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This paper develops a model evaluating the impact of mobility in heterogeneous wireless networks by the way of analytical expressions of the spatio-temporal evolution of QoS indicators. Such formulas are obtained by introducing a multiuser averaged mobility pattern named density of users. Among the set of densities, we use a Gaussian form of this quantity, which results from a modeling method based...
In this paper we evaluate the energy efficiency of a 5G radio access network (RAN) based on LTE technology when comparing two small cell deployment strategies to enhance the RAN capacity. Specifically, we compare densifying a 3-sector macrocell RAN with small cells against first upgrading to a 6-sector macrocell RAN before densifying with small cells. The latter strategy has been used in urban areas...
Cloud radio networks employ coordinated transmission among base stations (BSs) to reduce the interference effects. The practical limitations in implementing coordination results in suboptimal systems with limited performance. In this paper, we analyze the performance of a cloud network with clustering, where geographically close BSs form a clustered cloud. Coverage probability and rate distributions...
We consider user activity estimation for on-off random access in multi-base station systems. With on-off random access, each user, at a fixed slot, transmits its unique codeword (and is hence active) with probability p, and is heard by all base stations in its vicinity; the goal for each base station is then to determine which of the users in its coverage region are active. This problem models various...
Efficient secondary use of satellite spectrum is studied in this paper. Terrestrial mobile communication system accesses the C band spectrum using low power small cells or device-to-device (D2D) transmission mode. Link budget analysis conducted with a realistic path loss model in an urban environment shows that protection zones are dependent on multiple parameters such as antenna patterns, elevation...
With the constant increase in wireless handheld devices and the prospect of billions of connected machines one of the problems for future mobile networks, usually overlooked by the research community, is that more connected devices require proportionally more signalling overhead. Particularly, acquiring users' channel state information is necessary in order for the base station to assign frequency...
Dense interference-limited wireless networks can rely coordinated multipoint transmission (such as Network MIMO) as a way to improve on spectral efficiency. Unfortunately, Network MIMO requires global channel state information (CSI) at all transmitters, hence places stringent requirements on backhaul rate and even more on latency. As a solution, this paper investigates an emerging design philosophy...
This paper analyzes two-tier heterogeneous cellular network with decoupled downlink and uplink access. The basic performance benefits of uplink/downlink decoupling have been recently introduced. Here we provide a more elaborate treatment of the decoupling mechanism by analyzing spectral and energy efficiency of the system, as the joint improvement of these two features is crucial for the upcoming...
Unlicensed LTE system holds high potential to effectively offload data traffic/video traffic from the crowded LTE networks. Listen-before-talk is generally necessary for unlicensed LTE to coexist with existing transmissions in the unlicensed band (e.g. wireless LAN). This paper studies the interaction of clear channel assessment (how hard one should listen before talk) and transmit power control (how...
Mobile operators are moving towards sharing network capacity in order to reduce capital and operational expenditures, while meeting the increasing demand for mobile broadband data services. Radio access network sharing is a promising technique that leads to reduced number of physical base station deployments (required for coverage enhancement), increased base station utilization, and reduced overall...
We study co-primary spectrum sharing concept in two small cell multiuser network. Downlink transmission is explored with Rayleigh fading in interfering broadcast channel. Both base stations and all the users are equipped with multiple antennas. Resource allocation with joint precoder and decoder design is proposed for weighted sum rate (WSR) maximization problem. The problem becomes mixed-integer...
To tackle the challenge of providing higher data rates within limited spectral resources we consider the case of multiple operators sharing a common pool of radio resources in the downlink. The goal is to maintain a long term fairness of spectrum sharing with a no coordination among small cell base stations. It is assumed that the spectral allocations of the small cells are orthogonal to the macro...
This document reviews the main design decisions that have been made for the physical layer design of the Device-to-Device (D2D) synchronization signals and channels as part of the 3GPP Release-12 specification work. The intention is to provide some context and background to the agreed design decisions because this rationale will not be described in the 3GPP specifications.
The use of the unlicensed spectrum by LTE networks (LTE-U or LAA-LTE) is being considered by mobile operators in order to satisfy increasing traffic demands and to make better use of the licensed spectrum. However, coexistence issues arise when LTE-U coverage overlaps with other technologies currently operating in unlicensed bands, in particular WiFi. Since LTE uses a TDMA/OFDMA scheduled approach,...
Future device to device communication using the LTE system bring new opportunities for application development. In the case of wireless sensor networks, unmanned aerial vehicles with LTE capabilities could be used to increase the network lifetime, while ensuring high transfer rates between LTE capable sensor nodes and the aerial vehicles. In this article we propose a hybrid heuristic algorithm able...
Mobile communications are increasingly contributing to the Internet traffic. Users move within cellular networks and generate traffics of different types. In this paper, we propose to categorize cellular base stations from multiple dimensions. Key social characteristics of the base stations are jointly considered, including traffic fluctuation, user non-determinacy, temporal homogeneity and usage...
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