## 5G Coverage problem

By: Alain Palmer, Karmoko Sillah, Liuming Chen, Masum Hossain

This project is about the researching solution for the 5G coverage problem. The problem of 5G is its short effective range of each base station and mmWave frequency that cannot penetrate objects. Our recommendations are Advanced Antenna System, Massive MIMO, Small cells, Beamforming as outdoor solutions; a new indoor network architecture as the indoor solution; MapReduce and 2400 MHz-3800 MHz Band for further improvement of the network.

Project deliverables:

## Liuming Chen’s 750-Word Expanded Definition of Algorithm

TO: Prof. Jason Ellis

FROM: Liuming Chen

Date: 10/15/2019

SUBJECT: Expanded Definition of Algorithm

## Introduction

The intention of this document is to explain a term thatâ€™s frequently being used in the professional field, especially in IT. The term is â€śalgorithmâ€ť. It is not a word thatâ€™s only being used by professionals. It appears in the news and social media increasingly in recent years. This document will discuss the definitions of the term â€śalgorithmâ€ť, talk about some of the context that the term is being used, and provide a working definition for it.

## Definitions

This term was originally borrowed from Latin. The etymon is algorithmus in Medieval Latin. There are three definitions provided by the Oxford English Dictionary for this term, and which we are going to discuss in the following.

The first definition defines algorithm as, â€śThe Arabic system of numbering, characterized by a zero (cf. algorism n. 1; now rare). Formerly also: â€ calculus (obsolete).â€ť (â€śalgorithmâ€ť, 2019). The term algorithm derived from algorism in Middle English and algorism is derived from algorithmus, which is the etymon that we just mentioned. Algorism has the same definition as algorithm. From the Journal of Account Research, Williard Stone explains, â€śAlgorism, the science of calculating by nine figures and zeroâ€ť. (Stone, 1972, p.347). Algorithm is just another name for the Arabic numerals that the world uses nowadays, but we donâ€™t call it algorism or algorithm anymore.

The second definition is related to Mathematics and Computing, â€śA procedure or set of rules used in calculation and problem-solving; (in later use spec.) a precisely defined set of mathematical or logical operations for the performance of a particular task.â€ť (â€śalgorithmâ€ť, 2019). Algorithms in Mathematics and Computing are being used to calculate something. Something can be anything in this case. If one wants to sort a list of data for readability, a sorting algorithm can be implemented to sort the data. The sorting algorithm will take the data from the user as input, process the data step by step and return a sorted list of data. Usually in IT, engineers and programmers pursue the most effectiveness and efficient algorithm that uses less computer power and faster computation time.

The third definition is related to Medicine, â€śA step-by-step protocol used to reach a clinical diagnosis or decision.â€ť (â€śalgorithmâ€ť, 2019). This is almost identical to algorithm in mathematics and computer. Both algorithms are approaches to result a solution for a problem. In the medical field, result of a medical algorithm can be a confirmed diagnosis, a treatment, or a prescription, etc.

## Context

This section will discuss some contexts that the term â€śalgorithmâ€ť is being used, and how does the term mean differently in these contexts.

In the article â€śAlgorithm for architectural origamiâ€ť, Jamie Paik talk about an algorithm in architecture, â€śOvervelde et al. report an algorithm that allows the rational design of reconfigurable prismatic architected materials and determines their modes of deformation.â€ť (Paik, 2017, p.296-297). In this context, the term algorithm can be interpreted as a solution to an architectural problem.

This context is quoted from a journal article in the military field. Discussing the genetic algorithm in Weapon-Target Allocation Problem by Wang et al., â€śCompared with air defense interception, ground targets are diverse and suitable for many weaponry types, so the scale and complexity of the WTA problem are greater, requiring the use of more efficient algorithms.â€ť(Wang et al., 2019). The â€śalgorithmâ€ť that was mentioned in the quote is a type of algorithms in computational mathematics call a genetic algorithm. It was inspired by evolutionary biology. The algorithm will have an enormous amount of candidate solutions that may take over a trillion years to find the best solution if the algorithm search solutions one by one. The genetic algorithm is designed to find the near-perfect solution by evolving the solution candidate. Time is massively reduced because the algorithm eliminates a lot of solution, just like biological evolution eliminated a countless amount of extinct species that didnâ€™t adapt the nature. In this case, the algorithm is being used for finding the most optimal way of allocating ground targets.

In an antidepressant management paper, Adam et al. describe an algorithm as following, â€śA treatment algorithm was developed that enables clinically supervised, nonphysician depression care managers (DCMs) to track and monitor antidepressant tolerability and treatment response while supporting nonpsychiatric prescribers with antidepressant choice and dosing.â€ť (Adam et al., 2012, p.647). This is a medical algorithm that was mention in the definition section. In this paper, the algorithm is used for antidepressant treatment and prescription.

Posted by a famous YouTube technology channel content creator, Austin Evans on Twitter, â€śI almost forgot what day it is thanks YouTube algorithm (With a screenshot of September by Earth, Wind & Fire music video)â€ť (austinnotduncan, 2019). The YouTube algorithm that Austin talked about is a server process of YouTube that tracked user activities. Then it uses the activity data of users to guess, or compute usersâ€™ interests and recommend videos that the user might like to watch. The algorithm learned Austinâ€™s interests and recommended the music video of September because it knows Austin would like to watch it on that day.

## Working Definition

In conclusion, the term algorithm is a set of procedures that can be performed step by step to result a solution to a problem. It is like a cooking recipe. Following the recipe step by step will cook a delicious dish. The term algorithm is being used more often in the IT field in the past half-century. Algorithms in IT are different types of procedures that are being written by programmers or engineers and will be performed by the computer. It can be mathematical calculations or logical operations. It’s usually effectiveness and efficient. Different algorithm meets different needs. Just like people love a particular dish, and they will need that specific recipe to cook their favorite dish.

## References

Adams, J. L., Gaynes, B. N., McGuinness, T., Modi, R., Willig, J., & Pence, B. W. (2012). Treating Depression Within the HIV â€śMedical Homeâ€ť: A Guided Algorithm for Antidepressant Management by HIV Clinicians. AIDS Patient Care & STDs, 26(11), 647â€“654. https://doi-org.citytech.ezproxy.cuny.edu/10.1089/apc.2012.0113

Duan, M., Yang, H., Wang, S., & Liu, Y. (2019). Self-adaptive dual-strategy differential evolution algorithm. PLoS ONE, 14(10), 1â€“25. https://doi-org.citytech.ezproxy.cuny.edu/10.1371/journal.pone.0222706

Stone, W. E. (1972). Abacists versus algorists. Journal of Accounting Research, 345-350.

Wang, C., Fu, G., Zhang, D., Wang, H., & Zhao, J. (2019). Genetic Algorithm-Based Variable Value Control Method for Solving the Ground Target Attacking Weapon-Target Allocation Problem. Mathematical Problems in Engineering, 1â€“9. https://doi-org.citytech.ezproxy.cuny.edu/10.1155/2019/6761073

## Liuming Chen’s 500-Word Article Summary

Wang et al. published an article about some of the key technologies of 5G cellular network in IEEE communications magazine, titled â€śCellular architecture and key technologies for 5G wireless communication networksâ€ť. Major technologies discussed in the articles include a new heterogeneous 5G cellular architecture, some key technologies that can be implemented into 5G to improve performance, and some future challenges.

The article proposes the next-generation wireless communication technology 5G needs to be constructed in a new type of heterogeneous cellular architecture to achieve maximum, seamless coverage and high mobility. The new architecture will be separate indoor and outdoor access point because of the short-range RF (Radio Frequency) spectra of 5G. Outdoor base stations will be equipped with large antenna arrays. These antennae will connect to wireless access point inside buildings for indoor users. This will solve the short-range and penetration loss through walls issue. Not just stationary wireless communication has issues that need to be addressed, high mobility wireless communication also. According to Wang et al., â€śHigh-speed trains can easily reach 350 up to 500km/h, while 4G networks can only support communication scenarios up to 250 km/hâ€ť (Wang et al., 2014, p.123). The MFemtocell (Mobile Femtocell) concept, which combines the concepts of mobile relay and femtocell, is proposed to accommodate high mobility uses such as users in vehicles and highspeed trains. Access points can be deployed inside highspeed transportation. Instead of communicating directly to outdoor base stations, devices will be connecting to access points inside of these highspeed transportations.

Some key technologies have mentioned in the article that can improve the performance and power efficiency of 5G system. They are the following. Massive MIMO (Multiple Input Multiple Output) systems, by adding more antennae to a MIMO system to increase performance, reliability, spectral efficiency, and energy efficiency. SM (Spatial Modulation), a MIMO technique for low-complexity implementation of MIMO system. It can mitigate interchannel interference, interantanna synchronization, and multiple RF chains in conventional MIMO systems. This technique can be used in MIMO system with any number of transmit and receive antennae, even unbalanced MIMO system. CR (Cognitive Radio) network, an innovative software technology to improve the utilization of the RF spectrum. A large portion of the radio spectrum is underutilized most of the time, a CR network can detect, share, and use these spectrums when the system is loaded. Another viable technique that helps mitigate spectrum bottlenecks in RF communication is VLC (Visible Light Communication), which uses LED light as a signal transmitter. It can be implemented using the current lighting infrastructures.

Many technologies have proposed and discussed in this article, but there are still many challenges needs to be addressed. Such as realistic channel models for 5G wireless systems, reducing signal processing complexity for Massive MIMO, interference management for CR networks, and more importantly, green communications. A tremendous amount of base stations will be deployed in the 5G era because of the short-range signal. Performance is admittedly important, but it also needs to be energy efficient to reduce CO2 emission.

Reference:

Wang, C. X., Haider, F., Gao, X., You, X. H., Yang, Y., Yuan, D., â€¦ & Hepsaydir, E. (2014). Cellular architecture and key technologies for 5G wireless communication networks. IEEE communications magazine, 52(2), 122-130.