WO2013051866A1

WO2013051866A1 - Method and system for performing measurements during idle mode in a heterogeneous network environment

Info

Publication number: WO2013051866A1
Application number: PCT/KR2012/008046
Authority: WO
Inventors: Mangesh Abhimanyu INGALE; Sudhir Kumar Baghel
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2011-10-04
Filing date: 2012-10-04
Publication date: 2013-04-11

Abstract

The present invention provides a method for performing measurements during idle mode of a user equipment in a wireless communication environment, comprising: obtaining at least one measurement resource restriction pattern by a user equipment during an idle mode; performing unrestricted measurements of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) of a currently camped cell during the idle mode; determining whether an entry condition for applying at least one measurement resource restriction pattern is met using a cell re-selection rule based on the unrestricted measurements of RSRP and RSRQ of the currently camped cell; applying the at least one obtained measurement resource restriction pattern if the entry condition is met; and performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode of the user equipment. According to the present invention, a system and method for performing measurements during idle mode of user equipment in a heterogeneous network environment is provided.

Description

METHOD AND SYSTEM FOR PERFORMING MEASUREMENTS DURING IDLE MODE IN A HETEROGENEOUS NETWORK ENVIRONMENT

The present invention generally relates to the field of mobile communications, and more particularly relates to performing measurements during an idle mode of user equipment in a heterogeneous network environment.

A typical heterogeneous network environment includes a high power macro cell and low power pico/femto cells deployed in a geographical area and served on different carrier frequency or a single carrier frequency. An exemplary heterogeneous network environment is depicted in Figure 1. In the heterogeneous network environment, pico cells and/or femto cells are deployed within network coverage of a macro cell to improve spectral efficiency per unit area such that user equipments can be offloaded to the low power pico/femto cells from the high power macro cell. When there is sufficient number of low power pico/femto cells within the network coverage of the high power macro cell, then the user equipments in the network coverage of the high power macro cell experience uniform service quality (data rates/Quality of Service) throughout the heterogeneous network environment.

Generally in a heterogeneous network environment, user equipment within the coverage of small cell (e.g., a pico cell) may experience interference from a dominant interferer cell (e.g., a high power macro cell). Inter-cell Interference Co-ordination (ICIC) for data channel protection in Heterogeneous Network (HETNET) on same carrier frequency is handled through Time Division Multiplex (TDM) approach based on Almost Blank Subframe (ABS) concept. ABS refers to subframes with reduced power on some physical channels and/or reduced activity. Typically, a dominant interferer cell employs Almost Blank Frames such that data channel scheduled to a user equipment by a victim serving cell (e.g., a low power pico cell) is protected during the ABS. As a consequence, the user equipment does not experience interference from the dominant interferer cell during the ABS.

According to 3rd Generation Partnership Project (3GPP) release 10 Long Term Evolution Advanced (LTE-Advanced) specifications TS 36.300 and TS 36.331, when TDM ICIC is implemented by means of ABS, backward compatibility towards a user equipment is ensured by transmitting necessary control channels and physical signals as well as broadcasting System Information (SI). ABSs carry Cell-specific Reference Signals (CRS) and if PSS/SSS/PBCH/SIB1/Paging coincide with an ABS, they are transmitted in the ABS. The associated physical downlink control channel (PDCCH) is also transmitted when SIB-1/Paging message is transmitted. The different participating cells in HETNET coordinate subframe utilization either through backhaul signalling or through operation and maintenance (OAM) configuration to negotiate ABS based on interference situation and network load. The negotiated ABS is not signalled to the user equipment and is used by serving cells for scheduling decisions. However, the serving cells derive patterns based on the ABS and signal the patterns to the user equipment to restrict measurement to specific subframes. These patterns are called measurement restriction patterns.

Typically, a serving cell signals measurement restriction patterns to user equipments via a Radio Resource Control (RRC) dedicated signalling message. Each user equipment configured with measurement restriction pattern performs restricted measurement of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) based on the measurement restriction patterns. The measurement restriction patterns can be of three different types depending on type of measured cell (serving or neighbour cell) and measurement type (e.g., radio resource management (RRM), radio link monitoring (RLM) and channel state indication (CSI) feedback). The serving cell measurement restriction pattern is used for RLM/RRM purpose for the serving cell. The neighbour cell measurement restriction pattern is used for mobility management towards neighbour cells. The two subsets of resource restriction patterns for CSI measurement of the serving cell is used for providing scheduling flexibility at the serving cell. The measurement restriction patterns ensure accuracy of RSRP and RSRQ measurements for mobility management during connected mode. In other words, the RSRP and RSRQ measurements may become inaccurate if the user equipment performs measurements without applying any measurement restriction pattern, thereby leading to improper mobility management.

Typically, when the user equipment transitions from connected mode to idle mode, the user equipment performs unrestricted measurements of RSRP and RSRQ of the camped cell. When the measured RSRP and RSRQ of the camped cell are greater than threshold values, intra-frequency measurements for neighbour cells is not triggered. The measurement restriction patterns configured in connected mode are not used by the user equipment in idle mode.

If the user equipment performs unrestricted measurements of RSRP and RSRQ of the camped cell, measured RSRP and RSRQ values may be inaccurate, leading to frequent cell re-selection and unnecessary battery power consumption. Further, if the user equipment continuously apply measurement restriction pattern for performing restricted RSRP/RSRQ measurements in idle mode, then the restricted measurements have a negative impact on the battery power consumption of the user equipment.

In order to achieve the above objective, the present invention adopts the following technical scheme:

A method for performing measurements during idle mode of a user equipment in a wireless communication environment, comprising:

obtaining at least one measurement resource restriction pattern by a user equipment during an idle mode;

performing unrestricted measurements of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) of a currently camped cell during the idle mode;

determining whether an entry condition for applying at least one measurement resource restriction pattern is met using a cell re-selection rule based on the unrestricted measurements of RSRP and RSRQ of the currently camped cell ;

applying the at least one obtained measurement resource restriction pattern if the entry condition is met; and

performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode of the user equipment.

According to the present invention, a system and method for performing measurements during idle mode of user equipment in a heterogeneous network environment is provided.

Figure 1 is a diagrammatic view illustrating a heterogeneous network environment, in the context of the invention.

Figure 2 is a process flowchart illustrating an exemplary method of performing measurements during idle mode of user equipment, according to one embodiment.

Figure 3 is a schematic diagram illustrating a heterogeneous network environment with user equipment configured for performing restricted measurements during idle mode based on entry condition, according to one embodiment.

Figure 4 is a schematic diagram illustrating a heterogeneous network environment with user equipment configured for performing restricted measurements during idle mode based on entry condition, according to another embodiment.

Figure 5 is a schematic diagram illustrating a heterogeneous network environment with user equipment configured for performing restricted measurements during idle mode based on entry condition, according to yet another embodiment.

Figure 6 is a schematic diagram illustrating a heterogeneous network environment with user equipment configured for performing restricted measurements during idle mode based on entry condition, according to further another embodiment.

Figure 7 illustrates a block diagram of user equipment showing various components for implementing embodiments of the present subject matter.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

The present invention provides a system and method for performing measurements during idle mode of user equipment in a heterogeneous network environment. In the following detailed description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

Figure 2 is a process flowchart 200 illustrating an exemplary method of performing measurements during idle mode of user equipment, according to one embodiment. Consider that the user equipment transitions from connected mode to idle mode. At step 202, measurement resource restriction pattern for performing restricted measurements of RSRP and/or RSRQ of a camped cell is obtained by the user equipment, at step 202. The measurement resource restriction pattern may be a serving cell measurement resource restriction pattern or a neighbour cell measurement resource restriction pattern. In one embodiment, the measurement resource restriction pattern, configured by the camped cell during the connected mode, is inherited upon transitioning from the connected mode to the idle mode. In another embodiment, the measurement resource restriction pattern is acquired from broadcast system information received from the camped cell during the idle mode.

Upon transitioning to the idle mode, at step 203, unrestricted measurements of RSRP and RSRQ of the camped cell are performed by the user equipment. At step 204, it is determined, by the user equipment, whether an entry condition for applying the measurement resource restriction pattern is met. The entry condition is said to be met when a cell re-selection rule is satisfied for a predetermined evaluation period (also known as Trestrictioperiod). In an exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev < SIntraSearchP and Squal < SIntraSearchQ is true for the camped cell for the predetermined evaluation period. The parameter ‘Srxlev’ represents reference symbol received power (RSRP) measured for the camped cell during unrestricted measurements and the parameter ‘SIntraSearchP’ represents threshold RSRP while the parameter ‘Squal’ represents reference symbol received quality (RSRQ) measured for the camped cell during the unrestricted measurements and the parameter ‘SIntraSearchQ’ represents threshold RSRQ. In another exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev < SIntraSearchP is true for the predetermined evaluation period. In yet another exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev ? Noffset < SIntraSearchP and Squal < SIntraSearchQ is true for a predetermined evaluation period. In still another exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev ? Noffset < SIntraSearchP is true for a predetermined evaluation period. The predetermined evaluation period and Noffset are acquired from broadcast system information received from the serving cell. Alternatively, the predetermined evaluation period and Noffset configured during the connected mode are inherited upon transitioning to the idle mode.

If it is determined that the entry condition is met, then at step 206, the measurement resource restriction pattern for performing restricted measurements of RSRP and RSRQ of the camped cell is applied. At step 208, restricted measurements of RSRP and RSRQ of the camped cell are performed using the applied measurement resource restriction pattern during the idle mode. Also, at step 208, unrestricted measurements of RSRP and RSRQ of candidate neighbour cells are performed by the user equipment during the idle mode. At step 210, cell specific offset is applied to the restricted measurements of RSRP and RSRQ of the camped cell and cell ranking is performed for all cells (including the camped cell and the candidate neighbour cells) satisfying cell selection criterion (also known as S-criterion). In one embodiment, the cell specific offset is acquired from broadcast system information received from the camped cell. In another embodiment, the cell specific offset configured during the connected mode is inherited upon transitioning to the idle mode. If at step 204, it is determined that the entry condition is not met, the step 203 is repeated in which unrestricted measurements of RSRP and RSRQ of the camped cell are continued during the idle mode till the entry condition is met.

During the restricted measurements, it is determined whether an exit condition for releasing the applied measurement resource restriction pattern is met, at step 214. The exit condition is said to be met when a cell re-selection rule is satisfied for a predetermined evaluation period (also known as Trestrictioperiod). In an exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev > SIntraSearchP + hysteresis margin and Squal > SIntraSearchQ is true for the camped cell for the predetermined evaluation period. The hysteresis margin may be acquired from broadcast system information received from the serving cell during the idle mode. Alternatively, the hysteresis margin may be inherited from the connected mode upon transitioning to the idle mode. In another exemplary implementation, the cell re-selection rule is said to have satisfied when Srxlev > SIntraSearchP + hysteresis margin is true for the predetermined evaluation period.

In yet another exemplary implementation, the cell re-selection rule is said to have satisfied if the user equipment has re-selected another neighbour cell that is best ranked among other cells during cell ranking. If it is determined that the exit condition is met, then at step 214, the applied measurement resource restriction pattern is released. At step 216, unrestricted measurements of RSRP and RSRQ of the camped/re-selected cell are performed during the idle mode. However, if at step 212, it is determined that the exit condition is not met, the step 208 is repeated in which the restricted measurements of RSRP and RSRQ of the camped cell is continued using the measurement resource restriction pattern till the exit condition is met.

Figure 3 is a schematic diagram illustrating a heterogeneous network environment 300 with user equipment configured for performing restricted measurements during idle mode based on entry condition, according to one embodiment. Consider that the user equipment 302 is camped on a pico cell 304 and is located in a region 308. Also, consider that, the user equipment 302 has transitioned from the connected mode to idle mode when located in the region 308. When the user equipment is located in the region 308 and operates in the idle mode, the user equipment 302 performs unrestricted measurements of RSRP and RSRQ of the pico cell 304 (i.e., the camped cell). It is understood that, both the RSRP and RSRQ of the pico cell 304 are greater than the predetermined threshold values when the user equipment 302 is in the region 308 and hence the user equipment 302 remains camped on to the pico cell 304 during the idle mode. The RSRP and RSRQ values of the pico cell 304 may go high as the user equipment moves closer towards the pico cell 304 in the region 308. On the contrary, the RSRP and RSRQ values of the pico cell 304 may drop down as the user equipment 302 moves away from the pico cell 304 in the region 308.

Now consider a scenario wherein, the user equipment 302 is located at the edge of the region 308 and is moving into a region 310 (also referred to as Cell Range Expansion (CRE) bias region) while operating in the idle mode. In such case, an entry condition is triggered if the user equipment 302 determines that a cell re-selection rule is satisfied. The cell re-selection rule is said to have satisfied if the RSRP and/or the RSRQ values of the pico cell 304 are less than the predetermined threshold values for a predetermined evaluation period. Once the entry condition is triggered, the user equipment 302 dynamically applies serving cell measurement resource restriction pattern. Then, the user equipment 302 performs restricted measurements of RSRP and RSRQ of the pico cell 304 using the serving cell measurement resource restriction pattern. It can be noted that, the user equipment 302 performs the restricted measurements using the serving cell measurement resource restriction pattern till the user equipment 302 is in the CRE region 310. It is also to be noted that, once the cell re-selection rule is met, the user equipment 302 triggers intra-frequency measurements (i.e., unrestricted measurements of RSRP and/or RSRQ of candidate neighbour cell(s) (e.g., the macro cell 306)) for cell re-selection.

While the user equipment 302 is in the CRE region 310, it is a possibility that the user equipment 302 either move into the region 308 or move outside the region 310. In case, the user equipment 302 moves in the region 308 from the region 310, an exit condition is triggered. That is, the exit condition is triggered when a cell re-selection rule is satisfied. The cell re-selection rule is said to have satisfied if the RSRP and/or the RSRQ values of the pico cell 304 are greater than the predetermined threshold values for a predetermined evaluation period. Once the exit condition is triggered, the user equipment 302 releases the applied serving cell measurement resource restriction pattern and performs unrestricted measurements of RSRP and RSRQ of the pico cell 304. It is also to be noted that once the cell re-selection rule is met, the user equipment 302 stops performing intra-frequency measurements.

On the other hand, if the user equipment 302 moves outside the CRE region 310 (i.e., inside macro cell 306 coverage), an exit condition is triggered. The exit condition is triggered when the cell re-selection rule is satisfied. The cell re-selection rule is said to be satisfied if the RSRP and/or the RSRQ values of the pico cell 304 are less than the predetermined threshold values for a predetermined evaluation period or the user equipment 302 re-selects best ranked cell (e.g., the macro cell 306) for camping during cell ranking. Once the exit condition is triggered, the user equipment 302 releases the applied serving cell measurement resource restriction pattern and re-selects the macro cell 306 as a serving cell. Thus, upon successful reselection of the macro cell 306, the user equipment 302 performs unrestricted measurements of RSRP and RSRQ of the serving cell (i.e., the macro cell 306).

Figure 4 is a schematic diagram illustrating a heterogeneous network environment 400 with user equipment 402 performing restricted measurements during idle mode based on entry condition, according to another embodiment. Consider that the user equipment 402 is camped on a macro cell 404 and operating in idle mode. In such case, the user equipment 402 performs unrestricted measurements of RSRP and RSRQ of the macro cell 404 (i.e., the serving cell). Now consider that, the user equipment 402 moves in the vicinity of CRE region 408 and is moving towards the pico cell 406. In such case, an entry condition is triggered if the user equipment 402 determines that a cell re-selection rule is satisfied. In one embodiment, the cell re-selection rule is said to have satisfied if Srxlev < SIntraSearchP and Squal < SIntraSearchQ is true for a predetermined evaluation period. In another embodiment, the cell re-selection rule is said to have satisfied if Srxlev < SIntraSearchP is true for a predetermined evaluation period. It can be noted that once the cell re-selection rule is met, the user equipment 402 triggers intra-frequency measurements (i.e., measurements of RSRP and/or RSRQ of candidate neighbour cell(s) (e.g., the pico cell 406)) for cell re-selection.

Once the entry condition is triggered, the user equipment 402 determines whether the physical cell identifier (PCI) of the pico cell 406 is in a PCI list of a neighbour cell measurement resource restriction pattern. If the PCI of the pico cell 406 is in the PCI list, then the user equipment 402 applies neighbour cell measurement resource restriction pattern and performs restricted measurements of RSRP and RSRQ of the pico cell 406 using the neighbour cell measurement resource restriction pattern. It can be noted that, the user equipment 402 performs the restricted measurements using the neighbour cell measurement resource restriction pattern till the user equipment 402 is in the CRE region 408. If the PCI of the neighbour cell (e.g., the pico cell 406) is not in the PCI list, then the user equipment 402 does not apply neighbour cell measurement resource restriction pattern and performs unrestricted measurements of RSRP and RSRQ of the neighbour cell (e.g., the pico cell 406).

Figure 5 is a schematic diagram illustrating a heterogeneous network environment 500 with user equipment 502 performing restricted measurements during idle mode based on entry condition, according to yet another embodiment. Consider that the user equipment 502 is camped on a pico cell 504 and is in a CRE bias region 508 of the pico cell 504. In such case, the user equipment 502 performs restricted measurements of RSRP and RSRQ of the pico cell 504 (i.e., the serving cell) using a serving cell measurement restricted resource pattern. Now consider that, the user equipment 502 is moving towards a pico cell 506 located adjacent to the pico cell 504 and enters a CRE bias region 510 of the pico cell 506 during the idle mode. In such case, an entry condition is triggered if the user equipment 502 determines that cell re-selection rule is satisfied. In one embodiment, the cell re-selection rule is said to have satisfied if Srxlev - Noffset < SIntraSearchP and Squal < SIntraSearchQ is true for a predetermined evaluation period. In another embodiment, the cell re-selection rule is said to have satisfied if Srxlev - Noffset < SIntraSearchP is true for a predetermined evaluation period.

Once the entry condition is triggered, the user equipment 502 determines whether the physical cell identifier (PCI) of the pico cell 506 is in a PCI list of neighbour cell measurement resource restriction pattern. If the PCI of the pico cell 506 is not in the PCI list, then the user equipment 502 performs unrestricted measurements of RSRP and RSRQ of the pico cell 506. If the PCI of the pico cell 506 is in the PCI list, then the user equipment 502 applies the neighbour cell measurement resource restriction pattern and performs restricted measurements of RSRP and RSRQ of the pico cell 506 using the neighbour cell measurement resource restriction pattern. It can be noted that, the user equipment 502 performs the restricted measurements of the pico cell 506 using the neighbour cell measurement resource restriction pattern till the user equipment 502 is in the CRE region 510. Further, if the user equipment 502 re-selects the pico cell 506 as a serving cell during the restricted measurements of the pico cell 506, an exit condition is triggered and the applied neighbour cell measurement resources restriction pattern is released.

Figure 6 is a schematic diagram illustrating a heterogeneous network environment 600 with user equipment 602 for performing restricted measurements during idle mode based on entry condition, according to further another embodiment. Consider that the user equipment 602 is camped onto a macro cell 604 and is operating in the idle mode. In such case, the user equipment 602 performs unrestricted measurements of RSRP and RSRQ of the macro cell 604 (i.e., the serving cell). Now consider that, the user equipment 602 detects a Closed Group Subscriber (CSG) cell 606 in its vicinity and is moving towards the CSG cell 606. For example, the user equipment 602 detects that the neighbour cell 606 is a CSG cell based on the PCI and CSG identifier in the system information. In such case, an entry condition is triggered if the user equipment 602 determines that cell re-selection rule is satisfied for applying serving cell measurement resource restriction pattern. In one embodiment, the cell re-selection rule is said to have satisfied if Srxlev < SIntraSearchP and Squal < SIntraSearchQ is true for a predetermined evaluation period. In another embodiment, the cell re-selection rule is said to have satisfied if Srxlev < SIntraSearchP is true for a predetermined evaluation period.

Once the entry condition is triggered, the user equipment 602 applies the serving cell measurement resource restriction pattern and performs restricted measurements of RSRP and RSRQ of the serving macro cell 604. It can be noted that, the user equipment 602 applies a serving cell measurement resource restriction pattern when the user equipment 602 is in coverage area of the not allowed CSG cell 606 and remains camped on the macro cell 604 during the idle mode.

Once the user equipment 602 moves outside the coverage area of the not allowed CSG cell 606, an exit condition is triggered. That is, the exit condition is triggered when the cell re-selection rule is satisfied. Once the exit condition is triggered, the user equipment 602 releases the applied serving cell measurement resource restriction pattern and performs unrestricted measurements of RSRP and RSRQ of the macro cell 604.

Figure 7 is a block diagram of the user equipment 700 showing various components for implementing embodiments of the present subject matter. It is appreciated that, the user equipment 700 is an exemplary embodiment of the

user equipments

302, 402, 502 and 602 of Figures 3, 4, 5 and 6. In Figure 7, the user equipment 700 includes a processor 702, a memory 704, a read only memory (ROM) 706, a transceiver 708, a bus 710, a communication interface 712, a display 714, an input device 716, and a cursor control 718.

The processor 702, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction word microprocessor, an explicitly parallel instruction computing microprocessor, a graphics processor, a digital signal processor, or any other type of processing circuit. The processor 702 may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, smart cards, and the like.

The memory 704 and the ROM 706 may be volatile memory and non-volatile memory. The memory 704 includes a measurements module 720 configured for applying and releasing measurement resource restriction pattern during idle mode based on entry and exit conditions, performing restricted measurements of RSRP and RSRQ of camped cell using measurement resource restriction pattern when the entry condition is triggered, and performing unrestricted measurements of RSRP and RSRQ of the camped cell when an exit condition is triggered, according to one or more embodiments described above. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions, such as read only memory, random access memory, erasable programmable read only memory, electrically erasable programmable read only memory, hard drive, removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, Memory SticksTM, and the like. The measurements module 720 may be stored in the form of machine-readable instructions on any of the above-mentioned storage media. The machine-readable instructions stored on the above mentioned storage media, when executed by the processor 702; cause the processor 702 to perform one or more steps of Figure 2.

The machine-readable instructions may also be stored on a computer program, which when executed by the processor 702, cause the processor 702 to apply and release measurement resource restriction pattern during idle mode based on entry and exit conditions, perform restricted measurements of RSRP and RSRQ of camped cell using measurement resource restriction pattern when the entry condition is triggered, and perform unrestricted measurements of RSRP and RSRQ of the camped cell when an exit condition is triggered, according to the teachings and herein described embodiments of the present subject matter. In one embodiment, the computer program may be included on a compact disk-read only memory (CD-ROM) and loaded from the CD-ROM to a hard drive in the non-volatile memory.

The bus 710 acts as interconnect between various components of the user equipment 700. The components such as the transceiver 708, the communication interface 712, the display 714, the input device 716, and the cursor control 718 are well known to the person skilled in the art and hence the explanation is thereof omitted.

The present embodiments have been described with reference to specific example embodiments; it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. Furthermore, the various devices, modules, and the like described herein may be enabled and operated using hardware circuitry, for example, complementary metal oxide semiconductor based logic circuitry, firmware, software and/or any combination of hardware, firmware, and/or software embodied in a machine readable medium. For example, the various electrical structure and methods may be embodied using transistors, logic gates, and electrical circuits, such as application specific integrated circuit.

Claims

A method for performing measurements during idle mode of a user equipment in a wireless communication environment, comprising:

obtaining at least one measurement resource restriction pattern by a user equipment during an idle mode;

performing unrestricted measurements of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) of a currently camped cell during the idle mode;

determining whether an entry condition for applying at least one measurement resource restriction pattern is met using a cell re-selection rule based on the unrestricted measurements of RSRP and RSRQ of the currently camped cell ;

applying the at least one obtained measurement resource restriction pattern if the entry condition is met; and

performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode of the user equipment.
The method of claim 1, wherein determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met using the cell re-selection rule comprises:

continue performing unrestricted measurements of RSRP and RSRQ for the currently camped cell during the idle mode of the user equipment if the entry condition is not met.
The method of claim 1, wherein determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met using the cell re-selection rule comprises:

determining whether the measured RSRP and RSRQ values of the currently camped cell is less than pre-determined threshold values; and

triggering intra-frequency measurements for neighbour cells if the measured RSRP and RSRQ values of the currently camped cell is less than the pre-determined threshold values.
The method of claim 1, further comprising:

determining whether an exit condition for releasing the at least one applied measurement resource restriction pattern is met based on a cell re-selection rule;

releasing the at least one applied measurement resource restriction pattern if the exit condition is met; and

performing unrestricted measurements of RSRP and RSRQ of the currently camped cell during the idle mode of the user equipment.
The method of claim 4, wherein determining whether the exit condition for releasing the at least one applied measurement resource restriction pattern is met based on the cell re-selection rule comprises:

continue performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode of the user equipment if the exit condition is not met.
The method of claim 2, wherein determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met based on the cell re-selection rule comprises:

determining whether the cell re-selection rule is satisfied for a predetermined evaluation period.
The method of claim 5, wherein determining whether the exit condition for releasing the at least one applied measurement resource restriction pattern is met based on the cell re-selection rule comprises:

determining whether the cell re-selection rule is satisfied for a predetermined evaluation period.
The method of claim 6 or 7, wherein the predetermined evaluation period is acquired through broadcasted system information associated with the serving cell.
The method of claim 6 or 7, wherein the predetermined evaluation period is inherited from the connected mode upon transition of the user equipment from the connected mode to the idle mode.
The method of claim 1, further comprising:

applying cell specific offset to the restricted measurements of RSRP of the currently camped cell during ranking of neighbour cells.
The method of claim 10, wherein the cell specific offset is acquired through broadcasted system information associated with the serving cell.
The method of claim 10, wherein the cell specific offset is inherited from the connected mode upon transition of the user equipment from the connected mode to the idle mode.
The method of claim 1, wherein obtaining the at least one measurement resource restriction pattern by the user equipment during the idle mode comprises:

acquiring the at least one measurement resource restriction pattern from broadcast system information received from the currently camped cell during the idle mode.
The method of claim 1, wherein obtaining the at least one measurement resource restriction pattern by the user equipment during the idle mode comprises:

inheriting the at least one measurement resource restriction pattern configured by the currently camped cell during the connected mode upon transitioning from the connected mode to the idle mode.
The method of claim 1, wherein the at least one measurement resource restriction pattern comprises one of a serving cell measurement resource restriction pattern and a neighbour cell measurement resource restriction pattern.
The method of claim 15, wherein applying the at least one measurement resource restriction pattern if the entry condition is met comprises:

determining whether a physical cell identifier (PCI) of a neighbour cell belongs to a PCI list associated with the neighbour cell measurement resource restriction pattern if the entry condition for applying a neighbour cell measurement resource restriction pattern for the neighbour cell is met;

applying the neighbour cell measurement resource restriction pattern for the neighbour cell if the PCI of the neighbour cell belongs to the PCI list associated with the neighbour cell measurement resource restriction pattern; and

performing restricted measurements of RSRP and RSRQ for the neighbour cell using the applied neighbour cell measurement resource restriction pattern during the idle mode of the user equipment.
The method of claim 16, wherein determining whether the PCI associated with the neighbour cell belongs to the PCI list associated with the neighbour cell measurement resource restriction pattern comprises:

performing unrestricted measurements of RSRP and RSRQ for the neighbour cell during the idle mode of the user equipment if the PCI of the neighbour cell does not belong to the PCI list associated with the neighbour cell measurement resource restriction pattern.
The method of claim 15, wherein applying the at least one measurement resource restriction pattern if the entry condition is met comprises:

determining whether a detected neighbour cell is a not allowed closed subscriber group (CSG) cell if the entry condition for applying the at least one measurement resource restriction pattern is met;

applying a serving cell measurement resource restriction pattern for the camped cell if the detected neighbour cell is the not allowed CSG cell; and

performing restricted measurements of RSRP and RSRQ of the camped cell during the idle mode of the user equipment using the applied serving cell measurement resource restriction pattern.
An apparatus comprising:

a processor; and

a memory coupled to the processor, wherein the memory comprises a measurements module configured for:

obtaining at least one measurement resource restriction pattern during an idle mode;

performing unrestricted measurements of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) of a currently camped cell during the idle mode;

determining whether an entry condition for applying at least one measurement resource restriction pattern is met using a cell re-selection rule based on the unrestricted measurements of RSRP and RSRQ of the currently camped cell;

applying the at least one obtained measurement resource restriction pattern if the entry condition is met; and

performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode.
The apparatus of claim 19, wherein in determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met using the cell re-selection rule, the measurements module is configured for:

continue performing unrestricted measurements of RSRP and RSRQ for the currently camped cell during the idle mode if the entry condition is not met.
The apparatus of claim 19, wherein in determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met using the cell re-selection rule, the measurements module is configured for:

determining whether the measured RSRP and RSRQ values of the currently camped cell is less than pre-determined threshold values; and

triggering intra-frequency measurements for neighbour cells if the measured RSRP and RSRQ values of the currently camped cell is less than the pre-determined threshold values.
The apparatus of claim 19, wherein the measurements module is configured for:

determining whether an exit condition for releasing the at least one applied measurement resource restriction pattern is met based on a cell re-selection rule;

releasing the at least one applied measurement resource restriction pattern if the exit condition is met; and

performing unrestricted measurements of RSRP and RSRQ of the currently camped cell during the idle mode.
The apparatus of claim 22, wherein in determining whether the exit condition for releasing the at least one applied measurement resource restriction pattern is met based on the cell re-selection rule, the measurements module is configured for:

continue performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode if the exit condition is not met.
The apparatus of claim 20, wherein in determining whether the entry condition for applying the at least one configured measurement resource restriction pattern is met based on the cell re-selection rule, the measurements module is configured for:

determining whether the cell re-selection rule is satisfied for a predetermined evaluation period.
The apparatus of claim 24, wherein in determining whether the exit condition for releasing the at least one applied measurement resource restriction pattern is met based on the cell re-selection rule, the measurements module is configured for:

determining whether the cell re-selection rule is satisfied for a predetermined evaluation period.
The apparatus of claim 24 or 25, wherein the predetermined evaluation period is acquired through broadcasted system information associated with the serving cell.
The apparatus of claim 24 or 25, wherein the predetermined evaluation period is inherited from the connected mode upon transition from the connected mode to the idle mode.
The apparatus of claim 19, wherein the measurements module is configured for:

applying cell specific offset to the restricted measurements of RSRP of the currently camped cell during ranking of neighbour cells.
The apparatus of claim 28, wherein the cell specific offset is acquired through broadcasted system information associated with the serving cell.
The apparatus of claim 28, wherein the cell specific offset is inherited from the connected mode upon transition from the connected mode to the idle mode.
The apparatus of claim 19, wherein in obtaining the at least one measurement resource restriction pattern during the idle mode, the measurements module configured for:

acquiring the at least one measurement resource restriction pattern from broadcast system information received from the currently camped cell during the idle mode.
The apparatus of claim 19, wherein in obtaining the at least one measurement resource restriction pattern during the idle mode, the measurements module is configured for:

inheriting the at least one measurement resource restriction pattern configured by the currently camped cell during the connected mode upon transitioning from the connected mode to the idle mode.
The apparatus of claim 19, wherein the at least one measurement resource restriction pattern comprises one of a serving cell measurement resource restriction pattern and a neighbour cell measurement resource restriction pattern.
The apparatus of claim 33, wherein in applying the at least one measurement resource restriction pattern if the entry condition is met, the measurements module is configured for:

determining whether a physical cell identifier (PCI) of a neighbour cell belongs to a PCI list associated with the neighbour cell measurement resource restriction pattern if the entry condition for applying a neighbour cell measurement resource restriction pattern for the neighbour cell is met;

applying the neighbour cell measurement resource restriction pattern for the neighbour cell if the PCI of the neighbour cell belongs to the PCI list associated with the neighbour cell measurement resource restriction pattern; and

performing restricted measurements of RSRP and RSRQ for the neighbour cell using the applied neighbour cell measurement resource restriction pattern during the idle mode.
The apparatus of claim 34, wherein in determining whether the PCI associated with the neighbour cell belongs to the PCI list associated with the neighbour cell measurement resource restriction pattern, the measurements module is configured for:

performing unrestricted measurements of RSRP and RSRQ for the neighbour cell during the idle mode if the PCI of the neighbour cell does not belong to the PCI list associated with the neighbour cell measurement resource restriction pattern.
The apparatus of claim 33, wherein applying the at least one measurement resource restriction pattern if the entry condition is met, the measurements module is configured for:

determining whether a detected neighbour cell is a not allowed closed subscriber group (CSG) cell if the entry condition for applying the at least one measurement resource restriction pattern is met;

applying a serving cell measurement resource restriction pattern for the camped cell if the detected neighbour cell is the not allowed CSG cell; and

performing restricted measurements of RSRP and RSRQ of the camped cell during the idle mode using the applied serving cell measurement resource restriction pattern.
A non-transitory computer-readable storage medium with an executable program stored thereon, wherein the program causes a processor in a user equipment to perform the following steps comprising:

obtaining at least one measurement resource restriction pattern during an idle mode;

performing unrestricted measurements of Reference Symbol Received Power (RSRP) and Reference Symbol Received Quality (RSRQ) of a currently camped cell during the idle mode;

determining whether an entry condition for applying at least one measurement resource restriction pattern is met using a cell re-selection rule based on the unrestricted measurements of RSRP and RSRQ of the currently camped cell;

applying the at least one obtained measurement resource restriction pattern if the entry condition is met; and

performing restricted measurements of RSRP and RSRQ of the currently camped cell using the at least one applied measurement resource restriction pattern during the idle mode.
The storage medium of claim 37, wherein the program causes the processor to perform the following steps comprising:

determining whether an exit condition for releasing the at least one applied measurement resource restriction pattern is met based on a cell re-selection rule;

releasing the at least one applied measurement resource restriction pattern if the exit condition is met; and

performing unrestricted measurements of RSRP and RSRQ of the currently camped cell during the idle mode.