Error Control for Calcium Signaling based Molecular Communication Michael Taynnan Barros * , Sasitharan Balasubramaniam † , Brendan Jennings * * Telecommunication Software and Systems Group (TSSG), Waterford Institute of Technology (WIT), Ireland ‡ Nano Communications Center (NCC), Tampere University of Technology (TUT), Finland Emails: {mbarros,bjennings}@tssg.org, sasi.bala@tut.fi Abstract—Calcium signaling is one of the most widely studied means of providing communication for molecular communica- tions in nanonetworks. In this paper, we investigate error control approaches for calcium signaling based molecular communica- tions. Taking an information theoretic approach we show, using a stochastic simulation model, how error conditions such as signal fading, multipath propagation and spatial noise can affect the communication reliability. In order to counter these issues, we proposed using baseband modulations techniques (Return- to-zero (RZ) and Non-return-to-zero (NRZ)) in combination with channel coding (Reed Solomon) to improve the performance of the communication system. Index Terms—Molecular Communication, Nanonetworks, Cal- cium Signaling, Information Theory, Tissue deformation. I. I NTRODUCTION The advancements in nanotechnology has enabled nanoma- chines to be developed, where these devices are able to sense conditions at the molecular level. Due to the low processing capabilities of the nanomachines, the new paradigm of nano communications has been proposed to enable these miniature devices to interconnect in order to increase their functionalities [1]. Utilizing this new communication paradigm will open new application opportunities, one of which is in healthcare. Molecular communications is one form of nano communi- cations that utilizes biological components found in nature to develop communication systems. Unlike existing types of communication approaches, in molecular communications the molecules are encoded with information in the transmitter nanomachine, and carried along through space and time, towards the receiver nanomachine [2]. Calcium Signaling Molecular Communication Systems (CSMCS) use a cellular biological mechanism to perform communication between nanomachines [3], [4] and currently is one of the most studied types of molecular communi- cations. Calcium signaling (CS) is a short range signaling process that supports the biological cells’ regulatory function (e.g., cell growth and proliferation) [5]. It is composed of multiple stages of chemical reactions which are responsible for the stimulation, amplification and release (or diffusion) of Ca 2+ waves [6]. The process begins with the transmitter nanomachine stimulating the internal Ca 2+ ions store (we assume that the nanomachines are embedded within the cells). Once stimulated, the Ca 2+ ions will diffuse and invoke the neighboring cell’s intracellular store. This process continues as the Ca 2+ ions diffuse between the cells. The diffusion process is performed through the gap junction between the cells, which are gates that open and closes between the cytoplasms of two neighbor cells. Once the Ca 2+ ions arrives at the receiver, the quantity of Ca 2+ ions are sensed and triggers an internal reaction of the receiver nanomachine. The cellular tissue scenarios bring numerous error condi- tions to the CSMCS, including signal fading and multipath propagation. These properties usually lead to spatial noise that can occur in the tissue, and this is usually amplified as the cellular tissue goes through deformation. In this paper, we first investigate the signal fading and multipath propagation, as well as the resulting noise in the communication system. This is fol- lowed by applying baseband modulations techniques (Return- to-zero (RZ) and Non-return-to-zero (NRZ)) combined with channel coding (Reed Solomon) to improve the performance of the communication system. The results from our simulation study shows that using the error correction technique helps to improve the communication channel performance. This paper is organized as follows: §II presents the simu- lation model as well as a brief discussion about deformable tissues. We present analysis for the following channel prop- erties: Signal fading (§III), Multipath propagation (§IV) and Spatial noise (§V). Error control techniques are analyzed in §VI. Finally, the paper is concluded in §VII. Fig. 1: Calcium signaling molecular communication systems (CSMCS): (a) regular tissue, (b) double-sided compression. Our scenario application assumes that nanomachines (receiver and transmitter) are embedded in the cells and are able to stimulate the Ca 2+ ions for signaling. 1056 978-1-4799-2390-8/13/$31.00 ©2013 IEEE Asilomar 2013