Next Generation M2M Cellular Networks: Challenges and Practical Considerations

In this article, we present the major challenges of future machine-to-machine (M2M) cellular networks such as spectrum scarcity problem, support for low-power, low-cost, and numerous number of devices. As being an integral part of the future Internet-of-Things (IoT), the true vision of M2M communications cannot be reached with conventional solutions that are typically cost inefficient. Cognitive radio concept has emerged to significantly tackle the spectrum under-utilization or scarcity problem. Heterogeneous network model is another alternative to relax the number of covered users. To this extent, we present a complete fundamental understanding and engineering knowledge of cognitive radios, heterogeneous network model, and power and cost challenges in the context of future M2M cellular networks

A Critical Review of Practices and Challenges in Intrusion Detection Systems for IoT: Towards Universal and Resilient Systems

The Internet-of-Things (IoT) is rapidly becoming ubiquitous. However the heterogeneous nature of devices and protocols in use, the sensitivity of the data contained within, as well as the legal and privacy issues, make security for the IoT a growing research priority and industry concern. With many security practices being unsuitable due to their resource intensive nature, it is deemed important to include second line defences into IoT networks. These systems will also need to be assessed for their efficacy in a variety of different network types and protocols. To shed light on these issues, this paper is concerned with advancements in intrusion detection practices in IoT. It provides a comprehensive review of current Intrusion Detection Systems (IDS) for IoT technologies, focusing on architecture types. A proposal for future directions in IoT based IDS are then presented and evaluated. We show how traditional practices are unsuitable due to their inherent features providing poor coverage of the IoT domain. In order to develop a secure, robust and optimised solution for these networks, the current research for intrusion detection in IoT will need to move in a different direction. An example of which is proposed in order to illustrate how malicious nodes might be passively detected

Expression analysis of regulatory MicroRNA in bovine cumulus oocyte complex and preimplantation embryos

MicroRNAs (miRNAs) are small non coding endogenous molecules which participate in gene regulation post transcriptionally. These small RNAs are shown to be involved in a wide range of biological processes including development, cell differentiation, cell proliferation and apoptosis in diverse organisms. However, little is known about their abundance in bovine oocytes and their surrounding cumulus cells during oocyte development. To elucidate this, we investigated the relative expression pattern of a set of 88 miRNAs between bovine oocytes and the surrounding cumulus cells during in vitro maturation, using miRNA PCR array related to human cell development and differentiation. Results revealed a total of 47 and 51 miRNAs to be differentially expressed (p ≤ 0.05 and fold change ≥ 2) between immature (GV) and matured (MII) oocytes, respectively compared to their surrounding cumulus cells. However, 8 and 6 miRNAs were found to be highly abundant in cumulus cells compared to oocytes at immature and matured stages, respectively. The expression analysis of six oocytes enriched miRNAs (miR-205, -150, -122, -96, -146a and -146b-5p) in bovine preimplantation embryo stages was performed. Results showed that expression of these miRNAs were highly abundant in early stages of embryo development and reduced after 8-cell until the blastocyst stage following a typical maternal transcript profile. Comparable results were obtained by in situ localization of miR-205 in preimplantation embryo stages. However, the two selected miRNAs enriched in cumulus cells (miR-210 and miR-452) showed no defined profile. The same eight miRNAs were detected at high level in fully grown oocyte (BCB+) compared to growing one (BCB-). Interestingly, the presence or absence of oocytes or cumulus cells during maturation was found to affect the expression of selected miRNAs in each of the two cell types. Furthermore, miR-205 and miR-210 were in situ localized in ovarian follicle and revealed a spatio-temporal expression during follicular development. Hence, our results evidenced the presence of distinct set of miRNAs in oocytes and cumulus cells which may have potential role in regulation of bidirectional communication between the two cell types. Moreover, maternal miRNAs were found to persist until the major genome activation in bovine.Expressionsanalyse von regulierenden MircoRNA im bovinen Kumulus-Oocyten Komplex und präimplantierten Embryonen MicroRNAs (miRNAs) sind kleine nicht-kodierende endogene Moleküle, die an der post-trankriptionellen Genregulierung beteiligt sind. Diese kleinen RNAs sind an einer Reihe von biologischen Prozessen, wie Entwicklung, Zelldifferenzierung, Zellproliferation und Apoptose in verschiedenen Organismen, involviert. Jedoch ist bisher nur wenig über ihre Rolle in bovinen zellen und umgebenden Kumuluszellen während der Eizellenentwicklung bekannt. Um dieses aufzuklären, untersuchten wir die relativen Expressionsmuster zwischen bovinen Eizellen und den umgebenden Kumuluszellen während der in vitro Maturation. Die Expressionsmuster eines Sets von 88 miRNAs wurden mittels eines miRNA PCR Arrays für humane Zellentwicklung und-differenzierung erfasst. Die Ergebnisse zeigten, dass insgesamt 47 bzw. 51 miRNAs unterschiedlich zwischen immaturen (GV) bzw. reifen Eizellen (MII) und ihren umgebenden Kumuluszellen exprimiert waren (p ≤ 0.05, fold change ≥2). Dabei wurden 8 bzw. 6 miRNAs stärker in den Kumuluszellen exprimiert beim Vergleich von Eizellen im reifen bzw. unreifen Stadium. Weitere Expressionsanalysen wurden von sechs ausgewählten miRNAs (miR-205, -150, -122, -96, -146a und 146b-5p) in bovinen Embryonen des Präimplantationsstadiums durchgeführt, da diese in Eizellen angereichert auftraten. Die Ergebnisse zeigten, dass die Expression dieser miRNAs stark erhöht in frühen Stadien der Embryonalentwicklung und reduziert nach dem 8- Zellen-Stadium. Zu beobachten waren bis zum Blastozysten Stadium folgten die Embryonen den typischen maternalen Transkriptionsmustern. Vergleichbare Ergebnisse wurden bei der in situ Lokalisierung von miR-205 in Embryonen des Präimplantationsstadiums beobachtet. Leider zeigten die ausgewählten miRNAs (miR- 210 und miR-452), die in Kumuluszellen vermehrt exprimiert waren, kein definiertes Profil. Die gleichen acht miRNAs wurden in einer hohen Menge in voll ausgewachsenen Eizellen (BCB+) im Vergleich zu noch wachsenden Eizellen (BCB-) detektiert. Interessanterweise konnte beobachtet werden, dass die Präsenz oder Abwesenheit von Eizelle oder Kumuluszellen während der Maturation einen Einfluss auf die Expression der ausgewählten miRNAs in den entsprechenden Zelltypen hatte. Des Weiteren wurden miR-205 und miR-210 in situ in Follikeln lokalisiert und zeigten eine raum-zeitliche Expression während der Follikelentwicklung. Unsere Ergebnisse zeigen die Präsenz einer definierten Gruppe von miRNAs in Eizellen und Kumuluszellen, welch möglicherweise eine Rolle in der Regulation der bidirektionellen Kommunikation zwischen diesen zwei Zelltypen spielen

Reduced Complexity MIMO Concatenated Code in Fading Channels

Abstract-In conventional concatenations of Convolutional Codes (CC) and Space-Time Block Codes (STBC), the CC and STBC are utilized to provide coding gain and spatial diversity, respectively. We propose a concatenated code that achieves the full system diversity by appropriately selecting the outer CC with an inner reduced-rank STBC. The advantage of the lower rank STBC is that the number of RF chains can be reduced. For any number of RF chains, , we show that a desirable diversity order can be easily achieved i.e., 1 ≤ ≤ . Using trellis diagram, we formalize the method to determine the maximum diversity