On Demand Dedicated PDCH

On-demand PDCH can be pre-empted by incoming circuit switched calls in congested cells, it should be noted that in a HSCSD, a user can never get more than a single channel through the pre-emption procedure.
There is no physical limit on how many on-demand PDCHs there can be in a cell. However the number of on-demand PDCHs depends on how much packet switched traffic there is, upto the limit where circuit switched traffic starts