Finally, all standardization and migration efforts discussed before seem to be mainly suitable for the mainstream fieldlevel networks we know today. There will, however, be application domains (andbuilding automation could be one of them) demanding sensor and actuator networks exhibiting very low power consumption, extreme simplicity, lowest cost, or utmost robustness. Networks designed for such niches—no matter if wired or wireless—will often be too specialized to care for backward protocol compatibility. At best, they may share highlevel profiles with the “large” networks for data compatibility. From the protocol viewpoint, they might be independent subsystems that are integrated via gateways or proxies into more powerful backbone networks.Atanyrate,the evolution of field level networks has not reached its end.