RU2777838C2 - Device, system, and method for reception of system information as needed - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: mobile terminal determines a condition for a request for transmission of another system information as needed; performs a random access procedure, and receives, by means of broadcasting, an information system message containing another system information requested as needed. The message of the system information request of the random access procedure contains an information element with a combination of bits, corresponding to a specific format, with at least part of a bit combination for the request for another system information. A conflict resolution message of the random access procedure contains the same bit combination or the same part of the bit combination for detection of conflicts during the random access procedure.

EFFECT: obtaining a system for the reception of system information.

17 cl, 8 dwg

Description

BACKGROUND OF THE INVENTION

Technical field

The present invention relates to a mobile terminal performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum information and other system information. The mobile terminal transmits a request message to the base station as needed. This request message requests the base station to transmit other system information.

State of the art

Currently, the 3rd ^Generation Partnership Project (3GPP) consortium is focusing on the next version (Release 15) of the technical specifications for next generation cellular technology, also referred to as fifth generation (5G) or new radio (new radio, NR).

3GPP Technical Specification Group (TSG) Radio Access Network (RAN) Meeting #71 (Gothenburg, March 2016) approved the first 5G Research Line, "Next-Generation Radio Access Technology Research" (" Study on New Radio Access Technology”), including the RAN1, RAN2, RAN3 and RAN4 specifications, and this study laid the foundation for the work of Version 15, which will define the first 5G standard.

One of the goals of 5G new radio (NR) is to create a single technical framework that satisfies all use cases, requirements, and deployment scenarios defined in 3GPP TSG RAN TR 38.913 v14.1.0, Scenario and Requirements Study for Next Generation Access Technologies ” (“ Study on Scenarios and Requirements for Next Generation Access Technologies ”), December 2016 (available at www.3gpp.org). These include at least an improved mobile broadband network (enhanced Mobile Broadband, eMBB), ultra-reliable low-latency communications (Ultra-Reliable Low-Latency Communications, URLLC), streaming machine type communication (massive Machine Type Communication, mMTC).

For example, eMBB deployment scenarios may include indoor access, dense urban, rural, macro-urban, and high speed; URLLC deployment scenarios may include industrial control systems; mobile medical care (remote monitoring, diagnosis and treatment), real-time vehicle control, global control and management systems for smart grids; mMTC can include scenarios with a large number of devices with non-time critical data transmission, such as smart wearable devices and sensor networks.

Another goal is to provide forward compatibility with future use/deployment scenarios in mind. Backward compatibility with Long Term Evolution (LTE) technology is not required, facilitating an entirely new system design and/or introduction of new functionality.

DISCLOSURE OF THE INVENTION

One non-limiting and exemplary embodiment contributes to improved acquisition of system information in a wireless communication system comprising a mobile terminal and a base station with a serving cell. Yet another non-limiting implementation example aims to reduce the (control) signaling overhead to obtain other system information as needed. And yet another implementation example aims to increase flexibility in obtaining other system information as needed.

In one embodiment, the methods disclosed herein are characterized by having a mobile terminal performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes a processor and a transceiver. Wherein, the mobile terminal is configured to determine the condition for the request as needed to transmit other system information; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as necessary.

The system information request message (msg3) contains an information element with a bit pattern corresponding to a specific format, wherein at least part of the bit pattern is for requesting other system information, and the contention resolution message (msg4) contains the same bit pattern or the same part bit pattern to detect conflicts during the random access procedure.

It should be noted that general or specific embodiments may be implemented as a system, method, integrated circuit, computer program, storage medium, or any selective combination thereof.

Additional benefits and advantages of the disclosed embodiments will be apparent from the description of the invention and the figures. Benefits and/or advantages may be achieved individually through various embodiments and features in the description and drawings, and it is not necessary to have all of them in order to obtain one or more of such benefits and/or advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

On FIG. 1 shows a block diagram of a mobile terminal and a base station in a wireless link system.

On FIG. 2 is a flowchart of acquiring system information according to an implementation example of the first embodiment in a 3GPP NR deployment scenario.

On FIG. 3 shows an example configuration of a request and response message for other system information in an implementation example of the first embodiment in a 3GPP NR deployment scenario.

On FIG. 4 shows another example of request and response message configuration for other system information in the implementation example of the first embodiment in the 3GPP NR deployment scenario.

On FIG. 5 is a flowchart of acquiring system information according to an implementation example of the first embodiment in a 3GPP NR deployment scenario.

On FIG. 6 shows a timing diagram of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the first example of the second aspect in the 3GPP NR deployment scenario.

On FIG. 7 shows a timing diagram of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the second example of the second aspect in the 3GPP NR deployment scenario.

On FIG. 8 shows a timing diagram of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the third example of the second aspect in the 3GPP NR deployment scenario.

As summarized in one of the NR Research Line Technical Reports (3GPP TSG TR 38.801 v2.0.0, Study on New Radio Access Technology; Radio Access Architecture and Interfaces), March 2017), the fundamental physical layer waveform will be based on Orthogonal Frequency Division Multiplexing (OFDM). Both the downstream and the upstream support a cyclic prefix OFDM (CP-OFDM) based waveform. Also supported is a Discrete Fourier Transformation (DFT) OFDM-based waveform (DFT-S-OFDM) complementary to the CP-OFDM waveform for at least eMBB in the uplink up to 40 GHz.

One of the design goals in NR is to improve user mobility while minimizing interruption to current traffic, if any, while at the same time not increasing the power consumption of the user equipment. At RAN meeting #78, the RAN2 team was tasked to investigate how the IMT-2020 requirement for a 0 ms handover interruption time could be met for LTE and NR within the Release 15 timeframe. handover in LTE. Discussions are ongoing in 3GPP working groups on what functionality needs to be added or changed to improve NR mobility.

The term "downlink" refers to communication from an upper node to a lower node (eg, from a base station to a relay node or to a User Equipment (User Equipment, UE), from a relay node to a UE, etc.). The term "uplink" refers to communication from a lower node to an upper node (eg, from a UE to a relay node or base station, from a relay node to a base station, etc.). The term "direct connection" refers to communication between nodes at the same level (eg, between two UEs, or between two relay nodes, or between two base stations).

In 3GPP NR, the acquisition of system information is significantly improved compared to the mechanisms known from previous versions, such as the LTE standards. For example, handling of system information is discussed in chapter 7.3 of 3GPP TS 38.300 V15.1.0: “NR; NR and NG-RAN Overall Description, March 2018. Only a brief discussion will be given below.

Review

According to the 3GPP NR standardization, System Information (SI) is divided into a minimum SI and another SI. The minimum SI is broadcast periodically and contains the basic information required for initial access, and the information to obtain any other SI is periodically broadcast or provided as needed, i.e. planning information. The other SI covers anything that is not broadcast in the minimum SI and can either be broadcast or provided ad hoc, or initiated by the network or upon request from the UE.

The UE is not required to request in another cell/frequency layer the contents of the minimum SI of the cell/frequency that the UE considers to select and enter the idle mode there. This does not preclude the UE from applying the stored SI from previously visited cells. If the UE cannot determine the full content of the minimum SI cell (by receiving from this cell or from the actual stored SI from previous cells), the UE shall consider that cell to be prohibited. In the case of Bandwidth Adaptation (BA), the UE receives SI only over the active Bandwidth Part (BWP).

Planning

The minimum SI is transmitted on two different downlink channels using different messages (MasterInformationBlock and SystemInformationBlockType1). The term Remaining Minimum SI (RMSI) is also used to refer to SystemInformationBlockType1 (SIB1). The other SI is passed in SystemInformationBlockType2 (SIB2) and higher.

For a UE in the RRC_IDLE and RRC_INACTIVE states, the request initiates a random access procedure and is executed by msg3 if the requested SI is not associated with a subset of Physical Random Access Channel (PRACH) resources, in which case msg1 can be used. When using msg1, the minimum request granularity is one SI message (i.e., a set of System Information Blocks (SIBs)), and a single RACH preamble and/or PRACH resource can be used to request multiple messages, and the gNB acknowledges receipt of the request in msg2. When using msg3, the gNB acknowledges receipt of the request in msg4.

The other SI may be broadcast at a configurable rate and for a specified amount of time. The other SI may also be broadcast upon request by the UE in the RRC_IDLE/RRC_INACTIVE state.

Each cell that is allowed for UE selection and sleep mode broadcasts at least some minimum SI content, while there may be cells in the system that the UE cannot select and sleep on. , and they do not broadcast the minimum SI.

Modification SI

The change in system information occurs only in specific radio frames, i.e. the concept of a modification period is used. System information may be transmitted multiple times with the same content within a modification period, as determined by its scheduling. The modification period configuration is determined by the system information.

When the network changes (some) system information, it first notifies the UE of the change, i. this can be done during the entire modification period. In the next modification period, the network transmits updated system information. After receiving the change notification, the UE receives new system information from the start of the next modification period. The UE applies the previously received system information until the UE receives new system information.

Paging is used to inform UEs of system information changes in RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED modes. If the UE receives such a paging message, it knows that the system information (other than ETWS/CMAS) will be changed at the boundary of the next modification period.

In addition to the 3GPP NR TS 38.300 technical standard, which reflects the efforts to deploy RAN#79, the processing of system information has also recently been discussed by Working Group 2 (WG2) on the technical specification of the radio access network (TSG Radio Access Network, TSG-RAN), this discussion briefly summarized below:

SI provided in broadcast mode

The scheduling information for the other SI includes SIB type, reliability information, periodicity, and SI window information in the minimum SI whether the other SI is broadcast or provided as needed.

- Planning information for another SI is provided in SIB1.

- SIB type: broadcast or as needed.

If the minimum SI indicates that the SIB is not broadcast, the UE does not assume that the SIB is periodically broadcast in its SI window in each SI period. Therefore, the UE may send an SI request to receive this SIB. After sending the SI request, the UE monitors the SI window of the requested SIB in one or more SI periods of that SIB in order to receive the requested SIB.

SI request method based on msg3

The UE determines the success of msg3 based on the reception of msg4. The question of which msg4 content details are used to confirm a successful msg3 is for further study (FFS). This must first be reviewed by the CP.

The preamble(s) for the SI request using the msg3-based method are not reserved. In addition, Radio Resource Control (RRC) signaling is used for the SI request in msg3. The question of how the RRC signaling indicates the requested SI/SIB information is also up for further study (FFS) by the ASN.1 Working Group. The Cell-Radio Network Temporary Identifier (C-RNTI) received in msg2 is used to receive msg4.

SI request as required

The UE ID is not included in msg3. For contention resolution, the UE MAC acts in the same manner as in other cases and checks the contention resolution MAC CE against the transmitted request (general RACH procedure in MAC).

One indicator in SystemInformationBlockType1 (SIB1) indicates whether an SI message is currently being broadcast. This indication is valid until the end of the modification period. The UE cannot infer whether it is a temporary broadcast SI as needed or a periodic broadcast SI.

Modification SI

As in LTE, the SI change/update is indicated to the UE by paging. UEs in the RRC_IDLE and RRC_INACTIVE states shall monitor the SI update notification in their own paging event in each Discontinuous Reception (DRX) cycle. UE in RRC_CONNECTED state The UE monitors the SI update notification on any paging event (if the UE is provided with a shared search space for paging control in the connected state).

NR adopts the concept of a modification period used in LTE for SI update processing. An SI update indication included in a page message is supported (this may be reconsidered if the DCI design allows SI update indication and scheduling of the page message at the same time). The SI refresh indication included in DCI is supported.

If the UE receives an SI update indication in a paging, then the UE receives the updated SI at the boundary of the next modification period, assuming that the network is broadcasting the updated SI (even if the updated SI is an SI as needed).

The present invention

In view of the foregoing, the present invention has been conceived with the understanding that this acquisition of system information can be further improved.

In particular, using the 3GPP NR random access procedure to obtain system information as needed has some advantages as well as disadvantages in terms of (control) signaling overhead for a wireless communication system. The disadvantages resulting from this feature are the focus of the present invention.

On the one hand, the random access procedure is a well-known mechanism that allows the mobile terminal to immediately start signaling (control) information to the base station. Namely, the random access procedure can be invoked by the mobile terminal regardless of whether it is in the RRC CONNECTED, RRC_IDLE or RRC_INACTIVE state. In other words, the random access procedure for acquiring system information as needed can be used immediately after the power is turned on.

On the other hand, the random access procedure introduces significant overhead of (control) signaling. As will be discussed in detail below, it is well known that a random access procedure (ie, a concurrent random access procedure) includes a sequence of four messages (hereinafter: msg1, msg2, msg3, and msg4). This four-message sequence is intended to provide reliable signaling between the mobile terminal and the base station, but at the cost of considerable (control) signaling overhead.

In view of these shortcomings, the present invention is directed to improving the acquisition of system information in a wireless communication system.

The non-limiting and exemplary embodiments can reduce the overhead of (control) signaling in a wireless communication system due to the random access procedure, particularly in situations where there are conflicts between attempts to obtain system information by different mobile terminals. In particular, the present invention attempts to avoid unnecessary retransmissions triggered by unsuccessful (ie, collision) attempts to obtain system information.

For a comprehensive discussion of the benefits provided by the present invention, two different scenarios are described in more detail below.

In the first scenario, the emphasis is on removing the cause for the (control) signaling overhead, i.e. understanding that there are conflicts in the random access procedure. To do this, in the random access procedure, when receiving system information, a different understanding of what conflicts are is assumed. This eliminates the additional (control) signaling that would normally result in retransmissions as dictated by the contention resolution mechanism in the random access procedure.

In the second scenario, emphasis is placed on the fact that the effect resulting in (control) signaling overhead, i.e., retransmissions, as prescribed by the contention resolution mechanism, can be eliminated to obtain system information without affecting the functionality of the wireless communication system. . To do this, special conditions are defined in which it is not required to initiate a conflict resolution mechanism in the random access procedure, and thus also excludes additional (control) signaling.

In other words, the two different scenarios of the present invention are causally related in the sense that they both solve the common technical problem of avoiding additional (control) signaling unless absolutely necessary in a wireless communication system. The (control) signaling overhead resulting from the collision resolution mechanism in the random access procedure is reduced accordingly.

The random access procedure (more specifically, the competitive random access procedure) includes four steps, which are briefly discussed below:

In the first step, the mobile terminal transmits a random access preamble signal, ie msg1 (in a word: preamble), to the base station. The preamble is randomly selected by the mobile terminal from all available preambles or from a specific subset of available preambles and/or transmitted over all available or specially selected physical random access channel (PRACH) resources.

Due to limitations on the number of available preambles and/or PRACH resources (resources at a specific time and on a specific spectrum frequency) and because the mobile terminal autonomously starts the random access procedure, collisions between preamble transmissions from two different mobile terminals cannot be avoided. In other words, the wireless communication system cannot prevent two different mobile terminals from transmitting the same preamble on the same PRACH resource.

In addition, and more importantly, the base station cannot distinguish between such collision transmissions because they originate from two different mobile terminals transmitting the same preamble on the same PRACH resource. Thus, the base station requires outside knowledge to detect such collision transmissions.

In the second step, the base station transmits a random access response message, ie, msg2 (in a word: response), to the mobile terminal. The response typically contains parameters for establishing a connection, such as, for example, an advance to be applied to the mobile terminal's uplink configuration, as well as a scheduling grant that allows the mobile terminal to transmit a subsequent uplink message.

In the third message, the mobile terminal sends a dedicated message to the base station, i. e. msg3 using the scheduling grant. For the sake of brevity, the following refers only to a system information request message, i.e., a message that serves the specific purpose of signaling, by the mobile terminal to the base station, a request to transmit (specific) system information as needed, for example, a (specific) system information message. information as needed.

In an exemplary implementation, the system information request message may comprise a request to receive a (specific) system information message as needed, such as a request for an as-needed message containing a type 4-6 system information block. Typically, the system information request message follows a specific format defined by the radio resource control (RRC) layer, for example, for an RRC system information request message.

Since the two different mobile terminals that are sources of contention in step 1 receive the same response in step 2, they will both send dedicated messages, i.e. msg3 using the specified scheduling grant. Accordingly, the two dedicated messages are also received by the base station as contention transmissions, i.e. messages colliding or overlapping in time and frequency spectrum, and (if at all) only one of the dedicated messages can be successfully decoded by the base station.

More importantly, it has been found that at certain points in time (for example, during radio frames and/or subframes with specific numbers), there is a high probability that two different mobile terminals that caused collision transmissions in step 1 both transmit as msg3 a request to receive the same system information message as needed. Thus, situations are possible in which the base station receives two conflicting or overlapping transmissions of a system information request message requesting the same or different system information messages as needed.

Again, and more importantly, the base station can recognize only one of the system information request messages from the mobile terminal whose signal is stronger.

In the fourth message, the base station sends a contention resolution message to the mobile terminals, i. e. msg4. This message is intended to put the mobile terminal in a situation where it can detect whether or not the base station intends to satisfy the request set out in the dedicated message sent in msg3. In other words, this msg4 message contains information that uniquely refers to msg3 or the mobile terminal generating that same msg3, and for this reason can serve for purposes of resolving collision situations.

It should be noted that the ability of the mobile terminal to detect and thereby resolve the collision situation depends on the information carried in the dedicated message, i.e. msg3. In particular, this ability is related to the question whether or not msg3 additionally or exclusively contains information that is unique among all mobile terminals.

Typically, this msg3 message is formatted to contain, for example, a unique random value (ie, the random value information element) in the context of an RRC connection request. In such a case, this unique random value ensures that two msg3s will never be the same (ie, unique) even if they come from two different mobile terminals using the same scheduling grant from msg2.

The base station then generates a contention resolution message by copying and pasting (or mirroring) the unique information from msg3, thereby allowing the mobile terminal to detect whether it has successfully placed its request as set forth in the custom message transmitted as msg3.

Only when the mobile terminal detects in msg4 the unique information that it transmitted via msg3 can it conclude that msg3 was successfully transmitted to the base station. If the mobile terminal fails, the random access procedure instructs it to start again by retransmitting the random access preamble signal, i. msg1. Thus, situations with conflicting transmissions are resolved.

So, in the context of the present invention, it is recognized that conflict resolution is not always favorable in the context of obtaining system information. In particular, there are situations where it is not necessary for the mobile terminal to start again by retransmitting the random access preamble signal, i. e. msg1 after conflict resolution failed. In other words, in some situations it is possible to avoid (control) signaling overhead arising from conflict resolution in the random access procedure.

As mentioned above, in the context of obtaining system information, there are situations where two different mobile terminals request the same system information message as needed via msg3. Then, in such a situation, it is not critical for the mobile terminal to know whether it (or the other of two different mobile terminals) has successfully placed its request as set out in the system information request message, or whether it is instructed to retransmit the same system information request message. as a result of a conflict transmission.

Once it is guaranteed that the base station responding with the msg4 message has received the request to transmit the required system information message, the requests of both two different mobile terminals are satisfied.

In other words, neither the cause (i.e., the realization that collisions have occurred in the random access procedure) nor the effect (i.e., retransmissions as prescribed by the conflict resolution mechanism) justify the resulting overhead (control) signal. Rather, once the base station satisfies the requests of both two different mobile terminals, it is no longer necessary to use the random access procedure conflict resolution mechanism.

First scenario

On FIG. 1 is a block diagram of a wireless communication system comprising a mobile terminal 110 (also referred to as a user equipment, UE) and a base station 160 (also referred to as a g Node B or gNB). This block diagram is used to describe the mechanism shown in FIG. 2, namely the first scenario where the cause for the (control) signaling overhead is eliminated.

The wireless communication system shown in the block diagram allows the mobile terminal 110 to receive system information, in particular, other system information (which is not the minimum system information) broadcast as needed from the base station 160 with a serving cell. Accordingly, both the mobile terminal 110 and the base station 160 actively participate in obtaining system information.

Typically, there are several conditions when the processor 130 of the mobile terminal 110 determines (see step S01 in FIG. 2) that it has a need for other system information and therefore wants to request its transmission from the base station 160 as needed.

For example, such a condition occurs when processor 130 detects a power-on event in a serving cell or a cell select/reselect event in a serving cell. Such a condition also occurs when processor 130 recovers from a loss of coverage event for a serving cell. In addition, such a condition may also occur when processor 130 determines that the serving cell has expired a timeout timer for other system information. In any of these example conditions, processor 130 does not have a valid copy of the other system information.

Provided that the processor 130 has determined the condition for requesting other system information to be transmitted as needed, it proceeds to the transceiver 120 of the mobile terminal 110 performing (see step S02 in FIG. 2) the random access procedure.

In the random access procedure, transceiver 120 first transmits a random access preamble signal (see msg1 of step S02 in FIG. 2) to base station 160. Transceiver 120 then receives a random access response message from base station 160 (see msg2 of step S02 in FIG. 2) . Thereafter, the transceiver 120 transmits a system information request message (see msg3 of step S02 in FIG. 2) to the base station 160 for other system information. Finally, transceiver 120 receives a contention resolution message from base station 160 (see msg4 of step S02 in FIG. 2).

Provided that the mobile terminal 110 has successfully placed a request for other system information at the base station 160, it proceeds to the transceiver 120 receiving (see step S03 in FIG. 2) by broadcasting a system information message containing other system information requested as needed.

To determine whether the mobile terminal 110 has successfully placed a request for other system information to the base station 160, it determines whether the following two conditions are met:

1) a system information request message (see msg3 of step S02 in FIG. 2) contains an information element with a bit pattern corresponding to a specific format with at least a portion of the bit pattern for requesting other system information, and

2) the contention resolution message (see msg4 of step S02 in FIG. 2) contains the same bit pattern or the same part of the bit pattern for detecting conflicts during the random access procedure.

The first of two conditions ensures that the mobile terminal 110 places a conventional request for other system information on the base station 160. For this purpose, the request is sent in an information element (eg, RRC messages) in a particular bit pattern. It is important that the bit pattern corresponds to a specific format (eg, a standardized format). This particular format dictates that at least a portion of the bit pattern is used to request other system information. Thus, the specific format allows the base station 160 to unambiguously identify the requested other system information.

The second of the two conditions ensures that the mobile terminal 110 is notified whether a request for other system information has been successfully placed at the base station 160. For this purpose, the contention resolution message contains the same bit pattern (as a whole) or at least the same part of the bit pattern specified by a specific format to request other system information. It is important to note that in the case where the same bit pattern or the same part of the bit pattern is included in the contention resolution message, the mobile terminal 110 can detect collisions (better, none) during the random access procedure.

It should be noted that under these two conditions, collision detection can be performed based on a bit pattern or a portion of a bit pattern prescribed by a particular format. Since all requests for other system information must follow the same specific format, even when originating from two different mobile terminals, collision detection also assumes successful placement in case of conflicting transmissions from two different mobile terminals for the same request for other system information. More importantly, it is an advantage that due to the particular format prescribing at least a portion of the bit pattern for conflict detection, the (control) signaling overhead is reduced.

These two conditions are exemplary in the detailed implementations shown in FIG. 3 and 4.

On FIG. 3 and 4 at the very top show examples of bit patterns and their specific formats for requesting other system information. The first of the two figures shows a detailed implementation, where the specific format dictates that part of the bit pattern is used to request other system information. And the second of the two figures shows a detailed implementation, where the specific format dictates that a bit pattern is used to request other system information (in general).

In particular, for both a part of the bit pattern and for the bit pattern (as a whole), the specific format determines the correspondence to requests for different types of system information messages (abbreviated as SI msg. 2-9). For example, SI msg. 3 may denote a request to transmit, as part of the same system information message, types 4-6 system information blocks. In both implementations, both the bit pattern part and the bit pattern are 8 bits, and each bit of the 8 bits corresponds to a different type of system information message request (for example, as shown, the second bit corresponds to SI msg. 3 and the fourth bit corresponds to SI msg . 5).

With respect to the first of the two figures as shown, the specific format dictates that the part of the bit pattern (i.e. 8 bits) for requesting other system information message is at the beginning (head) of the bit pattern (i.e. 40 bits in total) . This is shown in the left corner of the topmost part of the figure. In an alternative implementation, a portion of the bit pattern (ie, 8 bits) for requesting other system information message is at the end (tail) of the bit pattern (ie, total bits). This is shown in the right corner of the topmost part of the figure. It is obvious that the left and right corners of the uppermost part of the figure depict alternative implementations for a particular format, which is indicated by the term "or".

(Also), while not self-evident, the first of the two figures also shows that the particular format dictates that the rest of the bits of the bit pattern, excluding the bits forming part of the bit pattern for requesting other system information, have a value of zero.

Regardless of which particular format is used, the bit pattern is included in an RRC message information element that resembles a system information request message (ie, msg3 S02 in FIG. 2). The information element may be the first information element in the system information request message, or more preferably the only information element in the system information request message (ie, msg3), as also shown in the two figures.

For reasons of consistency with current definitions in the 3GPP RRC layer, NR is beneficial when the bit pattern is 40 bits. Thus, a MAC control element (CE) having the same size can be reused for a contention resolution message (eg, msg4) sent in response to an RRC connection establishment message (eg, msg3). In particular, this eliminates the need for different physical implementations for the contention resolution mechanisms in the base station and/or mobile station. However, the bit pattern may also be only 8 bits (or at least 8 bits) in order to accommodate all the bits corresponding to requests for various types of system information messages (abbreviated as SI msg. 2-9).

For clarity and to avoid confusion, an information element containing a bit pattern to request other system information is not an element for a mobile terminal identifier (called ue-identity in the RRC) and/or is not an element for a random value (called randomValue in the RRC).

As is commonly known from 3GPP NR, an information element containing a bit pattern is encoded in a MAC Service Data Unit (MAC SDU), which results in an additional 8 bits encoding service data at the beginning (in the head) of the MAC SDU, which together with a MAC header form a MAC Packet Data Unit (MAC PDU) as shown in the lower left corner of both figures. The mobile terminal 110 then transmits this MAC PDU as msg3 to the base station 160.

The detailed implementations show, in the lower right corner of the two figures, that in response, the mobile terminal 110 receives a MAC message from the base station 160 as a contention resolution message (msg4) containing a MAC header and a MAC CE. As shown, this MAC CE contains or does not contain the coding overhead of the extra 8 bits at the beginning (in the head) of the MAC CE.

Assume for example that the information element contains a bit pattern with a total size of 40 bits, and that only a portion containing 8 bits out of a total of 40 bits is prescribed in a specific format for requesting other system information. Then the contention resolution message (msg4) can contain either the same bit pattern (as a whole), resulting in a MAC CE of size 48 bits, or the same part of the bit pattern prescribed by a particular format, resulting in a MAC CE of size 8 bits.

In the first case, the success/failure of receiving a contention resolution message is determined by processor 130 checking whether the contention resolution message (msg4) contains only (i.e., exactly) the same bit pattern as conveyed by the information element included in the (msg3) message. system information request.

In the second case, the success/failure of receiving the contention resolution message is determined by processor 130 checking whether the contention resolution message (msg4) is a specific version of the contention resolution message (i.e., a shortened version) specifically used to acknowledge receipt of the request as needed for another system system. information. And in this case, too, the shortened version no longer corresponds to the normal MAC CE used in other contexts for conflict resolution.

In addition, the processor 130 checks if msg4 contains only the same part of the bit pattern (prescribed by a particular format for requesting other system information) as transmitted with the information element included in the system information request message msg3.

Suppose now for the sake of example that the information element contains a bit pattern with a total size of (only) 8 bits, and that these bits are prescribed by a specific format for requesting other system information. Then the contention resolution message (msg4) may contain either the same bit pattern (in general) with padding at the end to get a larger size, for example 48 bits again, or it may contain (only) the same bit pattern (in general) , resulting in a MAC CE of 8 bits.

In the first case, the success/failure of receiving a contention resolution message is determined by processor 130 checking whether a portion (i.e., non-zero-padded bits) of the contention resolution message (msg4) contains the same bit pattern as transmitted by the information element included to the system information request message (msg3).

In the second case, the success/failure of receiving the contention resolution message is determined by processor 130 checking whether the contention resolution message (msg4) is a specific version of the contention resolution message (i.e., a shortened version) specifically used to acknowledge receipt of the request as needed for another system system. information. And in this case, too, the shortened version no longer corresponds to the normal MAC CE used in other contexts for conflict resolution.

In addition, the processor 130 checks if msg4 contains the same bit pattern as transmitted by the information element included in the system information request message (msg3) corresponding to a particular format for requesting other system information.

Second scenario

The block diagram shown in FIG. 1 can equally be used to describe the mechanism shown in FIG. 5, namely the second scenario, in which the effect leading to the overhead of (control) signaling is eliminated without affecting the functionality of the system.

Again, in this case, too, the wireless communication system shown in the block diagram allows the mobile terminal to receive system information, in particular other system information (which is not the minimum system information) broadcast as needed from base station 160 with a serving hundredth.

Typically, there are several conditions when the processor 130 of the mobile terminal 110 determines (see step S01 in FIG. 5) that it has a need for other system information and therefore wants to request its transmission from the base station 160 as needed. For brevity, these are examples of the conditions discussed above.

Provided that the processor 130 has determined the condition for requesting other system information to be transmitted as needed, it proceeds to the transceiver 120 of the mobile terminal 110 performing (see step S02 in FIG. 5) the random access procedure.

In the random access procedure, transceiver 120 first transmits a random access preamble signal (see msg1 of step S02 in FIG. 5) to base station 160. Transceiver 120 then receives a random access response message from base station 160 (see msg2 of step S02 in FIG. 5) . Thereafter, the transceiver 120 transmits a system information request message (see msg3 of step S02 in FIG. 5) to the base station 160 for other system information. Finally, transceiver 120 receives a contention resolution message from base station 160 (see msg4 of step S02 in FIG. 5).

Now, in contrast to the above, this second scenario is related to the situation where, despite the unsuccessful reception of the contention resolution message (indicated by the lightning icon next to msg4), the mobile terminal does not need to start (begin) by retransmitting the random access preamble signal (msg1), as prescribed by the random access procedure.

In particular, it is recognized that a failed reception may be the result of a conflicting request for other system information that is directed to the same types (or subsets thereof) of system information messages.

For example, a conflicting transmission may be detected even when one mobile terminal unsuccessfully places a request on the SI msg. 3, and the second, another mobile terminal successfully places a request for the SI msg. 3 and SI msg. 5. Then, even if the base station satisfies (only) a successful request for SI msg. 3 and SI msg. 5, the failed mobile terminal need not retransmit the system information request (starting from msg1) as prescribed by the random access procedure.

However, it depends on whether it can get information about scheduled SI messages from an additional source other than msg4.

It is important to note that it has been found that at certain points in time (for example, during radio frames and/or subframes with specific numbers), there is a high probability that two different mobile terminals will request as msg3 system information messages of the same types (or their subsets). At least in these situations, retransmission of requests for system information can be avoided without affecting system performance. Again, for this, the failed mobile terminal must be provided with information about the scheduled SI messages from an additional source.

For this purpose, in case of unsuccessful reception (see the lightning icon in FIG. 5) of the contention resolution (msg4) message, the mobile terminal 110 performs as part of the random access procedure (see S02 in FIG. 5) the following:

First, processor 130 suspends retransmission of the random access preamble signal (msg1). In other words, by pausing the retransmission, the failed mobile terminal acquires additional time to determine whether one of the above conditions has occurred. Specifically, the processor suspends retransmission until the next minimum system information time point.

As already apparent from the previous section, minimal system information is broadcast continuously at certain periodic intervals and therefore does not need to be based on requests as needed. It is important to note that the minimum system information (in particular, SystemInformationBlock type 1, SIB1) includes an indicator that indicates whether another system information message is currently being broadcast or not, which is valid until the end of the modification period.

In the context of the present invention, it is assumed that the base station 160 indicates with this indicator in the minimum system information, for example, SIB1, what other system information, for example, what types of system information messages, it plans to broadcast until the end of the modification.

Returning to the example, when the second other mobile terminal successfully places a request for SI msg. 3 and SI msg. 5, the corresponding indicators in the minimum system information, for example SIB1, will give information about the scheduled SI messages to all mobile terminals, and not to one mobile terminal that successfully placed its request.

By receiving this minimum system information, all mobile terminals can infer which of the other system information is scheduled to be transmitted.

In view of the above, after pausing the retransmission, the transceiver 120 receives (see msg4 in FIG. 5) at the next time the minimum system information at the next time.

And further, the processor 130 determines (see step S02 in FIG. 5) based on the received minimum system information whether the requested other system information is scheduled to be broadcast by broadcast regardless of its retransmission. In such a situation, retransmission, as prescribed by the random access procedure, is optional.

After determining that the requested other system information is scheduled for transmission, the transceiver 120 proceeds to receive (see step S03 in FIG. 5) by broadcasting a system information message containing other system information requested as needed.

Thus, due to a separate (optional) receive operation (see msg4 in FIG. 5) of the minimum system information, the mobile terminal 110 can detect situations where, despite not being able to place a request for other system information, the mobile terminal can do without retransmissions. , which are prescribed by the random access procedure.

Thus, according to this second scenario, the signaling overhead effect (control) is eliminated without affecting the functionality of the system.

Referring again to the general description of FIG. 1, a useful implementation in 3GPP NR deployment scenario includes that the system information request message (msg3) is a radio resource control (RRC) message, preferably with an information element having a total size of 40 bits. And a useful implementation further includes that the contention resolution message (msg4) is a Medium Access Control (MAC) control element (CE), preferably having a total size of 48 bits. In this way, compatibility with existing formats in the random access procedure (for example, with an RRC connection request) can be ensured.

It goes without saying also that the system information can be received by the mobile terminal in one of the states RRC_CONNECTED, RRC_IDLE and RRC_INACTIVE.

Second aspects

Let us now turn to another, second aspect of the present invention. This second aspect stands apart from the previous description, although it also applies to obtaining system information. More precisely, the system information also contains the minimum system information and other system information.

It should be noted that the difference from the previous description is that the second aspect is focused on increasing flexibility in obtaining system information. This increase in flexibility can lead to a reduction in latency, i.e. to receive other system information requested as needed ahead of time, and/or may result in a reduction in (control) signaling overhead. In any case, the next aspect is related to the specification of the modification period.

In general, it is understood that a modification period is intended to describe a period of time during which a mobile terminal is expected to receive system information only once. This modification period is introduced to protect the power consumption of, for example, mobile terminals in the RRC_IDLE or RRC_INACTIVE state. If the mobile terminal is expected to wake up and receive system information more frequently, the power consumption of the mobile terminal will be adversely affected.

However, there are situations where the mobile terminal requests other system information as needed in one modification period, but due to system limitations, must receive other system information requested as needed during the next modification period. This results in a significant delay in obtaining system information in a wireless communication system.

In this situation, this aspect increases flexibility by allowing the system to more flexibly broadcast other system information, as shown in the implementation of FIG. 6.

On FIG. 6 shows a timing diagram of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the first example of this second aspect in the 3GPP NR deployment scenario. This first example shows a wireless communication system including two mobile terminals (ie, UE1 and UE2) and a base station with a serving cell.

At the beginning of the first modification period (modification period #1), other system information such as system information message 5 (SI_5) is not broadcast. This is indicated by a corresponding indicator in the minimum system information, for example, in a system information block type 1 (SIB1) having a value of zero ("broadcast = 0").

Thus, a mobile terminal with a need for such other system information (eg, SI_5) should proceed to request as needed to transmit it. This will be discussed in more detail in the part regarding the acquisition of system information performed by the second mobile terminal, i. e. UE2 as shown in this FIG. 6.

This mobile terminal (UE2) determines at the point in time indicated by the arrow in FIG. 6 that a condition has occurred to query other system information as needed (eg, SI_5). For brevity, these are examples of the conditions discussed above.

It goes without saying that determining the request condition as needed includes receiving the minimum system information (eg, SIB1) by the mobile terminal and making the determination based on that received minimum system information (eg, SIB1). Only when the mobile terminal determines that other system information (eg, SI_5) is transmitted as needed ("broadcast=0"), it actually starts with a random access procedure.

The mobile terminal UE2 performs a random access procedure including: transmitting a random access preamble message (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a contention resolution message (msg4).

In a typical configuration, the mobile terminal would have to wait until the next modification period (eg, modification period #2) to broadcast a system information message containing other system information requested as needed (eg, SI_5). In this particular case, this modification period also contains changed (new) other system information (eg, SI_5), which, however, does not affect the first example.

In contrast, in this example, the mobile terminal, UE2, may receive early.

For this purpose, the mobile terminal UE2 is (again) configured to reacquire, during the current modification period (eg, modification period #1), which is the same as the modification period during the random access procedure, the minimum system information (eg , SIB1). Based on this re-acquired minimum system information (eg, SIB1), the mobile terminal determines whether other system information requested as needed (eg, SI_5) is transmitted before the next modification period (eg, "broadcast = 1"). The mobile terminal receives other system information requested as needed (eg, SI_5) included in the system information message transmitted until the next modification period (until modification period #2).

It should be noted that during this modification period (eg, modification period #1), the current (old) rather than changed (new) other system information (eg, SI_5) is broadcast. Thus, it will have to accept the changed (new) other system information (for example, SI_5) again in the next modification period. Although repetitive, the advantage of this example is that it allows the modification period to be implemented without conflicting with current standardization.

Thus, this first example provides the advantages of less specification impact and the ability for UE2 to obtain SI_5 immediately. Other mobile terminals (UE1) are not affected. These advantages come at a cost with the following disadvantages: SI request overhead is increased for a soon-changing (new) SI, which actually results in more power consumption for UE2 (it is necessary to check SIB1 in two consecutive modification periods after requesting other system information as needed ) and overhead when transmitting SI in broadcast mode.

On FIG. 7 is a diagram of the timing of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the second example of this second aspect in the 3GPP NR deployment scenario. This second example shows a wireless communication system including two mobile terminals (ie, UE1 and UE2) and a base station with a serving cell.

At the beginning of the first modification period (modification period #1), other system information such as system information message 5 (SI_5) is not broadcast. This is indicated by a corresponding indicator in the minimum system information, for example, in the system information block type 1 (SIB1), having a value of zero ("broadcast = 0").

Thus, a mobile terminal with a current version of other system information (eg, SI_5) would have no reason to receive its transmission again. However, the situation is different when the mobile terminal is indicated to change (update) other system information (eg, SI_5). This will be discussed in more detail in the part concerning the acquisition of system information performed by the first mobile terminal, i. e. UE1 as shown in this FIG. 7.

For clarity, it should be emphasized that the mobile terminal UE1 already has a current version of other system information (eg SI_5). The mobile terminal UE1 could receive it by obtaining system information as discussed above, namely by first determining whether a condition has occurred to request other system information as needed (eg, SI_5), and then performing a random access procedure. Finally, the mobile terminal UE 1 could receive other system information (eg, SI_5) requested as needed, as discussed above.

So, in order to receive the changed (updated) other system information, the mobile terminal UE1 receives a paging message (located in the Paging Occasion (PO) No. i for UE1). This page message indicates a change in other system information in the requested message as needed (eg, "SI_5 change = true"). This paging message is received in the current modification period (modification period #1).

Then, the mobile terminal UE1 reacquires, during the current modification period, which is the same as the period of the received paging message (modification period #1), each minimum system information (eg, SIB1).

Simultaneously, the mobile terminal (UE2) determines at the time indicated by the arrow in FIG. 7 that a condition has occurred to query other system information as needed (eg, SI_5).

It goes without saying that determining the request condition as needed includes receiving the minimum system information (eg, SIB1) by the mobile terminal and making the determination based on that received minimum system information (eg, SIB1). Only when the mobile terminal determines that other system information (eg, SI_5) is transmitted as needed ("broadcast=0"), it actually starts with a random access procedure.

The mobile terminal UE2 performs a random access procedure including: transmitting a random access preamble message (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a contention resolution message (msg4). And in this example, the base station successfully receives the system information request as needed from UE2, and thereafter changes the requested other system information indicator (eg, SI_5) to the minimum system information.

In addition, the mobile terminal UE1 is configured to determine, based on the re-acquired minimum system information (eg, SIB1), whether changed other system information is transmitted as needed (eg, new SI_5) ("broadcast = 1") until the next modification period ( until modification period #2) due to other system information request as needed sent by UE2.

Finally, both mobile terminals UE1 and UE2 receive modified other system information as needed (eg, SI_5) included in the system information message transmitted until the next modification period (up to modification period #2).

Thus, this second example provides the advantage that it allows both UE1 and UE2 to immediately receive an updated SI_5, resulting in reduced power consumption for UE2 (you only need to obtain SI_5 once). These advantages come at a price with the following disadvantages: in the same modification period, different UEs may operate based on different system information, eg, SI_5; increased overhead when transmitting SI in broadcast mode; the power consumption for UE1 increases; increases the impact on the specification.

On FIG. 8 is a diagram of the timing of two mobile terminals (ie, UE1 and UE2) performing system information acquisition in the third example of this second aspect in the 3GPP NR deployment scenario. This third example shows a wireless communication system including two mobile terminals (ie, UE1 and UE2) and a base station with a serving cell.

At the beginning of the first modification period (modification period #1), other system information such as system information message 5 (SI_5) is not broadcast. This is indicated by a corresponding indicator in the minimum system information, for example, in the system information block type 1 (SIB1), having a value of zero ("broadcast = 0").

Thus, a mobile terminal with a need for such other system information (eg, SI_5) will need to proceed to request as it needs to be transmitted. Next, an alternative configuration will be discussed in detail regarding the acquisition of system information performed by the second mobile terminal, i. e. UE2 as shown in this FIG. eight.

In particular, it is further assumed that the mobile terminal UE2 performs the random access procedure, as discussed earlier, only when the next procedure is determined to have failed before the end of the current modification period.

And in this case too, before executing the random access procedure, the mobile terminal UE2 receives a paging message (located in a paging event, PO) with number #k for some UE) for another mobile terminal (i.e., UE1) indicating a change in the requested as other system information (eg, SI_5) is needed in the current modification period (modification period #1).

Then, the mobile terminal UE2 determines based on the paging message (eg, located in PO #k) to the other mobile terminal (i.e., UE1) whether other system information requested as needed (i.e., "SI_5 change = true" is transmitted) ) during the next modification period (modification period #2).

Finally, the mobile terminal UE2 skips execution of the random access procedure, and then the mobile terminal UE2 receives other system information requested as needed (eg, SI_5) included in the system information message transmitted in the next modification period (modification period #2).

Thus, this third example provides the benefit of reducing the number of SI requests as needed; thereby reducing the broadcast overhead SI; and also in achieving a minimum impact on the specification. These advantages come at the cost of the following disadvantage: increased waiting time to receive the missing SI.

The present invention may be implemented in software, hardware, or software and hardware. Each functional block used in the description of each embodiment set forth above may be partially or wholly implemented by an LSI (LSI) such as an integrated circuit, and each process described in each embodiment may be controlled partially or wholly by the same LSI or a combination of LSI. The LSI may be formed separately as chips, or a single chip may be formed to contain some or all of the functional blocks. The LSI may have a data input and output connected to it. In this document, the LSI may be referred to as IC (IC), system LSI, super-LSI or ultra-LSI, depending on the differences in the degree of integration.

However, the implementation method of the integrated circuit is not limited to LSIs, and may be implemented using a dedicated circuit, a general purpose processor, or a special purpose processor. In addition, an FPGA (Field Programmable Gate Array) can be used, which can be programmed after the LSI is manufactured or configured to change the processor configuration, in which the connection configuration and settings of the circuit cells located inside the LSI can be changed. The present invention may be implemented as digital processing or analog processing. If future integrated circuit technology replaces LSIs as a result of the development of semiconductor technology or other derivative technology, functional blocks can be integrated using future integrated circuit technology. Biotechnology may also be applied.

According to a first aspect, a mobile terminal is disclosed for performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes a processor and a transceiver. Wherein, the mobile terminal is configured to determine the condition for the request as needed to transmit other system information; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

The system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least part of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern or the same part bit pattern to detect conflicts during the random access procedure.

According to a second aspect, which may be combined with the first aspect, the information element is the first information element in the system information request message (msg3).

According to a third aspect, which may be combined with the first or second aspect, the information element is the only information element in the system information request message (msg3).

According to a fourth aspect, which can be combined with the first to third aspects, the information element is not a mobile terminal identifier information element and/or a random value information element.

According to a fifth aspect, which can be combined with the first to fourth aspects, an information element with a bit pattern corresponding to a particular format contains at least 8 bits, preferably 40 bits.

According to a sixth aspect, which may be combined with the first to fifth aspects, the specific format determines for the bit pattern portion of the information element to correspond to requests for different types of system information messages.

According to the seventh aspect, which can be combined with the sixth aspect, the bit pattern part of the information element consists of 8 bits, and each of the 8 bits corresponds to a request for a different type of system information message.

According to the eighth aspect, which may be combined with the sixth or seventh aspect, the specific format dictates that a part of the bit pattern, preferably 8 bits, is at the beginning or end of the bit pattern.

According to the ninth aspect, which may be combined with the sixth to eighth aspects, the specific format dictates that all other bits in the information element bit pattern, except for the bits of this part of the bit pattern, have a value of zero.

According to the tenth aspect, which can be combined with the first to the ninth aspects, the mobile terminal starts receiving a system information message containing other system information requested as needed, depending on the bit pattern in the contention resolution message (msg4).

According to an eleventh aspect, a mobile terminal is disclosed for performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes: a processor and a transceiver configured to determine a condition for requesting other system information to be transmitted as needed; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

In case of unsuccessful reception of the contention resolution message (msg4), the mobile terminal performs a random access procedure including: suspending the retransmission of the random access preamble signal (msg1) until the next time of the minimum system information, receiving, at the next time, the minimum system information, and determining on based on the received minimum information of whether the requested other system information is scheduled to be transmitted via broadcast regardless of its retransmission.

In accordance with the twelfth aspect, which can be combined with the eleventh aspect, the success/failure of the message (msg4) contention resolution is determined by at least one of:

checking whether the contention resolution message (msg4) contains only the same bit pattern as conveyed by the information element included in the system information request message (msg3) corresponding to a specific format for requesting other system information, and

checking whether the contention resolution message (msg4) is a special version of the contention resolution message used to acknowledge receipt of a request as needed for other system information, and whether msg4 contains only the same part of the bit pattern as transmitted with the information element included to the system information request message (msg3), and

checking whether a portion of the contention resolution message (msg4) contains the same bit pattern as that transmitted by the information element included in the system information request message (msg3) corresponding to a particular format for requesting other system information, and

checking whether the contention resolution message (msg4) is a special version of the contention resolution message used to acknowledge receipt of a request as needed for other system information, and whether msg4 contains only the same bit pattern as conveyed by the information element included in a system information request message (msg3) corresponding to a specific format for requesting other system information.

According to a thirteenth aspect, which may be combined with the first to twelfth aspects, the system information request message (msg3) is a radio resource control (RRC) message, preferably with an information element having a total size of 40 bits.

According to a fourteenth aspect, which may be combined with the first to thirteenth aspects, the contention resolution message (msg4) is a media access control (MAC) control element (CE), preferably having a total size of 48 bits.

According to the fifteenth aspect, which may be combined with the first to fourteenth aspects, in order to perform system information acquisition, the mobile terminal is in one of the RRC_CONNECTED, RRC_IDLE, and RRC_INACTIVE states.

According to a sixteenth aspect, which may be combined with the first to fifteenth aspects, the conditions for requesting other system information to be transmitted as needed include at least one of: detecting a power-on event or a cell selection/reselection event in a serving cell , recovering from a loss of coverage event for the serving cell, determining that a timeout timer for other system information has expired.

According to a seventeenth aspect, a base station in a wireless communication system allowing a mobile terminal to perform system information acquisition with a base station configured with a serving cell is disclosed. The system information contains the minimum system information and other system information.

The base station contains a processor and a transceiver. At the same time, the base station is configured to perform a random access procedure, including: receiving a random access preamble signal (msg1), transmitting a random access response message (msg2), receiving a system information request message (msg3), and transmitting a conflict resolution message (msg4); and broadcasting a system information message containing other system information requested as necessary.

The system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least part of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern or the same part bit pattern to detect conflicts during the random access procedure.

According to an eighteenth aspect, which may be combined with a seventeenth aspect, the information element is the first information element in the system information request message (msg3).

According to the nineteenth aspect, which may be combined with the seventeenth or eighteenth aspect, the information element is the only information element in the system information request message (msg3).

According to the twentieth aspect, which may be combined with the seventeenth to nineteenth aspects, the information element is not a mobile terminal identifier information element and/or a random value information element.

According to the twenty-first aspect, which can be combined with the seventeenth to twentieth aspects, the format-specific bit pattern information element contains at least 8 bits, preferably 40 bits.

According to the twenty-second aspect, which may be combined with the seventeenth to twenty-first aspects, a particular format specifies for a subset of bits in an information element bit pattern to correspond to requests for different types of system information messages.

According to the twenty-third aspect, which may be combined with the twenty-second aspect, the information element bit pattern bit subset consists of 8 bits, and each of the 8 bits corresponds to a request for a different type of system information message.

According to a twenty-fourth aspect, which may be combined with a twenty-second or twenty-third aspect, the specific format dictates that a subset of bits of a bit pattern, preferably 8 bits, be at the beginning or end of the bit pattern.

According to the twenty-fifth aspect, which may be combined with the twenty-second to twenty-fourth aspects, the specific format dictates that all other bits in the information element bit pattern, except for the bits of this subset of bits, have a value of zero.

According to the twenty-sixth aspect, which may be combined with the seventeenth to twenty-fifth aspects, the base station starts transmitting a system information message containing other system information requested as necessary, depending on the bit pattern in the contention resolution message (msg4).

According to a twenty-seventh aspect, a method for performing system information acquisition by a mobile terminal in a wireless communication system comprising at least one base station configured with a serving cell is disclosed. The system information contains the minimum system information and other system information.

The method includes the steps of: determining a condition for the request as necessary to transmit other system information; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

The system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least part of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern or the same part bit pattern to detect conflicts during the random access procedure.

According to a twenty-eighth aspect, a method for performing system information acquisition by a mobile terminal in a wireless communication system comprising at least one base station configured with a serving cell is disclosed. The system information contains the minimum system information and other system information.

The method includes the steps of: determining a condition for the request as necessary to transmit other system information; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

In case of unsuccessful reception of the contention resolution message (msg4), the execution of the random access procedure includes: suspending the retransmission of the random access preamble signal (msg1) until the next time of the minimum system information, receiving, at the next time, the minimum system information, and determining, based on the received minimum information as to whether the requested other system information is scheduled to be transmitted via broadcast regardless of its retransmission.

According to a twenty-ninth aspect, a method for a base station is disclosed for enabling a mobile terminal to perform system information acquisition in a wireless communication system with a base station configured with a serving cell. The system information contains the minimum system information and other system information.

The method includes the steps of: performing a random access procedure, including: receiving a random access preamble signal (msg1), transmitting a random access response message (msg2), receiving a system information request message (msg3), and transmitting a conflict resolution message (msg4); and broadcasting a system information message containing other system information requested as necessary.

The system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least part of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern or the same part bit pattern to detect conflicts during the random access procedure.

According to a thirtieth aspect, a mobile terminal is disclosed for performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes a processor and a transceiver. Wherein, the mobile terminal is configured to determine a condition for requesting other system information as needed; performing a random access procedure including: transmitting a random access preamble message (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as necessary.

In particular, the mobile terminal is configured to obtain, as part of determining the request condition as needed, the minimum system information and determine that other requested system information is transmitted as needed.

In addition, the mobile terminal is configured, within the scope of receiving the system information message, to reacquire, during the current modification period, which is the same as the modification period during the random access procedure, the minimum system information to determine based on the reacquired minimum system information, whether other system information requested as needed is transmitted until the next modification period, and receiving other system information requested as necessary included in the system information message transmitted until the next modification period.

According to a thirty-first aspect, a mobile terminal is disclosed for performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes a processor and a transceiver. Wherein, the mobile terminal is configured to determine a condition for requesting other system information as needed; performing a random access procedure including: transmitting a random access preamble message (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

In particular, the mobile terminal is configured, within the scope of receiving the system information message, to receive a paging message indicating a change in other system information requested as needed in the current modification period, to reacquire during the current modification period, which is the same , which is the period of the received paging message, the minimum system information for determining, based on the re-acquired minimum system information, whether changed other system information is transmitted as necessary until the next modification period, and receiving changed other system information as necessary included in the system information message transmitted until the next modification period.

According to a thirty-second aspect, a mobile terminal is disclosed for performing system information acquisition in a wireless communication system comprising at least one base station configured with a serving cell. The system information contains the minimum system information and other system information.

The mobile terminal includes a processor and a transceiver. Wherein, the mobile terminal is configured to determine a condition for requesting other system information as needed; performing a random access procedure including: transmitting a random access preamble message (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3), and receiving a conflict resolution message (msg4); and receiving, on the broadcast channel, a system information message containing other system information requested as needed.

In particular, the mobile terminal is configured, before executing the random access procedure, to receive a paging message for another mobile terminal indicating a change in other system information requested as needed in the current modification period, to determine based on the paging message for another mobile terminal, is transmitted or other system information requested as needed in the next modification period to skip execution of the random access procedure and receive other system information requested as needed included in the system information message transmitted in the next modification period.

Claims (77)

1. A mobile terminal (110) configured to obtain system information in a wireless communication system comprising at least one base station configured with a serving cell, where the system information contains minimum system information and other system information, wherein the mobile terminal comprises a processor (130) and a transceiver (120) that, during operation, determine a condition for requesting other system information to be transmitted as needed; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a conflict resolution message (msg4); receiving by broadcasting a system information message containing other system information requested as necessary; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure. 2. The mobile terminal of claim 1, wherein the information element is the first information element in the system information request message (msg3), and/or wherein the information element is the only information element in the system information request message (msg3), and/or in which the information element is not a mobile terminal identifier information element and/or a random value information element, and/or an information element with a bit pattern corresponding to a specific format contains at least 8 bits. 3. The mobile terminal according to claim 1 or 2, wherein the specific format determines for the bit pattern part of the information element to correspond to requests for different types of system information messages, and in which the bit pattern part of the information element consists of 8 bits, and each of 8 bits matches a request for a different type of system information message, and also in which the specific format dictates that this part of the bit pattern, 8 bits, is at the beginning or at the end of the bit pattern, and further, in which the specific format dictates that all other bits in the bit pattern of the information element, except for the bits of that part of the bit pattern, have a value of zero. 4. Mobile terminal according to paragraphs. 1-3, which starts receiving a system information message containing other system information requested as necessary, depending on the bit pattern in the contention resolution message (msg4). 5. A mobile terminal (110) configured to obtain system information in a wireless communication system comprising at least one base station configured with a serving cell, where the system information contains minimum system information and other system information, wherein the mobile terminal comprises processor (130) and transceiver (120), which during operation determining a condition for the request as necessary to transmit other system information; performing a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a conflict resolution message (msg4); and receiving by broadcasting a system information message containing other system information requested as necessary; and in case of unsuccessful reception of the conflict resolution message (msg4), the execution of the random access procedure includes: pausing the retransmission signal (msg1) of the random access preamble until the next minimum system information time, receiving, at the next point in time, the minimum system information, and determining, based on the received minimum system information, whether the requested other system information is scheduled to be transmitted by broadcast, regardless of its retransmission. 6. Mobile terminal according to paragraphs. 1-5, in which the success/failure of receiving a contention resolution message (msg4) is determined by at least one of: checking whether the contention resolution message (msg4) contains only the same bit pattern as is transmitted by the information element included in the system information request message (msg3) corresponding to a particular format for requesting other system information, checking whether the contention resolution message (msg4) is a special version of the contention resolution message used to acknowledge receipt of a request as needed for other system information, and whether msg4 contains only the same part of the bit pattern as transmitted with the information element included in the message (msg3) requesting system information, checking whether a portion of the contention resolution message (msg4) contains the same bit pattern as is transmitted by the information element included in the system information request message (msg3) corresponding to a specific format for requesting other system information, checking whether the contention resolution message (msg4) is a special version of the contention resolution message used to acknowledge receipt of a request as needed for other system information, and whether (msg4) contains the same bit pattern as conveyed by the information element included to a system information request message (msg3) corresponding to a specific format for requesting other system information. 7. Mobile terminal according to paragraphs. 1-6, wherein the system information request message (msg3) is a radio resource control (RRC) message with an information element having a total size of 40 bits, and/or wherein the contention resolution message (msg4) is a Media Access Control (MAC) control element (CE) having a total size of 48 bits, and/or wherein the mobile terminal is in one of the RRC_CONNECTED, RRC_IDLE, and RRC_INACTIVE states to perform system information acquisition. 8. Mobile terminal according to paragraphs. 1-7, wherein the condition for requesting other system information to be transmitted as needed includes at least one of: detecting a power-on event in the serving cell or a cell selection/reselection event in the serving cell, recovering from a loss of coverage event for a serving cell, determining that a timeout timer for other system information has expired. 9. A base station (160) in a wireless communication system that allows a mobile terminal to perform system information acquisition using a base station configured with a serving cell, where the system information contains minimum system information and other system information, and the base station contains: processor (180) and transceiver (170), which during operation performing a random access procedure including: receiving a random access preamble signal (msg1), transmitting a random access response message (msg2), receiving a system information request message (msg3) for other system information, and transmitting a conflict resolution message (msg4); and broadcasting a system information message containing other system information requested as needed; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is intended to request other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure. 10. The base station of claim 9, wherein the information element is the first information element in the system information request message (msg3), and/or wherein the information element is the only information element in the system information request message (msg3), and/or wherein the information element is not a mobile terminal identifier information element and/or a random value information element, and/or an information element with a bit pattern corresponding to a specific format contains at least 8 bits. 11. Base station according to claim 9 or 10, in which a specific format defines for a subset of bits in an information element bit pattern corresponding to requests for different types of system information messages, wherein the subset of bits in the information element bit pattern consists of 8 bits, and each of the 8 bits corresponds to a request for a different type of system information message, and also in which the specific format dictates that a subset of bits is at the beginning or at the end of a bit pattern, and further, in which the particular format dictates that all other bits in the bit pattern of the information element, except for the bits of this subset of bits, have a value of zero. 12. Base station according to paragraphs. 9-11, which starts transmission of a system information message containing other system information requested as needed, depending on the bit pattern in the contention resolution message (msg4). 13. A method for performing system information acquisition by a mobile terminal in a wireless communication system comprising at least one base station configured with a serving cell, the system information comprising minimum system information and other system information, the method including the steps of: determining (S01) a condition for requesting, as necessary, transmission of other system information; performing (S02) a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a conflict resolution message (msg4); receiving (S03) by broadcasting a system information message containing other system information requested as needed; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure. 14. A method for performing system information acquisition by a mobile terminal in a wireless communication system comprising at least one base station configured with a serving cell, the system information comprising minimum system information and other system information, the method including the steps of: determining (S01) a condition for requesting, as necessary, transmission of other system information; performing (S02) a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a conflict resolution message (msg4); receiving (S03) by broadcasting a system information message containing other system information requested as needed; and in case of unsuccessful reception of the conflict resolution message (msg4), the step of executing the random access procedure also includes: pausing the retransmission signal (msg1) of the random access preamble until the next minimum system information time, receiving, at the next point in time, the minimum system information, determining (S02') based on the received minimum system information whether the requested other system information is scheduled to be broadcast by broadcast regardless of its retransmission. 15. A method for a base station to enable a mobile terminal to perform system information acquisition in a wireless communication system by a base station configured with a serving cell, the system information comprising minimum system information and other system information, the method including the steps of: performing a random access procedure including: receiving a random access preamble signal (msg1), transmitting a random access response message (msg2), receiving a system information request message (msg3) for other system information, and transmitting a conflict resolution message (msg4); broadcasting a system information message containing other system information requested as needed; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure. 16. An integrated circuit that, during operation, controls a method for a mobile terminal to obtain system information by a mobile terminal in a wireless communication system comprising at least one base station configured with a serving cell, the system information comprising minimum system information and other system information, wherein the method includes determining (S01) a condition for requesting, as necessary, transmission of other system information; performing (S02) a random access procedure including: transmitting a random access preamble signal (msg1), receiving a random access response message (msg2), transmitting a system information request message (msg3) for other system information, and receiving a conflict resolution message (msg4); and receiving (S03) by broadcasting a system information message containing other system information requested as needed; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure. 17. An integrated circuit that, during operation, controls a method for a base station to enable a mobile terminal to perform system information acquisition in a wireless communication system by a base station configured with a serving cell, the system information including minimum system information and other system information, when this method includes performing a random access procedure including: receiving a random access preamble signal (msg1), transmitting a random access response message (msg2), receiving a system information request message (msg3) for other system information, and transmitting a conflict resolution message (msg4); broadcasting a system information message containing other system information requested as needed; wherein the system information request message (msg3) contains an information element with a bit pattern corresponding to a particular format, wherein at least a portion of the bit pattern is for requesting other system information, and the conflict resolution message (msg4) contains the same bit pattern, or the same part of the bit pattern to detect collisions during the random access procedure.

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