Hermitian u-invariants over function fields of p-adic curves

Let $p$ be an odd prime. Let $F$ be the function field of a $p$-adic curve. Let $A$ be a central simple algebra of period 2 over $F$ with an involution $\sigma$. There are known upper bounds for the $u$-invariant of hermitian forms over $(A, \sigma)$. In this article we compute the exact values of the $u$-invariant of hermitian forms over $(A, \sigma)$.