This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

The network simulator 2 (ns-2) is a popular and powerful simulation tool for the simulation of packet-switched networks, which provides substantial support for simulation of TCP, routing, and MAC protocols over wired and wireless networks, such as wireless LANs, mobile ad hoc networks (MANETs), and satellite communications, etc, and is widely used in both academia and industry. Although many protocol modules have been implemented in the ns-2, the IEEE 802.16 broadband wireless access networks (BWANs) or WiMAX module has not been contributed yet. Thus, in this paper, we present our detailed design and implementation of the WiMAX module based on the IEEE 802.16 standard with the point-to-multipoint (PMP) mode for the ns-2. The implemented module comprises fundamental functions of the service-specific convergence sublayer (CS), the MAC common part sublayer (CPS), and the PHY layer. A simple call admission control (CAC) mechanism and the scheduler are also included in this module.

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The design and implementation of WiMAX module for ns-2 simulator

A dynamic strategy for packet scheduling and bandwidth allocation based on channel quality in IEEE 802.16e OFDMA system

The most challenging research issue of investigating broadband wireless access (BWA) technologies is how to support mobility in WiMAX networks smoothly and seamlessly. It is essential that providing continuous services of multimedia streaming data when a mobile subscriber station (MSS) is across a boundary of a serving area to another one. Although the IEEE 802.16e standard is proposed to tackle this difficult problem, the disruption time (DT) of handover is still too long to overcome the maximum delay time of real-time services. To deal with this problem, this paper proposes a pre-coordination mechanism (PCM) for supporting fast handover in WiMAX networks. This goal is achieved by measuring the distance between the BS and the MSS and predicting the time of handover occurs, and thus pre-allocating available resources for handover usages. Simulation results show that the enhanced DT of handover can achieve approximately to 11 milliseconds. The proposed mechanism is fully compatible with the IEEE 802.16e standard.

Pre-Coordination Mechanism for Fast Handover in WiMAX Networks

The design of an efficient handover technique is considered as one of the crucial topics in the cellular-based wireless networks. Feasible handover process can minimize the performance degradation as the mobile device is moving between different base stations. Based on the IEEE 802.16e standard, it is required to provide satisfactory handover performance under a wide-range of moving speeds of the mobile device. In this paper, a predictive movement-based handover (PMHO) algorithm is proposed. Without incurring excessive overheads as from the conventional location estimation and tracking techniques, the proposed sideline-traveling scheme within the PMHO algorithm employs the moving state indicator (MSI) to predict the potential moving characteristics of the mobile device. The handover decision of the PMHO approach is determined based on the MSI values associated with the neighbor base stations. Numerical results show that the proposed PMHO algorithm can effectively reduce both the number of handover and the size of the neighbor-scanning set within the mobile device.

A Predictive Movement Based Handover Algorithm for Broadband Wireless Networks

The radio spectrum of IEEE 802.16 medium access control (MAC) protocol ranges from 2-66 GHz, which is one of potential solutions for broadband wireless access (BWA) or beyond third generation (B3G)/ 4G networks. The maximum transmission range can reach about 48 km. However, with the property of radio propagation, the maximum transmission distance is proportioned inversely to the frequency the mobile subscriber station (MSS) carries. According to this property, the channel allocation can be based on how far the distance between the MSS and the base station (BS) in a macrocell. Therefore, this paper first proposes a new concept of channel allocation model for BWA system and investigates the relations between the signal propagation and the distance as well as propose a signal-aware dynamic channel allocation (SDCA) scheme for dynamic channel allocation (DCA) in BWA networks (BWANs). The SDCA enables the BS to allocate appropriate channels to MSSs according to the received signal-to-noise ratio (SNR) value from the MSSs. Besides, according to the frequency, the SDCA can estimate a minimum power for MSS to communicate. The SDCA not only increases the capacity of the system but saves the overall power consumption of the system well. We also present a new out-of-service prevention scheme for supporting mobility in the system. Simulation results show that the proposed SDCA can achieve the channel utilization (throughput) by up to 94.4% when the spectrum ranges from 2-11 GHz.

/pdf/predictive-dynamic-channel-allocation-scheme-for-improving-41swjoynnf.pdf

Predictive dynamic channel allocation scheme for improving power saving and mobility in BWA networks

The radio spectrum of the IEEE 802.16 medium access control (MAC) protocol ranges from 2 to 66 GHz, which is one of the potential solutions for broadband wireless access (BWA) or beyond third generation (B3G)/4G networks. However, with the characteristic of radio propagation, the maximum transmission distance is proportioned inversely to the frequency which the subscriber station (SS) carries. According to this property, the base station (BS) can easily allocate appropriate channels for SSs according to the received signals which SSs transmit. Therefore, in this paper, we investigate the relationship between the signal propagation and the distance, and then we proposed a novel macrocell channel allocation scheme (MCAS) for dynamic channel allocation (DCA) in radio access networks (RAN). The MCAS enables the BS to allocate appropriate channels to SSs according to the received signal-to-noise ratio (SNR) value from the SSs. The MCAS not only increases the capacity of the system but also saves the overall power consumption of the system well. Simulation results show that the proposed MCAS increases the power saving up to 47.83% over the original IEEE 802.16 standard specifications.

/pdf/mcas-a-macrocell-channel-allocation-scheme-for-broadband-4uj0ksflrv.pdf

Wei-Kuang Tan

Papers

Predictive dynamic channel allocation scheme for improving power saving and mobility in BWA networks

MCAS: a macrocell channel allocation scheme for broadband wireless access networks