Survey of Spectrum Sharing for Inter-Technology Coexistence

Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms should be designed to allow spectrum access for multiple technologies, while efficiently utilizing the spectrum resources overall. Importantly, it is not trivial to design such efficient mechanisms, not only due to technical aspects, but also due to regulatory and business model constraints. In this survey we address spectrum sharing mechanisms for wireless inter-technology coexistence by means of a technology circle that incorporates in a unified, system-level view the technical and non-technical aspects. We thus systematically explore the spectrum sharing design space consisting of parameters at different layers. Using this framework, we present a literature review on inter-technology coexistence with a focus on wireless technologies with equal spectrum access rights, i.e. (i) primary/primary, (ii) secondary/secondary, and (iii) technologies operating in a spectrum commons. Moreover, we reflect on our literature review to identify possible spectrum sharing design solutions and performance evaluation approaches useful for future coexistence cases. Finally, we discuss spectrum sharing design challenges and suggest future research directions

An Overview and Assessment of Wireless Technologies and Co- existence of ZigBee, Bluetooth and Wi-Fi Devices

AbstractWi-Fi, ZigBee and Bluetooth wireless communication systems utilize the Industrial Scientific and Medical-(ISM) Band, which results in a high mutual interference between these technologies since they all these systems operate at the same or very close frequency bands. The interference problem increases with an in-device Co-existence (technologies existing on same device). This is primarily due to the characteristics of each technology such as access mechanism, frame structure, peak transmit power and frequency of operation. This work describes the interference between the Wi-Fi mostly as an aggressor on Bluetooth and ZigBee wireless networks. So the experimental analysis of the coexistence of these three technologies in an assumed home environment is studied especially when ZigBee is enabled for a Home Automation Network where there could be close proximity of Wi-Fi and Bluetooth devices such as PDAs and mobile phones. The obtained result shows that there is severe degradation on ZigBee and Bluetooth packet transmission of packets as well as re-transmission of ZigBee packets when Wi-Fi is operating

Performance measurements of Bluetooth 5 technique under interference

Abstract. This thesis focuses on experimental performance of the Bluetooth 5 technology and compares results with the previous version. Bluetooth technology, institute of electrical and electronics engineers (IEEE) Std. 802.15.4, and other techniques share the same unlicensed 2.4 GHz industrial, scientific, and medical (ISM) spectrum. Various technologies are operating in the same frequency band, and if the channel utilized by these technologies overlap, end in cross-technology interference (CTI). Measurements have been performed in indoor scenario and ZigBee nodes were used as an interference. Performance output of the Bluetooth 5 is compared to a previous release Bluetooth low energy (BLE) 4 which is currently one of the popular technologies in commercial wireless devices and expected to be even more widespread in the future. This new Bluetooth technology has featured increased data rate, low power consumption, longer range, higher broadcasting capacity, and improved coexistence with other wireless technologies operating in the same frequency band. The main goal of this work was to evaluate the experimental communication range and throughput of the BLE 5 coded version under interference. Nordic Semiconductor nRF52840 chipset has been used for measurements and result shows the practical communication range and throughput of BLE 5 coded version under interference. In this work, with error correction coding, one-third BLE link gain was achieved when considering packet error rate (PER) less than 10%. In addition, ZigBee interference was found to be very harmful for the Bluetooth communication when operating in the same frequency band

Experimental Evaluation of a SIP-Based Home Gateway with Multiple Wireless Interfaces for Domotics Systems

In modern houses, the presence of sensors and actuators is increasing, whilecommunication servicesandentertainment systemshad long since settled into everyday life. The utilization of wireless communication technologies, such as ZigBee, Wi-Fi, and Bluetooth, is attractive because of their short installation times and low costs. The research is moving towards the integration of the various home appliances and devices into a single domotics system, able to exploit the cooperation among the diverse subsystems and offer the end-user a single multiservice platform. In this scenario, the paper presents the experimental evaluation of a domotics framework centered on a SIP-based home gateway (SHG). While SIP is used to build a common control plane, the SHG is in charge of translating the user commands from and to the specific domotics languages. The analysis has been devoted to assess both the performance of the SHG software framework and the negative effects produced by the simultaneous interference among the three widespread wireless technologies

Spectrum Sharing and Interference in Smart Homes

Internet of Things networks using Zigbee are very popular in smart homes. However, Zigbee networks are vulnerable to the interference of Wi-Fi networks because they share the same 2.4 GHz Industrial, Scientific, and Medical radio frequency band. Studies have shown that weaker Zigbee signals might be significantly interfered by stronger Wi-Fi signals. This type of interference may cause severe problems when these types of networks coexist in an indoor environment such as in a smart home. In this thesis, the performance of a Zigbee network with and without the presence of a Wi-Fi network has been evaluated in an apartment-based indoor environment mimicking a smart home. The experimental results are obtained and analyzed in terms of received signal strength indicator, packet delay, packet drop rate, and loopback throughput by changing operating channels, distances between Zigbee and Wi-Fi devices, transmission intervals of Zigbee packets, Zigbee transmit power, and Zigbee packet lengths

Interference mitigation strategy design and applications for wireless sensor networks

The Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard presents a very useful technology for implementing low-cost, low-power, wireless sensor networks. Its main focus, which is to applications requiring simple wireless connectivity with relaxed throughout and latency requirements, makes it suitable for connecting devices that have not been networked, such as industrial and control instrumentation equipments, agricultural equipments, vehicular equipments, and home appliances. Its usage of the license-free 2.4 GHz frequency band makes the technique successful for fast and worldwide market deployments. However, concerns about interference have arisen due to the presence of other wireless technologies using the same spectrum. Although the IEEE 802.15.4 standard has provided some mechanisms, to enhance capability to coexist with other wireless devices operating on the same frequency band, including Carrier Sensor Multiple Access (CSMA), Clear Channel Assessment (CCA), channel alignment, and low duty cycle, it is essential to design and implement adjustable mechanisms for an IEEE 802.15.4 based system integrated into a practical application to deal with interference which changes randomly over time. Among the potential interfering systems (Wi-Fi, Bluetooth, cordless phones, microwave ovens, wireless headsets, etc) which work on the same Industrial, Scientific, and Medical (ISM) frequency band, Wi-Fi systems (IEEE 802.11 technique) have attracted most concerns because of their high transmission power and large deployment in both residential and office environments. This thesis aims to propose a methodology for IEEE 802.15.4 wireless systems to adopt proper adjustment in order to mitigate the effect of interference caused by IEEE 802.11 systems through energy detection, channel agility and data recovery. The contribution of this thesis consists of five parts. Firstly, a strategy is proposed to enable IEEE 802.15.4 systems to maintain normal communications using the means of consecutive transmissions, when the system s default mechanism of retransmission is insufficient to ensure successful rate due to the occurrence of Wi-Fi interference. Secondly, a novel strategy is proposed to use a feasible way for IEEE 802.15.4 systems to estimate the interference pattern, and accordingly adjust system parameters for the purpose of achieving optimized communication effectiveness during time of interference without relying on hardware changes and IEEE 802.15.4 protocol modifications. Thirdly, a data recovery mechanism is proposed for transport control to be applied for recovering lost data by associating with the proposed strategies to ensure the data integrity when IEEE 802.15.4 systems are suffering from interference. Fourthly, a practical case is studied to discuss how to design a sustainable system for home automation application constructed on the basis of IEEE 802.15.4 technique. Finally, a comprehensive design is proposed to enable the implementation of an interference mitigation strategy for IEEE 802.15.4 based ad hoc WSNs within a structure of building fire safety monitoring system. The proposed strategies and system designs are demonstrated mainly through theoretical analysis and experimental tests. The results obtained from the experimental tests have verified that the interference caused by an IEEE 802.11 system on an IEEE 802.15.4 system can be effectively mitigated through adjusting IEEE 802.15.4 system s parameters cooperating with interference pattern estimation. The proposed methods are suitable to be integrated into a system-level solution for an IEEE 802.15.4 system to deal with interference, which is also applicable to those wireless systems facing similar interference issues to enable the development of efficient mitigation strategies

Design of Wireless Sensors for IoT with Energy Storage and Communication Channel Heterogeneity

Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them

Interference issues and mitigation method in WSN 2.4GHz ISM band: A survey

Current lifestyles promote the development and advancement in wireless technologies, especially in Wireless Sensor Networks (WSN) due to its several benefits.WSN offers a low cost, low data rate, flexible routing, longer lifetime, and low-energy consumption suitable for unmanned and long term monitoring.Among huge WSN applications, some key applications are smart houses, environmental monitoring, military applications, and other monitoring applications.As a result, ubiquitous increase in the number of wireless devices occupying the 2.4GHz frequency band.This causes a dense wireless connection followed by interference problem to WSN in the 2.4GHz frequency band. WSN is most affected by the interference issue because it has a lower data rate and transmission power compared to WLAN.Despite efforts made by researchers, to the author's knowledge, the interference issue is still a major problem in wireless networks.This paper aims to review the coexistence and interference issues of existing wireless technologies in the 2.4GHz Industrial, Scientific and Medical (ISM) band.Keywords— Coexistence, Frequency Spectrum, IEEE 802.15.4, Interference, WSN, 2.4GHz ISM ban