Cross Layer Scheduling Algorithm for IEEE 802.16

2011 Eighth International Conference on Wireless and Optical Communications Networks, 2011

One of the fundamental requirements for IEEE 802.16/WiMAX, to become a key technology for high-speed multimedia service delivery, is QoS (Quality of Service) differentiation. Although different types of QoS classes have been defined by the IEEE 802.16 standard, the scheduling architecture is left to be vendor specific. In this paper, new modifications are purposed, and a detailed simulation study is performed, for different scheduling algorithms which are: RR (Round Robin), WRR (weighted Round Robin) and DRR (Deficit Round Robin). Analysis and evaluation of the performance of each scheduler to support the different QoS classes have been performed. The simulation results show that the purposed channel aware modified DRR scheduler can provide higher service standards to support the QoS in terms of packet loss ratio and bounded delay, which is required by different types of traffic in a time varying channel. Keywords-IEEE 802.16, WiMAX, scheduling algorithms, quality of service.

2010 IEEE Global Telecommunications Conference GLOBECOM 2010, 2010

The IEEE 802.16 standard for broadband wireless access is a low cost solution for Internet access in metropolitan and rural areas. Although it defines five service levels to support real-time and bandwidth demanding applications, scheduling mechanisms are not specified in the standard. Due to the wireless channel variability, scheduling mechanisms widely studied for wired networks are not suitable for IEEE 802.16 networks. This paper proposes an uplink cross-layer scheduler which makes bandwidth allocation decisions based on information about the channel quality and on the Quality of Service requirements of each connection. Simulation results show that the proposed scheduler improves the network performance when compared with a scheduler which does not take into account the channel quality.

WiMAX is one of the broadband wireless access networks with promising technology for providing better coverage and quality of service (QoS) to subscribers in the network. It supports different scheduling services with different QoS requirements the challenge here is how to efficiently scheduling the packets of subscribers having different QoS queuing in different buffers? We proposed a new algorithm capable of scheduling of all service flows type considering the nature of the wireless link, delay and buffer size. Performance of the proposed algorithm is evaluated by computer simulations it showed that the algorithm developed has achieved high throughput and good frame utilization.

IEEE Communications Letters, 2000

The IEEE 802.16 standard was designed to support real-time and bandwidth demanding applications with Quality of Service (QoS). Although the standard defines a QoS signaling framework and five service levels, scheduling disciplines for these service levels are unspecified. In this paper, we propose a scheduling scheme for the uplink traffic which is fully standardcompliant and can be easily implemented in the base station. Simulation results show that this scheme is able to meet the QoS requirements of the service flows.

2007

IEEE 802.16 standard defines the specifications for emerging WiMAX networks. It did not however define the scheduling algorithms that determine the uplink and downlink bandwidth allocation. This paper proposes a Preemptive Deficit Fair Priority Queue (PDFPQ) scheduling architecture for QoS management for the IEEE 802.16 standard. The proposed scheduling architecture is an extension of the DFPQ scheduling technique found in the literature. It enhances the QoS requirements of real time polling service (rtPS) flow class, and improves its delay and throughput. Compared to DFPQ, preliminary results show that a significant rtPS delay reduction and throughput increase can be realized with our new scheduling technique.

Proceedings of the 3rd international conference on Quality of service in heterogeneous wired/wireless networks - QShine '06, 2006

In this paper, we propose a novel scheduling scheme for the downlink of IEEE 802.16 networks. A scheduler at the Base Station (BS) decides the order of downlink bursts to be transmitted. The decision is made based on the quality of the channel and the history of transmissions of each Subscriber Station (SS). The scheduler takes advantage of temporal channel fluctuations to increase the BS's throughput and maintain fairness by balancing the long term average throughput of SSs. Simulation results are given to demonstrate the performance of the proposed scheduling scheme.

— The Quality of Service (QoS) provided for different types of multimedia applications such as audio, video, etc. The IEEE 802.16 standard defines different service classes with their associated (QoS) parameters. The MAC scheduling algorithm is the main role performing in QoS provisioning over such broadband wireless access (BWA) network and it is important that the scheduling algorithm have a multi-dimensional objective of satisfying QoS requirements of the users, maximizing system utilization and ensuring fairness among users. In this paper, we present comparative analysis for different types of MAC scheduling algorithms for the uplink (UL) connection. The proposed scheduling algorithms are compared to several other MAC scheduling algorithms for UL traffic under different mixes of traffic and for various characteristics of the IEEE 802.16 MAC layer such as throughput & delay. Simulation results indicate that MAC scheduling algorithms are not suitable for the multi-class traffic in IEEE 802.16 since they do not explicitly incorporate the QoS parameters for the given standard.

IEEE Globecom 2006, 2006

We present a novel scheme for uplink scheduling in WiMax networks that attempts to balance worst-case fairness in bandwidth allocation with the delay requirements of multiclass traffic, while taking the varying nature of the wireless channel into account. We assume a polling mode of operation at the base station (BS), and provide an analytical technique for obtaining an optimal polling interval k at which the BS should poll the subscriber stations (SSs) to ensure that the delay requirements of traffic are met, while the relative unfairness in bandwidth allocation remains bounded. We also devise an opportunistic deficit round robin (O-DRR) scheme that schedules sessions by taking into account the variations in the wireless channel and the delay constraints of multiclass traffic. We demonstrate that our scheduler provides fairness in bandwidth allocation and robust delay guarantees, thus giving a provider a choice of balancing fairness with delay.

This paper provides an efficient channel aware resource allocation scheme for IEEE 802.16e and 802.16m WiMAX Mobile, real-time and delay sensitive service. Compared to a similar scheduling approach, our considered scheduler can guarantee and achieve lower delay with a good average throughput. In order to achieve this object, we introduce a scheduling scheme with three different segments in a decision making process. The first part, a time dependent function that considers the time when packets wait in queues and in a jitter area to prevent packet deadline. The second part, retrieved from proportional fairness algorithms, which in normal conditions gives a fair share to users. Channel SNR and service class weight are also involved in this part. The final section of scheduling relationship, channel condition, is defined more accurately by CQI, RSSI and CINR parameters. The simulation results in OPNET show that our proposed scheme has a very good delay and packet loss ratio accompanied by a high throughput. In another scenario, with different number of users and limit resources, we show relationship between admission control and scheduling.

International Journal of Computer Applications, 2010

In this paper we have presented the literature survey of proposed MAC based quality of service (QoS) architecture for Wi-MAX Point-to-Multipoint networks scheduling algorithm. The Wi-MAX is IEEE 802.16 Wireless network standard which recently for Broadband Wireless communication. The IEEE 802.16 advantages includes variable bit rate and high data rate, last mile wireless access, point to multipoint communication, large frequency range and QoS for various types of applications. With respect of the above advantages of IEEE 802.16 Wireless network is drawback in MAC scheduling architecture in uplink as well as downlink direction. In this paper we propose