A method and system for supporting voice over Internet protocol (VoIP) services over a wireless communication network are disclosed. Data is encoded at a coding rate specified by a controller for generating a VoIP packet. Among the encoded data, bits sensitive to errors and bits not sensitive to errors are identified and error protection is performed separately by a medium access control layer and/or physical layer. A header of the VoIP packet may be selectively compressed in accordance with an indication from the controller. A user datagram protocol (UDP)-Lite may be used for partial coverage of the sensitive bits. A comfort noise may be generated by a receiving end during a silence period without receiving a comfort noise packet from a transmitting end. If the VoIP packet is not fit into a currently assigned radio resource, the VoIP packet may be fragmented.