has significantly increased chance of realizing successful random access.

[0021] A possible embodiment of the invention is characterized comprising the steps of;

[0022] - by user equipment in first group of user equipment, attempting to random access using first priority random access resources,

[0023] - by user equipment in second group of user equipment, attempting to random access using second priority random access resources.

[0024] A possible embodiment of the invention is characterized in that assignation of resources units is realized based on estimated number of active devices for a next random access period.

[0025] Another possible embodiment of the invention is characterized in that comprising following steps realized by the NTN satellite;

[0026] - determining a threshold for number of transmission attempts;

[0027] - broadcasting determined threshold to user equipment; further comprising following step realized by user equipment:

[0028] - attempting to random access until number of attempts reaches to said threshold.

[0029] Invention is also a system which is configured to realize steps of a method above.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a drawing illustrating top schematic view of the system. Figure 2 is a drawing illustrating radio resources.

[0032] Figure 3 is a drawing illustrating communication between user equipment and NTN satellite while realizing subject matter method.

[0033] REFERENCE NUMBERS GIVEN IN THE FIGURE

[0034] 100 NTN Satellite

[0035] 200 User equipment

[0036] 310 First group of user equipment

[0037] 320 Second group of user equipment

[0038] 400 RA resources

[0039] 410 First priority RA resources

[0040] 420 Second priority RA resources

[0041] 500 Scheduled resources

[0042] DETAILED DESCRIPTION OF THE INVENTION

[0043] In this detailed description, the subject matter is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

[0044] Figure 1 illustrates a structure of a wireless communication system to which the present disclosure may be applied.

[0045] Invention is a method realized by a NTN satellite (100) which essentially assigns random access resources and transmission probability based on priority of the user equipment (200).

[0046] Referring to figure 1 , system comprises a non-terrestrial network (NTN). Said NTN comprises an NTN satellite (100) and plurality of user equipment (200) which are able to communicate with said NTN satellite (100).

[0047] User equipment (200) comprises a communication means which provides radio frequency signal transmission and radio frequency signal reception. Such communication means are well known in the art. Wireless device may comprise a processing unit that executes steps of subject matter method. Wireless device may further comprise a data source which provides data to be transmitted. Processor unit, transmits data to be transmitted using communication means. NTN Satellite (100) may be a LEO satellite.

[0048] NTN satellite (100) is capable of covering N number of user equipment. (200) User equipment (200) are grouped into a first user equipment group and a second user equipment group. First user equipment group has higher priority than second user equipment group. First user equipment group may have critical data to be transmitter over random access, may require realizing a successful random access more than user equipment (200) in second user equipment group.

[0049] NTN satellite (100) is capable of managing a resource pool having M number of resource units (RU). RU is the smallest unit of resources that can be allocated to a user. It represents a fundamental building block in the resource grid of these cellular communication systems. Resource units may be random access preambles, resource blocks, times slots etc.

[0050] NTN satellite (100) allocates resource units for scheduled transmission or random access depending on network status. NTN (100) satellite assigns resource units to first user equipment group as a first priority RA resource (410) and to second user equipment group as second priority RA resource (420). In a possible embodiment NTN satellite (100) may group resource units that are dedicated to random access into more than two group user equipment (200) group which has hierarchical priority requirements. NTN satellite (100).

[0051] Classification may be realized based on device type, data type, or predetermined parameters.

[0052] Figure 2 illustrates section resources. Resources are assigned to scheduled transmission and random access. Resources assigned for random access are further assigned to user equipment (200) based on their priority.

[0053] NTN satellite (100) realizes assignation of resource units based on estimated active user equipment (200) on network. Estimated active user equipment (200) may be determined by a network estimator. Network estimators are means that determine network status based on measurements and received signals.

[0054] User equipment (200) are configured to attempt random access using resource units received from NTN satellite (100) and based on a transmission probability. If the result of the probability function (P(t)) determines whether user equipment (200) will try to realize random access or not.

[0055] Referring to figure 3, subject matter method following steps realized by the NTN satellite: (100)

[0056] - assigning resource units (RU) from a resource pool to a first user equipment group as a first priority random access (RA) resource and to a second user equipment group as a second priority RA resource (420) for a next random access period where said first group of user equipment (310) have higher priority than second group of user equipment (320) for data transmission through random access,

[0057] - determining a first transmission probability for said first user equipment group and a second transmission probability for said second user equipment group where first transmission probability is higher than second transmission probability,

[0058] - broadcasting transmission probabilities to first group of user equipment (310) and second group of user equipment (320).

[0059] User equipment (200) in first group of user equipment (310), attempts to random access using first priority random access resources. User equipment (200) in second group of user equipment (320), attempts to random access using second priority random access resources. Information relating to first priority random access resources and second parameter random access parameter may be transmitted to first group of user equipment (310) and second group of user equipment (320) via a random access response after said groups transmit a random access request to NTN satellite (100).

[0060] Some of resource units are assigned to scheduled access. Resource units are assigned as random access (RA) resource (400) and scheduled resource (500). RA resources (400) are divided into first priority RA resources (410) and second priority RA resources (420).

[0061] Assignation of RU is realized based on estimated number of active devices for a next random access period. Determination of first transmission probability and second access probability is realized based on estimated number of active devices for a next random access period. The NTN satellite (100) estimates active devices according to packet inter-arrival rates (how frequently devices send packets), past RA transmission outcomes (successful random accesses and failed random accesses (collisions)), and the NTN satellites’ (100) orbital data.

[0062] The network estimating means of NTN satellite (100) finds the estimated / expected number of device arrivals. This provides estimation relating to how many devices are likely to need resources in a future access period. Thus, NTN satellite (100) can manage those resources effectively for the upcoming access period. NTN satellite (100) updates the first transmission probability and second transmission probability for the next access period based on the estimated number of active devices and the available resources.

[0063] In a possible embodiment, NTN satellite (100) determines a threshold for number of transmission attempts and broadcasts determined threshold to user equipment. (200). The user equipment (200) attempts to random access until number of attempts reaches to said threshold. Threshold may be predetermined based on average network conditions. When number of attempts are reached, user equipment (200) may realize a predetermined action. Said predetermined action may for example be operating in idle mode, realizing backoff, or requesting scheduled transmission.

[0064] User equipment (200) may request scheduled transmission from NTN satellite (100) when it requires to for instance send large data. User equipment (200) may attempt to random access while transmitting small data.

[0065] The NTN satellite (100) broadcasts transmission probability to user equipment (200) before each access period.

[0066] The scope of protection of the invention is specified in the attached claims and cannot be limited to those explained for sampling purposes in this detailed description. It is evident that a person skilled in the art may exhibit similar embodiments in light of the above-mentioned facts without drifting apart from the main theme of the invention.

Claims

CLAIMS1. A method for managing radio resources suitable for a system in a non-terrestrial network (NTN) comprising at least a NTN satellite (100) and plurality of user equipment (200) that are configured to transmit data to NTN satellite (100) through random access characterized in that comprising following steps realized by the NTN satellite (100);- assigning resource units (RU) from a resource pool to a first user equipment group as a first priority random access (RA) resource and to a second user equipment group as a second priority RA resource (420) for a next random access period where said first group of user equipment (310) have higher priority than second group of user equipment (320) for data transmission through random access,- determining a first transmission probability for said first user equipment group and a second transmission probability for said second user equipment group where first transmission probability is higher than second transmission probability,- broadcasting transmission probabilities to first group of user equipment (200) (310) and second group of user equipment (320).

2. The method according to claim 1 , characterized in that comprising the steps of;- by user equipment (200) in first group of user equipment (310), attempting to random access using first priority random access resources,- by user equipment (200) in second group of user equipment (320), attempting to random access using second priority random access resources.

3. The method according to claim 1 wherein assignation of resources units is realized based on estimated number of active devices for a next random access period.

4. The method according to claim 1 wherein determining first transmission probability and second transmission probability is realized based on estimated number of active devices for a next random access period.

5. The method according to claim 1 , characterized in that comprising following steps realized by the NTN satellite;- determining (100) a threshold for number of transmission attempts;- broadcasting determined threshold to user equipment (200); further (200) comprising following step realized by user equipment (200):- attempting to random access until number of attempts reaches to said threshold.

6. A system characterized in that comprising user equipment (200) and NTN satellite (100) which are configured to realize steps of one of method from claim 1 to 5.

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