In this paper, we present a network-aware source coding (NASC) approach for wireless broadcast channels with multiple sources. The proposed NSAC approach takes into account the information of the network topology during the source coding process and the cross-layer design approach may be beneficial for wireless networks. We derive the optimal bounds using network-aware source coding in wireless networks for two scenarios: the minimization of the total traffic load and the minimization of the total required energy. Implementation issues are also discussed.