A method for mapping from an MPEG-2 transport stream to an IP-based RTP/UDP/IP stack for broadcasting service in a WLAN. All the mapping functions may be performed in a receiver transcoder (FIG. 2). Mobile devices such as laptop computers, cell phones and PDAs have limited battery power, CPU processing and memory resources. To reduce CPU processing power and consumption battery power in these devices certain data processing functions are achieved in the communicating systems, such as the de-multiplexer function that typically prepares an MPEG-2 for retransmission at the local level. When a transcoder, capable of de-multiplexing and MPEG-2 transport stream receives a program it de-multiplexes the stream based on PIDs assigned to each transport packet. This de-multiplexing function extracts several components from a transport stream: video and audio PES/ES associated with programs and PSI (PAT and PMTs).