A Comprehensive Analysis of Literature Reported Mac and Phy Enhancements of Zigbee and its Alliances

Wireless communication is one of the most required technologies by the common man. The strength of this technology is rigorously progressing towards several novel directions in establishing personal wireless networks mounted over on low power consuming systems. The cutting-edge communication technologies like bluetooth, WIFI and ZigBee significantly play a prime role to cater the basic needs of any individual. ZigBee is one such evolutionary technology steadily getting its popularity in establishing personal wireless networks which is built on small and low-power digital radios. Zigbee defines the physical and MAC layers built on IEEE standard. This paper presents a comprehensive survey of literature reported MAC and PHY enhancements of ZigBee and its contemporary technologies with respect to performance, power consumption, scheduling, resource management and timing and address binding. The work also discusses on the areas of ZigBee MAC and PHY towards their design for specific applications

A quality of service architecture for WLAN-wired networks to enhance multimedia support

Includes abstract.Includes bibliographical references (leaves 77-84).The use of WLAN for the provision of IP multimedia services faces a number of challenges which include quality of service (QoS). Because WLAN users access multimedia services usually over a wired backbone, attention must be paid to QoS over the integrated WLAN-wired network. This research focuses on the provision of QoS to WLAN users accessing multimedia services over a wired backbone. In this thesis, the IEEE 802.11-2007 enhanced data channel access (EDCA) mechanism is used to provide prioritized QoS on the WLAN media access control (MAC) layer, while weighted round robin (WRR) queue scheduling is used to provide prioritized QoS at the IP layer. The inter-working of the EDCA scheme in the WLAN and the WRR scheduling scheme in the wired network provides end-to-end QoS on a WLAN-wired IP network. A mapping module is introduced to enable the inter-working of the EDCA and WRR mechanisms

Greediness control algorithm for multimedia streaming in wireless local area networks

This work investigates the interaction between the application and transport layers while streaming multimedia in a residential Wireless Local Area Network (WLAN). Inconsistencies have been identified that can have a severe impact on the Quality of Experience (QoE) experienced by end users. This problem arises as a result of the streaming processes reliance on rate adaptation engines based on congestion avoidance mechanisms, that try to obtain as much bandwidth as possible from the limited network resources. These upper transport layer mechanisms have no knowledge of the media which they are carrying and as a result treat all traffic equally. This lack of knowledge of the media carried and the characteristics of the target devices results in fair bandwidth distribution at the transport layer but creates unfairness at the application layer. This unfairness mostly affects user perceived quality when streaming high quality multimedia. Essentially, bandwidth that is distributed fairly between competing video streams at the transport layer results in unfair application layer video quality distribution. Therefore, there is a need to allow application layer streaming solutions, tune the aggressiveness of transport layer congestion control mechanisms, in order to create application layer QoE fairness between competing media streams, by taking their device characteristics into account. This thesis proposes the Greediness Control Algorithm (GCA), an upper transport layer mechanism that eliminates quality inconsistencies caused by rate / congestion control mechanisms while streaming multimedia in wireless networks. GCA extends an existing solution (i.e. TCP Friendly Rate Control (TFRC)) by introducing two parameters that allow the streaming application to tune the aggressiveness of the rate estimation and as a result, introduce fair distribution of quality at the application layer. The thesis shows that this rate adaptation technique, combined with a scalable video format allows increased overall system QoE. Extensive simulation analysis demonstrate that this form of rate adaptation increases the overall user QoE achieved via a number of devices operating within the same home WLAN

Methods and tools for network reconnaissance of IoT devices

The Internet of Things (IoT) impacts nearly all aspects surrounding our daily life, including housing, transportation, healthcare, and manufacturing. IoT devices communicate through a variety of communication protocols, such as Bluetooth Low Energy (BLE), Zigbee, Z-Wave, and LoRa. These protocols serve essential purposes in both commercial industrial and personal domains, encompassing wearables and intelligent buildings. The organic and decentralized development of IoT protocols under the auspices of different organizations has resulted in a fragmented and heterogeneous IoT ecosystem. In many cases, IoT devices do not have an IP address. Furthermore, some protocols, such as LoRa and Z-Wave, are proprietary in nature and incompatible with standard protocols. This heterogeneity and fragmentation of the IoT introduce challenges in assessing the security posture of IoT devices. To address this problem, this thesis proposes a novel methodology that transcends specific protocols and supports network and security monitoring of IoT devices at scale. This methodology leverages the capabilities of software-defined radio (SDR) technology to implement IoT protocols in software. We first investigate the problem of IoT network reconnaissance, that is the discovery and characterization of all the IoT devices in one’s organization. We focus on four popular protocols, namely Zigbee, BLE, Z-Wave, and LoRa. We introduce and analyze new algorithms to improve the performance and speed-up the discovery of IoT devices. These algorithms leverage the ability of SDRs to transmit and receive signals across multiple channels in parallel. We implement these algorithms in the form of an SDR tool, called IoT-Scan, the first universal IoT scanner middleware. We thoroughly evaluate the delay and energy performance of IoT-Scan. Notably, using multi-channel scanning, we demonstrate a reduction of 70% in the discovery times of Bluetooth and Zigbee devices in the 2.4GHz band and of LoRa and Z-Wave devices in the 900MHz band, versus single-channel scanning. Second, we investigate a new type of denial-of-service attacks on IoT cards, called Truncate-after-Preamble (TaP) attacks. We employ SDRs to assess the security posture of off-the-shelf Zigbee and Wi-Fi cards to TaP attacks. We show that all the Zigbee devices are vulnerable to TaP attacks, while the Wi-Fi devices are vulnerable to the attack to a varying degree. Remarkably, TaP attacks demand energy consumption five orders of magnitude lower than what is required by a continuous jamming mechanism. We propose several countermeasures to mitigate the attacks. Third, we devise an innovative approach for the purpose of identifying and creating unique profiles for IoT devices. This approach leverages SDRs to create malformed packets at the physical layer (e.g., truncated or overlapping packets). Experiments demonstrate the ability of this approach to perform fine-grained timing experiments (at the microsecond level), craft multi-packet transmissions/collisions, and derive device-specific reception curves. In summary, the results of this thesis validate the feasibility of our proposed SDR-based methodology in addressing fundamental security challenges caused by the heterogeneity of the IoT. This methodology is future-proof and can accommodate new protocols and protocol upgrades

A real-time packet scheduling system for a 6LoWPAN industrial application

Nowadays, the industrial Wireless Sensor Networks (WSN) are crucial for the monitoring and control of the modern smart factory floor that is relying on them for critical applications and tasks that were performed by wired systems in the past. For this reason, it is required that the transmission mechanisms of wireless sensor networks are efficient and robust and that they guarantee realtime responses with low data losses. Furthermore, it is required that they utilize common networking standards, such as the Internet Protocol (IP), that provides interoperability with already existing infrastructures and offers widely tested security and transmission control protocols. The theoretical part of this document focuses on the description of the current panorama of the industrial WSN, its applications, design challenges and standardizations. It describes the 6LoWPAN standard and the wireless transmission technology that it uses for its lower layers, the IEEE 802.15.4 protocol. Later, it describes the principles behind the wireless scheduling, a state-of-the-art in the IEEE 802.15.4 scheduled channel access and the features of the most used operating systems for WSN. The practical part presents the real-time packet scheduling system for a 6LoWPAN industrial application proposed by this thesis work that adapts the HSDPA scheduling mechanisms to the IEEE 802.15.4 beacon-enabled mode. The system implemented manages the channel access by allocating Guaranteed Time Slots to sensor nodes according to the priority given by three scheduling algorithms that can be selected according to the traffic condition of the network. The system proposed was programmed using Contiki OS. It is based on the eSONIA 6LoWPAN firmware developed for the European Research Project and it was deployed on the FAST WSN for testing. The results, discussion and conclusions are documented at the final sections of this part

Mitigating the Impact of Physical Layer Capture and ACK Interference in Wireless 802.11 Networks

Ph.DDOCTOR OF PHILOSOPH

Ultra-Wideband Transceiver Design And Optimization

University of Minnesota Ph.D. dissertation. July 2015. Major: Electrical Engineering. Advisor: Ramesh Harjani. 1 computer file (PDF); xiii, 128 pages.The technology landscape has quickly changed over the last few years. Developments in personal area networks, IC technology, DSP processing and bio-medical devices have enabled the integration of short range communication into low cost personal health care solutions. Newer technologies and solutions are being developed to cater to the personal operating space(POS) and body area networks(BAN). Health care is driving towards using multiple sensor and therapeutic nodes inside the POS. Technology has enabled remote patient care where the patient has low cost on-body wearables that allow the patient/physician to access vital signs without the patient physically visiting the clinic. Big semiconductor giants want to move into the wearable health monitor space. Along with the developments in fitness based health wearables, there has been a lot of interest towards developing BAN devices catering to the 'mission-critical' wearables and implants. Hearing aids, EKG monitors, neurostimulators are some examples. This work explores the use of the 802.15 ulta wideband (UWB) standard for designing a radio to operate in the a wireless sensor network in the BAN. The specific application targeted is a hearing aid. However, the design in this work is capable of working in a low power low range application with the ability to have multiple data rates ranging from a few kHz to 10's of MHz. The first radio designed by Marconi using spark-gap transmitters was an impulse radio (IR). The IR UWB technology boasts of low power, low cost, high data rates, multiple channels, simultaneous networking, the ability to carry information through obstacles that more limited bandwidths cannot, and also potentially lower complexity hardware design. The inherent timing accuracy associated with the technology gives UWB transmissions immunity to multipath fading and are hence make them more suitable for a cluttered indoor environment. The key difference with the traditional narrowband transceiver is that instead of using continuous wave (CW) transmission, impulses in time are used. The timing accuracy associated with these impulses require synchronization in time, rather than synchronization in frequency for carrier-based CW systems. A complete fully integrated system is presented in thesis. This work presents a low-power noncoherent IR UWB transceiver operating at 5GHz in 0.13um CMOS. A fully-digital transmitter generates a shaped output pulse of 1GHz 3-dB bandwidth. DLLs provide a PVT-tolerant time-step resolution of 1ns over the entire symbol period and regulate the pulse generator center frequency. The transmitter outputs -31dBm (0.88pJ/pulse at 1Mpulse/s) with a dynamic (energy) efficiency of 16pJ/pulse. The transmit out pulse is FCC part 15 compliant over process voltage and temperature (PVT) variations. The transmitter is semi-compliant with IEEE 802.15.6 and IEEE 802.15.4 standards and will become completely compliant with minor modifications. The receiver presented in this work is a non-coherent energy detect IR UWB receiver. The receiver has an on-chip transformer preceding the LNA, which is followed by a super-regenerative amplifier (SRA), envelope detector, sample-and-holds, and a bank of comparators. The design is SRA based energy-detection receiver. Measured results show a receiver efficiency of 0.32nJ/bit at 20.8Mb/s and operation with inputs as low as -70dBm. The SRA based energy-detection receiver utilizes early/late detection for a two-step baseband synchronization algorithm. An integrated solution to the issue of synchronization is also proposed. The system proposed is capable of synchronization and tracking control. The system in this work utilizes early/late detection for a two-step baseband synchronization algorithm. The algorithm is implemented in Matlab and the time to synchronization is observed to be between 250us to a few couple of ms. Measurements have also been made using the receiver and manually implementing the algorithm. This work addresses all aspects time synchronization in an IR transceiver. The initial mismatch is addressed by two methods. Beyond the initial synchronization, the system presented in this system is also capable of tracking. This would mean that once the transceiver has been synchronized, the timing generation would continue to track the phase and the frequency changes depending upon crystal drift over time or movement between the receiver and the transmitter. A test was also performed on the complete transceiver system with two radios talking to each other over a highly attenuated wired channel

Routing algorithms for wireless sensor : networks based on the duty cycle of its components

[eng] Wireless sensor network is one of the most important topics in the current data transferring. In fact regarding to data gathering and transformation, cost effective is the top topic and optimum point, which every vendors and sector are focusing on it. In the field of petrochemical regarding sensitive processes could not stay out of this scope and start to monitor the gas pipes and processes over the wireless fashion. Therefore some items should have been taking into considerations such as: instant monitoring, nonstop characteristic, long term investing and energy consuming. According to those aforesaid items, we have planned to do an investigation and find the feasibly of how we can to create and distribute a network to have accuracy to measurement , sending data reliability, having long term network life cycle and having minimum energy consuming. Therefore the only technology could help us was IEEE 802.15.4 with mixed of microcontrollers and transceivers, able to manipulate to reach out our objects in maximizing lifetime and minimizing latency in wsn, as an unique routing algorithm in Mobile ad Hoc Network. WSN in fact is a relatively new section of networking technology and nowadays is more popular. The reason of these advantages instead of others is low-power microcontroller and inexpensive sensor usage for any communications and also simple sensor designing. Regarding to network layers, Physical layer for WSN based on IEEE802.15.4 is fundamental of frames and packets transactions. So two main devices which are involving in this project: transceivers such as CC2520 and CC3200 ZigBee/IEEE 802.15.4 RF, managed by microcontrollers. Common controller for those transceivers such as MSP430F1611 16-bit MSP430 family for Texas instrument in the nodes and coordinators ideas were selected. One step more close to the idea, was other layer so called Link layer or in other hand MAC layer. Another advantage of WSN is ability to manipulate MAC layer, because modifications in lower layer always has low Energy consuming than other layers. Therefore according to these circumstances, MAC protocols are able to energy efficiency, also reduce and achieve to zero based of unused time in WSN. So any WSN, energy wasting could be control in MAC sub layer and even though MAC protocols. Other layer in WSN is declared as a Network layer, the logical way which those packets could be find the best way and shortest path in minimum time as possible and reachability to the main point based on node and coordinator. Nodes are programmed in upper layer and have been matched with MAC layer, now it's time to join and stick the frames in a packet and involving to each other. Meanwhile we decided to create a middle layer through MAC and Network layer to play as a bridge, mainly called VRT (Variable Response Time) and FRT (Fixed Response Time) to control the energy consumption in the process of routing in network layer. This algorithm is cooperating with MAC layer in sleep and wake up modes, in fact with VRT, nodes just received their needs and captured the vital packet in wake up mode, sends back the answer, now the task is finished and both sided transaction is done. After that, it's not need to have more listening and capturing packets from the remote nodes as a coordinator therefore, left the transmission process to save more energy for further wireless communication stream in sleep mode. Also FRT is another algorithm in MAC layer, to decrease the energy consumption. This algorithm is switch based energy control, as a same concept in VRT in sleeping and wakeup mode. Finally we have design this algorithm in Simulator and real world. The results correlate quite well results showing as a good agreement between two worlds, also we have obtained better results in battery consumption over network life cycle to other business algorithms.[spa] En este trabajo nos focalizaremos en la minimización del consumo a partir de la minimización del número de transmisiones. Buscamos por tanto aquel algoritmo que nos permita aumentar la probabilidad de aciertos. Esta idea, diseñará el algoritmo de enrutamiento que mejor se ajusta a la red MANET. Una vez simulada la red se diseñará un "testbed" en donde una parte de la red se implementará de forma real, mediante la introducción de sensores inalámbricos y la otra parte se hará de forma simulada, a través de una interfaz que interconecta el mundo real con la simulación de Spyder. Se pretende ver que ambos mundos progresan de forma similar. Con respecto a la capa de OSI en WSN, sería prioritaria la capa física o capa de hardware, por este motivo nuestra proyecto también se centra en el tipo determinado de hardware que debe aplicarse para obtener resultados satisfactorios. Entonces tratamos las características de los dos hardwares, el transceiver y el microcontroller. También se trata en este apartado su concepto lógico de acuerdo con la ficha técnica oficial IEEE802.15.4. La segunda prioridad de la capa OSI se centra en el Medium Access Control (MAC) de la capa. En esta capa nuestro objetivo se logrará mediante la manipulación de las addresses MAC. Los protocolos MAC deben estar orientados a la reducción del consumo de energía y también a la reducción del tiempo no utilizado en WSN, para ello aplicamos algunas políticas para controlar los comportamientos del tráfico en esta capa para cambiar el consumo de energía, la vida útil de la red y evitar el gasto innecesario de recursos, en realidad concentramos a nuestro algoritmo VRT y FRT. Respecto de la idea principal, de controlar los sensores para aumentar la vida útil de la red y disminuir el consumo de energía. En realidad se explica cómo controlar la capa MAC y forzar el hardware para lograr el objetivo principal de este proyecto. De hecho podemos decir que mejoramos el reenvío de paquetes entre los sensores intermedios, buscando el promedio de distancia HOP más corta desde el origen al destino, así como la disminución del consumo de energía en cada sensor