Handover Approach Research Articles

Trust-Assisted Handover Approach in Hybrid Wireless Networks

In Next-Generation (NG) hybrid wireless networks, Mobile-Controlled Handover (MCHO) is expected to be employed as the handover control mechanism, in contrast to Network-Controlled Handover (NCHO) used in homogeneous wireless networks. As more independent network operators get involved in providing Internet access, roaming mobile users would have to deal with complex trust relationships between heterogeneous network domains. The state-of-the-art handover approaches just take into account Quality of Service (QoS), but ignore the complexities arising from the coexistence of multiple network operators in the NG networks. The existence of a complex trust relationship between networks may lead to unnecessary handover attempts in service roaming. In this regard, this paper introduces a novel approach of dynamically retrieving network trust information, and using it in MCHO. We show how network trust information can be utilised to obtain a 35% reduction in handover delay, meanwhile retain QoS in a handover. The proposed scheme does not need bulk storage in mobile handsets, and can react to changes to network topology and trust relationships dynamically. Analytical results are provided to demonstrate how roaming mobile users make more intelligent and reliable handover if implementing the proposed handover approach in a multi-operator and multi-technology environment.

An efficient approach for DVB-H handover in DVB-H/UMTS hybrid networks

Handover in Digital Video Broadcasting for Handhelds (DVB-H) aims to provide continuous mobile broadcasting services when a user is traveling through cell boundaries. A good handover control can improve the power efficiency and gain much better reception quality. This letter provides a novel approach for DVB-H handover based on DVB-H/Universal Mobile Telecommunications System (UMTS) hybrid network, which moves the main handover function from the terminals to the networks, so that it reduces the operation complexity of the terminals and increases the power saving. When the terminal can not receive the DVB-H signal in the transmission shadow areas or because of some other reasons, the UMTS networks may offer the same service to users to make the service continuous. As the UMTS networks have the topology of the DVB-H networks, by communicating with the terminals, the UMTS networks can help the terminals to predict the handover, and avoid unnecessary handover.

Dynamic transport layer handover for heterogeneous communication environments

Vertical handovers between heterogeneous communication networks are required to provide seamless Internet access to mobile users. In this paper we present an approach for dynamic transport layer handover by utilizing the multihoming capabilities of SCTP. The architecture allows for selecting the most suitable communication path for an application depending on the user’s preferences, the application’s requirements as well as the current network characteristics. The evaluation results of the prototype implementation show that SCTP is very suitable for transport layer handovers and more robust against interferences than TCP.

Reactive Handover Optimization in IPv6-Based Mobile Networks

In recent years, there has been a rapid growth in the need to support moving hosts and moving networks in IPv6-based mobile networks. As the number of such hosts and networks grows, so will the demand for delay sensitive real-time applications, such as voice over IP (VoIP), that require seamless handover. Two well-known approaches to reduce the handover latency have been proposed in the literature: proactive and reactive approaches. While proactive handover is known to generally outperform reactive handover, its reliability and practicality are still questionable since it basically depends on predictive information which may be unreliable in some cases. In this paper, based on the standard specification for IPv6 mobility support, we analyze the existing movement detection and address configuration procedures which are the main components of reactive handover approach. We also propose a novel reactive handover procedure which employs our optimized movement detection and address configuration schemes. The proposal is simple and robust because it does not need any predictive information and it requires a minimum number of signaling messages. The performance evaluation shows that the proposal substantially reduces the signaling load on wireless/wired networks and its handover latency is reduced enough to support seamless services

Incorporating digital repeaters into the soft handover standard in digital video broadcasting for handhelds

Digital Video Broadcasting for Handhelds (DVB-H) is a standard for broadcasting IP data to portable devices. This paper proposes and analyses the Repeater-Aided Soft Handover (RA_handover) algorithm for a DVB-H receiver with Multiple Input-Multiple Output (MIMO) antennas and presents the benefits of implementing the RA_handover compared with a handover process without repeaters. Simulation models are developed to analyse the RA_handover approach. It is shown that the RA_handover could greatly improve the quality of service and consume much less front-end battery power than the handover method without repeaters. This paper also provides valuable outcomes for service providers and standard policymakers.

Trajectory Optimization for a Missile Using a Multitier Approach

A two-tier approach to the midcourse trajectory design for a surface-to-air missile to maximize the probability of hit is presented. The e rst tier represents the midcourse trajectory of the missile, and the second tier represents the terminal homing phase. The e rst-tier trajectory is optimized with an auxiliary constraint on the value of the approach angle to the intercept at handover to the terminal phase. The handover approach angle is used as the governing parameter in generating a e eld of optimum e rst-tier midcourse trajectories. The second-tier model estimates the probability of hit including a full suite of stochastic error sources on the seeker and missile. The optimal approach angleand midcoursetrajectory aredemonstrated to bedependent on the terminal homing noise contributors and the target maneuver.