Cellular Network Infrastructure » Radio Access Network » OsmoBSC

When a cell is enabled in presence of many (e.g. 10k) phones and no other network around, the network is severely overloaded. We should implement a variety of ramping mechanisms to slowly grow the cell. This includes

• ramping of transmit power (pretty useless in case of active antenna distribution system)
• ramping of access control classes (SIMs are assumed to have equal statistic distribution over all ACC)
• ramping of "rxlev access min"

The ramping could be split in two parts:

1. some generic ramping code that increments/decrements a certain value
   • the existing TX power ramping code of osmo-bts can be used as a template?
2. parameter-specific code that uses the generic code/api for the specific parameter
3. vty parameters to configure the ramping in terms of
   • initial value
   • maximum (normal) value
   • step size
   • delay between steps

There are some open questions, though:

• should all ramps execute concurrently?
• should they execute after each other? If yes, how do we trigger that?

Furthermore, aside the static ramping based on a timer, it would be great to be able to have a feedback loop that automatically runs those ramps using RACH / SDCCH load as input to the feedback loop. If theres no/low load, ramp fast. If load is high, ramp slower. Care must be taken not to completely stall any progress under high load.