How to call wcf service with out added service reference using channel factory

Can any one help me on this. "How to call wcf service with out added service reference using channel factory".

I have used this code :

        BasicHttpBinding binding = new BasicHttpBinding();
        EndpointAddress address = new EndpointAddress("");
        ChannelFactory factory = new ChannelFactory<IUnityServiceChannel>(binding, address);
        UnityServiceClient channel = new UnityServiceClient();
        string token = channel.GetSecurityToken(svcUsername, svcPassword);

But I want to create the IUnityServiceChannel run time. I don't have any information about the IUnityServiceChannel.

So can you help me how to crate interface using reflection or some thing else.