CE represents the processing capability of the DSP hardware,Each RAB type loads the DSP differently; therefore, the number of channel elements representing each service depends on the allocated UL/DL bit rate. If there is not enough DSP capacity, represented by the channel elements for a new connection, the BTS blocks the new service.The user can control the number of CEs with a license, up to the limit supported by the hardware.
If I use only one UARFCN for one cell, how many channel elements can I get for this cell for Voice (12.2 kbps)?
I means how to calculate the total number of Channel elements per cell for each service type?
Tipically you will need 256 CE (never more than 512) depending on the node b configuration (3 o 6 sectors) and the type of traffic that you are offering (speech, CS64, PS r99 or HSDPA). To support this you will need HW and SW licenses
In general the limiting factor will be the uplink CEs (try to avoid R99 connections of PS128 and PS384 kbps as they consume a lot of CE in Uplink and channalization codes in downlink)