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officers,
Edge is 3 times larger in GPRS baud rate data transfer not mentioning Air data interface as GPRS is only in the switch data transfer…so if thier is available TS space in a certain Abis thier will be no data jump in EDGE 32,64 then thier will be no congestion for data flow for PCU etc… what is needed is to have an experience Radio engineer and what kind of equipment you are involve. chap-chap the Interface of abis. may be you have fashionable results cheers
I need a desing plan for a GAM/GPRS network that is going to be upgraded to GSM/GPRS/EDGE.
Does any one have it?iking,
yes, upgrading the Abis interface is one of the main task when activating the Edge, but it is good to check the whole system from Air interface to the SGSN interface with the ISP.
May I too have fashionnable results 🙂
Pix
Hi Pix
Sorry I got out of touch for a while. Some equipment vendors do not populate measurement reports on Abis. In this case BTS will take care of administering the handovers. Example of this is Nortel and Siemens. I was wondering if you have heard anything about Alcatel.
Hi everyone
I would like to know that if suppose only one TS is enabled for EDGE/GPRS in the air interface should the Abis also have 1 64kbps dedicated for EDGE. Do both the Air and Abis interface TS for EDGE/GPRS be equal.Will any body will explain me that on abis interface how many TRX can be mapped and how to configure Abis interface for FR,HR,EDGE,GPRS .I m highly confused ..Please help me out
Thanks in advanceHii PIX
while explaining EDGE dimensioning u have use 4 bit as Abis timeslot but as per i no abis timeslot is 2 bit (16kbps) sub channel and 1 bit for 8 kbps channel.
please explainSasha,
Alcatel BTS are not “smart”, so they do not manage handovers. All the processing is performed by the BSC.
Victor,
An ABIS nibble is always using 1/4 of a timeslot, you cannot change that.
1 Abis TS = 64kbps
1 Abis nibble = 16kbpsIn the OMCR you can only allocate a full Abis TS, either for CS or for PS, but you can’t allocate just an abis nibble.
A TRX carrying voice = 2 Abis nibble
For signaling, you need to add additional dedicated Abis TS (usually one per 4 TRX)
For Packet, you can add as much as you want. It depends on how many PDCH you expect in your BTS at a certain instant. If you don’t put enough Abis TS for PS, subscribers can still access GPRS/EDGE, but not at full speed.Regards,
Hii PIX
thanks a lotta for the reply.i need t discuss more with you on this topic ,i still has some confusions..
1> Abis can carry 64 Full rate(16 kbps) ,128 half rate(8 kbps) calls provided no TS is allocated for DATA on TRX??????2>Abis has some free TS .when EDGE /GPRS occupy extra TS on abis ,are these time slots are FREE TS??????
3>In general wat is structure of Abis interface with all EDGE/GPRS/HR/FR configruation???
plz reply
thnksVictor,
1> if a radio TS of a TRX is carrying voice, then the associate abis TS will carry the voice.
if a radio TS is carrying one or many PDCHs, the associated abis TS will carry the E-GPRS data.2> Free TS are not extra TS. You have to define extra TS in the BTS view.
3> i’ll come back to you about this one.. long explanations…
Hii Pix
thnks .. i have bundle of questions regading Abis.
u replied
1>if a radio TS is carrying one or many PDCHs, the associated abis TS will carry the E-GPRS data. ..is this mean that a radio TS (on TRX) can carry more than 1 Data TS.??
2> cudnt got ur second reply.
if u keep 8 TRX for a abis …u will have 5 Free TS…m in write… 16 for TRAU frames 2 for ONM ,8 for signaling ,5 freeVictor,
1> yes, one radio ts can carry many PDCH… which means that the radio ts is shared between different users !
of course, each user will have less throughput. for instance, if you locate 3 PDCH on one TS, the throughput will be divided by three. It is like multiplexing…2> yes you will have 5 free TS. But if you leave them at “free”, they won’t be used for E-GPRS. You need to define them as “extra ts”, not “free ts”.
3> structure of abis… mmm. You can start from the typical “only voice” configuration (with TRAU, O&M, Signalling abis timeslots). Nothing will change here, except that you must define some of your FREE TS as EXTRA TS. Normally, for a 3×4 site, you should define at least 5 EXTRA TS, to allow MCS9. If your EDGE traffic is high, then 5 won’t be enough.
Abis configuration for EDGE should not be frozen : you can start with 5 extra TS, and closely monitor the QOS / Drive-tests for this site.
After a certain period of monitoring (days, weeks, months !), you might notice that the EDGE traffic has increased. There are more EDGE subscribers. Then, to satisfy your customers, you can decide to add additional EXTRA TS. And so on…
Hii Pix
thnks lotta…
1>Do we need these free(EXTRA ts for GPRS also)
2>if there is no extra TS on abis interface…and there is requirement for more Edge TS then the extra TS for edge will be provided on the cost Of voice calls?
3> Please explain me How Timing alignment of TRAU frames are done on th Abis interface For FR,HR,AMR1. You need these extra TS to provide additional throughput for eGPRS.
The free TS are useless and can be used by another BTS on the same ABIS.2. No, the voice TS will never be preempted by data TS.
3. The timing advance alignment is described in 3GPP specs… have a good read 🙂 TS 45.010.
Regards,
hii Pix
1> How many Abis TS does a HR enable TRX occupy…
2> The spec no u have given deal with Radio Sync no the TRAU frame Timing Alignment .:(Victor,
1. 1 TRX defined as a half-rate can carry up to 16 calls (if all ts are defined as TCH). On the Abis interface though, each HR call will only occupy half a nibble. On the opposite, a FR call occupy a full nibble.
In the end : a HR TRX occupies 2 ABIS timeslots, which is the same as a FR TRX.
It is at the BSC side that you will see a different, on the TCU. Roughly : the BSC capacity is divided by half (depending on your hardware release).2. Ok then, up to you to find it 🙂 I don’t know where this one is.
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