爱立信无线考试题(含答案)

GSM/GPRS test Radio Part

单选题：

1.What is GSM 900 and E-GSM 900 frequency band?

A. UL:890-915,DL:935-960, UL:880-890, DL:925-935

B. UL:890-915, DL:935-960; UL:880-915, DL:925-960

C. UL:890-915, DL:935-960, UL:885-890, DL:930-935

B

2. The design level, SSdesign, is

A) the signal strength value that should be used in the power budget

B) the signal strength value that should be obtained at the cell border

when planning with prediction tools like TEMS CellPlanner

C) the signal strength value obtained as EiRP - Lp

D) the signal strength value an MS of class 4 must be able to obtain

E) the required signal strength plus a Rayleigh fading margin

B

3. What is the most common value of the hysteresis used when estimating margins for log-normal fading?

A) 3 dB

B) 5 dB

C) 6 dB

D) 8 dB

E) 10 dB

A

4. A repeater can be used to

A) increase the capacity locally (in a traffic hot spot)

B) increase the capacity along highways

C) get better coverage on water

D) get better coverage where the area to be covered is blocked by

obstacles

E) for neither of these purposes

D

5. What expression is usually used for the paging success rate?

A) Successful repeated page attempts (in location area) of total number

of first and repeated page attempts (in location area).

B) Successful repeated page attempts (in location area) of total number

of repeated page attempts (in location area).

C) Rate of discarded paging messages in the BSC.

D) Successful first and repeated page attempts (in location area) of total number of first page attempts (in location area).

E) Successful first and repeated page attempts (in location area) of total number of first and second page attempts (in location area).

D

6. How many transmitters (TXs) can be configured to an omni antenna

using a CDU-C?

A) 1

B) 2

C) 4

D) 6

E) 8

B

7. The three radio network recording facilities in the BSC which

can be accessed from OSS to monitor the behavior of the mobile from

the network side is：

A) STS, CER and RNR

B) CER, MTR and RNR

C) MTR, RNR and CTR

D) CTR, RNR and STS

E) CTR, MTR and CER

E

8. Why are neighbouring cell relations created before using the frequency TCP?

A) To set hysteresis parameters

B) For export to CNA

C) To estimate adjacent-channel interference

D) For application of carrier separation constraints

E) To estimate co-channel interference

D

9. Which unit is used for the transcoding of speech information?

A) TRAU

B) TRH

C) TRX

A

10. What is true about microcells and picocells?

A) A picocell is an indoor cell and a microcell is an antenna placed

below the roof top

B) A picocell is an umbrella cell and a microcell is a normal cell

C) They are both the same thing

D) A picocell is used in Europe and a microcell are used in the USA

E) A picocell is an indoor cell and a microcell is a macro cell

A

11. What does the modified Keenan-Motley model for indoor wave

propagation path loss not take into account directly?

A) Transmitter to receiver separation distance

B) Floor attenuation (and the number of floors traversed by the direct

wave)

C) Wall attenuation (and the number of walls traversed by the direct

wave)

D) Distant dependent linear attenuation

E) Reflection and diffraction

E

10. Why is the GSM normal cell radius limited to 35 km with one time slot per traffic channel?

A) Problems with time alignment

B) The frequency re-use pattern sets the limit

C) The output power may not exceed 40 W

A

11. What type of system information message is mandatory to broadcast, when frequency hopping on SDCCH is used?

A) System information type 1

B) System information type 4

C) System information type 7

A

12. When is the priority class considered for GPRS cell re-selection?

A) Only, if there is no PBCCH in the cell.

B) Only, if there is a PBCCH in the cell and there are cells with C31>= 0.

C) Only, if there is a PBCCH in the cell and there are no cells with C31>= 0.

D) Only, if there is a PBCCH in the cell and (C1<0 for the serving cell or there is a “better” cell).

E) Only, if there is a PBCCH in the cell and C1>0 for the serving cell.

B

13. Are UL signal strength measurements used in the locating algorithm?

A) Yes, of course.

B) No, not at all.

C) Yes, but it is used only to check if conditions for intra-cell and

urgency handovers are fulfilled.

D) No, it is used only for power control of the mobile.

E) Yes, but it is used only to check if conditions for intra-cell handover

are fulfilled.

E

14. What is the parameter TINIT used for?

A) To set the initial value of the timer that inhibits handover after a change of channel.

B) To set the initial value of the timer that controls the measurement events of the mobile.

C) To set the initial value of the timer that controls if handover during signaling is allowed or not.

D) To set the initial value of the timer that controls if handover to another BSC is allowed or not.

E) To set the initial value of the timer that controls the filtering process.

A

15. The purpose of ramping is to avoid handover decisions to a new neighbor

based only on a few samples. What is a common parameter setting for

macro cells?

A) SSRAMPSI=10 and SSRAMPSD=20

B) SSRAMPSI=20 and SSRAMPSD=10

C) SSRAMPSI=10 and SSRAMPSD=10

D) SSRAMPSI=5 and SSRAMPSD=2

E) SSRAMPSI=2 and SSRAMPSD=5

E

16. What is true about inter-BSC handover?

A) It is possible to transfer a penalty list.

B) It is possible to indicate the cause of the handover.

C) It is possible to use the penalties set for the old cell.

D) TALLOC does not apply at inter-BSC handover.

E) TURGEN does not apply at inter-BSC handover.

B

17. What is the purpose of setting BSRXSUFF to –150 dBm and MSRXSUFF

to 0 dBm?

A) To make sure that the uplink signal strength influences the basic

ranking.

B) To enable path loss ranking.

C) To ensure that the signal strength on the uplink is always sufficient.

D) To obtain an absolute signal strength ranking.

E) To disable path loss ranking.

D

18. The figure below shows the outcome from basic ranking. Assuming all cells except D and H fulfil band and layer thresholds, what cells should

be prioritized and in what order?

A) A, B, E, and G

B) G, E, B, A, C, and F

C) G, E, B, and A

D) B, A, F, G, E, and C

E) A, B, F, G, E, and C

Basic Ranking Only

Cell SS Band Layer

G -68 8 7

E -72 8 6

B -73 4 4

A -74 4 3

C -75 8 7

F -78 4 4

D -95 4 4

H -96 8 7

A

19. The idle mobile derives an entity called C2. How is C2 used?

A) C2 for a particular cell must be larger than zero for a mobile to be allowed to camp on that cell.

B) C2 is a quality check, and if not fulfilled, the idle mobile must try another cell to camp on.

C) C2 and BSIC are reported to the serving cell, at least ,once every

five seconds to enable network controlled cell re-selection.

D) At cell re-selection, the cell with the largest derived C2 is chosen to camp on.

E) C2 is set to yes if both CB and CBQ are low.

D

20. Which of the following paging strategies is the most common?

A) First page global, no second page

B) First page global, second page global

C) First page in location area, no second page

D) First page in location area, second page in location area

E) First page in location area, second page global

E

21.. What is the paging capacity, if BCCHTYPE=NCOMB, AGBLK=1 and CBCH=YES assuming only IMSI pages are possible? 7*2/0.235

A) 8 pages/second

B) 16 pages/second

C) 32 pages/second

D) 64 pages/second

E) 128 pages/second

D

22. Which parameter(s) determine(s) whether assignment to another BSC is

possible or not?

A) ASSOC

B) IBHOASS

C) HNDSDCCHTCH

D) ASSOC, IBHOASS and HNDSDCCHTCH together

E) ASSOC and IBHOASS together

D

23.Which of these conditions for cell load sharing is not true?

A) CLS HO is not allowed during assignment.

B) CLS HO is not allowed, if there is an urgency condition.

C) When evaluating the amount of idle channels, CLS regards dedicated and on-demand PDCHs as idle full rate traffic channels.

D) The neighboring cell must belong to the same HCS layer.

E) The neighboring cell must have HOCLSACC=ON.

C

24. Which are the GPRS mobility management states?

A) Idle and dedicated states

B) Idle, standby, and ready states

C) Idle, standby, and dedicated states

D) Idle, dedicated, and ready states

E) Idle and standby states

B

25.. If a call is dropped during excessive TA, bad quality and poor signal

strength, which cause counter will step?

A) SS drop counter

B) Q drop counter

C) TA drop counter

D) All of these

E) None of these

C

26. Which is the most important factor for determining the paging capacity in

the BTS?

A) MFRMS (controls the number of paging groups)

B) AGBLK (reserves a paging block for access grant)

C) Paging strategy (for example, second page in the MSC service area

or in the LA)

D) Combined or non-combined mapping

E) The use of cell broadcast

D

27. What parameter is used for the output power at the locating reference point on non- BCCH carriers?

A) BSPWR

B) BSPWRB

C) BSRXSUFF

D) BSTXPWR

E) BSPWRT

D

28.Which function is used to get the accurate data from the real Network into CNA Valid Area?

1) Adjustment

2) Update

3) Consistency Check

4) Modify

A

29.What is added to the required MS sensitivity to obtain the required signal strength, SSreq?

A) Rayleigh fading margin

B) Rayleigh fading margin and interference margin

C) Rayleigh fading margin, interference margin and body loss

D) Rayleigh fading margin and body loss

E) Interference margin and body loss

C

30. Which set of features below could be used to reduce interference in the network?

A.BTS Power control and DTX

B.DTX and assignment to worse cell

C.Both a and b

A

多选题：

1. Which of the following is not a valid SDCCH configuration?

A. SDCCH/4 combined with CCCH on timeslot one

B. SDCCH/4 including CBCH combined with CCCH on timeslot zero

C. SDCCH/8 non-combined with CCCH on timeslot zero

D. SDCCH/8 including CBCH non-combined on timeslot one

E. SDCCH/8 non-combined on timeslot one

A,C

2. Which factor will have impact on the paging capacity in the BTS?

A. MFRMS (controls the number of paging groups)

B. AGBLK (reserves a paging block for access grant)

C. Paging strategy (for example, second page in the MSC service area or in the LA)

D. Combined or non-combined mapping

E. The use of cell broadcast or not

B,C,D,E

3. What is the correct protective equipment when handling replaceable units in the RBS?

A. Use of an approved ESD wrist strap

B. Use of a ground conductor

C. Use of insulated tools

D. Use of a multimeter

A

4. Which of the following is not a BSC KPI?

A. Channel Assignment Success Rate

B. Inter MSC Outgoing Handovers Success Rate

C. Location Update Success Rate

D. SDCCH Drop Rate

E. Traffic per TCH

B,C

5. How often are measurement reports delivered to the BSC?

A. About Once every second

B. About Two times per second

C. About Four times per second

D. Every second 26th multiframe

E. It depends on the parameter TINIT

B

6. What does the parameter GAMMA_CH control?

A. The nominal output power of the GPRS mobile when ALPHA=0.

B. The “forgetting factor”.

C. The desired received signal strength at the BTS.

D. The maximum output power of a GPRS mobile when accessing a system on a packet control channel.

E. The dynamic range of the power control algorithm.

C

7. Which sentence is not correct?

A. The Valid Area in CNA is the model of the real Network.

B. A Planned Area is an area in which the user can make changes, create, and delete

objects etc. without interfering with the real Network.

C. A Fallback Area is a copy of the changed part in Valid Area at the moment the Fallback Area was created.

D. When the Network is updated with a Planned Area, the Valid Area is not automatically updated as well.

C,D

8. Which of the following is a reason for Low TCH Assignment Success Rate?

A. Congestion

B. High TA

C. Interference

D. HW Problems

A.C.D

9. Which application is not available in RNO?

A. NCS

B. FOX

C. PMR

D. MRR

E. SMO

C,E

10. We have SDCCH congestion,Which of the following are true?

A.No call set-up is possible on SDCCH.

B.Features such as assignment to worse cell can be used to improve the situation.

C.Call set-up can be made on a traffic channel instead.

D.Too many SMS and location update may be the congestion reason.

A,C,D

11. What is meant by a “fractionally loaded planned” network?

A. A network where DTX is used on both uplink and downlink.

B. A network where the data transmission is very bursty.

C. A network where the number of TRXs per cell is smaller than the number of hopping frequencies.

D. A network where the channel utilization never goes above Aserved/#TCHs.

E. A network where the “hardware load” is higher than the “frequency load”.

C

12. Which of the following statements is incorrect in Ericsson’s R10 system?

A. One TG consists of up to 24 TRXs

B. One TG can be connected to a maximum of 32 cells

C. A cell can be connected to one TG only

B,C

https://www.360docs.net/doc/922521928.html,yer 3 provides the Mobile Network Signaling (MNS) service to the user application. To realize these functions in layer 3, separate protocol control

entities exist in the sub-layers, Which separate protocol control entities are in ?

A.Connection Management (CM)

B. Session Management(SM)

C. General Management(GM)

D. Mobility Management (MM)

E. Radio Resource management (RR)

A,D,E

14.dTRU – double TRU

What are double TRU(DTRU) characteristics in the following ?

A.Two transceivers in one unit of the same size as the current single TRU

B.Two versions, one for GMSK only and one for 8-PSK (EDGE) and GMSK

C.Supporting E-GSM 900, GSM 1800 or GSM 1900

D.Built in by-passable hybrid for TX combining together with CDU-G

E.Supports WCDMA

A,B,C,D

15.What are RBS 2206 Main Characteristics?

A.Antenna jumpers connected directly to the CDUs, which gives reduced RF power loss

B. not support WCDMA Plug-in transceiver unit (wTRU)

C. Can be co-sited with RBS 200 and RBS 2000 by use of Transceiver ,Group Synchronization (supporting up to 32 TRXs per cell)

D.Same footprint as RBS 200, RBS 2202 and RBS 3202 (WCDMA)

E.12 TRX capacity

A,C,D.E

16. For what is the parameter TBFDLLIMIT used?

A) To specify the maximum number of TBFs per PDCH DL.

B) To specify the maximum number of TBFs per PSET DL.

C) To specify the preferred number of TBFs per PDCH DL.

D) To specify the preferred number of TBFs per PSET DL.

E) To specify the maximum number of PDCHs per PSET DL.

C

17. Which of the following are Call Attempts Counter?

A) TASSALL

B) TATTALL

C) TFCASSALL

D) TASSATT

A,C,D

18. Which are new feature to increases end user application throughput in GPRS/EGPRS R10 network?

A.New efficient TBF handling

B.Dynamic handling of resources in DL and UL

C. Support more PSETs in one cell

D. Increased PDCH channels in one PSET

E. More flexible and adaptable GPRS cell plan

A,B,E,D

19. TEMS speech quality index, SQI, is capable of producing speech quality estimates. What is not taken into account?

A) Bit error ratio

B) Frame erasure ratio

C) Time advance

D) C/I distribution

E) DTX

C,D

20. What factors are wave propagation prediction algorithm 9999 takes into account

A) land usage

B) diffraction loss due to obstructing objects

C) curvature of the earth

D) vertical antenna gain

E) transmitter and receiver antenna effective heights

A,B,C,E

填空题：

1. The required isolation between two TX antennas at the same site is____________ dB?

30

2. The average TCH re-use in a 12/8/7/4 MRP is __________?

7.75

3. The channel separation in GSM 900 is__________?

200kHZ

4. The Assignment Command got by MS will contain the information about__________?

TCH

5. One paging block can take at most ________ paging requests?

4 TMSI

6.Assume that there are 12 frequencies (f1-f1B. in the hopping frequency set..default MAIO values allocated to the first seven TRXs in the cell are______________ Answer:

0, 2, 4, 6, 8, 10, and 1.

7.The number of on-demand and/or dedicated PDCHs can be included in one PSET is __________(R10)

Answer:

8

8.As to described in the following,the GPRS network operation mode is_______ “The network sends a CS pa ging message for a GPRS-attached MS, either

on the same channel as the GPRS paging channel, that is, on the PPCH, if

the MPDCH exists, otherwise on the PCH of the CCCH channel, or on the

PACCH, if the MS is in packet transfer mode. This means that the MS needs

only to monitor one channel.”

Answer:

GPRS network operation mode 1

9.If MBCR=2 what is a multi-band MS reporting, if the nine strongest measurements are (in SS order) A (900), B (900), C (900), D (1800), E

(900), F (1800), G (900), H (1800), I (900), and J (1800).

In a 900 cell, the MS reports _____ ,in an 1800 cell, the MS reports

____________

Answer:

A-F

A,B, D, F, H, and J.

10. AGBLK must be set to________ in Ericsson’s GSM system, if cell broadcast is used in a cell with a non-combined configuration.

Answer:

1

判断题：

1.Every 26th multiframe measurement reports delivered to the BSC.

F

2.Cells in the basic ranking list are divided into categories. 8 categories are there, if the serving cell is considered as a category of its own.

F

3.The idle mobile derives an entity called C1, C1 for a particular cell must be larger than zero for a mobile to be allowed to camp on that cell. one of the differences between the phase 1 and phase 2

T

4.establishment causes is Phase 2 establishment causes distinguish between MS originated calls and SMS.

T

5. The TX reference point, when we do the link budget, is where the jumper cable is connected to the antenna.

F

6. Null fill-in is obtained by adjusting the phase of the power fed to the different antenna elements slightly

F

7. In a 1:3 split the antenna directions on all sites that existed before must be changed 30 degreees.

T

8. The IMEI check is always done at call setup

F

9.According to GSM specification, required co-channel C/I>=9dB,adjacent C/I>=0dB. F

10. The parameters PSSTEMP and PTIMTEMP are used to penalize another cell in a lower layer.

T

简答题：

1. Logical channels, Please list all channels of following Logical channels contained. BCH:

CCCH:

DCCH:

Answer:

BCH:FCH,SCH,BCCH

CCCH:PCH,AGCH,RACH

DCCH:SDCCH,SACCH,FACCH,CBCH

2. How often the BSIC and the BCCH data must be decoded for the serving cell and for neighboringcells, both in idle and in active mode.

3. GPRS question:

A. The first message CHANNEL REQUEST of packet is sent on which logical

channel?

B.In which message old RAI (MCC+MNC+LAC+RAC) is sent?

C.If there is no MPDCH allocated in the cell, but GPRS is supported, which

System Information is informing about GPRS?

Answer:

A.RACH

B. Routing area update request

C.System information 13

4.Please give the method which can used to defend Multi-path Rayleigh Fading.

Answer:

Channel Coding, Interleaving, Frequency Hopping, Receive Diversity

5. Give out the command-file deblock MOs of BTS

A new site should be connected to the BSC which is part of a GSM-network. The site is of the type RBS 2000; After finished all defined data,the BTS should be operated,but some MOs are still in blocking status, which commands may use let it working?

Answer :the command should contained:

RXBLE:MO=xx,subord;

RXESI:MO=XX,subord;

RXESE:MO=XX,subord;

RXBLI:MO=xx,subord;

分析题：

1. There is a roaming customer from Hong Kong, every time he comes to mainland, his mobile will camp on Unicom’s network first. But he can switch the network t o CMCC manually after the mobile’s automatic PLMN selection. Please analyse the possible

reason, and give out at least 2 solutions. (Please also give out the background support theory for your reasons)

可能原因1，用户手机中联通为优选网络；

可能原因2，机场移动信号覆盖较差低于-85dBm，但联通信号高于－85dBm；或者移动和联通电平都低于－85dBm，但是移动信号比联通还弱；

可能原因3，机场移动和联通的信号都很强，但是用户手机扫频后优先选则了联通的BCCH频点

方案1，把机场降落跑道的覆盖增强（强过联通），把BCCH移动可用的最高端频点

方案2，让用户把移动加入其优先选网列表中

2.In your opinion, what is a possible explanation for the drop rate being

sometimes higher at night? How to improve it?

Reason:

1.lower DL/UL wireless signal strength

2.worse speech quality because low C/I in low signal strength.

3.more emergency handover in indoor area result in more handover lost

4.bad frequency planning and neighbor relation planning,such as less neighbor

relation and

Solution:

1.improve signal strength by add indoor site ,or repeater ,or add new macro site and

so on.

2.Improve C/I by change power and power control parameter.

3.careful check neighbor relation by collecting night hour data ,add necessary

neighbor relation

4.fine tuning frequency ,reduce frequency interference

5.reduce not needed handover .

6.Increase ACCMIN

3. When BTS occur “Rx diversity lost” alarm, what are the main reason and how to improve it?

Reason:

1.Antenna feeder wrong connected.

2.RBS line wrong connected.

3.DU/TRU hardware problem.

4.驻波比问题

Solution:

1.Drive test to confirm which cells have wrong coverage problem to located the

problem cell. If it have wrong coverage,

Check the antenna direction

Check all the jumpers and feeders from BTS to antenna and

Check all the lines and connectors in BTS

2.If no wrong coverage problem, pls check TRU problem or antenna RX problem.

4. Please complete the following signaling procedure

A. Subsequent HO from MSC B to MSC B’, MSC A is anchor MSC

B. MT Basic Call procedure: