Non-real Time Traffics Research Articles

AN ENHANCED RESOURCE ALLOCATION SCHEME FOR LONG TERM EVOLUTION ADVANCED NETWORK

The emerging Long-Term Evolution Advanced (LTE-A) is an extended version of Long-Term Evolution (LTE) fourth-generation (4G) wireless broadband technologies that supports high speed transmission of multimedia applications, like video streaming, multimedia online game, Voice over IP (VoIP), browsing over the web etc. The Third Generation Partnership Project (3GPP) does not define a standard packet scheduling strategy in LTE-A. Therefore, it is expected for researchers and network service providers to design efficient schemes. This paper proposed an Enhanced Resource Allocation Scheme (E-RAS) that improves the packet scheduling strategy of LTE-A by addressing issues related to delay and fairness of users with both high and low channel conditions, for both Real Time (RT) and Non-Real Time (NRT) flows. The aim was achieved by using a fair spectrum allocation mechanism that consider the priority of RT flows of cell-centre users, without neglecting the throughput requirements of edge-centre users. Moreover, the proposed algorithm introduces an efficient traffic load balancing mechanism to efficiently regulate traffic load in LTE-A network. To evaluate the proposed scheme, simulation was conducted using the MATLAB programming with LTE-A system level simulator. The result obtained shows that the proposed scheme achieves better delay for RT and NRT traffics by 7% and 11% respectively as against the Resource Allocation Scheme to Optimize the Throughput (RASOT) scheme.

Service-aware LSP selection with fuzzy based packet scheduling scheme for non-real time traffics

An essential solution is available in Multi-protocol label switching (MPLS), which solve the problems faced by present-day networks: speed, scalability, quality-of-service (QoS) management, and traffic engineering. This paper is an extension of work on Fuzzy based Packet Scheduling Algorithm (FPSA) combined with Packets Processing Algorithm (PPA) in an Internet Protocol/Multi-Protocol Label Switching (IP/MPLS) networks. This will make provision for an intelligent service to the Label Switched Path (LSP) in MPLS networks. Several research work have been proposed on the MPLS Traffic Engineering. However, it is still imperative to further research on the effect of bandwidth increment on the core network using different mechanisms such as the analytical model of MPLS, expert-based packet scheduling algorithm for MPLS QoS support. Since MPLS is not able to provide intelligent routing, it is necessary to propose an intelligent expert system of FPSA combined with PPA. And analytical model of packet forwarding in the MPLS network would be given to provide suitable solution to traffic congestion and reliable services. Furthermore, the network model created using Network Simulator (NS 2), which carries non-real time application such as File Transfer Protocol (FTP) with bandwidth variations. The results obtained from trace files are interpreted by AWK script and used for the further analysis.

Femtocell interference analysis based on the development of system-level LTE simulator

Abstract Although femtocell can confer various benefits to both operators and users, many technical issues, such as interference coordination, network synchronization, self-configuration, and self-optimization must be considered to effectively deploy femtocells in real environments. In this article, we develop a system-level simulator in order to evaluate performance of long-term evolution (LTE)-femtocell systems. The simulator consists of five functional modules which realize packet scheduling and call admission control functionalities and model various wireless channel effects, real and non-real time traffics, and user mobility. These modules are managed by operational modules that follow event-driven programming. In addition, the simulator adopts a graphical user interface (GUI) that facilitates configuration, management, and observation of simulations in real time. Based on the simulator, we analyze effects of signal interference between macro- and femtocells under four scenarios. From the results, we confirm that the developed LTE-femtocell simulator can effectively support performance evaluation and analysis on various femtocell deployment scenarios.

Frame-based adaptive uplink scheduling algorithm in orthogonal frequency division multiple access-based Worldwide Interoperability for Microwave Access networks

Because the orthogonal frequency division multiple access physical resource available for scheduling in Worldwide Interoperability for Microwave Access networks is frame by frame, an uplink scheduler located at the base station must efficiently allocate available resources to the subscriber stations in response to constant or bursty data traffic on a per-frame basis. Available resources for real-time and nonreal-time traffics, called frame-based adaptive bandwidth allocation and minimum guarantee and weight-based bandwidth allocation, respectively, are proposed in this paper. Moreover, both short-term and long-term bandwidth predictions for traffic are incorporated so that the long-term bandwidth prediction can have sustainable throughput requirement, and the short-term bandwidth prediction can meet the objectives of low delay and jitter. For the scenarios studied, it shows that system performance of the proposed algorithm is better than the hybrid (earliest deadline first + weighted fair queuing + FIFO) algorithm in terms of packet delay, jitter, throughput, and fairness. Copyright © 2011 John Wiley & Sons, Ltd.

Priority-Based Resource Allocation for Downlink OFDMA Systems Supporting RT and NRT Traffics

Efficient radio resource management is essential in Quality-of-Service (QoS) provisioning for wireless communication networks. In this paper, we propose a novel priority-based packet scheduling algorithm for downlink OFDMA systems. The proposed algorithm is designed to support heterogeneous applications consisting of both real-time (RT) and non-real-time (NRT) traffics with the objective to increase the spectrum efficiency while satisfying diverse QoS requirements. It tightly couples the subchannel allocation and packet scheduling together through an integrated cross-layer approach in which each packet is assigned a priority value based on both the instantaneous channel conditions as well as the QoS constraints. An efficient suboptimal heuristic algorithm is proposed to reduce the computational complexity with marginal performance degradation compared to the optimal solution. Simulation results show that the proposed algorithm can significantly improve the system performance in terms of high spectral efficiency and low outage probability compared to conventional packet scheduling algorithms, thus is very suitable for the downlink of current OFDMA systems.

Clustering-Based Multichannel MAC Protocols for QoS Provisionings Over Vehicular Ad Hoc Networks

Making the best use of the dedicated short range communications multichannel architecture, we propose a cluster-based multichannel communications scheme that can support not only public-safety message delivery but also a wide range of future multimedia (e.g., video/audio) and data (e.g., e-maps, road/vehicle traffic/weather information) applications. Our proposed scheme integrates clustering with contention-free and/or -based medium access control (MAC) protocols. In our scheme, the elected cluster-head vehicle functions as the coordinator to collect/deliver real-time safety messages within its own cluster and forward the consolidated safety messages to the neighboring cluster heads. In addition, the cluster-head vehicle controls channel assignments for cluster-member vehicles transmitting/receiving nonreal-time traffics, which makes the wireless channels more efficiently utilized for vehicle-to-vehicle (V2V) nonreal-time data transmissions. Our scheme uses the contention-free MAC within a cluster and the contention-based IEEE 802.11 MAC among cluster-head vehicles such that the real-time delivery of safety messages can be guaranteed. Under our proposed scheme, we develop an analytical model to study the delay for the consolidated safety messages transmitted by the cluster-head vehicles. Based on this analytical model, we derive the desirable contention-window size, which can best balance the tradeoff between the delay of safety messages and the successful rate of delivering safety messages. The extensive simulation results show that, under various highway traffic scenarios, our proposed scheme can efficiently support the nonreal-time traffics while guaranteeing the real-time delivery of the safety messages.

Wireless Packet Scheduling Algorithm for OFDMA System based on Time-utility and Channel State

In this paper, we propose an urgency- and efficiencybased wireless packet scheduling (UEPS) algorithm that is able to schedule real-time (RT) and non-real-time (NRT) traffics at the same time while supporting multiple users simultaneously at any given scheduling time instant. The UEPS algorithm is designed to support wireless downlink packet scheduling in an orthogonal frequency division multiple access (OFDMA) system, which is a strong candidate as a wireless access method for the next generation of wireless communications. The UEPS algorithm uses the time-utility function as a scheduling urgency factor and the relative status of the current channel to the average channel status as an efficiency indicator of radio resource usage. The design goal of the UEPS algorithm is to maximize throughput of NRT traffics while satisfying quality-of-service (QoS) requirements of RT traffics. The simulation study shows that the UEPS algorithm is able to give better throughput performance than existing wireless packet scheduling algorithms such as proportional fair (PF) and modifiedlargest weighted delay first (M-LWDF), while satisfying the QoS requirements of RT traffics such as average delay and packet loss rate under various traffic loads.