Fuzzy based scheduling technique for multiple service flows in 802.16 WiMAX

Adaptive REM(AREM) is proposed to support real time traffic from non real time traffic in routers. In AREM, we classify the traffics into real time flows and non real time flows and the marking probability of non real time traffic is increased proportional to the amount of protected real time traffic until the marking probability reaches its maximum limit. Our simulation result shows that AREM provides improved overall performance to real time traffic in a sense of low loss rate and bounded delay.

In last few years there has been significant growth in the area of wireless communication. Quality of Service (QoS) has become an important consideration for supporting variety of applications that utilize the network resources. These applications include voice over IP, multimedia services, like, video streaming, video conferencing etc. IEEE 802.16/WiMAX is a new network which is designed with quality of service in mind. This paper focuses on analysis of quality of service as implemented by the WiMAX networks. First, it presents the details of the quality of service architecture in WiMAX network. In the analysis, a WiMAX module developed based on popular network simulator ns-2, is used. Various real life scenarios like voice call, video streaming are setup in the simulation environment. Parameters that indicate quality of service, such as, throughput, packet loss, average jitter and average delay, are analyzed for different types of service flows as defined in WiMAX. Results indicate that better quality of service is achieved by using service flows designed for specific applications.

Wireless technologies have become the model for Entertainment, Communication and Education all over the world. Electrical and Electronics Engineering Departments of various Universities across the globe offer courses on Wireless Communication and Networks for Undergraduate and Postgraduate students by focusing on the latest teaching pedagogy. Recent advancements in health care services demand reliable transmission of medical images and videos for better diagnosis and treatment. The effective utilization of available spectrum is one of the requirements for stable transmission of medical information. A Long Term Evolution (LTE) system model for a real-time multimedia application must provide high Quality of Service (QoS). Scheduling and allocating resources for real-time downlink flows in LTE networks is a challenging issue, as the network excellence and assured output have to be confirmed together with decreasing the Head of Line (HOL) suspension. The ever increasing demand for higher data rates in uplink and downlink transmission services constraints on delay and bandwidth requirements. This leads the existing fourth generation LTE wireless networks to concentrate more on the resource scheduling techniques with acceptable levels of Quality of Service (QoS). In this paper, a Game theory based scheduling (GTBS) and resource allocation Algorithm multimedia traffic in LTE network is designed and studied. The Algorithm is simulated in LTE-sim for real time (RT) and Non-real time (NRT) data traffic. The work identified a new teaching pedagogy, the work is explained to the undergraduate Engineering students so that they can apply the knowledge to develop new innovative projects.

Deep space exploration has seen rapid advancements in recent years, accompanied by a surge in exploration equipment and service traffic. Delay/disruption‐tolerant networks (DTNs) offer a robust communication architecture to support these missions by providing unified and efficient communication services. A critical network metric, the service payoff, reflects the value delivered by the network and is directly tied to the ability to meet quality of service (QoS) requirements for diverse service flows. However, in the deep‐space DTN architecture, there is a lack of solutions for allocating corresponding network resources for different service flows to achieve QoS guarantees, making it challenging to improve network service payoff. Therefore, this paper introduces a fully centralized online resource allocation (FCORA) scheme to maximize the service payoff in deep space DTNs. By incorporating non‐orthogonal multiple access (NOMA) technology, the scheme enhances spectrum utilization through joint optimization of bandwidth allocation, user clustering, and power control. To address the computational challenges of centralized allocation, we propose a semicentralized online resource allocation (SCORA) algorithm, which offloads fine‐grained service flow control to edge nodes using parallel edge computing. Simulation results demonstrate that FCORA and SCORA significantly enhance service payoff, even under heavy traffic conditions. Furthermore, SCORA achieves low computational latency, meeting the real‐time requirements for online resource allocation in deep space DTNs.

Throughput Measurement for the Guaranteed QoS Real-time Traffic Flows in VANETs

An integrated bandwidth allocation and admission control framework for the support of heterogeneous real-time traffic in class-based IP networks

IEEE 802.16 standard provides a broadband wireless access solution. WiMAX (Worldwide interpretability for microwave access) is the business definition of the 802.16-2004 amendment. In WiMAX, quality of service (QoS) is provided through both classification and scheduling of the four different types of traffic classes defined by the standard. Each class has it own bandwidth requirements as well as its level of QoS, which has to be maintained. In this paper, we provide a performance analysis of three types of connections defined in the standard (UGS, rtPS, nrtPS). Different levels of priority and blocking probability are assigned to each class of service. This performance analysis has been done using an analytical model for evaluating admission control (AC) for the previous mentioned classes in WiMAX network.

A new Packet Scheduler whose architecture is based on the cross-layer paradigm is proposed for the IEEE 802.16j standard. The scheduler combines functionalities derived from the use of the utility function concept from economics, for the satisfaction of the maximum packet delay from real time service flows, and the token bucket principle for the support of minimum throughput requirements from non-real time service flows. Commonly used packet schedulers in the literature are used in the performance evaluation of the proposed scheduler, by means of System Level Simulations under a realistic network layout, conducted on a proprietary C++ platform, fully compatible with the IEEE802.16j standard. Performance is evaluated by means of the percentage of satisfied users for a given range of the system load (amount of active users in the system).

To analyze network QoS (Quality of Service) performance and better utilize network resources, this paper develops an analytical model of QoS class mapping for hybrid QoS domains based on network calculus theory. Based on this model, an elastic QoS Mapping scheme with Flow Aggregate (EQM-FA) is proposed to support end-to-end QoS of multimedia services over heterogeneous wireless networks. In EQM-FA, the QoS requirements of service flows are indicated by a unique flow aggregate identifier which can be described by the information describing QoS on a service flow map which is a multidimensional space of relevant QoS parameters. With flow aggregate identifier and mapping executors sitting at the border of different QoS domains, EQM-FA allows smooth QoS class mapping between different networks with different granularity of QoS class. Both numerical analysis and simulation studies are given to demonstrate the efficacy of the proposed method.

The TCP/IP internetworking technology has proven to be the means to build highly scalable, heterogeneous information infrastructures, as exemplified by the global Internet. Originally designed for data transport, the internet is being used increasingly for transport of multimedia information such as voice and video. With the increase in sophistication of desktop computers, and the availability of networked multimedia applications, private IP networks as well as the public Internet is likely to see more of this type of traffic. This type of usage, however, is ad-hoc in that the IP network architecture has been designed for “best-effort” delivery, without any guarantees on throughput or delay. To adequately support real-time traffic flows with bandwidth and delay requirements, the following features are needed: new service classes beyond best-effort to provide certain guarantees on throughput and delay to applications; a mechanism that allows applications to signal to the network their quality of service (QoS) requirements and to reserve network resources to obtain the desired QoS; traffic management mechanisms in hosts and routers, and a routing architecture that allows the dynamic discovery of QoS-accommodating paths in the network for data flows, in the presence of changes in network topology and loading.

This paper addresses the issue of provisioning end-to-end quality of service (QoS) for multimedia services over heterogeneous networks and introduces a parametric model by using network calculus theory for QoS class mapping between different QoS domains. Then, a QoS mapping scheme based on flow aggregation (QMS-FAG) is proposed in this paper to mitigate the information loss problem due to mapping between QoS domains with different granularity of QoS class and to provide efficient network resources utilization by considering user's quality of experience. In QMS-FAG, the QoS requirements of service flows are indicated by a unique FAG identifier, which is described in a service flow map of QoS parameters. With FAG identifier and mapping executors sitting at the border of different QoS domains, QMS-FAG allows smooth QoS class mapping between networks with different granularity of QoS class. Both numerical analysis and simulation studies are given to demonstrate the efficiency of the proposed method.

In this paper, a novel quality of service (QoS) class mapping and scheduling scheme for the LTE-WiFi converged network is proposed to ensure that end-to-end QoS support is provisioned seamlessly. A mapping among QoS classes of LTE and WiFi is performed first, then scheduling scheme is outlined. For scheduling scheme, traffic is separated into real-time (RT) and non-real-time (NRT) components, then a two-stage complex queuing strategy is performed. In the first stage, deficit weighted round robin queuing (DWRRQ) and class-based weighted fair queuing (CBWFQ) are used for RT and NRT applications respectively to segregate and forward traffic according to resource requirements. Whereas in the second stage, rate-control priority queuing (RCPQ) is used for all types of traffic to give each class appropriate priority level. Performance evaluation of the converged network was done based on different metrics such as jitter, end-to-end delay, throughput, and packet loss ratio. Simulation results show significant improvements for RT with slight degradation on NRT applications after using the new scheduling scheme.

The goal of 5G wireless networks is to support a diverse set of requirements spanning low-latency, high connectivity, and high bit-rates. Support for the multitude of deployment scenarios is enabled by 5G Quality of Service (QoS) flows. In 5G, an inbound service from outside the cellular network can be separated into multiple QoS flows and scheduled onto multiple data bearers; each 5G data bearer meets specific QoS requirements. These requirements include extended networks, as enabled by UE-to-Network Relays. Typical examples are the networks formed by Device to Device (D2D) User Equipment (UEs) and Internet of Things (IoT) devices. Traditional latency-driven assignment methodologies typically assign a fixed Latency / Sub-Carrier Spacing (SCS) to each multicast flow, as directed by the QoS requirements. A drawback to traditional approaches is they do not account for the impact of multi-path / delay spread, as such they are unable to efficiently utilize the allocated radio spectrum in high delay spread radio environments; low latency flows are more sensitive to high delay spread. In this research work we derive an optimal QoS to 5G data bearer mapping for an extended network, subject to the constraints imposed by UEs and the UE-to-Network Relay. Compared to legacy multicast methodologies, our methodology can achieve an equivalent or higher throughput while minimizing deviation from the original latency requirements.

The medium access control of IEEE 802.11e defines a novel coordination function, namely hybrid coordination function (HCF), which allocates transmission opportunity (TXOP) to stations taking their quality of service (QoS) requirements into account. However, the reference TXOP allocation scheme of HCF controlled channel access, a contention-free channel access function of HCF, is only suitable for constant bit rate traffic. For variable bit rate (VBR) traffic, serious packet loss may occur. In this article, we generalize the reference design with an efficient TXOP allocation algorithm, a multiplexing mechanism, and an associated admission control unit to guarantee QoS for VBR flows with different delay bound and packet loss probability requirements. We define equivalent flows and aggregate packet loss probability to take advantage of both intra-flow and inter-flow multiplexing gains so that high bandwidth efficiency can be achieved. Moreover, the concept of weighted-loss fair service scheduling is adopted to allocate the aggregate TXOP to individual flows. From numerical results obtained by computer simulations, we found that our proposed scheme meets QoS requirements and results in much higher bandwidth efficiency than previous algorithms.

<p>Understanding the current hydro-meteorological situation is critical to manage extreme events and water resources. The UK Water Resources Portal (UKWRP) has been developed to enable dynamic, interactive, real-time access to hydro-meteorological data, including catchment daily rainfall, real-time daily mean river flows, real-time soil moisture data from COSMOS-UK and standardised climate indices. Users can access and view data at the field, grid cell and catchment scale enabling holistic assessments of the hydro-meteorological status at a range of spatial scales. The portal offers a way of exploring the full range of river flow and rainfall variability, including comparing current conditions to those in the past, from droughts to floods. A variety of different plotting capabilities mean users can view and explore data in different ways depending on their requirements.</p><p>The UKWRP can be used alone or alongside other resources such as: the UK Hydrological Outlook seasonal forecasts, the Hydrological Summary for the UK and Environment Agency Water Situation Reports, to manage water resources, to plan and prepare for extreme events, and to understand and communicate their severity.  The UKWRP enables all water users, from farmers, to water companies to members of the general public to view and explore the data used by regulators to manage water supplies. Equalising access to data can be extremely powerful; for example in the case of farmers, it means they can easily view real time river flows in relation to conditions on their licence using the same data used by regulators to impose abstraction restrictions during a drought.</p><p>Here we present the stakeholder engagement story of how and why the UKWRP was developed, demonstrate the capability of the UKWRP to monitor the hydrological situation in real time, and present plans for its future development, such as the addition of more indicators and indices.</p>