Babak D. Beheshti

Review of Location Management in Cellular Networks

Location management is a paramount issue in wireless mobile station communication systems to enable the terminals to continuously receive services when moving from one location to another. In this paper, we study the trends in the latest cellular wireless systems to page terminals, update location area and make handover decisions for a mobile station. Topics covered include static and dynamic location management, dynamic location areas and techniques, future location management developments, location tracking evolution and location management in 3G. It will be shown that location-area based location management methods designed around a profile or history-based direction information offer the best performance, in terms of location management cost, compared to all other alternative approaches while distance based schemes are to be the most efficient ones.

Autonomous real-time water quality sensing as an alternative to conventional monitoring to improve the detection of food, energy, and water indicators

Advances in sensors and wireless sensor networks (WSNs) are enabling real-time environmental monitoring, which has the potential to provide a plethora of fine-grained data to assist in understanding the symbiosis between food, energy, and water (FEW) systems. This paper presents the advantages of autonomous real-time water quality monitoring systems over conventional systems and proposes cost-effective and feasible approaches to designing a system that autonomously collects environmental data by integrating digital and mechanical devices connected through various communication networks, both wired and wireless. More specifically, the autonomous sensing devices proposed include low-cost water quality sensors implemented on commercial hardware and cell-based biosensors using electric cell-substrate impedance sensing (ECIS), which are capable of detecting water and/or air toxicants in real time.The paper discusses the key design considerations of the underlying WSN communication system supporting autonomous data transmission, including the spatial distribution of sensors, costs, and operation autonomy. Communication among connected devices (e.g., sensors) requires both precision timing and network security against attacks, as well as means to ensure the privacy and integrity of the data being collected and transmitted through the network. Preliminary results demonstrate the importance of precision timing and synchronization by using measured timing information and signal strength to identify man-in-the-middle attacks in fixed wireless networks and to locate the attack source using machine-learning approaches. Data modeling and recovery methods are presented to efficiently analyze and process sensing data to address the missing measurement issue caused by noise and device failure. The system proposed herein can serve as a valuable tool for real-time monitoring of FEW resources and can be broadly applied to efficient management of their sustainability.

On performance of LTE UE DFT and FFT implementations in flexible software based baseband processors

The use of the Fast Fourier Transform (FFT) and the Discrete Fourier Transform (DFT) in the physical layer implementations of the latest cellular and wireless standards such as Long Term Evolution (LTE) is highly common place. Given that FFT and DFT algorithms consume a significant percentage of the processing power of a baseband processor, it is important to implement these algorithms with close attention to the underlying architecture of the platform for which they are being developed.

Middleware/API and data fusion in Wireless Sensor Networks

This paper reviews the state of the art of two important aspects of Wireless Sensor Networks (WSNs), namely: 1. Models or Implementations of middleware and/or Application Programmers Interfaces (APIs) to abstract the inner workings of heterogeneous WSNs, and 2. Methods and techniques in reducing pervasive data generated by thousands or tens of thousands of sensor nodes within a WSN in order to reduce transmission load of individual sensor nodes and thereby, the energy consumption of the overall WSN. These two aspects of WSN are inter-related in that together they contribute to a unifying model of vastly heterogeneous WSNs composed of many sensor nodes. A unifying model for WSN will serve as a reference model based on which application specific WSNs can be designed using a universal API for ease of programming, and using a library of data fusion capabilities built into the API of the reference model.

A proposed API for the control plane of the WSN Integrated Technical Reference Model (I-TRM)

The Integrated Technical Reference Model (I-TRM) for an autonomous Wireless Sensor Network (WSN) has been developed to be used as a guideline to develop a unified and standardized architecture for a diverse array of multi-platform WSNs. Based on the I-TRM proposed by Michel and Fortier, there are three planes to this reference model: The Information Plane, the Control Plane and the Behavior Plane. This reference model lays out a detailed layered model with functional description of each layer described in general terms. The Control Plane puts forward the goal setting and control of the system. The main focus is on the details about the control organization of the system including hierarchical control and task distribution, in coherence to the initial work done in the field of control architecture, authentication of the semantic correctness of the goal, decomposition of valid goals into functional tasks based on knowledge about the lower layers, and organization of system tasks for goal-achievement in accordance with spatial and temporal information by decomposing the task groups into sub-tasks and assigning priorities to them. This paper presents the follow up research performed on this I-TRM, by providing a platform independent API to aid designers of WSNs to develop a codified implementation of WSNs. The API has been implemented using C in a Windows™ platform running on a standard PC/laptop, as well as portions of it in NesC in a TinyOS environment, running on the Berkeley Motes.

Software implementation and performance analysis of the LTE physical layer blocks on a next generation baseband processor platform

Summary form only given. The Third Generation Partnership Project (3GPP) has been defining the Long Term Evolution (LTE) for 3G radio access. LTE has several areas of focus. These areas include enhancement of the Universal Terrestrial Radio Access (UTRA), as well as optimization of the network architecture with HSDPA (downlink) and HSUPA (uplink). LTE project aims to ensure the continued competitiveness of the 3GPP technologies for the future LTE focuses on download rates of 100 Mbit/s, upload rates of 50 Mbit/s per 20 MHz of bandwidth, increased spectrum efficiency and sub-5ms latency for small IP packets. This paper provides an overview of the radio interface physical layer requirements. The paper then presents the implementation of the current LTE standards on a second generation flexible baseband processor. The implementation will be be limited to the receiver chain blocks and will be entirely in ANSI C, written for a fixed point digital signal processors. The underlying assumption of this implementation is to avoid any hardware accelerators that would make the hardware platform for the baseband processing standard specific. The SB3500 is the second generation of SandBlaster-based low power, high performance system on a chip (SoC) products developed to serve the software defined radio (SDR) modem applications space. It is a multi-core device, containing 3 dasiaSBXpsila DSP cores. The software implementation of LTE physical layer includes implantation of OFDM and receiver chain processing in ANSI C. The projected processing requirements of an LTE UE on the SB3500 are presented with the expected number of cores needed for the data rates analyzed. The down-sampling filter used for the initial synchronization and for the fine synchronization, FFT block, Channel estimation for each reference symbol, MIMO detector and the CRC block are included in this analysis. The specific architectural features of the SB3500 and the compiler optimizations to yield a real time software implementation of LTE are also presented.

A cross layer, adaptive data aggregation algorithm utilizing spatial and temporal correlation for fault tolerant Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are ad hoc networks formed by tiny, low powered, and low cost devices. WSNs take advantage of distributed sensing capability of the sensor nodes such that several sensors can be used collaboratively to detect events or perform monitoring of specific environmental attributes. Since sensor nodes are often exposed to harsh environmental elements, and normally operate in an unsupervised fashion over long periods of time, within their MTBF, some of them are subject to partial failure in form of A/D readings that are permanently off the correct levels. Additionally, due to glitches in timing and in hardware or software, even healthy sensor nodes can occasionally report readings that are outside of the expected range. In this paper we present a novel approach that combines spatial and temporal correlation of the data collected by neighboring sensors to combat both error modes described above. We combine the weighted averaging algorithm across multiple sensors, with the LMS adaptive filtering of individual sensor data, in order to improve fault tolerance of WSNs. We present performance gains achieved by combining these methods; and analyze the computational and memory costs of these algorithms.

Light Weight Cryptography for Resource Constrained IoT Devices

The Internet of Things (IoT) is going to change the way we live dramatically. Devices like alarm clocks, lights and speaker systems can interconnect and exchange information. Billions of devices are expected to be interconnected by the year 2020, thus raising the alarm of a very important issue ‘security’. People have to be sure that their information will stay private and secure, if someone hacked into your medical device (hand watch) he will be able to view all your medical records, and he could be able to use it against you. If one device is hacked your entire network is going to be compromised. Transmitting your information securely between IoT devices using traditional crypto algorithms are not possible because those devices have limited energy supply, limited chip area and limited memory size; because of those constraints a new type of crypto algorithm came into place: the light weight crypto algorithms. As the name implies those algorithms are light and can be used in those devices with low computational power. In this paper, we start by describing some of the heavy ciphers. We also highlight some lightweight ciphers and the attacks known against them.

Linux kernel OS local root exploit

Dirty Copy on Write (COW) vulnerability, discovered by Phil Oester on October 2016, it is a serious vulnerability which could escalate unprivileged user to gain full control on devices (Computers, Mobile Smart Phones, Gaming devices that run Linux based operating systems). This means that any user who exploits this bug, would escalate his/her privileges; and can do anything either locally or remotely (with some modifications) to hijack the device, destroy data, create a backdoor, or to record all key strokes, use computer as an attack (object) to attack other computer in the internet (in the wild), etc., COW is a local root exploit in Linux causing vulnerability issues. This paper will discuss the copy on write issue in Linux, it will also explain the nature of the problem and how it is caused, and the different mechanism to mitigate it.

A framework for Wireless Sensor Network security

Wireless Sensor Networks (WSNs) have become prolific in the past few years as low cost and easily deployable means to collect environmental data. With the increased scope of applications of WSNs it is imperative to assure security of the network itself against attacks, as well as to assure privacy and integrity of the data that is being collected and transmitted through the network. The I-TRM (Integrated Technical Reference Model) of a WSN has been proposed to standardize these network models in a three faced pyramid, where the three faces are Control, Information and Behavior protocol stacks. In this paper, we expand the I-TRM into a four faced pyramid, where the fourth face is the Security Centric face. This paper introduces the proposed expansion at a high level, with system level requirements of the newly expanded I-TRM. Future papers will present more detailed specifications of the new I-TRM.