Cisco Logical/Virtual ethernet interface

Hello,
I have cisco 2610 with (1)The ethernet and (1) serial interface.
Existing configuration is:
!
interface ethernet 0/0
i.p address 192.168.150.1 255.255.255.0
interface serial 0/0
i.p address 192.168.10.2
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.10.1

what i want is to add logical/virtual network (192.168.160.x) just to devide the 2 segments. How do i do that? I tried adding secondary but it doesn’s work.
Is there anybody cangive me information with it.

Thanks.