TWI682676B - Method for handover based on uplink reference signal and wireless communication system - Google Patents

Method for handover based on uplink reference signal and wireless communication system Download PDF

Info

Publication number
TWI682676B
TWI682676B TW107143956A TW107143956A TWI682676B TW I682676 B TWI682676 B TW I682676B TW 107143956 A TW107143956 A TW 107143956A TW 107143956 A TW107143956 A TW 107143956A TW I682676 B TWI682676 B TW I682676B
Authority
TW
Taiwan
Prior art keywords
base station
user equipment
reference signal
source base
handover
Prior art date
Application number
TW107143956A
Other languages
Chinese (zh)
Other versions
TW202023305A (en
Inventor
葉哲瑋
劉和軒
Original Assignee
中華電信股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中華電信股份有限公司 filed Critical 中華電信股份有限公司
Priority to TW107143956A priority Critical patent/TWI682676B/en
Application granted granted Critical
Publication of TWI682676B publication Critical patent/TWI682676B/en
Publication of TW202023305A publication Critical patent/TW202023305A/en

Links

Images

Landscapes

  • Mobile Radio Communication Systems (AREA)

Abstract

The disclosure provides a method for handover based on uplink reference signal and a wireless communication system. The method includes: receiving, by a source eNB (SeNB) and a target eNB (TeNB), an uplink reference signal (ULRS) from user equipment (UE); determining, by the SeNB and the TeNB, whether a handover triggering event occurs based on the ULRS; in response to the handover triggering event occurs, sending, by the SeNB, a handover command to the UE to control the UE to handover to the TeNB.

Description

基於上行參考信號的換手方法及無線通訊系統Handover method and wireless communication system based on uplink reference signal

本發明是有關於一種換手機制及無線通訊系統,且特別是有關於一種基於上行參考信號的換手方法及無線通訊系統。The invention relates to a mobile phone changing system and a wireless communication system, and particularly relates to a handover method and a wireless communication system based on an uplink reference signal.

請參照圖1,其是習知的換手機制示意圖。如圖1所示,在現有通訊系統中,當基地台與使用者設備(user equipment,UE)處於連接(connected)狀態時,系統可能會隨著UE的移動而採取基於下行參考信號(downlink reference signal,DLRS)的換手機制。具體而言,在此機制中,UE接收並量測來自來源基地台(Source eNN,SeNB)以及目標基地台(Target eNB,TeNB)的下行參考訊號。Please refer to FIG. 1, which is a schematic diagram of a conventional mobile phone change system. As shown in FIG. 1, in the existing communication system, when the base station and the user equipment (UE) are in a connected state, the system may adopt a downlink reference signal (downlink reference signal) as the UE moves signal, DLRS). Specifically, in this mechanism, the UE receives and measures the downlink reference signals from the source base station (Source eNN, SeNB) and the target base station (Target eNB, TeNB).

若出現滿足某條件(例如TeNB的信號品質高於SeNB的信號品質超過一閾值)的觸發事件,且此條件維持達觸發時間(time-to-trigger,TTT)),則UE可發送測量報告(measurement report)給SeNB,以讓SeNB據以決定UE是否要執行換手。若SeNB決定須換手,則SeNB向TeNB發送換手請求(Handover request,HO request),而在TeNB收到換手請求後,可根據自身可用資源判斷是否准許換手。若TeNB准許換手,則可回覆HO回應(HO response)給SeNB,並於其中附加換手過程中所需的相關換手資訊(例如RACH可用通道)。在SeNB收到HO回應後,可將其中的換手資訊附於HO命令(HO command)中並傳給UE。If a trigger event occurs that meets a certain condition (for example, the signal quality of TeNB is higher than the signal quality of SeNB exceeds a threshold), and this condition is maintained for a trigger time (time-to-trigger, TTT)), the UE may send a measurement report ( measurement report) to the SeNB, so that the SeNB can decide whether the UE should perform handover. If the SeNB decides to change hands, the SeNB sends a handover request (HO request) to the TeNB, and after the TeNB receives the handover request, it can determine whether to allow the handover according to its own available resources. If the TeNB approves the handover, it can reply the HO response to the SeNB, and attach the relevant handover information required during the handover process (eg RACH available channel). After the SeNB receives the HO response, it can attach the handover information to the HO command and transmit it to the UE.

從SeNB收到測量報告開始,直到SeNB發送HO命令為止的流程可被定義為HO準備(HO preparation)。在UE收到HO命令後會對TeNB進行同步以及執行RACH流程。在UE連接上TeNB後,TeNB會將可用的上行(uplink,UL)資源透過UL分配的程序分配給UE,UE再回覆HO完成(HO complete)以告知TeNB,換手即完成。The flow from when the SeNB receives the measurement report until the SeNB sends the HO command can be defined as HO preparation. After the UE receives the HO command, it synchronizes the TeNB and executes the RACH procedure. After the UE connects to the TeNB, the TeNB will allocate the available uplink (UL) resources to the UE through the UL allocation procedure, and the UE will reply HO complete to inform the TeNB that the handover is completed.

然而,由於在發送測量報告之前需等待TTT,此不僅延遲了HO完成的時間點,更可能因為SeNB的信號品質已過度低落而降低HO的成功機率。However, since it is necessary to wait for the TTT before sending the measurement report, this not only delays the time point at which the HO is completed, it is also more likely to reduce the probability of HO's success because the signal quality of the SeNB has excessively deteriorated.

有鑑於此,本發明提出一種基於上行參考信號(uplink reference signal,ULRS)的換手機制及無線通訊系統,其可用以解決上述技術問題。In view of this, the present invention proposes a handover mechanism and wireless communication system based on uplink reference signal (ULRS), which can be used to solve the above technical problems.

本發明提供一種基於上行參考信號的換手方法,適於包括一使用者設備、一來源基地台及一目標基地台的一無線通訊系統,所述方法包括:由來源基地台及目標基地台接收來自使用者設備的一上行參考信號,其中上行參考信號專屬於使用者設備;由來源基地台及目標基地台基於上行參考信號判斷是否發生一換手觸發事件;以及反應於發生換手觸發事件,由來源基地台發送一換手命令至使用者設備,以控制使用者設備換手至目標基地台。The present invention provides a handover method based on an uplink reference signal, which is suitable for a wireless communication system including a user equipment, a source base station, and a target base station. The method includes: receiving by the source base station and the target base station An uplink reference signal from the user equipment, where the uplink reference signal is exclusive to the user equipment; the source base station and the target base station determine whether a handover trigger event occurs based on the uplink reference signal; and in response to the handover trigger event, The source base station sends a handover command to the user equipment to control the user equipment to handover to the target base station.

本發明提供一種無線通訊系統,包括使用者設備、來源基地台及目標基地台。使用者設備發送一上行參考信號,其中上行參考信號專屬於使用者設備。來源基地台服務使用者設備,並接收來自使用者設備的上行參考信號。目標基地台連接來源基地台,並接收來自使用者設備的上行參考信號。來源基地台及目標基地台基於上行參考信號判斷是否發生一換手觸發事件。反應於發生換手觸發事件,來源基地台發送一換手命令至使用者設備,以控制使用者設備換手至目標基地台。The invention provides a wireless communication system, including user equipment, a source base station and a target base station. The user equipment sends an uplink reference signal, where the uplink reference signal is dedicated to the user equipment. The source base station serves the user equipment and receives the uplink reference signal from the user equipment. The target base station connects to the source base station and receives the uplink reference signal from the user equipment. The source base station and the target base station determine whether a handover trigger event occurs based on the uplink reference signal. In response to the handover triggering event, the source base station sends a handover command to the user equipment to control the user equipment to handover to the target base station.

基於上述,本發明提出的基於上行參考信號的換手方法及無線通訊系統可讓UE發送專屬的ULRS至SeNB及TeNB,以讓SeNB及TeNB即時地測量並交換ULRS的信號強度。當發生換手觸發事件時,SeNB及TeNB可提早進行HO準備,進而能夠改善UE換手至TeNB的效率及成功機率。Based on the above, the handover method based on the uplink reference signal and the wireless communication system proposed by the present invention allow the UE to send dedicated ULRS to SeNB and TeNB, so that SeNB and TeNB can measure and exchange ULRS signal strength in real time. When a handover triggering event occurs, SeNB and TeNB can make HO preparation earlier, which can improve the efficiency and probability of success of UE handover to TeNB.

為讓本發明的上述特徵和優點能更明顯易懂,下文特舉實施例,並配合所附圖式作詳細說明如下。In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

本發明中的增強型節點「eNodeB」或「eNB」可為例如基站(BS)、節點-B、高級基站(advanced base station,ABS)、基站收發系統(base transceiver system,BTS)、接入點、歸屬基站(home base station)、中繼站(relay station)、散射器(scatterer)、轉發器(repeater)、中間節點、仲介以及/或者基於衛星的通信基站及其類似物。The enhanced node "eNodeB" or "eNB" in the present invention may be, for example, a base station (BS), a node-B, an advanced base station (ABS), a base transceiver system (BTS), an access point , Home base station (home base station), relay station (relay station), scatterer (scatterer), repeater (repeater), intermediate node, intermediary and/or satellite-based communication base station and the like.

本發明中的術語「使用者設備」(UE)可為例如移動台、高級移動台(advanced mobile station,AMS)、伺服器、用戶端、桌上型電腦、膝上型電腦、網路電腦、工作站、個人數位助理(personal digital assistant,PDA)、平板個人電腦(personal computer,PC)、掃描器、電話裝置、尋呼機、照相機、電視、掌上型視頻遊戲裝置、音樂裝置、無線感測器及其類似物。在一些應用中,UE可以是在例如公共汽車、火車、飛機、船舶、汽車及其類似物的移動環境中操作的固定的電腦裝置。The term “user equipment” (UE) in the present invention may be, for example, a mobile station, advanced mobile station (AMS), server, client, desktop computer, laptop computer, network computer, Workstation, personal digital assistant (PDA), tablet personal computer (PC), scanner, telephone device, pager, camera, TV, handheld video game device, music device, wireless sensor and their analog. In some applications, the UE may be a fixed computer device operating in a mobile environment such as a bus, train, airplane, ship, automobile, and the like.

請參照圖2,其是依據本發明之一實施例繪示的無線通訊系統示意圖。如圖2所示,無線通訊系統200包括UE 21、SeNB 22及TeNB 23,其中SeNB 22服務UE 21,而TeNB 23可透過回程(backhaul)網路連接至SeNB 22。Please refer to FIG. 2, which is a schematic diagram of a wireless communication system according to an embodiment of the present invention. As shown in FIG. 2, the wireless communication system 200 includes a UE 21, a SeNB 22, and a TeNB 23, where the SeNB 22 serves the UE 21, and the TeNB 23 can be connected to the SeNB 22 through a backhaul network.

依據LTE通信標準,無線通訊系統至少包含一個eNB,例如SeNB 22及TeNB 23。各eNB與至少一個UE(例如UE 21)通信。每個UE含有例如至少一個收發器電路、一個天線、類比數位(analog-to-digital,A/D)及數位類比(digital-to-analog,D/C)轉換器,以及一個處理電路。收發器電路能夠以無線的方式發射上行鏈路信號以及/或者接收下行鏈路信號。收發器電路也可執行例如低雜訊放大、阻抗匹配、混頻、向上或向下頻率轉換、濾波、放大以及類似的操作。收發器電路還包含天線單元。類比數位及數位類比轉換器經配置以在下行鏈路信號處理期間將類比信號格式轉換為數位信號格式,並在上行鏈路信號處理期間將數位信號格式轉換為類比信號格式。處理電路經配置以處理數位信號並執行依據本發明的示範性實施例的針對資料發射所提出的方法的程式。此外,處理電路可包含記憶體電路,用以存儲資料或記錄由eNB指派的配置。eNB含有類似元件,包含收發器單元、天線和類比數位(analog-to-digital,A/D)及數位類比(digital-to-analog,D/C)轉換器,這使得經轉換的數位信號由其處理電路處理,並且使用記憶體電路,從而實施依據本發明的示範性實施例的方法。According to the LTE communication standard, the wireless communication system includes at least one eNB, such as SeNB 22 and TeNB 23. Each eNB communicates with at least one UE (eg, UE 21). Each UE contains, for example, at least one transceiver circuit, an antenna, analog-to-digital (A/D) and digital-to-analog (D/C) converters, and a processing circuit. The transceiver circuit can wirelessly transmit uplink signals and/or receive downlink signals. The transceiver circuit can also perform operations such as low noise amplification, impedance matching, frequency mixing, up or down frequency conversion, filtering, amplification, and the like. The transceiver circuit also contains an antenna unit. The analog digital and digital analog converters are configured to convert the analog signal format to a digital signal format during downlink signal processing and convert the digital signal format to an analog signal format during uplink signal processing. The processing circuit is configured to process digital signals and execute the program of the proposed method for data transmission according to an exemplary embodiment of the present invention. In addition, the processing circuit may include a memory circuit for storing data or recording the configuration assigned by the eNB. The eNB contains similar components, including transceiver units, antennas, and analog-to-digital (A/D) and digital-to-analog (D/C) converters, which makes the converted digital signal from Its processing circuit processes and uses a memory circuit to implement the method according to the exemplary embodiment of the present invention.

請參照圖3,其是依據本發明之一實施例繪示的上行參考信號的換手方法流程圖。本實施例的方法可由所示的無線通訊系統200執行,以下將搭配圖2所示的元件說明圖3各步驟的細節。Please refer to FIG. 3, which is a flowchart of a handover method of an uplink reference signal according to an embodiment of the invention. The method of this embodiment can be performed by the wireless communication system 200 shown. The details of each step in FIG. 3 will be described below with the components shown in FIG. 2.

首先,在步驟S310中,SeNB 22及TeNB 23可接收來自UE 21的ULRS S1,而ULRS S1可專屬於UE 21。在一實施例中,SeNB 22可為UE 21分配一獨特的通訊資源,因而使得SeNB 22及TeNB 23在透過上述獨特的通訊資源接收到ULRS S1時,即可辨識出ULRS S1係來自於UE 21,但本發明可不限於此。First, in step S310, SeNB 22 and TeNB 23 may receive ULRS S1 from UE 21, and ULRS S1 may be dedicated to UE 21. In an embodiment, SeNB 22 may allocate a unique communication resource to UE 21, so that when SeNB 22 and TeNB 23 receive ULRS S1 through the unique communication resource, they can recognize that ULRS S1 is from UE 21 However, the present invention may not be limited to this.

之後,在步驟S320中,SeNB 22及TeNB 23可基於ULRS S1判斷是否發生換手觸發事件。在一實施例中,在SeNB 22接收到來自UE 21的ULRS之後,SeNB 22可測量此ULRS的第一信號強度,並將第一信號強度發送至TeNB 23。相似地,在TeNB 23接收到來自UE 21的ULRS之後,TeNB 23可測量此ULRS的第二信號強度,並將第二信號強度發送至SeNB 22。簡言之,SeNB 22及TeNB 23可在個別測量UE 21的ULRS的信號強度之後,將所測得的信號強度透過後端網路(例如Xn介面)告知對方。在一實施例中,若第二信號強度高於第一信號強度達預設門限值,則SeNB 22及TeNB 23可判斷發生換手觸發事件,但本發明可不限於此。Thereafter, in step S320, SeNB 22 and TeNB 23 may determine whether a handover trigger event occurs based on ULRS S1. In an embodiment, after the SeNB 22 receives the ULRS from the UE 21, the SeNB 22 may measure the first signal strength of the ULRS and send the first signal strength to the TeNB 23. Similarly, after the TeNB 23 receives the ULRS from the UE 21, the TeNB 23 may measure the second signal strength of this ULRS and send the second signal strength to the SeNB 22. In short, after measuring the signal strength of the ULRS of the UE 21 separately, the SeNB 22 and the TeNB 23 can inform the other party of the measured signal strength through the back-end network (such as the Xn interface). In an embodiment, if the second signal strength is higher than the first signal strength by a preset threshold, the SeNB 22 and the TeNB 23 can determine that a handover trigger event occurs, but the present invention is not limited thereto.

之後,在步驟S330中,反應於發生換手觸發事件,SeNB 22可發送換手命令至UE 21,以控制UE 21換手至TeNB 23。在一實施例中,假設SeNB 22及TeNB 23在第一時間點判斷發生換手觸發事件,則SeNB 22及TeNB 23可在第二時間點開始執行一提前準備(pre-preparation)換手操作,其中該第二時間點與該第一時間點之間的一時間差小於觸發時間(即,TTT)。Thereafter, in step S330, in response to the occurrence of a handover trigger event, the SeNB 22 may send a handover command to the UE 21 to control the UE 21 to handover to the TeNB 23. In an embodiment, assuming that SeNB 22 and TeNB 23 determine that a handover trigger event occurs at the first time point, SeNB 22 and TeNB 23 may start a pre-preparation handover operation at the second time point, A time difference between the second time point and the first time point is less than the trigger time (ie, TTT).

在一實施例中,上述提供準備換手操作可包括由SeNB 22發送HO請求至TeNB 23,並由TeNB 23反應於HO請求而回傳HO回應至SeNB 22。相關細節可參照圖1的說明,於此不另贅述。In one embodiment, the above-mentioned preparation for handover operation may include the SeNB 22 sending the HO request to the TeNB 23, and the TeNB 23 responding to the HO request and returning the HO response to the SeNB 22. Relevant details can refer to the description of FIG. 1 and will not be repeated here.

藉此,可讓UE 21因不需另行產生測量報告而較早地換手至TeNB 23。為彰顯本發明的有利效果,以下另輔以圖4作進一步說明。In this way, the UE 21 can switch to the TeNB 23 earlier because there is no need to generate another measurement report. In order to highlight the advantageous effects of the present invention, the following is supplemented by FIG. 4 for further explanation.

請參照圖4,其是習知作法與本發明方法的比較圖。在圖4中,上半部係經由習知作法進行的換手機制,而下半部係基於本發明提出的方法所進行的換手機制。Please refer to FIG. 4, which is a comparison diagram of the conventional method and the method of the present invention. In FIG. 4, the upper half is a mobile phone swapping mechanism performed by a conventional method, and the lower half is a mobile phone swapping mechanism based on the method proposed by the present invention.

如圖4所示,在習知作法中,在發生換手觸發事件之後需先等待TTT再發送測量報告,並接著開始HO準備。然而,在本發明的方法中,由於SeNB及TeNB不需等待來自UE的測量報告,而可在判斷發生換手觸發事件(發生於第一時間點T1)之後,隨即在第二時間點T2開始HO準備。由圖4可看出,由於第二時間點T2與第一時間點T1之間的時間差小於TTT,因而可讓UE的換手機制提早完成,從而增加換手的效率。As shown in FIG. 4, in the conventional method, after a handover trigger event occurs, it is necessary to wait for TTT before sending a measurement report, and then start HO preparation. However, in the method of the present invention, since the SeNB and the TeNB do not need to wait for the measurement report from the UE, they can immediately start at the second time point T2 after judging that the handover triggering event (occurring at the first time point T1) occurs. HO ready. It can be seen from FIG. 4 that since the time difference between the second time point T2 and the first time point T1 is less than TTT, the mobile phone switching mechanism of the UE can be completed earlier, thereby increasing the efficiency of the switching.

並且,由圖4還可看出,在習知作法中,執行HO時的第一信號強度已過於低落,因此將會影響到HO的成功機率。並且,UE所傳送的測量報告還可能會丟失。然而,在本發明提出的方法中,執行HO時的第一信號強度較高,且不需考慮測量報告,因而可達到較高的HO成功機率。In addition, as can be seen from FIG. 4, in the conventional method, the first signal strength when performing HO is already too low, so it will affect the success probability of HO. In addition, the measurement report transmitted by the UE may be lost. However, in the method proposed by the present invention, the first signal strength when performing HO is high, and the measurement report does not need to be considered, so a high probability of HO success can be achieved.

此外,本發明實施例還提出可讓UE適時地切換為以DLRS作為執行換手操作的依據的切換機制(下稱第一切換機制),藉以節省ULRS所耗用的通訊資源。概略而言,在不同的實施例中,上述第一切換機制可包括:由UE或SeNB判斷是否發生第一參考信號切換事件;以及反應於發生第一參考信號切換事件,SeNB可控制UE切換為以來自SeNB的DLRS為執行換手操作的依據。以下將分別輔以圖5A及圖5B作進一步說明。In addition, the embodiments of the present invention also propose a switching mechanism (hereinafter referred to as a first switching mechanism) that allows the UE to switch to the DLRS as the basis for performing the handover operation in a timely manner, so as to save the communication resources consumed by the ULRS. In summary, in different embodiments, the above-mentioned first handover mechanism may include: the UE or the SeNB determines whether a first reference signal handover event occurs; and in response to the occurrence of the first reference signal handover event, the SeNB may control the UE to hand over to The DLRS from the SeNB is used as the basis for performing the handover operation. The following will be supplemented by FIG. 5A and FIG. 5B for further explanation.

請參照圖5A,其是依據本發明之一實施例繪示的以UE主導第一切換機制的示意圖。如圖5A所示,UE 21可(週期性地)傳送ULRS予SeNB 22。在本實施例中,UE 21可儲存有自身的一換手記錄。在此情況下,UE 21可依據此換手記錄判斷UE 21是否在一預設時間內不會執行換手操作。若是,則UE 21可判斷發生第一參考信號切換事件,並相應地向SeNB 22發出第一參考信號切換請求,以請求SeNB 22控制UE 21切換為以DLRS作為執行換手操作的依據。亦即,若UE 21判斷自己在短時間內不會進行換手操作,則可要求SeNB 22控制UE 21切換為以DLRS作為執行換手操作的依據,藉以節省用於傳送ULRS的通訊資源。Please refer to FIG. 5A, which is a schematic diagram illustrating that the first handover mechanism is dominated by the UE according to an embodiment of the present invention. As shown in FIG. 5A, the UE 21 may (periodically) transmit ULRS to the SeNB 22. In this embodiment, the UE 21 may store its own hand-off record. In this case, the UE 21 can determine whether the UE 21 will not perform the handover operation within a preset time according to the handover record. If yes, the UE 21 may determine that a first reference signal switching event has occurred, and accordingly send a first reference signal switching request to the SeNB 22 to request the SeNB 22 to control the UE 21 to switch to DLRS as a basis for performing a handover operation. That is, if the UE 21 determines that it will not perform a handover operation in a short time, it may request the SeNB 22 to control the UE 21 to switch to use DLRS as the basis for performing the handover operation, thereby saving communication resources for transmitting ULRS.

相應地,SeNB 22可發送第一控制信號至UE 21,以通知UE 21準備接收DLRS。在一實施例中,若UE 21處於累計TTT的階段,則SeNB 22可在第一控制信號中附加當下TTT的值。並且,SeNB 22還可釋放ULRS對應的通訊資源。Accordingly, the SeNB 22 may send the first control signal to the UE 21 to notify the UE 21 that it is ready to receive DLRS. In an embodiment, if the UE 21 is in the stage of accumulating TTT, the SeNB 22 may append the current TTT value to the first control signal. In addition, SeNB 22 can also release the communication resources corresponding to ULRS.

在UE 21收到第一控制信號之後,可反應於第一控制信號回傳第一確收訊息至SeNB 22。接著,SeNB 22可反應於第一確收訊息而(週期性地)發送DLRS。After the UE 21 receives the first control signal, it may respond to the first control signal and send back the first confirmation message to the SeNB 22. Then, SeNB 22 may (periodically) send DLRS in response to the first acknowledgement message.

請參照圖5B,其是依據本發明之一實施例繪示的以SeNB主導第一切換機制的示意圖。如圖5B所示,UE 21可(週期性地)傳送ULRS予SeNB 22。接著,SeNB 22可判斷UE 21的換手頻率是否低於頻率門限值。若是,SeNB 22可判斷發生第一參考信號切換事件,並相應地控制UE 21切換為以DLRS作為執行換手操作的依據。亦即,SeNB 22可在判斷UE 21較不常進行換手操作之後,相應地控制UE 21切換為以DLRS作為執行換手操作的依據,藉以節省用於傳送ULRS的通訊資源。Please refer to FIG. 5B, which is a schematic diagram illustrating that the first handover mechanism is dominated by SeNB according to an embodiment of the present invention. As shown in FIG. 5B, the UE 21 may (periodically) transmit ULRS to the SeNB 22. Next, the SeNB 22 may determine whether the handover frequency of the UE 21 is lower than the frequency threshold. If so, the SeNB 22 may determine that the first reference signal switching event occurs, and accordingly control the UE 21 to switch to use DLRS as a basis for performing the handover operation. That is, after judging that the UE 21 is less frequently performing the handover operation, the SeNB 22 can correspondingly control the UE 21 to switch to the DLRS as a basis for performing the handover operation, thereby saving communication resources for transmitting ULRS.

相應地,SeNB 22可發送第一控制信號至UE 21,以通知UE 21準備接收DLRS。在一實施例中,若UE 21處於累計TTT的階段,則SeNB 22可在第一控制信號中附加當下TTT的值。並且,SeNB 22還可釋放ULRS對應的通訊資源。Accordingly, the SeNB 22 may send the first control signal to the UE 21 to notify the UE 21 that it is ready to receive DLRS. In an embodiment, if the UE 21 is in the stage of accumulating TTT, the SeNB 22 may append the current TTT value to the first control signal. In addition, SeNB 22 can also release the communication resources corresponding to ULRS.

在UE 21收到第一控制信號之後,可反應於第一控制信號回傳第一確收訊息至SeNB 22。接著,SeNB 22可反應於第一確收訊息而(週期性地)發送DLRS。在一實施例中,若SeNB 22在等待一段時間後仍未接收到第一確收訊息,則SeNB 22可再次發送第一控制信號至UE 21,但本發明可不限於此。After the UE 21 receives the first control signal, it may respond to the first control signal and send back the first confirmation message to the SeNB 22. Then, SeNB 22 may (periodically) send DLRS in response to the first acknowledgement message. In an embodiment, if the SeNB 22 does not receive the first acknowledgement message after waiting for a period of time, the SeNB 22 may send the first control signal to the UE 21 again, but the present invention is not limited thereto.

此外,本發明實施例還提出可讓UE適時地切換為以ULRS作為執行換手操作的依據的切換機制(下稱第二切換機制),藉以讓具較高移動性或較常換手的UE以較佳的效率進行幹手操作。概略而言,在不同的實施例中,上述第二切換機制可包括:由SeNB發送DLRS至UE,其中DLRS為UE執行一換手操作的依據;由UE或SeNB判斷是否發生第二參考信號切換事件 ;以及反應於發生第二參考信號切換事件,由SeNB評估是否允許UE切換為以ULRS作為執行換手操作的依據;若是,控制UE切換為以ULRS作為執行換手操作的依據。以下將分別輔以圖6A及圖6B作進一步說明。In addition, the embodiments of the present invention also provide a switching mechanism (hereinafter referred to as a second switching mechanism) that allows UEs to switch to ULRS as a basis for performing handover operations in a timely manner, so as to allow UEs with higher mobility or more frequent handovers Dry hands with better efficiency. In summary, in different embodiments, the second handover mechanism may include: the SeNB sends a DLRS to the UE, where the DLRS is the basis for the UE to perform a handover operation; the UE or the SeNB determines whether the second reference signal handover occurs Event; and in response to the occurrence of the second reference signal switching event, the SeNB evaluates whether the UE is allowed to switch to use ULRS as the basis for performing the handover operation; if so, the UE is controlled to switch to use ULRS as the basis for performing the handover operation. The following will be supplemented by FIG. 6A and FIG. 6B for further explanation.

請參照圖6A,其是依據本發明之一實施例繪示的以UE主導第二切換機制的示意圖。如圖6A所示,SeNB 22可(週期性地)發送DLRS至UE 21。在本實施例中,UE 21可判斷DLRS的一信號品質的一下降速度是否高於第一門限值或持續低於第二門限值達一預設時間。若是,UE 21可判斷發生第二參考信號切換事件,並向SeNB 22發出第二參考信號切換請求,以請求SeNB 22控制UE 21切換為以ULRS作為執行換手操作的依據。在不同的實施例中,DLRS的信號品質可能會因UE 21的高速移動而產生品質不佳的情況,因此UE 21可在判斷發生第二參考信號切換事件後,向SeNB 22要求切換為以ULRS作為執行換手操作的依據,藉以達到較佳的換手操作效率及成功率。Please refer to FIG. 6A, which is a schematic diagram illustrating that the second handover mechanism is dominated by the UE according to an embodiment of the present invention. As shown in FIG. 6A, SeNB 22 may (periodically) send DLRS to UE 21. In this embodiment, the UE 21 can determine whether a rate of decrease in a signal quality of the DLRS is higher than the first threshold or continuously lower than the second threshold for a preset time. If yes, the UE 21 may determine that a second reference signal switching event has occurred, and send a second reference signal switching request to the SeNB 22 to request the SeNB 22 to control the UE 21 to switch to ULRS as the basis for performing the handover operation. In different embodiments, the signal quality of the DLRS may be poor due to the high-speed movement of the UE 21, so the UE 21 may request the SeNB 22 to switch to ULRS after judging that the second reference signal switching event occurs As a basis for performing a hand-over operation, in order to achieve a better hand-over operation efficiency and success rate.

相應地,SeNB 22可發送第二控制信號至UE 21,其中第二控制信號包括ULRS對應的通訊資源。亦即,SeNB 22可為UE 21安排專用於發送ULRS的通訊資源。在一實施例中,在SeNB 22收到第二參考信號切換請求之後,SeNB 22可評估現有可用的ULRS數量是否足以讓UE 21切換為以ULRS作為執行換手操作的依據。若尚有ULRS資源,則SeNB 22可發送第二控制信號至UE 21,反之則SeNB 22可發送一拒絕信號至UE 21,以告知UE 21無法使用ULRS,但本發明可不限於此。Accordingly, the SeNB 22 may send a second control signal to the UE 21, where the second control signal includes the communication resource corresponding to the ULRS. That is, the SeNB 22 may arrange communication resources dedicated to transmitting ULRS for the UE 21. In an embodiment, after the SeNB 22 receives the second reference signal switching request, the SeNB 22 may evaluate whether the number of available ULRSs is sufficient for the UE 21 to switch to use ULRSs as the basis for performing the handover operation. If there are still ULRS resources, SeNB 22 may send a second control signal to UE 21, otherwise SeNB 22 may send a rejection signal to UE 21 to inform UE 21 that ULRS cannot be used, but the invention may not be limited to this.

之後,UE 21可反應於第二控制信號而回傳第一回應至SeNB 22,並在之後(週期性地)發送ULRS。在一實施例中,上述第一回應可包括UE 21當下的TTT記錄。相應地,SeNB 22可反應於第一回應而(週期性地)接收ULRS。After that, the UE 21 may respond to the second control signal and return the first response to the SeNB 22, and then (periodically) transmit the ULRS. In an embodiment, the first response may include the current TTT record of the UE 21. Accordingly, SeNB 22 may (periodically) receive ULRS in response to the first response.

請參照圖6B,其是依據本發明之一實施例繪示的以SeNB主導第二切換機制的示意圖。如圖6A所示,SeNB 22可(週期性地)發送DLRS至UE 21。由SeNB 22判斷UE 21的一換手頻率是否高於一頻率門限值。若是,SeNB 22可判斷發生第二參考信號切換事件,並控制UE 21切換為以ULRS作為執行換手操作的依據。亦即,SeNB 22可在判斷UE 21因高移動性等原因而頻繁進行換手操作之後,將UE 21切換為以ULRS作為執行換手操作的依據,藉以達到較佳的換手操作效率及成功率。Please refer to FIG. 6B, which is a schematic diagram of the second handover mechanism dominated by SeNB according to an embodiment of the present invention. As shown in FIG. 6A, SeNB 22 may (periodically) send DLRS to UE 21. SeNB 22 determines whether a handover frequency of UE 21 is higher than a frequency threshold. If so, the SeNB 22 can determine that the second reference signal switching event occurs, and control the UE 21 to switch to ULRS as the basis for performing the handover operation. That is, after judging that UE 21 frequently performs handover operations due to high mobility and other reasons, SeNB 22 can switch UE 21 to use ULRS as a basis for performing handover operations, so as to achieve better handover operation efficiency and success rate.

之後,SeNB 22可發送第二控制信號至UE 21,其中第二控制信號包括ULRS對應的通訊資源。亦即,SeNB 22可為UE 21安排專用於發送ULRS的通訊資源。接著,UE 21可反應於第二控制信號而回傳第一回應至SeNB 22,並在之後(週期性地)發送ULRS。在一實施例中,上述第一回應可包括UE 21當下的TTT記錄。在另一實施例中,若SeNB 22在等待一段時間後仍未從UE 21接收到第一回應,則SeNB 22可再次發送第二控制信號至UE 21,但本發明可不限於此。相應地,SeNB 22可反應於第一回應而(週期性地)接收ULRS。After that, the SeNB 22 may send a second control signal to the UE 21, where the second control signal includes the communication resource corresponding to the ULRS. That is, the SeNB 22 may arrange communication resources dedicated to transmitting ULRS for the UE 21. Then, the UE 21 may return the first response to the SeNB 22 in response to the second control signal, and then (periodically) transmit the ULRS. In an embodiment, the first response may include the current TTT record of the UE 21. In another embodiment, if the SeNB 22 does not receive the first response from the UE 21 after waiting for a period of time, the SeNB 22 may send the second control signal to the UE 21 again, but the present invention is not limited thereto. Accordingly, SeNB 22 may (periodically) receive ULRS in response to the first response.

在一些實施例中,由於可用於傳送ULRS的通訊資源有限,因此本發明更提出一篩選機制,其可用以從多個UE中找出較適合以ULRS作為執行換手操作的依據的一或多者。In some embodiments, due to the limited communication resources available for transmitting ULRS, the present invention further proposes a screening mechanism that can be used to find one or more UEs that are more suitable for performing handover operations based on ULRS from multiple UEs By.

請參照圖7,其是依據本發明之一實施例繪示的挑選採用ULRS的使用者設備的流程圖。在本實施例中,假設SeNB服務U個第一UE,而這些第一UE皆使用對應的DLRS作為執行換手操作的依據。Please refer to FIG. 7, which is a flowchart of selecting user equipment using ULRS according to an embodiment of the present invention. In this embodiment, it is assumed that the SeNB serves U first UEs, and these first UEs all use corresponding DLRSs as the basis for performing the handover operation.

在步驟S710中,SeNB可將第一UE區分為R個第二UE及(U-R)個第三UE,並控制第二UE個別切換為使用對應的ULRS作為執行換手操作的依據。在本實施例中,所述R個第二UE可由SeNB從所述U個第一UE中隨機挑選,但本發明可不限於此。In step S710, the SeNB may distinguish the first UE into R second UEs and (U-R) third UEs, and control the second UE to individually switch to use the corresponding ULRS as the basis for performing the handover operation. In this embodiment, the R second UEs may be randomly selected by the SeNB from the U first UEs, but the present invention may not be limited to this.

在步驟S720中,SeNB可在篩選週期中測量對應於各第二UE的ULRS的信號強度。並且,在步驟S730中,SeNB可從第二UE中找出N個第四UE,其中各第四UE對應的第一ULRS的信號強度高於一強度門限值。在一實施例中,SeNB可視為從第二UE中找出信號強度較佳的N個來作為第四UE,亦即從第二UE中找出較不可能執行換手操作的N個來作為第四UE,但本發明可不限於此。In step S720, the SeNB may measure the signal strength of the ULRS corresponding to each second UE in the screening period. Furthermore, in step S730, the SeNB may find N fourth UEs from the second UE, where the signal strength of the first ULRS corresponding to each fourth UE is higher than a strength threshold. In one embodiment, the SeNB can be regarded as finding the N UEs with better signal strength from the second UE as the fourth UE, that is, finding the N UEs from the second UE that are less likely to perform handover operations as the Fourth UE, but the invention may not be limited to this.

在步驟S740中,SeNB可控制第四UE個別切換為使用對應的DLRS作為執行換手操作的依據。亦即,對於較不可能執行換手操作的N個第四UE而言,SeNB可相應地控制各第四UE切換為以DLRS作為執行換手操作的依據,藉以節省用於傳送ULRS的通訊資源。In step S740, the SeNB may control the fourth UE to individually switch to use the corresponding DLRS as a basis for performing the handover operation. That is, for N fourth UEs that are less likely to perform a handover operation, the SeNB can accordingly control each fourth UE to switch to use DLRS as a basis for performing the handover operation, thereby saving communication resources for transmitting ULRS .

在步驟S750中,SeNB可從第三UE中挑選n個第五UE,並控制第五UE個別切換為使用對應的ULRS作為執行換手操作的依據。亦即,SeNB可從仍使用DLRS的(U-R)個第三UE中挑選n個作為第五UE,並讓各第五UE個別切換為使用對應的ULRS作為執行換手操作的依據。In step S750, the SeNB may select n fifth UEs from the third UEs, and control the fifth UEs to individually switch to use the corresponding ULRS as the basis for performing the handover operation. That is, the SeNB may select n out of (U-R) third UEs that still use DLRS as the fifth UE, and let each fifth UE switch to use the corresponding ULRS individually as a basis for performing the handover operation.

在步驟S760中,SeNB可判斷是否收到第二參考信號切換請求。若是,則接續執行步驟S780,反之則接續執行步驟S770。承先前實施例所述,第二參考信號切換請求係某UE(下稱第六UE)在判斷發生第二參考信號切換事件之後,向SeNB發出以請求SeNB控制第六UE切換為以ULRS作為執行換手操作的依據。In step S760, the SeNB may determine whether the second reference signal switching request is received. If yes, step S780 is continued, otherwise, step S770 is continued. As described in the previous embodiment, the second reference signal switching request is sent by a UE (hereinafter referred to as the sixth UE) to the SeNB to request the SeNB to control the switching of the sixth UE to ULRS as the execution after judging the occurrence of the second reference signal switching event. The basis for changing hands.

在步驟S780中,SeNB可評估是否允許第六UE切換為以對應的ULRS作為執行換手操作的依據。若是,則接續執行步驟S790,反之則接續執行步驟S770。在本實施例中,SeNB可判斷是否有可用的ULRS通訊資源,若是則可判定允許第六UE切換為以對應的ULRS作為執行換手操作的依據,並接著在步驟S790中控制第六UE切換為以對應的ULRS作為執行換手操作的依據(例如分配對應的ULRS通訊資源等)。In step S780, the SeNB may evaluate whether to allow the sixth UE to switch to use the corresponding ULRS as a basis for performing the handover operation. If yes, step S790 is continued, otherwise, step S770 is continued. In this embodiment, the SeNB can determine whether ULRS communication resources are available, and if so, it can determine that the sixth UE is allowed to switch to use the corresponding ULRS as the basis for performing the handover operation, and then control the sixth UE to switch in step S790 To use the corresponding ULRS as the basis for performing the handover operation (for example, to allocate the corresponding ULRS communication resources, etc.).

在步驟S770中,SeNB可判斷篩選週期是否結束。若是,則可返回步驟S720,反之則可返回步驟S760。在不同的實施例中,篩選週期的長度可由設計者依需求而定,本發明不加以限制。In step S770, the SeNB may determine whether the screening period is over. If yes, it can return to step S720, otherwise, it can return to step S760. In different embodiments, the length of the screening period can be determined by the designer according to requirements, and the invention is not limited.

綜上所述,本發明提出的基於上行參考信號的換手方法及無線通訊系統可讓UE發送專屬的ULRS至SeNB及TeNB,以讓SeNB及TeNB即時地測量並交換ULRS的信號強度。當發生換手觸發事件時,SeNB及TeNB可提早進行HO準備,進而能夠改善UE換手至TeNB的效率及成功機率。In summary, the handover method and wireless communication system based on the uplink reference signal proposed by the present invention allow the UE to send dedicated ULRS to SeNB and TeNB, so that SeNB and TeNB can measure and exchange ULRS signal strength in real time. When a handover triggering event occurs, SeNB and TeNB can make HO preparation earlier, which can improve the efficiency and probability of success of UE handover to TeNB.

並且,本發明還提出了適時讓UE切換為以ULRS/DLRS作為執行換手操作的依據的機制。藉此,可讓較頻繁地換手的UE能夠切換為以ULRS作為執行換手操作的依據,藉以善UE換手的效率及成功機率。同時,還可讓較不頻繁換手的UE切換為以DLRS作為執行換手操作的依據,藉以節省用於傳送ULRS的通訊資源。In addition, the present invention also proposes a mechanism to allow the UE to switch to ULRS/DLRS as the basis for performing the handover operation in a timely manner. In this way, UEs that change hands more frequently can be switched to use ULRS as a basis for performing handover operations, thereby improving the efficiency and probability of success of UE handovers. At the same time, UEs that change hands less frequently can be switched to use DLRS as the basis for performing handover operations, thereby saving communication resources for transmitting ULRS.

此外,本發明還提出了篩選機制,其可用以從多個UE中找出較適合以ULRS作為執行換手操作的依據的一或多者。藉此,可較有效率地利用ULRS的通訊資源。In addition, the present invention also proposes a screening mechanism that can be used to find one or more UEs that are more suitable for performing handover operations based on ULRS from multiple UEs. In this way, the communication resources of ULRS can be used more efficiently.

雖然本發明已以實施例揭露如上,然其並非用以限定本發明,任何所屬技術領域中具有通常知識者,在不脫離本發明的精神和範圍內,當可作些許的更動與潤飾,故本發明的保護範圍當視後附的申請專利範圍所界定者為準。Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

200‧‧‧無線通訊系統200‧‧‧Wireless communication system

21‧‧‧UE21‧‧‧UE

22‧‧‧SeNB22‧‧‧SeNB

23‧‧‧TeNB23‧‧‧TeNB

S1‧‧‧ULRSS1‧‧‧ULRS

S310~S330、S710~S790‧‧‧步驟S310~S330, S710~S790‧‧‧Step

圖1是習知的換手機制示意圖。 圖2是依據本發明之一實施例繪示的無線通訊系統示意圖。 圖3是依據本發明之一實施例繪示的上行參考信號的換手方法流程圖。 圖4是習知作法與本發明方法的比較圖。 圖5A是依據本發明之一實施例繪示的以UE主導第一切換機制的示意圖。 圖5B是依據本發明之一實施例繪示的以SeNB主導第一切換機制的示意圖。 圖6A是依據本發明之一實施例繪示的以UE主導第二切換機制的示意圖。 圖6B是依據本發明之一實施例繪示的以SeNB主導第二切換機制的示意圖。 圖7是依據本發明之一實施例繪示的挑選採用ULRS的使用者設備的流程圖。FIG. 1 is a schematic diagram of a conventional mobile phone replacement mechanism. 2 is a schematic diagram of a wireless communication system according to an embodiment of the invention. FIG. 3 is a flowchart of a handover method of an uplink reference signal according to an embodiment of the invention. FIG. 4 is a comparison diagram of the conventional method and the method of the present invention. FIG. 5A is a schematic diagram illustrating that the first handover mechanism is dominated by the UE according to an embodiment of the present invention. FIG. 5B is a schematic diagram illustrating that the first handover mechanism is dominated by SeNB according to an embodiment of the present invention. FIG. 6A is a schematic diagram illustrating that the second handover mechanism is dominated by the UE according to an embodiment of the present invention. FIG. 6B is a schematic diagram illustrating that the second handover mechanism is dominated by SeNB according to an embodiment of the present invention. FIG. 7 is a flowchart of selecting user equipment using ULRS according to an embodiment of the invention.

S310~S330‧‧‧步驟 S310~S330‧‧‧Step

Claims (14)

一種基於上行參考信號的換手方法,適於包括一使用者設備、一來源基地台及一目標基地台的一無線通訊系統,所述方法包括:由該來源基地台及該目標基地台接收來自該使用者設備的一上行參考信號,其中該上行參考信號專屬於該使用者設備;由該來源基地台及該目標基地台基於該上行參考信號判斷是否發生一換手觸發事件;以及反應於發生該換手觸發事件,由該來源基地台發送一換手命令至該使用者設備,以控制該使用者設備換手至該目標基地台;其中在由該來源基地台及該目標基地台接收來自該使用者設備的該上行參考信號的步驟之前,所述方法更包括:由該來源基地台服務U個第一使用者設備,其中該些第一使用者設備個別使用對應的一下行參考信號作為是否執行一換手操作的依據;由該來源基地台將該些第一使用者設備區分為R個第二使用者設備及(U-R)個第三使用者設備;由該來源基地台控制該些第二使用者設備個別切換為使用對應的一第一上行參考信號作為執行該換手操作的依據;在一篩選週期中,由該來源基地台測量對應於各該第二使用者設備的該第一上行參考信號的一信號強度; 由該來源基地台從該些第二使用者設備中找出N個第四使用者設備,其中各該第四使用者設備對應的該第一上行參考信號的該信號強度高於一強度門限值;由該來源基地台控制該些第四使用者設備個別切換為使用對應的該下行參考信號作為執行該換手操作的依據;以及由該來源基地台從該些第三使用者設備中挑選n個第五使用者設備,並控制該些第五使用者設備個別切換為使用對應的該第一上行參考信號作為執行該換手操作的依據。 A handover method based on an uplink reference signal is suitable for a wireless communication system including a user equipment, a source base station and a target base station. The method includes: receiving from the source base station and the target base station An uplink reference signal of the user equipment, wherein the uplink reference signal is dedicated to the user equipment; the source base station and the target base station determine whether a handoff trigger event occurs based on the uplink reference signal; and react to the occurrence In the handover triggering event, the source base station sends a handover command to the user equipment to control the user equipment to handover to the target base station; where the source base station and the target base station receive the Before the step of the uplink reference signal of the user equipment, the method further includes: serving U first user equipments by the source base station, wherein the first user equipments individually use corresponding downlink reference signals as The basis for whether to perform a handover operation; the source base station distinguishes these first user equipments into R second user equipments and (UR) third user equipments; the source base station controls these The second user equipment is individually switched to use a corresponding first uplink reference signal as a basis for performing the handover operation; in a screening period, the source base station measures the first corresponding to each second user equipment A signal strength of an uplink reference signal; The source base station finds N fourth user equipments from the second user equipments, wherein the signal strength of the first uplink reference signal corresponding to each fourth user equipment is higher than a strength threshold The source base station controls the fourth user equipment to individually switch to use the corresponding downlink reference signal as a basis for performing the handover operation; and the source base station selects n from the third user equipment A fifth user equipment, and control the fifth user equipment to individually switch to use the corresponding first uplink reference signal as a basis for performing the handover operation. 如申請專利範圍第1項所述的方法,其中該來源基地台及該目標基地台基於該上行參考信號判斷是否發生該換手觸發事件的步驟包括:由該來源基地台測量該上行參考信號的一第一信號強度,並將該第一信號強度發送至該目標基地台;由該目標基地台測量該上行參考信號的一第二信號強度,並將該第二信號強度發送至該來源基地台;以及若該第二信號強度高於該第一信號強度達一預設門限值,由該來源基地台及該目標基地台判斷發生該換手觸發事件。 The method according to item 1 of the patent application scope, wherein the step of the source base station and the target base station determining whether the handover trigger event occurs based on the uplink reference signal includes: the source base station measuring the uplink reference signal A first signal strength and send the first signal strength to the target base station; the target base station measures a second signal strength of the uplink reference signal and sends the second signal strength to the source base station ; And if the second signal strength is higher than the first signal strength by a preset threshold, the source base station and the target base station determine that the handover triggering event occurs. 如申請專利範圍第2項所述的方法,其中該換手觸發事件發生於一第一時間點,且在由該來源基地台及該目標基地台判斷發生該換手觸發事件之後,所述方法更包括: 由該來源基地台及該目標基地台在一第二時間點開始執行一提前準備換手操作,其中該第二時間點與該第一時間點之間的一時間差小於一觸發時間。 The method as described in item 2 of the patent application scope, wherein the handoff trigger event occurs at a first point in time, and after the source base station and the target base station determine that the handoff trigger event occurs, the method It also includes: The source base station and the target base station start a pre-handover operation at a second time point, where a time difference between the second time point and the first time point is less than a trigger time. 如申請專利範圍第3項所述的方法,其中執行該提前準備換手操作的步驟包括:由該來源基地台發送一換手請求至該目標基地台;由該目標基地台反應於該換手請求而回傳一換手回應至該來源基地台。 The method as described in item 3 of the patent application scope, wherein the step of performing the preparatory handover operation in advance includes: sending a handover request from the source base station to the target base station; the target base station reacting to the handover Request and return a handover response to the source base station. 如申請專利範圍第1項所述的方法,更包括:由該使用者設備或該來源基地台判斷是否發生一第一參考信號切換事件;以及反應於發生該第一參考信號切換事件,由該來源基地台控制該使用者設備切換為以來自該來源基地台的一下行參考信號作為執行一換手操作的依據。 The method as described in item 1 of the patent application scope further includes: determining whether a first reference signal switching event occurs by the user equipment or the source base station; and responding to the occurrence of the first reference signal switching event by the The source base station controls the user equipment to switch to the next reference signal from the source base station as a basis for performing a handover operation. 如申請專利範圍第5項所述的方法,其中該使用者設備儲存有一換手記錄,且由該使用者設備判斷是否發生該第一參考信號切換事件的步驟包括:由該使用者設備依據該換手記錄判斷該使用者設備是否在一預設時間內不會執行該換手操作;若是,由該使用者設備向該來源基地台發出一第一參考信號切換請求,以請求該來源基地台控制該使用者設備切換為以該下行參考信號作為執行該換手操作的依據。 The method as described in item 5 of the patent application scope, wherein the user equipment stores a handover record, and the step of determining whether the first reference signal switching event occurs by the user equipment includes: the user equipment according to the The handover record determines whether the user equipment will not perform the handover operation within a preset time; if so, the user equipment sends a first reference signal switching request to the source base station to request the source base station Controlling the user equipment to switch to use the downlink reference signal as a basis for performing the handover operation. 如申請專利範圍第5項所述的方法,其中由該來源基地台判斷是否發生該第一參考信號切換事件的步驟包括:由該來源基地台判斷該使用者設備的一換手頻率是否低於一頻率門限值;若是,由該來源基地台控制該使用者設備切換為以該下行參考信號作為執行該換手操作的依據。 The method according to item 5 of the patent application scope, wherein the step of determining whether the first reference signal switching event occurs by the source base station includes: determining whether a handover frequency of the user equipment is lower than the source base station A frequency threshold; if so, the source base station controls the user equipment to switch to the downlink reference signal as a basis for performing the handover operation. 如申請專利範圍第5項所述的方法,其中由該來源基地台控制該使用者設備切換為以來自該來源基地台的該下行參考信號作為執行該換手操作的依據的步驟包括:由該來源基地台發送一第一控制信號至該使用者設備,以通知該使用者設備準備接收該下行參考信號;由該來源基地台釋放該上行參考信號對應的一通訊資源;由該使用者設備反應於該第一控制信號回傳一第一確收訊息至該來源基地台;以及由該來源基地台反應於該第一確收訊息而發送該下行參考信號。 The method as described in item 5 of the patent application scope, wherein the step of controlling the user equipment switching by the source base station to use the downlink reference signal from the source base station as a basis for performing the handover operation includes: The source base station sends a first control signal to the user equipment to notify the user equipment that it is ready to receive the downlink reference signal; the source base station releases a communication resource corresponding to the uplink reference signal; the user equipment responds Return a first acknowledgement message to the source base station at the first control signal; and send the downlink reference signal by the source base station in response to the first acknowledgement message. 如申請專利範圍第1項所述的方法,其中在由該來源基地台及該目標基地台接收來自該使用者設備的該上行參考信號的步驟之前,所述方法更包括:由該來源基地台發送一下行參考信號至該使用者設備,其中該下行參考信號為該使用者設備執行一換手操作的依據; 由該使用者設備或該來源基地台判斷是否發生一第二參考信號切換事件;以及反應於發生該第二參考信號切換事件,由該來源基地台評估是否允許該使用者設備切換為以該上行參考信號作為執行該換手操作的依據;若是,控制該使用者設備切換為以該上行參考信號作為執行該換手操作的依據。 The method according to item 1 of the patent application scope, wherein before the step of receiving the uplink reference signal from the user equipment by the source base station and the target base station, the method further includes: the source base station Sending a downlink reference signal to the user equipment, wherein the downlink reference signal is the basis for the user equipment to perform a hand-over operation; The user equipment or the source base station determines whether a second reference signal switching event occurs; and in response to the second reference signal switching event, the source base station evaluates whether the user equipment is allowed to switch to the uplink The reference signal is used as a basis for performing the handover operation; if so, the user equipment is controlled to switch to use the uplink reference signal as the basis for performing the handover operation. 如申請專利範圍第9項所述的方法,其中由該使用者設備判斷是否發生該第二參考信號切換事件的步驟包括:由該使用者設備判斷該下行參考信號的一信號品質的一下降速度是否高於一第一門限值或持續低於一第二門限值達一預設時間;若是,由該使用者設備向該來源基地台發出一第二參考信號切換請求,以請求該來源基地台控制該使用者設備切換為以該上行參考信號作為執行該換手操作的依據。 The method as described in item 9 of the patent application range, wherein the step of determining by the user equipment whether the second reference signal switching event occurs includes: determining, by the user equipment, a rate of degradation of a signal quality of the downlink reference signal Whether it is higher than a first threshold or continuously lower than a second threshold for a preset time; if so, the user equipment sends a second reference signal switching request to the source base station to request the source The base station controls the user equipment to switch to use the uplink reference signal as a basis for performing the handover operation. 如申請專利範圍第9項所述的方法,其中由該來源基地台判斷是否發生該第二參考信號切換事件的步驟包括:由該來源基地台判斷該使用者設備的一換手頻率是否高於一頻率門限值;若是,由該來源基地台控制該使用者設備切換為以該上行參考信號作為執行該換手操作的依據。 The method as described in item 9 of the patent application scope, wherein the step of determining by the source base station whether the second reference signal switching event occurs includes: determining by the source base station whether a handover frequency of the user equipment is higher than A frequency threshold; if so, the source base station controls the user equipment to switch to use the uplink reference signal as a basis for performing the handover operation. 如申請專利範圍第9項所述的方法,其中由該來源基地台控制該使用者設備切換為以該上行參考信號作為執行該換手操作的依據的步驟包括:由該來源基地台發送一第二控制信號至該使用者設備,其中該第二控制信號包括該上行參考信號對應的一通訊資源;由該使用者設備反應於該第二控制信號回傳一第一回應至該來源基地台;以及由該來源基地台反應於該第一回應而接收該上行參考信號。 The method as described in item 9 of the patent application scope, wherein the step of controlling the user equipment to switch to use the uplink reference signal as the basis for performing the handover operation by the source base station includes: sending a first Two control signals to the user equipment, wherein the second control signal includes a communication resource corresponding to the uplink reference signal; the user equipment returns a first response to the source base station in response to the second control signal; And the source base station receives the uplink reference signal in response to the first response. 如申請專利範圍第1項所述的方法,更包括:反應於從一第六使用者設備接收到一參考信號切換請求,由該來源基地台評估是否允許該第六使用者設備切換為以對應的該第一上行參考信號作為執行該換手操作的依據;以及若是,由該來源基地台控制該第六使用者設備切換為以對應的該第一上行參考信號作為執行該換手操作的依據。 The method as described in item 1 of the patent application scope further includes: in response to receiving a reference signal switching request from a sixth user equipment, the source base station assesses whether the sixth user equipment is allowed to switch to correspond The first uplink reference signal as the basis for performing the handover operation; and if it is, the source base station controls the sixth user equipment to switch to use the corresponding first uplink reference signal as the basis for performing the handover operation . 一種無線通訊系統,包括:一使用者設備,其發送一上行參考信號,其中該上行參考信號專屬於該使用者設備;一來源基地台,其服務該使用者設備,並接收來自該使用者設備的該上行參考信號;一目標基地台,其連接該來源基地台,並接收來自該使用者設備的該上行參考信號, 其中,該來源基地台及該目標基地台基於該上行參考信號判斷是否發生一換手觸發事件;以及反應於發生該換手觸發事件,該來源基地台發送一換手命令至該使用者設備,以控制該使用者設備換手至該目標基地台,其中在該來源基地台接收來自該使用者設備的該上行參考信號之前,該來源基地台更經配置以:服務U個第一使用者設備,其中該些第一使用者設備個別使用對應的一下行參考信號作為是否執行一換手操作的依據;將該些第一使用者設備區分為R個第二使用者設備及(U-R)個第三使用者設備;控制該些第二使用者設備個別切換為使用對應的一第一上行參考信號作為執行該換手操作的依據;在一篩選週期中,測量對應於各該第二使用者設備的該第一上行參考信號的一信號強度;從該些第二使用者設備中找出N個第四使用者設備,其中各該第四使用者設備對應的該第一上行參考信號的該信號強度高於一強度門限值;控制該些第四使用者設備個別切換為使用對應的該下行參考信號作為執行該換手操作的依據;以及從該些第三使用者設備中挑選n個第五使用者設備,並控制該些第五使用者設備個別切換為使用對應的該第一上行參考信號作為執行該換手操作的依據。 A wireless communication system includes: a user equipment that sends an uplink reference signal, wherein the uplink reference signal is dedicated to the user equipment; a source base station that serves the user equipment and receives the user equipment from the user equipment The uplink reference signal; a target base station connected to the source base station and receiving the uplink reference signal from the user equipment, Wherein, the source base station and the target base station determine whether a handover trigger event occurs based on the uplink reference signal; and in response to the handover trigger event, the source base station sends a handover command to the user equipment, To control the user equipment to switch to the target base station, wherein before the source base station receives the uplink reference signal from the user equipment, the source base station is further configured to: serve U first user equipment , Where the first user equipment individually uses the corresponding next-line reference signal as a basis for whether to perform a hand-over operation; the first user equipment is divided into R second user equipment and (UR) third Three user equipments; controlling the second user equipments to individually switch to use a corresponding first uplink reference signal as a basis for performing the handover operation; during a screening period, measuring corresponding to each second user equipment A signal strength of the first uplink reference signal; find N fourth user equipments from the second user equipments, wherein the signal of the first uplink reference signal corresponding to each fourth user equipments The intensity is higher than an intensity threshold; controlling the fourth user equipment to individually switch to use the corresponding downlink reference signal as a basis for performing the handover operation; and selecting n fifths from the third user equipment User equipment, and control the fifth user equipment to switch to use the corresponding first uplink reference signal as a basis for performing the handover operation.
TW107143956A 2018-12-06 2018-12-06 Method for handover based on uplink reference signal and wireless communication system TWI682676B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
TW107143956A TWI682676B (en) 2018-12-06 2018-12-06 Method for handover based on uplink reference signal and wireless communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
TW107143956A TWI682676B (en) 2018-12-06 2018-12-06 Method for handover based on uplink reference signal and wireless communication system

Publications (2)

Publication Number Publication Date
TWI682676B true TWI682676B (en) 2020-01-11
TW202023305A TW202023305A (en) 2020-06-16

Family

ID=69942907

Family Applications (1)

Application Number Title Priority Date Filing Date
TW107143956A TWI682676B (en) 2018-12-06 2018-12-06 Method for handover based on uplink reference signal and wireless communication system

Country Status (1)

Country Link
TW (1) TWI682676B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070297364A1 (en) * 2003-03-14 2007-12-27 Nikolaos Fagridas Fast Handover In Mobile Communications Networks
US20140378144A1 (en) * 2012-03-05 2014-12-25 Huawei Technologies Co., Ltd. Handover method in a cellular wireless communication system
US20170230869A1 (en) * 2016-02-10 2017-08-10 Qualcomm Incorporated Beam selection for uplink and downlink based mobility
WO2018033136A1 (en) * 2016-08-19 2018-02-22 华为技术有限公司 Cell handover method, user equipment, and network device
WO2018079947A1 (en) * 2016-10-25 2018-05-03 엘지전자(주) Method for supporting ue mobility in wireless communication system and device therefor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070297364A1 (en) * 2003-03-14 2007-12-27 Nikolaos Fagridas Fast Handover In Mobile Communications Networks
US20140378144A1 (en) * 2012-03-05 2014-12-25 Huawei Technologies Co., Ltd. Handover method in a cellular wireless communication system
US20170230869A1 (en) * 2016-02-10 2017-08-10 Qualcomm Incorporated Beam selection for uplink and downlink based mobility
WO2018033136A1 (en) * 2016-08-19 2018-02-22 华为技术有限公司 Cell handover method, user equipment, and network device
WO2018079947A1 (en) * 2016-10-25 2018-05-03 엘지전자(주) Method for supporting ue mobility in wireless communication system and device therefor

Also Published As

Publication number Publication date
TW202023305A (en) 2020-06-16

Similar Documents

Publication Publication Date Title
US11582663B2 (en) Handover method and apparatus
US9730130B2 (en) Mobile communication system, handover control method, radio base station, and mobile station
EP3487218B1 (en) Inter-cell handover method and controller
KR102276720B1 (en) Handover method, terminal device and network device
CN109672512B (en) Data joint transmission method and related equipment
WO2017148399A1 (en) Communication method and apparatus applied to super cell
EP2993939B1 (en) Cell handover method and base station for user equipment (ue) handover in carrier aggregation mode
KR102122488B1 (en) Apparatus and method for handover in wireless communication system
WO2018127002A1 (en) Cell handover method, related device, and system
WO2019095088A1 (en) Method and device for switching
US20200120557A1 (en) Wireless communication method and wireless communication device
EP4195767A1 (en) Cell handover method and terminal
CN115348628A (en) Cell handover in a radio cellular system
US20230422138A1 (en) Successive conditional handover
JP2024518516A (en) METHOD FOR DETERMINING MEASUREMENT GAP, TERMINAL AND NETWORK SIDE DEVICE
TWI682676B (en) Method for handover based on uplink reference signal and wireless communication system
JP7042351B2 (en) Roaming handoff method, central control device, and station
CN110140397A (en) Information transferring method and device in cell switch process
US9743325B2 (en) Communication apparatus, storage apparatus, and control method
US20200092769A1 (en) Information transmission method, network device and terminal device
US11968579B2 (en) Communication control device, communication control method, communication terminal, and communication method for switching a terminal from a first connection to a second connection
WO2017152421A1 (en) Method and terminal for connectivity operation based on micro base station, and base station
JP2022133821A (en) Relay node and base station
JP2008211497A (en) Base station system, base station controller and cell-switching control method
US20180124672A1 (en) Method, communication device and communication system