Enforcement and Spectrum Sharing: Case Studies of Federal-Commercial Sharing

To promote economic growth and unleash the potential of wireless broadband, there is a need to introduce more spectrally efficient technologies and spectrum management regimes. That led to an environment where commercial wireless broadband need to share spectrum with the federal and non-federal operations. Implementing sharing regimes on a non-opportunistic basis means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable.\ud \ud With the significant exception of license-free wireless systems, commercial wireless services are based on exclusive use. With the policy change facilitating spectrum sharing, it becomes necessary to consider how sharing might take place in practice. Beyond the technical aspects of sharing, that must be resolved lie questions about how usage rights are appropriately determined and enforced. This paper is reasoning about enforcement in a particular spectrum bands (1695-1710 MHz and 3.5 GHz) that are currently being proposed for sharing between commercial services and incumbent spectrum users in the US. We examine three enforcement approaches, exclusion zones, protection zones and pure ex post and consider their implications in terms of cost elements, opportunity cost, and their adaptability

Dynamic Geospatial Spectrum Modelling: Taxonomy, Options and Consequences

Much of the research in Dynamic Spectrum Access (DSA) has focused on opportunistic access in the temporal domain. While this has been quite useful in establishing the technical feasibility of DSA systems, it has missed large sections of the overall DSA problem space. In this paper, we argue that the spatio-temporal operating context of specific environments matters to the selection of the appropriate technology for learning context information. We identify twelve potential operating environments and compare four context awareness approaches (on-board sensing, databases, sensor networks, and cooperative sharing) for these environments. Since our point of view is overall system cost and efficiency, this analysis has utility for those regulators whose objectives are reducing system costs and enhancing system efficiency. We conclude that regulators should pay attention to the operating environment of DSA systems when determining which approaches to context learning to encourage

Enforcement in Dynamic Spectrum Access Systems

The spectrum access rights granted by the Federal government to spectrum users come with the expectation of protection from harmful interference. As a consequence of the growth of wireless demand and services of all types, technical progress enabling smart agile radio networks, and on-going spectrum management reform, there is both a need and opportunity to use and share spectrum more intensively and dynamically. A key element of any framework for managing harmful interference is the mechanism for enforcement of those rights. Since the rights to use spectrum and to protection from harmful interference vary by band (licensed/unlicensed, legacy/newly reformed) and type of use/users (primary/secondary, overlay/underlay), it is reasonable to expect that the enforcement mechanisms may need to vary as well.\ud \ud In this paper, we present a taxonomy for evaluating alternative mechanisms for enforcing interference protection for spectrum usage rights, with special attention to the potential changes that may be expected from wider deployment of Dynamic Spectrum Access (DSA) systems. Our exploration of how the design of the enforcement regime interacts with and influences the incentives of radio operators under different rights regimes and market scenarios is intended to assist in refining thinking about appropriate access rights regimes and how best to incentivize investment and growth in more efficient and valuable uses of the radio frequency spectrum

Enforcement and Network Capacity in Spectrum Sharing: Quantifying the Benefits of Different Enforcement Scenarios

Recent studies have forecasted major growth in mobile broadband traffic. Due to the predicted high growth rate of mobile broadband traffic over the coming years (demand), there is a need for more wireless network capacity (supply). One of the major approaches to expand mobile wireless capacity is to add more spectrum to the market by enabling “spectrum sharing”. The FCC has issued many reports indicating that the US is dangerously close to running out of capacity for mobile data, which is why the FCC and the NTIA have been working continually to enable spectrum sharing.\ud \ud Spectrum sharing has moved from being a radical notion to a principal policy focus in the past decade. Enabling spectrum sharing regimes means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable. The focus of this paper is to determine the relationship between enforcement methodologies and benefits of spectrum sharing through sharing between government and commercial users. Sharing between the government incumbents (i.e. Federal or non-Federal agencies) and commercial wireless broadband operators/users is one of the key forms of spectrum sharing that is recommended by the NTIA, the FCC, and the PCAST report. To address this problem, we build a model to quantitatively examine the relationships between different enforcement scenarios and sharing benefits. We model two case studies, 1695-1710 MHz band and 3550-3650 MHz band

The Cost of Knowing: An Economic Evaluation of Context Acquisition in DSA Systems

Much of the research in Dynamic Spectrum Access (DSA) has focused on the details of the enabling technologies. While this has been quite useful in establishing the technical feasibility of DSA systems, it has missed an important aspect of the overall DSA problem space: in order for operators, regulators and users to be interested in deploying DSA based networks, the expected costs should be in proportion to what the users are realistically willing to pay for services. Consequently, it is important to conduct cost estimates for different DSA approaches in parallel with the technical research.\ud \ud In this paper, we will explore how the cost experienced by primary and secondary users can influence their incentives for participation in DSA. To do this, we compare the costs and cost structures of four context awareness approaches from each of them. The costs we will consider are incremental capital costs over a basic software radio using four different context acquisition approaches (sensing, databases, sensor networks, and cooperative sharing). Since DSA is still a relatively new research field, there is a lot of uncertainty associated with incremental cost analyses. As a result, the cost analysis is parameterized to allow for explicit reasoning about the bounds of cost components

Assessment of Plasma Cystatin C among Sudanese Patients with Type II Diabetes Mellitus

Background: Cystatin C is mainly used as a biomarker of kidney function. It is freely filtered by glomerulus, and does not return to the blood stream or secreted by renal tubules. It has been suggested to be closer to the “ideal” endogenous marker.Objectives: To assess the plasma levels of cystatin c, creatinine clearance, blood HbA1C% and body mass index among Sudanese with type 2  Diabetes.Materials and methods: This is a case-control study conducted in diabetic centers in Khartoum state, Sudan, from March 2010 to November 2013. A total of 300 Sudanese patients with type2 diabetes (49% males and 51% females) as a test group, and 150 healthy subjects (48%males and 52%females) as a control group were enrolled in this study. Both groups were matched for gender and age. The plasma levels of Cystatin C, creatinine and blood HbA1c were measured using Nephelometry technique. Creatinine clearance was calculated for each participant. SPSS was usedfor analysis of data.Results: The means of the plasma levels of Cystatin C, HbA1c% and the body mass index (BMI) were significantly raised in the diabetic group  compared to the control group (p<0.05).There is significant moderate negative correlation between Cystatin C and creatinine clearance (r=0.69,p=0.015) in the diabetic group, and there is a significant strong positive correlation between the plasma levels of Cystatin C and HbA1c%(r=o.78, p=0.044).Conclusion: The present data indicates that among Sudanese patients with Type 2 Diabetes Mellitus, plasma levels of Cystatin C are significantly raised and has a significant strong positive correlation with glycated  haemoglobin % and a significant moderate negative correlation with creatinine clearance.Key words: Type 2 Diabetes, Cystatin C, Glycated Heamoglobin, Sudan

Intimate partner violence and utilization of maternal health care services in Addis Ababa, Ethiopia

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Multiphysics simulation of a microfluidic perfusion chamber for brain slice physiology

Understanding and optimizing fluid flows through in vitro microfluidic perfusion systems is essential in mimicking in vivo conditions for biological research. In a previous study a microfluidic brain slice device (μBSD) was developed for microscale electrophysiology investigations. The device consisted of a standard perfusion chamber bonded to a polydimethylsiloxane (PDMS) microchannel substrate. Our objective in this study is to characterize the flows through the μBSD by using multiphysics simulations of injections into a pourous matrix to identify optimal spacing of ports. Three-dimensional computational fluid dynamic (CFD) simulations are performed with CFD-ACE + software to model, simulate, and assess the transport of soluble factors through the perfusion bath, the microchannels, and a material that mimics the porosity, permeability and tortuosity of brain tissue. Additionally, experimental soluble factor transport through a brain slice is predicted by and compared to simulated fluid flow in a volume that represents a porous matrix material. The computational results are validated with fluorescent dye experiments

Elimination of Schistosomiasis Transmission in Zanzibar: Baseline Findings before the Onset of a Randomized Intervention Trial.

Gaining and sustaining control of schistosomiasis and, whenever feasible, achieving local elimination are the year 2020 targets set by the World Health Organization. In Zanzibar, various institutions and stakeholders have joined forces to eliminate urogenital schistosomiasis within 5 years. We report baseline findings before the onset of a randomized intervention trial designed to assess the differential impact of community-based praziquantel administration, snail control, and behavior change interventions. In early 2012, a baseline parasitological survey was conducted in ∼20,000 people from 90 communities in Unguja and Pemba. Risk factors for schistosomiasis were assessed by administering a questionnaire to adults. In selected communities, local knowledge about schistosomiasis transmission and prevention was determined in focus group discussions and in-depths interviews. Intermediate host snails were collected and examined for shedding of cercariae. The baseline Schistosoma haematobium prevalence in school children and adults was 4.3% (range: 0-19.7%) and 2.7% (range: 0-26.5%) in Unguja, and 8.9% (range: 0-31.8%) and 5.5% (range: 0-23.4%) in Pemba, respectively. Heavy infections were detected in 15.1% and 35.6% of the positive school children in Unguja and Pemba, respectively. Males were at higher risk than females (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03-2.03). Decreasing adult age (OR: 1.04; CI: 1.02-1.06), being born in Pemba (OR: 1.48; CI: 1.02-2.13) or Tanzania (OR: 2.36; CI: 1.16-4.78), and use of freshwater (OR: 2.15; CI: 1.53-3.03) showed higher odds of infection. Community knowledge about schistosomiasis was low. Only few infected Bulinus snails were found. The relatively low S. haematobium prevalence in Zanzibar is a promising starting point for elimination. However, there is a need to improve community knowledge about disease transmission and prevention. Control measures tailored to the local context, placing particular attention to hot-spot areas, high-risk groups, and individuals, will be necessary if elimination is to be achieved