Providing information to AloT devices to improve random access procedures

Abstract

A power level is set for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave (CW) used at least for reading device(s) (e.g. ambient IoT devi

Description

Providing Information to AIoT Devices to Improve Random Access Procedures TECHNICAL FIELD

[0001] Examples of embodiments herein relate generally to wireless communications and, more specifically, relate to random access (RA) procedures in wireless communications. BACKGROUND

[0002] Random access (RA) procedures are used in wireless networks, particularly cellular networks, to allow multiple devices to access the network. In a contention-based system, the devices randomly select a parameter, and this reduces the chance that two devices will randomly select the same value of the parameter, limiting collisions for the RA procedures. Collisions do, however, occur. There are also contention-free systems, where parameters are assigned to the devices. The contention-free systems are more complex to implement, because all devices in part of the network should have different parameters.

[0003] The RA procedures are even harder when it comes to ambient internet of things (AIoT) devices, as these devices need to be accessed using a carrier wave or a similar radio wave and are not able to initiate any message. Consider a warehouse filled with AIoT devices, where an inventory is being performed. Because the AIoT devices have little power storage, they have to be woken up using the carrier wave (which helps with power storage and use), and the AIoT devices then perform an RA procedure to connect to the network to deliver their data to the network. While the RA procedures are designed to be relatively short and simple for these devices, the RA procedures still should be performed. Performance of the RA procedures for AIoT and similar devices could be improved. BRIEF SUMMARY

[0004] This section is intended to include examples and is not intended to be limiting.

[0005] In an exemplary embodiment, a method is disclosed that includes setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[0006] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0007] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[0008] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: setting a power level for a round of a defined number of rounds of 2 a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[0009] In another exemplary embodiment, an apparatus comprises means for: setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[0010] In an exemplary embodiment, a method is disclosed that includes receiving, by at least one device, information for the at least one device to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

[0011] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer 3 program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0012] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

[0013] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure m the selected random access occasion of the first round in the session.

[0014] In another exemplary embodiment, an apparatus comprises means for: receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings use reference numerals, where the same reference numerals may be used to refer to like parts throughout, but parts having the same reference numeral can differ in operation and components. In the attached drawings:

[0016] FIG. 1 illustrates a 4-step RA (random access) procedure for AIoT devices;

[0017] FIG. 2 presents an illustration of one inventory / information collection session;

[0018] FIG. 3 A illustrates a first topology for Ambient loT networks and devices;

[0019] FIG. 3B illustrates a second topology for Ambient loT networks and devices;

[0020] FIG. 4 is a flow diagram of a method for providing information to AIoT devices to improve random access procedures;

[0021] FIG. 5 illustrates a signaling diagram in accordance with a first example;

[0022] FIG. 5A is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using the signaling diagram of FIG. 5;

[0023] FIG. 5B is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 5;

[0024] FIG. 6 illustrates an example embodiment similar to FIG. 5 but using an RS SI based criterion;

[0025] FIG. 6A is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using the signaling diagram of FIG. 6;

[0026] FIG. 6B is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 6;

[0027] FIG. 7 illustrates a signaling diagram in accordance with a second example;

[0028] FIG. 7A is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using the signaling diagram of FIG. 7;

[0029] FIG. 7B is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 7;

[0030] FIG. 8 illustrates a power-based round assignment; and

[0031] FIG. 9 is a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced. DETAILED DESCRIPTION OF THE DRAWINGS

[0032] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the examples.

[0033] When more than one drawing reference numeral, word, or acronym is used within this description with “ / ”, and in general as used within this description, the “ / ” may be interpreted as “or”, “and”, or “both”. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or,” mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0034] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and or combinations thereof.

[0035] It is noted that capital and lowercase words or phrases are considered to be the same herein. For instance, the words Slice and slice are the same, as are the phrases Network Repository Function and network repository function.

[0036] Any flow diagram (see FIGS. 4, 5A, 5B, 6A, 6B, 7A, and 7B), or signaling diagram (see FIGS. 5, 6, and 7) herein is considered to be a logic flow diagram, and illustrates the operation of an exemplary method, results of execution of computer program instructions embodied on a computer readable memory, and / or functions performed by logic implemented in circuitry. For methods, flow diagrams, and signaling diagrams, the orders of method steps, blocks in the flow, or signaling are not critical and instead are examples.

[0037] Technical context is now provided for technical areas related to the understanding of the examples.

[0038] One area of interest includes energy harvesting technology. Typically, a terminal based on energy harvesting operates in an active or passive mode. The terminal itself uses energy harvested from wireless radio waves or any other form of energy that can be harvested in its particular deployment scenario and is expected to operate with ultra-low power in the range from tens of microwatts to hundreds of microwatts. For example, if energy is harvested from wireless radio waves, the output power of energy harvester would be from several micro-watts to tens of micro-watts. If a solar panel is used for energy harvesting from solar / light, the output power would be less than 1 milli-watt due to the small size of the solar panel.

[0039] An energy harvesting device can harvest energy and then use an active circuit to transmit like a conventional transmitter. On the other side, some energy harvesting devices, called passive devices or tags, do not possess active transmission circuitry, and use backscattering to transmit data.

[0040] Another area of interest includes 3GPP (third generation partnership project) studies on Ambient loT. RFID (radio-frequency identification) solutions are already widely used with backscattering technology. The goal of the Ambient loT study is to use 3GPP technology to enhance coverage for backscattering RFID solutions as well as introducing new solutions with advanced features like harvesting energy from the dedicated source or ambient energy source and spending energy efficiently for loT-type of data transmissions.

[0041] Within 3GPP, related work has started in SAI (3GPP TSG SA WG1, technical specification group service and system aspects, working group 1) where 3GPP TR 22.840 defines the relevant use cases, traffic scenarios, KPIs (key performance indicators) and the like. See 3GPP TR 22.840, Study on Ambient power-enabled Internet of Things, Release 19. The considered devices cover both battery-less type of devices or devices with limited energy storage capability and the energy can be provided via radio wave harvesting, light, motion or the like.

[0042] Use cases is a further technical area of interest. Ambient loTs have been widely used in various vertical industries including logistics, manufacture, transportation, energy industry or the like enabling passive / ambient loT devices, in both public and private networks would benefit the whole 5G (fifth generation) ecosystem. An ambient power-enabled Internet of Things device is an loT device powered by energy harvesting, being either battery-less or with limited energy storage capability (e.g., using a capacitor). Some areas of considerations for the Ambient loT studies include the following.

[0043] 1) Operation under extreme environmental conditions, e.g., high pressure, extremely high / low temperature, humid environment or the like, vibration.

[0044] 2) Ultra-low complexity (e.g., cost), very small terminal size / form factor (e.g., thickness of mm), maintenance-free and longer life cycle or the like are strongly required.

[0045] 3) Other scenarios where a terminal driven by a battery is not applicable

[0046] Therefore, support of ambient loTs using either a battery-less terminal or a terminal with limited energy storage capability (e.g., using a capacitor), could become a new requirement for the existing 3GPP technologies.

[0047] Another area of interest concerns 3 GPP Rei-19 (release 19) SI (study item) on AIoT in RAN (radio access network). 3GPP has approved a SI for AIoT RAN solutions in Rel-19 (see RP-234058, Study on solutions for Ambient loT (Internet of Things) in NR (New Radio), Dec 2023.

[0048] One example in this SI is to study necessary characteristics of carrier-wave waveform for a carrier wave provided externally to the Ambient loT device, including for interference handling at Ambient loT UL receiver, and at NR base station.

[0049] For Topology 2 (see FIG. 3B), there no difference in physical layer design from Topology 1 (see FIG. 3A).

[0050] The RAN2-led study includes the following. Study and decide which functions are needed for an Ambient loT compact protocol stack and lightweight signaling procedure to enable DO-DTT (device-originated, device-terminated triggered) and DT (deviceterminated) data transmission, and study those functions

[0051] A further topic of interest is Random Access (RA). An RA procedure is critical for A-IoT devices as the network needs to support a large number of devices. Random Access procedures are studied for AIoT devices in RAN2.

[0052] A general structure of the RA procedure is illustrated in FIG. 1 from an AIoT device 110 to a reader 120. Trigger message (MS GO) from the reader is required to start the RA procedure, followed by 4-step RA procedure (MSG1, random device identifier; MSG2, response for the random device identifier; MSG3, device identifier and D2R (device to receiver) transmission; and MSG4, response for the device identifier and R2D, receiver to device) transmission). This contention-based RA procedure is completed to give access to one device in a slot, which completes its transmission. This is completed in one access-occasion.

[0053] In further detail, all of these may occur in one RA occasion (see FIG. 2), e.g., 5 slots in one occasion, and each slot may be implemented in an example as a RE (resource element) (e.g., in a time-frequency resource space). If there is no reception, the device 110 marks this RA procedure as failed and will attempt another RA procedure the next round (if received).

[0054] RA for AIoT uses at least the following terminology.

[0055] Access occasions: The terminology of‘access occasion’ refers to each time slot for device to perform random access.

[0056] Access round: The terminology of ‘access round’ refers to a whole inventory procedure which consists of multiple access occasions.

[0057] However, completing full inventory in one round may not be feasible as increasing number of devices in one particular round results in high collision probability.

[0058] Now that technical context has been provided, technical problems to be solved are provided. Referring to FIG. 2, this figure presents an illustration of one inventory / information collection session. FIG. 2 illustrates structure for an “inventory” or “inventory and command” procedure, which starts with an AIoT paging message by the reader 120. These procedures are merely examples and other procedures may be used. Here, “session” refers to the procedure where the reader performs data communication with multiple or a group of AIoT devices as needed based on a service request that may be received from the CN / AIoTF (core network / Ambient internet of things function). The term “session” could also be “cycle”, “procedure” (such as an inventory procedure), or the like, any term where the AIoT devices are accessed and data from the AIoT devices is retrieved. One session 210 is divided into multiple RA rounds 220 (in this example RA rounds 220-1, 220-2, 220-3, and 220-4), where only a subset of devices can contend for network access, and each round 220 is further divided into RA occasions 230 (in this example, RA occasions 230-1 to 230-5), where devices in a particular round contend for RA. It is noted that contention-based RA has each device randomly selecting from a set of RA occasions, and two devices may therefore select the same RA occasion and collide. It is possible to use the same structure for contention-free random access as well, where devices in each round are assigned particular RA occasions for network access.

[0059] This example has the session 210 being (e.g., evenly) divided into four RA rounds 220-1, 220-2, 220-3, and 220-4, though there could be fewer or more RA rounds 220. Each new round 220 and new occasion usually starts based on an indication, e.g., at least that the RA occ (occasion) starts. After five (in this example) RA occasions 230, another indication of start of RA round is used to indicate start of the RA round 220. It is further noted that the resources for the RA occasions can be in time, frequency, or both. As previously stated, resource elements (REs) might be used, which are elements in a time-frequency resource grid having, e.g., subcarriers in frequency and OFDM (orthogonal frequency division multiplexing) symbols in time.

[0060] The number of RA rounds 220 is an arbitrary number that is based on underlying conditions. A reader that controls the session 210 can decide how many rounds, and this is a reader implementation issue. As another example, the network (NW) may indicate to the reader information for a session, including number of rounds 220 and RA occasions 230. Also, the RA rounds 220 may be changed in real-time, such as if the reader reassesses the rounds. Consider that a reader might not receive any RA procedures in RA round 220-2, and therefore may decide to eliminate one or both of RA rounds 220-3 or 220-4.

[0061] It is noted that there are multiple topologies that may configure and use the session 210 for interacting with AIoT devices. The examples herein address at least two of these topologies, which are referred to as a first topology and a second topology.

[0062] Referring to FIG. 3A, this figure illustrates a first topology (e.g., Topology 1) for Ambient loT networks and devices. This example may use a BS (base station, e.g., an access node providing access to a cellular network, as explained in more detail in FIG. 9) 70 and wireless signals 310 to an ambient loT device 110. The BS 70 is part of a cellular network 1, which will also be referred to simply as a network (NW) 1. The BS 70 communicates with a core network (CN) 90. In Topology 1, the Ambient loT device 110 directly and bidirectionally communicates with the BS 70 via the wireless signals 310, and the BS 70 acts as a reader 120. The communication between the BS 70 and the ambient loT device 110 includes Ambient loT data and / or signaling. This topology includes the possibility that the BS transmitting to the Ambient loT device is a different from the BS receiving from the Ambient loT device. This is illustrated by a CW (carrier wave) emitter 60, which transmits a carrier wave 320 that provides power for the AIoT device 110, which then provides (e.g., via backscattering) wireless signals 310 to the BS 70, which acts as a reader 120. The CW emitter 60 could be another BS or other device. It is noted that typically both the carrier wave 320 and wireless signals 310 are used to access the AIoT device 110.

[0063] Turning to FIG. 3B, this figure illustrates a second topology (e g., Topology 2) for Ambient loT networks and devices. This example has a BS 70 communicating over a radio link 11 using a Uu interface with an intermediate node 14, which acts as a reader 120, and which uses wireless signals 310 to communicate with the ambient loT device 110. The BS 70 is part of a cellular network 1, which will also be referred to simply as a network (NW) 1. The BS 70 communicates with a core network (CN) 90. In Topology 2, the Ambient loT device 110 communicates bidirectionally via the radio link 11 with an intermediate node 14 between the device and the BS 70. In this topology, the intermediate node 14 can be a relay, IAB (Integrated Access and Backhaul) node, UE (user equipment), repeater, or the like, which is capable of Ambient loT communications. The intermediate node 14 transfers Ambient loT data and / or signaling between the BS 70 and the Ambient loT device 110 using both the radio link 11 and the wireless signals 310.

[0064] Topology 2 is more complicated, because the UE (typically) is an intermediate node 14 and the BS 70 (e.g., assume a gNB) is not the reader 120, instead the UE is. The gNB 70 still determines all of the parameters (session ID to identify the session 210, RA rounds 220, and the like). However, the UE may be involved, e.g., which could result in more collisions, but the UE might be able to choose between two options provided by the gNB 70. That is, there could be a decision between gNB and UE, where the decision is between (1) Reader = gNB or UE; and (2) the “NW” = gNB (for the reader = UE) or CN (NF) (for the reader = gNB). The gNB may be expected to handle all the parameters at least for the sessions 210, but a network function (NF) in the CN could provide at least some parameters for the sessions 210. In the examples below, the phrase “network / reader” is used, and this indicates that the example being described could be performed or controlled by the network, performed or controlled by the reader, or partly performed or controlled by the network and partly performed or controlled by the reader.

[0065] Referring back to FIG. 2, if the network has complete information about identification (IDs) of all the devices in coverage area of a reader, designing rounds 220 and RA 11 occasions 230 is possible, as the network 1 can divide IDs in small groups / rounds and in each round, the number consists of RA occasions 230 equals the number of devices 110 in the group. The devices 110 can use contention-free or contention-based RA as configured.

[0066] In an alternate scenario, where the reader 120 is not aware of the exact IDs and / or number of IDs of the devices 110 in its proximity, and tries to collect ‘blind’ information / inventory, it is important to answer the following questions while designing the structure of the inventory or inventory and command procedures:

[0067] 1 ) How many rounds 220 will be enough to complete information / inventory collection?

[0068] 2) How many RA occasions 230 in each round are needed?

[0069] 3) If the devices 110 are not able to access the network 1 (e.g., via the reader 120, which could be the BS 70 or intermediate node 14) in their assigned round (likely due to collisions), how does the re-access mechanism need to be designed?

[0070] Having too many RA occasions 230 in one round when not enough devices 110 are present results in waste of time / frequency resources (as no device may be contending in many of the allocated resources), while having too few RA occasions 230 may result in too many collisions.

[0071] In this document, examples are provided to address the problem(s) above by designing RA procedure details for AIoT devices.

[0072] An overview of examples is provided now, and further details are provided below. As the network may not know IDs of the devices the network wants to communicate with, this kind of inventory procedure can be termed as ‘blind’. However, in most of the cases, the AIoT application function (AF) may have some estimate on the number of devices available or minimum number of devices the reader needs to communicate with. This information can be used to design number of rounds and size of each round (in terms of number of occasions). It is also assumed that network has no idea on location of the devices, or which readers can reach a specific device.

[0073] It is noted that the term “AIoT device” is mainly used below. The devices that can be used herein and read by a reader, however, can include the following: AIoT devices (e.g., an loT device powered by energy harvesting, being either battery-less or with limited energy storage capability such as using a capacitor); other battery-less type of devices or devices with 12 limited energy storage capability and the energy for communication can be provided via radio wave harvesting, such as radio frequency identification, RFID, tags; user equipment (UE) where energy for communication is provided via radio wave harvesting; or the like.

[0074] In this case, it is difficult for the network / reader to assign AIoT devices to a particular round. To address these and other issues, the examples propose at least the following. These are described in part using FIG. 4, which is a flow diagram of a method for providing information to AIoT devices to improve random access procedures.

[0075] A) In block 410, information is provided to an AIoT device to enable the determination of a round identifier and a session identifier with the purpose of allowing the AIoT device to select a single occasion within a round of a session to access.

[0076] B) In block 420, the AIoT device is provided with round access-related information such as the following. Two main examples are presented.

[0077] 1) In a first example (example 1), see block 430, the devices themselves decide on the round to which they belong, based on a criterion that is either transmitted by the reader or predefined. It is noted that the criterion can be at least one criterion, such that multiple criteria may be used. The reader 120 does not need to have a priori knowledge of this assignment, and each device randomly selects an RA occasion within a particular round and contends for access. See FIGS. 5, 5A, 5B, 6, 6A, and 6B.

[0078] 2) In a second example (example 2), see block 440, the reader 120 does not assign AIoT devices to a particular round but it (reader or a carrier wave emitter under direction of the reader) changes its power level in different rounds to allow devices at different distances to assign themselves to a single round based on the power level of the received signal. Once the AIoT device assigns itself to a particular round, the device contends for access only within that round. In this case, this assignment may be loose, and it may be harder to distinguish some devices based on their received power levels, and different access rounds may end up having a different number of devices contending for RA occasions. See FIGS. 7, 7A, 7B, and 8.

[0079] The details of both examples are provided below. Example 1 is described in more detail now and example 2 is described in more detail below. The following uses a nested topical structure for ease of reference. This nested topical structure has the following key: 1, 2, 3... are main categories; a, b, c... are subcategories; i, ii, iii... are further subcategories; and I, II, III... are even further subcategories.

[0080] Example 1 concerns criterion based round assignment. In this example, the reader receives information to start an inventory and / or command procedure. The reader 120 could be a gNB as in Topology 1 or a UE in Topology 2 (where, i.e., gNB forwards this trigger information from network). The example is illustrated in FIG. 5 and explained in the following. In FIG. 5, the RA rounds 220 are illustrated as rounds 520, and three examples are shown: round 520-1; round 520-2; and other (which could be extra) rounds 520-3. Within rounds 520 are signaling (e.g., signaling 1, 2, and 3) and then AIoT RA occasions 510, which correspond to RA occasions 230. There are only two AIoT RA occasions 510 shown: AIoT RA occasions 510-1; and AIoT RA occasions 510-2. However, each round 520 would have its own AIoT RA occasions 510.

[0081] 1. The reader or network assigns an ID to this session, shown as session ID, during which the reader 120 or network 1 completes, e.g., an inventory and / or command procedure with the AIoT devices 110-1 and 110-2 and in which the devices 110 are needed to respond. Including the session ID is one way to trigger that the session has started. For the devices 110, selecting the occasion 230 with the RA round 220 is random, but the devices 110 should know the number of occasions within a round, which is why the round size (occasions) is sent in an example. The random selection could be via a formula or uniform distribution, or the like.

[0082] The session identification serves the purpose to control the RA attempts by each device 110 within the session such that only a single successful RA attempt is required from each device during a session.

[0083] a. The session identification may be used to ensure that any device successfully accessing the network within a particular session knows that the device has accessed the network for this inventory and / or command session and does not need to attempt access even if the device receives another access indication signal from the reader in subsequent access rounds. It should be noted that the device 110 may decide whether its access trial is successful or not based on receiving an indication from the reader 120 as to whether the reader successfully received the device’s ID and / or any other upper layer data (based on service request) or not.

[0084] b. The reader 120 assigns a round identification at the start of each round:

[0085] i. The round ID(s) may be assigned by the initial paging / trigger message.

[0086] ii. The round ID may be indicated by a subsequent access round indication message being transmitted by the reader before each round starts to indicate the beginning of a new access round.

[0087] in. Optionally, each round identification may be preceded by information on whether devices with previous unsuccessful access attempts within a selected round are allowed to retry access. In a variant, the round identification can contain information whether the round is for a first attempt or retry attempt.

[0088] iv. The round IDs are unique at least within a session.

[0089] c. The reader 120 sets a criterion to assign rounds to the devices and the devices pick a particular round for RA based on the criterion.

[0090] The access criterion may be comprised of round size.

[0091] i. The rounds may be of equal size(s) to provide low complexity access using a single size indication. With respect to a fixed round size (e.g., a fixed number of RA occasions 230 in all rounds within a session), whether devices are allowed to re-access may be based on prior information on the number of devices trying to access based on a certain criterion.

[0092] ii. The rounds may have different sizes, indicated individually, based on an estimate of the devices which may access.

[0093] I. Such estimate may be provided by the CN or autonomously selected by the reader.

[0094] II. The estimate may be based on prior access information, or pre-provision information.

[0095] Alternately, the criterion may be predefined, e.g., based on device ID and the number of rounds, random selection by the device, or determined in part by priority level or device type, or the like.

[0096] As additional detail, the reader may not know the devices or their IDs, but would like to group the devices. Based on received signal power, devices then choose when to perform the RA procedure. One way to group is by providing different levels of power through a mapping table 525, which provides power range to round. That is, ranges of power levels and how these are related to rounds are provided by the table 525. Note that this table (or other technique for sending criteria to use to select a round) may explicitly or implicitly also provide the number of rounds in a session. This table 525 may be sent in first message, as indicated in FIG. 5. The table could be sent by the reader (e.g., a gNB) every time the gNB triggers a session, and this allows the gNB to set ranges of power levels, how related to rounds, e.g., 10 rounds and 10 levels, 1 to 1 mapping; or 3 levels, each level mapped to 3 rounds. This table could be defined within a specification; but could also be some criteria defined in the specification that is predefined, but the reader sends which criteria to use (from the specification). A drawback of specification is that the reader does not have flexibility to define the table 525. It is noted that the term “table” is used, but any structure that allows ranges of power to be related to different rounds is suitable for use.

[0097] Turning to FIG. 5A, this figure is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using the signaling diagram of FIG. 5. Blocks 540 and 545 would be performed for each round 520. As one example, the reader 120 sends information to AIoT devices 110 to enable determination of a round identifier and determination of a session identifier to allow the AIoT device to select a single occasion within a round (e.g., a defined number of rounds) of a session to access. That is, there could be, at least initially, a defined number of rounds of a session. In FIG. 2, for instance, there are four defined rounds. This defined number of rounds may be extended by extra rounds, such as having five or six rounds when the defined number or rounds is four, as described herein. It is also noted, as illustrated in FIG. 5, that the information typically changes per round. In more detail, in block 540, the reader 120 provides, to at least one device 110, information for the at least one device to select a random access occasion within a round of a defined number of rounds in a session for performing a random access procedure, wherein the information comprises a round identifier, a round size indicating a number of random access occasions per round, and a session identifier identifying the session. In block 545, the reader 120 performs random access procedures in random access occasions within at least the defined number of rounds in the session with one or more of the at least one devices. As illustrated in FIG. 5, there will be multiple rounds 520, and the information sent in block 540 changes based on the round 520.

[0098] Referring to FIG. 5B, this figure is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 5. In block 550, a device (e.g., AIoT device) receives information for the (e.g., at least one) device to select a random access occasion within a round of a defined number of rounds (or for extra round(s)) in a session for performing a random access procedure. The information comprises a round identifier, a round size indicating a number of random access occasions per round, and a session identifier identifying the session. The AIoT device 110, in block 555 determines if it has already accessed the network. If this is the first round 520-1, then the AIoT device 110 would not have accessed the network (block 555 = No), and in block 560, the AIoT device 110 decides on the round to which the device belongs, based (at least partially) on the information, such as one or more criteria that are either transmitted by the reader or predefined. As indicated in block 562, this may involve comparison of measurement(s) with the at least one criterion. For instance, the reader 120 could send the table 525 of ranges of power and how this is related to the rounds 520, and the AIoT device 110 would use this to determine power being received and then compare (see block 562) this with the ranges of power to select a round. In another example, some of the information such as how the power levels are related to the rounds 520 is predefined (before FIG. 5 or FIG. 5B is performed), e.g., Power Range #1 = Round 520-1; Power Range #2 = Round 520-2; and the like. The information in block 550 could fill in the Power Range #1; Power Range #2; and the like. Note that the AIoT device 110 can store the decided round when the current round is not the decided round. In block 563, the AIoT device 110 determines whether the current round is the decided round. If not (block 563 = No), the method ends in block 590.

[0099] Assume that round 520-1 is not the decided round, and the method ends in block 590. For round 520-2, in block 550, the AIoT device 110 receives the (previous) session ID and the round ID, so the AIoT device 110 knows this is the same session but a new round (e.g., because this round ID is different from previous round ID(s)), and in block 560, the AIoT device 110 can retrieve the stored decided round. In block 563, assume the current round is the decided round (block 563 = Yes), and the flow proceeds to block 565, where the AIoT device 110 decides which occasion 230 within decided round 520 to use. As previously described, this may be performed through any mechanism such as a random selection process.

[00100] In block 570, AIoT device 110 performs RA procedure in the session, based on the received information, the decided round and the occasion within the round. In block 575, the AIoT device 110 determines whether the RA procedure was successful. If so (block 575 = Yes), the AIoT device 110 stores indication that RA procedure was successful in block 585 and then the flow ends in block 590. This means for any additional rounds 520, in block 555, the AIoT device 110 should determine the network has already been accessed and the flow would end in block 590.

[00101] If the RA procedure was not successful (block 575 = No), the AIoT device 110 stores (block 580) indication that RA procedure failed and the flow ends in block 590. It is noted that the indication that the RA procedure failed is made because some examples herein allow the AIoT device 110 to attempt the RA procedure in rounds 520 that are not the assigned round. Consider the “Extra Round Flag” sent at what is shown as the beginning of round 3 or later rounds (e.g., 520-3). If the defined number of rounds is four, the extra round flag could (but may not be) sent in an extra round, the fifth round (or later). As described in more detail below, this allows the AIoT device 110 in block 560 to determine that the current round (round 520-3) is the decided round so that the AIoT device 110 would perform the other blocks 565 and later. To address this, in block 555, if the network has not been accessed and the information indicates the current round is an extra round, the path is modified so the flow proceeds to block 565 so the device attempts an RA procedure.

[00102] Within the first example, example 1, there are additional examples. An example embodiment 1 includes the following. One example of the criterion could be RSSI (Received Signal Strength Indicator)-based round assignment. The reader 120 sends specific thresholds to the devices 110 where each threshold corresponds to a specific round. Based on the received power level, the devices 110 assign themselves to different rounds. For example, for a specific round ID#X, only devices 110 which picked this access round ID use the access occasion within that round to access the network. Other devices 110 wait for their access turn, which is determined by receiving an access round ID similar to what they assigned themselves to. Signaling flow for this round assignment has been shown in FIG. 6, where threshold set is transmitted to the devices which they subsequently will use to access network in a particular round. FIG. 6 illustrates an example embodiment similar to FIG. 5 but using an RSSI based criterion 625 (thresholds to map RSSI on a particular round). It is noted that RSRP RSSI is defined for a specific reference signal but there may be no reference signal for A-IoT devices, so the metric for the thresholds could be expanded to be at least one of RSSI, RSRP, or a level of a received signal power. For ease of reference, the figure is described using RSSI.

[00103] Referring to FIG. 6A, this figure is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using 18 the signaling diagram of FIG. 6. This figure is similar to FIG. 5 A. As one example, the reader 120 sends information to AIoT devices 110 to enable determination of a round identifier using thresholds to map RSSI on a particular round and determination of a session identifier to allow the AIoT device to select a single occasion within a round of a session to access. In more detail, in block 640, the reader 120 provides, to at least one device, information for the at least one device to select a random access occasion within a round of a defined number of rounds (e.g., possibly with extra rounds beyond the defined number of rounds) and a particular round in a session for performing a random access procedure, wherein the information comprises a round identifier, a round size indicating a number of random access occasions per round, a session identifier identifying the session, and thresholds to map RSSI to the rounds and to select one of the rounds. As described previously, while RSSI is used in this figure, the metric for the thresholds could be at least one of RSSI, RSRP, or a level of a received signal power. See block 641. Block 545 is the same as in FIG. 5 A.

[00104] FIG. 6B is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 6. This figure is similar to FIG. 5B, and only the differences are described. In block 650, the (e.g., at least one) device (e.g., AIoT device) receives information for the at least one device to select a random access occasion within a round of a defined number of rounds (or for extra round(s)) in a session for performing a random access procedure, The information comprises a round identifier, a round size indicating a number of random access occasions per round, a session identifier identifying the session, and thresholds to map RSSI on particular round(s). In block 660, the AIoT device 110 decides on the round to which the device belongs, based on the thresholds to map RSSI on a particular round that is either transmitted by the reader or predefined (e.g., and store when current round not decided round). This may involve comparison of RSSI (e.g., or RSRP, or a level of a received signal power) measurement(s) with thresholds as indicated in block 662. As described previously, all the information for the thresholds to map RSSI on a particular round may be transmitted, e.g., RSSI values #1 map to round 520-1; RSSI values #2 map to round 520-2; and the like. As another option, the structure where RSSI values #1 map to round 520-1; RSSI values #2 map to round 520-2; and the like may be predefined, but the reader 120 may send the actual RSSI values to fill in the table in block 650. The other blocks are the same as in FIG. 5B.

[00105] In another embodiment, the devices receive measurement-based round selection criterion for a specific session, which includes association / mapping information between round IDs and received signal strength such as RSSI / RSRP (Reference Signal Received Power). This may be implemented similarly to FIGS. 6A and 6B.

[00106] An example embodiment 2 is described now. Another example embodiment could be based on device IDs. For instance, based on the total number of rounds decided based on estimate of the total number of devices to be accessed, a simple modulo function can be applied to device IDs to assign different devices to different rounds.

[00107] It is assumed that all the rounds have the same size (in terms of number of occasions), as having different size for different rounds requires more precise knowledge of number of devices in each round and synchronization on starting each round could be difficult.

[00108] Thus, the reader transmits three parameters, namely session ID, round assignment criterion and round size at the beginning of each session. When the devices 110 see a new session ID, the devices explicitly know that the new session ID is a new session / cycle (e.g., a new inventory and / or command procedure).

[00109] Refer back to FIG. 5 (although FIG. 6 also has the same signaling).

[00110] 2. After round 1, at the beginning of each new round, the network sends session ID as well as round ID. The session ID repetition informs devices which already accessed the network to ignore this indication for access. The round ID informs devices which assigned themselves to a particular round (based on any of the embodiments) to randomly select RA occasion within this round.

[00111] In an alternative embodiment, the round ID is not explicitly indicated by the reader. The round message at the beginning of each round contains the session ID, and the device keeps track of all round messages from the beginning of the session to determine the ID (e.g., index) of the current round for the session.

[00112] In another embodiment, the reader / CN indicates whether the failed UEs (during the previous round(s)) are allowed to use the access occasion within the new round or not. The decision on whether failed UEs are allowed to re-access is based on an estimate provided by CN or calculated by reader. For instance, if the rounds are of equal size, but few IDs were previously received within a specific mask, said round may be allowable for failed devices to access. On the other hand, if the reader / CN expects multiple access within a given round this is not allowed.

[00113] In an alternative embodiment, the reader 120 may indicate the devices 110 in the AIoT paging / triggering message that re-access is only during specific round(s) with specific ID(s). The device 110 can send their first access transmissions only during rounds with IDs that are different than the IDs assigned for “re-access rounds” (i.e., the contending devices during a “re-access round” are only the devices which failed to access the network during the previous rounds). The reader 120 may adjust the list of “re-access round IDs” based on the number of contentions in each access round. In such case, the reader may include the updated list of “reaccess round IDs” during the access round indication message.

[00114] 3. Step 2 is repeated for a given number of rounds (already decided by the network based on the number of estimated devices). In many cases, several devices may not be able to access the network within the allocated rounds due to the following reasons:

[00115] a. The number of devices estimated is vastly different from the actual number; and

[00116] b. The devices are unsuccessful in accessing the network due to collisions.

[00117] In this case, the network / reader may determine that there are devices that were unsuccessful in accessing the network due to collisions and add new (e.g., extra) access rounds at the end of the session. However, it is not mandatory to keep size of the extra rounds the same as previously decided by the reader / network. For instance, if the reader already knows that most of the devices have already accessed the network, the extra round could be of very small size (i.e., a fewer number of RA occasions) and vice versa.

[00118] Further, an extra round flag may be sent at the beginning of each one of these rounds. See the signaling of the extra round flag at the beginning of the third (e.g., or later) session 520-3. This message informs all the devices which have not accessed the network in current session / cycle to attempt accessing network regardless of their round assigned to them at the beginning of the session.

[00119] Thus, the network / reader adds extra access rounds at the end of the session while:

[00120] c. The size of the extra round may be variable depending on estimation of failed access attempts.

[00121] d. The extra round(s) may be indicated using an “round extension” bit / indication.

[00122] e. The extra round(s) may either have a new criterion for round selection, or be allowed for all devices that have previously failed access.

[00123] If needed (e.g., where some devices are unable to access in extra rounds), such extra rounds can still be repeated until network / reader meets its criterion for accessing devices. See block 521, where one to multiple (e.g., extra) rounds are added when not all devices have accessed the network (e.g., based on a known or estimated number of devices) or a target number of devices has not accessed the network. Whenever an extra round flag is signaled, an extra round size (indicating a number of RA occasions within a round) may also be signaled. Example of such criterion for accessing devices could also be the following:

[00124] A certain % (percentage) of devices already have provided requested information;

[00125] Not many devices (e.g., not meeting a threshold of devices) attempt to access network in an extra round; and / or

[00126] Little or no contention among devices is detected.

[00127] Now that example 1 has been described, example 2 is described. Example 2 concerns power based round assignment. Example 2 is easiest to describe using FIG. 7, which shows a signaling flow for the example 2, and FIG. 8, which shows a region 800 having multiple different sets 810 of AIoT devices 110 in the region. Flow diagrams for the reader and AIoT devices are in FIGS. 7A and 7B, but these are described after FIGS. 7 and 8 are described.

[00128] In the example of FIG. 7, the devices 110 do not assign themselves to a particular round, therefore no criterion is transmitted by the reader in the first signaling. Instead, the reader or carrier wave (CW) emitter 710 changes its power every access round (e.g., in a step-wise manner) to reach different devices in different rounds. There is communication between the reader 120 and the CW emitter 60 in signaling 720-1, which may be used to set an initial power level. An example is shown in FIG. 8 where the set of devices 800-1 close to the reader 120 attempt to access the network in the round with the lowest transmission power (e.g., round 1, illustrated by AIoT RA occasions in one round 520-1). Some of the devices in set 810-1 will be able to access the network in round 1 and some of them will fail due to collisions. Region 820-1 illustrates a region (to line 830-1) of the larger region 800 which would be reached by the power level, which is illustrated as Pl.

[00129] In the next round 520-2 (see FIG. 7), the power level is increased using the signaling 720-2. In this case, the devices m round 1 can still receive signal from the reader 120 in the next round. See FIG. 8, where the region 820-2 is now reached (which includes 820-1), and forms a larger part of region 800 indicated by the line 830-2, because of power P2, where P2>P1. Both sets 810-1 and 810-2 of AIoT devices can now be reached. The devices which already accessed the network will not try to access network in round 2 (and any subsequent rounds). For the devices that attempted access in round 1 but were unsuccessful, there are two options:

[00130] 1) These devices can continue to attempt accessing network in round 2 (and subsequent rounds if not successful).

[00131] 2) As these devices already attempted access once, they can decide not to access the network until the last round of the ongoing session is finished. They can attempt accessing network again in the extra rounds within the ongoing session as in example 1.

[00132] The option 1) has the advantage that the unsuccessful devices may well be able to access the network soon, but too many unsuccessful devices in round 1 will increase the number of devices attempting access in round 2 and subsequent rounds.

[00133] For the option 2), all the unsuccessful devices have to wait for the extra rounds for reattempt accessing network. This will result in some access delay, but it is not very critical for delay-tolerant A-IoT use cases (e.g., inventory and / or command).

[00134] Assume that AIoT device 110-1 was able to access the network in round 520-1, but AIoT device 110-2 was not able to access the network. For the second and subsequent rounds, the AIoT device 110-2 can determine to attempt to access the network, e.g., based on the options 1) or 2) described above.

[00135] As devices are not assigned a round based on a criterion, there is no need of sending new round ID, instead a simple new round flag should enough for the devices to let unsuccessful devices know that they are not able to access network in the current round and they can reattempt accessing network using one of the options 1) and 2) above as configured. That is, determination of the number of rounds is not necessary, only the start of the round is important. The AIoT devices 110 just need to know that a round has started. If an AIoT device 110 receives a same flag with a same session ID and has already successfully completed the RA procedure, then the AIoT device 110 determines not to do anything, i.e., do not perform another RA procedure.

[00136] Regarding the CW emitter 60, the CW helps an AIoT device 110 to backscatter to the reader 120, but the reader 120 still transmits too. For instance, the device gets R2D with parameters from the reader, and the AIoT device 110 receives the CW and uses the CW for backscatter for reading. The energy used will be a combination of R2D signal and CW signal, one or both. This is true for any devices for backscattering (Type 1 and 2A, but not Type 2B). The alignment of signals uses coordination between the reader 120 and the CW emitter 60 or some upper layer entity (e.g., including a CN function).

[00137] Concerning the types of devices, see RI-2401767, Ad-Hoc Chair (Huawei), “Session notes for 9.4 Study on solutions for Ambient loT (Internet of Things) in NR”, 3GPP TSGRAN WG1 #116, Athens, Greece, February 26th - March 1st, 2024. RI-2401767 defines the types of AIoT devices as follows:

[00138] Device 1: ~ 1 p W peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10x ppm, neither DL nor UL amplification in the device. The device’s UL transmission is backscattered on a carrier wave provided externally.

[00139] Device 2a: a few hundred pW peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10x ppm, both DL and / or UL amplification in the device. The device’s UL transmission is backscattered on a carrier wave provided externally.

[00140] Device 2b: a few hundred pW peak power consumption, has energy storage, initial sampling frequency offset (SFO) up to 10x ppm, both DL and / or UL amplification in the device. The device’s UL transmission is generated internally by the device.

[00141] The other signaling parameters for this example are the same as for the example 1. In round 3, the power level is increased using signaling 720-3, and this means the region 820-3 is available to access the AIoT devices, and the region 820-2 is the same as the region 800. Now, all sets 810-1, 810-2, and 810-3 of the AIoT devices 110 are available.

[00142] Turning to FIG. 7A, this figure is a flowchart illustrating a method of providing information to AIoT devices to improve random access procedures for a reader using the signaling diagram of FIG. 7. This is assumed to be performed by a reader 120. In block 725, the reader 120 sets power level for the current round. For the first round 520-1, the lowest power 24 (e.g., Pl) is set. In block 730, the reader provides, to the at least one device (e.g., AIoT device), information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session. This information can change per round as shown in FIG. 7. In the first round (see FIG. 7), the session ID and round size (occasions) and optionally a new round flag are sent. In the second and subsequent rounds, the same session ID is sent, and a new round flag is sent.

[00143] In block 735, if it is not the first round, the reader 120 may send a flag informing all the devices who have not accessed the network in current session to attempt accessing network regardless of their round assigned to them at the beginning of the session. See the options 1) and 2) above. In block 740, the reader 120 performs RA procedures with certain of the AIoT devices in session, round, and occasions. In block 745, the reader 120 determines if it is the end of rounds in the session. If not (745 = No), the flow proceeds to block 725, where another, higher power level is selected (e.g., P2 or P3). If the reader determines it is at the end of the rounds 520 in the session, the flow ends in block 750. That is, the power level of a current round is higher than the power level of an immediately preceding round. This may not always be the case, and other options are possible.

[00144] In the second round 520-2, only the AIoT devices 110 in the set 810-2 should respond, but this could provide re-access for the AIoT devices 110 in the set 810-1. There are three options:

[00145] I - second round for AIoT device 110 in the set 810-1;

[00146] 2 - only first time in session can content, others have to wait; or

[00147] 3 - any AIoT device 110 that has not accessed can contend.

[00148] This can be adjusted by, e.g., an exponential number of slots with increasing power. Round size may be fixed for all the rounds except the last one, as this allows the reader 120 to send round size once, except for the last round, which saves signal overhead. Other options are possible. For instance, if the reader 120 decides to have 10 rounds, but gets all feedback in five rounds, the reader 120 can terminate access procedure. Alternatively, if the reader 120 is still receiving information after 10 rounds, the reader can add rounds. It is noted that the reader 120 can determine that there are collisions in an occasion.

[00149] FIG. 7B is a flowchart illustrating a method providing information to AIoT devices to improve random access procedures for an AIoT device using the signaling diagram of FIG. 7. In block 755, the AIoT device 110 receives information to enable determination of a round identifier and / or session. In block 760, the AIoT device 110 receives (e.g., in second or subsequent round(s)) a flag informing the loT device that if the device has not accessed the network in the current session to attempt accessing the network regardless of a round previously assigned to the device. This flag may be sent in the in the second or subsequent round(s), to alert the AIoT device 110 to attempt to access the network if the AIoT device 110 has not been able to access the network. This has been described above.

[00150] The AIoT device 110 in block 765 determines whether it has already accessed the network. If not, the flow proceeds to block 770, where the AIoT device 110 decides which occasion within the current round to use. In block 775, the AIoT device 110 performs the RA procedure in the round and session and in the decided occasion within the round. The AIoT device 110 determines in block 780 whether the RA procedure was successful. If so (block 780 = successful), the AIoT device 110 stores indication that the RA procedure was successful m block 783 and the flow ends in block 790. If the RA procedure was not successful (block 780 = failed), the AIoT device 110 stores indication that the RA procedure failed in block 785, and the flow ends in block 790.

[00151] The storage of the indication that the RA procedure was successful (for this session with its session ID) in block 783 means that a subsequent round should cause the AIoT device 110 to determine it has already accessed the network in block 765 so that the flow ends in block 790. By contrast, the storage of the indication that the RA procedure was not successful (for this session with its session ID) in block 785 means that a subsequent round should cause the AIoT device 110 to determine it has not already accessed the network in block 765 so that the flow would proceed to block 770 and another attempt would be made to access the network, assuming the flag m block 760 has been received. This example assumes that the second and subsequent rounds 520 would have this flag, but this is only one possibility.

[00152] Turning to FIG. 9, this figure shows a block diagram of one possible and nonlimiting example of a cellular network 1 that is connected to a user equipment (UE) 10. A number of network elements are shown in the cellular network of FIG. 9: a base station 70; and a core network 90. An AIoT device 110 is also illustrated, connecting via wireless signals 310 to either the UE 10 (as one version of an intermediate node 14) or to the BS 70.

[00153] In FIG. 9, a user equipment (UE) 10 is in wireless communication via radio link 11 with the base station 70 of the cellular network 1. A UE 10 is a wireless communication device, such as a mobile device, that is configured to access a cellular network. The UE 10 is illustrated with one or more antennas 28. The ellipses 2 indicate there could be multiple UEs 10 in wireless communication via radio links with the base station 70. The UE 10 includes one or more processors 13, one or more memories 15, and other circuitry 16. The other circuitry 16 includes one or more receivers (Rx(s)) 17 and one or more transmitters (Tx(s)) 18. A program 12 is used to cause the UE 10 to perform the operations described herein. For a UE 10, the other circuitry 16 could include circuitry such as for user interface elements (not shown) like a display. The program 12 may be implemented via instructions stored in memory / memories 15 and executed by processor(s) 13, or by circuitry such being implemented as part of the processor(s) or other circuitry elements, or both.

[00154] The AIoT device 110 is illustrated with one or more antennas 928. The AIoT device 110 includes one or more processors 913, one or more memories 915, and other circuitry 916, which have access to the energy storage 920 (e.g., such as a capacitor). The other circuitry 916 includes one or more receivers (Rx(s)) 917 and one or more transmitters (Tx(s)) 918. A program 912 is used to cause the AIoT device 110 to perform the operations described herein. For an AIoT device 110, the other circuitry 916 could include circuitry. The program 912 may be implemented via instructions stored in memory / memories 915 and executed by processor(s) 913, or by circuitry such being implemented as part of the processor(s) or other circuitry elements, or both.

[00155] The base station 70, as a network element of the cellular network 1, provides the UE 10 access to cellular network 1 and to the data network 91 via the core network 90 (e.g., via a user plane function (UPF) of the core network 90). As such, the base station 70 may be considered to be an access node, which provides access by UE(s) 10 to the cellular network 1. The base station 70 is illustrated as having one or more antennas 58. In general, the base station 70 may be referred to as RAN node 70, although many will make reference to this as a gNB (gNode B, a base station for NR, new radio) instead. There are, however, many other examples of RAN nodes including an eNB (evolved Node B) or TRP (Transmission-Reception Point). The 27 base station 70 includes one or more processors 73, one or more memories 75, and other circuitry 76. The other circuitry 76 includes one or more receivers (Rx(s)) 77 and one or more transmitters (Tx(s)) 78. A program 72 is used to cause the base station 70 to perform the operations described herein. The program 72 may be implemented via instructions stored in memory / memories 75 and executed by processor(s) 73, or by circuitry such being implemented as part of the processor(s) or other circuitry elements, or both.

[00156] Two or more base stations 70 communicate using, e.g., link(s) 79. The link(s) 79 may be wired or wireless or both and may implement, e.g., an Xn interface for 5G (fifth generation), an X2 interface for LTE (Long Term Evolution), or other suitable interface for other standards.

[00157] The cellular network 1 may include a core network 90, as a second network element or elements, that may include core network functionality, and which provide connectivity via a link or links 81 with a data network 91, such as a telephone network and / or a data communications network (e.g., the Internet). The core network 90 includes one or more processors 93, one or more memories 95, and other circuitry 96. The other circuitry 96 includes one or more receivers (Rx(s)) 97 and one or more transmitters (Tx(s)) 98. A program 92 is used to cause the core network 90 to perform the operations described herein. The program 92 may be implemented via instructions stored in memory / memories 95 and executed by processor(s) 93, or by circuitry such being implemented as part of the processor(s) or other circuitry elements, or both.

[00158] The core network 90 could be a 5GC (5G core network). The core network 90 can implement or comprise multiple network functions (NF(s)) 99, and the program 92 may comprise one or more of the NFs 99. A 5G core network may use circuitry such as memory and processors, which may implement a virtualization layer. It could be a single standalone computing system, a distributed computing system, or a cloud computing system. The NFs 99, as network elements, of the core network could be containers or virtual machines running on the circuitry of the computing system(s) making up the core network 90.

[00159] Core network functionality for 5G may include access and mobility management functionality that is provided by a network function 99 such as an access and mobility management function (AMF), session management functionality that is provided by a network function such as a session management function (SMF). Core network functionality for 28 access and mobility management in an LTE (Long Term Evolution) network may be provided by an MME (Mobility Management Entity) and / or SGW (Serving Gateway) functionality, which routes data to the data network. Many others are possible, as illustrated by the examples in FIG. 9: AMF; SMF; MME; SGW; GMLC (Gateway Mobile Location Center); LMF (Location Management Function); UDM (Unified Data Management) / UDR (Unified Data Repository); NRF (Network Repository Function); and / or E-SMLC (Evolved Serving Mobile Location Center). The AIoTF (Ambient internet of things function) may be provided by a combination of an AIoT controller and an AF (application function) or only by an AIoT controller or by some other network function or combination of network functions. These are merely exemplary core network functionality that may be provided by the core network 90, and note that both 5G and LTE core network functionality might be provided by the core network 90. The base station 70 is coupled via a backhaul link 31 to the core network 90. The base station 70 and the core network 90 may include an NG (Next Generation) interface for 5G, or an SI interface for LTE, or other suitable interface for other radio access technologies for communicating via the backhaul link 31.

[00160] In the data network 91, there is a computer-readable medium 94. The computer-readable medium 94 contains instructions that, when downloaded and installed into the memories 15, 75, 915, or 95 of the corresponding UE 10, base station 70, and / or core network element(s) 90, and executed by processor(s) 13, 73, 913, or 93, cause the respective device to perform corresponding actions described herein. The computer-readable medium 94 may be implemented in other forms, such as via a compact disc or memory stick.

[00161] The programs 12, 72, 912, and 92 contain instructions (as part of a corresponding program 12, 72, 912, and 92) stored by corresponding one or more memories 15, 75, 915, or 95. These instructions, when executed by the corresponding one or more processors 13, 73, 913, or 93, cause the corresponding apparatus 10, 70, 110, or 90, to perform the operations described herein. The computer readable memories 15, 75, 915, or 95 are circuitry and may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, firmware, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The processors 13, 73, 913, and 93, are circuitry and may be of any type suitable to the local technical environment. For example, these processors may include one or more of general-purpose computers, special purpose computers, 29 microprocessors, digital signal processors (DSPs), processors based on a multi-core processor architecture, and may also include specialized circuits such as field-programmable gate arrays (FPGAs), application specific circuits (ASICs), signal processing devices and other devices, or combinations of these devices, as non-limiting examples. The processors 13, 73, 913, and 93 are circuitry that can be programmed to perform functions via software, firmware or the like (including microcode), but are not solely software.

[00162] The receivers 17, 77, 917, and 97, and the transmitters 18, 78, 918, and 98 may implement wired or wireless interfaces. The receivers and transmitters may be grouped together as transceivers.

[00163] The cellular network 1 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities (such as network functions 99) that result from the network virtualization are still implemented, at some level, using hardware such as processors 73 and / or 93 and memories 75 and / or 95, and also such virtualized entities create technical effects.

[00164] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect and / or advantage of one or more of the example embodiments disclosed herein provides at least a protocol based on multiple rounds, which is proposed for AIoT RA, where AIoT devices are indicated to access in multiple rounds to lower their collision probability and improve their access performance. Another technical effect and / or advantage of one or more of the example embodiments disclosed herein is the examples do not require any feedback information sent from the devices to the reader for round assignment.

[00165] The following are additional examples.

[00166] Example 1. A method, comprising: setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions 30 per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[00167] Example 2. The method according to example 1, wherein for the at least one of: second or additional rounds of the defined number of rounds, the new information comprises the session identifier, and a flag indicating the at least one of: second or additional rounds is a new round and indicating devices that have not performed a successful random access procedure to perform a random access procedure in the at least one of: second or additional rounds.

[00168] Example 3. The method according to examples 1 or 2, wherein the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round.

[00169] Example 4. The method according to any of examples 1 to 3, wherein the power level of a current round is higher than the power level of an immediately preceding round.

[00170] Example 5. A method, comprising: receiving, by at least one device, information for the at least one device to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

[00171] Example 6. The method according to example 5, wherein: for at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: the second or additional rounds is a new round and indicating the session identifier; and the method further comprises determining the at least one device has not successfully performed the random access procedure in a first round of the session based on the session identifier, and performing another random access procedure in the second or additional rounds for the session corresponding to the session identifier.

[00172] Example 7. The method according to example 5, wherein: for the at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: second or additional round is a new round and indicating the session identifier; the method further comprises determining the at least one device has successfully performed a random access procedure in one of the at least one of: second or additional rounds for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the at least one device has successfully performed a random access procedure in one of the at least one of: second or additional rounds.

[00173] Example 8. The method according to any of examples 5 to 7, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the method further comprises determining the at least one device has not successfully performed a random access procedure in the first round or the at least one of: second or additional rounds of the session based on the session identifier; and selecting a further occasion and performing a random access procedure in the extra round.

[00174] Example 9. The method according to example 8, wherein the random access procedure was attempted in one of: the defined number of rounds or the extra round.

[00175] Example 10. The method according to any of examples 5 to 7, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the method further comprises determining the at least one device has successfully performed a random access procedure in the extra round for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the at least one device has successfully performed a random access procedure in the extra round.

[00176] Example 11. An apparatus, comprising means for: setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[00177] Example 12. The apparatus according to example 11, wherein for the at least one of: second or additional rounds of the defined number of rounds, the new information comprises the session identifier, and a flag indicating the at least one of: second or additional rounds is a new round and indicating devices that have not performed a successful random access procedure to perform a random access procedure in the at least one of: second or additional rounds.

[00178] Example 13. The apparatus according to examples 11 or 12, wherein the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round.

[00179] Example 14. The apparatus according to any of examples 11 to 13, wherein the power level of a current round is higher than the power level of an immediately preceding round.

[00180] Example 15. An apparatus, comprising means for: receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

[00181] Example 16. The apparatus according to example 15, wherein: for at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: the second or additional rounds is a new round and indicating the session identifier; and the means are further configured for determining the apparatus has not successfully performed the random access procedure in a first round of the session based on the session identifier, and performing another random access procedure in the second or additional rounds for the session corresponding to the session identifier.

[00182] Example 17. The apparatus according to example 15, wherein: for the at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: second or additional round is a new round and indicating the session identifier; the means are further configured for determining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds.

[00183] Example 18. The apparatus according to any of examples 15 to 17, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the means are further configured for determining the apparatus has not successfully performed a random access procedure in the first round or the at least one of: second or additional rounds of the session based on the session identifier; and selecting a further occasion and performing a random access procedure in the extra round.

[00184] Example 19. The apparatus according to example 18, wherein the random access procedure was attempted in one of: the defined number of rounds or the extra round.

[00185] Example 20. The apparatus according to any of examples 15 to 17, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the means are further configured for determining the apparatus has successfully performed a random access procedure in the extra round for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the apparatus has successfully performed a random access procedure m the extra round.

[00186] Example 21. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device; providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; and for at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

[00187] Example 22. The apparatus according to example 21, wherein for the at least one of: second or additional rounds of the defined number of rounds, the new information comprises the session identifier, and a flag indicating the at least one of: second or additional rounds is a new round and indicating devices that have not performed a successful random access procedure to perform a random access procedure in the at least one of: second or additional rounds.

[00188] Example 23. The apparatus according to examples 21 or 22, wherein the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round.

[00189] Example 24. The apparatus according to any of examples 21 to 23, wherein the power level of a current round is higher than the power level of an immediately preceding round.

[00190] Example 25. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session; selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

[00191] Example 26. The apparatus according to example 25, wherein: for at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: the second or additional rounds is a new round and indicating the session identifier; and the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform determining the apparatus has not successfully performed the random access procedure in a first round of the session based on the session identifier, and performing another random access procedure m the second or additional rounds for the session corresponding to the session identifier.

[00192] Example 27. The apparatus according to example 25, wherein: for the at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: second or additional round is a new round and indicating the session identifier; the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform determining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds.

[00193] Example 28. The apparatus according to any of examples 25 to 27, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform determining the at apparatus has not successfully performed a random access procedure in the first round or the at least one of: second or additional rounds of the session based on the session identifier; and selecting a further occasion and performing a random access procedure in the extra round.

[00194] Example 29. The apparatus according to example 28, wherein the random access procedure was attempted in one of: the defined number of rounds or the extra round.

[00195] Example 30. The apparatus according to any of examples 25 to 27, wherein: the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round; the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform determining the apparatus has successfully performed a random access procedure in the extra round for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on the determining the apparatus has successfully performed a random access procedure in the extra round.

[00196] Example 31. A computer program, comprising instructions which, when executed by an apparatus, cause the apparatus to perform a method of any of examples 1 to 10.

[00197] Example 32. A computer program comprising instructions stored thereon for performing a method of any of examples 1 to 10.

[00198] Example 33. A non-transitory computer readable medium comprising program instructions, when executed by an apparatus, that cause the apparatus to perform at least a method of any of examples 1 to 10.

[00199] As used in this application, the term “circuitry” may refer to one or more or all of the following:

[00200] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[00201] (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) (including digital signal processor(s)) with software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[00202] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[00203] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[00204] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a “computer-readable medium” may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 9. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories 15, 75, 915, and 95 or other device) that may be any media or means that can contain, store, and / or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals, and therefore may be considered to be non-transitory. The term “non-transitory”, as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM, random access memory, versus ROM, read-only memory).

[00205] If desired, the different functions discussed herein may be performed in a different order and / or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[00206] Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and / or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out m the claims. 5

[00207] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

1. A method, comprising:setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device;providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session;performing random access procedures in random access occasions within the round in the session with one or more of the at least one device; andfor at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

2. The method according to claim 1, wherein for the at least one of: second or additional rounds of the defined number of rounds, the new information comprises the session identifier, and a flag indicating the at least one of: second or additional rounds is a new round and indicating devices that have not performed a successful random access procedure to perform a random access procedure in the at least one of: second or additional rounds.

3. The method according to claims 1 or 2, wherein the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra roundbeyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round.

4. The method according to any of claims 1 to 3, wherein the power level of a current round is higher than the power level of an immediately preceding round.

5. A method, comprising:receiving, by at least one device, information for the at least one device to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session;selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

6. The method according to claim 5, wherein:for at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: the second or additional rounds is a new round and indicating the session identifier; andthe method further comprises determining the at least one device has not successfully performed the random access procedure in a first round of the session based on the session identifier, and performing another random access procedure in the second or additional rounds for the session corresponding to the session identifier.

7. The method according to claim 5, wherein:for the at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: second or additional round is a new round and indicating the session identifier;the method further comprises determining the at least one device has successfully performed a random access procedure in one of the at least one of: second or additional rounds for the session corresponding to the session identifier; anddetermining that no random access procedure is to be performed based on the determining the at least one device has successfully performed a random access procedure in one of the at least one of: second or additional rounds.

8. The method according to any of claims 5 to 7, wherein:the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round;the method further comprises determining the at least one device has not successfully performed a random access procedure in the first round or the at least one of: second or additional rounds of the session based on the session identifier; and selecting a further occasion and performing a random access procedure in the extra round.

9. The method according to claim 8, wherein the random access procedure was attempted in one of: the defined number of rounds or the extra round.

10. The method according to any of claims 5 to 7, wherein:the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round;the method further comprises determining the at least one device has successfully performed a random access procedure in the extra round for the session corresponding to the session identifier; anddetermining that no random access procedure is to be performed based on the determining the at least one device has successfully performed a random access procedure in the extra round.

11. An apparatus, comprising means for:setting a power level for a round of a defined number of rounds of a session, the power level indicating received power of a carrier wave used at least for reading at least one device;providing, to the at least one device, information for the at least one device to select a random access occasion within the round, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session;performing random access procedures in random access occasions within the round m the session with one or more of the at least one device; andfor at least one of: second or additional rounds of the defined number of rounds, setting at least one new power level for the at least one of: second or additional rounds to a different power level compared to the power level for the round, and providing a new information and performing random access procedures based on the different power level.

12. The apparatus according to claim 11, wherein for the at least one of: second or additional rounds of the defined number of rounds, the new information comprises the session identifier, and a flag indicating the at least one of: second or additional rounds is a new round and indicating devices that have not performed a successful random access procedure to perform a random access procedure in the at least one of: second or additional rounds.

13. The apparatus according to claims 11 or 12, wherein the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round.

14. The apparatus according to any of claims 11 to 13, wherein the power level of a current round is higher than the power level of an immediately preceding round.

15. An apparatus, comprising means for:receiving information for the apparatus to select a random access occasion within first round of a defined number of rounds of a session, wherein the information comprises a round size indicating a number of random access occasions per round, and a session identifier indicating the session;selecting the random access occasion of one or more occasions within the first round; and performing a random access procedure in the selected random access occasion of the first round in the session.

16. The apparatus according to claim 15, wherein:for at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: the second or additional rounds is a new round and indicating the session identifier; andthe means are further configured for determining the apparatus has not successfully performed the random access procedure in a first round of the session based on the session identifier, and performing another random access procedure in the second or additional rounds for the session corresponding to the session identifier.

17. The apparatus according to claim 15, wherein:for the at least one of: second or additional rounds of the defined number of rounds, a new information comprises a flag indicating the at least one of: second or additional round is a new round and indicating the session identifier;the means are further configured for determining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds for the session corresponding to the session identifier; and determining that no random access procedure is to be performed based on thedetermining the apparatus has successfully performed a random access procedure in one of the at least one of: second or additional rounds.

18. The apparatus according to any of claims 15 to 17, wherein:the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round;the means are further configured for determining the apparatus has not successfully performed a random access procedure in the first round or the at least one of: second or additional rounds of the session based on the session identifier; and selecting a further occasion and performing a random access procedure in the extra round.

19. The apparatus according to claim 18, wherein the random access procedure was attempted in one of: the defined number of rounds or the extra round.

20. The apparatus according to any of claims 15 to 17, wherein:the information in a round after the defined number of rounds in the session is a further information comprising the session identifier, a flag indicating the round after the defined number of rounds is an extra round beyond the defined number of rounds, and an indication of round size indicating a number of random access occasions for the extra round;the means are further configured for determining the apparatus has successfully performed a random access procedure in the extra round for the session corresponding to the session identifier; anddetermining that no random access procedure is to be performed based on the determining the apparatus has successfully performed a random access procedure in the extra round.

21. A computer program, comprising instructions which, when executed by an apparatus, cause the apparatus to perform a method of any of claims 1 to 10.Tl. The computer program comprising instructions stored thereon for performing a method of any of claims 1 to 10.

23. A non-transitory computer readable medium comprising program instructions, when 5 executed by an apparatus, that cause the apparatus to perform at least a method of any ofclaims 1 to 10.

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