Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

# How the Value of E1=2.048 Mbps comes?

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

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

#65368
Tanuj
Guest

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

#65369
Bob
Guest

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

#65370
Bob
Guest

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,
Br

#65371
Anand
Guest

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)

#65372
Bob
Guest

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 air.now 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

#65373
Guest

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

=2x4Khzx8bitsx32slots
=2.048Mbps

#65374
Aman
Guest

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

#65375
Rahul
Guest

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

#65376
Assefa
Guest

Bob and Tanuj explained for you donot you understand!

#65377
Sri
Guest

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

#65378
Zoie
Guest

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

#65379
Muthulingam
Guest

#65380
Arun Kumar Mishra
Guest

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

#65381
Salil
Guest

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

Viewing 15 posts - 1 through 15 (of 26 total)
• The forum ‘Telecom Design’ is closed to new topics and replies.