On the Analysis of Cellular Networks with Caching and Coordinated Device-to-Device Communication

In this paper, we develop a comprehensive analytical framework for cellular networks that are enhanced with coordinated device-to-device (D2D) communication, where the D2D devices are equipped with content caching capabilities. The base station (BS) coordinates the D2D communication by establishing a D2D link between the requesting user and the nearest D2D helper within the same cell if the latter contains the requested content, otherwise, the BS serves the user itself. The motivation behind restricting D2D pairs within a macro cell is to make coordinated D2D communication realizable as the BS can keep track of the content of the devices without the increased overhead of inter-BS coordination. This approach is similar to LTE direct, where D2D pairing is managed by the BS. We model the locations of BS and D2D helpers using a homogeneous Poisson point process (HPPP). The distribution of the distance between the tagged user and its neighboring D2D helper within the cell is derived using disk approximation for the Voronoi cell, which is shown to be reasonably accurate. We fully characterize the cellular and D2D coverage and the link spectral efficiency of such a network. Our results reveal that cache enabled D2D communication becomes more effective as the requesting user moves away from the BS and high performance gains can be achieved compared to conventional cellular networks, especially when the popularity distribution is skewed and most popular files are requested

On the Analysis of Device-to-Device Overlaid Cellular Networks in the Uplink under 3GPP Propagation Model

In this article we employ the third generation partnership project (3GPP) recommended path loss models for the analysis of cellular networks overlaid with D2D communication and channel inversion power control in the uplink. We characterize the coverage and average network throughput with the help of stochastic geometry. More specifically, we develop tractable expressions for the coverage in cellular and D2D modes. Our theoretical results differ significantly from previous work, which uses simple power law path loss models. The traditional methodology does not account for the presence of line-of-sight (LoS), non-line-of-sight (NLoS) and free space (FS) links. We demonstrate that such classification of links significantly impacts the inference which can be derived from the analysis for the design of overlaid D2D networks. In particular, we show that, contrary to the previous findings, the average throughput of the network does not saturate with the increase in the density of base stations (BS), but there exists an optimal mode selection threshold and BS density which maximizes the average throughput

M2M meets D2D: Harnessing D2D Interfaces for the Aggregation of M2M Data

Direct device-to-device (D2D) communication presents as an effective technique to reduce the load at the base station (BS) while ensuring reliable localized communication. In this paper, we propose a large-scale M2M data Aggregation and Trunking (MAT) scheme, whereby the user equipments (UEs) aggregate M2M data from the nearby MTDs and trunk this data along with their own data to the BS in the cellular uplink. We develop a comprehensive stochastic geometry framework by considering a Poisson hard sphere model for UE coverage. The main motivation of this model is to capture the fact that a UE can gather data from short range, low-power MTDs located only in its close proximity while ensuring that an MTD is associated to at most one UE. We explore the inherent trade-off between the time reserved for aggregation and successful trunking of data to the BS and compare our results with the baseline case where no aggregation mechanism is used. We show that while the baseline case of connecting a bulk of MTDs directly with the BS is prohibitive, MAT scheme can efficiently gather data from selected MTDs in a distributed manner

Carpentier-Edwards PERIMOUNT Magna bioprosthesis: A stented valve with stentless performance?

ObjectiveWe designed this study to evaluate the early hemodynamic performance of the recently introduced Carpentier-Edwards PERIMOUNT Magna bioprosthesis (Edwards Lifesciences, Irvine, Calif) and compare it with those of the conventional Carpentier-Edwards PERIMOUNT stented bioprosthesis (Edwards Lifesciences) and Edwards Prima Plus porcine stentless bioprosthesis (Edwards Lifesciences).MethodsSixty-three patients (>70 years old) were enrolled in this prospective, randomized study. At operation, once the annulus had been measured, the best size suitable was assessed for each of the three valves before random assignment. Transthoracic echocardiography was performed before discharge to evaluate early postoperative hemodynamic performances of the different valves implanted.ResultsThe best size suitable of Edwards Prima Plus (24.3 ± 1.7 mm) was significantly superior to those of both the Carpentier-Edwards PERIMOUNT Magna (23.4 ± 2.1 mm) and Carpentier-Edwards PERIMOUNT (22.4 ± 1.8 mm). The best size suitable of the Carpentier-Edwards PERIMOUNT Magna, however, was significantly superior to that of the Carpentier-Edwards PERIMOUNT. Furthermore the best size suitable of the Carpentier-Edwards PERIMOUNT Magna was equal to the measured annulus in 55% of patients, as opposed to 25% for the Carpentier-Edwards PERIMOUNT (P < .001). Mean implanted labeled size of the Edwards Prima Plus was significantly higher than those of both the Carpentier-Edwards PERIMOUNT Magna and the Carpentier-Edwards PERIMOUNT (24.6 ± 1.9 mm, 23.1 ± 1.9 mm, and 22.5 ± 1.8 mm, respectively). Early postoperative hemodynamic performance of the Carpentier-Edwards PERIMOUNT Magna, however, was superior to those of both the Edwards Prima Plus and the Carpentier-Edwards PERIMOUNT in both effective orifice area index (1.07 ± 0.4 cm2/m2, 0.87 ± 0.3 cm2/m2, and 0.80 ± 0.2 cm2/m2, respectively) and mean peak gradient (20 ± 6 mm Hg, 27 ± 8 mm Hg, and 28 ± 12 mm Hg, respectively).ConclusionThe improved design of the recently introduced third-generation stented bioprosthesis Carpentier-Edwards PERIMOUNT Magna allows implantation of a significantly bigger valve than with the old generation. Furthermore, the improved hemodynamic performance of the Carpentier-Edwards PERIMOUNT Magna compares favorably with both the Carpentier-Edwards PERIMOUNT and the Edwards Prima Plus

Leveraging D2D Communication to Maximize the Spectral Efficiency of Massive MIMO Systems

In this paper, we investigate offloading of UEs in D2D mode for a massive MIMO system, where the base station (BS) is equipped with a large, but finite number of antennas and the total number of UEs is kept fixed. We derive closedform expressions for the bounds of the overall capacity of the system. Our results reveal that there exists an optimal user offload fraction, which maximizes the overall capacity. This fraction is strongly coupled with the network parameters such as the number of antennas at the BS, D2D link distance and the transmit SNR at both the UE and the BS. Given a set of network parameters, careful tuning of the offload fraction can provide up to 5× capacity gains

Solar Energy Empowered 5G Cognitive Metro-Cellular Networks

Harvesting energy from natural (solar, wind, vibration, etc.) and synthesized (microwave power transfer) sources is envisioned as a key enabler for realizing green wireless networks. Energy efficient scheduling is one of the prime objectives in emerging cognitive radio platforms. To that end, in this article we present a comprehensive framework to characterize the performance of a cognitive metro-cellular network empowered by solar energy harvesting. The proposed model allows designers to capture both the spatial and temporal dynamics of the energy field and the mobile user traffic. A new definition for the “energy outage probability” metric, which characterizes the self-sustainable operation of the base stations under energy harvesting, is proposed, and the process for quantifying is described with the help of a case study for various UK cities. It is shown that the energy outage probability is strongly coupled with the path-loss exponent, required quality of service, and base station and user density. Moreover, the energy outage probability varies both on a daily and yearly basis depending on the solar geometry. It is observed that even in winter, BSs can run for three to six hours without any purchase of energy from the power grid by harvesting instantaneous energy

Frequency of hepatitis E and Hepatitis A virus in water sample collected from Faisalabad, Pakistan

Hepatitis E and Hepatitis A virus both are highly prevalent in Pakistan mainly present as a sporadic disease. The aim of the current study is to isolate and characterized the specific genotype of Hepatitis E virus from water bodies of Faisalabad, Pakistan. Drinking and sewage samples were qualitatively analyzed by using RT-PCR. HEV Genotype 1 strain was recovered from sewage water of Faisalabad. Prevalence of HEV and HAV in sewage water propose the possibility of gradual decline in the protection level of the circulated vaccine in the Pakistani population

ASSESSMENT AND IMPORTANCE OF LIPID PROFILE IN PRE-ECLAMPSIA WOMEN

Objective: The aim of this study is to know the assessment and importance of lipid profile in preeclampsia women. Study Design: A cross-sectional analytical study. Place and Duration: In the Physiology Department of Nishtar Medical University, Multan in Collaboration with Gynecology and Obstetrics Department of Nishtar Hospital Multan for One year Duration from September 2017 to September 2018. Methods: The study consisted of 90 subjects, each of which consisted of 30 people. 30 were apparently healthy subjects, 30 mild preeclamptic and 30 severe preeclamptic. Clinical details were collected. Fasting blood samples were obtained by aseptic methods and serum lipid profile was analyzed. Results: Of the 90 subjects studied, 30 had normal triglycerides (176.76 mg / d1). However, 30 subjects with severe preeclampsia show serum triglycerides 242.mg / dl according to normal. The difference in both groups was statistically more significant than normal. Conclusion: It was concluded that high circulating levels increased with preeclampsia in the pathogenesis of preeclampsia associated with preeclampsia, which may be a risk factor during pregnancy. Key words: Lipids, Preeclampsia

DENTAL SENSITIVITY ASSOCIATED WITH CONSUMPTION OF FIZZY DRINKS: A CROSS SECTIONAL STUDY

Background: Sugary carbonated drinks might be the risk factor in patients with complaint of sensitivity. Therefore, the aim of the study was to evaluate consumption of fizzy drinks with sensitivity as consumption of fizzy drinks is being considered as a must societal habit. Methods: A cross-sectional study was carried out at private tertiary medical university among n=149 study subjects between nineteen to twenty-five years of age. A self-designed close ended structured questionnaire was used to assessed sample’s intake and effects of fizzy drinks on oral cavity. Percentages and frequencies were recorded for qualitative variables. However, means and standard deviation were recorded for quantitative variables. Furthermore, spearman rank correlation test was used to find out the association among intake of fizzy drinks with dental caries and sensitivity. Level of significance was considered as p<0.05. Results: Among n=149 study participants, 91.9% (n=137) were consuming fizzy drinks. Tooth ache and sensitivity (of mild degree) was reported in 73.7% of the students. Among those who were consuming fizzy drinks (n=137), 65.7% did not have a history of dental caries in recent past. However, 73.7% (n=101) were experiencing mild degree of sensitivity since the intake of soft drinks. Also, tooth ache was reported in 49.6% of those who were drinking carbonated (fizzy) drinks. A significant correlation was observed between the sensitivity and the duration of intake with a strong positive association r=.830 and a p value of 0.045. Conclusion: The dentine hypersensitivity is strongly associated with consumption and time to exposure of carbonated drinks