Apparatus and method for acquisition of system information in wireless communications

A wireless terminal communicates over a radio interface with a radio access node of a radio access network (RAN). The wireless terminal comprises receiver circuitry and processor circuitry. The receiver circuitry is configured to receive system information (SI) from the radio access node. The processor circuitry configured to perform an SI message acquisition process to acquire the system information, and terminate the SI message acquisition process after attempting SI message acquisition in accordance with configured information. The configured information may be a first number of modification periods or a prescribed number of transmission opportunities.

TECHNICAL FIELD

The technology relates to wireless communications, and particularly to methods, apparatus, and techniques for requesting, transmitting, updating, and using system information (SI) in wireless communications.

BACKGROUND

In wireless communication systems, a radio access network generally comprises one or more access nodes (such as a base station) which communicate on radio channels over a radio or air interface with plural wireless terminals. In some technologies such a wireless terminal is also called a User Equipment (UE). A group known as the 3rd Generation Partnership Project (“3GPP”) has undertaken to define globally applicable technical specifications and technical reports for present and future generation wireless communication systems. The 3GPP Long Term Evolution (“LTE”) and 3GPP LTE Advanced (LTE-A) are projects to improve an earlier Universal Mobile Telecommunications System (“UMTS”) mobile phone or device standard in a manner to cope with future requirements.

In typical cellular mobile communication systems, the base station broadcasts on the radio channels certain information which is required for mobile stations to access to the network. In Long-Term Evolution (LTE) and LTE Advanced (LTE-A), such information is called “system information” (“SI”). Each access node, such as an evolved NodeB (“eNB”), or a gNodeB or gNB in the 5G New Radio (NR) System, broadcasts such system information to its coverage area via a Master Information Block (MIB) and several System Information Blocks (SIBs) on downlink radio resources allocated to the access node.

A wireless terminal (“UE”), after entering a coverage area of an eNB or gNB, is required to obtain all the MIB/SIBs which are necessary to access to the system. For sake of UEs under coverage, the eNB or gNB periodically broadcasts all MIB/SIBs relevant for offered services, where each type of MIB or SIBs is transmitted in a designated radio resource(s) with its own pre-determined/configurable frequency.

This all-broadcast-based periodic delivery method (e.g., collective broadcast of all SIBs, not just those necessary for system access) is efficient under a condition where many UEs are almost always flowing into the coverage area (such as a macro cell). However, this approach may result in wasting valuable radio resources in case of small cell deployment. Therefore, more efficient methods of SIB transmission are desired.

What is needed, therefore, and an example object of the technology disclosed herein, are methods, apparatus, and techniques for obtaining and/or updating SIBs including controlling timing of an SI message acquisition process.

SUMMARY

In one of its example aspects, the technology disclosed herein concerns a wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN). The wireless terminal comprises receiver circuitry and processor circuitry. The receiver circuitry is configured to receive a first type system information (SI) block (SIB). The first type SIB comprises availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB; an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and; a number of transmission opportunities allowed for an SI message acquisition process to acquire an SI message. The processor circuitry is configured to perform the SI message acquisition process, wherein the SI message acquisition process is terminated after the number of transmission opportunities consumed for the SI message acquisition process without a successful reception of the SI message. Another aspect of the technology disclosed herein concerns a method of operation of such wireless terminal.

In another of its example aspects the technology disclosed herein concerns a radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal. The radio access node comprises transmitter circuitry and processor circuitry. The transmitter circuitry is configured to transmit a first type system information (SI) block (SIB). The first type SIB comprises availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB; an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and; a number of transmission opportunities allowed for an SI message acquisition process to acquire an SI message. The processor circuitry is configured to generate an SI message. The transmitter circuitry is further configured to transmit the SI message based on the indication of the delivery mode for the SI message and the number of transmission opportunities, wherein the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process. Another example aspect of the technology disclosed herein concerns method of operating such access node.

DETAILED DESCRIPTION

In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the technology disclosed herein. However, it will be apparent to those skilled in the art that the technology disclosed herein may be practiced in other embodiments that depart from these specific details. That is, those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the technology disclosed herein and are included within its spirit and scope. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the technology disclosed herein with unnecessary detail. All statements herein reciting principles, aspects, and embodiments of the technology disclosed herein, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

As used herein, the term “core network” can refer to a device, group of devices, or sub-system in a telecommunication network that provides services to users of the telecommunications network. Examples of services provided by a core network include aggregation, authentication, call switching, service invocation, gateways to other networks, etc.

As used herein, the term “wireless terminal” can refer to any electronic device used to communicate voice and/or data via a telecommunications system, such as (but not limited to) a cellular network. Other terminology used to refer to wireless terminals and non-limiting examples of such devices can include user equipment terminal, UE, mobile station, mobile device, access terminal, subscriber station, mobile terminal, remote station, user terminal, terminal, subscriber unit, cellular phones, smart phones, personal digital assistants (“PDAs”), laptop computers, netbooks, e-readers, wireless modems, etc.

As used herein, the term “access node”, “node”, or “base station” can refer to any device or group of devices that facilitates wireless communication or otherwise provides an interface between a wireless terminal and a telecommunications system. A non-limiting example of a base station can include, in the 3GPP specification, a Node B (“NB”), an enhanced Node B (“eNB”), a home eNB (“HeNB”), a 5G (New Radio [NR]) gNodeB or gNB, or some other similar terminology. Another non-limiting example of a base station is an access point. An access point may be an electronic device that provides access for wireless terminal to a data network, such as (but not limited to) a Local Area Network (“LAN”), Wide Area Network (“WAN”), the Internet, etc. Although some examples of the systems and methods disclosed herein may be described in relation to given standards (e.g., 3GPP Releases 8, 9, 10, 11, 12, or higher), the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems.

As used herein, the term “telecommunication system” or “communications system” can refer to any network of devices used to transmit information. A non-limiting example of a telecommunication system is a cellular network or other wireless communication system.

As used herein, the term “cellular network” can refer to a network distributed over cells, each cell served by at least one fixed-location transceiver, such as a base station. A “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (“IMTAdvanced”). All or a subset of the cell may be adopted by 3GPP as licensed bands (e.g., frequency band) to be used for communication between a base station, such as a Node B, and a UE terminal. A cellular network using licensed frequency bands can include configured cells. Configured cells can include cells of which a UE terminal is aware and in which it is allowed by a base station to transmit or receive information.

As used herein, “system information” (“SI”) may include a Master Information Block (MIB) and several System Information Blocks (SIBs) which are provided on downlink radio resources allocated to an access node. The system information may be broadcast, and some types of system information may be provided on demand, e.g., upon receipt of a request for system information from a wireless terminal.

In various aspects of the technology disclosed herein, system information is classified into plural categories or types. In an example embodiment and mode, first type of the system information (e.g. a first type SIB or SIB1) is Minimum System Information (Minimum SI), minimally containing information required for UEs initially access to the network, periodically broadcasted by each access node (e.g. eNB for LTE, gNB for 5G Radio System). In some configurations, Minimum System SI may consist of MIB and a limited number of SIBs. The MIB may contain essential information for the radio system to help wireless terminals to synchronize to the serving access node and may also contain instruction how to obtain at least one of the essential SIBs. The Minimum SI may be also referred as “essential SI”, or first type system information.

Second type of system information, e.g., “Other system information, “Other SI”, or second type system information, contains all the other types of information, i.e., all types of system information except the Minimum System Information. The Other SI may comprise several system information blocks (SIBs) that are not categorized as Minimum SI. The Other SI may be also referred as “non-essential SI”. However, second type system information is not to be confused with SIB Type 2, which is a particular (second) system information block (SIB) that may be included in the Minimum System Information or may be a part of the Other SI.

In some example embodiment and modes described herein, for each of the SIBs the access node may choose to broadcast the SIB periodically, similar to the SIBs in Minimum SI. Alternatively, the access node may choose to refrain from transmitting the SIB until receiving a request of on-demand delivery from a UE. In this case, the access node may advertise the availability of on-demand delivery using Minimum SI.

As described herein, both an access node and a wireless terminal may manage respective Radio Resource Control (RRC) state machines. The RRC state machines transition between several RRC states including RRC_IDLE, RRC_INACTIVE and RRC_CONNECTED.FIG. 1depicts the state transition diagram of the RRC states. From the vantage point of a wireless terminal e.g., user equipment (UE), the RRC states may be briefly characterized as follows:

A UE specific DRX (discontinuous reception) may be configured by upper layers;

UE controlled mobility based on network configuration;

The UE:Monitors a Paging channel;Performs neighboring cell measurements and cell (re-)selection;Acquires system information.
RRC_INACTIVE:

A UE specific DRX may be configured by upper layers or by RRC layer;

UE controlled mobility based on network configuration;

The UE stores the Access Stratum (AS) context;

The UE:Monitors a Paging channel;Performs neighboring cell measurements and cell (re-)selection;Performs RAN-based notification area updates when moving outside the RAN-based notification area;Acquires system information.
RRC_CONNECTED:

The UE stores the AS context.

Transfer of unicast data to/from UE.

At lower layers, the UE may be configured with a UE specific DRX;

Network controlled mobility, i.e. handover within NR and to/from E-UTRAN;

The UE:Monitors a Paging channel;Monitors control channels associated with the shared data channel to determine if data is scheduled for it;Provides channel quality and feedback information;Performs neighboring cell measurements and measurement reporting;Acquires system information.

The technology disclosed herein concerns, e.g., apparatus, methods, and procedures for obtaining and/or updating SIBs including controlling timing of an SI message acquisition process.

FIG. 2shows an example communications system20wherein radio access node22communicates over air or radio interface24(e.g., Uu interface) with wireless terminal26. As mentioned above, the radio access node22may be any suitable node for communicating with the wireless terminal26, such as a base station node, or eNodeB (“eNB”) or gNodeB (“gNB”), for example. The node22comprises node processor circuitry (“node processor30”) and node transceiver circuitry32. The node transceiver circuitry32typically comprises node transmitter circuitry34and node receiver circuitry36, which are also called node transmitter and node receiver, respectively.

The wireless terminal26comprises terminal processor40and terminal transceiver circuitry42. The terminal transceiver circuitry42typically comprises terminal transmitter circuitry44and terminal receiver circuitry46, which are also called terminal transmitter44and terminal receiver46, respectively. The wireless terminal26also typically comprises user interface48. The terminal user interface48may serve for both user input and output operations, and may comprise (for example) a screen such as a touch screen that can both display information to the user and receive information entered by the user. The user interface48may also include other types of devices, such as a speaker, a microphone, or a haptic feedback device, for example.

For both the radio access node22and radio interface24, the respective transceiver circuitries22include antenna(s). The transmitter circuit34and transmitter circuit44may comprise, e.g., amplifier(s), modulation circuitry and other conventional transmission equipment. The receiver circuit36and receiver circuit46may comprise, e.g., e.g., amplifiers, demodulation circuitry, and other conventional receiver equipment.

In general operation, access node,22and wireless terminal26communicate with each other across radio interface24using predefined configurations of information. By way of non-limiting example, the radio access node22and wireless terminal26may communicate over radio interface24using “frames” of information that may be configured to include various channels. In Long Term Evolution (LTE), for example, a frame, which may have both downlink portion(s) and uplink portion(s), may comprise plural subframes, with each LTE subframe in turn being divided into two slots. The frame may be conceptualized as a resource grid (a two dimensional grid) comprised of resource elements (RE). Each column of the two dimensional grid represents a symbol (e.g., an OFDM symbol on downlink (DL) from node to wireless terminal; an SC-FDMA symbol in an uplink (UL) frame from wireless terminal to node). Each row of the grid represents a subcarrier. The frame and subframe structure serves only as an example of a technique of formatting of information that is to be transmitted over a radio or air interface. It should be understood that “frame” and “subframe” may be utilized interchangeably or may include or be realized by other units of information formatting, and as such may bear other terminology (such as blocks, for example).

To cater to the transmission of information between radio access node22and wireless terminal26over radio interface24, the node processor30and terminal processor40ofFIG. 2are shown as comprising respective information handlers. For an example implementation in which the information is communicated via frames, the information handler for radio access node22is shown as node frame/signal scheduler/handler50, while the information handler for wireless terminal26is shown as terminal frame/signal handler52.

The node processor30of radio access node22also includes system information (SI) generator54. As described above, at least some of the system information generated and provided by the system information (SI) generator54is Minimum System Information (Minimum SI), also known as first type system information, represented by Minimum SI handler54M. Some of the system information may be Other system information (Other SI), also known as second type system information, represented by Other SI handler54O inFIG. 2. The wireless terminal26uses the system information (SI) generated by radio access node22. Some of the Minimum SI may inform the wireless terminal26of the availability of the Other IS.

FIG. 2illustrates a generic message2-1by which the node radio resource controller54may supply the Minimal SI to wireless terminal26. In some example implementations, upon knowing of the availability of the Other SI, due to the message2-1, for example, the wireless terminal26specifically requests the Other system information, in on-demand fashion, as described herein. The terminal processor40of wireless terminal26comprises, e.g., SI processor56, to facilitate obtaining and use of system information.

The technology disclosed herein concerns, e.g., apparatus, methods, and procedures for obtaining and/or updating system information blocks (SIBs) in/of the Other SI (Other SI SIBs) in on-demand basis. Since in at least some of the example embodiments and modes the technology disclosed herein involves the Radio Resource Control (RRC) procedures,FIG. 2shows terminal processor40as comprising node radio resource control (RRC) controller60, e.g., node RRC controller60. The node RRC controller60may execute an instance of the RRC state machine for each wireless terminal in which the access node20is in communication, with each instance keeping track of the RRC state transitions experienced by the wireless terminal associated with the respective instance.

FIG. 2also shows the terminal processor40of wireless terminal26as comprising, in addition to terminal SI processor56, a terminal RRC controller70. The terminal RRC controller70includes or executes the RRC state machine discussed above, which transitions through the RRC states, as described above and shown inFIG. 2, for a communication involving wireless terminal26.

FIG. 2thus shows that the access node22comprises node processor30, e.g., node processor circuitry30, transmitter circuit34, and, receiver circuit36. The transmitter circuit34is configured to transmit the first type system information over a radio interface, the first type system information including availability of a SI message belonging to the second type system information. The receiver circuit36is configured to receive from the wireless terminal a request message to request delivery of the SI message which is available by on-demand basis. The transmitter circuit34is further configured to transmit the SI message to the wireless terminal.

FIG. 2thus shows that the wireless terminal26communicates over radio interface24with access nodes, such as access node22, of a radio access network (RAN). The wireless terminal26comprises receiver circuit46, transmitter circuit44, and terminal processor40, e.g., terminal processor circuitry. The receiver circuit46is configured to receive first type system information over the radio interface. The terminal processor circuitry is configured to generate a request message to request the second type SIB which is available in an on-demand basis. The transmitter circuit44is configured to transmit the request message over the radio interface while in the connected state. The receiver circuit46is also configured to receive the SI message while in the connected state.

FIG. 3shows example, representative acts or steps performed in conjunction with a generic method of operating a wireless terminal of a radio access network (RAN), such as wireless terminal26ofFIG. 2. Act3-1comprises the wireless terminal acquiring, e.g., receiving, the Minimum SI that is broadcasted from the currently serving access node, e.g., access node22. The Minimum SI may be broadcast in a message such as message2-1ofFIG. 2. The Minimum SI may contain information about the Other SI, including the delivery method, e.g., periodic broadcast/on-demand, scheduling information, validity information, etc. Based on the information, the wireless terminal in act3-2may determine which SI message(s) to acquire by on-demand. As act3-3, the wireless terminal may send a request message (depicted as message2-2ofFIG. 2) to the access node, the request message indicating the SI message(s) that the wireless terminal desires to obtain. As act3-4the wireless terminal26may attempt to receive the requested SI message(s) which, e.g., was sent using message2-3ofFIG. 2.

It was mentioned above that the first type system information includes availability of a SI message belonging to the second type system information, that the request message requests delivery of a SI message which is available by on-demand basis, and that the SI message is transmitted to the wireless terminal. It should be understood that reference herein to “a SI message belonging to the second type system information” means one or more pieces of Other system information (Other SI), e.g., one or more SI messages belonging to the second type system information. In some example situations indeed only one SI message may be advertised as available and accordingly periodically broadcasted or requested on-demand. But in other example situations plural SI messages (e.g., plural pieces of Other SI) are advertised as available, some of which may be periodically broadcasted and the others may be requested on-demand. Furthermore, it should be noted that in some configurations (e.g. the configuration presented inFIG. 7, or inFIG. 13A-D) the availability may be included in the scheduling information (e.g. schedulingInfoList described below).

In some configurations, the availability and delivery method information for Other SI SIBs may be included in SIB Type 1, one of the SIBs in the Minimum SI.FIG. 4shows an example format of SIB Type 1, including schedulingInfoList, si-WindowLength, otherSIBInfoList, validity area identification (si-AreaID), and possibly other configuration parameters. The otherSIBInfoList is a list of otherSIBInfo, which comprises SIB-Type, an identifier of a SIB, validityInfo and validity information of the SIB (a value tag [valueTag], and other parameters, such as validity timer, etc.).

SIBs other than SIB1 are carried in SystemInformation (SI) messages and mapping of SIBs to SI messages is flexibly configurable by schedulingInfoList included in SIB1, with restrictions that: each SIB is contained only in a single SI message, only SIBs having the same scheduling requirement (periodicity given by si-periodicity) can be mapped to the same SI message. There may be multiple SI messages transmitted with the same periodicity.

In one configuration, each element, schedulingInfo, of schedulingInfoList may represent one SI message, comprising its periodicity (si-Periodicity), delivery method (deliveryMethod) indicating if this SIB is periodically broadcasted or to be transmitted upon request (on-demand), and associated SIB types (one or more SIB-Type's). The actual broadcast opportunity, e.g., timing/resources, of a given SI message may be determined by a pre-determined or a network-configured formula as a function of at least the corresponding periodicity. At each opportunity the broadcast of the SI message may occur within the duration of the window length (si-WindowLength). Hereafter a broadcast opportunity is also referred as a SI window. More than one SIB may be possibly transmitted on a same SI window.

In the configuration ofFIG. 4si-AreaID is common for all SI messages or SIB types, which means that all SIBs have the same validity area. Alternatively, in another configuration, each SI message may have a designated validity area.FIG. 5shows an example format of SIB1 for such a configuration wherein each SI message may have a designated validity area. Furthermore, in another configuration, having an example format such as shown inFIG. 6, each SIB type may have a designated validity area. Thus, in differing implementations, the system information (SI) generator54ofFIG. 2, working with node frame/signal scheduler/handler50, generates the differing formatted SI messages ofFIG. 4,FIG. 5, andFIG. 6, for transmission by node transmitter circuitry34over radio interface24.

FIG. 7is an alternative format for SIB1, which is logically equivalent to the format shown inFIG. 4. The si-BroadcastStatus information element ofFIG. 7may be functionally identical to deliveryMode information element described earlier. In one configuration, the information element sibValueTagList may comprise a list of value tags for the available SIBs included in schedulingInfoList, in the order of the SIB numbering scheme (e.g. SIB2, SIB3, SIB4, SIB5, . . . ). In another configuration, sibValueTagList may comprise a list of value tags for the available SIBs (included in schedulingInfoList) as well as the non-available SIBs (not included in schedulingInfoList), in the order of the SIB numbering scheme (e.g. SIB2, SIB3, SIB4, SIB5, . . . ). In this case, a pre-determined value may be set to the value tag for a non-available SIB. Accordingly, the si-BroadcastStatus information element may be used for indicating broadcast status (e.g. the broadcast status being either periodic broadcast or on-demand basis).

FIG. 8is an exemplary message flow diagram of on-demand based SI acquisition procedure. As shown by act8-0, wireless terminal26in either RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state stores the content of SIB #A with the validity information, valueTag=a, si-AreaID=2, which the wireless terminal has previously received. From the currently serving access node, as act8-1the wireless terminal may obtain SIB1 as Minimum SI. As shown inFIG. 4,FIG. 5,FIG. 6, andFIG. 7, the SIB1 includes the scheduleInfoList, which in turn may include one or more schedulingInfo information elements. An example scheduleInfoList for this scenario is shown in Table 1, wherein the k'th schedulingInfo indicates that the SI message associated with this schedulingInfo (SI #k, hereafter), containing SIB #A, will be available by on-demand delivery. Furthermore, the otherSIBInfo corresponding to SIB #A indicates that the validity information of SIB #A is valueTag=b, si-AreaID=3. It is assumed hereafter that whenever the wireless terminal receives SIB1, it has already received MIB beforehand.

Knowing that the stored SIB #A is now invalid, the wireless terminal may decide to obtain a valid version of SIB #A, and may initiate the SI request procedure represented by act8-2and explained herein. After the SI request procedure has a successful result, the wireless terminal may start the SI message acquisition, shown generally as act8-3inFIG. 8. In the SI message acquisition the wireless terminal monitors signals from the access node in the designated SI windows derived from the scheduling information (scheduleInfo) in the SIB1, and thereby attempts to receive the requested SI #k. The SI windows are shown by dotted rectangles inFIG. 8.FIG. 8shows by act8-3aa first transmission of the requested SI #k, which is unsuccessful, and by act8-3ba second transmission of the requested SI #k, which is successful. A tail of a vertical down-pointing arrow in the SI message acquisition depiction ofFIG. 8is associated with start of the SI message acquisition, while the head of the same vertical down-pointing arrow is associated with end of the SI message acquisition (at successful reception of the SI #k).FIG. 8also shows by act8-4that other transmissions of the requested system information may also be made even after the wireless terminal has successfully received the sought SI #k.

In one configuration, the wireless terminal may use a counter, which is incremented at every SI window of a particular SI message, e.g. SI #k. In this configuration, the SI message acquisition may end when the requested SI message(s) are successfully received, or when the counter reaches a maximum counter value. In another configuration the wireless terminal starts a timer at the beginning of the SI message acquisition. In this configuration, the SI message acquisition may end when the requested SI message(s) are successfully received, or when the timer expires. The maximum counter value, or the timer value, which may be common for all SI messages or per-SI message basis, may be pre-configured or configured by network via system information. The conditions for the wireless terminal to end the SI reception process is referred as “termination conditions” herein.

FIG. 9A,FIG. 9BandFIG. 9Cshow three options for the SI request procedure. InFIG. 9A, which may be applicable to wireless terminals in any of the RRC states, the request of on-demand delivery for SI messages may be accomplished by sending a Random Access Preamble, which may comprise a sequence selected from a set of available sequences configured by the access node via Minimum SI. A given sequence is identified by a Preamble Index. When the access node detects the transmission of a preamble sequence, it may respond to it with Random Access Response, which includes the Preamble Index corresponding to the sequence. Upon receiving the Random Access Response, the wireless terminal may validate that the Preamble index in the Random Access Response matches the one associated with the preamble sequence, and then send to the access node SystemInformationRequest message that includes the identity of the SI messages (e.g. SI #k) that the wireless terminal desires to receive. In response, the access node may send a SystemInformation message acknowledging the request, indicating that the requested SI message(s) will be broadcasted from the next SI window scheduled for the requested SI message(s).

In one configuration, the access node may include in Minimum SI a set of Preamble indices, each of which is designated for requesting on-demand delivery of one or more specific SI messages.FIG. 9Billustrates an example SI request procedure using this configuration, where the wireless terminal in any RRC state may transmit Random Access Preamble sequence given by the Preamble Index associated with the SI message(s) that the wireless terminal has selected. When the wireless terminal receives Random Access Response including the Preamble Index, it may consider that the request procedure is successful.

The SI request procedure inFIG. 9Cmay be applicable to wireless terminals in RRC_CONNECTED, wherein the SystemInformationRequest message is sent without the random access preamble/response.

In any of the three options disclosed above, the wireless terminal may proceed to the SI message acquisition if the SI request procedure is successful. Otherwise, the wireless terminal may think that the serving cell (controlled by the access node) is barred, which will invoke a cell reselection.

The SystemInformationRequest message shown inFIG. 9AorFIG. 9Cmay include an information element (e.g. siRequest) to indicate which SI message(s) that the wireless terminal desires to receive. In one configuration, as shown inFIG. 10, the siRequest may comprise a bit map, wherein each bit corresponds to a schedulingInfo information element in SIB1 of the current serving cell, the bits arranged in the order of schedulingInfo information elements. By doing so, each bit of the bit map may correspond to a specific SI message. Alternatively, siRequest may carry a field indicating that the wireless terminal desires to receive at least one on-demand basis SI message. In this case, the access node may start broadcasting all of the on-demand basis SI messages for a pre-configured duration. The SystemInformation message shown inFIG. 9AorFIG. 9Cmay include siAck, an information element for acknowledging siRequest. In one configuration, siAck may comprises the same bit map as the one in SystemInformationRequest, indicating the SI message(s) to be broadcasted. Alternatively, siAck may comprise one Boolean field, indicating whether the request has been accepted or not.

FIG. 11is an exemplary message flow diagram of SI acquisition procedure for a SI message broadcasted periodically. Act11-0comprises the wireless terminal26, in either RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state, storing the content of SIB #A with the validity information, e.g., valueTag=a and si-AreaID=2. Act11-1comprises the wireless terminal26obtaining, from the currently serving access node22, SIB1 as Minimum SI, which, as understood from previous description, includes one or more schedulingInfo information elements. In the scenario ofFIG. 11, and as shown by Table 2, the k'th schedulingInfo information element indicates that the SI message associated with this schedulingInfo (SI #k, hereafter), containing SIB #A, is currently broadcasted periodically. Furthermore, the SIB1 specifies (see Table 2) that otherSIBInfo corresponding to SIB #A indicates that the validity information of SIB #A is now valueTag=b and si-AreaID=3.

Knowing that the stored SIB #A is now invalid, as act11-3the wireless terminal26begins an SI message acquisition wherein the wireless terminal may attempt to acquire the SI message (SI #k) in the SI windows specified in SIB1. InFIG. 11, act11-3aillustrates an unsuccessful SI message reception attempt in a first SI window for SI #k, followed by act11-3bwhich is a successful SI message reception in a second SI window for SI #k, Thus, as shown inFIG. 11, if the SI message is not received by the end of the SI window (as was the case for act11-3a), the wireless terminal26may repeat reception at the next SI window occasion for the concerned SI message until it successfully receives the SI message (as was done in act11-3b).

Unsuccessful Attempted Reception of on-Demand System Information

FIG. 12shows an example communications system20(12) comprising wireless terminal26(12) configured to detect failure of a SI reception process involving an on-demand SI message, following a successful completion of an SI request. The access node22(12) and wireless terminal26(12) ofFIG. 12are essentially identical to the respective access node22and wireless terminal26ofFIG. 2, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(12) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(12) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70.

FIG. 12also shows that wireless terminal26(12) comprises system information acquisition failure detector80. The terminal processor40, and particularly SI processor56, may comprise or constitute the system information acquisition failure detector80. The system information acquisition failure detector80is configured to make a determination of a failure of the SI message acquisition process. The system information acquisition failure detector80may make such failure determination based on a termination condition, as herein explained.

The system information generator54of radio access node22(12) is configured to generate first type system information. For the example embodiment and mode ofFIG. 12, and in an example, non-limiting manner shown inFIG. 13, the first type system information comprises (information elements or the like which indicate): availability of second type SI messages; scheduling information of each of the SI messages; a delivery mode for each of the second type SI messages; and, a configuration parameter to configure at least one termination condition for determination of a failure of an SI message acquisition process for the on-demand based second type SI messages.

As understood herein, a second type SI message comprises at least one system information block (SIB), and the delivery mode may be either periodic broadcast or on-demand basis. The transmitter circuitry36of radio access node22(12) is configured to transmit the first type system information over the radio interface24to the wireless terminal26(12), as shown by arrow12-1inFIG. 12

As in the example embodiment and mode ofFIG. 2, the on-demand Other SI request generator72of wireless terminal26(12) may request at least one second type SI using a request message as indicated by arrow12-2inFIG. 12. The second type SI request message depicted by arrow12-2is received by node receiver circuitry36. The node processor30, and particularly the SI generator54, generates the requested (second type) SI message in one or more windows of transmission, the transmission of the requested SI message being depicted by arrow12-3inFIG. 12.

As mentioned above, system information acquisition failure detector80may make a determination of a failure of the SI message acquisition process. When so doing, in an example embodiment and mode, the terminal processor40, working in response to or with system information acquisition failure detector80, is configured to initiate acquisition of the first type system information. That is, the terminal processor40is configured, upon a failure of the SI message acquisition process, to initiate acquisition of the first type system information, e.g., to again request the first type system information (Minimum SI) from the radio access node22(12). InFIG. 12such request for first type system information is depicted by arrow12-4.

FIG. 13Ais an exemplary format of SIB1, which is based on the format shown inFIG. 7with an additional information element si-MaxAcqAttempts. The information element si-MaxAcqAttempts provides a termination condition for the SI message acquisition, indicating the maximum number of SI message reception opportunities (e.g. SI windows) allowed before the end of the SI message acquisition.FIG. 13Bis an alternative format of SIB1, wherein the information element ue-TimersAndConstants includes a timer configuration (T #x) to be used as a termination condition for the SI message acquisition.

FIG. 14is an exemplary message flow diagram of on-demand based SI acquisition procedure wherein system information acquisition failure is detected. As shown by act14-0, wireless terminal26, in either RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state stores the content of SIB #A with the validity information, valueTag=a, si-AreaID=2, which the wireless terminal has previously received. From the currently serving access node, as act14-1the wireless terminal may obtain SIB1 as Minimum SI, e.g., first type system information. Obtaining of the SIBI is depicted by arrow12-1inFIG. 12. As shown inFIG. 13, the SIB1 includes the scheduleInfoList, which in turn may include one or more schedulingInfo information elements. An example scheduleInfoList for this scenario is shown in previously-discussed Table 1, wherein the k'th schedulingInfo indicates that the SI message associated with this schedulingInfo (SI #k, hereafter), containing SIB #A, will be available by on-demand delivery. Furthermore, the otherSIBInfo corresponding to SIB #A indicates that the validity information of SIB #A is valueTag=b, si-AreaID=3. It is assumed hereafter that whenever the wireless terminal receives SIB1, it has already received MIB beforehand.

Knowing that the stored SIB #A is now invalid, the wireless terminal may decide to obtain a valid version of SIB #A, and may initiate the SI request procedure represented by act14-2and explained herein and illustrated by arrow12-2inFIG. 12. After the SI request procedure has a successful result, the wireless terminal may start the SI message acquisition, shown generally as act14-3inFIG. 14. In the SI message acquisition the wireless terminal monitors signals from the access node (depicted by arrow12-3inFIG. 12) in the designated SI windows derived from the scheduling information (scheduleInfo) in the SIB1, and thereby attempts to receive the requested SI #k. The SI windows are shown by dotted rectangles inFIG. 14.FIG. 14shows by act14-3a, act14-3b, and act14-3cthree successive transmissions of the requested SI #k, all of which are unsuccessful. A tail of a vertical down-pointing arrow in the SI message acquisition depiction ofFIG. 14is associated with start of the SI message acquisition, while the head of the same vertical down-pointing arrow is associated with end of the SI message acquisition. InFIG. 14, the SI message acquisition fails. Failure of the SI message acquisition is determined by system information acquisition failure detector80which, as indicated above, makes a determination of a failure of the SI message acquisition process based on a termination condition. Examples of the termination condition are described below.

Upon detection of failure of the SI message acquisition process, as act14-4the terminal processor40initiates (re)acquisition of the first type system information, e.g., the MINIMAL SI or SIB1, as shown by arrow12-4inFIG. 12. The wireless terminal26(12) thus attempts to again acquire the first type system information, in hopes that the SI message acquisition process can thereafter be repeated and perhaps in such repeat of the SI message acquisition process the requested SI message will be obtained. In an example implementation, the wireless terminal26(12) may optionally reacquire MIB prior to reacquisition of SIB1. Accordingly, not having a valid version of a stored SIB, upon detection of failure of the SI message acquisition process, the terminal processor40initiates (re)acquisition of the first type system information.

FIG. 15shows basic, representative, example acts or steps performed by the wireless terminal26(12) ofFIG. 12. Act15-1comprises receiving the first type system information (SI) from the base station apparatus. As mentioned above, the first type system information comprises: availability of a second type SI message, the second type SI message comprising at least one system information block (SIB); scheduling information for the SI message; an indication of a delivery mode for the second type SI message, the delivery mode being either periodic broadcast or on-demand basis; and, at least one termination condition for determination of a failure of an SI message acquisition process for the on-demand based second type SI message. Act15-2comprises transmitting an SI request message to request at least one second type SI message indicated as on-demand delivery. Act15-3comprises initiating the SI message acquisition process. Act15-4comprises determining a failure of the SI message acquisition process. Act15-5comprises, upon a failure of the SI message acquisition process, initiating acquisition of the first type system information

FIG. 16is a flowchart showing basic, representative, example acts or steps performed by the access node22(12) ofFIG. 12. Act16-1comprises transmitting first type system information (SI). The first type SI has been described above. Act16-2comprises receiving an SI request message to request at least one second type SI message. Act16-3comprises delivering the requested SI message. As understood from above, the requested SI message may be sent periodically, repeatedly transmitted at a predetermined interval, for a predetermined length of time

It was mentioned above that, in one configuration, the wireless terminal may use a counter, which is incremented at every SI window of a particular SI message, e.g. SI #k, and that the SI message acquisition may end when the requested SI message(s) are successfully received, or when the counter reaches a maximum counter value. In some configurations, the maximum counter value may be configured by SIB1 (e.g. si-MaxAcqAttempts shown inFIG. 13A).FIG. 17Ashows the system information acquisition failure detector80as comprising such counter as SI window counter82. Thus in one example implementation of theFIG. 12example embodiment and mode, the termination condition may comprise SI window counter82counting up to reach a maximum value, or counting down from a pre-set value to zero. Such maximum or pre-set value may be configured by the radio access node22(12). The SI window counter82is incremented (or decremented) in a case in which the requested SI message was not received by the end of one reception opportunity, e.g., a case in which the requested SI message was not received by the end of an SI window.

It was further mentioned above that, in another configuration the wireless terminal may start a timer at the beginning of the SI message acquisition, and that the SI message acquisition may end when the requested SI message(s) are successfully received, or when the timer expires. In some configuration, the timer is configured by SIB1 (e.g. the timer configuration T #x inFIG. 13B).FIG. 17Bshows the system information acquisition failure detector80as comprising such a timer: SI message acquisition process timer84. Thus in another example implementation of theFIG. 12example embodiment and mode, the termination condition may comprise SI message acquisition process timer84expiration of a timer configured by the base station apparatus. The SI message acquisition process timer84is started at the beginning of the SI message acquisition process. The timer expiration value may be configured by the radio access node22(12).

As understood from above, the Other SI may comprise one or more (Other) SI messages, also known as second type SI messages. In one example implementation, as reflected byFIG. 18A, the termination condition may be common for plural, e.g., all, SI messages. That is, in theFIG. 18Aimplementation, the maximum counter value in the case ofFIG. 17A, or the timer value in the case ofFIG. 17B, may be common for all SI messages. In this case, the counter value configuration or the timer configuration in Minimum SI (e.g., si-MaxAcqAttempts inFIG. 13A, or T #x inFIG. 13B) may comprise a single parameter. Alternatively, as shown in the example implementation ofFIG. 18B, the termination condition may be configured on a per-SI message basis, e.g., uniquely configured for one or more (Other SI) SI messages. In this case, the counter value configuration or the timer configuration in Minimum SI (e.g. si-MaxAcqAttempts inFIG. 13A, or T #x inFIG. 13B) may comprise a list of parameters, each of which configures a corresponding SI message. In either theFIG. 18AorFIG. 18Bimplementations, the termination condition(s), whether common or not common, e.g., unique, may be pre-configured or configured by network via system information. Thus, the condition for the wireless terminal to end the SI reception process is referred as a “termination condition” herein.

The foregoing is now discussed in context of a more general 3GPP TS SI acquisition procedure for a UE to acquire the access stratum, AS, and non-access stratum, NAS, information. This more 3GPP TS procedure applies to UEs in RRC_IDLE, in RRC_INACTIVE and in RRC_CONNECTED. The UE in RRC_IDLE and RRC_INACTIVE shall ensure having a valid version of (at least) the MIB, SIB1 as well as SIB X through SIB Y (depending on support of the concerned RATs for UE controlled mobility). The UE in RRC_CONNECTED shall ensure having a valid version of (at least) the MIB, SIB1 as well as SIB X (depending on support of mobility towards the concerned RATs).

For the acquisition of MIB and SIB1, the UE shall perform the acts of LISTING 1 below (wherein reference to any “section”, “clause”, or “sub-clause” is to the respective section, clause, or sub-clause of 3GPP TS 38.331.)

LISTING 11>if the cell is a PSCell:2>acquire the MIB;2>perform the actions specified in section 5.2.2.4.1;1>else:2>acquire the MIB;2> if the UE is unable to acquire the MIB;3> perform the actions as specified in clause 5.2.2.5;2>else:3>perform the actions specified in section 5.2.2.4.1.2>acquire the SIB1,2>if the UE is unable to acquire the SIB1:3> perform the actions as specified in clause 5.2.2.5;2>else:3>perform the actions specified in section 5.2.2.4.2.

From the foregoing it is understood that the UE shall apply the SI acquisition procedure as defined above upon cell selection (e.g. upon power on), cell-reselection, return from out of coverage, after reconfiguration with sync completion, after entering NR-RAN from another RAT, upon receiving an indication that the system information has changed, upon receiving a PWS notification, upon failing to acquire an SI message; whenever the UE does not have a valid version in the stored SI.

From the foregoing it is understood that, in an example implementation, when acquiring an SI message, the UE may perform the following acts of Listing 2.

LISTING 21>  determine the start of the SI-window for the concerned SI message.1> if SI message acquisition is not triggered due to UE request:2>  receive DL-SCH using the SI-RNTI from the start of the SI-window andcontinue until the end of the SI-window whose absolute length in time is givenby si-WindowLength, or until the SI message was received;2>  if the SI message was not received by the end of the SI-window, repeatreception at the next SI-window occasion for the concerned SI message;1> else if SI message acquisition is triggered due to UE request:2> Set the SI window counter 82 to 0 (or Start SI message acquisition process timer 84);2> [FFS receive DL-SCH using the SI-RNTI from the start of the SI-window andcontinue until the end of the SI-window whose absolute length in time is given by si-WindowLength, or until the SI message was received];2>[FFS if the SI message was not received by the end of the SI-window, increment theSI window counter 82 , repeat reception at the next SI-window occasion for theconcerned SI message];2>if the SI window counter 82 is equal to configured maximum value or counted downto zero (or timer SI message acquisition process timer 84 expires)3> Initiate the SI acquisition procedure.

When the UE acquires a MIB or a SIB1 or a SI message in a currently camped/serving cell as described in clause 5.2.2.3, the UE shall store the acquired SI. A version of the SI that the UE stored is out of date after 3 hours. The UE may use such a stored version of the SI e.g. after cell re-selection, upon return from out of coverage or after the reception of SI change indication. The storage and management of the stored SI in addition to the SI relevant for the current camped/serving cell is left to UE implementation. The UE shall:

1>delete any stored version of a SIB after 3 hours from the moment it wassuccessfully confirmed as valid;1>if UE has stored version of any SIB:2>for each SIB:3>if the stored SIB is area specific SIB and ifsystemInfoAreaIdentifier and systemInfoValueTag included in the SIB1 receivedfrom the currently camped/serving cell are identical to thesystemInfoAreaIdentifier and systemInfoValueTag associated with storedversion of that SIB; or3>if the stored SIB is cell specific and if systemInfoValueTagincluded in the SIB1 received from the currently camped/serving cell isidentical to the systemInfoValueTag associated with stored version of that SIB;4> consider the stored SIB as valid for the cell;3>else:4> (re)acquire the corresponding SI message as specified in clause5.2.2.3.1>if UE has no stored version of a SIB:2> (re)acquire the corresponding SI message as specified in clause 5.2.2.3.

Unsuccessful Attempted Reception of Broadcasted System Information

The previous embodiments disclose, e.g., procedure(s) for acquiring an SI message currently broadcasted periodically, wherein the wireless terminal may continue the SI message acquisition until successful completion. This operation may be valid if the concerned SI message is assumed to be broadcasted forever. By the introduction of on-demand SI, however, the assumption is not guaranteed to be true. For instance, when the wireless terminal sees deliveryMode=broadcast in SIB1 for the SI message of concern, it is possible that the access node may be temporarily broadcasting the SI message in response to a request from another wireless terminal, and that the access node may stop the periodic broadcast eventually.

Whereas the example communications system20(12) ofFIG. 12primarily concerns unsuccessful attempted reception of on-demand system information,FIG. 19shows an example communications system20(17) comprising wireless terminal26(17) configured to detect failure of a SI reception process involving a periodically broadcast SI message. The access node22(17) and wireless terminal26(17) ofFIG. 19are essentially identical to the respective access node22and wireless terminal26ofFIG. 2andFIG. 12, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(17) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(17) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70.

FIG. 19shows that wireless terminal26(17) also comprises system information acquisition failure detector80. As in the case ofFIG. 12, terminal processor40, and particularly SI processor56, may comprise or constitute the system information acquisition failure detector80. The system information acquisition failure detector80is configured to make a determination of a failure of the SI message acquisition process. The system information acquisition failure detector80may make such failure determination based on a termination condition, as herein explained.

As in theFIG. 12example embodiment and mode, system information generator54of radio access node22(12) is configured to generate first type system information. For the example embodiment and mode ofFIG. 19, and in the example, non-limiting manner shown inFIG. 13, the first type system information comprises (information elements or the like which indicate): availability of second type SI messages; scheduling information of each of the SI messages; a delivery mode for each of the second type SI messages; and, a configuration parameter to configure at least one termination condition for determination of a failure of an SI message acquisition process for the on-demand based second type SI messages. As understood herein, a second type SI message comprises at least one system information block (SIB), and the delivery mode may be either periodic broadcast or on-demand basis. The transmitter circuitry36of radio access node22(17) is configured to transmit the first type system information over the radio interface24to the wireless terminal26(17), as shown by arrow19-1inFIG. 19.

In theFIG. 19example embodiment and mode it is assumed that wireless terminal26(17) is presently concerned with acquiring a second type SI message for which the delivery mode is periodic broadcast. As such, the terminal processor40is controlling terminal receiver46to initiate a SI message acquisition process for a periodically broadcasted second type SI message. But it may turn out, however, after initiating the SI message acquisition process, that the expected periodically broadcasted second type SI message(s) are not received. Non-receipt of the periodically broadcasted second type SI message(s) may be for any of several reasons, including the fact that the broadcast of the periodically broadcasted second type SI message was at the behest of another wireless terminal, with the wireless terminal26(17) essentially being a third-party beneficiary of the broadcasts, and the access node has by now terminated the broadcast of the second type SI message intended for the another wireless terminal.

Thus, as in theFIG. 12example embodiment and mode, system information acquisition failure detector80may make a determination of a failure of the SI message acquisition process. When so doing, in an example embodiment and mode, the terminal processor40, working in response to or with system information acquisition failure detector80, is configured to initiate acquisition of the first type system information. That is, the terminal processor40is configured, upon a failure of the SI message acquisition process involving a periodically broadcasted second type SI message, to initiate acquisition of the first type system information, e.g., to again request the first type system information (Minimum SI) from the radio access node22(17). InFIG. 19such request for first type system information is depicted by arrow19-4(there being no arrow19-2or arrow19-3inFIG. 19).

FIG. 20is an exemplary message flow diagram of a periodic broadcast based SI acquisition procedure wherein system information acquisition failure is detected. As shown by act20-0, wireless terminal26, in either RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state stores the content of SIB #A with the validity information, valueTag=a, si-AreaID=2, which the wireless terminal has previously received. From the currently serving access node, as act20-1the wireless terminal may obtain SIB1 as Minimum SI, e.g., first type system information. Obtaining of the SIBI is also depicted by arrow19-1inFIG. 19. As shown inFIG. 13, the SIB1 includes the scheduleInfoList, which in turn may include one or more schedulingInfo information elements. An example scheduleInfoList for this scenario is shown in previously-discussed Table 1, wherein the k'th schedulingInfo indicates that the SI message associated with this schedulingInfo (SI #k, hereafter), containing SIB #A, will be available by broadcast. Furthermore, the otherSIBInfo corresponding to SIB #A indicates that the validity information of SIB #A is valueTag=b, si-AreaID=3. It is assumed hereafter that whenever the wireless terminal receives SIB1, it has already received MIB beforehand.

Having received the SIB1 as Minimum SI, e.g., first type system information, the wireless terminal26(17) knows when the radio access node22(17) is expected to broadcast the system information for the sought second type SI, e.g., SIB #A. As such, the terminal processor40of wireless terminal26(17) begins the SI message acquisition (represented by act20-3inFIG. 20).

In the SI message acquisition20-3, the wireless terminal monitors signals from the access node attempts to obtain the SI messages in the designated SI windows derived from the scheduling information (scheduleInfo) in the SIB1, and thereby attempts to receive the requested SI #k. The SI windows are shown by dotted rectangles inFIG. 20.FIG. 20shows by act20-3a, act20-3b, and act20-3cthree successive transmissions of the requested SI #k, all of which are unsuccessful. A tail of a vertical down-pointing arrow in the SI message acquisition depiction ofFIG. 20is associated with start of the SI message acquisition, while the head of the same vertical down-pointing arrow is associated with end of the SI message acquisition. InFIG. 20, the SI message acquisition20-3utterly fails. Failure of the SI message acquisition is determined by system information acquisition failure detector80which, as indicated above, makes a determination of a failure of the SI message acquisition process based on a termination condition. Examples of the termination condition are described herein.

Upon detection of failure of the SI message acquisition process, as act20-4the terminal processor40initiates (re)acquisition of the first type system information, e.g., the MINIMAL SI or SIB1, as shown by arrow14-4inFIG. 14. The wireless terminal26(14) thus attempts to again acquire the first type system information, in hopes that the SI message acquisition process can thereafter be repeated and perhaps in such repeat of the SI message acquisition process the requested SI message will be obtained. In an example implementation, the wireless terminal26(14) may optionally reacquire MIB prior to reacquisition of SIB1. Accordingly, not having a valid version of a stored SIB, upon detection of failure of the SI message acquisition process, the terminal processor40initiates (re)acquisition of the first type system information.

FIG. 21is a flowchart showing basic, representative, example acts or steps performed by the wireless terminal ofFIG. 19. Act21-1comprises receiving first type system information (SI) from the base station apparatus. As indicated previously, the first type system information comprises: availability of a second type SI message; scheduling information for the SI message; an indication of a delivery mode for the second type SI message, the delivery mode being either periodic broadcast or on-demand basis; and, at least one termination condition for determination of a failure of an SI message acquisition process. Act21-2comprises initiating the SI message acquisition process for a periodically broadcasted second type SI message. Act21-3comprises determining a failure of the SI message acquisition process. Act21-4comprises, upon a failure of the SI message acquisition process, initiating acquisition of the first type system information.

FIG. 22is a flowchart showing basic, representative, example acts or steps performed by the access node ofFIG. 19. Act22-1comprises transmitting first type system information (SI) from the base station apparatus. The first type system information comprises, e.g., configuration parameters to configure for at least one termination condition for determination of a failure of an SI message acquisition process. Act22-2comprises broadcasting the periodic broadcast-based SI messages.

As in theFIG. 12embodiment and mode, wireless terminal26(17) may use a counter, which is incremented at every SI window of a particular SI message, e.g. SI #k, and may end the SI message acquisition when the requested SI message(s) are successfully received, or when the counter reaches a maximum counter value. The system information acquisition failure detector80ofFIG. 19may comprise the aforementioned SI window counter82, shown inFIG. 17A, which may count up to reach a maximum value, or count down from a pre-set value to zero. Such maximum or pre-set value may be configured by the radio access node22(17). The SI window counter82is incremented (or decremented) in a case in which the requested SI message was not received by the end of one reception opportunity, e.g., a case in which the requested SI message was not received by the end of an SI window.

Also as in theFIG. 12embodiment and mode, wireless terminal26(17) may start a timer at the beginning of the SI message acquisition, and may end the SI message acquisition when the requested SI message(s) are successfully received, or when the timer expires. The system information acquisition failure detector80ofFIG. 19may comprise the aforementioned SI message acquisition process timer84shown inFIG. 17Bwhen the termination condition comprises expiration of acquisition process timer84. The SI message acquisition process timer84is started at the beginning of the SI message acquisition process. The timer expiration value may be configured by the radio access node22(17).

Thus, similar to the example embodiments and modes ofFIG. 2andFIG. 12, for acquisition of periodic broadcast-based SI message(s) as shown inFIG. 19an extra mechanism to terminate the SI message acquisition may employed. In one configuration, the wireless terminal may use a counter, which is incremented at every SI window of a particular SI message (e.g. SI #k). In this configuration, the SI message acquisition triggered by acquiring may end when the requested SI message is successfully received, or when the counter reaches a maximum counter value. (It should be understood that this counter implementation is logically identical to an alternative implementation, wherein the counter is set with the maximum counter value at the beginning of the SI message acquisition and decremented upon the end of the SI window. In this implementation, the SI message acquisition may end when the counter becomes a pre-determined value, such as zero). In another configuration the wireless terminal starts a timer at the beginning of the SI message acquisition. In this configuration, the SI message acquisition may end when the requested SI message is successfully received, or when the timer expires. Similar to the embodiment ofFIG. 12, and as understood byFIG. 18AandFIG. 18B, the maximum counter value, or the timer value, may be common for all SIB types, per-SIB type basis or per-SI message basis, may be pre-configured or configured by network via system information.

It should further be understood that a wireless terminal may be attempting to receive some second type SI by periodic broadcast, and one or more other second type SI by on-demand delivery. Hence, in a further example embodiment and mode the terminal processor40of a wireless terminal, such as wireless terminal26(17), may be configured to both detect failure of a SI message acquisition process for broadcasted second type system information and detect failure of a SI message acquisition process for on-demand second type system information. For this reason the terminal processor40of wireless terminal26(17) shows terminal processor40and SI processor56in particular as still comprising on-demand Other SI request generator72. Thus it is possible in some modes for both the process ofFIG. 14andFIG. 19to be executing essentially currently.

When a wireless terminal26is capable of both detecting failure of a SI message acquisition process for broadcasted second type system information and detecting failure of a SI message acquisition process for on-demand second type system information, the wireless terminal26may have separate termination conditions for each process. For that reason the wireless terminal26may comprise plural SI window counters82and/or plural SI message acquisition process timers84. For example, the wireless terminal may have a first SI window counter82(B) for a SI message acquisition process for broadcasted second type system information; and a second SI window counter82(D) for a SI message acquisition process for on-demand second type system information. Or, for example, wireless terminal may have a first SI message acquisition process timer84(B) for a SI message acquisition process for broadcasted second type system information; and a second SI message acquisition process timer84(D) for a SI message acquisition process for on-demand second type system information.

Furthermore, the counter configuration or the timer configuration for acquisition of periodic broadcast-based SI message(s) may be configured via system information (e.g. SIB1) separately from the configuration for acquisition of on-demand based SI message(s). In this case, SIB1 shown inFIG. 13Cwith two separate counter configurations (si-MaxAcqAttemptsOnDemand and si-MaxAcqAttemptsPeriodic) orFIG. 13Dwith two separate timer configurations (T #x for on-demand and T #y for periodic broadcast) may be used. Alternatively, the counter/timer configuration common for on-demand and periodic broadcast-based SI message acquisition may be configured. In this case, SIB1 shown inFIG. 13A(common counter configuration) orFIG. 13B(common timer configuration) may be used.

The aforementioned more general 3GPP TS SI acquisition procedure for a UE to acquire the AS- and NAS information may be modified in part, e.g., for acquisition of an SI Message, for the example embodiment and mode ofFIG. 19as shown below. As indicated earlier, the counters (SI window counter82(B) and SI window counter82(D)) or the timers (SI message acquisition process timer84(B) and SI message acquisition process timer84(D)) may be identical, or alternatively separately configured.

LISTING 3When acquiring an SI message, the UE shall:1>determine the start of the SI-window for the concerned SI message as follows:1> if SI message acquisition is not triggered due to UE request:2> Set the counter SI window counter 82(B) to 0 (or Start timer SI message acquisitionprocess timer 84(B));2>receive DL-SCH using the SI-RNTI from the start of the SI-window and continueuntil the end of the SI-window whose absolute length in time is given by si-WindowLength, or until the SI message was received;2>if the SI message was not received by the end of the SI-window, increment thecounter SI window counter 82(B), repeat reception at the next SI-window occasion forthe concerned SI message;2>if the counter SI window counter 82(B) is equal to [configured maximum value] (ortimer SI message acquisition process timer 84(B) expires)3> Initiate the SI acquisition procedure as defined in sub-clause 5.2.2.3.1> else if SI message acquisition is triggered due to UE request:2> Set the counter SI window counter 82(D) to 0 (or Start timer SI message acquisitionprocess timer 84(D));2> [receive DL-SCH using the SI-RNTI from the start of the SI-window and continueuntil the end of the SI-window whose absolute length in time is given by si-WindowLength, or until the SI message was received];2>[if the SI message was not received by the end of the SI-window, increment thecounter SI window counter 82(D) , repeat reception at the next SI-window occasionfor the concerned SI message];2>if the counter SI window counter 82(D) is equal to [configured maximum value] (ortimer SI message acquisition process timer 84(D) expires)3> Initiate the SI acquisition procedure as defined in sub-clause 5.2.2.3.

Limiting Duration of System Information Message Acquisition by Number of Modification Periods

FIG. 23shows an example communications system20(23) comprising wireless terminal26(23) configured to limit duration of system information message acquisition based on a number of modification periods. The example embodiment and mode ofFIG. 23may considered to be similar to previous embodiments and modes which employed a counter, but instead of counting a number of SI windows, the counter in the example embodiment and mode ofFIG. 23essentially counts a number of modification periods as a measure for determining when to terminate the SI message acquisition process.

The elements of access node22(23) and wireless terminal26(23) ofFIG. 23are essentially identical to the corresponding elements respective access node22and wireless terminal26ofFIG. 2that have same base reference numbers, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(23) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(23) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70.

FIG. 23also shows that wireless terminal26(23) comprises system information message acquisition terminator90. The terminal processor40, and particularly SI processor56, may comprise or constitute the system information message acquisition terminator90. The SI processor56performs an SI message acquisition process to acquire the system information transmitted from the network, e.g., from access node22(23). The system information message acquisition terminator90is configured to terminate the SI message acquisition process after attempting SI message acquisition for a first number of modification periods. Thus, the system information message acquisition terminator90essentially serves as and/or comprises a counter for counting up to the first number of modification periods as criteria for determining when to end the SI message acquisition process.

A modification period is a preconfigured time duration where the content of the system information is unchanged. A modification period may be defined as a time period wherein the system information may be transmitted a number of times with the same content (except some predefined parameters), as defined by its own scheduling. A modification period can be any predefined time duration established by any predetermined convention. For example, the modification periods may be the same or akin to the concept of modification period as defined for LTE in 3GPP TS 36.304, 38.304, 36.331 and/or 38.331, all of which are incorporated herein by reference.

FIG. 24depicts an example configuration of modification periods. In each modification period, defined between two adjacent modification period boundaries, there may be one or more transmission opportunities (e.g., SI windows) allocated for a designated SI message. The access node22(23) may choose to transmit, or not to transmit, the SI message on these opportunities.

The first number of modification periods may be obtained by any appropriate manner, and preferably is configured at the wireless terminal26(23) by access node22(23). For example, the node SI generator54may comprise modification period limit generator92, which generates the first number of modification periods which is sent to and used by wireless terminal26(23) for determining when to terminate the SI message acquisition process. For example,FIG. 23shows by arrow23-1transmission of an indication of the first number of modification periods to wireless terminal26(23). Alternatively, the first number of modification periods may be pre-configured at the wireless terminal26(23), e.g., stored in memory of wireless terminal26(23) via input other from the radio access network such as through user interface48upon programming of wireless terminal26(23).

In one configuration, transmission of such an SI message, either initiated autonomously by the radio access node or triggered by an on-demand request from a wireless terminal, may be started at the first boundary of a modification period. Alternatively, in another configuration, transmission of such an SI message may start at any SI window of a modification period. Nonetheless, in either configuration the SI transmission may end (if the access node decides to end) at the last SI window of a modification period.

FIG. 25is a flowchart showing basic, representative, example acts or steps performed by the wireless terminal ofFIG. 23. Act25-1comprises the wireless terminal26(3), e.g., via terminal receiver46, receiving system information (SI) from the radio access node in a SI message acquisition process. Act25-2comprises terminating the SI message acquisition process after attempting SI message acquisition for a first number of modification periods. As explained herein, a modification period is a preconfigured time duration where the content of the SI is unchanged. The first number of modification periods may be assessed or counted from a prescribed event, such as a network event or action of the wireless terminal. Act25-2may be performed by system information message acquisition terminator90, which may be realized by SI processor56.

FIG. 26is a flowchart showing basic, representative, example acts or steps performed by the access node ofFIG. 23. Act26-1comprises configuring the wireless terminal with the first number of modification periods. Act26-1may be performed by modification period limit generator92, and transmission of the first number of modification periods from access node22(23) to wireless terminal26(23) may be shown by arrow23-1inFIG. 23. Act26-2comprises transmitting system information (SI) to the wireless terminal.

The example embodiment and mode ofFIG. 27is a special case of the example embodiment and mode ofFIG. 23in which the system information takes the form of first type system information and second type system information, as previously discussed in conjunction with other example embodiments and modes. The elements of access node22(27) and wireless terminal26(27) ofFIG. 27are essentially identical to the corresponding elements respective access node22and wireless terminal26ofFIG. 2that have same reference numbers, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(23) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(23) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70. Further, like the example embodiment and mode ofFIG. 23, the wireless terminal26(27) ofFIG. 27comprises system information message acquisition terminator90and the access node22(27) ofFIG. 27comprises the modification period limit generator92. The system information message acquisition terminator90of wireless terminal26(27) is likewise configured to terminate the SI message acquisition process after attempting SI message acquisition for a first number of modification periods.

The node processor30of radio access node22includes a system information (SI) generator54similar to that of the example embodiment and mode ofFIG. 2wherein at least some of the system information generated and provided by the system information (SI) generator54is Minimum System Information (Minimum SI), also known as first type system information, represented by Minimum SI handler54M. Some of the system information may be Other system information (Other SI), also known as second type system information, represented by Other SI handler54O inFIG. 2. The wireless terminal26(27) ofFIG. 27may use the system information (SI) generated by radio access node22(27), and some of the Minimum SI may inform the wireless terminal26of the availability of the Other IS.

In the example embodiment and mode ofFIG. 27, the terminal receiver46is configured to receive first type system information (SI) from the radio access node. As understood herein, the first type SI comprises (1) availability of second type SI messages, and (2) an indication of a delivery mode for each of the second type SI messages. The second type SI message comprises at least one system information block (SIB). The delivery mode is either broadcast or on-demand basis. Further, in the example embodiment and mode ofFIG. 27, like the embodiment and mode ofFIG. 2, the terminal receiver46is configured to transmit an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand. Such SI request message is understood with reference to arrow2-2of the embodiment and mode ofFIG. 2and discussion thereof. In the embodiment and mode ofFIG. 27, the modification period is thus a preconfigured time duration where the content of the first type and second type system information is unchanged.

As was mentioned above, the number of modification periods that constitutes the first number of modification periods may be pre-configured in the wireless terminal as well as in the access node. Alternatively, the first number of modification periods may be configured by the access node via the minimum system information (e.g. SIB1). In the latter case, SI-SchedulingInfo in SIB1, mentioned in earlier example embodiments and modes, may be augmented to comprise a parameter, such as si-NumModBoundaries. The parameter si-NumModBoundaries, may express the first number of modification periods, and thereby to instruct the wireless terminal26(27) regarding the duration of the SI message acquisition in units of modification period boundaries. This parameter may apply to any cases of the SI message acquisition (on-demand request or not). If the wireless terminal26(27) is allowed to start the SI message acquisition in the middle of a modification period, in one configuration si-NumModBoundaries may include the modification period where the SI reception is started. In another configuration si-NumModBoundaries may include modification periods starting at the next modification period boundary. Listing 4A, shown below, illustrates use of a parameter, such as si-NumModBoundaries, to express the first number of modification periods.

Listing 4B is an alternative implementation of SI-SchedulingInfo that configures the number of modification period, wherein two parameters, si-NumModBoundariesOnDemand and si-NumModBoundariesPeriodic, may configure the duration of the SI message acquisition. The parameter NumModBoundariesOnDemand may be used in the scenario disclosed in the second embodiment, whereas the parameter NumModBoundariesPeriodic may be used in the scenario disclosed in a previous embodiment.

The procedure of the example embodiments and modes ofFIG. 23andFIG. 27may be akin to Listing 3, except that the counters (N1, N2) are replaced by si-NumModBoundaries. Alternatively, the counters may be replaced by si-NumModBoundariesPeriodic and si-NumModBoundariesOnDemand respectively.

Requiring Wireless Terminal to Wait an Offset Time Before Beginning SI Message Acquisition

FIG. 28shows an example communications system20(28) wherein wireless terminal26(28) may be configured, e.g., via the minimum system information (e.g. SIB1), with at least one offset value. The offset value indicates a duration, e.g., of time, that wireless terminal26(28) is required to wait before starting a SI message acquisition process.

The elements of access node22(28) and wireless terminal26(28) ofFIG. 28may be essentially identical to the corresponding elements respective access node22and wireless terminal26ofFIG. 2that have same base reference numbers, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(28) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(28) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70.

In the example embodiment and mode ofFIG. 28, the terminal receiver46is configured to receive first type system information (SI) from the radio access node. As understood herein, the first type SI comprises (1) availability of second type SI messages, and (2) an indication of a delivery mode for each of the second type SI messages. The second type SI message comprises at least one system information block (SIB). The delivery mode is either broadcast or on-demand basis. Further, in the example embodiment and mode ofFIG. 27, like the embodiment and mode ofFIG. 2, the terminal receiver46is configured to transmit an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand.

FIG. 28also shows that wireless terminal26(28) comprises system information acquisition delay controller94. The terminal processor40, and particularly SI processor56, may comprise or constitute the system information acquisition delay controller94. In theFIG. 28example embodiment and mode, the system information acquisition delay controller94is configured to require the SI processor56to wait, after receiving from the radio access node an acknowledgement for the SI request message, for a time duration specified by an offset value, before performing an SI message acquisition process.

FIG. 28further shows that the access node22(28) comprises offset value generator96. The node SI generator54of access node22(28) generates first type system information which is used to configure the wireless terminal with an offset value OFF. The offset value OFF is used to instruct the wireless terminal26(28) to wait, for a time duration specified by the offset value OFF, after the wireless terminal receives from access node22(28) an acknowledgement for the SI request message, before the wireless terminal performs an SI message acquisition process. Receipt from access node22(28) of an acknowledgement for the SI request message is understood to be an acknowledgment of the request message shown as arrow2-2ofFIG. 2.FIG. 28shows transmission of the offset value OFF as arrow28-1.

FIG. 29is a flowchart showing basic, representative, example acts or steps performed by the wireless terminal wireless terminal26(28) ofFIG. 28. Act29-1comprises receiving first type system information (SI) from the radio access node. As explained previously, the first type system information may comprise availability of second type SI messages. Act29-2comprises transmitting, to access node22(28), an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand. Act29-2may be performed by terminal frame/signal handler72in conjunction with terminal transmitter44, and is understood with reference to message2-2of the example embodiment and mode ofFIG. 2. Act29-3comprises, after receiving from the radio access node an acknowledgement for the SI request message and before performing an SI message acquisition process, waiting for a time duration specified by an offset value. The wait of act29-3may be assessed and controlled by system information acquisition delay controller94. Act29-4comprises performing the SI message acquisition process after the wait of the duration established by the offset value OFF.

FIG. 30is a flowchart showing basic, representative, example acts or steps performed by the access node access node22(28) ofFIG. 28. Act30-1comprises the access node22(28) transmitting the first type system information (SI) to the wireless terminal. Act30-1may be performed by node SI generator54in conjunction with core node transmitter34. Act30-2comprises the access node22(28) receiving an SI request message to request at least one second type SI message. The SI request message may be understood with reference to message2-2ofFIG. 2, for example, and may be received via node receiver36and handled by request handler72. Act30-3comprises the access node22(28) waiting for a time duration specified by the offset value (OFF). Act3-4comprises the access node22(28) starting to transmit the second type SI message. The offset value OFF may be generated by offset value generator96and transmitted from access node22(28) to wireless terminal26(28) by core node transmitter34. As explained previously, the offset value OFF serves to instruct the wireless terminal to wait for a time duration specified by an offset value after the wireless terminal receives, from the radio access node, an acknowledgement for the SI request message, before the wireless terminal performs an SI message acquisition process.

FIG. 31illustrates the scenario of the example embodiment and mode ofFIG. 28, where wireless terminal26(28), after completing the SI request procedure31-2, waits for the specified duration (offset value OFF) before starting the SI message acquisition procedure31-3.

In some configurations, the offset value (offset value OFF) may be used in a case where the access node22(28) desires to defer the transmission of an SI message from the reception of an SI request.

In one configuration the offset value may be provided in units of SI windows. In the SI window unit configuration, the wireless terminal may skip the specified number of SI windows.

In another configuration, the offset value may be provided in units of modification periods, which have been discussed above. In this modification period offset value embodiment, the wireless terminal may postpone the SI message acquisition until the specified number of modification periods is consumed.

Furthermore, in another configuration, the offset value may be a time duration specifying the time (e.g. in units of milliseconds). In this time case, after the successful completion of the SI request procedure, the wireless terminal may wait for the specified time and may start the SI message acquisition from the following SI window.

The offset value may be pre-configured in the wireless terminal26(28) as well as in the access node22(28). Alternatively, as explained above, the offset value OFF may be configured by the access node22(28), e.g., via the minimum system information (e.g. SIB1).

In the latter case, e.g., configuration of offset value OFF by the access node22(28), Listing 5A, Listing 5B and Listing 5C below show example formats of SI-SchedulingInfo, with the offset configured by the number of SI windows, the number of modification period, and the time duration, respectively. Listing 5D shows the case where the access node is able to choose one of these configurations, e.g., the configuration of the offset value OFF being expressed in terms of number of SI windows, number of modification periods, or time duration.

The counter values or the timers to limit the duration of a SI message acquisition, disclosed in a previous embodiment, may be started upon or after the end of the waiting duration specified by the offset value.

Limiting Duration of System Information Message Acquisition by Number of Transmission Opportunities

FIG. 32shows an example communications system20(32) comprising wireless terminal26(32) configured to limit duration of system information message acquisition based on a number of transmission opportunities. The number of transmission opportunities may mean the number of transmission opportunities that the access node is scheduling for transmission of a certain system information (SI) message. The number of transmission opportunities may be expressed in terms of any appropriate unit or event(s), such as system information windows or modification periods, for example, and may express the transmission opportunities with reference to timing of a certain network event or action of the wireless terminal.

The elements of access node22(32) and wireless terminal26(32) ofFIG. 32are essentially identical to the corresponding elements respective access node22and wireless terminal26ofFIG. 2that have same base reference numbers, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(32) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(32) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70.

FIG. 32also shows that wireless terminal26(32) comprises system information message acquisition terminator90(32). The terminal processor40, and particularly SI processor56, may comprise or constitute the system information message acquisition terminator90(32). The SI processor56performs an SI message acquisition process to acquire the system information transmitted from the network, e.g., from access node22(32). The system information message acquisition terminator90(32) is configured to terminate the SI message acquisition process after attempting SI message acquisition for a prescribed number of transmission opportunities. The prescribed number of transmission opportunities may be in time reference, e.g., occur after, a prescribed event such as a network event or an action by the wireless terminal26(32). Thus, the system information message acquisition terminator90(32) essentially serves as and/or comprises a counter for counting up to a prescribed number of transmission opportunities as criteria for determining when to end the SI message acquisition process.

The number of transmission opportunities may be obtained by any appropriate manner, and preferably is configured at the wireless terminal26(32) by access node22(32). For example, the node SI generator54may comprise transmission opportunity generator92(32), which generates a number of transmission opportunities which is sent to and used by wireless terminal26(32) for determining when to terminate the SI message acquisition process. For example,FIG. 32shows by arrow32-1transmission of an indication of the number of transmission opportunities to wireless terminal26(32). Alternatively, the number of transmission opportunities may be pre-configured at the wireless terminal26(32), e.g., stored in memory of wireless terminal26(32) via input other from the radio access network such as through user interface48upon programming of wireless terminal26(32).

FIG. 33is a flowchart showing basic, representative, example acts or steps performed by the wireless terminal ofFIG. 32. Act33-1comprises the wireless terminal26(32) e.g., via terminal receiver46, receiving first type system information (SI) from the radio access node in a SI message acquisition process. Act33-2comprises terminating the SI message acquisition process after attempting the SI message acquisition for a prescribed number of transmission opportunities. Act33-2may be performed by system information message acquisition terminator90(32), which may be realized by SI processor56.

FIG. 34is a flowchart showing basic, representative, example acts or steps performed by the access node ofFIG. 32. Act34-1comprises configuring the wireless terminal with a prescribed number of transmission opportunities for a system information message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message. Act34-1may be performed by transmission opportunity generator92(32), and transmission of the number of transmission opportunities from access node22(32) to wireless terminal26(32) may be shown by arrow32-1inFIG. 32. Act34-2comprises transmitting system information (SI) to the wireless terminal, e.g., for the prescribed number of transmission opportunities.

The example embodiment and mode ofFIG. 35is a special case of the example embodiment and mode ofFIG. 32in which the system information takes the form of first type system information and second type system information, as previously discussed in conjunction with other example embodiments and modes. The elements of access node22(35) and wireless terminal26(35) ofFIG. 35are essentially identical to the corresponding elements respective access node22and wireless terminal26ofFIG. 2that have same reference numbers, except as otherwise indicated herein. In terms of likeness, for example, the radio access node22(35) comprises node processor30and node transceiver circuitry32, with the node processor30comprising, e.g., node frame/signal scheduler/handler50, system information (SI) generator54, and node RRC controller60. Similarly, the wireless terminal26(35) comprises terminal processor40, terminal transceiver circuitry42, with terminal processor40comprising terminal frame/signal scheduler/handler52, system information (SI) processor56, and terminal RRC controller70. Further, like the example embodiment and mode ofFIG. 32, the wireless terminal26(35) ofFIG. 35comprises system information message acquisition terminator90(32) and the access node22(35) ofFIG. 35comprises the transmission opportunity generator92(32). The system information message acquisition terminator90of wireless terminal26(35) is likewise configured to terminate the SI message acquisition process after attempting SI message acquisition for a prescribed number of transmission opportunities.

The node processor30of radio access node22(35) includes a system information (SI) generator54similar to that of the example embodiment and mode ofFIG. 2wherein at least some of the system information generated and provided by the system information (SI) generator54is Minimum System Information (Minimum SI), also known as first type system information, represented by Minimum SI handler54M. Some of the system information may be Other system information (Other SI), also known as second type system information, represented by Other SI handler54O inFIG. 2. The wireless terminal26(35) ofFIG. 35may use the system information (SI) generated by radio access node22(35), and some of the Minimum SI may inform the wireless terminal26of the availability of the Other IS.

In the example embodiment and mode ofFIG. 35, the terminal receiver46is configured to receive first type system information (SI) from the radio access node. As understood herein, for the example embodiment and mode ofFIG. 35the first type SI comprises (1) availability of SI messages, (2) an indication of a delivery mode for each of the SI messages, and (3) the prescribed number of transmission opportunities for the SI messages. Each of the SI messages comprises at least one second type system information block (SIB). The delivery mode is either broadcast or on-demand basis. Further, in the example embodiment and mode ofFIG. 27, like the embodiment and mode ofFIG. 2, the terminal receiver46is configured to transmit an SI request message to request at least one SI message indicated as on-demand delivery in a case where the delivery mode of the SI message is on-demand. Such SI request message is understood with reference to arrow2-2of the embodiment and mode ofFIG. 2and discussion thereof. Thus, in the embodiment and mode ofFIG. 35, the prescribed number of transmission opportunities for at least one SI message indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI.

Thus, in the example embodiment and mode ofFIG. 35, in access node22(35) the transmitter circuitry34is configured to transmit first type system information (SI) for theFIG. 35embodiment and mode to the wireless terminal. The node receiver circuitry36configured to receive an SI request message to request at least one SI message. The node processor circuitry30and transmission opportunity generator92(32) configures the wireless terminal, e.g., via the first type SI, with the prescribed number of transmission opportunities for at least one SI message. As explained previously, in theFIG. 35embodiment and mode the prescribed number of transmission opportunities indicates at least how many transmission opportunities the radio access node is scheduling to transmit the second type SI message from the time of the transmission of the first type system information

In theFIG. 35example embodiment and mode, the minimum system information may indicate, for each SI message, the number of transmission opportunities that the access node is scheduling for transmission. For an SI message that is currently broadcasted, the number of transmission opportunities may indicate how many of the prescribed number of transmission opportunities are still remaining at the time of transmission for the minimum system information. Meanwhile, for an SI message that is NOT currently broadcasted (to be requested on-demand), the number of transmission opportunities may indicate at least how many transmission opportunities that the access node will use for the SI message once it is requested. In one example implementation of theFIG. 35example embodiment and mode, one transmission opportunity may be an SI window. In another example implementation of theFIG. 35example embodiment and mode, one transmission opportunity may be a modification period.

FIG. 36Aillustrates one exemplary operation scenario of the example embodiment and mode ofFIG. 35for the case or example implementation in which the transmission opportunities are SI windows. The first SIB1 transmission inFIG. 36Aindicates that the broadcast status (BS) (e.g. si-BroadcastStatus) of the SI message of concern is onDemand. Furthermore, the SIB1 also indicates that the number of transmission opportunities (TOs) is 6, meaning that six transmission opportunities (i.e., six SI windows) will be used to transmit the SI message once the SI message is requested. After the wireless terminal sends an SI request, the access node22(35) starts transmitting the SI message on the six subsequent SI windows. In the scenario ofFIG. 36A, the second SIB1 transmission, occurring after the fourth SI window, indicates two remaining TOs for the SI message that is being broadcasted (BS=broadcast). After consuming these six TOs, the TO indicated in the third SIB1 transmission goes back to 6, whereas BS becomes onDemand.

In the scenario ofFIG. 36A, after the successful completion of the SI request procedure, the wireless terminal26(35) may perform the SI message acquisition until it successfully receives the SI message or until it consumes the number of SI windows specified by the TO value received in the first SIB1. Furthermore, the wireless terminal26(35) may not attempt to receive the second SIB1 transmission (since not required to receive it). However, the second SIB1 transmission may possibly be received by another wireless terminal, which may attempt to receive the SI message in the next two subsequent SI windows.

In addition, when combined with BS=broadcast, the transmission opportunities (TOs) in SIB1 may be also used to provide the wireless terminal26(35) the maximum SI windows allowed in an SI message acquisition. For example, as illustrated inFIG. 36B, the wireless terminal26(35) may receive the first SIB1 transmission where TO=12 and BS=broadcast. The wireless terminal26(35), if desired, may start the SI message acquisition in up to the 12 subsequent SI windows of the SI message. After consuming all these SI windows without successful SI message acquisition, the wireless terminal26(35) may reacquire SIB1, as disclosed in the previous embodiments. It should be noted that the access node22(35) may choose to continue transmitting the SI message after 12 SI windows, as TO in SIB1 in this case is used only in sake of the wireless terminal26(35) to provide the maximum attempts (in units of SI windows) before the SIB1 reacquisition.

FIG. 37is another exemplary scenario where the transmission opportunities (TOs) are configured in units of modification periods. The first SIB1 transmission in Modification Period N (MP(N)) indicates two TOs (i.e., two modification periods) will be used for the transmission of a SI message. In the first modification period a SI request for the SI message is sent from the wireless terminal26(35), followed by the transmission of the SI message from access node22(35) in the subsequent designated SI windows, for the duration of two modification periods. In one configuration, as shown inFIG. 37, the configured TOs may include the modification period where the SI request occurs (MP(N)). In this case, as shown inFIG. 37, TO in the SIB1 transmitted in MP(N+1) may be decremented by one (i.e. TO=1). In another configuration, TO in the SIB1 may not include the modification period where the SI request occurs (MP(N)). In this case, TO=2 in MP(N+1), TO=1 in MP(N+2), and the SI message transmission may continue until the end of MP(N+2).

Listing 5 shows an example format and coding of SIB1 for the example embodiment and mode ofFIG. 35, where si-NumTransmissionOpportunities provide the number of TOs disclosed above, in units of SI-windows (or alternatively in units of modification periods).

Features from each of the example embodiments and modes described herein, including the example embodiments and modes ofFIG. 2,FIG. 23,FIG. 27,FIG. 28,FIG. 32, andFIG. 35may be combined with one another. Further, features of the “Example Embodiments” enumerated hereinafter may also be used in conjunction with one another.

The program instruction memory192may comprise coded instructions which, when executed by the processor(s), perform acts including but not limited to those described herein. Thus is understood that each of node processor30and terminal processor40, for example, comprise memory in which non-transient instructions are stored for execution.

The memory194, or computer-readable medium, may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, flash memory or any other form of digital storage, local or remote, and is preferably of non-volatile nature. The support circuits199are coupled to the processors190for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like.

Further, it should be understood that, when a processor or processor circuitry is mentioned in conjunction with any of the preceding example embodiments and modes, it should be understood that the device hosting the processor, whether wireless terminal or access node, may comprise at least one processor and at least one memory including computer program code, the memory and the computer program code being configured to, working with the at least one processor, to cause the host device to perform the functions afore-described.

Thus, the technology disclosed herein solves problems in the field of telecommunications, including problems in telecommunications nodes such wireless terminals and access nodes, as well as computers/processors and hardware comprising such nodes. System information is of utmost importance to the operation of telecommunication nodes, so that each node can obtain the necessary network information to coordinate and communicate with other nodes and to perform its desired functions. The system information is quite extensive and complex, and may be changeable/updateable due to network and operating conditions, for example. Efficiently obtaining and using the system information is challenging, particularly in view of numerous other telecommunications functions that may be simultaneously on-going based on the system information. The technology disclosed herein solves problem that may occur when SI messages are not timely received by, e.g., curtailing SI message acquisitions and initiating remedial measures such as re-acquiring SIB1. The technology disclosed herein thus avoids waste of time and undue expenditure of processing resources.

The technology of this application thus encompasses but is not limited to the following example embodiments, example features, and example advantages:

A wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the wireless terminal comprising:

receiver circuitry configured to receive system information (SI) from the radio access node

processor circuitry configured toperform an SI message acquisition process to acquire the system information, andterminate the SI message acquisition process after attempting SI message acquisition for a first number of modification periods, a modification period being a preconfigured time duration where the content of the system information is unchanged.

The wireless terminal of Example Embodiment 1, wherein the receiver circuitry is configured to receive first type system information (SI) from the radio access node, the first type SI comprising:

availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);

an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

the wireless terminal further comprising transmitter circuitry configured to transmit an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand; and

wherein the modification period is a preconfigured time duration where the content of the first type and second type system information is unchanged.

The wireless terminal of Example Embodiment 1, wherein the first number of modification periods is preconfigured.

The wireless terminal of Example Embodiment 2, wherein the first number of modification periods is configured by the radio access node via the first type SI.

The wireless terminal of Example Embodiment 2, wherein the wireless terminal is further configured with a second number of modification periods, the first number of modification periods being used for the SI message acquisition process of an SI message after transmitting the SI request message, whereas the second number of modification periods being used for the SI message acquisition process without transmitting the SI request message.

The wireless terminal of Example Embodiment 5, wherein the second number of modification periods is preconfigured.

The wireless terminal of Example Embodiment 5, wherein the second number of modification periods is configured by the radio access node via the first type SI.

The wireless terminal of Example Embodiment 2, wherein, in the case where the SI message acquisition process is terminated after the first number of modification periods, the wireless terminal initiates acquisition of the first type system information.

The wireless terminal of Example Embodiment 5, wherein, in the case where the SI message acquisition process is terminated after the second number of modification periods, initiate acquisition of the first type system information.

A radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, the radio access node comprising:

transmitter circuitry configured to transmit system information (SI) to the wireless terminal

processor circuitry configured to configure the wireless terminal with a first number of modification periods, the first number of modification periods being a termination condition of a SI message acquisition process, the modification period being a preconfigured time duration where the content of the system information is unchanged.

The radio access node of Example Embodiment 10, wherein:

the transmitter circuitry is configured to transmit first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

receiver circuitry configured to receive an SI request message to request at least one second type SI message;

the processor circuitry is configured to configure the wireless terminal via the first type SI message with the first number of modification periods, the first number of modification periods being a termination condition of a second type SI message acquisition process, the modification period being a preconfigured time duration where the content of the first type and second type SI is unchanged.

The radio access node of Example Embodiment 11, wherein the radio access node is further configured to configure the wireless terminal via the first type SI with a second number of modification periods, the first number of modification periods being used for the SI message acquisition process of an SI message after transmitting the SI request message, whereas the second number of modification periods being used for the SI message acquisition process without transmitting the SI request message.

The radio access node of Example Embodiment 11, wherein after receiving the SI request message requesting a SI message the radio access node transmits the SI message during the number of modification periods indicated in the first type SI.

A method for a wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the method comprising:

receiving system information (SI) from the radio access node in a SI message acquisition process;

terminating the SI message acquisition process after attempting SI message acquisition for a first number of modification periods, a modification period being a preconfigured time duration where the content of the SI is unchanged.

The method of Example Embodiment 14, further comprising:

receiving first type system information (SI) from the radio access node, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

transmitting an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand;

wherein the modification period is a preconfigured time duration where the content of the first type and second type SI is unchanged.

The method of Example Embodiment 15, wherein the first number of modification periods is preconfigured.

The method of Example Embodiment 15, wherein the first number of modification periods is configured by the radio access node via the first type SI.

The method of Example Embodiment 15, wherein further comprising being configured with a second number of modification periods, the first number of modification periods being used for the SI message acquisition process of an SI message after transmitting the SI request message, whereas the second number of modification periods being used for the SI message acquisition process without transmitting the SI request message.

The method of Example Embodiment 18, wherein the second number of modification periods is preconfigured.

The method of Example Embodiment 18, wherein the second number of modification periods is configured by the radio access node via the first type SI.

the method of example embodiment 15, wherein, in the case where the SI message acquisition process is terminated after the first number of modification periods, initiating acquisition of the first type system information.

The method of Example Embodiment 18, wherein, in the case where the SI message acquisition process is terminated after the second number of modification periods, initiating acquisition of the first type system information.

A method for a radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, comprising:

configuring the wireless terminal with a first number of modification periods, the first number of modification periods being a termination condition of a system information (SI) message acquisition process, a modification period being a preconfigured time duration where content of the system information (SI) is unchanged

transmitting system information (SI) to the wireless terminal.

The method of Example Embodiment 23, further comprising:

transmitting first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

receiving an SI request message to request at least one second type SI message;

wherein the first number of modification periods is a termination condition of a second type SI message acquisition process, and

wherein the modification period is a preconfigured time duration where the content of the first type and second type SI is unchanged.

The method of Example Embodiment 24, wherein further configuring the wireless terminal via the first type SI with a second number of modification periods, the first number of modification periods being used for the SI message acquisition process of an SI message after transmitting the SI request message, whereas the second number of modification periods being used for the SI message acquisition process without transmitting the SI request message.

The method of Example Embodiment 24, wherein, after receiving the SI request message requesting a SI message, transmitting the SI message during the number of modification periods indicated in the first type SI.

A wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the wireless terminal comprising:

receiver circuitry configured to receive system information (SI) from the radio access node

processor circuitry configured to:perform an SI message acquisition process;terminate the SI message acquisition process after attempting SI message acquisition for a prescribed number of transmission opportunities.

The wireless terminal of Example Embodiment 27, wherein:

the receiver circuitry is configured to receive first type system information (SI) from the radio access node, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;the prescribed number of transmission opportunities, the prescribed number of transmission opportunities for at least one second type message, the prescribed number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI;

the wireless terminal further comprising transmitter circuitry configured to transmit an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand.

The wireless terminal of Example Embodiment 28, wherein, in the case where the delivery method is broadcast for the second type SI message, the prescribed number of transmission opportunities indicates remaining transmission opportunities for a corresponding SI message.

The wireless terminal of Example Embodiment 29, wherein the prescribed number of transmission opportunities is updated at each time of first type SI transmission.

The wireless terminal of Example Embodiment 27, wherein the prescribed number of transmission opportunities is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The wireless terminal of Example Embodiment 27, wherein the prescribed number of transmission opportunities is a number of modification boundaries, the modification period being a preconfigured time duration where content of the system information is unchanged.

The wireless terminal of Example Embodiment 28, wherein, in the case where the SI message acquisition process is terminated after the first number of modification periods, the wireless terminal initiates acquisition of the first type system information.

A radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, the radio access node comprising:

transmitter circuitry configured to transmit system information (SI) to the wireless terminal;

processor circuitry configured to configure the wireless terminal with a prescribed number of transmission opportunities, the prescribed number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit an SI message.

The radio access node of Example Embodiment 34, wherein:

the transmitter circuitry configured to transmit first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;the prescribed number of transmission opportunities, the prescribed number of transmission opportunities being for at least one second type message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI;

the radio access node further comprising receiver circuitry configured to receive an SI request message to request at least one second type SI message;

wherein the processor circuitry configured to configure the wireless terminal via the first type SI with the prescribed number of transmission opportunities for at least one second type system information message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the second type SI message from the time of the transmission of the first type system information.

The radio access node of Example Embodiment 35, wherein, in the case where the delivery method is broadcast for the second type SI message, the prescribed number of transmission opportunities indicates remaining transmission opportunities for a corresponding SI message.

The radio access node of Example Embodiment 35, wherein the prescribed number of transmission opportunities is updated at each time of first type SI transmission.

The radio access node of Example Embodiment 34, wherein the prescribed number of transmission opportunities is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The radio access node of Example Embodiment 34, wherein the prescribed number of transmission opportunities is a number of modification boundaries, the modification period being a preconfigured time duration where content of the system information is unchanged.

A method for a wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the method comprising:

receiving system information (SI) from the radio access node in an SI message acquisition process;

terminating the SI message acquisition process after attempting the SI message acquisition for a prescribed number of transmission opportunities.

The method of Example Embodiment 40, further comprising:

receiving first type system information (SI) from the radio access node, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;the prescribed number of transmission opportunities, the prescribed number of transmission opportunities being for at least one second type message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI;

transmitting an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand; terminating the SI message acquisition process is terminated after attempting the SI message acquisition for the prescribed number of transmission opportunities.

The method of Example Embodiment 41, wherein, in the case where the delivery method is broadcast for the second type SI message, the prescribed number of transmission opportunities indicates remaining transmission opportunities for a corresponding SI message.

The method of Example Embodiment 42, wherein the prescribed number of transmission opportunities is updated at each time of first type SI transmission.

The method of Example Embodiment 40, wherein the prescribed number of transmission opportunities is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The method of Example Embodiment 40, wherein the prescribed number of transmission opportunities is a number of modification boundaries, the modification period being a preconfigured time duration where content of the system information is unchanged.

The method of Example Embodiment 41, wherein, in the case where the SI message acquisition process is terminated after the first number of modification periods, initiating acquisition of the first type system information.

A method for a radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, the method comprising:

configuring the wireless terminal with a prescribed number of transmission opportunities for a system information message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message;

transmitting system information (SI) to the wireless terminal for the prescribed number of transmission opportunities.

The method of Example Embodiment 47, further comprising:

transmitting first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;the prescribed number of transmission opportunities, the prescribed number of transmission opportunities being for at least one second type message, the number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI;

receiving an SI request message to request at least one second type SI message;

configuring the wireless terminal via the first type SI the prescribed number of transmission opportunities for at least one second type message, the prescribed number of transmission opportunities indicating at least how many transmission opportunities the radio access node is scheduling to transmit the SI message from the time of the transmission of the first type SI.

The method of Example Embodiment 48, wherein, in the case where the delivery method is broadcast for the second type SI message, the prescribed number of transmission opportunities indicates remaining transmission opportunities for a corresponding SI message.

The method of Example Embodiment 48 wherein the prescribed number of transmission opportunities is updated at each time of first type SI transmission.

The method of Example Embodiment 47, wherein the prescribed number of transmission opportunities is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The method of Example Embodiment 47, wherein the prescribed number of transmission opportunities is a number of modification boundaries, the modification period being a preconfigured time duration where content of the system information is unchanged.

A wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the wireless terminal comprising:

receiver circuitry configured to receive first type system information (SI) from the radio access node, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

transmitter circuitry configured to transmit an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand;

processor circuitry configured to:after receiving from the radio access node an acknowledgement for the SI request message and before performing an SI message acquisition process, wait for a time duration specified by an offset value;perform an SI message acquisition process.

The wireless terminal of Example Embodiment 53, wherein the offset value is preconfigured.

The wireless terminal of Example Embodiment 53, wherein the offset value is configured by the radio access node via the first type SI.

The wireless terminal of Example Embodiment 53, wherein the offset value is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The wireless terminal of Example Embodiment 53, wherein the offset value is a number of modification periods, the modification period being a preconfigured time duration where the content of the first type and second type SI is unchanged.

The wireless terminal of Example Embodiment 53, wherein the offset value is a time period.

A method for a wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), comprising:

receiving first type system information (SI) from the radio access node, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

transmitting an SI request message to request at least one second type SI message indicated as on-demand delivery in a case where the delivery mode of the second type SI message is on-demand;

after receiving from the radio access node an acknowledgement for the SI request message and before performing an SI message acquisition process, waiting for a time duration specified by an offset value, and;

performing an SI message acquisition process.

The method of Example Embodiment 59, wherein the offset value is preconfigured.

The method of Example Embodiment 59, wherein the offset value is configured by the radio access node via the first type SI.

The method of Example Embodiment 59, wherein the offset value is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The method of Example Embodiment 59, wherein the offset value is a number of modification periods, the modification period being a preconfigured time duration where the content of the first type and second type SI is unchanged.

The method of Example Embodiment 59 wherein the offset value is a time period.

A radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, the radio access node comprising:

transmitter circuitry configured to transmit first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

receiver circuitry configured to receive an SI request message to request at least one second type SI message;

processor circuitry configured to configure the wireless terminal via the first type SI message with an offset value, the offset value instructing the wireless terminal to wait for a time duration specified by an offset value after the wireless terminal receiving from the radio access node an acknowledgement for the SI request message and before the wireless terminal performing an SI message acquisition process.

The radio access node of Example Embodiment 65, wherein the offset value is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The radio access node of Example Embodiment 65, wherein the offset value is a number of modification periods, the modification period being a preconfigured time duration where the content of the first type and second type SI is unchanged.

The radio access node of Example Embodiment 65, wherein the offset value is a time period.

A method for a radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, comprising:

transmitting first type system information (SI) to the wireless terminal, the first type SI comprising:availability of second type SI messages, a second type SI message comprising at least one system information block (SIB);an indication of a delivery mode for each of the second type SI messages, the delivery mode being either broadcast or on-demand basis;

receiving an SI request message to request at least one second type SI message;

configuring the wireless terminal via the first type SI message with an offset value, the offset value instructing the wireless terminal to wait for a time duration specified by an offset value after the wireless terminal receives from the radio access node an acknowledgement for the SI request message and before the wireless terminal performs an SI message acquisition process.

The method of Example Embodiment 69, wherein the offset value is a number of SI windows, an SI windows being defined as a time window designated for a SI message.

The method of Example Embodiment 69, wherein the offset value is a number of modification periods, the modification period being a preconfigured time duration where the content of the first type and second type SI is unchanged.

The method of Example Embodiment 69, wherein the offset value is a time period.

A wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the wireless terminal comprising:

receiver circuitry configured to receive a first type system information (SI) block (SIB), the first type SIB comprising:availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB;an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and;a number of transmission opportunities allowed for an SI message acquisition process to acquire an SI message;

processor circuitry configured to perform the SI message acquisition process, wherein;

the SI message acquisition process is terminated after the number of transmission opportunities consumed for the SI message acquisition process without a successful reception of the SI message.

The wireless terminal of Example Embodiment 73, wherein the transmission opportunities comprise modification periods, a modification period being a preconfigured time duration where the content of the system information is unchanged.

The wireless terminal of Example Embodiment 73, wherein the transmission opportunities comprise SI windows, the SI windows being periodically occurring time domain windows, in each of the SI windows the SI message being transmitted.

The wireless terminal of Example Embodiment 73, wherein, in a case that the delivery mode of the SI message is on-demand basis, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after requesting the SI message.

The wireless terminal of Example Embodiment 73, wherein, in a case that the delivery mode of the SI message is broadcast, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after receiving the first type SIB.

A radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, the radio access node comprising:

transmitter circuitry configured to transmit a first type system information (SI) block (SIB), the first type SIB comprising:availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB;an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and;a number of transmission opportunities for an SI message acquisition process to acquire an SI message;

processor circuitry configured to generate an SI message, and;

the transmitter circuitry further configured to transmit the SI message based on the indication of the delivery mode for the SI message and the number of transmission opportunities, wherein;

the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process.

The radio access node of Example Embodiment 78, wherein the transmission opportunities comprise modification periods, a modification period being a preconfigured time duration where the content of the system information is unchanged.

The radio access node of Example Embodiment 78, wherein the transmission opportunities comprise SI windows, the SI windows being periodically occurring time domain windows, in each of the SI windows the SI message being transmitted.

The radio access node of Example Embodiment 78, wherein, in a case that the delivery mode of the SI message is on-demand basis, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after the wireless terminal requests the SI message.

The radio access node of Example Embodiment 78, wherein, in a case that the delivery mode of the SI message is broadcast, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after the wireless terminal receives the first type SIB.

A method for a wireless terminal that communicates over a radio interface with a radio access node of a radio access network (RAN), the method comprising:

receiving a first type system information (SI) block (SIB), the first type SIB comprising:availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB;an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and;a number of transmission opportunities allowed for an SI message acquisition process to acquire an SI message;

performing an SI message acquisition process, wherein;

the SI message acquisition process is terminated after the number of transmission opportunities consumed for the SI message acquisition process without a successful reception of the SI message.

The method of Example Embodiment 83, wherein the transmission opportunities comprise modification periods, a modification period being a preconfigured time duration where the content of the system information is unchanged.

The method of Example Embodiment 83, wherein the transmission opportunities comprise SI windows, the SI windows being periodically occurring time domain windows, in each of the SI windows the SI message being transmitted.

The method of Example Embodiment 83, wherein, in a case that the delivery mode of the SI message is on-demand basis, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after requesting the SI message.

The method of Example Embodiment 83, wherein, in a case that the delivery mode of the SI message is broadcast, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after receiving the first type SIB.

A method for a radio access node of a radio access network (RAN) that communicates over a radio interface with a wireless terminal, comprising:

transmitting a first type system information (SI) block (SIB), the first type SIB comprising:availability and scheduling information of SI message(s), each of the SI message(s) comprising at least one second type SIB;an indication of a delivery mode for each of the SI message(s), the delivery mode being either broadcast or on-demand basis, and;a number of transmission opportunities for an SI message acquisition process to acquire an SI message;

generating an SI message, and;

further transmitting the SI message based on the indication of the delivery mode for the SI message and the number of transmission opportunities, wherein;

the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process.

The method of Example Embodiment 88, wherein the transmission opportunities comprise modification periods, a modification period being a preconfigured time duration where the content of the system information is unchanged.

The method of Example Embodiment 88, wherein the transmission opportunities comprise SI windows, the SI windows being periodically occurring time domain windows, in each of the SI windows the SI message being transmitted.

The method of Example Embodiment 88, wherein, in a case that the delivery mode of the SI message is on-demand basis, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after the wireless terminal requests the SI message.

The method of Example Embodiment 88, wherein, in a case that the delivery mode of the SI message is broadcast, the number of transmission opportunities indicates the maximum number of transmission opportunities that the wireless terminal can use for the SI message acquisition process after the wireless terminal receives the first type SIB.

Although the processes and methods of the disclosed embodiments may be discussed as being implemented as a software routine, some of the method steps that are disclosed therein may be performed in hardware as well as by a processor running software. As such, the embodiments may be implemented in software as executed upon a computer system, in hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware. The software routines of the disclosed embodiments are capable of being executed on any computer operating system, and is capable of being performed using any CPU architecture. The instructions of such software are stored on non-transient computer readable media.

The functions of the various elements including functional blocks, including but not limited to those labeled or described as “computer”, “processor” or “controller”, may be provided through the use of hardware such as circuit hardware and/or hardware capable of executing software in the form of coded instructions stored on computer readable medium. Thus, such functions and illustrated functional blocks are to be understood as being either hardware-implemented and/or computer-implemented, and thus machine-implemented.

In terms of hardware implementation, the functional blocks may include or encompass, without limitation, digital signal processor (DSP) hardware, reduced instruction set processor, hardware (e.g., digital or analog) circuitry including but not limited to application specific integrated circuit(s) [ASIC], and/or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

In terms of computer implementation, a computer is generally understood to comprise one or more processors or one or more controllers, and the terms computer and processor and controller may be employed interchangeably herein. When provided by a computer or processor or controller, the functions may be provided by a single dedicated computer or processor or controller, by a single shared computer or processor or controller, or by a plurality of individual computers or processors or controllers, some of which may be shared or distributed. Moreover, use of the term “processor” or “controller” shall also be construed to refer to other hardware capable of performing such functions and/or executing software, such as the example hardware recited above.

The functions of the various elements including functional blocks, including but not limited to those labeled or described as “computer”, “processor” or “controller”, may be provided through the use of hardware such as circuit hardware and/or hardware capable of executing software in the form of coded instructions stored on computer readable medium. Thus, such functions and illustrated functional blocks are to be understood as being either hardware-implemented and/or computer-implemented, and thus machine-implemented.

Nodes that communicate using the air interface also have suitable radio communications circuitry. Moreover, the technology can additionally be considered to be embodied entirely within any form of computer-readable memory, such as solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

It will be appreciated that the technology disclosed herein is directed to solving radio communications-centric issues and is necessarily rooted in computer technology and overcomes problems specifically arising in radio communications. Moreover, in at least one of its aspects the technology disclosed herein improves the functioning of the basic function of a wireless terminal and/or node itself so that, for example, the wireless terminal and/or node can operate more effectively by prudent use of radio resources.