Parameter analysis for the coexistence of cognitive LTE and spectrum authorized systems

In order to realize the coexistence between the LTE system and the spectrum authorized systems over 700MHz frequency band,the geographical position and operation band location between long term evolution(LTE)base stations and digital tevevision transmission tower should satisfy certain constraints,which are analyzed and deduced in this paper.Under the concluded constraints,the interference to each other is lower than their interference tolerances,so that the coexistance between the two types of systems is performed.Based on the constraints for both LTE and spectrum authorized systems,numerical results of the geographical position interval and operation band location interval are obtained,which have significant practical value for the LTE base station placement,network planning and operation band selection.

Impacts of Bus Lane on Bus Travel Time Reliability:a Case Study in Shenzhen

The aim of the paper is to evaluate the impacts of bus lane on bus travel time reliability.The data used are the Geographic Positioning System(GPS) data of two bus lines running parallel streets in Shenzhen,China,one of which is a bus lane and the other is a regular lane.Two linear regression models are developed to evaluate the influence of bus lane which has a separated right of way.Other factors including running direction,day of week,time of day,dwell time,and delay at the start point are also considered in the model.Without published time tables,coefficient of variance(CV) of travel time is employed to explore the impacts of bus lane.The results indicate that bus lane can save 22.0% of travel time,reduce 11.5% of the CV of travel time,and decrease the variance of headway by 17.4%.The analysis on bus travel time reliability could help operators and drivers improve the quality of transit service.It also sheds light on how to assess the effectiveness of bus lane for transit planners and service operators.

A novel distributed algorithm for media access control address assignment in wireless sensor networks

This paper presents a novel distributed media access control(MAC)address assignment algorithm,namely virtual grid spatial reusing(VGSR),for wireless sensor networks,which reduces the size of the MAC address efficiently on the basis of both the spatial reuse of MAC address and the mapping of geographical position.By adjusting the communication range of sensor nodes,VGSR algorithm can minimize the size of MAC address and meanwhile guarantee the connectivity of the sensor network.Theoretical analysis and experimental results show that VGSR algorithm is not only of low energy cost,but also scales well with the network size,with its performance superior to that of other existing algorithms.

An Entrepot Of Opportunity

Situated in a unique geographical position with respect to the China-proposed Belt and Road Initiative, Nepal expects to gain momentum for its development by taking part in the regional development blueprint.