Abstract:
The present disclosure provides a novel method for feature activation in the Machine Type Communication and a device thereof. According to the present disclosure, the MTC device may actively trigger entry into or exit from a feature state of the MTC device, and inform the network to perform suitable configuration, so as to meet the requirements of the MTC scenario and optimize the network performance. Furthermore, for the Extra Low Power Consumption feature, it is also proposed to set a MTC device specific DRX cycle as its actual cycle such that the actual cycle may be not limited by the system default DRX configuration information. Therefore, power consumption for the MTC device in the Extra Low Power Consumption state may be reduced.

Description:
FIELD OF THE INVENTION 
       [0001]    The present disclosure relates to Machine Type Communication (MTC) technology, and more particularly to feature activation in Machine Type Communication and an MTC device thereof. 
       BACKGROUND 
       [0002]    Machine Type Communication (MTC) is a form of data communication which does not necessarily need human interactions. MTC has been identified as one efficient way to provide various practical applications, such as smart metering, road safety, etc. A basic communication scenario for MTC is illustrated in  FIG. 1 , where an MTC device communicates with an MTC server or an MTC User Equipment (MTC UE) via an operating network. To facilitate MTC, currently in 3GPP, more than fifteen features have been defined, such as Low Mobility, Extra Low Power Consumption, Priority Alarm, etc. The Extra Low Power Consumption feature is applicable for MTC devices that are powered by batteries but may not be charged anywhere and anytime, and especially applicable for gas metering MTC devices. 
         [0003]    Currently, features of a MTC device are subscribed in a subscriber database of a core network entity such as a Home Location Register (HLR) or a Home Subscriber Server (HSS). A user may activate or deactivate features of the MTC device by defined interfaces or Web interfaces. Therefore, feature activation and deactivation for the MTC device are triggered by the UE, instead of the MTC device itself. Such a procedure for feature activation and deactivation is relatively static and features will remain in an activated or deactivated state over time unless the user changes its status. However, there are many scenarios where an MTC device is required to actively trigger entry or exit of a certain feature state of the MTC device and to inform the network for suitable configuration. However, currently there are still no solutions for this problem. 
         [0004]    For the Extra Low Power Consumption feature in the MTC, there are many scenarios where an MTC device is required to move frequently and has to be charged in specific areas. That is to say, in some areas, the Extra Low Power Consumption feature is not necessary, while in other areas, it becomes necessary. For example, an MTC device used for tracking old people or children may be charged anytime when at home, while in the worst scenario, such as when the old people or the children are missing, the MTC device is required to enter into an Extra Low Power Consumption state so as to work longer. Therefore, as indicated in the Document [1] listed below, the MTC device should actively trigger entry or exit of the Extra Low Power Consumption state and inform the network for performance optimization. However, there are still no solutions for this problem. 
         [0005]    As another example, an MTC device used for medical sensing will transmit only a small amount of data to the user of the MTC device periodically in general scenarios, however, if an emergent event occurs, the Priority Alarm feature may be activated, and the MTC device may transmit an emergent alarm message to the network as well as a large amount of detected medical data. Therefore, the MTC device needs to actively inform the network of activation or deactivation of its Priority Alarm feature. 
         [0006]    In addition to the activation or deactivation of Extra Low Power Consumption feature and Priority Alarm feature as discussed above, there are also many scenarios where the MTC device needs to dynamically trigger various other features and inform the network. 
         [0007]    Furthermore, for the Extra Low Power Consumption of MTC, a UE in an idle state may reduce power consumption by means of Discontinuous Reception (DRX) mechanism, which is especially important for MTC devices with the Extra Low Power Consumption feature. To extend the serving life of an MTC device with the Extra Low Power Consumption feature, the DRX cycle should be configured to be far longer than the system default cycle. The UE only needs to monitor the control channel at certain subframes, and may turn off its receiver at other subframes so as to save power consumption. The Document indicates that the actual DRX cycle depends on the smaller value of a UE specific DRX cycle and the system default DRX cycle, wherein the former is configured by the administrator of the user, while the latter is broadcast by the system. In current standards, the system default cycle value may be 32, 64, 128 and 256 radio frames. To support the Extra Low Power Consumption feature, the MTC device specific DRX cycle will be configured to be a very large value, such as 1024 radio frames. Assuming that the system default DRX cycle is 256 radio frames, the actual DRX cycle for the MTC device will be of a value of 256, which departs from the initial system design concept. In this regard, for an MTC device with the Extra Low Power Consumption feature, the DRX cycle thereof is limited by the system default cycle, and thus a new mechanism is needed to save power. 
         [0008]    A possible solution is to define a system default DRX cycle specific for the MTC device with the Extra Low Power Consumption feature. According to an example in the LTE system, the LTE system may perform a system configuration through a PCCH-config (Paging Control Channel) where a system default DRX cycle suitable for the MTC device is newly defined. When the MTC device activates its Extra Low Power Consumption feature, it will compare values of the newly defined system default DRX cycle and the UE specific DRX cycle, and take the smaller value to be the DRX cycle. However, this method is not beneficial because it will introduce new signaling in the system broadcast messages and thus signaling overhead will be increased. In the meanwhile, if the current DRX mechanism is used, the DRX cycle may not be properly configured, which departs from the initial system design concept. 
         [0009]    In view of the above, it is necessary to design an efficient mechanism for the Extra Low Power Consumption feature, which is also one of the problems to be resolved by the present disclosure.
   [1] 3GPP TS 22.368 V1.1.1 Service requirements for machine-type communications, stage 1   [2] 3GPP TS 36.304 User Equipment (UE) procedures in idle mode   
 
       SUMMARY 
       [0012]    To overcome the above disadvantages in the prior art, the present disclosure provides a novel method for feature activation in MTC and an MTC device thereof. According to the present disclosure, the MTC device may actively trigger entry into or exit from a certain feature state of the MTC device and inform a network to perform a suitable configuration so as to meet the requirement of the MTC scenario and optimize the network performance. Furthermore, for the Extra Low Power Consumption feature, it is also proposed to set an MTC device specific DRX cycle as its actual cycle such that the actual cycle may not be limited by the system default DRX configuration information. Therefore, power consumption for the MTC device in the Extra Low Power Consumption state may be reduced. 
         [0013]    In particular, according to an embodiment of the present invention, a method for feature activation for Machine Type Communication MTC is provided, including:
       transmitting, by an MTC device, a feature activation request for a feature to a Mobility Management Entity MME;   checking, by the MME, whether the MTC device has subscribed to the feature;   if the MTC device has subscribed to the feature, permitting, by the MME, the feature activation request, and transmitting, by the MME, a feature state updating request to a core network entity to update feature state of the MTC device;   transmitting, by the core network entity, a feature state updating response to the MME;   transmitting, by the MME, a state change message to a Base Station (BS);   performing, by the BS, radio access network optimization, then the MTC device entering into a feature activated state; and   if the MTC device has not subscribed to the feature, transmitting, by the MME, a response message indicating refusal of the activation request, and the MTC device remaining in a feature deactivated state.       
 
         [0021]    According to an alternative embodiment of the present invention, if the MTC device has not subscribed to the feature, a subscription request is transmitted from the MME to the core network entity that inquires a MTC server about whether to perform a feature subscription. 
         [0022]    According to an alternative embodiment of the present invention, transmitting, by an MTC device, a feature activation request for a feature to an MME includes transmitting, by the MTC device, the feature activation request to the BS by using non-access layer signaling, the feature activation request being then transmitted by the BS to the MME. 
         [0023]    According to an alternative embodiment of the present invention, transmitting, by an MTC device, a feature activation request for a feature to an MME includes transmitting, by the MTC device, the feature activation request to the BS by using a Radio Resource Control (RRC) message, the feature activation request being then transmitted by the BS to the MME. 
         [0024]    According to an alternative embodiment of the present invention, transmitting, by an MTC device, a feature activation request for a feature to an MME includes transmitting a predefined parameter to the MME. 
         [0025]    According to an alternative embodiment of the present invention, the feature includes an Extra Low Power Consumption feature, the feature state includes an Extra Low Power Consumption feature state, and the radio access network optimization includes Radio Resource Control (RRC) connection reconfiguration. 
         [0026]    According to an alternative embodiment of the present invention, the feature includes a Priority Alarm feature, and the feature state includes a Priority Alarm feature state. 
         [0027]    According to an alternative embodiment of the present invention, the feature includes an Extra Low Power Consumption feature, the feature state includes an Extra Low Power Consumption feature state, the MTC device operates in a Discontinuous Reception (DRX) state when the feature state is the Extra Low Power Consumption feature state, and the predefined parameter is a predefined UE specific DRX cycle. 
         [0028]    According to an alternative embodiment of the present invention, after the radio access network optimization, the MTC device operates in a Discontinuous Reception (DRX) state when the feature state is the Extra Low Power Consumption feature state, and the DRX cycle is a UE specific DRX cycle. 
         [0029]    According to an embodiment of the present invention, a method for feature deactivation for Machine Type Communication MTC is provided, including:
       transmitting, by a MTC device, a feature deactivation request for a feature to a Mobility Management Entity (MME);   permitting, by the MME, the feature deactivation request, and transmitting, by the MME, a feature state updating request to a core network entity to update feature state of the MTC device;   transmitting, by the core network entity, a feature state updating response to the MME;   transmitting, by the MME, a state change message to a Base Station (BS); and   performing, by the BS, radio access network optimization, then the MTC device entering a feature deactivated state.       
 
         [0035]    According to an alternative embodiment of the present invention, transmitting, by a MTC device, a feature deactivation request for a feature to an MME includes transmitting, by the MTC device, the feature deactivation request to the BS by using non-access layer signaling, the feature deactivation request being then transmitted by the BS to the MME. 
         [0036]    According to an alternative embodiment of the present invention, transmitting, by an MTC device, a feature deactivation request for a feature to an MME includes transmitting, by the MTC device, the feature deactivation request to the BS by using a Radio Resource Control (RRC) message, the feature deactivation request being then transmitted by the BS to the MME. 
         [0037]    According to an alternative embodiment of the present invention, transmitting, by an MTC device, a deactivation request for a feature to an MME includes transmitting a predefined parameter to the MME. 
         [0038]    According to an alternative embodiment of the present invention, the feature includes an Extra Low Power Consumption feature, the feature state includes an Extra Low Power Consumption feature state, and the radio access network optimization includes Radio Resource Control (RRC) connection reconfiguration. 
         [0039]    According to an alternative embodiment of the present invention, the feature includes a Priority Alarm feature, and the feature state includes a Priority Alarm feature state. 
         [0040]    According to an alternative embodiment of the present invention, the feature includes an Extra Low Power Consumption feature, the feature state includes an Extra Low Power Consumption feature state, the MTC device operates in a Discontinuous Reception (DRX) state when it exits the Extra Low Power Consumption feature state, and the predefined parameter is the smaller value of a predefined UE specific DRX cycle and a system default cycle. 
         [0041]    According to an alternative embodiment of the present invention, after the radio access network optimization, the MTC device operates in a Discontinuous Reception (DRX) state when the feature state is the Extra Low Power Consumption feature state, and DRX cycle is the smaller value of a UE specific DRX cycle and a system default cycle. 
         [0042]    According to an embodiment of the present invention, a Machine Type Communication MTC device is provided, including:
       first transmitting means configured to transmit a feature activation request;   second transmitting means configured to transmit a feature deactivation request;   receiving means configured to receive a feature configuration message;   feature activation means configured to activate a feature such that the MTC device operates in a feature activated state when the received feature configuration message indicates permission of feature activation; otherwise, to keep the MTC device in a feature deactivated state when the received feature configuration message indicates refusal of feature activation; and   feature deactivation means configured to deactivate a feature such that the MTC device operates in a feature deactivated state when the received feature configuration message indicates permission of feature deactivation; otherwise, to keep the MTC device in a feature activated state when the received feature configuration message indicates refusal of feature deactivation.       
 
         [0048]    According to an alternative embodiment of the present invention, in the MTC device, the first transmitting means is configured to transmit an Extra Low Power Consumption feature activation request;
       the second transmitting means is configured to transmit an Extra Low Power Consumption feature deactivation request;   the receiving means is configured to receive an Extra Low Power Consumption feature configuration message;   the feature activation means is configured to activate an Extra Low Power Consumption feature such that the MTC device operates in an Extra Low Power Consumption feature activated state when the received Extra Low Power Consumption feature configuration message indicates permission of Extra Low Power Consumption feature activation; otherwise, to keep the MTC device in an Extra Low Power Consumption feature deactivated state when the received feature configuration message indicates refusal of Extra Low Power Consumption feature activation; and   the feature deactivation means is configured to deactivate an Extra Low Power Consumption feature such that the MTC device operates in an Extra Low Power Consumption feature deactivated state when the received Extra Low Power Consumption feature configuration message indicates permission of Extra Low Power Consumption feature deactivation; otherwise, to keep the MTC device in an Extra Low Power Consumption feature activated state when the received Extra Low Power Consumption feature configuration message indicates refusal of Extra Low Power Consumption feature deactivation       
 
         [0053]    Further, the MTC device also includes Discontinuous Reception (DRX) cycle setting means configured to set a UE specific DRX cycle as an actual cycle value for the DRX when the MTC device operates in the Extra Low Power Consumption feature activated state, and to set the smaller value of the UE specific DRX cycle and a system default cycle as the actual cycle value for the DRX. 
         [0054]    According to an alternative embodiment of the present invention, the first transmitting means is configured to transmit a Priority Alarm feature activation request;
       the second transmitting means is configured to transmit a Priority Alarm feature deactivation request;   the receiving means is configured to receive a Priority Alarm feature configuration message;       
 
         [0057]    the feature activation means is configured to activate a Priority Alarm feature such that the MTC device operates in a Priority Alarm feature activated state when the received Priority Alarm feature configuration message indicates permission of Priority Alarm feature activation; otherwise, to keep the MTC device in a Priority Alarm feature deactivated state when the received Priority Alarm feature configuration message indicates refusal of Priority Alarm feature activation; and
       the feature deactivation means is configured to deactivate a Priority Alarm feature such that the MTC device operates in a Priority Alarm feature deactivated state when the received Priority Alarm feature configuration message indicates permission of Priority Alarm feature deactivation; otherwise, to keep the MTC device in a Priority Alarm feature activated state when the received Priority Alarm feature configuration message indicates refusal of Priority Alarm feature deactivation.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         [0059]    Other objectives and effects will become more apparent and easily understood after a more thorough understanding of the present invention from the following descriptions taken in connection with the accompanying drawings in which: 
           [0060]      FIG. 1  illustrates a basic communication system architecture of MTC. 
           [0061]      FIG. 2  illustrates a schematic diagram of the feature activation/deactivation procedure according to an embodiment of the present invention. 
           [0062]      FIG. 3  illustrates a flow chart of the DRX mechanism according to an embodiment of the present invention. 
           [0063]      FIGS. 4   a  and  4   b  illustrate schematic diagrams of the structure of the MTC device according to embodiments of the present invention. 
       
    
    
       [0064]    Like numeric references indicate the same, similar or corresponding features or functions throughout all of the above figures. 
       DETAILED DESCRIPTION 
       [0065]    Hereinafter, various embodiments of the present invention will be described in detail in connection with the accompanying figures. 
         [0066]      FIG. 2  illustrates a schematic diagram of the feature activation/deactivation procedure according to an embodiment of the present invention, which is applicable in a 3GPP network where an MTC device actively initiates feature activation or feature deactivation. In an embodiment for initiating a request for feature activation, in step S 201 , the MTC device initiates a feature activation request to a Mobile Management Entity (MME), which in turn determines whether to permit the feature activation request. 
         [0067]    If the list of features subscribed by the MTC device includes features that are requested to be activated, the procedure proceeds to step S 202  where the MME permits the feature activation request and transmits a feature state updating request to a core network entity. At step S 203 , the core network entity returns a feature state updating response to the MME. At step S 204 , the MME transmits the feature state updating response to a base station (BS). Subsequently, at step S 205 , the radio access network is configured. For example, the BS performs Radio Resource Control (RRC) connection reconfiguration for the MTC device, and the MTC device transmits a RRC connection reconfiguration complete message. After the configuration of the radio access network, the MTC device enters into a feature activated state. 
         [0068]    If the list of features subscribed by the MTC device does not include features that are requested to be activated, the MME may refuse the feature activation request, and then step S 222  is performed, where the MME transmits a response of refusing the feature activation request. 
         [0069]    Alternatively, if the list of features subscribed by the MTC device does not include features that are requested to be activated, at step S 212 , the MME may transmit a feature subscription request to the core network entity. At step S 213 , the core network entity transmits the feature subscription request to the MTC server. At step S 214 , the MTC server returns a feature subscription response to the core network entity. 
         [0070]    The embodiment for a feature deactivation procedure is similar to the above, and thus is not described in detail here. 
         [0071]    There are various manners for the MTC device to initiate feature activation/deactivation request to the MME at step S 201  such as those described below. 
       Implicit Method 
       [0072]    In this method, rules should be predefined between the MTC device and the network. The MTC device indicates its state change to the network in the implicit method. Based on the predefined rules between the MTC device and the network, the network may identify the state change of the MTC device. Specifically, when the MTC device enters into or exits from a feature state, it triggers a feature activation/deactivation request message including UE specific parameters. The network may identify the state of the MTC device according to a predefined UE specific parameter value. This method just employs predefined rules, and thus may operate with minimum specification efforts. 
       Explicit Method 1 
       [0073]    In this method, the MTC device transmits an explicit message to the network via a non-access layer signaling to indicate its state change. This function may be implemented by defining a new non-access layer signaling or extending the current signaling. 
       Explicit Method 2 
       [0074]    In this method, Radio Resource Control (RRC) messages are used. This method may extend the conventional RRC messages such as a measurement report message, or define a new RRC message. If the BS receives such a message, it will transfer the message to the MME. 
         [0075]    Hereinafter, taking the Extra Low Power Consumption feature as an example, a detailed description is given as follows. 
         [0076]    Since the conventional DRX can not meet the requirement of Extra Low Power Consumption feature, the present invention proposes a solution in which the MTC device in the Extra Low Power Consumption state only utilizes a UE specific DRX cycle value. In particular, when the MTC device enters into the Extra Low Power Consumption state, it will use the UE specific DRX cycle value as its actual cycle value, instead of the system default cycle. On the other hand, when the MTC device exits from the Extra Low Power Consumption state, it turns back to the conventional DRX mechanism, i.e., using a cycle value depending on the smaller value of the UE specific cycle value and the system default cycle value. 
         [0077]      FIG. 3  illustrates the DRX mechanism according to an embodiment of the present invention. 
         [0078]    The procedure begins with steps S 301 . At step S 302 , the MTC device checks whether an Extra Low Power Consumption state has been entered into. If YES, the procedure proceeds to step S 303  where the UE specific cycle is set as the actual DRX cycle value, and then the procedure ends at step S 307 . If NO, the procedure proceeds to step S 304  where it is determined whether a UE specific cycle smaller than the default cycle value has been assigned. If the UE specific cycle smaller than the default cycle value has been assigned, the procedure proceeds to step S 305  where the UE specific cycle is set as the actual DRX cycle value, and then the procedure ends at step S 307 . If the UE specific cycle smaller than the default cycle value has not been assigned, the procedure will proceed to step S 306  where the default value is set as the actual DRX cycle value, and then the procedure ends at step S 307 . 
         [0079]    Based on the procedure of feature activation/deactivation as shown in  FIG. 2 , the network may identify when the MTC device should activate or deactivate the Extra Low Power Consumption state such that the network may keep DRX in synchronization with the MTC device. In this way, the network and the MTC device may work properly. This mechanism does not have any effect on other UEs or MTC devices in the system, and thus will minimize the specification efforts. 
         [0080]    For the implicit method for activating/deactivating of the Extra Low Power Consumption feature, more specifically, once the MTC device enters into or exits from the Extra Low Power Consumption state, it will transmit to the network information including the predefined UE specific DRX parameter, the transmission access request message or the tracking area update (TAU) request message. For example, when the MTC device enters into the Extra Low Power Consumption state, it will transmit to the MME the UE specific DRX parameter such as 512 subframes, with which the MME may identify that the MTC device requests to enter into the Extra Low Power Consumption state. Similarly, when the UE specific DRX parameter is 32 subframes for example, the MME may identify that the MTC device requests for deactivation of the Extra Low Power Consumption state. 
         [0081]    In the explicit methods, the MTC device transmits, through a non-access layer signaling, to the network an explicit message indicating that its power state has been changed. This may be implemented by defining a new non-access layer signaling or extending the current signaling. The signaling flowchart is illustrated in  FIG. 2 , with the detailed procedure specified as follows. 
         [0082]    When the MTC device needs to enter into or exit from the Extra Low Power Consumption state, it transmits an explicit non-access layer message to the MME (see step S 201 ). 
         [0083]    If the MTC device reports that it has entered into the Extra Low Power Consumption state, the MME determines whether to permit the activation request. If the list of features subscribed by the MTC device includes the requested feature, the MME permits the request and updates the feature state of the MTC device, and the procedure proceeds to step S 202 . Otherwise, the MME may perform any of the following:
       refusing the activation request directly, and indicating the reason of refusal in a response message (see step S 222 ); or   transmitting a subscription request to the core network entity such as the subscriber database (see step S 212 ), the subscriber database then transmitting the subscription request to the MTC server (see step S 213 ).       
 
         [0086]    The MME transmits a feature state updating request to the core network entity such as the subscriber database (see step S 222 ), and the core network entity such as the subscriber database returns a state updating response (see step S 203 ). 
         [0087]    The MME transmits a state change message to the BS such that the BS may perform network optimization such as RRC connection reconfiguration, so as to reduce power consumption of the MTC device. 
         [0088]    In another explicit method using the RRC message, it extends the conventional RRC message. For example, it may extend the measurement report message or define a new RRC message. The subsequent procedures are very similar to those in the explicit method using a non-access layer message, and thus the detailed description thereof is omitted. 
         [0089]    In addition to the activation or deactivation of the Extra Low Power Consumption state as stated above, there are still many scenarios where the MTC device will always dynamically activate various features based on the measurement mechanism or certain events and inform the network. For example, the MTC device used for medical sensing will transmit only a small amount of data to the user of the MTC device periodically in general scenarios; however, if an emergent event occurs, the Priority Alarm feature may be activated, and the MTC device may transmit an emergent alarm message to the network as well as a large amount of detected medical data. Therefore, the MTC device needs to actively inform the network of activation or deactivation of its Priority Alarm feature. It is apparent that the explicit methods for activation or deactivation of the Extra Low Power Consumption feature may also be used for activation or deactivation of other features. 
         [0090]      FIG. 4  illustrates schematic diagrams of the structure of the MTC device according to embodiments of the present invention. In  FIG. 4   a , a schematic diagram of a general MTC device  400  with the feature activation/deactivation function of the present invention is illustrated. The MTC device  400  includes a first transmitting means  401 , a second transmitting means  402 , a receiving means  403 , a feature activation means  404  and a feature deactivation means  405 . 
         [0091]    In particular, the first transmitting means  401  is configured to transmit a feature activation request. When the MTC device  400  needs to enter into a feature state, the first transmitting means  401  is triggered to transmit the feature activation request. The feature activation request may be transmitted in either the implicit method or the explicit methods, depending on the system design constraint. In the implicit method, rules should be predefined between the MTC device and the network. The MTC device indicates its state change to the network in the implicit method. Based on the predefined rules between the MTC device and the network, the network may clearly identify the state change of the MTC device. Specifically, when the MTC device needs to enter into or exit from a feature state, it triggers a feature activation request message including a UE specific parameter. The network may identify the state of the MTC device according to a predefined UE specific parameter. This method just employs predefined rules, and thus may minimize the specification efforts. In the explicit method 1, the MTC device transmits an explicit message to the network via a non-access layer signaling to indicate its state change. This function may be implemented by defining a new non-access layer signaling or extending the current signaling. In the explicit method 2, a RRC message is used. This method may extend the conventional RRC message such as a measurement report message, or define a new RRC message. If the BS receives such a message, it will transfer the message to the MME. 
         [0092]    The second transmitting means  402  is configured to transmit a feature deactivation request. The second transmitting means  402  is different in operation from the first transmitting means  401  only in that the second transmitting means  402  transmits the feature deactivation request instead of the feature activation request, and thus it will not be detailed here. 
         [0093]    The receiving means  403  is configured to receive a feature configuration message. If the received feature configuration message indicates permission of feature activation, it will be input into the feature activation means  404  which may activate the feature such that the MTC device may operate in a feature activated state. If the received feature configuration message indicates refusal of feature activation, the feature activation means  404  may keep the MTC device in the feature deactivated state. If the received feature configuration message indicates permission of feature deactivation, it will be input into the feature deactivation means  405  which may deactivate the feature such that the MTC device may operate in a feature deactivated state. Otherwise, if the received feature configuration message indicates refusal of feature deactivation, the feature deactivation means  405  may keep the MTC device in the feature activated state. 
         [0094]    In one example, the MTC device is an MTC device with Priority Alarm feature. In this example, the first transmitting means  401  is configured to transmit a Priority Alarm feature activation request. The second transmitting means  402  is configured to transmit a Priority Alarm feature deactivation request. The receiving means  403  is configured to receive a Priority Alarm feature configuration request. The feature activation means  404  is configured to activate the Priority Alarm feature such that the MTC device may operate in a Priority Alarm feature activated state if the received Priority Alarm feature configuration message indicates permission of Priority Alarm feature activation; otherwise, to keep the MTC device in the Priority Alarm feature deactivated state if the received feature configuration message indicates refusal of Priority Alarm feature activation. The feature deactivation means  405  is configured to deactivate the Priority Alarm feature such that the MTC device may operate in a Priority Alarm feature deactivated state if the received Priority Alarm feature configuration message indicates permission of Priority Alarm feature deactivation; otherwise, to keep the MTC device in the Priority Alarm feature activated state if the received feature configuration message indicates refusal of Priority Alarm feature deactivation. 
         [0095]    In  FIG. 4   b,  a schematic diagram of a general MTC device  400  with the Extra Low Power Consumption feature activation/deactivation function of the present invention is illustrated. The MTC device  400  includes a first transmitting means  401 , a second transmitting means  402 , a receiving means  403 , a feature activation means  404 , a feature deactivation means  405  and a DRX cycle setting means  406 . 
         [0096]    In particular, when the MTC device  400  needs to enter into an Extra Low Power Consumption feature state, the first transmitting means  401  is triggered to transmit an Extra Low Power Consumption feature activation request. The Extra Low Power Consumption feature activation request may be transmitted in either the implicit method or the explicit methods, depending on the system setting. In the implicit method, the MTC device transmits an Extra Low Power Consumption feature activation request including a predefined UE specific DRX parameter to the network. For example, in case where the UE specific DRX parameter such as the information of 512 subframes is to be transmitted to the MME, the MME may identify that the MTC device needs to enter into the Extra Low Power Consumption state. In the explicit method 1, the first transmitting means  401  transmits an explicit message to the network via a non-access layer message to indicate its state change and requests for activation of the Extra Low Power Consumption feature. In the explicit method 2, the first transmitting means  401  transmits a RRC message to indicate its state change and requests for activation of the Extra Low Power Consumption feature. This method may extend the conventional RRC messages such as the measurement report message or define a new RRC message. 
         [0097]    On the other hand, when the MTC device  400  needs to exit from an Extra Low Power Consumption feature state, the second transmitting means  402  is triggered to transmit an Extra Low Power Consumption feature deactivation request. The Extra Low Power Consumption feature deactivation request may be transmitted in either the implicit method or the explicit methods, depending on the system design constraint. In the implicit method, the MTC device transmits an Extra Low Power Consumption feature deactivation request including a predefined UE specific DRX parameter to the network. For example, in case where the UE specific DRX parameter such as the information of 32 subframes is transmitted to the MME, the MME may identify that the MTC device needs to exit from the Extra Low Power Consumption state. In the explicit method 1, the first transmitting means  401  transmits an explicit message to the network via a non-access layer message to indicate its state change and request for deactivation of the Extra Low Power Consumption feature. In the explicit method 2, the first transmitting means  401  transmits a RRC message to indicate its state change and requests for deactivation of the Extra Low Power Consumption feature. This method may extend the conventional RRC messages such as the measurement report message or define a new RRC message. 
         [0098]    The receiving means  403  is configured to receive an Extra Low Power Consumption feature configuration message. If the received feature configuration message indicates permission of the Extra Low Power Consumption feature activation, it will be input into the Extra Low Power Consumption feature activation means  404  which may activate the Extra Low Power Consumption feature such that the MTC device may operate in the Extra Low Power Consumption feature activated state. If the received feature configuration message indicates refusal of the Extra Low Power Consumption feature activation, the feature activation means  404  may keep the MTC device in the feature deactivated state. If the received Extra Low Power Consumption feature configuration message indicates permission of the Extra Low Power Consumption feature deactivation, it will be input into the Extra Low Power Consumption feature deactivation means  405  which may deactivate the Extra Low Power Consumption feature such that the MTC device may operate in the Extra Low Power Consumption feature deactivated state. Otherwise, if the received feature configuration message indicates refusal of feature deactivation, the feature deactivation means  405  may keep the MTC device in the feature activated state. 
         [0099]    Furthermore, the MTC device  400  includes DRX cycle setting means  406  which is configured to set the UE specific DRX cycle as the actual cycle value for the DRX when the MTC device  400  operates in the Extra Low Power Consumption feature activated state, and to set the smaller of the UE specific DRX cycle and a system default cycle as the actual cycle value for the DRX. 
         [0100]    It may be understood that the present invention may be implemented in hardware, software, firmware or the combination thereof. It will be appreciated for those skilled in the art that the present invention may also be embodied in a computer program product embodied on a signal bearing medium for use by any suitable data processing system. The signal bearing medium may be a transmission medium or recordable medium for machine readable information, including magnetic medium, optical medium or other suitable medium. Examples of the recordable medium include disk or floppy disk in a hard disk drive, an optical disc drive for optical discs, magnetic tape and other medium that may be conceived by those skilled in the art. It will be appreciated for those skilled in the art that any communication device with suitably programmed means may implement the method steps of the present invention embodied in the program product. 
         [0101]    It may be appreciated from the above that, various embodiments of the present invention may be modified or varied without departing from the scope of the present invention. The description is only illustrative and not for limitation. The scope of the present invention is defined by the claims.