ON PERFORMANCE ANALYSIS OF AMBR PROTOCOL IN MOBILE AD HOC NETWORKS

Due to mobility of nodes in ad hoc networks, the most challenging issue is to design and to make sound analysis of a routing protocol that determines its robustness to deliver packets in low routing packet overhead. In this paper, we thoroughly analyzed the Adaptive Monitor Based Routing (AMBR) protocol by varying different parameters that affect a routing protocol to measure its performance. Analysis shows that it requires less routing control overhead comparing with other prevalent routing protocols. An improved analytical model is also presented in this paper. All these analyses firmly prove that AMBR is a sound and robust protocol in terms of flooding, routing overhead and hence, enhances reliabilit

Solving signaling storms in LTE networks: a software-defined cellular architecture

The LTE network infrastructure is composed by monolithic devices that carry out a convoluted set of tasks in a vendor-speci c manner. Therefore, LTE networks are largely in exible, and consequently unable to adapt to a constantly increasing number of mobile subscribers and the changeable usage pattern of the Internet service. In fact, current LTE networks are a ected by signaling storms, which come from the inability to reduce the number of signals exchanged among the infrastructural elements of the network when the number of subscribers' requests grows. In this work, we propose a software-de ned cellular architecture, whose logical entities can be mapped to an arbitrary number of physical devices, allowing di erent implementations depending on the speci c use case. In particular, we show that the proposed model actually mitigates the impact of signaling storms, as it can be tailored to reduce signi cantly the number of signals owing in the network during the occurrences of the most frequent network events

Modeling and Performance Analysis of Relay-based Cooperative OFDMA Networks

Next generation wireless communication networks are expected to provide ubiquitous high data rate coverage and support heterogeneous wireless services with diverse quality-of-service (QoS) requirements. This translates into a heavy demand for the spectral resources. In order to meet these requirements, Orthogonal Frequency Division Multiple Access (OFDMA) has been regarded as a promising air-interface for the emerging fourth generation (4G) networks due to its capability to combat the channel impairments and support high data rate. In addition, OFDMA offers flexibility in radio resource allocation and provides multiuser diversity by allowing subcarriers to be shared among multiple users. One of the main challenges for the 4G networks is to achieve high throughput throughout the entire cell. Cooperative relaying is a very promising solution to tackle this problem as it provides throughput gains as well as coverage extension. The combination of OFDMA and cooperative relaying assures high throughput requirements, particularly for users at the cell edge. However, to fully exploit the benefits of relaying, efficient relay selection as well as resource allocation are critical in such kind of network when multiple users and multiple relays are considered. Moreover, the consideration of heterogeneous QoS requirements further complicate the optimal allocation of resources in a relay enhanced OFDMA network. Furthermore, the computational complexity and signalling overhead are also needed to be considered in the design of practical resource allocation schemes. In this dissertation, we conduct a comprehensive research study on the topic of radio resource management for relay-based cooperative OFDMA networks supporting heterogeneous QoS requirements. Specifically, this dissertation investigates how to effectively and efficiently allocate resources to satisfy QoS requirements of 4G users, improve spectrum utilization and reduce computational complexity at the base station. The problems and our research achievements are briefly outlined as follows. Firstly, a QoS aware optimal joint relay selection, power allocation and subcarrier assignment scheme for uplink OFDMA system considering heterogeneous services under a total power constraint is proposed. The relay selection, power allocation and subcarrier assignment problem is formulated as a joint optimization problem with the objective of maximizing the system throughput, which is solved by means of a two level dual decomposition and subgradient method. The computational complexity is finally reduced via the introduction of two suboptimal schemes. The performance of the proposed schemes is demonstrated through computer simulations based on OFDMA network. Numerical results show that our schemes support heterogeneous services while guaranteeing each user's QoS requirements with slight total system throughput degradation. Secondly, we investigate the resource allocation problem subject to the satisfaction of user QoS requirements and individual total power constraints of the users and relays. The throughput of each end-to-end link is modeled considering both the direct and relay links. Due to non-convex nature of the original resource allocation problem, the optimal solution is obtained by solving a relaxed problem via two level dual decomposition. Numerical results reveal that the proposed scheme is effective in provisioning QoS of each user's over the conventional resource allocation counterpart under individual total power constraints of the users and relays . Lastly, decentralized resource allocation schemes are proposed to reduce the computational complexity and CSI feedback overhead at the BS. A user centric distributed (UCD) scheme and a relay centric distributed (RCD) scheme are proposed, where the computation of the centralized scheme is distributed among the users and relays, respectively. We also proposed suboptimal schemes based on simplified relay selection. The suboptimal schemes can be combined with the distributed schemes to further reduce of signalling overhead and computational complexity. Numerical results show that our schemes guarantee user's satisfaction with low computational complexity and signalling overhead, leading to preferred candidates for practical implementation. The research results obtained in this dissertation can improve the resource utilization and QoS assurance of the emerging OFDMA networks.4 month

Performance Evaluation of Real Time Traffic in LTE Networks

Long-Term Evolution, commonly known as 4G LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. TCP protocol plays a significant role in LTE network. Congestion control algorithm is an integral module of TCP that directly determines the performance of the protocol in IP Network. Many TCP variants like TCP-Vegas, TCP-Tahoe, TCP-Reno, TCP-NewReno, TCP-SACK, and TCP-FACK have been proposed for high bandwidth real time services in LTE network [1]. These TCP variants can be used to improve quality of service parameters i.e., throughput, average delay and lost packet in LTE network [2]. Since LTE systems has high-data-rate, low-latency and packet-optimized radio access technology therefore these parameters directly affect the traffic. In this paper, complete LTE Network is simulated using the OPNET simulator to evaluate network performance in real time [3]. The simulated LTE network is tested for each type of TCP protocol and the result is monitored for throughput, end to end delay, http and FTP traffic, re-transmission response time and packets drop etc and the results are plotted. At the end, it is concluded that TCP New Reno has outperformed in terms of throughput, re-transmission rate and http uplink and downlink traffic. In medium size network, the performance of Reno is satisfactory. Similarly changes in mobility rate enhance the performance of TCP Reno in other congestion control algorithms. On the other hand, TCP Cubic is found to be the worst performer for throughput, re-transmission rate and http traffic parameters. Keywords: LTE, QoS, EUTRAN, TCP, http, Opne

Ubiquitous Computing for Remote Cardiac Patient Monitoring: A Survey

New wireless technologies, such as wireless LAN and sensor networks, for telecardiology purposes give new possibilities for monitoring vital parameters with wearable biomedical sensors, and give patients the freedom to be mobile and still be under continuous monitoring and thereby better quality of patient care. This paper will detail the architecture and quality-of-service (QoS) characteristics in integrated wireless telecardiology platforms. It will also discuss the current promising hardware/software platforms for wireless cardiac monitoring. The design methodology and challenges are provided for realistic implementation

Performance analysis of long term evolution (LTE) network

University of Technology Sydney. Faculty of Engineering and Information Technology.The demand for high speed network has led to the development of LTE. The LTE replaced circuit switched legacy systems into packet switched network. The high speed simultaneous transmission of data is achieved by using Orthogonal Frequency Division Multiple Access (OFDMA) in the downlink. To achieve high speed multimedia services in the downlink various packet scheduling algorithms have been proposed in the past. The LTE architecture has been simplified compared to 2G or 3G systems to a greater extent. The network elements namely Base Station Controller (BSC) and Radio Network Controller (RNC) have been replaced with eNodeB. The Radio Resource Management (RRM) functionality has been confined to eNodeB. To enable end users to achieve high data rates Heterogeneous Networks (HetNets) are used. In HetNets, the pico cells and femto cells work alongside the macro cells to deliver the required QoS. The objective of this thesis is to study the performance of LTE network through simulation and by observing the KPIs from real-time network. The thesis starts with the performance analysis of downlink scheduling algorithms through simulations. The scheduling algorithms were simulated using NS-3 and LTE-Sim and various performance factors were studied. Thereafter, a model HetNet was simulated with a macro cell and pico cells. In the simulated LTE network environment, impact of pico cells on macro has been studied along with the scheduling algorithms. After simulations, a more practical approach has been taken to study the performance of the LTE network. The performance analysis of Proportional Fair (PF) scheduler has been made in the real-time LTE network. In this study, the end users were classified as Gold, Silver and Bronze based on the subscription plans. A combination of various scenarios has been was tested to analyse the throughput of the scheduler. Then the performance of RAN and Evolved Packet Core has been made by observing the Key Performance Indicators (KPIs). To obtain RAN KPIs drive tests were made in various modes such as walking around the city centre, travelling in train, driving in the car and in indoor environments. The KPIs were collected using Nemo Handy RF planning tool. The final part of the thesis covers the performance analysis of EPC. The KPIs such as accessibility, retainability, traffic, mobility, and Automatic Neighbour Relations (ANR) were collected for three months and the EPC performance was analysed. In the analysis, a critical issue in retainability was identified and this issue was impacting the accessibility of the network. After thorough analysis of KPIs, the root cause of the issue was identified as the Mobility Management Entity (MME) sending fake Serving Gateway (SGW) relocation request to eNodeB when there is only one SGW configured. This issue was identified and resolved using the KPIs

VoLTE service implementation in EPS-IMS networks

Diplomová práce popisuje VoLTE službu, vývoj a nasazení LTE (zaváděcí fázi, skutečný LTE stav a výhledy do budoucna atd.), EPC-IMS architekturu (popis funkce uzlu, rozhraní atd.) Komunikace mezi uzly a funkce, rozhraní a protokoly jsou používány v průběhu signalizace (SIP SDP) a datový tok (RTCP RTP). Práce stručně popisuje základní toky hovorů, typy nosičů (GBR and N-GBR), a to vytvoření / mazaní nosičů během komunikace. Další část diplomové práce o implementaci volte, instalace a konfigurace IMS. Závěrečná část diplomové práce popisuje zkoušky sítě a, analýzu protokolu.The master's thesis describes VoLTE service, LTE evolution and deployment (deployment phases, actual LTE state and future perspectives etc.), EPC-IMS architecture (functional node description, interfaces etc.). Communications between nodes and functions, interfaces and protocols which are used during signaling (SIP-SDP) and data flow (RTCP RTP). Thesis briefly describe basic call flows, bearers types (GBR and N-GBR) and their establishment/delete during communication. The next part of master's thesis is about VoLTE implementation solutions, IMS installation and configuration. The final part of master's thesis describes the network and protocols tests, analyzes.

Deployment of Beyond 4G Wireless Communication Networks with Carrier Aggregation

With the growing demand for new blend of applications, the user’s dependency on the Internet is increasing day by day. Mobile Internet users are giving more attention to their own experience, especially in terms of communication reliability, high data rate and service stability on the move. This increase in the demand is causing saturation of existing radio frequency bands. To address these challenges, many researchers are finding the best approach, Carrier Aggregation (CA) is one of the newest innovations which seems to fulfil the demands of future spectrum, CA is one the most important feature for Long Term Evolution - Advanced. In direction to get the upcoming International Mobile Telecommunication Advanced (IMT-Advanced) mobile requirements 1 Gb/s peak data rate, the CA scheme is presented by 3GPP to sustain high data rate using widespread frequency bandwidth up to 100 MHz. Technical issues containing the aggregation structure, its implementation, deployment scenarios, control signal technique and challenges for CA technique in LTE-Advanced, with consideration backward compatibility are highlighted. Performance evaluation in macrocellular scenarios through a simulation approach shows the benefits of applying CA and low-complexity multi-band schedulers in service quality and system capacity enhancement. The Enhanced multi-band scheduler is less complex than the General multi-band scheduler and performs better for cell radius longer than 1800 m (and a PLR threshold of 2%).This work is funded by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/EEA/50008/2020, COST CA 15104 IRACON, ORCIP and CONQUEST (CMU/ECE/0030/2017), TeamUp5G project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie project number 813391.info:eu-repo/semantics/acceptedVersio