Optimal placement and channel assignment of relay stations in heterogeneous wireless mesh networks b

A cost-effective WDM-PON architecture simultaneously supporting wired, wireless and optical VPN services Original Research Article

Optics Communications

It is believed that next-generation passive optical networks (PONs) are required to provide flexible and various services to users in a cost-effective way. To address this issue, for the first time, this paper proposes and demonstrates a novel wavelength-division-multiplexed PON (WDM-PON) architecture to simultaneously support three types of services: 1) wireless access traffic, 2) optical virtual passive network (VPN) communications, and 3) conventional wired services. In the optical line terminal (OLT), we use two cascaded Mach–Zehnder modulators (MZMs) on each wavelength channel to generate an optical carrier, and produce the wireless and the downstream traffic using the orthogonal modulation technique. In each optical network unit (ONU), the obtained optical carrier is modulated by a single MZM to provide the VPN and upstream communications. Consequently, the light sources in the ONUs are saved and the system cost is reduced. The feasibility of our proposal is experimentally and numerically verified.

Article Outline

1. Introduction

2. Principle and architecture

3. Experiment and simulation

3.1. Results of downstream transmission

3.2. Results for upstream and VPN transmissions

4. Conclusion

Acknowledgements

References

Research highlights

A WDM-PON architecture supports wired, wireless and optical VPN services. The system is

cost-effective. The orthogonal modulation technique is used. A single MZM is used to provide the

VPN and upstream communications. Source-free ONU is realized.

Multipath routing with spatial separation in wireless multi-hop networks without location information Original Research Article

Computer Networks

We develop an on-demand multipath routing protocol for multi-hop wireless networks (MWNs), capable of finding spatially disjoint paths (paths physically distant from each other) without the need of location information. Multipath routing can enable various applications and enhancements in MWNs, such as load balancing, bandwidth aggregation, reliability and secure communications. The use of spatially disjoint routes is important to effectively achieve these gains, due to the non-interfering nature and distance of the paths. Most of the proposed multipath protocols for MWNs focus on reliability and do not find spatially separate paths. We propose a new on-demand protocol called Spatially Disjoint Multipath Routing (SDMR), capable of finding multiple paths in one route discovery, measuring the distance between them and choosing paths with most separation. A new distance metric is presented to measure path separation, which proves to be congruent with Euclidean distance across nodes in the paths. We develop a heuristic algorithm which, given a topology graph and utilizing the proposed distance metric, can discover spatially disjoint paths between any two nodes in the graph. To evaluate the protocol, we have studied the overhead both analytically in comparison with OLSR, and by simulation. The simulations also demonstrate the effectiveness of the protocol in finding spatially separate routes.

Article Outline

1. Introduction and motivation

2. Related work

3. Spatially Disjoint Multipath Routing protocol

3.1. SDMR overview

3.2. Definitions

3.3. Neighbor detection

3.4. Routing packets at the source

3.5. Topology discovery

3.5.1. Topology Request propagation

3.5.2. Topology Reply propagation

3.5.3. Topology discovery resolution

3.6. Path calculation

3.7. Route maintenance

4. Path Calculation

4.1. Definitions and assumptions

4.2. Path distance metric

4.3. Path Calculation Algorithm

4.3.1. Algorithm overview

4.3.2. Algorithm

4.4. Time complexity of Path Calculation Algorithm

5. Protocol overhead study

5.1. Best case scenario

5.1.1. OLSR

5.1.2. SDMR

5.1.3. Comparison of SDMR and OLSR

5.2. Worst case scenario

5.2.1. OLSR

5.2.2. SDMR

5.2.3. Comparison of SDMR and OLSR

6. Performance evaluation

6.1. Simulation environment

6.2. Performance metrics

6.3. Distance between paths found by SDMR

6.4. Comparison of protocol performance

6.5. Analysis of session interception

6.6. Performance under mobility

7. Conclusions

Acknowledgements

References

Energy efficient and perceived QoS aware video routing over Wireless Multimedia Sensor Networks Original Research Article

Ad Hoc Networks

Wireless Sensor Networks (WSNs) have an ever increasing variety of multimedia based applications. Ιn these types of applications, network nodes should ideally maximize QoS and minimize energy expenditures in video communication. This article presents PEMuR, a novel dual scheme for efficient video communication, which aims at both energy saving and high QoS attainment. To achieve its objectives, PEMuR proposes the combined use of an energy aware hierarchical routing protocol with an intelligent video packet scheduling algorithm. The adopted routing protocol enables the selection of the most energy efficient routing paths, manages the network load according to the energy residues of the nodes and prevents useless data transmissions through the proposed use of an energy threshold. In this way, an outstanding level of energy efficiency is achieved. Additionally, the proposed packet scheduling algorithm enables the reduction of the video transmission rate with the minimum possible increase of distortion. In order to do so, it makes use of an analytical distortion prediction model that can accurately predict the resulted video distortion due to any error pattern. Thus, the algorithm may cope with limited available channel bandwidth by selectively dropping less significant packets prior to their transmission. Simulation results demonstrate the effectiveness of the proposed scheme.

Article Outline

1. Introduction

2. Related work

2.1. Hierarchical routing protocols

2.2. Route selection schemes

2.3. Wireless video communication

2.4. Packet loss models

3. Proposed scheme overview

3.1. Energy efficient hierarchical routing protocol

3.2. Video packet scheduling

3.2.1. Video distortion model

3.2.2. Video transmission rate adaptation

3.3. PEMuR algorithm overview

4. Simulation setup description

5. Simulation results presentation

6. Simulation results evaluation

7. Conclusions

References

Vitae

QoSNET: An integrated QoS network for routing protocols in large scale wireless sensor networks Original Research Article

Computer Communications

Numerous QoS routing strategies focus on end-to-end delays to provide time constrained routing protocols in wireless sensor networks (WSNs). With the arrival of wireless multimedia sensor networks, traffic can be composed of time sensitive packets and reliability-demanding packets. In such situations, some works also take into account link reliability to provide probabilistic QoS. The trade-off between the guarantee of the QoS requirements and the network lifetime remains an open issue, especially in large scale WSNs. This paper proposes a promising multipath QoS routing protocol based on a separation of the nodes into two sub-networks: the first part includes specific nodes that are occasionally involved in routing decisions, while the remaining nodes in the second sub-network fully take part in them. The QoS routing is formulated as an optimization problem that aims to extend the network lifetime subject to QoS constraints. Using the percolation theory, a routing algorithm is designed to solve the problem on the respective sub-networks. Simulation results show the efficiency of this novel approach in terms of average end-to-end delays, on-time packet delivery ratio, and network lifetime.

Article Outline

1. Introduction

2. Related work

3. The system model

3.1. The QoS network model

3.2. End-to-end QoS parameters

3.3. Switching QoS routing

3.4. Mapping QoSNet resolution to site percolation

4. Performance evaluation

5. Conclusion

References

Distributed energy balanced routing for wireless sensor networks Original Research Article

Computers & Industrial Engineering

Most routing algorithms for sensor networks focus on finding energy efficient paths to prolong the lifetime of sensor networks. As a result, the power of sensors on efficient paths depletes quickly, and consequently sensor networks become incapable of monitoring events from some parts of their target areas. In many sensor network applications, the events that must be tracked occur at random locations and have non-deterministic generation patterns. Therefore, ideally, routing algorithms should consider not only energy efficiency, but also the amount of energy remaining in each sensor, thus avoiding

non-functioning sensors due to early power depletion. This paper introduces a new metric, energy cost, devised to consider a balance of sensors? remaining energies, as well as energy efficiency. This metric gives rise to the design of the distributed energy balanced routing (DEBR) algorithm devised to balance the data traffic of sensor networks in a decentralized manner and consequently prolong the lifetime of the networks. DEBR is scalable in the number of sensors and also robust to the variations in the dynamics of event generation. We demonstrate the effectiveness of the proposed algorithm by comparing three existing routing algorithms: direct communication approach, minimum transmission energy, and

self-organized routing and find that energy balance should be considered to extend lifetime of sensor network and increase robustness of sensor network for diverse event generation patterns.

Article Outline

1. Introduction

2. Sensor network model

2.1. Network topology

2.2. Energy consumption model

2.3. Lifetime of sensor network

2.4. Event generation functions

3. Routing in wireless sensor networks

4. Integer programming (IP) model for energy balanced routing

4.1. Traffic equations

4.2. Energy constraints

4.3. Integer programming (IP) formulation

5. Distributed energy balanced routing (DEBR)

5.1. Example

5.2. Steps in the DEBR algorithm

5.3. Algorithm characteristics

5.3.1. Observation 1

5.3.2. Observation 2

5.3.3. Observation 3

6. Experimental results

6.1. Lifetime of sensor network

6.2. Energy balancing

6.3. Different event generation functions

6.4. Neighbor distance

7. Conclusion and future works

Acknowledgements

SubCast: A distributed addressing and routing system for large scale wireless sensor and actor networks Original Research Article

Computer Networks

Wireless sensor and actor networks (WSANs) are made up of a large number of sensing devices which are resource-impoverished nodes and powerful actuation devices: both are equipped with computation

and communication capabilities. These devices cooperate to manage sensing and perform acting tasks. Numerous work conducted in the field of WSANs assumes the existence of addresses and routing infrastructure to validate their proposals. However, assigning addresses and delivering detected events in these networks remains highly challenging, specifically due to the sheer number of nodes. To address these issues, this paper proposes SubCast, a novel distributed address assignment and routing scheme based on a topic clustering system and fractal theory iterated function systems. In order to minimize data delivery costs among actors, the proposed architecture first builds an actor overlay network before allocating addresses to network nodes. Location information in the allocated addresses allows establishing data delivery paths. Simulation results confirm that the proposed system efficiently guarantees the allocation of unique addresses and performs efficient data delivery while reducing communication costs, delays as well as the impact of imprecise locations.

Article Outline

1. Introduction

2. Related work

3. Design overview

4. System model

4.1. The actors? overlay network (AON)

4.1.1. Topic-based PS system for WSANs

4.1.2. Algorithms and complexity

4.2. Distributed address assignment

4.2.1. Basic idea

4.2.2. Address allocation

4.2.2.1. Cell computing

4.2.2.2. Neighborhood discovery

4.2.2.3. Identifier assignments

4.3. Design rationale

4.4. Routing

4.4.1. Fractal cell routing

4.4.2. Sensor-actor communication

4.4.3. Actor–actor communication

4.4.4. Sensor–actor to sink communication

4.5. Handling topology changes

4.5.1. Joining nodes

4.5.2. Departing nodes

5. Performance evaluation

6. Conclusion

Appendix A. Notations used in this paper

Appendix B. Frame used for all exchanges

References

A reactive role assignment for data routing in event-based wireless sensor networks Original Research Article

Computer Networks

In this work, we show how we can design a routing protocol for wireless sensor networks (WSNs) to support an information-fusion application. Regarding the application, we consider that WSNs apply information fusion techniques to detect events in the sensor field. Particularly, in event-driven scenarios there might be long intervals of inactivity. However, at a given instant, multiple sensor nodes might detect one or more events, resulting in high traffic. To save energy, the network should be able to remain in a latent state until an event occurs, then the network should organize itself to properly detect and notify the event. Based on the premise that we have an information-fusion application for event detection, we propose a role assignment algorithm, called Information-Fusion-based Role Assignment (InFRA), to organize the network by assigning roles to nodes only when events are detected. The InFRA algorithm is a distributed heuristic to the minimal Steiner tree, and it is suitable for networks with severe resource constraints, such as WSNs. Theoretical analysis shows that, in some cases, our algorithm has a

O(1)-approximation ratio. Simulation results show that the InFRA algorithm can use only 70% of the communication resources spent by a reactive version of the Centered-at-Nearest-Source algorithm. Article Outline

2. Related work

3. Background

3.1. Network and event model

3.2. Deployment model

3.3. Role assignment model

4. Problem statement

5. InFRA: Information-Fusion-based Role Assignment 5.1. Cluster formation

5.2. Route formation

5.3. Information fusion

5.3.1. Intra-cluster fusion

5.3.2. Inter-cluster fusion

5.4. Event detection

5.5. Dynamic topologies

5.6. Role migration

6. Theoretical results

6.1. Approximation ratio

6.2. A complexity analysis

7. Simulation results

7.1. Methodology

7.2. Reactive vs. proactive role assignment

7.3. Communication range

7.4. Network scalability

7.5. Event scalability

7.6. Event size

7.7. Density

7.8. Event duration

8. Final remarks

Acknowledgements

Vitae

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Energy efficient and QoS based routing protocol for wireless sensor networks Original Research Article

Journal of Parallel and Distributed Computing

The increasing demand for real-time applications in Wireless Sensor Networks (WSNs) has made the Quality of Service (QoS) based communication protocols an interesting and hot research topic. Satisfying Quality of Service (QoS) requirements (e.g. bandwidth and delay constraints) for the different QoS based applications of WSNs raises significant challenges. More precisely, the networking protocols need to cope up with energy constraints, while providing precise QoS guarantee. Therefore, enabling QoS applications in sensor networks requires energy and QoS awareness in different layers of the protocol

stack. In many of these applications (such as multimedia applications, or real-time and mission critical applications), the network traffic is mixed of delay sensitive and delay tolerant traffic. Hence, QoS routing becomes an important issue. In this paper, we propose an Energy Efficient and QoS aware multipath routing protocol (abbreviated shortly as EQSR) that maximizes the network lifetime through balancing energy consumption across multiple nodes, uses the concept of service differentiation to allow delay sensitive traffic to reach the sink node within an acceptable delay, reduces the end to end delay through spreading out the traffic across multiple paths, and increases the throughput through introducing data redundancy. EQSR uses the residual energy, node available buffer size, and Signal-to-Noise Ratio (SNR) to predict the best next hop through the paths construction phase. Based on the concept of service differentiation, EQSR protocol employs a queuing model to handle both real-time and non-real-time traffic.

By means of simulations, we evaluate and compare the performance of our routing protocol with the MCMP (Multi-Constraint Multi-Path) routing protocol. Simulation results have shown that our protocol achieves lower average delay, more energy savings, and higher packet delivery ratio than the MCMP protocol.

Article Outline

1. Introduction

2. Multipath routing

2.1. Benefits of multipath routing

2.1.1. Load balancing

2.1.2. Reliability and fault tolerance

2.1.

3. Highly aggregated bandwidth

2.1.4. Minimizing end to end delay

2.2. Problems with multipath routing

3. Related work

4. Description of EQSR protocol

4.1. Assumptions

4.2. Link cost function

4.3. Paths discovery phase

4.4. Path refreshment

4.5. Paths selection

4.6. Traffic allocation and data transmission

4.7. Data transfer across multiple paths

4.7.1. Data packet segmentation and encoding

4.7.2. Traffic allocation

4.7.3. Data forwarding and recovery

5. Performance evaluation of EQSR protocol

5.1. Impact of packets generation rate

5.1.1. Average end-to-end delay

5.1.2. Packet delivery ratio

5.1.3. Average energy consumption

5.2. Impact of node failure probability

5.2.1. Average delay

5.2.2. Average delivery ratio

5.2.3. Average energy consumption

6. Conclusion

Network Engineering

Wired and wireless communications

Routing, switching and other wired communications and wireless communications Basic principles

Proficient

The commonly used

Network Communications Equipment

Involved

Campus network level

LAN or wireless communication network

Network and maintenance

Graph partitioning algorithm for opportunistic routing in large-scale wireless network Original Research Article

The Journal of China Universities of Posts and Telecommunications

Opportunistic routing takes advantage of the broadcast nature of wireless communications by forwarding data through a set of opportunistic paths instead of one …best? path in traditional routing. However, using the global scheduling opportunistic scheme like the existing opportunistic routing protocol (ExOR) would consume considerable transmission latency and energy in large-scale wireless topologies. In this article, a graph partitioning algorithm is proposed, namely, minimum cut with laplacians (MCL), to divide the Ad-hoc network topology into subgraphs with minimized edge cuts across them. Then the existing opportunistic routing can be applied locally in each subgraph. In this way, forwarders in different subgraphs can transmit simultaneously, and each node only needs to maintain a local forwarder list instead of a global one. The simulations show that using MCL scheme in the opportunistic routing can reduce the end-to-end delay by about 49%, and increase the life time of the wireless node by about 39%.

SafeMesh: A wireless mesh network routing protocol for incident area communications Original Research Article

Pervasive and Mobile Computing

Reliable broadband communication is becoming increasingly important during disaster recovery and emergency response operations. In situations where infrastructure-based communication is not available or has been disrupted, an Incident Area Network needs to be dynamically deployed, i.e. a temporary network that provides communication services for efficient crisis management at an incident site. Wireless Mesh Networks (WMNs) are multi-hop wireless networks with self-healing and self-configuring capabilities. These features, combined with the ability to provide wireless broadband connectivity at a comparably low cost, make WMNs a promising technology for incident management communications. This paper specifically focuses on hybrid WMNs, which allow both mobile client devices as well as dedicated infrastructure nodes to form the network and provide routing and forwarding functionality. Hybrid WMNs are the most generic and most flexible type of mesh networks and are ideally suited to meet the requirements of incident area communications. However, current wireless mesh and ad-hoc routing protocols do not perform well in hybrid WMN, and are not able to establish stable and high throughput communication paths. One of the key reasons for this is their inability to exploit the typical high degree of heterogeneity in hybrid WMNs. SafeMesh, the routing protocol presented in this paper, addresses the limitations of current mesh and ad-hoc routing protocols in the context of hybrid WMNs.

SafeMesh is based on the well-known AODV routing protocol, and implements a number of modifications and extensions that significantly improve its performance in hybrid WMNs. This is demonstrated via an extensive set of simulation results. We further show the practicality of the protocol through a prototype implementation and provide performance results obtained from a small-scale testbed deployment. Article Outline

1. Introduction

2. Related work

3. Adaptation of wireless mesh routing metrics to AODV

3.1. AODV

3.2. AODV-ETT

3.3. AODV-WCETT

4. SafeMesh

4.1. Node type aware routing

4.2. Multi-link discovery

4.3. Link selection based on congestion and channel diversity

4.4. Local link repairing

4.5. Qualitative comparison

5. Simulation results

5.1. Simulation environment

5.2. Performance metrics

5.3. Results and analysis

5.3.1. Simulation 1: Varying the maximum mesh client speed

5.3.2. Simulation 2: Varying the number of flows

5.3.3. Simulation 3: Varying the number of mesh routers

5.3.4. Simulation 4: Varying the number of radios in each mesh router

5.3.5. Simulation 5: Varying the speed of the mesh routers

6. Prototype implementation and evaluation

6.1. Prototype implementation

6.2. Test-bed set-up

6.3. Test scenario

6.4. Results

7. Conclusions

Acknowledgements

References

Vitae

RETT-gen: A globally efficient routing protocol for wireless sensor networks by equalising sensor energy and avoiding energy holes Original Research Article

Ad Hoc Networks

Wireless sensor networks are composed of a large number of sensor nodes with limited energy resources. Once deployed, the sensor nodes are usually inaccessible to the user, and thus replacement of the energy resource is not feasible. Hence, energy efficiency is a key design issue that needs to be enhanced in order to improve the life span of the entire network. Several routing protocols have been proposed to improve the effective lifetime of the network with limited energy supply. In this paper, we propose routing based on energy–temperature transformation, RETT-gen, a scalable energy-efficient clustering and routing protocol designed for wireless sensor networks. The main goal of RETT-gen is to evenly distribute the energy load among all the sensor nodes in the network so that there are no

overly-utilized sensor nodes that will run out of energy before the others. To achieve this goal, RETT-gen uses heat conductivity as a metaphor and uses the heat dissipation difference equations. In RETT-gen, we transform the expected lifetime of each sensor node to an equivalent temperature, and then by using the heat dissipation equations, we find the hottest path for sending data to the base station, which will not always be the shortest path. We evaluate the performance of the RETT-gen protocol via simulations, and compare it to the performance of well-known routing protocols (i.e. LEACH [W. Heinzelman, A. Chandrakasan, H. Balakrishnan, Energy-efficient communication protocol for wireless microsensor networks, in: Proceedings of the 33rd Hawaii International Conference on System Sciences (HICSS?00), 2000.] and EEUC [C. Li, M. Ye, G. Chen, J. Wu, An energy-efficient unequal clustering mechanism for wireless sensor networks, in: Proceedings of the International IEEE Conference on Mobile Adhoc and Sensor Systems (MASS), 2005.]). Simulation results show that by equalizing the sensor nodes energy,

RETT-gen insures that the lifetime of the entire sensor network is maximized, the connectivity in a sensor network is maintained for as long as possible, and that the residual energy of the entire network is of the same order.

Article Outline

1. Introduction

2. System model and objectives

2.1. Energy consumption model

2.1.1. Communication energy consumption

2.1.2. Computation energy consumption

2.1.

3. Sensing energy consumption

3. The RETT-gen protocol

3.1. Clustering

3.2. Cluster-head election architecture

3.3. Network clusters localization

3.4. Cluster-head functions

3.5. Equalization based routing

3.5.1. Heat diffusion equation

3.5.2. Cluster-head temperature calculation

3.5.2.1. Temperature calculation (phase one)

3.5.2.2. Temperature calculation (phase two)

3.6. Resource requirements

3.7. Connectivity

4. Performance evaluation

4.1. Simulation experiments setup and goals

4.2. Simulation results and analysis

4.2.1. Average energy dissipation

4.2.2. System and sensor nodes lifetime

4.2.3. Network utility performance

4.2.4. Received data messages

4.3. The effects of network parameters on performance

4.3.1. Varying the number of sensor nodes

4.3.2. Varying the network area

4.3.3. Varying the distance between the base station and the sensor network

4.3.4. Varying the base station temperature value

4.3.

5. Varying the heat conductivity coefficient

4.3.6. Varying the cluster-heads selection probability

4.3.7. Changing the scaling variable used for cluster-heads rotation process

5. Related work

6. Conclusions

Appendix 1. Using the Gauss–Seidal method for solving M finite-difference equations

References

An efficient Neighbourhood Load Routing metric for Wireless Mesh Networks Original Research Article

Simulation Modelling Practice and Theory

The Wireless Mesh Network (WMN) is a highly capable technology that can offer low-cost and

easy-deployable network connectivity to both small-size community networks and large-scale metropolitan networks. As a key emerging technology to provide the next generation broadband networking, WMN combines the advantages of both mobile ad hoc network (MANET) and traditional fixed network, attracting significant industrial and academic attentions. In WMN, the load balancing has already shown its key role in enhancing communication quality by providing reduced latency, jitter and error rate as well as improving bandwidth utilisation and allocation polices. Although there are a number of proposals on using load-aware strategy in WMN, the neighbourhood load has not been considered within the context of load balancing and high efficient WMNs. In this paper, we propose a Neighbourhood Load Routing metric to further improve the performance of existing routing protocols such as AODV in WMN. We have conducted extensive simulation experiments and our results confirm the superiority of our proposed scheme over its well-known counterparts, especially in grid topologies.

Article Outline

1. Introduction

2. Related work

3. System model

3.1. Network model

3.2. Problem description

4. Proposed solution

4.1. Definition

4.2. NLR: The proposed routing metric

4.3. Case study

4.4. Comparisons of routing metrics

5. Simulation

5.1. NLR in grid topology

5.2. NLR in random/irregular topology

6. Conclusion and future work

References

A power-efficient routing protocol for underwater wireless sensor networks Original Research Article

Applied Soft Computing

Underwater wireless sensor networks have attracted significant attention recently from both academia and industry to explore natural undersea resources and gathering of scientific data in aqueous environments. The nature of an underwater sensor network, such as low bandwidth and large propagation latency, floating node mobility, and power efficiency, is significantly different from traditional ground-based wireless sensor networks. Power-efficient communication protocols are thus urgently demanded in the deployment of underwater sensor networks. In this paper, a routing protocol is developed to tackle these problems in underwater wireless sensor networks. A forwarding node selector is employed to determine the appropriate sensors to forward the packets to the destination, and a forwarding tree trimming mechanism is adopted to prevent excess spread of forwarded packets. The proposed protocol is compared with a representative routing protocol for UWSNs in the literature. The experimental results verify the effectiveness and feasibility of the proposed work.

1. Introduction

2. Related work

3. Architecture of power-efficient routing protocol

3.1. Fuzzy logic inference system

3.2. Decision trees

3.3. Forwarding tree trimming mechanism

4. Simulation results

5. Conclusion

Acknowledgements

Adaptive state-based multi-radio multi-channel multi-path routing in Wireless Mesh Networks Original Research Article

Pervasive and Mobile Computing

Wireless Mesh Networks (WMNs) are envisioned to seamlessly extend the network connectivity to end users by forming a wireless backbone that requires minimal infrastructure. Unfortunately for WMNs, frequent link quality fluctuations, excessive load on selective links, congestion, and limited capacity due to the half-duplex nature of radios are some key limiting factors that hinder their deployment. To address these problems, we propose a novel Adaptive State-based Multi-path Routing Protocol (ASMRP), which constructs Directed Acyclic Graphs (DAGs) from each Mesh Router (MR) to Internet Gateways (IGWs) and effectively discovers multiple optimal path set between any given MR-IGW pair. A congestion aware traffic splitting algorithm to balance traffic over these multiple paths is presented which synergistically improves the overall performance of the WMNs. We design a novel Neighbor State Maintenance module that innovatively employs a state machine at each MR to monitor the quality of links connecting its neighbors in order to cope with unreliable wireless links. We also employ a 4-radio architecture for MRs, which allows them to communicate over multiple radios tuned to non-overlapping channels and better utilize the available spectrum. Through extensive simulations using ns-2, we observe that ASMRP substantially improves the achieved throughput ( 5 times gain in comparison to AODV), and significantly minimizes end-to-end latencies. We also show that ASMRP ensures fairness in the network under varying traffic load conditions.