A tower with non-Galois steps which attains the Drinfeld–Vladut bound

We introduce a new tower of function fields over a finite field of square cardinality, which attains the Drinfeld–Vladut bound. One new feature of this new tower is that it is constructed with non-Galois steps; i.e., with non-Galois function field extensions. The exact value of the genus g(Fn) is also given (see Lemma 4).