Based on the introduction of the WiMAX standards, relevant technologies and applications, three essential factors for WiMAX networking are analyzed. They are the frequency plan, Authentication Authorization Accounting...Based on the introduction of the WiMAX standards, relevant technologies and applications, three essential factors for WiMAX networking are analyzed. They are the frequency plan, Authentication Authorization Accounting (AAA) and the mobility management. Networking solutions for the fixed and mobile applications are presented respectively. It is noted that the evolution of wireless WiMAX networking will go through four phases: the outdoor access phase, the indoor access phase, the seamed roaming phase and the seamless mobility phase. It is predicted that WiMAX will eventually converge with the NGN and the mobile cellular networks.展开更多
It is a difficult problem to improve network performance and resource utilization efficiency in wireless communications. As a standard of broadband wireless access systems, IEEE 802.16 adopts Orthogonal Frequency Divi...It is a difficult problem to improve network performance and resource utilization efficiency in wireless communications. As a standard of broadband wireless access systems, IEEE 802.16 adopts Orthogonal Frequency Division Multiplexing (OFDM) and multi-modulation/coding techniques at the physical layer, combines contend and pre-contract mechanisms at the Medium Access Control (MAC) layer. Based on the QoS-related concepts such as connection and service flow, IEEE 802.16 optimizes network entry and initialization, and frame format in order to improve network throughput, reduce network delay, and increase the flexibility of network configuration. Based on IEEE 802.16, WiMAX adopts Point-to-Multipoint (PMP) network topology to realize flexible networking. It is a typical application technology of broadband wireless access systems.展开更多
WiMAX distributed scheduling can be modeled as two procedures：three-way handshaking procedure and data subframe scheduling procedure.Due to manipulating data transmission directly,data subframe scheduling has a close...WiMAX distributed scheduling can be modeled as two procedures：three-way handshaking procedure and data subframe scheduling procedure.Due to manipulating data transmission directly,data subframe scheduling has a closer relationship with user Quality of Service（QoS） satisfaction,and has more severe impact on network performance,compared with handshaking procedure.A QoS guaranteed Throughput-Efficiency Optimal distributed data subframe Scheduling scheme,named as QoS-TEOS,is proposed.QoS-TEOS achieves QoS guarantee through modeling services into different ranks and assigning them with corresponding priorities.A service with higher priority is scheduled ahead of that with lower priority and offered with high QoS quality.Same kinds of services that request similar QoS quality are classified into one service set.Different service sets are scheduled with different strategies.QoS-TEOS promotes network performance through improving network throughput and efficiency.Theoretical analysis shows that the scheduled data transmission should balance data generation rate from upper layer and transmission rate of physical layer,to avoid network throughput and efficiency declining.Simulation results show that QoS-TEOS works excellently to achieve throughput-efficiency optimization and guarantee a high QoS.展开更多
文摘Based on the introduction of the WiMAX standards, relevant technologies and applications, three essential factors for WiMAX networking are analyzed. They are the frequency plan, Authentication Authorization Accounting (AAA) and the mobility management. Networking solutions for the fixed and mobile applications are presented respectively. It is noted that the evolution of wireless WiMAX networking will go through four phases: the outdoor access phase, the indoor access phase, the seamed roaming phase and the seamless mobility phase. It is predicted that WiMAX will eventually converge with the NGN and the mobile cellular networks.
文摘It is a difficult problem to improve network performance and resource utilization efficiency in wireless communications. As a standard of broadband wireless access systems, IEEE 802.16 adopts Orthogonal Frequency Division Multiplexing (OFDM) and multi-modulation/coding techniques at the physical layer, combines contend and pre-contract mechanisms at the Medium Access Control (MAC) layer. Based on the QoS-related concepts such as connection and service flow, IEEE 802.16 optimizes network entry and initialization, and frame format in order to improve network throughput, reduce network delay, and increase the flexibility of network configuration. Based on IEEE 802.16, WiMAX adopts Point-to-Multipoint (PMP) network topology to realize flexible networking. It is a typical application technology of broadband wireless access systems.
基金Supported by Intel Project under Grant No.4507336215Huawei Project under Grant No.YBCB2007025the University of Science and Technology of China Innovation Foundation under Grant No.KD2008053.
文摘WiMAX distributed scheduling can be modeled as two procedures：three-way handshaking procedure and data subframe scheduling procedure.Due to manipulating data transmission directly,data subframe scheduling has a closer relationship with user Quality of Service（QoS） satisfaction,and has more severe impact on network performance,compared with handshaking procedure.A QoS guaranteed Throughput-Efficiency Optimal distributed data subframe Scheduling scheme,named as QoS-TEOS,is proposed.QoS-TEOS achieves QoS guarantee through modeling services into different ranks and assigning them with corresponding priorities.A service with higher priority is scheduled ahead of that with lower priority and offered with high QoS quality.Same kinds of services that request similar QoS quality are classified into one service set.Different service sets are scheduled with different strategies.QoS-TEOS promotes network performance through improving network throughput and efficiency.Theoretical analysis shows that the scheduled data transmission should balance data generation rate from upper layer and transmission rate of physical layer,to avoid network throughput and efficiency declining.Simulation results show that QoS-TEOS works excellently to achieve throughput-efficiency optimization and guarantee a high QoS.
