KR101590737B1 - Releasing time domain measurement restrictions - Google Patents

Abstract

In some implementations, the method includes identifying a reestablishment with a subsequent eNB after handover from the source eNodeB (eNB) to the target eNB or loss of connection with the initial eNB. A time domain measurement resource limit for the UE is identified. The time domain measurement resource limitation for the UE is released with respect to identifying the handover or re-establishment.

Description

{RELEASING TIME DOMAIN MEASUREMENT RESTRICTIONS}

Field of the Invention [0002] The present invention relates to communication networks, and more particularly, to canceling time domain measurement restrictions.

A heterogeneous network (HetNet) is a network that includes low-power nodes and macrocells such as picocells, femtocells, and repeaters. Low power nodes or small cells are often overlaid on top of macrocells, and it is also possible to share the same frequency. Such small cells may offload macrocells, improve indoor and cell edge performance, or provide other advantages. The 3GPP study for LET-Advanced (Release 10) includes a HetNet deployment as a major performance-enhancing enabler. In HetNet deployment, inter cell interference coordination (ICIC) plays a key role, time domain based resource sharing or coordination is adopted as enhanced ICIC (eICIC), and eICIC is called ABS (Almost Blank Subframe ) Based solutions. LTE-Advanced (LET-A) identifies two major deployment scenarios where eICIC is used. In the first or CSG (femtocell) scenario, the dominant interference condition may occur when the non-member user is in close proximity to the CSG cell. In some cases, the downlink transmission from the non-member CSG cell may significantly interfere with the physical downlink control channel (PDCCH). Interference on the PDCCH of the macrocell may have a deleterious effect on both the uplink data transmission and the downlink data transmission between the UE and the macrocell. In addition, the downlink transmission from the non-member CSG cells may also interfere with other downlink control channels and reference signals, other downlink control channels and reference signals may originate from macro cells and neighbor cells, Link monitoring can be used. Depending on the network deployment and strategy, the system can not convert a user experiencing inter-cell interference to another E-UTRA carrier or other Radio Access Technology (RAT). Time domain ICIC may be used to allow such non-member UEs to continue to be serviced by the macrocell on the same frequency layer. In order to protect the sub-frames of the corresponding macro cell from interference, the interference can be removed, minimized, or reduced by the CSG cell using ABS (Almost Blank Subframe). The non-member UE is signaled to use protected resources for radio resource measurement (RRM), radio link monitoring (RLM) and channel state information (CSI) measurements for the serving macrocell , Which allows the UE to continue to be serviced by the macrocell under strong interference from the CSG cell.

In a second or picocell scenario, a time domain ICIC can be used for picocell users, and picocell users are served on the edge of a serving picocell as in the case of traffic offloading from a macrocell to a picocell. Typically, downlink transmissions from macrocells can severely interfere with the PDCCH. In addition, the downlink transmission from the macrocell may also interfere with the reference signal from the picocell or neighbor picocell and other downlink control channels. Other downlink control channels and reference signals may be used for cell measurement and radio link monitoring. Time domain ICIC may be used to allow such UEs to continue to be served by the picocell on the same frequency layer. This interference can be reduced by the macro cell (s) using ABS to protect the sub-frames of the corresponding picocell from interference. A UE served by a picocell can use protected resources for radio resource measurement (RRM), radio link monitoring (RLM) and channel state information (CSI) measurements on a serving picocell.

In the case of time domain ICIC, the use of subframes across different cells is adjusted in time via backhaul signaling of the so-called ABS pattern or an operations and management (OAM) configuration. In general, the ABS of the attacker cell is used to protect the resources of the subframe in the victim cell receiving strong intercell interference from the attacker cell. The ABS is a subframe with reduced transmit power (including no transmission) and / or reduced activity on some physical channels. The eNB ensures backward compatibility towards the UEs by transmitting system information as well as necessary control channels and physical signals. A pattern based on ABS is signaled to the UE to limit the UE's measurement for a particular subframe, which is referred to as time domain measurement resource limitation. Different patterns may be implemented according to the type of cell (serving cell or neighboring cell) and type of measurement (e.g., RRM, RLM) being measured. In some cases, the macro eNB (attacker) constructs an ABS pattern and delivers it to the pico eNB (victim). The macro eNB does not schedule data transmission in the ABS subframe to protect the UEs served by the pico eNB at the edge of the picocell. The pico eNB can schedule transmissions with the cell center UEs regardless of the ABS pattern. On the other hand, the pico eNB can only schedule transmissions with UEs at the edge of the cell only in the ABS. The picocell can configure the UE with three different measurement resource limits independently at the edge of the cell based on the received ABS pattern. The first limitation is for radio link monitoring (RLM) and RRM measurements on PCell (in this case, serving picocells on the primary frequency). If configured, the RLM of the PCell is measured and performed only in the configured subframe. The second limitation is for the RRM measurement of neighboring cells on the primary frequency. If configured, the UE measures neighbor cells only in the configured subframe. This restriction may also include target neighbor cells to which the restriction applies. The third limitation is to estimate the channel state of PCell. If configured, the UE may estimate CSI and CQI / PRM / RI only in the configured subframe.

According to the current radio resource control (RRC) protocol specification, MeasSubframePatternConfigNeigh is an information element (IE) in the EUTRA measurement object (measObjectEUTRA). The phrase "Need ON" means that, in the absence of this information element, the UE does not take any action and, if applicable, continues to use the existing value (and / or associated function).

In some scenarios, in-frequency handover is performed in an area managed by an LTE-A system or an LTE system with no eICIC / HetNet feature, or a Release 8 or 9 eNB in contrast to LTE-A systems with support for the eICIC / HetNet feature. UE can be switched. The target eNB prepares the handover command, but the target eNB does not support the time domain measurement resource limitation. The target Release 8 or 9 eNB can not release this restriction on the prepared handover command or can not release this restriction by the reconfiguration message after handover without using the full configuration option, Lt; / RTI > is released. With the full configuration option, the size of the reconfiguration message is larger than without this option. Therefore, the use of these options should be limited to maintain efficient operation. Also, the target LTE-A eNB without the eICIC / HetNet feature can not instruct the UE to release the measurement limit. Then, the UE will continue to apply this restriction since measSubframePatternConfigNeigh is not included in the handover command. In an intra-frequency handover example, measurement resource limits for neighboring cells may be applied incoherently. That is, the UE applies the restriction but does not apply the eNB. Such an incoherent application may cause unintended handover or radio link failure due to the difference in performance requirements (RSRP and RSRQ accuracy and detection time of neighboring cells) depending on whether there is a measurement resource limitation for neighboring cells. Using measurement resource limits allows better signal-to-interference and noise (RSRP) to have the same Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) A signal to interference and noise ratio (SINR) is required, and the measurement results reported by the UE applying this restriction may be less accurate than the eNB expects, which may lead to unintended handover . In addition, using these measurement limits may take longer to detect cells in neighboring frequencies, which may cause radio link failure. The source eNB can perform measurement reconfiguration while preparing for handover with the target eNB. However, due to this additional processing, the handover execution can be delayed, resulting in a higher handover failure rate.

For the inter-frequency handover case, after the inter-frequency handover (from f1 to f2), the time domain measurement resource constraints configured for the primary frequency f1 of the source are not applied to f1 (That is, not released) unless explicitly done by the RRC Connection Reconfiguration message because it is no longer the primary frequency. Depending on the release of the target eNB or the support of the eICIC / HetNet feature, time domain measurement resource limits for neighboring cells may be applied incoherently. That is, the UE applies the restriction but does not apply the eNB. Such an incoherent application may cause unintended handover or radio link failure as described above.

In some scenarios, subsequent handover (from f1 to f2), subsequent inter-frequency handover (from f2 to f1) is managed by an LET-A eNB or Release 8 or 9 eNB with no eICIC / Lt; RTI ID = 0.0 > UE. ≪ / RTI > The target eNB prepares a handover command. In this case, the target eNB does not support time domain measurement resource limitation. The target Release 8 or 9 eNB can not release this restriction on the prepared handover command or can not release this restriction by the reconfiguration message after handover without using the full configuration option, Lt; / RTI > is released. With the full configuration option, the size of the reconfiguration message is larger than without this option. Therefore, the use of these options should be limited to maintain efficient operation. Also, the target LTE-A eNB without the eICIC / HetNet feature can not instruct the UE to release the measurement limit. Then, the UE restarts to apply the restriction on f1 upon handover. This problem is also applicable when the UE re-establishes the RRC connection. The time domain measurement resource constraints for neighboring cells may be applied incoherently, which may cause another radio link failure or an unintended handover.

In some scenarios, after experiencing a radio link failure, the UE may find the appropriate cell and may determine that the RRC connection is not available in the cell controlled by the LET-A eNB or Release 8 or 9 eNB without the eICIC / HetNet feature Can be established. In this case, the subsequent eNB does not support the time domain measurement resource limitation. Subsequent Release 8 or 9 eNBs can not indicate the release of this restriction by a reconfiguration message after re-establishment without using the full configuration option, and all configuration including the measurement configuration is released by the prerequisite configuration option. With the full configuration option, the size of the reconfiguration message is larger than without this option. Therefore, the use of these options should be limited to maintain efficient operation. In addition, subsequent LTE-A eNBs without the eICIC / HetNet feature can not instruct the UE to release measurement limits. The UE will then begin to apply this restriction upon re-establishment. This problem applies regardless of the frequency of the cell in which the UE re-establishes the RRC connection.

In some scenarios, the UE re-establishes the RRC connection in the cell for which the restriction is no longer applicable. The eNB releases this restriction by sending a reconfiguration message after the re-establishment procedure, but this message transmission is delayed due to overload on the eNB, or this message can not reach the UE due to poor radio conditions. In the meantime, the UE restarts to apply this restriction. This problem applies regardless of the frequency of the cell in which the UE re-establishes the RRC connection.

It is an object of the present invention to provide a method and apparatus for canceling time domain measurement limitations.

In some implementations, the method includes identifying a reestablishment with a subsequent eNB after handover from the source eNodeB (eNB) to the target eNB or loss of connection with the initial eNB. A time domain measurement resource limit for the UE is identified. The time domain measurement resource limitation for the UE is released with respect to identifying the handover or re-establishment.

According to the present invention, it is possible to provide a method and apparatus for canceling time domain measurement restrictions.

Figure 1 is an exemplary system for releasing time domain measurement limitations in accordance with some embodiments of the present disclosure.
2 is an exemplary LTE system of Fig.
3 shows an exemplary UE of Fig.
Figures 4 and 5 illustrate an exemplary method for canceling time domain measurement limitations.
6 shows an exemplary MobilityControlInfo information element including preserveMeasSubframePatternNeigh.
Figure 7 shows an exemplary RRCConnectionReestablishment message including preserveMeasSubframePatternNeigh.
Figure 8 shows another exemplary method for canceling the time domain measurement limitations.
Figure 9 shows an exemplary MeasObjectEUTRA information element.
10 shows an exemplary HandoverPreparationInformation message.
11 is a flow chart illustrating another exemplary method for canceling time domain measurement limitations.
Figure 12 is a flow diagram illustrating another exemplary method for canceling time domain measurement limitations.
In the various drawings, like reference numerals designate like elements.

The present disclosure is directed to a system and method for releasing a time domain measurement resource limitation in accordance with some embodiments of the present disclosure. For example, the UE may release the time domain measurement resource limit for neighboring cells upon handover or re-establishment. The UE may release the time domain measurement resource limit for neighboring cells configured for the primary frequency of the source, the primary frequency of the target, or any EUTRA frequency. In general, LTE-A systems or LTE systems without eICIC / HetNet features include eNBs or legacy eNBs that do not support time domain measurement resource constraints, as opposed to LTE-A systems with eICIC / HetNet features. In order to eliminate the problems caused by eNBs without eICIC / HetNet features, the measurement resource limitation for neighboring cells configured for the primary frequency of the target is limited by the problem associated with the UE performing this restriction while the eNB does not support the restriction Can be automatically released to avoid the problem. For example, the UE may identify the handover or re-establishment and may automatically limit any time domain measurement resource limits configured for the primary frequency of the target, for the primary frequency of the source, or for any EUTRA frequency Can be released. By automatically releasing limits configured for the primary frequency of the target, at least in response to handover or re-establishment, the effects of the pre-configured limit can be minimized or reduced and the problem can be sufficiently prevented. This implementation is a simple solution and can be executed without regard to RRC signaling or without any change to RRC signaling. In addition, such a solution can be implemented in accordance with the Release 10 standard. After releasing the restriction, the target eNB may reestablish the restriction if the same restriction is necessary in the target cell.

When the source eNB requests handover preparation from the target eNB, the source eNB indicates ue-ConfigRelease indicating the RRC protocol release applicable to the current UE configuration. For example, if a UE with a time domain measurement limit is configured, ue-ConfigRelease is set to Release 10. This information can be used by the target eNB to determine if the entire configuration option should be used. If this field is not present, the target assumes that the current UE configuration is based on the Release 8 version of the RRC protocol. The overall configuration options include initialization of the wireless configuration and initialization of such a wireless configuration creates a procedure independent of the configuration used for the source cell (s) except that the security algorithm continues during RRC re-establishment. The size of the reconfiguration message with the total configuration option increases, so its use should be limited to maintain efficient operation. Using the proposed automatic release of measurement limits by the UE, the source eNB will also set the ue-ConfigRelease to Release 8 or 9 to avoid full configuration by the target Release 8 or 9 eNB, even if a UE with time- Can be set. In areas of the network where time domain measurement constraints are used, the serving eNB may avoid the use of a more rewritten multi-antenna transmission technique as defined in Release 10. Therefore, using the automatic release of the time domain measurement limit by the UE, the change to avoid the entire configuration in the handover or re-establishment from the LTE-A system with the eICIC / HetNet feature to the LET system will increase. Alternatively, a handover preparation request may be extended to indicate that no total reconfiguration is required, as shown in FIG. 10, and FIG. 10 illustrates an exemplary andoverPreparationInformation message 1000.

In some implementations, the time domain measurement resource limit may be released for neighboring cells by defining measSubframePatternConfigNeigh as "Need OR" in the MeasObjectEUTRA information element. The phrase "Need OR" means that if a message is received by the UE, the UE can pause, stop using, delete or release any existing values if this information element is absent. In other words, the UE can maintain the time domain measurement resource limitation if the information element instructs the UE to maintain its limit. The absence of this information element may instruct the UE to release the time domain measurement resource restriction. To implement this solution, the RRC signaling definition in Release 10 can be updated.

In some implementations, the target eNB may indicate to the handover command whether the time domain measurement resource limit for the neighboring cell should be preserved. The retention indication may be for a measurement object dedicated to the primary frequency of the target, a measurement object dedicated to the primary frequency of the source, or a measurement object of any EUTRA frequency. For example, if the same limit is applicable in the target cell, conservation may be indicated for the target frequency, which may eliminate reconstitution of the limit. This indication may be sent to the UE in an RRC Connection Reconfiguration message. When the UE receives the retention indication in the reconfiguration message, the UE can maintain the measurement resource limit for the frequency specified by the retention indication and release the measurement resource limit for other EUTRA frequencies. If there is no retention indication, the UE may release the time domain measurement resource limit for neighboring cells configured for the primary frequency of the target, the primary frequency of the source, or any EUTRA frequency. If the target eNB is Release 8 or 9 and there is no retention indication, the UE may release the measurement limit configured for the primary frequency of the target, the primary frequency of the source, or any EUTRA frequency. In the reestablishment procedure, the eNB dealing with re-establishment indicates whether this limit on the primary frequency of the target, the primary frequency of the source, or any EUTRA frequency should be preserved. If a previously configured restriction is applicable to the cell where re-establishment occurs, an indication may be sent in the RRC Connection Reestablishment message.

In some implementations, the target LTE-A eNB without the eICIC / HetNet feature instructs the UE to release the time domain measurement restriction if the UE with the restriction is configured by setting the measSubframePatternConfigNeigh for release to the prepared handover command.

As described above, some implementations may include additional information elements to indicate whether the constraints should be preserved. Another solution may be that the source eNB adds a measurement configuration information element to the handover command prepared by the target eNB. For example, if an explicit release of a measurement resource limit is desired, the source eNB may include this indication in a handover command prepared by the target eNB. The source eNB may obtain knowledge about the target eNB release information through the OAM system. Alternatively or additionally, the X2 interface may be extended to convey eNB Release information.

 Referring to the environment description, FIG. 1 shows an exemplary system 100 for releasing time domain measurement resource constraints in connection with handover or re-establishment. For example, the system 100 may release a time domain measurement resource limit for a specified frequency, a predetermined frequency, or a preconfigured frequency in response to at least handover or re-establishment. As illustrated, the system 100 includes an LTE system or an LTE-A system (non-eICIC LTE system) 102 with no eICIC / HetNet feature configured to communicate with the UE 106 and an LTE system with an eICIC / HetNet feature eICIC LTE system) 104. The non-eICIC system 102 includes a base station 108a for wireless communication with the UE 106 and the base station 108a may have a signal coverage area that is partially indicated by a dashed line 110a. As noted above, the non-eICIC system 102 is not configured to perform time domain measurement resource limitation as compared to an LTE-A system with eICIC / HetNet features such as eICIC system 104. [ eICIC system 104 includes base station 108b for wireless communication with UE 106 and base station 108b may have a signal coverage area that is partially indicated by dashed line 110b. eICIC system 104 is configured to perform time domain measurement resource limitation using ABS. In some implementations, the UE 106 identifies a handover or re-establishment; Release the time domain measurement resource limitation with respect to handover or re-establishment; Automatically release the time domain measurement resource limit in response to handover or re-establishment; Receive a message from the eICIC system 104 that includes information indicating to the UE 106 whether to release or maintain the time domain measurement resource limit; Canceling the restriction on at least one of the primary frequency of the target, the primary frequency of the source, the initial primary frequency, the subsequent primary frequency, or any EUTRAN frequency. By releasing the time domain restriction, the incoherent application of the constraints can be eliminated or reduced, which can improve mobility robustness by avoiding unintentional handover and radio link failures.

Referring to the more detailed description of the elements, the non-eICIC system 102 wirelessly communicates using the base station 108a or the eNB 108a. In some implementations, the non-eICIC system 102 may include a plurality of eNBs. In some implementations, the non-eICIC system 102 communicates with other wireless communication systems and networks that provide connectivity to wired communication systems. The non-eICIC system 102 may communicate with the UE 106 using orthogonal frequency division multiplexing (OFDM) radio technology. Similarly, eICIC system 104 includes eNB 108b and communicates using OFDM. In addition, the eICIC system 104 may implement ABS (Almost Blank Subframe) to reduce inter-cell interference by adjusting in time through backhaul signaling or operations and management (OAM) configurations. eICIC system 104 may utilize ABS in the attacker cell to protect the resources of the subframe in the victim cell receiving strong intercell interference from the attacker cell. As noted above, ABS is a subframe with reduced transmit power (including no transmissions) and / or reduced activity on some physical channels. The eNB 108b may signal patterns based on the ABS to the UE 106 to limit the UE's measurement for a particular subframe, which is referred to as a time domain measurement resource limit. Different patterns may be implemented according to the type of cell (serving cell or neighboring cell) and type of measurement (e.g., RRM, RLM) being measured.

In general, UE 106 may receive and transmit wireless and / or non-contact communication signals in system 100. As used in this disclosure, UE 106 may be a cellular phone, a data phone, a pager, a portable computer, a SIP phone, a smart phone, a personal digital assistant (PDA), a digital camera, an MP3 player, Is intended to include one or more processors in other devices, or any other suitable processing device capable of communicating information with the LTE system 102 and the LTE-A system 104. In some implementations, the UE 106 may be based on cellular radio technology. For example, the UE 106 may be a PDA operable to establish a wireless connection with an external or non-secure network. In another example, the UE 106 may include an input device such as a keypad, a touch screen, a mouse, or other device capable of receiving information, and digital data, visual information, or graphical user interface (GUI) 112 ) And an output device that is capable of communicating information associated with the LTE system 102 and the LTE-A system 104. [

The GUI 112 is a graphical user interface that is operable to allow the user of the UE 106 to interface with at least a portion of the system 100 for any suitable purpose (e.g., authorizing the presentation of an alert notification enablement) Interface. Generally, the GUI 112 may include an efficient and user-friendly display of data communicated to the particular user by the system 100 or communicated within the system 100 and / or an access service provided by the PLMN 102 and / Provides an efficient and user-friendly means for users to manage settings. GUI 112 may include a plurality of customized frames or views having interactive fields, pull-down lists, and / or buttons that are operated by the user. The term graphical user interface may be used singly or in combination to describe each of the one or more graphical user interfaces and the displays of a particular graphical user interface. The GUI 112 may include any graphical user interface, such as a conventional web browser or touch screen, that processes information of the system 100 and displays the results to the user.

2, the LTE network 200 includes a core network called an evolved packet core (EPC) and an LTE radio access network (e.g., an evolved UTRAN (E-UTRAN)). The core network provides a connection to an external network, such as the Internet 230. LTE network 200 includes one or more base stations such as eNodeB (eNB) base stations 210a and 210b that provide wireless service (s) to one or more devices, such as UE 205.

The EPC-based core network may include a Serving Gateway (SGW) 220, a Mobility Management Entity (MME) 215, and a Packet Gateway (PGW) SGW 220 may route traffic within the core network. The MME 215 is responsible for attaching the core network mobility control of the UE 205 to the core network 205 and for maintaining contact with the idle mode UEs. The PGW 225 is responsible for enabling input / output of traffic from / to the Internet 230. The PGW 225 may assign an IP address to the UEs 205.

An LTE based wireless communication system has a network interface defined between system elements. The network interface is defined between UU interface defined between UE and eNB, S1U user plane interface defined between eNB and SGW, S1C control plane interface defined between eNB and MME (also known as S1-MME), and between SGW and PGW Gt; S5 / S8 < / RTI > interface. Note that the combination of S1U and S1C is usually simplified to "S1 ".

FIG. 3 illustrates an exemplary UE 305 that includes a processor electronics 310, such as a processor, that implements one or more of the techniques presented herein. The UE 305 may include a transceiver electronics 315 to send and receive wireless signals via one or more communication interfaces, such as one or more antennas 320. The UE 305 may include other communication interfaces for transmitting and receiving data. In some implementations, the UE 305 may include one or more wired network interfaces to communicate with a wired network. In other implementations, the UE 305 may provide input / output (I / O) data for user data (e.g., text input from a keyboard, graphical output to a display, touch screen input, vibrator, accelerometer, test port, O). ≪ / RTI > The UE 305 may include one or more memories 340 configured to store information such as data and / or instructions. In yet other embodiments, the processor electronics 310 may include at least a portion of the transceiver electronics 315.

Figures 4, 5 and 8 are flow charts illustrating exemplary methods 400, 500, and 800 for releasing time domain measurement resource limits. Although the illustrated methods 400, 500, and 800 are described for the system 100 of FIG. 1, the method may be utilized by any other suitable system. Moreover, the system 100 may utilize any other suitable techniques for performing these tasks. Thus, many of the steps in this flowchart may occur in a different order than the concurrent and / or illustrated order. As long as the methods remain appropriately, the system 100 may also use additional steps, fewer steps, and / or methods with different steps. In addition, the system 100 may have other granularity-based settings without departing from the scope of the present disclosure.

Referring to FIG. 4, method 400 is a flowchart for automatically releasing a time domain measurement resource limit in response to a handover or re-establishment. For E-UTRAN that performs handover, measObjectId corresponding to the primary frequency of each handover target is configured. For E-UTRAN that performs re-establishment, measObjectId corresponding to the primary frequency of each handover target is configured and the subsequent connection reconfiguration procedure immediately follows re-establishment.

The method 400 begins at step 402, where the UE 106 identifies each measId contained in the measIdList in the VarMeasConfig. In decision step 404, if the triggerType is set periodically, then in step 406, the UE 106 removes this measId from measIdList in VarMeasConfig. Otherwise, execution proceeds to step 408, where the UE releases MeasSubframePatternConfigNeigh if MeasSubframePatternConfigNeigh is configured in measObject for the primary frequency of the target. If the procedure has been triggered by a handover or a successful re-establishment and at decision step 410 the process includes a change in the primary frequency, then at step 412, the UE 106 updates the measId value in the measIdList in VarMeasConfig do. If, in decision step 414, a measObjectId value corresponding to the primary frequency of the target exists, then in step 416, if the measId value is linked to a measObjectId value corresponding to the primary frequency of the source, Is linked to the measObjectId value corresponding to the primary frequency. If, in step 418, the measId value is linked to a measObjectId value corresponding to the primary frequency of the target, then this measId value is linked to the measObjectId value corresponding to the primary frequency of the source. Returning to decision step 414, if there is no measObjectId value corresponding to the primary frequency of the target, then in step 420, all measId values linked to the measObjectId value corresponding to the primary frequency of the source are removed. At step 422, the UE 106 removes all measurement report entries in the VarMeasReportList. Next, at step 424, the UE 106 stops the periodic reporting timer or associated information (e.g., timeToTrigger) for all measId as well as timer T321 (whichever timer is active). In step 426, the UE 106 releases the measurement gap if the measurement gap is activated. If the UE requires a measurement gap to perform inter-frequency measurements or inter-RAT measurements, the UE may resume inter-frequency measurements and inter-RAT measurements after the E-UTRAN has set up the measurement gap.

Referring to Fig. 11, a method 1100 is a flow chart for handover preparation by the eICIC LTE eNB 104 as a source eNB. The method 1100 begins at step 1102, at which the source eNB 104 selects the target eNB to which the UE 106 is switched. In step 1104, the source eNB 104 generates the handover preparation command shown in Fig. At step 1106, if a UE is configured without any Release 10 features except time domain measurement constraints, then the source eNB will release the features configured in the UE 106 to prevent the target eNB from applying the full configuration option And sets the ue-ConfigRelease (1002 in FIG. Ue-ConfigRelease may not be included if only Release 8 features are configured, except for time domain measurement limits. The source eNB 104 may also set FullConfig (1004 in FIG. 10) to FALSE to prevent the target eNB from applying the full configuration option. If at step 1106 a UE with Release 10 features is configured except for the time domain measurement restriction, then at step 1110 the source eNB sets the ue-ConfigRelease to release 10. In step 1112, the source eNB 104 sends a handover prepare command to the target eNB. The method may be applied to other Release 10 features other than time domain measurement limitations.

Referring to FIG. 5, method 500 is a flow chart for releasing a time domain measurement resource restriction when a retention indication is omitted from communication in connection with handover or re-establishment. For example, the measurement resource limitation for neighbor cells may be released by the UE 106 upon handover or re-establishment if its conservation is not indicated as shown below. For E-UTRAN that performs handover, measObjectId corresponding to the primary frequency of each handover target is configured. For the E-UTRAN that performs re-establishment, the measObjectId corresponding to the primary frequency of each handover target is configured and the subsequent connection reconfiguration procedure immediately follows re-establishment.

The method 500 begins at step 502, where the UE 106 identifies each measId contained in the measIdList in the VarMeasConfig. In decision step 504, if the triggerType is set periodically, then in step 506 UE 106 removes measId from measIdList in VarMeasConfig. Otherwise, execution proceeds to decision step 508. [ If PreserveMeasSubframePatternNeigh is not included, then UE 106 releases MeasSubframePatternConfigNeigh if MeasSubframePatternConfigNeigh is configured on the primary frequency of the target, on the primary frequency of the source, or on measObject for any EUTRA frequency, do. If PreserveMeasSubframePatternNeigh is included, then at step 512, UE 106 releases MeasSubframePatternConfigNeigh if MeasSubframePatternConfigNeigh is configured in measObject for frequencies not indicated by PreserveMeasSubframePatternNeigh. For handover, FIG. 6 shows an exemplary MobilityControlInfo information element 600 that includes preserveMeasSubframePatternNeigh. This field is used to indicate the frequency at which measSubframePatternConfigNeigh should be maintained at handover. SOURCE means to preserve the limit on the primary frequency of the source, TARGET means to preserve the limit on the primary frequency of the target, and ANY means to preserve the limit on any EUTRA frequency. Regarding re-establishment, FIG. 7 shows an exemplary RRCConnectionReestablishment message 700 containing preserveMeasSubframePatternNeigh. This field is used to indicate the frequency at which measSubframePatternConfigNeigh should be maintained at re-establishment. SOURCE means to preserve the limit on the primary frequency of the source, TARGET means to preserve the limit on the primary frequency of the target, and ANY means to preserve the limit on any EUTRA frequency. If the procedure is triggered by a handover or a successful re-establishment and the process includes a change in the primary frequency in decision step 514, then in step 516, the UE 106 updates the measId value in measIdList in VarMeasConfig. If, in decision step 518, there is a measObjectId value corresponding to the primary frequency of the target, then in step 520, if the measId value is linked to a measObjectId value corresponding to the primary frequency of the source, Is linked to the measObjectId value corresponding to the primary frequency. In step 522, if the measId value is linked to a measObjectId value corresponding to the primary frequency of the target, then this measId value is linked to the measObjectId value corresponding to the primary frequency of the source. Returning to decision step 518, if there is no measObjectId value corresponding to the primary frequency of the target, then in step 524 all measId values linked to the measObjectId value corresponding to the primary frequency of the source are removed.

Referring to FIG. 8, method 800 relates to redefining the current information element or measSubframePatternConfigNeigh such that the time domain measurement resource restriction is released when no explicit signaling is received with respect to handover or re-establishment. Currently, measSubframePatternConfigNeigh is defined as OPTIONAL-Need ON, and an explicit release is required to stop this application. The method 800 changes its value from Need ON to Need OR so that the configured measSubframePatternConfigNeigh is released if no explicit signaling is received during handover or re-establishment. An example of measSubframePatternConfigNeigh, an exemplary MeasObjectEUTRA information element containing the value of Need OR, appears in FIG.

The method 800 begins at step 802, where each measObjectId contained in the received measObjectToAddModList is identified. If, at decision 804, an entry with a corresponding measObjectId exists in the measObjectList in VarMeasConfig, then at step 806, the UE 106 receives, for measObject, the fields measSubFrameNum You can replace the entry with a value that is not a valid value. If measSubframePatternConfigNeigh is configured in measObject with a matching measObjectId and the received measObject does not contain measSubframePatternConfigNeigh, the configured measurement limit will be released. If, at decision 808, the received measObject contains cellsToRemoveList, at step 810, for each cellIndex contained in the cellsToRemoveList, the UE 106 removes the entry with the matching cellIndex from cellsToAddModList. Otherwise, execution proceeds to decision step 812. If the received measObject contains cellsToAddModList, for each cellIndex value contained in cellsToAddModList, at step 814, the UE 106, if an entry with a matching cellIndex exists in cellsToAddModList, returns the value received for this cellIndex Replace the entry. Otherwise, at step 816, the UE 106 adds a new entry for the received cellIndex to cellsToAddModList. If, in decision step 818, the received measObject contains a blackCellsToRemoveList, for each cellIndex contained in the blackCellsToRemoveList, then in step 820, the UE 106 removes the entry with the matching cellIndex from blackCellsToAddModList. Otherwise, execution proceeds to decision step 822. [ If the received measObject contains blackCellsToAddModList, for each cellIndex contained in the blackCellsToAddModList, at step 824, the UE 106 determines if the entry with the matching cellIndex is included in the blackCellsToAddModList, . If not, at step 826, the UE 106 adds a new entry for the received cellIndex to the blackCellsToAddModList. At step 832, for each measId associated with measObjectId in measIdList in VarMeasConfig, if any, UE 106 removes the measurement report entry for measId from VarMeasReportList, if included. Next, at step 834, the UE 106 suspends the periodic reporting timer or timer T321 (whichever timer is active) and resets the associated information (e.g., timeToTrigger) for measId. Returning to decision step 804, if a matching measObjectId is not present in the measObjectList in VarMeasConfig, then at step 836, the UE 106 adds a new entry for the measObject received in the measObjectList in VarMeasConfig.

Referring to FIG. 12, method 1200 is a flow chart for handover preparation by LTE-A non-ICIC eNB 102 as a target eNB. In step 1202, the target eNB 102 receives the handover preparation command shown in Fig. 10 from the source eNB. In step 1204, the target eNB 102 reserves radio resources for the UE 106 and generates a handover command. In step 1206, the target eNB 102 determines whether the UE 106 has a time domain measurement limit, in step 1206. In step 1206, Set measSubframePatternConfigNeigh to off in measObject. In step 1210, the target eNB 102 sends a handover command back to the source eNB. The method may be applied to release 10 features that are not supported by LTE-A target eNBs other than time domain measurement limitations.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, if the source eNB knows that the target eNB is Release 8/9, the source eNB adds measurement configuration information elements to the handover command prepared by the target eNB before sending the handover command to the UE, Can be released. Accordingly, other embodiments are within the scope of the following claims.

Claims (41)

In the method,
Setting a value of MeasObjectEUTRA information element measSubframePatternConfigNeigh to Need OR;
Identifying a reestablishment with a subsequent eNB after a handover from the source eNodeB (eNB) to the target eNB or loss of connection with the initial eNB;
Determining that the wireless communication for the handover or reestablishment does not include a measSubframePatternConfigNeigh information element;
Identifying a time domain measurement resource limit for a user equipment (UE); And
In response to the determination, releasing a time domain measurement resource limitation for the UE with respect to identifying the handover or re-establishment,
≪ / RTI > 2. The method of claim 1, wherein releasing the time domain measurement resource restriction comprises automatically releasing the time domain measurement resource restriction in response to the handover or re-establishment. delete delete delete delete 2. The method of claim 1, wherein the step of canceling the time domain measurement resource limitation comprises: determining a target frequency, a target frequency, a source primary frequency, an initial primary frequency, a subsequent primary frequency, an arbitrary EUTRA frequency, And canceling the time domain measurement resource limit for neighboring cells for at least one of the preconfigured frequencies. 1. A user equipment (UE)
The one or more processors comprising:
MeasObjectEUTRA Set the value of the information element measSubframePatternConfigNeigh to Need OR;
Identify re-establishment with a subsequent eNB after loss of a handover from the source eNodeB (eNB) to the target eNB or connection with the initial eNB;
Determine that the wireless communication for the handover or reestablishment does not include a measSubframePatternConfigNeigh information element;
Identify a time domain measurement resource limit for the UE;
Wherein the UE is configured to release a time domain measurement resource limit for the UE in connection with identifying the handover or re-establishment in response to the determination. 9. The method of claim 8, wherein the one or more processors configured to release the time domain measurement resource limit include one or more processors configured to automatically release the time domain measurement resource limit in response to the handover or re- Equipment (UE). delete delete delete delete 9. The method of claim 8, wherein the one or more processors configured to release the time domain measurement resource limitations are selected from the group consisting of a primary frequency of a target, a primary frequency of a source, an initial primary frequency, a subsequent primary frequency, an arbitrary EUTRA frequency, Wherein the at least one processor is configured to release a time domain measurement resource limit for neighboring cells for at least one of a predetermined or preconfigured frequency. A computer program product encoded with a computer program product, the computer program product comprising:
MeasObjectEUTRA Set the value of the information element measSubframePatternConfigNeigh to Need OR;
Identifying re-establishment with a subsequent eNB after loss of a handover from the source eNodeB (eNB) to the target eNB or loss of connection with the initial eNB;
Determining that the wireless communication for the handover or reestablishment does not include a measSubframePatternConfigNeigh information element;
Identifying a time domain measurement resource limit for a user equipment (UE); And
In response to the determination, releasing a time domain measurement resource limit for the UE in connection with identifying the handover or re-establishment
Readable instructions to cause at least one processor to perform operations comprising: 16. The computer-readable medium of claim 15, wherein the act of releasing the time domain measurement resource limitation comprises an act of automatically releasing the time domain measurement resource limit in response to the handover or re-establishment. Readable storage medium. delete delete delete delete 16. The method of claim 15, wherein the act of releasing the time domain measurement resource limitation comprises: determining a target frequency, a target frequency, a source primary frequency, an initial primary frequency, a subsequent primary frequency, an arbitrary EUTRA frequency, And canceling a time domain measurement resource limit for neighboring cells for at least one of a predetermined or preconfigured frequency. In the method,
Sending a command to the user equipment (UE) to set the value of MeasObjectEUTRA information element measSubframePatternConfigNeigh to Need OR;
Identifying, by the source eNB, a handover to a target eNB;
Identifying a time domain measurement resource limit for the UE; And
Transmitting, by the source eNB, a handover command having a measSubframePatternConfigNeigh information element to maintain a time domain measurement resource limit for the UE based on the handover
≪ / RTI > delete 23. The method of claim 22,
Sending a request to the target eNB for information identifying a type of network; And
Further comprising determining, based on a response from the target eNB, that the target eNB is served by an LTE (Long Term Evolution) network,
Wherein the handover command indicates that the target eNB is serviced by the LTE network. 25. The method of claim 24, wherein the request is sent using an X2 interface or an operations and management (OAM) system. 23. The method of claim 22 wherein the handover command instructs to maintain a time domain measurement resource limit for neighboring cells for at least one of a target primary frequency, a source primary frequency, or an arbitrary EUTRA frequency . 23. The method of claim 22, wherein the handover command comprises a SubframePatternConfigNeigh information element set by the target eNB to cancel the primary frequency of the target, the primary frequency of the source, or any Evolved Universal Terrestrial Radio Access (EUTRA) information element (IE)
The method further comprising transmitting the handover command to the UE. In the source eNB,
The one or more processors comprising:
Send a command to User Equipment (UE) to set the value of MeasObjectEUTRA information element measSubframePatternConfigNeigh to Need OR;
Identify, by the source eNB, a handover to the target eNB;
Identify a time domain measurement resource limit for the UE;
Wherein the source eNB is configured to send to the UE a handover command having a measSubframePatternConfigNeigh information element to maintain a time domain measurement resource limit for the UE based on the handover. delete 29. The computer program product of claim 28,
Send a request to the target eNB for information identifying a type of network;
And based on a response from the target eNB, the target eNB is configured to be serviced by an LTE (Long Term Evolution) network. 31. The source eNB of claim 30, wherein the request is sent using an X2 interface or an operations and management (OAM) system. 29. The method of claim 28, wherein the handover command instructs to maintain a time domain measurement resource limit for neighboring cells for at least one of a target primary frequency, a source primary frequency, or an arbitrary EUTRA frequency. Source eNB. 29. The method of claim 28, wherein the handover command comprises a SubframePatternConfigNeigh information element set by the target eNB to cancel a primary frequency of a target, a primary frequency of a source, or any Evolved Universal Terrestrial Radio Access (EUTRA) information element (IE)
Wherein the at least one processor is further configured to transmit the handover command to the UE. A computer program product encoded with a computer program product, the computer program product comprising:
MeasObjectEUTRA sending a command to the User Equipment (UE) to set the value of the information element measSubframePatternConfigNeigh to Need OR;
Identifying, by the source eNB, a handover to the target eNB;
Identifying a time domain measurement resource limit for the UE;
Sending, by the source eNB, a handover command having a measSubframePatternConfigNeigh information element to the UE to maintain a time domain measurement resource limit for the UE based on the handover
Readable instructions to cause at least one processor to perform an operation comprising: delete 35. The computer readable medium of claim 34, wherein the instructions for causing the at least one processor to perform operations comprise:
Sending to the target eNB a request for information identifying a type of network; And
Further comprising determining, based on a response from the target eNB, that the target eNB is serviced by an LTE (Long Term Evolution) network. 38. The computer readable storage medium of claim 36, wherein the request is sent using an X2 interface or an Operational and Management (OAM) system. 35. The computer-readable medium of claim 34, wherein the handover command instructs to maintain a time domain measurement resource limit for neighboring cells for at least one of a target primary frequency, a source primary frequency, or an arbitrary EUTRA frequency. Readable storage medium. 35. The method of claim 34, wherein the handover command comprises a SubframePatternConfigNeigh information element set by the target eNB to cancel the primary frequency of the target, the primary frequency of the source, or any Evolved Universal Terrestrial Radio Access (EUTRA) information element (IE)
Wherein the instructions further comprise transmitting the handover command to the UE. delete delete

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