Handover for 5G Networks using Fuzzy Logic: A Review

— The future organization world will be inserted with various ages of remote advances, like 4G and 5G. Simultaneously, the advancement of new gadgets outfitted with different interfaces is filling quickly as of late. As a result, the upward handover convention is created to give pervasive availability in the heterogeneous remote climate. Handover might be a fundamental a piece of any remote Mobile Communication Network. It is a way of mobile communication and portable communication during which cellular broadcast is relocate from one base station to another without losing connection to the mobile communication. Handover is one problem on Wireless Network (WN) and to unravel this problem various sorts of HO methods utilized in network. Fuzzy logic, Machine Learning and Optimization are the handover solving methods that are studied during this paper. This paper is a review of the handoff techniques. Fuzzy logic is that the best technique to unravel the HO problem and it's further implemented in 4G/5G network.


I. INTRODUCTION
The utilization of versatile Internet has been unequivocally expanded over late years because of two significant variables. The principal factor is that the versatile media communications industry has grown new remote correspondence advancements, like 4G (fourth era) and 5G (fifth era). The subsequent one is that the versatile media communications industry has grown new portable terminals outfitted with different interfaces. The conjunction of different passages driven by various frameworks fabricates a Heterogeneous Wireless Networks Environment (HWNE). In this HWNE, 3G organizations and 4G organizations have been broadly embraced by various portable clients to run various types of sight and sound applications, like online media, versatile TV, video web based, and so on, and they are constantly advancing to guarantee the necessities of things to come Internet of numerous applications, for example, Internet of Vehicles (IoV), Wireless Sensor Networks (WSN), Internet of Energy (IoE) and Internet of Things (IoT), while 5G organizations are relied upon to arrive at the market by 2020 [1]. Additionally, each radio access organization can give an alternate information rate and can guarantee an alternate inclusion region with an alternate portability.

II. PROBLEMS IN WIRELSS NETWORK
Remote organizations have amazing potential since they will grow our ability to watch and relate with genuine world. These can accumulate gigantic measures ofobscure in data. These are frequently access distantly and put where it's illogical to send information and electrical cables to exploit the total organizations. Remote Networks to develop ubiquitous, various debate and impediment ought to survive. • Energy: The essential and at times most crucial plan challenge for a remote organization is energy effectiveness. Force utilization is frequently distributed to 3 utilitarian areas: detecting, correspondence, and preparing, every one of which needs streamlining. The hub lifetime ordinarily displays a powerful reliance on battery life. The limitation most often identified with network configuration is that hubs work with restricted energy financial plans. For non-battery-powered batteries, a hub should be prepared to measure until its functional time is going or the batteries are regularly supplanted. • Handover in WN: Handover is another issue happened in remote organization. Handover might be characterized as a manner by which portable correspondence move information and data starting with one base station then onto the next without losing association with the cell organization. Handover might be a focal part in sending versatile transmission since it makes information meetings or associates calls between cell phones which are continually progressing.

III. HANDOVER
A handover is a strategy where portable organization move the information and data structure one organization zone to another organization zone without upsetting the meeting. Cell administrations are upheld portability and handover, permitting the client to be moved from one zone territory to an alternate or to be changed to the nearest cell site for better execution. It permits clients to make information meetings or associate calls moving. This cycle keeps the calls and information meetings associated however a client moves from one zone to an alternate. There are two kinds of handovers: 1. Hard Handover: A moment handover during which the current association is ended and accordingly the association objective channel is shaped. It's additionally alluded to as a break before make handover. The strategy is momentary to the point that the client doesn't hear any recognizable interference.

Soft Handover:
A significant handover where the connection with new channel is framed before the relationship from base channel is disengaged. It's executed through the equal utilization of source and sink interface throughout a time of your time. Delicate handovers license equal correspondence between different channels to supply better assistance. This kind of handover is incredibly successful in helpless inclusion regions. 3. Softer Handover: Softer handover might be a nostalgic handover where the telecom stations are added and taken out. In gentler Handover, the hub can get signals in large scale range with most extreme proportion consolidating. In delicate handover full scale variety with determination consolidating is picked.

IV. METHODS OF HANDOVER 1. Machine learning:
AI is a proficient more current innovation which makes handover utilizing programmed expectation and anticipating. It's a relatively new discipline inside registering that gives assortment of information strategies. AI is a world discussion for research on computational methodologies. Here various calculations were applied for different purposes like grouping and anticipating application. The different explores research correlation utilizing AI strategies are as below: Accumulated reward at α = 0.9, γ = 0.5, and ɛ = 0.9 A notable contribution to determine the optimal route of drones for researchers who are exploring UAV use cases in cellular networks where a large testing site comprised of several cells with multiple UAVs is under consideration.

Discussion:
In the above table different researcher's research work is studied along with different techniques used in that work. The problems faced by the researcher are also explained. The results are evaluated with different optimization techniques. In this table, most of the researchers faced the handover problem in their research work. All the handover failure problems are resolved with optimization approach and different results are produced.

Fuzzy logic :
The fuzzy systems related to advances of 5G networks (Fifth Generation Mobile Networks).The research and development of the fuzzy systems applied to telecommunications, specifically 5G technologies. The review of researchers on fuzzy logic in 5G network is as below:-

S.No .
Author Name Technique Used Problems Parameter Results The results are evaluated with fuzzy logic and fuzzy logic techniques. In this table most of the researchers faced the handover and ping-pong problem in their research work. All the problems are resolved with fuzzy logic and different results are produced.

V. CONCLUSION AND FUTURE WORK
Handover is the procedure in cellular communication for transferred data from one BS to another without losing the connection. During this paper the prevailing techniques of handover is studied and different problems are identified with literature review. It's found that the increasing probability of HOs may cause HO failure (HOF) or HO Ping-Pong (HOPP) which degrades the system performance. The author widely study that if Mobile Station moves faraway from Base Terminal Station, signal gets weaker after reaching a particular threshold, control of that decision is transferred to a different base station with strong signal. During this paper machine learning, optimization and symbolic logic based research papers are studied and supported these techniques fuzzy logic is best method to resolve the various problems. It's implementing in future work.