Distributed real-time systems present a particular challenge, because two key problems have to be solved during their development: First, deployed protocols must provide deterministic behavior to enable a predictable outcome. Second, the implementations of the protocols have to be in compliance with the stringent timing constraints stated by the protocols to ensure that their runtime behavior remains deterministic. This, particularly, requires an adequate isolation of time-critical protocols from less preferential applications installed on the same node. In this paper, we present the protocol framework BiPS, which tackles these challenges for wireless sensor networks and Imote 2 hardware platforms. Besides summarizing the various MAC protocols - both best effort and real-time-capable protocols - and operating system functionalities provided by BiPS, this paper presents comparative evaluations with TinyOS, a state-of-the-practice operating system for wireless sensor networks, and the real-time operating system RIOT. The results show that protocols realized with BiPS outperforms these solutions w.r.t. predictability of execution times, thereby providing evidence of the advantages of BiPS for real-time systems.