Due to the emergence of the Internet of Things, the need for effective identification and traceability has increased. Radio-frequency identification (RFID), a simple and cheap approach for gathering information, has therefore drawn the attention of research communities. However, this system suffers from problems caused by high density, such as collisions and duplication. Thus, the deployment of RFID is more effective in a dense environment where it may improve overage and delays. A wide range of solutions have been proposed; however, the majority of these are based on the application context. In this paper, we propose a general MAC layer protocol FTSMAC (Frequency Time Scheme MAC) in which the spectrum frequency is efficiently used by dividing the signal into different time slots via a messaging mechanism used by RFID readers. This limits the collisions in high-density RFID deployment that affect the performance of the system. Thus, our solution allows the communication system to converge to a stable state within a convenient time.

The unexpected change in user equipment (UE) velocity is recognized as the primary explanation for poor handover quality. In order to resolve this issue, while limiting ping-pong (PP) events we carefully and dynamically optimized handover parameters for each UE unit according to its velocity and the coverage area of the access point (AP). In order to recognize any variations in velocity, we applied Allan variance (AVAR) to the received signal strength (RSS) from the serving AP. To assess our approach, it was essential to configure a heterogeneous network context (LTE-WiFi) and interconnect Media-Independent Handover (MIH) and Proxy Mobile IPv6 (PMIPv6) for seamless handover. Reproduction demonstrated that our approach does not only result in a gain in relatively accurate velocity but in addition reduces the number of PP and handover failures (HOFs).

We consider the user equipment (UE) velocity as a vital trend in association problem in heterogeneous networks (HetNets), since there is a considerable relation between the velocity and the handover failure (HOF) as well as the probability of unnecessary handovers (ping-pong (PP) events). Several works have been carried out, in the context of standards and scientific research to perform the vertical handover process, such as the IEEE 802.21 Media Independent Handover(MIH) framework and Network Mobility Basic Support Protocol as a proxy mobile internet protocol version 6 (PMIPV6). Therefore, in our paper, we found that interconnecting those two frameworks will be effective in terms of handover decision-making. In addition, to solve the impact of velocity in handover process, we need to carefully and dynamically optimize handover parameters for each UE according to his velocity and coverage area of the access point (AP). To detect any variation in the velocity and evaluate if a transfer is necessary: MIH will study periodically the Allan Variance (AVAR) of received signal strength (RSS) from the serving AP and PMIPv6 will take over the control and execute the handover based on the results obtained by MIH. To evaluate our contribution, it was necessary to configure a heterogeneous network environment (LTE-WIFI) and to integrate MIH PMIPv6 for seamless handover. Simulation results show that it can not only gain relatively accurate velocity, but also reduces the number of PP and HOF.

One of the biggest challenges of Next-generation wireless network (4G) is to integrate different wireless access technologies, each with its own characteristics, into a common IP-based core network to provide mobile user with service continuity and seamless roaming. Nowadays there are different wireless access technologies allowing users to stay “always on”, of which one of the most important is WiFi because of the range of its utilization (used in standard personal devices, like laptop, mobile devices...) to connect to the Internet. But its range is very limited, contrary to WiMax, who is a relatively new but very promising standard for wireless communication because it provides the speed of WiFi and the coverage of UMTS (Universal Mobile Telecommunications System). Hence it is natural to combine WiMax and WiFi and create a better wireless solution to provide high speed Internet for mobile users. Currently, the mobility of a terminal is a requirement of great importance, supported by a procedure known as handover. One of the major issues for the converged heterogeneous networks is providing a seamless handover with QoS support.

In this paper, we address the problem of cell association during a handover performed in a dense heterogeneous network, where the preference of a mobile user’s equipment in terms of uplink traffic is not the same as for the downlink traffic. Therefore, since mobility is an intrinsic element of cellular networks, designing a handover from the perspective of the uplink and downlink is mandatory in the context of 5G cellular networks. Based on this arena, we propose a decoupled uplink-downlink handover scheme while making use of femtocells in order to maximize the overall network entity utilities and avoid overloading macrocells. However, the fact that the handover process is performed in a dense heterogeneous network makes the issue NP-hard. Therefore, taking into account the need for self-organizing solutions, we modeled the handover process as a matching game with externalities. Thus, we will provide an aspect of intelligence for the execution of the handover process to mobile user’s equipment (UE). To make the proposition more efficient, we integrate an assignment step to assist the matching game. Hence, the base stations will be investigated and filtered, keeping only the helpful base stations as the players in terms of the quality of service for the uplink and downlink. The numerical results verify the superiority of the proposed context-aware algorithm over traditional downlink handover and traditional decoupled uplink and downlink handover schemes, by improving the load balancing, increasing rates and reducing delays.