PATENT DOCUMENT

Publication Number: US-10904945-B2
Application Number: US-201816157715-A
Country: US
Kind Code: B2

Title: Reduced signaling associated with activation and deactivation of a mode of operation of a mobile device

Abstract:
A device and method for a user equipment (UE) to reduce signaling with a network by conditionally barring the transmission of a particular signal to the network. The UE determines that a first predetermined condition related to radio conditions between the UE and the first cell is satisfied. The UE determines whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition. The first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN). The second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN.

Claims:
What is claimed: 
     
       1. A method, comprising:
 at a user equipment (UE) configured to camp on a first cell to establish a connection to a first network:
 determining a first predetermined condition related to radio conditions between the UE and the first cell is satisfied; and 
 determining whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition, wherein the first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN) and the second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN, the second predetei mined condition relating to a number of times the signal that is intended to cause the release of the bearer between the UE and the PDN was previously transmitted. 
 
 
     
     
       2. The method of  claim 1 , further comprising:
 when the second mode of operation is activated, setting a timer to a predetermined duration; 
 determining whether a third predetermined condition is satisfied; and 
 when the third predetermined condition is satisfied, deactivating the second mode of operation. 
 
     
     
       3. The method of  claim 2 , wherein the third predetermined condition is related to whether the predetermined duration of the timer has expired. 
     
     
       4. The method of  claim 2 , wherein the third predetermined condition is related to whether measurement data corresponding to the first cell satisfies a predetermined threshold. 
     
     
       5. The method of  claim 2 , wherein the third predetermined condition is related to whether a cell reselection from the first cell to a second cell has occurred. 
     
     
       6. The method of  claim 5 , wherein the third predetermined condition is related to whether measurement data corresponding to the second cell satisfies a predetermined threshold. 
     
     
       7. The method of  claim 2 , wherein deactivating the second mode of operations comprises sending an IP multimedia subsystem (IMS) reregistration message. 
     
     
       8. The method of  claim 1 , wherein the first predetermined condition includes at least one of a measurement data threshold and a transmission parameter threshold. 
     
     
       9. The method of  claim 1 , wherein the second predetermined condition relates to the number of times the signal that is intended to cause the release of the bearer between the UE and the PDN has been transmitted within a predetermined duration. 
     
     
       10. The method of  claim 1 , wherein barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN is based on preventing a baseband processor of the UE from transmitting the signal to the network. 
     
     
       11. The method of  claim 1 , wherein the signal that is intended to cause the release of the bearer between the UE and the PDN comprises one of a PDN disconnect request or an IP multimedia subsystem (IMS) deregistration message. 
     
     
       12. A user equipment (UE), comprising:
 a transceiver configured to establish a connection to a first network via a first cell; and 
 a processor configured to perform operations comprising:
 determine a first predetermined condition related to radio conditions between the UE and the first cell is satisfied; and 
 determine whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition, wherein the first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN) and the second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN, the second predetermined condition relating to a number of times the signal that is intended to cause the release of the bearer between the UE and the PDN was previously transmitted. 
 
 
     
     
       13. The UE of  claim 12 , wherein the first predetermined condition includes at least one of a measurement data threshold and a transmission parameter threshold. 
     
     
       14. The UE of  claim 12 , wherein the second predetermined condition relates to the number of times the signal that is intended to cause the release of the bearer between the UE and the PDN has been transmitted within a predetermined duration. 
     
     
       15. The method of  claim 12 , the operations further comprising:
 when the second mode of operation is activated, set a timer to a predetermined duration; 
 determine whether a third predetermined condition is satisfied; and 
 when the third predetermined condition is satisfied, deactivate the second mode of operation. 
 
     
     
       16. The method of  claim 15 , wherein deactivating the second mode of operation includes transmitting a IP multimedia subsystem (IMS) reregistration message. 
     
     
       17. The method of  claim 15 , wherein the third predetermined condition is related to whether the UE is to connect to the first network via a second cell and whether measurement data corresponding to the second cell satisfies a predetermined threshold. 
     
     
       18. The method of  claim 15 , wherein the third predetermined condition is related to whether the predetermined duration of the timer has expired. 
     
     
       19. An integrated circuit for a user equipment (UE), comprising:
 circuitry configured to establish a connection for the UE to a first network via a first cell; 
 circuitry configured to determine a first predetermined condition related to radio conditions between the UE and the first cell is satisfied; and 
 circuitry configured to determine whether to activate a first mode of operation or a second mode of operation for the UE based on a second predetermined condition, wherein the first mode of operation includes the UE transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN) and the second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN, the second predetermined condition relating to a number of times the signal that is intended to cause the release of the bearer between the UE and the PDN was previously transmitted. 
 
     
     
       20. The integrated circuit of  claim 19 , wherein the signal that is intended to cause the release of the bearer between the UE and the PDN is one of a PDN disconnect request or a IP multimedia subsystem (IMS) deregistration message.

Description:
BACKGROUND 
     A user equipment (UE) may be configured to establish a connection to at least one of a plurality of different networks or types of networks. To establish the connection and access the full scope of services normally available to the UE via the network connection, the UE may camp on a cell of the corresponding network. However, due to a variety of different factors, the UE may activate a mode of operation that limits the access to a particular service that is normally available to the UE via the network connection. 
     Activating and deactivating a mode of operation that limits the access to a particular service may include an exchange of a plurality of signals between the UE and the network. Under conventional systems, the UE may activate this mode of operation despite it being likely that the UE will soon be triggered to deactivate this mode of operation. Similarly, the UE may deactivate this mode of operation despite it being likely that the UE will soon be triggered to reactivate this mode of operation. Accordingly, the UE may get stuck in a cycle of performing signaling that is intended to limit access to a particular service, performing signaling that is intended to establish access to the particular service and then performing signaling that is once again intended to limit access to the particular service. The excessive signaling performed by the UE due to activating and deactivating this mode of operation may increase power consumption. 
     SUMMARY 
     According to an exemplary embodiment, a method may be performed by a user equipment (UE) configured to camp on a first cell to establish a connection to a first network. The method includes determining a first predetermined condition related to radio conditions between the UE and the first cell is satisfied. The method further includes, determining whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition. The first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN). The second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN. 
     According to another exemplary embodiment, a user equipment (UE) includes a transceiver configured to establish a connection to a first network via a first cell. The UE further includes a processor configured to perform operations. The operations comprising determining that a first predetermined condition related to radio conditions between the UE and the first cell is satisfied. The operations further comprising, determining whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition. The first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the UE and a packet data network (PDN). The second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the UE and the PDN. 
     According to a further exemplary embodiment, an integrated circuit has circuitry configured to establish a connection to a first network via a first cell. The integrated circuit further includes circuitry configured to determine that a first predetermined condition related to radio conditions between the UE and the first cell is satisfied. The integrated circuit further includes circuitry configured to determine whether to activate a first mode of operation or a second mode of operation based on a second predetermined condition. The first mode of operation includes transmitting a signal that is intended to cause the release of a bearer between the IC and a packet data network (PDN). The second mode of operation includes barring the transmission of the signal that is intended to cause the release of the bearer between the IC and the PDN. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exemplary network arrangement according to various exemplary embodiments described herein. 
         FIG. 2  shows an exemplary UE according to various exemplary embodiments described herein. 
         FIG. 3  shows an exemplary method for the UE to determine whether to activate CMAS mode or to activate enhanced CMAS mode according to various exemplary embodiments. 
         FIG. 4  shows an exemplary method for the UE to operate in enhanced CMAS mode according to various exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments describe an apparatus, system and method for a UE to reduce signaling with a network by conditionally barring the transmission of a particular signal to the network. For example, prior to the transmission of the particular signal, the UE may identify conditions that correspond to excessive signaling. As a result, the UE may bar the transmission of the particular signal to the network. Transmission of the particular signal may resume when it is determined that the UE is unlikely to perform excessive signaling with the network. 
     The exemplary embodiments are described with regard to a UE. However, the use of term UE is merely for illustrative purposes. The exemplary embodiments may be utilized with any electronic component that may establish a connection with a network and is configured with hardware, software, and/or firmware to exchange signals with the network. Therefore, the UE as described herein represents any electronic component. 
     The UE may establish the connection to the network by camping on a cell of the network. In one example, the network may be a Long Term Evolution (LTE) network and the cell may be an Evolved Node B (eNB). In another example, the network may be a 5G new radio (NR) network and the cell may be a next generation Node B (gNB). However, reference to a particular network or a particular type of cell is merely provided for illustrative purposes. Those skilled in the art will understand that the network may be any type of network and the cell may be any type of cell within the corresponding network. 
     The UE may be configured to camp on a cell of a corresponding network via a plurality of different mechanisms including but not limited to, cell reselection and handover. Throughout this description, reference to the UE being configured to camp on a cell of the corresponding network based on any particular mechanism is merely provided for illustrative purposes. The exemplary embodiments may apply to a UE that is configured to camp on a particular cell via any appropriate mechanism. 
     Further, the UE may be configured to collect measurement data corresponding to the currently camped cell. The measurement data may be a factor in a variety of different operations and/or mechanisms. The measurement data may be based on a single measurement, based on a plurality of measurements, derived from a measurement, derived from a plurality of measurements or based on a combination thereof. Throughout this description, any reference to a particular type of measurement or data is merely provided for illustrative purposes, the exemplary embodiments may apply to the UE collecting any type of measurement or data. 
     When configured to camp on a cell, the UE may exchange a plurality of signals with the corresponding network to establish access to particular services via the network connection. For example, internet protocol (IP) connectivity may be available to the UE via the network connection. This may include access to multimedia services such as, but not limited to, voice over LTE (VoLTE), short message service (SMS), multimedia message service (MMS), video messages, streaming audio, streaming video, packet-based communications, etc. The multimedia services may be transported through the network via a communication path between the UE and an IP multimedia subsystem (IMS). However, reference to the IMS is merely exemplary. A person of ordinary skill in the art would understand that multimedia services may be made available to the UE from any type of packet data network (PDN). 
     Throughout this description, the communication path between the UE and the IMS may be referred to as a bearer. Establishing the bearer may include assigning the UE an IP address. The bearer may exist until the UE initiates the release of the bearer or the network triggers the release of the bearer. However, reference to the term bearer is merely provided for illustrative purposes. The exemplary embodiments may apply to any type of communication path between the UE and an entity that provides the UE access to a particular multimedia service. Further, reference to a single bearer is merely exemplary, the UE may be simultaneously configured with a plurality of bearers between the UE and the IMS and/or a different entity. 
     The UE may activate a mode of operation that limits access to a particular service. For example, the UE may collect measurement data corresponding to the currently camped cell. The measurement data, at least in part, may trigger the UE to activate a power efficient mode of operation that is intended to decrease power being used by the UE when the UE is within an environment that offers poor radio frequency (RF) conditions. The exemplary embodiments will be described with regard to the UE activating and deactivating a power efficient mode of operation during which emergency messages or indications of emergency messages are processed while access to other services (e.g., multimedia) may be limited. The emergency messages may be provided by a Commercial Mobile Alert System (CMAS) or an Earthquake and Tsunami Warning Service (ETWS). Accordingly, throughout this description, this power efficient mode of operation may be referred to as CMAS mode. However, this is merely exemplary, as there may be other types of power efficient modes and similar modes of operation may be referred to by different names. 
     In CMAS mode, the UE may limit various operations including but not limited to the processing of non-critical/background data traffic and the processing of foreground/user initiated traffic. For example, incoming data may be analyzed and only emergency related data may be used for subsequent processing while non-emergency related data may be ignored or buffered for later use. 
     Activating and deactivating CMAS mode, may include an exchange of various signals between the network and the UE. For example, activating CMAS mode may include but is not limited to, the UE sending a request to the network to disconnect the UE from the IMS and release the bearer. Without a bearer the UE may not have access to multimedia services. Thus, activating CMAS mode may release the bearer and cause access to particular services (e.g., multimedia, VoLTE, etc.) to be unavailable. This may prevent an increased amount of power from being utilized by the UE when the UE is operating in poor RF conditions. Alternatively, deactivating CMAS mode may include, but is not limited to, the UE sending a request to the network to establish the bearer between the UE and the IMS. Accordingly, deactivating CMAS mode may restore access to services (e.g. multimedia, VoLTE, etc.) that were limited during CMAS mode. 
     In conventional operations, the UE may be triggered to activate CMAS mode despite it being likely that the UE will soon deactivate CMAS mode. Similarly, the UE may be triggered to deactivate CMAS mode despite it being likely that the UE will soon reactivate CMAS mode. As a result, the UE may get stuck in a cycle of activating/deactivating CMAS mode which may cause the UE to perform excessive signaling. For example, consider a scenario where the UE is at the edge of a cell&#39;s coverage area where the radio conditions fluctuate rapidly between poor radio conditions and adequate radio conditions. When in poor radio conditions the UE may trigger CMAS mode and cause the bearer between the UE and the IMS to be torn down. The radio conditions may then recover and the UE may be triggered to deactivate CMAS mode and perform signaling that establishes a bearer between the UE and the IMS. Subsequently, the radio conditions may degrade and the UE may be triggered to reactivate CMAS mode and perform signaling that tears down the bearer that was just established between the UE and the IMS. This cycle may continue relatively frequently causing excessive signaling between the UE and the cell due to activating/deactivating CMAS mode. Thus, the power saving resulting from CMAS mode are squandered because of the excessive signaling performed by the UE. 
     The exemplary embodiments may relate to a UE that is configured to identify when excessive signaling is likely to occur and alters the operation of the UE to prevent the excessive signaling. Throughout this description, this altered mode of operation may be referred to as enhanced CMAS mode. In enhanced CMAS mode, the UE may utilize the same power saving mechanisms utilized in CMAS mode except unlike CMAS mode, the UE may bar the transmission of signals that are intended to cause the bearer between the UE and the IMS to be released. For example, in either CMAS mode or enhanced CMAS mode the UE may utilize power saving mechanisms including but not limited to, limiting the processing of non-critical/background data traffic, limiting the processing of foreground/user initiated traffic, analyzing incoming data and only using emergency data for subsequent processing, analyzing incoming data and ignoring non-emergency related data, analyzing incoming data and buffering non-emergency related data for later use, etc. However, unlike CMAS mode, in enhanced CMAS mode the UE will bar the transmission of signals that are intended to cause a tear down of the bearer. Thus, in enhanced CMAS mode, from the UE perspective the UE is operating in CMAS mode. From the network perspective, the bearer between the UE and the IMS still exists. Accordingly, if the UE is in enhanced CMAS mode and the IMS transmits signals over the bearer to the UE, the UE may ignore the signals transmitted by the IMS. 
       FIG. 1  shows an exemplary network arrangement  100  according to various exemplary embodiments. The exemplary network arrangement  100  includes a UE  110 . Those skilled in the art will understand that the UE  110  may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, Internet of Things (IoT) devices, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of a single UE  110  is merely provided for illustrative purposes. 
     The UE  110  may be configured to communicate directly with one or more networks. In the example of the network configuration  100 , the networks with which the UE  110  may wirelessly communicate are a LTE radio access network (LTE-RAN)  120 , a 5G New Radio (NR) radio access network (5G NR-RAN)  122 , a legacy radio access network (RAN)  124  and a wireless local access network (WLAN)  126 . However, it should be understood that the UE  110  may also communicate with other types of networks and the UE  110  may also communicate with networks over a wired connection. Therefore, the UE  110  may include a LTE chipset to communicate with the LTE-RAN  120 , a 5G NR chipset to communicate with the 5G NR-RAN  122 , a legacy chipset to communicate with the legacy RAN  124  and a WLAN chipset to communicate with the WLAN  126 . 
     The LTE-RAN  120 , the 5G NR-RAN  122  and the legacy RAN  124  may be portions of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&amp;T, Sprint, T-Mobile, etc.). These networks  120 ,  122 ,  124  may include, for example, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. The WLAN  126  may include any type of wireless local area network (WiFi, Hot Spot, IEEE 802.11x networks, etc.). 
     The UE  110  may connect to the LTE-RAN  120  via an evolved Node B (eNB)  120 A,  120 B. Those skilled in the art will understand that any association procedure may be performed for the UE  110  to connect to the LTE-RAN  120 . For example, as discussed above, the LTE-RAN  120  may be associated with a particular cellular provider where the UE  110  and/or the user thereof has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the LTE-RAN  120 , the UE  110  may transmit the corresponding credential information to associate with the LTE-RAN  120 . More specifically, the UE  110  may associate with a specific base station (e.g., the eNB  120 A of the LTE-RAN  120 ). As mentioned above, the use of the LTE-RAN  120  is for illustrative purposes and any type of network may be used. For example, the UE  110  may also connect to the 5G NR-RAN  122  via the next generation Node B (gNB)  122 A. 
     In addition to the networks  120 ,  122 ,  124  and  126  the network arrangement  100  also includes a cellular core network  130 , the Internet  140 , an IP Multimedia Subsystem (IMS)  150 , and a network services backbone  160 . The cellular core network  130  may be considered to be the interconnected set of components that manages the operation and traffic of the cellular network. The cellular core network  130  also manages the traffic that flows between the cellular network and the Internet  140 . The IMS  150  may be generally described as an architecture for delivering multimedia services to the UE  110  using the IP protocol. The IMS  150  may communicate with the cellular core network  130  and the Internet  140  to provide the multimedia services to the UE  110 . The network services backbone  160  is in communication either directly or indirectly with the Internet  140  and the cellular core network  130 . The network services backbone  160  may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE  110  in communication with the various networks. 
     The network arrangement  100  may further include a CMAS server  170 . The CMAS server  170  may generate emergency messages and/or emergency message indications (e.g., pings) to be broadcast over the cellular networks  120 ,  122 ,  124  to the UE  110 . Since the CMAS messages are only broadcast over a cellular network, to comply with various regulations and/or standards the UE  110  may remain connected, in some manner, to a cellular network, even when the UE  110  has established a connection to a non-cellular network such as the WLAN  126 . Thus, the CMAS server  170  may broadcast the emergency messages only over the cellular networks  120 ,  122 ,  124  and not the WLAN  126 . 
     The exemplary embodiments may relate to the UE  110  activating and deactivating CMAS mode. Consider an exemplary scenario where the UE  110  is camped on the eNB  120 A. The UE  110  may initiate an attach procedure to gain access to the multimedia services that may be available to the UE  110  via the IMS  150 . The attach procedure may include the UE  110  and the LTE-RAN  120  exchanging a plurality of signals to establish a bearer between the UE  110  and the IMS  150  through the LTE-RAN  120 . As mentioned above, establishing the bearer may include the UE  110  registering with the IMS  150  and the UE  110  being assigned an IP address for IP communications. 
     The UE  110  may be triggered to activate CMAS mode for any of a variety of different reasons. Activating CMAS mode may include the UE  110  sending a signal to a network that requests that the bearer between UE  110  and the IMS  150  be released. This signal may be referred to as a packet data network (PDN) disconnect request. Further, the UE  110  may send an IMS deregistration message to the network that requests that the UE  110  no longer be registered with the IMS  150  for IP connectivity. Both the PDN disconnect request and the IMS deregistration message are intended to cause a tear down of the bearer between the UE  110  and the IMS  150  and thus, terminate the communication path in which the UE  110  may access multimedia services. When in CMAS mode, the UE  110  may be triggered to deactivate CMAS mode. This may include the UE  110  sending a PDN connectivity request that is intended to establish a bearer between the UE  110  and the IMS  150 . This may also include the UE  110  sending an IMS registration message to the LTE-RAN  120 . 
     Reference to a PDN connect/disconnect request and an IMS registration/deregistration message are merely provided for illustrative purposes. Different networks may refer to similar signals by different names. The exemplary embodiments may apply to any type of signal that is intended to limit the access to a particular service (e.g. multimedia) that is normally available to the UE  110  via the network connection. 
       FIG. 2  shows an exemplary UE  110  according to various exemplary embodiments. The UE  110  will be described with regard to the network arrangement  100  of  FIG. 1 . The UE  110  may represent any electronic device and may include a processor  205 , a memory arrangement  210 , a display device  215 , an input/output (I/O) device  220 , a transceiver  225 , and other components  230 . The other components  230  may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE  110  to other electronic devices, sensors to detect conditions of the UE  110 , etc. 
     The processor  205  may be configured to execute a plurality of engines of the UE  110 . For example, the engines may include a CMAS mode engine  235  and an enhanced CMAS mode engine  240 . The CMAS mode engine  235  may be configured to activate and deactivate CMAS mode. For example, the CMAS mode engine  235  may identify various predetermined conditions that indicate that the UE  110  is experiencing poor radio conditions. Accordingly, to conserve power, the CMAS mode engine  235  may activate CMAS mode. When in CMAS mode, the CMAS mode engine  235  may identify various predetermined conditions that indicate that the UE  110  is experiencing adequate radio conditions. Accordingly, to resume access to services, the CMAS mode engine  235  may deactivate CMAS mode. The enhanced CMAS mode engine  240  may be configured to activate and deactivate enhanced CMAS mode. For example, the enhanced CMAS mode engine  240  may identify that the UE  110  is likely to perform excessive signaling. To prevent excessive signaling, the enhanced CMAS mode engine  240  may bar the transmission of particular signals. 
     The above referenced engines each being an application (e.g., a program) executed by the processor  205  is only exemplary. The functionality associated with the engines may also be represented as a separate incorporated component of the UE  110  or may be a modular component coupled to the UE  110 , e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor  205  is split among two or more processors such as a baseband processor and an applications processor, as will be described in further detail below. The exemplary embodiments may be implemented in any of these or other configurations of a UE. 
     The memory  210  may be a hardware component configured to store data related to operations performed by the UE  110 . As will be described in further detail below, the memory  210  may store data associated with the conditions of the UE  110  when a determination of the operating mode is performed. The display device  215  may be a hardware component configured to show data to a user while the I/O device  220  may be a hardware component that enables the user to enter inputs. The display device  215  and the I/O device  220  may be separate components or integrated together such as a touchscreen. The transceiver  225  may be a hardware component configured to establish a connection with the LTE-RAN  120 , the 5G NR-RAN  122 , the legacy RAN  124 , the WLAN  126 , etc. Accordingly, the transceiver  225  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). 
     CMAS mode is a power efficient mode of operation and thus, activating CMAS mode may provide power saving benefits to the UE  110 . However, when radio conditions fluctuate between poor and adequate, the UE  110  may get stuck in a cycle of activating/deactivating CMAS mode relatively frequently causing excessive signaling between the UE  110  and the currently camped cell. In conventional systems, the intended power saving benefits of CMAS mode may be negated by the excessive signaling. Accordingly, the exemplary embodiments may relate to identifying when excessive signaling is likely to be performed and utilizing an enhanced CMAS mode to prevent excessive signaling. 
       FIG. 3  shows an exemplary method  300  for the UE  110  to determine whether to activate CMAS mode or to activate enhanced CMAS mode according to various exemplary embodiments. The method  300  will be described with regard to the network arrangement  100  of  FIG. 1  and the UE  110  of  FIG. 2 . 
     Consider an exemplary scenario where the UE  110  is experiencing adequate radio conditions. Accordingly, the UE  110  has access to the full scope of services normally available to the UE  110  via the network connection. This may be referred to as a “full service” condition. 
     In  305 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is experiencing poor radio conditions. Thus, in  305  the UE  110  determines whether the radio conditions degrade from adequate to poor. In one exemplary embodiment, the predetermined condition may include whether a reference signal received power (RSRP) satisfies a predetermined threshold. Examples of predetermined threshold values may include but are not limited to, −90 dBm, −120 dBm, −150 dBm, etc. However, reference to RSRP and specific RSRP values are merely provided for illustrative purposes, any appropriate measurement or data such as but not limited to, reference signal received quality (RSRQ), signal-to-noise ratio (SNR), etc. may at least be a factor in triggering CMAS mode. 
     In another exemplary embodiment, the predetermined condition may include whether the UE  110  is utilizing a high transmission power cost. The high transmission power cost may be considered a high energy-per-bit cost for uplink data. This high transmission power cost may be determined based on one or more parameters. For example, one parameter may relate to transmission power. Thus, the predetermined condition may include whether transmission power satisfies a predetermined threshold which may be set to values including but not limited to, 5 dBm, 10 dBm, 20 dBm, 22 dBm, 35 dBm, etc. Another exemplary parameter may relate to retransmissions. Thus, the predetermined condition may include whether a number of retransmissions satisfies a predetermined threshold which may be set to values including but not limited to, 2, 3, 5, 7, 8, 10, etc. However, reference to transmission power and a number of retransmissions is merely exemplary, the UE  110  may utilize any appropriate transmission parameter to determine whether the UE  110  is utilizing a high transmission power cost. Any of these predetermined thresholds may be based on a single occurrence or based on average values within a predetermined duration. Accordingly, the UE  110  may determine that the UE  110  is experiencing poor radio conditions based on the RSRP threshold, the transmission power threshold, the retransmission threshold or any combination, or any appropriate predetermined condition. 
     If the predetermined condition in  305  is not satisfied, this may indicate the UE  110  is still experiencing adequate radio conditions. Thus, the UE  110  may continue to be in a full service condition. Accordingly, the UE  110  may continue to monitor measurement data and/or transmission parameters to determine whether the radio conditions subsequently degrade. 
     If the predetermined condition in  305  is satisfied the method  300  continues to  310 . In  310 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is likely to perform excessive signaling is satisfied. This predetermined condition may relate to whether the UE  110  has previously activated CMAS mode and/or transmitted a signal that is intended to cause the release of the bearer between the UE  110  and the IMS  150 . In one exemplary embodiment, the predetermined condition may include whether a PDN disconnect request has been sent to the network a predetermined number of times within a predetermined duration. Since this signal may be included in the process of activating CMAS mode, this may indicate that the UE  110  has been experiencing conditions that have been causing the UE  110  to activate and deactivate CMAS mode relatively frequently within a short time period. Thus, the predetermined condition in  310  may enable the UE  110  to identify behavior that may precede excessive signaling. In one exemplary configuration, the predetermined number of transmissions may be set to three PDN disconnect requests and the predetermined duration may be set to one minute. However, these values are merely provided for illustrative purpose. The number of PDN disconnect requests may be set to one, two, four, five, seven, ten, etc. The predetermined duration may be set to ten seconds, thirty seconds, one minute, one minute thirty seconds, two minutes, four minutes, 5 minutes, ten minutes, etc. 
     In another exemplary embodiment, the predetermined condition that indicates that the UE  110  is likely to perform excessive signaling may include whether an IMS deregistration message has been sent to the IMS  150  a predetermined number of times within a predetermined duration. Since this signal may also be included in the process of activating CMAS mode, this may also indicate that the UE  110  has been experiencing conditions that have been causing the UE  110  to activate and deactivate CMAS mode relatively frequently within a short time period. In one exemplary configuration, the predetermined condition may be set to three IMS deregistration messages being transmitted within one minute. However, these values are merely provided for illustrative purpose. Setting the predetermined conditions to be based on PDN disconnect requests and/or IMS deregistration messages is merely provided for illustrative purposes. Different networks and/or different chipset providers may refer to similar signaling by a different name. 
     If the predetermined condition is not satisfied in  310  the method  300  continues to  315 . In  315 , the UE  110  operates in CMAS mode. As mentioned above, activating CMAS mode may include the UE  110  transmitting a signal that is intended to cause the release of the bearer between the UE  110  and the IMS  150 . When in CMAS mode, the UE  110  may provide power saving benefits by limiting the processing of non-critical/background data traffic and limiting the processing of foreground/user initiated traffic. For example, incoming data may be analyzed and only emergency related data may be used for subsequent processing while non-emergency related data may be ignored or buffered for later use. 
     When the UE  110  operates in CMAS mode the UE  110  may store CMAS mode related information. The CMAS mode related information may provide an indication as to when the UE  110  has activated CMAS mode. The UE  110  may reference the CMAS mode related information when the UE  110  determines whether the predetermined condition in  305  is satisfied. For example, the UE  110  may store an indication that the UE  110  transmitted a PDN disconnect request and/or an IMS deregistration message including time stamps as to when these requests/messages were sent. The UE  110  may utilize a counter to track the number of times these signals have been transmitted and/or the number of times the UE  110  has activated CMAS mode. The UE  110  may also utilize a timer to track when these signals were transmitted relative to one another. However, this is merely exemplary, the UE  110  may store indications corresponding to when the UE  110  has activated CMAS mode and/or transmitted particular signals in any appropriate manner. 
     In  320 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is experiencing adequate radio conditions is satisfied. Since CMAS mode limits the services available to the UE  110 , the UE  110  monitors for this predetermined condition to determine when the UE  110  may reestablish access to the services that may be limited in CMAS mode. This determination is similar to the determination made in  305  but instead of the UE  110  determining whether the radio conditions have degraded, here, the UE  110  determines whether the radio condition have improved. Accordingly, the predetermined condition may include but is not limited to, an RSRP threshold, a transmission power threshold, a retransmissions threshold or a combination thereof. The UE  110  may be configured to utilize the same factors or different factors when making the determinations in  305  and  320 . Further, the UE  110  may be configured to utilize the same threshold values or different threshold values when making the determinations in  305  and  320 . 
     If the predetermined condition is not satisfied in  320 , this indicates that the UE  110  is still experiencing poor radio conditions. Accordingly, the method  300  returns to  315  and the UE  110  continues to operate in CMAS mode. 
     If the predetermined condition is satisfied, the method  300  continues to  325 . In  325 , the UE  110  deactivates CMAS mode. Deactivating CMAS mode may include the UE  110  transmitting a signal to the network that is intended to establish a bearer between the UE  110  and the IME  150 . Since CMAS mode may limit the services available to the UE  110 , deactivating CMAS mode may enable to the UE  110  to regain access to services that may have been limited in CMAS mode, e.g., enter a full service condition. 
     Returning to  310 , if the predetermined condition is satisfied in  310  the method  300  continues to  330  where the UE  110  operates in enhanced CMAS mode. Subsequently,  335  and  340  relate to deactivating enhanced CMAS mode. Operating in enhanced CMAS mode and deactivating enhanced CMAS mode will be described generally with regard to  FIG. 3 . Operating in enhanced CMAS mode and determining when to deactivate enhanced CMAS mode will be described in further detail with regard to  FIG. 4 . 
     Operating in enhanced CMAS mode in  330  may include the UE  110  utilizing the same power saving mechanisms of CMAS mode. However, when the UE  110  is in enhanced CMAS mode, unlike CMAS mode, the UE  110  is configured to bar signals intended to cause the release of the bearer between the UE  110  and the IMS  150 . For example, the UE  110  may prevent the baseband processor from transmitting a PDN disconnect request to the network and/or the UE  110  may prevent the IMS protocol stack from sending IMS deregistration messages to the IMS  150 . Thus, in enhanced CMAS mode, from the perspective of the UE  110 , the UE  110  is operating in CMAS mode. From the network perspective, the bearer between the UE  110  and the IMS  150  still exists. Barring a signal at the baseband processor or the IMS protocol stack is merely exemplary. When in enhanced CMAS mode, the UE  110  may bar the transmission of these signals in any appropriate manner. 
     In  335 , the UE  110  determines whether a predetermined condition has been satisfied. The predetermined condition may indicate that the UE  110  is no longer likely to perform excessive signaling. For example, the predetermined condition may relate to whether the radio conditions experienced by the UE  110  have improved. Further, the predetermined condition may include a time factor that may indicate to the UE  110  that despite not identifying an improvement in the radio conditions, the cause of the UE  110  activating/deactivating CMAS mode has likely been resolved. Accordingly, the predetermined condition may include but is not limited to, an RSRP threshold, a transmission power threshold, a retransmissions threshold, a timer, the UE  110  being configured to camp on a new cell or a combination thereof. If the predetermined condition is not satisfied, the UE  110  returns to  330  where the UE  110  remains in enhanced CMAS mode. 
     If the predetermined condition in  335  is satisfied, the method  300  continues to  340 . In  340 , the UE  110  deactivates enhanced CMAS mode. When the UE  110  deactivates enhanced CMAS mode, the UE  110  may be able to reestablish access to services that were limited in enhanced CMAS mode e.g., enter full service condition. However, as mentioned above, the predetermined condition in  335  may include a time factor. Therefore, the UE  110  may also be triggered to deactivate enhanced CMAS mode despite being in poor radio conditions. Accordingly, when the UE  110  deactivates enhanced CMAS mode, the UE  110  may be triggered to activate CMAS mode due to the poor radio conditions. 
       FIG. 4  shows an exemplary method  400  for the UE  110  to operate in enhanced CMAS mode according to various exemplary embodiments. The method  400  will be described with regard to the network arrangement  100  of  FIG. 1 , the UE  110  of  FIG. 2  and the method  300  of  FIG. 3 . 
     Consider an exemplary scenario where the UE  110  has activated enhanced CMAS mode. As described above with regard to  310  of the method  300 , the UE  110  may activate enhanced CMAS mode if the UE  110  determines that a predetermined condition that indicates that the UE  110  is likely to perform excessive signaling is satisfied. This may include determining whether a predetermined number of PDN disconnect requests and/or IMS deregistration messages have been transmitted within a predetermined duration. When in enhanced CMAS mode, the UE  110  may utilize the power saving mechanisms of CMAS mode such as ignoring particular signals and only processing emergency messages. However, unlike CMAS mode, the UE  110  bars the transmission of signals that are intended to cause the release of the bearer between the UE  110  and the IMS  150 . From the UE  110  perspective the UE  110  is operating in CMAS mode. From the network perspective, the bearer between the UE  110  and the IMS still exists. Accordingly, in enhanced CMAS mode, signals received over the bearer from the IMS  150  may be ignored due to the power saving mechanisms that may be implemented by the UE  110  when operating in enhanced CMAS mode. Since the bearer still exists, when the UE  110  deactivates enhanced CMAS mode, the UE  110  may reestablish a full service condition without having to perform signaling related to reestablishing the bearer (e.g., PDN connectivity request, IMS reregistration message, etc.). 
     In  405 , the UE  110  starts a timer. During the duration of the timer, the UE  110  may be configured to operate in enhanced CMAS mode. When the timer expires, the UE  110  may be configured to deactivate enhanced CMAS mode. Accordingly, the expiration of the timer may indicate to the UE  110  that despite not identifying an improvement in radio conditions, the cause of the UE  110  activating/deactivating CMAS mode has likely been resolved and thus, deactivating enhanced CMAS mode may either result in attempting to reestablish a full service condition or activating CMAS mode. 
     In one exemplary embodiment the length of the timer may be set to five minutes. However, this is merely provided for illustrative purposes. The timer may be configured to be any appropriate duration (e.g., thirty seconds, one minute, one minute thirty second, two minutes, two minutes forty-five seconds, four minutes, five minutes, ten minutes, etc.). The UE  110  may set the length of the timer based on a variety different factors. For instance, the length of the timer may be based on previous interactions with the currently camped cell by the UE  110  or other UEs, previous interactions with other cells by the UE or other UEs, the speed and/or direction in which the UE  110  is traveling, information received from the network, the configuration of surrounding cells, a look up table managed by the network or a provider, historical data, testing data, or any other appropriate basis. 
     In  410 , the UE  110  operates in enhanced CMAS mode. As mentioned above, in enhanced CMAS mode, the UE  110  may utilize the same power saving mechanisms utilized in CMAS mode. However, unlike CMAS mode, the UE  110  may bar the transmission of signals that are intended to cause the bearer between the UE  110  and the IMS  150  to be released (e.g., PDN disconnect request, IMS deregistration, etc.). 
     In  415 , the UE  110  determines whether the UE  110  has been configured to camp on a new cell. For example, consider an exemplary scenario where the UE  110  is currently camped on the eNB  120 A. The UE  110  may collect measurement data and be triggered to perform cell reselection while a handoff of the UE  110  from the eNB  120 A to the eNB  120 B may be initiated. As a result, the UE  110  may be now camped on the eNB  120 B. 
     If the UE  110  has been configured to camp on a new cell in  415 , the method  400  continues to  420 . In  420 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is within adequate radio conditions is satisfied. Since the UE  110  may have activated enhanced CMAS mode because the UE  110  experienced poor radio conditions, the UE  110  may utilize the predetermined condition in  420  to ensure that radio conditions of the new cell are adequate to reestablish access to a full service condition. Thus, the determination in  420  may be similar to the determinations made in  305  and  320  of  FIG. 3 . Accordingly, the predetermined condition may include but is not limited to, an RSRP threshold, a transmission power threshold, a retransmissions threshold, a combination thereof, etc. 
     If the UE  110  determines that the predetermined condition in  420  is satisfied, the method  400  continues to  450  where enhanced CMAS mode is deactivated. When enhanced CMAS mode is deactivated in response to the determination made in  420 , the UE  110  is camped on a cell that provide adequate radio conditions. Accordingly, the UE  110  may reestablish access to services that were limited during enhanced CMAS mode. 
     If the UE  110  determines that the predetermined condition in  425  is not satisfied, the method  400  continues to  425 . In  425  the UE  110  determines whether the timer has expired. 
     In  425 , if the timer has not expired the method  400  returns to  410  where the UE  110  continues to operate in enhanced CMAS mode while camped on the new cell  120 B. If the timer has expired, the method  400  continues to  450  where enhanced CMAS mode is deactivated. When enhanced CMAS mode is deactivated in response to the expiration of the timer started in  405 , the radio conditions may cause the UE  110  to subsequently enter CMAS mode. However, due to the duration of the timer, the conditions that caused the UE  110  to transmit a signal that is intended to cause the release of the bearer between the UE  110  and the IMS  150  enough times within a predetermined duration to satisfy  310  and thus, activate enhanced CMAS mode may no longer be experienced by the UE  110 . However, if those conditions remain, the UE  110  may once again utilize the predetermined condition of  310  and trigger the activation of enhanced CMAS mode to avoid excessive signaling. 
     Returning to  415 , if the UE  110  was not configured to camp on a new cell, the method  400  continues to  430 . In  430 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is within adequate radio conditions is satisfied. Since the UE  110  may have activated enhanced CMAS mode because the UE  110  experienced poor radio conditions, the UE  110  may utilize the predetermined condition in  430  to determine whether the radio conditions of the currently camped cell have improved and a full service condition may be reestablish. Thus, the determination in  430  may be similar to the determinations made in  420  and  305 ,  320  of  FIG. 3 . 
     If the predetermined condition in  430  is not satisfied, the method  400  continues to  435 . In  435 , the UE  110  determines whether the timer has expired. 
     In  435 , if the timer has not expired the method  400  returns to  410  where the UE  110  continues to operate in enhanced CMAS mode. If the timer has expired the method  400  continues to  450  where enhanced CMAS mode is deactivated. Similar to  425 , when enhanced CMAS mode is deactivated in response to the expiration of the timer started in  405 , the radio conditions may cause the UE  110  to subsequently enter CMAS mode. However, due to the duration of the timer, the conditions that caused the UE  110  to transmit a signal that is intended to cause the release of the bearer between the UE  110  and the IMS  150  enough times within a predetermined duration to satisfy  310  and thus, activate enhanced CMAS mode may no longer be experienced by the UE  110 . However, if those conditions remain, the UE  110  may once again utilize the predetermined condition of  310  and trigger the activation of enhanced CMAS mode to avoid excessive signaling. 
     Returning to  430 , if the predetermined condition in  430  is satisfied the method  400  continues to  440 . In  440 , since the radio condition are adequate, the UE  110  may cease the utilization of any CMAS mode power saving mechanisms and may reestablish access to services that may have been limited in enhanced CMAS mode. Accordingly, the UE  110  is in full service. However, the UE  110  has not triggered the deactivation of enhanced CMAS mode. 
     In  445 , the UE  110  determines whether a predetermined condition that indicates that the UE  110  is experiencing poor radio conditions is satisfied. Thus, the determination in  430  may be similar to the determinations made in  420 ,  430  and  305 ,  320  of  FIG. 3 . 
     If the UE  110  determines that the predetermined condition in  445  is not satisfied, this indicates to the UE  110  that the radio conditions are still adequate and thus, the UE  110  remains in full service. If the predetermined condition in  445  is satisfied, the method  400  continues to  435 . As mentioned above, in  435  the UE  110  determines whether the timer has expired. If the UE  110  determines that the timer has not expired in  435 , the method  400  returns to  410  where the UE  110  operates in enhanced CMAS mode. If the UE  110  determines that the timer has expired in  435 , the method  400  continues to  450  where enhanced CMAS mode is deactivated. When enhanced CMAS mode is deactivated in response to the expiration of the timer started in  405 , the radio conditions may cause the UE  110  to subsequently enter CMAS mode. However, due to the duration of the timer, the conditions that caused the UE  110  to transmit a signal that is intended to cause the release of the bearer between the UE  110  and the IMS  150  enough times within a predetermined duration to satisfy  310  and thus, activate enhanced CMAS mode may no longer be experienced by the UE  110 . However, if those conditions remain, the UE  110  may once again utilize the predetermined condition of  310  and trigger the activation of enhanced CMAS mode to avoid excessive signaling. 
     As mentioned above, in  450  the UE  110  deactivates enhanced CMAS mode. The method  400  described a plurality of different configurations that may cause the UE  110  to deactivate enhanced CMAS mode. When the UE  110  is in enhanced CMAS mode, from the network perspective, the bearer between the UE  110  and the IMS  150  still exists. Thus, the IMS  150  may have attempted to send control information and/or data to the UE  110  over the bearer. Since a power saving mechanism may include the UE ignoring received signals that are not emergency related, the IMS  150  may not receive a response to signals sent to the UE  110  over the bearer. This may cause the IMS  150  to delete stored UE  110  context information and effectively release the bearer between the UE  110  and the IMS  150 . Accordingly, when the UE  110  deactivates CMAS mode, the UE  110  may trigger an IMS reregistration process to bring the UE  110  context stored in the IMS  150  up to date and reestablish access to services normally provided by the IMS  150 . The UE  110  may be configured with a timer that triggers the UE  110  to send an IMS reregistration message to the IMS  150  periodically. When the UE  110  send the IMS reregistration message to the IMS  150  upon the deactivation of enhanced CMAS mode the UE  110  may reset this timer. 
     Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. In a further example, the exemplary embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor. 
     It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Metadata:
Filing Date: 20181011
Publication Date: 20210126
Grant Date: 20210126
Priority Date: 20181011
Inventors: PRABHAKAR, ALOSIOUS PRADEEP
VENKATARAMAN, VIJAY
LIN, ZAY YAR
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W36/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W76/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/34", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/08", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 70160711