In this chapter, the path loss and molecular absorption noise models for the in vivo THz communication are introduced. Moreover, the analytical results on SNR and information rate with flat and Gaussian pulse-based power allocation scheme are presented. It indicates that the maximum achievable transmission distance of in vivo THz communication should be restrained to approximately 1-2 mm, and more specific transmission distance limitation depends on the composition of the transmission medium, especially the water concentration of the medium. The operation band of iWNSNs is limited to the frequencies lower than 1 THz. The information rate decreases steadily with the increase in the transmission distance regardless of the type of the medium and can reach several Gbps when the transmission distance is 0.5 mm. Afterwards, an interference model for iWNSNs with the utilisation of TS-00K is developed based on the mathematical apparatus of stochastic geometry. The performance of the multi-user communication inside human blood, skin and fat is comparatively illustrated, showing that blood is the worst performing scenario because of higher water concentration than skin and fat. In all three kinds of tissues, the obtained results show that high node density and pulse transmission probability would potentially decrease SINR of the system and impair the system performance. Flat and Gaussian-pulse based power distribution scheme behaves differently in different tissues in the THz frequencies. Therefore, a proper power allocation should be selected based on the specific application. The presented results provide an important basis for more practical network-level modelling, stimulating further research on simple, reliable and energy efficient communication protocols and coding schemes.

Chapter Contents:

• 6.1 End-to-end terahertz propagation
• 6.1.1 Molecular absorption
• 6.1.2 Scattering
• 6.1.3 Path loss
• 6.1.4 Molecular absorption noise
• 6.1.4.1 Flat power distribution
• 6.1.4.2 Pulse-based power distribution
• 6.1.5 Signal-to-noise ratio
• 6.1.6 Time spread on–off keying
• 6.1.7 Information rate
• 6.2 Multi-user terahertz propagation
• 6.2.1 Interference model
• 6.2.1.1 Single node interference model
• 6.2.1.2 Aggregate interference model
• 6.2.2 SINR distribution
• 6.2.2.1 Effect of the node density
• 6.2.2.2 Effect of the probability of transmitting pulses
• 6.3 Summary
• References

Inspec keywords: biological tissues; wireless sensor networks; nanocommunication (telecommunication); resource allocation; electromagnetic interference

Other keywords: coding schemes; energy efficient communication protocols; distance 0.5 mm; molecular absorption noise; Gaussian pulse-based power allocation; stochastic geometry; mathematical apparatus; multiuser communication; interference model; water concentration; transmission distance; electromagnetic nanocommunication; pulse transmission probability; iWNSN; in vivo THz communication; Gaussian-pulse based power distribution; human blood

Subjects: Acoustic and other telecommunication systems and equipment; Wireless sensor networks; Electromagnetic compatibility and interference