An ultra low power wireless node (50) sends (100) a packet on at least two radio channels to a network of backbone nodes (65, 70, 75, 80). Which of the radio channels are listened for at the backbone nodes is allocated (130) according to detected reception performance. The allocating is coordinated for different ones of the backbone nodes. By combining sending on multiple radio channels with dynamically allocating the listening channels according to reception performance and with coordinated allocations for different backbone nodes, the spatial diversity and channel diversity of the separate receiving locations can be exploited. This can make the system more resilient to time varying location specific interference or channel specific interference for example.