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Thread: please post UMTS interview questions

  1. #1
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    Lightbulb please post UMTS interview questions

    Please post UMTS questions that are likely to be asked in an interview along with the answers if possible ?

    thanks in advance..

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    Unhappy Re: please post UMTS interview questions

    some questions about WCDMA. I don´t have the answer. Only for UMTS interview example.

    1 what is meaning of Ec/Io? what is the best value of Ec/Io when there is 75% of downlink load simulated, while the PCPICH power is 33dBm (total power of the cell is 43dBm).


    2 how to find missing neighbor cell list during the drive test?

    3 what is the relationship between "singaling flow", "counter" and "KPI"?

    4. what should be the normal value range of RTWP, assume there is no any interference and any user.

    5why we need the antenna isolation? how to calculate the anatenna isolation distance?

    6.what is the relationship between link budget and simulation?
    Last edited by mike; 2010-07-21 at 12:22 PM

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    Default Re: please post UMTS interview questions

    What is the main difference between RB (Radio Bearer) and RAB (Radio Access Bearer)?
    Last edited by eg7014; 2010-07-21 at 01:22 PM

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    Default Re: please post UMTS interview questions

    Here are some more to Mike's questions:

    - Differentiate between the uplink and downlink modulation techniques used in UMTS.
    - What is the range of spreading factors used in the uplink and downlink?
    - Differentiate between channelization and scrambling codes.
    - What is softhandover? How does it impact performance and network capacity?
    - What is compressed mode operation? How does it impact cell capacity?

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    Default Re: please post UMTS interview questions

    Thanks to all for the questions..But can you provide answers to these questions ?
    Differentiate between channelization and scrambling codes?

    - Differentiate between the uplink and downlink modulation techniques used in UMTS.
    - What is the range of spreading factors used in the uplink and downlink?

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    Default Re: please post UMTS interview questions

    Quote Originally Posted by coursekec View Post
    Thanks to all for the questions..But can you provide answers to these questions ?
    Differentiate between channelization and scrambling codes?

    - Differentiate between the uplink and downlink modulation techniques used in UMTS.
    - What is the range of spreading factors used in the uplink and downlink?
    channelization vs. scrambling codes:
    The former spreads the signal; has good cross correlation properties; orthogonal to one another, variable code
    The latter does not spread the signal; has good auto-correlation properties; almost orthogonal to one another; not variable in size.

    Uplink vs. Downlink modulation:
    Downlink uses QPSK
    Uplink uses Dual BPSK (biomedical compatibility reasons)

    Range of Spreading Factors:
    Downlink : 4 to 512
    Uplink: 4 to 256

    Hope it helps.

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    Default Re: please post UMTS interview questions

    Quote Originally Posted by coursekec View Post
    Please post UMTS questions that are likely to be asked in an interview along with the answers if possible ?

    thanks in advance..
    Hi,

    Below are the questions given to me during my interview.


    1. Protocol Messages between network elements
    WBTS and RNC – NBAP
    RNC and RNC – RNSAP
    RNC and MSC – RANAP
    RNC and SGSN – RANAP

    2. Signaling Protocol Message between UE and RNC
    RRC

    3. Factors that affect HSDPA bit rate. Explain relationship
    A. Modulation
    B. Channel Quality
    C. Number of Codes

    4. Causes of HO
    Just explain the events

    5. What is the value for soft handover overhead
    I told him that some design are 30% some are 40%

    These are the things that i remember back then.

    Hope this might help.

    Br,

    Sen

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    Default Re: please post UMTS interview questions

    thanks a lot to both of you..
    i've added reputation to both of you..

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    Default Re: please post UMTS interview questions

    pl give the anwsers of thses questions.

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    Default Re: please post UMTS interview questions

    Who will give answers to these questions ? pl give.

    Quote Originally Posted by mike View Post
    some questions about WCDMA. I don´t have the answer. Only for UMTS interview example.

    1 what is meaning of Ec/Io? what is the best value of Ec/Io when there is 75% of downlink load simulated, while the PCPICH power is 33dBm (total power of the cell is 43dBm).


    2 how to find missing neighbor cell list during the drive test?

    3 what is the relationship between "singaling flow", "counter" and "KPI"?

    4. what should be the normal value range of RTWP, assume there is no any interference and any user.

    5why we need the antenna isolation? how to calculate the anatenna isolation distance?

    6.what is the relationship between link budget and simulation?

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