Minimum Interference Channel Assignment in Multiradio Wireless Mesh Networks (original) (raw)
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An interference-aware channel assignment scheme for wireless mesh networks
2007
Multichannel communication in a Wireless Mesh Network with routers having multiple radio interfaces significantly enhances the network capacity. Efficient channel assignment and routing is critical for realization of optimal throughput in such networks. In this paper, we investigate the problem of finding the largest number of links that can be activated simultaneously in a Wireless Mesh Network subject to interference, radio and connectivity constraints. Our goal is to activate all such links and we present an interference aware channel assignment algorithm that realizes this goal. We show that the Link Interference Graph created by utilizing a frequently used interference model gives rise to a special class of graphs, known as Overlapping Double-Disk (ODD) graphs. We prove that the Maximum Independent Set computation problem is NP-complete for this special class of graphs. We provide a Polynomial Time Approximation Scheme (PTAS) for computation of the Maximum Independent Set of an ODD graph. We use this PTAS to develop a channel assignment algorithm for a multiradio multichannel Wireless Mesh Network. We evaluate the performance of our channel assignment algorithm by comparing it with the optimal solution obtained by solving an integer linear program. Experimental results demonstrate that our channel assignment algorithm produces near optimal solution in almost all instances of the problem.
Ad Hoc Networks, 2015
We study the impact of three different interference models on channel assignment in multi-radio multi-channel wireless mesh networks, namely the protocol model, the signal-to-interference ratio (SIR) model and the SIR model with shadowing. The main purpose is to determine the minimum number of non-overlapping frequency channels required to achieve interference-free communication among the mesh nodes based on a realistic interference model. We propose novel, effective, and computationally simple methods for building the conflict graph based on the SIR model with shadowing, and for finding channel assignments from the resulting conflict graph. We find that channel assignment using a realistic interference model (SIR model with shadowing) requires more frequency channels for network throughputs at different node-degree constraints as compared to using simpler interference models.
In recent years, multi-channel multi-radio wireless mesh networks are considered a reliable and cost effective way for internet access in wide area. A major research challenge in this network is, selecting a least interference channel from the available channels, efficiently assigning a radio to the selected channel, and routing packets through the least interference path. Many algorithms and methods have been developed for channel assignment to maximize the network throughput using orthogonal channels. Recent research and test-bed experiments have proved that POC (Partially Overlapped Channels) based channel assignment allows significantly more flexibility in wireless spectrum sharing. In this paper, first we represent the channel assignment as a graph edge coloring problem using POC. The signal-to-noise plus interference ratio is measured to avoid interference from neighbouring transmissions, when a channel is assigned to the link. Second we propose a new routing metric called signal-to-noise plus interference ratio (SINR) value which measures interference in each link and routing algorithm works based on the interference information. The simulation results show that the channel assignment and interference aware routing algorithm, proposed in this paper, improves the network throughput and performance.
2018
Wireless mesh networks (WMN) have arose as a technology for subsequent generation wireless networks due to its cost effectiveness and effortless deployment. The performance of wireless mesh networks can be considerably improved by multi-channel communication. The existence of interference confines the use of channel assignment in wireless mesh networks.The significance of inter-flow and intra-flow interference is ignored in existing solutions, so the information is erroneous leads to inaccurate bandwidth estimation and reservation. All the techniques to measure interference is measurement based that not holds good for practical applications.This approach proposes a distributed and polynomial-time heuristic channel assignment to minimize interference in WMNs. Inchannel allocation route delay restriction is measured to avoid every node on the tree interfering with several other nodes. Packettransmission will be affected by this interference. There will be a huge delay in packet transm...
In this work, we present a distributed channel assignment technique for wireless mesh networks. According to this work, first of all we utilized graph coloring theory for mesh network modeling. With the help of this, interference range and communication range are established for wireless mesh network. Further, we use conflict graph and connectivity graphs for network modeling. Later, we have developed a distributed channel assignment technique using link capacity and load criticality estimation. Link capacity and load criticality estimation models have been discussed in literature and have been considered as promising technique but due to huge amount of data traffic, these techniques are unable to provide the significant performance. In order to address this issue, here we present a greedy approach for channel selection. This approach results in significant channel selection resulting in interference reduction.
Channel assignment model in wireless mesh networks
2011
A wireless mesh network is a multi-hop network consisting of nodes called mesh routers and mesh clients. The network is self-organized and it is capable of covering a large geographical area for purposes like data gathering, communication and information processing. For communication, the nodes in the network are allocated with one or more channels based on the IEEE 802.11 protocol. Channels in a wireless mesh network are allocated in such a way to minimize the bandwidth with the constraint of avoiding the electromagnetic interferences. In this paper we propose a model called XION which allocate channels based on minimum bandwidth with the adjacency channel constraint. Our model is efficient in performing minimization in the number of channels and schedules the tasks in the network with minimum completion time.
Jurnal Teknologi Constrained Channel Assignment in Multi-channel Wireless Mesh Network
2013
A wireless mesh network is a multi-hop network consisting nodes called mesh routers and mesh clients. In the network, communication between a pair of nodes happens when both nodes share a same channel. Channel assignment is an application in graph theory on the vertex coloring. The channels are allocated in such a way to minimize the bandwidth with the constraints of avoiding the electromagnetic interference. In this paper, we focus on the channel allocation for multi-channel which considers adjacent-channel constraint, cochannel and cosite constraint. The minimum number of the channels that are used in the network with minimum completion time shows the effectiveness of the work.
Partially overlapped channel assignment for multi-channel wireless mesh networks
Communications, 2007. ICC' …, 2007
The aggregate capacity of wireless mesh networks can be increased by the use of multiple frequency channels and multiple network interface cards in each router. Recent results have shown that the performance can further be increased when both non-overlapped and partially overlapped channels are being used. In this paper, we propose a linear model for a joint channel assignment, interface assignment, and scheduling design. We propose the channel overlapping matrix and mutual interference matrices to model the non-overlapped and partially overlapped channels. Since the model is formulated as a linear mixedinteger program with a few integer variables, the computation complexity is low and it is feasible for implementation. Simulation results show that the aggregate network capacity increases by 90% when all partially overlapped channels within the 802.11b frequency band are being used. • Our proposed model takes into account various parameters including the number of available frequency channels, the number of available NICs in each wireless router, transmission power, path loss information, signal to interference plus noise ratio, expected traffic load, and frequency response of each channel filter.
Interference and traffic aware channel assignment in WiFi-based wireless mesh networks
Ad Hoc Networks, 2011
Wireless mesh networks (WMN) typically employ mesh routers that are equipped with multiple radio interfaces to improve network capacity. The key aspect is to cleverly assign different channels (i.e., frequency bands) to each radio interface to form a WMN with minimum interference. The channel assignment must obey the constraints that the number of different channels assigned to a mesh router is at most the number of interfaces on the router, and the resultant mesh network is connected. This problem is known to be NP-hard. In this paper we propose a hybrid, interference and traffic aware channel assignment (ITACA) scheme that achieves good multi-hop path performance between every node and the designated gateway nodes in a multi-radio WMN network. ITACA addresses the scalability issue by routing traffic over low-interference, high-capacity links and by assigning operating channels in such a way to reduce both intra-flow and inter-flow interference. The proposed solution has been evaluated by means of both simulations and by implementing it over a real-world WMN testbed. Results demonstrate the validity of the proposed approach with performance increase as high as 111%.
Optimal Channel Assignment Algorithm for Least Interfered Wireless Mesh Networks
International Journal of Mobile Computing and Multimedia Communications, 2014
Unlike most of proposed solutions that usually consider the overall throughput as the main optimization, Channel Assignment in Wireless Mesh Networks has to ensure connectivity, minimize interference level and guarantee an acceptable throughput. This problem must be solved taking into account all the parameters that influence the output of the proposed algorithm. In this paper, the authors propose an efficient multi-objective optimization model that, simultaneously, optimizes two conflicting objective functions in order to assign channel to radio interfaces subject to connectivity, interference and bandwidth requirements. Then they use the Multi-Objective Particle Swarm Optimization Technique to resolve this problem and provide a non-dominated set of near optimal solutions.