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Molecular devices, which consist of single or a few molecules, are envisioned to perform advanced tasks such as molecular information processing and collaborative sensing/actuating if they are operated in a cooperative manner. To connect these nanoscopic primitive devices with each other and with macroscale networks, and thus, to realize the internet of molecular devices, requires fundamentally different and novel approaches, other than the molecular or electromagnetic nanocommunications. Recently, we proposed and studied the use of Förster resonance energy transfer (FRET), which is a short-range nonradiative energy transfer process between fluorophores, as a high-rate and reliable wireless communication mechanism to connect fluorophore-based photoactive molecular devices. In this paper, we provide an in-depth architectural view of this new communication paradigm with a focus on its peculiarities, fundamental principles, and design requirements by comprehensively surveying the theoretical and experimental positions and ideas. We give an overview of networking opportunities offered by the intrinsic capabilities of fluorophores under the novel concept of Internet of Molecular Things. We present some prospective applications, theoretical modeling approaches, and experimental opportunities, and finally discuss the implementation challenges., European Research Council (ERC); Minerva; Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (TÜBA-GEBİP); IBM Faculty Award

The emerging technology Terahertz Band (0.3 - 10 THz) communication is envisioned to accommodate high speed wireless communication. Large bandwidth makes it a good candidate for 5G mobile networks. In this paper, fundamental experiments on channel modeling at THz Band are presented with detailed analysis of the setup. The measurement setup consisted of subharmonic mixer and vector network analyzer. Path loss and phase delay measurements from 260 GHz to 400 GHz for different distances, angles of arrival and objects acting as reflectors were examined along with their capacity limits. We have shown that LOS link can reach speeds of terabits per second. In addition, reflections from materials were also examined and results indicated that, in case of signal obstruction, a reflector can be used for establishing NLOS link., Scientific and Technological Research Council of Turkey (TÜBİTAK)

The demand on performance of wireless networks is constantly increasing. To date, conventional sub 6 gigahertz (GHz) bands were able to keep up with the requirements through continuous spectral efficiency improvements. Consequently, advancing this area further became exceptionally costly. Therefore, despite the industry resistance towards changing the already established communications spectrum and unavailability of sufficient number of suitable frequency bands for typical communication purposes, carrier frequency, hence operation bandwidth, increase method is chosen as an alternative. In this paper, the first spectrum chosen for utilization, the 60 GHz band, is surveyed. Detailed explanations of the standards and their processes are provided, in addition to the characteristics of the channel and 60 GHz technologies, devices and consumer applications. As its initial standards are already complete and widespread communications usage expected to start in 2016, the 60 GHz band is a genuine candidate for the next generation of mass market wireless communication systems., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Molecular communication (MC) is a bio-inspired communication method based on the exchange of molecules for information transfer among nanoscale devices. Although MC has been extensively studied from various aspects, limitations imposed by the physical design of transceiving units have been largely neglected in the literature. Recently, we have proposed a nanobioelectronic MC receiver architecture based on the nanoscale field effect transistor-based biosensor (bioFET) technology, providing noninvasive and sensitive molecular detection at nanoscale while producing electrical signals at the output. In this paper, we derive analytical closed-form expressions for the capacity and capacity-achieving input distribution for a memoryless MC channel with a silicon nanowire (SiNW) FET-based MC receiver. The resulting expressions could be used to optimize the information flow in MC systems equipped with nanobioelectronic receivers., European Research Council (ERC) under grant ERC-CoG; Minerva

Molecular communication (MC) is a bio-inspired communication method based on the exchange of molecules for information transfer among nanoscale devices. MC has been extensively studied from various aspects in the literature; however, the physical design of MC transceiving units is largely neglected with the assumption that network nodes are entirely biological devices, e.g., engineered bacteria, which are intrinsically capable of receiving and transmitting molecular messages. However, the low information processing capacity of biological devices and the challenge to interface them with macroscale networks hinder the true application potential of nanonetworks. To overcome this limitation, recently, we proposed a nanobioelectronic MC receiver architecture exploiting the nanoscale field-effect transistor-based biosensor (bioFET) technology, which provides noninvasive and sensitive molecular detection while producing electrical signals as the output. In this paper, we introduce a comprehensive model for silicon nanowire FET-based MC receivers by integrating the underlying processes in MC and bioFET to provide a unified analysis framework. We derive closed-form expressions for the noise statistics, the signal-to-noise ratio (SNR) at the receiver output, and the symbol error probability (SEP). Performance evaluation in terms of SNR and SEP reveals the effects of individual system parameters on the detection performance of the proposed MC receiver., ERC project MINERVA (ERC-CoG); European Union project CIRCLE (EU-H2020-FET-Open)

Molecular communications, where molecules are used to encode, transmit, and receive information, are a promising means of enabling the coordination of nanoscale devices. The paradigm has been extensively studied from various aspects, including channel modeling and noise analysis. Comparatively little attention has been given to the physical design of molecular receiver and transmitter, envisioning biological synthetic cells with intrinsic molecular reception and transmission capabilities as the future nanomachines. However, this assumption leads to a discrepancy between the envisaged applications requiring complex communication interfaces and protocols, and the very limited computational capacities of the envisioned biological nanomachines. In this paper, we examine the feasibility of designing a molecular receiver, in a physical domain other than synthetic biology, meeting the basic requirements of nanonetwork applications. We first review the state-of-the-art biosensing approaches to determine whether they can inspire a receiver design. We reveal that the nanoscale field effect transistor-based electrical biosensor technology (bioFET) is particularly a useful starting point for designing a molecular receiver. Focusing on bioFET-based molecular receivers with a conceptual approach, we provide a guideline elaborating on their operation principles, performance metrics, and design parameters. We then provide a simple model for signal flow in silicon nanowire FET-based molecular receiver. Finally, we discuss the practical challenges of implementing the receiver and present the future research avenues from a communication theoretical perspective., European Research Council (ERC); Minerva

We utilize the well known Additive Inverse Gaussian Noise (AIGN) communication channel to investigate the effect of diversity in diffusion-based molecular communication with drift, where the transmitter releases different types of molecules to the fluid medium by encoding the information onto the release time and type of molecules. The fluid channel imposes extra delay on the communication, and the receiver decodes the encoded information by solely utilizing the molecular arrival times. In this paper, simple receiver models based on maximum likelihood estimation (MLE) are investigated. Furthermore, upper and lower bounds on the capacity of AIGN communication channel with molecular diversity are derived., European Research Council; European Union; Horizon 2020; Minerva

This letter presents first results of a Terahertz (THz) band line-of-sight 2 x 2 multiple-input multiple-output (MIMO) channel. The system architecture is based on a subharmonic mixer that translates the measuring frequency of vector network analyzer in the range of 298-313 GHz. The system uses a virtual antenna array technique to characterize a MIMO channel. The antenna element spacing is derived from the principles of diffraction limited optics to establish parallel channels for higher system throughput and reliability. The MIMO channel measurements are then used in simulations to evaluate the performance of the communication system operating in THz band MIMO communication channel. Finally, we have shown the MIMO link in THz band operating at 7 Gb/s, with higher reliability, in comparison with the single channel operating at 5.55 Gb/s., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Cognitive radio sensor networks (CRSNs) are event-based systems such that sensor nodes detect events and the event readings of the sensors are collaboratively conveyed in a multi-hop manner through vacant channels from event regions to a sink. Hence, the event-to-sink communication and the dynamic radio environment require a coordination scheme in CRSNs. In this paper, we propose a spectrum-aware clustering protocol to address the event-to-sink communication coordination issue in mobile CRSNs. Our clustering scheme consists of two phases. The first phase is the determination of nodes eligible for clustering, and the second phase is to form clusters among those nodes according to vacant spectrum bands. Clusters are temporary and they are not preserved after the end of events. Furthermore, we find average re-clustering probability, expected cluster coverage area, and find maximum event generation frequency for energy-efficient operation of our protocol. We study performance of our protocol in terms of control and data packet exchange, time steps required for clustering, connectivity of clusters, energy consumed for clustering, and re-clustering ratio due to the mobility. Performance comparison simulations show that our algorithm has better performance in terms of connectivity and energy consumption., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Considering the inability of the existing energy resources to satisfy the current needs, the right and efficient. use of the energy has become compulsory. To make energy sustainability permanent, management and planning activities should be carried out by arranging the working hours and decreasing the energy wasting. For all these, power metering, managing and controlling systems or plugs has been proposed in recent efforts. Starting from this point, a new DASH7-based Smart Plug (D7SP) is designed and implemented to achieve a better structure compared to ZigBee equipped models and reduce the drawbacks of current applications. DASH7 technology reaches nearly 6 times farther distances in comparison with 2.4 GHz based protocols and provides multi-year battery life as a result of using limited energy during transmission. Performing in the 433 MHz band prevents the possible interference from overcrowded 2.4 GHz and the other frequencies which helps to gather a more reliable working environment. To shorten the single connection delays and human oriented failures, the MCU was shifted directly into the plug from the rear-end device. Working hours arrangement and standby power cutting off algorithms are implemented in addition to these energy saving targeted improvements to enhance more efficient systems. With the collaboration of the conducted hardware and software oriented adjustments and DASH7-based improvements, a more reliable, mobile and efficient system has been obtained in this work., NA

Atmospheric ducts, which are caused by the rapid decrease in the refractive index of the lower atmosphere, can trap the propagating signals. The trapping effects of the atmospheric ducts can be utilized as a communication medium for beyond-line-of-sight (b-LoS) links. Although the wave propagation and the refractivity estimation techniques for the atmospheric ducts are well studied, there is no work that provides a channel model for the atmospheric ducts. Therefore, we develop a large-scale path-loss model for the surface ducts based on the parabolic equation (PE) methods for the first time in the literature. In addition, we develop a ray-optics (RO) method to analyze the delay spread and angle-of-arrival (AOA) of the ducting channel with the surface ducts. Using the developed RO method, we derive an analytical expression for the effective trapping beamwidth of the transmitter to predict the ranges of the beamwidth that can be trapped by the surface ducts according to the refractivity and the channel parameters., NA

An accurate model for neuro-spike communication is important in understanding the fundamentals of molecular communication. However, none of the existing models in the literature studied variations in the shape of action potentials during Axonal propagation, one of the steps during neuro-spike communication. These variations affect the amount of information communicated through a neuron. Hence, analyzing effects of these variations in the release of neurotransmitter, the carrier of information in neuro-spike communication, is imperative in deriving a realistic model for neuro-spike communication. In this work, we improve the existing channel models for synaptic communication to cover the effect of changes in the width of action potential on hippocampal pyramidal neurons based on the experimental data reported in the literature. The receiver neuron is assumed to detect spikes based on Neyman-Pearson method. We derive the structure of this detector for the proposed channel model. Numerical results depict that an increase in the spike width decreases the error probability., European Research Council (ERC); Scientific and Technological Research Council of Turkey (TÜBİTAK); Minerva

Two major wireless communication evolutions, the fifth generation (5G) mobile systems and machine-to-machine (M2M) communication boom, are imminent. A major 5G challenge is supplying the higher than ever data rate and traffic demands using the already crunched conventional spectrum, where the expected addition of billions of new M2M connections will worsen the situation. Millimetre wave (mm-wave) band offers one substantial solution, through the utilization of parts of its vast frequency range. Following a general overview and the theoretical background, this paper provides the first realistic channel capacity and bit rate analyses in the literature for the 60 gigahertz (GHz) and low-terahertz bands, and compares those with the sub 6 GHz band links from the perspective of Internet of Things (IoT) application deployments. It is found that, considering the network densification intrinsic to the M2M communications, the use of the mm-wave band is a viable method to form stable and high performance links which are capable of supporting advanced IoT services., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Mobile data traffic is constantly rising at huge growth rates. One evolving method to counter this expansion is operation frequency, and so bandwidth, increase, as formal standardization activities on 60 gigahertz industrial, scientific and medical radio band began in 2005. In line with this, this paper proposes the utilization of low terahertz (THz) band for the next-generation of mobile and wireless communications systems. Following the introduction and an overview of the low-THz band propagation properties, representative indoor simulations comparing the current fourth generation and proposed high frequency fifth generation networks are presented. The results show that, while it is possible to form and maintain stable communication links at low-THz band, techniques to reduce signal attenuation should be researched within all related subjects., Scientific and Technological Research Council of Turkey (TÜBİTAK)

As the demand for wireless bandwidth rapidly increases, alternative methods to radio frequency-based communication are investigated to overcome the limited bandwidth problem. Visible light communication (VLC) using light emitting diodes (LEDs) is one of these alternatives. LEDs are estimated to replace the incandescent bulbs within the decade. Since, LEDs can be intensity modulated faster than the human eye can detect, illumination and communication can both be provided by the same lighting system. Indoors communication constitutes 70% of the overall traffic, and VLC is a promising technology to complement Wi-Fi and cellular wireless systems. However, proper handover mechanism should be developed for VLC to be a complete indoors solution. In this paper, we present two soft handover methods for VLC. Simulation results indicate our solutions provide higher data rate for both the overall system and individual users in the handover region., Türk Telekom

In the near future, the available radio-frequency (RF) bandwidth will not be sufficient to meet the ever increasing demand for wireless access. Visible light communication (VLC) is an alternative method to reduce the burden of RF-based communication, especially in indoor communications. 70% of the communication is indoors, and light emitting diode (LED) arrays are spreading for illumination purposes thanks to their low energy and higher lifetime. VLC can be realized as a secondary application in LED arrays that are placed for lighting. In this way, some of the wireless traffic can be sent using light, with less cost and less carbon footprint. For these reasons, VLC attracts significant research interests. We provide an extensive survey of the current literature by outlining challenges and future research areas in order to facilitate future research in this area., Türk Telekom

The integration of wireless communication and control systems revealed wireless networked control systems (WNCSs). One fundamental problem in WNCSs is to have a wide coverage area. For the first time in the literature, we address this problem and we obtain the maximum coverage area by solving an optimization problem. In this technical note, we consider a WNCS where the output sensor measurements are transmitted over separate heterogeneous multi-hop wireless ad-hoc subnetworks. The observation process is divided into N parts and the system state is estimated using the Kalman filter. We present the critical arrival probability for a sensor measurement packet such that if the packet arrival probability is larger than the critical value, it is guaranteed that the estimator of the WNCS converges. We derive the maximum total coverage area of the heterogeneous wireless subnetworks having maximum cost-efficiency under the constraint of the convergence of the WNCS estimator., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Nanonetworks is an emerging field of study where nanomachines communicate to work beyond their individual limited processing capabilities and perform complicated tasks. The human body is an example of a very large nanoscale communication network, where individual constituents communicate by means of molecular nanonetworks. Amongst the various intra-body networks, the nervous system forms the largest and the most complex network. In this paper, we introduce a queueing theory based delay analysis model for neuro-spike communication between two neurons. Using standard queueing model blocks such as servers, queues and fork-join networks, impulse reception and processing through the nervous system is modeled as arrival and service processes in queues. Simulations show that the response time characteristics of the model are comparable to those of the biological neurons., European Research Council (ERC); Minerva; Scientific and Technological Research Council of Turkey (TÜBİTAK) (Scientific and Technological Research Council of Turkey (TÜBİTAK)); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBİP); IBM through IBM Faculty Award

Seamless connection of molecular nanonetworks to macroscale cyber networks is envisioned to enable the Internet of Bio-NanoThings, which promises for cutting-edge applications, especially in the medical domain. The connection requires the development of an interface between the biochemical domain of molecular nanonetworks and the electrical domain of conventional electromagnetic networks. To this aim, in this paper, we propose to exploit field effect transistor based biosensors (bioFETs) to devise a molecular antenna capable of transducing molecular messages into electrical signals. In particular, focusing on the use of SiNW FET-based biosensors as molecular antennas, we develop deterministic and noise models for the antenna operation to provide a theoretical framework for the optimization of the device from communication perspective. We numerically evaluate the performance of the antenna in terms of the Signal-to-Noise Ratio (SNR) at the electrical output., European Research Council (ERC); Minerva

Planning and management of energy are among the most important topics nowadays due to the fact that the existing power plants and systems fail to satisfy the energy demand and keep up with the daily developing technologies. To maintain the energy need of the existing systems, researchers are aiming to improve usage and savings of available resources and systems. For example, power metering system has been proposed to decrease the energy wasting. The purpose of this system can be explained as limiting the energy consumption in some cases like stand-by or while switching programs or devices which the system is installed on. By blocking the unnecessary consumption of energy, profits and savings are targeted. In this work, a new power meter system based on ZigBee technology is designed and implemented to obtain a more efficient structure and reduce the number of disadvantages of the existing technologies. In SmartPlug, the MCU was moved into the plug from outer environment and shifting the host to a spectator to eliminate user based faults and/or problems. Moreover, the proposed structure enhances the safety by detecting the sudden voltage fluctuations and preventing the possible damages of end-devices. In addition to these, we prove that cutting of stand-by powers and limiting the energy consumption by arranging the working hours of devices based on energy unit prices provide efficient, right and cheap usage of the energy., NA

Nanocommunications via Förster Resonance Energy Transfer (FRET) is a promising means of realising collaboration between photoactive nanomachines to implement advanced nanotechnology applications. The method is based on exchange of energy levels between fluorescent molecules by the FRET phenomenon which intrinsically provides a virtual nanocommunication link. In this work, further to the extensive theoretical studies, we demonstrate the first information transfer through a FRET-based nanocommunication channel. We implement a digital communication system combining macroscale transceiver instruments and a bulk solution of fluorophore nanoantennas. The performance of the FRET-based Multiple-Input and Multiple-Output (MIMO) nanocommunication channel between closely located mobile nanoantennas in the sample solution is evaluated in terms of Signal-to-Noise Ratio (SNR) and Bit Error Rate (BER) obtained for the transmission rates of 50 kbps, 150 kbps and 250 kbps. The results of the performance evaluation are very promising for the development of high-rate and reliable molecular communication networks at nanoscale., European Research Council (ERC); Scientific and Technological Research Council of Turkey (TÜBİTAK); IBM Faculty Award; Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBİP); Minerva; European Union; Horizon 2020

Nanonetworks refer to a group of nano-sized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Forster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRETMAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth death processes with continuous time Markov chains. We evaluate the performance of FRETMSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award

Wireless data traffic is continuously increasing due to the steady rise in both connected device number and traffic per device. Wireless networks, traditionally confined below 6 giga-hertz, are getting clogged and unable to satisfy the ever-increasing demands of its users. Already aware of this, telecommunications industry and academia have been working on solutions. One of the main methods for throughput increase is operation bandwidth expansion; however, sufficient spectrum is not available within the conventional frequencies. Following various considerations, 60 GHz industrial, scientific and medical radio band has been selected as the new spectrum to be utilized and wireless personal and local area network standards for the band are already completed. In line with the stated developments, this paper proposes the use of 60 GHz band for the fifth generation (5G) communication systems. After very briefly setting the scene of the current wireless communication networks, the physical layer properties of the 60 GHz band are presented. A representative indoor simulation between the fourth generation and proposed 5G cases is set and performed. The results are assessed and compared before concluding the paper., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Nanonetworks are envisaged to expand the capabilities of single nanomachines by enabling collaboration through communication between them. Forster Resonance Energy Transfer (FRET) observed among fluorescent molecules is a promising means of high-rate and reliable information transfer between single fluorophore-based nanoscale molecular machines. Recent theoretical studies have underlined its practicality for mobile ad hoc nanonetworks consisting of functionalized fluorescent molecules. In this study, we focus on the spatial characteristics of FRET-Based Mobile Molecular Sensor/Actor Nanonetworks (FRET-MSAN) by investigating the network performance in terms of communication coverage, network throughput and information propagation rate through extensive Monte Carlo simulations. The effect of fundamental system parameters related to FRET and to the mobility of the network nodes on the network performance is revealed. The results of the simulations indicate that the throughput and propagation rate as a function of distance from the information source are well-fitted by exponential curves. We also observe that the impact of FRET mechanism suppresses the effect of Brownian motion of network nodes on the exciton mobility., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award

Nanonetworks constructed by interconnecting nanodevices using wireless communication allow the nanodevices to perform more complex functions by means of cooperation between them. For the first time in the literature, a novel and physically realizable nanoscale communication technique is introduced: Nanoscale Heat Communication (NHC) in which the heat transfer is used for communication at the nanoscale. The transmitted information is encoded in temperature signals using Magneto-Caloric Effect (MCE) which is the change in temperature of a magnetic material exposed to a varying magnetic field. Thermal energy emitted or absorbed by a transmitter nanodevice is subject to the laws of thermal diffusion which changes the temperature of the communication medium. The transmitted information is decoded by a receiver nanodevice that senses the temperature variations. Using information theoretical analysis, a closed-form expression for the channel capacity is obtained. According to the performance evaluation of the channel capacity, NHC provides a significantly higher capacity communication compared with the existing molecular communication techniques. Therefore, NHC stands as a promising solution to nanoscale communication between nanomachines based on its channel capacity performance, advantages, and possible applications for the emerging field of nanonetworks., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award

The integration of wireless communication and control systems revealed wireless networked control systems (WNCSs). One fundamental problem in WNCSs is to have a wide coverage area. For the first time in the literature, we address this problem and we obtain the maximum coverage area by solving an optimization problem. In this paper, we consider a WNCS where the output sensor measurements are transmitted over separate multi-hop wireless ad-hoc subnetworks. The system state is estimated using the Kalman filter. We present the critical arrival probability for a sensor measurement packet such that if the packet arrival probability is larger than the critical value, it is guaranteed that the expected state estimation error covariance is bounded, and hence the WNCS is stable. We find the optimum hop-diameter of a multi-hop wireless ad-hoc subnetwork under the constraints of both the stability of the WNCS and the cost-efficiency of the multi-hop wireless network. Furthermore, under these constraints, we derive the maximum total coverage area of the wireless subnetworks. The numerical analyses show that the maximum total coverage area can be increased by appropriately adjusting the number of sensors, the successful packet transmission probability between relay nodes, and the eigenvalues of the system matrix., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through the IBM Faculty Award

In the Molecular Communication (MC), molecules are utilized to encode, transmit, and receive information. Transmission of the information is achieved by means of diffusion of molecules and the information is recovered based on the molecule concentration variations at the receiver location. The MC is very prone to intersymbol interference (ISI) due to residual molecules emitted previously. Furthermore, the stochastic nature of the molecule movements adds noise to the MC. For the first time, we propose four methods for a receiver in the MC to recover the transmitted information distorted by both ISI and noise. We introduce sequence detection methods based on maximum a posteriori (MAP) and maximum likelihood (ML) criterions, a linear equalizer based on minimum mean-square error (MMSE) criterion, and a decision-feedback equalizer (DFE) which is a nonlinear equalizer. We present a channel estimator to estimate time varying MC channel at the receiver. The performances of the proposed methods based on bit error rates are evaluated. The sequence detection methods reveal the best performance at the expense of computational complexity. However, the MMSE equalizer has the lowest performance with the lowest computational complexity. The results show that using these methods significantly increases the information transmission rate in the MC., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through the IBM Faculty Award

Molecular communication (MC) is a promising paradigm to communicate at nanoscale and it is inspired by nature. One of the MC methods in nature is the gap junction (GJ) communication between cardiomyocytes. The GJ communication is achieved by diffusion of ions through GJ channels between the cells. The transmission of the information is realized by means of the propagation of the action potential (AP) signal. The probabilities of both the AP propagation failure and the spontaneous AP initiation are obtained. For the first time in the literature, the GJ communication channel is modeled and analyzed from the information theoretical perspective to find the communication channel capacity. A closed-form expression is derived for the capacity of the GJ communication channel. The channel capacity, propagation delay, and information transmission rate are analyzed numerically for a three-cell network. The results of the numerical analyses point out a correlation between an increase in the incidence of several cardiac diseases and a decrease in the channel capacity, an increase in the propagation delay, and either an increase or a decrease in the transmission rate. The method that we use and results that are presented may help in the investigation, diagnosis, and treatment of cardiac diseases as well as help in the design of nanodevices communicating via GJ channels., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award

It is essential to develop energy-efficient communication techniques for nanoscale wireless communications. In this paper, a new modulation and a novel minimum energy coding scheme (MEC) are proposed to achieve energy efficiency in wireless nanosensor networks (WNSNs). Unlike existing studies, MEC maintains the desired code distance to provide reliability, while minimizing energy. It is analytically shown that, with MEC, codewords can be decoded perfectly for large code distances, if the source set cardinality is less than the inverse of the symbol error probability. Performance evaluations show that MEC outperforms popular codes such as Hamming, Reed-Solomon and Golay in the average codeword energy sense., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award; Turk Telekom

Nanoscale communication based on Forster Resonance Energy Transfer (FRET) is a promising paradigm that allows future molecular-size machines to communicate with each other over distances up to 10 nm using the excited state energies of fluorescent molecules. In this study, we propose a novel nanoscale communication method based on multi-step FRET using identical fluorophores as relay nodes between communicating nanomachines, and utilizing multi-exciton transmission scheme in order to improve the limited range of the communication and achievable transmission rate over the nanoscale channel. We investigate two communication scenarios: immobile nanomachines communicating through a channel in a host material with linearly located relay nodes, and mobile nanomachines communicating through a channel in a 3-dimensional aqueous environment with randomly deployed relay nodes. We simulate the communication over these channels with realistic algorithms considering the high degree of randomness intrinsic to FRET phenomenon. Using the simulation results and following a Monte Carlo approach, we evaluate the performance of the channels by means of information theoretical capacity and interference probability. We show that multi-step FRET-based communication significantly outperforms the other biologically inspired nanocommunication techniques proposed so far in terms of maximum achievable data transmission rates. The results underline the compatibility and practicality of the FRET-based communication for several applications ranging from molecular computers to nanosensor networks., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through the IBM Faculty Award

Nanonetworks refer to a group of nano-sized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Forster resonance energy transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, we focus on network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation exploiting the SIR model of epidemics. We derive closed form expressions for the probability of the actor nodes to detect a message generated on the sensor nodes in FRET-MSAN, and for the average detection time of the transmitted message by the nanoreceivers in FRET-MAMNET. We numerically evaluate the performance of these networks in terms of reliability and transmission delay for varying number of nanonodes and varying size of nanomachines, as well as, for several FRET-related parameters., NA

Nanoscale communication based on Forster Resonance Energy Transfer (FRET) enables nanomachines to communicate with each other using the excited state of the fluorescent molecules as the information conveyer. In this study, FRET-based nanoscale communication is further extended to realize FRET-based nanoscale broadcast communication with one transmitter and many receiver nanomachines, and the performance of the broadcast channel is analyzed information theoretically. Furthermore, an electrically controllable routing mechanism is proposed exploiting the Quantum Confined Stark Effect (QCSE) observed in quantum dots. It is shown that by appropriately selecting the employed molecules on the communicating nanomachines, it is possible to control the route of the information flow by externally applying electric field in FRET-based nanonetworks., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBIP); IBM through IBM Faculty Award

Recent developments in nanotechnology have enabled the fabrication of nanomachines with very limited sensing, computation, communication, and action capabilities. The network of communicating nanomachines is envisaged as nanonetworks that are designed to accomplish complex tasks such as drug delivery and health monitoring. For the realization of future nanonetworks, it is essential to develop novel and efficient communication and networking paradigms. In this paper, the first step toward designing a mobile ad hoc molecular nanonetwork (MAMNET) with electrochemical communication is taken. MAMNET consists of mobile nanomachines and infostations that share nanoscale information using electrochemical communication whenever they have a physical contact with each other. In MAMNET, the intermittent connectivity introduced by the mobility of nanomachines and infostations is a critical issue to be addressed. An analytical framework that incorporates the effect of mobility into the performance of electrochemical communication among nanomachines is presented. Using the analytical model, numerical analysis for the performance evaluation of MAMNET is obtained. Results reveal that MAMNET achieves adequately high throughput to enable frontier nanonetwork applications with acceptable communication latency., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences (Turkish Academy of Sciences (TÜBA)); IBM

In this study, a novel and physically realizable nanoscale communication paradigm is introduced based on a well-known phenomenon, Forster resonance energy transfer (FRET), for the first time in the literature. FRET is a nonradiative energy transfer process between fluorescent molecules based on the dipole-dipole interactions of molecules. Energy is transferred rapidly from a donor to an acceptor molecule in a close proximity such as 0 to 10 nm without radiation of a photon. Low dependence on the environmental factors, controllability of its parameters, and relatively wide transfer range make FRET a promising candidate to be used for a high-rate nanoscale communication channel. In this paper, the simplest form of the FRET-based molecular communication channel comprising a single transmitter-receiver nanomachine pair and an extended version of this channel with a relay nanomachine for long-range applications are modeled considering nanomachines as nanoscale electromechanical devices with some sensing, computing, and actuating capabilities. Furthermore, using the information theoretical approach, the capacities of these communication channels are investigated and the dependence of the capacity on some environmental and intrinsic parameters is analyzed. It is shown that the capacity can be increased by appropriately selecting the donor-acceptor pair, the medium, the intermolecular distance, and the orientation of the molecules., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences; IBM