A Fair and Efficient Packet Scheduling Scheme for IEEE 802.16 Broadband Wireless Access Systems

This paper proposes a fair and efficient QoS scheduling scheme for IEEE 802.16 BWA systems that satisfies both throughput and delay guarantee to various real and non-real time applications. The proposed QoS scheduling scheme is compared with an existing QoS scheduling scheme proposed in literature in recent past. Simulation results show that the proposed scheduling scheme can provide a tight QoS guarantee in terms of delay, delay violation rate and throughput for all types of traffic as defined in the WiMAX standard, thereby maintaining the fairness and helps to eliminate starvation of lower priority class services. Bandwidth utilization of the system and fairness index of the resources are also encountered to validate the QoS provided by our proposed scheduling scheme

New contention resolution schemes for WiMAX

Abstract—The use of Broadband Wireless Access (BWA) technology is increasing due to the use of Internet and multimedia applications with strict requirements of end–to–end delay and jitter, through wireless devices. The IEEE 802.16 standard, which defines the physical (PHY) and the medium access control (MAC) layers, is one of the BWA standards. Its MAC layer is centralized basis, where the Base Station (BS) is responsible for assigning the needed bandwidth for each Subscriber Station (SS), which requests bandwidth competing between all of them. The standard defines a contention resolution process to resolve the potential occurrence of collisions during the requesting process. In this paper, we propose to modify the contention resolution process to improve the network performance, including end–to–end delay and throughput

Bandwidth Recycling using Variable Bit Rate

IEEE 802.16 standard was designed to support the bandwidth demanding applications with quality of service (QoS). Bandwidth is reserved for each application to ensure the QoS. For variable bit rate (VBR) applications, however, it is difficult for the subscriber station (SS) to predict the amount of incoming data. To ensure the QoS guaranteed services, the SS may reserve more bandwidth than its demand. As a result, the reserved bandwidth may not be fully utilized all the time. In this paper, we propose a scheme, named Bandwidth Recycling, to recycle the unused bandwidth without changing the existing bandwidth reservation. The idea of the proposed scheme is to allow other SSs to utilize the unused bandwidth when it is available. Thus, the system throughput can be improved while maintaining the same QoS guaranteed services. Mathematical analysis and simulation are used to evaluate the proposed scheme. Simulation and analysis results confirm that the proposed scheme can recycle 35% of unused bandwidth on average. By analyzing factors affecting the recycling performance, three scheduling algorithms are proposed to improve the overall throughput. The simulation results show that our proposed algorithm improves the overall throughput by 40% in a steady network. Keywords: WiMAX, IEEE 802.16, Bandwidth Recyclin

Efficient Resource Management Mechanism for 802.16 Wireless Networks Based on Weighted Fair Queuing

Wireless Networking continues on its path of being one of the most commonly used means of communication. The evolution of this technology has taken place through the design of various protocols. Some common wireless protocols are the WLAN, 802.16 or WiMAX, and the emerging 802.20, which specializes in high speed vehicular networks, taking the concept from 802.16 to higher levels of performance. As with any large network, congestion becomes an important issue. Congestion gains importance as more hosts join a wireless network. In most cases, congestion is caused by the lack of an efficient mechanism to deal with exponential increases in host devices. This can effectively lead to very huge bottlenecks in the network causing slow sluggish performance, which may eventually reduce the speed of the network. With continuous advancement being the trend in this technology, the proposal of an efficient scheme for wireless resource allocation is an important solution to the problem of congestion. The primary area of focus will be the emerging standard for wireless networks, the 802.16 or “WiMAX”. This project, attempts to propose a mechanism for an effective resource management mechanism between subscriber stations and the corresponding base station

Medium access control design for all-IP and ad hoc wireless network

Medium Access Control (MAC) protocol in a wireless network controls the access of wireless medium by mobile terminals, in order to achieve its fair and efficient sharing. It plays an important role in resource management and QoS support for applications. All-IP wireless WAN is fully IP protocol-based and it is a strong candidate beyond 3G (Third Generation Wireless Network). Ad hoc wireless network has recently been the topic of extensive research due to its ability to work properly without fixed infrastructure. This dissertation is composed of two main parts. The first part pursues a Prioritized Parallel Transmission MAC (PPTM) design for All-IP Wireless WAN. Two stages are used and each packet is with a priority level in PPTM. In stage 1, a pretransmission probability is calculated according to the continuous observation of the channel load for a certain period of time. In stage 2, a packet is prioritized and transmitted accordingly. It is modeled and analyzed as a nonpreemptive Head-Of-the-Line prioritized queueing system with Poisson arrival traffic pattern. Its performance is analyzed under three other traffic patterns, which are Constant Bit Rate, Exponential On/Off, and Pareto On/Off, by using a NS-2 simulator, and compared with that of Modified Channel Load Sensing Protocol. PPTM supports dynamic spread code allocation mechanism. A mobile terminal can apply for a spreading code according to the current channel condition. To use the idea of dynamic bandwidth allocation in PPTM for adhoc wireless network, a Dynamic-Rate-with-Collision-Avoidance (DRCA) MAC protocol is proposed in the second part of the dissertation. DRCA is based on spread spectrum technology. In DRCA, a terminal sets the spreading factor for a packet according to the activity level of neighboring nodes. If the total number of usable spreading codes with this spreading factor is less than the total number of mobile terminals in the network, to avoid collision, the spreading code id is broadcast such that other terminals can avoid using it when the packet is being transmitted. The performance of DRCA is theoretically analyzed in a slotted, single-hop, multi-user environment. To evaluate DRCA\u27s performance in an environment closed to a real one, a simulator that supports multi-hop, random mobility pattern is created with OPNET. Both theoretical and simulation results show that DRCA outperforms MACA/CT (Multiple Access with Collision Avoidance with Common Transmitter-based) in case if there are more than one communication pair and the ratio of inactive mobile terminals to active ones is high

Improving Quality of Vehicle Tracking Systems in Hill Stations Using IEEE 802.16 Networks

IEEE 802.16 standard was designed to support the vehicle tracking system applications with quality of service(QOS). Tracking system is used for tracking the vehicles in hill stations with quality of service(QOS). With the help of subscriber station(SS) can track the vehicles. Subscriber station’s will provide signals to the mobiles and vehicles .In this paper, we propose a scheme, named vehicle tracking system, to track the vehicles without any interrupt in hill stations with quality of service(QOS). The idea of the proposed scheme is to track the vehicles in the roads of the hill stations which is coming in opposite direction and back of the vehicle. Analysis and simulations are used to evaluate the proposed scheme. Simulation and analysis results confirm  that the proposed can track the vehicles with the help of subscriber station by given quality of service(QOS). Scheduling algorithms are proposed to improve the overall throughput. The simulation results show that our proposed algorithm improves the overall throughput by 40% in a steady network.DOI:http://dx.doi.org/10.11591/ijece.v3i1.213

Connection admission control and packet scheduling for IEEE 802.16 networks

Includes bibliographical references.The IEEE 802.16 standard introduced as one of the Wireless Metropolitan Area Networks (WMAN) for Broadband Wireless Access (BWA) which is known as Worldwide Interoperability for Microwave Access (WiMAX), provides a solution of broadband connectivity to areas where wired infrastructure is economically and technically infeasible. Apart from the advantage of having high speeds and low costs, IEEE 802.16 has the capability to simultaneously support various service types with required QoS characteristics. ... While IEEE 802.16 standard defines medium access control (MAC) and physical (PHY) layers specification, admission control and packet scheduling mechanisms which are important elements of QoS provisioning are left to vendors to design and implement for service differentiation and QoS support