Time synchronization among nodes in a wireless mobile ad hoc network (MANET) is obtained using a cross layer approach. Each node maintains a routing table that contains entries corresponding to other nodes of the network that are one or more hops away from the node, and topology messages are exchanged periodically among the nodes in order to update their routing tables. A network master node is selected, and remaining nodes that are one or more hops away from the master node are defined as slave nodes. The master node includes master timing information in the topology messages it transmits. The timing information is concatenated to include a first time (T1) at which a topology message was received by the master from each of the slave nodes, and a second time (td) at which the master node transmits a topology message after receiving all the topology messages from the slave nodes.