Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/10—Connection setup
  • H04W76/15—Setup of multiple wireless link connections
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/02—Selection of wireless resources by user or terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/20—Manipulation of established connections
  • H04W76/25—Maintenance of established connections
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/20—Manipulation of established connections
  • H04W76/27—Transitions between radio resource control [RRC] states
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/30—Connection release
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/02—Terminal devices
  • H04W88/06—Terminal devices adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/30—Connection release
  • H04W76/38—Connection release triggered by timers

Definitions

• the disclosed embodiments relate generally to mobile communication networks, and, more particularly, to UE enhancement for enhanced protocols for suspending UE data and resuming data transmission.
• Dual-SIM Dual-Standby is a very popular feature in smart phone markets today, especially in developing countries such as China and India. Many mobile phone users have multiple SIM cards for various purposes - having different phone numbers for different uses (e.g., one for business and one for personal), saving roaming fee, compensating non-contiguous network coverage, and sharing one device for multiple family members. With DSDS feature, mobile phone users can use single device to enjoy multiple SIM services.
• DSDS UE User Equipment
• a first type is called Single Talk, where two baseband modules share the same RF module. Single Talk device has low cost and no RF coexistence interference. However, Single Talk requires complex implementation to support Dual-Standby.
• Dual Talk only supports one voice call, and requires gap to monitor paging signals.
• a second type is called Dual Talk, where two baseband modules utilize tow individual RF modules. Dual Talk only requires simple implementation to support dual standby and can support voice calls over both SIM cards simultaneously. However, Dual Talk device has high cost and RF coexistence interference.
• UE may not be able to continue the active data connection and would like to request data suspension for a certain period. For example, when channel quality is suddenly degraded, when battery being exhausted, or when UE could standby in multiple access networks with shared RF resources intends to temporarily switch access from one access network to another. In current UMTS network, it is difficult for the network to learn such behavior initiated by UE. UE may have no choice but perform local release to end the connection, which may result in the problem that the network does not know UE has ended the connection and keeps trying to send data to UE. Consequently, the network capacity may be degraded due to useless transmission and the network may consider radio link failure.
• the network may hold the radio resource for a short time and wait for the UE's reestablishment. If the UE had entirely released the connection base on local decision, the reestablishment will not happen and hence result in unnecessary waste on network resources.
• a DSDS UE may want to access the second network registered by the second SIM card whiling having active connection with the first network registered by the first SIM card.
• the UE may have difficulty to keep simultaneous radio connections with two different networks due to the limitation on RF resources and may directly release the radio connection from the first network in order to access the second network. This will result in the data connection with the first network be suspended, where the data connection may not able to be resumed when UE switch back to the first network after finishing the access to the second network. This is because the original data connection in the first network may be timed out due to the configuration by application, which is managed by the application server (e.g.
• the application server may consider the connection be disconnected and will not resume the suspended data connection even if the UE retries after radio connection is resumed. Then the UE may need to initiate a new data connection to request the previous data again. Such behavior will result in increase of signaling overhead and degrade user experience due to longer application resume processing time.
• a method for UE to indicate its upcoming transceiver operation status to network and help network to avoid inefficient radio resource schedule for better network efficiency is proposed.
• the proposed method also helps network to manage the connections for user applications to prevent unnecessary disruption due to short-term radio link disconnection.
• the method proposes that UE sends an indication to network when a suspension event is received to trigger the UE to switch the RF resources away from receiving signal from one registered network temporarily.
• the suspension event may include UE needs to receive signal from another registered network, UE battery or other hardware status is lower than a predefined threshold, UE received signal quality is extremely low, UE is in high-speed mobility, or UE packet loss and data error rate are high, etc.
• the proposed indication may further contain a suspension period to inform the network that the UE may not be able to receive its downlink signal or transmit its uplink signal in this upcoming period. After this suspension period, or when one or more resume events are received, the UE may determine to switch the RF resource back to the original registered network.
• the resume event may include UE determines to continue previous active PS data connection in the original registered network, UE battery or other hardware status is recovered, or UE is not in high-speed mobility anymore, etc.
• This invention in addition proposes a resume method for the UE to resume normal operation and keeping communicating with the network.
• the UE is a dual SIM dual standby (DSDS) UE in a UMTS network.
• DSDS dual SIM dual standby
• the UE establishes an RRC connection in a first network registered by a first SIM.
• a suspension event e.g., to receive signal from a second network registered by a second SIM
• the UE sends an enhanced signaling for UE requested PS data suspension.
• the UE sends a signaling connection release indication (SCRI) with a new cause for "UE requested PS data suspension”.
• SCRI may further include a suspension reason and a suspension period.
• the network initiates a state transition to move UE to CELL PCH or URA PCH state and keep the RRC connection until the UE reselect back to the network again.
• the benefit to move UE into CELL PCH or URA PCH state is that the UE can directly resume the RRC connection by initiating cell update procedure instead of reestablishing the RRC connection.
• a new cell update cause of "Resume PS data" is proposed. By receiving the cell update with the "Resume PS data" cause, the network understands that the UE is requesting for continuing previous data operation. The network could reply a cell update confirm message and then initiate a radio bearer control procedure as required.
• FIG. 1 illustrates a user equipment (UE) having dual SIM card dual standby (DSDS) feature in accordance with one novel aspect.
• UE user equipment
• DSDS dual SIM card dual standby
• FIG. 2 is a simplified block diagram of a UE having DSDS feature in accordance with one novel aspect.
• Figure 3 illustrates an example of signaling connection release indication (SC I) information element (IE) and cell update IE.
• SC I signaling connection release indication
• IE information element
• Figure 4 illustrates one embodiment of UE sending SCRI to network.
• Figure 5 illustrates an example of UE being in different states before/after sending SCRI.
• Figure 6 illustrates one embodiment of UE resuming a connection via cell update procedure.
• Figure 7 illustrates one embodiment of UE autonomously release RRC connection upon timer expiry.
• Figure 8 illustrates one embodiment of UE force releasing an RRC connection.
• Figure 9 is a flow chart of a method of suspending and resuming UE data in accordance with one novel aspect.
• FIG. 1 illustrates a user equipment (UE) 101 having dual SIM card dual standby (DSDS) feature in a mobile communication system 100 in accordance with one novel aspect.
• Mobile communication system 100 comprises UE 101 and a first network #1 and a second network #2.
• UE 101 supports DSDS feature such that multiple SIM cards can be used to access multiple networks, e.g., SIM1 used to access network #1 and SIM2 used to access network #2.
• UE 101 is a Single Talk UE with DSDS feature, where two baseband modules share the same RF module. Single Talk device has low cost and no RF coexistence interference. However, Single Talk requires complex implementation to support Dual-Standby. Single Talk UE only supports one voice call, and requires gap to monitor paging signals.
• UE 101 establishes an active data connection with Network #1 registered by SIM1.
• UE 101 transmits and/or receives ongoing data traffic over the data connection.
• UE 101 also monitors paging signals or system information over Network #2 registered by SIM2. If UE 101 receives actual paging over Network #2, UE 101 may have difficulty to keep simultaneous radio connections with two different networks due to the limitation on RF resources and may directly release the radio connection from the first network in order to access the second network.
• Network #1 does not know UE 101 needs to monitor the paging or system information over Network #2.
• eNodeB radio resource control e.g., link adaptation
• UE 101 indicates upcoming gaps due to DSDS operation by sending an indication 110 to Network #1 when the UE monitors radio signals or performs periodic location update to Network #2 whiling having active PS data connection with Network #1. For example, UE 101 sends the indicator with "UE requested PS data suspension" before switching the RF resources from Network #1 to Network #2.
• eNodeB in Network #1 can avoid radio resource allocation to the DSDS UE and allocate the reserved resources to other UEs more efficiently.
• eNodeB can prevent error interpretation due to the unexpected gap for DSDS.
• UE 101 may also indicates its DSDS capability to the network. As a result, eNodeB can be less sensitive to (or ignore) the unexpected gap generated by DSDS UE and thereby minimizing signaling overhead.
• FIG. 2 is a simplified block diagram of a UE 201 having DSDS feature in accordance with one novel aspect.
• UE 201 comprises RF module 205, coupled with antenna 206, receives RF signals from antenna 206, converts them to baseband signals, and sends them to processor 202.
• RF module 205 also converts received baseband signals from the processor 202, converts them to RF signals, and sends out to antenna 206.
• Processor 202 processes the received baseband signals and invokes different functional modules to perform features in the UE.
• Memory 203 stores program instructions and data 204 to control the operations of the UE.
• UE 201 comprises two SIM cards, SIM1 and SIM2, to support DSDS feature, where SIM1 and SIM2 are coupled to their corresponding baseband modules BB1 and BB2 respectively.
• UE 201 is a Single Talk UE, where BB1 and BB2 share the same RF module 205 (e.g., RF transceiver, RF filter, etc.). By sharing the same RF module, UE 201 has low cost and no RF coexistence interference. However, UE 201 only supports one voice call. If SIM1 has voice call, then SIM2 cannot have any MT/MO call. UE 201 also requires gap to monitor paging signals.
• FIG. 2 further illustrates three functional modules 211 to 213 in the UE that carry out embodiments of the current invention.
• the functional modules may be implemented by hardware, firmware, software, or any combination thereof.
• RRC configuration module 211 manages radio resource control (RRC) layer configuration and RRC connection establishment.
• Condition detection module 212 detects various triggering conditions that trigger the suspension or resuming of an ongoing RRC data connection. For example, when a UE detects certain conditions while having ongoing packet switch (PS) data, the UE sends out a signaling connection release indication (SCRI) for UE requested PS suspension. Similarly, when a UE determines to resume the previous active PS data transmission upon detecting certain conditions, the UE initiates a resume procedure such as an RRC cell update procedure.
• Timer 213 starts timers associated with the suspension or resuming of the RRC data connection.
• FIG. 3 illustrates an example of a signaling connection release indication (SCRI) information element (IE) and an example of a cell update IE.
• SCRI signaling connection release indication
• IE information element
• FIG. 3 illustrates an example of a signaling connection release indication (SCRI) information element (IE) and an example of a cell update IE.
• the original SCRI procedure defined in 3GPP Rel-8 specification is for fast dormancy.
• the SCRI IE is used by the UE to indicate to the UMTS network that one of its signaling connections has been released or to request the UMTS network to initiate a state transition to a battery efficient RRC state.
• the associated cause of the SCRI for fast dormancy is UE requested PS data session end. Without the SCRI, it may take up to ten minutes for the UMTS network to decide whether to release the RRC connection.
• SCRI is specifically designed for enabling fast dormancy. Upon receiving the SCRI, the network simply releases the RRC connection quickly or initiates a state transition to move the UE to a battery efficient RRC state.
• the traditional SCRI procedure is enhanced and is used to temporality suspend an ongoing RRC data connection and/or to resume temporarily suspended RRC data connection.
• UE requested PS data suspension a new cause of such SCRI is referred to as "UE requested PS data suspension".
• the SCRI may also comprise parameters including suspension reason and suspension period.
• the network decides whether to release the RRC connection based on the suspension reason, suspension period, and/or other information. For example, the network may decide to temporality send UE from CELL FACH or CELL DCH state to CELL PCH or URA PCH state by reconfiguring radio bearer.
• Another new cause/flag of such SCRI is force release.
• the network releases the RRC connection directly without attempt to initiate any other procedures.
• cell update procedure is used to resume the previously suspended PS data transmission.
• a new cause of cell update is referred to as "Resume PS data”.
• the network reconfigures radio bearer and initiates state transmission for the UE to move from CELL PCH or URA PCH state back to CELL FACH or CELL DCH state.
• Cell update procedure saves signaling overhead as compared to reestablish the RRC connection.
• FIG 4 illustrates one embodiment of a user equipment UE 401 sending SCRI to network for UE requested PS suspension.
• UE 401 may be a DSDS UE having two SIM cards (SIM1 and SIM2) for accessing multiple networks.
• SIM1 and SIM2 SIM cards
• UE 401 establishes an RRC connection with a network.
• the network is a first network registered by SIM1.
• UE 401 maintains ongoing PS data transmission with the network.
• UE 401 detects one or more trigger conditions to suspend the data transmission.
• the trigger condition is based on upcoming activity for the UE to access a second network registered by SIM2.
• the upcoming activity may be the UE needs to switch the RF resources away from the first network and to monitor paging from the second network.
• the upcoming activity may be the UE needs to switch the RF resources away from the first network and to access the second network.
• the trigger condition is based on comparison of a measurement result of radio signal quality, an error probability of downlink data, a UE mobility level, or a UE battery level below a corresponding threshold.
• UE 401 After detecting a trigger condition, in step 414, UE 401 sends a signaling connection release indication (SCRI) IE to the network.
• SCRI comprises a cause for UE requested PS suspension.
• the network decides whether to release the RRC connection. If the network decides to release the RRC connection, in step 415, the network sends a RRC connection release message to UE 401 to release the RRC connection. On the other hand, if the network decides not to release the RRC connection, then in step 415, the network performs radio bearer reconfiguration for UE 401. For example, the network could initiate state transition to move UE 401 from CELL DCH state to CELL PCH or URA PCH state until UE 401 reselect back to the network again.
• FIG. 5 illustrates an example of UE being in different states before/after sending the SCRI IE.
• a UE can have different RRC states as defined by the specification.
• CELL DCH state dedicated traffic and control is carried over DCH for data transmission of large amount of data.
• Circuit-switched (CS) data only uses CELL DCH for transmission.
• CELL FACH state dedicated traffic and control is carried over RACH or FACH for data transmission of small amount of data.
• CELL PCH state no air interface resources are required under dormant RB.
• the UE receives paging on cell basis rather than standard routing area (RA).
• RA standard routing area
• UTRA PCH state is similar to CELL PCH state except that paging is received in UTRAN Routing Area (URA), which is usually in the order of ten cells.
• UTRA UTRAN Routing Area
• a UE stays in CELL_DCH state with large amount of data and dynamic RB reconfiguration. If the UE has low traffic, then the UE is moved to CELL FACH state. If the UE had no data activity, then the UE is moved to CELL PCH or URA PCH state, which is based on network configuration. Similarly, in CELL FACH state, the UE moves to CELL DCH state when it has high traffic, and moves to CELL PCH or URA PCH state when it has no data activity. Finally, in CELL PCH or URA PCH state, the UE moves to CELL FACH or CELL DCH state when the UE starts to have data activity.
• URA UTRAN Routing Area
• the SCRI when UE 401 sends the SCRI to the network in CELL DCH state, instead of releasing the RRC connection, the network may decide to move the UE from CELL DCH state to CELL PCH or URA PCH state.
• the SCRI also comprises a suspension reason and a suspension period to assist the network to make corresponding decision.
• the suspension reason may include poor signal quality, high error rate, high UE mobility, low battery level, and/or DSDS operation.
• the suspension period may include a predefined or negotiated duration for suspension, or a level of suspension (e.g., temporary, short-term, long-term).
• the network decision on whether to release the RRC connection may be based on the UE provided suspension reason, suspension period, and/or some other additional information. If the network decides not to release the RRC connection, later on, when UE 401 determines to resume the suspended data transmission, UE 401 may initiate a cell update procedure.
• the cell update procedure reduces signaling overhead as compared to reestablishing the RRC connection.
• FIG. 6 illustrates one embodiment of UE resuming RRC connection via cell update procedure.
• UE 601 detects one or more trigger conditions to resume the previously suspended RRC connection.
• the trigger condition may include a measurement result of radio signal quality, an error probability of downlink data, a UE mobility level, or a UE battery level is above a corresponding threshold.
• UE 601 is a DSDS UE having two SIM cards (SIM1 and SIM2). UE 601 first access the network registered by SIM1 and establishes a RRC connection for data transmission. Later, UE 601 may want to access another network registered by SIM2 or simply monitor paging from another network.
• UE 601 then switches RF resources away from the network and suspends the RRC connection.
• the trigger condition may be UE 601 determines to switch RF resources back to the original registered network of the previous active SIM1, and to continue the previous active PS data communication.
• UE 601 sends a cell update IE to the network.
• the cell update IE comprises a cause of Resume PS data.
• the network sends a cell update confirm message back to UE 601.
• UE 601 sends a radio bearer setup complete message to the network to resume the RRC connection.
• UE 601 resumes the suspended PS data transmission.
• FIG. 7 illustrates one embodiment of UE autonomously release RRC connection upon timer expiry.
• UE 701 establishes an RRC connection with a network.
• UE 701 maintains ongoing PS data transmission with the network.
• UE 701 detects certain trigger condition for suspending the PS data transmission.
• UE 701 sends an SCRI to the network.
• the SCRI has a cause of UE requested PS suspension, a suspension reason, and a suspension period. According to 3GPP Rel-8 specification, the UE shall not locally release the RRC connection after it has sent the SCRI message.
• a timer-based protect mechanism is proposed.
• UE 701 also starts a timer and waits for network response. If the network does not respond to the SCRI before expiry of the timer, then UE 701 performs local release in step 714.
• UE wants to enter IDLE state (i.e., RRC connection released) by sending SCRI, but the network decides to move to CELL PCH or URA PCH state.
• IDLE state i.e., RRC connection released
• the network decides to move to CELL PCH or URA PCH state.
• the misinterpretation of the SCRI would still result in local release at the end.
• a proposed solution is to have an additional flag referred to as "Force Release" in the RRC SCRI message.
• FIG. 8 illustrates one embodiment of UE force releasing an RRC connection.
• UE 801 establishes an RRC connection with a network.
• UE 801 maintains ongoing PS data transmission with the network.
• UE 801 detects certain trigger condition for terminating the PS data transmission and releasing the RRC connection.
• UE 801 sends an SCRI to the network.
• the SCRI has a cause of "Force Release".
• the network upon receiving the SCRI with force release cause, the network sends an RRC connection release command to release the RRC connection directly instead of initiating other procedures.
• Unexpected collision scenarios may occur when the UE is sending the SCRI message for PS data suspension, e.g., RLC reestablishment and Inter-RAT handover, etc.
• RLC reestablishment and Inter-RAT handover etc.
• the following solutions are proposed. First, when a reestablishment of the transmitting side of the RLC entity occurs before the successful delivery of the SCRI message has been confirmed by RLC while the SCRI cause is included and is set to "UE Requested PS Data Suspension", the UE could not retransmit the message using AM RLC in case the new RNC does not support URPDS.
• the UE could determine whether to abort the signaling connection while in the new RAT. If the UE does not locally release the PS signaling connection after it has sent the SCRI message with SCRI cause set to "UE Requested PS Data Suspension", the UE could abort the signaling connection while in the new RAT. If not, the UE could maintain the signaling connection.
• Other collision scenarios could also be handled base on the principle described above. It is noted that the aforementioned solutions are complementary and may be jointly applied for different scenarios.
• FIG. 9 is a flow chart of a method of suspending and resuming UE data in accordance with one novel aspect.
• a UE establishes an RRC connection and performs ongoing data transmission in a mobile communication network.
• the UE detects a suspension condition.
• the UE transmits a signaling connection release indication (SCRI) message to the network before suspending the ongoing data transmission over the RRC connection.
• SCRI message comprises a connection release cause of UE Requested PS data suspension.
• the SCRI may further comprises a suspension reason and a suspension period to assist network decision.
• the UE suspends the ongoing data transmission over the RRC connection for the suspension period.
• the UE resumes the suspended RRC connection upon detecting a resume condition.
• the UE resumes the previous data communication by applying a cell update procedure without reestablishing the RRC connection and thereby reducing signaling overhead.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)

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• 2012
  • 2012-06-27 CN CN201210216246.3A patent/CN103517454A/zh active Pending
• 2013
  • 2013-06-26 CN CN201380009355.0A patent/CN104115454A/zh active Pending
  • 2013-06-26 IN IN30MUN2015 patent/IN2015MN00030A/en unknown
  • 2013-06-26 EP EP13810650.5A patent/EP2724502A4/en not_active Withdrawn
  • 2013-06-26 BR BR112014032891A patent/BR112014032891A2/pt not_active IP Right Cessation
  • 2013-06-26 WO PCT/CN2013/078037 patent/WO2014000650A1/en not_active Ceased
• 2014
  • 2014-04-14 US US14/251,884 patent/US20140220981A1/en not_active Abandoned

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