A split implementation of the dynamic source routing protocol for lunar/planetary surface communications

Future NASA exploration missions will involve teams of humans and robots working together to achieve science objectives on lunar and planetary surfaces. Members of these teams must be able to communicate with each other interactively as they work together in close proximity. However, current operational procedures and technologies are based on the assumption that surface elements operate in isolation and communicate solely with the Earth, either directly or through orbiting relays. The use of direct wireless communications among local surface elements will be necessary to achieve optimal communications efficiency. However, the surface elements are mobile and may lose communication with one another, due to traveling either out of range or behind an obstruction. This problem can be addressed through the use of a mobile ad hoc network routing protocol, allowing nodes unable to communicate directly to remain in contact by relaying data through one or more intermediate nodes. To test this method of dynamic surface-to-surface communications, we have implemented the dynamic source routing (DSR) protocol in a UNIX-based test environment. DSR is an efficient routing protocol that allows independent wireless nodes to self-organize into an ad hoc network. To enhance performance, forwarding and routing functions are split between kernel and user space, respectively. We have conducted field testing to determine the performance and effectiveness of DSR in maintaining connectivity among mobile nodes in the presence of communications outages caused by distance or obstructions. The results suggest that mobile ad hoc routing is a promising basis for communications among surface elements