data rate in digital communications

I am a beginner in digital communications and I have question for the data rate with CDMA. Let, the length of the spreading sequence is $L_c$, The modulation is BPSK and the symbol time is $T_s$.

To calculate the data rate, I make the following reasoning: I have $1$ bit for $1$ symbol. After, the spreading, the length is $L_c$.

Here my questions:

1. What is the duration of the spreading sequence?


2. On the internet, I found that the data rate for CDMA is $D=\frac{1}{L_cT_s}$. Why $L_cT_s$?


3. Many people calculate the data rate with the length of a frame, can you explain to me how to do that?