I saw this information in some documentations.
@malviska In a 4G (LTE) cellular network, cell IDs are typically 28 bits in length. The maximum value a 28-bit binary number can represent is 2^28 - 1, which is 268,435,455 in decimal. This means that 4G cell IDs can range from 0 to 268,435,455.
So, no, not all 4G cell IDs are greater than 0xFFFF or 65535 in decimal. They can be much larger than that, up to 268,435,455. The value 0xFFFF corresponds to 65,535 in decimal, which is just a small fraction of the possible range of 4G cell IDs.