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GSM basics

Viewing 15 posts - 1 through 15 (of 157 total)
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  • #34415
    Charlie
    Guest

    Hi

    I am very new to GSM network and already I am ecountering basic problems.

    sampling frquency for voice is standardised to 8Khz…which means (i guess) that a voice signal is sampled every 0.125ms (right?)..but a GSM channel (Time slot) last for 0.577ms…which is too long for the next sample…how was this value (0.577ms) worked out ?
    regards
    Charlie

    #34416
    serena
    Guest

    hi charlie

    pls note that the time slot isnt the one thats doing the sampling. In one time slot there could be a number of samples that are taken through.

    #34417
    Arun
    Guest

    How can i improve the Quality of GSm Networks.Pls give me the basics and guidelines related to this topic.

    #34418
    Muzammil
    Guest

    Hi Charlie,
    Sampling freq. for Voice is 8Khz for PSTN, i.e, there are 8000 voice samples/sec. And We ger .125ms is 1/8000. You are right!. This is very true to the PSTN trunks.
    But in GSM traffic channels, due to the scarcity of open air frequencies. The vocie channel in GSM network (in Air Interface) is 13kbps. And the framing methods are also entirely different from the PSTN trunks.

    Below link is the detailed overview of GSM technology …
    http://ccnga.uwaterloo.ca/~jscouria/GSM/gsmreport.html

    In the report u can find the framing information and the air interface specs.

    #34419
    Stefano
    Guest

    Hi Arun,
    could you explain better your topic ?

    #34420
    faris
    Guest

    hi all
    can nyone tell me how they rech the standard in GSM :8 time slot per frame

    #34421
    Arun
    Guest

    What are the basic thing which i need to take care in the planning of BSC Planning in a Network.Also please tell me the basic things for BSC Integaration which ralates to their planning in the new network.

    Also if possible,give me the details about frequency hopping.

    #34422
    Sanjeev
    Guest

    Hi All,

    Can any1 explain me what are the advantages of SS7 over R2MF signalling ?

    Regards
    Sanjeev

    #34423
    Monica
    Guest

    Hi Sanjeev,
    SS7 is CCS signaling whereas R2MF is CAS signalling.

    Suppose if u have ten PCM stream connectivity between ur exchange and other exchange , then in case of SS7 signalling only one signalling channel (64Kbps of any PCM stream) is sufficient so totally u will get (10*31-1{sig})= 309 traffic channels (64 Kbps of each), implied it can carry 309 simultaneous calls with one (64kbps) signalling channel.

    In case of R2MF signalling its mandatory that u have to reserve one channel (64Kbps) per PCM stream so if have ten PCM streams between exchange u will get
    (30*10) 300 traffic channel.

    Visit Cisco web site to get fundamentals

    I hope i made it clear

    #34424
    Arun Verma
    Guest

    I m having 2 BSC’s of Ericsson in my network.Now we are thinking to switch over to Nokia BSC’s.So we are planning to make 5 BSC’s of Nokia in comparison to 2 BSC’s of Ericsson.So what are the basic parameters and things which i need to take care about these BSC’s.i mean to say that what kind of Precautions i need to take care before making my city into 5 BSC’s of Nokia

    #34425
    Sanjeev,
    Guest

    Tahnx Monica,

    Let me know are ther any more advantages of ss7 , from one of the document I got that CIC or traffic channel will not be engaged until the distant party picks up the receiver, is it true.

    #34426
    Tech
    Guest

    Hi Arun Varma,

    Are you working in India ?
    I would like ask some more question regarding AXE-BSC.

    Can you send me a mail to telecomtech@rediffmail.com

    Rgds

    #34427
    Hans
    Guest

    Arun Verma,

    Can I have your email so I can send you some questions re the ERI BSC’s

    #34428
    Arun verma
    Guest

    My mail id is arun23mail@yahoo.com
    So, i think we can talk now.

    #34429
    prakash raj bhatt.
    Guest

    hi ALL
    ANY ONE HELP ME FOR THE KNOWLEDGE ABOUT
    SATELLITE SYSTEM.

Viewing 15 posts - 1 through 15 (of 157 total)
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