CN106576273B - Circuit switched fallback with improved reliability in pool overlap regions - Google Patents

Abstract

The invention discloses performing Circuit Switched Fallback (CSFB) calls with improved reliability. The request to establish the CSFB call may be received by a UE (106) currently located in a pool overlap region. A network resource controller (172) or base station (102) transmits information to the UE indicating the pool in which the neighboring cell is operating. For CSFB operation, the UE uses the information to select a circuit switched cell to operate on, wherein the selected CS cell is located in the same pool area as the current pool area. This prevents the UE from accidentally camping on a CS cell in another pool area, which may lead to a call failure on some networks. The information provided by the base station may include a pool area id or may include mapping relationship information that can be used by the UE to determine the current pool area.

Description

Translated fromChinese

池重叠区域中的具有改善的可靠性的电路交换回退Circuit-Switched Fallback with Improved Reliability in Pool Overlap Regions

技术领域technical field

本专利申请涉及无线装置，并且更具体地涉及一种用于建立具有改善的可靠性的电路交换回退呼叫的系统和方法。This patent application relates to wireless devices, and more particularly, to a system and method for establishing circuit-switched fallback calls with improved reliability.

背景技术Background technique

无线通信系统的使用正在快速增长。另外，无线通信技术已从仅语音通信演进到还包括对数据诸如互联网和多媒体内容的传输。随着无线通信系统演进，趋于开发出连续几代的无线通信技术。采用新一代无线技术可能是一个渐进过程，在此期间前一代或前几代类似技术可例如在一段时间内与该新一代技术共存，直到该新一代无线技术被完全开发。The use of wireless communication systems is growing rapidly. In addition, wireless communication technology has evolved from only voice communication to also include the transmission of data such as the Internet and multimedia content. As wireless communication systems evolve, successive generations of wireless communication technologies tend to be developed. Adoption of a new generation of wireless technology may be a gradual process during which a previous generation or similar technologies of previous generations may coexist with the new generation of technology, eg, for a period of time until the new generation of wireless technology is fully developed.

无线技术中的向下一代的转换的一个示例是从GSM和UMTS向LTE的转换。LTE使用完全分组交换网络，而不提供电路交换服务。UMTS提供电路交换服务和分组交换服务。GSM最初仅提供电路交换服务，但后来被增强以还提供一些分组交换服务。向LTE迁移的一种转换技术是电路交换回退(CSFB)呼叫。在这种情况下，当无线装置在支持CSFB的LTE网络上注册并且电路交换呼叫被发起时，无线装置被重新导向到可支持电路交换呼叫的2G/3G网络。An example of the transition to the next generation in wireless technology is the transition from GSM and UMTS to LTE. LTE uses a fully packet-switched network and does not provide circuit-switched services. UMTS provides circuit-switched services and packet-switched services. GSM initially only provided circuit-switched services, but was later enhanced to also provide some packet-switched services. One transition technique migrating to LTE is Circuit Switched Fallback (CSFB) calling. In this case, when the wireless device registers on the LTE network that supports CSFB and a circuit-switched call is initiated, the wireless device is redirected to a 2G/3G network that can support circuit-switched calls.

因此，无线通信中特别是处理CSFB呼叫过程中的改善将是期望的。特别地，期望改善CSFB呼叫的可靠性。Therefore, improvements in wireless communications, particularly in handling CSFB calls, would be desirable. In particular, it is desirable to improve the reliability of CSFB calls.

发明内容SUMMARY OF THE INVENTION

出于前述以及其他考虑，期望为无线用户设备(UE)装置提供一种执行具有改善的可靠性的电路交换回退(CSFB)呼叫的方式。For the foregoing and other considerations, it is desirable to provide a way for wireless user equipment (UE) devices to perform circuit switched fallback (CSFB) calls with improved reliability.

当在驻留在不提供电路交换服务的分组交换网络(例如，LTE网络)上并且能够支持电路交换回退的无线装置处发起(例如，接收)电路交换呼叫时，UE可被重新导向以回退到提供电路交换服务的电路交换网络(例如，UTMS)。然而，在CSFB期间当UE当前驻留在第一池中的小区上时，如果UE处于池重叠区域中，则UE可能在转换到电路交换网络时意外选择驻留在不同MSC(移动交换中心)池的小区上。这可能使UE附接到另一MSC服务器，并且因此如果在网络中还没有部署MTRF(移动台被叫漫游转发)则可能导致呼叫失败。因此，本文公开了为UE提供足够的信息以供其在其已操作于其中的相同池上并因此在相同MSC服务器上选择合适的小区以避免呼叫失败的多种方法。When initiating (eg, receiving) a circuit-switched call at a wireless device that resides on a packet-switched network that does not provide circuit-switched services (eg, an LTE network) and is capable of supporting circuit-switched fallback, the UE may be redirected back to Fall back to circuit-switched networks (eg, UTMS) that provide circuit-switched services. However, when the UE is currently camping on a cell in the first pool during CSFB, if the UE is in a pool overlap area, the UE may accidentally choose to camp on a different MSC (Mobile Switching Center) when switching to a circuit switched network on the pool area. This may cause the UE to attach to another MSC server and thus may cause the call to fail if MTRF (Mobile Station Called Roaming Forwarding) has not been deployed in the network. Thus, disclosed herein are various methods of providing the UE with sufficient information to select a suitable cell on the same pool it already operates in, and thus on the same MSC server, to avoid call failures.

在各种实施方案中，UE知道或被提供有用于识别其驻留在其上的当前池的信息。例如，UE可根据其自身的TMSI(临时移动站识别)而知道其当前池例如其池id。在一些实施方案中，还为UE提供关于其他相邻候选小区的池信息。该池信息可包括该多个候选小区中的每个候选小区的池id’。在一些运营方网络中，小区的池id是网络资源识别(NRI)的一部分，例如NRI位字段包括指定池id的一个或多个位。在第一实施方案中，基站子系统/无线电网络控制器(BSS/RNC)接收并存储来自各个候选小区的池id’，该池id’例如从OAM服务器或相应MSC服务器接收。BSS/RNC然后在CSFB操作之前或在CSFB操作期间向UE广播(传输)这些池id’。在另一个实施方案中，基站从BSS/RNC或者从OAM服务器或相应的MSC服务器接收这些候选小区的池id’。基站然后可向UE传输这些池id’。例如，基站、eNodeB可在CSFB操作期间向UE传输RRC释放消息中的池id’。在其他实施方案中，可为UE提供其他信息来识别各个候选小区当前附接到的一个或多个MSC服务器，诸如每个MSC服务器的MSC地址或其他信息。In various embodiments, the UE knows or is provided with information identifying the current pool on which it resides. For example, a UE may know its current pool, eg its pool id, from its own TMSI (Temporary Mobile Station Identity). In some embodiments, the UE is also provided with pool information about other neighboring candidate cells. The pool information may include a pool id' of each candidate cell of the plurality of candidate cells. In some operator networks, the pool id of the cell is part of the network resource identification (NRI), eg the NRI bit field includes one or more bits specifying the pool id. In a first embodiment, the base station subsystem/radio network controller (BSS/RNC) receives and stores the pool id' from each candidate cell, e.g. from the OAM server or the corresponding MSC server. The BSS/RNC then broadcasts (transmits) these pool ids' to the UE before or during CSFB operation. In another embodiment, the base station receives the pool id' of these candidate cells from the BSS/RNC or from the OAM server or corresponding MSC server. The base station may then transmit these pool ids' to the UE. For example, the base station, eNodeB, may transmit the pool id' in the RRC release message to the UE during CSFB operation. In other embodiments, other information may be provided to the UE to identify one or more MSC servers to which each candidate cell is currently attached, such as the MSC address or other information for each MSC server.

当UE接收到移动终端(MT)(传入)呼叫并执行CSFB操作时，UE可执行小区选择以选择要驻留在其上的新的CS小区。UE知道其驻留的当前池id。UE可还已从BSS/RNC或基站接收多个其他小区的小区频率/池id信息。BSS/RNC继而可已从OAM服务器接收该信息，该OAM服务器已从各个MSC服务器收集该信息。另选地，UE可从空中下载(OTA)服务器或者从不同相邻候选小区中的可能的各个相邻候选小区接收小区频率/池id信息。对于每个相应候选小区，由UE所接收的信息可包括对该候选小区的识别(例如，该小区的频率)，并且还包括相应候选小区的池id，以及其他可能的信息。When the UE receives a mobile terminal (MT) (incoming) call and performs CSFB operations, the UE may perform cell selection to select a new CS cell to camp on. The UE knows the current pool id on which it resides. The UE may also have received cell frequency/pool id information for multiple other cells from the BSS/RNC or base station. The BSS/RNC may then have received this information from the OAM server, which has collected this information from the various MSC servers. Alternatively, the UE may receive cell frequency/pool id information from an over-the-air (OTA) server or from possibly each of the different neighbor candidate cells. For each respective candidate cell, the information received by the UE may include an identification of the candidate cell (eg, the frequency of the cell), and also the pool id of the respective candidate cell, among other possible information.

当UE接收关于各个可能候选小区的信息(小区频率/池id)时，UE可将候选小区频率和对应池id中的每一者存储在存储器中，诸如存储在数据结构中。当UE正在搜索新小区时，UE然后可将其当前所驻留在其上的池id与这些候选小区的池id’进行比较。因此，UE使用该信息来选择属于与其在CSFB操作之前驻留在其上的相同池(具有相同池id)的候选小区。这用于防止在UE驻留在另一MSC池上并因此附接到另一MSC服务器并且MTRF不可用的情况下可能发生的呼叫失败。这帮助防止由于缺乏MTRF部署而导致的呼叫失败。When the UE receives information about each possible candidate cell (cell frequency/pool id), the UE may store each of the candidate cell frequency and the corresponding pool id in memory, such as in a data structure. When the UE is searching for a new cell, the UE may then compare the pool id on which it is currently camped with the pool ids' of these candidate cells. Therefore, the UE uses this information to select candidate cells belonging to the same pool (with the same pool id) on which it camped before the CSFB operation. This is used to prevent call failures that may occur if the UE is camped on another MSC pool and thus attached to another MSC server and the MTRF is not available. This helps prevent call failures due to lack of MTRF deployment.

因此，本文呈现了一种用于执行CSFB呼叫的方法以及被配置为实施该方法的UE和基站或其他蜂窝联网硬件(BSS/RNC)的实施方案。该UE、基站和其他硬件可包括用于彼此执行无线通信的一个或多个无线电部件(包括一个或多个天线)。该UE和/或基站还可包括被配置为实施该方法的装置逻辑部件(其可包括处理器和存储器介质和/或硬件逻辑部件)。在本文中还呈现了存储能够由处理器执行以执行所述方法的部分或全部的程序指令的存储器介质(例如，非暂态计算机可访问存储器介质)的实施方案。Accordingly, presented herein is a method for performing a CSFB call and an implementation of a UE and a base station or other cellular networking hardware (BSS/RNC) configured to implement the method. The UE, base station, and other hardware may include one or more radios (including one or more antennas) for performing wireless communications with each other. The UE and/or base station may also include device logic (which may include a processor and a memory medium and/or hardware logic) configured to implement the method. Also presented herein are embodiments of a memory medium (eg, a non-transitory computer-accessible memory medium) storing program instructions executable by a processor to perform some or all of the described methods.

附图说明Description of drawings

当结合以下附图来考虑实施方案的以下详细描述时，可获取对本发明的更好的理解。A better understanding of the present invention can be obtained when the following detailed description of the embodiments is considered in conjunction with the following drawings.

图1示出了根据一些实施方案的示例性(简化)无线通信系统；1 illustrates an exemplary (simplified) wireless communication system in accordance with some embodiments;

图2示出了根据一些实施方案的与用户设备进行通信的一种基站；Figure 2 illustrates a base station in communication with user equipment in accordance with some embodiments;

图3示出了根据一些实施方案的UE的示例性框图；3 illustrates an exemplary block diagram of a UE in accordance with some embodiments;

图4示出了根据一些实施方案的UE的示例性框图；4 illustrates an exemplary block diagram of a UE in accordance with some embodiments;

图5是根据一些实施方案的示例性蜂窝通信网络的框图；5 is a block diagram of an exemplary cellular communication network in accordance with some embodiments;

图6是包括LTE网络和3GPP网络两者的蜂窝通信网络的更详细的框图；6 is a more detailed block diagram of a cellular communication network including both an LTE network and a 3GPP network;

图7示出了包括重叠的MSC池的蜂窝网络的一部分；Figure 7 shows a portion of a cellular network comprising overlapping MSC pools;

图8和图9示出了根据一些实施方案的导致呼叫失败的至不同池的电路交换回退的示例；8 and 9 illustrate examples of circuit-switched fallbacks to different pools that result in call failures, according to some embodiments;

图10是示出了根据第一实施方案的改进的CSFB操作的流程图，其中从BSS/RNC向UE提供池id信息；FIG. 10 is a flow chart illustrating the operation of the improved CSFB according to the first embodiment, wherein pool id information is provided to the UE from the BSS/RNC;

图11是示出了根据第二实施方案的改进的CSFB操作的流程图，其中从基站向UE提供池id信息；FIG. 11 is a flow chart illustrating the improved CSFB operation according to the second embodiment, wherein pool id information is provided from the base station to the UE;

图12是示出了根据图10的流程图的改进的CSFB操作的更详细的流程图；FIG. 12 is a more detailed flow diagram illustrating the operation of the improved CSFB according to the flow diagram of FIG. 10;

图13是示出了根据图11的流程图的改进的CSFB操作的更详细的流程图；并且FIG. 13 is a more detailed flow diagram illustrating improved CSFB operation according to the flow diagram of FIG. 11; and

图14示出了根据一些实施方案的从MSC服务器向UE提供池id信息的方式。Figure 14 illustrates the manner in which pool id information is provided to a UE from an MSC server, according to some embodiments.

尽管本发明易受各种修改形式和替代形式的影响，但其具体实施方案在附图中以举例的方式示出并在本文中详细描述。然而，应当理解，附图及对附图的详细描述并非旨在将本发明限制于所公开的特定形式，而正相反，其目的在于覆盖落在由所附权利要求所限定的本发明的实质和范围内的所有修改形式、等同形式和替代形式。While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereof are not intended to limit the invention to the particular form disclosed, but on the contrary, the intent is to cover the spirit of the invention as defined by the appended claims and all modifications, equivalents and alternatives within the scope.

具体实施方式Detailed ways

首字母缩略词acronym

在本专利申请中使用了以下首字母缩略词。The following acronyms are used in this patent application.

UE：用户设备UE: User Equipment

BS：基站BS: base station

ENB：eNodeB(基站)ENB: eNodeB (base station)

GSM：全球移动通信系统GSM: Global System for Mobile Communications

UMTS：通用移动通信系统UMTS: Universal Mobile Telecommunications System

LTE：长期演进LTE: Long Term Evolution

CS：电路交换CS: Circuit Switched

PS：分组交换PS: packet switching

CSFB：电路交换回退CSFB: Circuit Switched Fallback

MME：移动管理实体MME: Mobility Management Entity

MSC：移动交换中心MSC: Mobile Switching Center

RNC：无线电网络控制器RNC: Radio Network Controller

OAM：操作、经营和管理OAM: Operations, Operations and Management

RRC：无线电资源控制RRC: Radio Resource Control

MT：移动台被叫MT: mobile station called

MTRF：移动台被叫漫游转发MTRF: mobile station called roaming forwarding

术语the term

以下是本专利申请中所使用的术语表：The following is a glossary of terms used in this patent application:

存储器介质-各种类型的存储器装置或存储装置中的任一者。术语“存储器介质”意在包括安装介质，例如CD-ROM、软盘104或磁带装置；计算机系统存储器或随机存取存储器，诸如DRAM、DDR RAM、SRAM、EDO RAM、Rambus RAM等；非易失性存储器，诸如闪存、磁介质，例如硬盘或光学存储装置；寄存器，或其他类似类型的存储器元件等。该存储介质也可包括其他类型的存储器或它们的组合。此外，存储器介质可被定位在执行程序的第一计算机中，或者可被定位在通过网络诸如互联网连接到第一计算机的不同的第二计算机。在后一情况下，第二计算机可为第一计算机提供程序指令以用于执行。术语“存储器介质”可包括可驻留在不同位置例如通过网络而连接的不同计算机中的两个或更多个存储器介质。memory medium - any of various types of memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROM, floppy disk 104, or tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile Memory, such as flash memory, magnetic media such as hard disks or optical storage devices; registers, or other similar types of memory elements, and the like. The storage medium may also include other types of memory or combinations thereof. Furthermore, the storage medium may be located in the first computer executing the program, or may be located in a second, different computer connected to the first computer through a network such as the Internet. In the latter case, the second computer may provide program instructions for execution by the first computer. The term "memory medium" may include two or more memory media that may reside in different locations, such as in different computers connected by a network.

载体介质-如上所述的存储器介质，以及物理传输介质诸如总线、网络和/或传送信号诸如电信号、电磁信号或数字信号的其他物理传输介质。Carrier media - storage media as described above, as well as physical transmission media such as buses, networks and/or other physical transmission media that carry signals such as electrical, electromagnetic or digital signals.

计算机系统-各种类型的计算系统或处理系统中的任一者，包括个人计算机系统(PC)、大型计算机系统、工作站、网络家电、互联网家电、个人数字助理(PDA)、电视机系统、网格计算系统、或其他装置或装置的组合。通常，术语“计算机系统”可广义地被定义成包含具有执行来自存储器介质的指令的至少一个处理器的任何装置(或装置的组合)。Computer System - any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, network Lattice computing system, or other device or combination of devices. In general, the term "computer system" may be broadly defined to include any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

用户设备(UE)(或“UE装置”)-执行无线通信的各种类型的计算机系统或装置中的任一者。UE装置的示例包括移动电话或智能电话(例如，iPhone^TM、基于Android^TM的电话)、可穿戴装置(诸如智能手表)、便携式游戏装置(例如，Nintendo DS^TM、PlayStationPortable^TM、Gameboy Advance^TM、iPhone^TM)、膝上型电脑、PDA、便携式互联网装置、音乐播放器、数据存储装置、或其他手持装置等。通常，术语“UE”或“UE装置”可广义地被定义成包含能够进行无线通信的任何电子装置、计算装置和/或电信装置(或装置的组合)。UE装置通常可以是移动式或便携式的并且容易被使用者运送，但在一些情况下，基本上固定式的装置也可被配置为执行无线通信。User Equipment (UE) (or "UE device") - any of various types of computer systems or devices that perform wireless communications. Examples of UE devices include mobile phones or smart phones (eg, iPhone^™ , Android^™ based phones), wearable devices (eg, smart watches), portable gaming devices (eg, Nintendo DS^™ , PlayStationPortable^™ , Gameboy Advance^™ , iPhone^TM ), laptop computers, PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. In general, the terms "UE" or "UE device" may be broadly defined to encompass any electronic, computing and/or telecommunication device (or combination of devices) capable of wireless communication. A UE device may generally be mobile or portable and easily transported by a user, although in some cases a substantially stationary device may also be configured to perform wireless communications.

信道-用于将信息从发送器(发射器)传送至接收器的介质。应当指出的是，由于术语“信道”的定义可根据不同无线协议而有所不同，因此本文所使用的术语“信道”应被视为以符合参考被使用的术语的装置的类型的标准的方式进行使用。在一些标准中，信道宽度可为可变的(例如，取决于装置能力、频带条件等)。例如，LTE可支持1.4MHz到20MHz的可扩展信道带宽。相比之下，WLAN信道可为22MHz宽，而蓝牙信道可为1MHz宽。其他协议和标准可包括对信道的不同定义。此外，一些标准可定义并使用多种类型的信道，例如用于上行链路或下行链路的不同信道和/或针对不同用途诸如数据、控制信息等的不同信道。Channel - The medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the definition of the term "channel" may vary according to different wireless protocols, the term "channel" as used herein should be considered in a manner consistent with the standard of the type of device in which the term is used with reference to to use. In some standards, the channel width may be variable (eg, depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4MHz to 20MHz. In contrast, a WLAN channel can be 22MHz wide and a Bluetooth channel can be 1MHz wide. Other protocols and standards may include different definitions of channels. Furthermore, some standards may define and use multiple types of channels, eg, different channels for uplink or downlink and/or different channels for different purposes such as data, control information, and so on.

自动-是指由计算机系统(例如，由计算机系统所执行的软件)或装置(例如，电路、可编程硬件元件、ASIC等)执行动作或操作，而无需用户输入直接指定或执行该动作或操作。因此，术语“自动”与用户手动执行或指定操作形成对比，在用户手动执行或指定操作中，用户提供输入来直接执行该操作。自动过程可由用户所提供的输入发起，但“自动”执行的后续动作不是由用户所指定的，即不是“手动”执行的，在“手动”执行中，用户指定要执行的每个动作。例如，通过选择每个字段并提供输入指定信息，用户填写电子表格(例如，通过键入信息、选择复选框、单选选择等)为手动填写表格，即使计算机系统必须响应于用户动作来更新该表格。该表格可通过计算机系统自动填写，其中计算机系统(例如，在计算机系统上执行的软件)分析表格的字段并填写该表格，而无需任何用户输入指定字段的答案。如上所示，用户可调用表格的自动填写，但不参与表格的实际填写(例如，用户没有手动指定字段的答案而是它们被自动完成)。本说明书提供了响应于用户已采取的动作而自动执行操作的多种示例。Automatically - means that an action or operation is performed by a computer system (eg, software executed by a computer system) or device (eg, a circuit, programmable hardware element, ASIC, etc.) without the need for user input to directly specify or perform the action or operation . Thus, the term "automatically" contrasts with a user manually performing or specifying an operation in which the user provides input to perform the operation directly. An automatic process may be initiated by input provided by the user, but subsequent actions performed "automatically" are not specified by the user, ie are not performed "manually" in which the user specifies each action to be performed. For example, by selecting each field and providing input specifying information, a user filling out an electronic form (eg, by typing in information, selecting check boxes, radio selections, etc.) is filling out the form manually, even though the computer system must update the form in response to user action sheet. The form can be automatically filled out by a computer system, wherein the computer system (eg, software executing on the computer system) analyzes the fields of the form and fills in the form without any user entering answers to the specified fields. As shown above, the user may invoke auto-filling of the form, but not participate in the actual filling of the form (eg, the user does not manually specify the answers to the fields but they are auto-completed). This specification provides various examples of actions that are automatically performed in response to actions that the user has taken.

图1和图2-通信系统Figure 1 and Figure 2 - Communication System

图1示出了根据一些实施方案的示例性(简化)无线通信系统。需注意，图1的系统是可能的系统的仅一个示例，并且可根据需要在各种系统中的任一系统中实现本发明的实施方案。1 illustrates an exemplary (simplified) wireless communication system in accordance with some embodiments. Note that the system of FIG. 1 is only one example of a possible system, and embodiments of the present invention may be implemented in any of a variety of systems as desired.

如图所示，示例性无线通信系统包括基站102，该基站通过传输介质与一个或多个用户设备106-A到106-N进行通信。在本文中，可将用户设备中的每个用户设备称为“用户设备”(UE)。因此，用户设备106被称为UE或UE装置。As shown, the exemplary wireless communication system includes abase station 102 that communicates with one or more user equipments 106-A through 106-N over a transmission medium. Herein, each of the user equipments may be referred to as "User Equipment" (UE). Hence, theuser equipment 106 is referred to as a UE or UE device.

基站102可以是收发器基站(BTS)或小区站点，并且可包括实现与UE 106A到106N的无线通信的硬件。基站102还可装配成与网络100进行通信。因此，基站102可有助于UE之间和/或UE与网络100之间的通信。基站的通信区域(或覆盖区域)可被称为“小区”。基站102和UE可被配置为使用各种无线通信技术诸如GSM、UMTS、LTE、CDMA、WLL、WAN、WiFi、WiMAX等中的任一无线通信技术通过传输介质进行通信。基站102和根据相同或不同蜂窝通信标准操作的其他类似基站因此可被提供作为小区网络，该小区网络可经由一个或多个蜂窝通信标准在广阔的地理区域上向UE 106和类似的装置提供连续或近乎连续的重叠服务。Base station 102 may be a base transceiver station (BTS) or a cell site, and may include hardware that enables wireless communication with UEs 106A-106N.Base station 102 may also be configured to communicate with network 100 . Accordingly,base station 102 may facilitate communication between UEs and/or between UEs and network 100 . The communication area (or coverage area) of a base station may be referred to as a "cell". Thebase station 102 and the UE may be configured to communicate over a transmission medium using any of a variety of wireless communication technologies, such as GSM, UMTS, LTE, CDMA, WLL, WAN, WiFi, WiMAX, and the like. Thebase station 102 and other similar base stations operating according to the same or different cellular communication standards can thus be provided as a network of cells that can provide continuous access toUEs 106 and similar devices over a wide geographic area via one or more cellular communication standards. or near-continuous overlapping services.

在一些实施方案中，UE 106可能够使用多个无线通信标准来进行通信。例如，UE106可被配置为使用GSM、UMTS、LTE、CDMA2000、WiMAX、WLAN、蓝牙、一个或多个全球导航卫星系统(GNSS，例如GPS或GLONASS)、一个和/或多个移动电视广播标准(例如，ATSC-M/H或DVB-H)等中的两者或更多者进行通信。无线通信标准的其他组合(包括多于两个无线通信标准)也是可能的。In some embodiments,UE 106 may be capable of communicating using multiple wireless communication standards. For example, theUE 106 may be configured to use GSM, UMTS, LTE, CDMA2000, WiMAX, WLAN, Bluetooth, one or more global navigation satellite systems (GNSS such as GPS or GLONASS), one and/or more mobile television broadcast standards ( For example, two or more of ATSC-M/H) or DVB-H) etc. communicate. Other combinations of wireless communication standards, including more than two wireless communication standards, are also possible.

图2示出了根据一些实施方案的与基站102进行通信的用户设备106(例如，装置106-A到106-N中的一个装置)。如上所述，UE 106可为具有无线网络连接性的装置，诸如移动电话、手持装置、计算机或平板电脑、或几乎任何类型的无线装置。2 illustrates user equipment 106 (eg, one of apparatuses 106-A through 106-N) in communication withbase station 102 in accordance with some embodiments. As mentioned above,UE 106 may be a device with wireless network connectivity, such as a mobile phone, handheld device, computer or tablet, or virtually any type of wireless device.

UE可包括被配置为执行被存储在存储器中的程序指令的处理器。UE可通过执行此类所存储的指令来执行本文所述的方法实施方案中的任一方法实施方案。在一些实施方案中，UE可包括被配置为执行本文所述的方法实施方案中的任一方法实施方案、或本文所述的方法实施方案的任一方法实施方案的任何部分的可编程硬件元件诸如FPGA(现场可编程门阵列)。The UE may include a processor configured to execute program instructions stored in memory. The UE may perform any of the method embodiments described herein by executing such stored instructions. In some embodiments, the UE may include programmable hardware elements configured to perform any of the method embodiments described herein, or any portion of any of the method embodiments described herein Such as FPGA (Field Programmable Gate Array).

在一些实施方案中，UE 106可被配置为使用上述多个无线通信协议中的任一无线通信协来进行通信。UE 106可包括用于使用一个或多个无线通信协议进行通信的一个或多个天线。在一些实施方案中，UE 106可在多个无线通信标准之间共享接收链和/或发射链的一个或多个部分；共享的无线电部件可包括单个天线或可包括用于执行无线通信的多个天线(例如，对于MIMO来说)。在其他实施方案中，UE 106针对被配置为利用其进行通信的每个无线通信协议可包括独立的发射链和/或接收链(例如，包括独立的天线和其他无线电部件)。在另外的实施方案中，UE 106可包括在多个无线通信协议之间共享的一个或多个无线电部件、以及专门供单个无线通信协议使用的一个或多个无线电部件。例如，在一组实施方案中，UE 106可包括用于使用LTE或1xRTT中的任一者来进行通信的共享的无线电部件，以及用于使用Wi-Fi和蓝牙中的每一者来进行通信的独立的无线电部件。其他配置也是可能的。In some embodiments, theUE 106 may be configured to communicate using any of the plurality of wireless communication protocols described above.UE 106 may include one or more antennas for communicating using one or more wireless communication protocols. In some embodiments,UE 106 may share one or more portions of the receive chain and/or transmit chain among multiple wireless communication standards; the shared radio may include a single antenna or may include multiple antennas (eg, for MIMO). In other embodiments, theUE 106 may include separate transmit and/or receive chains (eg, including separate antennas and other radios) for each wireless communication protocol it is configured to communicate with. In further embodiments, theUE 106 may include one or more radios that are shared among multiple wireless communication protocols, and one or more radios that are dedicated to a single wireless communication protocol. For example, in one set of implementations,UE 106 may include a shared radio for communicating using either LTE or IxRTT, and for communicating using each of Wi-Fi and Bluetooth independent radio components. Other configurations are also possible.

在一些实施方案中，UE 106可被配置为建立并执行电路交换回退(CSFB)呼叫。例如，UE 106可被配置为使用提供分组交换(PS)服务但不提供电路交换(CS)服务的第一无线通信技术和提供PS服务和CS服务的第二无线通信技术中的任一者来进行通信。如果UE 106正在使用第一无线通信技术并且CS呼叫被发起或接收，则UE 106可能够切换到使用第二无线通信技术以便建立该呼叫。In some embodiments, theUE 106 may be configured to establish and perform a circuit switched fallback (CSFB) call. For example, theUE 106 may be configured to use either a first wireless communication technology that provides packet-switched (PS) services but no circuit-switched (CS) services and a second wireless communication technology that provides PS services and CS services. to communicate. If theUE 106 is using the first wireless communication technology and a CS call is initiated or received, theUE 106 may be able to switch to using the second wireless communication technology in order to establish the call.

特别地，在一组实施方案中，UE 106可被配置为以通过确保UE在处于池重叠区域中时选择合适的小区而有利地改善可靠性的方式来执行CSFB呼叫，如下文进一步所述的。In particular, in one set of embodiments, theUE 106 may be configured to perform CSFB calls in a manner that advantageously improves reliability by ensuring that the UE selects an appropriate cell when in a pool overlap area, as described further below .

图3-UE的示例性框图Figure 3 - Exemplary block diagram of UE

图3示出了根据一些实施方案的UE 106的示例性框图。如图所示，UE 106可包括片上系统(SOC)300，该SOC可包括用于各种目的的各个部分。例如，如图所示，SOC 300可包括可执行UE 106的程序指令的一个或多个处理器302和可执行图形处理并将显示信号提供到显示器340的显示电路304。一个或多个处理器302还可被耦接至存储器管理单元(MMU)340，该MMU可被配置为从一个或多个处理器302接收地址并将那些地址转换成存储器(例如，存储器306、只读存储器(ROM)350、NAND闪存存储器310)中的位置和/或其他电路或设备，诸如显示电路304、无线电部件330、连接器I/F 320、和/或显示器340。MMU 340可被配置为执行存储器保护和页表转换或设置。在一些实施方案中，MMU 340可被包括作为一个或多个处理器302的一部分。FIG. 3 shows an exemplary block diagram ofUE 106 in accordance with some embodiments. As shown, theUE 106 may include a system on a chip (SOC) 300, which may include various parts for various purposes. For example, as shown,SOC 300 may include one or more processors 302 that can execute program instructions forUE 106 anddisplay circuitry 304 that can execute graphics processing and provide display signals to display 340 . The one or more processors 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from the one or more processors 302 and translate those addresses into memory (eg,memory 306, read only memory (ROM) 350 , NAND flash memory 310 ) and/or other circuits or devices, such asdisplay circuit 304 ,radio 330 , connector I/F 320 , and/or display 340 . MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of one or more processors 302 .

在所示的实施方案中，ROM 350可包括可在启动或初始化期间由一个或多个处理器302来执行的引导加载程序。另外如图所示，SOC 300可被耦接至UE 106的各种其他电路。例如，UE 106可包括各种类型的存储器(例如，包括NAND闪存310)、连接器接口320(例如，用于耦接至计算机系统)、显示器340、和无线通信电路(例如，用于LTE、CDMA2000、蓝牙、WiFi等)。In the embodiment shown,ROM 350 may include a bootloader that may be executed by one or more processors 302 during startup or initialization. Also as shown, theSOC 300 may be coupled to various other circuits of theUE 106 . For example,UE 106 may include various types of memory (eg, including NAND flash memory 310), connector interface 320 (eg, for coupling to a computer system), display 340, and wireless communication circuitry (eg, for LTE, CDMA2000, Bluetooth, WiFi, etc.).

UE装置106可包括至少一个天线，并且在一些实施方案中可包括用于执行与基站和/或其他装置的无线通信的多个天线。例如，UE装置106可使用天线335来执行无线通信。如上所述，在一些实施方案中，UE可被配置为使用多个无线通信标准来进行无线通信。UE device 106 may include at least one antenna, and in some embodiments may include multiple antennas for performing wireless communications with base stations and/or other devices. For example,UE device 106 may use antenna 335 to perform wireless communication. As described above, in some embodiments, a UE may be configured to communicate wirelessly using multiple wireless communication standards.

如本文所述，UE 106可包括用于实施根据本公开的实施方案的用于执行CSFB呼叫的方法的硬件部件和软件部件。As described herein,UE 106 may include hardware and software components for implementing methods for performing CSFB calls according to embodiments of the present disclosure.

UE装置106的处理器302可被配置为例如通过执行被存储在存储器介质(例如，非暂态计算机可读存储器介质)上的程序指令来实施本文所述的方法的一部分或全部。在其他实施方案中，处理器302可被配置作为可编程硬件元件，诸如FPGA(现场可编程门阵列)或者作为ASIC(专用集成电路)。The processor 302 of theUE device 106 may be configured to implement some or all of the methods described herein, eg, by executing program instructions stored on a memory medium (eg, a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application specific integrated circuit).

图4-基站Figure 4 - Base Station

图4示出了根据一些实施方案的基站102的示例性框图。需注意，图4的基站是可能的基站的仅一个示例。如图所示，基站102可包括可执行针对基站102的程序指令的一个或多个处理器404。一个或多个处理器404也可被耦接至存储器管理单元(MMU)440、或其他电路或装置。该MMU可被配置为接收来自一个或多个处理器404的地址并将这些地址转换为存储器(例如，存储器460和只读存储器(ROM)450)中的位置。FIG. 4 shows an exemplary block diagram ofbase station 102 in accordance with some embodiments. Note that the base station of Figure 4 is only one example of a possible base station. As shown,base station 102 may include one ormore processors 404 that may execute program instructions forbase station 102 . One ormore processors 404 may also be coupled to a memory management unit (MMU) 440, or other circuit or device. The MMU may be configured to receive addresses from one ormore processors 404 and translate these addresses to locations in memory (eg, memory 460 and read only memory (ROM) 450).

基站102可包括至少一个网络端口470。网络端口470可被配置为耦接至电话网络，并为多个装置诸如UE装置106提供对电话网络的访问权限，如上所述。Base station 102 may include at least onenetwork port 470 . Thenetwork port 470 may be configured to couple to the telephony network and provide access to the telephony network for various devices, such as theUE device 106, as described above.

网络端口470(或附加网络端口)还可或可另选地被配置为耦接至蜂窝网络，例如蜂窝服务提供商的核心网络。核心网络可向多个装置诸如UE装置106提供与移动相关的服务和/或其他服务。在某些情况下，网络端口470可经由核心网络耦接至电话网络，和/或核心网络可提供电话网络(例如，在蜂窝服务提供商所服务的其他UE装置106中)。Network port 470 (or additional network ports) may also or alternatively be configured to couple to a cellular network, such as a cellular service provider's core network. The core network may provide mobility-related and/or other services to various devices, such asUE device 106 . In some cases,network port 470 may be coupled to a telephony network via a core network, and/or the core network may provide a telephony network (eg, inother UE devices 106 served by a cellular service provider).

基站102可包括至少一个天线434。该至少一个天线434可被配置为用作无线收发器并且可被进一步配置为经由无线电部件430来与UE装置106进行通信。天线434经由通信链432来与无线电部件430进行通信。通信链432可以是接收链、发射链或两者。无线电部件430可被配置为经由各种RAT进行通信，该RAT包括但不限于GSM、UMTS、LTE、WCDMA、CDMA2000等。Base station 102 may include at least one antenna 434 . The at least one antenna 434 may be configured to function as a wireless transceiver and may be further configured to communicate with theUE device 106 via theradio 430 . Antenna 434 communicates withradio 430 viacommunication link 432 .Communication chain 432 may be a receive chain, a transmit chain, or both.Radio 430 may be configured to communicate via various RATs including, but not limited to, GSM, UMTS, LTE, WCDMA, CDMA2000, and the like.

基站102的处理器404可被配置为例如通过执行被存储在存储器介质(例如，非暂态计算机可读存储器介质)上的程序指令来实施本文所述的方法的一部分或全部。另选地，处理器404可被配置作为可编程硬件元件，诸如FPGA(现场可编程门阵列)或作为ASIC(专用集成电路)，或它们的组合。Theprocessor 404 of thebase station 102 may be configured to implement some or all of the methods described herein, eg, by executing program instructions stored on a memory medium (eg, a non-transitory computer-readable memory medium). Alternatively, theprocessor 404 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application specific integrated circuit), or a combination thereof.

图5-通信系统Figure 5 - Communication System

图5示出了根据一些实施方案的示例性(简化)无线通信系统。需注意，图5的系统是可能的系统的仅一个示例，并且根据需要可在各种系统中的任一种系统中实现该实施方案。5 illustrates an exemplary (simplified) wireless communication system in accordance with some embodiments. Note that the system of FIG. 5 is only one example of a possible system, and this embodiment may be implemented in any of a variety of systems as desired.

如图所示，该示例性无线通信系统包括通过传输介质与一个或多个用户设备(UE)装置(被表示为UE 106)进行通信的基站102A和102B。基站102可以是收发器基站(BTS)或小区站点，并且可包括实现与UE 106的无线通信的硬件。每个基站102也可装备为与核心网络100进行通信。例如，基站102A可被耦接到核心网络100A，而基站102B可被耦接到核心网络100B。每个核心网络可由相应的蜂窝服务提供商来操作，或者多个核心网络100A可由同一蜂窝服务提供商来操作。每个核心网络100还可耦接到一个或多个外部网络(诸如外部网络108)，该外部网络可包括互联网、公共交换电话网络(PSTN)、和/或任何其他网络。因此，基站102可有助于UE装置106之间和/或UE装置106与网络100A、100B和108之间的通信。As shown, the example wireless communication system includes base stations 102A and 102B in communication with one or more user equipment (UE) devices (represented as UE 106 ) over a transmission medium.Base station 102 may be a base transceiver station (BTS) or a cell site, and may include hardware that enables wireless communication withUE 106 . Eachbase station 102 may also be equipped to communicate with the core network 100 . For example, base station 102A may be coupled tocore network 100A, and base station 102B may be coupled tocore network 100B. Each core network may be operated by a respective cellular service provider, ormultiple core networks 100A may be operated by the same cellular service provider. Each core network 100 may also be coupled to one or more external networks, such asexternal network 108, which may include the Internet, a public switched telephone network (PSTN), and/or any other network. Accordingly,base station 102 may facilitate communication betweenUE devices 106 and/or betweenUE devices 106 andnetworks 100A, 100B, and 108 .

基站102和UE 106可被配置为使用各种无线电接入技术(RAT，也被称为无线通信技术或电信标准)中的任一种无线电接入技术通过传输介质进行通信，该各种无线电接入技术诸如GSM、UMTS(WCDMA)、LTE、高级LTE(LTE-A)、3GPP2 CDMA2000(例如，1xRTT、1xEV-DO、HRPD、eHRPD)、IEEE 802.11(WLAN或Wi-Fi)、IEEE 802.16(WiMAX)等。Thebase station 102 and theUE 106 may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs, also known as wireless communication technologies or telecommunications standards) that Access technologies such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), 3GPP2 CDMA2000 (eg, 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX )Wait.

基站102A和核心网络100A可根据第一RAT(例如，LTE)操作，而基站102B和核心网络100B可根据第二(例如，另一)RAT(例如，GSM、CDMA 2000或其他传统或电路交换技术)操作。这两个网络可由同一网络运营商(例如，蜂窝服务提供商或“运营商”)控制，或者根据需要可由不同网络运营商控制。此外，这两个网络可彼此独立地操作(例如，如果它们根据不同的RAT来操作)，或可以一定程度耦接或紧密耦接的方式操作。Base station 102A andcore network 100A may operate according to a first RAT (eg, LTE), while base station 102B andcore network 100B may operate according to a second (eg, another) RAT (eg, GSM, CDMA 2000, or other legacy or circuit-switched technology) )operate. The two networks may be controlled by the same network operator (eg, a cellular service provider or "operator"), or by different network operators as desired. Furthermore, the two networks may operate independently of each other (eg, if they operate according to different RATs), or may operate in a somewhat coupled or tightly coupled manner.

还要指出，虽然可使用两个不同的网络来支持两个不同的RAT(诸如图5中所示示的例性网络配置中所示出的)，但其他网络配置实施多个RAT也是可能的。例如，基站102A和102B可根据不同RAT来操作，但被耦接到同一核心网络。又如，能够同时支持不同RAT(例如，LTE和GSM、LTE和CDMA2000 1xRTT、和/或任何其他RAT组合)的多模基站可被耦接到同样支持不同蜂窝通信技术的核心网络。在一个实施方案中，UE 106可被配置为使用作为分组交换技术的第一RAT(例如，LTE)和作为电路交换技术的第二RAT(例如，GSM或1xRTT)。Also note that while two different networks may be used to support two different RATs (such as shown in the example network configuration shown in Figure 5), other network configurations are also possible to implement multiple RATs . For example, base stations 102A and 102B may operate according to different RATs, but be coupled to the same core network. As another example, a multimode base station capable of simultaneously supporting different RATs (eg, LTE and GSM, LTE and CDMA2000 IxRTT, and/or any other combination of RATs) may be coupled to a core network that also supports different cellular communication technologies. In one embodiment, theUE 106 may be configured to use a first RAT (eg, LTE) as a packet-switched technology and a second RAT (eg, GSM or IxRTT) as a circuit-switched technology.

如上所述，UE 106可能够使用多个RAT进行通信，诸如3GPP、3GPP2、或任何所期望的蜂窝标准中的那些RAT。UE 106还可被配置为使用WLAN、蓝牙、一个或多个全球导航卫星系统(GNSS，例如GPS或GLONASS)、一个和/或多个移动电视广播标准(例如，ATSC-M/H或DVB-H)等进行通信。网络通信标准的其他组合也是可能的。As mentioned above,UE 106 may be capable of communicating using multiple RATs, such as those in 3GPP, 3GPP2, or any desired cellular standard. TheUE 106 may also be configured to use WLAN, Bluetooth, one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one and/or more mobile television broadcasting standards (eg, ATSC-M/H or DVB- H) etc. to communicate. Other combinations of network communication standards are also possible.

基站102A和102B和根据相同或不同RAT或蜂窝通信标准操作的其他基站因此可被提供作为小区的网络，该小区的网络可经由一个或多个无线电接入技术(RAT)在广阔的地理区域上向UE 106和类似的装置提供连续的或近乎连续的重叠服务。Base stations 102A and 102B and other base stations operating according to the same or different RAT or cellular communication standards may thus be provided as a network of cells that may be available over a wide geographic area via one or more radio access technologies (RATs) Continuous or near-continuous overlapping services are provided to UEs 106 and similar devices.

图6-具有CSFB的通信场景Figure 6 -Communication Scenario with CSFB

图6示出了根据现有技术的可涉及电路交换回退的通信场景的示例。图6描绘了当前现有技术的CSFB操作以及在现有技术CSFB操作中出现的某些问题。如图所示，图6示出了具有并行的LTE和2G/3G网络的示例性网络架构的简化视图。如图所示，LTE网络142和传统2G/3G网络144可在同一地理区域中共存，其中这两个网络驻留在移动用户的用户设备(UE)和公共核心网络之间。公共核心网络可包括MME(移动管理实体)152、SGSN(服务GPRS支持节点)154、和MSC(移动交换中心)服务器156。GPRS是指通用分组无线电服务，该通用分组无线电服务是2G和3G GSM(全球移动通信系统)网络上的面向分组的移动数据服务。Figure 6 shows an example of a communication scenario that may involve circuit-switched fallback according to the prior art. Figure 6 depicts current prior art CSFB operation and some of the problems that arise in prior art CSFB operation. As shown, FIG. 6 shows a simplified view of an exemplary network architecture with parallel LTE and 2G/3G networks. As shown, theLTE network 142 and the legacy 2G/3G network 144 may coexist in the same geographic area, where the two networks reside between the mobile subscriber's user equipment (UE) and a common core network. The common core network may include MME (Mobility Management Entity) 152 , SGSN (Serving GPRS Support Node) 154 , and MSC (Mobile Switching Center)server 156 . GPRS refers to General Packet Radio Service, which is a packet-oriented mobile data service on 2G and 3G GSM (Global System for Mobile Communications) networks.

MME 152用于在使用LTE进行通信期间服务UE。SGSN 154用于在UE在2G/3G网络中使用数据服务进行通信时服务UE。MSC服务器156用于在2G/3G网络中利用语音服务时服务UE。MSC服务器156被连接到运营方(运营商)的电话网络。MME 152被连接到MSC服务器156以支持LTE装置的CS回退(CSFB)信令和SMS传送。MME 152 is used to serve UEs during communications using LTE. TheSGSN 154 is used to serve the UE when the UE communicates using data services in the 2G/3G network. TheMSC server 156 is used to serve UEs when utilizing voice services in 2G/3G networks. TheMSC server 156 is connected to the operator's (operator's) telephone network. TheMME 152 is connected to theMSC server 156 to support CS fallback (CSFB) signaling and SMS delivery for LTE devices.

MSC服务器156和LTE移动管理实体(MME)152之间的接口(SG)使得UE能够当在LTE接入网络上时进行电路交换(CS)注册和分组交换(PS)注册两者。该接口还使得能够经由LTE接入来递送CS寻呼以及SMS通信，而UE不得不离开LTE网络。The interface (SG) between theMSC server 156 and the LTE Mobility Management Entity (MME) 152 enables the UE to perform both circuit switched (CS) and packet switched (PS) registrations while on the LTE access network. The interface also enables delivery of CS pages and SMS communications via LTE access without the UE having to leave the LTE network.

CSFB操作通常如下进行操作。假设当UE当前正与LTE网络进行通信，即默认LTE数据网络连接处在操作过程中时，移动台被叫(呼入)CS语音呼叫到达MSC服务器156处。该传入CS语音呼叫经由LTE来触发对用户的UE装置的寻呼。该寻呼引发CSFB操作。在执行CSFB操作时，UE向网络发送扩展服务请求以转换到2G/3G。基站利用无线电资源控制(RRC)释放消息进行响应，以将UE从LTE网络释放。一旦UE已从LTE转换到2G/3G，便执行传统呼叫建立过程以建立CS呼叫。移动台主叫(传出)呼叫遵循从LTE(PS)到2G/3G(CS)的相同的转换，但不需要寻呼步骤。当进行从LTE向3G网络的CSFB时，PS数据会话也可移动到3G网络，以用于同时的语音服务和数据服务。当进行从LTE向2G网络的CSFB时，PS数据会话可被暂停直到语音呼叫结束并且装置返回到LTE，除非2G网络支持允许同时的语音和数据的双传输模式(DTM)。当语音呼叫结束时，UE装置经由空闲模式或连接模式移动性过程而返回到LTE。CSFB operations generally operate as follows. Assume that a mobile station called (incoming) CS voice call arrives at theMSC server 156 when the UE is currently communicating with the LTE network, ie the default LTE data network connection is in operation. The incoming CS voice call triggers a paging of the user's UE device via LTE. This paging initiates CSFB operation. When performing CSFB operation, the UE sends an extended service request to the network to switch to 2G/3G. The base station responds with a radio resource control (RRC) release message to release the UE from the LTE network. Once the UE has transitioned from LTE to 2G/3G, conventional call setup procedures are performed to establish a CS call. Mobile originating (outgoing) calls follow the same transition from LTE (PS) to 2G/3G (CS), but no paging steps are required. When doing CSFB from LTE to 3G network, PS data sessions can also be moved to 3G network for simultaneous voice and data services. When doing CSFB from LTE to a 2G network, the PS data session may be suspended until the voice call ends and the device returns to LTE, unless the 2G network supports Dual Transfer Mode (DTM) which allows simultaneous voice and data. When the voice call ends, the UE device returns to LTE via idle mode or connected mode mobility procedures.

因此，如上所述，当传入呼叫到达时或当UE发起传出呼叫时，UE装置从LTE切换到2G/3G。2G/3G网络的获取和呼叫的建立可采用两种过程中的任一过程，该过程是切换或重定向。在切换过程中，目标小区由网络选择并事先准备，并且UE可在连接模式中直接进入该小区。在仍处于LTE中时，可在进行切换之前执行信号强度测量的无线电接入技术间(IRAT)测量。在重定向过程中，不是为UE预先选择目标小区，而是为UE提供多个小区的一个或多个可能的候选频率。然后允许UE选择这些候选频率中的一个候选频率上的任何小区。如果在所提供的候选频率上不能找到任何小区，则UE还可尝试其他频率/RAT。因此可为UE提供包含其能选择的小区的可能频率的频率列表。一旦UE选择了小区，UE便发起正常呼叫建立过程。因此，使用重定向执行的CSFB与切换过程相比可需要更少的时间来识别最佳小区。Therefore, as described above, when an incoming call arrives or when the UE initiates an outgoing call, the UE device switches from LTE to 2G/3G. The acquisition of the 2G/3G network and the establishment of the call can use either of two processes, which is handover or redirection. During handover, the target cell is selected by the network and prepared in advance, and the UE can directly enter this cell in connected mode. While still in LTE, Inter-Radio Access Technology (IRAT) measurements of signal strength measurements may be performed prior to handover. In the redirection process, instead of pre-selecting the target cell for the UE, the UE is provided with one or more possible candidate frequencies of multiple cells. The UE is then allowed to select any cell on one of these candidate frequencies. If no cell can be found on the provided candidate frequencies, the UE may also try other frequencies/RATs. The UE can thus be provided with a frequency list containing the possible frequencies of the cells it can select. Once the UE has selected a cell, the UE initiates a normal call setup procedure. Therefore, CSFB performed using redirection may require less time to identify the best cell than a handover procedure.

呼叫建立可靠性是语音呼叫用户体验的重要问题。呼叫建立可靠性是指不指示呼叫建立失败的在某时间帧内成功建立传入呼叫或传出呼叫的能力，其中优选地在第一次尝试中建立呼叫建立。针对CSFB呼叫建立的所期望的目标是至少匹配传统性能。因此，期望在该领域中进行改进。Call setup reliability is an important issue for the user experience of voice calls. Call set-up reliability refers to the ability to successfully set up an incoming or outgoing call within a certain time frame without indicating a call set-up failure, where call set-up is preferably set up on the first attempt. The desired goal for CSFB call setup is to at least match legacy performance. Therefore, improvements in this field are desired.

LTE小区可重叠两个或更多个2G/3G小区。因此，常常不确定哪个2G/3G小区是对于从LTE小区切换的最佳目标。在某些情况下，LTE向2G/3G小区切换可在MSC服务器“边界”区域中发生，其中LTE向2G/3G的切换涉及MSC服务器的可能的改变。然而，如果UE在CSFB期间选择使其附接到另一MSC服务器的新小区，则这可在某些网络上产生问题。An LTE cell may overlap two or more 2G/3G cells. Therefore, it is often uncertain which 2G/3G cell is the best target for handover from an LTE cell. In some cases, the LTE to 2G/3G cell handover may occur in the MSC server "border" area, where the LTE to 2G/3G handover involves a possible change of the MSC server. However, this can create problems on some networks if the UE chooses to attach to a new cell of another MSC server during CSFB.

可部署MSC池架构来应对MSC“边界”区域中的建立延迟和失败风险，并且消除LAU延迟时间。MSC池架构遵循3GPP Release 5规范来将无线电接入网络(RAN)节点连接到多个核心网络(CN)节点(MSC服务器)。利用MSC池架构，池区域中的所有MSC服务器为池中的所有小区服务，从而消除了池内的MSC“边界”和MSC间LAU的时间延迟。然而，MSC池架构在至少某些网络中并未广泛实施。An MSC pool architecture can be deployed to address setup delays and failure risks in MSC "boundary" regions, and eliminate LAU latency times. The MSC pool architecture follows the3GPP Release 5 specification to connect a radio access network (RAN) node to multiple core network (CN) nodes (MSC servers). With the MSC pool architecture, all MSC servers in the pool area serve all cells in the pool, thereby eliminating time delays between MSC "borders" within the pool and inter-MSC LAUs. However, the MSC pool architecture is not widely implemented in at least some networks.

MT漫游转发(MTRF)也可用作对MSC池架构的补充。MTRF是MT漫游重试(MTRR)标准的更新版本。当跨MSC边界来执行回退时，MTRF将呼叫直接从旧的MSC服务器转发到新的MSC服务器，由此克服MSC服务器边界问题。MTRF相对于MTRR(MT漫游重试)具有以下优势：无需运营商之间达成协议并且不将呼叫重新路由回到GMSC以用于第二HLR查询。这使MTRF更可靠并且更容易部署。然而，同样，MTRF在至少某些网络中并未广泛实施。MT Roaming Forwarding (MTRF) can also be used as a complement to the MSC pool architecture. MTRF is an updated version of the MT Roaming Retry (MTRR) standard. When the fallback is performed across MSC boundaries, the MTRF forwards the call directly from the old MSC server to the new MSC server, thereby overcoming the MSC server boundary problem. MTRF has the following advantages over MTRR (MT Roaming Retry): no agreement between operators is required and calls are not rerouted back to the GMSC for the second HLR query. This makes MTRF more reliable and easier to deploy. However, again, MTRF is not widely implemented in at least some networks.

图7示出了可在典型网络中进行的可能的池区域配置的大部分。UE只要在池区域的无线电覆盖范围中便由该池区域的一个专用核心网络(CN)节点(MSC服务器)来服务。如图所示，图7包含电路交换(CS)池区域1(由MSC 1、2、3服务的RAN区域1、2、5、6)、CS池区域2(由MSC 4、5、6服务的RAN区域2、3、6、7)、PS池区域1(由SGSN 1、2服务的RAN区域1、5)和PS池区域2(由SGSN 3、4、5服务的RAN区域2、3、6、7)。此外，RAN区域4和8由MSC 7和SGSN 6服务，而无需使用RAN节点与多个CN节点的域内连接。CS池区域1和2示出了配置重叠池区域的可能性。PS池区域1和2被配置为不重叠。CS和PS域的池区域可被相同地配置到CS池区域2和PS池区域2，或者它们可被不同地配置，如CS池区域1和PS池区域1所示。可为每个池区域独立地配置CN节点(MSC服务器)的数量或容量。Figure 7 shows most of the possible pool area configurations that can be made in a typical network. The UE is served by a dedicated Core Network (CN) node (MSC server) of the pool area as long as it is within the radio coverage of the pool area. As shown, Figure 7 contains Circuit Switched (CS) Pool Area 1 (RAN Areas 1, 2, 5, 6 served byMSCs 1, 2, 3), CS Pool Area 2 (served byMSCs 4, 5, 6)RAN area 2, 3, 6, 7), PS pool area 1 (RAN area 1, 5 served bySGSN 1, 2) and PS pool area 2 (RAN area 2, 3 served bySGSN 3, 4, 5) , 6, 7). Furthermore,RAN areas 4 and 8 are served byMSC 7 andSGSN 6 without the use of intra-domain connections of RAN nodes to multiple CN nodes.CS pool areas 1 and 2 show the possibility to configure overlapping pool areas.PS pool areas 1 and 2 are configured not to overlap. The pool areas of the CS and PS domains may be configured identically toCS Pool Area 2 andPS Pool Area 2, or they may be configured differently as shown inCS Pool Area 1 andPS Pool Area 1. The number or capacity of CN nodes (MSC servers) can be configured independently for each pool area.

池(或池区域)可被定义为UE可在其中漫游而无需改变服务CN节点(MSC服务器156)的区域。池区域可由一个或多个CN节点(MSC服务器)并行服务。RAN节点(RNC或BSC)的完整服务区域属于一个或多个相同的池区域。RAN节点服务区域可属于多个池区域，当多个重叠的池区域包括该RAN节点服务区域时是这样的情况。CS和PS域的池区域可独立地配置有RAN节点服务区域的粒度。A pool (or pool area) can be defined as an area in which UEs can roam without changing the serving CN node (MSC server 156). The pool area can be served by one or more CN nodes (MSC servers) in parallel. The complete service area of a RAN node (RNC or BSC) belongs to one or more of the same pool areas. A RAN node service area may belong to multiple pool areas, which is the case when multiple overlapping pool areas include the RAN node service area. The pool areas of CS and PS domains can be independently configured with the granularity of the RAN node service area.

网络资源识别符(NRI)从服务池区域的所有CN节点中唯一地识别各个CN节点(MSC服务器)。NRI的长度在一个池区域中的域的所有节点中是相同的。在池区域重叠的区域中，NRI从服务所有这些重叠的池区域的所有CN节点中唯一地识别CN节点，即NRI可在RAN节点内唯一地识别CN节点。对于重叠的池区域，NRI长度可被配置为在服务这些池区域的特定域的所有节点中是相同的。CS和PS域的NRI可彼此独立，因为PS和CS域CN节点是独立寻址的。可为CN节点分配多于一个NRI。A Network Resource Identifier (NRI) uniquely identifies each CN node (MSC server) from among all CN nodes in the service pool area. The length of the NRI is the same in all nodes of the domain in a pool area. In areas where the pool areas overlap, the NRI uniquely identifies the CN node from all CN nodes serving all these overlapping pool areas, ie the NRI can uniquely identify the CN node within the RAN node. For overlapping pool areas, the NRI length can be configured to be the same across all nodes serving a particular domain of those pool areas. The NRIs of the CS and PS domains can be independent of each other because the PS and CS domain CN nodes are independently addressed. More than one NRI may be allocated for a CN node.

NRI是服务CN节点(MSC服务器)分配给UE的临时身份TMSI(CS域)或P-TMSI(PS域)的一部分。支持“RAN节点与多个CN节点的域间连接”的每个CN节点被配置有其特定的一个或多个NRI。CN节点中的(P-)TMSI分配机制生成在相关位位置中包含所配置的NRI的(P-)TMSI。NRI具有介于10个位和0个位之间的灵活长度(需注意，0个位意味着不使用NRI并且不实施该特征)。The NRI is part of the temporary identity TMSI (CS domain) or P-TMSI (PS domain) assigned to the UE by the serving CN node (MSC server). Each CN node supporting "inter-domain connection of RAN node with multiple CN nodes" is configured with its specific one or more NRIs. The (P-)TMSI allocation mechanism in the CN node generates the (P-)TMSI containing the configured NRI in the relevant bit positions. NRI has a flexible length between 10 bits and 0 bits (note that 0 bits means that NRI is not used and this feature is not implemented).

因此，如上所述，并且如图7所示，电路交换(CS)池区域可在某些地理区域中重叠。当UE开始CSFB过程时，其将从LTE网络断开连接，从而该基站向UE发送无线电资源控制(RRC)释放消息。然而，LTE中的RRC释放可包括来自不同MSC池的小区候选频率，并且因此UE可能不小心选择另一MSC池中的小区，并因此需要附接到另一MSC服务器。因此，这里出现的问题是，如果UE在CSFB移动台被叫(MT)(传入)呼叫过程期间处于CS池重叠区域中，则UE可能最终选择与其在MT呼叫之前所位于的不同的MSC池并驻留在其上。如果在网络系统中还没有部署MTRF，则这可能导致MT呼叫失败。另外，UE向网络发送扩展服务请求消息以发起CSFB或CSFB呼叫，或者对来自网络的MT CS回退请求进行响应。通常，当发生ESR失败时，UE可选择另一无线电接入网络(RAN)中的GSM或UTMS(GERAN/UTRAN)小区，这可能提高失败率。例如，假定UE在RAN(无线电接入网络)服务区域2中发起针对CSFB移动台被叫(MT)呼叫的ESR，其中MSC1是服务MSC。在当前小区选择中ESR已失败之后，UE可驻留在属于RAN服务区域3的小区中。在该示例中，则MSC4将是服务MSC。在还未部署MTRF能力的网络中，则CSFB MT呼叫将失败。这将对用户体验产生不利影响。还未部署MTRF能力的网络的一个示例是中国移动(CMCC)网络，即CMCC在其当前网络中只部署少量MTRF能力。Thus, as described above, and as shown in Figure 7, circuit switched (CS) pool areas may overlap in certain geographic areas. When the UE starts the CSFB procedure, it will disconnect from the LTE network, so the base station sends a Radio Resource Control (RRC) release message to the UE. However, RRC release in LTE may include cell candidate frequencies from different MSC pools, and thus the UE may inadvertently select a cell in another MSC pool and thus need to attach to another MSC server. So the problem that arises here is that if the UE is in the CS pool overlap area during the CSFB mobile station called (MT) (incoming) call procedure, the UE may end up choosing a different MSC pool than it was in before the MT call and reside on it. This may cause MT calls to fail if MTRF has not been deployed in the network system. Additionally, the UE sends an Extended Service Request message to the network to initiate a CSFB or CSFB call, or to respond to an MT CS fallback request from the network. Typically, when an ESR failure occurs, the UE may select a GSM or UTMS (GERAN/UTRAN) cell in another radio access network (RAN), which may increase the failure rate. For example, assume that the UE initiates an ESR for a CSFB mobile station called (MT) call in a RAN (Radio Access Network)service area 2, where MSC1 is the serving MSC. The UE may camp in a cell belonging toRAN service area 3 after the ESR has failed in the current cell selection. In this example, then MSC4 would be the serving MSC. In networks where MTRF capability has not been deployed, then CSFB MT calls will fail. This will adversely affect the user experience. An example of a network that has not yet deployed MTRF capability is the China Mobile (CMCC) network, ie CMCC deploys only a small amount of MTRF capability in its current network.

图8和图9-到不同池的CSFB导致呼叫失败Figures 8 and 9 -CSFB to different pool causes call to fail

图8示出了根据一些实施方案的导致MT呼叫失败的CSFB回退过程的一个示例。如图所示，当MT(传入)呼叫经由对基站的寻呼消息802而到达并且寻呼被提供给UE(未示出)时，UE响应于MT呼叫而向基站发出扩展服务请求(ESR)804。基站(eNodeB)然后用RRC释放806进行响应，以将UE从LTE网络释放。来自基站的RRC释放消息806可包括一个或多个绝对射频信道号(ARFCN)。RRC释放消息可包括属于两个或更多个不同MSC池的绝对射频信道号(ARFCN)。需注意，在GSM蜂窝网络中，绝对射频信道号(ARFCN)是指定用于移动无线网络中的传输和接收的一对物理无线电载波的代码，一个物理无线电载波用于上行链路信号并且一个物理无线电载波用于下行链路信号。因此，GSM中的上行链路/下行链路信道对由ARFCN来识别。Figure 8 illustrates one example of a CSFB fallback procedure that results in a failed MT call, according to some embodiments. As shown, when an MT (incoming) call arrives via apaging message 802 to the base station and the page is provided to the UE (not shown), the UE issues an Extended Service Request (ESR) to the base station in response to the MT call )804. The base station (eNodeB) then responds with anRRC release 806 to release the UE from the LTE network. TheRRC release message 806 from the base station may include one or more absolute radio frequency channel numbers (ARFCN). The RRC release message may include absolute radio frequency channel numbers (ARFCN) belonging to two or more different MSC pools. Note that in GSM cellular networks, the absolute radio frequency channel number (ARFCN) is a code that specifies a pair of physical radio carriers used for transmission and reception in mobile wireless networks, one physical radio carrier for uplink signals and one physical radio carrier. Radio carriers are used for downlink signals. Therefore, uplink/downlink channel pairs in GSM are identified by ARFCN.

响应于从基站接收的RRC释放消息，UE执行至2G/3G网络的回退808。在CS回退期间，UE可从与其在MT呼叫到达时驻留在其上的池不同的MSC池选择2G/3G小区。需注意，在该示例中，UE选择驻留在来自另一MSC池(MSC池2)的小区上。UE选择驻留在另一MSC池上可能导致MT呼叫失败。如图8所示，失败可能是由于IAM消息不能在操作这些不同池的MSC服务器之间转发，即IAM消息不能在先前的MSC池(池1)和新选择的MSC池(池2)之间转发的事实。因此，没有向UE提供CC_setup 810，从而导致呼叫失败。In response to the RRC release message received from the base station, the UE performs a fallback 808 to the 2G/3G network. During CS fallback, the UE may select a 2G/3G cell from a different MSC pool than the pool it camped on when the MT call arrived. Note that in this example, the UE chooses to camp on a cell from another MSC pool (MSC Pool 2). The UE choosing to camp on another MSC pool may cause the MT call to fail. As shown in Figure 8, the failure may be due to IAM messages not being able to be forwarded between MSC servers operating these different pools, i.e. IAM messages cannot be between the previous MSC pool (pool 1) and the newly selected MSC pool (pool 2) retweeted fact. Therefore, theCC_setup 810 is not provided to the UE, causing the call to fail.

图9示出了在涉及ESR失败情景的情况下导致MT呼叫失败的CSFB回退过程的另一示例。如图所示，与图8中相同，当MT(传入)呼叫寻呼802到达并被提供至UE时，UE响应于MT呼叫而向基站发出扩展服务请求(ESR)804。然而，在本示例中，由UE发送的ESR消息以ESR失败807结束。当ESR失败807发生时，UE可执行对GERAN(GSM)的通常小区选择，GERAN将可能位于另一MSC池中。这可能导致呼叫失败，例如没有CC_setup 810。需注意，ESR失败与RRC释放相比具有更高的可能性导致UE选择另一MSC池。例如需注意，网络(NW)可采取某种动作来避免发送ESR失败，这可包括向UE分配属于另一MSC池的小区。这样分配属于另一MSC池的小区将导致UE驻留在这另一MSC池上，从而导致MT呼叫失败。Figure 9 shows another example of a CSFB fallback procedure that results in a failed MT call in a situation involving an ESR failure scenario. As shown, as in Figure 8, when an MT (incoming)call page 802 arrives and is provided to the UE, the UE issues an Extended Service Request (ESR) 804 to the base station in response to the MT call. However, in this example, the ESR message sent by the UE ends with anESR failure 807 . WhenESR failure 807 occurs, the UE may perform normal cell selection for GERAN (GSM), which will likely be located in another MSC pool. This can cause the call to fail e.g. withoutCC_setup 810. Note that ESR failure has a higher probability than RRC release to cause the UE to select another MSC pool. For example, it should be noted that the network (NW) may take some action to avoid failure to send the ESR, which may include assigning the UE a cell belonging to another MSC pool. Such allocation of cells belonging to another MSC pool will cause the UE to camp on this other MSC pool, resulting in MT call failure.

因此对于图8和图9的示例中的每个示例，都发生MT呼叫失败，从而导致性能劣化。该性能劣化在RRC释放或ESR失败中的任一者的情况下发生。Thus for each of the examples of Figures 8 and 9, MT call failures occur, resulting in performance degradation. This performance degradation occurs in the case of either RRC release or ESR failure.

图10和图11：流程图实施方案Figures 10 and 11: Flowchart Embodiments

图10和图11是示出了一种用于提供CSFB呼叫操作的改善可靠性的方法的实施方案的简单流程图。在这里，为UE提供关于其各个相邻或候选小区当前附接到的MSC服务器的信息，使得其能选择与同一MSC服务器对应的小区。这用于帮助防止由于缺乏MTRF部署而导致的呼叫失败。10 and 11 are simple flow diagrams illustrating an embodiment of a method for providing improved reliability of CSFB call operations. Here, the UE is provided with information about the MSC server to which its respective neighboring or candidate cells are currently attached, enabling it to select a cell corresponding to the same MSC server. This is used to help prevent call failures due to lack of MTRF deployment.

在本文所述的实施方案中，UE接收关于当前服务UE的当前MSC服务器的信息。例如，UE可知道其自身的MSC服务器，例如可根据其TMSI(临时移动站标识符)而知道其自身的池id。UE可还接收关于相邻候选小区的MSC服务器的信息。提供该当前MSC服务器信息的一种方式是向UE提供各个候选小区的池区域id’(或池id’)，特别是这各个其他小区当前操作于其中的池的池id’。由于相同池中的小区使用相同的MSC服务器，因此该池id信息使UE能够通过选择相同池中的小区来选择与相同MSC服务器对应的小区。因此，池id用作用于针对这些候选小区中的每个候选小区来识别当前MSC服务器的代理。需注意，代替这些小区的池id’或者除了这些小区的池id’之外，可向UE提供识别当前MSC服务器(各个候选小区当前附接到的MSC服务器)的其他信息，诸如MSC服务器地址、或各种其他类型的MSC服务器识别信息中的任一者。例如，在相同池中的小区并非必然使用相同MSC服务器的一些具体实施中，可使用其他信息来识别这些候选小区的MSC服务器，诸如MSC服务器地址。In the embodiments described herein, the UE receives information about the current MSC server currently serving the UE. For example, the UE may know its own MSC server, eg its own pool id from its TMSI (Temporary Mobile Station Identifier). The UE may also receive information about the MSC server of the neighboring candidate cells. One way of providing this current MSC server information is to provide the UE with the pool area id' (or pool id') of each candidate cell, in particular the pool id' of the pool in which each other cell is currently operating. Since cells in the same pool use the same MSC server, the pool id information enables the UE to select a cell corresponding to the same MSC server by selecting cells in the same pool. Therefore, the pool id serves as a proxy for identifying the current MSC server for each of these candidate cells. Note that instead of or in addition to the pool id' of these cells, the UE may be provided with other information identifying the current MSC server (the MSC server to which each candidate cell is currently attached), such as the MSC server address, or any of various other types of MSC server identification information. For example, in some implementations where cells in the same pool do not necessarily use the same MSC server, other information may be used to identify the MSC server of these candidate cells, such as the MSC server address.

现在参见图10，网络系统包括与UE 106进行无线通信的基站子系统/无线电网络控制器(BSS/RNC)172。BSS/RNC 172被耦接到MSC服务器156。BSS/RNC 172还被耦接到OAM服务器174，OAM服务器174继而被耦接到MSC服务器156和MME 152。在图10中的“1”处，BSS/RNC可从OAM服务器获取这些候选小区的当前UE MSC池频率和NRI池id’，OAM服务器可继而已从MSC服务器获取该信息。该步骤通常将在MT呼叫请求之前进行，但也可在CSFB操作期间进行。因此，如图13中进一步所描绘的，BSS/RNC还可获取多个其他小区的小区频率/池id信息，并且可向UE广播该信息。BSS/RNC可从由OAM服务器采集的相应MSC服务器获取多个其他小区的小区频率/池id信息。Referring now to FIG. 10 , the network system includes a base station subsystem/radio network controller (BSS/RNC) 172 in wireless communication with theUE 106 . The BSS/RNC 172 is coupled to theMSC server 156 . The BSS/RNC 172 is also coupled to theOAM server 174 , which in turn is coupled to theMSC server 156 and theMME 152 . At "1" in Figure 10, the BSS/RNC may obtain the current UE MSC pool frequency and NRI pool id' for these candidate cells from the OAM server, which may then have obtained this information from the MSC server. This step will normally be done before the MT call request, but can also be done during CSFB operation. Thus, as further depicted in Figure 13, the BSS/RNC may also obtain cell frequency/pool id information for a number of other cells and may broadcast this information to the UE. The BSS/RNC may obtain cell frequency/pool id information of multiple other cells from the corresponding MSC server collected by the OAM server.

更具体地，当UE最初连接到网络时，其经由2G/3G网络而被附接到MSC服务器。MSC服务器然后向UE分配有效的TMSI(临时移动站ID)。TMSI包含32位，其中TMSI的一部分具有NRI字段。NRI字段可被包含在TMSI的中间0-10位中。NRI字段的一个或多个位包含UE当前驻留在其上的池(或池区域)的池id。More specifically, when the UE initially connects to the network, it is attached to the MSC server via the 2G/3G network. The MSC server then assigns a valid TMSI (Temporary Mobile Station ID) to the UE. TMSI contains 32 bits, and a part of TMSI has NRI field. The NRI field may be included in the middle 0-10 bits of the TMSI. One or more bits of the NRI field contain the pool id of the pool (or pool region) on which the UE currently resides.

BSS/RNC可针对多个可能的候选小区中的每个候选小区直接地或经由OAM服务器从MSC服务器获取NRI。如上所述，NRI字段包含小区当前操作于其上的池的池id，因此允许BSS/RNC知道该池id。对于3GPP Iu模式，BSS/RNC可经由RRC中的IDNNS来获取NRI。BSS/RNC可附加地(或替代地)获取可用于识别这些相邻小区的当前MSC服务器的其他信息，诸如MSC寻址信息。The BSS/RNC may obtain the NRI from the MSC server for each of the multiple possible candidate cells, either directly or via the OAM server. As mentioned above, the NRI field contains the pool id of the pool on which the cell is currently operating, thus allowing the BSS/RNC to know this pool id. For 3GPP Iu mode, BSS/RNC can acquire NRI via IDNNS in RRC. The BSS/RNC may additionally (or alternatively) obtain other information, such as MSC addressing information, that may be used to identify the current MSC server of these neighboring cells.

在CSFB回退操作之前或期间，BSS/RNC经由SI/SIB(系统信息/系统信息块)来向UE广播潜在回退小区的频率列表及其相应池id’。Before or during CSFB fallback operation, the BSS/RNC broadcasts the frequency list of potential fallback cells and their corresponding pool ids' to the UE via SI/SIB (System Information/System Information Block).

在图10的“2”处，UE然后基于该信息来执行小区选择，以选择被映射到与初始小区相同的池或被映射到相同MSC服务器的小区。更具体地，当UE接收到移动台被叫(MT)(传入)呼叫并执行CSFB操作时，UE执行小区选择以选择要驻留在其上的新的CS小区。UE知道其驻留在其上的当前池id，该当前池id已从其自身的TMSI获取或者从BSS/RNC或基站接收。UE还可知道多个候选小区的小区频率/池id信息，该小区频率/池id信息已如上所述从BSS/RNC或者可能从OTA服务器接收。另选地，UE接收来自不同相邻小区中的各个相邻小区的广播，并且对于每个相应小区，该广播信息包括小区的频率和相应小区的池id(或其他池或MSC识别信息)。At "2" of Figure 10, the UE then performs cell selection based on this information to select a cell mapped to the same pool as the initial cell or mapped to the same MSC server. More specifically, when the UE receives a mobile station called (MT) (incoming) call and performs a CSFB operation, the UE performs cell selection to select a new CS cell to camp on. The UE knows the current pool id it resides on, which it has acquired from its own TMSI or received from the BSS/RNC or base station. The UE may also know the cell frequency/pool id information of the multiple candidate cells, which cell frequency/pool id information has been received from the BSS/RNC or possibly from the OTA server as described above. Alternatively, the UE receives broadcasts from each of the different neighbor cells, and for each corresponding cell, the broadcast information includes the cell's frequency and the corresponding cell's pool id (or other pool or MSC identification information).

当UE接收到关于各个可能小区的小区频率/池id信息时，UE可将新小区的频率和相应小区的对应池id存储在存储器诸如数据结构中。UE然后将这些潜在小区(这些候选小区的至少一个复数子集)的池id与其当前驻留在其上的小区的池id进行比较。因此，UE使用该信息来选择属于与其在CSFB操作之前驻留在其上的相同的池的小区。When the UE receives the cell frequency/pool id information for each possible cell, the UE may store the frequency of the new cell and the corresponding pool id of the corresponding cell in a memory such as a data structure. The UE then compares the pool ids of these potential cells (at least a plural subset of these candidate cells) with the pool ids of the cells on which it is currently camped. Therefore, the UE uses this information to select cells belonging to the same pool on which it camped before the CSFB operation.

因此，UE选择与其在MT呼叫请求到达之前所处于的相同的池中的小区，并且因此继续使用与之前相同的MSC服务器。换句话讲，选择相同池中的小区使得MSC服务器不变。在其他实施方案中，UE基于其他信息(诸如MSC服务器地址、或其他id、或能够识别MSC服务器的其他类型的信息)来选择已知与其当前所附接的相同MSC服务器相关联的小区。Therefore, the UE selects a cell in the same pool that it was in before the MT call request arrived, and therefore continues to use the same MSC server as before. In other words, selecting cells in the same pool leaves the MSC server unchanged. In other embodiments, the UE selects cells known to be associated with the same MSC server to which it is currently attached based on other information such as MSC server addresses, or other ids, or other types of information capable of identifying the MSC server.

图11是与以上参考图10所述类似的第二实施方案的简单流程图。因此只详细指出与图10的主要区别。在该实施方案中，基站(eNodeB)存储与上述BSS/RNC所存储的相同的池id信息(或可能其他信息诸如MSC寻址信息)。在该实施方案中，假设网络运营商已在基站和BSS/RNC之间部署了OAM系统。OAM系统然后被网络运营商配置作为一种类型的中继节点，其中BSS/RNC向OAM传送小区频率/池id信息，并且OAM向基站(eNodeB)传送该信息。基站然后诸如在CSFB期间在RRC释放消息中将该小区频率/池id信息转发给UE。因此，在CSFB期间，UE将具有必需的信息以知道当前MSC池以及大量其他小区的池id’，并且可选择属于相同池的小区。FIG. 11 is a simple flow diagram of a second embodiment similar to that described above with reference to FIG. 10 . Therefore only the main differences from FIG. 10 are specified in detail. In this embodiment, the base station (eNodeB) stores the same pool id information (or possibly other information such as MSC addressing information) that is stored by the BSS/RNC described above. In this embodiment, it is assumed that the network operator has deployed an OAM system between the base station and the BSS/RNC. The OAM system is then configured by the network operator as a type of relay node, where the BSS/RNC transmits cell frequency/pool id information to the OAM and the OAM transmits this information to the base station (eNodeB). The base station then forwards this cell frequency/pool id information to the UE in an RRC release message, such as during CSFB. Therefore, during CSFB, the UE will have the necessary information to know the current MSC pool and the pool id' of a large number of other cells, and can select cells belonging to the same pool.

如图11所示，在“1”处，基站(eNodeB)从OAM服务器获取各个候选小区的池id信息。如上所述，OAM服务器将事先已从MSC服务器或可能从BSS/RNC接收了此信息。在“2”处，基站在CSFB呼叫操作期间向UE传输RRC释放消息。基站将作为RRC释放消息的一部分的该相邻小区的池id信息(和/或MSC寻址信息)传输至UE。RRC释放消息因此可包括对应候选小区的频率的列表/池id’。如上所述，UE可附加地或替代地从OTA服务器或从小区自身接收这些候选小区中的每个候选小区的小区频率和池id信息。UE然后基于从基站接收的各个候选小区的所接收池id信息来选择属于相同池的适当CS小区。换言之，UE然后执行小区选择，其中UE使用候选小区的所接收的池id信息来确定要选择的属于与其当前操作于其中的相同池区域的适当CS小区。As shown in FIG. 11, at "1", the base station (eNodeB) obtains the pool id information of each candidate cell from the OAM server. As mentioned above, the OAM server will have previously received this information from the MSC server or possibly from the BSS/RNC. At "2", the base station transmits an RRC release message to the UE during CSFB call operation. The base station transmits the neighbor cell's pool id information (and/or MSC addressing information) to the UE as part of the RRC release message. The RRC release message may thus include a list/pool id' of frequencies corresponding to candidate cells. As described above, the UE may additionally or alternatively receive cell frequency and pool id information for each of these candidate cells from the OTA server or from the cell itself. The UE then selects an appropriate CS cell belonging to the same pool based on the received pool id information for each candidate cell received from the base station. In other words, the UE then performs cell selection, wherein the UE uses the received pool id information of the candidate cell to determine an appropriate CS cell to select that belongs to the same pool area in which it is currently operating.

图12-详细流程图Figure 12 -Detailed Flowchart

图12是在图10中所示的方法的更详细的流程图。图12所示方法对应于在图10中所示的流程。在图10所描绘的实施方案中，在CSFB操作之前或期间，BSS/RNC 172可在801处向UE传输关于各个候选小区正操作于其中的池的池信息(在图14中示出)。需注意，BSS/RNC可替代地或附加地发送能够识别这些候选小区的当前MSC服务器的其他信息，诸如当前MSC服务器地址。FIG. 12 is a more detailed flowchart of the method shown in FIG. 10 . The method shown in FIG. 12 corresponds to the flow shown in FIG. 10 . In the embodiment depicted in FIG. 10 , before or during CSFB operation, the BSS/RNC 172 may transmit pool information (shown in FIG. 14 ) to the UE at 801 regarding the pool in which each candidate cell is operating. Note that the BSS/RNC may alternatively or additionally send other information that can identify the current MSC server of these candidate cells, such as the current MSC server address.

BSS/RNC装置因此在801向UE广播这各个候选小区的小区频率/池id信息，其中该信息可已由OAM服务器从不同MSC服务器收集。参照图14来对该操作进行描述。当UE从BSS/RNC装置接收关于各个可能小区的广播信息时，对于每个相应小区，UE存储相应小区的频率以及相应小区的对应池id。例如，UE可将该信息存储在数据结构诸如表格中，以允许在小区重新选择期间(在CSFB期间)容易搜索。BSS/RNC或UE可替代地(或附加地)从OTA服务器接收其他小区的小区频率/池id信息。The BSS/RNC device thus broadcasts the cell frequency/pool id information for these respective candidate cells at 801 to the UE, where this information may have been collected by the OAM server from different MSC servers. This operation is described with reference to FIG. 14 . When the UE receives broadcast information about each possible cell from the BSS/RNC device, for each corresponding cell, the UE stores the frequency of the corresponding cell and the corresponding pool id of the corresponding cell. For example, the UE may store this information in a data structure such as a table to allow easy searching during cell reselection (during CSFB). The BSS/RNC or UE may alternatively (or additionally) receive cell frequency/pool id information for other cells from the OTA server.

如图12所示，假定网络在UE驻留于或操作于分组交换(PS)网络上时接收到要与UE建立CSFB呼叫的移动台被叫(MT)呼叫请求。需注意，本发明的实施方案可与源自UE的呼叫以及对UE的呼叫(MT呼叫)一起操作。该MT呼叫请求可以由基站(eNodeB)接收的寻呼消息802的形式被接收，其然后在803处被提供给UE。此类PS网络的一个示例是LTE。在MT呼叫之前(或在MT呼叫被接收时)，UE驻留在MSC池1上，如图所示。响应于在网络上接收的MT呼叫，MSC p1向基站发出寻呼消息802，该基站然后在803处寻呼UE。如图所示，响应于寻呼消息，UE在804处向基站(eNodeB)传输扩展服务请求(ESR)，如图所示。As shown in Figure 12, it is assumed that the network receives a Mobile Station Called (MT) call request to establish a CSFB call with the UE while the UE is camping on or operating on a Packet Switched (PS) network. Note that embodiments of the present invention may operate with calls originating from the UE as well as calls to the UE (MT calls). The MT call request may be received in the form of apaging message 802 received by the base station (eNodeB), which is then provided at 803 to the UE. An example of such a PS network is LTE. Before the MT call (or when the MT call is received), the UE camps onMSC pool 1 as shown. In response to the MT call received on the network, the MSC p1 sends apaging message 802 to the base station, which then pages the UE at 803. As shown, in response to the paging message, the UE transmits an Extended Service Request (ESR) to the base station (eNodeB) at 804, as shown.

基站(eNodeB)然后利用RC释放806进行响应，以将UE从LTE网络释放。来自基站的RRC释放消息可包括UE可驻留在其上的小区的频率列表，即可包括一个或多个绝对射频信道号(ARFCN)，其包括属于两个或更多个不同MSC池的小区的绝对射频信道号(ARFCN)。The base station (eNodeB) then responds withRC release 806 to release the UE from the LTE network. The RRC Release message from the base station may include a frequency list of cells on which the UE may camp, i.e. one or more Absolute Radio Frequency Channel Numbers (ARFCN), which include cells belonging to two or more different MSC pools Absolute Radio Channel Number (ARFCN).

在82处的小区选择期间，UE然后将其当前驻留在其上的小区的池id与这些潜在小区(例如，这些潜在小区的至少一个子集，优选一个复数子集)的池id’进行比较。例如，UE可使用其当前小区的池id来搜索具有相同池id的其他候选小区频率，并选择这些小区中的具有相同池id的一个小区。需注意，UE在执行其小区选择过程中当然可附加地使用其他标准，诸如接收信号强度等。因此，基于池信息来执行对候选小区的选择包括至少部分地基于池信息来执行选择，即该选择还可基于其他因素。UE然后在828处选择处于与UE之前操作于其中的池相同的MSC池中的即具有其已驻留于其上的小区的相同池id的小区例如小区1。这导致成功的呼叫。During cell selection at 82, the UE then compares the pool id' of the cell it is currently camping on with the pool id' of these potential cells (eg, at least a subset, preferably a plural subset of these potential cells) Compare. For example, the UE may use the pool id of its current cell to search for other candidate cell frequencies with the same pool id and select one of these cells with the same pool id. Note that the UE may of course additionally use other criteria, such as received signal strength, etc. in performing its cell selection procedure. Accordingly, performing the selection of candidate cells based on the pool information includes performing the selection based at least in part on the pool information, ie the selection may also be based on other factors. The UE then selects, at 828, a cell, eg,cell 1, that is in the same MSC pool as the pool in which the UE was previously operating, ie, has the same pool id of the cell it already camped on. This results in a successful call.

因此，概括地说，BSS/RNC向UE广播各个可能候选小区的当前池区域的池区域id’(或可能其他信息诸如MSC地址)。因此，UE事先已从BSS/RNC接收了这些相邻小区的池信息，并且当UE正在执行CSFB操作并且相应UE处于池重叠区域中时，UE使用该信息来选择位于与其当前操作于其中(即其之前所处于)的相同池区域中的小区。位于与之前相同的池中的小区还将共享相同的MSC服务器。这用于防止UE不小心选择另一池区域中的小区并因此使用另一MSC服务器，从而提供CSFB操作的改善的可靠性。换句话讲，这帮助避免在UE选择另一池区域中的小区并因此选择另一MSC服务器的情况下可能导致的呼叫失败。Thus, in summary, the BSS/RNC broadcasts the pool area id' (or possibly other information such as the MSC address) of the current pool area of each possible candidate cell to the UE. Therefore, the UE has previously received the pool information of these neighboring cells from the BSS/RNC, and when the UE is performing CSFB operation and the corresponding UE is in the pool overlap area, the UE uses this information to select the location in which it is currently operating (i.e. cell in the same pool area as it was previously in). Cells located in the same pool as before will also share the same MSC server. This serves to prevent the UE from accidentally selecting a cell in another pool area and thus using another MSC server, thereby providing improved reliability of CSFB operation. In other words, this helps to avoid call failures that might result if the UE selects a cell in another pool area and therefore another MSC server.

图13：第二实施方案Figure 13: Second Embodiment

现在参见图13，现在将参考在图11中所示的流程来描述该方法。如图13所示，假定网络在UE驻留于或操作于分组交换(PS)网络上时接收到要与UE建立CSFB呼叫的移动台被叫(MT)呼叫请求。此类PS网络的一个示例是LTE。在MT呼叫之前，UE驻留在MSC池1上，如图所示。响应于在网络上接收的MT呼叫，MSC p1向基站发出寻呼消息802，该基站然后在803处寻呼UE。如图所示，响应于寻呼消息，UE向基站(eNodeB)传输扩展服务请求(ESR)804，如图所示。Referring now to FIG. 13 , the method will now be described with reference to the flow shown in FIG. 11 . As shown in Figure 13, it is assumed that the network receives a Mobile Station Called (MT) call request to establish a CSFB call with the UE while the UE is camping on or operating on a Packet Switched (PS) network. An example of such a PS network is LTE. Before the MT call, the UE camps on theMSC pool 1 as shown. In response to the MT call received on the network, the MSC p1 sends apaging message 802 to the base station, which then pages the UE at 803. As shown, in response to the paging message, the UE transmits an Extended Service Request (ESR) 804 to the base station (eNodeB), as shown.

基站(eNodeB)然后在826处利用RRC释放进行响应，以将UE从LTE网络释放。来自基站的RRC释放消息826可包括包含UE能驻留于的小区频率的频率列表、以及这些小区频率的对应池id信息。换句话讲，该信息可包括一个或多个绝对射频信道号(ARFCN)，其包括属于两个或更多个不同MSC池的绝对射频信道号(ARFCN)，以及这些小区频率中的每个小区频率的对应池id信息。基站在826处发送的RRC释放消息也可包括用于识别与各个候选小区相关联的MSC服务器或池的其他信息，诸如MSC服务器地址。The base station (eNodeB) then responds at 826 with an RRC release to release the UE from the LTE network. TheRRC release message 826 from the base station may include a frequency list containing cell frequencies on which the UE can camp, and corresponding pool id information for these cell frequencies. In other words, the information may include one or more absolute radio frequency channel numbers (ARFCNs), which include absolute radio frequency channel numbers (ARFCNs) belonging to two or more different MSC pools, and each of these cell frequencies Corresponding pool id information of the cell frequency. The RRC release message sent by the base station at 826 may also include other information identifying the MSC server or pool associated with each candidate cell, such as an MSC server address.

因此，当UE正在执行CSFB操作并且相应UE处于池重叠区域中时，在该实施方案中，基站(eNodeB 102)在826处在RRC消息中向UE广播相邻或候选小区的小区频率和对应池id’。UE在RRC消息中接收来自各个候选小区的小区频率/池id信息，并使用该信息来在828选择位于与其之前所位于的相同池区域中的小区。例如，UE可将各个小区的小区频率/池id信息存储在数据结构中并使用搜索，如上所述。这帮助避免在UE选择另一池区域中的小区并因此由另一MSC服务器服务的情况下可能导致的呼叫失败。换言之，当UE然后执行小区选择时，UE使用其自身的池id以及其他候选小区的池id’来选择属于与其当前正操作于其中的相同池区域的CS小区。这用于防止UE不小心选择另一池区域中的小区，因此防止可能的呼叫失败并提供CSFB操作的改善的可靠性。Thus, when the UE is performing CSFB operation and the corresponding UE is in the pool overlap region, in this embodiment, the base station (eNodeB 102) broadcasts the cell frequency and corresponding pool of the neighbor or candidate cell to the UE in an RRC message at 826 id'. The UE receives the cell frequency/pool id information from each candidate cell in the RRC message and uses this information to select at 828 a cell located in the same pool area as it was located before. For example, the UE may store the cell frequency/pool id information for each cell in a data structure and use a search, as described above. This helps avoid call failures that may result if the UE selects a cell in another pool area and is thus served by another MSC server. In other words, when the UE then performs cell selection, the UE uses its own pool id and the pool ids' of other candidate cells to select CS cells belonging to the same pool area in which it is currently operating. This serves to prevent the UE from accidentally selecting a cell in another pool area, thus preventing possible call failures and providing improved reliability of CSFB operation.

图14-向UE提供信息Figure 14 -Providing information to UE

图14示出了用于向UE提供候选小区的MSC服务器信息的两种不同方法，如上文在图12和图13中所描绘。如上所述，在本文所述的实施方案中，所提供的MSC服务器信息包括池信息，例如每个相应小区的当前池id’。因此，每个小区的池id’被传输给UE，其中在小区选择中使用池id’，如本文所述。Figure 14 shows two different methods for providing the UE with MSC server information of candidate cells, as depicted in Figures 12 and 13 above. As mentioned above, in the embodiments described herein, the provided MSC server information includes pool information, such as the current pool id' for each respective cell. Therefore, the pool id' of each cell is transmitted to the UE, where the pool id' is used in cell selection, as described herein.

在第一实施方案中，其他候选小区的池id’在BSS/RNC广播消息中被传输给UE。如图所示，OAM服务器针对多个候选小区从多个MSC服务器中的每个MSC服务器收集MSC服务器信息(池id信息)和位置区域代码(LAC)。池id信息采用NRI位的形式。因此，从OAM服务器收集的信息例如可采用以下形式：In the first embodiment, the pool ids' of other candidate cells are transmitted to the UE in the BSS/RNC broadcast message. As shown, the OAM server collects MSC server information (pool id information) and location area codes (LAC) from each of the plurality of MSC servers for the plurality of candidate cells. The pool id information is in the form of NRI bits. Thus, the information collected from the OAM server may, for example, take the form of:

MSC池1：NRI 00011，LAC 1和NRI 00013，LAC 2；MSC Pool 1:NRI 00011,LAC 1 andNRI 00013,LAC 2;

MSC池2：NRI 00112，LAC 3；MSC Pool 2:NRI 00112,LAC 3;

MSC池3：NRI 00212，LAC 4；MSC Pool 3:NRI 00212,LAC 4;

OAM服务器然后向相应的一个或多个UE的BSS/RNC服务器提供多个小区的对应池id信息和LAC号，并且实际上可向多个BSS/RNC服务器提供该信息，如图所示。BSS/RNC服务器然后可对每组信息添加附加信息，诸如频率和小区ID。因此，BSS/RNC可生成信息，诸如：The OAM server then provides the corresponding pool id information and LAC number of the plurality of cells to the BSS/RNC server of the corresponding one or more UEs, and may in fact provide this information to the plurality of BSS/RNC servers as shown. The BSS/RNC server may then add additional information, such as frequency and cell ID, to each set of information. Therefore, the BSS/RNC can generate information such as:

BSS/RNC 1：ARFCN 1，NRI 00011，小区ID A，LAC1BSS/RNC 1:ARFCN 1,NRI 00011, Cell ID A, LAC1

BSS/RNC 2：ARFCN 2，NRI 00011，小区ID B，LAC1BSS/RNC 2:ARFCN 2,NRI 00011, Cell ID B, LAC1

BSS/RNC 3：ARFCN 3，NRI 00013，小区ID C，LAC2BSS/RNC 3:ARFCN 3,NRI 00013, Cell ID C, LAC2

BSS/RNC 4：ARFCN 4，NRI 00111，小区ID D，LAC3BSS/RNC 4:ARFCN 4,NRI 00111, Cell ID D, LAC3

BSS/RNC 5：ARFCN 5，NRI 00112，小区ID E，LAC3BSS/RNC 5:ARFCN 5,NRI 00112, Cell ID E, LAC3

BSS/RNC 6：ARFCN 6，NRI 00212，小区ID F，LAC4BSS/RNC 6:ARFCN 6,NRI 00212, Cell ID F, LAC4

BSS/RNC向UE广播这组小区频率/池id信息/小区ID/LAC，如图所示。如图所示，OAM服务器向多个不同的BSS/RNC服务器提供包括各个小区频率和对应池id信息的这组信息，使得该方法可在多个不同的小区区域中实施，即针对由不同BSS/RNC装置服务的UE来实施。The BSS/RNC broadcasts this set of cell frequency/pool id information/cell ID/LAC to the UE, as shown in the figure. As shown in the figure, the OAM server provides this set of information including the frequency of each cell and the corresponding pool id information to a plurality of different BSS/RNC servers, so that the method can be implemented in a plurality of different cell areas, that is, for different BSS/RNC servers. Implemented by the UE served by the /RNC device.

在第二实施方案中，其他候选小区的池id’在RRC释放消息中从基站(eNB)传输给UE。如图所示，OAM服务器针对多个候选小区从多个MSC服务器中的每个MSC服务器收集MSC服务器信息(池id信息)和位置区域代码(LAC)，如上所述，并且将其提供给基站(eNB)。基站然后诸如在RRC释放消息期间并且在CSFB期间来将该信息与小区频率信息一起传输至UE。需注意，在这里，基站可如BSS/RNC那样而不具有小区ID或LAC号信息，并且因此不包括该信息。因此，基站可向UE传输类似如下的信息：In a second embodiment, the pool ids' of other candidate cells are transmitted from the base station (eNB) to the UE in the RRC release message. As shown, the OAM server collects MSC server information (pool id information) and location area code (LAC) from each of the plurality of MSC servers for the plurality of candidate cells, as described above, and provides it to the base station (eNB). The base station then transmits this information together with the cell frequency information to the UE, such as during the RRC release message and during CSFB. Note that here, the base station may not have cell ID or LAC number information like the BSS/RNC, and therefore does not include this information. Therefore, the base station can transmit information similar to the following to the UE:

ARFCN 1，NRI 00011，ARFCN 1,NRI 00011,

ARFCN 2，NRI 00011，ARFCN 2,NRI 00011,

ARFCN 3，NRI 00013，ARFCN 3,NRI 00013,

ARFCN 4，NRI 00111，ARFCN 4,NRI 00111,

ARFCN 5，NRI 00112，ARFCN 5,NRI 00112,

ARFCN6，NRI 00212，ARFCN6,NRI 00212,

如上所述，UE可利用从基站接收的信息来在CSFB期间选择与其当前驻留在其上的池相同的池中(具有相同池id)的小区。As described above, the UE may utilize the information received from the base station to select a cell in the same pool (with the same pool id) during CSFB as it is currently camping on.

以下段落描述了附加实施方案。The following paragraphs describe additional embodiments.

A.一种包含程序指令的非暂态计算机可访问存储器介质，该程序指令用于无线用户设备(UE)装置建立电路交换回退(CSFB)呼叫，其中该程序指令可执行以：A. A non-transitory computer-accessible memory medium containing program instructions for a wireless user equipment (UE) device to establish a circuit-switched fallback (CSFB) call, wherein the program instructions are executable to:

接收以用建立CSFB呼叫的请求，其中UE正操作于具有第一池id的当前池中；receiving a request to establish a CSFB call where the UE is operating in the current pool with the first pool id;

接收多个候选小区中的每个候选小区的池id，其中每个相应候选小区的池id识别相应小区正操作于其中的池；receiving a pool id for each of the plurality of candidate cells, wherein the pool id of each respective candidate cell identifies the pool in which the respective cell is operating;

至少部分地基于第一池id和多个候选小区中的每个候选小区的至少一个复数子集的池id’来选择要驻留在其上的电路交换小区，其中所选择的电路交换小区位于当前池中。selecting a circuit-switched cell to camp on based at least in part on a first pool id and a pool id' of at least a plural subset of each of the plurality of candidate cells, wherein the selected circuit-switched cell is located in in the current pool.

B.一种用于无线用户设备(UE)装置建立电路交换回退(CSFB)呼叫的方法，该方法包括：B. A method for a wireless user equipment (UE) device to establish a circuit switched fallback (CSFB) call, the method comprising:

建立与第一小区的第一无线链路，其中第一小区提供与网络的连接，其中第一小区提供分组交换服务，其中第一小区不提供电路交换服务，其中第一小区位于第一池中；establishing a first radio link with a first cell, wherein the first cell provides a connection to the network, wherein the first cell provides packet-switched services, wherein the first cell does not provide circuit-switched services, wherein the first cell is located in a first pool ;

接收用于建立呼叫的请求；receive a request for establishing a call;

经由第一无线链路来接收源于将呼叫建立成CSFB呼叫的指令，其中该指令指示UE释放与第一小区的第一无线链路并建立与第二小区的第二无线链路；receiving, via the first radio link, an instruction resulting from establishing the call as a CSFB call, wherein the instruction instructs the UE to release the first radio link with the first cell and establish a second radio link with the second cell;

从基站接收池信息，其中该池信息识别与与UE相邻的多个候选小区对应的池；以及receiving pool information from a base station, wherein the pool information identifies a pool corresponding to a plurality of candidate cells adjacent to the UE; and

基于所接收的池信息来选择要驻留在其上的电路交换小区，其中所选择的电路交换小区位于第一池中。A circuit-switched cell to camp on is selected based on the received pool information, wherein the selected circuit-switched cell is located in the first pool.

C.一种用于无线用户设备(UE)装置执行电路交换回退(CSFB)呼叫的方法，该方法包括：C. A method for a wireless user equipment (UE) device to perform a circuit switched fallback (CSFB) call, the method comprising:

由UE执行，performed by the UE,

接收用于建立CSFB呼叫的请求，其中UE正操作于当前池中；receiving a request for establishing a CSFB call, where the UE is operating in the current pool;

从基站接收关于多个候选小区的第一池信息，其中该池信息识别多个候选小区中的每个候选小区的相应池；receiving, from a base station, first pool information about a plurality of candidate cells, wherein the pool information identifies a respective pool of each candidate cell of the plurality of candidate cells;

基于第一池信息来选择要驻留在其上的电路交换小区，其中A circuit-switched cell to camp on is selected based on the first pool information, wherein

所选择的电路交换小区位于当前池中。The selected circuit switched cell is in the current pool.

可通过各种形式中的任一种形式来实现本发明的实施方案。例如，在一些实施方案中，可将本发明实现为计算机实现的方法、计算机可读存储器介质或计算机系统。在其他实施方案中，可使用一个或多个定制设计的硬件装置诸如ASIC来实现本发明。在其他实施方案中，可使用一个或多个可编程硬件元件诸如FPGA来实现本发明。Embodiments of the invention may be implemented in any of a variety of forms. For example, in some embodiments, the present invention can be implemented as a computer-implemented method, computer-readable storage medium, or computer system. In other embodiments, the present invention may be implemented using one or more custom-designed hardware devices, such as ASICs. In other embodiments, the present invention may be implemented using one or more programmable hardware elements, such as an FPGA.

在一些实施方案中，非暂态计算机可读存储器介质可被配置为使得其存储程序指令和/或数据，其中该程序指令如果由计算机系统执行，则使得计算机系统执行一种方法，例如本文所述的方法实施方案中的任一种方法实施方案，或本文所述的方法实施方案的任何组合，或本文所述的任何方法实施方案中的任何子集或此类子集的任何组合。In some embodiments, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and/or data that, if executed by a computer system, cause the computer system to perform a method, such as those described herein Any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

在一些实施方案中，装置(例如，UE)可被配置为包括处理器(或一组处理器)和存储器介质，其中存储器介质存储程序指令，其中该处理器被配置为从该存储器介质中读取并执行该程序指令，其中该程序指令能被执行以实现本文所述的各种方法实施方案中的任一种方法实施方案(或本文所述方法实施方案的任何组合，或本文所述的任何方法实施方案中的任何子集或此类子集的任何组合)。可以各种形式中的任一种形式来实现该装置。In some embodiments, an apparatus (eg, a UE) may be configured to include a processor (or set of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read from the memory medium Fetch and execute the program instructions, wherein the program instructions are executable to implement any one of the various method embodiments described herein (or any combination of the method embodiments described herein, or the any subset of any method embodiment or any combination of such subsets). The apparatus may be implemented in any of a variety of forms.

尽管已相当详细地描述了上述实施方案，但是一旦完全理解了上述公开，许多变型和修改对于本领域的技术人员而言将变得显而易见。本发明旨在使以下权利要求书被解释为涵盖所有此类变型和修改。Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be construed to cover all such variations and modifications.

Claims (20)

1. A method for a wireless user equipment, UE, device to perform a circuit switched fallback, CSFB, call, the method comprising:

performing, by the wireless User Equipment (UE) device:

receiving a request to perform a CSFB operation to process a call, wherein the wireless User Equipment (UE) device is operating in a current pool when the request is received;

receiving pool information identifying a plurality of pools in which each candidate cell of a plurality of candidate cells is operating;

selecting a circuit switched cell to camp on, wherein the circuit switched cell is selected based on the pool information such that the selected circuit switched cell is operating in the current pool; and

performing the CSFB operation with the selected circuit-switched cell to process the call.

2. The method of claim 1, wherein the pool information comprises a pool id for each of the candidate cells.

3. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein said receiving said pool information occurs prior to said receiving said request to perform said CSFB operation.

4. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein the wireless User Equipment (UE) device is operating in a pool overlap region during the receiving the request to perform the CSFB operation and the performing the CSFB operation.

5. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein said receiving said pool information occurs during said performing said CSFB operation.

6. The method of claim 5, wherein the first and second light sources are selected from the group consisting of,

wherein the receiving the pool information comprises receiving the pool information in a Radio Resource Control (RRC) release message from a base station during the CSFB operation.

7. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein for each respective candidate cell of the plurality of candidate cells, the pool information comprises a frequency of the respective candidate cell and a pool id of a pool in which the respective candidate cell is operating;

wherein the selecting the circuit switched cell to camp on comprises selecting the circuit switched cell based on comparing a pool id of the current pool in which the wireless user equipment, UE, device is operating with a pool id' of at least a subset of each of the plurality of candidate cells.

8. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein the pool information comprises, for each candidate cell of the plurality of candidate cells, a cell frequency, a pool id, a cell id, and a location area code.

9. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein the current pool in which the wireless user equipment, UE, device is operating has a first pool-id;

wherein the selecting the circuit switched cell to camp on comprises selecting a first cell frequency of the selected circuit switched cell from a plurality of candidate cell frequencies;

the method further includes storing, by the wireless user equipment, UE, device, the pool information for each candidate cell of the plurality of candidate cells in a data structure, wherein for each candidate cell, the data structure stores a candidate cell frequency and a corresponding pool-id of a pool to which the cell frequency belongs;

wherein the selecting the circuit switched cell to camp on comprises comparing the first pool id to a pool id' in the data structure to select the first cell frequency.

10. A wireless user equipment, UE, device, the wireless user equipment, UE, device comprising:

a radio comprising one or more antennas to perform wireless communication;

a processor;

a memory medium having stored thereon program instructions executable by the processor to:

receiving a request to perform a circuit switched fallback, CSFB, operation to handle a call, wherein the wireless user equipment, UE, device is operating in a current pool when the request is received:

receiving first information, wherein the first information identifies a plurality of pools in which each candidate cell of a plurality of candidate cells is operating;

selecting a circuit switched cell to camp on, wherein the circuit switched cell is selected based on the received first information such that the selected circuit switched cell is operating in the current pool;

performing the CSFB operation with the selected circuit-switched cell to process the call.

11. The wireless user equipment, UE, device of claim 10, wherein the first information includes a plurality of MSC addresses, wherein each of the MSC addresses identifies a respective MSC server for at least one of the plurality of candidate cells;

wherein the circuit switched cell is selected such that the circuit switched cell is served by a current MSC server currently serving the wireless user equipment, UE, device.

12. The wireless user equipment, UE, device of claim 10, wherein the first information comprises pool information for each candidate cell of the plurality of candidate cells;

wherein the circuit switched cell is selected based on the received pool information such that the selected circuit switched cell is located in the same pool as the pool in which the wireless user equipment, UE, device is currently operating.

13. The wireless user equipment, UE, device of claim 10,

wherein the wireless user equipment, UE, device has a current pool-id;

wherein the first information comprises a list of cell frequencies and a corresponding pool id for each of the cell frequencies;

wherein the selecting the circuit switched cell to camp on comprises selecting a cell frequency of the circuit switched cell based on the current pool id of a current pool in which the wireless user equipment, UE, device is operating and a pool id' of each cell of at least a subset of the plurality of cells.

14. The wireless user equipment, UE, device of claim 13,

wherein the memory medium is further configured to store a data structure containing the first information, wherein the data structure stores a cell frequency and a pool id for each of the plurality of cells;

wherein the program instructions are further executable to select the circuit switched cell to camp on by comparing the current pool id to at least one complex subset of pool ids' stored in the data structure.

15. The wireless user equipment, UE, device of claim 10,

wherein the first information is received from a radio network controller.

16. The wireless user equipment, UE, device of claim 10,

wherein the first information is received in a Radio Resource Control (RRC) release message from a base station during the CSFB operation.

17. The wireless user equipment, UE, device of claim 10,

wherein the wireless user equipment UE device is operating in a network that does not support MT roaming Forwarding (MTRF).

18. A base station, comprising:

a radio comprising one or more antennas to perform wireless communication;

a processor;

a memory medium having stored thereon program instructions executable by the base station to:

receiving and storing first information, wherein the first information includes a pool id identifying a plurality of pools in which each cell of a plurality of cells is operating;

sending a request to a first user equipment, UE, device to perform a circuit switched fallback, CSFB, operation to handle a call;

transmitting the first information to the first user equipment, UE, device in a Radio Resource Control (RRC) release message;

wherein the first information is usable by the first user equipment, UE, device to select a circuit switched cell to camp on during the CSFB operation, wherein the circuit switched cell is selected based on the received first information such that the circuit switched cell is located in a same pool in which the first user equipment, UE, device was previously operating.

19. The base station as set forth in claim 18,

wherein the first information comprises a list of cell frequencies and a corresponding pool id'.

20. The base station as set forth in claim 19,

wherein each of the pool ids' is derived from a Network Resource Information (NRI) field obtained from the MSC server.

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