Multi-agent exploration of unknown environments with limited communication is a rapidly emerging area of research with applications including surveying and robotic rescue. Quantifying different approaches is tricky, with different schemes favouring one parameter of the exploration, such as the total time of exploring 90% of the environment, at the expense of another parameter, like the rate of ...

This paper proposes a centralized algorithm for cluster-head-selection in a mobile wireless sensor network. Before execution of algorithm in each round, Base station runs centralized localization algorithm whereby sensors update their locations to base station and accordingly Base station performs dynamic clustering. Afterwards Base station runs CA-MWSN for cluster-head-selection. The proposed ...

An ad-hoc wireless sensor network is also called self-organized networking that wireless sensor nodes can automatically communicate for each other. Therefore, each sensor node is no need for the information such as location of each sensor. Similarly, it consumes much energy on the information exchanged of each sensor node in order to maintain the entire ad-hoc wireless sensor network alive. The...

—In order to achieve high spectral efficiency with improved peak data rates of cell-edge uses and enable an enhanced network coverage with good throughput both in downlink and uplink, LTE-Advanced proposes separately base station coordination and relaying techniques. In the purpose to increase the cell-edge user data rates beyond what can be reached by using either one of the techniques alone, ...

The multiuser detection problem applies when we are sending data on the uplink channel from a handset to a base station. The base station must demodulate and decode signals from K−1 interfering handsets. A related problem known as interference cancellation arises on the down-link channel from the base station to the handset in which the handset must separate the signal intended for it, from the...

Security is a very important issue when designing or deploying any network or protocol. The nature of large, ad-hoc, wireless sensor networks presents significant challenges in designing security schemes. One or several sensors then collect the detection results from other sensors. The collected data must be processed by the sensor to reduce the transmission burden before they are transmitted t...

In this paper we consider massive MIMO Multi-cell TDD systems. In order to eliminate the effect of pilot contamination, a new scheme is proposed. In the same cell all transmitted signals from base station or user are multiplied same precoding sequences. The precoding sequences are orthogonal for different cell. The received signals at base station or terminals are multiplied the conjugate trans...

The aim of this paper is to study the impact of the base station site locations and antenna orientations on UMTS radio network performance under different traffic distributions, and to find an optimum deployment strategy from 3-sectored to 6-sectored site solutions. A radio network planning tool has been used to verify the radio network system performance of different network scenarios. The res...

We consider a packet switched wireless network in which a base station serves the mobiles. The packets for the mobiles arrive at the base station and have to be scheduled for transmission to the mobiles. The capacity of the channel from the base station to the mobiles is varying with time due to fading. We assume the mobiles can obtain different types of service based on the prices they are wil...

We proposed an authentication mechanism in the wireless sensor network. Sensor network uses the Kerberos authentication scheme for the authentication of bases station in the network. Kerberos provides a centralized authentication server whose function is to authenticate user by providing him the ticket to grant request to the base station. In this paper we have provided architecture for the aut...