Abstract:
An apparatus and method for controlling idle mode radio measurements comprising: determining if a radio measurement is less than a radio threshold; determining a time duration in which the radio measurement is less than the radio threshold; determining if the time duration is greater than a time measurement threshold; and obtaining at least one other radio measurement from at least one base station which is not a serving cell.

Description:
FIELD 
       [0001]    This disclosure relates generally to apparatus and methods for wireless communication. In particular, the disclosure relates to controlling idle-mode radio measurements. 
       BACKGROUND 
       [0002]    In many communication systems, communications networks are used to exchange messages among several interacting nodes which are separated apart in space. There are many types of networks which may be classified in different aspects. In one example, the geographic scope of the network could be over a wide area, a metropolitan area, a local area, or a personal area, and the corresponding networks are designated as wide area network (WAN), metropolitan area network (MAN), local area network (LAN), or personal area network (PAN). Networks may also differ in the switching/routing technique used to interconnect the various network nodes and devices (e.g. circuit switching, packet switching, etc.), in the type of physical media employed for waveform propagation (e.g. wired vs. wireless), or in the set of communication protocols used (e.g. Internet protocol suite, SONET (Synchronous Optical Networking), Ethernet, wireless LAN protocols, etc.). 
         [0003]    One important characteristic of communications networks is the choice of wired or wireless media for the transmission of electrical signals among the network nodes. In the case of wired networks, tangible physical media such as copper wire, coaxial cable, fiber optic cable, etc. are employed to propagate guided electromagnetic waveforms which carry message traffic over a distance. Wired networks are a traditional form of communications networks and may be favored for interconnection of fixed network elements or for bulk data transfer. For example, fiber optic cables are often the preferred transmission media for very high throughput transport applications over long distances between large network hubs, for example, bulk data transport across or between continents over the Earth&#39;s surface. 
         [0004]    On the other hand, in many cases, wireless networks are preferred when the network elements are mobile with dynamic connectivity or if the network architecture is formed in an ad hoc, rather than fixed, topology. Wireless networks employ intangible physical media in an unguided propagation mode using electromagnetic waves in the radio, microwave, infrared, optical, etc. frequency bands. Wireless networks have the distinct advantage of facilitating user mobility and rapid field deployment compared to fixed wired networks. However, usage of wireless propagation requires significant active resource management among the network users and high levels of mutual coordination and cooperation for compatible spectrum utilization. 
         [0005]    Wireless networks also require a mechanism to regulate user access to the shared radio spread spectrum. That is, wireless networks must utilize a multiple access protocol to arbitrate mutual access to the common radio spectrum. Types of multiple access protocols include frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), orthogonal frequency division multiple access (OFDMA), space division multiple access (SDMA), etc. In addition to multiple access technique, wireless systems may be classified by the wireless protocol family used for user transmissions, network services, signaling, etc. For example, commonly used wireless protocols include Global System for Mobile Communications (GSM), cdmaONE (IS-95), cdma 2000-1x, cdma 2000 EV-DO (Evolution-Data Optimized), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), etc. In particular, UMTS includes various operational modes including wideband code division multiple access (WCDMA) as an air interface and high speed packet access (HSPA) as an enhanced packet data service. 
       SUMMARY 
       [0006]    Disclosed is an apparatus and method for controlling idle mode measurements. According to one aspect, a method for controlling idle mode radio measurements comprising determining if a radio measurement is less than a radio threshold; determining a time duration in which the radio measurement is less than the radio threshold; determining if the time duration is greater than a time measurement threshold; and obtaining at least one other radio measurement from at least one base station which is not a serving cell. 
         [0007]    According to another aspect, an apparatus for controlling idle mode radio measurements comprising means for determining if a radio measurement is less than a radio threshold; means for determining a time duration in which the radio measurement is less than the radio threshold; means for determining if the time duration is greater than a time measurement threshold; and means for obtaining at least one other radio measurement from at least one base station which is not a serving cell. 
         [0008]    According to another aspect, a user equipment comprising a processor and a memory, the memory containing program code executable by the processor for performing the following: determining if a radio measurement is less than a radio threshold; determining a time duration in which the radio measurement is less than the radio threshold; determining if the time duration is greater than a time measurement threshold; and obtaining at least one other radio measurement from at least one base station which is not a serving cell. 
         [0009]    According to another aspect, a computer-readable medium storing a computer program, wherein execution of the computer program is for: determining if a radio measurement is less than a radio threshold; determining a time duration in which the radio measurement is less than the radio threshold; determining if the time duration is greater than a time measurement threshold; and obtaining at least one other radio measurement from at least one base station which is not a serving cell. 
         [0010]    Advantages of the present disclosure may include improving the quality of RF radio measurements in idle mode by using a time measurement threshold, and thus prolonging UE battery life and improving user experience. 
         [0011]    It is understood that other aspects will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described various aspects by way of illustration. The drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates an example block diagram of an access node/UE system. 
           [0013]      FIG. 2  illustrates an example of a user equipment (UE) within one coverage area A with access nodes A 1 , A 2 , A 3 , A 4  and approaching the edge of another coverage area B with access nodes B 1  and B 2 . 
           [0014]      FIG. 3  illustrates an example application of a configurable time measurement threshold for idle mode radio measurements. 
           [0015]      FIG. 4  illustrates a first example of a flow diagram for controlling idle mode radio measurements. 
           [0016]      FIG. 5  illustrates a second example of a flow diagram for controlling idle mode radio measurements. 
           [0017]      FIG. 6  illustrates an example of a device comprising a processor in communication with a memory for controlling idle mode radio measurements. 
           [0018]      FIG. 7  illustrates a first example of a device suitable for controlling idle mode radio measurements. 
           [0019]      FIG. 8  illustrates a second example of a device suitable for controlling idle mode radio measurements. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The detailed description set forth below in connection with the appended drawings is intended as a description of various aspects of the present disclosure and is not intended to represent the only aspects in which the present disclosure may be practiced. Each aspect described in this disclosure is provided merely as an example or illustration of the present disclosure, and should not necessarily be construed as preferred or advantageous over other aspects. The detailed description includes specific details for the purpose of providing a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present disclosure. Acronyms and other descriptive terminology may be used merely for convenience and clarity and are not intended to limit the scope of the present disclosure. 
         [0021]    While for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more aspects, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more aspects. 
         [0022]    The techniques described herein may be used for various wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms “networks” and “systems” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) and Low Chip Rate (LCR). Cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM are part of Universal Mobile Telecommunication System (UMTS). Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known in the art. For clarity, certain aspects of the techniques are described below for UMTS and LTE, and UMTS/LTE terminology is used in much of the description below. 
         [0023]      FIG. 1  illustrates an example block diagram of an access node/UE system  100 . One skilled in the art would understand that the example access node/UE system  100  illustrated in  FIG. 1  may be implemented in an FDMA environment, an OFDMA environment, a CDMA environment, a WCDMA environment, a TDMA environment, a SDMA environment or any other suitable wireless environment. 
         [0024]    The access node/UE system  100  includes an access node  101  (e.g., base station) and a user equipment or UE  201  (e.g., wireless communication device). In the downlink leg, the access node  101  (e.g., base station) includes a transmit (TX) data processor A  110  that accepts, formats, codes, interleaves and modulates (or symbol maps) traffic data and provides modulation symbols (e.g., data symbols). The TX data processor A  110  is in communication with a symbol modulator A  120 . The symbol modulator A  120  accepts and processes the data symbols and downlink pilot symbols and provides a stream of symbols. In one aspect, it is the symbol modulator A  120  that modulates (or symbol maps) traffic data and provides modulation symbols (e.g., data symbols). In one aspect, symbol modulator A  120  is in communication with processor A  180  which provides configuration information. Symbol modulator A  120  is in communication with a transmitter unit (TMTR) A  130 . The symbol modulator A  120  multiplexes the data symbols and downlink pilot symbols and provides them to the transmitter unit A  130 . 
         [0025]    Each symbol to be transmitted may be a data symbol, a downlink pilot symbol or a signal value of zero. The downlink pilot symbols may be sent continuously in each symbol period. In one aspect, the downlink pilot symbols are frequency division multiplexed (FDM). In another aspect, the downlink pilot symbols are orthogonal frequency division multiplexed (OFDM). In yet another aspect, the downlink pilot symbols are code division multiplexed (CDM). In one aspect, the transmitter unit A  130  receives and converts the stream of symbols into one or more analog signals and further conditions, for example, amplifies, filters and/or frequency upconverts the analog signals, to generate an analog downlink signal suitable for wireless transmission. The analog downlink signal is then transmitted through antenna  140 . 
         [0026]    In the downlink leg, the UE  201  includes antenna  210  for receiving the analog downlink signal and inputting the analog downlink signal to a receiver unit (RCVR) B  220 . In one aspect, the receiver unit B  220  conditions, for example, filters, amplifies, and frequency downconverts the analog downlink signal to a first “conditioned” signal. The first “conditioned” signal is then sampled. The receiver unit B  220  is in communication with a symbol demodulator B  230 . The symbol demodulator B  230  demodulates the first “conditioned” and “sampled” signal (e.g., data symbols) outputted from the receiver unit B  220 . One skilled in the art would understand that an alternative is to implement the sampling process in the symbol demodulator B  230 . The symbol demodulator B  230  is in communication with a processor B  240 . Processor B  240  receives downlink pilot symbols from symbol demodulator B  230  and performs channel estimation on the downlink pilot symbols. In one aspect, the channel estimation is the process of characterizing the current propagation environment. The symbol demodulator B  230  receives a frequency response estimate for the downlink leg from processor B  240 . The symbol demodulator B  230  performs data demodulation on the data symbols to obtain data symbol estimates on the downlink path. The data symbol estimates on the downlink path are estimates of the data symbols that were transmitted. The symbol demodulator B  230  is also in communication with a RX data processor B  250 . 
         [0027]    The RX data processor B  250  receives the data symbol estimates on the downlink path from the symbol demodulator B  230  and, for example, demodulates (i.e., symbol demaps), deinterleaves and/or decodes the data symbol estimates on the downlink path to recover the traffic data. In one aspect, the processing by the symbol demodulator B  230  and the RX data processor B  250  is complementary to the processing by the symbol modulator A  120  and TX data processor A  110 , respectively. 
         [0028]    In the uplink leg, the UE  201  includes a TX data processor B  260 . The TX data processor B  260  accepts and processes traffic data to output data symbols. The TX data processor B  260  is in communication with a symbol modulator D  270 . The symbol modulator D  270  accepts and multiplexes the data symbols with uplink pilot symbols, performs modulation and provides a stream of symbols. In one aspect, symbol modulator D  270  is in communication with processor B  240  which provides configuration information. The symbol modulator D  270  is in communication with a transmitter unit B  280 . 
         [0029]    Each symbol to be transmitted may be a data symbol, an uplink pilot symbol or a signal value of zero. The uplink pilot symbols may be sent continuously in each symbol period. In one aspect, the uplink pilot symbols are frequency division multiplexed (FDM). In another aspect, the uplink pilot symbols are orthogonal frequency division multiplexed (OFDM). In yet another aspect, the uplink pilot symbols are code division multiplexed (CDM). In one aspect, the transmitter unit B  280  receives and converts the stream of symbols into one or more analog signals and further conditions, for example, amplifies, filters and/or frequency upconverts the analog signals, to generate an analog uplink signal suitable for wireless transmission. The analog uplink signal is then transmitted through antenna  210 . 
         [0030]    The analog uplink signal from UE  201  is received by antenna  140  and processed by a receiver unit A  150  to obtain samples. In one aspect, the receiver unit A  150  conditions, for example, filters, amplifies and frequency downconverts the analog uplink signal to a second “conditioned” signal. The second “conditioned” signal is then sampled. The receiver unit A  150  is in communication with a symbol demodulator C  160 . One skilled in the art would understand that an alternative is to implement the sampling process in the symbol demodulator C  160 . The symbol demodulator C  160  performs data demodulation on the data symbols to obtain data symbol estimates on the uplink path and then provides the uplink pilot symbols and the data symbol estimates on the uplink path to the RX data processor A  170 . The data symbol estimates on the uplink path are estimates of the data symbols that were transmitted. The RX data processor A  170  processes the data symbol estimates on the uplink path to recover the traffic data transmitted by the wireless communication device  201 . The symbol demodulator C  160  is also in communication with processor A  180 . Processor A  180  performs channel estimation for each active terminal transmitting on the uplink leg. In one aspect, multiple terminals may transmit pilot symbols concurrently on the uplink leg on their respective assigned sets of pilot subbands where the pilot subband sets may be interlaced. 
         [0031]    Processor A  180  and processor B  240  direct (i.e., control, coordinate or manage, etc.) operation at the access node  101  (e.g., base station) and at the UE  201 , respectively. In one aspect, either or both processor A  180  and processor B  240  are associated with one or more memory units (not shown) for storing of program codes and/or data. In one aspect, either or both processor A  180  or processor B  240  or both perform computations to derive frequency and impulse response estimates for the uplink leg and downlink leg, respectively. 
         [0032]    In one aspect, the access node/UE system  100  is a multiple-access system. For a multiple-access system (e.g., frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), code division multiple access (CDMA), time division multiple access (TDMA), space division multiple access (SDMA), etc.), multiple terminals transmit concurrently on the uplink leg, allowing access to a plurality of UEs. In one aspect, for the multiple-access system, the pilot subbands may be shared among different terminals. Channel estimation techniques are used in cases where the pilot subbands for each terminal span the entire operating band (possibly except for the band edges). Such a pilot subband structure is desirable to obtain frequency diversity for each terminal. 
         [0033]      FIG. 2  illustrates an example of a user equipment (UE) within one coverage area A with access nodes A 1 , A 2 , A 3 , A 4  and approaching the edge of another coverage area B with access nodes B 1  and B 2 . As shown in  FIG. 2 , UE  201  is located within the source cell within coverage area A and approaching the target cell within coverage area B. Coverage area A employs radio access technology A while coverage area B employs radio access technology B. Wireless system A is associated with coverage area A, and wireless system B is associated with coverage area B. In one aspect, as the UE  201  approaches the target cell, a comparison is made to determine if the signal quality from the target cell (e.g., target cell signal quality) is higher than the signal quality from the source cell (e.g., source cell signal quality). If the signal quality from the target cell is higher, than a transition is made from the source cell to the target cell, i.e., an inter-radio access technology (IRAT) transition is triggered from the source cell to the target cell. In one aspect, the signal quality from the target cell must be higher than the signal quality from the source cell for a continuous X time interval before the transition is made. In one example, the X time interval is 5 seconds. One skilled in the art would understand that although the example given relates to inter-radio access technology (IRAT), the present disclosure is equally applicable to either intra-frequency or inter-frequency cases. 
         [0034]    Transitioning the wireless access connection of the UE  201  between wireless systems A and B requires a finite amount of time to complete. For example, if the UE  201  starts in the source cell within coverage area A (e.g., a 2G coverage area employing 2G radio access technology by a 2G wireless system) and moves towards the target cell within coverage area B (e.g., a 3G coverage area employing 3G radio access technology by a 3G wireless system), the UE  201  may reselect to wireless system B (e.g., 3G wireless system) and start collecting system information from the access nodes within coverage area B. This process may not be completed for some time, e.g., several seconds such as 3-5 seconds for some systems. Meanwhile, wireless system A (e.g., 2G wireless system) may be sending a page to the UE  201  via the access node A 1  within the source cell within the coverage area A (e.g., the 2G coverage area). If the UE  201  has already reselected to wireless system B (e.g., 3G wireless system), it does not monitor the incoming page sent to wireless system A (e.g., 2G wireless system), resulting in an unsuccessful page and a poor experience for the UE user. The UE  201  does not start to monitor the paging channel in the target cell within coverage area B until the UE  201  has completed collecting all the essential system information from the target cell and until the UE  201  has performed mobility information update on the target cell and its associated radio access technology (RAT). In one aspect, the paging cycle is either 1.28 or 2.56 seconds which means that during this paging cycle (for example, of either 1.28 or 2.56 seconds), pages are missed by the UE  201 . One skilled in the art would understand that the scope and spirit of the present disclosure are not affected by other examples of radio access technologies employed by other wireless systems, including but not limited to, UMTS, WCDMA, GSM, GSM/GPRS/EDGE, LTE, IS-95, CDMA2000, EVDO or UMB, etc. 
         [0035]    The Third Generation Partnership Project (3GPP) is an international consortium responsible for the definition and maintenance of next generation wireless systems that evolve from the second generation GSM wireless system. In one aspect, 3GPP has defined the types of radio measurements a UMTS UE should perform in idle mode. For example, UMTS document TS 25.304 “User Equipment (UE) procedures in idle mode and procedures for cell reselection in connected mode” and LTE document TS 36.304 “Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode” specify various radio quality measurement requirements on the UE while in idle mode (i.e., not actively transmitting or receiving information). In one example, for UMTS the UE performs intra-frequency, inter-frequency, and inter-RAT (radio access technology) radio quality measurements (e.g., received signal code power (RSCP)) on the common pilot channel (CPICH) signal and compares the measurements to a configurable RSCP threshold. Alternatively, the radio quality measurements are compared to an energy to noise density ratio (E/N o ) threshold, for example, a chip energy to noise density ratio (E c /N o ) threshold or a bit energy to noise density ratio (E b /N o ) threshold. In another example for LTE, the UE performs radio quality measurements on a reference signal (RS) and compares them to a reference signal received power (RSRP) threshold or a reference signal received quality (RSRQ) threshold. 
         [0036]    One issue with the current 3GPP specifications for idle mode measurements is that the defined procedures may lead to frequent and unnecessary UE measurements which cause further energy consumption and result in decreased battery life, thus adversely affecting user satisfaction. For example, in a dynamic wireless propagation environment where the RF power level varies considerably, following the 3GPP specifications for idle mode may result in power measurements taken more frequently than necessary. The present disclosure discloses adding a time measurement threshold to the idle mode measurement procedures. 
         [0037]    In one aspect, the current 3GPP specifications on UE procedures in idle mode, TS 25.304 and TS 36.304, may be modified to add certain conditions to improve overall UE performance. For example, while operating within a given serving cell in the wireless network, the UE performs radio measurements on other cells if the serving cell quality is below a configurable quality threshold for a time duration exceeding a certain time measurement threshold, T measurement  (e.g., seconds). If the serving cell quality is below a configurable quality threshold for a time duration less than the time measurement threshold T measurement , then radio measurements on other cells are not performed. In one example, the serving cell quality and quality threshold are based on a received radio measurement (e.g., RSCP or RSRP) or on a received energy-to-noise density level (e.g., E b /N 0 , E c /N 0 , etc.) or on a received quality (e.g., reference signal received quality, RSRQ). 
         [0038]    In one example, the time measurement threshold T measurement  is a broadcast Radio Resource Control (RRC) parameter. In one aspect, RRC is part of the UMTS protocol stack and is responsible for control plane signaling between the UEs and the network infrastructure. One skilled in the art would understand that the value of the time measurement threshold T measurement  may depend on different factors, such as but not limited to, particular application and design parameters, user choice, etc. without affecting the scope or spirit of the present disclosure. 
         [0039]    In another example, there may be several implementations of the usage of the time measurement threshold (T measurement ), for example, in a 3GPP wireless network. For example, there could be different time measurement threshold (T measurement ) for different types of radio measurements (intra-frequency, inter-frequency, and inter-RAT). Alternatively, the same time measurement threshold (T measurement ) may be used for all radio measurements. 
         [0040]    In one example, a scaling factor K for the time measurement threshold (T measurement ) may be broadcasted and applied for high mobility UE scenarios. For example, a modified time measurement threshold defined by T modified =KT measurement , where K is a scaling factor, may be used when the UE speed v exceeds a speed threshold v T  which defines a high mobility regime. One skilled in the art would understand that the value of the scaling factor K and/or the value of the speed threshold v T  may depend on different factors, such as but not limited to, particular application and design parameters, user choice, etc. without affecting the scope or spirit of the present disclosure. Additionally, different scaling factor may be used depending on the type of radio measurement (e.g., intra-frequency, inter-frequency, inter-radio access technology (IRAT), etc.) 
         [0041]      FIG. 3  illustrates an example application of a configurable time measurement threshold for idle mode radio measurements. Shown is a graph of radio measurements versus time as well as a predefined radio threshold R T . The radio measurements first drop below the predefined radio threshold R T  during a first epoch for a first time duration of Δt 1  seconds. At a later time, the radio measurements next drop below the predefined radio threshold R T  during a second epoch for a second time duration of Δt 2  seconds. In one example, if the first time duration Δt 1  is less than the time measurement threshold T measurement  then no radio measurements on other cells would be performed. However, if the second time duration Δt 2  is greater than the time measurement threshold T measurement , the UE would perform radio measurements on other cells as a result of the radio measurements dropping below the predefined radio threshold R T  during the second epoch. 
         [0042]    The example presented in  FIG. 3  may be extended to the case where different time measurement thresholds are defined for different types of radio measurements (e.g. intra-frequency, inter-frequency, inter-RAT, etc.). In this case, some of the rules for performing each radio measurement may be governed by the relationship between the radio measurements and the different time measurement thresholds. In one example, the radio measurement is a power measurement and the radio threshold R T  is a power threshold P T . 
         [0043]      FIG. 4  illustrates a first example of a flow diagram for controlling idle mode radio measurements. In block  410 , determine if a radio measurement is less than a radio threshold R T . If the radio measurement is less than the radio threshold R T , proceed to block  420 . In block  420 , determine a time duration in which the radio measurement is less than the radio threshold R T . In block  430 , determine if the time duration is greater than a time measurement threshold T measurement . If yes, proceed to block  440  and obtain at least one other radio measurement from at least one base station which is not a serving cell. In one aspect, the time measurement threshold T measurement.  is configurable. 
         [0044]      FIG. 5  illustrates a second example of a flow diagram for controlling idle mode radio measurements. In block  510 , receive a time measurement threshold T measurement  and a radio threshold R T . In one example, the time measurement threshold T measurement  and the radio threshold R T  are received by a UE and broadcasted by a base station (e.g. eNodeB). In one example, the base station is the serving cell to the UE. In block  520 , obtain a radio measurement. In one example, the radio measurement pertains to the base station (e.g., eNodeB). In block  530 , determine if the radio measurement is greater than or equal to the radio threshold R T . If the radio measurement is greater than or equal to the radio threshold R T , then return to block  520  to obtain a new radio measurement. If the radio measurement is less than the radio threshold R T , proceed to block  540 . In block  540 , record a current time that the radio measurement is below the radio threshold R T  and compute a delta time (i.e., time duration) between the current time and a start time of which the radio measurement was first below the radio threshold R T . In block  550 , determine if the delta time is less than the time measurement threshold T Measurement . If the delta time is less than the time measurement threshold T Measurement , then return to block  520  to obtain another new radio measurement. If the delta time is greater than or equal to the time measurement threshold T Measurement , then proceed to block  560 . In block  560 , obtain at least one other radio measurement from at least one other base station. The one other base station is different from the base station that is the serving cell. In one aspect, the time measurement threshold T measurement.  is configurable. In one example, the process described in the example flow diagram of  FIG. 5  is repeated with one or more new radio measurements. 
         [0045]    One skilled in the art would understand that the steps disclosed in the example flow diagrams in  FIGS. 4 and 5  may be interchanged in their order without departing from the scope and spirit of the present disclosure. Also, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope and spirit of the present disclosure. 
         [0046]    Those of skill would further appreciate that the various illustrative components, logical blocks, modules, circuits, and/or algorithm steps described in connection with the examples disclosed herein may be implemented as electronic hardware, firmware, computer software, or combinations thereof. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and/or algorithm steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope or spirit of the present disclosure. 
         [0047]    For example, for a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described therein, or a combination thereof. With software, the implementation may be through modules (e.g., procedures, functions, etc.) that perform the functions described therein. The software codes may be stored in memory units and executed by a processor unit. Additionally, the various illustrative flow diagrams, logical blocks, modules and/or algorithm steps described herein may also be coded as computer-readable instructions carried on any computer-readable medium known in the art or implemented in any computer program product known in the art. 
         [0048]    In one or more examples, the steps or functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
         [0049]    In one example, the illustrative components, flow diagrams, logical blocks, modules and/or algorithm steps described herein are implemented or performed with one or more processors. In one aspect, a processor is coupled with a memory which stores data, metadata, program instructions, etc. to be executed by the processor for implementing or performing the various flow diagrams, logical blocks and/or modules described herein.  FIG. 6  illustrates an example of a device  600  comprising a processor  610  in communication with a memory  620  for controlling idle mode radio measurements. In one example, the device  600  is used to implement the algorithm illustrated in  FIG. 4 . In another example, the device  600  is used to implement the algorithm illustrated in  FIG. 5 . In one aspect, the memory  620  is located within the processor  610 . In another aspect, the memory  620  is external to the processor  610 . In one aspect, the processor includes circuitry for implementing or performing the various flow diagrams, logical blocks and/or modules described herein. 
         [0050]      FIG. 7  illustrates a first example of a device  700  suitable for controlling idle mode radio measurements. In one aspect, the device  700  is implemented by at least one processor comprising one or more modules configured to provide different aspects of controlling idle mode radio measurements as described herein in blocks  710 ,  720 ,  730  and  740 . For example, each module comprises hardware, firmware, software, or any combination thereof. In one aspect, the device  700  is also implemented by at least one memory in communication with the at least one processor. 
         [0051]      FIG. 8  illustrates a second example of a device  800  suitable for controlling idle mode radio measurements. In one aspect, the device  800  is implemented by at least one processor comprising one or more modules configured to provide different aspects of controlling idle mode radio measurements as described herein in blocks  810 ,  820 ,  830 ,  840 ,  850  and  860 . For example, each module comprises hardware, firmware, software, or any combination thereof. In one aspect, the device  800  is also implemented by at least one memory in communication with the at least one processor. 
         [0052]    The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of the disclosure.