welcome to the forums; I'm not entirely sure what you are trying to achieve from your question.
If you are sniffing your local network, are you connected via a hub or a switch? If a switch, you'll need to research some arp spoofing/MitM techniques to convince the switch to send other clients traffic out through your port.
If you are trying to sniff traffic beyond your local subnet (comment on WImax connection) then this won't work as sniffing is limited to the local layer 2 subnet.
Hope this helps point you in the right direction, let me know if you have any further queries.