The advent of fifth-generation (5G) systems and their mechanics have introduced an unconventional frequency spectrum of high bandwidth with most falling under the millimeter wave (mmWave) spectrum. The benefit of adopting these bands of the frequency spectrum is two-fold. First, most of these bands appear to be unutilized and they are free, thus suggesting the absence of interference from other technologies. Second, the availability of a larger bandwidth offers higher data rates for all users, as there are higher numbers of users who are connected in a small geographical area, which is also stated as the Internet of Things (IoT). Nevertheless, high-frequency band poses several challenges in terms of coverage area limitations, signal attenuation, path and penetration losses, as well as scattering. Additionally, mmWave signal bands are susceptible to blockage from buildings and other structures, particularly in higher-density urban areas. Identifying the channel performance at a given frequency is indeed necessary to optimize communication efficiency between the transmitter and receiver. Therefore, this paper investigated the potential ability of mmWave path loss models, such as floating intercept (FI) and close-in (CI), based on real measurements gathered from urban microcell outdoor environments at 38 GHz conducted at the Universiti Teknologi Malaysia (UTM), Kuala Lumpur campus. The measurement data were obtained by using a narrow band mmWave channel sounder equipped with a steerable direction horn antenna. It investigated the potential of the network for outdoor scenarios of line-of-sight (LOS) and non-line-of-sight (NLOS) with both schemes of co- (vertical-vertical) and cross (vertical-horizontal) polarization. The parameters were selected to reflect the performance and the variances with other schemes, such as average users cell throughput, throughput of users that are at cell-edges, fairness index, and spectral efficiency. The outcomes were examined for various antenna configurations as well as at different channel bandwidths to prove the enhancement of overall network performance. This work showed that the CI path loss model predicted greater network performance for the LOS condition, and also estimated significant outcomes for the NLOS environment. The outputs proved that the FI path loss model, particularly for V-V antenna polarization, gave system simulation results that were unsuitable for the NLOS scenario.

https://www.mdpi.com/2079-9292/8/5/495/pdf

Investigation of Future 5G-IoT Millimeter-Wave Network Performance at 38 GHz for Urban Microcell Outdoor Environment

With the advancement in technology, the network has also adapted itself to be in recent trends. Mobile Ad hoc Network or MANET is the technology which is a collection of mobile nodes (MN). These nodes are connected with each other for communication without any central administering node. MANET has many applications in different areas of technology like communication, in battlefields, etc. with this the challenges of MANET like load balancing, energy efficiency, packet loss, connection failure. Typical features of MANET routing is so complex that routing is more important for defining the performance of the network and its connectivity capacity. Mobile nodes are battery dependent and not easily rechargeable which makes the energy consumption as an important issue in MANET. This paper presents various techniques to solve the problem of energy efficiency and load balancing in MANET. A comparative analysis is also provided for summarizing the survey.

Energy Efficiency and Load Balancing in MANET: A Survey

Mobile Ad Hoc Network (MANET) is a group of mobile nodes that are capable of forming a network without the need of any administrator. Nodes in such a network are battery operated and are self organized and maintained. Energy consumption is considered as a major challenging task in MANETs. In general nodes choose shortest path to transmit the packets. Using single path to transmit packets might lead to congestion, energy depletion and network failure. Instead, identifying multiple paths and transmitting packets through available multiple paths ensure reliable communication, efficient load balancing and reduces energy consumption. An Energy Efficient Load Balancing approach for multipath AOMDV protocol (EELB-AOMDV) is proposed in this paper. NS 2.35 simulator is used and the results are compared with latest multipath routing protocols. Results show that, EELB-AOMDV achieves an improvement of upto 33%, 48% and 34% in packet delivery ratio and upto 78%, 84% and 80% in end to end delay compared to FF-AOMDV, AOMDV and AOMR-LM protocols respectively. In addition, simulation is carried out with standard AOMDV protocol and the results are compared with EELB-AOMDV protocol. Results show that the protocol outperforms standard AOMDV with an improvement of 11.11% in packet delivery ratio. End to end delay, energy consumption and routing overhead are decreased upto 63.35%, 43.95% and 3.66% respectively compared to standard AOMDV protocol.

Energy Efficient Load Balancing Approach for Multipath Routing Protocol in Ad Hoc Networks

BladderWorts Suction (BWS) Algorithm is proposed in this article, which is a novel Plant intelligence inspired meta-heuristic non-swarm algorithm. The concept of non-swarm intelligence is focused in this paper because of the autonomous behavior of the individuals. In the swarm intelligence algorithms, the individuals are influenced by the global knowledge. Sometimes, the small change by an individual may result in group level behavior. The core inspiration for this non-swarm optimization algorithm is the foraging suction mechanism of the aquatic plant Utricularia (Bladderworts). The worst bladders are regenerated periodically to accelerate the solution search of the stagnant bladders at local optima. It is tested with different benchmark test functions. The optimizing tendency of this algorithm is studied empirically, which yields good results. Comparatively, BWS algorithm also produces positive insights like various other popular optimization techniques.

Non-Swarm Plant Intelligence Algorithm: BladderWorts Suction (BWS) Algorithm

A channel state information (CSI) feedback algorithm based on scalar quantization is proposed for a multiple-input multiple-output (MIMO) transmission. The performance of the proposed algorithm is evaluated using the effective transmission rate, which incorporates the effect of the CSI feedback overhead on transmission time. Besides that, the power consumed due to the computational complexity of the CSI feedback algorithm is taken into account together with the transmit power when evaluating the energy efficiency. We compare our proposed algorithm to other typical CSI feedback algorithms under correlated channel conditions. Simulation results show that the proposed algorithm enables practical MIMO transmission to achieve an relative transmission rate at 95% of the ideal rate.

On the Efficiency of MIMO Transmission with Channel State Information Feedback

By the virtue of the large number of antennas, the massive Multiple Input Multiple Output (MIMO) systems grant high spectral efficiency along with the promising gain in capacity. For the optimal detection of system parameters, generally perfect Channel State Information (CSI) is assumed to be known at both transmitter and receiver. However, in practice, due to mobility of communication environment, the impulse response of the channel varies, thus inducing the need of channel estimation. In addition, a permanent feedback signalling is required to notify the estimated CSI at the transmitter. Large number of time slots are engaged during the feedback, thus reducing the bandwidth efficiency of the system. This paper deals with reduction of feedback overhead by using Arithmetic coding for the estimated channel in the massive MIMO systems. Block type pilot estimation technique has been considered for the channel estimation.

Channel State Information feedback overhead reduction using Arithmetic coding in massive MIMO systems

Development of an efficient energy-aware routing protocol is the need of today's MANETs (Mobile Adhoc Networks). A lot of research has been devoted to develop energy-aware routing protocols. In this paper we have combined a few existing methods along with some new changes and reviewed the response of two popular on-demand routing protocols “Dynamic Source Routing (DSR)” and “Ad-hoc On-Demand Distance Vector (AODV)”. We rely on network simulator ns-2.35 for our simulation and results. The results reveal that modified protocols produce better results in all aspects of network parameters.

Shivika Pathania

Papers

Channel State Information feedback overhead reduction using Arithmetic coding in massive MIMO systems

Energy efficient path selection in MANET