Predicting Performance of Channel Assignments in Wireless Mesh Networks through Statistical Interference Estimation

Wireless Mesh Network (WMN) deployments are poised to reduce the reliance on wired infrastructure especially with the advent of the multi-radio multi-channel (MRMC) WMN architecture. But the benefits that MRMC WMNs offer viz., augmented network capacity, uninterrupted connectivity and reduced latency, are depreciated by the detrimental effect of prevalent interference. Interference mitigation is thus a prime objective in WMN deployments. It is often accomplished through prudent channel allocation (CA) schemes which minimize the adverse impact of interference and enhance the network performance. However, a multitude of CA schemes have been proposed in research literature and absence of a CA performance prediction metric, which could aid in the selection of an efficient CA scheme for a given WMN, is often felt. In this work, we offer a fresh characterization of the interference endemic in wireless networks. We then propose a reliable CA performance prediction metric, which employs a statistical interference estimation approach. We carry out a rigorous quantitative assessment of the proposed metric by validating its CA performance predictions with experimental results, recorded from extensive simulations run on an ns-3 802.11g environment

Sustaining Rural Livelihoods in Fragile Environments : Resource Endowments or Policy Interventions?

This paper primarily assesses the status of rural livelihoods in fragile environments with diverse resource endowments and policy interventions. The objective was to examine the effectiveness of resource enhancing policy interventions like watershed development in reducing resource endowment imbalances across villages and regions. Livelihood assessment was carried out using the sustainable rural livelihoods (SRL) framework in the fragile regions of Andhra Pradesh. Qualitative and quantitative approaches were used to assess the rural livelihoods covering all the 555 households in three sample villages. It is argued that resource endowments determine the level and dynamics of livelihoods at the household level rather than policy interventions per se. On the other hand, policy interventions, given the status and structure of the economy, only act as catalysts. Policies for strengthening the resource base are necessary but not sufficient to address the livelihood issues. In the present case it is shown that availability of water (irrigation) is more important than the recent policy interventions like watershed development for improving the livelihoods. Nevertheless, policy interventions towards human capital development (education, skills, etc) could be rewarding in the long run. Unless policies are directed towards bringing changes in natural resource endowments (especially water) at the household level, it is unlikely that the on going policy interventions would transform the rural livelihoods in the fragile environments.Rural livelihoods, resource endowments, watershed development, policy

Sustaining rural livelihoods in fragile environments: Resource endowments or policy interventions?

This paper primarily assesses the status of rural livelihoods in fragile environments with diverse resource endowments and policy interventions. The objective was to examine the effectiveness of resource enhancing policy interventions like watershed development in reducing resource endowment imbalances across villages and regions. Livelihood assessment was carried out using the sustainable rural livelihoods (SRL) framework in the fragile regions of Andhra Pradesh. Qualitative and quantitative approaches were used to assess the rural livelihoods covering all the 555 households in three sample villages.Rural livelihoods, resource endowments, watershed development, policy interventions, Andhra Pradesh

Reliable Prediction of Channel Assignment Performance in Wireless Mesh Networks

The advancements in wireless mesh networks (WMN), and the surge in multi-radio multi-channel (MRMC) WMN deployments have spawned a multitude of network performance issues. These issues are intricately linked to the adverse impact of endemic interference. Thus, interference mitigation is a primary design objective in WMNs. Interference alleviation is often effected through efficient channel allocation (CA) schemes which fully utilize the potential of MRMC environment and also restrain the detrimental impact of interference. However, numerous CA schemes have been proposed in research literature and there is a lack of CA performance prediction techniques which could assist in choosing a suitable CA for a given WMN. In this work, we propose a reliable interference estimation and CA performance prediction approach. We demonstrate its efficacy by substantiating the CA performance predictions for a given WMN with experimental data obtained through rigorous simulations on an ns-3 802.11g environment.Comment: Accepted in ICACCI-201

Radio Co-location Aware Channel Assignments for Interference Mitigation in Wireless Mesh Networks

Designing high performance channel assignment schemes to harness the potential of multi-radio multi-channel deployments in wireless mesh networks (WMNs) is an active research domain. A pragmatic channel assignment approach strives to maximize network capacity by restraining the endemic interference and mitigating its adverse impact on network performance. Interference prevalent in WMNs is multi-faceted, radio co-location interference (RCI) being a crucial aspect that is seldom addressed in research endeavors. In this effort, we propose a set of intelligent channel assignment algorithms, which focus primarily on alleviating the RCI. These graph theoretic schemes are structurally inspired by the spatio-statistical characteristics of interference. We present the theoretical design foundations for each of the proposed algorithms, and demonstrate their potential to significantly enhance network capacity in comparison to some well-known existing schemes. We also demonstrate the adverse impact of radio co- location interference on the network, and the efficacy of the proposed schemes in successfully mitigating it. The experimental results to validate the proposed theoretical notions were obtained by running an exhaustive set of ns-3 simulations in IEEE 802.11g/n environments.Comment: Accepted @ ICACCI-201

Hybrid stars that masquerade as neutron stars

We show that a hybrid (nuclear + quark matter) star can have a mass-radius relationship very similar to that predicted for a star made of purely nucleonic matter. We show this for a generic parameterization of the quark matter equation of state, and also for an MIT bag model, each including a phenomenological correction based on gluonic corrections to the equation of state. We obtain hybrid stars as heavy as 2 M_solar for reasonable values of the bag model parameters. For nuclear matter, we use the equation of state calculated by Akmal, Pandharipande, and Ravenhall using many-body techniques. Both mixed and homogeneous phases of nuclear and quark matter are considered.Comment: 22 pages, LaTeX. Extra figure and explanation adde