CN112788663A - Discarding forwarded PDCP SDU during dual active protocol stack handover - Google Patents

Abstract

The application relates to discarding forwarded PDCP SDUs during dual active protocol stack handover. An embodiment relates to an apparatus of a first BS, the apparatus comprising: a memory; processing circuitry operatively coupled to the memory; and an interface to communicate with at least one second BS, the apparatus configured to: sending a HO command to the UE to perform a HO procedure; assigning a SN for each PDCP SDU; and forwarding PDCP SDUs having SNs to the at least one second BS as part of the HO procedure, wherein the HO command indicates a DAPS HO with the at least one second BS. According to the embodiment of the application, the discarding of the PDCP SDU which is forwarded can be realized.

Description

Discarding forwarded PDCP SDU during dual active protocol stack handover

RELATED APPLICATIONS

The present application claims priority rights entitled "DISCARDING FORWARDED PACKET DATA CONVERGENCE PROTOCOL SERVICE DATA UNITS discarding valid ACTIVE PROTOCOL STACK hand over DURING DUAL ACTIVE PROTOCOL STACK handoff", U.S. provisional application serial number 62/933,251 filed 11, 8, 2019. The disclosure of this provisional application is incorporated herein by reference in its entirety.

Technical Field

Embodiments of the present invention relate generally to the field of wireless communications. More particularly, embodiments of the invention relate to discarding forwarded Packet Data Convergence Protocol (PDCP) Service Data Units (SDUs) during a Dual Active Protocol Stack (DAPS) Handover (HO).

Background

DAPS HO is being studied as part of Work Items (WI) "Even funtter Mobility Enhancement in E-UTRAN (evolved UMTS Terrestrial Radio Access network)", and "NR (new Radio) Mobility enhancements". In case of DAPS handover, a User Equipment (UE) receives Downlink (DL) user data from a source and a target until a source cell is released. To support this functionality, the RAN3 recently agreed that the source forwards PDCP SDUs with source assigned Sequence Numbers (SNs) to the target over a General Packet Radio Service (GPRS) tunneling protocol user plane (GTP-U) tunnel to support simultaneous DL delivery from the target.

What also needs to be achieved is how the source distributes the packets over two paths (one directly to the UE and the other through the target). It may act like a split bearer or the source may replicate the packet through two paths to improve reliability.

If PDCP duplication is used, the source should be able to indicate to the target to discard PDCP SDUs that have been forwarded, as in a split bearer using PDCP duplication. The destination does not have to pass the same data packet if it has been successfully transmitted over the source link. If the source decides to repeat forwarding for reliability, but the source link quality is still good and a large number of DL transfers are made from the source side, but such dropping is particularly useful for DAPS HO.

Such discarding has been done on X2-U/Xn-U/F1-U as a flow control mechanism for PDCP PDUs (see 3GPP TS 38.425V15.6.0(2019-07-13), hereinafter referred to as "TS 38.425"), but in a DAPS HO, the PDCP SDUs are forwarded so that the source can be duplicated with PDCP, which is still at a stage to be developed.

Disclosure of Invention

The present application is intended to propose several embodiments enabling the discarding of PDCP SDUs already forwarded in a DAPS HO.

According to an aspect of the present application, there is provided an apparatus of a first Base Station (BS), the apparatus including: a memory; processing circuitry operatively coupled to the memory; and an interface to communicate with at least one second BS, the apparatus configured to: transmitting a Handover (HO) command to a User Equipment (UE) to perform a HO procedure, wherein the HO command indicates a Dual Active Protocol Stack (DAPS) HO with the at least one second BS; assigning a Sequence Number (SN) for each Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU); and forwarding the PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

According to another aspect of the application, there is provided a method for a DAPS HO, the method comprising: transmitting, by a first BS, a HO command to a UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second BS; allocating, by the first BS, a SN for each PDCP SDU; and forwarding, by the first BS, PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

According to another aspect of the present application, there is provided one or more non-transitory computer-readable media comprising instructions to cause a first electronic device, when executed by processing circuitry of the first electronic device, to perform: sending a HO command to the UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second electronic device; assigning a SN for each PDCP SDU; and forwarding PDCP SDUs having SNs to the at least one second electronic device as part of the HO procedure.

According to another aspect of the present application, there is provided an apparatus of a BS, the apparatus including: a memory; processing circuitry operatively coupled to the memory; and an interface to communicate with another BS, the apparatus configured to: receiving a PDCP SDU with a SN assigned by the other BS as part of a HO procedure of the UE, wherein the HO procedure is a DAPS HO for the BS.

Embodiments of the present application enable the discarding of PDCP SDUs that have been forwarded in a DAPS HO.

Drawings

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the invention.

However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

Fig. 1 illustrates a method for a DAPS HO performed in a BS, in accordance with various embodiments.

Fig. 2 illustrates an example architecture of a system 200 of networks according to various embodiments.

Figure 3 illustrates an example architecture of a system 300 including a first CN 320, in accordance with various embodiments.

Figure 4 illustrates an example architecture of a system 400 including a second CN 420, in accordance with various embodiments.

Fig. 5 illustrates an example of an infrastructure device 500 according to various embodiments.

Fig. 6 illustrates an example of a platform 600 (or "device 600") according to various embodiments.

Fig. 7 illustrates example components of a baseband circuit 7110 and a wireless front end module (RFEM)7115, in accordance with various embodiments.

Fig. 8 illustrates various protocol functions that may be implemented in a wireless communication device, in accordance with various embodiments.

Fig. 9 is a block diagram illustrating components capable of reading instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and performing any one or more of the methodologies discussed herein, according to some example embodiments.

Detailed Description

A detailed description of systems and methods consistent with embodiments of the present invention is provided below. While several embodiments have been described, it should be understood that the present invention is not limited to any one embodiment, but includes many alternatives, modifications, and equivalents. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments may be practiced without some or all of these details. Moreover, for the purpose of clarity, certain technical material that is known in the prior art has not been described in detail in order to avoid unnecessarily obscuring the present invention.

Several embodiments are presented in this application to enable the discarding of PDCP SDUs that have been forwarded in a DAPS HO.

DL user frames in TS 38.428 are reused for dropping:

it may be considered to reuse the NR-U flow control mechanism defined in TS 38.425, which is supported by the NR RAN Container GTP-U extension header. However, the NR-U flow control mechanism has been specified for split bearers for forwarding PDCP PDUs. During HO it is never used on data forwarding (of PDCP SDU). If this principle is modified, it may have a great impact on the implementation. Furthermore, all that is required for a DAPS HO is a drop function, which does not require all of the functions already developed in the flow control mechanism defined in TS 38.425. In addition, a DAPS HO is supported between LTE enbs. X2-U flow control between LTE enbs is defined in 3GPP TS 36.425V15.0.0(2018-06) (hereinafter "TS 36.425"), where there is no such drop functionality. TS 36.425 also requires enhancements.

There was no signalling impact other than TS 38.425 or some descriptions in the Stage-2 specification (TS 36.300V15.7.0(2019-09-26) and TS 38.300v15.7.0 (2019-09-26)). The NR-U flow control mechanism specified in TS 38.425 (or simply by the discard function of DL user frames) shall now be described as also being used for data forwarding during DAPS HO (of PDCP SDUs), which was previously only used for split bearers (in which to forward PDCP PDUs).

Some example implementations of TS 38.425 in section 4.1, "general aspects" are as follows:

note that: the user data radio bearer can be set for data forwarding purposes during Xn HO, or during DC related mobility, without performing any other data radio bearer related user plane protocol functions related to the NR user plane protocol instance,except for DAPS handover where the NR user plane protocol instance supports dropping from source NG- PDCP that RAN node forwards to target NG-RAN node SDU。

2. Dropping PDCP that has been forwarded via X2/XnAP Explicit indication of SDU:

signaling explicit discard indications on the control plane may be considered. For example, the DL COUNT in the existing X2/XnAP SN STATUS TRANSFER message may be used as an indication, such that the target discards such forwarded PDCP SDUs: its COUNT is less than the value provided.

Some example implementations in Stage-33 GPP TS 36.423V15.7.0(2019-09) (hereinafter "TS 36.423") and 3GPP TS 38.423V15.5.0(2019-09) (hereinafter "TS 38.423") are as follows:

for TS 36.423

9.1.1.4SN STATUS TRANSFER (SN STATUS TRANSFER)

This message is sent by the source eNB to the target eNB to transmit the uplink/downlink PDCP SN and HFN status during handover or for EN-DC.

The direction is as follows: source eNB → target eNB (handover), eNB from which E-RAB context is transferred → eNB to which E-RAB context is transferred (RRC connection re-establishment or dual connection), MeNB/EN-gNB from which E-RAB context is transferred → EN-gNB/MeNB to which E-RAB context is transferred (EN-DC).

For TS 38.423

9.2.1.14 DRB bound by status transport manifest

The IE contains a DRB list containing information about the transmission status of the PDCP PDUs.

Range limitations	Explanation of the invention
		maxnoofDRBs	Maximum number of allowed DRBs for one UE. The value is 32.

Fig. 1 illustrates a method for a DAPS HO performed in a BS, in accordance with various embodiments.

As shown in fig. 1, the method for a DAPS HO includes: deciding, by the first BS, to discard some PDCP SDUs that have been forwarded to the second BS (S12); transmitting, by the first BS, a message containing the COUNT threshold to the second BS (S14); upon receiving the message, the second BS discards PDCP SDUs having the COUNT value less than the COUNT threshold (S16).

According to the illustrated method, the discarding of PDCP SDUs that have been forwarded can be implemented in a DAPS HO.

System and implementation

Fig. 2 illustrates an example architecture of a system 200 of networks according to various embodiments. The following description is provided for an example system 200, the example system 200 operating in conjunction with the LTE system standard and the 5G or NR system standard provided by the 3GPP technical specification. However, the example embodiments are not limited in this respect, and the described embodiments may be applied to other networks benefiting from the principles described herein, such as future 3GPP systems (e.g., sixth generation (6G) systems, IEEE 802.16 protocols (e.g., WMAN, WiMAX), etc.).

As shown in fig. 2, system 200 includes UE201 a and UE201 b (collectively referred to as "UE 201" or "UE 201"). In this example, the UE201 is shown as a smartphone (e.g., a handheld touchscreen mobile computing device connectable to one or more cellular networks), but may also include any mobile or non-mobile computing device, such as a consumer electronic device, a cellular phone, a smartphone, a feature phone, a tablet, a wearable computer device, a Personal Digital Assistant (PDA), a pager, a wireless handset, a desktop computer, a laptop computer, an in-vehicle infotainment (IVI), an in-vehicle entertainment (ICE) device, an instrument panel (IC), a heads-up display (HUD) device, an in-vehicle diagnostics (OBD) device, a dashboard mobile Device (DME), a Mobile Data Terminal (MDT), an Electronic Engine Management System (EEMS), an electronic/Engine Control Unit (ECU), an electronic/Engine Control Module (ECM), an embedded system, a microcontroller, a mobile computing device (EEMS), a mobile computing device, a, A control module, an Engine Management System (EMS), a network or "smart" device, a Machine Type Communication (MTC) device, a machine-to-machine (M2M), an internet of things (IoT) device, and the like.

In some embodiments, any UE201 may be an IoT UE, which may include a network access layer designed for low power IoT applications that utilize short-term UE connections. IoT UEs may communicate over public land mobile network PLMN, ProSe, or device-to-device D2D using M2M or MTC like technologies, the sensor network or IoT network exchanging data with MTC servers or devices. The M2M or MTC data exchange may be a machine initiated data exchange. An IoT network describes interconnected IoT UEs that may contain uniquely identifiable embedded computing devices (within the Internet infrastructure) with ephemeral connections. The IoT UE may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate connection of the IoT network.

The UE201 may be configured to connect or communicatively couple with a Radio Access Network (RAN)210, for example. In an embodiment, RAN 210 may be a NG RAN or a 5G RAN, an E-UTRAN, or a legacy RAN, such as UTRAN or GERAN. As used herein, the term "NG RAN" or the like may refer to the RAN 210 operating in the NR or 5G system 200, while the term "E-UTRAN" or the like may refer to the RAN 210 operating in the LTE or 4G system 200. The UE201 utilizes connections (or channels) 203 and 204, respectively, each of which includes a physical communication interface or layer (discussed in further detail below).

In this example, connections 203 and 204 are shown as implementing communicatively coupled air interfaces, and may be consistent with cellular communication protocols, such as GSM protocols, CDMA network protocols, PTT protocols, POC protocols, UMTS protocols, 3GPP LTE protocols, 5G protocols, NR protocols, and/or any other communication protocol discussed herein. In an embodiment, the UE201 may exchange communication data directly via the ProSe interface 205. The ProSe interface 205 may alternatively be referred to as a SL interface 205 and may include one or more logical channels including, but not limited to, PSCCH, pscsch, PSDCH, and PSBCH.

The UE201 b is shown configured to access an Access Point (AP)206 (also referred to as "WLAN node 206", "WLAN 206", "W") via a connection 207LAN terminal 206 "," WT 206 ", etc.). Connection 207 may comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, where AP 206 would include wireless fidelity

A router. In this example, the AP 206 is shown connected to the internet without being connected to the core network of the wireless system (described in further detail below). In various embodiments, UE201 b, RAN 210, and AP 206 may be configured to operate with LWA and/or LWIP. LWA operation may involve UE201 b in RRC _ CONNECTED being configured by RAN nodes 211a-b to utilize radio resources of LTE and WLAN. LWIP operations may involve the UE201 b using WLAN radio resources (e.g., connection 207) through an IPsec protocol tunnel to authenticate and encrypt data packets (e.g., IP data packets) sent over the connection 207. An IPsec tunnel may include encapsulating the entire original IP data packet and adding a new header to protect the original header of the IP data packet.

The RAN 210 may include one or more Access Network (AN) nodes or RAN nodes 211a and 211b (collectively "RAN nodes 211" or "RAN nodes 211") that enable the connections 203 and 204. As used herein, the terms "access node," "access point," and the like may describe a device that provides radio baseband functionality for data and/or voice connections between a network and one or more users. These access nodes may be referred to as base stations BS, gnbs, RAN nodes, enbs, nodebs, road side units RSUs, transmission reception points TRxP or TRPs, etc., and may comprise ground stations (e.g., ground access points) or satellite station areas (e.g., cells) providing coverage within a geographical area. As used herein, the term "NG RAN node" or the like may refer to RAN node 211 operating in an NR or 5G system 200 (e.g., a gNB), and the term "E-UTRAN node" or the like may refer to RAN node 211 operating in an LTE or 4G system 200 (e.g., an eNB). According to various embodiments, RAN node 211 may be implemented as one or more of dedicated physical devices, such as a macro cell base station and/or a Low Power (LP) base station, for providing a femto cell, pico cell, or other similar cell with a smaller coverage area, smaller user capacity, or higher bandwidth than a macro cell.

In some embodiments, all or part of the RAN node 211 may be implemented as one or more software entities running on a server computer as part of a virtual network, which may be referred to as a cloud radio access network CRAN and/or a virtual baseband unit pool (vbbp). In these embodiments, the CRAN or vbbp may implement: RAN functional partitioning, e.g., PDCP partitioning, where radio resource control, RRC, and packet data convergence protocol, PDCP, layers are operated by the CRAN/vbbp, while other L2 protocol entities are operated by a separate RAN node 211; MAC/PHY division, where RRC, PDCP, radio control link RLC and medium access control MAC layers are operated by the CRAN/vbbp, while the physical layer (PHY layer) is operated by the respective RAN node 211; or "lower layer PHY" division, where the upper parts of RRC, PDCP, RLC, MAC and PHY layers are operated by the CRAN/vbbp, while the lower parts of PHY layers are operated by the respective RAN nodes 211. This virtualization framework allows the processor cores of RAN node 211 to be freed up to execute other virtualized applications. In some embodiments, a separate RAN node 211 may represent a separate gNB-DU connected to the gNB-CU through a separate F1 interface (not shown in fig. 2). In these embodiments, the gNB-DUs may include one or more remote radio heads or RFEMs (see, e.g., fig. 5), and the gNB-CUs may be operated by a server (not shown) located in the RAN 210, or by a server pool in a similar manner as the CRAN/vbbp. Additionally or alternatively, one or more RAN nodes 211 may be next generation enbs (NG-enbs), which are RAN nodes (e.g., CN 420 of fig. 4) that provide E-UTRA user plane and control plane protocol terminations towards UE201 over a NG interface (described below) and are connected to a5 GC.

In the V2X scenario, one or more RAN nodes 211 may be or act as road side units, RSUs. The term "road side unit" or "RSU" may refer to any transportation infrastructure entity for V2X communication. The RSU may be implemented in or by an appropriate RAN node or a fixed (or relatively fixed) UE, where the RSU in or implemented by the UE may be referred to as a "UE-type RSU", the RSU in or implemented by the eNB may be referred to as an "eNB-type RSU", the RSU in or implemented by the gNB may be referred to as a "gNB-type RSU", and so on. In one example, the RSU is a computing device coupled with radio frequency circuitry located at the roadside that provides connection support to passing vehicular UEs 201 (vues 201). The RSU may also include internal data storage circuitry for storing the geometry of the intersection map, traffic statistics, media, and applications/software for sensing and controlling ongoing vehicular and pedestrian traffic. The RSU may operate on the 5.9GHz Direct Short Range Communications (DSRC) band to provide very low latency communications required for high speed events (e.g., avoiding collisions, traffic warnings, etc.). Additionally or alternatively, the RSU may operate on the cellular V2X frequency band to provide the aforementioned low latency communications as well as other cellular communication services. Additionally or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4GHz band) and/or provide connectivity to one or more cellular networks to provide uplink and downlink communications. The computing equipment and some or all of the radio frequency circuitry of the RSU may be encased in a weatherproof housing suitable for outdoor installation and may include a network interface controller to provide wired connection (e.g., ethernet) signal control and/or backhaul network with the service.

Any of RAN nodes 211 may terminate the air interface protocol and may be a first point of contact for UE 201. In some embodiments, any of the RAN nodes 211 may implement various logical functions of the RAN 210, including, but not limited to, functions of a Radio Network Controller (RNC), such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

In an embodiment, UE201 may be configured to communicate with each other or with any of RAN nodes 211 using OFDM communication signals over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, OFDMA communication techniques (e.g., for downlink communications) or SC-FDMA communication techniques (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signal may include a plurality of orthogonal subcarriers.

In some embodiments, the downlink resource grid may be used for downlink transmissions from any RAN node 211 to UE201, while uplink transmissions may utilize similar techniques. The grid may be a time-frequency grid, referred to as a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. For OFDM systems, such a time-frequency plane representation is common practice, which makes radio resource allocation intuitive. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one time slot in a radio frame. The smallest time-frequency unit in the resource grid is denoted as a resource element. Each resource grid includes a plurality of resource blocks that describe the mapping of certain physical channels to resource elements. Each resource block includes a set of resource elements. In the frequency domain, this may represent the least resources that may currently be allocated. Several different physical downlink channels are transmitted using such resource blocks.

According to various embodiments, UE201 and RAN node 211 communicate (e.g., transmit and receive) data over a licensed medium (also referred to as "licensed spectrum" and/or "licensed band") and an unlicensed shared medium (also referred to as "unlicensed spectrum" and/or "unlicensed band"). The licensed spectrum may include channels operating in the frequency range of about 400MHz to about 3.8GHz, while the unlicensed spectrum may include a 5GHz band.

To operate in unlicensed spectrum, the UE201 and the RAN node 211 may operate using licensed assisted access, LAA, enhanced licensed assisted access, eLAA, and/or further enhanced licensed assisted access, feLAA mechanisms. In these embodiments, UE201 and RAN node 211 may perform one or more known medium sensing operations and/or carrier sensing operations in order to determine whether one or more channels in the unlicensed spectrum are unavailable or otherwise occupied prior to transmission in the unlicensed spectrum. The medium/carrier sensing operation may be performed according to a Listen Before Talk (LBT) protocol.

LBT is a mechanism by which a device (e.g., UE201 RAN node 211, etc.) may sense a medium (e.g., a channel or carrier frequency) and transmit when it is sensed that the medium is in an idle state (or when it is sensed that a particular channel in the medium is unoccupied). The medium sensing operation may include CCA that determines whether there are other signals on the channel, at least with the ED, to determine whether the channel is occupied or clear. This LBT mechanism allows the cellular/LAA network to coexist with existing systems in unlicensed spectrum as well as other LAA networks. ED may include sensing RF energy over an entire expected transmission band for a period of time and comparing the sensed RF energy to a predetermined or configured threshold.

Typically, the existing system in the 5GHz band is a WLAN based on IEEE 802.11 technology. WLANs employ a contention-based channel access mechanism called CSMA/CA. Here, when a WLAN node (e.g., a Mobile Station (MS) such as UE201, AP 206, etc.) intends to transmit, the WLAN node may first perform a CCA before transmitting. In addition, in the case where more than one WLAN node perceives the channel as idle and transmits simultaneously, a back-off mechanism is used to avoid collisions. The back-off mechanism may be a counter drawn randomly within the CWS that will increment exponentially when a collision occurs and reset to a minimum value when the transmission is successful. The LBT mechanism designed specifically for LAA is similar to CSMA/CA for WLAN. In some embodiments, an LBT procedure for a DL or UL transmission burst including PDSCH or PUSCH transmissions, respectively, may have an LAA contention window whose length is variable between X and Y ECCA slots, where X and Y are the minimum and maximum values of the CWS of the LAA. In one example, the minimum CWS for LAA transmission may be 9 microseconds (μ β); however, the size of the CWS and MCOT (e.g., transmission bursts) may be based on government regulatory requirements.

The LAA mechanism is built on the carrier aggregation CA technology of the LTE-Advanced system. In CA, each aggregated carrier is referred to as a component carrier CC. The CCs may have a bandwidth of 1.4, 3, 5, 10, 15, or 20MHz, and up to five CCs may be aggregated, and thus, the maximum aggregated bandwidth is 100 MHz. In an FDD system, the number of aggregated carriers may be different for DL and UL, where the number of UL CCs is equal to or less than the number of DL component carriers. In some cases, a single CC may have a different bandwidth than other CCs. In a TDD system, the number of CCs and the bandwidth of each CC are typically the same for DL and UL.

The CA also includes respective serving cells to provide respective CCs. The coverage of the serving cell may differ, for example, because CCs on different frequency bands will experience different path losses. The primary serving cell or PCell may provide a primary component carrier PCC for UL and DL and may handle RRC and non-access stratum NAS related activities. The other serving cells are referred to as scells, and each SCell may provide a separate SCC for UL and DL. SCCs may be added and deleted as needed, while changing PCC may require the UE201 to switch. In LAA, eLAA, and feLAA, some or all scells may operate in unlicensed spectrum (referred to as "LAA scells"), and the LAA scells are assisted by PCell operating in licensed spectrum. When a UE is configured with more than one LAA SCell, the UE may receive UL grants on the configured LAA SCell indicating different PUSCH starting positions within the same subframe.

The PDSCH carries user data and higher layer signaling to the UE 201. The PDCCH carries information about a transmission format and resource allocation related to the PDSCH channel. It may also inform the UE201 of transport format, resource allocation and HARQ information related to the uplink shared channel. Downlink scheduling (allocation of control and shared channel resource blocks to UEs 201b within a cell) can typically be performed on any RAN node 211 based on channel quality information fed back from any UE 201. The downlink resource allocation information may be sent on the PDCCH for (e.g., allocated to) each UE 201.

The PDCCH conveys control information using Control Channel Elements (CCEs). The PDCCH complex-valued symbols may first be organized into quadruplets before being mapped to resource elements, and then the quadruplets may be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine groups of four physical resource elements called REGs. Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. Depending on the size of the DCI and the channel conditions, the PDCCH may be transmitted using one or more CCEs. There may be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L ═ 1, 2, 4, or 8).

Some embodiments may use the concept of resource allocation for control channel information, which is an extension of the above concept. For example, some embodiments may utilize EPDCCH which uses PDSCH resources for control information transmission. One or more ECCEs may be used to transmit EPDCCH. Similar to the above, each ECCE may correspond to a set of nine physical resource elements, referred to as an Enhanced Resource Element Group (EREG). In some cases, ECCE may have other numbers of EREGs.

The RAN nodes 211 may be configured to communicate with each other via an interface 212. In embodiments where system 200 is an LTE system (e.g., when CN 220 is EPC 320 as in fig. 3), interface 212 may be an X2 interface 212. An X2 interface may be defined between two or more RAN nodes 211 (e.g., two or more enbs, etc.) connected to the EPC 220, and/or between two enbs connected to the EPC 220. The X2 interfaces may include an X2 user plane interface (X2-U) and an X2 control plane interface (X2-C). The X2-U may provide a flow control mechanism for user data packets transmitted over the X2 interface and may be used to communicate information about the transfer of user data between enbs. For example, X2-U may provide specific sequence number information for user data transmitted from MeNB to SeNB; information on successful transmission of PDCP PDUs from the SeNB to the UE201 to user data; information of PDCP PDUs that have not been delivered to the UE 201; information on a current minimum expected buffer size at the SeNB for transmitting user data to the UE; and so on. X2-C may provide intra-LTE access mobility functions including context transfer from source to target eNB, user plane transfer control, etc.; a load management function; and an inter-cell interference coordination function.

In embodiments where the system 200 is a 5G or NR system (e.g., when the CN 220 is a 5GC 420 as in fig. 4), the interface 212 may be an Xn interface 212. An Xn interface is defined between two or more RAN nodes 211 (e.g., two or more gnbs, etc.) connected to the 5GC 220, between a RAN node 211 (e.g., a gNB) connected to the 5GC 220 and an eNB, and/or between two enbs connected to the 5GC 220. In some implementations, the Xn interface can include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U can provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functionality. The Xn-C may provide management and error handling functions, i.e., functions to manage the Xn-C interface; mobility support for UE201 in CONNECTED mode (e.g., CM-CONNECTED) includes functionality to manage CONNECTED mode UE mobility between one or more RAN nodes 211. Mobility support may include context transfer from the old (source) serving RAN node 211 to the new (target) serving RAN node 211; and controls user plane tunneling between the old (source) serving RAN node 211 to the new (target) serving RAN node 211. The protocol stack of the Xn-U may comprise a transport network layer built on top of an Internet Protocol (IP) transport layer, a GTP-U layer on top of UDP and/or IP layers for carrying user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol, referred to as the Xn application protocol (Xn-AP), and a transport network layer established over the stream control transport protocol SCTP. SCTP can be located above the IP layer and can provide guaranteed delivery of application layer messages. In the transport IP layer, point-to-point transport is used to deliver signaling PDUs. In other embodiments, the Xn-U protocol stack and/or the Xn-C protocol stack may be the same as or similar to the user plane and/or control plane protocol stacks shown and described herein.

The RAN 210 is shown communicatively coupled to a core network, in this embodiment a Core Network (CN) 220. The CN 220 may include a plurality of network elements 222 configured to provide various data and telecommunications services to clients/subscribers (e.g., users of the UE 201) connected to the CN 220 via the RAN 210. The components of CN 220 may be implemented in one physical node or separate physical nodes that include components that read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments, any or all of the above network node functions may be virtualized using Network Function Virtualization (NFV) via executable instructions stored in one or more computer-readable storage media (described in further detail below). Logical instances of the CN 220 may be referred to as network slices, and logical instances of a portion of the CN 220 may be referred to as network subslices. The NFV architecture and infrastructure may be used to virtualize one or more network functions onto physical resources, which may alternatively be performed by proprietary hardware, including industry standard server hardware, storage hardware, or a combination of switches. In other words, the NFV system may be used to perform a virtual or reconfigurable implementation of one or more EPC components/functions.

In general, the application server 230 may be an element that provides applications using IP bearer resources to the core network (e.g., UMTS PS domain, LTE PS data services, etc.). Application server 230 may also be configured to support one or more communication services (e.g., VoIP sessions, PTT sessions, group communication sessions, social networking services, etc.) for UE201 via EPC 220.

In an embodiment, the CN 220 may be a 5GC (referred to as "5 GC 220" or the like), and the RAN 210 may be connected with the CN 220 via the NG interface 213. In an embodiment, NG interface 213 may be split. The signaling interface between NG user plane (NG-U) interface 214 and RAN S1 control plane (NG-C) interface 215 is divided into two parts: the NG user plane (NG-U) interface 214 transports traffic data nodes 211 and AMFs between the RAN nodes 211 and UPFs. An embodiment in which the CN 220 is a 5GC 220 is discussed in more detail with respect to figure 4.

In an embodiment, the CN 220 may be a 5G CN (referred to as "5 GC 220", etc.), while in other embodiments, the CN 220 may be an EPC. In the case where CN 220 is an EPC (referred to as "EPC 220", etc.), RAN 210 may be connected with CN 220 via S1 interface 213. In an embodiment, the S1 interface 213 may be divided into two parts, i.e., the S1 user plane (S1-U) interface 214 carries traffic data between the RAN node 211 and the S-GW, while the S1-MME interface 215 is a signaling interface between the RAN node 211 and the Mobility Management Entity (MME).

Figure 3 illustrates an example architecture of a system 300 including a first CN 320, in accordance with various embodiments. In this example, system 300 may implement the LTE standard, where CN 320 is EPC 320 corresponding to CN 220 of fig. 2. Additionally, UE 301 may be the same as or similar to UE201 of fig. 2, and E-UTRAN 310 may be the same as or similar to RAN 210 of fig. 2, and may include RAN node 211, discussed previously. CN 320 may include MME 321, serving gateway (S-GW)322, PDN gateway (P-GW)323, Home Subscriber Server (HSS)324, and Serving GPRS Support Node (SGSN) 325.

The MME 321 may be similar in function to the control plane of a conventional SGSN and may implement Mobility Management (MM) functions to track the current location of the UE 301. The MME 321 may perform various MM procedures to manage mobility aspects in access such as gateway selection and tracking area list management. MM (also referred to as "EPS MM" or "EMM" in E-UTRAN systems) may refer to all applicable procedures, methods, data stores, etc. for maintaining knowledge about the current location of UE 301, providing user identity confidentiality, and/or performing other similar services to the user/subscriber. Each UE 301 and MME 321 may include an MM or EMM sublayer and when the attach procedure is successfully completed, an MM context may be established in UE 301 and MME 321. The MM context may be a data structure or database object that stores MM-related information of UE 301. The MME 321 may be coupled with the HSS 324 via an S6a reference point, with the SGSN325 via an S3 reference point, and with the S-GW322 via an S11 reference point.

The SGSN325 may be a node serving the UE 301 by tracking the location of the individual UE 301 and performing security functions. In addition, SGSN325 may perform inter-EPC node signaling to enable mobility between 2G/3G and E-UTRAN 3GPP access networks. PDN and S-GW selection specified by MME 321; the handling of the UE 301 time zone function is as specified by the MME 321; and MME selection for handover to an E-UTRAN 3GPP access network. The S3 reference point between MME 321 and SGSN325 may enable inter-3 GPP access network mobility for user and bearer information exchange in idle and/or active states.

The HSS 324 may include a database for network users that includes subscription-related information to support the handling of communication sessions by network entities. The EPC 320 may include one or more HSS 324, depending on the number of mobile subscribers, the capacity of the devices, the organization of the network, etc. For example, the HSS 324 may provide support for routing/roaming, authentication. The S6a reference point between the HSS 324 and the MME 321 may enable the transfer of subscription and authentication data for authenticating/authorizing user access to the EPC 320 between the HSS 324 and the MME 321.

The S-GW322 may terminate the S1 interface 213 ("S1-U" in fig. 3) to the RAN 310 and route data packets between the RAN 310 and the EPC 320. In addition, S-GW322 may be a local mobility anchor for inter-RAN node handovers and may also provide an anchor for inter-3 GPP mobility. Other responsibilities may include lawful interception, charging, and certain policy enforcement. An S11 reference point between the S-GW322 and the MME 321 may provide a control plane between the MME 321 and the S-GW 322. The S-GW322 may be coupled with the P-GW323 via an S5 reference point.

The P-GW323 may terminate the SGi interface towards the PDN 330. P-GW323 may route data packets between EPC 320 and an external network, such as a network (alternatively referred to as an "AF") that includes application server 230, through IP interface 225 (see, e.g., fig. 2). In an embodiment, the P-GW323 may be communicatively coupled to an application server (application server 230 of fig. 2 or PDN 330 of fig. 3) via an IP communication interface 225 (see, e.g., fig. 2). An S5 reference point between P-GW323 and S-GW322 may provide user plane tunneling and tunnel management between P-GW323 and S-GW 322. The S5 reference point may also be used for the S-GW 322. Relocation is caused by the mobility of the UE 301 and whether the S-GW322 needs to connect to a non-collocated P-GW323 to achieve the required PDN connectivity. The P-GW323 may further include a node (e.g., PCEF (not shown)) for policy enforcement and charging data collection. In addition, the SGi reference point between the P-GW323 and the Packet Data Network (PDN)330 may be an operator external public network, a private PDN, or an operator internal packet data network, e.g., for providing IMS services. The P-GW323 may be coupled with a policy control and charging rules function (PCRF)326 via a Gx reference point.

PCRF 326 is a policy and charging control element of EPC 320. In a non-roaming case, there may be only one PCRF 326 in a Home Public Land Mobile Network (HPLMN) associated with an Internet protocol connected access network (IP-CAN) session for UE 301. In a roaming scenario with local traffic disruption, there may be two PCRFs associated with the IP-CAN session of UE 301, a local PCRF (H-PCRF) in HPLMN and a visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 326 may be communicatively coupled to the application server 330 via the P-GW 323. Application server 330 may signal PCRF 326 to indicate the new service flow and select the appropriate QoS and charging parameters. PCRF 326 may provide the rules to a PCEF (not shown) with appropriate TFTs and QCIs, which starts QoS and charging as specified by application server 330. A Gx reference point between PCRF 326 and P-GW323 may allow QoS policy and charging rules to be transferred from PCRF 326 to PCEF in P-GW 323. The Rx reference point may reside between the PDN 330 (or "AF 330") and the PCRF 326.

Figure 4 illustrates an architecture of a system 400 including a second CN 420, in accordance with various embodiments. The illustrated system 400 includes a UE 401, which may be the same as or similar to UE201 and UE 301 previously discussed; AN 410, which may be the same as or similar to RAN 210 and RAN 310 discussed previously, and may include RAN node 211 discussed previously; DN 403, which may be, for example, an operator service, internet access, or third party service; and a 5G core network (5GC) 420. The 5GC 420 may include an authentication server function (AUSF) 422; an access and mobility management function (AMF) 421; a Session Management Function (SMF) 424; a Network Exposure Function (NEF) 423; a Policy Control Function (PCF) 426; (network function storage function) NRF 425; unified Data Management (UDM) 427; an Application Function (AF) 428; a User Plane Function (UPF) 402; and a Network Slice Selection Function (NSSF) 429.

The UPF 402 may serve as an anchor point for intra-RAT and inter-RAT mobility, an interconnecting external PDU session point to DN 403, and a branch point for supporting multi-homed PDU sessions. The UPF 402 may also perform packet routing and forwarding, perform packet inspection, perform the user plane part of policy rules, lawfully intercept packets (UP collection), perform traffic usage reporting, perform QoS processing for the user plane (e.g., packet filtering), gating, UL/DL rate enforcement, perform uplink traffic validation (e.g., SDF to QoS flow mapping), transmit level packet marking in uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. The UPF 402 may include an uplink classifier to support routing of traffic flows to a data network. DN 403 may represent various network operator services, Internet access, or third party services. DN 403 may include or be similar to application server 230 previously discussed. The UPF 402 may interact with the SMF 424 via an N4 reference point between the SMF 424 and the UPF 402.

The AUSF 422 may store data for authentication of the UE 401 and handle functions related to authentication. The AUSF 422 can facilitate a universal authentication framework for various access types. AUSF 422 may communicate with AMF421 via an N12 reference point between AMF421 and AUSF 422; and may communicate with UDM 427 via an N13 reference point between UDM 427 and AUSF 422. Further, the AUSF 422 may expose a Nausf service based interface.

The AMF421 may be responsible for registration management (e.g., registering the UE 401, etc.), connection management, reachability management, mobility management, and lawful interception of AMF-related events and access authentication and authorization. The AMF421 may be the termination point of the N11 reference point between the AMF421 and the SMF 424. AMF421 may provide for the transmission of SM messages between UE 401 and SMF 424 and act as a transparent proxy for routing SM messages. AMF421 may also provide for transmission of SMS messages between UE 401 and an SMSF (not shown in fig. 4). AMF421 may act as a SEAF, which may include interactions with AUSF 422 and UE 401, receiving intermediate keys established as a result of UE 401 authentication procedures. In case USIM based authentication is used, the AMF421 may retrieve security material from the AUSF 422. The AMF421 may also include an SCM function that receives a key from the SEA, which is used to derive the visited network specific key. Further, the AMF421 may be a termination point of the RAN CP interface, which may include or may be AN N2 reference point between the (R) AN 410 and the AMF 421; the AMF421 may be the termination point of NAS (N1) signaling and performs NAS ciphering and integrity protection.

AMF421 may also support NAS signaling with UE 401 through an N3IWF (interworking function) interface. The N3IWF may be used to provide access to untrusted entities. The N3IWF may be AN endpoint of the N2 interface between the (R) AN 410 and the AMF421 for the control plane and may be AN endpoint of the N3 reference point between the (R) AN 410 and the UPF 402 for the user plane. In this way, AMF421 can process N2 signaling for PDU session and QoS from SMF 424 and AMF421, encapsulate/decapsulate packets for IPSec and N3 tunnel, mark N3 user plane packets in uplink, and enforce QoS corresponding to QoS. N0 packet marking is performed on N3 packet marking taking into account the QoS requirements associated with such marking received through N2. The N3IWF may also relay uplink and downlink control plane NAS signaling between the UE 401 and the AMF421 via the N1 reference point between the UE 401 and the AMF421, and relay uplink and downlink user plane packets between the UE 401 and the UPF 402. The N3IWF also provides a mechanism for establishing an IPsec tunnel with UE 401. The AMF421 may expose an interface based on the Namf service and may be a termination point of an N14 reference point between two AMFs 421 and an N17 reference point between the AMFs 421 and 5G-EIR (not shown in fig. 4).

UE 401 may need to register with AMF421 in order to receive network services. The RM is used to register or deregister the UE 401 with the network (e.g., the AMF 421) and establish a UE context (e.g., the AMF 421) in the network. The UE 401 may operate in an RM-REGISTERED (RM REGISTERED) state or an RM-DEREGISTERED (RM DEREGISTERED) state. In the RM deregistered state, UE 401 is not registered with the network and the UE context in AMF421 does not retain valid location or routing information for UE 401, so AM 421 cannot reach UE 401. In the RM registration state, UE 401 has registered with the network, and the UE context in AMF421 may hold valid location or routing information of UE 401 so that AMF421 may access UE 401. In the RM registration state, UE 401 may perform a mobility registration update procedure, perform a periodic registration update procedure triggered by the expiration of a periodic update timer (e.g., to inform the network that UE 401 is still in an active state), and perform a registration update procedure to update UE capability information or renegotiate protocol parameters with the network, etc.

AMF421 may store one or more RM contexts for UE 401, where each RM context is associated with a particular access to the network. The RM context may be a data structure, database object, etc. that indicates or stores registration status and periodic update timers, etc. for each access type. The AMF421 may also store a 5GC MM context that is the same as or similar to the (E) MM context previously discussed. In various embodiments, AMF421 may store the CE mode B restriction parameters for UE 401 in the associated MM context or RM context. The AMF421 may also derive this value from the UE usage setting parameters already stored in the UE context (and/or MM/RM context) when needed.

A Connection Management (CM) may be used to establish and release a signaling connection between the UE 401 and the AMF421 through the N1 interface. The signaling connection is used to enable NAS signaling exchange between UE 401 and CN 420 and includes a signaling connection between the UE and AN (e.g., AN RRC connection for non-3 GPP access or a UE-N3IWF connection) and AN N2 connection of UE 401 between AN (e.g., RAN 410) and AMF 421. UE 401 may operate in one of the two CM states, CM-IDLE mode or CM-CONNECTED mode. When the UE 401 is operating in the CM-IDLE state/mode, the UE 401 may not have AN NAS signaling connection established with the AMF421 over the N1 interface, and there may be AN (R) AN 410 signaling connection (e.g., AN N2 and/or N3 connection). When the UE 401 is operating in the CM-CONNECTED state/mode, the UE 401 may establish a NAS signaling connection with the AMF421 through the N1 interface and AN (R) AN 410 signaling connection (e.g., N2 and/or N3 connection) for the UE 401. Establishing AN N2 connection between the (R) AN 410 and the AMF421 may transition the UE 401 from a CM-IDLE mode to a CM-CONNECTED mode, and the UE 401 may transition from the CM-CONNECTED mode to the CM-IDLE mode when N2 signaling between the (R) AN 410 and the AMF421 is released.

SMF 424 may be responsible for SM (e.g., session establishment, modification, and release, including tunnel maintenance between UPF and AN nodes); UE IP address assignment and management (including optional authorization); selection and control of the UP function; configuring flow control on the UPF to route the flow to the correct destination; terminating the interface with the policy control function; controlling a portion of policy enforcement and QoS; lawful interception (for SM events and interface with LI system); termination of the SM part of the NAS message; downlink data notification; starting a specific SM message, which is sent to the AN through the AMF on N2; the SSC pattern for the session is determined. SM may refer to the management of PDU sessions, and a PDU session or "session" may refer to a PDU connection service that provides or enables the exchange of PDUs between a UE 401 and a Data Network (DN)403 identified by a Data Network Name (DNN). The PDU session may be established according to the UE 401 request, modified according to the UE 401 and 5GC 420 requests, and released according to the UE 401 and 5GC 420 requests, using NAS SM signaling exchanged between the UE 401 and SMF 424 at the N1 reference point. On the application server, the 5GC 420 may trigger a specific application in the UE 401. In response to receiving the trigger message, UE 401 may pass the trigger message (or a relevant portion/information of the trigger message) to one or more applications in one or more identified UEs 401. One or more applications identified in UE 401 may establish a PDU session to a particular DNN. SMF 424 may check whether UE 401 request conforms to user subscription information associated with UE 401. In this regard, the SMF 424 can retrieve and/or request to receive update notifications from the UDM 427 regarding SMF 424 level subscription data.

SMF 424 may include the following roaming functions: processing local enforcement to apply QoS SLA (VPLMN); a charging data collection and charging interface (VPLMN); lawful interception (in VPLMN for SM events and connected to LI system); interaction with the foreign DN is supported to transmit signaling of PDU session authorization/authentication through the foreign DN. An N16 reference point between two SMFs 424 may be included in system 400, and this N16 reference point may be between another SMF 424 in the visited network and an SMF 424 in the home network in the roaming scenario. Additionally, SMF 424 may expose an Nsmf service based interface.

NEF 423 may provide various means for securely exposing services and capabilities provided by 3GPP network functions for third parties, internal exposure/re-exposure, application functions (e.g., AF 428), edge computing or fog computing systems, and the like. In embodiments, NEF 423 may authenticate, authorize and/or restrict AF. NEF 423 may also translate information exchanged with AF 428 and information exchanged with internal network functions. For example, the NEF 423 may convert between the AF service identifier and the internal 5GC information. NEF 423 may also receive information from other Network Functions (NFs) based on exposed capabilities of the other network functions. This information may be stored as structured data at NEF 423 or may be stored at data store NF using a standardized interface. The stored information may then be re-exposed by NEF 423 to other NFs and AFs, and/or used for other purposes, such as analysis. In addition, NEF 423 may expose an interface based on the Nnef service.

NRF 425 may support a service discovery function, receive NF discovery requests from NF instances, and provide information of discovered NF instances to NF instances. NRF 425 also maintains information of available NF instances and their supported services. As used herein, the term "instantiation" or the like may refer to the creation of an instance, while "instance" may refer to the specific occurrence of an object, which may occur, for example, during execution of program code. Additionally, NRF 425 may expose an interface based on nrrf services.

PCF 426 may provide policy rules to control plane functions to perform them and may also support a unified policy framework to manage network behavior. The PCF 426 may also implement a Front End (FE) to access subscription information related to policy decisions in the UDR of the UDM 427. The PCF 426 may communicate with the AMF421 via an N15 reference point between the PCF 426 and the AMF421, which may include: PCF 426 in the visited network and AMF421 in roaming situations. The PCF 426 may communicate with the AF 428 via an N5 reference point between the PCF 426 and the AF 428; and communicates with SMF 424 via an N7 reference point between PCF 426 and SMF 424. In the visited network, system 400 and/or CN 420 may also include an N24 reference point between PCF 426 (in the home network) and PCF 426. In addition, PCF 426 may expose an interface based on Npcf services.

UDM 427 may process subscription-related information to support processing of communication sessions by network entities and may store subscription data for UE 401. For example, subscription data may be transferred between UDM 427 and AMF421 via the N8 reference point between UDM 427 and AMF. The UDM 427 may include two parts, an application FE and a UDR (FE and UDR not shown in FIG. 4). The UDR may store subscription data and policy data for UDM 427 and PCF 426 of NEF 423 and/or structured data for exposure and application data (including PFD for application detection, application request information for multiple UEs 401). The UDR may expose a service-based interface to allow UDM 427, PCF 426, and NEF 423 to access a particular set of stored data, as well as read, update (e.g., add, modify), delete, and subscribe to notifications of relevant data changes in the UDR. The UDM may include a UDM-FE that is responsible for handling credentials, location management, subscription management, and the like. Several different front ends may serve the same user in different transactions. The UDM-FE accesses the subscription information stored in the UDR and performs authentication credential processing, user identification processing, access authorization, registration/mobility management and subscription management. The UDR may interact with SMF 424 via an N10 reference point between UDM 427 and SMF 424. UDM 427 may also support SMS management, where an SMS-FE implements similar application logic as previously discussed. Additionally, the UDM 427 may expose a numm service based interface.

The AF 428 may have an application impact on traffic routing, provide access to NCE, and interact with the policy framework for policy control. The NCE may be a mechanism that allows the 5GC 420 and the AF 428 to provide information to each other via the NEF 423, which may be used for edge computing implementation. In such embodiments, network operator and third party services may be hosted at access points close to the UE 401 access point to enable efficient service delivery with reduced end-to-end latency and load on the transport network. For edge calculation implementation, the 5GC may select a UPF 402 close to the UE 401 and perform flow control from the UPF 402 to the DN 403 through the N6 interface. This may be based on the UE subscription data, UE location and information provided by the AF 428. In this way, the AF 428 may affect UPF (re) selection and traffic routing. Based on operator deployment, the network operator may allow the AF 428 to interact directly with the relevant NFs when the AF 428 is considered a trusted entity. In addition, the AF 428 may expose a Naf service-based interface.

NSSF429 may select a set of network slice instances that serve UE 401. NSSF429 may also determine allowed Network Slice Selection Assistance Information (NSSAI) and mapping to subscribed S-NSSAI, if desired. NSSF429 may also determine the set of AMFs or candidate AMF list 421 to be used to serve UE 401 based on a suitable configuration and possibly by querying NRF 425, which may be done by querying the network slice instance. The movement of UE 401 may be triggered by interacting with AMF421 registered with UE 401 with NSSF429, which may result in a change of AMF 421. NSSF429 may interact with AMF421 via the N22 reference point between AMF421 and NSSF 429; and may communicate with another NSSF429 in the visited network via an N31 reference point (not shown in fig. 4). Further, NSSF429 may expose an NSSF service based interface.

As previously described, CN 420 may include an SMSF that is responsible for SMS subscription checking and verification and relays SM messages to and from UE 401 to and from other entities, such as SMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF421 and UDM 427 for notification procedures that UE 401 may use for SMS transmission (e.g., set a UE unreachable flag, and notify UDM 427 when UE 401 is available for SMS).

CN 420 may also include other elements not shown in fig. 4, such as a data storage system/architecture, a 5G device identification register (5G-EIR), a Secure Edge Protection Proxy (SEPP), and the like. The data storage system may include a Structured Data Storage Function (SDSF), an Unstructured Data Storage Function (UDSF), and the like. Any Network Function (NF) may store and retrieve unstructured data to and from the UDSF (e.g., UE context) via an N18 reference point (not shown in fig. 4) between any NF and the UDSF. The various NFs may share a UDSF for storing their respective unstructured data, or the various NFs may have their respective UDSF at or near the various NFs. Additionally, the UDSF may show an interface based on the Nudsf service (not shown in fig. 4). The 5G-EIR may be a NF to check the status of a permanent device identifier (PEI) to determine whether a particular device/entity is blacklisted from the network. The SEPP may be a non-transparent proxy and may perform topology hiding, message filtering and policy management on the control plane interface between Public Land Mobile Networks (PLMNs).

Additionally, there may be more reference points and/or service-based interfaces between NF services in the NF; however, for clarity, these interfaces and reference points have been omitted from FIG. 4. In one example, CN 420 may include an Nx interface, which is an inter-CN interface between an MME (e.g., MME 321) and AMF421, in order to enable interworking between CN 420 and CN 320. The reference point may comprise an interface based on the N5G-EIR service, shown by the 5G-EIR, an N27 reference point between the NRF in the visited network and the NRF in the home network; the N31 reference point between the NSSF in the visited network and the NSSF in the home network.

Fig. 5 illustrates an example of an infrastructure device 500 according to various embodiments. Infrastructure device 500 (or "system 500") may be implemented as a base station, a radio head, a RAN node such as RAN node 211 and/or AP 206 shown and described previously, application server 230, and/or any other element/device discussed herein. In other examples, system 500 may be implemented in or by a UE.

The system 500 includes an application circuit 505, a baseband circuit 510, one or more Radio Front End Modules (RFEM)515, a memory circuit 520, a Power Management Integrated Circuit (PMIC)525, a power tee circuit 530, a network controller circuit 535, a network interface connector 540, a satellite positioning circuit 545, and a user interface 550. In some embodiments, device 500 may include other elements, such as memory/storage, a display, a camera, a sensor, or an input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device. For example, the circuitry may be included separately in one or more devices for cloud radio access networks CRAN, vbub, or other similar implementations.

Application circuit 505 includes circuitry such as, but not limited to, one or more processors (or processor cores), cache memory, and one or more low dropout regulators (LDOs), interrupt controllers, serial interfaces such as serial peripheral interface SPI, I2C, or a universal programmable serial interface module, Real Time Clock (RTC), timers including interval and watchdog timers, universal input/output (I/O or IO), memory card controllers (e.g., Secure Digital (SD), multimedia card (MMC), etc.), Universal Serial Bus (USB) interfaces, Mobile Industry Processor Interface (MIPI) interfaces, and Joint Test Access Group (JTAG) test access ports. The processor (or core) of the application circuitry 505 may be coupled with or may include memory/storage elements and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the system 500. In some embodiments, the memory/storage elements may be on-chip memory circuits, which may include any suitable volatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, flash, solid-state memory, and/or any other type of storage device technology (e.g., the technology discussed herein).

The processors of application circuitry 505 may include, for example, one or more processor Cores (CPUs), one or more application processors, one or more Graphics Processing Units (GPUs), one or more Reduced Instruction Set Computing (RISC) processors, one or more Acorn RISC Machine (ARM) processors, one or more Complex Instruction Set Computing (CISC) processors, one or more Digital Signal Processors (DSPs), one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, or any suitable combination thereof. In some embodiments, the application circuitry 505 may include or may be a dedicated processor/controller operating in accordance with various embodiments herein. As an example, the processor of the application circuit 505 may include one or more Intels

Or

A processor; advanced Micro Devices (AMD)

Processors, Accelerated Processing Units (APUs) or

A processor; ARM-based processors that have been licensed by ARM Holdings, Ltd., such as the ARM Cortex-A family of processors and the processor provided by Cavium (TM), Inc

MIPS-based designs from MIPS Technologies, inc, such as MIPS Warrior class P processors; and the like. In some embodiments, the system 500 may not utilize the application circuitry 505, but may include a dedicated processor/controller toIP data received from, for example, EPC or 5GC is processed.

In some implementations, the application circuitry 505 can include one or more hardware accelerators, which can be microprocessors, programmable processing devices, or the like. The one or more hardware accelerators may include, for example, Computer Vision (CV) and/or Deep Learning (DL) accelerators. By way of example, the programmable processing device may be one or more Field Programmable Devices (FPDs), such as Field Programmable Gate Arrays (FPGAs), or the like; programmable Logic Devices (PLDs), such as complex PLDs (cplds), high capacity PLDs (hcplds), and the like; ASICs, such as structured ASICs and the like; programmable soc (psoc); and so on. In such implementations, the circuitry of the application circuitry 505 may include logic blocks or logic structures, as well as other interconnected resources that may be programmed to perform various functions, such as the processes, methods, functions, etc. of the various embodiments discussed herein. In such embodiments, the circuitry of the application circuit 505 may include storage units (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., Static Random Access Memory (SRAM), anti-fuses, etc.)) for storing logic blocks, logic structures, data, etc. in a look-up table (LUT), etc.

The baseband circuitry 510 may be implemented, for example, as a soldered lower substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module containing two or more integrated circuits. The various hardware electronics of baseband circuit 510 are discussed below with reference to fig. 7.

The user interface circuitry 550 may include one or more user interfaces designed to enable a user to interact with the system 500 or user interfaces where peripheral components are designed to enable peripheral devices to interact with the system 500. The user interface may include, but is not limited to, one or more physical or virtual buttons (e.g., a reset button), one or more indicators (e.g., Light Emitting Diodes (LEDs)), a physical keyboard or keypad, a mouse, a touchpad, a touch screen, a speaker or other audio emitting device, a microphone, a printer, a scanner, a headset, a display screen or display device, and the like. Peripheral component interfaces may include, but are not limited to, non-volatile memory ports, Universal Serial Bus (USB) ports, audio jacks, power interfaces, and the like.

The radio front-end module (RFEM)515 may include a millimeter wave (mmWave) RFEM and one or more sub-millimeter wave Radio Frequency Integrated Circuits (RFICs). In some implementations, the one or more sub-millimeter wave RFICs may be physically separate from the millimeter wave RFEM. RFICs may include connections to one or more antennas or antenna arrays (see, e.g., antenna array 7111 of fig. 7 below), and RFEM may be connected to multiple antennas. In alternative embodiments, both millimeter-wave and sub-millimeter-wave radio functions may be implemented in the same physical RFEM 515, which physical RFEM 515 incorporates a millimeter-wave antenna and sub-millimeter waves.

Memory circuit 520 may include one or more of the following: volatile memory including Dynamic Random Access Memory (DRAM) and/or Synchronous Dynamic Random Access Memory (SDRAM), and non-volatile memory (NVM) including high speed electrically erasable memory (commonly referred to as flash memory), phase change random access memory (PRAM), Magnetoresistive Random Access Memory (MRAM), and the like, and may include

And

a three-dimensional (3D) cross point (XPOINT) memory. Memory circuit 520 may be implemented as one or more of a solder-down packaged integrated circuit, a socket memory module, and a plug-in memory card.

The PMIC 525 may include a voltage regulator, a surge protector, a power alarm detection circuit, and one or more backup power sources, such as a battery or a capacitor. The power alarm detection circuit may detect one or more of power down (under-voltage) and surge (over-voltage) conditions. Power tee circuit 530 may provide power drawn from a network cable to provide power and data connections to infrastructure equipment 500 using a single cable.

The network controller circuit 535 may provide connectivity to the network using a standard network interface protocol such as ethernet, ethernet over GRE tunnels, ethernet over multiprotocol label switching (MPLS), or some other suitable protocol. The network connection may be provided to/from the infrastructure equipment 500 via the network interface connector 540 using a physical connection, which may be electrical (commonly referred to as a "copper interconnect"), optical, or wireless. Network controller circuitry 535 may include one or more special purpose processors and/or FPGAs to communicate using one or more of the above-described protocols. In some embodiments, the network controller circuit 535 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

The positioning circuitry 545 includes circuitry for receiving and decoding signals transmitted/broadcast by a positioning network of a Global Navigation Satellite System (GNSS). Examples of navigation satellite constellations (or GNSS) include the Global Positioning System (GPS) in the united states, the global navigation system in russia (GLONASS), the galileo system in the european union, the beidou navigation satellite system in china, the regional navigation system or the GNSS augmentation system (for example, for indian constellation Navigation (NAVIC), the quasi-zenith satellite system (QZSS) in japan, doppler orbit imaging in france, and satellite integrated radio positioning (DORIS), etc.). The positioning circuitry 545 includes various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, etc. to facilitate OTA communication) to communicate with components of a positioning network, such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry 545 may include a Micro-technology (Micro-PNT) IC for positioning, navigation, and timing that performs position tracking/estimation using a master timing clock without GNSS assistance. The positioning circuitry 545 may also be part of or interact with the baseband circuitry 510 and/or the RFEM 515 to communicate with nodes and components of a positioning network. The positioning circuitry 545 may also provide location data and/or time data to the application circuitry 505, which the application circuitry 505 may use to synchronize operations with various infrastructure (e.g., RAN node 211, etc.) and/or the like.

The components shown in fig. 5 may communicate with each other using interface circuitry that may include any number of bus and/or Interconnect (IX) technologies such as Industry Standard Architecture (ISA), extended ISA (eisa), Peripheral Component Interconnect (PCI), extended peripheral component interconnect (PCI x), PCI Express (PCIe), or any number of other technologies. The bus/IX may be a dedicated bus, for example, for use in a SoC-based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, a point-to-point interface, and a power bus.

Fig. 6 illustrates an example of a platform 600 (or "device 600") according to various embodiments. In embodiments, computer platform 600 may be suitable for use as UE201, 301, 401, application server 230, and/or any other element/device discussed herein. The platform 600 may include any combination of the components shown in the examples. The components of platform 600 may be implemented as Integrated Circuits (ICs), portions thereof, discrete electronic or other modules, logic, hardware, software, firmware, or combinations thereof suitable for computer platform 600, or as components otherwise incorporated in the chassis of a larger system. The block diagram of FIG. 6 is intended to illustrate a high-level view of the components of computer platform 600. However, some of the components shown may be omitted, additional components may be present, and a different arrangement of the components shown may occur in other implementations.

Application circuit 605 includes circuitry such as, but not limited to, one or more processors (or processor cores), cache memory, and one or more LDOs, interrupt controllers, serial interfaces such as SPI, I2C, or a universal programmable serial interface module, RTCs, timer counters (including interval timers and watchdog timers), universal I/O, memory card controllers (e.g., SD MMC or similar products), USB interfaces, MIPI interfaces, and JTAG test access ports. The processor (or core) of the application circuitry 605 may be coupled with or may include memory/storage elements and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the system 600. In some embodiments, the memory/storage elements may be on-chip memory circuits, which may include any suitable volatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, flash, solid-state memory, and/or any other type of storage device technology (e.g., the technology discussed herein).

The processors of application circuitry 505 may include, for example, one or more processor cores, one or more application processors, one or more GPUs, one or more RISC processors, one or more ARM processors, one or more CISC processors, one or more DSPs, one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, a multi-threaded processor, an ultra-low voltage processor, an embedded processor, some other known processing element, or any other suitable combination thereof. In some embodiments, the application circuitry 505 may include or may be a dedicated processor/controller operating in accordance with various embodiments herein.

As an example, the processor of the application circuit 605 may include a microprocessor based microprocessor

Processors for Architecture core, such as Quark, AtomTM, i3, i5, i7 or MCU grade processors, or may be selected from

Corporation, Santa Clara, Calif. obtains another such processor. The processor of the application circuit 605 may also be one or more of the following: advanced Micro Devices (AMD)

A processor or Accelerated Processing Unit (APU);

company a5-a9 processor,

snapdragon (tm) processors by Technologies, inc, Texas Instruments,

open type multiA media application platform (OMAP) TM processor; MIPS-based designs from MIPS Technologies, inc, such as MIPS Warrior M-class, Warrior I-class, and Warrior P-class processors; ARM-based designs, such as the ARM Cortex-A, Cortex-R, and Cortex-M series of processors, licensed by ARM Holdings, Ltd; and so on. In some embodiments, the application circuit 605 may be part of a system on a chip (SoC), where the application circuit 605 and other components are formed as a single integrated circuit or a single package, e.g.

Edison (TM) or Galileo (TM) SoC boards from Corporation.

Additionally or alternatively, the application circuitry 605 may include circuitry such as, but not limited to, one or more Field Programmable Devices (FPDs) such as FPGAs or the like; programmable Logic Devices (PLDs), such as complex PLDs (cplds), high capacity PLDs (hcplds), and the like; ASICs, such as structured ASICs and the like; programmable soc (psoc); and so on. In such embodiments, the circuitry of the application circuitry 605 may comprise logic blocks or logic structures, as well as other interconnected resources that may be programmed to perform various functions, such as the processes, methods, functions, etc. of the various embodiments discussed herein. In such embodiments, the circuitry of the application circuit 605 may include a storage unit (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., static random access memory).

The baseband circuit 610 may be implemented, for example, as a solder substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module containing two or more integrated circuits. Various hardware electronic components of the baseband circuitry 610 are discussed below with reference to fig. 7.

The RFEM615 may include a millimeter wave (mmWave) RFEM and one or more sub-millimeter wave Radio Frequency Integrated Circuits (RFICs). In some implementations, the one or more sub-millimeter wave RFICs may be physically separate from the millimeter wave RFEM. RFICs may include connections to one or more antennas or antenna arrays (see, e.g., antenna array 7111 of fig. 7 below), and RFEM may be connected to multiple antennas. In an alternative implementation, both millimeter wave and sub-millimeter wave radio functions may be implemented in the same physical RFEM615, which physical RFEM615 contains both millimeter wave antennas and sub-millimeter waves.

Memory circuit 620 may include any number and type of memory devices for providing a given amount of system memory. By way of example, memory circuit 620 may include one or more of the following: volatile memory including Random Access Memory (RAM), dynamic RAM (dram), and/or synchronous dynamic RAM (sdram), and non-volatile memory (NVM) including high speed electrically erasable memory (commonly referred to as flash memory), phase change random access memory (PRAM), Magnetoresistive Random Access Memory (MRAM), and the like. The memory circuit 620 may be developed according to the Joint Electronic Device Engineering Council (JEDEC) design based on Low Power Double Data Rate (LPDDR) such as LPDDR2, LPDDR3, LPDDR4, etc. The memory circuit 620 may be implemented as one or more of the following: solder-down packaged integrated circuits, Single Die Packages (SDP), Dual Die Packages (DDP) or quad die packages (Q17P), slot-in memory modules, dual in-line memory modules (DIMMs), including micro DIMMs or MiniDIMMs, and/or soldered to a motherboard via a Ball Grid Array (BGA). In a low power implementation, memory circuit 620 may be an on-die memory or a register associated with application circuit 605. To provide persistent storage of information, such as data, applications, operating systems, etc., memory circuit 620 may include one or more mass storage devices, which may include, among others, a Solid State Disk Drive (SSDD), a Hard Disk Drive (HDD), a micro HDD, a resistance change memory, a phase change memory, a holographic memory, or a chemical memory. For example, computer platform 600 may incorporate information from

And

three-dimensional (3D) intersection ofA point (XPOINT) memory.

Removable storage circuit 623 may include devices, circuitry, enclosures/housings, ports or sockets, etc. for coupling a portable data storage device with platform 600. These portable data storage devices may be used for mass storage purposes and may include those used for example for flash memory cards (e.g., Secure Digital (SD) cards, microSD cards, xD picture cards, etc.), as well as USB flash drives, optical disks, external HDDs, etc.

The platform 600 may also include interface circuitry (not shown) for interfacing external devices with the platform 600. External devices connected to the platform 600 through interface circuits include sensor circuits 621 and electro-mechanical components (EMC)622, and a removable memory device coupled to removable memory circuit 623.

The sensor circuit 621 includes a device, module, or subsystem whose purpose is to detect an event or a change in its environment and to send information (sensor data) about the detected event to other devices, modules, subsystems, and the like. Examples of sensors include, inter alia, Inertial Measurement Units (IMUs) including accelerometers, gyroscopes, and/or magnetometers; a microelectromechanical system (MEMS) or nanoelectromechanical system (NEMS) comprising a 3-axis accelerometer, a 3-axis gyroscope and/or magnetometer; a liquid level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; an air pressure sensor; a gravimeter; an altimeter; an image capture device (e.g., a camera or a lens-less aperture); a light detection and ranging (LiDAR) sensor; proximity sensors (e.g., infrared radiation detectors, etc.), depth sensors, ambient light sensors, ultrasonic transceivers; a microphone or other similar audio capture device; and so on.

EMC 622 includes devices, modules, or subsystems whose purpose is to enable platform 600 to change its state, position, and/or orientation, or to move or control a mechanism or (subsystem). Additionally, EMC 622 may be configured to generate and send messages/signaling to other components of platform 600 to indicate the current state of EMC 622. Examples of EMC 622 include one or more power switches, relays including electromechanical relays (EMRs) and/or Solid State Relays (SSRs), actuators (e.g., valve actuators, etc.), sound generators, visual warning devices, motors (e.g., dc motors, stepper motors, etc.), wheels, propellers, claws, clamps, hooks, and/or other similar electromechanical components. In an embodiment, platform 600 is configured to operate one or more EMCs 622 based on one or more captured events and/or instructions or control signals received from a service provider and/or various clients.

In some implementations, interface circuitry may connect platform 600 with positioning circuitry 645. Positioning circuitry 645 includes circuitry for receiving and decoding signals transmitted/broadcast by the positioning network of the GNSS. Examples of navigation satellite constellations (or GNSS) include GPS in the united states, GLONASS in russia, galileo in the european union, beidou navigation satellite system in china, regional navigation system or GNSS augmentation system (e.g., NAVIC), QZSS in japan, DORIS in france, and so on. The positioning circuitry 645 includes various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, etc. to facilitate OTA communication) to communicate with components of a positioning network such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry 645 may include a Micro-PNT IC that uses a master timing clock to perform position tracking/estimation without GNSS assistance. The positioning circuitry 645 may also be part of or interact with the baseband circuitry 510 and/or the RFEM615 to communicate with nodes and components of the positioning network. The positioning circuitry 645 may also provide location data and/or time data to the application circuitry 605, which the application circuitry 605 may use to operate in synchronization with various infrastructure (e.g., radio base stations), for line-by-line navigation applications, and so forth.

In some implementations, interface circuitry may connect platform 600 with Near Field Communication (NFC) circuitry 640. NFC circuitry 640 is configured to provide contactless, short-range communication based on Radio Frequency Identification (RFID) standards, where magnetic field induction is used to communicate between NFC circuitry 640 external to platform 600 and NFC-enabled devices (e.g., "NFC contacts"). NFC circuitry 640 includes an NFC controller coupled with the antenna element and a processor coupled with the NFC controller. The NFC controller may be a chip/IC that provides NFC functionality to the NFC circuitry 640 by executing NFC controller firmware and an NFC stack. The NFC stack may be executable by the processor to control the NFC controller, and the NFC controller firmware may be executable by the NFC controller to control the antenna element to transmit the short-range radio frequency RF signal. The RF signal may power a passive NFC tag (e.g., a microchip embedded in a sticker or wristband) to transfer stored data to NFC circuit 640, or to activate NFC circuit 640 with another active NFC device (e.g., a smartphone or NFC-enabled POS terminal near platform 600).

The driver circuit 646 may include software and hardware elements for controlling specific devices embedded in the platform 600, attached to the platform 600, or otherwise communicatively coupled with the platform 600. The driver circuit 646 may comprise individual drivers that allow other components of the platform 600 to interact with or control various input/output (I/O) devices that may be present in the platform 600 or connected to the platform 600. For example, driver circuit 646 may include a display driver to control and allow access to a display device, a touch screen driver to control and allow access to a touch screen interface of platform 600, a sensor driver to obtain sensor readings of sensor circuit 621 and control and allow access to sensor circuit 621, an EMC driver to obtain EMC actuator positions 622 and/or control and allow access to EMC 622, a camera driver to control and allow access to an embedded image capture device, and an audio driver to control and allow access to one or more audio devices.

A Power Management Integrated Circuit (PMIC)625 (also referred to as a "power management circuit 625") may manage power provided to various components of platform 600. In particular, with respect to the baseband circuitry 610, the PMIC 625 may control power source selection, voltage scaling, battery charging, or DC-DC conversion. PMIC 625 is typically included when platform 600 is capable of being powered by battery 630 (e.g., when the device is included in UE201, 301, 401).

In some embodiments, PMIC 625 may control or otherwise be part of various power saving mechanisms of platform 600. For example, if the platform 600 is in RRC _ Connected state, which is still Connected to the RAN node to receive traffic for a short time as expected, discontinuous reception mode (DRX) may be entered after a period of inactivity. During this state, the platform 600 may be powered down for a brief interval of time, thereby conserving power. If there is no data traffic activity for an extended period of time, the platform 600 may transition to an RRC _ Idle state where it is disconnected from the network and does not perform operations such as channel quality feedback, handover, etc. The platform 600 enters a low power state and performs paging during which it periodically wakes up to listen to the network and then powers down again. In this state, the platform 600 may not be able to receive data; to receive data, it must transition back to the RRC _ Connected state. The additional power-save mode may allow the device to be unavailable to the network for a period of time that exceeds the paging interval (ranging from a few seconds to a few hours). During this time, the device is completely inaccessible to the network and may be completely powered down. Any data transmitted during this period will incur a large delay and it is assumed that the delay is acceptable.

The battery 630 may provide power to the platform 600, although in some examples, the platform 600 may be deployed to be deployed in a fixed location and may have a power source coupled to a power grid. The battery 630 may be a lithium ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, or the like. In some implementations, such as in a V2X application, battery 630 may be a typical lead-acid automotive battery.

In some embodiments, battery 630 may be a "smart battery" that includes or is coupled to a Battery Management System (BMS) or a battery monitoring integrated circuit. The BMS may be included in the platform 600 to track the state of charge (SoCh) of the battery 630. The BMS may be used to monitor other parameters of the battery 630 to provide fault predictions, such as the state of health (SoH) and the functional state (SoF) of the battery 630. The BMS may communicate the information of the battery 630 to the application circuit 605 or other components of the platform 600. The BMS may also include an analog-to-digital (ADC) converter that allows the application circuit 605 to directly monitor the voltage of the battery 630 or the current from the battery 630. The battery parameters may be used to determine actions that platform 600 may perform, such as transmission frequency, network operation, sensing frequency, and the like.

A power block or other power source coupled to the grid may be coupled with the BMS to charge the battery 630. In some examples, power block XS30 may be replaced with a wireless power receiver to obtain power wirelessly, e.g., via a loop antenna in computer platform 600. In these examples, the wireless battery charging circuit may be included in a BMS. The particular charging circuit selected may depend on the size of the battery 630 and, therefore, the current required. The charging may be performed using an air fuel standard promulgated by the air fuel Alliance (air fuel Alliance), a Qi Wireless charging standard promulgated by the Wireless Power Consortium (Wireless Power Consortium), or a rezene charging standard promulgated by the Wireless Power Consortium (Alliance for Wireless Power).

The user interface circuitry 650 includes various input/output (I/O) devices present in the platform 600 or connected to the platform 600, and includes one or more user interfaces designed to enable a user to interact with the platform 600 and/or peripheral components. These interfaces are designed to enable peripheral components to interact with platform 600. The user interface circuitry 650 includes input device circuitry and output device circuitry. The input device circuitry includes any physical or virtual means for accepting input, including, inter alia, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touch screen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying or otherwise communicating information, such as sensor readings, actuator positions, or other similar information. The output device circuitry may include any number and/or combination of audio and/or visual displays, including, among other things, one or more simple visual outputs/indicators (e.g., binary status indicators (e.g., Light Emitting Diodes (LEDs))) and multi-character visual outputs, or more complex outputs, such as a display device or touch screen (e.g., Liquid Crystal Display (LCD), LED display, quantum dot display, projector, etc.), and outputs characters, graphics, multimedia objects, etc. generated or produced by operation of platform 600. Output device circuitry may also include speakers or other audio emitting devices, printers, etc. In some embodiments, sensor circuit 621 may be a circuit that functions as an input device (e.g., an image capture device, a motion capture device, etc.), and one or more EMCs may function as an output device circuit (e.g., an actuator that provides haptic feedback). In another example, an NFC circuit including an NFC controller and a processing device coupled with an antenna element may be included to read an electronic tag and/or connect with another NFC-enabled device. Peripheral component interfaces may include, but are not limited to, non-volatile memory ports, USB ports, audio jacks, power interfaces, and the like.

Although not shown, the components of platform 600 may communicate with each other using appropriate bus or Interconnect (IX) technology, which may include a variety of technologies including ISA, EISA, PCI x, PCIe, Time Triggered Protocol (TTP) systems, FlexRay systems, or many other technologies. The bus/IX may be a dedicated bus/IX, e.g. for use in a SoC based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, a point-to-point interface, a power bus, and the like.

Fig. 7 illustrates example components of a baseband circuit 7110 and a Radio Front End Module (RFEM)7115, in accordance with various embodiments. Baseband circuit 7110 corresponds to baseband circuits 510 and 610 of fig. 5 and 6, respectively. RFEM 7115 corresponds to RFEM 515 and 615 of fig. 5 and 6, respectively. As shown, the RFEM 7115 may include Radio Frequency (RF) circuitry 7106, Front End Module (FEM) circuitry 7108, antenna array 7111 coupled together at least as shown.

The baseband circuitry 7110 includes circuitry and/or control logic configured to perform various radio/network protocol and radio control functions that enable communication with one or more radio networks via the RF circuitry 7106. The radio control functions may include, but are not limited to: signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 7110 may include Fast Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 7110 may include convolution, tail-biting convolution, turbo, viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments. Baseband circuitry 7110 is configured to process baseband signals received from the receive signal path of RF circuitry 7106 and generate baseband signals for the transmit signal path of RF circuitry 7106. The baseband circuitry 7110 is configured to interface with application circuitry 505/605 (see fig. 5 and 6) for generating and processing baseband signals and controlling the operation of the RF circuitry 7106. The baseband circuit 7110 may handle various radio control functions.

The aforementioned circuitry and/or control logic of baseband circuit 7110 may include one or more single-core or multi-core processors. For example, the one or more processors may include a 3G baseband processor 7104A, a 4G/LTE baseband processor 7104B, a 5G/NR baseband processor 7104C, or some other baseband processor 7104D for other existing generations, generations under development, or to be developed in the future (e.g., sixth generation (6G), etc.). In other embodiments, some or all of the functions of the baseband processors 7104A-D may be included in modules stored in the memory 7104G and executed via a Central Processing Unit (CPU) 7104E. In other embodiments, some or all of the functions of baseband processors 7104A-D may be provided as hardware accelerators (e.g., FPGAs, ASICs, etc.) loaded with appropriate bit streams or logic blocks stored in various memory locations. In various embodiments, the memory 7104G may store program code for a real-time os (rtos) that, when executed by the CPU 7104E (or other baseband processor), will cause the CPU 7104E (or other baseband processor) to manage resources. Examples of an RTOS may include

Embedded Operating System (OSE) TM, Mentor is provided

Provided nucleous RTOSTM, Mentor

Multifunctional real-time executor (VRTX) provided by Express

ThreadXTM, FreeRTOS, provided by

REX OS, provided by Open Kernel (OK)

OKL4 provided or any other suitable RTOS, such as those discussed herein. In addition, the baseband circuitry 7110 includes one or more audio Digital Signal Processors (DSPs) 7104F. The audio DSP 7104F includes elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments.

In some embodiments, each processor 7104A-7104E includes a respective memory interface to send and receive data to and from memory 7104G. Baseband circuitry 7110 may further include one or more interfaces communicatively coupled to other circuits/devices, such as interfaces for sending/receiving data to/from memory external to baseband circuitry 7110; an application circuit interface to send/receive data to/from the application circuit 505/605 of fig. 5-7; an RF circuit interface for transmitting/receiving data to/from the RF circuit 7106 of fig. 7; a wireless hardware connection interface to connect one or more wireless hardware elements (e.g., Near Field Communication (NFC) components,

the Low Energy component is a component of the Low Energy,

components and/or others); a power management interface for transmitting/receiving power or control signals to/from the PMIC 625.

In alternative embodiments (which may be combined with the above embodiments), baseband circuit 7110 includes one or more digital baseband systems coupled to each other and to the CPU subsystem, audio subsystem and interface subsystem through an interconnection subsystem. The digital baseband subsystem may also be coupled to the digital baseband interface and the mixed signal baseband subsystem through another interconnection subsystem. Each interconnect subsystem may include a bus system, point-to-point connections, a Network On Chip (NOC) fabric, and/or some other suitable bus or interconnect technology, such as those discussed herein. The audio subsystem may include DSP circuitry, buffer memory, program memory, speech processing accelerator circuitry, data converter circuitry (e.g., analog-to-digital and digital-to-analog converter circuitry), analog circuitry including one or more of amplifiers and filters, and/or other similar components. In an aspect of the disclosure, the baseband circuitry 7110 may include protocol processing circuitry having one or more instances of control circuitry (not shown) to provide control functions for digital baseband circuitry and/or radio frequency circuitry (e.g., radio front end module 7115).

Although not shown in fig. 7, in some embodiments, baseband circuitry 7110 includes a single processing device (e.g., a "multi-protocol baseband processor" or "protocol processing circuitry") for processing one or more wireless communication protocols, and a single processing device that implements PHY layer functionality. In these embodiments, the PHY layer functions include the aforementioned radio control functions. In these embodiments, the protocol processing circuitry operates or implements various protocol layers/entities of one or more wireless communication protocols. In a first example, when baseband circuitry 7110 and/or RF circuitry 7106 is part of mmWave communication circuitry or some other suitable cellular communication circuitry, the protocol processing circuitry may operate LTE protocol entities and/or 5G/NR protocol entities. In a first example, the protocol processing circuitry will operate MAC, RLC, PDCP, SDAP, RRC and NAS functionality. In a second example, the protocol processing circuitry may operate one or more IEEE-based protocols when the baseband circuitry 7110 and/or the RF circuitry 7106 are part of a Wi-Fi communication system. In a second example, the protocol processing circuit will operate Wi-Fi MAC and Logical Link Control (LLC) functions. The protocol processing circuitry may include one or more memory structures (e.g., 7104G) for storing program code and data used to operate the protocol functions, and one or more processing cores for executing the program code and performing various operations using the data. The baseband circuitry 7110 may also support radio communications for more than one wireless protocol.

The various hardware elements of baseband circuit 7110 discussed herein may be implemented as, for example, a solder substrate including one or more Integrated Circuits (ICs), a single packaged IC soldered to a main circuit board, or a multi-chip module containing two or more ICs. In one example, the components of baseband circuit 7110 may be combined in a single chip or chipset, or disposed on the same circuit board, as appropriate. In another example, some or all of the constituent components of the baseband circuitry 7110 and the RF circuitry 7106 may be implemented together, e.g., a system on a chip (SoC) or a System In Package (SiP). In another example, some or all of the constituent components of baseband circuitry 7110 may be implemented as separate socs communicatively coupled with RF circuitry 7106 (or multiple instances of RF circuitry 7106). In yet another example, some or all of the constituent components of baseband circuitry 7110 and application circuitry 505/605 may be implemented together as a single SoC mounted to the same circuit board (e.g., a "multi-chip package").

In some embodiments, the baseband circuitry 7110 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 7110 may support communication with E-UTRAN or other WMANs, WLANs, WPANs. Embodiments of the baseband circuitry 7110 configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuit 7106 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuit 7106 may include switches, filters, amplifiers, and the like to facilitate communication with a wireless network. RF circuitry 7106 may include a receive signal path, which may include circuitry to down-convert RF signals received from FEM circuitry 7108 and provide baseband signals to baseband circuitry 7110. The RF circuit 7106 may also include a transmit signal path, which may include: the circuitry up-converts the baseband signal provided by baseband circuitry 7110 and provides the RF output signal to FEM circuitry 7108 for transmission.

In some embodiments, the receive signal path of RF circuit 7106 may include a mixer circuit 7106a, an amplifier circuit 7106b, and a filter circuit 7106 c. In some embodiments, the transmit signal path of RF circuit 7106 may include filter circuit 7106c and mixer circuit 7106 a. The RF circuit 7106 may also include a synthesizer circuit 7106d for synthesizing the frequencies used by the mixer circuits 7106a of the receive and transmit signal paths. In some embodiments, the mixer circuit 7106a of the receive signal path may be configured to down-convert RF signals received from the FEM circuit 7108 based on the synthesized frequency provided by the synthesizer circuit 7106 d. The amplifier circuit 7106b may be configured to amplify the downconverted signal, and the filter circuit 7106c may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to remove unwanted signals from the downconverted signal to produce an output baseband signal. The output baseband signal may be provided to baseband circuitry 7110 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, although this is not required. In some embodiments, mixer circuit 7106a of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 7106a of the transmit signal path may be configured to upconvert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 7106d to generate an RF output signal for the FEM circuit 7108. The baseband signal may be provided by baseband circuitry 7110 and may be filtered by filter circuitry 7106 c.

In some embodiments, the mixer circuit 7106a of the receive signal path and the mixer circuit 7106a of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and up-conversion, respectively. In some embodiments, the mixer circuit 7106a of the receive signal path and the mixer circuit 7106a of the transmit signal path may comprise two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuit 7106a of the receive signal path and the mixer circuit 7106a of the transmit signal path may be arranged for direct down-conversion and direct up-conversion, respectively. In some embodiments, the mixer circuit 7106a of the receive signal path and the mixer circuit 7106a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuitry 7106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 7110 may include a digital baseband interface to communicate with the RF circuitry 7106.

In some dual-mode embodiments, separate radio IC circuits may be provided to process signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 7106d may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, the synthesizer circuit 7106d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.

The synthesizer circuit 7106d may be configured to synthesize an output frequency based on the frequency input and the divider control input for use by the mixer circuit 7106a of the RF circuit 7106. In some embodiments, synthesizer circuit 7106d may be a fractional N/N +1 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), although this is not required. The divider control input may be provided by baseband circuit 7110 or application circuit 505/605 depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by the application circuit 505/605.

Synthesizer circuit 7106d of RF circuit 7106 may include frequency dividers, Delay Locked Loops (DLLs), multiplexers, and phase accumulators. In some embodiments, the divider may be a dual-mode divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to divide an input signal by N or N +1 (e.g., based on a carry) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to divide the VCO period into Nd equal phase groups, where Nd is the number of delay elements in the delay line. Thus, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuit 7106d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and frequency divider circuit to produce a plurality of signals at the carrier frequency having a plurality of different phases relative to each other. In some embodiments, the output frequency may be the LO frequency (fLO). In some embodiments, the RF circuit 7106 may include an IQ/polarity converter.

FEM circuitry 7108 may include a receive signal path, which may include circuitry configured to operate on RF signals received from antenna array 7111, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 7106 for further processing. FEM circuitry 7108 may also include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 7106 for transmission by one or more antenna elements of antenna array 7111. In various embodiments, amplification of the receive signal path by transmission or the receive signal path may be done in RF circuit 7106 only, FEM circuit 7108 only, or in both RF circuit 7106 and FEM circuit 7108.

In some embodiments, FEM circuit 7108 may include TX/RX switches to switch between transmit mode and receive mode operation. FEM circuit 7108 may include a receive signal path and a transmit signal path. The receive signal path of FEM circuit 7108 may include an LNA to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to RF circuit 7106). The transmit signal path of FEM circuitry 7108 may include a Power Amplifier (PA) to amplify the incoming RF signal (e.g., provided by RF circuitry 7106), and one or more filters to generate the RF signal for subsequent transmission through one or more antenna elements of antenna array 7111.

The antenna array 7111 comprises one or more antenna elements, each configured to convert electrical signals to radio waves for propagation in the air and to convert received radio waves to electrical signals. For example, digital baseband signals provided by baseband circuitry 7110 are converted to analog RF signals (e.g., modulation waveforms) that are to be amplified and transmitted via antenna elements of antenna array 7111, which includes one or more antenna elements (not shown). The antenna elements may be omnidirectional, directional, or a combination thereof. The antenna elements may be formed in a variety of arrangements as is known and/or discussed herein. The antenna array 7111 may comprise microstrip antennas or printed antennas fabricated on the surface of one or more printed circuit boards. The antenna array 7111 may be formed as various shapes of metal foils (e.g., patch antennas) and may be coupled with the RF circuitry 7106 and/or the FEM circuitry 7108 using metal transmission lines or the like.

The processor of the application circuit 505/605 and the processor of the baseband circuit 7110 may be used to execute elements of one or more instances of a protocol stack. For example, the processor of the baseband circuit 7110 may be used alone or in combination to perform layer 3, layer 2, or layer 1 functions, while the processor of the application circuit 505/605 may start at these layers with received data (e.g., packet data) and further perform layer 4 functions (e.g., TCP and UDP layers). As referred to herein, layer 3 may include an RRC layer, as described in further detail below. As mentioned herein, layer 2 may include a MAC layer, an RLC layer, and a PDCP layer, which will be described in further detail below. As mentioned herein, layer 1 may comprise the PHY layer of the UE/RAN node, as will be described in further detail below.

Fig. 8 illustrates various protocol functions that may be implemented in a wireless communication device, in accordance with various embodiments. In particular, fig. 8 includes an arrangement 800 that illustrates interconnections between various protocol layers/entities. The following description of fig. 8 is provided for various protocol layers/entities that operate in conjunction with the 5G/NR system standard and the LTE system standard, although some or all aspects of fig. 8 may be applicable to other wireless communication network systems.

The protocol layers of the arrangement 800 may include one or more of PHY 810, MAC 820, RLC 830, PDCP 840, SDAP 847, RRC 855, and NAS layer 857, among other higher layer functions not shown. The protocol layers may include one or more service access points (e.g., items 859, 856, 850, 849, 845, 835, 825, and 815 in fig. 8), which may provide communication between two or more protocol layers.

PHY 810 may transmit and receive physical layer signals 805 that may be received or transmitted from one or more other communication devices. Physical layer signal 805 may include one or more physical channels, such as those discussed herein. PHY 810 may further perform link adaptive or Adaptive Modulation and Coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers (e.g., RRC 855). 810 may further perform error detection on the transport channel, Forward Error Correction (FEC) encoding/decoding on the transport channel, modulation/demodulation on the physical channel, interleaving, rate matching, mapping on the physical channel, and MIMO antenna processing. In an embodiment, an instance of PHY 810 may process and provide an indication to a request from an instance of MAC 820 via one or more PHY-SAPs 815. According to some embodiments, the requests and indications transmitted via the PHY-SAP 815 may include one or more transport channels.

An instance of MAC 820 may process and provide an indication to a request from an instance of RLC 830 via one or more MAC-SAPs 825. These requests and indications communicated via MAC-SAP 825 may include one or more logical channels. MAC 820 may perform mapping between logical channels and transport channels, multiplexing MAC SDUs from one or more logical channels onto TBs to be delivered to PHY 810 through transport channels, and demultiplexing MAC SDUs from TBs onto one or more logical channels. Transmitted from the PHY 810 through a transport channel, MAC SDUs multiplexed to TBs, scheduling information reports, error correction through HARQ, and logical channel prioritization.

The instance of the RLC 830 can process requests from the instance of the PDCP 840 and provide indications to the instance of the PDCP 840 via one or more radio link control service access points (RLC-SAPs) 835. These requests and indications communicated via the RLC-SAP 835 may include one or more RLC channels. RLC 830 may operate in a variety of operating modes, including: transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). RLC 830 may perform transmission of higher layer Protocol Data Units (PDUs), error correction by automatic repeat request (ARQ) for AM data transmission, and concatenation, segmentation, and reassembly of RLC SDUs for UM and AM data transmission. RLC 830 may also perform re-segmentation of RLC data PDUs for AM data transmission, re-order RLC data PDUs for UM and AM data transmission, detect duplicate data for UM and AM data transmission, discard RLC SDUs for UM and AM data transmission, detect protocol errors for AM data transmission, and perform RLC re-establishment.

One or more instances of PDCP 840 may process and provide an indication to one or more packet data convergence protocol service access points (PDCP-SAPs) 845 from one instance of RRC 855 and/or one instance of SDAP 847. These requests and indications conveyed via the PDCP-SAP 845 may include one or more radio bearers. PDCP 840 may perform header compression and IP data decompression, maintain PDCP Sequence Numbers (SNs), perform sequenced transmission of higher layer PDUs upon lower layer re-establishment, eliminate duplicate entries of lower layer SDUs mapping to the radio bearer layer of RLC AM upon lower layer re-establishment, cipher and decipher control plane data, integrity protect and verify control plane data, control timer-based data discard and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

An instance of the service data adaptation protocol, SDAP 847, may process and provide indications to requests from one or more higher layer protocol entities via one or more SDAP-SAPs 849. These requests and indications communicated via the SDAP-SAP 849 may include one or more QoS flows. The SDAP 847 may map QoS flows to data radio carriers DRB and vice versa and may also mark QoS flow identifiers QFI in DL and UL packets. A single SDAP entity 847 may be configured for a single PDU session. In the UL direction, the NG-RAN 210 can control the mapping of QoS flows to DRBs in two ways, i.e., reflection mapping or explicit mapping. For reflection mapping, the SDAP 847 of the UE201 may monitor the QFI of the DL packets of each DRB and may apply the same mapping to packets flowing in the UL direction. For a DRB, the SDAP 847 of the UE201 may map UL packets belonging to a QoS flow corresponding to the QoS flow ID and PDU session observed in the DL packets for that DRB. To enable reflection mapping, the NG-RAN 410 may label DL packets with QoS flow IDs on the Uu interface. Explicit mapping may involve the RRC 855 configuring the SDAP 847 with the explicit QoS flow as a DRB mapping rule, which may be stored and followed by the SDAP 847. In an embodiment, the SDAP 847 may be used only in NR implementations and may not be used in LTE implementations.

The RRC 855 may configure aspects of one or more protocol layers, which may include one or more instances of the PHY 810, MAC 820, RLC 830, PDCP 840, and SDAP 847, via one or more management service access points (M-SAPs). In an embodiment, an instance of RRC 855 may process and provide an indication to one or more NAS entities 857 via one or more RRC-SAPs 856. The main services and functions of the RRC 855 may include the broadcasting of system information (e.g., included in MIB or SIB related to NAS), broadcasting system information related to Access Stratum (AS), paging, establishing, maintaining and releasing RRC connections (e.g., RRC connection paging), RRC connection establishment, RRC connection modification and RRC connection release) between the UE201 and the RAN 210, establishment, configuration, maintenance and release of point-to-point radio bearers, methods of security function UE measurement reporting including key management, inter-RAT mobility and measurement configuration. The MIB and SIBs may include one or more IEs, each of which may include a separate data field or data structure.

The NAS 857 may form the highest layer of a control plane between the UE201 and the AMF 421. The NAS 857 may support mobility of the UE201 and session management procedures to establish and maintain IP connectivity between the UE201 and the P-GW in the LTE system.

According to various embodiments, one or more protocol entities of the arrangement 800 may be implemented in: UE201 in NR implementation, RAN node 211, AMF421, or MME 321 in LTE implementation, UPF 402 in NR implementation, or S-GW322 and P-GW323 in LTE implementation, etc. for control plane or user plane communication protocol stack between the aforementioned devices. In such embodiments, one or more protocol entities, which may be implemented in one or more of the UE201, the gNB 211, the AMF421, etc., may communicate with a corresponding peer protocol entity, which may be implemented in or on another device that performs such communication using the services of the corresponding lower layer protocol entity. In some embodiments, the gNB-CU of gNB 211 may host RRC 855, SDAP 847, and PDCP 840 of the gNB that controls the operation of one or more gNB-DUs, and the gNB-DUs of gNB 211 may each host RLC 830, MAC 820, and PHY 810 of gNB 211.

In a first example, the control plane protocol stack may include NAS 857, RRC 855, PDCP 840, RLC 830, MAC 820 and PHY 810 in order from the highest layer to the lowest layer. In this example, upper layer 860 may be built on top of NAS 857, which includes IP layer 861, SCTP 862, and application layer signaling protocol (AP) 863.

In the NR implementation, the AP863 may be a NG application protocol layer (NGAP or NG-AP)863 for the NG interface 213 defined between the NG-RAN node 211 and the AMF421, or the AP863 may be an Xn application protocol layer (XnAP or Xn-AP)863 for the Xn interface 212 defined between two or more RAN nodes 211.

NG-AP 863 may support the functionality of NG interface 213 and may include a basic procedure (EP). The NG-AP EP may be a unit of interaction between the NG-RAN node 211 and the AMF 421. The NG-AP 863 service may include two groups: UE-related services (e.g., service related to UE 201) and UE-related services (e.g., service related to the entire NG interface instance between NG-RAN node 211 and AMF 421). These services may include functions including, but not limited to: a paging function for sending a paging request to the NG-RAN node 211 involved in a particular paging area; and a UE context management function for allowing the AMF421 to establish, modify and/or release UE contexts in the AMF421 and the NG-RAN node 211; the mobile function of the UE201 in ECM-CONNECTED mode is used for the intra-system HO to support the movement in NG-RAN and the inter-system HO to support the movement to and from EPS system; NAS signaling transport function, configured to transport or reroute NAS messages between UE201 and AMF 421; NAS node selection functionality for determining an association between the AMF421 and the UE 201; the NG interface management function is used for setting the NG interface and monitoring errors on the NG interface; a warning message transmission function for providing a means of transmitting a warning message or canceling an ongoing warning message broadcast via the NG interface; a configuration transfer function for requesting and transferring RAN configuration information (e.g., SON information, Performance Measurement (PM) data, etc.) between the two RAN nodes 211 via the CN 220; and/or other similar functions.

XnAP 863 may support the functionality of the Xn interface 212 and may include XnAP basic mobility procedures and XnAP global procedures. The XnAP basic mobility procedures may include procedures for handling UE mobility within the NG RAN 211 (or E-UTRAN 310), such as handover preparation and cancellation procedures, SN state transfer procedures, UE context retrieval and UE context release procedures, RAN paging, procedures related to dual connectivity, and so forth. The XnAP global procedure may include procedures unrelated to the particular UE201, such as an Xn interface setup and reset procedure, an NG-RAN update procedure, a cell activation procedure, and the like.

In an LTE implementation, the AP863 may be an S1 application protocol layer (S1-AP)863 for an S1 interface 213 defined between the E-UTRAN node 211 and the MME, or the AP863 may be an X2 application protocol layer (X2AP or X2-AP)863 for an X2 interface 212 defined between two or more E-UTRAN nodes 211.

The S1 application protocol layer (S1-AP)863 may support the functionality of the S1 interface, and similar to the NG-AP discussed previously, the S1-AP may include the S1-AP EP. The S1-AP EP may be a unit of interaction between the E-UTRAN node 211 and the MME 321 within the LTE CN 220. The S1-AP863 service may include two groups: UE-related services and non-UE-related services. The functions performed by these services include, but are not limited to: E-UTRAN radio access bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM) and configuration transport.

The X2AP 863 may support the functionality of the X2 interface 212 and may include X2AP basic mobility procedures and X2AP global procedures. The X2AP basic mobility procedures may include procedures for handling UE mobility within the E-UTRAN 220, such as handover preparation and cancellation procedures, SN state transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, procedures related to dual connectivity, and so forth. The X2AP global procedure may include procedures unrelated to the specific UE201, such as an X2 interface set and reset procedure, a load indication procedure, an error indication procedure, a cell activation procedure, and the like.

The SCTP layer (alternatively referred to as the SCTP/IP layer) 862 can provide guaranteed delivery of application layer messages (e.g., NGAP or XnAP messages in NR implementations, or S1-AP or X2AP messages in LTE implementations). SCTP 862 may ensure reliable transfer of signaling messages between RAN node 211 and AMF 421/MME 321 based in part on the IP protocol supported by IP 861. Internet protocol layer (IP)861 may be used to perform packet addressing and routing functions. In some implementations, IP layer 861 may use point-to-point transport to communicate and transport PDUs. In this regard, the RAN node 211 may include L2 and L1 layer communication links (e.g., wired or wireless) with the MME/AMF to exchange information.

In a second example, the user plane protocol stack may include, in order from the highest layer to the lowest layer, the SDAP 847, the PDCP 840, the RLC 830, the MAC 820, and the PHY 810. The user plane protocol stack may be used for communication between the UE201, RAN node 211 and UPF 402 in NR implementations, or may be used for communication between the S-GW322 and P-GW323 in LTE implementations. In this example, upper layers 851 may be established on top of the SDAP 847 and may include a User Datagram Protocol (UDP) and IP Security layer (UDP/IP)852, a General Packet Radio Service (GPRS) tunneling protocol for a user plane layer (GTP-U)853, and a user plane PDU layer (UP PDU) 863.

The transport network layer 854 (also referred to as the "transport layer") may be built on top of the IP transport and GTP-U853 may be used on top of the UDP/IP layer 852 (including UDP layer and IP layer) to carry user plane PDUs (UP-PDUs). The IP layer (also referred to as the "Internet layer") may be used to perform packet addressing and routing functions. The IP layer may assign IP addresses to user data packets, for example, in any of IPv4, IPv6, or PPP formats.

GTP-U853 may be used to carry user data within the GPRS core network and between the radio access network and the core network. The user data transmitted may be, for example, data packets in IPv4, IPv6, or PPP format. UDP/IP 852 may provide a checksum of data integrity, port numbers for addressing different functions at the source and destination, as well as encryption and authentication of selected data streams. The RAN node 211 and the S-GW322 may utilize the S1-U interface to exchange user plane data via a protocol stack including an L1 layer (e.g., PHY 810), an L2 layer (e.g., MAC 820, RLC 830, PDCP 840, and/or SDAP 847), a UDP/IP layer 852, and a GTP-U853. The S-GW322 and the P-GW323 can exchange user-plane data via a protocol stack including a L1 layer, an L2 layer, a UDP/IP layer 852 and a GTP-U853 using an S5/S8a interface. As previously described, the NAS protocol may support mobility of the UE201 and session management procedures to establish and maintain IP connections between the UE201 and the P-GW 323.

Further, although not shown in fig. 8, an application layer may exist above the AP863 and/or the transport network layer 854. The application layer may be a layer in which UE201, RAN node 211, or other users. The network elements interact with software applications, for example, executed by the application circuits 505 or 605, respectively. The application layer may also provide one or more interfaces for software applications to interact with the communication system (e.g., baseband circuitry 7110) of UE201 or RAN node 211. In some implementations, the IP layer and/or the application layer can provide the same interface or functionality similar to layers 5-7 or portions thereof of the Open Systems Interconnection (OSI) model (e.g., OSI layer 7-application layer, OSI layer 6-presentation layer, OSI layer 5-session layer).

Fig. 9 is a block diagram illustrating components capable of reading instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and performing any one or more of the following, according to some example embodiments. The methods discussed herein. In particular, fig. 9 shows a schematic diagram of a hardware resource 900, the hardware resource 900 including one or more processors (or processor cores) 910, one or more memory/storage devices 920, and one or more communication resources 930, each of which may be communicatively coupled. For embodiments utilizing node virtualization (e.g., NFV), hypervisor 902 may be executed to provide an execution environment for one or more network slices/subslices to utilize hardware resources 900.

Processor 910 may include, for example, processor 912 and processor 914. Processor 910 may be, for example, a Central Processing Unit (CPU), a Reduced Instruction Set Computing (RISC) processor, or a complex instruction. A set computing (CISC) processor, a Graphics Processing Unit (GPU), a DSP (e.g., baseband processor), an ASIC, an FPGA, a Radio Frequency Integrated Circuit (RFIC), another processor (including the processors discussed herein), or any suitable combination thereof.

Memory/storage 920 may include a main memory, a disk storage, or any suitable combination thereof. The memory/storage 920 may include, but is not limited to, any type of volatile or non-volatile memory, such as Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid state memory, and the like.

The communication resources 930 may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices 904 or one or more databases 906 via the network 908. For example, communication resources 930 may include wired communication components (e.g., for coupling via USB), cellular communication components, NFC components,

(or

Low power consumption) components are used in the system,

components and other communication components.

The instructions 950 may include software, a program, an application, an applet, an application or other executable code for causing at least any one of the processors 910 to perform any one or more of the methodologies discussed herein. The instructions 950 may reside, completely or partially, within at least one of the processor 910 (e.g., within a cache memory of the processor), the memory/storage 920, or any suitable combination thereof. Further, any portion of instructions 950 may be communicated to hardware resource 900 from any combination of peripherals 904 or database 906. Thus, the memory of the processor 910, the memory/storage 920, the peripherals 904, and the database 906 are examples of computer-readable and machine-readable media.

For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, procedures, and/or methods as set forth in the example section below. For example, baseband circuitry as described above in connection with one or more of the foregoing figures may be configured to operate in accordance with one or more examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc., as described above in connection with one or more of the preceding figures, can be configured to operate in accordance with one or more examples set forth below in the examples section.

Examples of the invention

Example 1 may include an apparatus of a first Base Station (BS), the apparatus comprising: a memory; processing circuitry operatively coupled to the memory; and an interface to communicate with at least one second BS, the apparatus configured to: transmitting a Handover (HO) command to a User Equipment (UE) to perform a HO procedure, wherein the HO command indicates a Dual Active Protocol Stack (DAPS) HO with the at least one second BS; assigning a Sequence Number (SN) for each Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU); and forwarding the PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

Example 2 may include the apparatus of example 1 or other examples described herein, wherein the apparatus is further configured to: transmitting a Downlink (DL) user frame to the at least one second BS through a General Packet Radio Service (GPRS) tunneling protocol user plane (GTP-U) forwarding tunnel, thereby causing the at least one second BS to perform discard of the PDCP SDU that has been forwarded, based on the received DL user frame.

Example 3 may include the apparatus of example 1 or other examples described herein, wherein the apparatus is further configured to: transmitting a message to the at least one second BS, thereby causing the at least one second BS to perform discarding of the PDCP SDUs that have been forwarded, based on the received message.

Example 4 may include the apparatus of example 3 or other examples described herein, wherein each forwarded PDCP SDU includes a COUNT value, the message including a COUNT threshold such that the at least one second BS discards PDCP SDUs having COUNT values less than the COUNT threshold.

Example 5 may include the apparatus of example 1 or other examples described herein, wherein the first BS serves as a source and the second BS serves as a target.

Example 6 may include the apparatus of example 1 or other examples described herein, wherein the first BS operates as an evolved node b (eNB) and the at least one second BS operates as an eNB.

Example 7 may include the apparatus of example 6 or other examples described herein, wherein the interface is an X2 interface or an S1 interface.

Example 8 may include the apparatus of example 1 or other examples described herein, wherein the first BS is to function as a fifth generation (5G) eNB or a next generation (NR) gNB, and/or the at least one second BS is to function as a 5G eNB or an NR gNB.

Example 9 may include the apparatus of example 8 or other examples described herein, wherein the interface is an Xn interface or an NG interface.

Example 10 may include a method for a DAPS HO, the method comprising: transmitting, by a first BS, a HO command to a UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second BS; allocating, by the first BS, a SN for each PDCP SDU; and forwarding, by the first BS, PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

Example 11 may include the method of example 10 or other examples described herein, wherein the method further comprises: transmitting, by the first BS, the DL user frame to the at least one second BS through a GTP-U forwarding tunnel, thereby causing the at least one second BS to perform discarding of the PDCP SDU that has been forwarded, based on the received DL user frame.

Example 12 may include the method of example 10 or other examples described herein, wherein the method further comprises: transmitting, by the first BS, a message to the at least one second BS, thereby causing the at least one second BS to perform discarding of the PDCP SDUs that have been forwarded, based on the received message.

Example 13 may include the method of example 12 or other examples described herein, wherein each forwarded PDCP SDU includes a COUNT value, the message including a COUNT threshold such that the at least one second BS discards PDCP SDUs having COUNT values less than the COUNT threshold.

Example 14 may include one or more non-transitory computer-readable media comprising instructions to, when executed by processing circuitry of a first electronic device, cause the first electronic device to perform: sending a HO command to the UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second electronic device; assigning a SN for each PDCP SDU; and forwarding PDCP SDUs having SNs to the at least one second electronic device as part of the HO procedure.

Example 15 may include one or more non-transitory computer-readable media of example 14 or other examples described herein, wherein the instructions further cause the first electronic device to perform: transmitting the DL user frame to the at least one second electronic device through a GTP-U forwarding tunnel, thereby causing the at least one second electronic device to perform discarding of the PDCP SDUs that have been forwarded based on the received DL user frame.

Example 16 may include one or more non-transitory computer-readable media of example 14 or other examples described herein, wherein the instructions further cause the first electronic device to perform: transmitting a message to the at least one second electronic device, thereby causing the at least one second electronic device to perform discarding of PDCP SDUs that have been forwarded based on the received message.

Example 17 may include the one or more non-transitory computer-readable media of example 16 or other examples described herein, wherein each forwarded PDCP SDU comprises a COUNT value, the message including a COUNT threshold value, such that the at least one second electronic device discards PDCP SDUs having a COUNT value less than the COUNT threshold value.

Example 18 may include an apparatus of a BS, the apparatus comprising: a memory; processing circuitry operatively coupled to the memory; and an interface to communicate with another BS, the apparatus configured to: receiving a PDCP SDU with a SN assigned by the other BS as part of a HO procedure of the UE, wherein the HO procedure is a DAPS HO for the BS.

Example 19 may include the apparatus of example 18 or other examples described herein, wherein the apparatus is further configured to: receiving a DL user frame from the other BS through a GTP-U forwarding tunnel, thereby performing discarding of the PDCP SDU that has been forwarded, based on the received DL user frame.

Example 20 may include the apparatus of example 18 or other examples described herein, wherein the apparatus is further configured to: receiving a message from the other BS, thereby performing discarding of the PDCP SDU that has been forwarded, based on the received message.

Example 21 may include the apparatus of example 20 or other examples described herein, wherein each forwarded PDCP SDU includes a COUNT value, the message including a COUNT threshold such that the BS discards PDCP SDUs having COUNT values less than the COUNT threshold.

Any of the above examples can be combined with any other example (or combination of examples) unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the implementations to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

Term(s) for

For purposes of this document, the following terms and definitions apply to the examples and embodiments discussed herein.

As used herein, the term "circuitry" refers to hardware components, such as, for example, electronic circuitry, logic circuitry, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group), an Application Specific Integrated Circuit (ASIC), a Field Programmable Device (FPD) (e.g., a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a complex PLD (cpld), a high-capacity PLD (hcpld) configured to provide the above-described functionality, a structured ASIC or programmable SoC, a Digital Signal Processor (DSP), or the like. In some embodiments, circuitry may execute one or more software or firmware programs to provide at least some of the described functionality. The term "circuitry" may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) and program code for performing the functions of the program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuitry.

The term "processor circuit" as used herein refers to, is part of, or includes a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations, or recording, storing and/or transmitting digital data. The term "processor circuit" may refer to one or more application processors, one or more baseband processors, physical Central Processing Units (CPUs), single-core processors, dual-core processors, tri-core processors, quad-core processors, and/or any other device capable of executing or otherwise operating computer-executable instructions (e.g., program code, software modules, and/or functional processes). The terms "application circuitry" and/or "baseband circuitry" may be considered synonymous with "processor circuitry" and may be referred to as "processor circuitry".

As used herein, the term "interface circuit" refers to, is part of, or includes a circuit capable of exchanging information between two or more components or devices. The term "interface circuit" may refer to one or more hardware interfaces, such as a bus, an I/O interface, a peripheral component interface, a network interface card, and the like.

The term "user equipment" or "UE" as used herein refers to devices having radio communication capabilities and may describe remote users of network resources in a communication network. The term "user equipment" or "UE" may be considered synonymous with client, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote device, and may be referred to as "UE". Furthermore, the terms "user equipment" or "UE" may include any type of wireless/wired device or any computing device, including wireless communication interfaces.

The term "network element" as used herein refers to a physical or virtualized device and/or infrastructure for providing wired or wireless communication network services. The term "network element" may be considered and/or referred to as a networked computer, networking hardware, network device, network node, router, switch, hub, bridge, radio network controller, RAN device, RAN node, gateway, server, virtualized virtual network function VNF, network function virtualization infrastructure NFVI, etc.

The term "computer system" as used herein refers to any type of interconnected electronic devices, computer devices, or components thereof. In addition, the terms "computer system" and/or "system" may refer to various components communicatively coupled to each other on a computer. Moreover, the terms "computer system" and/or "system" may refer to multiple computing devices and/or multiple computing systems communicatively coupled to one another and configured to share computing and/or network resources.

As used herein, the terms "device," "computer device," and the like refer to a computer device or computer system having program code (e.g., software or firmware) specially designed to provide specific computing resources. A "virtual appliance" is a virtual machine image implemented by a virtual machine hypervisor-equipped device that virtualizes or emulates a computer device, or is dedicated to providing specific computing resources.

As used herein, the term "resource" refers to a physical or virtual device, a physical or virtual component within a computing environment and/or a physical or virtual component within a particular device, such as a computer device, a mechanical device, a memory space, processor/CPU time, processor/CPU usage, processor and accelerator load, hardware time or usage, electrical power, input/output operations, ports or network sockets, channel/link assignments, throughput, memory usage, storage, networks, databases and applications, units of workload, and the like. "hardware resources" may refer to computational, storage, and/or network resources provided by physical hardware elements. "virtual resources" may refer to computing, storage, and/or network resources provided by a virtualization infrastructure to an application, device, system, etc. The term "network resource" or "communication resource" may refer to a resource that is accessible by: computer device/system over a communication network. The term "system resource" may refer to any kind of shared entity that provides a service, and may include computing and/or network resources. A system resource can be thought of as a set of coherent functions, network data objects or services, accessible through a server, where the system resources reside on a single host or multiple hosts and are clearly identifiable.

The term "channel" as used herein refers to any tangible or intangible transmission medium to communicate data or streams. The term "channel" may be synonymous and/or equivalent to "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," and/or any other similar term denoting the path or medium through which data is communicated. In addition, the term "link" as used herein refers to a connection between two devices over a RAT for the purpose of transmitting and receiving information.

The term "instantiation" or the like as used herein refers to the creation of an instance. An "instance" also refers to a specific occurrence of an object, such as might occur during execution of program code.

The terms "coupled," "communicatively coupled," and their derivatives are used herein. The term "coupled" may mean that two or more elements are in direct physical or electrical contact with each other, that two or more elements are in indirect contact with each other but yet still co-operate or interact with each other, and/or that one or more elements are coupled or connected between what is referred to as being coupled to each other. The term "directly coupled" may mean that two or more elements are in direct contact with each other. The term "communicatively coupled" may mean that two or more elements may be in contact with each other through communications, including through wires or other interconnection connections, through wireless communications channels or ink, or the like.

The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the respective content of an information element or a data element containing content.

The term "master cell" refers to a master cell group, MCG, cell operating on a master frequency, where a UE performs an initial connection establishment procedure or initiates a connection re-establishment procedure.

The term "primary secondary cell group SCG cell" refers to an SCG cell in which a UE performs random access when performing a reconfiguration procedure with synchronization for DC operation.

The term "second cell" refers to a cell that provides additional radio resources for a UE configured with CA over a dedicated cell.

The term "secondary cell group" refers to a subset of serving cells that includes the PSCell for DC-configured UEs and zero or more secondary cells.

The term "serving cell" refers to a primary cell of a UE in RRC _ CONNECTED that is not configured with CA/DC, and only one serving cell includes the primary cell.

The term "serving cell" or "serving cell" refers to a set of cells including one or more special cells and all secondary cells of a UE in RRC _ CONNECTED with CA/configuration.

The term "special cell" refers to either the PCell of a DC operated MCG or the PSCell of an SCG; otherwise, the term "special cell" refers to Pcell.

The foregoing description of one or more embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments of the disclosure.

Claims (21)

1. An apparatus of a first base station, BS, the apparatus of the first BS comprising:

a memory;

processing circuitry operatively coupled to the memory; and

an interface to communicate with at least one second BS,

the apparatus is configured to:

sending a Handover (HO) command to a User Equipment (UE) for an HO process, wherein the HO command indicates a Dual Activation Protocol Stack (DAPS) HO with the at least one second BS;

assigning a sequence number SN for each packet data convergence protocol PDCP service data unit SDU; and is

Forwarding PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

2. The apparatus of claim 1, wherein the apparatus is further configured to:

transmitting the downlink DL user frame to the at least one second BS through a general packet radio service GPRS tunneling protocol user plane GTP-U forwarding tunnel, thereby causing the at least one second BS to perform discarding of the PDCP SDU that has been forwarded based on the received DL user frame.

3. The apparatus of claim 1, wherein the apparatus is further configured to:

transmitting a message to the at least one second BS, thereby causing the at least one second BS to perform discarding of the PDCP SDUs that have been forwarded, based on the received message.

4. The apparatus according to claim 3, wherein each forwarded PDCP SDU comprises a COUNT value, the message containing a COUNT threshold such that the at least one second BS discards PDCP SDUs having a COUNT value less than the COUNT threshold.

5. The apparatus of claim 1, wherein the first BS acts as a source and the second BS acts as a target.

6. The apparatus of claim 1, wherein the first BS acts as an evolved node B, eNB, and the at least one second BS acts as an eNB.

7. The apparatus of claim 1, wherein the interface is an X2 interface or an S1 interface.

8. The apparatus of claim 1, wherein the first BS functions as a fifth generation 5G eNB or next generation NR gNB and/or the at least one second BS functions as a 5G eNB or NR gNB.

9. The apparatus of claim 8, wherein the interface is an Xn interface or an NG interface.

10. A method for a DAPS HO, the method comprising:

transmitting, by a first BS, a HO command to a UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second BS;

allocating, by the first BS, a SN for each PDCP SDU; and is

Forwarding, by the first BS, PDCP SDUs with SNs to the at least one second BS as part of the HO procedure.

11. The method of claim 10, wherein the method further comprises:

transmitting, by the first BS, the DL user frame to the at least one second BS through a GTP-U forwarding tunnel, thereby causing the at least one second BS to perform discarding of the PDCP SDU that has been forwarded, based on the received DL user frame.

12. The method of claim 10, wherein the method further comprises:

transmitting, by the first BS, a message to the at least one second BS, thereby causing the at least one second BS to perform discarding of the PDCP SDUs that have been forwarded, based on the received message.

13. The method of claim 12 wherein each forwarded PDCP SDU comprises a COUNT value, the message containing a COUNT threshold such that the at least one second BS discards PDCP SDUs having a COUNT value less than the COUNT threshold.

14. One or more non-transitory computer-readable media comprising instructions to cause a first electronic device, when executed by processing circuitry of the first electronic device, to perform:

sending a HO command to the UE to perform a HO procedure, wherein the HO command indicates a DAPS HO with at least one second electronic device;

assigning a SN for each PDCP SDU; and is

Forwarding PDCP SDUs with SNs to the at least one second electronic device as part of the HO procedure.

15. The one or more non-transitory computer-readable media of claim 14, wherein the instructions further cause the first electronic device to perform:

transmitting the DL user frame to the at least one second electronic device through a GTP-U forwarding tunnel, thereby causing the at least one second electronic device to perform discarding of the PDCP SDUs that have been forwarded based on the received DL user frame.

16. The one or more non-transitory computer-readable media of claim 14, wherein the instructions further cause the first electronic device to perform:

transmitting a message to the at least one second electronic device, thereby causing the at least one second electronic device to perform discarding of PDCP SDUs that have been forwarded based on the received message.

17. The one or more non-transitory computer-readable media as recited in claim 16, wherein each forwarded PDCP SDU comprises a COUNT value, the message containing a COUNT threshold, such that the at least one second electronic device discards PDCP SDUs having a COUNT value less than the COUNT threshold.

18. An apparatus of a BS, the apparatus comprising:

a memory;

processing circuitry operatively coupled to the memory; and

an interface for communicating with another BS,

the apparatus is configured to:

receiving a PDCP SDU having a SN assigned by the other BS as part of a HO procedure of the UE,

wherein the HO procedure is a DAPS HO for the BS.

19. The apparatus of claim 18, wherein the apparatus is further configured to:

receiving a DL user frame from the other BS through a GTP-U forwarding tunnel, thereby performing discarding of the PDCP SDU that has been forwarded, based on the received DL user frame.

20. The apparatus of claim 18, wherein the apparatus is further configured to:

receiving a message from the other BS, thereby performing discarding of the PDCP SDU that has been forwarded, based on the received message.

21. The apparatus of claim 20 wherein each forwarded PDCP SDU comprises a COUNT value, the message containing a COUNT threshold such that the BS discards PDCP SDUs having a COUNT value less than the COUNT threshold.

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