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How the Value of E1=2.048 Mbps comes?

Viewing 15 posts - 1 through 15 (of 26 total)
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  • #65367
    Anand Singh

    Pls Dear experts explain in details .How the Value of E1=2.048 Mbps comes?


    32 TS of 64kbps make the e1=2.048Mbps, as 32*64=2048 Kbps or 2.048 Mbps


    Lets go thorough ITU 7.11 or PCM
    The original standard for converting analog voice to a digital signal is called pulse-code modulation (PCM).
    PCM defines that an incoming analog voice signal should be sampled 8000 times per second by the analog-to-digital (A/D) converter( according to Nyquist’s theorem states that you need twice the number of samples as the highest frequency . As before mentioned the required bandwidth of human’s voice is 4000Hz so 4000×2=8000 samples are needed). A/D converters that are used specifically for processing voice are called codecs (meaning encoder/decoder). For each sample, the codec measures the frequency, amplitude, and phase of the analog signal. PCM defines a table of possible values for frequency/amplitude/phase. The codec finds the table entry that most closely matches the measured values. Along with each entry is an 8-bit binary code, which tells the codec what bits to use to represent that single sample. So PCM, sampling at 8000 times per second finds the best match of frequency /amplitude/phase in the table, finds the matching 8-bit code, and sends those 8 bits as a digital signal. Therefore bit rate can be easily calculated
    8bits ×8000samples=64Kbps


    And as a brief conclusion:
    In binary with 8 digits.
    8000 samples per second
    which each sample consists of
    8 bits 8000 × 8=64Kbps
    For transferring them we need
    a media which provide such
    bit rate
    DS0: provides one 64kbps channel.
    E1: 32 DS0 or 32 channels with 64kbp.
    Hope they come in use,


    Actualy i want to know :
    1–>(at which voice data rate mobile (MS) transmitter transmit the voice in uplink in air ?)
    2–>(what is the voice data rate when the signal is radiated by BTS in air in downlink )
    3–>( & how it becomes 2.048 Mbps on E1-connection between BTS & BSC)
    Finally–need to know that the mapping of voice data rate in air on E1(=2.048Mbps)


    Voice is sent FR-AMR-HR-EFR these are codec in air or between BSS and MS – except HR you can generally consider voice is 16k ,each channel of TS in E1 is 64kbps so each Chanel of E1 can carry 4*16kbps TCH. It means 2 ch of E1 belong to one TRX (just TCH ,not signalling) since TRX creates 8TS in for signalling you can assign 16k,32k or 64kbps in E1 for each TRX.
    don’t forget these codec (GSM codec) are changed in Transcoder to PCM(64kbps) it means 16kbps of a tch changes to 64kbps -wow, in 3g very simply you can use TRFO then no needs to adapt the codec , it is a perfect feature, even in 2g if you migrate A interface from TDM to IP , it is possibleto run it. with what being said one E1 in ABIS interface can carry maximum 12 TRX information with 12*32kbps signalling(12*2=24 (for voice)+ 12/2(6 for signalling)=30 +1 omu+1 syn=32). 15 trx is also possible but needs some features
    so in uplinke/downlink+ ABIS interface before Transcoder all bit rate are same as MS after Transcoder 64kbps

    Sanjay Yadav

    As we know that voice signal is of frequency 3.3 Khz,and as per the Nyquist Rate or PCM quantization rate for transmission we required signal of >=2f(here ‘f’ is GIF [3.3]=4).and each sample of data is a byte. DS0: provides one 64kbps channel.E1: 32 DS0 or 32 channels with 64kbps

    Also we know that voice signal frame consisits of 32 bytes .Hence value of an E1 will be



    What is the Data rate of signaling of one channel in PCM frame Or E1?


    I need one information on which basis RF engineer decide HR and FR TS


    Bob and Tanuj explained for you donot you understand!


    How many KB’s of GSM data is one DATA erlang?


    What is threshold for the stacking Erlangs for the Edge data after which you assign one additional time slot for data?


    Please anyone give explanation about LTE ?

    Arun Kumar Mishra

    As we know one E1 having 32 channel and each channel consist 4 slot of 16kb so 16kb*4*32=2048kbps or 2.048mbps.


    What is the maximum amount of traffic that one signalling link can support?

Viewing 15 posts - 1 through 15 (of 26 total)
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