Channel allocation schemes

About: Channel allocation schemes is a research topic. Over the lifetime, 10656 publications have been published within this topic receiving 182117 citations.

Joint logical topology design, interface assignment, channel allocation, and routing for multi-channel wireless mesh networks

Abstract: A multi-channel wireless mesh network (MC-WMN) consists of a number of stationary wireless routers, where each router is equipped with multiple network interface cards (NICs). Each NIC operates on a distinct frequency channel. Two neighboring routers establish a logical link if each one has an NIC operating on a common channel. Given the physical topology of the routers and other constraints, four important issues should be addressed in MC-WMNs: logical topology formation, interface assignment, channel allocation, and routing. Logical topology determines the set of logical links. Interface assignment decides how the logical links should be assigned to the NICs in each wireless router. Channel allocation selects the operating channel for each logical link. Finally, routing determines through which logical links the packets should be forwarded. In this paper, we mathematically formulate the logical topology design, interface assignment, channel allocation, and routing as a joint linear optimization problem. Our proposed MC-WMN architecture is called TiMesh. Extensive ns-2 simulation experiments are conducted to evaluate the performance of TiMesh and compare it with two other MC-WMN architectures Hyacinth [1] and CLICA [2]. Simulation results show that TiMesh achieves higher aggregated network throughput and lower end-to-end delay than Hyacinth and CLICA for both TCP and UDP traffic. It also provides better fairness among different flows.

Priority-Based Traffic Scheduling and Utility Optimization for Cognitive Radio Communication Infrastructure-Based Smart Grid

Abstract: Smart grid can be visualized as an intelligent control system over sensors and communication platforms. Recently, wireless multimedia sensor networks (WMSNs) have shown its advantages for smart grid by providing rich surveillance information for grid failure detection and recovery, energy source monitoring, asset management, security, etc. On the other hand, cognitive radio (CR) networks have been identified as a key wireless technology to reduce the communication interferences and improve the bandwidth efficiency for smart grid communication. There is an essential need to use the CR communication platform to support large-size and time-sensitive multimedia delivery for future smart grid system. In this paper, we consider the heterogeneous characteristics of smart grid traffic including multimedia and propose a priority-based traffic scheduling approach for CR communication infrastructure based smart grid system according to the various traffic types of smart grid such as control commands, multimedia sensing data and meter readings. Specifically, we develop CR channel allocation and traffic scheduling schemes taking into consideration of channel switch and spectrum sensing errors, and solve a system utility optimization problem for smart grid communication system. Our solutions are demonstrated through both analyzes and simulations. This research opens a new vista of future smart grid communications.

On the design of device-to-device autonomous discovery

Abstract: This paper proposes a synchronous device discovery solution for ad-hoc networks based on the observations that time synchronization, along with an FDM based channel resource allocation, can lead to gains in terms of energy consumption, discovery range, and the number of devices discovered. These attributes are important for the success of proximity-aware networking, where devices autonomously find peer-groups over human mobility scales. In this paper, we develop the PHY and MAC protocols to enable autonomous device discovery. Using both simulations and stochastic-geometry based analysis, we validate our design, and argue that there can be significant gains over a conventional Wi-Fi based solution.

A Practical Multi-channel Media Access Control Protocol for Wireless Sensor Networks

Abstract: Despite availability of multiple orthogonal communication channels on common sensor network platforms, such as MicaZ motes, and despite multiple simulation-supported designs of multi-channel MAC protocols, most existing sensor networks use only one channel for communication, which is a source of bandwidth inefficiency. In this work, we design, implement, and experimentally evaluate a practical MAC protocol which utilizes multiple channels efficiently for WSNs. A control theory approach is used to dynamically allocate channels for each mote in a distributed manner transparently to the application and routing layers. The protocol assumes that sensor nodes are equipped with one half-duplex radio interface which is most common in current hardware platforms. The protocol does not require time synchronization among nodes and takes the channel switching cost of current hardware into account. Evaluation results on a real testbed show that it achieves a non-trivial bandwidth improvement using 802.15.4 radios in topologies which are typical in WSNs. The MAC protocol was implemented in TinyOS-2.x and packaged as a software component to enable seamless use with existing applications.

Downlink Spectrum Sharing for Cognitive Radio Femtocell Networks

Abstract: Femtocell is envisioned as a highly promising solution for indoor wireless communications. The spectrum allocated to femtocells is traditionally from the same licensed spectrum bands of macrocells. In this case, the capacity of femtocell networks is highly limited due to the finite number of licensed spectrum bands and also the interference with macrocells and other femtocells. In this paper, we propose a radically new communication paradigm by incorporating cognitive radio in femtocell networks. The cognitive radio enabled femtocells are able to access spectrum bands not only from macrocells but also from other licensed systems (e.g. TV systems) provided the interference from femtocells to the existing systems is not harmful. It results in more channel opportunities for femtocells. Thus, the co-channel interference in femtocells can be greatly reduced and the network capacity can be significantly improved. Because of the difference from other traditional wireless networks, we argue the traditional spectrum sharing schemes such as coloring methods are not efficient to femtocell networks especially for dense deployment scenarios. We formulate the downlink spectrum sharing problem in cognitive radio femtocell networks, and employ decomposition theories to solve the problem. Simulation results indicate that cognitive radio enabled femtocells could achieve much higher capacity than the femtocell networks which do not employ agile spectrum access. Simulation results also show that our proposed scheme without any iteration can achieve almost twice of the average capacity by coloring method when the number of available channels is less than five. Moreover, our proposed scheme can converge very fast with a typical value of only five iterations, and it can achieve around two percent extra average capacity than the fixed power control scheme.