WiMAX Quality Of Service Research Articles

An Improvement of Power Saving Class Type II Algorithm in WiMAX Sleep-mode

Because of the fact that users can connect to a WiMAX (IEEE 802.16) network wirelessly with large-scale movement capability, it is inevitable that they cannot access electrical power sources at their desired time. As a result, a mechanism is needed to reduce power consumption; and therefore three power saving classes have been defined in WiMAX that each one is designed for a specific application. Although using a suitable power saving class (PSC) can reduce power consumption significantly, but lack of cross-layer coordination can reduce the efficiency of the power saving mechanism. Since real-time services which are related to power saving class type II (PSC II) have great importance and vast applications, an improved PSC II algorithm for WiMAX is proposed in this paper which not only guarantees WiMAX quality of service (QoS), but also makes the cross-layer coordination using a proactive buffer resulting in less power consumption. There is also a comparison made between the performance of the proposed algorithm and the predefined PSC II algorithm in WiMAX using computer simulations and it shows that using the proposed algorithm reduces power consumption by 60 percent, while WiMAX QoS is still guaranteed.

Novel user centric, game theory based bandwidth allocation mechanism in WiMAX

AbstractBandwidth allocation plays a crucial role in ensuring overall quality of service in WiMAX. WiMAX supports non-contention based bandwidth allocation mechanism, where the responsibility of bandwidth allocation lies with the base station. In this paper, a novel user- centric, Game Theory-based bandwidth allocation algorithm is proposed. The Users/Mobile Station shall be grouped in pairs and bandwidth allocation is performed alternately between the two users of a group. In any given frame only one user from a pair is allocated bandwidth. The bandwidth thus allocated shall satisfy the requirements of the user/mobile station for two consecutive frames. Since, in any given frame, only one user/MS is allocated the bandwidth, the proposed algorithm reduces the frame overhead, thereby saving precious bandwidth that can be utilized to improve throughput. Simulation results show a 50% decrease in the uplink frame overhead and about 8% improvement in the uplink throughput per user/mobile station.

Cross‐layer channel selection and reward‐based power allocation for increasing system capacity and reward in multiple‐input–multiple‐output wireless communications

For increasing network bandwidth and guaranteeing quality of service in WiMAX, IEEE 802.16 m proposes the multiple-input–multiple-output (MIMO) technique that offers compatible specifications with the existing IEEE 802.16 family specifications. However, the performance of the IEEE 802.16 MIMO specification is significantly degraded in the high-mobility environment and high communication interference. As a result, a sender easily uses inaccurate modulation and coding scheme (MCS) and improper power allocation for different-priority users having different received signal-to-noise ratios. The system capacity is thus affected significantly. Additionally, the multiuser MIMO systems seldom consider that different-priority users and different-class traffic bring different rewards to the system. This study thus proposes a cross-layer reward-based approach (namely CLR) that consists of three schemes: adaptive modulation and coding determination, cross-layer dynamic channel selection, and reward-based weighting power allocation. The proposed CLR approach achieves accurate channel state information determination, optimal channel selection, and adaptive reward power allocation. Numerical results demonstrate that the proposed approach significantly outperforms the other approaches in system reward, system capacity, and the accuracy of the MCS determination.

On QoE monitoring and E2E service assurance in 4G wireless networks

From the users and service providers point of view, the upcoming 4G wireless (WiMAX and LTE) networks are expected to deliver high performance sensitive applications like live mobile TV, video calling, mobile video services, etc. The 4G networks are intended to provide an accurate service view of customer-perceived service quality ? their ?Quality of Experience? or QoE. Delivering high QoE depends on factors that contribute to the user?s perception of the target services as well as the Quality of Service (QoS) of the network. Although a better network QoS in many cases will result in better QoE, fulfilling all traffic QoS parameters alone may not guarantee satisfied users. On the other hand, if the QoS of the network degrades, the QoE of users' applications could be affected significantly. This article presents an integrated view of End-to- End (E2E) QoS and service assurance support in WiMAX and LTE networks. The integrated view also considers the existing cross-layer implementations to achieve the necessary E2E QoS and how the QoS and QoE should and can be monitored over the network in an E2E fashion. The existing cross-layer implementations ensure the E2E QoS performance before establishing the applications. However, even though the network has strong QoS support, the service providers should still monitor the QoS of the network and QoE of users? applications accurately to achieve service quality assurance.

Survey on Handoff with QoS in WIMAX

stands for worldwide interoperability for microwave access. Wimax Technology that enables ubiquitous delivery of the wireless broadband service for fixed and/or for mobile users . wimax is wireless digital communication system also known as 802.16 . which is intended for wireless Metropolitan area networks .The challenge for Broadband Wireless Access networks is in provides the quality of service (QoS) simultaneously to services with very different characteristics. QoS support in wireless networks is a much more difficult task than in wired networks, mainly because the characteristics of a wireless link are highly variable and unpredictable, both on a time-dependent basis and a location dependent basis. A special requirement for mobile device is ability to change the serving BS ,if there exists another BS , for example better link quality to reach of MS . we consider an interworking architecture of wireless mesh backbone and propose an effective vertical handoff scheme between 802.11 and 802.16 wireless access networks. The proposed reducing handoff signaling overhead on the wireless backbone and providing a low handoff delay to mobile nodes. While handoff a mechanism to maintain uninterrupted user communication session during a user movements from one location to another . Wimax supports for various types off handoff to maintain communication .

QUALITY OF SERVICE (QOS) IN WI-MAX

This paper is mainly concern with Quality of service in WI-MAX technology. WI-MAX is providing broadband wireless access to the masses and presenting alternatives to digital subscriber lines (DSL) and cable broadband access. WI-MAX is based on IEEE 802.16 standard and is scalable. Super narrow lanes can enables a lot of traffic over them without disturbance. Many technologies and softwares like pathloss4.0,Global Mapper are used for line of sight (LOS) clearance coverage; the technology behind WI-MAX has been optimized to provide excelled non-line of sight (NLOS) coverage.QOS in broadband wireless access is a difficult and complicated business, as it adds an unpredictable radio link and potentially heavy user contention to the usual non-deterministic behavior of IP packet networks. Carriers therefore need to be aware of how QOS works – and what it can do – in the different flavors of 802.16, and how it relates to the more familiar 3G technologies. WiMAX quality of service (QOS) depends crucially on the 802.16 Layers 1 and 2, as these govern the all-important base-station/user-terminal radio access – an inherently difficult environment compared to, say, a wireline broadband network. Because the d/e forms of 802.16 are aimed at different applications – fixed terminals only and mobile terminals, respectively – there are significant differences in technology between them. In particular, 802.16d used Orthogonal Frequency Division Multiplexing.

PolyMAX, a Mobile WiMAX module for the ns-2 simulator with QoS and AMC support

In this paper, we present the PolyMAX module which enhances network simulator 2 (ns-2), the most popular network simulator used in academia, to provide one of the most complete simulation tools to evaluate the performance of Mobile WiMAX networks. PolyMAX is based on the National Institute of Standards and Technology (NIST) module and our specific contributions consist on the design and implementation of the Quality of Service (QoS) classes and QoS management messages, the uplink access grant-request mechanisms, Adaptive Modulation and Coding, and a scheduler handling all five WiMAX QoS classes. We also present validation results for the different components of our module and typical WiMAX simulation scenarios illustrating its flexibility and some of its features. The PolyMAX module represents an important tool enabling researchers to easily implement their Mobile WiMAX scheduling and Adaptive Modulation and Coding (AMC) algorithms and accurately evaluate their performance for realistic scenarios.

Quality of service in WiMAX and LTE networks [Topics in Wireless Communications

A quality of service framework is a fundamental component of a 4G broadband wireless network for satisfactory service delivery of evolving Internet applications to end users, and managing the network resources. Today's popular mobile Internet applications, such as voice, gaming, streaming, and social networking services, have diverse traffic characteristics and, consequently, different QoS requirements. A rather flexible QoS framework is highly desirable to be future-proof to deliver the incumbent as well as emerging mobile Internet applications. This article highlights QoS frameworks and features of OFDMA-based 4G technologies - IEEE 802.16e, IEEE 802.16m, and LTE - to support various applications' QoS requirements. A few advanced QoS features such as new scheduling service (i.e., aGP), quick access, delayed bandwidth request, and priority controlled access in IEEE 802.16m are explained in detail. A brief comparison of the QoS framework of the aforementioned technologies is also provided.

Cross-Layer MAC Protocol and Holistic Opportunistic Scheduling with Adaptive Power Control for QoS in WiMAX

Providing quality of service (QoS) to different service classes with integrated real-time and non-real-time traffic is an important issue in broadband wireless access networks. Opportunistic MAC (OMAC) is a novel view of communication over spatiotemporally varying wireless link whereby the multi-user diversity is exploited rather than combated to maximize bandwidth efficiency or system throughput. It combines cross-layer design features and opportunistic scheduling scheme to achieve high utilization while providing QoS support to various applications. Channel characteristics, traffic characteristics and queue characteristics are the essential factors in the design of opportunistic scheduling algorithms. In this paper, we propose a cross-layer MAC scheduling framework in WiMAX point-to-multipoint (PMP) systems and a corresponding opportunistic scheduling algorithm with an adaptive power control scheme to provide QoS support to the heterogeneous traffic. Extensive simulation experiments have been carried out to evaluate the performance of our proposal. The simulation results show that our proposed solution can improve the performance of the WiMAX PMP systems in terms of packet loss rate, packet delay and system throughput.