In military units of the size of a brigad or a battalion, several radio networks are often needed to be interconnected into a heterogeneous network. These interconnections can be designed in many different ways. In this report, different designs to interconnect radio networks based on OLSR routing at OSI layer 3 were investigated. The goal of the design was to keep the overhead generated by the OLSR control traffic low, while at the same time maintaining a high packet delivery ratio. For each radio network, two setups were used. In the first, the waveforms used Synchronized Cooperative Broadcast (SCB) to which a devised neighbourhood discovery procedure was integrated. In the second setup, the waveforms used OLSR on OSI layer 2 and TDMA at the MAC layer. To accomplish the interconnection, OLSR and modified versions of OLSR at OSI layer 3 were analysed. The results showed that the overhead was reduced considerably by introducing the OLSR modifications. In general, the setup with waveforms based on SCB worked better than the OLSR and TDMA setup.