Hybrid random access process configured by base station

Abstract

A method includes: configuring, by a base station, a first mode for performing a random access procedure to a device. The method includes: configuring, by the base station, a second mode for performing a random access procedure to the device. The device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure. The method also includes: configuring the availability of the second mode for performing the random access procedure.

Description

Technical Field

[0001] Teachings according to exemplary embodiments of the present invention generally relate to radio standards including physical layer (PHY), medium access control (MAC), radio link control (RLC), radio resource control (RRC), etc., and specifically to downlink control channel transmission and reception. Background Art

[0002] In LTE or current Rel-15 NR, only 4-step RACH procedure is supported. However, the 4-step RACH procedure suffers from many uncertainties and large delays due to LBT failure on unlicensed spectrum. In a recent 3GPP RAN1 meeting, a proposal was made to support a 2-step RACH procedure for unlicensed NR to mitigate the problems caused by LBT failure.

[0003] Certain abbreviations that may be found in the specification and / or drawings are defined as follows:

[0004] ACK

[0005] BPL Beam Pair Link

[0006] DL Downlink

[0007] gNB 5G enhanced Node B (base station)

[0008] HARQ Hybrid Automatic Repeat Request

[0009] IMSI International Mobile Subscriber Identity

[0010] LBT Listen before talking

[0011] LTE Long Term Evolution

[0012] MAC Media Access Control

[0013] MCS Modulation Coding Scheme

[0014] MEC Multi-access Edge Computing

[0015] MME Mobility Management Entity

[0016] Msg

[0017] NACK Negative Acknowledgement

[0018] NCE Network Control Element

[0019] NR New Radio

[0020] NR-PDCCH New Radio Physical Downlink Control Channel

[0021] N / W Network

[0022] OCC Orthogonal Cover Code

[0023] PDCCH Physical Downlink Control Channel

[0024] PDSCH Physical Downlink Shared Channel

[0025] PHY Physical

[0026] PRACH Physical Random Access Channel

[0027] PRB Physical Resource Block

[0028] RACH Random Access Channel

[0029] RF

[0030] RMSI Remaining Minimum System Information

[0031] RNTI Radio Network Temporary Identifier

[0032] RRC Radio Resource Control

[0033] RS reference signal

[0034] SSB Synchronous Signal Block

[0035] TPC Transmit Power Control

[0036] TXRU Transceiver Unit

[0037] UE User Equipment

[0038] UL Uplink

[0039] 5G fifth generation mobile communication system Summary of the invention

[0040] This section contains examples of possible implementations and is not intended to be limiting:

[0041] According to one aspect, an example method includes: configuring, by a base station, a first mode for performing a random access procedure to a device; configuring, by a base station, a second mode for performing a random access procedure to the device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and configuring availability of the second mode for performing the random access procedure.

[0042] According to another aspect, an example apparatus includes: at least one processor; and at least one non-volatile memory including computer program code, which at least one memory and the computer program code can be configured to, together with the at least one processor, enable the apparatus to: configure a first mode for performing a random access procedure to a device; configure a second mode for performing a random access procedure to a device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and control availability of the second mode for performing the random access procedure.

[0043] According to another aspect, an example apparatus includes: a component for configuring a first mode for performing a random access procedure to a device; a component for configuring a second mode for performing a random access procedure to a device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and a component for configuring availability of the second mode for performing the random access procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The foregoing and other aspects of embodiments of the present invention will become more apparent in the following detailed description when read in conjunction with the accompanying drawings, in which:

[0045] Figure 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

[0046] Figure 2 A method according to an example embodiment that may be performed by an apparatus is shown;

[0047] Figure 3 A method according to an example embodiment that may be performed by an apparatus is shown;

[0048] Figure 4 A method according to an example embodiment that may be performed by an apparatus is shown; and

[0049] Figure 5 Another method according to an example embodiment that may be performed by an apparatus is shown. DETAILED DESCRIPTION

[0050] In example embodiments described herein, a method and apparatus for providing a base station configured hybrid random access procedure is disclosed.

[0051] Go to Figure 1 , which shows a block diagram of one possible and non-limiting example system in which the example embodiments may be practiced. Figure 1In the embodiment of the present invention, a user equipment (UE) 110 wirelessly communicates with a wireless network 100. A UE is a wireless device (typically a mobile device) that can access a wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each transceiver 130 in the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be an address, data, or control bus, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, an optical fiber or other optical communication device, etc. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a signaling module 140, which includes one or both of the parts 140-1 and / or 140-2 that can be implemented in a variety of ways. The signaling module 140 may be implemented in hardware as a signaling module 140-1, such as being implemented as part of the one or more processors 120. The signaling module 140-1 may also be implemented as an integrated circuit or implemented by other hardware, such as a programmable gate array. In another example, the signaling module 140 may be implemented as a signaling module 140-2, which is implemented as a computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and the computer program code 123 may be configured to perform one or more operations described herein with the user equipment 110 with one or more processors 120. The UE 110 communicates with the eNB 170 via a wireless link 111.

[0052] The gNB (NR / 5G Node B, but possibly an evolved NodeB) 170 is a base station (e.g., for LTE Long Term Evolution or for NR New Radio) that provides access to the wireless network 100 for wireless devices such as UE 110. The gNB 170 includes one or more processors 152, one or more memories 155, one or more network interfaces ((multiple) N / WI / F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The gNB 170 includes a reporting module 150, which includes one or both of the parts 150-1 and / or 150-2 that can be implemented in a variety of ways. The reporting module 150 can be implemented in hardware as the reporting module 150-1, such as being implemented as part of the one or more processors 152. The reporting module 150-1 may also be implemented as an integrated circuit or implemented by other hardware, such as a programmable gate array. In another example, the reporting module 150 may be implemented as a reporting module 150-2, which is implemented as a computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153 may be configured to, together with one or more processors 152, cause the gNB 170 to perform one or more operations described herein. One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an X2 interface.

[0053] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication device, a wireless channel, etc. For example, one or more transceivers 160 may be implemented as a remote radio head (RRH) 195, with other elements of the gNB 170 physically located in a different location from the RRH, and the one or more buses 157 may be partially implemented as a fiber optic cable to connect the other elements of the gNB 170 to the RRH 195.

[0054] It should be noted that the description in this article indicates that a "cell" performs a function, but it should be clear that the gNB forming the cell will perform the function. A cell constitutes a part of a gNB. That is, there can be multiple cells per gNB. Each cell can contain one or more transmission and reception points (TPRs).

[0055] The wireless network 100 may include a network control element (NCE) 190, which may include MME (mobility management entity) / SGW (serving gateway) functionality and provide connectivity to another network such as a telephone network and / or a data communication network (e.g., the Internet). The gNB 170 is coupled to the NCE 190 via a link 131. The link 131 may be implemented as, for example, an S1 interface. The NCE 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces ((multiple) N / WI / F) 180 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, together with the one or more processors 175, cause the NCE 190 to perform one or more operations.

[0056] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single software-based managed entity (virtual network). Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is classified as external, combining many networks or portions of networks into virtual units, or as internal, providing network-like functionality to software containers on a single system. It is noted that, to some extent, hardware such as processors 152 or 175 and memories 155 and 171 are still used to implement the virtualized entities resulting from network virtualization, and such virtualized entities also produce technical effects.

[0057] Computer readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories 125, 155, and 171 may be components for performing storage functions. Processors 120, 152, and 175 may be of any type suitable for the local technical environment and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be components for performing functions such as controlling UE 110, gNB 170, and other functions described herein.

[0058] Generally, various embodiments of user device 110 may include, but are not limited to, cellular phones such as smart phones, tablet computers, personal digital assistants (PDAs) with wireless communication capabilities, portable computers with wireless communication capabilities, image capture devices with wireless communication capabilities (such as digital cameras), gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, Internet devices that allow wireless Internet access and browsing, tablet computers with wireless communication capabilities, and portable units or terminals that incorporate a combination of such functionality.

[0059] The embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In examples of embodiments, the software (e.g., application logic, instruction sets) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" may be a medium that can contain, store, communicate, propagate, or convey instructions for use by, for example, a computer program product. Figure 1 Any medium or component for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer) of an example of a computer described and depicted. Computer-readable media may include computer-readable storage media or other devices, which may be any medium or component that can contain or store instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer).

[0060] The current architecture in LTE networks is completely distributed in the radio and completely centralized in the core network. Low latency requires bringing content close to the radio, leading to local breakout and multi-access edge computing (MEC). 5G can use edge cloud and local cloud architecture. Edge computing covers a wide range of technologies, such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networks and processing, and can also be classified as local cloud / fog computing and grid / net computing, dew computing, mobile edge computing, micro cloud, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services and augmented reality. In radio communications, the use of edge cloud may mean that node operations will be performed at least in part in a server, host or node that is operably coupled to a remote radio head or base station including a radio part. It is also possible that node operations will be distributed among multiple servers, nodes or hosts. It should also be understood that the labor distribution between core network operations and base station operations may be different from LTE, or even non-existent. Some other technological advances that may be used are software defined networking (SDN), big data and all-IP, which may change the way networks are built and managed.

[0061] Example embodiments may be implemented in network backhaul. Example embodiments may also be implemented in a relay node (e.g., with respect to the functionality described herein below with respect to UE 110). Additionally, in a multi-hop relay scenario, a radio network (RN) (e.g., network 100) may implement the functionality described herein below with respect to gNB 170.

[0062] Having thus introduced a suitable and non-limiting technical context for practicing example embodiments of the present invention, the example embodiments will now be described in more detail.

[0063] Figure 2 is an example flow chart 200 illustrating a method according to an example embodiment that may be performed by an apparatus or a combination of apparatuses, such as the gNB 170 and UE 110 described herein.

[0064] To ensure fair coexistence in unlicensed spectrum, example embodiments may include (or incorporate) an LBT mechanism used by UE 110 / gNB 170 to assess whether a radio channel is available for use. UE 110 / gNB 170 allows transmission only if the radio channel is assessed to be sufficiently free from interference (LBT successful). Example embodiments may include (or incorporate) a 4-step RACH procedure and a 2-step RACH procedure. For each step of the 4-step RACH procedure, the transmission is subject to the risk of LBT failure (blocking). LBT failure will typically result in increased latency because the target transmission is blocked and a new transmission opportunity is required, and if one of the steps in the access chain is lost, the entire process may need to be started from the beginning or extended.

[0065] The 2-step RACH procedure involves only two steps and can reduce the impact of LBT failures by reducing the number of transmissions from 4 to 2. This reduction in the number of transmissions also reduces the amount of LBT actions required, thereby reducing the probability of delays. However, in some instances, the 2-step RACH procedure may create additional (or different) problems.

[0066] 2-step RACH may require a large amount of physical channel resources to transmit what is generally denoted as "Msg1+3" (i.e., a message including a preamble, IMSI, RRC connection establishment cause, etc.). Msg1+3 may contain information that is generally contained in Msg1 (random access preamble) and Msg3 (UE 110 identification and additional information). Unlike the preamble (Msg1) transmission, multiple UEs 110 transmitting Msg1+3 at the same resources may cause a conflict, resulting in reception loss on the gNB 170 side. If many resources are reserved for Msg1+3, this situation may be alleviated to a certain extent, but on the other hand, such over-reservation may result in a large system overhead. If too few resources are reserved for Msg1+3, the probability of conflict may be very high.

[0067] In scenarios where too many UEs 110 are performing random access simultaneously, the probability of collision becomes very high. The 2-step RACH procedure generally does not work in this scenario because the gNB 170 loses control of the use of these RACH resources. A fallback 4-step RACH procedure (or the ability to perform a fallback 4-step RACH procedure) may be necessary or required by example embodiments (e.g., as a failsafe in instances where too many UEs 110 are performing random access simultaneously).

[0068] The 4-step RACH procedure has been used in LTE and Rel-15 NR. The details of the 4-step RACH are shown as follows.

[0069] In block 210, gNB 170 may broadcast the configuration of the preamble (Msg1) in the RMSI. UE 110 obtains the configuration by receiving the SSB and the corresponding RMSI.

[0070] In box 220 (step 1), UE 110 can randomly select a preamble from the configured set based on the configuration (e.g., the configured time and frequency resources) and transmit the random access preamble (Msg1) to gNB 170.

[0071] In box 230 (step 2), gNB 170 can receive the preamble and respond with a random access response (RAR) (Msg2).

[0072] At block 240 (step 3), the UE may obtain the RAR and transmit Msg3 based on the UL grant in the RAR.

[0073] In box 250 (step 4), gNB 170 can receive Msg3 and send Msg4 to complete the contention resolution.

[0074] Since Msg3 is transmitted based on the UL grant, gNB 170 has the possibility to schedule the retransmission request by indicating a new UL grant that UE 110 should attempt to retransmit. If any of steps 2 to 4 fails due to LBT, there is a risk that UE 110 has to retransmit the preamble again (e.g., go to block 210 (step 1)) or UE 110 has to wait longer for a message from gNB 170. That is, a higher latency is accepted for the process to complete.

[0075] Figure 3 is an example flow chart 300 illustrating a method according to an example embodiment that may be performed by an apparatus or a combination of apparatuses, such as the gNB 170 and UE 110 described herein.

[0076] In block 310, gNB 170 may broadcast the configuration of Msg1+3 (including legacy Msg1 and Msg3) in RMSI. UE 110 may obtain the configuration by receiving SSB and the corresponding RMSI.

[0077] In box 320 (step 1), UE 110 can send Msg1+3 to gNB 170 based on the configuration.

[0078] In box 330 (step 2), gNB 170 can receive Msg1+3 and, if it successfully decodes Msg1+3, respond with Msg2+4 (corresponding to the combination of Msg2 and Msg4, but excluding the UL grant in Msg2).

[0079] It should be noted that the HARQ protection for Msg3 transmission may not exist, and if step 2 fails, UE 110 must retransmit the preamble again, for example, go to step 1, or UE 110 switches to the above-mentioned Figure 2 The 4-step RACH process is described.

[0080] Example embodiments provide for the control of the probability of collision on the allocated resources by the gNB 170 and the conditions under which the UE 110 is allowed to use the secondary set of RACH resources (2-step RACH resources). For example, in certain embodiments, the 2-step RACH procedure is used only when the UE 110 reestablishes an RRC connection, or alternatively when an immediate small data payload is transmitted without an established RRC connection; or the 2-step RACH procedure is valid only for the duration of a timer configured by the gNB 170 for the UE 110; or the configuration by the gNB 170 applies only to (a set of) specific cells; or when the UE 110 has traffic for scheduling on a specific logical channel or logical channel group.

[0081] Example embodiments overcome the disadvantages of 2-step RACH (large message size and high collisions) and take advantage of this (fast access) by specifically avoiding the use (limitation) of 2-step RACH during initial access (instead using a 4-step RACH procedure during initial access) and instead using a 2-step RACH procedure in response to a specific trigger, e.g. during RRC connection reestablishment (e.g. as compared to Figure 3 ). Example embodiments may enable gNB 170 to control the probability of collision by determining how many UEs 110 may use the 2-step RACH procedure and for how long the UEs 110 may use the 2-step RACH procedure, and configuring such configuration to the UEs 110 via RRC signaling.

[0082] Figure 4 is an example flow chart 400 illustrating a method according to an example embodiment that may be performed by an apparatus or a combination of apparatuses, such as the gNB 170 and UE 110 described herein.

[0083] Example embodiments provide a method for controlling a gNB 170 for a hybrid RACH procedure that can combine a 4-step RACH procedure (e.g., Figure 2 described) and the 2-step RACH process (as compared to Figure 3 The example embodiments provide a mechanism by which UE 110 may use a gNB 170 controlled 2-step RACH procedure while allowing gNB 170 to exercise (e.g., some) control over the probability of collision on the allocated resources.

[0084] At block 410 (step 1), during initial access, all UEs 110 may use the 4-step RAHC procedure (described above with respect to Figure 2 described).

[0085] At block 420 (step 2), gNB 170 and UE 110 may determine (e.g., upon reestablishing the RRC connection) that UE 110 is eligible for low latency access to the cell. According to an example embodiment, this determination (gNB 170 and UE 110 determine that UE 110 is eligible for low latency access to the cell) should be established before UE 110 exits RRC connected mode (i.e., before entering idle mode or RRC inactive mode). In other example embodiments, other modes may be implemented, such as radio link recovery or device timing recovery may also be part of the mechanism.

[0086] The request (for access) may come from the UE 110 side (e.g., an RRC or MAC-based request from the UE 110). The gNB 170 may determine to assign the UE 110 to low-latency access due to the service class. The gNB 170 may receive a configuration from the core network to assign the UE 110 for low-latency access.

[0087] At block 430 (step 3), the gNB 170 may provide a configuration to the UE 110 to use the 2-step RACH for RRC connection reestablishment or immediate small data payload transmission without an established RRC connection, which includes one or more of the following: a) resource configuration to be used; b) associated preamble set to be used; c) associated user connection ID; d) power ramping rule for Msg1 and Msg3 transmission (there may be different rules for power ramping); e) configuration of the set of cells that make the configuration available. The configuration may be provided separately for each cell; f) configuration of the amount of time that resources are reserved for the UE 110; g) association of which logical channels or logical channel groups are allowed to trigger the 2-step RACH procedure (if required); h) The gNB 170 may provide the configuration via UE-specific higher layer signaling (e.g., RRC signaling or MAC signaling or a combination of both).

[0088] The resource configuration to be used (it should be noted that the parameters for 2-step RACH can be a separate resource or partially overlap with the existing resources used for 4-step RACH). Regarding the resource: i) The resource can be in the time domain (defined as a pattern, periodicity or other manner indicating the time-wise resource allocation). ii) The resource can be in the frequency domain (such as specific PRBs to be used, selected interlaces to be used, etc.). iii) The resource can be in the code domain (such as OCC, cyclic shift, etc.). iv) There can be separate configurations for Msg1 and Msg3 transmissions.

[0089] Regarding c) associated user connection ID, this may be used when accessing the cell using 2-step RACH resources (eg in the form of RNTI). Such a user connection ID may be required if the UE 110 has lost the RRC connection with the cell.

[0090] Regarding f) configuration of the amount of time to reserve resources for this UE 110, the configuration of the time availability may depend on an absolute time or a relative time (e.g. as the time elapsed since the last connection, the time elapsed after RRC release signaling, the time elapsed since receiving the configuration, the time elapsed since updating the configuration, etc.). The gNB 170 may have the possibility (e.g. the capability) to indicate extended time resources for configuring the UE 110 via system broadcast signaling.

[0091] At block 440 (step 4), based on detecting a predetermined trigger provided by gNB 170 (e.g., upon loss of connection with gNB 170), UE 110 may perform a 2-step RACH procedure based on the configuration provided by gNB 170, in the event that UE 110 has traffic arriving for an associated logical channel or logical channel group or it receives a page from gNB 170. Triggers for 2-step RACH resources may include traffic for a logical channel. Other triggers may include a "PDCCH order" or a "paging message". A PDCCH order is a special command used to indicate to UE 110 from gNB 170 that a RACH procedure should be initiated. This procedure is used for UEs that are in RRC connected mode, but no longer have a suitable timing relationship between UE 110 and gNB 170. The definition of a suitable timing relationship is derived based on the time that has passed since the last time UE 110 and gNB 170 exchanged messages on the physical layer. A "paging message" is a signal broadcast from gNB 170 to the entire cell. The paging message contains an indication that UE 110 should establish a connection with gNB 170. The indication is typically based on a unique identification of UE 110, such as by an IMSI (International Mobile Subscriber Identity). Such a paging message is typically used to establish a connection between gNB 170 and UE 110 when UE 110 is in idle mode or RRC inactive mode.

[0092] At block 450 (step 5), UE 110 may default to a normal 4-step RACH procedure based on a predetermined trigger for defaulting to a 4-step RACH procedure, such as if arriving traffic is not in a configured set of logical channels or logical channel groups.

[0093] Depending on the resources allocated in box 430 (step 3), gNB 170 may have configured the selected UE 110 so that there is contention-free access during step 4 (box 440) and UE 110 can access the gNB 170 (or a set of gNBs 170) that allows a shorter access time.

[0094] In an example embodiment, the target UE 110 may not be associated with a serving cell, and the example embodiments may be applied to a random access procedure.

[0095] Figure 5 is an example flow chart 500 illustrating a method according to an example embodiment that may be performed by an apparatus.

[0096] about Figure 5 The described examples may provide a device (eg, UE 110) with the ability to access multiple ways of performing a random access procedure.

[0097] In box 510, gNB 170 can configure a first way (e.g., mode) to perform a random access process to UE 110 through broadcast signaling.

[0098] In box 520, gNB 170 can configure UE 110 with a second manner (e.g., mode) to perform the random access procedure via device-specific signaling.

[0099] At block 530, gNB 170 may limit the availability of the second mode of performing the random access procedure. The limitation may consist of being available only for a duration after the last connection to the connected cell (the second way of performing the random access procedure). The limitation may consist of being applicable only to (a set of) specific cells (multiples). The limitation may consist of the device having a service for scheduling on a specific logical channel or logical channel group.

[0100] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is to provide a mechanism by which UE 110 may use a gNB 170 controlled 2-step RACH procedure while allowing gNB 170 to exercise some control over the probability of collision on the allocated resources.

[0101] An example embodiment may provide a method, comprising: configuring, by a base station, a first mode for performing a random access procedure to a device; configuring, by a base station, a second mode for performing a random access procedure to the device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and configuring availability of the second mode for performing the random access procedure.

[0102] According to the example embodiments described in the above paragraphs, the first mode in which the random access procedure is performed includes a 4-step RACH procedure.

[0103] According to the example embodiments described in the above paragraphs, the second mode in which the random access procedure is performed comprises a 2-step RACH procedure.

[0104] According to the example embodiment described in the above paragraphs, configuring the availability of the second mode for performing the random access procedure further comprises: configuring the second mode for performing the random access procedure to be available for a predetermined duration after the last connection to the connected cell.

[0105] According to the example embodiment described in the above paragraphs, wherein configuring the availability of the second mode for performing the random access procedure further comprises: configuring, for the device, a predetermined duration during which at least one resource is available to the device.

[0106] According to the example embodiment described in the above paragraphs, configuring the availability of the second mode for performing the random access procedure further comprises: configuring the second mode for performing the random access procedure applicable to at least one specific cell.

[0107] According to the example embodiment described in the above paragraphs, wherein configuring the availability of the second mode for performing the random access procedure further comprises: scheduling the traffic on at least one of a specific logical channel or a logical channel group.

[0108] According to the example embodiment described in the above paragraphs, wherein configuring the availability of the second mode for performing the random access procedure further comprises: configuring the availability of the second mode based on a collision probability on at least one allocated resource.

[0109] According to the example embodiments described in the above paragraphs, the request for configuration is received from the device via at least one of radio resource control signaling and medium access control signaling.

[0110] According to the example embodiment described in the above paragraphs, configuring the device with the second mode of performing a random access procedure further comprises: providing an associated user connection identifier for use when accessing a base station using resources associated with the second mode of performing a random access procedure.

[0111] According to the example embodiment described in the above paragraphs, configuring the first mode of performing the random access procedure to the device further comprises: configuring the device through broadcast signaling.

[0112] According to the example embodiment described in the above paragraphs, wherein configuring the device with the second mode of performing the random access procedure further comprises: configuring the device through device-specific signaling.

[0113] An example embodiment may be provided in an apparatus comprising: a component for configuring a first mode for performing a random access procedure to a device; a component for configuring a second mode for performing a random access procedure to a device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and a component for configuring availability of the second mode for performing the random access procedure.

[0114] According to the example embodiments described in the above paragraphs, the first mode in which the random access procedure is performed includes a 4-step RACH procedure.

[0115] According to the example embodiments described in the above paragraphs, the second mode in which the random access procedure is performed comprises a 2-step RACH procedure.

[0116] According to the example embodiment described in the above paragraphs, the means for configuring the availability of the second mode for performing the random access procedure further comprises: means for configuring the second mode for performing the random access procedure to be available only for a predetermined duration after the last connection to the connected cell.

[0117] According to the example embodiment described in the above paragraphs, the means for configuring availability of the second mode of performing the random access procedure further comprises: means for performing the second mode of performing the random access procedure applicable only to at least one specific cell.

[0118] According to the example embodiment described in the above paragraphs, the means for configuring availability of the second mode for performing a random access procedure further comprises: means for scheduling traffic on at least one of a specific logical channel or a logical channel group.

[0119] According to the example embodiment described in the above paragraphs, the means for configuring the device with the first mode of performing the random access procedure further comprises: means for configuring the device through broadcast signaling.

[0120] An example embodiment may provide a method, comprising: at a device, receiving a configuration of a first mode for performing a random access procedure from a base station; receiving a configuration of a second mode for performing a random access procedure, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and receiving a configuration of availability of the second mode for performing the random access procedure.

[0121] According to the example embodiments described in the above paragraphs, the first mode in which the random access procedure is performed includes a 4-step RACH procedure.

[0122] According to the example embodiments described in the above paragraphs, the second mode in which the random access procedure is performed comprises a 2-step RACH procedure.

[0123] According to the example embodiment described in the above paragraphs, receiving a configuration of availability of the second mode for performing a random access procedure further comprises: receiving a configuration of the second mode for performing a random access procedure to be available for a predetermined duration after last connecting to the connected cell.

[0124] According to the example embodiment described in the above paragraphs, wherein receiving the configuration of the availability of the second mode for performing the random access procedure further comprises: configuring, for the device, a predetermined duration during which at least one resource is available to the device.

[0125] According to the example embodiment described in the above paragraphs, the configuration of receiving availability of the second mode of performing the random access procedure further comprises: configuring the second mode of performing the random access procedure applicable to at least one specific cell.

[0126] According to the example embodiment described in the above paragraphs, the configuration in which receiving the availability of the second mode of performing the random access procedure further comprises: scheduling the traffic on at least one of a specific logical channel or a logical channel group.

[0127] According to the example embodiment described in the above paragraphs, wherein receiving a configuration of availability of the second mode for performing a random access procedure further comprises: configuring the availability of the second mode based on a collision probability on at least one allocated resource.

[0128] According to the example embodiment described in the above paragraph, receiving the configuration of the device having a second mode for performing a random access process through device-specific signaling also includes: receiving a resource configuration used by the device, the resource being from at least one of time domain resources, frequency domain resources, and code domain resources.

[0129] An example embodiment may be provided in an apparatus comprising: a component for receiving, at a device, a configuration of a first mode for performing a random access procedure from a base station; a component for receiving a configuration of a second mode for performing a random access procedure, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and a component for configuring availability of the second mode for performing the random access procedure.

[0130] An example embodiment may be provided in an apparatus comprising: at least one processor; and at least one non-volatile memory comprising computer program code, the at least one memory and the computer program code being configurable to, together with the at least one processor, cause the apparatus to: configure a first mode for performing a random access procedure to the device; configure a second mode for performing a random access procedure to the device, wherein the device is configured to access the first mode for performing the random access procedure or the second mode for performing the random access procedure; and control availability of the second mode for performing the random access procedure.

[0131] An example embodiment may be provided in an apparatus comprising: at least one processor; and at least one non-volatile memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to: receive a configuration of a first mode for performing a random access procedure from a base station; receive a configuration of a second mode for performing a random access procedure, wherein the apparatus is configured to access the first mode for performing a random access procedure or the second mode for performing a random access procedure; and control availability of the second mode for performing a random access procedure.

[0132] The embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, instruction set) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" may be a medium that can contain, store, communicate, propagate, or transport instructions for use by, for example, a computer program product. Figure 1 Any medium or component for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer) of an example of a computer described and depicted. Computer-readable media may include computer-readable storage media (e.g., memory 125, 155, 171 or other devices), which may be any medium or component that can contain, store, and / or convey instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer). Computer-readable storage media do not include propagating signals.

[0133] If desired, the different functions discussed herein may be performed in different orders and / or concurrently with each other. In addition, if desired, one or more of the above functions may be optional or may be combined.

[0134] While various aspects are set out above, other aspects include other combinations of features from the described embodiments, not just the combinations described above.

[0135] It is also noted herein that, although the above describes example embodiments, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications that may be made without departing from the scope of the present invention.

[0136] Although various aspects of the invention are set out in the independent claims, further aspects of the invention comprise other combinations of features from the described embodiments and / or the dependent claims with features of the independent claims than just the combinations explicitly set out in the claims.

[0137] It is also noted herein that although the above describes example embodiments, 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.

[0138] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, although the invention is not limited thereto. Although various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other graphical representation, it is fully understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof as non-limiting examples.

[0139] Embodiments may be practiced in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0140] 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 those skilled in the art to make or use the invention, rather than to limit the scope of the invention, which is defined by the claims.

[0141] The foregoing description has provided by way of exemplary and non-limiting examples a complete and informative description of the best method and apparatus presently contemplated by the inventors for carrying out the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. Nevertheless, all such modifications and similar modifications of the teachings of the present invention will still fall within the scope of the present invention.

[0142] It should be noted that the terms "connected," "coupled," or any variations thereof, refer to any direct or indirect connection or coupling between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between elements may be physical, logical, or a combination thereof. As employed herein, two elements may be considered to be "connected" or "coupled" together through the use of one or more wires, cables, and / or printed electrical connections and through the use of electromagnetic energy, such as, as a few non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (visible and invisible) region.

[0143] Furthermore, some of the features of the preferred embodiments of this invention may be used to advantage without the corresponding use of other features.The foregoing description should therefore be considered as merely illustrative of the principles of the invention, and not in limitation thereof.

Claims

1. A method for communication, comprising: The base station configures the device to perform a first mode of a random access process, wherein the first mode of performing the random access process includes a four-step RACH process; configuring, for the device, a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure, the 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identity, and additional information, wherein the device is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure; Wherein configuring the device with the second mode for performing the random access procedure comprises: configuring availability of the second mode for performing the random access procedure; wherein configuring the availability of the second mode for performing a random access procedure comprises: configuring the availability of the second mode based on a collision probability on at least one allocated resource; and It is characterized in that configuring the second mode for performing a random access process to the device also includes: configuring resources for use by the device from at least one of time domain resources, frequency domain resources and code domain resources.

2. The method of claim 1 , wherein configuring the availability of the second mode of performing a random access procedure further comprises: The second mode of performing a random access procedure is configured to be available for a predetermined duration after a last connection to the connected cell.

3. The method of claim 1 , wherein configuring the availability of the second mode of performing a random access procedure further comprises: The device is configured with a predetermined duration during which at least one resource is available to the device.

4. The method according to any one of claims 1 to 3, wherein configuring the availability of the second mode for performing a random access procedure further comprises: The second mode for performing a random access procedure applicable to at least one specific cell is configured.

5. The method according to any one of claims 1 to 3, wherein configuring the availability of the second mode for performing a random access procedure further comprises: Traffic is scheduled on at least one of a specific logical channel or a group of logical channels.

6. The method according to any one of claims 1 to 3, further comprising: A request for configuration is received from the device via at least one of radio resource control signaling and medium access control signaling.

7. The method according to any one of claims 1 to 3, wherein configuring the second mode of performing a random access procedure to the device further comprises: An associated user connection identifier is provided for use in accessing the base station using resources associated with the second mode of performing a random access procedure.

8. The method according to any one of claims 1 to 3, wherein configuring the first mode of performing a random access procedure to the device further comprises: The device is configured via broadcast signaling.

9. The method according to any one of claims 1 to 3, wherein configuring the second mode of performing a random access procedure to the device further comprises: The devices are configured via device-specific signaling.

10. An apparatus for communication, comprising: means for configuring the device with a first mode of performing a random access procedure, wherein the first mode of performing a random access procedure comprises a 4-step RACH procedure; means for configuring the device with a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure, the 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identity, and additional information, wherein the device is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure; wherein the means for configuring the device with a second mode for performing a random access procedure comprises: means for configuring availability of the second mode for performing a random access procedure; wherein the means for configuring the availability of the second mode for performing a random access procedure comprises: means for configuring the availability of the second mode based on a probability of collision on at least one allocated resource; and It is characterized in that configuring the second mode for performing a random access process to the device also includes: configuring resources for use by the device from at least one of time domain resources, frequency domain resources and code domain resources.

11. The apparatus of claim 10, wherein the means for configuring the availability of the second mode of performing a random access procedure further comprises: The second mode for performing a random access procedure is configured for components available for a predetermined duration after a last connection to a connected cell.

12. The apparatus of claim 10, wherein the means for configuring the availability of the second mode of performing a random access procedure further comprises: means for configuring said second mode of performing a random access procedure applicable only to at least one specific cell.

13. The apparatus of claim 10, wherein the means for configuring the availability of the second mode of performing a random access procedure further comprises: Means for scheduling traffic on at least one of a specific logical channel or a group of logical channels.

14. The apparatus according to any one of claims 10 to 13, wherein the means for configuring the device with a first mode of performing a random access procedure further comprises: Means for configuring the device via broadcast signaling.

15. A method for communication, comprising: Receiving, at a device, from a base station, a configuration of a first mode of performing a random access procedure, wherein the first mode of performing a random access procedure comprises a 4-step RACH procedure; receiving a configuration of a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure, the 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identity, and additional information, wherein the device is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure, and wherein the configuration of the second mode of performing a random access procedure comprises: configuring availability of the second mode of performing a random access procedure; wherein the configuring of the availability of the second mode for performing a random access procedure comprises: configuring the availability of the second mode based on a probability of collision on at least one allocated resource; and Characterized in that receiving, by device-specific signaling, the configuration of the device having the second mode of performing a random access procedure further comprises: A configuration of resources for use by the device is received, the resources being from at least one of time domain resources, frequency domain resources, and code domain resources.

16. The method of claim 15, wherein the configuring of the availability of the second mode of performing a random access procedure further comprises: A configuration of the second mode of performing a random access procedure is received to be available for a predetermined duration after last connecting to the connected cell.

17. The method of claim 15, wherein the configuring of the availability of the second mode of performing a random access procedure further comprises: The device is configured with a predetermined duration during which at least one resource is available to the device.

18. The method according to any one of claims 15 to 17, wherein the configuring of the availability of the second mode of performing a random access procedure further comprises: The second mode for performing a random access procedure applicable to at least one specific cell is configured.

19. The method according to any one of claims 15 to 17, wherein the configuring of the availability of the second mode of performing a random access procedure further comprises: Traffic is scheduled on at least one of a specific logical channel or a group of logical channels.

20. An apparatus for communication, comprising: means for receiving, at a device, from a base station, a configuration for performing a first mode of a random access procedure, wherein the first mode of performing a random access procedure comprises a 4-step RACH procedure; means for receiving a configuration of a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identification, and additional information, wherein the device is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure; means for configuring availability of said second mode of performing a random access procedure; The means for configuring the availability of the second mode for performing a random access procedure comprises: means for configuring the availability of the second mode based on a probability of collision on at least one allocated resource; and Characterized in that receiving, by device-specific signaling, the configuration of the device having the second mode of performing a random access procedure further comprises: A configuration of resources for use by the device is received, the resources being from at least one of time domain resources, frequency domain resources, and code domain resources.

21. An apparatus for communication, comprising: at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code being configurable to, with the at least one processor, cause the apparatus to: perform: Configuring a first mode of performing a random access procedure for a device, wherein the first mode of performing a random access procedure includes a four-step RACH procedure; configuring, for the device, a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure, the 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identity, and additional information, wherein the device is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure; configuring availability of the second mode for performing a random access procedure; Configuring the availability of the second mode for performing a random access procedure comprises: configuring the availability of the second mode based on a probability of collision on at least one allocated resource; and It is characterized in that configuring the second mode for performing a random access process to the device also includes: configuring resources for use by the device from at least one of time domain resources, frequency domain resources and code domain resources.

22. An apparatus for communication, comprising: at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code being configurable to, with the at least one processor, cause the apparatus to: perform: receiving, from a base station, a configuration for a first mode of performing a random access procedure, wherein the first mode of performing a random access procedure comprises a 4-step RACH procedure; receiving a configuration of a second mode of performing a random access procedure, wherein the second mode of performing a random access procedure comprises a 2-step RACH procedure, the 2-step RACH procedure comprising transmitting information contained in a message comprising a random access preamble, a device identity, and additional information, wherein the apparatus is configured to access the first mode of performing a random access procedure or the second mode of performing a random access procedure; receiving a configuration of availability of said second mode for performing a random access procedure; Configuring the availability of the second mode for performing a random access procedure comprises: configuring the availability of the second mode based on a probability of collision on at least one allocated resource; and Characterized in that receiving, by device-specific signaling, the configuration of the device having the second mode of performing a random access procedure further comprises: A configuration of resources for use by the device is received, the resources being from at least one of time domain resources, frequency domain resources, and code domain resources.

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