 as well as the extent of those measurements. The needed signalling bandwidth is larger if there are heavy measurement reports to be frequently signalled to the RNC. NBAP signalling is also used for adding, releasing and reconfiguring radio links, controlling dedicated and shared channels, controlling softer handover combining in base stations and initialising and reporting radio link measurement as well as managing radio link faults. Dimensions of the NBAP signalling channel depend on radio network parameters and radio access conditions, which affect the number of radio link additions, releases and reconfigurations per time unit. Controlling softer handover combining can also create significant signalling traffic into the NBAP signalling channel in certain conditions. Finally, reporting the measurements of radio links can require significant signalling bandwidth if done extensively. NBAP capacity requirement after all these considerations is likely to be slightly more than for transport signalling. The final capacity estimate again depends on SO many variables and parameters that giving one number or even a simple formula is impossible, but the allocated capacity should be according to simu- lations from 40 kbps (single carrier rural base station) to 250 kbps (urban high capacity base station) and even up to 500 kbps (multicarrier urban base station), depending heavily on the capacity of the base station. RNSAP signalling can be used for signalling information about a user moving across the RNC bound- aries, organising the establishment of a user connection between RNCs for soft handover and eventually releasing such a connection as well as transferring cell and base station information between RNCs. RNSAP signalling channel dimensions therefore heavily depend on how the RNC boundaries are planned. The need for RNSAP signalling between two RNCs that share a boundary where the highway goes across the boundary is obviously different compared to the case where the RNCs have a boundary in a moun- tainous, uninhabite