37 research outputs found
A Centralized SDN Architecture for the 5G Cellular Network
In order to meet the increasing demands of high data rate and low latency
cellular broadband applications, plans are underway to roll out the Fifth
Generation (5G) cellular wireless system by the year 2020. This paper proposes
a novel method for adapting the Third Generation Partnership Project (3GPP)'s
5G architecture to the principles of Software Defined Networking (SDN). We
propose to have centralized network functions in the 5G network core to control
the network, end-to-end. This is achieved by relocating the control
functionality present in the 5G Radio Access Network (RAN) to the network core,
resulting in the conversion of the base station known as the gNB into a pure
data plane node. This brings about a significant reduction in signaling costs
between the RAN and the core network. It also results in improved system
performance. The merits of our proposal have been illustrated by evaluating the
Key Performance Indicators (KPIs) of the 5G network, such as network attach
(registration) time and handover time. We have also demonstrated improvements
in attach time and system throughput due to the use of centralized algorithms
for mobility management with the help of ns-3 simulations
Model of expatriate adjustment and framework for organisational support
Increasing globalisation of workforce has resulted into a large population of expatriate workers who engage in temporary work outside their home country. Along with monetary benefits, expatriate assignment is closely associated with a number of challenges which influence adjustment of an expatriate in a foreign country. This paper presents an expatriate adjustment model derived from review of research papers published on expatriate adjustment in the last two decades. Later section of this paper presents major internal and external expatriate support factors. The paper concludes with suggestion of a multilevel action plan at organisational level to support expatriate adjustment
An Opportunistic-Non Orthogonal Multiple Access based Cooperative Relaying system over Rician Fading Channels
Non-orthogonal Multiple Access (NOMA) has become a salient technology for
improving the spectral efficiency of the next generation 5G wireless
communication networks. In this paper, the achievable average rate of an
Opportunistic Non-Orthogonal Multiple Access (O-NOMA) based Cooperative
Relaying System (CRS) is studied under Rician fading channels with Channel
State Information (CSI) available at the source terminal. Based on CSI, for
opportunistic transmission, the source immediately chooses either the direct
transmission or the cooperative NOMA transmission using the relay, which can
provide better achievable average rate performance than the existing
Conventional-NOMA (C-NOMA) based CRS with no CSI at the source node.
Furthermore, a mathematical expression is also derived for the achievable
average rate and the results are compared with C-NOMA based CRS with no CSI at
the transmitter end, over a range of increasing power allocation coefficients,
transmit Signal-to-Noise Ratios (SNRs) and average channel powers. Numerical
results show that the CRS using O-NOMA with CSI achieves better spectral
efficiency in terms of the achievable average rate than the Conventional-NOMA
based CRS without CSI. To check the consistency of the derived analytical
results, Monte Carlo simulations are performed which verify that the results
are consistent and matched well with the simulation results.Comment: arXiv admin note: substantial text overlap with arXiv:1709.0822
Performance analysis of FSO using relays and spatial diversity under log-normal fading channel
The performance analysis of free space optical communication (FSO) system
using relays and spatial diversity at the source is studied in this paper. The
effect of atmospheric turbulence and attenuation, caused by different weather
conditions and geometric losses, has also been considered for analysis. The
exact closed-form expressions are presented for bit error rate (BER) of M-ary
quadrature amplitude modulation (M-QAM) technique for multi-hop multiple-input
single-output (MISO) FSO system under log-normal fading channel. Furthermore,
the link performance of multi-hop MISO and multi-hop single-input and
single-output (SISO) FSO systems are compared to the different systems using
on-off keying (OOK), repetition codes (RCs) and M-ary pulse amplitude
modulation (M-PAM) techniques. A significant performance enhancement in terms
of BER analysis and SNR gains is shown for multi-hop MISO and multi-hop SISO
FSO systems with M-QAM over other existing systems with different modulation
schemes. Moreover, Monte-Carlo simulations are used to validate the accuracy
and consistency of the derived analytical results. Numerical results show that
M-QAM modulated multi-hop MISO and multi-hop SISO FSO system with relays and
spatial diversity outperforms other systems while having the same spectral
efficiency of each system.Comment: 4 pages, 4 figures, 4th International Conference on Electrical Energy
Systems (ICEES), Feb. 7-9, 2018, SSNCE, Chennai, TN, INDI