# A Fuzzy Based Handover Decision Scheme for Mobile Devices Using Predictive Model
## 1 Introduction
The prediction of handover for triggering a link is very important for coherent mobility; because previously, when the link layer predicts WLAN signal loss and when the 3G network connection was made before the link interruption, the break time of the link was reduced and services were continued with no disruption. In a wireless network, there are two forms of handover: horizontal handover and vertical handover. Horizontal handover is a handover process (within the device handover) that happens between the same network's access points and base stations. It occurs between the homogeneous cells of a wireless access system at the end of the day. Vertical handover (outside framework handover) is characterized as a handover instrument that happens between the various purposes of connection of various networks. In any case, it might influence the connection, network and transport layers [11]. The three phases of the vertical handover process are network exploration, handover judgement and handover execution. During the handover decision stage, access focuses can choose when to play out the vertical handover, and it can locate the best handover competitor access network. Contingent upon serving of base station, the handover is grouped into soft and hard handover. Hard handover implies that all old radio connections are ended before setting up new radio connections. Hard handover can be either coherent or non-coherent. Coherent hard handover isn't noticeable to the client and requires a difference in the bearer frequency (between frequency handover) [12], whereas in soft handover, radio links are joined and removed in a radio link and this is performed with the help of macro diversity when several radio links are active concurrently. If the cells operating in the same frequency change, soft handover can be preferred. Requirements of handover mechanisms are network cost, handover latency, energy consumption, velocity, bandwidth, network throughput, load-balancing, security, received signal strength, etc. [12]. However, handover management in a 3G network has several challenges. The vertical handover among different wireless communication systems is very hard to understand while satisfying QoS requirements. The major challenge of handover with high user mobility is call dropping, which occurs due to frequent handover, and the resources are not available in the target base station [13]. If handover latency is long, the packets could be disconnected or lost during the handover [14]. Mobility Rate: The important criterion to be considered in research on the mobility of wireless networks is mobility rate. Many UEs may have different speeds and have different effects on the received signal strength during UE mobility, which may have different effects on the stability of the communication. The maximum user speeds supported by wireless communications systems with mobility capabilities vary. For example, 4G in, the maximum supported speed per hour 350 km [15] It was the case, the 5G cellular system per hour 500 km can support up to [16]. As the maximum speed increases, not only the required transfer process, but also the decision making of high-speed transfer becomes an essential requirement.