The WiMAX mesh networks based on IEEE 802.16 standard was developed with the base station (BS) as a coordinator for centralized scheduling. However, interferences from transmission of the neighbouring nodes within the mesh networks are inevitable. This paper proposes a centralized scheduling algorithm that can reduce interferences by constructing routing tree with multi-channel single transceiver system in WiMAX mesh networks. In this algorithm, each node has one transceiver that can be tuned to any of the channels, intending to eliminate the secondary interference. The parameters of interference, hop-count, no. of children per node, spatial reuse, fairness, load balancing, quality of services (QoS) and node identifier (ID) are considered. The results of analysis show that this proposed algorithm greatly improves the length of scheduling and the channel utilization ratio (CUR).

High quality of data transmission services is an important task for wireless broadband communication systems. This paper is concerned with the design problem of real-time wireless data transmission which provides unequal error protection (UEP). Using superposition coding, the rea-time data stream is divided into two streams, high priority (HP) and low priority LP streams depending on their interest. These two bit streams are encoded separately, and then superimposed together with two different level of power to achieve the UEP for them in the receiver end. Feedback of channel state information (CSI) is used in adaptive physical layer channel for efficient use of the current available bandwidth. In this proposed scheme, same recourses; time, bandwidth and power are used to increase the transmission efficiency compared with other schemes which are use transmission of one data stream with one power level but in different techniques to exploit the available bandwidth.

The IEEE 802.16 standard defines WiMax (worldwide interoperability for microwave access) mesh network, using the base station (BS) as a coordinator for centralized scheduling. This paper proposes a centralized scheduling algorithm by constructing routing tree in WiMax mesh network, which introduces the cross-layer concept between the media access controller (MAC) and the network layers. The interference, hop-count, spatial reuse and quality of services (QoS) guarantee are considered. In our scheme, each node has one transceiver and can be tuned between multiple channels, intending to eliminate the secondary interference. The result of analysis shows this algorithm greatly improves the length of scheduling, channel utilization ratio (CUR) and average transmission scheduling.

The WiMAX mesh networks based on IEEE 802.16 standard is a key topology for the next generation wireless networking. However, interferences from transmission of the neighboring nodes within the mesh networks are inevitable. Cross-layer design for tree-type routing and level-based centralized scheduling is proposed as the optimization strategy. The cross-layer design here is relying on the routing information in network layer and centralized scheduling in the medium access control (MAC) layer. This paper proposes a centralized scheduling algorithm that can reduce interferences by constructing routing tree with multi-channel single transceiver system in WiMAX mesh networks. In this algorithm, each node has one transceiver that can be tuned to any of the channels, intending to eliminate the secondary interference. The results of analysis show that this proposed algorithm greatly improves the length of scheduling, channel utilization ratio (CUR) and throughput.

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In the last few years, demand for high speed internet access service has increased greatly so the IEEE 802.16 working group on broadband wireless access (BWA) is developing the worldwide interoperability for microwave access (WiMAX) standard for wireless metropolitan area networks (MANs) which aims to provide broadband wireless last mile access, easy deployment, and high speed data rate for large spanning area. This paper propose an efficient routing and collision free centralized scheduling (CS) algorithms using single channel single transceiver system in WiMAX mesh network, which introduces the cross layer concept between the network layer and media access controller (MAC) layer. The proposed approach has improved the system performance in the aspects of scheduling length, channel utilization ratio (CUR), and the throughput of the system.

In the last few years, demand for high-speed internet access and multimedia service has increased greatly. The IEEE 802.16 standard defines the wireless broadband access technology called WiMAX (Worldwide Interoperability Microwave Access) aims to provide broadband wireless last-mile access, easy deployment, high speed data rate for large spanning area. In this paper, we propose an Energy/bit Minimization routing and centralized scheduling (EbM-CS) based algorithm to multi-transceiver in WiMax mesh network (WMN), which introduces the cross-layer concept between the MAC and network layers. The results show that our algorithm has improved the system performance in the aspect of system throughput.

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