NSN_WCDMA_北京高级考试20091012.doc

北京WCDMA高级考试A. Please fill in blanks(1 points each, totally 6 points)1. WCDMA REL99 PS is using RLC layer retransmission protocol, it is running between RNC and _.2. HSDPA is using HARQ protocol for MAC layer retransmission between UE and _.3. Its important to make sure that the cells are in normal working order before doing any drive testing._ is a KPI to show if a cell is in a normal working state.4. _is a KPI to measure Downlink coverage and _is a KPI to measure Downlink quality.5. _is a KPI to measure Uplink coverage in WCDMA system.B. Please select correct answer (single choice, 1 point each, total 12 points) 1. You want to know a reason for RAB setup failures, you are interested in the following counter: M1001C81_RAB_STP_FAIL_CS_VOICE_BTS. Which measurement you need to activate in RNC(OSS) to be able to see the counter value?A. No need, measurement is always active B. C81 measurement C. M1001 measurement D. BTS measurement 2. You are doing drive test, UE TX Power is 20 dBm and RSCP is -45dBm. What kind of analysis can you make of the situation?A. Network is working normally, since RSCP is good B. Missing neighborC. RX feeders between 2 NobeBs are crossed D. Synchronization problem3. Downlink power control range has been changed from 20dB to 12 Db. What kind of effect it has for your drive test statistics?A. Increase in UL TX powerB. Amount of DL power has been increased in bad Ec/No situation.C. BLER statistics have improved 4. -?A. Downlink interference B. Uplink interference C. Receiver noise figureD. Downlink power for common channels RT and NRT services.5. What is the most reasonable target for Voice call drop rate in a well optimized network (RU10 network KPI target)?A. 1% B. 0% C. 2% D. 99%6. Mobility related KPI is _.A. Call setup success rate B. Call drop rate C. SHO success rate D. CPICH RSCP7. You doubt that you have a mistake in Scrambling Code (SC) planning. With NSNs Batrana tool you can check SC error. What you need to do first to be able to start the SC error verification?A. Load KPI data from OSS B. Load configuration data from OSS C. Can start SC error verification without any OSS data P表统计表 C表邻区配置的表8. How to describe RRC access phase?A. Its a phase after RRC connection request messageB. Its a phase after RRC connection setup completion9. _?A. Ptx_NonHSDPA is reported periodically by BTS to RNCB. Ptx_NonHSDPA is reported periodically by RNC to BTSC. Ptx_NonHSDPA is reported by UE(mobile) D. Ptx_NonHSDPA is reported by RNC to UE within power control commands.10. You use Batrana to analyze a heavy loaded network, you can pinpoint a cell, where a number of RRC connection setup attempts(M1001C242) is 0 for last 2 days. What is the most obvious reason for that?A. Its a sleeping cell.B. Its a sleeping RNC.C. There is just no traffic even though all the neighboring cells are heavy loaded.D. All calls drop in the cell.11. Some call setups fail due to AC (Admission Control).You suspect that there are not enough code resources available. Which counters/KPI you should use to verify the problem?A. NBR_SUCC_CODE_THREE_ALLOB. Compare NO_CODES_ALAILABLE_SFx against NBR_SUCC_CODE_THREE_ALLOC. RB_RELEASE_DUE_DYLO_RL_POWERD. AVE_CE_USED_AMR12. Mobile reports CQI values to the network normally by every TTI period. From drive test tool, it is possible to get CQI distribution to evaluate the quality of the network. If average CQI value is 11, what does it tell about the network?A. Uplink quality of HSPA service is bad.B. Downlink quality of HSDPA service is good C. Downlink quality of HSDPA service is badD. Channel Quality Index for voice service is bad.C. Please select correct answers(Multiple choice, 2 points each , total 12 points)1. What is Accessability related KPIs?A. RRC drop rate B. RAB setup success rate C. Voice call setup success rate D. HSDPA drop rate 2. Prx_noise counter value includes_?A. Own cell traffic interference loadB. Other cell traffic interference loadC. External interference loadD. Wrong commissioning parameter setting of MHA and antenna cable3. From DT result, it was found that there are many call setup failures due to an AMR congestion from NW. What parameters could be tuned to improved the situation?A. Increase PRACH Required Received C1B. Increase Power PRACH preamble C. Increase number of preamblesD. Increase UL interference parameter.4. Please saw signaling chart below. Why measurement _? A. SHO measurement has been triggered.B. IFHO/ISHO measurement has been triggered.C. UE has data in the buffer.D. NodeB has data in the buffer.5. You are doing HSPA testing. Happy bit sent by UE shows value 0%. What is/are correct conclusion /conclusions?A. Mobile buffer is full of data.B. Network may not grant enough power for mobile.C. Mobile buffer is empty.D. Cannot make any conclusion.6. During DT, you make a mobile (MOC) to mobile (MTC) call in MOC side. RAB is setup normally. In MTC side, after “RRC connection setup complete”, there is no RAB setup. Then MTC side is released. The reason is: Normal , unspecified in MOC side .A. Admission control rejects the MOC call.B. Admission control rejects the MTC call.C. MTC call is dropped because of bad coverage.D. There is Test system failure.7. Which one/ones of the following HSUPA KPIs exist in NSN OSS, and can be used to describe HSUPA performance? A. HSUPA MAC-es BLERB. HSUPA average throughput: HSUPA_AVE_MACD_THRC. HSUPA MAC_e retransmissions: MACE_PDU_RETR_00_COUNTERD. HSDPA average throughput 8. OSS counter M1009C78:SRNS_RELOC_COMPL_RNC_SGSN has been triggered. What has happened?A. Mobile has performed SHO for a voice call.B. Mobile has performed serving RNC relocation for a voice call. C. Mobile has performed serving RNC relocation for a data call.D. Mobile has start serving RNC relocation for a data call.9. OSS KPI RAB_ACT_FAIL_PS_BACKG_RADIO has been triggered. Which explanation/explanations below may be correct.A. RAB setup has been failed due to bad coverage.B. PS RAB has been dropped due to bad coverage.C. By allowing more DL power for PS RAB. Connection might not have dropped10. You are doing HSDPA drive testing, Your DL throughput is low. “Effective coding rate” shows value 0.2 and “HS-DSCH activity rate” shows value 100%. Why throughput is reduced?A. There are other HSDPA users in the network.B. There are no other HSDPA users in the network sharing the same resource with you.C. Downlink quality is bad.D. You have uplink problem.D. 实验题：1. 指出错误原因？ 2. You are doing driver test with Nemo Outdoor with 2 test terminals and with a frequency scanner.I. You want to test voice call performance, but you want to detect missing neighbors at the same time. How to configure your DT tool before starting the measurement, to be able to detect missing neighbors automatically? (2 points) II. Detected set measurement feature has been enabled in RNC, How you can utilize this feature in your drive test tool to detect missing neighbor? (2 points)III. You want to do drive test, and simultaneously there is a RNC engineer in RNC site capturing ICSU log file. Before you start to make drive test, what kind of communication you need to have with the RNC engineer (2 issues) (1 points) 3. You are troubleshooting a WCELL by using _ can you find and what are the actions to solve the problem? (5 point)4. What RAB active failure causes you can find in OSS statistics? (1 point per failure cause, 5 points totally)5. You want to calculate SHO overhead based on OSS KPIs, you have following counter values:- M1007C0 One_Cell_In_ACT_SET_RT=5- M1007C19 One_Cell_In_ACT_SET_NRT=5- M1007C1 Two_Cell_In_ACT_SET_RT=4- M1007C20 Two_Cell_In_ACT_SET_NRT=3E. Please calculate SHO overload in RNC level. (5 points)Please there are 2 ways to calculate SHO, _please describe_different results.6. Please _? F. Please answer following scenario questions (Total 21 Points)1. Scenario KPI Optimization (Total 13 points)Now you are in charge of KPI optimization project, you will make OSS KPI analysis first, then drive test together with RNC ICSU log analysis.I. Why you need to make drive tests and RNC ICSU analysis? Why it is not sometimes enough just to analyze OSS KPIs? (1 point)II. You will run Network Health Check to get an overall picture of the quality and condition of the network.a. What tool/tools can you use for the health check? (1 point) b. Do you perform the health check in RNC, WBTS or WCELL level? (1 point)c. Which time granularity are you going to use hourly, daily or weekly data at the phase? Why? (1 point)III. You have found out from Batrana statistics (see below) that Video call setup success rate is very low. What are the further actions to find out the failure reasons?(2 point)IV. _?V. You get the below information from RNC engineer. What kind of call failed (red color)? What was the reason for failed call? (2 point)VI. During o