Biological Oscillators in Nanonetworks-Opportunities and Challenges.

One of the major issues in molecular communication-based nanonetworks is the provision and maintenance of a common time knowledge. To stay true to the definition of molecular communication, biological oscillators are the potential solutions to achieve that goal as they generate oscillations through periodic fluctuations in the concentrations of molecules. Through the lens of a communication systems engineer, the scope of this survey is to explicitly classify, for the first time, existing biological oscillators based on whether they are found in nature or not, to discuss, in a tutorial fashion, the main principles that govern the oscillations in each oscillator, and to analyze oscillator parameters that are most relevant to communication engineer researchers.

OrMAC: A Hybrid MAC Protocol Using Orthogonal Codes for Channel Access in M2M Networks.

This paper proposes a hybrid medium access protocol named thogonal coded edium ccess ontrol (OrMAC), which extends the principle of distributed queuing collision avoidance protocol (DQCA) of wireless local area network (WLAN) to delay-sensitive machine-to-machine (M2M) networks. OrMAC pre-assigns orthogonal codes, which serve as the channel contention signals, to the nodes entering the network. The "pre-assignment" eliminates contention collisions since it guarantees that no two nodes share the same contention code.

Network Allocation Vector (NAV) Optimization for Underwater Handshaking-Based Protocols.

In this paper, we obtained the optimized network allocation vector (NAV) for underwater handshaking-based protocols, as inefficient determination of the NAV leads to unnecessarily long silent periods. We propose a scheme which determines the NAV by taking into account all possible propagation delays: propagation delay between a source and a destination; propagation delay between a source and the neighbors; and propagation delay between a destination and the neighbors. Such an approach effectively allows the NAV to be determined precisely equal to duration of a busy channel, and the silent period can be set commensurate to that duration.

A Biochemical Oscillator Using Excitatory Molecules for Nanonetworks.

For nanonetworks to be able to achieve large-scale functionality, such as to respond collectively to a trigger, synchrony between nanomachines is essential. However, to facilitate synchronization, some sort of physical clocking mechanism is required, such as the oscillators driven by auto-inhibitory molecules or by auto-inducing molecules. In this study, taking inspiration from the widely studied biological oscillatory phenomena called Calcium (Ca) oscillations, we undertake a different approach to design an oscillator.