Abstract:
A method in a wireless communication system is provided. The method includes receiving a reconfiguration message, and stopping and resetting a timer inhibiting a mobile device from transmitting a signaling connection release indication message while the timer is running and clearing any value associated with the timer if the received reconfiguration message is for radio bearer reconfiguration and a new universal mobile telecommunications system terrestrial radio access network (UTRAN) radio network temporary identifier (U-RNTI) is included.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application of a prior application Ser. No. 13/504,674, filed on Apr. 27, 2012, which issued as U.S. Pat. No. 8,965,372 on Feb. 24, 2015; which was a U.S. National Stage application under 35 U.S.C. §371 of an International application filed on Aug. 26, 2010 and assigned application serial number PCT/KR2010/005748; and which claimed the benefit under 35 U.S.C §119(a) of an Indian patent application filed on Aug. 26, 2009 in the Indian Intellectual Property Office and assigned application serial number 2035/CHE/2009, the entire disclosures of each of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to the field of wireless communication. More particularly, the present disclosure relates to a method and system for handling a signaling connection release process in a wireless communication system. 
     BACKGROUND 
     A signaling connection release indication (SCRI) message with cause was typically introduced to indicate a packet switched (PS) domain dormancy to a network and thereby to effect a transition of a mobile device to a battery efficient state. The PS domain dormancy includes disconnecting a connection between the network and the mobile device when no PS data exchange takes place. Transmission of the SCRI message is dependent upon a timer, for example a timer T323, which can be indicated in an information element (IE) present in radio resource control (RRC) signaling messages. In case of a serving radio network subsystem (SRNS) relocation process, the mobile device in a dedicated control channel (DCH) and a forward access channel (FACH) state incorrectly continues with a status and value of the timer until any modifications in the support or value of the timer is indicated in a universal mobile telecommunication system terrestrial radio access network (UTRAN) Mobility Information (UMI) message after moving from a first radio network controller (RNC) to a second RNC. 
     Fast dormancy feature is an optional feature for the network and is applicable from a release-8 version. If the second RNC does not support fast dormancy, the second RNC can still receive the SCRI with cause from the mobile device if the UMI is not sent to the mobile device resulting in mismatch of PS domain signaling connection status between the mobile device and the network. Another problem can occur when a timer value of the timer is changed due to the SRNS relocation process but the network has delayed to indicate the change of the timer value using the UMI. If the mobile device has initiated the SCRI message with cause, then the mobile device starts the timer using a previous timer value which is incorrect as the SCRI message with cause can increase a load at the network until the mobile device receives UMI with another timer value. If the successful transmission of SCRI message with cause is interrupted due to radio link control (RLC) re-establishment procedure, the SCRI message is lost. The RLC re-establishment procedure results when the mobile device moves from the first RNC to the second RNC. The RLC re-establishment procedure includes re-establishing the protocol layers by the mobile device. The mobile device further remains in a battery inefficient state as the timer is running which controls the mobile device from retransmitting the SCRI message with cause until the timer ceases and there are no PS data indications from upper layers. 
     SUMMARY 
     In the light of the foregoing discussion, there is a need for handling the signaling connection release indication (SCRI) message with cause during the serving radio network subsystem (SRNS) relocation process and the radio link control (RLC) re-establishment procedure by handling the timer. 
     Embodiments of the present disclosure described herein provide a method and system of handling a signaling connection release process in a wireless communication system. 
     A method of handling a signaling connection release process in a wireless communication system includes receiving a reconfiguration message by a mobile device. The method also includes interpreting the reconfiguration message to effect a SRNS relocation process for the mobile device from the presence and value of information element Universal Mobile Telecommunication System Terrestrial Radio Access Network (UTRAN) radio network temporary identifier (RNTI), U-RNTI, integrity protection mode information message, and downlink counter synchronization information message. Further, the method includes causing a timer to cease running. Moreover, the method includes resetting the timer to a predefined value. Further, the method includes clearing a variable associated with the timer from the mobile device. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     A method of handling a signaling connection release process in a wireless communication system includes receiving a reconfiguration message by a mobile device. The method also includes interpreting the reconfiguration message to effect a SRNS relocation process for the mobile device from the presence and value of IE&#39;s new U-RNTI, integrity protection mode information message, and downlink counter synchronization information message. The method further includes allowing a timer to run based on the triggering. Further, the method includes clearing a variable associated with the timer from the mobile device. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     A method of handling a signaling connection release process in a wireless communication system includes transmitting a SCRI message with cause to a network by a mobile device. The method also includes receiving a reconfiguration message by the mobile device. The method further includes interpreting the reconfiguration message to effect a SRNS relocation process for the mobile device from the presence and value of information element U-RNTI, integrity protection mode information message, and downlink counter synchronization information message. Further, the method includes causing a timer to cease running. Moreover, the method includes resetting the timer to a predefined value. Further the method includes clearing a variable associated with the timer from the mobile device. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     A method of handling a signaling connection release process in a wireless communication system includes receiving a reconfiguration message by a mobile device. The method also includes interpreting the reconfiguration message to effect a SRNS relocation process for the mobile device from the presence and value of an information element U-RNTI, integrity protection mode information message, and downlink counter synchronization information message. The method further includes allowing a timer to run for a first timer value. Further, the method includes clearing a variable associated with the timer from the mobile device. Moreover, the method includes receiving a second timer value in an information message from a network. Further the method includes restarting the timer with a difference between the second timer value and the first timer value. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     A method of handling a signaling connection release process in a wireless communication system includes transmitting a SCRI message with cause to a network by a mobile device. The method also includes causing a timer to start running. The method further includes receiving a reconfiguration message by a mobile device to effect a RLC layer re-establishment at the mobile device. Further, the method includes causing a timer to cease running. Moreover, the method includes retransmitting the SCRI message with cause to the network by the mobile device upon successful re-establishment. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     A method of handling a signaling connection release process in a wireless communication system includes transmitting a SCRI message with cause to a network by a mobile device. The method also includes causing a timer to start running. The method further includes receiving a reconfiguration message by a mobile device to effect a RLC re-establishment at the mobile device. Further, the method includes allowing a timer to run for the timer value. The method also includes checking buffer occupancy for a packet switched domain on end of a timer value of a timer. Moreover, the method includes retransmitting the SCRI message with cause to the network if the buffer occupancy is at zero value. Moreover, the method includes the above modifications to the timer and the associated variable at the reception of the reconfiguration message, or at the transmission of the response to the reconfiguration message. 
     An example of a system for handling a signaling connection release process in a wireless communication system includes a mobile device comprising a processor responsive to a reconfiguration message to trigger a serving radio network subsystem (SRNS) relocation process, cause a timer to cease running based on the triggering, reset the timer to a predefined value, clear a variable associated with the timer from the mobile device. The system also includes a radio network controller to transmit a SCRI message with cause to a network. Further the system includes a communication interface in electronic communication with a network to send the SCRI message and receive the reconfiguration message. 
     A method in a wireless communication system includes receiving a reconfiguration message, and stopping and resetting a timer inhibiting a mobile device from transmitting a signaling connection release indication message while the timer is running and clearing any value associated with the timer if the received reconfiguration message is for radio bearer reconfiguration and a new universal mobile telecommunications system terrestrial radio access network (UTRAN) radio network temporary identifier (U-RNTI) is included. 
     A method in a wireless communication system includes receiving a reconfiguration message, and stopping and resetting a timer inhibiting a mobile device from transmitting a signaling connection release indication message while the timer is running and clearing any value associated with the timer if the received reconfiguration message includes a downlink counter synchronization information parameter. 
     A mobile device for use in a wireless communication system includes a controller configured to receive a reconfiguration message, and to stop and reset a timer inhibiting a mobile device from transmitting a signaling connection release indication message while the timer is running and clear any value associated with the timer if the received reconfiguration message is for radio bearer reconfiguration and a new universal mobile telecommunications system terrestrial radio access network (UTRAN) radio network temporary identifier (U-RNTI) is included. 
     A mobile device for use in a wireless communication system includes a controller configured to receive a reconfiguration message, and to stop and reset a timer inhibiting a mobile device from transmitting a signaling connection release indication message while the timer is running and clear any value associated with the timer if the received reconfiguration message includes a downlink counter synchronization information parameter. 
     According to the present invention, the wireless communication system can handle the SCRI message with cause during the SRNS relocation process and the RLC re-establishment procedure by handling the timer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figure, similar reference numerals may refer to identical or functionally similar elements. These reference numerals are used in the detailed description to illustrate various embodiments and to explain various aspects and advantages of the present disclosure. 
         FIG. 1  illustrates a universal mobile telecommunication system (UMTS) radio interface protocol architecture layer, in accordance with which various embodiments can be implemented; 
         FIG. 2  illustrates a signaling connection release indication process, in accordance with a prior art; 
         FIG. 3  illustrates a signaling connection release indication process with cause, in accordance with a prior art; 
         FIG. 4  illustrates a signaling connection release indication process with cause on cease of a timer, in accordance with one embodiment; 
         FIG. 5  illustrates interruption of a signaling connection release indication process due to radio link control (RLC) re-establishment procedure, in accordance with a prior art; 
         FIG. 6  is a flowchart illustrating a method of handling a signaling connection release indication (SCRI) process in a wireless communication system, in accordance with one embodiment; 
         FIG. 7  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with another embodiment; 
         FIG. 8  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with yet another embodiment; 
         FIG. 9  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with one another embodiment; 
         FIG. 10  illustrates handling a signaling connection release indication process, in accordance with one embodiment; 
         FIG. 11  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with one embodiment; 
         FIG. 12  illustrates handling a signaling connection release indication process, in accordance with another embodiment; and 
         FIG. 13  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with another embodiment. 
     
    
    
     Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present disclosure. 
     DETAILED DESCRIPTION 
     It should be observed the method steps and system components have been represented by conventional symbols in the figure, showing only specific details which are relevant for an understanding of the present disclosure. Further, details may be readily apparent to person ordinarily skilled in the art may not have been disclosed. In the present disclosure, relational terms such as first and second, and the like, may be used to distinguish one entity from another entity, without necessarily implying any actual relationship or order between such entities. 
     Embodiments of the present disclosure described herein provide a method and system for handling a signaling connection release indication (SCRI) message with cause during a serving radio network subsystem (SRNS) relocation process and a radio link control (RLC) re-establishment procedure by handling a timer, for example a timer T323. 
       FIG. 1  illustrates a universal mobile telecommunication system (UMTS) radio interface protocol architecture, in accordance with which various embodiments can be implemented. The UMTS radio interface protocol architecture layer includes a physical layer  105 , a media access control layer  110 , a service access point (SAP)  115 , a radio link control (RLC) layer  120 , a radio resource control layer (RRC)  125 , a broadcast-multicast control layer (BMC)  130  and a packet data convergence protocol layer (PDCP)  135 . The SAP  115  is used for a peer-to-peer communication between the UMTS radio interface protocol architecture layers. The SAP  115  present between the MAC layer  110  and the physical layer  105  provides a transport channel. The SAP  115  between the RLC layer  120  and the MAC layer  110  provides a logical channel. Three RLC modes of operation include an unacknowledgement mode (UM), an acknowledgement mode (AM), and a transparent mode (TM). The PDCP layer  135  is accessed by a PDCP SAP and the BMC layer  130  is accessed by a BMC SAP. Service provided by the RLC layer  120  is referred to as a radio bearer. The radio bearer provided by the RLC layer  120  to the RRC layer  125  is denoted as a signaling radio bearer. There exists an RLC mode of operation in a mobile device and a corresponding RLC mode of operation at a network, for example a universal mobile telecommunication system terrestrial radio access network (UTRAN). The RLC mode of operation at the mobile device and the RLC mode of operation at the UTRAN includes receiving a payload from an upper layer by the RLC layer  120 . The payload is referred to as a Service Data Unit (SDU). 
     The RLC layer  120  adds control information, referred to as header, for processing the SDU by an upper layer. The header combined with the SDU is referred to as a Protocol Data Unit (PDU). The AM RLC mode of operation includes a transmitter and a receiver. The transmitter of the AM RLC mode of operation transmits an RLC PDU and the receiver side of the AM RLC mode of operation receives the RLC PDU. The UM RLC mode of operation and the TM RLC mode of operation includes either the transmitter or the receiver. The RLC layer  120  is responsible for a reliable transmission of the SDU received from the upper layer. To achieve the reliability, a feedback process for intimating the transmitter about the reception of the PDU is employed by the receiver. An RLC re-establishment procedure is used for initialization of an upper RLC layer. The RLC re-establishment is performed by a mobile device upon request by the upper layer. 
       FIG. 2  illustrates a signaling connection release indication process, in accordance with a prior art. For a release version prior to release-8 version, a signaling connection release indication (SCRI) process can be initiated without cause. The SCRI process without cause can be initiated if some malfunction occurs at a mobile device  205  and the mobile device wants to release the connection with a universal mobile telecommunication system terrestrial radio access network (UTRAN)  210 . An SCRI message  215  is transmitted on a dedicated control channel (DCCH) using an acknowledgement mode (AM) radio link control (RLC) mode of operation. The procedure ends at mobile device  205  when the SCRI message  215  is delivered successfully to the UTRAN  210 . 
       FIG. 3  illustrates a signaling connection release indication process with cause, in accordance with a prior art. If the UTRAN supports the SCRI process with cause, then it can initiate a state transition for the mobile device to a battery efficient state. The battery efficient states includes an idle state, a cell paging channel state, a UTRAN registration area (URA) paging channel state and a cell forward access channel state. Upper layers  320  indicate that there is no packet switched (PS) data present for transmission as shown in step  325 . A radio resource control layer (RRC)  315  of the mobile device, on reception of the indication, transmits the SCRI with cause to the network, for example the UTRAN, and starts the timer as shown in step  330 . The UTRAN, on reception of the SCRI with cause, transmits an acknowledgement, at step  335 , for signaling connection release to a radio link control layer (RLC)  310  of the mobile device. The UTRAN makes a transition for the mobile device to a battery saving state as shown in step  340 . The SCRI message with cause can lead to signaling load at the UTRAN, to reduce this load a timer  345  is introduced at the mobile device. If the timer  345  is running, the mobile device is prohibited from transmitting the SCRI message with cause. The timer then expires or ceases to run. 
       FIG. 4  illustrates a signaling connection release indication process with cause on cease of a timer. If the UTRAN supports the SCRI process with cause, then it can initiate a state transition for a mobile device to a battery efficient state. The battery efficient state includes an idle state, a cell paging channel state, a UTRAN registration area (URA) paging channel state and a cell forward access channel state. Upper layers  320  indicate that there is no packet switched (PS) data present for transmission as shown in step  405 . A radio resource control layer (RRC)  315  of the mobile device, on reception of the indication, transmits the SCRI message with cause to the network, for example the UTRAN, and starts a timer, for example the timer T323, as shown in step  410 . 
     The UTRAN, on reception of the SCRI message with cause, transmits an acknowledgement for signaling connection release at step  415  to a radio link control layer (RLC)  310  of the mobile device. The upper layers  320  sends a no more PS data indication at step  420 , to the RRC  315  of the mobile device but as the timer is still running so the mobile device shall be inhibited from sending the SCRI message with cause. The timer expires as shown in step  425 . The RRC  315  transmits the SCRI to the UTRAN at step  430  and starts the timer. The UTRAN transmits an acknowledgement at step  435  for signaling connection release to the RLC  310  of the mobile device. The UTRAN further makes a transition for the mobile device to a battery saving state as shown in step  440 . 
       FIG. 5  illustrates interruption of a signaling connection release indication process due to radio link control (RLC) re-establishment procedure, in accordance with a prior art. Upper layers  320  transmit a no more packet switch (PS) data indication at step  505  to a radio resource control layer (RRC)  315  of a mobile device. The RRC  315  of the mobile device on reception of the indication, transmits an SCRI message with cause to a network  305 , for example a universal mobile telecommunication system terrestrial radio access network (UTRAN), and starts a timer as shown in step  510 . The mobile device relocates from a first RNC to a second RNC. The UTRAN transmits a radio link control re-establishment message at step  515  to the RRC of the mobile device, to indicate the relocation to the mobile device. The RRC  315  of the mobile device retransmits the SCRI message as shown in step  520 . The retransmission of the SCRI message by the RRC  315  of the mobile device is blocked as the timer is running as shown in step  525 . In step  530 , the timer expires or ceases to run. Even after the expiry of the timer, the RRC  315  of the mobile device cannot transmit the SCRI message as the RRC  315  of the mobile device does not receive the no more packet switch data indication at step  545  from the upper layers  320 . 
       FIG. 6  is a flowchart illustrating a method of handling a signaling connection release indication (SCRI) process in a wireless communication system, in accordance with one embodiment. At step  605 , a reconfiguration message is received by a mobile device from a network, for example a universal mobile telecommunication system terrestrial radio access network (UTRAN). At step  610 , the mobile device triggers a serving radio network subsystem relocation (SRNS) process based on the receiving. At step  615 , a timer is caused to cease running based on the triggering. At step  620 , the timer is reset to a predefined value. At step  625 , a variable associated with the timer is cleared. 
       FIG. 7  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with another embodiment. At step  705 , a mobile device receives a reconfiguration message from a universal mobile telecommunication system terrestrial radio access network (UTRAN). At step  710 , the mobile device triggers a serving radio network subsystem relocation (SRNS) process. At step  715 , a timer is allowed to start running. At step  720 , a variable associated with the timer is cleared. 
       FIG. 8  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with yet another embodiment. At step  805 , a mobile device transmits a signaling connection release indication with cause to a network, for example a UTRAN. At step  810 , the mobile device receives a reconfiguration message from the UTRAN. At step  815 , the mobile device triggers a serving radio network subsystem relocation (SRNS) process. At step  820 , a timer is caused to cease running. At step  825 , the timer is reset to a predefined value. At step  830 , a variable associated with the timer is cleared from the mobile device. 
       FIG. 9  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with one another embodiment. At step  905 , a mobile device receives a reconfiguration message. At step  910 , the mobile device triggers a serving radio network subsystem relocation (SRNS) process. At step  915 , a timer is allowed to start running for a first timer value. At step  920 , a variable associated with the timer is cleared. At step  925 , the mobile device receives a second timer value in an information message. At step  930 , the timer is restarted with a difference between the second timer value and the first timer value. 
       FIG. 10  illustrates handling a signaling connection release indication process, in accordance with one embodiment. Upper layers  320 , transmits a no more packet switch (PS) data indication  1005  to a radio resource control layer (RRC)  315  of a mobile device. The RRC  315  of the mobile device on reception of the no more PS data indication  1005 , transmits an SCRI message with cause to a universal mobile telecommunication system terrestrial radio access network (UTRAN) and starts a timer as shown in step  1010 . The mobile device relocates from a first RNC to a second RNC. The UTRAN transmits a radio link control re-establishment message at step  1015  to the RRC  315  of the mobile device, to indicate the relocation to the mobile device. On reception of the radio link control re-establishment message by the RRC  315  of the mobile device, the timer is stopped as shown in step  1020 . Once the timer is stopped, the RRC  315  of the mobile device retransmits the SCRI message with cause to the UTRAN as shown in step  1025 . 
       FIG. 11  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with one embodiment. At step  1105 , a mobile device transmits a signaling connection release indication with cause to a universal mobile telecommunication system terrestrial radio access network (UTRAN). At step  1110 , a timer is caused to start running. At step  1115 , the mobile device receives a reconfiguration message from the UTRAN. At step  1120 , a timer is caused to cease running. At step  1125 , the mobile device retransmits the signaling control release indication message with cause to the UTRAN. 
       FIG. 12  illustrates handling a signaling connection release indication process, in accordance with another embodiment. Upper layers  320  transmits a no more packet switch (PS) data indication  1205  to a radio resource control layer (RRC)  315  of a mobile device. The RRC  315  of the mobile device on reception of the no more PS data indication, transmits an SCRI message with cause to a universal mobile telecommunication system terrestrial radio access network (UTRAN) and starts a timer as shown in step  1210 . The mobile device relocates from a first RNC to a second RNC. The UTRAN transmits a radio link control re-establishment message  1215  to the RRC  315  of the mobile device, to indicate the relocation to the mobile device. On reception of the radio link control re-establishment message  1215  by the RRC of the mobile device, the timer is stopped as shown in step  1220 . The RRC  315  of the mobile device checks for the buffer occupancy (BO). The BO indicates if PS data for transmission is present. If the BO is zero, the RRC  315  of the mobile device retransmits the SCRI message with cause to the UTRAN. The BO at zero indicates to the mobile device that there is no PS data for transmission. 
       FIG. 13  is a flowchart illustrating a method of handling a signaling connection release indication process, in accordance with another embodiment. At step  1305 , a mobile device transmits a signaling connection release indication with cause to a universal mobile telecommunication system terrestrial radio access network (UTRAN). At step  1310 , a timer is caused to start running. At step  1315 , the mobile device receives a reconfiguration message from the UTRAN to configure the mobile device. At step  1320 , the mobile device checks if buffer occupancy is zero for a packet switched domain on end of a timer value of a timer. At step  1325 , the mobile device retransmits signaling control release indication message with cause to the UTRAN. 
     In the preceding specification, the present disclosure and its advantages have been described with reference to specific embodiments. However, it will be apparent to a person of ordinary skill in the art that various modifications and changes can be made, without departing from the scope of the present disclosure, as set forth in the claims below. Accordingly, the specification and figures are to be regarded as illustrative examples of the present disclosure, rather than in restrictive sense. All such possible modifications are intended to be included within the scope of the present disclosure.