Simultaneous vibration and humidity measurement using a hybrid WDM/OCDMA sensor network

Optical Fiber Technology

Rahimian

Glesk

et al. 2017

The emergence of heterogeneous applications such as internet data, video streaming, and online gaming, brings in a demand for a network environ- ments with capability of supporting diverse Quality of Services (QoS). Prioritizing the services is essential to ensure the delivery of information is at their best. This paper proposes a new code family to support optical domain service differentiation using spectral amplitude coding techniques within an optical code division multiple access (OCDMA) scenario. A particular user or service has a varying weight applied in order to obtain the desired signal quality. The proposed variable-weight code (VW-code) is constructed based on basic multi-service (MS) code. Mathematical model is developed to for performance evaluation of VW-MS code. In addition, the properties of pro- posed code is compared with other VW-OCDMA codes. It is shown that the proposed VW-MS provide an optimal code length with minimum cross- correlation compared to other VW-codes. Performance of VW-MS designed for triple-play services operating at bit rates of 0.622, 1.25 and 2.5 Gbps is demonstrated

“…3. The total length of code is 31 and can be calculated from (6). It can be seen that in order to support 4 users with weight 2, two matrices with W B = 2 are used.…”

Section: Variable Weight Code Construction Using Ms Codementioning

confidence: 99%

“…Further, multilevel OCDMA system was intruded in which high and low weight users transmit their signal at a lower and higher power levels, respectively [4]. OCDMA systems have also received attention in last mile access networks [5], optical sensor networks [6,7] and free space optical communication [8].…”

Section: Introductionmentioning

confidence: 99%

Variable weight spectral amplitude coding for multiservice OCDMA networks

Optical Fiber Technology

Rahimian

Glesk

et al. 2017

“…Optical multiplexing techniques including time and wavelength division multiplexing [ 14 ] and optical code division multiple access (OCDMA) have been adopted to connect distributed sensing points [ 15 ]. In wavelength division multiplexing, each sensor is assigned a single wavelength from the source optical spectrum [ 16 ]. Time division multiplexing dedicates different time slots to individual sensors.…”

Section: Introductionmentioning

confidence: 99%

WON-OCDMA System Based on MW-ZCC Codes for Applications in Optical Wireless Sensor Networks

Agapiou

Moghaddasi³

et al. 2021

Sensors

The growing demand for extensive and reliable structural health monitoring resulted in the development of advanced optical sensing systems (OSS) that in conjunction with wireless optical networks (WON) are capable of extending the reach of optical sensing to places where fibre provision is not feasible. To support this effort, the paper proposes a new type of a variable weight code called multiweight zero cross-correlation (MW-ZCC) code for its application in wireless optical networks based optical code division multiple access (WON-OCDMA). The code provides improved quality of service (QoS) and better support for simultaneous transmission of video surveillance, comms and sensor data by reducing the impact of multiple access interference (MAI). The MW-ZCC code’s power of two code-weight properties provide enhanced support for the needed service differentiation provisioning. The performance of this novel code has been studied by simulations. This investigation revealed that for a minimum allowable bit error rate of 10−3, 10−9 and 10−12 when supporting triple-play services (sensing, datacomms and video surveillance, respectively), the proposed WON-OCDMA using MW-ZCC codes could support up to 32 simultaneous services over transmission distances up to 32 km in the presence of moderate atmospheric turbulence.

“…Due to the problems with the mentioned techniques such as cost, low SNR and scanning time and need for synchronisation, Optical Code Division Multiple Access (OCDMA) sensor network using synchronous and asynchronous techniques was proposed [5]. The asynchronous OCDMA technique namely spectral amplitude coding (SAC) has satisfied the requirement among other OCDMAs due to better multiple access interference (MAI) cancellation and simplicity of implementation [6]. Majority of researches have focused on equally distributed sensor points where the received optical power (ROP) for each sensor is supposed to be similar.…”

Section: Introductionmentioning

confidence: 99%

Variable Weight Code Division Multiple Access System for Monitoring Vibration of Unequally Distributed Points

2019 21st International Conference on Transparent Optical Networks (ICTON)

Glesk

Rahimian

et al. 2019

The ever-growing demand for more accurate structural health monitoring of large scale facilities such as modern high-speed railways and bridges have resulted in the development of optical sensor networks (OSN), which help eliminate the disadvantages of conventional electric sensors, the most significant of which are sensitivity to electromagnetic interferences and larger sizes. The existing fibre optic infrastructures that are implanted mainly for communication purposes are not widely used by OSNs, due to the lack of appropriate multiplexing techniques. This study proposes an optical code division multiple access (OCDMA) system for support vibration sensing of unequally distributed points. The proposed system takes the advantages of spectral amplitude encoding (SAC) technique in providing differentiated services in physical layer by varying code weights. Simulation results monitoring three vibration sensor nodes with different distances are presented in the paper. The simulation and mathematical analysis indicate the suitability and simple implementation of the proposed system for supporting vibration sensing with high accuracy.