JP2020114010A - Fast cell reselection - Google Patents

Abstract

To provide a method for user equipment (UE) expediting cell reselection.SOLUTION: The UE starts a reselection timer for reselecting to a neighbor cell when the signal quality of a serving cell is determined to fall below a first threshold and when the signal quality of the neighbor cell is above a neighbor cell threshold. The UE then speeds up reselecting to the neighbor cell based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell falls below a second threshold. The step of speeding up reselecting to the neighbor cell is reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer without changing the reselection timer.SELECTED DRAWING: Figure 11

Description

[0001] Aspects of the disclosure relate generally to wireless communication systems, and more particularly to expedited cell reselection.

[0002] Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcast, and so on. Such networks, typically multiple access networks, support communication for multiple users by sharing the available network resources. One example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). UTRAN is a radio access network defined as part of Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the Third Generation Partnership Project (3GPP®). RAN). UMTS, which is a successor to the Global System (GSM (registered trademark)) technology for mobile communication, currently uses wideband code division multiple access (W-CDMA (registered trademark)) and time division code division multiple access (TD-CDMA). ), and Time Division Synchronous Code Division Multiple Access (TD-SCDMA). For example, China is promoting TD-SCDMA as the underlying air interface in the UTRAN architecture, with its existing GSM infrastructure as the core network. UMTS also supports enhanced 3G data communication protocols, such as High Speed Packet Access (HSPA), which provides associated UMTS networks with higher data rates and capacities. HSPA is a collection of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), which extend and improve the performance of existing broadband protocols.

[0003] As the demand for mobile broadband access continues to grow, there is a need for further improvements in wireless technology. Desirably, these improvements should be applicable to LTE and other multi-access technologies and telecommunications standards using these technologies.

[0004] According to one aspect of the present disclosure, a method of wireless communication starts a reselection timer for reselecting to a neighbor cell when it is determined that the signal quality of a serving cell is below a first threshold. Including that. The method also speeds up reselection to the neighbor cell based on the difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold ( speeding up reselecting) is included.

[0005] According to another aspect of the present disclosure, an apparatus for wireless communication reselection timer for reselecting to a neighbor cell when it is determined that the signal quality of a serving cell is below a first threshold. Including means for initiating. The apparatus is also for speeding up reselection to a neighbor cell based on the difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold. Means may be included.

[0006] Another aspect discloses an apparatus for wireless communication, including a memory and at least one processor (eg, one or more processors) coupled to the memory. The processor(s) is configured to start a reselection timer for reselecting to a neighbor cell when it is determined that the signal quality of the serving cell is below a first threshold. The processor(s) may also reconnect to the neighbor cell based on the difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold. Configured to speed selection.

[0007] Yet another aspect, when executed by the processor(s), determines to the processor(s) that the signal quality of the serving cell is below a first threshold. At this time, a non-transitory computer readable storage medium having a non-transitory program code recorded therein for causing a neighboring cell to start a reselection timer for reselection is disclosed. The program code may also inform the processor(s) based on the difference between the signal quality of the serving cell and the signal quality of the neighboring cell when the signal quality of the serving cell is below a second threshold. Speed up reselection to the cell.

[0008] This rather broadly outlines the features and technical advantages of the present disclosure so that the following detailed description can be better understood. Additional features and advantages of the disclosure are described below. It should be understood by one of ordinary skill in the art that the present disclosure can be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the present disclosure. It should also be appreciated by those skilled in the art that such equivalent structures do not depart from the teachings of the present disclosure as set forth in the appended claims. The novel features, which are considered as characteristic of the disclosure, both as to the manner of construction and operation thereof, as well as further objects and advantages, are better understood from the following description when considered in connection with the accompanying drawings. Will However, it should be clearly understood that each of the drawings are provided for purposes of illustration and description only and are not intended as definitions of the limitations of the present disclosure.

[0009] The features, characteristics, and advantages of the present disclosure will become more apparent from the detailed description set forth below, when like reference numerals are considered in conjunction with the drawings to refer to like things throughout.
[0010] FIG. 1 is a diagram illustrating an example of a network architecture. [0011] FIG. 2 is a diagram illustrating an example of a downlink frame structure in Long Term Evolution (LTE). [0012] FIG. 3 is a diagram illustrating an example of an uplink frame structure in Long Term Evolution (LTE). [0013] FIG. 4 is a block diagram that conceptually illustrates an example of a telecommunications system that uses the Time Division Synchronous Code Division Multiple Access (TD-SCDMA) standard. [0014] FIG. 5 is a block diagram conceptually illustrating an example of a frame structure for a time division synchronization code division multiple access carrier. [0015] FIG. 6 is a block diagram conceptually illustrating an example of a base station in communication with a user equipment (UE) in a telecommunications system. [0016] FIG. 7 is a diagram illustrating a network coverage area according to aspects of the disclosure. [0017] FIG. 8 is a block diagram illustrating measurement and evaluation of serving cells and intra/inter-frequency cells.

[0018] A plurality of cells according to an aspect of the disclosure.
[0019] FIG. 9 is a flow diagram illustrating an example process, according to aspects of the disclosure. [0020] FIG. 10 is a block diagram illustrating measurement and evaluation of a serving cell and an intra/inter frequency cell according to an aspect of the disclosure. [0021] FIG. 11 is a block diagram illustrating a method for facilitating cell reselection, according to an aspect of the disclosure. [0022] FIG. 12 is a diagram illustrating an example of a hardware implementation for an apparatus using a processing system in accordance with an aspect of the present disclosure.

Detailed Description of the Invention

[0023] The detailed description set forth below in connection with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be implemented without these specific details. In some cases, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0024] FIG. 1 is a diagram illustrating a network architecture 100 for a Long Term Evolution (LTE) network. LTE network architecture 100 may be referred to as Evolved Packet System (EPS) 100. The EPS 100 includes one or more user equipments (UEs) 102, an evolved UMTS Terrestrial Radio Access Network (E-UTRAN) 104, an evolved packet core (EPC) 110, a home subscriber server (HSS) 120, and an operator ( operator) IP service 122. EPS can interconnect with other access networks, but for simplicity their entities/interfaces are not shown. As shown, the EPS 100 provides packet-switched services, however, as will be readily appreciated by those skilled in the art, various concepts presented throughout this disclosure may be used in networks that provide circuit-switched services. Can be extended to.

[0025] The E-UTRAN 104 includes an evolved Node B (eNode B) 106 and another eNodeB 108. The eNodeB 106 provides user and control plane protocol terminations to the UE 102. The eNodeB 106 may be connected to another eNodeB 108 via a backhaul (eg, X2 interface). The eNodeB 106 may also be referred to as a base station, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), or some other suitable term. The eNodeB 106 provides an access point to the EPC 110 for the UE 102. Examples of UEs 102 are cellular phones, smartphones, session initiation protocol (SIP) phones, laptops, notebooks, netbooks, smartbooks, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video. Device, digital audio player (eg, MP3 player), camera, gaming device, or any other similarly functioning device. The UE 102 may also be a mobile station or device, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, according to those skilled in the art. , Mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

[0026] The eNodeB 106 is connected to the EPC 110, for example, via the S1 interface. The EPC 110 includes a mobility management entity (MME) 112, other MMEs 114, a serving gateway 116, and a packet data network (PDN) gateway 118. The MME 112 is a control node that handles signaling between the UE 102 and the EPC 110. Generally, the MME 112 provides bearer and connection management. All user IP packets are forwarded through the serving gateway 116, which is itself connected to the PDN gateway 118. The PDN gateway 118 provides not only UE IP address allocation, but also other functions. The PDN gateway 118 is connected to the operator's IP service 122. The operator's IP services 122 may include the Internet, Intranet, IP Multimedia Subsystem (IMS), and PS Streaming Services (PSS).

[0027] FIG. 2 is a diagram 200 illustrating an example of a downlink frame structure in LTE. A frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent two time slots, each time slot containing a resource block. The resource grid is divided into a plurality of resource elements. In LTE, a resource block contains 12 consecutive subcarriers in the frequency domain and, in the case of a regular cyclic prefix, 7 consecutive OFDM symbols in the time domain in each OFDM symbol, ie 84 Contains resource elements. For the extended cyclic prefix, the resource block contains 6 consecutive OFDM symbols in the time domain and has 72 resource elements. Some of the resource elements, shown as R202, 204, include downlink reference signals (DL-RS). The DL-RS includes a cell-specific RS (CRS: cell-specific RS (sometimes called a common RS)) 202 and a UE-specific RS (UE-RS: UE-specific RS) 204. UE-RS204 is transmitted only on the resource block to which the corresponding physical downlink shared channel (PDSCH) is mapped. The number of bits carried by each resource element depends on the modulation scheme. Therefore, the more resource blocks the UE receives and the more sophisticated the modulation scheme, the higher the data rate for the UE.

[0028] FIG. 3 is a diagram 300 illustrating an example of an uplink frame structure in LTE. The resource blocks available for the uplink may be partitioned into a data section and a control section. The control section may be formed at the two edges of the system bandwidth and may have a configurable size. Resource blocks in the control section may be assigned to the UE for transmission of control information. The data section may include all resource blocks not included in the control section. The uplink frame structure results in a data section containing consecutive subcarriers, which may allow a single UE to be assigned all consecutive subcarriers in the data section.

[0029] The UE may be assigned resource blocks 310a, 310b in the control section to send control information to the eNodeB. The UE may also be assigned resource blocks 320a, 320b in the data section to send data to the eNodeB. The UE may send control information on the Physical Uplink Control Channel (PUCCH) on the allocated resource blocks in the control section. The UE may send only data or both data and control information on the Physical Uplink Shared Channel (PUSCH) on the allocated resource blocks in the data section. Uplink transmissions may span both slots of a subframe and may hop across frequencies.

[0030] The set of resource blocks may be used to perform initial system access and achieve uplink synchronization on a physical random access channel (PRACH) 330. The PRACH 330 carries a random sequence and cannot carry any uplink data/signaling. Each random access preamble occupies a bandwidth corresponding to 6 consecutive resource blocks. The starting frequency is specified by the network. That is, the transmission of random access preambles is limited to certain time and frequency resources. For PRACH, there is no frequency hopping. A PRACH attempt is carried in a single subframe (1 ms) or in a sequence of a small number of consecutive subframes, and the UE only makes a single PRACH attempt per frame (10 ms). be able to.

[0031] Referring now to FIG. 4, a block diagram illustrating an example of a telecommunications system 400 is shown. The various concepts presented throughout this disclosure may be implemented across a wide variety of telecommunications systems, network architectures, and communication standards. By way of example and not limitation, the aspects of the present disclosure illustrated in FIG. 4 are presented in the context of a UMTS system using the TD-SCDMA standard. In this example, the UMTS system includes a radio access network (RAN) 402 (eg, UTRAN) that provides various wireless services, including telephony, video, data, messaging, broadcast, and/or other services. The RAN 402 may be divided into a number of Radio Network Subsystems (RNSs) such as the RNS 407, each controlled by a Radio Network Controller (RNC) such as the RNC 406. Although only RNC 406 and RNS 407 are shown for clarity, RAN 402 may include any number of RNCs and RNSs in addition to RNC 406 and RNS 407. The RNC 406 is, among other things, the device responsible for allocating, reconfiguring and releasing radio resources within the RNS 407. RNC 406 uses any suitable transport network to communicate with other RNCs (not shown) in RAN 402 through various types of interfaces, such as direct physical connections, virtual networks, or the like. Can be connected.

[0032] The geographic area covered by RNS 407 may be divided into a number of cells, with a radio transceiver device serving each cell. Wireless transceiver devices are commonly referred to as Node Bs in UMTS applications, but those skilled in the art will appreciate that base stations (BS), base transceiver stations (BTS), wireless base stations, wireless transceivers, transceiver functions, basic service sets (BSS), It may also be referred to as extended service set (ESS), access point (AP), or some other suitable term. Two Node Bs 408 are shown for clarity, but the RNS 407 may include any number of wireless Node Bs. Node B 408 provides wireless access points to core network 404 for any number of mobile devices. For illustration purposes, three UEs 410 are shown in communication with the Node B 408. The downlink (DL), also called the forward link, refers to the communication link from the Node B to the UE, and the uplink (UL), also called the reverse link, refers to the communication link from the UE to the Node B.

[0033] The core network 404 includes a GSM core network, as shown. However, as one of ordinary skill in the art will recognize, various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable, to provide a UE with access to a type of core network other than a GSM network. Can be implemented in any access network.

[0034] In this example, the core network 404 supports circuit switched services using a mobile switching center (MSC) 412 and a gateway MSC (GMSC) 414. One or more RNCs, eg, RNC 406, may be connected to MSC 412. The MSC 412 is a device that controls call setup, call routing, and UE mobility functions. The MSC 412 also includes a visitor location register (VLR) (not shown) that contains subscriber related information for the duration that the UE is within the coverage area of the MSC 412. The GMSC 414 provides a gateway through the MSC 412 for the UE to access the circuit switched network 416. The GMSC 414 includes a Home Location Register (HLR) (not shown) that contains subscriber data, such as data that reflects details of the service that a particular user is subscribed to. The HLR is also associated with an authentication center (AuC) that contains subscriber-specific authentication data. When a call is received for a particular UE, the GMSC 414 queries the HLR to determine the location of the UE and forwards the call to the particular MSC serving that location.

[0035] The core network 404 also supports packet data services using a serving GPRS support node (SGSN) 418 and a gateway GPRS support node (GGSN) 420. General packet radio services (GPRS) are designed to provide packet data services at higher speeds than are available with standard GSM circuit switched data services. The GGSN 420 provides the RAN 402 with a connection to the packet-based network 422. Packet-based network 422 may be the Internet, a private data network, or some other suitable packet-based network. The main function of GGSN 420 is to provide UE 410 with packet-based network connectivity. Data packets are primarily transferred between GGSN 420 and UE 410 through SGSN 418, which performs the same functions in the packet-based domain that MSC 412 performs in the circuit-switched domain.

[0036] The UMTS air interface is a spread spectrum direct sequence code division multiple access (DS-CDMA) system. Spread spectrum DS-CDMA spreads user data over a much wider bandwidth through multiplication by a sequence of pseudo-random bits called chips. The TD-SCDMA standard is based on such direct sequence spread spectrum techniques, and further, rather than the FDD used in many frequency division duplex (FDD) mode UMTS/W-CDMA systems, time division duplex ( TDD) calls for. TDD uses the same carrier frequency for both the uplink (UL) and downlink (DL) between Node B 408 and UE 410, but splits the uplink and downlink transmissions into different time slots on the carrier.

[0037] FIG. 5 shows a frame structure 500 for a TD-SCDMA carrier. The TD-SCDMA carrier has a frame 502 that is 10 ms long as illustrated. The chip rate in TD-SCDMA is 1.28 Mcps. Frame 502 has two 5 ms sub-frames 504, each sub-frame 504 including seven time slots, TS0-TS6. The first time slot, TS0, is typically allocated for downlink communications, while the second time slot, TS1, is typically allocated for uplink communications. The remaining time slots, TS2-TS6, may be used for either the uplink or the downlink, which gives greater flexibility during higher data transmission in either the uplink or downlink direction. Enable sex. A downlink pilot time slot (DwPTS) 506, a guard period (GP) 508, and an uplink pilot time slot (UpPTS) 510 (also known as an uplink pilot channel (UpPCH)) are located between TS0 and TS1. To do. Each time slot, TS0-TS6, may enable multiplexed data transmission on up to 16 code channels. Data transmission on the code channel consists of two data portions 512 (each having a length of 352 chips) separated by a midamble 514 (having a length of 144 chips) followed by a guard period (GP) 516. (Having a length of 16 chips). Midamble 514 may be used for functions such as channel estimation, while guard period 516 may be used to avoid inter-burst interference. Also, in the data portion, some layer 1 control information is transmitted, including synchronous shift (SS) bits 518. The sync shift bit 518 only appears in the second part of the data part. The sync shift bit 518 immediately after the midamble may indicate three cases at the upload transmission timing: reduce shift, increase shift, or do nothing. The position of the sync shift bit 518 is generally not used during uplink communication.

[0038] FIG. 6 is a block diagram of a base station (eg, eNodeB or NodeB) 610 in communication with a UE 650 in an access network. On the downlink, upper layer packets from the core network are provided to controller/processor 675. The controller/processor 675 implements the functionality of the L2 layer. On the downlink, the controller/processor 675 may include header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radios to the UE 650 based on various priority metrics. Provides resource allocation. Controller/processor 675 is also responsible for HARQ operation, retransmission of lost packets, and signaling to UE 650.

[0039] The TX processor 616 implements various signal processing functions for the L1 layer (ie, the physical layer). Signal processing functions include coding and interleaving to facilitate forward error correction (FEC) at UE 650 and various modulation schemes (eg, 2-phase phase shift keying (BPSK), 4-phase phase shift keying (QPSK). ), M-phase shift keying (M-PSK), M-ary quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then split into multiple parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (eg, pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT), Generate a physical channel that carries the time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. The channel estimates from channel estimator 674 may be used for spatial processing as well as to determine coding and modulation schemes. Channel estimates may be derived from channel state feedback and/or reference signals transmitted by UE 650. Each spatial stream is then provided to a different antenna 720 via a separate transmitter (TX) 618. Each transmitter (TX) 618 modulates an RF carrier with a respective spatial stream for transmission.

[0040] At the UE 650, each receiver (RX) 654 receives a signal through its respective antenna 652. Each receiver (RX) 654 recovers the information modulated on the RF carrier and provides that information to a receiver (RX) processor 656. RX processor 656 implements various signal processing functions of the L1 layer. RX processor 656 performs spatial processing on the information to recover any spatial stream destined for UE 650. If multiple spatial streams are destined for UE 650, they may be combined by RX processor 656 into a single OFDM symbol stream. RX processor 656 then transforms the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are reconstructed and demodulated by determining the most likely signal constellation point transmitted by base station 610. These soft decisions may be based on the channel estimates calculated by channel estimator 658. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 610 on the physical channel. The data and control signals are then provided to controller/processor 659.

[0041] The controller/processor 659 implements the L2 layer. The controller/processor may be associated with memory 660 that stores program code and data. Memory 660 may be referred to as a computer-readable medium. On the uplink, the controller/processor 659 demultiplexes between transport and logical channels, reassembles packets, decrypts, decompresses headers to decompress upper layer packets from the core network. header decompression) and control signal processing. The upper layer packet is then provided to the data sink 662, which represents all protocol layers above the L2 layer. Various control signals may also be provided to data sink 662 for L3 processing. The controller/processor 659 is also responsible for error detection using acknowledgment (ACK) and/or negative acknowledgment (NACK) protocols to support HARQ operation.

[0042] On the uplink, a data source 667 is used to provide upper layer packets to the controller/processor 659. The data source 667 represents all protocol layers above the L2 layer. Similar to the functions described in connection with the downlink transmission by the base station 610, the controller/processor 659 controls the multiplexing between logical channels and transport channels based on radio resource allocation by the base station 610, packet segments. Implement the L2 layer for the user and control planes by providing encryption and reordering, encryption, and header compression. Controller/processor 659 is also responsible for HARQ operations, retransmission of lost packets, and signaling to base station 610.

[0043] The channel estimate derived by the channel estimator 658 from the feedback or reference signal transmitted by the base station 610 is TX selected to select an appropriate coding and modulation scheme and to facilitate spatial processing. It may be used by the processor 668. The spatial streams generated by TX processor 668 are provided to different antennas 652 via separate transmitters (TX) 654. Each transmitter (TX) 654 modulates an RF carrier with a respective spatial stream for transmission.

[0044] The uplink transmissions are processed at the base station 610 in a similar manner as described in relation to the receiver function at the UE 650. Each receiver (RX) 618 receives a signal through its respective antenna 620. Each receiver (RX) 618 recovers the information modulated on the RF carrier and provides that information to the RX processor 670. RX processor 670 may implement the L1 layer.

[0045] The controller/processor 675 implements the L2 layer. Controllers/processors 675 and 659 can be associated with memories 676 and 660 that store program code and data, respectively. For example, controllers/processors 675 and 659 may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memories 676 and 660 may be referred to as computer readable media. For example, the memory 660 of the UE 650 may store the wireless communication module 691 which, when executed by the controller/processor 659, configures the UE 650 to facilitate cell reselection according to aspects of this disclosure.

[0046] On the uplink, the controller/processor 675 demultiplexes between transport and logical channels, reassembles packets, decrypts, compresses headers to recover upper layer packets from the UE 650. Provides release and control signal processing. Upper layer packets from controller/processor 675 may be provided to the core network. The controller/processor 675 is also responsible for error detection using the ACK and/or NACK protocols to support HARQ operation.

[0047] Some networks may be deployed with multiple radio access technologies. FIG. 7 includes, but is not limited to, GSM (2nd Generation (2G)), TD-SCDMA (3rd Generation (3G)), LTE (4th Generation (4G)) and 5th Generation (5G). ), which utilizes multiple types of Radio Access Technology (RAT). Multiple RATs may be deployed in the network to increase capacity. Typically, 2G and 3G are configured with a lower priority than 4G. In addition, multiple frequencies in LTE (4G) may have equal or different priority configurations. The reselection rules depend on the defined RAT priority. Different RATs are not configured with equal priority.

[0048] In one example, the geographical area 700 includes a RAT-1 cell 702 and a RAT-2 cell 704. In one example, the RAT-1 cell is a 2G or 3G cell and the RAT-2 cell is an LTE cell. However, one of ordinary skill in the art will appreciate that other types of radio access technologies may be utilized within these cells. User equipment (UE) 706 may move from one cell, eg, RAT-1 cell 702, to another cell, eg, RAT-2 cell 704. Movement of the UE 706 may specify handover or cell reselection.

[0049] Handover or cell reselection may be performed when the UE moves from the coverage area of the first RAT to the coverage area of the second RAT, or vice versa. Handover or cell reselection is also performed when there is a hole or lack of coverage in one network when there is traffic balancing between the first RAT network and the second RAT network. It may be obtained or based on the type of communication desired by the UE. As part of the handover or cell reselection process, while in the first system or RAT (eg, TD-SCDMA) connected mode or discontinuous reception mode (DRX), the UE may communicate with one or more neighboring cells. An activity may be designated to be performed. For example, the UE may perform neighbor cell measurements of the first, second, and/or third RAT (eg, GSM cell, LTE or TD-SCDMA). The discontinuous reception mode may include an idle mode, a cell paging channel (CELL_PCH) mode, a forward access channel (FACH) and a universal terrestrial radio access network (UTRAN) registered area paging channel (URA_PCH) mode.

[0050] The UE may tune away from the first RAT to perform activities in the second (and/or third) RAT. Activities performed while tuned away include selecting and monitoring the indicated paging indicator channel (PICH) and paging channel (PCH), monitoring for paging information for the second (or third) RAT. Monitoring and collecting system information (eg, frequency of the second (or third) RAT) of the second (or third) RAT, (one or more of the first RAT). ) Performing measurements (eg, inter radio access technology measurements) on the cell and neighbor cells of the second (or third) RAT, performing a cell reselection evaluation process, and And/or performing cell reselection to reselect to a neighboring cell of a second (or third) RAT when a cell reselection trigger condition is met.

[0051] In some networks, a UE may be notified of multiple neighbor cells when the UE is camped on or connected to the serving cell of the first RAT. These neighbor cells may be of the same RAT, may have different frequencies, or may be of different RATs having the same and/or different frequencies. For example, the UE may be notified or receive an LTE neighbor frequency/cell with or without a cell identifier while camping on a TD-SCDMA cell. Neighbor cell information may be broadcast from a network (eg, a TD-SCDMA network). In some cases, only certain RAT (eg, LTE) frequencies are broadcast to the UE.

[0052] According to the reselection procedure, the UE performs inter-radio access technology (IRAT) measurements on neighbor cells (eg, LTE neighbor cells/frequencies). For example, the UE may measure a neighbor cell of the second network for signal strength, frequency channel, and base station identification code (BSIC). The UE may then connect to the strongest cell of the second network. Such measurements may be referred to as Inter Radio Access Technology (IRAT) measurements.

[0053] During the IRAT measurement, if the cell reselection trigger condition is continuously met at the expiration of the reselection timer (eg Treselection), the serving RAT detects the target RAT during the IRAT measurement. Notify the target RAT to initiate cell reselection to the marked cell. The reselection timer governs when the UE may reselect to a new cell. The UE may not be allowed to reselect to the desired target RAT until the reselection timer expires. Therefore, the UE reselects to the target cell if the cell reselection trigger condition is continuously satisfied when the reselection timer expires. For example, the TD-SCDMA module of the UE notifies the LTE module of the UE to initiate cell reselection to the target LTE cell/frequency detected during IRAT measurement. After that, the LTE module of the UE starts acquisition on the LTE frequency of the detected target LTE cell. The LTE module then attempts to camp on the target LTE cell after collecting the broadcasted system information block (SIB).

[0054] As mentioned, after the UE determines that the trigger condition is met for cell reselection, the UE waits until the reselection for the UE expires to reselect to a new cell. However, in some cases, waiting for the reselection timer reselection to expire results in a RAT failure event. For example, a RAT failure event may include call setup failure or dropped call when the UE attempts to perform call setup on a degraded serving cell.

Fast cell reselection
[0055] Aspects of the present disclosure are based on a difference between a signal quality of a serving RAT cell/frequency and a signal quality of an adjacent RAT when the signal quality of a serving cell is below a threshold. It is directed to facilitating cell reselection from an access technology (RAT) to a second RAT. When the user equipment (UE) camps on the first RAT and the UE is within the coverage area of the second RAT, the UE may either one (corresponding to one or more cells) or Multiple frequencies are searched and the signal quality of one or more detected cells is measured. When the measurement result indicates that the cell reselection trigger condition is satisfied, the UE starts a cell reselection timer or a time to trigger. For example, the UE may reconnect to the neighbor cell when it is determined that the signal quality of the neighbor cell of the second RAT exceeds the neighbor cell threshold when the signal quality of the serving cell is below the first threshold. Start a reselection timer for selection.

[0056] In an aspect of the present disclosure, a UE is configured to connect to a neighbor cell based on a difference between a signal quality of the serving cell and a signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold. Speed up reselection of. For example, the UE speeds up cell reselection when the difference between the signal quality of the serving cell and the signal quality of the neighboring cell exceeds a third threshold. Cell reselection is facilitated by reselecting to a neighboring cell prior to the scheduled expiration of the reselection timer. Reselection may occur prior to call setup on the UE. The UE avoids dropped or failed calls by facilitating reselection to a neighboring cell. In one aspect of the disclosure, each of the thresholds is independently defined by the UE and/or the network.

[0057] Cell reselection is a procedure triggered by a user equipment (UE) in idle mode to determine which cell to camp on. Cell reselection may depend on measured radio frequency (RF) quality and system parameters broadcast from the network. For example, the mobile UE observes (eg, searches for and/or measures) signal quality of the serving cell and neighbor cells.

[0058] In idle mode (and in connected mode (eg, in forward access channel (FACH)/cell paging channel (CELL_PCH)/universal terrestrial radio access network (UTRAN) registered area paging channel (URA_PCH) states), UE Performs various activities such as serving cell measurement, neighbor cell measurement, and cell reselection.

[0059] Upon receiving a measurement request according to the Radio Resource Control (RRC) protocol with the configuration that occurred in the System Information Block (SIB), the protocol layer of the UE (Layer 1) configures the UE for measurement. Configure and start measuring serving cells and other cells (Intra/Inter Frequency/Inter Radio Access Technology (RAT)) as configured by Radio Resource Control (RRC).

[0060] The UE evaluates the signal quality of the serving cell to determine whether the signal quality of the serving cell meets a criterion for serving the UE (eg, signal strength threshold). The UE also evaluates the signal quality of the neighbor cells and ranks the neighbor cells based on their measured signal quality to determine if the signal quality of the neighbor cells meets the criteria.

[0061] If the cell reselection criteria for the neighbor cell is met, the UE initiates reselection to the neighbor cell (eg, the highest ranked neighbor cell).

[0062] Aspects of the disclosure include, but are not limited to, Universal Mobile Telecommunications System (UMTS), Time Division Code Division Multiple Access (TD-CDMA), and Long Term Evolution (LTE). It is directed to a fast cell reselection scheme that can be applied to the network.

[0063] FIG. 8 is a diagram illustrating measurement and evaluation of a serving cell and an intra/inter frequency cell. Serving cell measurements may include measuring and evaluating serving cell S criteria (eg, signal quality criteria) once every discontinuous reception (DRX) cycle. If the S criteria failed for a defined number (Nserv) of consecutive DRX cycles, the UE initiates neighbor cell measurements.

[0064] For intra/inter frequency cell measurement, the UE performs an intra frequency measurement if Sserv (eg, serving cell signal quality) <= SintraSearch (eg, intra frequency threshold). The UE performs inter-frequency measurement if Sserv <= SinterSearch (eg, inter-frequency threshold),

Is.

[0065] Cell reselection is triggered when Treselection expires.

[0066] FIG. 9 illustrates an example flow diagram in accordance with aspects of this disclosure, including the following variables: where Qmeas,s is a serving cell signal quality/strength measurement (eg, reference signal reception). Quality),
Qhysts,s is the hysteresis value of the serving cell,
Qmeas,n is the signal quality/strength measurement of the adjacent cell,
Qoffset,n is the offset between the serving cell and the neighbor cell,
Srxlev (eg, S or Sservingcell) is a cell reselection received level or value such as signal quality of the serving cell,
Qrxlevmin is the minimum specified or required receive level in the cell,
Qrxlevminoffset is the offset from the minimum specified or required receive level in the cell,
Ppowerclass is the transmission power of the UE,
Pmax is the maximum transmission power,
Rs is the serving cell rank,
Rn is an adjacent cell (non-serving cell) rank.

[0067] The variable S intrasearch (eg, intra frequency threshold) controls whether the UE should camp on the current cell while taking measurements of the intra frequency cell. In addition, Sintersearch (eg, inter-frequency threshold) controls whether the UE should camp on the current cell while taking measurements of inter-frequency cells. Treselection (reselection timer) manages when the UE may reselect to a new cell. Qrxlevmeas is the reference signal received power (RSRP) of the current cell. Pcomp is a power compensation value for uplink and/or downlink communication.

[0068] Problems with current approaches may include call setup failure due to slow reselection. For example, call setup failure due to radio link failure (RLF) caused by a bad serving cell of the network (eg, TD-SCDMA, WCDMA® or LTE).

[0069] Slow reselection can cause call disconnection during call setup for connected mode. When the UE is in connected mode and wants to switch to a better cell, the handover message may be a measurement control message and a radio bearer (RB) message (eg RB3), eg for call setup after RRC connection setup. Easily delayed by. Downlink (DL) conditions can degrade rapidly, especially for bandwidth limited cases, resulting in call disconnection before the UE receives a complete handover message.

[0070] This type of call setup failure is a result of the UE camping on a better cell prior to call setup, ie there is insufficient serving cell (eg serving cell received signal code power (RSCP) or signaling). Opportunity to trigger the cell reselection procedure before the trigger time (TTT) or reselection timer expires if there is a much better neighbor cell (quality is below threshold) Can be avoided if

[0071] Aspects of the disclosure are applicable to WCDMA, TD-SCDMA, LTE or other Radio Access Technology (RAT).

[0072] FIG. 10 is a block diagram illustrating measurement and evaluation of a serving cell and an intra/inter frequency cell. Cell reselection is triggered first before the expiration of the reselection timer, eg T_reselection, when the following conditions are met:

[0073] Tresh _fastresel and delta may be configured differently for different systems, where Tresh _fastresel is a signal quality/strength threshold for fast reselection.

[0074] FIG. 11 illustrates a wireless communication method 1100 for facilitating reselection, according to one aspect of the disclosure. At block 1102, a user equipment (UE) starts a reselection timer to reselect to a neighbor cell when it is determined that the signal quality of the serving cell is below a first threshold. At block 1104, the UE speeds up reselection to a neighbor cell based on the difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold. To do.

[0075] FIG. 12 is a diagram illustrating an example of a hardware implementation for an apparatus 1200 using a processing system 1214. Processing system 1214 may be implemented with a bus architecture, generally represented by bus 1224. Bus 1224 may include any number of interconnected buses and bridges, depending on the particular application of processing system 1214 and the overall design constraints. Bus 1224 links together various circuits including processor 1222, modules 1202, 1204, and one or more processors and/or hardware modules represented by non-transitory computer readable media 1226. Bus 1224 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore not described further. ..

[0076] The apparatus includes a processing system 1214 coupled to a transceiver 1230. Transceiver 1230 is coupled to one or more antennas 1220. Transceiver 1230 enables communication with a variety of other devices via a transmission medium. The processing system 1214 includes a processor 1222 coupled to a non-transitory computer readable medium 1226. Processor 1222 is responsible for general-purpose processing, including execution of software stored on computer readable media 1226. The software, when executed by the processor 1222, causes the processing system 1214 to perform the various functions described for any particular device. Computer readable media 1226 may also be used to store data manipulated by processor 1222 when executing software.

[0077] The processing system 1214 includes a timing module 1202 for starting a reselection timer for reselecting to a neighbor cell when the signal quality of the serving cell is determined to be below a first threshold. The processing system 1214 also speeds up reselection to a neighbor cell based on the difference between the signal quality of the serving cell and the signal quality of the neighbor cell when the signal quality of the serving cell is below a second threshold. Reselection module 1204 for. Modules 1202 and 1204 are software modules that are executing on processor 1222 and reside/store on computer readable medium 1226, one or more hardware modules coupled to processor 1222, or some combination thereof. obtain. Processing system 1214 may be a component of UE 650 of FIG. 6 and may include memory 660 and/or controller/processor 659.

[0078] In one configuration, a device such as UE 650 is configured for wireless communication including means for starting a reselection timer. In one aspect, the means for starting the reselection timer is a receive processor 656, a controller/processor 659, a memory 660, a wireless communication module 691, a timing module 1202, and/or a process configured to perform the aforementioned means. System 1214. In one configuration, these means functions correspond to the structure described above. In another aspect, the aforementioned means can be a module or any device configured to perform the functions described by the means for starting the reselection timer.

[0079] The UE 650 is also configured to include means for speeding up reselection to a neighboring cell. In one aspect, the speeding means is configured to perform the functions described by the identifying means, antenna 652/920, receiver 654, transceiver 1230, receiving processor 656, controller/processor 659, memory 660. , Reselection module 1204, and/or processing system 1214. In one configuration, these means and functions correspond to the structures described above. In another aspect, the aforementioned means may be a module or any device configured to perform the functions described by the speeding means.

[0080] Some aspects of telecommunications systems have been presented with reference to LTE, TD-SCDMA and GSM systems. As will be readily appreciated by one of ordinary skill in the art, various aspects described throughout this disclosure include those with high throughput and low latency, such as 4G systems, 5G systems, and the like, It can be extended to other telecommunications systems, network architectures, and communication standards. By way of example, the various aspects apply to other UMTS systems such as W-CDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+) and TD-CDMA. Can be extended. Various aspects also include Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, evolution data. Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.11 (WiMAX), IEEE 802.20, Ultra Wide Band (UWB), Bluetooth (registered trademark), and/or Or it can be extended to systems using other suitable systems. The actual telecommunications standard, network architecture, and/or communication standard used will depend on the overall design constraints imposed on the particular application and system.

[0081] Several processors have been described in connection with various devices and methods. These processors may be implemented using electronic hardware, computer software, or any combination thereof. Whether such a processor is implemented as hardware or software will depend on the overall design constraints imposed on the particular application and system. By way of example, a processor, any portion of a processor, or any combination of processors presented in this disclosure may be a microprocessor, microcontroller, digital signal processor (DSP), field programmable gate array (FPGA), programmable logic device ( PLD), state machines, gating logic, discrete hardware circuits, and other suitable processing components configured to perform the various functions described throughout this disclosure. The functionality of the processor, any portion of the processor, or any combination of processors presented in this disclosure may be implemented using software executed by a microprocessor, microcontroller, DSP, or other suitable platform.

[0082] Software, whether referred to by software, firmware, middleware, microcode, hardware description language, or other names, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, It should be understood broadly to mean software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc. The software may reside on non-transitory computer-readable media. Computer-readable media include, by way of example, magnetic storage devices (eg, hard disks, floppy disks, magnetic strips), optical disks (eg, compact disks (CD), digital versatile disks (DVD)), smart cards, flash memory. Devices (eg, cards, sticks, key drives), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM ( )), registers, or memory such as removable disks. Although memory is shown separately from the processor in various aspects presented throughout this disclosure, memory may be internal to the processor (eg, cache or registers).

[0083] A computer-readable medium may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging material. Those of skill in the art will recognize the best way to implement the described functionality presented throughout this disclosure, depending on the particular application and the overall design constraints imposed on the overall system. Let's do it.

[0084] It should be understood that the term "signal quality" is non-limiting. Signal quality includes received signal code power (RSCP), reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), signal to noise ratio (SNR), signal to interference plus noise ratio. It is intended to cover any type of signal metric, such as (SINR), and so on.

[0085] It should be understood that the particular order or hierarchy of steps in the methods disclosed is exemplary of exemplary processes. It will be appreciated that the particular order or hierarchy of steps in the methods may be rearranged based on design choices. The accompanying method claims present elements of the various steps in a sample order, and are not intended to be limited to the specific order or hierarchy presented unless explicitly stated otherwise. Not done.

[0086] The preceding description has been provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but instead are to be given the full range of language consistent with the wording of the claims, where the singular element References to are not intended to mean “one, and only one,” but to “one or more,” unless expressly specified otherwise. Unless otherwise specified, the term "some" refers to one or more. The expression referring to "at least one of" a list of items refers to any combination of those items, including single members. By way of example, "at least one of a, b, or c" is intended to cover a, b, c, a and b, a and c, b and c, and a and b and c. It All structural and functional equivalents to elements of various aspects described throughout this disclosure that are known to, or will be known to, those of ordinary skill in the art are expressly incorporated herein by reference, It is intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be abandoned to the public regardless of whether such disclosure is explicitly set forth in the claims. The elements of any claim are, unless the element is explicitly stated using the phrase "means for", or in the case of a method claim. It should not be construed under the provisions of 35 USC 112 paragraph 6 unless stated using the phrase "step for".

[0086] The preceding description has been provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but instead are to be given the full range of language consistent with the wording of the claims, where the singular element References to are not intended to mean “one, and only one,” but to “one or more,” unless expressly specified otherwise. Unless otherwise specified, the term "some" refers to one or more. The expression referring to "at least one of" a list of items refers to any combination of those items, including single members. By way of example, "at least one of a, b, or c" is intended to cover a, b, c, a and b, a and c, b and c, and a and b and c. It All structural and functional equivalents to elements of various aspects described throughout this disclosure that are known to, or will be known to, those of ordinary skill in the art are expressly incorporated herein by reference, It is intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be abandoned to the public regardless of whether such disclosure is explicitly set forth in the claims. The elements of any claim are, unless the element is explicitly stated using the phrase "means for", or in the case of a method claim. It should not be construed under the provisions of 35 USC 112 paragraph 6 unless stated using the phrase "step for".
The inventions described in the claims at the initial application of the present application will be additionally described below.
[C1]
A method for wireless communication,
Starting a reselection timer for reselecting to a neighboring cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. To speed up selection
A method comprising.
[C2]
Further comprising accelerating the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold, C1 The method described in.
[C3]
The method of C1, wherein accelerating the reselection to the neighbor cell comprises reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer.
[C4]
The method of C1, wherein the reselecting occurs prior to call setup on user equipment.
[C5]
The method of C1, wherein the first threshold is a user equipment (UE) defined threshold.
[C6]
A device for wireless communication,
A memory unit,
At least one processor coupled to the memory unit;
And the at least one processor comprises:
Starting a reselection timer for reselecting to a neighboring cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. To speed up selection
A device configured to perform.
[C7]
The at least one processor speeds up the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold. The device according to C6, further configured to:
[C8]
The apparatus of C6, wherein the at least one processor is further configured to speed up the reselection by reselecting to the neighboring cell prior to the scheduled expiration of the reselection timer. ..
[C9]
The apparatus of C6, wherein the reselecting occurs prior to call setup on user equipment.
[C10]
The apparatus of C6, wherein the first threshold is a user equipment (UE) defined threshold.
[C11]
A device for wireless communication,
Means for starting a reselection timer for reselecting to a neighbor cell when the signal quality of the serving cell is determined to be below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. Means to speed up selection
A device comprising.
[C12]
Further comprising means for speeding up the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold. , C11.
[C13]
The apparatus of C11, wherein the means for speeding up the reselection to the neighbor cell comprises means for reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer. ..
[C14]
The apparatus of C11, wherein the reselecting occurs prior to call setup on user equipment.
[C15]
The apparatus of C11, wherein the first threshold is a user equipment (UE) defined threshold.
[C16]
A non-transitory computer-readable medium having program code recorded thereon, wherein the program code is executed by a processor,
A program code for starting a reselection timer for reselecting to a neighboring cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. With program code to speed up the selection
A non-transitory computer-readable medium comprising.
[C17]
The program code is for accelerating the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell is above a third threshold. The non-transitory computer readable medium according to C16, further comprising:
[C18]
The program code for accelerating the reselection to the neighbor cell further comprises a program code for reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer, at C16. The non-transitory computer-readable medium described.
[C19]
The non-transitory computer-readable medium of C16, wherein the reselecting occurs prior to call setup on user equipment.
[C20]
The non-transitory computer readable medium of C16, wherein the first threshold is a user equipment (UE) defined threshold.

Claims (20)

A method for wireless communication,
Starting a reselection timer for reselecting to a neighboring cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. Speeding up the selection. Further comprising accelerating the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold. The method according to Item 1. The method of claim 1, wherein speeding up the reselection to the neighbor cell comprises reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer. The method of claim 1, wherein the reselecting occurs prior to call setup on user equipment. The method of claim 1, wherein the first threshold is a user equipment (UE) defined threshold. A device for wireless communication,
A memory unit,
At least one processor coupled to the memory unit, the at least one processor comprising:
Starting a reselection timer for reselecting to a neighboring cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. A device configured to speed up selection. The at least one processor speeds up the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold. 7. The device of claim 6, further configured to: 7. The at least one processor is further configured to speed up the reselection by reselecting to the neighboring cell prior to the scheduled expiration of the reselection timer. Equipment. 7. The apparatus of claim 6, wherein the reselecting occurs prior to call setup on user equipment. The apparatus of claim 6, wherein the first threshold is a user equipment (UE) defined threshold. A device for wireless communication,
Means for starting a reselection timer for reselecting to a neighbor cell when the signal quality of the serving cell is determined to be below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. A device for speeding up the selection. Further comprising means for speeding up the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell exceeds a third threshold. An apparatus according to claim 11. 12. The means for speeding the reselection to the neighbor cell comprises means for reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer. Equipment. The apparatus of claim 11, wherein the reselecting occurs prior to call setup on user equipment. The apparatus of claim 11, wherein the first threshold is a user equipment (UE) defined threshold. A non-transitory computer-readable medium having program code recorded thereon, wherein the program code is executed by a processor,
A program code for starting a reselection timer for reselecting to a neighbor cell when it is determined that the signal quality of the serving cell is below a first threshold;
When the signal quality of the serving cell is below a second threshold, re-transmission to the neighbor cell is based at least in part on a difference between the signal quality of the serving cell and the signal quality of the neighbor cell. A non-transitory computer readable medium comprising program code for speeding up selection. The program code is for accelerating the reselection to the neighbor cell when the difference between the signal quality of the serving cell and the signal quality of the neighbor cell is above a third threshold. The non-transitory computer-readable medium of claim 16, further comprising the program code of: The program code for speeding up the reselection to the neighbor cell further comprises a program code for reselecting to the neighbor cell prior to a scheduled expiration of the reselection timer. A non-transitory computer-readable medium as described in 16. The non-transitory computer-readable medium of claim 16, wherein the reselecting occurs prior to call setup on user equipment. The non-transitory computer readable medium of claim 16, wherein the first threshold is a user equipment (UE) defined threshold.

Images