Naomi
Naomi: Nano-Machines to MIMO Wearables and Smart Phones Communications
Background: Nano Networks: Wireless Communications Between Nanomachines
The idea of molecular communication or nanonetworks, as a new paradigm for engineered biological nanomachines (NMs) that communicate with each other and with natural biological systems, has attracted attention within the research community as well as for commercial interests [1], [2], [3]. NMs can perform simple tasks of computation, sensing, and actuation in a closed environment such as the human body. These tasks include e.g., detection of molecules, generation of motion, or performing chemical reactions. In addition to communicating with each other and effectively forming an inside the body (ITB) sensor network, NMs including purified protein molecules, genetically engineered cells, artificial protocells, and bio-silicon hybrid devices, can interact with existing biological systems to enable a set of new functions. Such new functions include medical (e.g., nanomedicine and tissue engineering), environmental (e.g., quality control), information and communication technology (e.g., implantable bio-sensor and actuator networks), and defense systems (e.g., biochemical sensing) applications.
Nano wireless communication aims at allowing NMs to communicate using either electromagnetic waves, similar to existing wireless technologies, or molecular and chemical communications [4], [5]. Although using electromagnetic waves is attractive, existing wireless technology must be adopted to the nanoscale environment due to requirements on device size, required energy, and the frequency bands that may be used for nanoscale communication. Recent works have shown that it appears possible to design nanoantennas of a few hundred nanometers operating in the terahertz (THz) band [4], [5]. Some experimental antennas have already been implemented using graphene or carbon nanotubes, but further work is needed to identify the exact operating frequency, radiation efficiency, and coverage. When an NM wants to communicate with another NM, the information is encoded into an electromagnetic wave modulated at a very high frequency. It is envisioned to use an adapted modulation scheme that works properly at this frequency [4], [5]. Among the possibilities of implementing electromagnetic wireless nanosensor networks, continuous waves or tiny bursts of a few nanoseconds are possible to implement. Transmitting NMs can modulate the sequence of bits 0 or 1 using appropriate modulation schemes such as quadrature amplitude modulation, phase shift keying, pulse position modulation, and pulse rate modulation.
Background: Concurrent Research on Terahertz Communications
On-going advances in semiconductor processes point at the emergence of transistors with transit frequencies that are high enough to start servicing the low end of the THz band (300 GHz to 600 GHz) for wireless personal area and wearable networks [8], [9], for which these bands can support data rates up to 10 Gbit/s. The currently unallocated THz frequency region, offers the potential for systems with much larger bandwidth, ranging from a few GHz to more than 100 GHz. Thus, a variety of international standards organizations are exploring the technical and operational characteristics of services in the unallocated frequency range above 275 GHz. Research groups in Europe, Japan, the Americas and elsewhere, supported by both industry and government funding, are moving forward with research and development in THz wireless link technology. One technical issue in these efforts involves the current lack of compact, efficient generation and detection systems, which has so far limited access to the THz communication bands. However, recent advances in device and antenna technologies can enable short-range (less than 100 m), high-capacity (greater than 10 Gbit/s) transmission in the THz region [10], [11], [12].
Naomi: Objectives
The basic objective of the Naomi project is to develop techniques that facilitate communications between out-of-body (OOB) devices such as wearables (that can be potentially mounted on the skin) and smart phones and ITB NMs. Specifically, our objective is to investigate whether OOB electromagnetic devices such as wearables (that can act as a relay towards a smart phone) and smart phones equipped with multiple antennas operating at very high frequencies beyond 60 GHz (approaching the 300 GHz bands) can use special multiple antenna techniques, such as multiple input multiple output coding and modulation schemes to exchange information with ITB NMs, which are also equipped with multiple antennas operating in the THz band. Currently the ITB NM antennas are used to form ITB wireless sensor networks, but they could also be used to send/receive electromagnetic signals to an OOB device.
This basic objective is motivated by the observation that while molecular communication and networking are making rapid progress in understanding the new information theoretic aspects of communicating in fluid media, that is in aqueous environments, using Terahertz communications, our understanding of how communications between ITB and OOB devices can be supported is limited. One reason for this is that although THz channel models for ITB NMs as well as for wireless personal area networks are available, our understanding of hybrid channels in which the THz transceivers are both ITB and OOB devices is limited.
From a practical perspective, it appears that being able to transfer information from ITB devices (such as neural dust networks and various electroceuticals) to OOB devices (such as a specific wearable or a smart phone) could open up for a plethora of new applications ranging from health monitoring to treatment recommendation systems. From an information theoretic point of view, the channel capacity and the propagation characteristics of a medium consisting of mixed (hybrid) fluid and electromagnetic environment are largely unknown and call for some basic research considerations. Considering the rapid advancements in ITB sensor networks and their information theoretic foundations and the progress in THz communications, communication between OOB and ITB transceivers seem feasible in the 2020-2025 time frame.
The Naomi project will consider the following scenarios and target the associated research questions:
1. From ITB Tx to OOB Rx communication: A very low power ITB transmitter (Tx) is associated with an ITB wireless nanosensor network that uses THz electromagnetic communications to maintain the sensor network structure. The low power transmitter transmits very low duty cycle electromagnetic signals to an OOB receiver (Rx) device, which can be a wearable or smart phone, possibly equipped with multiple receive antennas. In this case, there is a need to understand if the hybrid channel between the ITB Tx and the OOB Rx is applicable for information transfer and how this channel can be modelled and characterized in terms of channel capacity. A fundamental question is that given the hybrid channel characteristics, and transmit signal characteristics achievable with reported existing technologies, what distances and data rates can be supported between ITB sensor networks and OOB receivers.
2. From OOB Tx to ITB Rx communication: A low power OOB transmitter (Tx) uses multiple antennas to transmit signals that can be received by the ITB Rx NMs using its nanosensors, as used for the intra-NM communication as described in [4]. It is necessary to develop proper models for the hybrid channel through which the electromagnetic signal needs to propagate from an OOB Tx device (wearable or smart phone) to the ITB Rx (nanosensor) [4], [13]. A fundamental question is that given the existing receiver sensitivities of nanosensors and the hybrid channel characteristics, what distances and data rates can be achieved between an OOB Tx and an ITB Rx sensor.
Possible Next Steps beyond the Seed Project Naomi
The idea of the Naomi project is that it should lay the foundation -- in terms understanding the propagation characteristics and developing PHY channel models for situations in which an ITB sensor network communicates with an OOB transceiver which can be part of a wearable device or a smart phone -- of further research on PHY layer procedures and medium access control algorithms.
Current research efforts in the area of (1) electromagnetic communication between NMs in ITB sensor networks and (2) THz band communication in wireless personal area networks have largely enhanced our understanding of the feasibility of short range communications and ITB sensor networks in the THz band, but there is a research gap regarding how one can “connect” (1) and (2). Therefore, in the continuation of Naomi, we plan to device PHY and MAC layer procedures that would ultimately lead to connecting the ITB sensor networks to the Internet of Things. Applications of this type of IoT would include connected health monitoring, real time medication control and diagnostic services.
Expected Outcome of Naomi and Relations to Wireless Systems for the TERA Age
First, the expected outcome of Naomi is a PHY layer model of an ITB-OOB transceiver model, including the frequency dependent model of the hybrid channel between ITB and OOB transmitters and receivers. A verification of this model should be based on available measurement results for the special cases when the entire transceiver chain is ITB [4], [5], [6] or OOB operating in the beyond 60 GHz spectrum [14]. Based on this transceiver and channel model, the second planned output of Naomi is a first set of basic PHY and MAC layer procedures that are needed in order to connect ITB NMs to an external wearable “gateway” or directly to a smart phone with multiple antennas. Our vision is that NMs will be integrated into the internet of (nano-)things, and Naomi can be seen as a first step in that direction.
References
[1] T. Nakano, M. J. Moore, F. Wei, A. V. Vasilakos, and J. Shuai, “Molecular Communication and Networking: Opportunities and Challenges”, IEEE Transactions on Nanobioscience, Vol. 11, No. 2, pp. 135-148, June 2012.
[2] A. Gohari, M. Mirmohseni, and M. Nasiri-Kenari, “Information Theory of Mulecular Communication: Directions and Challenges”, IEEE Transactions on Molecular, Biological, and Multi-scale Communications, Vol. 2, No. 2, December 2016.
[3] K. V. Srinivas, A. W. Eckford, R. S. Adve, ”Molecular Communication in Fluid Media: The Additive Inverse Gaussian Noise Channel”, IEEE Transactions in Information Theory, Vol. 58, No. 7, pp. 4678-4692, July 2012.
[4] N. Agoulmine, K. Kim, S. Kim, T. Rim, J. S. Lee, M. Meyyappan, “Enabling Communication and Cooperation in Bio-Nanosensor Networks: Toward Innovative Healthcare Solutions”, IEEE Wireless Communications, Vol. 19, Issue 5, pp. 42-51, Octrober 2012.
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[7] T. Nakano, Y. Okaie, and J. Q. Liu, “Channel Model and Capacity Analysis of Molecular Communication with Brownian Motion”, IEEE Communications Letters, Vol. 16, No. 6, pp. 797-800, June 2012.
[8] R. Piesiewicz, T. Kleine-Ostmann, N. Krumbholz, D. Mittleman, M. Koch, J. Schoebei, and T. Kurner, “Short-Range Ultra.Broadband Terahertz Communications: Concepts and Perspectives”, IEEE Antennas and Propagation Magazine, Vol. 49, Issue 6, pp. 24-39, December 2007.
[9] C. Yi, M. Urteaga, S. H. Choi, M. Kim, “A 280 GHz InP DHBT Receiver Detector Containing a Differential Preamplifier”, IEEE Transactions on Terahertz Science and Technology, pp. 1-9, March 2017.
[10] K. Murano, I. Watanabe, A. Kasamatsu, S. Suzuki, M. Asada, W. Withayachumnankul, T. Tanaka, Y. Monnai, “Low-Profile Terahertz Radar Based on Broadband Leaky-Wave Beam Steering”, IEEE Transactions on Terahertz Science and Technology, Vol. 7, Issue 1, pp. 60-69, January 2017.
[11] Ho-Jin Song; Nagatsuma, T.: "Present and Future of Terahertz Communications," IEEE Transactions on Terahertz Science and Technology, vol.1, no.1, pp.256-263, September 2011.
[12] T. Kürner.: “Launching a Study Group on THz,” IEEE 802 Plenary Session, IEEE 802.15 Document 15-13-0130-01-0thz, Orlando, March 2013, https://mentor.ieee.org/802.15/dcn/13/15-13-0130-01-0thz-launching-a-study-group-on-thz.pdf.
[13] N. Chopra, K. Yang, Q. H. Abbasi, K. A. Qaraqe, M. Philpott, A. Alomainy, “THz Time-Domain Spectroscopy of Human Skin Tissue for In-Body Nanonetworks”, IEEE Transactions on Terahertz Science and Technology, Vol. 6, Issue 6, pp. 803-809, August 2016.
[14] C. Jastrow, K. Munter, R. Piesiewicz, T. Kurner, M. Koch, T. Kleine-Ostmann, “300 GHz Transmission System”, Electronics Letters, Vol. 44, No. 3, January 2008.
