A-bis interface over satellite

**aaa12345** · 2012-03-17, 04:44 PM

Hi
I would like to know if someone can help me to active "A-bis interface over satellite" in E// BTS/BSC .
thanks

**Finetopix** · 2012-03-17 04:44 PM

**plannerguy** · 2012-03-19, 01:35 AM

which vendor?

Regards
Planneguy

**mamine** · 2012-03-25, 02:09 AM

1-Ater-Interface over Satellite
Capabilities
• Adaptation of signaling system no. 7 and data communication parameters.
• Adaptation of Time Alignment timers.
Limitations
• The MCC feature in either TRA or EC pool will not work due to the long
round trip delay.

2-Transmission Requirements on Interfaces Using the Satellite
Connection
• The system needs a 2.048 Mbit/s or 1.544 Mbit/s interface at the points of
interconnection, MSC, BSC, SGSN or BTS (ITU-T G.703, G.704).
• Clear Channel Capability (see Chapter 6) e.g. no ADPCM or echo
cancelling.
• Synctransparency If the synchronization of the remote node shall be
provided by the transmission interface, the satellite transmission must
be synctransparent:
The synchronization provided by the transmission interface at the BTS side
shall be traceable to a clock complying with the G.812 Class II or ANSI
T.101 Stratum II specification (better than +/- 0,016 ppm)
The synchronization provided by the transmission interface at the BSC
side shall be traceable to a clock complying with the G.812 PRC or ANSI
T.101 Stratum I PRS.
(The synctransparency requirement is not applicable if the remote nodes
are locally synchronized, e.g. through a local GPS receiver.)
• BER better than 1*10–6
• Jitter according to ITU-T G.823 and G.824.
• Idle Pattern on not used time slots in the point of interconnection [MSC,
BSC and BTS].

3-Ater-Interface over Satellite
3.1 MSC
Data Services
The Radio Link Protocol works between an MS and the DTI or GIWU for
non-transparent data services. The protocol uses a retransmission timer T1
which is located in the DTI or GIWU. The timer value of this timer has to be
increased to avoid cyclic retransmissions. It is recommended to increase
the timer with 500 ms.
The names of the parameters controlling the T1 timer are in the DTI:
T1FR1458 for 14.5kbit/s full rate
T1FR1211 for 12kbit/s full rate.
T1FR1609 for 6kbit/s full rate
T1HR1609 for 6kbit/s half rate
The names of the parameters controlling the T1 timer are in the GIWU:
T1FR12 for 12kbit/s full rate.
T1FR6 for 6kbit/s full rate.
T1HR6 for 6kbit/s half rate.
3.2 Stand Alone BSC

Signalling:

Long delays such as satellite delays and link disturbances are not a good
combination since they hamper throughput of messages over the link.
The signalling system no 7 has a method called Preventive Cyclic
Retransmission PCR which is specially designed to cope with the above
situation. The idea is to retransmit frames cyclically and not wait a long time
(time-out) before retransmitting (see Chapter 6).
PCR can be activated by using the parameter PARAMG and the size of the
retransmission buffer can be set with parameter ERC .
Note: The parameters have to be changed in both the BSC/TRC and in
the Stand-Alone BSC.
Ater flow control
The parameters ATERFCWINMIN and ATERFCWINMAX are used to control
the number of outstanding transmission requests towards the TRC node.
ATERFCWINMAX is the maximum number used at the startup. This window
value can later on be decreased at e.g. overload situations in the TRC node.
The parameters are changeable exchange properties in the BSC. The default
parameter values have to be increased to compensate for the long round trip
delay.
3.3 BSC/TRC

Signalling:

Long delays such as satellite delays and link disturbances are not a good
combination since they hamper throughput of messages over the link.
The signalling system no 7 has a method called Preventive Cyclic
Retransmission PCR which is specially designed to cope with the above
situation. The idea is to retransmit frames cyclically and not wait a long time
(time-out) before retransmitting (see Chapter 6.)
PCR can be activated by using the parameter PARAMG and the size of the
retransmission buffer can be set with parameter ERC.

Note: The parameters have to be changed in both the BSC/TRC and in
the Stand-Alone BSC.

4-Parameters:
Satellite over Ater-Interface :

a-BSC/TRC PARAMETERS:

PARMG Used in combination with ERC to set Preventive Cyclic Retransmission
PCR as error correction method.
ERC Used in combination with the PARMG to set the buffer size for the PCR
mode.

b- Stand Alone BSC PARAMETERS:

PARMG Used in combination with ERC to set Preventive Cyclic Retransmission
PCR as error correction method.
ERC Used in combination with the PARMG to set the buffer size for the PCR
mode.
ATERFCWINMAX ATER flow control parameter, maximum number of
outstanding transmission requests to TRC. The parameter is a changeable
BSC exchange property.
ATERFCWINMIN ATER flow control parameter, minimum number of
outstanding transmission requests to TRC. The parameter is a changeable
BSC exchange property.

Value Ranges and Defaults Values:

Parameter name	Default value	Recommended	Range
ATERFCWINMIN	1	7	0-32
ATERFCWINMAX	12	32	0-64

**feryh** · 2012-10-11, 07:20 PM

HI all,

can u give me explanation for minimum datarate that we need to deploy 1 bts with 1 TRX, because i have some problem using Huawei BTS 3900... as calculation for 1 TRX is only need 192kbps, but after we set 192kbps BTS is not up... minimum datarate that we set over is 384kbps.. need support please..

Regard's

Fery

**scorpion** · 2012-10-28, 03:29 PM

@ feryh

Which VSAT Equipment is connecting the BTS to BSC. E******* solution is different, you cannot simply do Apple to Apple comparison with Huawei ...also look at the EDGE Throughput you ar supporting, if you are using MCS-9 coding form an example and enabled 2/3 PDTCH then you will be in trouble ...optimize there to cut down the demand.....