No valid security context for the caller identity

Issue

I have an EJB that contains the following code

public @Stateless
class SecIDBean implements SecIDRemote, SecIDLocal {
@Resource SessionContext ctx;
    public String sayHello() {
      ctx.getCallerPrincipal().getName();

when the method is called remotely or locally without credential the call ctx.getCallerPrincipal().getName() throws the exception :

No valid security context for the caller identity

I still want to be able to get the caller name in case there is a one. I expect that this call returns "Anonymous" or at worse returns a null. How can I avoid this exception please ?