- This topic has 12 replies, 1 voice, and was last updated 8 years, 7 months ago by gm.
7th July 2010 at 17:13 #63453RF OPT.Guest
please correct me if I’m wrong; as I know that an E1 can support 2Mbps; each TRX need 128 kbps then one E1 can support 12 (+-1) depending on the multiplexing type; and MCS9 can support 59.2 kbps which it’s mean that each TRX can carried 2TS of MCS9 but we see within the field that TRX carried more,
within the same TRX there is 8TS of PDCH and TCH; sure those 8TS spend much more than 128kbps?
or may there No. of PDCH TS and No. of TCHs and all are working within one E1 but if you calculate the size will be much more than 2Mbps,
Br.7th July 2010 at 18:54 #63454pixGuest
hi rf opt,
here is your mistake : the TRX doesn’t need 128kbps.
It needs as much kbps as the TCH + PDCH require !
So yes, if you have a BTS with 12 TRXs and if the EGPRS traffic is high, then 1 Abis is not enough. You’ll need 2.
This is a dimension study you need to do. But don’t think “per TRX”, indeed it should be done “per BTS”, because the EGPRS traffic of one BTS will share the usage of the whole Abis. The Abis is not “split” per TRX.
pix8th July 2010 at 17:06 #63455RF OPT.Guest
Thanks pix; It’s clear 🙂
kindly; can you give us a short explanation regarding the TBF? and how the system decide the no. TBFs of each MS for UL or DL?
Br.9th July 2010 at 12:10 #63456pixGuest
if MS wants to send data in UL, the MFS allocates 1 UL TBF.
if network wants to send data to the MS (in DL), then the MFS allocates 1 DL TBF.
One MS can have 1 UL TBF, or 1 DL TBF, or 1 UL + 1 DL TBF.
In each “xL” TBF, a certain number of “xL” PDCH (timeslots) are allocated. (replace “xL” by UL or DL)
pîx29th July 2010 at 11:42 #63457khanGuest
how many E1s are required to on air a BTS site? plwase xplain in detail2nd August 2010 at 04:48 #63458jaihuGuest
i think 1 E1 supports max 16 TRXs for Siemens.26th August 2011 at 06:28 #63459ErrfanGuest
1). Is there any measurement parameter (Huawei systems)on which we can check Congestion on a particular-E1(2Mbps)?
2). What is the maximum capacity of an E1, in terms of traffic?
i mean to say how much traffic can one E1 take at a particular time?15th December 2011 at 16:41 #63460ERLANG!!!!!Guest
HI PLS ANYONE EXPLAIN ME THE TRX CAPACITY IN ERLANG ?????????25th January 2012 at 08:54 #63461deepakGuest
i don’t know about this matter , so i can’t give u any sassesion !!2nd April 2012 at 07:49 #63462SanjeevGuest
May anybody tell,can a Ericsson BTS be connected to BSC by 2 or more E1 links and how the data and speech traffic can be distributed between these E1s.23rd July 2012 at 08:24 #63463amit singhGuest
how may sites will be work on one e1.23rd July 2012 at 19:00 #63464pixGuest
it depends on how many cells, and hiw many TRX per cell.
you can pack roughly around 10 to 14 TRX per E1.
Each TRX uses 2 E1 timeslots (for user plane traffic)
Each cell uses 1 E1 timeslot (for control plane traffic)
EGPRS requires additional timeslots for optimal throughput, but if you can live with lower throughputs, then you don’t need to keep any specific EGPRS capacity on the E1.
pix7th September 2012 at 01:06 #63465gmGuest
about voice: at the air interface 1 time slots uses 16kbs for voice. for simplification, lets say, 1 trx has 8 time slots, so you need 16kbs x 8 ts. so, 1 trx needs 2x64kbs at the abis interface. now, 1E1 has 32x 64kbs. lets say, 30 x64kbs can be used for voice. it is clear, that 1 E1 can serve 30/2=15TRX if only voice is considered. EGPRS is more difficult and depends on the supplier. Some systems can dynamically switch between voice and EGPRS, other systems require (partly) a fixed allocation of time slots for EGPRS. As a consequence, you may need more than 1 E1 per BTS, if the demand for EGPRS traffic is high.