Browsing by Author "Fang, Ku-Han"

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Facilitating the network entry and link establishment processes of IEEE 802.16 mesh networks
(2007)
Wang, Shie-Yuan
;
Lin, Chih-Che
;
Fang, Ku-Han
;
Hsu, Teng-Wei
;
資訊工程學系
The IEEE 802.16 standard is a promising next-generation broadband technology. It contains two operational modes - PMP and mesh. The PMP mode defines one-hop communication between a base station (BS) and a subscriber station (SS), while the mesh mode allows traffic to be directly exchanged and forwarded among neighboring SSs. In the mesh mode, network initialization is composed of the network entry (NENT) and link establishment (LinkEst) processes. In this paper, we identify that the NENT process is prone to fail in dense networks and propose a solution to remedy this problem. Besides, we propose an extension to the LinkEst process to improve its efficiency. Both proposals are compatible with the current standard. Our simulation results show that our solution to the NENT process can on average increase the success rate by 22.5%, and our extension to the LinkEst process can on average speed up the process by 2.57 times.
Improving the Data Scheduling Efficiency of the IEEE 802.16(d) Mesh Network
(2008)
Wang, Shie-Yuan
;
Lin, Chih-Che
;
Fang, Ku-Han
;
資訊工程學系
;
Department of Computer Science
In an IEEE 802.16(d) (WiMAX) mesh network, network bandwidth can be managed by either the centralized scheduling (CS) mode or the distributed scheduling (DS) mode. Compared with the CS mode, the DS mode provides a larger bandwidth capacity and is more scalable. However, because the DS mode uses an on-demand three-way handshake procedure to establish data schedules, the network quality experienced by application programs may fluctuate drastically. To address this problem, in this paper we propose three schemes to improve the data scheduling efficiency of the DS mode of the IEEE 802.16(d) mesh network. Our simulation results show that network performances and qualities experienced by application programs are significantly improved under our schemes.
Improving the performances of distributed coordinated scheduling in IEEE 802.16 mesh networks
(2008-07-01)
Wang, Shie-Yuan
;
Lin, Chih-Che
;
Chu, Han-Wei
;
Hsu, Teng-Wei
;
Fang, Ku-Han
The IEEE 802.16 mesh network is a promising next-generation wireless backbone network. In such a network, setting the holdoff time for nodes is essential to achieving good performances of medium-access-control-layer scheduling. In this paper, we propose a two-phase holdoff time setting scheme to improve network utilization. Both static and dynamic approaches of this scheme are proposed, and their performances are compared against those of the original schemes. Our simulation results show that both approaches significantly increase the utilization of the control-plane bandwidth and decrease the time required to establish data schedules. In addition, both approaches provide efficient and fair scheduling for IEEE 802.16 mesh networks and generate good application performances.