WO2016154880A1

WO2016154880A1 - A method to pull ue back to high speed dedicated network

Info

Publication number: WO2016154880A1
Application number: PCT/CN2015/075466
Authority: WO
Inventors: Congchong Ru; Jie Mao
Original assignee: Qualcomm Incorporated
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2016-10-06
Also published as: WO2016155543A1

Abstract

A method for wireless communication is described. A request is received to establish, at a network node of a first wireless network, a connection with a user equipment (UE). An identity is received of a source network node of a high-speed dedicated wireless network to which the UE was previously connected. The identity is checked against a first neighbor list comprising identifying information for one or more neighbor network nodes of the high-speed dedicated wireless network. A reconfiguration command is sent to the UE to direct the UE to one of the one or more neighbor cells of the high-speed dedicated wireless network if the UE was previously connected to a network node of the high-speed dedicated wireless network.

Description

A METHOD TO PULL UE BACK TO HIGH SPEED DEDICATED NETWORK

BACKGROUND

FIELD OF THE DISCLOSURE

The present disclosure, for example, relates to wireless communication systems, and more particularly to improving wireless mobility in a high-speed dedicated wireless network, such as a high-speed train (HST) wireless network.

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.

By way of example, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs) . A base station may communicate with UEs on downlink channels (e.g., for transmissions from a base station to a UE) and uplink channels (e.g., for transmissions from a UE to a base station) .

A dedicated wireless network may be deployed along a railway to serve the UEs being transported at a high speed, including on a high-speed train (HST) . A HST-dedicated wireless network may be isolated from a nearby non-HST wireless network except at a railway station. As a result of this isolation, the cells of the HST-dedicated wireless network may not be not configured with information concerning the cells in the non-HST wireless network, and the cells of the non-HST wireless network are not configured with information concerning the cells in the HST-dedicated wireless network. During the normal course of operation, it is expected that UEs in the non-HST wireless network may not impact the HST wireless network, and the UEs in the HST-dedicated wireless network may not establish a connection with cells of the non-HST wireless network since the non-HST wireless network is not optimized to handle a scenario where the UEs are traveling at high speed. However, the reference signal received power (RSRP) received by a UE from a cell of the HST-dedicated wireless network and the RSRP received by a UE from a cell of the non-HST wireless network may be similar along certain portions of a high-speed railway. Due to the mobility of a UE, that UE may establish a connection with a cell of the non-HST wireless network. In such case, the UE may not be able to re-establish a connection to the HST-dedicated wireless network if the cells of the non-HST wireless network are not configured with neighbor information for the HST-dedicated wireless network. Performance of the HST-dedicated wireless network and/or the UEs connected to the HST-dedicated wireless network may be diminished because the non-HST wireless network is not configured to handle UEs being transported at a high speed.

SUMMARY

Methods and systems to pull or re-establish a user equipment (UE) to a high-speed dedicated wireless network are disclosed. A high-speed dedicated wireless network, such as a high-speed train (HST) wireless network, may be used for UEs being transported through a high-speed system, such as on a HST. Such UEs may drop off from the HST wireless network in certain circumstances. In systems where the UE is travelling at high speed, it may be desirable to re-establish a wireless link with the HST network quickly due to this high speed. Thus, neighboring network nodes of wireless networks other than the dedicated HST wireless network may maintain both a list of neighbor network nodes (eNodeBs) for the wireless network as well as a separate list that indicates and identifiesneighbor cells and frequencies for neighbor network nodes of the dedicated HST wireless network. Thus, ifa UE that was previously connected with a network node of the HST wireless network sends a re-establishment request to a eNB of the wireless network other than the dedicated HST wireless network, the UE may report to that eNBthe cell identification (ID) and frequency of the network node of the HST wireless network to which it was previously connected. The eNB receiving the re-establishment request may then compare the reported ID and frequency against the separate list of neighbor nodes of the HST wireless network. This neighbor list includes the identifying information for one or more neighbor network nodes of the dedicated HST wireless network. The eNB may also keep a neighbor list for the wireless network to which it belongs that is separate from this list. As a result of the comparison, if the eNB finds that the UE dropped from a network node of the HST wireless network, then the eNB sends a reconfiguration command directly to the UE to direct it back to a frequency of the HST wireless network. In the same message, eNB may also send the UE identifying information for neighboring network nodes of the HST wireless network from the separate list of HST wireless network neighbor nodes, in case the original network node from which the UE dropped is already gone.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purpose of illustration and description only, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present invention may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1 shows a block diagram of a wireless communication system, in accordance with various aspects of the present disclosure；

FIG. 2 shows a block diagram of a wireless communication system, including a high-speed wireless network and a neighboring non-high-speed wireless network, in accordance with various aspects of the present disclosure；

FIG. 3 is a flow chart illustrating an example of a method for wireless communication, in accordance with various aspects of the present disclosure.

FIG. 4 is a flow chart illustrating an example of a method for wireless communication, in accordance with various aspects of the present disclosure.

DESCRIPTION

Methods and systems to pull or re-establish a user equipment (UE) to a high-speed dedicated wireless network are disclosed. A high-speed dedicated wireless network, such as a high-speed train (HST) wireless network, may be used for UEs being transported through a high-speed system, such as on a HST. Such UEs may drop off from the HST wireless network in certain circumstances. In systems where the UE is travelling at high speed, it may be desirable to re-establish a wireless link with the HST network quickly due to this high speed. Thus, neighboring network nodes of wireless networks other than the dedicated HST wireless network may maintain both a list of neighbor network nodes (eNodeBs) for the wireless network as well as a separate list that indicates and identifies neighbor cells and frequencies for neighbor network nodes of the dedicated HST wireless network. Thus, if a UE that was previously connected with a network node of the HST wireless network sends a re-establishment request to a eNB of the wireless network other than the dedicated HST wireless network, the UE may report to that eNB the cell identification (ID) and frequency of the network node of the HST wireless network to which it was previously connected. The eNB receiving the re-establishment request may then compare the reported ID and frequency against the separate list of neighbor nodes of the HST wireless network. This neighbor list includes the identifying information for one or more neighbor network nodes of the dedicated HST wireless network. The eNB may also keep a neighbor list for the wireless network to which it belongs that is separate from this list. As a result of the comparison, if the eNB finds that the UE dropped from a network node of the HST wireless network, then the eNB sends a reconfiguration command directly to the UE to direct it back to a frequency of the HST wireless network. In the same message, eNB may also send the UE identifying information for neighboring network nodes of the HST wireless network from the separate list of HST wireless network neighbor nodes, in case the original network node from which the UE dropped is already gone.

The following description provides examples, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples.

FIG. 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The base stations 105 interface with the core network 130 through backhaul links 132 (e.g., S1, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115, or may operate under the control of a base station controller (not shown) . In various examples, the base stations 105 may communicate, either directly or indirectly (e.g., through core network 130) , with each other over backhaul links 134 (e.g., X1, etc. ) , which may be wired or wireless communication links.

The base stations 105 may wirelessly communicate with the UEs 115 via one or more base station antennas. Each of the base station 105 sites may provide communication coverage for a respective geographic coverage area 110. In some examples, base stations 105 may be referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB (eNB) , Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area 110 for a base station 105 may be divided into sectors making up only a portion of the coverage area (not shown) . The wireless communications system 100 may include base stations 105 of different types (e.g., macro and/or small cell base stations) . There may be overlapping geographic coverage areas 110 for different technologies.

In some examples, the wireless communications system 100is an LTE/LTE-A network. In LTE/LTE-A networks, the term evolved Node B (eNB) may be generally used to describe the base stations 105, while the term UE may be generally used to describe the UEs 115. The wireless communications system 100 may be a Heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographical regions. For example, each eNB or base station 105 may provide communication coverage for a macro cell, a small cell, and/or other types of cell. The term “cell” is a 3GPP term that can be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc. ) of a carrier or base station, depending on context.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell is a lower-powered base station, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell may cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell also may cover a relatively small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers) .

The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

The communication networks that may accommodate some of the various disclosed examples may be packet-based networks that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use Hybrid ARQ (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and the base stations 105 or core network 130 supporting radio bearers for the user plane data. At the Physical (PHY) layer, the transport channels may be mapped to Physical channels.

The UEs 115 are dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also include or be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A UE 115 may be a cellular phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. A UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.

The communication links 125 shown in wireless communications system 100 may include uplink (UL) transmissions from a UE 115 to a base station 105, and/or downlink (DL) transmissions, from a base station 105 to a UE 115. The downlink transmissions may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions. Each communication link 125 may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies) modulated according to the various radio technologies described above. Each modulated signal may be sent on a different sub-carrier and may carry control information (e.g., reference signals, control channels, etc. ) , overhead information, user data, etc. The communication links 125 may transmit bidirectional communications using FDD (e.g., using paired spectrum resources) or TDD operation (e.g., using unpaired spectrum resources) . Frame structures for FDD (e.g., frame structure type 1) and TDD (e.g., frame structure type 2) may be defined.

In some embodiments of the system 100, base stations 105 and/or UEs 115 may include multiple antennas for employing antenna diversity schemes to improve communication quality and reliability between base stations 105 and UEs 115. Additionally or alternatively, base stations 105 and/or UEs 115 may employ multiple-input, multiple-output (MIMO) techniques that may take advantage of multi-path environments to transmit multiple spatial layers carrying the same or different coded data.

Wireless communications system 100 may support operation on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may also be referred to as a component carrier (CC) , a layer, a channel, etc. The terms “carrier, ” “component carrier, ” “cell, ” and “channel” may be used interchangeably herein. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation may be used with both FDD and TDD component carriers.

FIG. 2illustrates the UE 115-a being transported on a high-speed train 215 along high-speed tracks 220, where the UE 115-a communicating 225 with an access point 205 (or base station or eNB) of the HST wireless network, having a coverage area 210. As described above, the UE 115-a may send a request to base station 105-a to re-establish a connection 125-a with base station 105-a after being dropped or otherwise disconnected from base station 205. UE 115-a may report to that base station 105-a the cell identification (ID) and frequency of base station 205 of the HST wireless network to which it was previously connected. Base station 105-a may then compare the reported ID and frequency against the separate list of neighbor nodes of the HST wireless network, and direct UE 115-a back to a frequency of the HST wireless network, which may include base station 205, or another base station of the HST wireless network identified on the separate list of neighbor nodes.

FIG. 3 is a flow chart illustrating an example of a method 300 for wireless communication, in accordance with various aspects of the present disclosure. In some examples, a UE may execute one or more sets of codes to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may perform one or more of the functions described below using special-purpose hardware.

At block 305, the method 300 may include receiving a request to establish, at a network node of a first wireless network, a connection with a user equipment (UE) .

At block 310, the method 300 may include receiving an identity of a source network node of a high-speed dedicated wireless network to which the UE was previously connected.

At block 315, the method 300 may include checking the identity against a first neighbor list comprising identifying information for one or more neighbor network nodes of the high-speed dedicated wireless network.

At block 320, the method 300 may include sending a reconfiguration command to the UE to direct the UE to one of the one or more neighbor cells of the high-speed dedicated wireless network if the UE was previously connected to a network node of the high-speed dedicated wireless network.

Thus, the method 300 may provide for wireless communication. It should be noted that the method 300 is just one implementation and that the operations of the method 300 may be rearranged or otherwise modified such that other implementations are possible.

FIG. 4 is a flow chart illustrating an example of a method 400 for wireless communication, in accordance with various aspects of the present disclosure. In some examples, a access point may execute one or more sets of codes to control the functional elements of the access point to perform the functions described below. Additionally or alternatively, the access point may perform one or more of the functions described below using special-purpose hardware.

At block 405, the method 400 may include sending a request to establish a connection with a network node of a first wireless network.

At block 410, the method 400 may include sending a message from a user equipment (UE) to the network node identifying a network node of a high-speed dedicated wireless network to which the UE was previously connected.

At block 415, the method 400 may include receiving a reconfiguration command directing the UE to re-establish a connection with one of one or more neighbor nodes of the high-speed dedicated wireless network based on the network node of the wireless network checking a neighbor list comprising identifying information for the one or more neighbor nodes of the high-speed dedicated wireless network.

Thus, the method 400 may provide for wireless communication. It should be noted that the method 400 is just one implementation and that the operations of the method 400 may be rearranged or otherwise modified such that other implementations are possible.

In some examples, aspects from two or more of the

methods

300 or 400 may be combined. It should be noted that the

methods

300 and 400 are just example implementations, and that the operations of the

methods

300 and 400 may be rearranged or otherwise modified such that other implementations are possible.

Techniques described herein may be used for various wireless communications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” are often used interchangeably. ACDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , IEEE 802.11 (WiFi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM^TM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over an unlicensed and/or shared bandwidth. The description above, however, describes an LTE/LTE-A system for purposes of example, and LTE terminology is used in much of the description above, although the techniques are applicable beyond LTE/LTE-A applications.

The detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The terms “example” and “exemplary, ” when used in this description, mean “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP) , an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. As used herein, including in the claims, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone； B alone； C alone； A and B in combination； A and C in combination； B and C in combination； or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) .

Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication, comprising:

receiving a request to establish, at a network node of a first wireless network, a connection with a user equipment (UE) ；

receiving an identity of a source network node of a high-speed dedicated wireless network to which the UE was previously connected；

checking the identity against a first neighbor list comprising identifying information for one or more neighbor network nodes of thehigh-speed dedicated wireless network； and

sending a reconfiguration command to the UE to direct the UE to one of the one or more neighbor cells of the high-speed dedicated wireless network if the UE was previously connected to a network node of the high-speed dedicated wireless network.
A method for wireless communication, comprising:

sending a request to establish a connection with a network node of a first wireless network；

sending a message from a user equipment (UE) to the network node identifying a network node of a high-speed dedicated wireless network to which the UE was previously connected； and

receiving a reconfiguration command directing the UE to re-establish a connection with one of one or more neighbor nodes of the high-speed dedicated wireless network based on the network node of the wireless network checking a neighbor list comprising identifying information for the one or more neighbor nodes of the high-speed dedicated wireless network.