Rough set based QoS enabled multipath source routing in MANET

The single constrained Quality of Service (QoS) routing in Mobile Ad-hoc NETwork (MANET) is disastrous in consideration of MANET characteristics, inference, collision and link failure as it maintains a single path. The QoS enabled routing yields better packet delivery and maintains consistency among nodes in the network by incorporating multi-constrained and multipath routing. The Dynamic Source Routing (DSR) is best suited source routing algorithm to maintain multipath information at the source node, but performance degrades with larger number of mobile nodes. Multi-layer mechanism should be incorporated to maintain QoS metric information spreads across multiple layers of TCP/IP protocol stack. The proposed multipath QoS enabled source routing provides balanced routing by making use of all these features. The imprecise decision making strategy called Rough Set Theory (RST) is used at destination node for decision making. The Route REQuest (RREQ) messages coming from different routes are filtered by considering the QoS metrics of each and every route by making use of RST. The Route REPly (RREP) messages are generated and delivered to the source node for filtered RREQ messages. The proposed routing algorithm will reduce load on the network by reducing number of control messages exchanged for route establishment. This will evenly distribute load among all the nodes and it also avoid the scenarios like few nodes starved for resources. Finally, multipath routing always provides alternate routing option in case of route failure

InfiniBand-Based Mechanism to Enhance Multipath QoS in MANETs

Mobile Ad-hoc Networks (MANETs), the continuous changes in topology and the big amounts of data exchanged across the network makes it difficult for a single routing algorithm to route data efficiently between nodes. MANETs usually suffer from high packet loss rates and high link failure rates, which also makes it difficult to exchange data in effective and reliable fashion. These challenges usually increase congestion on some links while other links are almost free. In this thesis, we propose a novel mechanism to enhance QoS in multipath routing protocols in MANETs based on the InfiniBand (IB) QoS architecture. The basic idea of our approach is to enhance the path balancing to reduce congestion on overloaded links. This mechanism has enabled us to give critical applications higher priority to send them packet when routing their packets across the network, effectively manage frequent connections and disconnections and thus help reduce link failures and packet loss rates, and reduce the overall power consumption as a consequence of the previous gains. We have tested the scheme on the (IBMGTSim) simulator and achieved significant improvements in QoS parameters compared to two well-known routing protocols: AODV and AOMDV.هناك نوع من الشبكات حيث يكون كل المكونات فيها عبارة عن اجهزة متحركة بدون اي بنية تحتية تسمى "MANET "في هذا النوع من الشبكات تتعاون االجهزة ذاتيا لتحديد الطرق في ما بينها والنها متحركة تقوم هذه االجهزة بحساب اكثر من طريق عو ًضا عن حساب طريق واحد لتقليل من احتمالية فشل في االرسال حيث اذا تم فشل في طريق معينة تبقى الطرق االخرة سليمة. وفي ناحية اخرى ولتنوع اهمية البرامج والخدمات التي توفرها هذه االجهزة هناك ما يسمى "بجودى الخدمات Service of Quality" حيث يقوم المستخدم بوضع اولويات للبرامج والخدمات من استهالك المصادر المتاحة, والطريق الشائعة هي ان يقوم المستخدم بوضع حدود على سرعة استعمال الشبكة من قبل البرامج االقل اهمية لترك المصادر متاحة للبرامج الاكثر المهمة بشكل اكثر وهذا الحل يحتوي على الكثير من المشاكل في هذا النوع من الشبكات, حيث ان مواصفات الطرق غير معروفة وغير ثابتة وقد تحتوي او تتغير الى قيم اقل من الحدود الموضوعة للبرمج الغير مهمة فتتساوى البرامج والخدمات االقل اهمية بالبرامج االكثر اهمية مما يعني فشل في جودة الخدمات. من خالل بحثنا عن حلول ودراسة انواع مختلفة من الشبكات وجدنا نوع من تطبيق جودة الخدمات في نوع الشبكات المسمى بInfiniBand حيث يتم تطبيق جودة الخدمات من خالل تغيير عدد الرسال المبعثة من قبل البرامج, حيث تقوم االجهزة بارسال عدد اكبر من الرسال التابعة للبرامج المهمة مقارنة بعدد الرسال التابعة للبرامج االقل اهمية, ويتم ذلك باستخدام الصفوف, حيث تصطف الرسال من البرامج المهمة بصف يختلف عن الصف الذي يحتوي على رسال البرامج الغير مهمة. هذا الحل له فائدتان مهمتان االولى انه ال يوثر عالطريقة التقليدية ويمكن ان يستخدم معها والفائدة الثانية انه وبخالف الطريقة التقليدية, الطريقة الجديدة ال تتاثر بصفات الطريق المحسوبة او بتغير صفاتها فنسبة عدد الرسال تكون نفسها مهما اختلفت الطرق و صفاتها, بعد تطبيق هذا النوع وجددنا تحسين في كفائة االرسال تصل الى 18 %في جودة التوصيل و 10 %في سرعة الوصول مع العلم ان جودة الخدمات لم تفشل على غرار الطريقة التقليدية

Quality aspects of Internet telephony

Internet telephony has had a tremendous impact on how people communicate. Many now maintain contact using some form of Internet telephony. Therefore the motivation for this work has been to address the quality aspects of real-world Internet telephony for both fixed and wireless telecommunication. The focus has been on the quality aspects of voice communication, since poor quality leads often to user dissatisfaction. The scope of the work has been broad in order to address the main factors within IP-based voice communication. The first four chapters of this dissertation constitute the background material. The first chapter outlines where Internet telephony is deployed today. It also motivates the topics and techniques used in this research. The second chapter provides the background on Internet telephony including signalling, speech coding and voice Internetworking. The third chapter focuses solely on quality measures for packetised voice systems and finally the fourth chapter is devoted to the history of voice research. The appendix of this dissertation constitutes the research contributions. It includes an examination of the access network, focusing on how calls are multiplexed in wired and wireless systems. Subsequently in the wireless case, we consider how to handover calls from 802.11 networks to the cellular infrastructure. We then consider the Internet backbone where most of our work is devoted to measurements specifically for Internet telephony. The applications of these measurements have been estimating telephony arrival processes, measuring call quality, and quantifying the trend in Internet telephony quality over several years. We also consider the end systems, since they are responsible for reconstructing a voice stream given loss and delay constraints. Finally we estimate voice quality using the ITU proposal PESQ and the packet loss process. The main contribution of this work is a systematic examination of Internet telephony. We describe several methods to enable adaptable solutions for maintaining consistent voice quality. We have also found that relatively small technical changes can lead to substantial user quality improvements. A second contribution of this work is a suite of software tools designed to ascertain voice quality in IP networks. Some of these tools are in use within commercial systems today

Selected Papers from the First International Symposium on Future ICT (Future-ICT 2019) in Conjunction with 4th International Symposium on Mobile Internet Security (MobiSec 2019)

The International Symposium on Future ICT (Future-ICT 2019) in conjunction with the 4th International Symposium on Mobile Internet Security (MobiSec 2019) was held on 17–19 October 2019 in Taichung, Taiwan. The symposium provided academic and industry professionals an opportunity to discuss the latest issues and progress in advancing smart applications based on future ICT and its relative security. The symposium aimed to publish high-quality papers strictly related to the various theories and practical applications concerning advanced smart applications, future ICT, and related communications and networks. It was expected that the symposium and its publications would be a trigger for further related research and technology improvements in this field