Learn More
The WiMax mesh networks based on IEEE 802.16 standard (2004) was developed with the goal of providing for easy, fast and cost-effective network set-up, deployment and extension. The standard defines scheduling scheme in mesh mode, but don't specify spatial resource management in the protocol. In this paper, we design a general algorithm for SSs to achieve(More)
Vehicular wireless communication should be able to provide vehicles with reliable and efficient data transmissions for various applications, especially safety applications. We present a dedicated multi- channel MAC protocol that has an adaptive broadcasting mechanism, specifically designed to provide collision-free and delay-bounded transmissions for safety(More)
The MAC protocol of IEEE 802.16 standard specifies scheduling mechanisms about mesh mode in detail, while its channel resource allocation and reservation management protocols are open for further standardization. This paper proposes a slot allocation algorithm based on priority, which is to achieve QoS on MAC layer. We conducted a simulation to study packet(More)
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Abstract—In this paper, we investigate the opportunistic spectrum access for cognitive radio vehicular ad hoc networks (CR-VANETs). The probability distribution of the channel availability is first(More)
Improving the admission control process in wireless metropolitan area networks (WMAN) based on the IEEE 802.16e standard can improve the QoS. Because IEEE 802.16e supports five classes of service as well as mobility, an admission control policy for non-preprovisioned service flow is proposed. This policy is compatible with the QoS parameters for each(More)
Nowadays many systems with diverse technologies such as (GPS, Wi-Fi, Bluetooth, ZigBee, Ultra Wide Band, Ultrasounds, Infrared, etc) can be used for indoor location. One of the biggest challenges in indoor location systems is to determine the actual indoor position of the user using a smart device (Phone, PC, etc), due to their instability, cost, high-power(More)
Spectrum sensing is the necessary function to achieve spectrum sharing. Distributed and collaborative spectrum sensing can improve the sensing credibility greatly, however when there are too many sensing nodes in the cognitive radio system, for example IEEE802.22 Wireless Regional Area Network system, it will produce large signaling overhead. To reduce the(More)
Device-to-device (D2D) communications as underlays of cellular networks facilitate diverse local services and reduce base station traffic. However, D2D communication may cause interference with the primary cellular network. To avoid this problem, the network should flexibly allocate its resources and select a proper mode for users. Here, we formulate a(More)
Broadband wireless communication systems should be able to support users moving at high speeds. Groups of users in large vehicles moving along approximate straight ways usually need to perform handovers more frequently, and this drastically increases system overhead. Conventional handover methods cannot promise a good enough handover success rate for(More)