PATENT DOCUMENT

Publication Number: US-11290943-B2
Application Number: US-201816609312-A
Country: US
Kind Code: B2

Title: Access control for user equipment with coverage enhancement level support

Abstract:
The techniques, described herein, may enable a wireless telecommunication network to manage Mobility Management Entity (MME) overload scenarios by causing a Radio Access Network (RAN) node to temporarily bar certain User Equipment (UEs) from connecting to the RAN node. In some embodiments, UEs may be barred from connecting to the RAN node based on which UEs are operating in an enhanced coverage mode, Coverage Enhancement (CE) levels of each UE, and/or a measured Reference Signal Received Power (RSRP) of each UE.

Claims:
What is claimed is: 
     
       1. An apparatus of a Mobility Management Entity (MME), comprising:
 one or more processors configured to execute one or more instructions to:
 detect that the MME is overloaded; 
 determine at least one Coverage Enhancement (CE) level of a User Equipment (UE) to bar from connecting with a Radio Access Network (RAN) node; and 
 cause instructions, to be communicated to the RAN node, to block UEs of the at least one CE level from establishing connections with the RAN node. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the instructions for the RAN node to block the UEs of the at least one CE level include instructions for the RAN node to reject Radio Resource Control (RRC) requests from the UEs of the at least one CE level. 
     
     
       3. The apparatus of  claim 1 , wherein the instructions for the RAN node to block the UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     
     
       4. The apparatus of  claim 1 , wherein the one or more processors are further to:
 monitor a load status of the MME; 
 determine that the MME is not overloaded; and 
 notify the RAN node that the UEs of the at least one CE level are not to be blocked from establishing the connections with the RAN node. 
 
     
     
       5. The apparatus of  claim 1 , wherein the at least one CE level of the UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     
     
       6. An apparatus of a Radio Access Network (RAN) node, comprising:
 an interface to radio frequency (RF) circuitry; and 
 one or more processors that are controlled to:
 process instructions, received from a Mobility Management Entity (MME), to block UEs of at least one Coverage Enhancement (CE) level from establishing a connection with the RAN node; and 
 cause system information to be broadcasted, via the interface to the radio frequency (RF) circuitry, indicating that the at least one CE level is blocked. 
 
 
     
     
       7. The apparatus of  claim 6 , wherein the system information includes a System InformationBlockType14 Information Element (IE) for enhanced Machine-Type-Communication (eMTC) indicating the at least one CE level. 
     
     
       8. The apparatus of  claim 6 , wherein the system information includes a System InformationBlockType14-NB Information Element (IE) for Narrowband Internet-of-Things (NB-IoT) devices indicating the at least one CE level. 
     
     
       9. The apparatus of  claim 6 , wherein the at least one CE level includes all CE levels that UEs may use to communicate with the RAN node. 
     
     
       10. The apparatus of  claim 6 , wherein the one or more processors are further to:
 process instructions from the MME to discontinue blocking UEs of the at least one CE level; and 
 update the system information broadcasted by the RAN node to indicate that the UEs of the at least one CE level are no longer being blocked by the RAN node. 
 
     
     
       11. An apparatus of a User Equipment (UE), comprising:
 an interface to radio frequency (RF) circuitry; and 
 one or more processors that are controlled to:
 receive, via the interface to the RF circuitry, system information, from a Radio Access Network (RAN) node, that notifies that UEs of one or more Coverage Enhancement (CE) levels are to be blocked from establishing a connection with the RAN node by indicating the one or more CE levels to be blocked; 
 determine a CE level of the UE; 
 determine that the UE is blocked from establishing the connection with the RAN node by comparing the CE level of the UE to the one or more CE levels; and 
 refrain from attempting to establish the connection with the RAN node; 
 
 wherein the system information further includes a duration during which the one or more CE levels are to be blocked. 
 
     
     
       12. The apparatus of  claim 11 , wherein the system information includes a SystemInformationBlockType14 Information Element (IE) indicating the one or more CE levels. 
     
     
       13. The apparatus of  claim 11 , wherein the one or more processors are further controlled to:
 receive, via the interface to the RF circuitry, a notification that the system information has changed; and 
 cause, via the interface to the RF circuitry, to receive an updated system information, in response to receiving the notification. 
 
     
     
       14. The apparatus of  claim 11 , wherein the one or more processors are further controlled to determine a measured Reference Signal Received Power (RSRP) of the UE and determine the CE level of the UE based on the measured RSRP of the UE. 
     
     
       15. A non-transitory computer-readable medium containing program instructions for causing one or more processors, associated with a Mobility Management Entity (MME), to:
 detect that the MME is overloaded; 
 determine at least one Coverage Enhancement (CE) level of a User Equipment (UE) to bar from connecting with a Radio Access Network (RAN) node; and 
 cause instructions, to be communicated to the RAN node, to block UEs of the at least one CE level from establishing connections with the RAN node. 
 
     
     
       16. The non-transitory computer-readable medium of  claim 15 , wherein the instructions for the RAN node to block the UEs of the at least one CE level include instructions for the RAN node to reject Radio Resource Control (RRC) requests from the UEs of the at least one CE level. 
     
     
       17. The non-transitory computer-readable medium of  claim 15 , wherein the instructions for the RAN node to block the UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     
     
       18. The non-transitory computer-readable medium of  claim 15 , wherein the one or more processors are further to:
 monitor a load status of the MME; 
 determine that the MME is not overloaded; and 
 notify the RAN node that the UEs of the at least one CE level are not to be blocked from establishing the connections with the RAN node. 
 
     
     
       19. The non-transitory computer-readable medium of  claim 15 , wherein the at least one CE level of the UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     
     
       20. A non-transitory computer-readable medium containing program instructions for causing one or more processors, associated with a Radio Access Network (RAN) node, to:
 process instructions, received from a Mobility Management Entity (MME), to block UEs of at least one Coverage Enhancement (CE) level from establishing a connection with the RAN node; and 
 cause system information to be broadcasted, via an interface to radio frequency (RF) circuitry, indicating that the at least one CE level is blocked. 
 
     
     
       21. The non-transitory computer-readable medium  claim 20 , wherein the system information includes a SystemInformationBlockType14 Information Element (IE) for enhanced Machine-Type-Communication (eMTC) indicating the at least one CE level. 
     
     
       22. The non-transitory computer-readable medium  claim 20 , wherein the system information includes a SystemInformationBlockType14-NB Information Element (IE) for Narrowband Internet-of-Things (NB-IoT) devices indicating the at least one CE level. 
     
     
       23. The non-transitory computer-readable medium of  claim 20 , wherein the at least one CE level includes all CE levels that UEs may use to communicate with the RAN node. 
     
     
       24. The non-transitory computer-readable medium of  claim 20 , wherein the one or more processors are further to:
 process instructions from the MME to discontinue blocking UEs of the at least one CE level; and 
 update the system information broadcasted by the RAN node to indicate that the UEs of the at least one CE level are no longer being blocked by the RAN node.

Description:
RELATED APPLICATIONS 
     This application is a National Phase entry application of International Patent Application No. PCT/US2018/039042 filed Jun. 22, 2018, which claims priority to U.S. Provisional Patent Application No. 62/523,384, which was filed on Jun. 22, 2017 and is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Wireless telecommunication networks may include User Equipment (UE) (e.g., smartphones, tablet computers, laptop computers, etc.) Radio Access Networks (RANs) (that often include one or more base stations), and a core network. A UE may connect to the core network by communicating with a base station and registering with the core network. Communications between the UE and the base station may occur over one or more wireless channels established between the UE and the base station. 
     In some scenarios, a wireless telecommunication network may provide Coverage Enhancement (CE) for certain UEs within the network. A UE with CE may be permitted to perform a greater number of retransmissions when attempting to contact a RAN. As such, providing CE to a UE may help ensure that the UE is able to successfully communicate with the network, which may be particularly beneficial to UEs in poor coverage areas within the RAN. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments described herein will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals may designate like structural elements. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 
         FIG. 1  illustrates an architecture of a system of a network in accordance with some embodiments; 
         FIG. 2  is a flowchart diagram of an example process for controlling network access for User Equipment (UEs) with Coverage Enhancement (CE) level support; 
         FIG. 3  is a table of an example of controlling network access for UEs with different CE levels; 
         FIG. 4  is a block diagram of an example process for controlling network access for UEs while a Mobility Management Entity (MME) is overloaded; 
         FIG. 5  is a sequence flow diagram of an example process for managing MME overload scenarios by controlling network access for UEs; 
         FIG. 6  is a block diagram of example components of a device in accordance with some embodiments; 
         FIG. 7  is a block diagram of example interfaces of baseband circuitry in accordance with some embodiments; 
         FIG. 8  is a block diagram of an example control plane protocol stack in accordance with some embodiments; 
         FIG. 9  is a block diagram of an example user plane protocol stack in accordance with some embodiments; 
         FIG. 10  illustrates components of a core network in accordance with some embodiments; 
         FIG. 11  is a block diagram illustrating components, according to some example embodiments, of a system  1100  to support Network Functions Virtualization (NFV); and 
         FIG. 12  is a block diagram of example components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. It is to be understood that other embodiments may be utilized, and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents. 
     The techniques, described herein, may enable a wireless telecommunication network to manage Mobility Management Entity (MME) overload scenarios by causing a Radio Access Network (RAN) node to temporarily bar certain User Equipment (UEs) from connecting to the RAN node. In some embodiments, UEs may be barred from connecting to the RAN node based on which UEs are operating in an enhanced coverage mode, CE levels of each UE, and/or a measured RSRP of each UE. UEs operating in an enhanced coverage mode are also referred to herein as implementing Coverage Enhancement (CE). 
     Coverage Enhancement (CE) may include a technique, implemented by a wireless telecommunication network, to better enable UEs to communicate with RAN nodes (e.g., to perform Random Access Procedure (RACH) procedures) by increasing a number of repetitions that the UE may use to communicate with RAN nodes. CE may include two modes (e.g., CE mode A and CE mode B) and four levels (e.g., 0-3). CE levels 0 and 1 may correspond to CE mode A, which may be for moderate signaling enhancement, while CE levels 2 and 3 may correspond to CE mode B, which may be for more extreme signaling enhancement. A CE level may be determined based on a Reference Signal Received Power (RSRP) measured by the UE. Generally, weaker RSRP measurements may result in higher CE levels, meaning a greater number of retransmissions being available to a UE, while stronger RSRP measurements may result in lower CE levels, meaning fewer number retransmissions being available to a UE. In short, a UE may have a CE level commensurate with a difficulty that the UE may experience in communicating with the RAN to establish a connection. 
     While implementing CE may help ensure effective communications between a UE and a RAN node, the UE using CE may be a greater burden on the MME to which the UE is registered. For example, the MME may use an extended Non-Access Stratum (NAS) timer for UEs operating in enhanced coverage mode. As a result, UEs using CE may have a more significant contribution to an MME becoming overloaded. An MME being overloaded may include the MME experiencing a level of activity that exceeds a threshold of activity and/or that is otherwise beyond a level of activity deemed acceptable for the MME. The level of activity may include a variety of conditions and/or factors, including a number of UEs registered with the MME, a number of UEs in an enhanced coverage mode, a number of active connections between UEs and the network, etc. 
     The techniques, described herein, may enable MMEs to implement overload start and stop procedures to control MME overload within a wireless telecommunication network. For example, an MME may determine if/when the MME is overloaded, determine CE levels for which UEs are to be blocked from establishing connections with a corresponding RAN node, and communicating instructions to the RAN node about blocking UEs based on the determined CE levels. In response to the instructions, the RAN node may bar, block, ignore, reject, etc., subsequent connection requests from UEs operating at the CE levels indicated by the MME. Additionally, or alternatively, the RAN node may provide UEs with system information to enable the UEs to determine whether they are being blocked. For example, system information broadcasted by the RAN node may include RSRP thresholds by which each UE may measure a RSRP and determine a corresponding CE level for the UE. As such, when the RAN node provides system information indicating CE levels that are blocked from accessing the RAN node, each UE may compare their CE level with the CE levels to be blocked to determine whether the UE is being blocked. In some embodiments, system information may also include a duration for which UEs are blocked, such that UEs may not attempt to connect with the RAN node for at least that duration. Later, the MME may determine that the MME is no longer overloaded and may inform the RAN node to resume normal operating procedures (e.g., so that the UEs previously barred from the RAN node may now access the RAN node). In some embodiments, the RAN node may respond by discontinuing the blocking of connection requests from UEs at the previously blocked CE levels and/or broadcasting updated system information, indicating that CE levels or no longer being blocked. In some embodiments, the RAN node may use paging messages to prompt blocked UEs to obtain updated system information (which may indicate that UEs operating and previously blocked CE levels are no longer being blocked). 
       FIG. 1  illustrates an architecture of a system  100  of a network in accordance with some embodiments. The system  100  is shown to include UE  101  and a 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 comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface. 
     In some embodiments, any of the UEs  101  and  102  can comprise an Internet of Things (IoT) UE or Narrowband (NB-IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M), machine-type communications (MTC), enhanced 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 IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network. 
     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. 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 fifth generation (5G) protocol, a New Radio (NR) protocol, and the like. 
     In this embodiment, 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 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), and a Physical Sidelink Broadcast Channel (PSBCH). 
     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 a connection consistent with any IEEE 802.11 protocol, wherein the AP  106  would comprise a wireless fidelity (Wi-Fi®) 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). 
     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, eNBs, next Generation NodeBs (gNB), RAN nodes, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). 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 . 
     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 embodiments, 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 accordance with some embodiments, the UEs  101  and  102  can be configured to communicate using Orthogonal Frequency-Division Multiplexing (OFDM) communication signals with each other or with any of the RAN nodes  111  and  112  over a multicarrier communication channel in accordance various communication techniques, such as, but not limited to, an Orthogonal Frequency-Division Multiple Access (OFDMA) communication technique (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers. 
     In some embodiments, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes  111  and  112  to the UEs  101  and  102 , while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. 
     The physical downlink shared channel (PDSCH) may carry user data and higher-layer signaling to the UEs  101  and  102 . The physical downlink control channel (PDCCH) may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs  101  and  102  about the transport format, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE  102  within a cell) may be performed at any of the RAN nodes  111  and  112  based on channel quality information fed back from any of the UEs  101  and  102 . The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs  101  and  102 . 
     The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8). 
     Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced the control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations. 
     The RAN  110  is shown to be communicatively coupled to a core network (CN)  120 —via an S1 interface  113 . In embodiments, the CN  120  may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment, the S1 interface  113  is split into two parts: the S1-U interface  114 , which carries traffic data between the RAN nodes  111  and  112  and the serving gateway (S-GW)  122 , and the S1-mobility management entity (MME) interface  115 , which is a signaling interface between the RAN nodes  111  and  112  and MMEs  121 . 
     In this embodiment, 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&#39; 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. 
     The S-GW  122  may terminate the S1 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 may include lawful intercept, charging, and some policy enforcement. 
     The P-GW  123  may terminate an SGi interface toward a PDN. The P-GW  123  may route data packets between the EPC network  123  and external networks such as a network including the application server  130  (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface  125 . Generally, the application server  130  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 embodiment, the P-GW  123  is shown to be communicatively coupled to an application server  130  via an IP communications interface  125 . The application server  130  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 . 
     The P-GW  123  may further be a node for policy enforcement and charging data collection. Policy and Charging Enforcement Function (PCRF)  126  is the policy and charging control element of the CN  120 . In a non-roaming scenario, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE&#39;s Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE&#39;s IP-CAN session: a Home PCRF (H-PCRF) within a 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  130  via the P-GW  123 . The application server  130  may signal the PCRF  126  to indicate a new service flow and select the appropriate Quality of Service (QoS) and charging parameters. The PCRF  126  may provision this rule into a Policy and Charging Enforcement Function (PCEF) (not shown) with the appropriate traffic flow template (TFT) and QoS class of identifier (QCI), which commences the QoS and charging as specified by the application server  130 . 
     The quantity of devices and/or networks, illustrated in  FIG. 1 , is provided for explanatory purposes only. In practice, system  100  may include additional devices and/or networks; fewer devices and/or networks; different devices and/or networks; or differently arranged devices and/or networks than illustrated in  FIG. 1 . For example, while not shown, environment  100  may include devices that facilitate or enable communication between various components shown in environment  100 , such as routers, modems, gateways, switches, hubs, etc. Alternatively, or additionally, one or more of the devices of system  100  may perform one or more functions described as being performed by another one or more of the devices of system  100 . Additionally, the devices of system  100  may interconnect with each other and/or other devices via wired connections, wireless connections, or a combination of wired and wireless connections. In some embodiments, one or more devices of system  100  may be physically integrated in, and/or may be physically attached to, one or more other devices of system  100 . Also, while “direct” connections may be shown between certain devices in  FIG. 1 , some of said devices may, in practice, communicate with each other via one or more additional devices and/or networks. 
       FIG. 2  is a flowchart diagram of an example process  200  for controlling network access for UEs with CE level support. Process  200  may be implemented by MME  121 . In some embodiments, one or more of the operations described in  FIG. 2  may be performed in whole, or in part, by another device described above with reference to  FIG. 1 . 
     As shown, process  200  may include detecting that MME  121  is overloaded (block  210 ). For example, MME  121  may monitor one or more functions, operations, processes, etc., to determine a current load state of MME  121 . In some embodiments, this may include monitoring a number of UEs  101  registered with MME  121 , a level of activity associated with UEs  101  registered with MME  121 , a number of UEs  101  that are registered with MME  121  and operating in an enhanced coverage mode, etc. Additionally, or alternatively, MME  121  may apply one or more rules and/or thresholds to the current load state of MME  121  to determine whether MME  121  is overloaded. For example, MME  121  may determine that MME  121  is overloaded upon determining that a current load state of MME  121  exceeds a load state threshold. In some embodiments, MME  121  may also apply one or more rules to analyze the current load state of MME  121  and to determine, for example, a degree to which MME  121  is overloaded, reasons for which MME  121  is overloaded (e.g., which UEs, and/or CE levels of UEs, are contributing to the overloaded state), etc. 
     Process  200  may also include determining the coverage (CE levels, CE modes, or repetition levels) in which UEs  101  to be bar from RAN node  111  (block  220 ). For example, in response to determining that MME  121  is overloaded, MME  121  may determine the coverage levels (e.g., CE levels, CE modes, or repetition levels) in which to block UEs  101  from connecting (and/or reconnecting) with RAN node  111 . In some embodiments, MME  121  may determine to bar any and all CE levels, CE modes, and/or repetition levels. In some embodiments, MME  121  may determine to bar only one or some CE levels, CE modes, and/or repetition levels. 
     Process  200  may also include providing instruction to RAN node  111  regarding the coverage (CE levels, CE modes, or repetition levels) in which UEs  101  are to be barred (block  230 ). For example, MME  121  may generate instructions for baring UEs  101  of certain CE levels, CE modes, and/or repetition levels and may transmit the instructions to RAN node  111 . In some embodiments, MME  121  may use an overload start message to provide the instructions to RAN node  111 . Additionally, or alternatively, MME  121  may use one or more Information Elements (IE) to provide the instructions. Table 1, below, includes an example of an overload start message IE that may be used by MME  121  to provide instructions to RAN node  111  about which UEs  101  to block. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Overload Start Message Information Element (IE) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 IE type 
                   
                   
                   
               
               
                   
                   
                   
                 and 
                 Semantics 
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 description 
                 Criticality 
                 Criticality 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Message Type 
                 M 
                   
                 9.2.1.1 
                 YES 
                 ignore 
               
               
                 Overload 
                 M 
                   
                 9.2.3.19 
                 YES 
                 reject 
               
               
                 Response 
               
               
                 GUMMEI List 
                   
                 0 . . . 1 
                   
                 YES 
                 ignore 
               
               
                 &gt;GUMMEI List 
                   
                 1 . . . &lt;maxnoofMMECs&gt; 
                   
                 EACH 
                 ignore 
               
               
                 Item 
               
               
                 &gt;&gt;GUMMEI 
                 M 
                   
                 9.2.3.9 
                 — 
               
               
                 Traffic Load 
                 O 
                   
                 9.2.3.36 
                 YES 
                 ignore 
               
               
                 Reduction 
               
               
                 Indication 
               
               
                   
               
            
           
         
       
     
     Another example of an IE that may be used by MME  121  to provide RAN node  111  with instructions is provided below in Table 2, which includes an example of an overload start message IE. The example of Table 2 may be used with, or in place of, one or more of the other IEs described herein. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Overload Response Information Element (IE) 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                 IE type and 
                 Semantics 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 description 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 CHOICE Overload 
                 M 
                   
                   
               
               
                 Response 
                   
                   
                   
               
               
                 &gt;Overload Action 
                   
                   
                   
               
               
                 &gt;&gt;Overload Action 
                 M 
                 9.2.3.20 
               
               
                   
               
            
           
         
       
     
     Yet another example of an IE that may be used by MME  121  to provide RAN node  111  with instructions is provided below in Table 3, which includes an example of an overload action IE. The example of Table 3 may be used with, or in place of, one or more of the other IEs described herein. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Overload Action Information Element (IE) 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                 IE type and 
                 Semantics 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 description 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Overload Action 
                 M 
                 ENUMERATED 
               
               
                   
                   
                 (Reject RRC connection establishments for 
               
               
                   
                   
                 non-emergency MO DT, Reject RRC 
               
               
                   
                   
                 connection establishments for Signalling, 
               
               
                   
                   
                 Permit Emergency Sessions and mobile 
               
               
                   
                   
                 terminated services only, . . . , Permit High 
               
               
                   
                   
                 Priority Sessions and mobile terminated 
               
               
                   
                   
                 services only, reject delay tolerant access, not 
               
               
                   
                   
                 accept mo-data or delay tolerant access from 
               
               
                   
                   
                 CP CIoT, Reject RRC connection request for 
               
               
                   
                   
                 data transmission from UE s with CE support) 
               
               
                 &gt;OverloadCElevel 
                 O 
                 BIT STRING 
               
               
                   
                   
                 (SIZE(16)) 
               
               
                   
                   
                 CE_Level_All 
               
               
                   
                   
                 CE_Level_0 
               
               
                   
                   
                 CE_Level_1 
               
               
                   
                   
                 CE_Level_2 
               
               
                   
                   
                 CE_Level_3 
               
               
                   
                   
                 CE_Level_0_1 
               
               
                   
                   
                 CE_Level_2_3 
               
               
                   
                   
                 And so on . . . (all combinations) 
               
               
                   
               
            
           
         
       
     
     As noted above, an overload action IE may include an instruction to reject RRC connection requests for data transmission from UEs with CE support and/or an indication of UEs  101 , using one or more CE levels, to be block. 
     Process  200  may also include determining that MME  121  is no longer overloaded (block  240 ). For example, after providing RAN node  111  with instruction to block UEs  101  at certain CE levels, MME  121  may continue to monitor a load state of MME  121  to determine when MME  121  is no longer overloaded. Determining that MME  121  is no longer overloaded may include one or more operations that are similar to the manner in which MME  121  determined that MME  121  was overloaded. Examples of such operations may include monitoring a number of UEs  101  registered with MME  121 , monitoring a number of UEs  101  operating in a CE mode, monitoring a level of MME activity relating to one or more UEs  101  registered with MME  121 , etc., in addition to comparing such information to one or more load state thresholds. 
     As shown, process  200  may also include providing instruction to RAN node  111  to resume normal operations (block  250 ). For example, upon determining that MME  121  is no longer overloaded, MME  121  may generated and communicate an indication, instructions, etc., for RAN node  111  to resume normal operating condition by, for example, stop blocking UEs  101  of certain CE levels from establishing (and/or reestablishing) connections with RAN node  111 . In some embodiments, MME  121  may provide this information using one or more types of messages and/or IEs. Table 4, below, includes an example an overload stop message IE that may be used by MME  121  to cause RAN node  111  to resume normal operating conditions. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Overload Stop Message Information Element (IE) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 IE type and 
                 Semantics 
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 description 
                 Criticality 
                 Criticality 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Message Type 
                 M 
                   
                 9.2.1.1 
                 YES 
                 reject 
               
               
                 GUMMEI List 
                   
                 0 . . . 1 
                   
                 YES 
                 ignore 
               
               
                 &gt;GUMMEI List 
                   
                 1 . . . &lt;maxnoofMMECs&gt; 
                   
                 EACH 
                 ignore 
               
               
                 Item 
               
               
                 &gt;&gt;GUMMEI 
                 M 
                   
                 9.2.3.9 
                 — 
               
               
                 Overload Stop 
                 O 
                   
                 ENUMERATED 
               
               
                 Cause 
                   
                   
                 Resume RRC 
               
               
                   
                   
                   
                 connection 
               
               
                   
                   
                   
                 request for data 
               
               
                   
                   
                   
                 transmission 
               
               
                   
                   
                   
                 from UE s with 
               
               
                   
                   
                   
                 CE support 
               
               
                 &gt;OverloadCElevel 
                 C 
                   
                 BIT STRING 
               
               
                   
                   
                   
                 (SIZE(16)) 
               
               
                   
                   
                   
                 CE_Level_All 
               
               
                   
                   
                   
                 CE_Level_0 
               
               
                   
                   
                   
                 CE_Level_1 
               
               
                   
                   
                   
                 CE_Level_2 
               
               
                   
                   
                   
                 CE_Level_3 
               
               
                   
                   
                   
                 CE_Level_0_1 
               
               
                   
                   
                   
                 CE_Level_2_3 
               
               
                   
                   
                   
                 . . . so on (all 
               
               
                   
                   
                   
                 combinations) 
               
               
                   
               
            
           
         
       
     
     As noted above, an overload stop message IE may include an instruction to resume accepting and/or responding to RRC connection requests from UEs  101  of previously blocked CE levels and/or to notify UEs  101  of previously blocked CE levels  101  that such UEs  101  are no longer blocked. In some embodiments, the overload stop message IE may indicate that RAN node  111  is to resume normal operating conditions with respect to all CE levels that were previously blocked, while in other embodiments, the overload stop message IE may indicate that only certain CE levels that were previously blocked should no longer be blocked (such that other CE levels previously identified by instructions from MME  121  may continue to be blocked). 
       FIG. 3  is a diagram of an example table  300  of controlling network access for UEs with different CE levels. As shown, example table  300  may include RSRP measurement on a vertical axis and CE levels on a horizontal axis. Additionally, each change in CE level (e.g., CE level 0 to CE level 1, etc.) may include a corresponding entry value (e.g., a first entry value between CE level 0 and CE level 1, etc.) that is associated with a threshold for determining whether RAN node  111  is to block a particular UE  101 . 
     In some embodiments, example table  300  may represent different types of instructions that MME  121  may provide to RAN node  111  about which UEs  101  are to be blocked from obtaining network access. In some embodiments, the instructions from MME  121  to RAN node  111  may include one criteria for blocking UEs  101 . For example, MME  121  may provide RAN node  111  with a single CE level, such that RAN node  111  is to block any UEs  101  operating at the indicated CE level (e.g., level 2) and any inferior CE level (e.g., level 3). In some embodiments, the instructions from MME  121  to RAN node  111  may include one criteria for blocking UEs  101 . For example, the instructions from MME  121  to RAN node  111  may include an indication that UEs  101  to be block include any UE that: 1) is operating at any CE level; and 2) is currently associated with a RSRP measurement below a particular threshold, which may be represented by one of the entry values (the first entry value, second entry value, or third entry value) of example table  300 . Additionally, one or more of the information, show in example table  300 , may be provided by MME  121  using one or more of the message and/or information described herein, and/or by any analogous message and/or IE. 
     In some embodiments, some or all of the information provided in example table  300  may be provided to UE  101 . For example, some or all of the information provided in example table  300  may be broadcasted to UEs  101  as system information, which may include information (e.g., SysteminformationType14) discussed below with reference to Table 10). In some embodiments, for example, the first entry value, second, and third entry value, may correspond to index values in a rsrp-ThresholdsPrachInfoList parameter broadcasted to UEs  101  as system information. Providing UE  101  with such information may enable UE  101  to determine an appropriate CE mode and/or CE level based on a RSRP measured by UE  101 . 
     In some embodiments, the entry values of  FIG. 3  may correspond to values of the index parameter rsrp-ThresholdsPrachInfoList, which may be used by UE  101  to determine a CE level of the UE. For example, UE  101  may determine the CE level for the UE by measuring an RSRP and comparing the measured RSRP with RSRP thresholds associated with different CE levels. As described herein, when the UE receives information from RAN node  111  about which CE levels are blocked (e.g., SysteminformationType14 discussed below with respect to  FIG. 10 ) UE  101  may determine whether it is blocked by comparing the received information with the determined CE level of UE  101 . 
       FIG. 4  is a block diagram of an example process  400  for controlling network access for UEs while MME  121  is overloaded. Process  400  may be implemented by RAN node  111 . In some embodiments, one or more of the operations described in  FIG. 4  may be performed in whole, or in part, by another device described above with reference to  FIG. 1 . 
     As shown, process  400  may include receiving instructions from MME  121  to block UEs  121  based on one or more CE levels (block  410 ). For example, RAN node  111  may receive, from MME  121 , instructions to block one or more UEs  101  of one or more CE levels from establishing a connection with RAN node  111 . In some embodiments, the instructions from MME  121  may correspond to one or more entry values. 
     Process  400  may also include notifying UEs  101  that are to be blocked from connecting to RAN node  111  (block  420 ). For example, based on instructions received from MME  121 , RAN node  111  may notify UEs  101 , within a coverage area of RAN node  111 , regarding UEs  101  that are to be blocked from establishing (and/or reestablishing) a connection with RAN node  111 . In some embodiments, RAN node  111  may notify which UEs  101  are to be blocked by indicating one or more CE levels that are to be blocked. RAN node  111  may use paging message and/or broadcasted system information to notify UEs of CE levels being blocked. RAN node  111  may provide UEs in RRC_CONNECTED state and/or RRC_IDLE state information about CE levels being blocked. 
     In some embodiments, RAN node  111  may notify UEs  101  using one or more types of communications, such as paging message, broadcast message, etc. In some embodiments, RAN node  111  may use a paging message to indicate, to UEs  101 , that system information (e.g., SIBs) for the RAN has changed, which may cause UEs  101  to obtain updated system information from RAN node  111 , and thereby determine which UEs  101  are to be blocked by RAN node  111 . In some embodiments, RAN node  111  may also indicate a duration for which UEs  101  of one or more CE levels are barred from connecting to RAN node  111 . In such embodiments, blocked UEs  101  may refrain from attempting to establish a connection with RAN node  111  for the duration indicated, and at the end of the duration, may attempt to establish a connection with RAN node  111  and/or obtain new system information to determine whether the UE is still barred from connecting with RAN node  111 , and may proceeding accordingly. In some embodiments, UE  101  may also, or alternatively, attempt to connect to another RAN node  111  in response to a notification of being blocked. 
     In some embodiments, RAN node  111  may use one or more IEs in a paging message to indicate which UEs  101  are to be barred by RAN node  111  and/or for how long the UEs  101  are to be barred. An example of such an IE is provided below in Table 5. 
     
       
         
           
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Paging Message IE Indicating Barred Access for Certain UEs 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 aging-v1310-IEs ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   
                 redistributionIndication-r13 
                 ENUMERATED {true} 
                 OPTIONAL,  --Need ON 
               
               
                   
                 systemInfoModification-eDRX-r13 
                 ENUMERATED {true} 
                 OPTIONAL,  -- Need ON 
               
               
                   
                 nonCriticalExtension 
                 Paging-v15xy-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 Paging-v15xy-IEs ::= 
                 SEQUENCE { 
               
               
                  ce-AccessBarNotification-r15 
                 ENUMERATED {ce0, ce1, ce2, ce3, ce0123, ce23, ce13, ce12} 
               
            
           
           
               
               
               
            
               
                   
                 OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
            
               
                  ce-AccessBarDuration-r15 
                 ENUMERATED {10s, 50s, 100s, 500s, 1000s spare, spare, 
               
            
           
           
               
               
            
               
                 spare}  OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
               
               
            
               
                   
                 nonCriticalExtension 
                 SEQUENCE { } 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
               
                   
               
            
           
         
       
     
     A description of certain fields (e.g., ce-AccessBarNotification and ce-AccessBarDuration) represented in the example IE of Table 5 are provided below in Table 6. 
     
       
         
           
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 Examples of certain fields of the Example IE of Table 5 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 ce-AccessBarNotification 
               
               
                 If present: indication of a cell access barring. ce0 may indicate UEs supporting CE level 
               
               
                 zero are barred, ce2e may indicate UEs supporting CE level 2 and CE level 3 are barred, 
               
               
                 and so on. If absent: an indication of release of cell access barring to all UEs supporting 
               
               
                 any CE level. 
               
               
                 ce-AccessBarDuration 
               
               
                 If present: indication of duration of the cell access barring. 10 s may indicate 10 seconds, 
               
               
                 50 s may indicate 50 seconds, and so on. If absent: indication of infinite duration of the cell 
               
               
                 access barring. This field may only be applicable when ce-AccessBarNotification is 
               
               
                 present. 
               
               
                   
               
            
           
         
       
     
     As mentioned above, RAN node  111  may use a paging message to indicate, to UEs  101 , that system information for the RAN has been changed, updated, etc. Such a paging message may cause UEs  101  to obtain the updated system information and/or determine which UEs  101  are to be blocked by RAN node  111 . Additionally, a paging message may include one or more IEs, such as the example IE provided below in Table 7. 
     
       
         
           
               
             
               
                 TABLE 7 
               
               
                   
               
               
                 Paging Message IE Indicating Barred Access for CE level(s) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 Paging-v1310-IEs ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   
                 redistributionIndication-r13 
                 ENUMERATED {true} 
                 OPTIONAL,  --Need ON 
               
               
                   
                 systemInfoModification-eDRX-r13 
                 ENUMERATED {true} 
                 OPTIONAL,  -- Need ON 
               
               
                   
                 nonCriticalExtension 
                 Paging-v15xy-IEs 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 Paging-v15xy-IEs ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   
                 ce-AccessBarNotification-r15 
                 ENUMERATED {TRUE} 
                 OPTIONAL,  -- Need ON 
               
               
                   
                 nonCriticalExtension 
                 SEQUENCE { } 
                 OPTIONAL 
               
            
           
           
               
            
               
                 } 
               
               
                   
               
            
           
         
       
     
     The presence (and/or TRUE status) of the ce-AccessBarNotification field, provided above with respect to Table 7, may indicate to UEs  101  that system information for the RAN has been updated, which may prompt UEs  101  to obtain the updated system information from RAN node  111 . 
     Additionally, or alternatively, one or more bits of Direct Indication information (which may be transmitted via an MTC physical downlink control channel (MPDCCH) using a Paging-Radio Network Temporary Identifier (P-RNTI) but without an associated Paging message) may be used to indicate the CE level baring information (e.g., whether all CE levels are barred, a particular CE level, or all the CE levels greater than a given CE level, etc.). Table 8, provided below, may include an example of Direct Indication signaling, where one or more of bits 6-8 may be used to indicate CE level baring information. 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 Example of Indicating CE Level Barring 
               
               
                 in Direct Indication Information 
               
            
           
           
               
               
            
               
                 Bit 
                 Direct Indication information 
               
               
                   
               
               
                 1 
                 systemInfoModification 
               
               
                 2 
                 etws-Indication 
               
               
                 3 
                 cmas-Indication 
               
               
                 4 
                 eab-ParamModification 
               
               
                 5 
                 systemInfoModification-eDRX 
               
               
                 6, 7, 8 
                 Used for indicating CE level baring information. 
               
               
                 . . . 
               
               
                   
               
            
           
         
       
     
     In some embodiments, one or more of bits 6-8 may be used, dedicate, etc., to indicating whether all CE levels are barred. In some embodiments, bits 6 and 7 may indicate whether all CE levels that are the same, or equal to, a given CE level, are barred. More particularly, bit values 0,0 may indicate that no CE level are barred; bit values 0,1 may indicate that CE levels greater than, or equal to, CE level 0 are barred; bit values 1,0 may indicate that CE levels less than, or equal to, CE level 1 are barred; and bit values 1,1 may indicate that CE levels less than, or equal to, CE level 1 are barred. In some embodiments, bits 6 and 7 may indicate whether all the CE levels, greater than a given CE level, are barred. For example, bit values 0,0 may indicate that no CE levels are barred; bit values 0,1 may indicate that CE levels greater than CE level 0 are barred; bit values 1,0 ma indicate that CE levels greater than CE level 1 are barred, etc. 
     In some embodiments, RAN node  111  may use a Narrowband Physical Downlink Control Channel (NPDCCH) and a P-RNTI to notify certain UEs  101  (e.g., NB-IoT UEs) about UEs blocked by RAN node  111 . Table 9, provided below, includes an example of Direct Indication message bits that may be used to notify UEs about which UEs  101  are being blocked. 
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Example of Direct Indication Bits for Indicating Barred UEs 
               
            
           
           
               
               
            
               
                 Bit 
                 Field in Direct Indication information 
               
               
                   
               
               
                 1 
                 SystemInfoModification 
               
               
                 2 
                 systemInfoModification-Edrx 
               
               
                 3, 4, 5, 
                 Used to indicate barred UEs 
               
               
                 6, 7, 8 
               
               
                   
               
            
           
         
       
     
     In some embodiments, bit 3 may indicate whether all CE levels are barred. In some embodiments, bits 3 and 4 may be used to indicate which UEs  101  or CE levels are barred. For example, bit values 0,0 may indicate that no CE levels are barred; bit values 0,1 may indicate that CE levels other than CE level 0 are barred; bit values 1,0 may indicate that CE levels greater than CE level 0 (e.g., CE level 1, CE level 2, etc.) are to be barred; and so on. 
     Additionally, or alternatively, RAN node  111  may use broadcast messages to indicate CE levels that are to be blocked by RAN node  111 . For example, when RAN node  111  receives a notification indicating that: 1) MME  121  is overloaded; and 2) certain UEs  101  (and/or UEs of certain CE levels) are to be barred, RAN node  111  may broadcast one or more IEs to notify UEs  101  about which UEs  101  are to be blocked. In some embodiments, providing such a notification to blocked UEs  101  may cause blocked UEs  101  to refrain from attempting to establish (and/or re-establish) a connection with RAN node  111  (e.g., via a RRC Connection Request message). In some embodiments, RAN node  111  may schedule, or otherwise use, SystemInformationBlockType14, and/or other SIBs, to provide UEs  101  with such a notification, an example of which is provided below in Table 10. Doing so may notify UEs  101  about the cell access baring information before the UEs send RRC connection request messages, and may therefore cause UEs  101  from not doing so. In some embodiments, RAN node  111  may use SystemInformationBlockType14 for notifying certain types of UEs (e.g., NB-IoT UEs) about being barred. For NB-IoT UEs, ab-Enabled in the MasterinformationBlock-NB may be set to TRUE and SystemInformationBlockType14-NB may be broadcasted. In some embodiments, a SystemInformationBlockType14 for enhanced MTC (eMTC) may be used in a similar way as the SystemInformationBlockType14-NB. 
     
       
         
           
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 Example of SystemInformationBlockType14 with UE Barring Information 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 -- ASN1START 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType14-NB-r13 ::= 
                  SEQUENCE { 
               
               
                  ab-Param-r13 
                  CHOICE { 
               
               
                   ab-Common-r13 
                   AB-Config-NB-r13, 
               
               
                   ab-PerPLMN-List-r13 
                   SEQUENCE (SIZE (1..maxPLMN-r11)) OF AB- 
               
            
           
           
               
            
               
                 ConfigPLMN-NB-r13 
               
            
           
           
               
               
            
               
                  } 
                 OPTIONAL, -- Need OR 
               
            
           
           
               
               
            
               
                  lateNonCriticalExtension 
                  OCTET STRING (CONTAINING AB-Config-NB-r15) 
               
            
           
           
               
            
               
                  OPTIONAL, 
               
               
                  ... 
               
               
                 } 
               
            
           
           
               
               
            
               
                 AB-ConfigPLMN-NB-r13 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
            
               
                  ab-Config-r13 
                  AB-Config-NB-r13 
                 OPTIONAL -- Need OR 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 AB-Config-NB-r13 ::= 
                 SEQUENCE { 
               
               
                  ab-Category-r13 
                  ENUMERATED {a, b, c}, 
               
               
                  ab-BarringBitmap-r13 
                  BIT STRING (SIZE(10)), 
               
            
           
           
               
               
               
               
            
               
                  ab-BarringExceptionData-r13 
                  ENUMERATED {true} 
                 OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
            
               
                  ab-BarringForSpecialAC-r13 
                  BIT STRING (SIZE(5)) 
               
            
           
           
               
            
               
                 } 
               
               
                 AB-Config-NB-r15 ::=SEQUENCE { 
               
            
           
           
               
               
            
               
                  ab-CELevel-r15 
                  ENUMERATED {ce0, ce1, ce2, ce3, ce0123, ce23, ce13, ce12}, 
               
            
           
           
               
            
               
                 OPTIONAL,  -- Need OR 
               
            
           
           
               
               
            
               
                  ab-CELevelDuration-r15 
                  ENUMERATED {10s, 50s, 100s, 500s, 1000s spare, spare, 
               
               
                 spare},   OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
               
            
               
                  lateNonCriticalExtension 
                  OCTET STRING 
                 OPTIONAL, 
               
            
           
           
               
            
               
                 } 
               
               
                 -- ASN1STOP 
               
               
                   
               
            
           
         
       
     
     A description of certain fields (e.g., ab-CELevel and ab-CELevelDuration) represented in the example IE of Table 10 are provided below in Table 11. 
     
       
         
           
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Examples of certain fields of the example IE of Table 10 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 ab-CELevel 
               
               
                 May indicate cell access barring for UE supporting a CE level. ce0 may indicate UEs 
               
               
                 supporting CE level zero are barred, ce23 may indicate UEs supporting CE level 2 and CE 
               
               
                 level 3 are barred, and so on. 
               
               
                 ab-CELevelDuration 
               
               
                 If present: may indicate of duration of the cell access barring. 10 s may indicate 10 seconds, 
               
               
                 50 s may indicate 50 seconds, and so on. If absent: may signify infinite duration of cell 
               
               
                 access barring. This field may be applicable only when ab-CELevel is present. 
               
               
                   
               
            
           
         
       
     
     SystemInformationBlockType14, as described above with respect to Tables 10 and 11, may be examples of an IE that RAN node  111  may provide to a particular type of UE  101  (e.g., NB-IoT UEs). In some embodiments, for other types of UEs  101 , RAN node  111  may use SystemInformationBlockType14 in a different manner, an example of which is provided below in Table 12. 
     
       
         
           
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 Example of SystemInformationBlockType14 with UE Barring Information 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 -- ASN1START 
               
            
           
           
               
               
            
               
                 SystemInformationBlockType14-r11 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 eab-Param-r11 
                 CHOICE { 
               
            
           
           
               
               
               
            
               
                   
                 eab-Common-r11 
                 EAB-Config-r11, 
               
               
                   
                 eab-PerPLMN-List-r11 
                 SEQUENCE (SIZE (1..maxPLMN-r11)) OF 
               
            
           
           
               
            
               
                 EAB-ConfigPLMN-r11 
               
            
           
           
               
               
               
            
               
                   
                 } 
                 OPTIONAL, -- Need OR 
               
            
           
           
               
               
               
            
               
                   
                 lateNonCriticalExtension 
                 OCTET STRING (CONTAINING AB-Config-r15) 
               
            
           
           
               
               
            
               
                   
                 OPTIONAL, 
               
               
                   
                 ... 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 EAB-ConfigPLMN-r11 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
               
            
               
                   
                 eab-Config-r11 
                 EAB-Config-r11 
                 OPTIONAL -- Need OR 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 EAB-Config-r11 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 eab-Category-r11 
                 ENUMERATED {a, b, c}, 
               
               
                   
                 eab-BarringBitmap-r11 
                 BIT STRING (SIZE (10)) 
               
            
           
           
               
            
               
                 } 
               
            
           
           
               
               
            
               
                 AB-Config-r15 ::= 
                 SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 ab-CELevel-r15 
                 ENUMERATED {ce0, ce1, ce2, ce3, ce0123, ce23, 
               
            
           
           
               
               
            
               
                 ce13, ce12},  OPTIONAL, 
                 -- Need OR 
               
            
           
           
               
               
            
               
                 ab-CELevelDuration-r15 
                 ENUMERATED {10s, 50s, 100s, 
               
            
           
           
               
               
               
            
               
                 500s, 1000s spare, spare, spare }, 
                 OPTIONAL, 
                 -- Need OP 
               
            
           
           
               
               
               
               
            
               
                   
                 lateNonCriticalExtension 
                 OCTET STRING 
                 OPTIONAL, 
               
            
           
           
               
            
               
                 } 
               
               
                 -- ASN1STOP 
               
               
                   
               
            
           
         
       
     
     A description of certain fields (e.g., ab-CELevel and ab-CELevelDuration) represented in the example IE of Table 10 are provided below in Table 13. 
     
       
         
           
               
             
               
                 TABLE 13 
               
               
                   
               
               
                 Examples of certain fields of the example IE of Table 12 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 ab-CELevel 
               
               
                 May indicate cell access barring for UE supporting a CE level. ce0 may indicate UEs 
               
               
                 supporting CE level zero are barred, ce23 may indicate UEs supporting CE level 2 and CE 
               
               
                 level 3 are barred, and so on. 
               
               
                 ab-CELevelDuration 
               
               
                 If present: may indicate of duration of the cell access barring. 10 s may indicate 10 seconds, 
               
               
                 50 s may indicate 50 seconds, and so on. If absent: may signify infinite duration of cell 
               
               
                 access barring. This field may be applicable only when ab-CELevel is present. 
               
               
                   
               
            
           
         
       
     
     Referring to  FIG. 4 , process  400  may include barring one or more UEs  101  from connecting (and/or reconnecting) with RAN node  111  (block  430 ). For example, based on instructions received from MME  121 , RAN node  111  may bar, block, prevent, etc., one or more UEs  101  from establishing a connection (and/or reconnecting) with RAN node  111 . In some embodiments, the instructions form MME  121  may pertain to one or more types of UEs  101  (e.g., broadband UEs, NB-IoTs, etc.). Additionally, or alternatively, the instructions may pertain only to UEs  101  operating in a particular mode (e.g., an idle mode). For instance, based on the instructions from MME  121 , RAN node  111  may block, ignore, etc., subsequent connections requests from UEs  101  of the temporarily prohibited CE level(s) identified by MME  121 ; however, RAN node  111  may not interrupt, discontinue, etc., current and active connections with UEs  101  regardless of a CE level corresponding to the UE. 
     As noted above, the instructions from MME  121  may pertain to blocking UEs  101  based on one criteria (e.g., UEs  101  operating in one or more CE levels specified by MME  121 ). Additionally, or alternatively, the instruction may pertain to blocking UEs  101  based one multiple criterium (e.g., UEs  101  that: 1) are operating in a CE mode; and 2) are associated with a measured RSRP below a particular signaling threshold. Examples of such scenarios are discussed above with reference to  FIG. 3 . 
     In time, RAN node  11  may receive a notification that MME  121  is not overloaded, and in response thereto, may resume normal operating conditions (block  440 ). For example, when MME  121  is no longer overloaded, MME  121  may notify, send instructions to, etc., RAN node  111  to indicate that MME  121  is no longer overloaded. The information from MME  121  may also, or alternatively, include instructions from RAN node  111  to resume normal operating conditions (e.g., by discontinuing the barring of certain UEs  101 ). As such, upon receiving an indication that MME  121  is not overloaded, and or instructions corresponding thereto, RAN node  111  may resume normal operating conditions by, for example, permitting barred UEs  101  to connection to RAN node  111 . 
       FIG. 5  is a sequence flow diagram of an example process for managing MME  121  overload scenarios by controlling network access for UEs  101 . As shown, the example of  FIG. 3  may include UE  101 , RAN node  111 , and MME  121 . The example of  FIG. 5  is provided as a non-limiting example. In practice, the example of  FIG. 5  may include fewer, additional, alternative, operations or functions. Additionally, one or more of the operations or functions of  FIG. 5  may be performed by fewer, additional, or alternative devices, which may include one or more of the devices described above with reference to  FIG. 1 . 
     As shown, as MME  121  operates under normal condition, MME  121  may monitor a level of activity of MME  121 . At some point, MME  121  may determine that MME  121  is overloaded (at  510 ) which may be based on one or more a variety of factors, such as a number of UEs  101  registered with MME  121 , a current mode of operation (e.g., active, idle, etc.) of UEs  101  registered with MME  121 , a quantity and activity level of certain types of UEs  101  (e.g. broadband UEs, narrowband UEs, IoT devices, MTC device, etc.), a number of UEs  101  in one or more CE modes and/or CE levels, a quantity of one or more resources (e.g., processing resources, memory resources, communication resources, etc.) available to MME  121 , etc. 
     In response to determining that MME  121  is overloaded, MME  121  may determine UEs  101  (and/or CE levels) to be barred from establishing a connection with RAN node  111  (at  520 ). In some embodiments, MME  121  may also, or alternative, determine UEs  101  to be barred by determining which CE levels to bar from accessing RAN node  111 , and by extension, determine UEs  101  to be barred. In some embodiments MME  121  may determine which UEs  101  (and/or CE levels) to bar based on one or more factors, which may include, be a result of, or otherwise relate to, one or more of the conditions that has contributed to MME  121  becoming overloaded (e.g., a quantity, activity level, and/or operational mode (e.g., active mode, idle mode, etc.) of one or more types of UEs  101  registered with MME  121 ). 
     As shown, MME  121  may communicate instructions to RAN node  111  to bar, block, reject, etc., connection requests from certain UEs  101  (e.g., UEs  101  corresponding to one or more CE levels indicated by the instructions) (at  530 ) and in response, RAN node  111  may proceed to block such communications from UEs  101  accordingly (at  540 ). Based on the instructions from MME  121 , RAN node  111  may block connections requests from UEs  101  and/or bar UEs  101  from otherwise accessing the cell. In some embodiments, RAN node  111  may also, or alternately, notify one or more UEs  101  about being barred (at  550 ). As described above, RAN node  111  may notify UEs  101  using a paging or broadcast, which may involve one or more of a variety of IEs. This notification may be broadcasted to UEs  101  as system information. 
     In response, each UE  101  may determine whether the UE is barred from connecting (and/or reconnecting) with RAN node  111  (at  560 ). For example, UE  111  may measure an RSRP and compare the measured RSRP to thresholds (e.g., entry value 1, entry value 2, entry value 3, described above with reference to  FIG. 3 ) to determine a CE level of UE  111 . UE  111  may then determine, based on the system information from RAN node  111  (e.g., SysteminformationType14, described above with reference to Table 10) whether the CE level of UE  111  is barred). If UE  101  is blocked, UE  101  may respond by refraining from attempting to connect (and/or reconnect) with RAN node  111  for a period of time (which may also be indicated in the system information or otherwise). At some point, MME  121  may determine that MME  121  is no longer overloaded (at  570 ). In response, MME  121  may contact RAN node  111  about change in status, which may include one or more RRC messages with instructions for RAN node  111  to return to normal operating conditions by, for example, no longer blocking connection requests from UEs  101 , broadcasting updated system information to UEs  101  (about not blocking CE levels), and/or accepting RRC connection requests from UEs  101  (at  580 ). In some embodiments, RAN node  111  may send paging messages to UEs  101  previous blocked to notify UEs  101  to obtain new system information broadcasted by RAN node  111 , which (per the instructions from MME  121 ) may indicate to the UEs  101  that they are no longer blocked (e.g., that the CE level of the UEs  101  is no longer blocked) such that the UEs  101  may establish a connection with the RAN node  121 . 
       FIG. 6  illustrates example components of a device  600  in accordance with some embodiments. In some embodiments, the device  600  may include application circuitry  602 , baseband circuitry  604 , Radio Frequency (RF) circuitry  606 , front-end module (FEM) circuitry  608 , one or more antennas  610 , and power management circuitry (PMC)  612  coupled together at least as shown. The components of the illustrated device  600  may be included in a UE or a RAN node. In some embodiments, the device  600  may include less elements (e.g., a RAN node may not utilize application circuitry  602 , and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device  600  may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations). 
     The application circuitry  602  may include one or more application processors. For example, the application circuitry  602  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the device  600 . In some embodiments, processors of application circuitry  602  may process IP data packets received from an EPC. 
     The baseband circuitry  604  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry  604  may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry  606  and to generate baseband signals for a transmit signal path of the RF circuitry  606 . Baseband processing circuity  604  may interface with the application circuitry  602  for generation and processing of the baseband signals and for controlling operations of the RF circuitry  606 . For example, in some embodiments, the baseband circuitry  604  may include a third generation (3G) baseband processor  604 A, a fourth generation (4G) baseband processor  604 B, a fifth generation (5G) baseband processor  604 C, or other baseband processor(s)  604 D for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), si6h generation (6G), etc.). The baseband circuitry  604  (e.g., one or more of baseband processors  604 A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry  606 . In other embodiments, some or all of the functionality of baseband processors  604 A-D may be included in modules stored in the memory  604 G and executed via a Central Processing Unit (CPU)  604 E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry  604  may include Fast-Fourier Transform (FFT), preceding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry  604  may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. 
     In some embodiments, the baseband circuitry  604  may include one or more audio digital signal processor(s) (DSP)  604 F. The audio DSP(s)  604 F may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry  604  and the application circuitry  602  may be implemented together such as, for example, on a system on a chip (SOC). 
     In some embodiments, the baseband circuitry  604  may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry  604  may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry  604  is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. 
     RF circuitry  606  may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry  606  may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry  606  may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry  608  and provide baseband signals to the baseband circuitry  604 . RF circuitry  606  may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry  604  and provide RF output signals to the FEM circuitry  608  for transmission. 
     In some embodiments, the receive signal path of the RF circuitry  606  may include mixer circuitry  606   a , amplifier circuitry  606   b  and filter circuitry  606   c . In some embodiments, the transmit signal path of the RF circuitry  606  may include filter circuitry  606   c  and mixer circuitry  606   a . RF circuitry  606  may also include synthesizer circuitry  606   d  for synthesizing a frequency for use by the mixer circuitry  606   a  of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry  606   a  of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry  608  based on the synthesized frequency provided by synthesizer circuitry  606   d . The amplifier circuitry  606   b  may be configured to amplify the down-converted signals and the filter circuitry  606   c  may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry  604  for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry  606   a  of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  606   a  of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry  606   d  to generate RF output signals for the FEM circuitry  608 . The baseband signals may be provided by the baseband circuitry  604  and may be filtered by filter circuitry  606   c.    
     In some embodiments, the mixer circuitry  606   a  of the receive signal path and the mixer circuitry  606   a  of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry  606   a  of the receive signal path and the mixer circuitry  606   a  of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry  606   a  of the receive signal path and the mixer circuitry  606   a  may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry  606   a  of the receive signal path and the mixer circuitry  606   a  of the transmit signal path may be configured for super-heterodyne operation. 
     In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry  606  may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry  604  may include a digital baseband interface to communicate with the RF circuitry  606 . 
     In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the synthesizer circuitry  606   d  may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry  606   d  may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. 
     The synthesizer circuitry  606   d  may be configured to synthesize an output frequency for use by the mixer circuitry  606   a  of the RF circuitry  606  based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry  606   d  may be a fractional N/N+1 synthesizer. 
     In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry  604  or the applications processor  602  depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor  602 . 
     Synthesizer circuitry  606   d  of the RF circuitry  606  may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. 
     In some embodiments, synthesizer circuitry  606   d  may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry  606  may include an IQ/polar converter. 
     FEM circuitry  608  may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas  610 , amplify the received signals and provide the amplified versions of the received signals to the RF circuitry  606  for further processing. FEM circuitry  608  may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry  606  for transmission by one or more of the one or more antennas  610 . In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry  606 , solely in the FEM  608 , or in both the RF circuitry  606  and the FEM  608 . 
     In some embodiments, the FEM circuitry  608  may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry  606 ). The transmit signal path of the FEM circuitry  608  may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry  606 ), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas  610 ). 
     In some embodiments, the PMC  612  may manage power provided to the baseband circuitry  604 . In particular, the PMC  612  may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC  612  may often be included when the device  600  is capable of being powered by a battery, for example, when the device is included in a UE. The PMC  612  may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics. 
     While  FIG. 6  shows the PMC  612  coupled only with the baseband circuitry  604 . However, in other embodiments, the PMC  6   12  may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry  602 , RF circuitry  606 , or FEM  608 . 
     In some embodiments, the PMC  612  may control, or otherwise be part of, various power saving mechanisms of the device  600 . For example, if the device  600  is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device  600  may power down for brief intervals of time and thus save power. 
     If there is no data traffic activity for a period of time, then the device  600  may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device  600  goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device  600  may not receive data in this state, in order to receive data, it must transition back to RRC_Connected state. 
     An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable. 
     Processors of the application circuitry  602  and processors of the baseband circuitry  604  may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry  604 , alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry  604  may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below. 
       FIG. 7  illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry  604  of  FIG. 6  may comprise processors  604 A- 604 E and a memory  604 G utilized by said processors. Each of the processors  604 A- 604 E may include a memory interface,  704 A- 704 E, respectively, to send/receive data to/from the memory  604 G. 
     The baseband circuitry  604  may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface  712  (e.g., an interface to send/receive data to/from memory external to the baseband circuitry  604 ), an application circuitry interface  714  (e.g., an interface to send/receive data to/from the application circuitry  602  of  FIG. 6 ), an RF circuitry interface  716  (e.g., an interface to send/receive data to/from RF circuitry  606  of  FIG. 6 ), a wireless hardware connectivity interface  718  (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface  720  (e.g., an interface to send/receive power or control signals to/from the PMC  612 . 
       FIG. 8  is an illustration of a control plane protocol stack in accordance with some embodiments. In this embodiment, a control plane  800  is shown as a communications protocol stack between the UE  101  (or alternatively, the UE  102 ), the RAN node  111  (or alternatively, the RAN node  112 ), and the MME  121 . 
     The PHY layer  801  may transmit or receive information used by the MAC layer  802  over one or more air interfaces. The PHY layer  801  may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC layer  805 . The PHY layer  801  may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and Multiple Input Multiple Output (MIMO) antenna processing. 
     The MAC layer  802  may perform mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) from one or more logical channels onto transport blocks (TB) to be delivered to PHY via transport channels, de-multiplexing MAC SDUs to one or more logical channels from transport blocks (TB) delivered from the PHY via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), and logical channel prioritization. 
     The RLC layer  803  may operate in a plurality of modes of operation, including: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer  803  may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC layer  803  may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment. 
     The PDCP layer  804  may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.). 
     The main services and functions of the RRC layer  805  may include broadcast of system information (e.g., included in Master Information Blocks (MIBs) or System Information Blocks (SIBs) related to the non-access stratum (NAS)), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting. Said MIBs and SIBs may comprise one or more information elements (IEs), which may each comprise individual data fields or data structures. 
     The UE  101  and the RAN node  111  may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack comprising the PHY layer  801 , the MAC layer  802 , the RLC layer  803 , the PDCP layer  804 , and the RRC layer  805 . 
     The non-access stratum (NAS) protocols  806  form the highest stratum of the control plane between the UE  101  and the MME  121 . The NAS protocols  806  support the mobility of the UE  101  and the session management procedures to establish and maintain IP connectivity between the UE  101  and the P-GW  123 . 
     The S1 Application Protocol (S1-AP) layer  815  may support the functions of the S1 interface and comprise Elementary Procedures (EPs). An EP is a unit of interaction between the RAN node  111  and the CN  120 . The S1-AP layer services may comprise two groups: UE-associated services and non UE-associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer. 
     The Stream Control Transmission Protocol (SCTP) layer (alternatively referred to as the SCTP/IP layer)  814  may ensure reliable delivery of signaling messages between the RAN node  111  and the MME  121  based, in part, on the IP protocol, supported by the IP layer  813 . The L2 layer  812  and the L1 layer  811  may refer to communication links (e.g., wired or wireless) used by the RAN node and the MME to exchange information. 
     The RAN node  111  and the MME  121  may utilize an S1-MME interface to exchange control plane data via a protocol stack comprising the L1 layer  811 , the L2 layer  812 , the IP layer  813 , the SCTP layer  814 , and the S1-AP layer  815 . 
       FIG. 9  is an illustration of a user plane protocol stack in accordance with some embodiments. In this embodiment, a user plane  900  is shown as a communications protocol stack between the UE  101  (or alternatively, the UE  102 ), the RAN node  111  (or alternatively, the RAN node  112 ), the S-GW  122 , and the P-GW  123 . The user plane  900  may utilize at least some of the same protocol layers as the control plane  800 . For example, the UE  101  and the RAN node  111  may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange user plane data via a protocol stack comprising the PHY layer  801 , the MAC layer  802 , the RLC layer  803 , the PDCP layer  804 . 
     The General Packet Radio Service (GPRS) Tunneling Protocol for the user plane (GTP-U) layer  904  may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. The UDP and IP security (UDP/IP) layer  903  may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication on the selected data flows. The RAN node  111  and the S-GW  122  may utilize an S1-U interface to exchange user plane data via a protocol stack comprising the L1 layer  811 , the L2 layer  812 , the UDP/IP layer  903 , and the GTP-U layer  904 . The S-GW  122  and the P-GW  123  may utilize an S5/S8a interface to exchange user plane data via a protocol stack comprising the L1 layer  811 , the L2 layer  812 , the UDP/IP layer  903 , and the GTP-U layer  904 . As discussed above with respect to  FIG. 8 , NAS protocols support the mobility of the UE  101  and the session management procedures to establish and maintain IP connectivity between the UE  101  and the P-GW  123 . 
       FIG. 10  illustrates components of a core network in accordance with some embodiments. The components of the CN  120  may be implemented in one physical node or separate physical nodes including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments, Network Functions Virtualization (NFV) is utilized to virtualize any or all of the above described network node functions via executable instructions stored in one or more computer readable storage mediums (described in further detail below). A logical instantiation of the CN  120  may be referred to as a network slice  1001 . A logical instantiation of a portion of the CN  120  may be referred to as a network sub-slice  1002  (e.g., the network sub-slice  1102  is shown to include the PGW  123  and the PCRF  126 ). 
     NFV architectures and infrastructures may be used to virtualize one or more network functions, alternatively performed by proprietary hardware, onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches. In other words, NFV systems can be used to execute virtual or reconfigurable implementations of one or more EPC components/functions. 
       FIG. 11  is a block diagram illustrating components, according to some example embodiments, of a system  1100  to support NFV. The system  1100  is illustrated as including a virtualized infrastructure manager (VIM)  1102 , a network function virtualization infrastructure (NFVI)  1104 , a VNF manager (VNFM)  1106 , virtualized network functions (VNFs)  1108 , an element manager (EM)  1110 , an NFV Orchestrator (NFVO)  1112 , and a network manager (NM)  1114 . 
     The VIM  1102  manages the resources of the NFVI  1104 . The NFVI  1104  can include physical or virtual resources and applications (including hypervisors) used to execute the system  1100 . The VIM  1102  may manage the life cycle of virtual resources with the NFVI  1104  (e.g., creation, maintenance, and tear down of virtual machines (VMs) associated with one or more physical resources), track VM instances, track performance, fault and security of VM instances and associated physical resources, and expose VM instances and associated physical resources to other management systems. 
     The VNFM  1106  may manage the VNFs  1108 . The VNFs  1108  may be used to execute EPC components/functions. The VNFM  1106  may manage the life cycle of the VNFs  1108  and track performance, fault and security of the virtual aspects of VNFs  1108 . The EM  1110  may track the performance, fault and security of the functional aspects of VNFs  1108 . The tracking data from the VNFM  1106  and the EM  1110  may comprise, for example, performance measurement (PM) data used by the VIM  1102  or the NFVI  1104 . Both the VNFM  1106  and the EM  1110  can scale up/down the quantity of VNFs of the system  1100 . 
     The NFVO  1112  may coordinate, authorize, release and engage resources of the NFVI  1104  in order to provide the requested service (e.g., to execute an EPC function, component, or slice). The NM  1114  may provide a package of end-user functions with the responsibility for the management of a network, which may include network elements with VNFs, non-virtualized network functions, or both (management of the VNFs may occur via the EM  1110 ). 
       FIG. 12  is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,  FIG. 12  shows a diagrammatic representation of hardware resources  1200  including one or more processors (or processor cores)  1210 , one or more memory/storage devices  1220 , and one or more communication resources  1230 , each of which may be communicatively coupled via a bus  1240 . For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor  1202  may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources  1200   
     The processors  1210  (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor  1212  and a processor  1214 . 
     The memory/storage devices  1220  may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices  1220  may include, but are not limited to any type of volatile or non-volatile memory such as dynamic random access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc. 
     The communication resources  1230  may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices  1204  or one or more databases  1206  via a network  1208 . For example, the communication resources  1230  may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components. 
     Instructions  1250  may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors  1210  to perform any one or more of the methodologies discussed herein. The instructions  1250  may reside, completely or partially, within at least one of the processors  1210  (e.g., within the processor&#39;s cache memory), the memory/storage devices  1220 , or any suitable combination thereof. Furthermore, any portion of the instructions  1250  may be transferred to the hardware resources  1200  from any combination of the peripheral devices  1204  or the databases  1206 . Accordingly, the memory of processors  1210 , the memory/storage devices  1220 , the peripheral devices  1204 , and the databases  1206  are examples of computer-readable and machine-readable media. 
     A number of examples, relating to embodiments of the techniques described above, will next be given. 
     In a first example, an apparatus of a Mobility Management Entity (MME) may comprise: a storage device configured to store one or more instructions; and one or more processors configured to execute the one or more instruction to: detect that the MME is overloaded; determine at least one Coverage Enhancement (CE) level of User Equipment (UEs) to bar from connecting with a Radio Access Network (RAN) node; and cause instructions, to be communicated to the RAN node, to block UEs of the at least one CE from establishing connections with the RAN. 
     In example 2, the subject matter of example 1, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level include instructions to for the RAN node to reject Radio Resource Control (RRC) requests from UEs of the at least one CE level. 
     In example 3, the subject matter of example 1, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     In example 4, the subject matter of example 1, or any of the examples herein, wherein the one or more processors are further to: monitor a load status of the MME; determine that the MME is not overloaded; and notify the RAN node that the UEs of the at least one CE level are not to be blocked from establishing connection with the RAN. 
     In example 5, the subject matter of example 1, or any of the examples herein, wherein a CE level of a UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     In a sixth example, an apparatus of a Radio Access Network (RAN) node may comprise an interface to radio frequency (RF) circuitry; and one or more processors that are controlled to: process instructions, received from a Mobility Management Entity (MME), to block UEs of at least one Coverage Enhancement (CE) level from establishing a connection with the RAN node; and cause system information to be broadcasted, via the interface to radio frequency (RF) circuitry, indicating that the at least one CE level is blocked. 
     In example 7, the subject matter of example 6, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14 Information Element (IE) for enhanced Machine-Type-Communication (eMTC) indicating the at least one CE level. 
     In example 8, the subject matter of example 6, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14-NB Information Element (IE) for Narrowband Internet-of-Things (NB-IoT) devices indicating the at least one CE level. 
     In example 9, the subject matter of example 6, or any of the examples herein, wherein the at least one CE level includes all CE levels that UEs may use to communicate with the RAN node. 
     In example 10, the subject matter of example 6, or any of the examples herein, wherein the one or more processors are further to: process instructions from the MME to discontinue blocking UEs of the at least one CE level; and update the system information broadcasted by the RAN node to indicate that the UEs of the at least one CE level are no longer being blocked by the RAN node 
     In an eleventh example, an apparatus of a User Equipment (UE) may comprise an interface to radio frequency (RF) circuitry; and one or more processors that are controlled to: receive, via the interface to the RF circuitry, system information, from a Radio Access Network (RAN) node, that UEs of at least one CE level are being blocked from establishing a connection with the RAN node; determine a measured Reference Signal Received Power (RSRP) of the UE; determine a CE level of the UE based on the measured RSRP of the UE; determine that the UE is blocked from establishing a connection with the RAN node by comparing the CE level of the UE to the at least one CE level; and refrain from attempting to establish a connection with the RAN node. 
     In example 12, the subject matter of example 11, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14 Information Element (IE) indicating the at least one CE level. 
     In example 13, the subject matter of example 11, or any of the examples herein, wherein the one or more processors are further controlled to: receive, via the interface to the RF circuitry, a notification that UEs of the at least one CE level are not being blocked from establishing a connection with the RAN node; and cause, via the interface to the RF circuitry, a connection to be established with the RAN node. 
     In a fourteenth example, a computer-readable medium containing program may include instructions for causing one or more processors, associated with a Mobility Management Entity (MME), to: detect that the MME is overloaded; determine at least one Coverage Enhancement (CE) level of User Equipment (UEs) to bar from connecting with a Radio Access Network (RAN) node; and cause instructions, to be communicated to the RAN node, to block UEs of the at least one CE from establishing connections with the RAN. 
     In example 15, the subject matter of example 14, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level include instructions to for the RAN node to reject Radio Resource Control (RRC) requests from UEs of the at least one CE level. 
     In example 16, the subject matter of example 14, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     In example 17, the subject matter of example 14, or any of the examples herein, wherein the one or more processors are further to: monitor a load status of the MME; determine that the MME is not overloaded; and notify the RAN node that the UEs of the at least one CE level are not to be blocked from establishing connection with the RAN. 
     In example 18, the subject matter of example 14, or any of the examples herein, wherein a CE level of a UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     In a nineteenth example, a computer-readable medium containing program may include instructions for causing one or more processors, associated with a Radio Access Network (RAN) node, to: process instructions, received from a Mobility Management Entity (MME), to block UEs of at least one Coverage Enhancement (CE) level from establishing a connection with the RAN node; and cause system information to be broadcasted, via the interface to radio frequency (RF) circuitry, indicating that the at least one CE level is blocked. 
     In example 20, the subject matter of example 19, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14 Information Element (IE) for enhanced Machine-Type-Communication (eMTC) indicating the at least one CE level. 
     In example 21, the subject matter of example 19, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14-NB Information Element (IE) for Narrowband Internet-of-Things (NB-IoT) devices indicating the at least one CE level. 
     In example 22, the subject matter of example 19, or any of the examples herein, wherein the at least one CE level includes all CE levels that UEs may use to communicate with the RAN node. 
     In example 23, the subject matter of example 19, or any of the examples herein, wherein the one or more processors are further to: process instructions from the MME to discontinue blocking UEs of the at least one CE level; and update the system information broadcasted by the RAN node to indicate that the UEs of the at least one CE level are no longer being blocked by the RAN node. 
     In a twenty-fourth example, a computer-readable medium containing program may include instructions for causing one or more processors, associated with a User Equipment (UE), to: receive, via the interface to the RF circuitry, system information, from a Radio Access Network (RAN) node, that UEs of at least one CE level are being blocked from establishing a connection with the RAN node; determine a measured Reference Signal Received Power (RSRP) of the UE; determine a CE level of the UE based on the measured RSRP of the UE; determine that the UE is blocked from establishing a connection with the RAN node by comparing the CE level of the UE to the at least one CE level; and refrain from attempting to establish a connection with the RAN node. 
     In example 25, the subject matter of example 24, or any of the examples herein, wherein the system information includes a SystemInformationBlockType14 Information Element (IE) indicating the at least one CE level. 
     In example 26, the subject matter of example 24, or any of the examples herein, wherein the one or more processors are further controlled to: receive a notification that UEs of the at least one CE level are not being blocked from establishing a connection with the RAN node; and cause a connection to be established with the RAN node. 
     In a twenty-seventh example, an apparatus of a Mobility Management Entity (MME), may comprise: means for detecting that the MME is overloaded; means for determining means for at least one Coverage Enhancement (CE) level of User Equipment (UEs) to bar from connecting with a Radio Access Network (RAN) node; and means for causing instructions, to be communicated to the RAN node, to block UEs of the at least one CE from establishing connections with the RAN. 
     In example 28, the subject matter of example 27, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level include instructions to for the RAN node to reject Radio Resource Control (RRC) requests from UEs of the at least one CE level. 
     In example 29, the subject matter of example 27, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     In example 30, the subject matter of example 27, or any of the examples herein, further comprising: means for monitoring a load status of the MME; means for determining that the MME is not overloaded; and means for notifying the RAN node that the UEs of the at least one CE level are not to be blocked from establishing connection with the RAN 
     In example 31, the subject matter of example 27, or any of the examples herein, wherein a CE level of a UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     In a thirty-second example, method, performed by an apparatus of an Mobility Management Entity (MME), may comprise: detecting that the MME is overloaded; determining means for at least one Coverage Enhancement (CE) level of User Equipment (UEs) to bar from connecting with a Radio Access Network (RAN) node; and causing instructions, to be communicated to the RAN node, to block UEs of the at least one CE from establishing connections with the RAN. 
     In example 33, the subject matter of example 1, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level include instructions to for the RAN node to reject Radio Resource Control (RRC) requests from UEs of the at least one CE level. 
     In example 34, the subject matter of example 32, or any of the examples herein, wherein the instructions for the RAN node to block UEs of the at least one CE level cause the RAN node to broadcast system information indicating that cell access to the at least one CE level is blocked. 
     In example 35, the subject matter of example 33, or any of the examples herein, further comprising: monitoring a load status of the MME; determining that the MME is not overloaded; and notifying the RAN node that the UEs of the at least one CE level are not to be blocked from establishing connection with the RAN. 
     In example 36, the subject matter of example 34, or any of the examples herein, wherein a CE level of a UE is based on a measured Reference Signal Received Power (RSRP) of the UE. 
     In the preceding specification, various embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. 
     For example, while series of signals and/or operations have been described with regard to  FIGS. 2, 4, and 5  the order of the signals/operations may be modified in other implementations. Further, non-dependent signals may be performed in parallel. 
     It will be apparent that example aspects, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement these aspects should not be construed as limiting. Thus, the operation and behavior of the aspects were described without reference to the specific software code—it being understood that software and control hardware could be designed to implement the aspects based on the description herein. 
     Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to be limiting. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. 
     No element, act, or instruction used in the present application should be construed as critical or essential unless explicitly described as such. An instance of the use of the term “and,” as used herein, does not necessarily preclude the interpretation that the phrase “and/or” was intended in that instance. Similarly, an instance of the use of the term “or,” as used herein, does not necessarily preclude the interpretation that the phrase “and/or” was intended in that instance. Also, as used herein, the article “a” is intended to include one or more items, and may be used interchangeably with the phrase “one or more.” Where only one item is intended, the terms “one,” “single,” “only,” or similar language is used.

Metadata:
Filing Date: 20180622
Publication Date: 20220329
Grant Date: 20220329
Priority Date: 20170622
Inventors: KEDALAGUDDE, MEGHASHREE DATTATRI
JAIN, PUNEET
SHRESTHA, BHARAT
MARTINEZ TARRADELL, Marta
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W4/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W48/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W4/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/70", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 62909630