WO2019074430A1 - X2ap synchronization signal broadcast request - Google Patents

Abstract

According to the present invention, an improved parameterization time for access of a wireless device to a new radio base station (NR) in a dual connectivity deployment EUTRAN-NR (EN-DC) is obtained by request of a synchronization signal block (SSB) transmission more common when an EN-DC compatible wireless device is present. A new signal is sent on the X2AP interface, referred to herein as the Broadcast System Information Request (BSIR) message. The BSIR message requests the NR node to increase the broadcasts of its system information (SI) by requesting a periodicity or latency between SI broadcast repetitions. The BSIR may include a period during which the reduced period of SI broadcasts is requested, or may identify one or more particular NR cells for which a reduction in the SI broadcast period is requested. Upon receipt of the BSIR message, the NR node may ignore the BSIR message, may adopt the requested SI broadcast frequency, or may reduce the SI broadcast period by a different amount. This may change the SI broadcast period for a specified duration in the BSIR message, or for a different duration.

Description

X2AP SYNCHRONIZATION SIGNAL BROADCAST REQUEST

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/572062, filed October 13, 2017, titled "X2AP Synchronization Signal Broadcast Request."

TECHNICAL FIELD

The present invention relates generally to wireless communication networks, and in particular to a system and method of improved setup time for a wireless device to access a New Radio (NR) base station in a EUTRAN-NR Dual Connectivity (EN-DC) deployment, by requesting more frequent SSB transmission from a NR base station when a EN-DC capable wireless device is present.

BACKGROUND

Wireless communication networks, including network nodes and radio network devices such as cellphones and smartphones, are ubiquitous in many parts of the world. These networks continue to grow in capacity and sophistication. To accommodate both more users and a wider range of types of devices that may benefit from wireless communications, the technical standards governing the operation of wireless communication networks continue to evolve. The fourth generation (4G) of network standards, known as Long Term Evolution (LTE), has been deployed, and the fifth generation (5G) is in development.

In LTE, the core network is the Evolved Packet Core (EPC); the Radio Access

Technology (RAT) is EUTRAN; and base stations are known as enhanced Node Bs, or eNBs. When fully deployed as a Stand Alone (SA) system, the corresponding terminology in 5G are that the core network is 5^th Generation Core Network (5GCN); the RAT is New Radio (NR); and the base stations are known as gNBs.

The NR air interface targets spectrum in the range from below 1 GHz up to 100 GHz, with extensive use of both multiple antenna technology (MIMO) and beamforming. A general description of the agreements on 5G NR Access Technology so far is contained in 3GPP TR 38.802 V0.3.0 (2016-10), of which a draft version has been published as R1 -1610848. Final specifications may be published inter alia in the future 3GPP TS 38.2** series.

However, at least in initial deployments, full Stand Alone 5G networks are not anticipated. Not only are the system specifications not fully defined yet, but neither the network infrastructure, nor wireless devices implementing it, are expected to be widely available for some time. In the short term, 4G and 5G networks are expected to co-exist, in various hybrid system architectures, known collectively as Non-Stand Alone (NSA). The 3GPP publication R1 - 161266 (2016-06) depicts 12 possible SA/NSA architectures. Figure 1 depicts one NSA architecture, known as EUTRAN-NR Dual Connectivity (EN- DC). In EN-DC, wireless devices (such as User Equipment, or UE) that have the capability to communicate with both LTE and NR networks may take advantage of the high throughput of the NR technology, even before 5GCN is developed and deployed. In this case, the LTE eNB is the master base station, and the NR gNB is a secondary cell or node. The NR gNB has user plane connection (solid line) to the EPC (or alternatively, it could be routed through the eNB, over an X2/Xn link between the eNB and gNB); however, the gNB has no control plane connection (dashed line) to the EPC. Instead, the NR gNB relies on the LTE eNB, acting as a master node (MeNB).

Configuring a UE with EN-DC is initiated when the UE is connected to LTE node (master node) and there is at least a candidate NR node (secondary node). The UE may or may not be asked to perform NR measurement before dual connectivity setup. When a secondary node is chosen, the UE attempts to access the candidate NR cell based on the required information received through the master node.

After successful connection to the NR cell, data transmission through the secondary node can be started. Depending on the configuration, a UE configured with EN-DC may be able to receive and transmit data on both LTE and NR legs (i.e., data aggregation is possible). The time it takes to setup the secondary leg (i.e., NR) is an important factor on the total delay to the first data transmission on NR.

Once the LTE eNB (master node) detects that the UE is NR capable, it will order measurements on the NR frequencies. The UE will be required to listen in the NR frequencies long enough to receive the Synchronization Signal (SS) Block (SSB), which in NR is

broadcasted periodically, with a periodicity of 5, 10, 20, 40, 80 or 160 ms. The SSB carries information necessary for synchronizing with the network and to operate properly with the cell. It includes the Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS) and the Physical Broadcast Channel (PBCH). The PSS and the SSS carry together the Physical Cell ID (PCI), which is used to differentiate the cell at a physical level. The SS Block is also used for UE measurements on NR cell radio condition, including Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) measurements.

In higher frequencies, where beamforming is required to cover the cell area, multiple SS

Blocks are bundled together as SS Block bursts. Transmission of SS Block burst may involve beam sweeping. SS Burst transmission (sweeping though all beams) happens in the first 5 ms of the SS burst set period. Beam sweeping may imply a longer time for UE to detect the NR cell, especially with long SS block burst periodicity. For comparison, in LTE the Cell Reference Signal (CRS) is broadcast with a fixed periodicity of 5 ms. Long periods of the SSB are beneficial in cells that are either empty or have few users, as it saves energy in the node and reduces interference in neighboring cells. However, longer SSB periodicity implies longer average listening times for UE trying to read the SS The Background section of this document is provided to place embodiments of the present invention in technological and operational context, to assist those of skill in the art in understanding their scope and utility. Approaches descried in the Background section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Unless explicitly identified as such, no statement herein is admitted to be prior art merely by its inclusion in the Background section.

SUMMARY

The following presents a simplified summary of the disclosure in order to provide a basic understanding to those of skill in the art. This summary is not an extensive overview of the disclosure and is not intended to identify key/critical elements of embodiments of the invention or to delineate the scope of the invention. The sole purpose of this summary is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.

Embodiments of the present invention allow for improved NR setup time in an EN-DC deployment. This is achieved by more frequent SSB transmission when there is a EN-DC capable UE. This is based on the information exchanged from master node to secondary node when there is a UE with DC setup possibility. Embodiments are also applicable to NR-NR DC and NR-NR mobility over the Xn interface.

A new signal is sent over the X2AP interface, referred to herein as the Broadcast

System Information Request (BSIR) message, although of course the signal designation will be determined by the standards bodies (e.g., 3GPP). The purpose and functionality of the BSIR message is to request the NR node to broadcast its System Information (SI) as often as possible for a period of time - or at least at a periodicity with lower delay between broadcast repetitions. In some embodiments, the BSIR message may specify a requested periodicity, or delay between SI broadcast repetitions. In some embodiments, the BSIR message may include a duration for which the reduced period of SI broadcasts is requested. In some embodiments, the BSIR message identify one or more particular NR cells for which a reduction in the period of periodically broadcasting SI is requested.

Upon receipt of the BSIR message, in various embodiments, the NR node may take various actions. In one embodiment, the NR node may ignore the BSIR message, and continue to broadcast SI according to a periodicity otherwise adopted. In some embodiments, the NR node, in response to the BSIR message, may adopted the requested SI broadcast periodicity, if specified. In other embodiments, the NR node may reduce the period of periodically broadcasting SI, but by an amount that differs from that requested in the BSIR message.

Similarly, in some embodiments, the NR node may reduce the period of periodically

broadcasting SI for a duration specified in the BSIR message, if any. In other embodiments, the NR node may reduce the period of periodically broadcasting SI for a duration that differs from the duration requested in the BSIR message. Also, in some embodiments, the NR node may reduce the period of periodically broadcasting SI for by an amount, and for a duration, in one or more of the cells requested by the BSIR message, if any. In other embodiments, the NR node may decide in which cells, if any, to reduce the period of periodically broadcasting SI.

By broadcasting the information more often, the UEs that perform NR measurements can detect the cells faster, speeding up dual connectivity scenarios, or some mobility scenarios, when X2/Xn is used.

One embodiment relates to a method, performed by a first base station operative in a wireless communication network, of assisting the connection of a wireless device to a second base station. The second base station is operative in a New Radio (NR) network. The first base station ascertains that a wireless device connected to the first base station is capable of communicating with the second base station. The first base station then sends a Broadcast System Information Request (BSIR) message to the second base station. The BSIR message requests that the second base station reduce the period of periodically broadcasting System Information (SI).

Another embodiment relates to a method, performed by a second base station operative in a New Radio (NR) wireless communication network, of assisting the connection of a wireless device to the second base station. The second base station receives a Broadcast System Information Request (BSIR) message from a first base station. The BSIR message requests that the second base station reduce the period of periodically broadcasting system information (SI). In response to the BSIR message, the second base station reduces the period of periodically broadcasting SI in one or more cells.

Yet another embodiment relates to a method, performed by a wireless device, of accessing a New Radio (NR) base station. The wireless device communicates to a Long Term Evolution (LTE) base station that the wireless device is capable of communication with a NR base station. The wireless device receives System Information (SI) from the NR base station as a result of the LTE base station requesting the NR base station to reduce a latency of broadcasting the SI.

Still another embodiment relates to a first base station operative in a wireless communication network that includes a second base station operative in a New Radio (NR) network. The first base station includes communication circuitry and processing circuitry operatively connected to the communication circuitry. The processing circuitry is adapted to ascertain that a wireless device connected to the first base station is capable of communicating with the second base station; and send a Broadcast System Information Request (BSIR) message to the second base station, the BSIR message requesting that the second base station reduce the period of periodically broadcasting System Information (SI).

Still another embodiment relates to a second base station operative in a New Radio (NR) wireless communication network. The second base station includes communication circuitry and processing circuitry operatively connected to the communication circuitry. The processing circuitry is adapted to receive a Broadcast System Information Request (BSIR) message from a first base station. The BSIR message requests that the second base station reduce the period of periodically broadcasting system information (SI). The processing circuitry is also adapted to, in response to the BSIR message, reduce the period of periodically broadcasting SI in one or more cells.

Still another embodiment relates to a wireless device operative in a wireless

communication network including an LTE base station and a New Radio (NR) base station. The wireless device includes communication circuitry and processing circuitry operatively connected to the communication circuitry. The processing circuitry is adapted to communicate to the LTE base station that the wireless device is capable of communication with a NR base station; and receive System Information (SI) from the NR base station as a result of the LTE base station requesting the NR base station to reduce a latency of broadcasting the SI.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Figure 1 is a block diagram of a EUTRAN-NR Dual Connectivity (EN-DC) wireless network.

Figure 2 is a signaling diagram of setup for a EN-DC capable wireless device.

Figure 3 is a flow diagram of a method of a first base station assisting the connection of a wireless device to a second base station operative in a NR network.

Figure 4 is a flow diagram of a method of a second base station in a NR network assisting the connection of a wireless device to the second base station.

Figure 5 is a flow diagram of a method of a wireless device accessing a NR base station.

Figure 6 is a hardware block diagram of a LTE base station node.

Figure 7 is a functional block diagram of a LTE base station node.

Figure 8 is a hardware block diagram of a NR base station node.

Figure 9 is a functional block diagram of a NR base station node.

Figure 10 is a hardware block diagram of a wireless device.

Figure 1 1 is a functional block diagram of a wireless device. DETAILED DESCRIPTION

For simplicity and illustrative purposes, the present invention is described by referring mainly to an exemplary embodiment thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent to one of ordinary skill in the art that the present invention may be practiced without limitation to these specific details. In this description, well known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention.

Figure 2 shows the signaling involved in setup for a EN-DC capable wireless device (also referred to herein as a UE). Configuring a UE with EN-DC is initiated when the UE is connected to LTE node (master node) and there is at least a candidate NR node (secondary node). To detect which NR cell is a suitable candidate, the UE may be asked to perform NR measurement before dual connectivity setup.

Embodiments of the present invention provide a solution to speed up the measurement time. A new signal is defined, to be sent to candidate secondary nodes. This X2AP signal in this diagram is represented with the name Broadcast System Information Request (BSIR), although of course the signal may be named anything. This message will notify the NR node that there might be a UE listening in for the SSB information on its cells. This knowledge will make possible for the NR node to increase the frequency of broadcasting the SSB, so the UE can detect the neighboring cells faster.

Once the EN-DC possibility has been detected in the LTE node and at least one UE with EN-DC support is connected, the LTE node sends the proposed signal to neighboring NR nodes. The timing of the signals in the flowchart is one example, as it could be sent before, during or after "RRC Connection Reconfiguration NR Meas Config."

Upon reception of the BSIR message, the NR node will speed up the SSB broadcast resulting in faster measurement reporting from the UE, detecting the appropriate NR cell. When a NR cell (secondary node) is chosen, the UE attempts to access the NR cell based on the required information received through master node (random access procedure).

After successful connection to NR cell, data transmission through secondary node can be started. Depending on the configuration, a UE configured with EN-DC may be able to receive and transmit data on both LTE and NR legs (i.e. data aggregation is possible).

The time it takes to setup the secondary leg (i.e., NR) is expected to be shorted as a result of more frequent transmission of SSB, which reduces both UE measurement reporting time and random access. Thus the total delay to the first data transmission on NR is also reduced.

For example, in the case where the cell has a SSB periodicity of 20 ms, a change to 5 ms periodicity during measurement time will translate on a 7.5 ms shorter measurement period, when the UE is configured to finish measurement as soon as the target cell is found. This signal is presented in the context of EN-DC, but it can also be implemented in any scenario where the UE needs to detect NR cells, and an X2/Xn connection between nodes is possible.

For example, three additional scenarios envisioned are:

Enhanced LTE-NR mobility. In this case, the LTE node will be connected to the 5GCN. If a UE were candidate to perform IRAT mobility towards a NR node, the Enhanced LTE node could send the previously presented signal towards the wanted NR nodes.

In NR-NR DC, the master NR node will send the signal to neighboring NR nodes when the UE is requested to perform measurements on possible secondary cells.

In the NR mobility case, if the NR node were to detect that the NR UE is in bad coverage, it could request external NR cells using the same synchronization frequency(GSCN) to start broadcasting with the SSB with a higher periodicity.

In the case the external NR cells used other GSCN, the NR node would wait to send the BroadcastSystemlnformationRequest message until the UE is requested to perform NR cell measurements on the wanted GSCN.

In all these cases, the effect of the BSIR signal is the same as in the EN-DC case described above.

An example of possible embodiment of a BSIR signal, defined in the X2AP context, could be:

Figure 3 depicts a method 100 in accordance with particular embodiments. The method 100 is performed by a first base station operative in a wireless communication network, and is a method of assisting the connection of a wireless device to a second base station, the second base station operative in a New Radio (NR) network. The method 100 includes ascertaining that a wireless device connected to the first base station is capable of communicating with the second base station (block 102). The method 100 further includes sending a Broadcast System Information Request (BSIR) message to the second base station, the BSIR message requesting that the second base station reduce the period of periodically broadcasting System Information (SI) (block 104).

Note that the term "Broadcast System Information Request (BSIR)" is a descriptive title for the proposed new signaling message. The message may, of course, be assigned a different label.

Figure 4 depicts a method 200 in accordance with other particular embodiments. The method 200 is performed by a second base station operative in a New Radio (NR) wireless communication network, and is a method of assisting the connection of a wireless device to the second base station. The method 200 includes receiving a Broadcast System Information Request (BSIR) message from a first base station, the BSIR message requesting that the second base station reduce the period of periodically broadcasting system information (SI) (block 202). The method 200 further includes, in response to the BSIR message, reducing the period of periodically broadcasting SI in one or more cells (block 204).

Figure 5 depicts a method 300 in accordance with other particular embodiments. The method 300 is performed by a wireless device, and is a method of accessing a New Radio (NR) base station. The method 300 includes communicating to a Long Term Evolution (LTE) base station that the wireless device is capable of communication with a NR base station (block 302). The method 300 further includes receiving System Information (SI) from the NR base station as a result of the LTE base station requesting the NR base station to reduce a latency of broadcasting the SI (block 304).

Apparatuses described herein may perform the methods 100, 200, 300 herein and any other processing by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and/or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the techniques described herein.

Figure 6 illustrates a first network node 10 as implemented in accordance with one or more embodiments. As shown, the first network node 10 includes processing circuitry 12 and communication circuitry 16. The communication circuitry 16 is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. The communication circuitry 16 may comprise a transceiver, antenna(s), and other circuitry operative to wirelessly transmit and/or receive information to and/or from one or more wireless device, such as User Equipment (UE). The processing circuitry 12 is configured to perform processing described above, such as by executing instructions stored in memory 14. The processing circuitry 12 in this regard may implement certain functional means, units, or modules. In some embodiments, the first node 10 is operative in an LTE network. In other embodiments, the first node 10 is operative in a NR network.

Figure 7 illustrates a schematic block diagram of a first network node 20 in a wireless network according to still other embodiments. As shown, the first network node 20 implements various functional means, units, or modules, e.g., via the processing circuitry 12 in Figure 6 and/or via software code. These functional means, units, or modules, e.g., for implementing the method(s) herein, include for instance: wireless device NR capability ascertaining unit 22, and Broadcast System Information Request (BSIR) message sending unit 24. Wireless device NR capability ascertaining unit 22 is configured to ascertain that a wireless device connected to the first base station is capable of communicating with the second base station. Broadcast System Information Request (BSIR) message sending unit 24 is configured to send a BSIR message to the second base station, the BSIR message requesting that the second base station reduce the period of periodically broadcasting SI.

Figure 8 illustrates a second network node 30 as implemented in accordance with one or more embodiments. As shown, the second network node 30 includes processing circuitry 32 and communication circuitry 36. The communication circuitry 36 is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. The communication circuitry 36 may comprise a transceiver, antenna(s), and other circuitry operative to wirelessly transmit and/or receive information to and/or from one or more wireless device, such as UEs. The processing circuitry 32 is configured to perform processing described above, such as by executing instructions stored in memory 34. The processing circuitry 32 in this regard may implement certain functional means, units, or modules. The second node 30 is operative in a NR network.

Figure 9 illustrates a schematic block diagram of a network node 40 in a wireless network according to still other embodiments. As shown, the second network node 40 implements various functional means, units, or modules, e.g., via the processing circuitry 32 in Figure 8 and/or via software code. These functional means, units, or modules, e.g., for implementing the method(s) herein, include for instance: Broadcast System Information

Request (BSIR) message receiving unit 42, and SI broadcast period reducing unit 44. BSIR message receiving unit 42 is configured to receive a BSIR message from a first base station, the BSIR message requesting that the second base station reduce the period of periodically broadcasting SI. SI broadcast period reducing unit 44 is configured to, in response to the BSIR message, reduce the period of periodically broadcasting SI in one or more cells.

Figure 10 for example illustrates a wireless device 50 as implemented in accordance with one or more embodiments. As shown, the wireless device 50 includes processing circuitry 52 and communication circuitry 56. The communication circuitry 56 (e.g., transceiver and other radio circuitry) is configured to transmit and/or receive information to and/or from one or more other nodes, e.g., via any communication technology. Such communication may occur via one or more antennas that are either internal or external to the wireless device 50. The processing circuitry 52 is configured to perform processing described above, such as by executing instructions stored in memory 54. The processing circuitry 52 in this regard may implement certain functional means, units, or modules.

Figure 1 1 illustrates a schematic block diagram of a wireless device 60 in a wireless network according to still other embodiments. As shown, the wireless device 60 implements various functional means, units, or modules, e.g., via the processing circuitry 52 in Figure 10 and/or via software code. These functional means, units, or modules, e.g., for implementing the method(s) herein, include for instance: NR capability communicating unit 62, and NR SI receiving unit 64. NR capability communicating unit 62 is configured to communicate to a LTE base station that the wireless device is capable of communication with a NR base station. NR SI receiving unit 64 is configured to receive SI from the NR base station as a result of the LTE base station requesting the NR base station to reduce a latency of broadcasting the SI.

Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs. A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium. In this regard, embodiments herein also include a computer program product stored on a non-transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform, e.g., the methods 100, 200, or 300, as described herein.

Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium.

Embodiments of the present invention present numerous advantages compared to the prior art, including improved wireless device performance. As the dual connectivity setup time is reduced, time to first packet on NR is reduced. Hence, potentially higher throughput can be achieved earlier. This is achieved by shortening SSB periodicity when needed. Embodiments also provide energy savings, as the NR node will be able to broadcast signals less often when there is no need. Embodiments facilitate better downlink utilization of the air interface, as the slots scheduled for SS broadcasting can now be used for other data. Additionally, by avoiding SSB transmission with short periodicity, inter-cell interference is reduced.

The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Claims

CLAIMS What is claimed is:

1 . A method (100), performed by a first base station (10) operative in a wireless communication network, of assisting the connection of a wireless device (50) to a second base station (30), the second base station (30) operative in a New Radio, NR, network, the method (100) comprising:

ascertaining that a wireless device (50) connected to the first base station (10) is

capable of communicating with the second base station (30); and sending a Broadcast System Information Request, BSIR, message to the second base station (30), the BSIR message requesting that the second base station (30) reduce the period of periodically broadcasting System Information, SI.

2. The method (100) of claim 1 wherein the BSIR message is an X2 Application Protocol, X2AP, message.

3. The method (100) of any preceding claim wherein the BSIR message requests the second base station (30) to periodically broadcast system information at a reduced period for a duration.

4. The method (100) of any preceding claim wherein the first base station (10) is operative in a Long Term Evolution, LTE, network and is serving as a master node , MeNB, to the second base station (30), which has no control plane connection to the LTE network, and is operating in EUTRAN-NR Dual Connectivity, EN CR, mode.

5. The method (100) of any preceding claim wherein the first base station (10) is operative in a Long Term Evolution, LTE, network and is also connected to the second base station's 5G Core Network, 5GCN, and wherein the mobile terminal (50) is a candidate for Inter Radio Access Technology, IRAT, mobility.

6. The method (100) any of claims 1 -3 wherein the first base station (10) is operative in a NR network supporting NR-NR Dual Connectivity, and the second base station (30) is a candidate secondary cell.

7. The method (100) of any of claims 1 -3 wherein the first base station (10) is operative in a NR network using the same Global Synchronization Channel Number, GSCN, as the second base station (30), and the second base station (30) is a candidate target for a handover procedure.

8. The method (100) of any of claims 1 -3 wherein the first base station (10) is operative in a NR network using a different Global Synchronization Channel Number, GSCN , than the second base station (30), and wherein the first base station (10) is operative to send the SIBR message after requesting the wireless device (50) to perform NR cell measurements on the GSCN of the second base station (30).

9. A method (200), performed by a second base station (30) operative in a New Radio (NR) wireless communication network, of assisting the connection of a wireless device (50) to the second base station (30), the method (200) comprising:

receiving a Broadcast System Information Request (BSIR) message from a first base station (10), the BSIR message requesting that the second base station (30) reduce the period of periodically broadcasting system information (SI); and in response to the BSIR message, reducing the period of periodically broadcasting SI in one or more cells.

10. The method (200) of claim 9 wherein the BSIR message is an X2 Application Protocol (X2AP) message.

1 1 . The method (200) of any of claims 9-10 wherein the BSIR message includes a duration for which the reducing the periods of broadcasting SI is requested.

12. The method (200) of claim 1 1 wherein the second base station (30) reduces the period of periodically broadcasting SI in one or more cells for the requested duration.

13. The method (200) of claim 1 1 wherein the second base station (30) reduces the period of periodically broadcasting SI in one or more cells for a duration other than the requested duration.

14. The method (200) of any of claims 9-13 wherein the BSIR message includes a requested period of periodically broadcasting SI.

15. The method (200) of claim 14 wherein the second base station (30) periodically broadcasts SI at the requested period for a duration.

16. The method (200) of claim 14 wherein the second base station (30) decreases the period of periodically broadcasting SI for a duration, but the decreased period is other than the requested period.

17. The method (200) of any of claims 9-16 wherein the BSIR message includes an identification of one or more NR cells for which a period of periodically broadcasting SI should be reduced.

18. The method (200) of claim 17 wherein the second base station (30) reduces a period of periodically broadcasting SI in at least one of the requested cells.

19. The method (200) of claim 17 wherein the second base station (30) reduces a period of periodically broadcasting SI in one or more cells, without regard to the cells identified in the BSIR message.

20. The method (200) of any of claims 9-19 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is serving as a master node (MeNB) to the second base station (30), which has no control plane connection to the LTE network, and is operating in EUTRAN-NR Dual Connectivity (EN CR) mode.

21 . The method (200) of any of claims 9-20 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is also connected to the second base station's 5G Core Network (5GCN), and wherein the mobile terminal (50) is a candidate for Inter Radio Access Technology (IRAT) mobility.

22. The method (200) of any of claims 9-21 wherein the first base station (10) is operative in a NR network supporting NR-NR Dual Connectivity, and the second base station (30) is a candidate secondary cell.

23. The method (200) of any of claims 9-22 wherein the first base station (10) is operative in a NR network using the same Global Synchronization Channel Number (GSCN) as the second base station (30), and the second base station (30) is a candidate target for a handover procedure.

24. The method (200) of any of claims 9-22 wherein the first base station (10) is operative in a NR network using a different Global Synchronization Channel Number (GSCN) than the second base station (30), and wherein the first base station (10) is operative to send the SIBR message after requesting the wireless device (50) to perform NR cell measurements on the GSCN of the second base station (30).

25. A method (300) performed by a wireless device (50) for accessing a New Radio (NR) base station, the method (300) comprising:

communicating to a Long Term Evolution base station (10) that the wireless device (50) is capable of communication with a NR base station (30); and

receiving System Information (SI) from the NR base station (30) as a result of the LTE base station (10) requesting the NR base station (30) to reduce a latency of broadcasting the SI.

26. A first base station (10), operative in a wireless communication network including a second base station (30) operative in a New Radio (NR) network, the first base station (10) comprising:

communication circuitry (16); and

processing circuitry (12) operatively connected to the communication circuitry (16), and adapted to

ascertain that a wireless device (50) connected to the first base station (10) is capable of communicating with the second base station (30); and send a Broadcast System Information Request (BSIR) message to the second base station (30), the BSIR message requesting that the second base station (30) reduce the period of periodically broadcasting System

Information (SI).

27. The first base station (10) of claim 26 wherein the BSIR message is an X2 Application Protocol (X2AP) message.

28. The first base station (10) of any of claims 26-27 wherein the BSIR message requests the second base station (30) to periodically broadcast system information at a reduced period for a duration.

29. The first base station (10) of any of claims 26-28 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is serving as a master node (MeNB) to the second base station (30), which has no control plane connection to the LTE network, and is operating in EUTRAN-NR Dual Connectivity (EN CR) mode.

30. The first base station (10) of any of claims 26-29 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is also connected to the second base station's 5G Core Network (5GCN), and wherein the mobile terminal (50) is a candidate for Inter Radio Access Technology (IRAT) mobility.

31 . The first base station (10) of any of claims any of claims 26-28 wherein the first base station (10) is operative in a NR network supporting NR-NR Dual Connectivity, and the second base station (30) is a candidate secondary cell.

32. The first base station (10) of any of claims 26-28 wherein the first base station (10) is operative in a NR network using the same Global Synchronization Channel Number (GSCN) as the second base station (30), and the second base station (30) is a candidate target for a handover procedure.

33. The first base station (10) of any of claims 26-28 wherein the first base station (10) is operative in a NR network using a different Global Synchronization Channel Number (GSCN) than the second base station (30), and wherein the first base station (10) is operative to send the SIBR message after requesting the wireless device to perform NR cell

measurements on the GSCN of the second base station (30).

34. A second base station (30) operative in a New Radio (NR) wireless communication network, comprising:

communication circuitry (36); and

processing circuitry (32) operatively connected to the communication circuitry (36), and adapted to

receive a Broadcast System Information Request (BSIR) message from a first base station (10), the BSIR message requesting that the second base station (30) reduce the period of periodically broadcasting system information (SI); and

in response to the BSIR message, reduce the period of periodically broadcasting SI in one or more cells.

35. The second base station (30) of claim 34 wherein the BSIR message is an X2

Application Protocol (X2AP) message.

36. The second base station (30) of any of claims 34-35 wherein the BSIR message includes a duration for which the reducing the periods of broadcasting SI is requested.

37. The second base station (30) of claim 36 wherein the processing circuitry (32) is further adapted to reduce the period of periodically broadcasting SI in one or more cells for the requested duration.

38. The second base station (30) of claim 36 wherein the processing circuitry (32) is further adapted to reduce the period of periodically broadcasting SI in one or more cells for a duration other than the requested duration.

39. The second base station (30) of any of claims 34-38 wherein the BSIR message includes a requested period of periodically broadcasting SI.

40. The second base station (30) of claim 39 wherein the processing circuitry (32) is further adapted to periodically broadcast SI at the requested period for a duration.

41 . The second base station (30) of claim 39 wherein the processing circuitry (32) is further adapted to decrease the period of periodically broadcasting SI for a duration, but the decreased period is other than the requested period.

42. The second base station (30) of any of claims 34-41 wherein the BSIR message includes an identification of one or more NR cells for which a period of periodically broadcasting SI should be reduced.

43. The second base station (30) of claim 42 wherein the processing circuitry (32) is further adapted to reduce a period of periodically broadcasting SI in at least one of the requested cells.

44. The second base station (30) of claim 42 wherein the processing circuitry (32) is further adapted to reduce a period of periodically broadcasting SI in one or more cells, without regard to the cells identified in the BSIR message.

45. The second base station (30) of any of claims 34-44 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is serving as a master node (MeNB) to the second base station (30), which has no control plane connection to the LTE network, and is operating in EUTRAN-NR Dual Connectivity (EN CR) mode.

46. The second base station (30) of any of claims 34-45 wherein the first base station (10) is operative in a Long Term Evolution (LTE) network and is also connected to the second base station's 5G Core Network (5GCN), and wherein the mobile terminal (50) is a candidate for Inter Radio Access Technology (IRAT) mobility.

47. The second base station (30) of any of claims 34-46 wherein the first base station (10) is operative in a NR network supporting NR-NR Dual Connectivity, and the second base station (30) is a candidate secondary cell.

48. The second base station (30) of any of claims 34-47 wherein the first base station (10) is operative in a NR network using the same Global Synchronization Channel Number (GSCN) as the second base station (30), and the second base station (30) is a candidate target for a handover procedure.

49. The second base station (30) of any of claims 34-48 wherein the first base station (10) is operative in a NR network using a different Global Synchronization Channel Number (GSCN) than the second base station (30), and wherein the first base station (10) is operative to send the SIBR message after requesting the wireless device (50) to perform NR cell measurements on the GSCN of the second base station (30).

50. A wireless device (50) operative in a wireless communication network including an LTE base station (10) and a New Radio (NR) base station (30), the wireless device comprising: communication circuitry (16); and

processing circuitry (12) operatively connected to the communication circuitry (16), and adapted to

communicate to the LTE base station (10) that the wireless device (50) is

capable of communication with a NR base station (30); and

receive System Information (SI) from the NR base station (30) as a result of the

LTE base station (10) requesting the NR base station (30) to reduce a latency of broadcasting the SI.