LTE Initial Access, Cell search Procedure - UE

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  • Опубліковано 5 лис 2024

КОМЕНТАРІ • 38

  • @sharadsontakke3974
    @sharadsontakke3974 6 років тому +3

    very good explanation, but I hve Q. supposed I have inserted Sprint sim card in my mobile when it switch on it will start scanning RF channel after that it will do the slote snych & frame synch ,will UE will do slot snych & frame synch for all other operator also if they satisfied Drs criteria greater than -110 ??

    • @HirenDharani
      @HirenDharani  6 років тому +3

      Very good question, Yes it will scan RSRP of all operators greater than -110, also one more thing, lets say SPRINT has two cells transmitting in that area, one at -90 and other at -100 it will pick up the strongest one of the two, so it will pick one best cell of all operators in case of sprint the -90 cell and also read the PSS and SSS of all of them and then there is next step of PLMN selection which is only after reading SIB1 and matching with the USIM, if you see in unlocked UE's , UE provides two options for network selection (Automatic and Manual) , When you select Manual it will show you all the operators such as ATT, VZW, SPR and TMO and you choose manually, this is possible only after it is synchronized and read pss , sss for all those operators, Again in case of manual if you choose the operator it will go and match the PLMN from SIB1 with the USIM PLMN, in case of automatic it will read PSS and SSS and do the synchronization of 'best cell' that is strongest cell of all the operators(Scan every operators strongest cell, also read pss-sss) based on bands supported by UE ,so again answer to your question is yes and then finally after matching the SIB1 PLMN and USIM PLMN it will go and camp, more detailed PLMN selection process, refer 3GPP TS 36.304 , hopefully it solves your Q. Thanks !!

    • @sharadsontakke3974
      @sharadsontakke3974 6 років тому

      Thanks for reply..Now I got clear idea, adding two thngs in UE handset ( manual & automatic network selection that clear my dought )

    • @pinakimohapatra1998
      @pinakimohapatra1998 5 років тому

      @@HirenDharani very good informatics video can you post all LTE handover and volte call flow with log analysis which would helpful for day to day analysis

  • @shivanidave9365
    @shivanidave9365 5 років тому +5

    One of the best lectures I could come across to understand the entire flow from UE for operator selection and the procedure. Thanks a lot for such an informative video.

  • @talkinghat88
    @talkinghat88 4 роки тому +1

    The huge screen and yourself are a great combination. Great video and content. Thanks

  • @kuttikumar4711
    @kuttikumar4711 3 роки тому +1

    Beat explanation...and need further topics videos..rach nd attach

  • @srinisarva9003
    @srinisarva9003 3 роки тому +1

    Very Good explaination

  • @bhavinjoshi6780
    @bhavinjoshi6780 2 роки тому +1

    Excellent video

  • @electricoservices475
    @electricoservices475 5 років тому +1

    I loved the simplicity in explanation so one without depth knowledge can understand the valuable information as LTE techies. where can i find the whole treasure of your videos regarding LTE?

    • @HirenDharani
      @HirenDharani  5 років тому

      I do it when I get time, For now, this is what I have. I will be soon working on 5G NR newly released 3GPP standards in 2018

  • @LIFE-hm8wp
    @LIFE-hm8wp 5 років тому +1

    Awesome explanation sir. Can you make step by step after UE power on till acquire network.

  • @Mdsultan-gn9kr
    @Mdsultan-gn9kr 6 років тому +1

    Simple explaination and pretty informative. My doubt is,
    1.consider i have Sprint SIM in my UE and the RSRP of Sprint in that location is -100db and RSRP of ATT is -80db. In this case UE first scans ATT then it goes to next strongtest (consider verizon -90db) then it goes for Sprint. So it has to scan all the networks/Cells in the increasing order of RSRP.
    2. consider i have Sprint SIM in my UE and RSRP of Sprint in that location is -111. here it just scans all the Networks/Cells till SIB reading and finally shows no network to UE.
    Please correct if am wrong.

    • @HirenDharani
      @HirenDharani  6 років тому +4

      Answer to your question 1. It will scan RSRP of all operators greater than -110 , doesn't matter what values, please check my detailed reply to Sharad, pinned above
      2. If it can't find LTE network with a matched PLMN in SIB1 along with USIM PLMN, then it will go and look for alternate i.e 3G and 2G whichever is available or provided by that operator. There is a detailed PLMN search procedure which UE will follow 4G->3G->2G (LTE-WCDMA-GSM)

  • @saravanakumar-mr9fq
    @saravanakumar-mr9fq 6 років тому +1

    Good one. Waiting next video for continuity

  • @hsar25
    @hsar25 5 років тому

    Nice explaination...sir please solve this doubt...there is no problem with UE as well as network side..but still UE unable to camp on the network..what might be the reason.. please solve

  • @Vitulli1970
    @Vitulli1970 2 роки тому +1

    Thank you!

  • @lalitkumarchoudhary6167
    @lalitkumarchoudhary6167 6 років тому +1

    thanks sir . waiting for your upcoming videos

  • @shivakrishnamurimadugula9209
    @shivakrishnamurimadugula9209 6 років тому +1

    great explanation. hoping to watch more videos

  • @bouthibawiam7252
    @bouthibawiam7252 3 роки тому +1

    thank u from algeria , mashallah .

  • @tejas_bodhe
    @tejas_bodhe 4 роки тому +1

    Very nice sir.

  • @amoltembhurne4671
    @amoltembhurne4671 6 років тому

    Nice information sir ...waiting for new video.Thank you

  • @arunkrbaidya6377
    @arunkrbaidya6377 4 роки тому

    Dear Sir,
    Please clarify me, if I am wrong.
    As per 3GPP specification:
    PSS is Zadoff-Chu Sequence.
    SSS is a m-Sequence which is a pseudorandom binary sequence.
    Here, Zadoff-Chu Sequence and m-Sequenceare are different or same???

  • @aniket0405
    @aniket0405 3 роки тому

    Pls upload more videos on protocol testing

  • @narendrapatel7297
    @narendrapatel7297 6 років тому +2

    please upload more videos sir....

  • @abdulrahmanalmeqdad8111
    @abdulrahmanalmeqdad8111 2 роки тому

    PSS in what symbol number coming for FDD and TDD ? And also with SSS what the symbol number for FDD and TDD?

  • @arunbaidya286
    @arunbaidya286 4 роки тому

    Sir,
    Pls clarify:
    Is it SF1 & SF6 and corresponding TS 1 & TS 6 / TS2 &TS12 ???

  • @bsrinivas6034
    @bsrinivas6034 4 роки тому +1

    Good

  • @veerojumanasa7948
    @veerojumanasa7948 6 років тому +2

    how UE is able to identitify " central 62 subcarriers" with out knowing the bandwidth of the cell

    • @HirenDharani
      @HirenDharani  6 років тому +1

      62 of the 72 reserved subcarriers are around the Direct Current Subcarrier in center , DC carrier is having no information, It is very important carrier in ODFM system, based on which UE will locate the center of the ODFM frequency. UE will scan DC carrier (no info carrier) which is also in center and then locates the other 62 carriers around it left and right. I will prepare separate topic on ODFM / Radio Frames and structure, stay tuned

    • @veerojumanasa7948
      @veerojumanasa7948 6 років тому

      @@HirenDharani thanks for the explanation,i cud see only this video in you channel.may i kno wer d other videos are, as u mentioned at 2:58

  • @PalashDolai-eh8xf
    @PalashDolai-eh8xf Рік тому


    ❤❤❤❤❤

  • @shatabdichoudhury802
    @shatabdichoudhury802 6 років тому

    Pls explain about PRACH SEQUENCE ...PLS

  • @text2babu
    @text2babu 5 років тому

    Can you please let me know - For measuring RsRp, how will UE know where the reference signal is present?

    • @souleymaneaziz4552
      @souleymaneaziz4552 4 роки тому +1

      After UE getting the PCI and with mod3, will get the RS position.
      Exp. PCI=10 so after applying mod3, 10MOD(3)= 1, the RS Position in subcarrier 1

  • @AbhishekSingh-pg3ji
    @AbhishekSingh-pg3ji 5 років тому

    Plz make on RACH process

    • @HirenDharani
      @HirenDharani  5 років тому

      There is a partial video on RACH (Timing Adv.) here :
      ua-cam.com/video/VA057nlzlqg/v-deo.html

  • @HarshaVardhan-vk8ld
    @HarshaVardhan-vk8ld 6 років тому +1

    Nice information sir ...waiting for new video.Thank you