NR MRO中RLF report信息閱讀

繼續(xù)總結(jié)NR MRO中所使用的幾個(gè)流程的進(jìn)一步信息，本篇文章也可以算作2021精華文（17）MRO相關(guān)規(guī)范總結(jié)的續(xù)集，用于進(jìn)一步聊聊MRO中可能使用的幾條消息的詳細(xì)內(nèi)容。首先在2021精華文（17）MRO相關(guān)規(guī)范總結(jié)講到RLF report的上報(bào)機(jī)制。UE使用在如下幾條RRC消息中的IE rlf-InfoAvailable-r16來告知網(wǎng)絡(luò)側(cè)它已經(jīng)獲取到了相應(yīng)的rlf信息，即為：

然后gNB收到UE的這個(gè)IE通知后，會(huì)通過如下這兩個(gè)消息要求UE上報(bào)已經(jīng)獲取的rlf info，UE繼而將之報(bào)告gNB：

從上面這對(duì)RRC消息來看，gNB在UEInformationRequest-r16中包含了請(qǐng)求UE上報(bào)rlf的信息rlf-ReportReq-r16，然后UE在使用UEinformationResponse回應(yīng)時(shí)將rlf report上報(bào)給gNB。RLF Report里的信息非常豐富，在MRO中的判決流程的主要信息依據(jù)，尤其重要，我們將之詳細(xì)展開，這里我們將重點(diǎn)關(guān)注NR rlf信息部分，重點(diǎn)的部分做了編號(hào)，如下所示：

1. 即 measResultLastServCell-r16

MeasResultRLFNR-r16,包含了NR服務(wù)小區(qū)的測量結(jié)果信息。這些信息包含了基于cell的測量結(jié)果和精細(xì)到cell內(nèi)所使用的每個(gè)RS的測量結(jié)果，當(dāng)然是可選的IE。

2和3. 第2和第3分別是針對(duì)NR鄰區(qū)和EUTRAN鄰區(qū)的測量結(jié)果，我們以NR鄰區(qū)為例，主要也是上報(bào)的NR鄰區(qū)及鄰區(qū)內(nèi)各個(gè)RS的測量結(jié)果，那個(gè)CGIinfo-NR主要用于相關(guān)ANR流程：

measResultListNR-r16???????????????? MeasResultList2NR-r16

measResultListNR

This field refers to the last measurement results taken in the neighboring NR Cells, when the radio link failure or handover failure happened.

4.第四個(gè)是c-RNTI-r16，有關(guān)c-RNTI的規(guī)范文本如下，比較清晰：

This field indicates the C-RNTI used in the PCell upon detecting radio link failure or the C-RNTI used in the source PCell upon handover failure.

5.和6.用于指示之前切換中源cell所使用的兩類PCI，

This field is used to indicate the source PCell of the last handover (source PCell when the last RRCReconfiguration message including reconfigurationWithSync was received). For intra-NR handover nrPreviousCell is included and for the handover from EUTRA to NR eutraPreviousCell?is included.

7.和8.用于指示RLF發(fā)生所在的cell，包括了PCI（PCI+頻點(diǎn)）和eCGI：

This field is used to indicate the PCell in which RLF is detected or the target PCell of the failed handover. For intra-NR handover nrFailedPCellId is included and for the handover from NR to EUTRA eutraFailedPCellIdis included. The UE sets the ARFCN according to thefrequency band used for transmission/ reception when the failure occurred.

9.和10.指示的是在經(jīng)歷了failure和重建失敗后最終實(shí)際連接的cell。使用CGI+TAC。

This field is used to indicate the cell in which the UE comes back to connected after connection failure and after failing to perform reestablishment. If the UE comes back to RRC CONNECTED in an NR cell then nrReconnectCellID is included and if the UE comes back to RRC CONNECTED in an LTE cell then eutraReconnectCellID is included.

11.?TimeUntilReconnection-r16::= INTEGER (0..172800)，記錄UE從RLF到重新進(jìn)入連接態(tài)的時(shí)段。

This field is used to indicate the time that elapsed between the connection (radio link or handover) failure and the next time the UE comes to RRC CONNECTED in an NR or EUTRA cell, after failing to perform reestablishment.Value in seconds. The maximum value 172800 means 172800s or longer.

12.reestablishmentCellId，規(guī)范中定義如下，也是使用使用CGI+TAC：This field is used to indicate the cell in which the re-establishment attempt was made after connection failure.

13.timeConnFailure-r16，用于記錄從最近一次發(fā)起切換直到RLF發(fā)生的時(shí)段，規(guī)范中定義如下：

This field is used to indicate the time elapsed since the last HO initialization until connection failure. Actual value = field value * 100ms. The maximumvalue 1023 means 102.3s or longer.

14.timeSinceFailure-r16，用于記錄從RLF發(fā)生迄今為止所經(jīng)歷的時(shí)間，規(guī)范文本如下：

This field is used to indicate the time that elapsed since the connection (radio link or handover failure）.Value in seconds. The maximum value 172800 means 172800s or longer.

15.connectionFailureType-r16，用于UE報(bào)告該failure是RLF還是切換失敗。就是connection failure類型。

16.rlf-Cause-r16，顧名思義即為RLF的原因值，即此字段用于指示上次檢測到的RLF的原因。在切換失敗的情況下（即connectionFailureType設(shè)置為“hof”），允許UE將該字段設(shè)置為任何值。

17. locationInfo-r16，用于指示報(bào)告各類location的，如下：

LocationInfo-r16::=????? SEQUENCE {

commonLocationInfo-r16??? CommonLocationInfo-r16????????? OPTIONAL,

bt-LocationInfo-r16?????? LogMeasResultListBT-r16???????? OPTIONAL,

wlan-LocationInfo-r16???? LogMeasResultListWLAN-r16?????? OPTIONAL,

sensor-LocationInfo-r16?? Sensor-LocationInfo-r16???????? OPTIONAL,

...

}

18. noSuitableCellFound-r16，UE在T311超時(shí)的時(shí)候使用它，表明搜不到合適的cell駐留。

在前文2021精華文（17）MRO相關(guān)規(guī)范總結(jié)已經(jīng)說了RLF report報(bào)告的流程已經(jīng)在Xn，NG，F(xiàn)1接口上的傳遞過程和消息。請(qǐng)參考之，此處不再贅述。