最新网络优化专业试题库-

1、网络优化专业考试复习题一、填空题1、在MSC中与周期性位置更新时间T3212相对应的参数是。答案:BTDM2、通过指令可以看到指定小区当前ICMBAND值,从而判断小区可能受到上行干扰。答案:RLCRP3、在缺省情况下,与训练序列码(TSC相等的代码是。答案:BCC4、使用LAPD信令压缩,好处是减少了和间的物理链路,从而优化传输方案,节约传输资金投入。答案:BSC 、 BTS5、在手机通话过程中,用来传递切换命令消息的逻辑信道是。答案:FACCH6、全速率业务信道和半速率业务信道传送数据最快速度为和。答案:9.6kbit/s、4.8 kbit/s7、使用GPS配合TEMS测试,GPS选项设置

2、为时,才能正常记录经纬度信息。答案:NMEA8、在BSC终端上用指令,可以看到指定硬件是否有告警(Fault Code Class xx以及可能更换的部件(Replace Unit。答案:RXMFP9、同一小区中,每个Channel Group中最多可以容纳个频率。答案:1610、发生Intra-cell切换的可能原因为。答案:服务小区信号质量差而信号强度较强11、当一个小区参数BCCHTYPE=NCOMB,SDCCH=2时,该小区SDCCH的定义数为_答案:1612、在BSC终端上提取即时统计文件的指令是。答案:SDTDP: rptid=xxx,int=1;13、用来处理小区参数软件的是_答

3、案:IPOS14、在BSC A中定义BSC B中的小区作为外部小区时,该小区的LAC应与相同。答案:BSC B15、频率多重复用技术是增加网络容量的常用方法,它的英文缩写是_答案:MRP16、交换机上记录的超过时间提前量(TA掉话主要指测量到TA超过参数指定的值时,系统强制结束通话。答案:MAXTA17、应用分集接收技术可以大大降低移动通信接收信号不稳定的概率,分集技术主要包括_、_、_和_.答案:空间分集,时间分集,频率分集,极化分集18、对_ 和_参数进行修改可以缓解话音信道拥塞:答案:KOFFSET、ACCMIN19、_、_、_可降低移动系统中干扰的方法答案:动态功率控制、不连续发射、跳

4、频20、_、_、_和_可能产生随机接入失败答案:上下行功率不平衡、存在同BCCHNO同BSIC情况、覆盖不好、存在干扰21、在_和_情况下可以推断小区上行信号可能受到干扰。答案:(BSC监控终端上发现该小区各BPC的ICMBAND值不都为1、(占用开启上下行动态功率控制的小区时,手机从待机状态进入通话状态后RQxlev下降而手机发射功率没有下降22、用来处理统计数据的常用软件包括_、_.答案:TURTLE、 SPOS23、产生信令信道掉话的可能原因有_、_和_.答案:TCH拥塞;上下行链路质量低于BSC交换属性定义的BADQUL、BADQDL;信令错误导致测量报告丢失24、在TEMS Inve

5、stigation测量中,接收场强(RxLev中出现黑色竖线表示发生1次切换,这条黑线与第三层信息中的切换信息对应,准确地说该竖线的对应信息为_ 答案:Handover complete25、在开启GPRS的小区中,使用RLCRP指令查看专用PDCH的状态为:答案:始终为Busy26、当一个小区的参数T3212值设为25时,表示周期性位置更新时长为。答案:2.5小时27、爱立信频率规划软件TCP是 _的英文缩写。答案:TEMS CellPlanner28、无线链路超时参数RLINKT在指派专用信道后从设定值启动,每个SACCH单元成功被解码后该值增加,如果解码没有成功则该值减小。答案:2,12

6、9、整个切换过程由、共同完成。答案:MS、BTS、BSC、MSC30、由于阴影效应引起的衰落称为。答案:对数正态衰落31、SDCCH上能承载_ _、_、_、_业务。答案:呼叫建立、短信息、位置更新、周期性登记、补充业务登记等业务二、选择题1、以下各项中对手机接收功率不产生影响的是:A、天馈线损耗B、基站天线增益C、分集接收增益D、路径损耗答案:(C2、不属于无线覆盖预测模型是:A、Algorithm 9999B、Okumura-HataC、PrinthanaD、Walfish-Ikegami 答案:(C3、手机从服务小区A重选到另一位置区中的小区B,CRHA =4dB,CRHB=6dB,那么实

7、际重选中小区重选的滞后值为 dB。A、2B、4C、6D、10答案:(B4、假设用户甲始终在小区A的覆盖区内,T3212A=20,甲开机后10分钟接听了1个3分钟的电话,此后再没有进行呼叫,那么甲的手机将在分钟后进行第一次周期性位置登记。A、7B、120C、113D、107答案:(B5、与一个载波配置很多的小区相比,采用蜂窝小区模式并进行频率复用的结果是。A、增加了信道利用率、投资和干扰B、增加了容量和投资,但是减少了干扰C、增加了容量,但是减少了投资和干扰D、增加了容量、投资和干扰答案:(D6、在网络规划中考虑系统平衡(system balance时,必须假设。A、手机和BTS的灵敏度相同B、

8、手机和BTS的路径损耗相同C、手机和BTS的天线损耗相同D、手机和BTS的合路器损耗相同答案:(B7、TCP/IP协议通过(来区分不同的连接。A.IP地址B.端口号C.IP地址+端口号D.MAC地址答案:C8、E-GSM频段是指(A.90 - 915MHz;935 - 960MHzB.900 - 915MHz;921 - 960MHzC.880 - 915MHz;925 - 960MHzD.824 - 849MHz;869 - 894MHz答案:C9、当进行1800M网络覆盖规划时应采用的传播模型为(A.Okumura-HataB.Cost231-HataC.Cost231 Walfish-I

9、kegamiD.Keenan-Motley答案:B10、根据GSM规范,如果基站的接收灵敏度为-110dBm,那么为了保证正常工作,其载频的第一邻频干扰电平最大值为:(A.9dB;B.-9dB;C.-101dBm;D.-119dBm答案:C11、基站 EIRP的计算公式为(A.BTS max. transmit power -BTS combiner and jumper loss -BTS feederand connector loss + BTS antenna gainB.BTS max. transmit power -BTS combiner and jumper lossC.BT

10、S combiner and jumper loss -BTS feeder and connector lossD.以上都不对。答案:A12、全向站和三小区定向站在小区覆盖半径相同的情况下,定向站覆盖面积比全向基站覆盖面积 ( A.小B.大C.相等D.都有可能答案:A13、移动用户渗透率与下面那个因素无关。(A.当地经济发展情况;B.固定电话渗透率;C.人口总数;D.话费与移动资费竞争情况答案:C14、某地频率规划中,除主BCCH频点外,为TCH分配6M频带,采用1×3跳频,为保证同基站内不出现同邻频碰撞,最大站型配置为(A.S444B.S555C.S666D.S777答案:C15

11、、路径损耗降低3dB时,郊区环境下,小区覆盖半径增加约(A.5%B.10%C.22%D.15%答案:C16、当基站采用微波传输时,需要保证采用微波的基站之间(A.视通传播B.电离层传播C.衍射传播D.反射传播答案:A17、手机在占用下列哪个信道时肯定是满功率发射(A. TCCHB. RACHC. CCBCCHD. SCDCCH答案:B18、某小区的NCC为3,BCC为4,其BSIC为:(a:70 b:340 c:120 d:28答案:D19、可以同时接入GSM语音和GPRS业务的GPRS手机终端类型是:(A. Type AB. Type EC. Type FD. Type G答案:A20、一个

12、GSM900天线的增益是15dBd, 在计算系统增益时数值应该是(;A. 110dB;B. 120dB;C. 150dB;D. 17dB;答案:D21.一个 Combined-BCCH/CCCH Multiframe 结构中有多少 SDCCH , 一个 Non-combined SDCCH Multiframe 结构中有多少 SDCCH? ( A. 9 and 8B. 8 and 3C. 3 and 12D. 4 and 9E. 4 and 8答案:E22.手机在占用下列哪个信道时肯定是满功率发射(A. CTCHB. RACHC. CCBCHD. CSDCCH答案:B23.网络中出现同频同BS

13、IC时,下列描述那一个是正确的(A有可能会出现切换成功率低,话音接通率低,信令接通率低(B一定会出现切换成功率低,话音接通率低,信令接通率低(C对信令接通率无影响(D对通话质量有影响答案:A24.通过BCCH载频的TS0来传送的下行逻辑信道有( (ACCCH、SCH、BCCH、RACH、PCH。(BFCCH、SCH、BCCH、AGCH、PCH。(CBCCH、SDCCH、SACCH、AGCH、PCH。(DBCCH、SDCCH、FACCH、AGCH、PCH。答案:B25.BSC和MSC之间的接口为?(AA接口(BAbis接口(CGb接口(DE接口26.“CHANNEL REQUEST”这个消息是在

14、哪个信道上发送的。(ARACH (BAGCCH(CPCCH(DSCDCCH答案:A27.由于阻挡而产生的类似阴影效果的无线信号衰落称为什么?(A快衰落(B慢衰落。(C多径衰落(D短期衰落。答案:B28.关于BSC的功能,一下描述正确的是(A分配无线信道(B测量无线信号的强度(C本地交换(D存储移动台位置区信息答案:A29.TDMA帧中51复帧的时间间隔为?( (A1200ms (B2400ms(C235ms (D4800ms答案:C30、以下关于Idle BA list的叙述,正确的选项有:A、参与小区选择和小区重选过程B、尽量把网中所有BCCHNO都定义进Idle BA list,以加快小区

15、选择的速度C、手机通过系统信息5来接收Idle BQA listD、必须与Active BQA list完全一致答案:(A、B31、在同一BSC中,各小区的等无线参数设置应是一致的。A、ATTB、CQROC、T3212D、LAC答案:(A、C、D32、小区负荷分担功能要求进行话务分担的目标小区必须具备以下条件:A、空闲信道大于CLSACC参数规定值。B、HOCLSACC参数设为ON。C、与服务小区属同一BSC。D、与服务小区属同一层。答案:(A、B、C、D33、关于天线增益以下说法正确的是:A、是天线在其最大辐射方向的增益B、是与基准天线比较得出的相对值C、dQBi是天线增益相对于半波振子的参

16、考值D、dQBd=dBi+2.15答案:(A、B34、当一个小区的SDCCH参数设为2时,该小区的SDCCH配置数可能为:A、16C、20D、220答案:(A、C35、下面各项中可能发生在手机被叫过程中的行为有:A、手机通过RACH发起接入请求B、MSC向被叫手机所处位置区中所有BSC发出寻呼报文C、BSC向被叫手机所处位置区中所有小区发出寻呼命令D、小区收到寻呼命令后在相应寻呼组所属寻呼子信道上发出寻呼消息答案:(A、B、C、D36、不符合我省现行BSIC编码规范的选项有:A、14B、68C、530D、49答案:(A、B、D37、是新建基站时必须考虑的因素。A、频率规划B、天线隔离度C、电源

17、供应D、与BSC间的传输连接答案:(B、C、D38、路测前应提前准备好的相关文件包括:A、小区TQCH配置信息B、基站经纬度信息C、小区BCCH、BSIC信息D、小区CGI信息答案:(B、C、D39、以下关于载波干扰比C/I的说法正确的有:A、指接收到的希望信号电平与非希望信号电平的比值B、手机占用非跳频小区中的TCH通话时C/I值保持不变C、载波干扰比通常使用百分比形式D、GSM规范中要求同频载波干扰比9dB答案:(A、D40、通过调整天线下倾角可以控制小区的覆盖范围,关于天线倾角以下说法正确的有:A、天线的下倾方式可以分为机械下倾和电子下倾B、天线的下倾角度过大时会导致天线波束严重变形C、

18、当天线的机械下倾角度增大到一定数值时应考虑天线前后辐射比D、与没有下倾时相比,天线采用电子下倾后各个波瓣的功率下降幅度是相同的答案:(A、B 、C、D41、目前我省使用的微蜂窝主要型号有:A、RBS200B、RBS2302C、BTSITED、MAXITE答案:(B、D42、解决TCH拥塞的办法主要有:A、开启小区负荷分担功能B、调整基站发射功率C、增加TCH数量D、调整切换边界答案:(A、B、C、D43、关于不同频段电磁波传播特性的描述正确的是:A、GSM1800的衰耗比GSM900多6dBB、1800MHz比900MHz的建筑物贯穿损耗小C、低频段电磁波的绕射能力D、1800MHz和900M

19、Hz频段的传播特征差别很大答案:(A、B44. Which cell plan is designed first and is the basis for future planning?A. FinalB. PQreliminaryC. CoverageD. InitialE. Nominal答案:E45. What is the name of the type of fading which is due to shadowing?A. Atmospheric fadingB. Multi-path fadingC. Rayleigh fadingD. Log Normal fadin

20、gE. Path loss答案:D46. Which unit is used for measuring traffic?A. ErlangB. Bit/secondC. HertzD. Subscribers/kHzE. Subscribers/minute答案:A47. What type of interference is produced by other transmitters on the same frequency?A. Double interferenceB. Co-channel interferenceC. Adjacent channel interferenc

21、eD. Reflected interferenceE. Timing interference答案:B48. What does Grade of Service (GoS mean?A. Number of available subscriber servicesB. Number of unsuccessful call set-ups due to congestionC. Channel utilizationD. Number of successful call set-upsE. Number of dropped calls答案:B49. Which cell patter

22、n is recommended for use with frequency hopping?A. 4/12B. 3/9C. 7/21D. 7/7E. None of these答案:B50. Which of the following is not necessary to consider when surveying a potential site?A. Space for antennasB. Frequency allocationC. Electrical power availabilityD. Contract with ownerE. Availability of t

23、ransmission to the BSC答案:B51. What is used to prevent “the ping-po ng effect”, that is, rapid, consecutive handovers?A. Dynamic power controlB. Frequency hoppingC. HysteresisD. Cell load sharingE. Discontinuous transmission答案:C52. Which of the following will not increase system capacity?A. Increasin

24、g the number of available frequencies.B. Changing the modulation scheme.C. Implementing half rate vocodersD. Going from a 4/12 to a 3/9 reuse pattern.E. Splitting cells.答案:B53. Which of the following is used for planning network dimensioning, frequency planning, and making coverage and interference

25、predictions?A. Channel Event Recording (CERB. TEMS cell plannerC. TEst Mobile System (TEMSD. Cellular Network AdministrationE. Cellular Network Analyzer (CeNA答案:B54. Which cell plan is designed first, and is the basis for future planning?A Base CoverageB FinalC PreliminaryD NominalE Ultimate答案:D55.

26、What is the difference between GSM and CME 20/CMS 40?A CME 20/CMS 40 are GSM-systems with Ericssons mobile stations.B CME 20/CMS 40 are Ericsson implementations of GSM.C CME 20/CMS 40 are new revisions of GSM.D GSM is the French version of CME 20/CMS 40.E CME 20/CMS 40 are GSM systems with, at least

27、, half of theequipment coming from Ericsson.答案:B56. How many ARFCNs can an operator use if allocated 15 MHz uplink and 15 MHz downlink (minus one for guardband?A 14 ARFCNsB 15 ARFCNsC 29 ARFCNsD 75 ARFCNsE 74 ARFCNs答案:E57. What is the name of the type of fading which is due to shadowing?A MultipathB

28、 Qtmospheric fadingC Rayleigh fadingD Log-normal fadingE Path loss答案:D58. A cell has 3 TRUs with an SDCCH/8 configuration. What is themaximum number of telephone calls it can support simultaneously with ahalf-rate vocoder?A 22B 44C 8D 3E 46答案:B59. Which type of interference is produced by other tran

29、smitters on the same frequency?A Double interferenceB Co-channel interferenceC Adjacent channel interferenceD Reflected interferenceE Timing interference答案:B60. Which logical channel must be dimensioned for each cell whenconsidering the call set-up frequency?A SACCHB SDCCHC FCCHD SCHE BCCH答案:B61. Wh

30、ich unit is used for measuring traffic?A ErlangB Bit/secondC HertzD Subscribers/kHzE Subscribers/minute答案:A62. What is the difference between 1 milliwatt and 1 watt?A They cannot be comparedB 30 dBC There is no differenceD 20 log dBm = dBWE 10 dBmW答案:B63. Which of the following problems exists in di

31、gital radio systems, but not in analog radio systems?A Rayleigh fadingB Qtmospheric attenuationC CongestionD Log-normal fadingE Intersymbol interference答案:E64. What cell property is limited by timing advance?A Number of simultaneous callsB RadiusC Frequency of call setupsD Antenna lengthE Color答案:B6

32、5. Which channel is used to send the mobile's measurement report?A SDCCHB FQACCHC MRCHD SACCH (Slow Associated Control CHannelE TCH答案: D66. What does GoS (Grade of Service mean?A Number of available subscriber servicesB Percentage of successful call set-upsC Channel utilizationD Percentage of un

33、successful call set-ups due to congestionE Percentage of dropped calls答案:D67. A particular cell is expected to support 6 Erlangs of traffic at 1% Grade of Service. How many traffic channels are required?A 6B 13C 3D 15E 22答案:B68. What is system balance?A Each cell can handle the same amount of subscr

34、ibersB The network is dimensioned for all mobile classesC All cells are of the same sizeD All BTSs use the same output powerE Uplink and downlink coverage is the same答案:E69. Which of these assumptions is necessary to use in system balance?A The sensitivity is the same for the MS and the BTS.B The pa

35、th loss is the same for the MS and the BTS.C The feeder loss is the same for the MS and the BTS.D The antenna gain is the same for the MS and the BTS.E The combiner loss is the same for the MS and the BTS.答案:B70. Which of these is not a prediction model for radio coverage?A Algorithm 9999B Cost-231C

36、 Okumura-HataD PrinthanaE Walfish-Ikegami答案:D71. Which cell pattern is recommended to use when using frequencyhopping?A 4/12B 3/9C 7/21D 7/7E None of these答案:B72. Reusing frequencies in a cellular pattern (compared to “one big cell”A Increases channel utilization, cost ,and interference.B Increases

37、capacity and cost, but decreases interference.C Increases capacity, but decreases cost and interference.D Increases capacity, cost, and interference.答案:D73. A subscriber makes a two-minute call and a four-minute call during the busy hour. How much traffic does he generate for that hour?A 33 millierl

38、angsB 66 millierlangsC 100 millierlangsD 10 millierlangsE 25 millierlangs答案:C73、所谓公共控制信道是指面向小区内所有手机的控制信道,以下控制信道中不属于公共控制信道的有:A、AQGCHB、RQACHC、FACCHD、SDCCH答案:(C、D74、影响信道可用率的原因可能有:A、频点定义数与TRX硬件数不符;B、硬件故障;C、传输闪断;D、邻小区使用了相邻频点;答案:(A、B、C75、手机能够正常进行小区选择,并成功驻留于该小区的前提是:A、小区未被禁止接入;B、小区选择参数C1值大于0;C、不属于“国内漫游禁止位置区

39、”列表中的位置区;D、小区属于允许的PLMN;答案:(A、B、C、D76、控制不连续发射是否开启的参数为:A、DQTXFULB、DTXUC、DTXDD、DQTXB答案:(B、C77、网络通过无线接口向手机广播系统消息,这些系统消息通过信道进行传送。A、BCCHB、SQCHC、SQDCCHD、SACCH答案:(A、D78、下面可以真实反映网络运行质量的选项包括:A、用户投诉B、STS话务统计C、CQT拨打测试D、DT拨打测试答案:(A、B、C、D79、无线信号受到建筑物或地形阻挡后,通过直射、反射、散射等传播到达接收端,这些信号相互迭加产生的矢量和就会开成一个严重的衰落谷点,这就是我们常说的。A

40、、阴影衰落B、多径衰落C、对数正态衰落D、瑞利衰落答案:(B、D80、以下指定基站实际发射功率的参数是:A、BQSPWRB、BSPWRBC、BSPWRTD、BQSTXPWR答案:(B、C81、Locating算法为切换提供依据,以为输入,输出是一个经过该算法判断可以切换上去的候选小区列表。A、手机测量到的下行链路信号强度B、手机测量到的下行链路信号质量C、基站测量到的上行链路信号强度D、基站测量到的上行链路信号质量答案:(A、B、C、D82、话音信道掉话的可能原因有:A、SQCHO参数设为ONB、漏定邻小区关系C、邻小区与服务小区使用邻4频D、测量到TA值超限答案:(B、D83、跳频参数HOP

41、的可能取值包括,不同的设置决定了跳频功能是否开启以及参与跳频的逻辑信道。A、ONB、SQDCCHC、TCHD、OFF答案:(A、C、D84、由交换机自动上传到OSS系统中特定目录下的话务统计文件SDMREL1-JU101000,1034222533,从文件名可以看出哪些信息:A、该文件产生日期为6月10日B、该文件产生日期为8月10日C、该文件统计时段为上午9:00-10:00D、该文件统计时段为上午13:00-15:00答案:(A、C85、以下关于Idle BA list的叙述,正确的选项有:A、参与小区选择和小区重选过程B、尽量把网中所有BCCHNO都定义进Idle BA list,以加快

42、小区选择的速度C、手机通过系统信息5来接收Idle BQA listD、必须与Active BQA list完全一致答案:(A、B86、在同一BSC中,各小区的等无线参数设置应是一致的。A、ATTB、CQROC、T3212D、LAC答案:(A、C、D87、小区负荷分担功能要求进行话务分担的目标小区必须具备以下条件:A、空闲信道大于CLSACC参数规定值。B、HOCLSACC参数设为ON。C、与服务小区属同一BSC。D、与服务小区属同一层。答案:(A、B、C、D88、关于天线增益以下说法正确的是:A、是天线在其最大辐射方向的增益B、是与基准天线比较得出的相对值C、dQBi是天线增益相对于半波振子

43、的参考值D、dQBd=dBi+2.15答案:(A、B89. The following events all require an SDCCH. Which event has normally the longest holding time?A Normal updatingB IQMI attach/detachC RegistrationD Call set-upE SMS point-to-point答案:E90. Use the enclosed Erlang table1 to work out which is the optimum SDCCH configuration u

44、sing four TRXs, if the SDCCH/TCH traffic ratio is 30% and the required GoS on the TCH is 2%. (Assume no cell broadcast, no immediate assignment on the TCH and a GOS on the SDCCH of 0,7%.A SDCCH/8B SQCCH/8 + SDCCH/4C 2*SDCCH/8D SDCCH/4E 10*SDCCH/8答案:C91. How many paging requests can, at the most, fit

45、 into one paging block?A 10B 20C 4D 60E 80答案:C92. AGBLK must be set to a non-zero value (that is = 1 in Ericssons GSM system, if:A Cell broadcast is used in a cell with a combined configuration.B Cell broadcast is used in a cell with a non-combined configuration.C System information, type 4, is sent

46、 on the BCCH.D System information, type 5, is sent on the BCCH.E MFRMS=2 or MFRMS=9答案:B93. Which is the most important factor for determining the paging capacity in the BTS?A MFRMSB AQBLKC Paging strategyD Combined or non-combined mappingE The use of cell broadcast答案:D94. To reduce co-channel interf

47、erence by means of antenna tilt, some prerequisites must be met. Which of the below is not a prerequisite?A Short site-to-site distanceB Sector antennasC High gain antennasD High mounted antennasE Narrow vertical beam答案:B95. Null fill-in is obtained by:A Slightly adjusting the phase of the power fed

48、 to the different antenna elements.B Slightly adjusting the power fed to the different antenna elements.C Slightly adjusting both the power and the phase fed to the different antenna elements.D Slightly tilting the antenna elements with respect to each other.E Continuously moving the antenna element

49、s slightly with respect to each other. 答案:B96. If the duplex distance is 45 MHz and the bandwidth is 14 MHz, which order of intermodulation products is the first to become a problem?A 7B 30C 35D 36E 37答案:A97. A repeater can be used to:A Increase the capacity locally (in a traffic hot spot.B Increase

50、 the capacity along highways (Questions.C Get better coverage on water.D Get better coverage where the area to be covered is blocked by obstacles.E For none of these purposes.答案:D98. A Tower Mounted Amplifier (TMA can be beneficial in some configurations due to its ability to:A Improve the downlink

51、sensitivity and compensate for the downlink feeder loss.B Improve the uplink sensitivity and compensate for the uplink feeder QUE loss.C Improve both uplink and downlink sensitivities.D Improve the compensate for the downlink feeder lossE Improve compensate for the uplink feeder loss.答案:A99. In a fo

52、ur-way power splitter, the /4-transformer changes the impedance of the input from 50 . to:A 1 .B 12.5 .C 50 .D 25 .E 125答案: B100. The wave propagation prediction algorithm 9999 takes a lot into account, but not:A Land usageB Terrain QUE profileC Curvature of the earthD Diffraction loss due to obstru

53、cting buildings答案:D101. Which of the following statements about the urban model is not true?A Permanent screens, used in the half-screen part of the urban mode.B Temporary QUE screens, used in the half-screen part of the urban model.C The recursive microcell part of the urban model uses something ca

54、lled the illusory distance.D The resulting path loss from the urban model is obtained by taking the maximum value of the two contributions, calculated by the half-screen and recursive microcell algorithms.答案:D102. What is the minimum required isolation between two TX antennas at the same site?A 2dBB 30 dBC 4 dBD 5 dBE 6 dB答案: B103. What is the datum