Cellular Network Infrastructure » Radio Access Network » OsmoBSC

If a MS is requesting a channel indicating a SDCCH type (e.g. for LU or SMS), osmo-bsc currently will fail if no SDCCH are available.

It's questionable whether this is a good idea, if at the same time we have plenty of TCH/H or TCH/F sitting idle. A "larger" channel would also allow the MS to complete the related SMS/LU/USSD, i.e. we are rejecting a sequest for a given service despite being able to fulfill it.

The current behavior prioritizes holding traffic channels available for MT voice calls over providing chnanels for new MO services. There is some logic to it, but I think it's flawed: We don't yet know if any of those idle channels will ever be needed for MT calls, and on that basis we're denying service to other requests?

Maybe it should be a VTY option, with the default to use "larger" channels if no SDCCH are available.