Search results for "D2D"

Improving RF Fingerprinting Methods by Means of D2D Communication Protocol

2019

Radio Frequency (RF) fingerprinting is widely applied for indoor positioning due to the existing Wi-Fi infrastructure present in most indoor spaces (home, work, leisure, among others) and the widespread usage of smartphones everywhere. It corresponds to a simple idea, the signal signature in a location tends to be stable over the time. Therefore, with the signals received from multiple APs, a unique fingerprint can be created. However, the Wi-Fi signal is affected by many factors which degrade the positioning error range to around a few meters. This paper introduces a collaborative method based on device-to-device (D2D) communication to improve the positioning accuracy using only fingerprin…

Perceived need to increase physical activity levels among adults at high risk of type 2 diabetes. A cross-sectional analysis within a community-based…

2012

Abstract Background Increased physical activity is a cornerstone of type 2 diabetes prevention. The perception of a need to change is considered essential in behaviour change processes. However, the existing literature on individuals’ perceived need to change health behaviour is limited. In order to improve understanding of diabetes prevention through increased physical activity levels (PAL), we assessed factors associated with perceiving a need to increase PAL among adults at high risk of diabetes. Methods Opportunistic screening was used within a primary-care based lifestyle intervention covering 10 149 men and women at high risk of type 2 diabetes. Data were obtained at baseline visits. …

Advanced voice and data solutions for evolution of cellular network system

2014

Perceived sufficiency of physical activity levels among adults at high risk of type 2 diabetes. The FIN-D2D study

2012

Purpose. This study assessed the determinants of perceived physical activity levels (PALs) among adults at high risk of diabetes, and the associations with self-reported physical activity. Methods. In total, 10,149 adults participated in the FIN-D2D lifestyle intervention at baseline. Opportunistic screening was used in identifying high risk individuals. Physical activity and perceived PAL sufficiency were assessed and compared. Key risk factors for diabetes and psychosocial and demographic characteristics were analyzed as determinants using logistic regression. Results. PAL sufficiency was rated realistically by 73% of men and 75% of women. Perception of sufficient PAL was more likely amon…

Device-to-device communication for LTE-advanced network system

2014

Device-to-device (D2D) communication has been proposed as a mean for local connections in future ellular networks in order to provide improved throughput, spectrum savings, and longer battery lives. Here we widen the investigations of D2D communication to a 3GPP Long Term Evolution (LTE) system simulated in the interference limited macro-cellular environment, in which D2D communication is applied with D2D specific power control and resource allocation schemes and with a wide range of deployment ratios. Furthermore, we introduce channel model parameters applicable for a fair performance comparison between conventional cellular and D2D enhanced systems. The simulation results demonstrate that…

Operator Revenue Analysis for Device-to-Device Communications Overlaying Cellular Network

2018

Device-to-device (D2D) communications has recently gathered significant research interest due to its efficient utilization of already depleting wireless spectrum. In this article, we considered a scenario where D2D users communicate in the presence of cellular users in an overlay network setup. In order to analyze the revenue of service providers in monetary terms, the paper provides exact expressions of operator profit for both D2D and cellular users. More specifically, we take into account different network parameters including user density, transmit power and channel variations to understand their impact on the total revenue of the operator. Finally, we derive the balancing value of freq…

Multi-hop D2D Communications with Network Coding : From A Performance Perspective

2019

Multi-hop device-to-device (D2D) communications play an important role in expanding D2D coverage. In this paper, we study a relay-based and network-coding-assisted (in particular, XOR coding) multi-hop D2D communication system. In the system, toward jointly considering the impact of interference and network traffic conditions on the quality of D2D communications, various channel fading models and traffic models are investigated, and the packet loss probability of D2D links is meticulously computed using these models. With the packet loss probability of D2D links, the general closed-form expressions of end-to-end packet loss probability (E2EPLP) of the system with the presence (or absence) o…

Elintapaohjauksen lähtökohtia korkeassa diabetesriskissä olevilla henkilöillä tyypin 2 diabeteksen ehkäisyn toimeenpanohankkeessa (D2D) : elintapaohj…

2012

Perceived need to increase physical activity levels among adults at high risk of type 2 diabetes. A cross-sectional analysis within a community-based…

2012

Background. Increased physical activity is a cornerstone of type 2 diabetes prevention. The perception of a need to change is considered essential in behaviour change processes. However, the existing literature on individuals' perceived need to change health behaviour is limited. In order to improve understanding of diabetes prevention through increased physical activity levels (PAL), we assessed factors associated with perceiving a need to increase PAL among adults at high risk of diabetes. Methods. Opportunistic screening was used within a primary-care based lifestyle intervention covering 10 149 men and women at high risk of type 2 diabetes. Data were obtained at baseline visits. Th…