Handover Blocking Probability Research Articles

Tunnel-Free Distributed Mobility Management (DMM) Support Protocol for Future Mobile Networks

The number of wireless services and devices have remarkably increased, especially since the introduction of smart phones. The population of mobile nodes (MNs) is now exceeding the traditional non-mobile nodes. Mobility is a key factor in mobile core networks as it is responsible for providing continuous communication when a MN is on the move. Currently, a centralized mobile core network architecture is implemented, which has certain limitations. Distributed mobility management (DMM) is often seen as a solution to the problems associated with centralized mobility management (CMM). Address and tunneling management are big challenges for current DMM-based mobility protocols. Keeping in mind the current advancement of mobile network architecture, this paper proposes a novel tunnel-free distributed mobility management support protocol intended for such an evolution. In addition, the performance of the existing DMM IPv6 mobility management protocols in the context of handover latency, handover blocking probability, and data packet loss is analyzed and compared to the proposed framework. The performance analyses show that the proposed tunnel-free method can reduce about 12% of handover latency, 71% of handover blocking probability, and 82% of data packet loss.

SDN-based handover scheme for multi-tier LTE/Femto and D2D networks

Femto Access Points (FAP) and Device-to-Device (D2D) communications have recently been considered as potential candidates for 5G network densification and cell-edge performance. Mobility and handover management is a major issue in heterogeneous networks (HetNet) offering different access technologies. Recently, many Fuzzy and Multi-Attribute Decision Making (MADM) handover decision algorithms have been proposed to ensure Quality of Service (QoS), reduce the number of handovers and handover blocking probability of mobile users. However, network discovery is still an issue as it increases the total handover delay and drains the battery of the user equipment (UE). In addition, the UE may undergo high interference with other co-channel users after the handover is executed, thus limiting the overall network performance. Currently, the emerging Software Defined Networking (SDN) has been proposed in which one centralized controller can assist in the handover discovery, handover decision, and co-channel interference coordination. SDN-based handover algorithms ensure QoS, Quality of Experience (QoE), reduce delay and interference. In this paper, we will integrate the Fuzzy logic into the SDN to assist in FAPs and D2D discovery, and the decision of candidate networks based on the networks’ QoS parameters. Then, the UE will make the final handover decision by selecting the best network based on the predicted QoE using TOPSIS and AHP algorithms. Frequency reuse and appropriate power control are also applied in order to increase network capacity and reduce interference. Performance results show that the proposed SDN-based Fuzzy MADM handover scheme reduces unnecessary handovers, blocking probability and total handover delay. In addition, throughput is increased as the number of users increases.

Effective management of handover process in mobile communication network

This paper presents the effective management of handover process in mobile communication networks, aims to determine effective utilization of signaling channels in mobile communication network to avoid incessant of handover drop calls in the mobile network. Data were obtained from the Operation and Maintenance Centre (OMC). Analytical method known as Markovian chain analysis of continuous time and discrete space was used in the modeling, of handover blocking probability in mobile communication network. In addition, it was validated using MATLAB software. The causes of handover calls failure were analysis in network B. It was observed that handover blocking probability increases as the number of offered traf?ic load in erlang increases with a given number of transmission channels (V+g). Handover call blocking probability traf?ic model performance of the system is function of offered traf?ic in erlang and number of transmission channels (Pb = f(A,(V+g)). The handover blocking probability decreases, as both number of transmission channels (V+g) and traf?ic load in erlang increase. In order, to obtain satisfactory handover blocking probability the number of channels must be increased in proportion to offered traf?ic load in erlang

A Resource Allocation Scheme of Low-Earth Orbit Satellite System Based on the Traffic Modelling

Traffic modelling is the foundation of satellite resource management. Considering the uneven traffic distribution in China, a traffic model of low-earth orbit satellite is established in this study according to the per-capita GDP and the density of population. Base on this model, a new dynamic channel allocation and reservation (DCAR) technique is proposed. The performance of the call blocking probability, the handoff blocking probability and the channel utilisation is evaluated by simulation. Different from the fixed channel allocation, DCAR implements channel allocation by estimating the traffic conditions of all spot beams. The simulation results show that DCAR achieves a significant improvement on call blocking probability and handover blocking probability, particularly under heavy traffic load.

Regular User Priority Scheme for Performance Improvement in 4G Network

Wireless network are growing rapidly, leading to overloaded systems, unacceptable delays and increasing computational costs due to inefficient channel allocation strategy. Handoff call is more important over new call so it must provide some priority; this is the prime objective of all channel allocation strategy. In this paper we propose regular users priority scheme to better utilization of channel and reduce handover blocking probability. We have analyzed a particular path for several users and assign a symbol for regular, medium and normal users. These symbols are also inserted with other related information of user in HLR. Some channels are reserve for regular and medium users over normal users. Strategy of channel reservation schemes provides priority to regular and medium user over normal user. The aim of proposed scheme will use to increase user loyalty by reducing handover blocking probability. Now-a-days it is important not only to acquire new mobile users for mobile companies but also retain them. We can retain mobile users by providing them good channel facility as described in proposed scheme.

Spectrum Pooling-Based Vertical Handover for Heterogeneous Cognitive Radio Networks with QoS Constrains

Vertical handover, which often occurs in wireless mobile communication, is very important for heterogeneous wireless networks based on the cognitive radio (CR). However, a major issue is how to control vertical handover for secondary user without interfering primary user while achieving the desired quality of service (QoS) and eliminating the influence caused by hidden channel and exposed channel, simultaneously. To address this issue, this paper proposes a flexible vertical channel handover algorithm for heterogeneous cognitive radio networks. This algorithm is very flexible and effective. It can adaptively schedule channel sensing by utilizing the concept of spectrum pooling. The key QoS parameter adopted in this algorithm is channel bandwidth which denotes the heterogeneity of the networks. We evaluate the major performance metrics such as handover blocking probability, hand over cost and collision probability by simulation. The results indicate the proposed algorithm can significantly improve the performance and provide stable communication in the synchronous and asynchronous CR networks.

A preemptive dynamic bandwidth reallocation algorithm for group handover in IEEE 802.16j-enabled vehicular networks

Current researches on vehicular networks usually assume one hop between roadside infrastructure such as a base station (BS) and a vehicle. Less research has concerned about a common scenario where there is another layer of nodes between a BS and a vehicle, i.e., a mobile relay station (MRS). This paper proposes to utilise IEEE 802.16j as an enabling technology, which supports multi-hop relaying services, to implement a vehicular network with particular focus on group handover (GHO), i.e., a group of MS is handed over to a new BS at the same time. A preemptive dynamic bandwidth reallocation algorithm that is able to borrow subchannels from other services is proposed for GHO. A Markov chain model is devised to evaluate the overall performance of the algorithm. The evaluation results have shown that the proposed algorithm leads to lower handover blocking probability and less latency than multiple single handovers.

광대역 통합 망에서 이동단말의 핸드오버 가용성 향상을 위한 방안

We propose the scheme that supports continuously service when a user tries to contact new target network in broadband convergence network even though the network resource for the service is not enough. The proposed scheme transforms original service capacity into suitable QoS for the target network using the scalable service techniques in the oncoding/decoding and supports handover for the user. We analyzed the handover blocking probability of two schemes using queueing system to show the improvement of performance by the proposed scheme. Subsequently, we showed that the handover blocking probability in the proposed scheme is lower than that in the existing scheme.

A flexible UMTS/WLAN architecture for improved network performance

Current trends in cellular telecommunications suggest the incorporation of Wireless Local Area Networks (WLANs) as supplementary access technologies into the existing cellular infrastructure. Overlay network architectures are expected to improve both service provision and resource utilization under the condition that sophisticated architectural options are followed. Many proposals suggest that all active connections be handled through the same access network technology. However, this is not believed to be efficient in a heterogeneous environment. Therefore, a mechanism that allows each connection of a terminal to be served by different radio access technology is introduced. Based on a tight coupling architecture for interworking between Universal Mobile Telecommunications System (UMTS) and WLANs, the proposed scheme combines a sophisticated decision mechanism with flexible connection management in a way that ensures seamless service continuity during handover. The performance of the system is evaluated using a detailed simulation model and compared against existing architectures. Simulation results indicate an improvement in parameters such as connection and handover blocking probabilities, which justifies the enhancement in the overall usage of network resources when connections are handled separately.

Satellite mobility pattern scheme for centrical and seamless handover management in LEO satellite networks

Since low earth orbit (LEO) satellite constellations have important advantages over geosynchronous earth orbit (GEO) systems such as low propagation delay, low power requirements, and more efficient spectrum allocation due to frequency reuse between satellites and spotbeams, they are considered to be used to complement the existing terrestrial fixed and wireless networks in the evolving global mobile network. However, one of the major problems with LEO satellites is their higher speed relative to the terrestrial mobile terminals, which move at lower speeds but at more random directions. Therefore, handover management in LEO satellite networks becomes a very challenging task for supporting global mobile communication. Efficient and accurate methods are needed for LEO satellite handovers between the moving footprints. In this paper, we propose a new seamless handover management scheme for LEO satellites (SeaHO-LEO), which utilizes the handover management schemes aiming at decreasing latency, data loss, and handover blocking probability. We also present another interesting handover management model called satellite mobility pattern based handover management in LEO satellites (PatHO-LEO) which takes mobility pattern of both satellites and mobile terminals into account to minimize the handover messaging traffic. This is achieved by the newly introduced billboard manager which is used for location updates of mobile users and satellites. The billboard manager makes the proposed handover model much more flexible and easier than the current solutions, since it is a central server and supports the management of the whole system. To show the performance of the proposed algorithms, we run an extensive set of simulations both for the proposed algorithms and well known handover management methods as a baseline model. The simulation results show that the proposed algorithms are very promising for seamless handover in LEO satellites.

Performance evaluation of product form cellular mobile communications networks

This paper proposes and analyzes a queueing network model of a cellular mobile communications network including the multiway connection. This model is formulated as a queueing network with multiple call classes and state-dependent transition rates. As the performance measure a handover blocking probability is evaluated based on the product form equilibrium distribution and the constraint matrix whose elements consist of the mean arrival and service rates for individual cells. As a numerical example, an eight-cell cellular system is considered and blocking probabilities for a two-way handover between neighbouring cells are calculated for several network loads and constraint matrices. Since results represent the characteristics depending on individual cells or neighbouring cells, it can be emphasized that this model is useful for the control of QoS taking account of the spatial traffic.

Transient handover blocking probabilities in road covering cellular mobile networks

This paper investigates handover and fresh call blocking probabilities for subscribers moving along a road in a traffic jam passing through consecutive cells of a wireless network. It is observed and theoretically motivated that the handover blocking probabilities show a sharp peak in the initial part of a traffic jam roughly at the moment when the traffic jam starts covering a new cell. The theoretical motivation relates handover blocking probabilities to blocking probabilities in the M/D/C/C queue with time-varying arrival rates. We provide a numerically efficient recursion for these blocking probabilities.

A new connection admission control for spotbeam handover in LEO satellite networks

Frequent spotbeam handovers in low earth orbit (LEO) satellite networks require a technique to decrease the handover blocking probabilities. A large variety of schemes have been proposed to achieve this goal in terrestrial mobile cellular networks. Most of them focus on the notion of prioritized channel allocation algorithms. However, these schemes cannot provide the connection-level quality of service (QoS) guarantees. Due to the scarcity of resources in LEO satellite networks, a connection admission control (CAC) technique becomes important to achieve this connection-level QoS for the spotbeam handovers. In this paper, a geographical connection admission control (GCAC) algorithm is introduced, which estimates the future handover blocking performance of a new call attempt based on the user location database, in order to decrease the handover blocking. Also, for its channel allocation scheme, an adaptive dynamic channel allocation (ADCA) scheme is introduced. By simulation, it is shown that the proposed GCAC with ADCA scheme guarantees the handover blocking probability to a predefined target level of QoS. Since GCAC algorithm utilizes the user location information, performance evaluation indicates that the quality of service (QoS) is also guaranteed in the non-uniform traffic pattern.