Hi,
I have noticed that when there are many MS connecting to my BTS if I try to page (call or send SMS) a specific MS it takes a long time and sometimes just fails. Is there a way to give a higher priority for paging under high network loads ?
from vty: Current Channel Load: CCCH+SDCCH4: 100% (4/4) TCH/F: 100% (2/2) SDCCH8: 100% (40/40)
best regards,
On 9. Aug 2017, at 16:37, robert robert.steve07@gmail.com wrote:
Hi,
Hey!
I have noticed that when there are many MS connecting to my BTS if I try to page (call or send SMS) a specific MS it takes a long time and sometimes just fails. Is there a way to give a higher priority for paging under high network loads ?
if you have a busy cell and can't contribute with code. Have you considered contributing financially to the project?
At this point there is no "priority" handling. The BSC will instruct the BTS to page IMSIs round-robin. This logic can surely be changed. If you only want to provide service to a subset of MS you could use special access classes.
holger
Hi
On Aug 9, 2017, at 2:55 PM, Holger Freyther holger@freyther.de wrote:
On 9. Aug 2017, at 16:37, robert robert.steve07@gmail.com wrote:
Hi,
Hey!
I have noticed that when there are many MS connecting to my BTS if I try to page (call or send SMS) a specific MS it takes a long time and sometimes just fails. Is there a way to give a higher priority for paging under high network loads ?
if you have a busy cell and can't contribute with code. Have you considered contributing financially to the project?
At this point there is no "priority" handling. The BSC will instruct the BTS to page IMSIs round-robin. This logic can surely be changed. If you only want to provide service to a subset of MS you could use special access classes.
Actually its not a busy cell, I only have two MS connected to it and the rest of MS trying to connect are rejected. But the problem is that the channels are being exhausted while rejecting the other MS. I only have one MS being paged in the cell but it is not always doable because of the high load. If I may ask the question in another way, is it possible to prevent this load by just ignoring the location update of certain MS instead of responding to them and rejecting them ?
Hi Robert,
On Wed, Aug 09, 2017 at 04:52:39PM +0300, robert wrote:
Actually its not a busy cell, I only have two MS connected to it and the rest of MS trying to connect are rejected. But the problem is that the channels are being exhausted while rejecting the other MS.
So you're not talking about paging load or paging priority here.
What you're experiencing is SDCCH exhaustion due to high number of concurrent accesses.
I only have one MS being paged in the cell but it is not always doable because of the high load.
The *paging* is for sure doable, as the paging channel is empty if you're only paging a single MS.
If I may ask the question in another way, is it possible to prevent this load by just ignoring the location update of certain MS instead of responding to them and rejecting them ?
No. You don't know from whom a given request is, and that it actually is a location update, until you have established a dedicated radio channel at L1 + L2 and are receiving L3 signaling messages.
This general problem is about fundamental aspects of the GSM radio interface, not really related to Osmocom. There are various different solutions, such as using SIM cards with specific access classes, making sure your downlink signal doesn't even reach all those other MSs, properly configuring the reject causes to make sure they permanently go away, gradually ramping up transmit power upone enabling the cell, gradually ramping up access control classes of the cell, using cell barring + MS with cell-bar-override, etc.
-
Harald Welte -
Holger Freyther -
robert