GSM RF related doubt??

[atul22]

hi ,
i have doubt in GSM planning.
suppose,
Operator has 5 MHz available for GSM
Operator makes the TCH frequency plan according to specifications (SINR > 9dB) but add 6dB marginal for BCCH SINR.
Propagation exponent is 4, system is interference limited

What are the cluster sizes for BCCH and TCH?
How many TRX’s are needed
What is the number of TCH/F and TCH/H speech channels per cell?

and one more thing how to calculate the spectral effi. in GSM ?? is thr any formulla >>?