WO2022150156A1 - Blockage map operations - Google Patents

Abstract

A system, apparatus, and method are disclosed to generate a map of communication blockages. Base stations and UEs exchange link problem information, analyze the information, infer the cause of the link problems, and determine the presence of blockages in different locations or identify the locations with high chances of blockage existence. In response to the map, the UEs and base stations take actions based on the blockage characteristics.

Description

BLOCKAGE MAP OPERATIONS

PRIORITY CLAIM

[0001] This application claims the benefit of priority to United States Provisional Patent Application Serial No. 63/133,956, filed January 5, 2021, and United States Provisional Patent Application Serial No. 63/153,816, filed February 25, 2021, each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to next generation wireless communications. In particular, some embodiments relate to blockage maps in wireless communications.

BACKGROUND

[0003] The use and complexity of wireless systems, which include 5^th generation (5G) networks and are starting to include sixth generation (6G) networks among others, has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. With the vast increase in number and diversity of communication devices, the corresponding network environment, including routers, switches, bridges, gateways, firewalls, and load balancers, has become increasingly complicated. As expected, a number of issues abound with the advent of any new technology.

BRIEF DESCRIPTION OF THE FIGURES

[0004] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. [0005] FIG. 1 A illustrates an architecture of a network, in accordance with some aspects.

[0006] FIG. 1B illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0007] FIG. 1C illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0008] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments.

[0009] FIG. 3 illustrates an exchange of collected information between a UE and a radio access network (RAN) in accordance with some embodiments.

[0010] FIG. 4 illustrates an example of Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) layer interactions in accordance with some embodiments.

DETAILED DESCRIPTION

[0011] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0012] FIG. 1 A illustrates an architecture of a network in accordance with some aspects. The network 140 A includes 3 GPP LTE/4G and NG network functions that may be extended to 6G functions. Accordingly, although 5G will be referred to, it is to be understood that this is to extend as able to 6G structures, systems, and functions. A network function can be implemented as a discrete network element on a dedicated hardware, as a software instance running on dedicated hardware, and/or as a virtualized function instantiated on an appropriate platform, e.g., dedicated hardware or a cloud infrastructure.

[0013] The network 140A is shown to include user equipment (UE) 101 and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as portable (laptop) or desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs 101 and 102 can be collectively referred to herein as UE 101, and UE 101 can be used to perform one or more of the techniques disclosed herein.

[0014] Any of the radio links described herein (e.g., as used in the network 140 A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard. Any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and other frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and other frequencies). Different Single Carrier or Orthogonal Frequency Domain Multiplexing (OFDM) modes (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.), and in particular 3GPP NR, may be used by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0015] In some aspects, any of the UEs 101 and 102 can comprise an Intemet-of-Things (loT) UE or a Cellular loT (CIoT) UE, which can comprise a network access layer designed for low-power loT applications utilizing shortlived UE connections. In some aspects, any of the UEs 101 and 102 can include a narrowband (NB) loT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An loT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or loT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An loT network includes interconnecting loT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The loT UEs may execute background applications (e.g., keepalive messages, status updates, etc.) to facilitate the connections of the loT network. In some aspects, any of the UEs 101 and 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs. [0016] The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN.

[0017] The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a 5G protocol, a 6G protocol, and the like.

[0018] In an aspect, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink (SL) interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), a Physical Sidelink Broadcast Channel (PSBCH), and a Physical Sidelink Feedback Channel (PSFCH).

[0019] The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi®) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0020] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes 111 and 112 can be transmission/reception points (TRPs). In instances when the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The

RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 111, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112. [0021] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some aspects, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes 111 and/or 112 can be a gNB, an eNB, or another type of RAN node.

[0022] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an SI interface 113. In aspects, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the SI interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the Sl-mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121.

[0023] In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

[0024] The S-GW 122 may terminate the SI interface 113 towards the RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawfid intercept, charging, and some policy enforcement.

[0025] The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123 may route data packets between the CN 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks

131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 101 and 102 via the CN 120.

[0026] The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some aspects, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P-GW 123. [0027] In some aspects, the communication network 140 A can be an loT network or a 5G or 6G network, including 5G new radio network using communications in the licensed (5G NR) and the unlicensed (5GNR-U) spectrum. One of the current enablers of loT is the narrowband-IoT (NB-IoT). Operation in the unlicensed spectrum may include dual connectivity (DC) operation and the standalone LTE system in the unlicensed spectrum, according to which LTE-based technology solely operates in unlicensed spectrum without the use of an “anchor” in the licensed spectrum, called MulteFire. Further enhanced operation of LTE systems in the licensed as well as unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operations can include techniques for sidelink resource allocation and LJE processing behaviors for NR sidelink V2X communications.

[0028] An NG system architecture (or 6G system architecture) can include the RAN 110 and a 5G core network (5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The CN 120 (e.g., a 5G core network/5GC) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some aspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces. [0029] In some aspects, the NG system architecture can use reference points between various nodes. In some aspects, each of the gNBs and the NG- eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some aspects, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

[0030] FIG. IB illustrates a non-roaming 5G system architecture in accordance with some aspects. In particular, FIG. IB illustrates a 5G system architecture 140B in a reference point representation, which may be extended to a 6G system architecture. More specifically, UE 102 can be in communication with RAN 110 as well as one or more other 5GC network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as an AMF 132, session management function (SMF) 136, policy control function (PCF) 148, application function (AF) 150, UPF 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM)/home subscriber server (HSS) 146.

[0031] The UPF 134 can provide a connection to a data network (DN)

152, which can include, for example, operator services, Internet access, or third- party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The AMF 132 may provide UE-based authentication, authorization, mobility management, etc., and may be independent of the access technologies. The SMF 136 can be configured to set up and manage various sessions according to network policy. The SMF 136 may thus be responsible for session management and allocation of IP addresses to UEs. The SMF 136 may also select and control the UPF 134 for data transfer. The SMF 136 may be associated with a single session of a UE 101 or multiple sessions of the UE 101. This is to say that the UE 101 may have multiple 5G sessions. Different SMFs may be allocated to each session. The use of different SMFs may permit each session to be individually managed. As a consequence, the functionalities of each session may be independent of each other.

[0032] The UPF 134 can be deployed in one or more configurations according to the desired service type and may be connected with a data network. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

[0033] The AF 150 may provide information on the packet flow to the PCF 148 responsible for policy control to support a desired QoS. The PCF 148 may set mobility and session management policies for the UE 101. To this end, the PCF 148 may use the packet flow information to determine the appropriate policies for proper operation of the AMF 132 and SMF 136. The AUSF 144 may store data for UE authentication.

[0034] In some aspects, the 5G system architecture 1406 includes an IP multimedia subsystem (IMS) 1686 as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS 1688 includes a CSCF, which can act as a proxy CSCF (P-CSCF) 1628E, a serving CSCF (S-CSCF) 1648, an emergency CSCF (E-CSCF) (not illustrated in FIG. IB), or interrogating CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain aspects of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's network for all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's service area. In some aspects, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g. an IMS operated by a different network operator.

[0035] In some aspects, the UDM/HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS). The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0036] A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. IB illustrates the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM 146 and the SMF 136, not shown), N11 (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of a non-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. IB can also be used.

[0037] FIG. 1C illustrates a 5G system architecture 140C and a servicebased representation. In addition to the network entities illustrated in FIG. IB, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some aspects, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces.

[0038] In some aspects, as illustrated in FIG. 1C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following service-based interfaces: Namf 158H (a service-based interface exhibited by the AMF 132), Nsmf 1581 (a service-based interface exhibited by the SMF 136), Nnef 158B (a service-based interface exhibited by the NEF 154), Npcf 158D (a service-based interface exhibited by the PCF 148), aNudm 158E (a service-based interface exhibited by the UDM 146), Naf 158F (a service-based interface exhibited by the AF 150), Nnrf 158C (a service-based interface exhibited by the NRF 156), Nnssf 158 A (a service-based interface exhibited by the NSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in FIG. 1C can also be used.

[0039] NR-V2X architectures may support high-reliability low latency sidelink communications with a variety of traffic patterns, including periodic and aperiodic communications with random packet arrival time and size. Techniques disclosed herein can be used for supporting high reliability in distributed communication systems with dynamic topologies, including sidelink NR V2X communication systems.

[0040] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments. The communication device 200 may be a UE such as a specialized computer, a personal or laptop computer (PC), a tablet PC, or a smart phone, dedicated network equipment such as an eNB, a server running software to configure the server to operate as a network device, a virtual device, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. For example, the communication device 200 may be implemented as one or more of the devices shown in FIGS. 1A-1C. Note that communications described herein may be encoded before transmission by the transmitting entity (e.g., UE, gNB) for reception by the receiving entity (e.g., gNB, UE) and decoded after reception by the receiving entity.

[0041] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0042] Accordingly, the term “module” (and “component”) is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general -purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0043] The communication device 200 may include a hardware processor (or equivalently processing circuitry) 202 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The main memory 204 may contain any or all of removable storage and non-removable storage, volatile memory or non-volatile memory. The communication device 200 may further include a display unit 210 such as a video display, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The communication device 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 200 may further include an output controller, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0044] The storage device 216 may include a non-transitory machine readable medium 222 (hereinafter simply referred to as machine readable medium) on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, completely or at least partially, within the main memory 204, within static memory 206, and/or within the hardware processor 202 during execution thereof by the communication device 200. While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224.

[0045] The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 200 and that cause the communication device 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks.

[0046] The instructions 224 may further be transmitted or received over a communications network using a transmission medium 226 via the network interface device 220 utilizing any one of a number of wireless local area network (WLAN) transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks. Communications over the networks may include one or more different protocols, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, IEEE 802.16 family of standards known as WiMax, IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, a next generation (NG)/5^th generation (5G) standards among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phonejacks) or one or more antennas to connect to the transmission medium 226.

[0047] Note that the term “circuitry” as used herein refers to, is part of, or includes hardware components such as an electronic circuit, a logic circuit, 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), a structured ASIC, or a programmable SoC), digital signal processors (DSPs), etc., that are configured to provide the described functionality. In some embodiments, the 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) with the program code used to carry out the functionality of that program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuitry.

[0048] The term “processor circuitry” or “processor” as used herein thus refers to, is part of, or includes circuitry capable of sequentially and automatically carrying out a sequence of arithmetic or logical operations, or recording, storing, and/or transferring digital data. The term “processor circuitry” or “processor” may refer to one or more application processors, one or more baseband processors, a physical central processing unit (CPU), a single- or multi-core processor, and/or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, and/or functional processes.

[0049] Any of the radio links described herein may operate according to any one or more of the following radio communication technologies and/or standards including but not limited to: a Global System for Mobile Communications (GSM) radio communication technology, a General Packet Radio Service (GPRS) radio communication technology, an Enhanced Data Rates for GSM Evolution (EDGE) radio communication technology, and/or a Third Generation Partnership Project (3GPP) radio communication technology, for example Universal Mobile Telecommunications System (UMTS), Freedom of Multimedia Access (FOMA), 3GPP Long Term Evolution (LTE), 3GPP Long Term Evolution Advanced (LTE Advanced), Code division multiple access 2000 (CDMA2000), Cellular Digital Packet Data (CDPD), Mobitex, Third Generation (3G), Circuit Switched Data (CSD), High-Speed Circuit-Switched Data (HSCSD), Universal Mobile Telecommunications System (Third Generation) (UMTS (3G)), Wideband Code Division Multiple Access (Universal Mobile Telecommunications System) (W-CDMA (UMTS)), High Speed Packet Access (HSPA), High-Speed Downlink Packet Access (HSDPA), High-Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+), Universal Mobile Telecommunications System-Time-Division Duplex (UMTS-TDD), Time Division-Code Division Multiple Access (TD-CDMA), Time Division- Synchronous Code Division Multiple Access (TD-CDMA), 3rd Generation Partnership Project Release 8 (Pre-4th Generation) (3 GPP Rel. 8 (Pre-4G)), 3GPP Rel. 9 (3rd Generation Partnership Project Release 9), 3GPP Rel. 10 (3rd Generation Partnership Project Release 10) , 3GPP Rel. 11 (3rd Generation Partnership Project Release 11), 3GPP Rel. 12 (3rd Generation Partnership Project Release 12), 3GPP Rel. 13 (3rd Generation Partnership Project Release 13), 3GPP Rel. 14 (3rd Generation Partnership Project Release 14), 3GPP Rel. 15 (3rd Generation Partnership Project Release 15), 3GPP Rel. 16 (3rd Generation Partnership Project Release 16), 3GPP Rel. 17 (3rd Generation Partnership Project Release 17) and subsequent Releases (such as Rel. 18, Rel. 19, etc.), 3GPP 5G, 5G, 5G New Radio (5GNR), 3GPP 5G New Radio, 3GPP LTE Extra, LTE-Advanced Pro, LTE Licensed-Assisted Access (LAA), MuLTEfire, UMTS Terrestrial Radio Access (UTRA), Evolved UMTS Terrestrial Radio Access (E-UTRA), Long Term Evolution Advanced (4th Generation) (LTE Advanced (4G)), cdmaOne (2G), Code division multiple access 2000 (Third generation) (CDMA2000 (3G)), Evolution-Data Optimized or Evolution-Data Only (EV-DO), Advanced Mobile Phone System (1st Generation) (AMPS (1G)), Total Access Communication System/Extended Total Access Communication System (TACS/ETACS), Digital AMPS (2nd Generation) (D-AMPS (2G)), Push-to-talk (PTT), Mobile Telephone System (MTS), Improved Mobile Telephone System (IMTS), Advanced Mobile Telephone System (AMTS), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD (Swedish abbreviation for

Mobiltelefoni system D, or Mobile telephony system D), Public Automated Land Mobile (Autotel/PALM), ARP (Finnish for Autoradiopuhelin, "car radio phone"), NMT (Nordic Mobile Telephony), High capacity version of NTT (Nippon Telegraph and Telephone) (Hicap), Cellular Digital Packet Data (CDPD), Mobitex, DataTAC, Integrated Digital Enhanced Network (iDEN), Personal Digital Cellular (PDC), Circuit Switched Data (CSD), Personal Handyphone System (PHS), Wideband Integrated Digital Enhanced Network (WiDEN), iBurst, Unlicensed Mobile Access (UMA), also referred to as also referred to as 3 GPP Generic Access Network, or GAN standard), Zigbee, Bluetooth(r), Wireless Gigabit Alliance (WiGig) standard, mmWave standards in general (wireless systems operating at 10-300 GHz and above such as WiGig, IEEE 802.11 ad, IEEE 802.1 lay, etc.), technologies operating above 300 GHz and THz bands, (3GPP/LTE based or IEEE 802.1 Ip or IEEE 802.1 Ibd and other) Vehicle-to-Vehicle (V2V) and Vehicle-to-X (V2X) and Vehicle-to- Infrastructure (V2I) and Infrastructure-to-Vehicle (I2V) communication technologies, 3GPP cellular V2X, DSRC (Dedicated Short Range Communications) communication systems such as Intelligent-Transport-Systems and others (typically operating in 5850 MHz to 5925 MHz or above (typically up to 5935 MHz following change proposals in CEPT Report 71)), the European ITS-G5 system (i.e. the European flavor of IEEE 802.1 Ip based DSRC, including ITS-G5A (i.e., Operation of ITS-G5 in European ITS frequency bands dedicated to ITS for safety re-lated applications in the frequency range 5,875 GHz to 5,905 GHz), ITS-G5B (i.e., Operation in European ITS frequency bands dedicated to ITS non- safety applications in the frequency range 5,855 GHz to 5,875 GHz), ITS-G5C (i.e., Operation of ITS applications in the frequency range 5,470 GHz to 5,725 GHz)), DSRC in Japan in the 700MHz band (including 715 MHz to 725 MHz), IEEE 802.1 Ibd based systems, etc.

[0050] Aspects described herein can be used in the context of any spectrum management scheme including dedicated licensed spectrum, unlicensed spectrum, license exempt spectrum, (licensed) shared spectrum (such as LSA = Licensed Shared Access in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz and further frequencies and SAS = Spectrum Access System / CBRS = Citizen Broadband Radio System in 3.55-3.7 GHz and further frequencies). Applicable spectrum bands include IMT (International Mobile Telecommunications) spectrum as well as other types of spectrum/bands, such as bands with national allocation (including 450 - 470 MHz, 902-928 MHz (note: allocated for example in US (FCC Part 15)), 863-868.6 MHz (note: allocated for example in European Union (ETSI EN 300220)), 915.9-929.7 MHz (note: allocated for example in Japan), 917-923.5 MHz (note: allocated for example in South Korea), 755-779 MHz and 779-787 MHz (note: allocated for example in China), 790 - 960 MHz, 1710 - 2025 MHz, 2110 - 2200 MHz, 2300 - 2400 MHz, 2.4-2.4835 GHz (note: it is an ISM band with global availability and it is used by Wi-Fi technology family (1 Ib/g/n/ax) and also by Bluetooth), 2500 - 2690 MHz, 698-790 MHz, 610 - 790 MHz, 3400 - 3600 MHz, 3400 - 3800 MHz, 3800 - 4200 MHz, 3.55- 3.7 GHz (note: allocated for example in the US for Citizen Broadband Radio Service), 5.15-5.25 GHz and 5.25-5.35 GHz and 5.47-5.725 GHz and 5.725-5.85 GHz bands (note: allocated for example in the US (FCC part 15), consists four U-NII bands in total 500 MHz spectrum), 5.725-5.875 GHz (note: allocated for example in EU (ETSI EN 301 893)), 5.47-5.65 GHz (note: allocated for example in South Korea, 5925-7125 MHz and 5925-6425MHz band (note: under consideration in US and EU, respectively. Next generation Wi-Fi system is expected to include the 6 GHz spectrum as operating band but it is noted that, as of December 2017, Wi-Fi system is not yet allowed in this band. Regulation is expected to be finished in 2019-2020 time frame), IMT-advanced spectrum, IMT-2020 spectrum (expected to include 3600-3800 MHz, 3800 - 4200 MHz, 3.5 GHz bands, 700 MHz bands, bands within the 24.25-86 GHz range, etc.), spectrum made available under FCC's "Spectrum Frontier" 5G initiative (including 27.5 - 28.35 GHz, 29.1 - 29.25 GHz, 31 - 31.3 GHz, 37 - 38.6 GHz, 38.6 - 40 GHz, 42 - 42.5 GHz, 57 - 64 GHz, 71 - 76 GHz, 81 - 86 GHz and 92 - 94 GHz, etc), the ITS (Intelligent Transport Systems) band of 5.9 GHz (typically 5.85-5.925 GHz) and 63-64 GHz, bands currently allocated to WiGig such as WiGig Band 1 (57.24-59.40 GHz), WiGig Band 2 (59.40-61.56 GHz) and WiGig Band 3 (61.56-63.72 GHz) and WiGig Band 4 (63.72-65.88 GHz), 57- 64/66 GHz (note: this band has near-global designation for Multi-Gigabit Wireless Systems (MGWS)/WiGig . In US (FCC part 15) allocates total 14 GHz spectrum, while EU (ETSI EN 302 567 and ETSI EN 301 217-2 for fixed P2P) allocates total 9 GHz spectrum), the 70.2 GHz - 71 GHz band, any band between 65.88 GHz and 71 GHz, bands currently allocated to automotive radar applications such as 76-81 GHz, and future bands including 94-300 GHz and above. Furthermore, the scheme can be used on a secondary basis on bands such as the TV White Space bands (typically below 790 MHz) where in particular the 400 MHz and 700 MHz bands are promising candidates. Besides cellular applications, specific applications for vertical markets may be addressed such as PMSE (Program Making and Special Events), medical, health, surgery, automotive, low-latency, drones, etc. applications.

[0051] Aspects described herein can also implement a hierarchical application of the scheme is possible, e.g., by introducing a hierarchical prioritization of usage for different types of users (e.g., low/medium/high priority, etc.), based on a prioritized access to the spectrum e.g., with highest priority to tier-1 users, followed by tier-2, then tier-3, etc. users, etc.

[0052] Aspects described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0053] Some of the features in this document are defined for the network side, such as APs, eNBs, NR or gNBs - note that this term is typically used in the context of 3GPP 5G and 6G communication systems, etc. Still, a UE may take this role as well and act as an AP, eNB, or gNB; that is some or all features defined for network equipment may be implemented by a UE.

[0054] As above, next generation wireless communication systems are expected to handle a variety of potentially dynamic environments under challenging conditions, including losses of connection, communication blockages especially for operations in higher frequency bands, potentially limited network coverage, etc. Availability of blockage maps can benefit both UEs and the network by providing a good extent of predictability about several uncertainties that communications between the network and the UE may face. Accordingly, the network and UEs may adjust their actions and/or parameters towards providing more preparedness, reactiveness, and proactiveness in the system based on the blockage maps.

[0055] To this end, a system, methods, and apparatus of identifying blockages, which may potentially involve radio link failure (RLF) events, i.e., blockages with long enough duration and/or extensive enough impact, that may not be handled/recovered by beam-failure recovery procedure (BFR) (e.g., UE not able to find beams to recover the link in the cell), is described, as well as to create/update a map of such blockages. Blockage size/duration relative to the operation frequency/wavelength, UE speed (and if applicable, blocker’s speed) (and even the level of traffic congestion) setting of counters/timers’ durations (e.g., timers T310, T311, T301, N310, N311) and other parameters, determines the (experienced) lasting impact of the blockage. One focus is on blockages that may have a medium-large scale from the perspective of dimension and/or the lasting impact on UE-network communication. Such impact may be mainly due more stationary or veiy limited mobility blockers (especially compared to UE mobility). Considering high-band operation, even a blocker’s size that is on the order of human body or smaller may have a long enough impact on UE operation and may potentially even trigger RLF. [0056] The wireless communication system may include a network of one or more cells provided by base stations (eNBs or gNBs that may or may not provide ubiquitous coverage within the network deployment area), and a plurality of UEs that can establish/re-establish and lose wireless connections with the base stations as the UEs can move relative to the cells and there are blocking objects that can reside within the network, either statically, or with mobility, which can block the UE and network communication link. Systems, methods, and apparatus in which the base stations and mobile stations collaboratively exchange information with respect to the link problems, analyze the information, infer the cause of link problems, decide on existence of communication blockages in different locations within the cell(s), and/or identify the locations with high chances of blockage existence. Base stations and mobile stations collaboratively evolve and share their understanding of the link problems and corresponding locations within the network coverage.

[0057] To handle link problems in the current technology design, counters and timers may be used to track in-sync and out-of-sync events. Out- of-sync status is defined based on a signal measurement being below a threshold for a certain timer duration. This is determined based on UE observing “out-of- sync” and “in-sync” events/indications. When a UE first experiences a certain number (N310) of consecutive out-of-sync events (defined in NR as measured Reference Signal Received Power (RSRP) being below a threshold that corresponds to the RSRP for decoding of a Synchronization Signal Block (SSB) or a predefined physical downlink control channel (PDCCH) format), the UE initiates counters to count the number of in-sync indications and a timer, T310 (also called RLF declaration timer). If a certain number (N311) of consecutive in-sync indications are observed/received before expiration of timer T310, the UE returns to normal operation. If the timer expires without the UE observing enough in-sync indications, the UE considers itself in a RLF condition.

[0058] In 3 GPP systems, Radio Resource Control (RRC) manages control signaling between UEs and the network, including (re-)establi shing and releasing connections. The state in which a UE is connected to the network is referred to as the RRC CONNECTED state. Going out of network’s coverage area (e.g., in deployments with non-ubiquitous coverage which may be motivated in future cellular system design), as well as facing some blockages inside the network coverage area (a serious challenge for operation in higher frequency bands), amongst other reasons such as handover failures (which is out of the scope of this disclosure), can make the RRC CONNECTED UE undergo physical layer RLE.

[0059] As specified in TS 38.331 subclause 5.3.10.3, RLE detection may be due to T310 expiry, a random access problem indication from a Medium Access Control (MAC) entity, or indication from RLC entity that the maximum number of retransmissions has been reached. Each of these causes, amongst different reasons, may happen due to blockages (e.g., happening at different stages of different UE’s procedures/operation), and/or coverage limitations. In response to a determination of RLE then initiates the steps for connection reestablishment. This includes a reset of the MAC, suspension of all DRBs and performing cell selection to identify a cell to perform reestablishment. Each UE, upon detecting a RLE condition, starts a timer that expires after a pre-determined configured time period (RLE timer duration) as part of a reestablishment procedure. In NR and prior technologies, this timer is called T311, and ends once the UE finds a suitable cell for RRC connection reestablishment or expires after a predetermined time period. If the UE identifies and selects a suitable cell for reestablishment within the T311 time period, the UE transmits an RRC reestablishment request message and a second phase of RRC Connection Reestablishment includes starting another timer T301. Timer T301 is used, once the UE has found a suitable cell, to start a contention-based Random Access Channel (RACH) procedure to enable the RRC Connection Reestablishment Request message to be sent. Currently, the maximum time allowed for the T311 timer is 30s, while the T310/T301 timer can be up to 2s. If the T311 timer expires without the UE being able to select a suitable cell, UE transitions to RRC IDLE. Particularly, amongst other reasons, the RRC IDLE state can be reached through T311 expiry, T301 expiry (related to random access problem/failure during connection reestablishment phase), or RRC Connection Reestablishment Reject being received by the UE (selected cell no longer being suitable), with release cause 'RRC connection failure'. Timers T301, T310, T311 and constants N310, N311, are included in ue-TimersAndConstants received in system information broadcast 1 (SIB1). [0060] Blockage Map

[0061] In one embodiment, effective blockage-map(s) are developed based on categorization or ranges of UE speed, operation frequencies, implementation, deployment, etc. In one example, different maps may be developed for different speed ranges (speed-dependent blockage maps) and/or different operation frequency ranges (frequency-band-dependent blockage maps), and/or different ranges of relevant timer durations, or any combination of these. In such case, the areas with commonality between subsets of these maps, provide the most reliable locations of blockage detection. In another example, the blockage map(s) are generated with a certain confidence level, inheriting some level of variation in speed, frequency, blockage size, etc. (e.g., within certain ranges).

[0062] In one embodiment, detection of blockages and consequently creation of a blockage map is based on collecting proper data, observing the events carefully, and analyzing events, causes, timers triggers/stops/expiries (especially RLF-related timers), etc. Through proper analysis and processing at the network and/or UE(s) and/or both sides (partially or fully), it is then possible to distinguish the link problem, e.g., RLFs caused by limited coverage problems from those caused by blockages, and from other reasons. In one example, existence of some blockages may be interpreted/detected and reported by UE(s) to the network. In another example, the network may mainly be responsible for interpreting/detecting blockages from the collected data. With proper analysis, it is also possible to categorize blockages into blockages caused by mobile blockers and blockages caused by more stationary objects, shorter-term blockages vs middle-term blockages vs longer-term blockages, etc. Being able to make such differentiations enables the UE and the network to take proper further steps, according to the identified underlying cause. For more accuracy, some of the categorizations (e.g., for short-term blockages) may also benefit from information beyond RLF-related data, e.g., information related to BFD events. Just as a brief enlightening example, it is possible to build a map based on Beam Failure Detection (BFD) locations/statistics, etc., for short-term blockages. Transient blockages may be due to mobile blockers for which it may not be feasible and/or desired to build a map. On the other hand, it is possible and beneficial to build a map to identify areas with likelihood of high traffic of blocking objects, e.g., using beam-failure-related information, etc. This provide a good extent of statistical predictability about the more transient uncertainties that are experienced during the communication and prepare the UE/network to take proper actions, e.g., timers/counters (including any of BFR, RLE, and/or L2-related timers/parameters) adjustment, etc. In one embodiment, some lifetime for the blockage information may be considered, e.g., according to the inferred nature of the blockage up to the current time. This consequently impacts how frequently the information and the map should be updated. Depending on the events and types of information used to generate the map, and the nature of underlying blockages, the lifetime can be different.

[0063] Naturally, the transient/temporary blockages and/or the blockages that may block part of the communication beams between the UE and base station may not involve RLF events. On the other hand, UEs and network can (maybe indirectly) benefit from the predictability of more-lasting blockages (provided by blockage map as disclosed in this IDF), even in expecting/handling the more transient blockages e.g., caused by mobile blockers, etc. For example, when a UE faces link problems, by locating UE’s current location on the maps and comparing the current location to the locations of more lasting blockages, implicit understanding of the nature of the experienced blockages can be inferred, e.g., if current blockage is transient (ruling/filtering out the more- lasting blockages). This can be thought as an indirect way of shorter-term blockages predictability. Accordingly, the network/UE may avoid a RLF declaration, e.g., by setting a longer T310 duration and broadcasting this information along with modified N310/N311 values (potentially corresponding to the specific location), and/or (researching for a suitable beam, triggering use of a second best-beam or any available beam, reperforming random access procedure (potentially after some optional wait time depending on estimations of temporary blockage duration), etc.

[0064] As disclosed herein, blockage identification and blockage map generation/update are based on operations/information of connected-mode UEs. However, the generated blockage map may benefit UEs in the initial access phase as well as connected mode UEs. For example, if the UE in the initial access phase has had any prior access to the network (which is very likely in a sparse limited-coverage deployment), the UE may have some knowledge about the blockages, etc., and adjust its procedures accordingly. Further, depending on how, at what stage, and through which messages the network may communicate blockage-map-related information, the UE may be able to further benefit from some level of information along the procedure. While blockage identification and development of blockage maps are discussed herein, the manner that system can apply maps information are also disclosed.

[0065] Collecting relevant information (such as RLF-related information, etc.) [0066] Background on RLF report [0067] In current system design, upon RLF detection, for a UE that, prior to RLF detection, had been operating in the RRC connected state (with activated Access Stratum (AS) security and established DRB), the radio link failure information is stored in a VarRLF-Report as described in TS 38.331 subclause 5.3.10.5. The UE then initiates a connection re-establishment procedure as specified in 5.3.7 and starts the T311 timer. If the AS security has not been activated, or AS security has been activated but signaling radio bearer2 (SRB2) and at least one DRB have not been set up, upon RLF detection, the UE performs actions upon entering the RRC IDLE state as specified in Clause 5.3.11. Generally, the RLF report contains information related to the latest connection failure experienced by UE, due to RLF or Handover Failure. The contents of RLF report and procedure for retrieving the RLF report by the base station are specified in TS 38.331. The following radio link failure information can be stored in the VarRLF-Report-.

[0068] if the failure is detected due to RLF as described in 5.3.10.3, cormectionFailureType is set to rtf

[0069] plmn-IdentityList to include the list of EPLMNs stored by the UE (i.e., includes the RPLMN);

[0070] measResultLastServCell to include the RSRP, RSRQ and the available SINK, of the source PCell (in case handover (HO) failure) or PCell (in case of RLF) based on the available SSB and CSI-RS measurements collected up to the moment the UE detected failure [0071] ssbRLMConjigBitinap and/or csi-rsRLMConfigBitmap in measResultLastServCell to include radio link monitoring configuration of the source PCell (in case HO failure) or PCell (in case of RLF)

[0072] for each configured NR/EUTRA frequency (measObjectNR) in which measurements are available, if SS/PBCH block-based or CSI-RS-based measurement quantities are available, to include all available measurement quantities of the best measured cells (based on the available measurements collected up to the moment UE detected failure), other than the source PCell (jneasResultListNR in measResultNeighCells/ measResultListEUTRA in measResultNeighCells)

[0073] locationinfo to include location information if available

[0074] failedPCellld to include global cell identity and tracking area code, if available, and otherwise to include physical cell identity and carrier frequency of the PCell where RLF is detected

[0075] RRCReconfiguration message including reconfigurationWithSync, if received before connection failure (in case of HO failure)

[0076] Cell Radio Network Temporary Identifier (C-RNTI) used in the source PCell(in case HO failure) or PCell (in case of RLF)

[0077] rlf-Cause that triggered RLF detection (if the rlf-Cause is set to randomAccessProblem or beamFailureRecovery Failure, meaning UE declares RLF due to random access problem indication from MAC, a bunch of related information is also stored, e.g., ra-InformationCommon to include randomaccess related information as described in TS 38.331 subclause 5.7.10.5).

[0078] As such, after link failure occurs, the UE provides relevant information on the local cell and neighboring cells, such as measurement information and location information, etc., to the network based on request. The UE may discard the RLF information, i.e., release the UE variable VarRLF- Report, 48 hours after the RLF is detected.

[0079] Background on minimization of drive tests (MDT) functionality

[0080] TS 37.320 elaborates functions and procedures to support collection of UE-specific measurements for Minimizing Drive Testing (MDT) using Control Plane (CP) architecture, where the focus is on conventional macro cellular network deployments. There are different modes of MDT: Logged MDT and Immediate MDT, and measurement collection not specified as either immediate or logged MDT, e.g., accessibility measurements.

[0081] Immediate MDT : involves measurements performed by a CONNECTED state LIE and reporting of the measurements to the RAN available at the time of the reporting condition as well as measurements by the network/RAN for MDT purposes. The configuration/reporting of UE measurements is based on existing RRC measurement procedures, with some extensions for location information. The RAN initiates an MDT measurements collection task, with or without targeting a specific UE (the former by signalingbased trace activation messages from CN nodes, and the latter via the cell traffic management-based trace function).

[0082] Logged MDT: involves measurement logging by an IDLE/INACTIVE state UE for reporting to the base station at a later point in time (sent on SRB2 when the UE is in the RRC CONNECTED state), and is configured with an MDT Measurement Configuration (unidirectional dedicated RRC signaling in connected state) procedure, configuring the following, amongst several other configurations:

[0083] logging of downlink (DL) pilot strength measurements (of RSRP and RSRQ), logging duration (defining a timer starting upon configuration, running independent of state changes) network absolute time stamp to be used as a time reference to UE, optionally a logging (geographical) area (UE keeps logging only as long as it is within the configured logging area), and

[0084] triggering of logging events: periodic (with configurable logging interval for storing logged measurements), and event-based (with configurable logging interval for periodical logging of available data (e.g. time stamp, location information)). Two types of events are supported: measurement quantity-based event LI, for which the event threshold and time to trigger are configurable, and out-of-coverage detection trigger.

[0085] Note that measurement logging is differentiated based on UE states in IDLE mode, i.e., camped normally (this state includes a period between cell selection criteria not being met and UE entering "any cell selection" state, i.e., 10s for NR (See TS 38.133), any cell selection or camped on any cell. The UE performs measurement logging in "camped normally" state and "any cell selection" state. In the "camped on any cell" state, the UE is not required to perform MDT measurement logging and periodic logging stops (including time and location information).

[0086] While the logging configuration for event-based and periodical DL pilot strength logged measurements can be configured independently, only one type of event can be configured to the UE.

[0087] For NR, in addition to the logged measurement quantities of the camped serving cell, the best beam index (SSB Index) as well as best beam RSRPZRSRQ is logged as well as the 'number of good beams' associated to the cells within the R value range (configured by network for cell reselection) of the highest ranked cell as part of the beam level measurements. Sensor measurements are logged if available.

[0088] UE MDT measurement logs include multiple events and measurements taken over time. The time interval for measurement collection and reporting is decoupled to limit impact on UE battery consumption and network signaling load. Measurements are linked to available location information and/or other information or measurements that can be used to derive location information. The measurements in logs are also linked to a (relative) time stamp and can be linked to available sensor information related to UE orientation in a global coordinate system and UE speed.

[0089] The UE measurement logging mechanism may be optional, and, to limit impact on UE power consumption and processing, measurement logging may rely on available measurements in the UE according to radio resource management enforced by the access network, as much as possible. The UE collects MDT measurements and continues logging according to the logged measurement configuration until the UE memory reserved for MDT is full. In this case, the UE stops logging, stops the log duration timer and starts the 48- hour timer.

[0090] A UE configured for logged MDT indicates availability of logged measurements, via a bit in an RRCCormectionSetupComplete,

RRCSetupComplete, RRCCormectionResumeComplete, or RRCResumeComplete message during connection establishment, or within NR re-establishment, or reconfiguration. The UE includes the indication in one of these messages at every transition to RRC Connected mode even though the logging period has not ended, upon connection. For Logged MDT, the measurement reporting is triggered by an on-demand mechanism, i.e., the UE is asked by the network to send the collected measurement logs via RRC signaling. The reporting may occur in different cells than that which the logged measurement configuration is signaled. Transport of Logged MDT reports in multiple RRC messages is supported (multiple RRC transmissions for self-decodable segmented Logged MDT reporting).

[0091] For both MDT modes, depending on location information availability, the measurement log/report includes time information, RF measurements, detailed location information (beyond RF fingerprints, e.g., GNSS location information), sensor information. Availability of location information (as well as speed and/or orientation measurement information) is subject to UE capability and/or implementation. Solutions that location information may consider UE power consumption (due to running positioning components). The network may use UE capabilities to select terminals for MDT measurements (e.g., the UE uses a capability bit to indicate support of DL pilot strength measurements and event-triggered logging).

[0092] Accessibility measurements: the UE logs any failed connection establishment attempt, i.e., a log is created when the RRC setup (or resume) procedure fails, i.e., when timer T300 expires (without need for prior configuration by network) (Subclause 5.1.6 of TS 37.320). The UE can store following information related to the failed RRC connection establishment/ resume procedure: Time stamp, global cell identity of serving cell when the RRC connection establishment/resume fails, i.e., the cell which the UE attempted to access, latest available radio measurements for any frequency or RAT, latest detailed location information, if available, SSB index of DL beams of serving cell, latest number of consecutive connection failures in the last failed cell UE has experienced independent of RRC state transition, RACK failure report (tried SSB index and number of Random Access Preambles transmitted for each tried

SSB, contention detected as per RACK attempt, indication whether selected SSB is above or below rsrp-ThresholdSSB as per RACK attempt, TAC of the cell in which UE performs RA), latest sensor information, if available.MDT measurements/information have some overlaps with contents of RLF report. MDT can then use contents of RLF report, whenever possible/available. For example, MDT may use following content from RLF report: latest radio measurement results (including SSB/CSI-RS index and associated measurements) of serving and neighboring cells, "No suitable cell is found" flag when T311 expires, available location/sensor information, RACH failure report (if the cause for RLF is RA problem or BFR failure), etc. (TS 37.320, subclause 5.4.1.2).

[0093] MDT data reported from UEs and the RAN may be used to monitor and detect coverage problems in the network and perform coverage optimizations/dimensioning by the network. Example use cases are provided in Annex A of TS 37.320. Coverage-map is a use case enabling the network to have a complete view of the coverage and knowledge about signal levels in cell areas, via measurements collected in all parts of network (not just in areas with potential coverage issues). Solutions for MDT can work independently from self-organizing network (SON) support in network. Relations between measurements/ solution for MDT and UE-side SON functions re-use of functions is achieved where possible. While some of the MDT report contents can be used for the purpose of blockage map generation/refinement, unlike MDT use cases, blockage map is cooperatively built, maintained, and refined by UE(s) and network, with continuously infening/analyzing collected data. The UE(s) and network may share the map and take/adjust actions based on the map.

[00941 Information collection for blockage detection and map generation/update

[0095] In one embodiment, some or all UEs are capable of storing and transmitting a report of a radio link problem to the network. This report may contain information about the cause, timers’ expiry, etc., and/or may be (in-part) common with VarRLF-Report and/or MDT measurements reports, and/or contain information beyond VarRLF-Report and/or MDT measurements reports The UE may also be specifically configured to gather and store such information and utilize the information for sharing.

[0096] In one embodiment, the network collects information on one or multiple of the following: at least a subset of the UEs’ success and/or failure in (re-) establishing connections with the network; at least a subset of UEs’ speeds or speed ranges; at least a subset of the UEs’ locations (location may be the UE’s latest knowledge of its location or the UE may have the capability of saving a snapshot of its info on location etc., with certain periodicity, which may have enable more accurate estimation/mapping between location and link problems); at least a subset of the UEs’ timestamp of identifying a radio link problem at their physical layer, and the timestamps when the UEs could successfully (re-) establish the connection or declared failure; and at least a subset of the UEs’ timers/counters status information e.g., including T310, T311, T301, N310, N311.

[0097] In one example, the network may use and/or expand the information the UEs store and report via VarRLF-Report and/or MDT report. In another example, the network may derive/infer some of such information through analysis/processing of other available information/data, without UE direct reporting of such information. FIG. 3 illustrates an exchange of collected information between a UE and a RAN in accordance with some embodiments.

Once the UE has collected information related to RLF or other (configured) measurements, the UE may let the network know using one of the RRC messages when applicable. At a later time, the network/RAN may send a UEInJormationRequest to fetch the collected reports from the UE.

[0098] In one example, at least a subset of UEs may be able to provide (within VarRLF-Report, and/or MDT reports, or separately) one or more of the following (whenever/whichever applicable): a location (and a time point) where (and when) a UE has detected a disconnection from the network, e.g., T310 is triggered; a location (and a time point) where (and when) T310 stops; a location (and a time point) where (and when) the UE determines that an RLF has happened, i.e., T310 expiry (or T311 start); for network-request-based RLF reports (and/or MDT reports), a location (and a time point) where (and when) the UE receives the report request from the network; a location (and a time point) where (and when) the UE transmits a radio problem (and/or RLF report and/or MDT) report (response); a location (and a time point) where (and when) T311 stops (T301 starts); a location (and a time point) where (and when) T311 expires; and a location (and a time point) where (and when) T301 expires.

[0099] For example, the network may form a database from the collected information and keep updating/maintaining it. It is noted that the blockage map generation/update is not exactly real-time (near real-time as much as possible). The network may receive RLE information, just after recovery, and incorporate that information. The faster UE can communicate such information with the network, the more up to date the map is, which directly improves the system performance.

[00100] In another embodiment, the procedures of requesting/configuring and/or collecting data may be performed with some predetermined periodicity, triggered dynamically, or UEs may always automatically report available stored information for each RLE experience, as soon as the UEs access the network. For example, the network may request/configure UEs to report any relevant information (e.g., as disclosed above) upon facing (and recovering from) an RLE (even in a standalone operation, and with no handover triggered) or a UE may transmit information whenever link problems have been experienced, or may transmit, with a predetermined periodicity, information related to any link problems experienced within a particular period. In one example, the UE may transmit, upon request or being configured to, a subset of applicable information (e.g., from the above disclosed lists or beyond), upon experiencing conditions that may be assumed as indicators of link quality degradations, e.g., any retransmission being triggered, etc. In another example, the UE may first indicate through one of exiting signaling (e.g., one of RRC messaging) or new signaling, availability of any link-problem related information/report. Further, the duration over which the data collection is performed, may be predetermined or dynamically indicated by the network. In one example, the network requests and collects information at least on a subset of UEs success or failure in (re-) establishing connections with the network.

[00101] During network operation, there may be different causes of link failure. In one embodiment, the content of RLE information may be further extended to include some extent of a UE side’s analysis and inference about the cause of RLE. This helps the network with determining a root cause of the link failure, and hence more accurately detect blockages. For example, detailed information, such as detailed triggering information causing the link failure (on physical layer problem due to consecutive out-of-sync events within T310, MAC layer triggering of RACK problems, or RLC layer triggering due to reaching max number of retransmissions), complemented with some of the UE’s analysis may be provided to the network. In one example, the UE may analyze and infer that certain triggering causes may be due to some type of blockage, while other triggering causes may be due to a coverage problem or another reason, and the UE may also transmit such analysis to the network. Alternatively, the network may perform such analysis and inference. In another example, a correlation may be identified (by the UE or network) between physical layer and/or MAC layer triggering, and the underlying problem being existence of blockage, while a correlation may be identified between RLC layer triggering, and the underlying problem being coverage issues (e.g., due to poor channel conditions at cell-edge and potential for RLC retransmissions).

[00102] In one example, the UE transmits the cause of link failure obtained by analysis to the network, e.g., in detailed configuration information, and the network determines a root cause of the link failure according to the reported cause, potentially in combination with some measurement results obtained from UEs and/or performed by the network itself (e.g., SRS measurement, etc.).

[00103] For instance, the cause of link problem/failure may be included in link failure information 0ink failure report and/or MDT report) or may be separately transmitted to network. Furthermore, the analysis result may be transmitted upon request by the network, may be transmitted immediately after the analysis result is obtained, or the transmission may be triggered according to a certain situation. Performing analysis at the UE side may also be requested by the network or may be triggered according to predefined conditions.

[00104] Blockage detection/identification and blockage map generation/update

[00105] As mentioned earlier, one possible approach to generate a blockage map is through monitoring and analyzing information about events experienced by UEs, RLF-related, etc., at the network side and/or UE side (whenever possible, and to the extent possible). Generation of a blockage map using the information gathered based on current functionalities of counters/timers, triggers, and transitions is described. Future cellular system design may inherently avoid triggers and transitions, or even counter/timer functionalities, which will be discussed and disclosed below. Future designs can itself be founded based upon and/or benefit from the availability of a blockage map (and/or equivalently any extent/form of predictability of the link issues), regardless of how the map is originally developed, e.g., based on current counter/timer settings, functionalities, etc.

[00106] Varying some predetermined param eters/timers and monitoring the impact

[00107] In one embodiment, decisions about existence of blockage (and consequently creating and maintaining/updating a blockage map for the cellular wireless network) is made based on modifying the setting of UE specific parameters/timers/counters and observing the impact. Particularly, decisions on blockage detection (deciding whether the link problem is due to blockage) can be made by analyzing the correlation between the settings/tuning of one or more UE’s timers/counters, e.g., T311, T310, T301, N310, N311, i.e., by varying their predetermined expiry period in one or more steps, and the resultant UE behaviors, such as rate of the UEs RLF declarations, UEs RLF/MDT report contents, UEs successfill RRC reestablishments, or reestablishment failures and transitioning to RRC IDLE state. Such analysis may be based on collected information on the incurred events. The settings of the timers/counters can be systematically varied to evaluate characteristics of the observed link problems. This method is also helpful for cases where it is not (always) possible to rely on some/all UEs logging and reporting information upon facing a link problem, RLF, and/or configured for MDT. By proper variation and observation, it may be even possible to also (roughly) estimate the size of an identified blockage.

[00108] As mentioned earlier, expiry of T310 occurs when a certain number of consecutive in-sync indications are not observed while T310 is running, and the UE considers itself to be in the RLF condition. Hence, in one embodiment, if a certain percentage of operating UEs (e.g., in a vicinity of location or time) observe a certain number (N311) of consecutive in-sync indications during their T310s and return to normal operation, the radio link problem may be inferred due to a ‘short-term blockage’, which has been long enough to trigger T310, but not long enough to cause expiry of T310.

[00109] Expiry of T311, on the other hand, occurs when the UE is unable to find any suitable cell while timer T311 is running. Hence, in one embodiment, during the RRC connection reestablishment process upon an RLF, if a certain percentage of operating UEs (e.g., in a vicinity of location or time) can find a suitable cell during T311 and can successfully complete RRC connection reestablishment process, then the RLF may be inferred due to a ‘middle-term blockage’ problem, that has been long enough to trigger RLF and T311 but not long enough to cause expiry of T311.

[00110] In one embodiment, the aforementioned information/inference is used to develop/update blockage map(s). If the UEs are able to report detailed information (potentially complemented with some level of UE-side analysis/inference as well) about radio link problems (e.g., timer/counter information, causes, at which stage of the operation they faced problems, etc.), differentiation between different types of link issues and between different types of blockages is more straightforward. Without such reporting from the UEs, the network can infer and interpret the events to some extent (e.g., based on measurements, RRC state transitions, etc.), and may continually refine the inference/interpretation. For example, the network can detect the UE transitioning to the RRC IDLE state if, while the network assumes that the UE is in RRC CONNECTED state, the UE does not reply to RRC messages or does not send expected RRC messages or through other implementation specific solutions. With reports and information provided by the UEs, analysis and monitoring the impact of vaiying a parameter such as T310 and/or T311 and/or T301 duration on the UEs behavior/actions/transitions is more straightforward; hence, the blockage map can be updated faster.

[00111] It is noted that by varying the setting of T311 and/or T310 and/or

T301 duration parameters (their predetermined expiry time) within properly selected ranges, on the one hand, if a blockage exists around the UE(s), it becomes more or less likely for the UE(s) to suffer from blockage issues. On the other hand, if there are no blockage problems, there will be little or no influence on UE operation due to vaiying the timer setting.

[00112] In one embodiment, in a wireless communication system in which UEs (re-)establish connections through RRC signaling, and expiry of RLF timer causes the UE to transition to the RRC IDLE state, base stations may monitor the impact of varying RLF timer duration on transitions to the RRC IDLE state to interpret existence of blockages. [00113] In another embodiment, the network may monitor the impact of varying the durations of the counters/timers on link problem reports/causes from UEs (and/or information of T310 and/or T311 and/or T301 expiry by UEs, if any). Particularly, since these timer/counter runs and triggers are happening within UEs, the network may not be able to immediately realize the exact causes without help from the UEs.

[00114] This further motivates the use of an analyzing entity that may reside within the network and can: collect information, including event data about RLFs, RRC connection reestablishment process-related events, etc., as well as any related observations; infer and learn from the data; and update the decisions with respect to: determining success or failure of reestablishment, reasons for any failed reestablishment, and existence of a blockage (blockage detection). The analyzing entity may keep updating the corresponding blockage map.

[00115] For example, monitoring the impact on UE behavior of varying parameters such as the expiry duration of T301 and/or T311 may let the network verify that the reason for the UE transiting to the RRC IDLE mode is the expiry of T301 and/or T311 (if such information is not provided by the UE). Once this can be verified, and by monitoring several UEs over a period of time for transitions to RRC IDLE state, the existence of a ‘middle/long-term’ blockage may be detected/inferred. In another example, monitoring the impact of varying a parameter such as the expiry duration of N310/N311 and/or T310 on UE behavior may let the network verify the reason for the UE declaring RLF, and by monitoring several UEs over a period of time for RLF declaration, the existence of a ‘short/middle-term’ blockage may be detected/inferred.

[00116] How to enable/realize the variation-monitoring approach

[00117] In one embodiment, triggering the timer-tuning/varying processes may be based on RLF detection(s) in a vicinity (whether through direct reports from UEs or inferenced by network). Detection of RLF events may include successful and unsuccessful RRC Connection Reestablishment events (reception of RRC Connection Reestablishment Request message at the base station), any UE indication or UEs transitioning to the RRC IDLE state. In one example, if the ratio of the number of RLF occurrences to the number of active connections

(or to the traffic load) in a cell per a predetermined duration exceeds a predefined threshold, the network can start to modify the settings of timer T310 and/or T311 and/or T301 for at least some of the UEs in that cell (e.g., via signaling) to test the correlation between varying the timer(s) and UE behavior. [00118] The results of varying the timers/counters settings are collected and analysis of the event data observed/gathered over a suitable observation time period obtained. This observation time depends on the targeted confidence level for the detection of a blockage and the number of UEs per time unit that experience the blockage. The confidence level increases with increasing number of observations of UEs that are affected by the blockage (i.e., for which the network receives RLE and/or MDT reports/information and/or observes whether or not the UEs enter the RRC IDLE state, etc.). In one example, the settings of timer T310 and/or T311 and/or T301 are varied for certain percentage(s) of UEs in a cell to examine the change in UE behavior. For example, if the detected ratio of RLF declarations and/or detected ratio of transitioning to the RRC IDLE state is high, a smaller percentage of UEs may be used for which the settings of timer T310 and/or T311 and/or T301 are modified; otherwise, a higher percentage of UEs may be placed in the subset for a given time period for monitoring. Alternatively, it is possible to tune the settings of timer(s) for a fixed percentage of UEs in a cell and use various time periods to collect UE behavior information, e.g., if the detected ratio of RLF declarations and/or detected ratio of transitioning to the RRC IDLE state is high, the time period used for UE information collection is shorter; otherwise, a longer time period may be used.

[00119] In one example, the settings of the timers/counters may be set a plurality of times, to different values, each for a defined period to allow data to be collected. Changing the expiry value of the timers in a series of finer steps may avoid user experience degradation. In one example, it may be preferable to change the setting of a subset of UEs at the same time and/or to the same value/ranges, or using a predefined table, etc. to avoid additional signaling. [00120] Increasing T310 and T311 durations may be preferable from the standpoint of user operation since fewer UEs will declare RLF or transition to the RRC IDLE state, respectively. However, for the purpose of blockage detection and map generation/update, both decreasing and increasing the counter/timer durations may be beneficial, e.g., to ensure not missing a blockage for a medium/high speed UE, etc. Whether to increase or decrease the timer setting from its initial value may also depend on the initial setting of each timer (operator choice) with respect to the possible range of values. In one embodiment, the range(s) of T301 and/or T311 setting(s) can be based on the deployment, the implementation, UE expected speed range(s) (details will be disclosed in a later embodiments), operation frequency, etc. In one example, for the purpose of map generation, the maximum and/or minimum values of the timers/counters can be set/varying beyond the specified operation ranges. There is a relationship between the ranges used in this process and accuracy of the blockage maps, e.g., in terms of the locations and sizes of the blockages identified in the map.

[00121] In one example, the initial value of T311 may be set based on the estimated minimum time for the UE to complete cell search. For example, this value may be considered as Nfreq*Tsearch for a cell search without stored information, where Nfreq is number of frequencies the UE checks and Tsearch is the time to select a cell .

[00122] In one embodiment, the network varies the predetermined timer(s) duration(s) (e.g., altering the duration from an initial value to at least one other value) for one or more UEs in at least one cell in the deployment, e.g., through signaling or according to a predetermined table(s) known at both the UE and the base station, and measures and collects the effect of such variation on the RLF declaration and/or connection reestablishment procedure. In one example, the network varies the RLF timer duration for one or multiple of UEs that reported failure in reestablishing connections with the network within a past certain time duration.

[00123] In an extended embodiment, the network may use speed information in selecting the UEs for which the network varies one or multiple (predetermined) counter/timer durations, and/or selecting UEs for which the network measures the effect of such variation, and/or selecting the ranges of values for such variations. For example, the time until an RLF is declared or until a transition to the RRC IDLE state may be varied based on UE speed. In one example, knowledge of speeds or speed ranges of UEs can be obtained through channel estimation. Alternatively, UEs may directly report their speeds to the network. In another alternative, each UE varies its counter/timer values, based on its speed knowledge/measurements, and according to a predefined or signaled values/tables/pattem. In one example, the UEs may be classified into one of a plurality speed-states, e.g., slow, medium, and/or high speed, or more speed states, based on the speed. The counter/timer variation ranges corresponding to each speed state may be predefined and/or may be communicated to the UE by the base station. In another example, a scaling factor may be defined or signaled to apply to the range of values based on the speed category. In yet another example, the UE may run different RLF declaration timers (T310s) and/or different RLF timers (T3 Ils) and/or T301s, and/or different N310/N311 counters, corresponding to the different speed states (including the current speed) to help with the process of inference of link problem cause, blockage detection, etc. In one example, link problem handling parameters may be predefined or signaled to the UE/UEs and may include scaling factors or ranges to be used for different speed states, cutoffs for speed states, and/or the like. In addition, the counter/timer parameters/ranges may be selected based on certain characteristics of the underlying deploy ment/scenario and/or characteristics of operating UEs.

[00124] From the operational point of view, a choice of counter/timer durations may be preferred by UEs, depending on UE’s speed, for more efficient handling of link problems. For example, in a scenario where a target cell is available and ready, if the RLF declaration timer has a duration that is set too long, a slowly moving UE may experience a bad link condition that lasts for an extended period of time, while the UE may be able to establish a connection with a new base station through reestablishment and resolve the bad link condition with a short timer duration. Or for example, in a standalone sparse deployment with limited coverage where another base station may not be available (such deployments may be motivated in future cellular system design) when a link problem occurs, a short T310 timer results in pointless start of the reestablishment procedure. This either results in transitioning to the RRC IDLE state if the link problem (e.g., blockage size/UE speed) lasts longer than T311 timer duration, or results in reestablishing the connection with the current base station if the link problem is resolved in the meantime. For such deployment scenarios, it may be more efficient to allow the UE to wait long enough for the poor link condition to pass (depending on blockage size/UE speed) and the UE can recover its connection with the current base station. However, it is important to note that for the purpose of blockage detection and blockage map generation, the focus is not on finding the optimum values of counters/timers in terms of operation, but on ensuring that with the proper variation of the counters/timers, the existence, the location, and preferably the size of blockages can be identified. [00125] In one embodiment, if location information preceding an RLF can be provided to the network by UEs (e.g., similar to the above) or can be inferred by the network, then the location of blockage can be estimated more accurately, and/or suitable candidate UEs whose T310 and/or T311 and/or T301 settings may be varied can be selected accordingly. Particularly, it becomes possible to modify the settings of timer T310 and/or T311 and/or T301 especially for UEs liable to pass through the problematic area. In other words, the network may vary the timer(s) for selected UEs that are in the vicinity of the UE location information already available, and/or whose current velocity is expected to bring the UEs to that area. In one example, location information in combination with speed range of the UEs is taken into account when selecting the UEs for which the timer duration is varied. In this way, behavioral information can be collected from those UEs that are more likely to be affected by varying the setting of timers T310 and/or T311 and/or T301 and/or N310/N311, which can make the collection of valuable UE behavioral information more efficient and reduce deleterious effects on other users. In another example, the network varies the RLF timer duration for one more UEs that recently (within a past certain duration) reported the same or close locations to those of the UE that had reported at least an RLF and/or a failure in (re-establishing connections with the network. In other words, selecting UEs for vaiying the RLF timer duration is based on the proximity of the UEs to an origin of a physical radio link failure report.

[00126] In one example, the UE speed and location information can be obtained from the inherent locating ability of the system or from the UE, e.g., GPS-assisted location/ speed information, and/or any kind of positioning system distinct from the inherent locating ability of the network, whether satellite-based or not.

[00127] Detection and inference from the analyzed information [00128] In one embodiment, considering a number of UEs within the same vicinity, if there is a correlation between varying the setting of timer T310 and the rate of RLF events/declarations, the existence of short-term blockages may be inferred. Similarly, if there is a correlation between varying the setting of timer T311 and/or T301 and the probability of successful or failed reestablishment and transitioning to the RRC IDLE state, then the existence of a middle-term or long-term blockage can be detected.

[00129] If the above timers/counters/events are uncorrelated, there may be other causes for the link problem and/or RLF. For example, if the timer duration for UEs in the vicinity has been adjusted to several values and the probability of transitioning to the RRC IDLE state remains high in a sparse deployment with limited coverage, especially for different UE speeds, the RLF may be due to the UE going out of coverage.

[00130] In general, depending on the operation frequency and UE speed, experienced blockage duration may also be estimated. According to one of the above examples in which the UEs may report location information associated to each of timers’ triggers and/or expiry and/or report request reception and/or report transmission, such information (e.g., together with speed information) can be directly used by the network (and/or a processing unit) to estimate blockage boundaries/location/size.

[00131] In one embodiment, if certain percentage of UEs (e.g., in a vicinity of location and/or time) can find a suitable cell during T311, but still enter the RRC IDLE mode due to other reasons (e.g. T301 expires, or RRC Connection Reestablishment Reject), then another blockage may be inferred as the cause of transitioning to the RRC IDLE mode (one blockage may have caused RLF declaration in the first place, and another may have caused unsuccessful RRC Connection reestablishment). Expiry of T301 may be due to failure of RACH procedure that has been triggered for a connection reestablishment request. If a blockage happens during the RACH procedure, the blockage can cause RACH failure and transition to the RRC IDLE state.

[00132] In one embodiment, after collecting UE event data, the existence of a blockage can be identified by comparing the ratio of the number of RLF experience of the UEs to the number of active connections (or to the traffic load) in a cell, per a unit of time before and after varying the setting of timer T310 and/or T311 and/or T301. In one example, the ratio of the number of UEs transitioning to the RRC IDLE state to the number of active connections (or to the traffic load) in a cell per some unit of time before and after varying the setting of timer T310 and/or T311 and/or T301 may be considered if the UE RLE and/or MDT reports are not available.

[00133] Further, when the existence of a blockage is determined, the blockage map is updated, e.g., with its location and/or size, and/or lasting-impact (e.g., frequency-dependent and/or speed-dependent), etc. Actions may also be taken in response, which may include taking remedial action and/or notifying a higher-level entity. The procedure for blockage map generation/update may evolve over time: the longer the procedure runs, the more accurate the procedure gets.

[00134] In one embodiment, base stations may be linked to a SelfOrganizing Network (SON) server to control the analysis, decision-making, and signaling. The methods disclosed herein can be adopted by a SON server to automatically detect the existence of blockages in the network and generate/ update the blockage map. Depending on where the SON server is located, the base station may pass collected relevant information higher up in the network, e.g., to measure the correlation effect in a more reliable way and perform further processing of the event data collected from the UEs before making decisions on blockage detection, blockage location/size/number determination, and/or updating the blockage map. Particularly, data processing can improve the robustness of the procedure against various implementation scenarios affecting the evaluation reliability of the decisions. For example, since there is no a priori knowledge of blockages in the network at the beginning, e.g., the size or location or the number of blockages when varying the timer value within the permissible range, circumstances with certain traffic speed distributions and traffic type variations that can make the inference through the event data collected from UEs more difficult than the other cases. This approach further facilitates using event data collected from different scenarios to accurately and reliably evaluate the effect of varying the timer setting.

[00135] In one embodiment, the UE(s) and network/base station(s) train the blockage detection models based on collected/observed data (e.g., to detect blockage events, blockage duration, etc. in an efficient fast manner). In one example, the UE(s) and network/base station(s) share and jointly refine the trained models. Signaling is defined between the UE and network/base station(s) for model sharing/training coordination and model deployment. Input parameters to the model training are defined to align the UE side training/inference and network/base station(s) side training/inference. This can be a good use case for an artificial intelligence (AI)-assisted air interface.

[00136] Distinguishing between long-term blockage problems and coverage issues (in sparse deployments with limited coverage)

[00137] The above assumes that expiry of T311 and/or T301 can have a high correlation with the presence of a relatively longer-term blockage. Note that T311 and/or T301 expiry in a sparse network deployment with limited coverage may also be due to the UE going out of coverage. It may become even more useful to be able to predict blockages for such deployments to enable the UE to take proper actions upon facing a radio link problem. If it is possible that upon network deployment/operation, a map of (sparse) coverage area is first developed, then coverage limitations can be ruled out during the blockage detection and blockage map generation procedure. For example, for private networks such as factory deployments, it may be possible that the network runs procedures/tests/experience in an initial stage to identify coverage area (the sparse regions) and/or generate a coverage map.

[00138] On the other hand, whether or not the UE actually transits to the RRC IDLE state when encountering a long-term blockage depends on the UE speed, the blockage size, and the configuration of T311 and/or T301 timer duration. In one embodiment, if T311 and/or T301 is varied to a predefined number of different values for UE(s) in a vicinity of a sparse deployment with limited coverage and still results in high rate of transition to the RRC IDLE state, RLF may be declared due to out-of-coverage and may not contribute to blockage map generation. In one example, if varying T311 and/or T301 to one or more values for UE(s) in a vicinity impacts the rate of transitions to the RRC IDLE state, the presence of a long-term blockage may be detected.

[00139] In one embodiment, if a first value of T311/T301 duration results in T311/T301 expiry for at least a certain percentage of UEs in the vicinity but at least another (longer) duration does not result in T311/T301 expiry (e.g., for a certain percentage of UEs in the vicinity), then a middle or long-term blockage can be declared. The fact that at least for some timer durations a certain percentage of UEs were able to reestablish their connection shows that the extent and lasting impact of the link problem has been more limited than other coverage issues. In one example, if multiple values of T311 and/or T301 all expire (e.g., for at least a certain percentage of UEs in the vicinity) in a sparse deployment with limited coverage, especially if multiple RLFs has been observed from one or more UEs in the vicinity with likely different speed ranges, an out-of- coverage may be assumed as the cause of RLFs and may not contribute to the blockage map. In one example, after the initial value of T311 and/or T301 results in transition to the RRC IDLE state, the network tunes the timer(s) duration(s) to a maximum value. If the maximum value also results in transition to the RRC IDLE state, out-of-coverage is assumed as the cause of RLF.

[00140] As disclosed above, detection of coverage area/edges, as well as identification of middle/long-term blockages within a coverage area and ability to create blockage map, is dependent on collecting proper data, observing events carefully, and accurately analyzing, processing, inferring events, causes, counter/timer triggers/stops/expiries (e.g., those related to radio link problem). It is then possible to distinguish link problems caused by limited coverage from those caused by blockages, and other reasons.

[00141] When inferring and analyzing the data, in one embodiment, the existence of a recently successful (one-shot) transmission especially with high- data rate can also be an indicator of a blockage (in high-band operation) (and not out of-coverage). This is because at the cell-edge, the data rate can be low and/or the transmissions may not get through without retransmissions. In one example, recent PHY and/or RLC retransmissions may further be an indicator that the link issue is likely due to out-of-coverage and not a blockage. In general, the nature of blockage is such that the quality of communication suddenly drops or the connection is suddenly interrupted, while for out-of- coverage there may be indicators shortly ahead of time (depending on UEs’ speed as well). For example, the UE may also indicate/report the number of RLC retransmissions and/or if RLF has been due to an RLC layer problem, along with other reported information as disclosed earlier, to aid the analysis accuracy. [00142] Sharing blockage map between the network and UEs [00143] As above, the blockage map generation/update procedure may evolve over time. The more time the network has been running this procedure, the more accurate the process gets.

[00144] In one embodiment, after a certain stage of map development (since at the beginning, the network may not have much map information to share except general information), the network may indicate blockage map availability to all or some UEs.

[00145] In one embodiment, the network may schedule downlink transmission for map download at the UEs or wait for the UE to request such scheduling. Alternatively, incremental updates may be transmitted upon availability, with some preconfigured periodicity, or upon UE request. In one example, the network broadcasts blockage map information at predetermined times.

[00146] In another embodiment, the UE may itself develop a blockage map, e.g., based on the types of information discussed above (gathered based on its own experience and potentially from other UEs as well). Especially for the deployments in which the UEs may operate in a certain network area for a long time (potentially with same speed range, though this is not essential), UE-side map generation can be of value. In one example, UEs with a developed blockage-map may also communicate the map and/or updates (e.g., incremental update) with the network and/or directly with other UEs.

[00147] Some basic straightforward applications of blockage map information

[00148] In general, adaptive recognition of blockage (e.g., an up-to-date blockage map) enables the system to better predict the environment conditions, proactively adjust the values of timers and counters (including any of BFR, RLE, and/or L2-related timers/parameters), adapt the RLE handling procedures (e.g., access and reestablishment or the equivalent procedures), adapt the flow control, etc., based on UE location and blockage location/duration. For example, the (re- ) establishment procedure (or equivalent) may be adjusted knowing the blockage location/duration. In one embodiment, UEs may use blockage map information to adjust speed and/or directions/path/trajectory when approaching a likely location of blockage or a location with high traffic of mobile blockers, etc. Alternatively, depending on the situation, the UE may choose to wait until the blockage situation is lifted, e.g., by keeping its speed and/or extending its counters/timers durations (e.g., to avoid state transition), etc. In one example, in locations where the UE is more likely to experience blockages, lower or higher RLF-related counter-thresholds and/or RLF-related timer durations may be considered, depending on UE speed, and other factors. Particularly, locationspecific and/or speed-specific counter/timer thresholds/durations may be considered. In the way the current protocols are defined, the UE and network may share the same understanding on any counters/timers/parameters adjustment to avoid getting out-of-sync. As such, any new values should be set in-sync between the UE and network. This can be achieved through different predefining and/or broadcasting and/or unicasting mechanisms. On the other hand, one can also consider protocol design that could allow potentially different values from the UE and network sides. This may be evaluated based on the exact scenario.

[00149] In the above, methods for reliable detection of blockage have been described. Particularly, the primary focus was on the system, methods, and apparatus of identifying blockages that may potentially involve RLF events, i.e., blockages with long enough duration and/or extensive enough impact, which may not be handled/recovered by a BFR procedure (e.g., the UE not able to find beams to recover the link in the cell), and create/update a map of such blockages. It is noted that the blockage size/duration relative to the operation frequency/ wavelength, the UE speed (and if applicable, blocker’s speed) and the level of traffic congestion, and the setting of counter/timer durations (e.g., T310, T311, T301, N310, N311) and other parameters determines the (experienced) lasting impact of the blockage. The above primarily focused on blockages that may have a medium-large scale impact from the perspective of dimension and/or the lasting impact on UE-network communication (relative to the above factors), while approaches to develop predictability with respect to the shorter-term blockages were also disclosed, e.g. by filtering out short terms when building a longer-term blockage map and inferring a short-blockage based on the longer- term blockage map, or building a statistical/probabilistic blockage map, for shorter-term blockages, etc. The longer blockage impact may be mainly due to more limited mobility blockers (compared to UE mobility). Considering high- band operation (e.g., 60 GHz), even a blocker size on the order of a human body or smaller may have a significant impact on UE operation and may potentially even trigger RLF.

[00150] Accordingly, the network and the mobile stations may collaboratively exchange information with respect to the link problems, analyze the information, infer the cause of link problems, decide on existence of communication blockages in different locations within the cell(s), and/or identify the locations with high chances of blockage existence. Base stations and mobile stations collaboratively evolve and share their understanding of the link problems and corresponding locations within the network coverage, and build, maintain, and update blockage map. As such, the blockage map contains information on locations within the coverage area (with some granularity), and mapping between the locations, existence of a blockage or likelihood of blockage existence, and potentially with an expected duration (lasting impact) based on blockages size, UE and blocking objects relative speed, operation frequency, and other potential factors.

[00151] How the dynamic aspect of blockage is captured by the blockage map also depends on the underlying methodology used to identify blockages when generating the map. For example, as disclosed above, the identification in an initial phase of map generation may be based on variations of RLF-related timers, as well as observing and analyzing the impact of such variation on potential consequence events at the UEs, such as RLF declaration, reestablishment triggering, etc. Accordingly, a blockage duration that is also based on UEs’ relative speed can be estimated. Alternatively, the inference about blockage duration may be estimated based on the time difference where UEs face a link issue until the time the UEs send an RLF report. In general, there are several ways how to estimate the lasting impact corresponding to an identified blockage and reflect the blockage in the map.

[00152] As above, a wireless communication system is described that has a network of one or more cells provided by base stations (that may or may not provide ubiquitous coverage within the network deployment area), and a plurality of UEs that can establish/re-establish and lose wireless connections with base stations as the UEs move relative to the cells and there are blocking objects that reside within the network, either statically, or with mobility, which can block UE and network communication link. Systems, methods, and apparatuses are described in which mobile stations and/or base stations take actions based on the knowledge of blockage (e.g., blockage map or any other knowledge), i.e., the use cases and applications of the blockage knowledge/map. Note that the disclosed are not tied to the existence of a blockage map; the disclosure is applicable to any knowledge or prediction of a blockage and do not require availability of a map which may mean a broader established information of the lockage locations within the network coverage area.

[00153] List of Applications of blockage map information (in handling blockage) [00154] In general, adaptive recognition/knowledge of blockage location/duration (up-to-date blockage map) as well as UE location enables better prediction of the environment conditions, and accordingly taking proper actions. For example, based on expected blockage and also expected duration of the blockage (based on the time variation of the blockage and/or based on expected UE mobility trajectory), the at least seven categories of actions can be defined.

[00155] A first category includes adapting the values of timers and counters (BFR and RLF - related timers/parameters), e.g., location-specific counter/timer thresholds. For example, in locations where a UE is more likely to experience blockages, lower or higher RLF-related counter-thresholds or RLF- related timer durations may be considered, depending on UE speed, deployments, availability of other cells, and other factors (location- or speedspecific counter/timer thresholds/durations). Particularly, from the operational point of view, a choice of counter/timer durations may be preferred by UEs, depending on UE’s speed, for more efficient handling of link problem. For example, in a scenario where a target cell is available and ready, if the RLF declaration timer is set too long, a slowly moving UE may unnecessarily experience a bad link condition that lasts for an extended period of time, while the UE may be able to establish a connection with a new base station through reestablishment and resolve the bad link condition with a short timer duration.

Or, in a standalone sparse deployment with limited coverage where another base station may not be available, when a link problem occurs, a short T310 timer results in pointless start of the reestablishment procedure, which either results in transitioning to the RRC IDLE state if the link problem (e.g., blockage size/UE speed) lasts longer than the T311 timer duration or results in reestablishing connection with the current base station (if in the meanwhile, the link problem is lifted). For such deployment scenarios, it may be more efficient to allow the UE to wait long enough for the poor link condition to pass (depending on blockage size/UE speed) and the UE can recover its connection with the current base station.

[00156] A second category includes adapting/redefining the RLF handling procedures (e.g., access and reestablishment or the equivalent procedures) as above. Particularly, the (re-)establishment procedure or equivalent can be adjusted/redefmed knowing the blockage location/duration. Both the triggering of the cell selection procedure, as well as the process of cell selection itself, can be optimized/directed/redefmed based on map information/knowledge by (and/or between) the UE and network. For example, if a UE has had prior access to network, the UE may have knowledge about the blockages, etc. and adjust its access/re-access procedures accordingly. With knowledge-based triggering of cell selection and camping, such as knowledge of the blockage map, etc., the cell selection procedure can be performed only when desired and in a directed way quickly. For example, based on prior knowledge, e.g., location, map, etc., if the UE knows it is in the same cell, the UE can avoid the reestablishment procedure upon facing RLF, and may only perform a random access procedure to re-access the cell similar to beam failure recovery. In such example, the system information does not change before and after the RLF and the reestablishment (if any) for the same cell can be much quicker than a reestablishment to a different cell. In the deployments with frequent blockages, it is not ideal for UE to perform cell search and cell selection every time the UE faces a link blockage; for example, the UE may be better off staying in the same cell and attempting recovery in the same cell.

[00157] A third category includes adapting beam failure handling. Currently, when random access procedure failure occurs, the UE may try finding a suitable cell and attempting a random access procedure in another cell. There may be ways to restrict when random access failure triggers RLF and cell selection. For example, if the UE has already found other candidate beams, e.g., backup beams, the UE may continue the random access procedure using those beams. In another example, the UE may re-perform the random access procedure using the previous/original selected beams after waiting a certain amount of time, e.g., which may depend on characteristics of the link problem, UE speed, location e.g., the duration of blockage or coverage problem. It is also possible to consider scenarios and/or UE implementations in which the UE is able to realize/identify the nature of the link problem, based on whether the UE has moved and/or the UE speed, and accordingly take the appropriate actions. For example, if the UE realizes that it has not made any meaningful movement (which could result in a link problem), the UE waits until the (mobile) blockage is cleared and assumes that the UE is (most likely) in the same cell. This behavior may be beneficial if there is no other alternative cell available or if the blockage duration is expected to be less than the time to handover or establish connection with another cell.

[00158] In another example, a statistical/probabilistic blockage map may be built based on beam-failure detection/recovery related information reported by UEs, e.g., including UE location, speed, direction, related timer/counter values, along with time tags of when the beam failure was detected/recovered by the UE and/or when the failure was reported, etc. Based on the knowledge of such a map, a UE may then adjust UE actions upon facing a BFD for which the UE may have prior knowledge about the expected lasting blockage impact, or the UE may adjust UE actions in anticipation of a BFD based on the blockage map. In one example, upon facing a BFD, the UE may (re-)perform a random access procedure by using back-up beams (back-up RACK preamble resources). This action may be more relevant in cases where the expected duration of the anticipated BFD is not long enough to trigger an RLF declaration (considering the RLF-related timer values).

[00159] A fourth category includes adapting the UE speed and/or directions/path/trajectory. For example, adjusting the above, when approaching a likely location of blockage or a location with high traffic of mobile blockers (e.g., high number of passing by of mobile blockers), etc., or depending on the situation, the UE may choose to wait until the blockage situation is lifted, e.g., by keeping its speed and/or extending its counter/timer durations (e.g., to avoid state transition), etc. While some of the expected use cases of the blockage map are to define actions to be taken upon the UE hitting an RLF/blockage, one benefit of the map is prior knowledge that a blockage may happen. As such, one possible UE action is to avoid the blockage. This could be possible for example in a factory floor of moving robots, etc. For example, the UE may use map information to adjust speed as well as the directions/path/trajectory. In addition, if the blockage is stationary, the UE can take an action; otherwise, the UE can wait until the blockage passes. Particularly, actions based on blockage mobility and duration, e.g., actions in response to expected mobile blockages vs expected stationary blockages, and/or based on how long the blockage lasts compared to timer values, UE speed, etc., can be defined.

[00160] A fifth category includes L2-protocol-stack-related adaptations, such as proactively adjusting the values of L2-protocol-stack-related timers and parameters, timer suspensions/extensions, adjusting buffer sizes, adjusting the RLC mode of operation, etc.

[00161] A sixth category includes adapting flow control and adaptation for different upper layers (Transmission Control Protocol (TCP), Quick UDP Internet Connection (QUIC), etc.).

[00162] A seventh category includes using alternate devices when a UE experiences blockage at the presence of multiple devices in the coverage. While multiple devices may cooperate with themselves as well with as the network to jointly build/maintain the blockage map, the devices can also act based on map knowledge upon a UE facing blockages and handle the issue, e.g., by serving as relays for data transmissions on its behalf (mainly for longer-term blockages).

[00163] The identified solutions provide smoothing over of the effects of the blockage. This also depends on the type of applications running on the UE at the time of the blockage, as discussed below.

[00164] Distinctions between characteristics/use cases of blockage map and existing methods involving collecting information and coverage optimizations (e.g., MDT, SON, RLF-report) [00165] In general, the blockage map applications/use cases can be categorized using different angles/criteria. Most of the listed applications of the blockage map include taking (proactive) actions from the UE side based on the knowledge of the blockage map and UE’s location. Some of these actions are synchronized with the network, while some actions (e.g., the speed adaptation, etc.) may be autonomously performed by the UE. This is one difference between existing features/algorithms, which may involve information collection and performance optimization, and the blockage map generation, its information exchange, and its applications. Particularly, MDT/SON approaches have been mainly designed to enable the network to collect proper information from the UEs on link problems, etc. so that the network can monitor and better optimize/dimension its coverage. Thus, allowing/enabling the UEs to also take proper actions based on the collected/analyzed information (map information), for better handling of link problems is disclosed herein. The information provided by the blockage map on the expected lasting impact/duration of blockages (e.g., time variation of the blockage, potentially based on expected UE mobility trajectory, etc.), also allows the UE to make better autonomous decisions.

[00166] This also means that the blockage map (unlike MDT use cases such as a coverage map) is cooperatively built/maintained/updated between the network and UEs, and the information is (frequently enough) exchanged between the UEs and the network - the UEs and network may also jointly train blockage detection models based on collected/observed data. This is also another difference between the blockage map and existing features where the network would only collect information from UEs and make decisions on its side, without map information availability at the UEs, and without the inference/ leaming/analysis of data by the UEs to identify blockages and corresponding characteristics, and contribute to the map generation/update.

[00167] The granularity of the blockage map depends on the underlying method of map generation. For example, if the granularity is based on the UE information/reports on the locations where the UEs face a link issue, then the granularity depends on the UE trajectory within the area, speed, and several other factors. Other methods may span beyond the locations that the UEs happened to face link issues. For example, a coverage map is a use case of MDT enables the network to have a complete view of the coverage and knowledge about signal levels in cell areas via measurements collected in all parts of network (not just in areas with potential coverage issues). Similarly, more thorough methods can be used to test existence of a blockage in a particular location within the network’s coverage area with the desired granularity.

[00168] Besides the significant difference in the UE role in use cases of existing approaches such as MDT/SON compared to those of a blockage map (as well as the UE contribution in building the blockage map), another difference between existing features such as an MDT-based coverage-map-generation or coverage optimization, compared to a blockage map, is in the collected information to build and maintain/update the map. Particularly, in the process of blockage detection and map generation/update, information (e.g., raw measurements/observations or analyzed/processed/inferred knowledge) are exchanged between the UEs and network as shown in FIG. 3 (also potentially between UEs). While there may be overlap between the blockage map information and the contents of MDT and/or RLF report, addition information not included in MDT/RLF-reports may be used. For example, the location, speed, direction (or deltas compared to the previous corresponding reported values) along with time tags of when the UE detected a link issue, when the UE recovered, and when the report was transmitted, as well as the BED and RLF- related timer values/status are information used to build and update the blockage map, while absent in the MDT/RLF report. As the exiting approaches are mainly concerned with larger scale link problems such as coverage gaps, the collected information is also reflective of such characteristics. For a blockage map, the collected information should be reflective of relatively smaller scale link problems (e.g., in terms of the lasting impact of the blockage, which depends on operation frequency, UE speed and direction relative to the blocking object, etc.) and avoid overlooking blockage existence/detection due to misinterpretation or not having collected detailed-enough information. The information to be collected also depends on how the blockages are identified in the process of generating the map. For example, if the blockage detection for building the map is based on variation of RLF-related timers and observing the consequences, then the timer values, time/location/speed/direction tags of when facing RLF, when reporting RLF, when re-establishing connection, or failing to do so, when transitioning state, etc., are used to accurately infer blockage existence, duration, etc. Further, UE reported information for the blockage map also includes the cause of link problem (based on UEs inference/analysis), timer/counter status information e.g., including T310, T311, T301, N310, N311, as well as the time and locations of when such timers start, stop, and/or expire. Detailed triggering information causing the link failure (on a physical layer problem due to consecutive out-of-sync events within T310, MAC layer triggering of RACK problems, or RLC layer triggering due to reaching max number of retransmissions), complemented with some extent of the UE analysis may also be provided to the network. None of such information are present in the contents of MDT/RLF reports.

[00169] To be able to differentiate blockages based on the lasting impact and duration of the blockages and build a corresponding map, which enables the UE and the network to take proper further actions, information beyond RLF- related data, e.g., information related to BFD/BFR events, are also used. As mentioned earlier, a statistical/probabilistic blockage map may be built based on BFD/BFR-related information reported by UEs, e.g., including UE location, speed, direction, any related timer/counter values, time tags of when the beam failure was detected/recovered by the UE and/or when the failure was reported, etc. None of such information is included in the MDT/RLF reports.

[00170] In one example, an NR-based approach for the network to build a blockage map relies on information related to link issues reported by UE (based on existing protocols) and the network to determine a root cause of the link failure, in combination with measurement results obtained from UEs and/or performed by the network itself (e.g., SRS measurement, SINR estimates, SRS failure, no reception of ACK/NACK feedback from UE for a recent DL transmission, etc.). But such network-centric approach does not result in an accurate/up-to-date map, and relying on the map to take further actions does not result in optimum performance. Further, if the generated map is not communicated with UEs and only the network takes actions based on the map, blockage handling would not be dynamic and is likely not efficient and fast.

[00171] Applications of blockage map in L2-protocol-stack-related adaptations [00172] Motivation

[00173] Next generations of cellular technologies, such as 6G, will support diverse use cases with different and sometimes contradictory requirements. Further, 6G deals with frequent channel variations, blockages, and uncertainties specially for high band operation, which impacts the effective available bandwidth at different time instances.

[00174] Particularly, molecular absorption at high frequency bands results in band splitting and spectrum shrinking at larger communication distances.

Distance-adaptive solutions in which antenna array designs and resource allocation criteria are optimized tackle spectrum shrinking. The path loss seen by a THz signal in the presence of water vapor is dominated by spikes that represent molecular absorption losses originating at specific resonant frequencies due to excited molecule vibrations. Higher densities of absorbing molecules make the peaks stronger and wider (broadening of absorption lines). Because of these lines, the spectrum is divided into smaller windows (sub-bands), each of which has a width of tens or hundreds of GHz. These windows are distance- dependent since some spikes are significant only at specific distances (by increasing the distance from 1 to 10 meters, the transmission windows are reduced by order of magnitude). Hence, variations in the communication distance affect both the available bandwidths and the path loss (the available bandwidth shrinks at higher frequencies).

[00175] The diverse use cases, requirements, variable channel conditions, and available bandwidth come with the challenge of how to handle packet loss, retransmissions, in-sequence delivery of packets of different services, etc., while maintaining unified schemes across services. The RLC and PDCP layers have several parameters and timers that can significantly impact the performance, depending on the scenarios at hand. The RLC entity is established from the RRC layer upon radio bearer setup and involves initializing the protocol state variables. For the PDCP layer, a PDCP entity is established for a radio bearer and state variables are set upon a request from the upper layers. While the parameters can be reconfigured by RRC signaling (which imposes delays including the processing times), for future technologies the choice of configurations may be adapted more dynamically (e.g., without requiring network reconfiguration). Efficient handling of packet transmissions and dynamics (e.g., channel variations, blockages, etc.) at L2 reduces reliance on the higher layers (e.g., TCP, etc.) to handle the losses, the gaps in transmissions, etc. that would otherwise degrade the performance.

[00176] RLC/PDCP related parameters, timers, and characteristics/dynamics and potential adaptations

[00177] There are two timers operating at the PDCP layer: discardTimer and t-Reordering. At the transmitter side, a new discardTimer timer is started upon reception of a service data unit (SDU) from the upper layer. User data from the higher layers is stored in the PDCP transmission buffer as a PDCP SDU. The PDCP layer processed such data to generate the PDCP PDU that is sent to the RLC layer as an RLC SDU. For each PDCP SDU arriving in the PDCP transmitter buffer, an individual discard timer is started. After expiry of this timer, it is assumed that the PDCP PDU was successfully delivered and both PDCP SDU and PDCP PDU can be removed from the transmitter buffer. This timer is configured only for data radio bearers (DRBs) and its duration is configured by the upper layers.

[00178] At the receiver side, the t-Reordering timer is used to detect the loss of PDCP data PDUs. The timer duration is configured by the upper layers. To manage the information flow between the RLC and PDCP layers in NR and prior technologies, the t-Reassembly and t-Reordering timers are used, respectively. In NR, re-ordering functionality is done by the PDCP layer to deliver the packets in sequence to the upper layers. If missing packets exist, the PDCP waits a certain duration (T-reordef) for the RLC to recover and deliver the missing packets. The PDCP receiver entity maintains the t-Reordering timer started upon receiving an out-of-order PDU from the RLC. When the t- Reordering timer is running, the PDCP entity waits for the reception of all the missed PDUs from the RLC. Upon expiry of the t-Reordering timer, the PDCP pushes the received in-order PDUs to the higher layer and moves the lower bound of the window irrespective of any missed PDUs. The RLC Acknowledged Mode (AM) recovers the missed packets even after the PDCP window is moved (while these packets are discarded by the PDCP). The missed PDUs may be retransmitted by RLC before the t-Reordering timer expires. With respect to the setting of the timer, the t-Reordering timer may cause more latency for packets directly/indirecdy impacting the higher layer (e.g., TCP) performances if the t-Reordering timer duration is too high. On the other hand, the PDCP receive window may slide at a faster rate, which can cause a significant number of PDCP packet discards if the t-Reordering timer is too low. This may also lead to a significant number of holes/gaps in the transmission while delivering packets to upper layer, and the upper layer thus take cares of such gaps, which is a costly operation. As such, in one example, the t- Reordering timer is dynamically adjusted, in coordination with RLC, and according to the variations in the effective bandwidth and over-the-air conditions. For example, the t-Reordering timer and PDCP receive window for which the lower bound is correlated to the t-Reordering timer are adjusted in coordination with the t-Reassembly timer, according to the over-the-air conditions and effective bandwidth, based on the knowledge of blockage map. The behavior and tradeoffs depend on the available effective system bandwidth, which may frequently change especially for operation in high frequency bands. But current technologies are not designed in a way to handle such dynamics, efficiently. FIG. 4 illustrates an example of PDCP/RLC layers interactions in accordance with some embodiments. For example, in future technologies, the configuration parameters may not be adequate, or the parameters may be adequate but more dynamic tuning of the parameters may be used. As such, the PDCP and RLC layers dynamically adjust their timers/parameters in coordination with each other, and also according to the effective bandwidth and over-the air conditions. In one example, RLC mode (UM vs AM) may also be adaptively switched depending on the effective bandwidth and over-the-air conditions. For example, in deployments and scenarios with frequently expected blockages, depending on the requirements and characteristics of the underlying application/traffic, the RLC Unacknowledged Mode (UM) mode may be configured as the prior mode of operation, and the RLC AM mode may be triggered in certain situations. In general, efficient handling of the packet transmissions and dynamics at L2 reduces reliance on the higher layers to handle the packet losses, the transmission gaps, etc. Another example of dynamic handling of RLC mode reconfiguration is to use a split bearer with one RLC bearer using the RLC AM mode and another using the RLC UM mode. This may permit switching between RLC bearers based on the knowledge of blockages.

[00179] Blockage impact on RLC/PDCP timers and application of blockage map on their potential suspensions and/or extension

[00180] When the blockage is short-term (e.g., the UE can continue the interrupted operation through beam failure recovery), the transmissions are stalled during the blockage, but the L2-related timers may still continue. This can impact the performance of L2 and the upper layers and may cause issues. For example, the t-reassembly timer at the RLC may expire, resulting in the device trying to trigger a retransmission in the RLC AM mode. For the RLC AM mode, the t-StatusProhibit and t-PollRetransmit timers also greatly impact the end-to-end (E2E) throughput, the delay experienced by packets during the transmission, and the quality of experience (QoE). For the RLC AM mode, the t-Reassembly timer expiry triggers RLC retransmission, i.e., the receiver window maintains the t-Reassembly timer to support retransmissions and update acknowledgment/negative acknowledgment (ACK/NACK) status to the transmitter side. Without an RLC-level retransmission, even if the transmission is blocked, the data transmission can be managed by Hybrid automatic repeat request (HARQ) retransmission. As such, triggering undue RLC retransmissions is inefficient and should be avoided. It is noted that even with expiry of the t- reassembly timer at RLC, the status report may also face blockage, i.e., during blockage the status report may not be delivered (assuming blockage happens in FR2, which is time domain duplexed (TDD) only), and an actual retransmission may not happen.

[00181] Moreover, the discard timer for a PDCP SDU may expire (packet not being delivered due to temporary blockages) and the SDU may be dropped, resulting in TCP congestion control actions.

[00182] In addition, the PDCP waits for the T-reorder timer duration for RLC to recover and deliver missing packets. When the T-reorder timer is running, the PDCP entity waits for reception of all of the missed PDUs from the RLC. Upon expiry, the PDCP pushes all received PDUs in order to the higher layer and moves the lower bound of the window irrespective of any missed PDUs. [00183] As NR adopts a simplified version of RLC, RLC does not take a large number of actions for RLF at least in the cunent architecture. The role of the PDCP layer and its discard and reordering timers is used in handling the link issues. Depending on the type of underlying application, and its requirements and characteristics (e.g., packet-based, streaming, real-time, latency-sensitive, etc.), these behaviors impact the performance differently.

[00184] In one example, the blockage detection/identification (e.g., based on the knowledge of UE’s location as well as the blockage map) can enable selective timer suspensions that temporarily halt each timer to freeze the timer in place and provide more time for the blockage to take its course and conclude. The timers may then restart or continue. Particularly, with periods of blockage (even short periods), the usable period of the access time may be reduced if the timers are not extended. Thus, the timers may be frozen and, if desired, allow the timers to be extended to let the blockage finish.

[00185] Since different timers behave differently, the blockage detection may selectively suspend the timers. The timers that are able to be suspended can be selected. For example, the timers related to discarding the data (e.g., the PDCP discard timer), the timers related to retransmissions if the RLC AM mode is configured, and/or the timers related to being in discontinuous reception (DRX) active time (any timer whose functionality is to keep the LIE in DRX active time and gives the UE more time to receive/transmit), may be suspended/extended or reset when facing/expecting a blockage. The latter of which uses a map and knowledge of the UE location to provide the predicted blockage. In DRX operation, is the UE periodically wakes up and monitors for a particular duration. If there is data activity during the duration, the monitoring duration is extended. The active time is the total amount of time that the UE monitors.

[00186] Such directions/ solutions may help to extend the time before the reset/re-establishment of the L2 layers occur or to avoid reset/re-establishment of the L2 layers. Further, the suspension durations are selected to avoid the upper layers (TCP and above) running into issues.

[00187] There are several aspects to be considered with respect to the functionalities of different timers and the impact from suspending each timer, also depending on the traffic requirements. For example, for latency-sensitive traffic, the PDCP discard timer can keep track of the latency requirement. As such, a latency-sensitive packet may be better discarded if the delay budget is exceeded. Accordingly, for such traffic, suspension of the discard timers may not help with the performance, and even if blockage occurs, it may be reasonable to keep the timer running. In such cases, proper higher layer congestion control may be used. For example, it may also be possible to discard the low-latency packets at higher layers to avoid congestion. It is also noted that in NR and LTE, the timers are protocol-specific. Depending on the protocol architectures and the corresponding behavior in 6G, these aspects should be accordingly dimensioned.

[00188] Considerations with respect to RLC buffer and potential application of blockage map in buffer dimensioning

[00189] The transmitter RLC entity receives packets from the PDCP layer and stores the packets in a transmitter buffer, waiting for a transmission opportunity notification from the MAC layer. There may be two potential sources of losses and degradation of the transmitted service: the discard of packets due to the lack of available space in the RLC transmitter buffer, and the delays produced by the accumulation of packets in the buffer. Currently, in LTE/NR, the L2 buffer size is not dimensioned per entity; rather, a combined L2 buffer per UE is defined covering all DRBs, SRBs, and transmitter and receiver sides. A UE can dimension the buffer for each DRB, and each transmitter and receiver entity. Further, the L2 buffer is normally dimensioned for the UE peak data rate.

[00190] The receiver RLC entity receives the packets from the MAC layer, stores the packets in a receiver buffer, and waits for reassembly before sending the complete reassembled packet to the upper layer (PDCP). In general, the transmitter buffer is not expected to impose issues on the performance, while in some scenarios, accumulations are expected at the receiver side due to missing packets, e.g., in dual-connectivity (DC) scenarios. Accordingly, a large L2 buffer size may be used for such scenarios.

[00191] Regarding the potential delays produced by accumulation of packets in the buffer, the flow/congestion control mechanisms in the current technologies limit the generated data at the transmitter side, e.g., Explicit Congestion Notification (ECN) defined for IP protocols. In traditional cellular systems, the base station handles congestion issues or is dimensioned to avoid any such congestion, e.g., if there is congestion issue in one cell, the base station may move UEs to other cells that have the capacity. However, future generations of cellular network should also be able to manage new applications, with much more challenging QoS/QoE requirements, available effective bandwidth variations, and link/channel uncertainties including the blockage, especially in high-band operation.

[00192] In general, if the available effective system bandwidth (considering all the uncertainties the channel may face at a given time) is enough to cover the traffic demand from the server, packets are sent to the receiver and packets in the RLC transmission buffer are not accumulated. If the packet transmission and delivery rate is not less than the packet generation rate, losses and delays caused at this layer are insignificant. If the available effective system bandwidth (considering all the uncertainties the channel may face at a given time) is too small (e.g., when best beams are blocked or the attenuation is high), accumulation of the packets in the RLC buffer can cause the communication to continuously collapse, producing a high packet loss rate (i.e., the server packet generation rate is higher than the packet transmission rate at the MAC level). [00193] For each effective system bandwidth size (as mentioned earlier, the effective available system bandwidth can have high fluctuations in the high frequency band), RLC buffer size(s) may maximize QoE. This may involve a tradeoff between losses caused by a too small buffer size and delays caused by a too large buffer size. Too small Tx buffer size results in a small storage space for packets received from the PDCP layer, and as a result, the RLC transmitter buffer may quickly collapse, causing packet loss. On the other hand, too large buffer size may result in accumulation of packets in the buffer and the maximum E2E delay exceeded if the packets cannot be processed fast enough. In other words, if the packet processing rate is slower than packet arrival rate, a large buffer full of packets is expected. The delay is determined by how fast the packets can be processed. If packet cannot be timely processed, a large buffer may be used due to high (arrival) data-rate. Such dynamics depend on the relationship between the server packet generation rate, the packet processing rate, and the transmission and delivery rate, as well as the available effective bandwidth, and define how the system performs. However, the current system is not designed in a way to handle these dynamics efficiently. In one example, for future technologies such as 6G, the UE can adjust its (per-entity) buffer size dynamically, based on the knowledge of its location and the blockage map, and depending on the service, the QoS requirements, and the effective available bandwidth.

[00194] Use case of blockage map in handling applications on a device facing blockages (application-specific adaptations)

[00195] If a device has different types of applications running, the latency sensitive applications (real time voice/video streaming) are generally better equipped to handle some degree of packet loss. As long as the packet loss is not too much to cause total asynchronization, latency sensitive applications can handle occasional packet loss, since they are designed around using packets within a certain time window (while there might exist some jitter behavior, experiencing interruptions in voice or video, etc.). As such, one possibility is to distinguish latency-sensitive traffic and only drop packets from latency sensitive application traffic/ streams, when a blockage is expected/faced. This provides the other traffic with more chance to go through. Packet inspection may be employed using this approach, unless mapping to different radio bearers, etc. is present. Whether such adaptation should be managed at upper layers, or can be managed at lower layers, may be further investigated. For example, for voice over IP traffic, if a packet is not received within the latency window, other ways of adaptations and handling is already available, e.g., at the receiver, the ambient noise is played, using higher layers approaches to compensate for the packet loss, etc. Examples of the interactions between lower layers and upper layers on blockage-related information are disclosed below.

[00196] Applications of blockage map in How control adaptations

[00197] In this section, the impact of blockage on upper layer (e.g., TCP/QUIC) throughput and protocol/application specific adaptations to blockages are discussed. Investigations on blockage impact on TCP throughput and potential solutions have been performed in NR; no specific approach has been adopted in NR to handle blockages efficiently, however. While HARQ retransmissions and the L2 timers (to allow reassembly in RLC/PDCP layers), handle the link problems to some extent, for more frequent blockages, the transport layer performance and throughput may still be impacted (e.g., TCP, QUIC, etc.). In current cellular technologies, when a communication faces a blockage, the transmissions are suspended, which potentially impacts the upper layer transmissions. However, minimization of the impact to the upper layers may be desired. In addition to a high likelihood of blockages, futuristic deployments with coverage islands (not static ubiquitous coverage) further motivate proper handling of link problem to avoid degradations at the transport layer.

[00198] In summary, blockages and link issues cause the queues at the higher layers to build up. Accordingly, packets may be dropped at point on the route due to the build-up. For TCP protocol, this causes the TCP congestion window to collapse since an ACK is not received in time. The TCP then assumes that congestion exists, and the congestion window decreases to a small number, which reduces the throughput. In other words, the effect of one packet loss or one ACK not being received can be disproportionately large.

[00199] It is likely that in future technologies, the QUIC protocol will coexist alongside the TCP, and applications may use either QUIC or TCP (even currently, the QUIC protocol is used for video streaming applications). While the use of the QUIC protocol reduces/avoids the TCP congestion window/slow start issues due to blockages or coverage loss events, impact to the radio layer is still present and the arising issues exist. Particularly, issues due to link problems exist with TCP such that if the UE misses acknowledgments for some packets, the TCP can be slowed down disproportionately. The QUIC operation can also be slowed down because of the link problems, but the impact may not be as disproportionate and may not affect the TCP congestion window. Thus, while some of the issues with TCP (where the throughput falls if there is a packet dropped due to congestion, the slow start, etc.) are less prevalent with QUIC, any issues related to the radio layer still have to be solved even with use of the QUIC protocol. In summary, the impact of link issues and the manner in which the design handles the link issues on the QUIC protocol may be similar to that of TCP, but likely to exist to a lesser extent. [00200] From the perspective of adaptation to blockages, it is beneficial to manage feedback within the RAN so that the other end (i.e., application layer) does not initiate flow control related actions. In one example, the flow control feedback is reduced for scenarios/locations with more expected blockages. As the transmitter is not aware of one packet being missing in the sequence (a packet hole), this means that the congestion window grows more slowly. For example, for TCP protocol, packets are inspected, and TCP ACKs are selectively slowed down (by deprioritizing its transmission). As such, the growth of congestion window is slowed during the blockage period or more generally, if more frequent occurrences of blockage are expected (for example upon experiencing a set number of blockages within a given time interval or based on blockage map knowledge). This criterion may be similar to experiencing a degraded average data rate. In the case of a degraded data rate, TCP is automatically affected, while here the ACKs are selectively slowed down and other data prioritized for the available time periods when the UE can actually transmit.

[00201] In one example, considering downstream traffic with TCP ACKs on UL, the device deprioritizes the TCP ACK transmission. Particularly, the MAC layer should identify a TCP ACK and associate a lower priority to the TCP ACK (e.g., in a logical channel sense), so that the TCP ACK may be transmitted in later packets. Such an approach may face potential issues. For example, if the TCP ACK is a part of another UL TCP packet, handling further considerations may exist since there are headers in the TCP packet (to indicate how far is received).

[00202] This general strategy can be useful for QUIC protocol as well. QUIC protocol uses UDP instead of TCP, but flow control exists above UDP. As such, a similar approach can be used for the flow control feedback to slow down specific streams/flows within multiple QUIC streams/flows.

[00203] Instead of selectively slowing down the TCP ACKs, other ways to slow down the overall TCP may exist, as well as other types of TCP feedback that could slow the transmitter down, and TCP configuration itself may be modified.

[00204] Instead of a top-down approach (where at the lower layer, Deep

Packet Inspection (DPI) should be performed to track down out and deprioritize TCP ACKs selectively), the lower layers may send information to the upper layer and the TCP settings can be changed to slow down TCP data rate. Particularly, as one embodiment, constant pinging from the lower layer to upper layer may be considered to adjust the parameter accordingly. Consequently, the ACKs may be accumulated and held in the upper layer (not sent to lower layer for transmission). However, this approach depends on end-to-end TCP control settings. Further, there is not much control over the TCP at the RAN level in 3GPP. As mentioned above, the flow/congestion control mechanisms in the current technologies limit the generated data at the transmitter side, e.g., ECN defined for IP protocols. At the RAN-level, a notification to upper layer may be provided. For example, if a blockage is expected, the RAN may send an ECN- like message, a pause, or a blockage notification to the upper layer.

[00205] Various TCP implementations (e.g., TCP freeze) may, to some extent, handle link issues. In one example, if the UE can predict a link issue such as blockage (e.g., based on a blockage map and its location), the UE may be able to advertise a window size of zero (e.g., included in the TCP ACK packet), which sets the transmit size window to zero and puts the TCP state machine on hold. When the link issue is resolved, the UE can resume and pick up from where the UE left off. As such, the transmitting side is put on hold while the congestion window is not changed. With knowledge about expected link problems and location information, the UE can then take proactive actions; from one perspective, this is similar to the approach of timer expansion for the RLC and PDCP radio layers discussed above. The window size (e.g., TCP receive window size) included in the ACK packet indicates how many more packets the receiver is able to receive. When the receiver indicates that no more packets can be supported, the receiver may request temporary transmission suspension so that the sender does not send further packets. When the link issue is resolved, the UE sends another ACK with a different window size to resume transmission, which may essentially be seen as a congestion window from the UE perspective. Although two ACKs are involved, performance degradation is avoided.

However, in this case, changes to the TCP stack may occur as the UE provides information to the source/destination of TCP layer as mentioned above. Since TCP is outside of the central network and the server generates TCP packets, the UE and server coordinate on TCP parameters. As such aspects are not in the scope of the current 3 GPP ecosystem, the approaches with defined action purely by the UE in which the server may not provide acknowledgment or take instructed actions by the UE may be more desirable.

[00206] Currently, inter-layer interaction has been less well defined, e.g., between RAN and TCP layers (e.g., due to the reasons mentioned above). In one example, assuming that blockage-related information or the blockage map is handled at the RRC layer, a signaling or communication link is defined between the RRC layer and the TCP layer so that the RRC layer is able to advertise/notify an expected blockage, the window size, etc. to the TCP layer. For example, a blockage notification may be defined to be sent from the lower layers to the upper layer using which the TCP makes decisions and/or takes actions on its side. For example, the notification can be handled by non-access stratum (NAS) or other signaling protocols. The blockage notification can be similar to how RLF-related information can be notified from the lower layers to the upper layers.

[00207] Inter-layer communication on blockage-related information [00208] As discussed so far, different applications and use cases of the blockage map may involve actions from different protocol layers, e.g., actions involving the RLC, PDCP, TCP layers, etc. As disclosed above, a blockage notification may be defined to notify different layers (within RAN or from RAN to the upper layers). For example, if it assumed that blockage-related information or a blockage map is handled at the RRC layer, the RRC layer notifies higher layers (PDCP, RLC, etc.) via a blockage notification, for example, depending on the actions that the higher layers are to take based on the blockage knowledge.

[00209] UE and network synchronization with respect to the actions taken based on blockage knowledge (L2-related actions, etc.)

[00210] In the current system, reconfiguration/adjustment (e.g., on RLC mode switch, timers, etc.) is synchronized with the network, i.e., the network and

UE have an in-sync understanding of the operation mode, timers, e.g., same timer status, etc. As such, following the current system design, while for example, the timers can be suspended at the UE, the network should also be aware of the suspension. As such, reconfigurations/adjustments based on the location and map knowledge may also be performed based on prior agreements between the UE and the network, e.g., via pre-configuration, according to predefined behaviors, etc. As the blockage map is also shared and exchanged between the UE and the network (during the connected mode operation), synchronous operation is facilitated, especially accompanied with network knowledge of the UE location. In general, assuming a framework where both the UE and network know that both have knowledge of the blockage map and are aware of the UE location, coordinated operation and actions are possible, and UE behavior and actions are known or predictable to the network as well. To enable such coordinated and/or synchronized and/or network-aware operation based on the blockage map knowledge, the network may have knowledge about the UE location with time granularity. How frequently location information is to be available at the network depends on several factors, deployments, expected UE speed range, etc.

[00211] One example to synchronize the network and UE actions/ adjustments/configurations is to have the UE provide/indicate the change to the network (or resolve that with the network later) when the UE performs an autonomous adjustment/reconfiguration based on its blockage knowledge (in response to or in anticipation of blockage). In another example, the network may indicate to the UE beforehand under what conditions and/or according to what observations the UE may take actions and/or make decisions on its side. The network may then follow/support UE’s actions/decisions.

[00212] On the other hand, protocol design may be considered that could allow potentially different configurations and/or parameters/values from the UE and network sides, and the UE autonomous adjustments.

[00213] As an NR-based incremental example application of the blockage map (e.g., based on NR where the related actions are network-centric and further synchronization between the UE actions and network is not used), if the blockage-related information is provided periodically to the network along with location information, the network learns over a period of time to adjust the control plane (CP) related to RLF declaration, re-establishment, etc. and/or user plane (UP) timer/counter thresholds accordingly, i.e., more adaptive based on the received feedback/reporting from the UEs and the formed blockage map. However, such an approach does not allow immediate response to the blockage detection and may not efficiently handle the incurred blockages. With respect to the configuration of the thresholds, in one example, the network may have a table instead of one set of values, which can be pre-configured (may not be dynamic). For example, information can be included in the system information based on the location, e.g., if a gNB is located in an area with a large number of obstacles, and based on the underlying application/service requirements, certain thresholds are configured/assumed.

[00214] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00215] The subject matter may be referred to herein, individually and/or collectively, by the term “embodiment” merely for convenience and without intending to voluntarily limit the scope of this application to any single inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. [00216] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[00217] The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus for a base station, the apparatus comprising: processing circuitry configured to: exchange link problem information related to at least one of a beam failure detection, a beam failure recovery, a random access (RA) procedure, a radio link failure declaration, or a connection reestablishment procedure, with other base stations and user equipments (UEs) in a network that includes the base station and the other base stations; determine causes of link problems in the network based on the link problem information; determine whether the link problem is due to a transient or permanent communication blockage; determine locations of a set of communication blockages that include identified communication blockages and potential communication blockages within the network based on the causes of the link problems; create a blockage map based on the link problems and the locations of the set of communication blockages; and share information of the blockage map with the other base stations and UEs; and memory configured to store the blockage map.

2. The apparatus of claim 1, wherein the processing circuitry is configured to determine the causes of the link problems in the network based further on UE information, the UE information comprises at least one of locations, speeds, and directional information of the UEs.

3. The apparatus of claim 1, wherein: the set of communication blockages include blockages caused by blockers, the blockers including stationary communication blockers and mobile communication blockers; and the processing circuitry is configured to determine blockage characteristics to at least one of: identify whether each of the link problems is caused by one of the blockers, estimate a size of each of the set of communication blockages, or estimate a location of each of the set of communication blockages.

4. The apparatus of claim 3, wherein the processing circuitiy is configured to estimate a size of each of the set of communication blockages based on at least one of: an operating frequency band of the UEs, relative speed of UEs to the blockers, or durations of the at least one of timers or counters.

5. The apparatus of claim 1, wherein the link problem information includes at least one of timers or counters that have been triggered or have expired for at least one of a beam failure detection or a radio link failure declaration or a connection re-establishment procedure.

6. The apparatus of claim 5, wherein the processing circuitry is configured to determine blockage characteristics based on an effect on connectivity of at least one of the UEs of at least one of: a period of at least one of the timers, or a threshold of at least one of the counters, and the effect on connectivity comprises at least one of: radio link failure declaration, re-establishment success or failure, or transition from a radio resource control (RRC) CONNECTED state to an RRC IDLE state.

7. The apparatus of claim 5, wherein the processing circuitiy is configured to: select, based on a number of UEs having the effect on connectivity, a percentage of UEs in the network to vary the at least one of the period of at least one of the timers or the threshold of at least one of the counters; and indicate, to at least one of the UEs, to vary the at least one of the period of at least one of the timers or the threshold of at least one of the counters beyond a specified operating range to determine impact on UE connectivity, and create the blockage map.

8. The apparatus of claim 5, wherein: the timers include at least one of T310, T311, or T301 timers, and the counters include at least one of N310 and N311 counters, and the processing circuitry is configured to instruct at least one of the UEs to set the at least one of the timers or counters using a value dependent on a location of the at least one of the UEs based on the blockage map.

9. The apparatus of claim 1, wherein the processing circuitry is configured to: train, based on the link problem information, a blockage detection model to detect blockage events, durations, and locations; share the blockage detection model among the UEs and other base stations; and refine the blockage detection model based on other blockage detection models provided by the UEs and other base stations.

10. An apparatus for a user equipment (UE), the apparatus comprising: processing circuitry configured to: exchange link problem information with at least one base station in a network, the link problem information comprising link problems in the network for a plurality of UEs, the link problems including communication blockages and potential communication blockages caused by blockers in the network; cooperate with at least one base station, to build, maintain, and update a blockage map dependent on an operation frequency of the UE, the blockage map comprising, for each of the communication blockages and potential communication blockages: a location, size, estimated duration based on the size, and relative speed and direction of travel of the UE and blocker; and take action based on the blockage map; and memory configured to store the blockage map.

11. The apparatus of claim 10, wherein the processing circuitry is configured to: train, based on the link problem information, a blockage detection model to detect blockage events, durations, and locations, the blockage detection model shared among the plurality of UEs and other base stations in the network; and refine the blockage detection model based on other blockage detection models provided by the plurality of UEs and other base stations.

12. The apparatus of claim 10, wherein to take action, the processing circuitry is configured to adapt at least one of Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) layer parameters or timers.

13. The apparatus of claim 12, wherein to adapt the at least one of the PDCP and RLC layer parameters or timers, the processing circuitry is configured to: determine over-the-air conditions and effective bandwidth for communication with the base station; and at least one of: dependent on over-the-air conditions and effective bandwidth, at least one of: adjust a T-reordering timer and a PDCP receive window for which a lower bound is correlated to the T-reordering timer in coordination with a T-reassembly timer; or dependent on the over-the-air conditions and the effective bandwidth, switch a radio link control (RLC) mode between an Acknowledged Mode (AM) and Unacknowledged Mode (UM); or suspend or reset at least one of the timers, the timers related to: discarding data, dependent on latency sensitivity of the data, retransmissions in response to the RLC AM being configured, and discontinuous reception (DRX) active time.

14. The apparatus of claim 12, wherein the processing circuitiy is further configured to at least one of:

Indicate, to the base station, adaption of the at least one of the PDCP and RLC layer parameters or timers; or receive, from the base station, conditions for adaption of the at least one of the PDCP and RLC layer parameters or timers based on the blockage map.

15. The apparatus of claim 12, wherein the processing circuitry is further configured to at least one of: periodically provide the link problem information to the base station, the link problem information comprising UE location, and receive, from the base station, system information comprising a table of values of the timers; or adjust, dependent on effective bandwidth and service and quality of service (QoS) requirements, buffer size based on the UE location and blockage map.

16. The apparatus of claim 10, wherein: the blockage map indicates a likelihood or relative amount of the communication blockages and potential communication blockages, and the processing circuitiy is further configured to deprioritize and slow flow control feedback to the base station for locations with higher communication blockages and potential communication blockages based on the blockage map, and at least one of: slow down growth of a transmission control protocol (TCP) congestion window during a period of blockage or in response to a determination that blockage occurrences are to be more frequent based on the blockage map; identify, by a media access control (MAC) layer, a TCP acknowledgment (ACK) transmission and associate a lower priority with of the TCP ACK transmission to deprioritize the TCP ACK transmission; or adjust the flow control feedback based on periodic pings from a lower layer to an upper layer.

17. The apparatus of claim 10, wherein the processing circuitry is further configured to at least one of: in response to a predicted link issue, advertise a window size of zero in an acknowledgment (ACK) packet to set a transmit size window to zero and place a transmission control protocol (TCP) state machine on hold until the link issue is resolved and another ACK packet with a different window size is transmitted; or in response to handling blockage-related information occurring at a radio resource control (RRC) layer, notify at least one of a TCP layer, a Packet Data Convergence Protocol (PDCP), or a Radio Link Control (RLC) layer of an expected blockage or window size.

18. The apparatus of claim 10, wherein: the blockage map incorporates at least one of beam-failure detection, recovery-related information, or radio link failure-related information, including at least one of UE location, speed, direction, timer and counter values, and time tags of when a beam failure or a radio link failure was detected or recovered or reported by the UE, and the processing circuitry is further configured to at least one of: in response to facing a Beam Failure Detection (BFD), use backup beams to perform a random access procedure; adjust at least one of mobility, speed, or direction based on information of the blockage map, the information including expected mobile blockages, expected stationary blockages, and duration of blockages.

19. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a base station, the one or more processors to configure the base station to, when the instructions are executed: exchange link problem information with other base stations and user equipments (UEs) in a network that includes the base station and the other base stations, the link problem information including at least one of timers or counters that have expired for at least one of a radio link failure declaration or a connection re-establishment procedure; determine causes of link problems in the network based on the link problem information; determine locations of communication blockages and potential communication blockages within the network based on the causes of the link problems; create a blockage map based on the link problems and the locations of the communication blockages and potential communication blockages, the blockage map comprising, for each of the communication blockages and potential communication blockages: a location, size, estimated duration based on the size, and relative speed and direction of travel of the UE and blocker; and share the blockage map with the other base stations and UEs.

20. The non-transitory computer-readable storage medium of claim 19, wherein the one or more processors further configure the base station to, when the instructions are executed, determine the causes of the link problems in the network based further on UE information, the UE information comprises locations, speeds, and directional information of the UEs.