Abstract: Despite the central role of mobility in wireless networks, analytical study on its impact on network performance is notoriously difficult. This paper aims to address this gap by proposing a random waypoint (RWP) mobility model defined on the entire plane and applying it to analyze two key cellular network parameters: handover rate and sojourn time. We first analyze the stochastic properties of the proposed model and compare it to two other models: the classical RWP mobility model and a synthetic truncated Levy walk model which is constructed from real mobility trajectories. The comparison shows that the proposed RWP mobility model is more appropriate for the mobility simulation in emerging cellular networks, which have ever-smaller cells. Then we apply the proposed model to cellular networks under both deterministic (hexagonal) and random (Poisson) base station (BS) models. We present analytic expressions for both handover rate and sojourn time, which have the expected property that the handover rate is proportional to the square root of BS density. Compared to an actual BS distribution, we find that the Poisson-Voronoi model is about as accurate in terms of mobility evaluation as hexagonal model, though being more pessimistic in that it predicts a higher handover rate and lower sojourn time.

Abstract: IPv6 mobility management is one of the most challenging research topics for enabling mobility service in the forthcoming mobile wireless ecosystems. The Internet Engineering Task Force has been working for developing efficient IPv6 mobility management protocols. As a result, Mobile IPv6 and its extensions such as Fast Mobile IPv6 and Hierarchical Mobile IPv6 have been developed as host-based mobility management protocols. While the host-based mobility management protocols were being enhanced, the network-based mobility management protocols such as Proxy Mobile IPv6 (PMIPv6) and Fast Proxy Mobile IPv6 (FPMIPv6) have been standardized. In this paper, we analyze and compare existing IPv6 mobility management protocols including the recently standardized PMIPv6 and FPMIPv6. We identify each IPv6 mobility management protocol's characteristics and performance indicators by examining handover operations. Then, we analyze the performance of the IPv6 mobility management protocols in terms of handover latency, handover blocking probability, and packet loss. Through the conducted numerical results, we summarize considerations for handover performance.

Abstract: Self-organizing networks (SONs) aim to raise the level of automated operation in next-generation networks. One of the use cases defined in this field is the optimization of the handover (HO) process, which involves a tradeoff between the amount of signaling load due to HOs and the quality of the active connections in the network. In this paper, first, a sensitivity analysis of the two main HO parameters, i.e., the HO margin (HOM) and the time-to-trigger (TTT), is carried out for different system load levels and user speeds in a Long-Term Evolution (LTE) network. Second, a fuzzy logic controller (FLC) that adaptively modifies HOMs is designed for HO optimization. In this case, different parameter optimization levels (network-wide, cell-wide, and cell-pair-wide) and the impact of measurement errors have been considered. Results of the sensitivity analysis show that tuning HOMs is an effective solution for HO optimization in LTE networks. In addition, the FLC is shown as an effective technique to adapt HOM to different network conditions so that the signaling load in the network is decreased while an admissible level of call dropping is achieved.

Abstract: The long-Term Evolution (LTE) of the 3GPP (3rd Generation Partnership Project) radio access network is in early stage of specification. Self-tuning and self-optimisation algorithms are currently studied with the aim of enriching the LTE standard. This paper investigates auto-tuning of LTE mobility algorithm. The auto-tuning is carried out by adapting handover parameters of each base station according to its radio load and the load of its adjacent cells. The auto-tuning alleviates cell congestion and balances the traffic and the load between cells by handing off mobiles close to the cell border from the congested cell to its neighbouring cells. Simulation results show that the auto-tuning process brings an important gain in both call admission rate and user throughput.

Abstract: Objective:This study was aimed at examining team communication during postoperative handover and its relationship to clinicians’ self-ratings of handover quality.Background:Adverse events can often be traced back to inadequate communication during patient handover. Research and improvement efforts have mostly focused on the information transfer function of patient handover. However, the specific mechanisms between handover communication processes among teams of transferring and receiving clinicians and handover quality are poorly understood.Method:We conducted a prospective, cross-sectional observation study using a taxonomy for handover behaviors developed on the basis of established approaches for analyzing teamwork in health care. Immediately after the observation, transferring and receiving clinicians rated the quality of the handover using a structured tool for handover quality assessment. Handover communication during 117 handovers in three postoperative settings and its relationship to clinicians’ ...

Abstract: In this paper, we present a novel controller for safe, efficient, and intuitive robot-to-human object handovers and a set of experiments to evaluate user responses to the robot's handover behavior. The controller enables a robot to mimic human behavior by actively regulating the applied grip force according to the measured load force during a handover. We provide an implementation of the controller on a Willow Garage PR2 robot, demonstrating the feasibility of realizing our design on robots with basic sensor/actuator capabilities. A user study comparing four variations of our controller shows that our design yields both human-like and human-preferred object handovers.

Abstract: The present invention relates to a method for a base station to control a proximity service (ProSe) in a wireless communication system including the steps of: tracking at least two or more terminals which camp on the base station and have a ProSe relationship with each other on a direct data path; and determining whether to switch the direct data path in the case where one or more terminals from among the two or more terminals try to perform a handover or in the case where the distance between the two or more terminals is equal to or greater than a preset value.

Abstract: Background The analysis of nursing errors in clinical management highlighted that clinical handover plays a pivotal role in patient safety. Changes to handover including conducting handover at the bedside and the use of written handover summary sheets were subsequently implemented. Aim The aim of the study was to explore nurses’ perspectives on the introduction of bedside handover and the use of written handover sheets. Method Using a qualitative approach, data were obtained from six focus groups containing 30 registered and enrolled (licensed practical) nurses. Thematic analysis revealed several major themes. Findings Themes identified included: bedside handover and the strengths and weaknesses; patient involvement in handover, and good communication is about good communicators. Finally, three sources of patient information and other issues were also identified as key aspects. Conclusions How bedside handover is delivered should be considered in relation to specific patient caseloads (patients with cognitive impairments), the shift (day, evening or night shift) and the model of service delivery (team versus patient allocation). Implications for nursing management Flexible handover methods are implicit within clinical setting issues especially in consideration to nursing teamwork. Good communication processes continue to be fundamental for successful handover processes.

Abstract: Load balancing is considered by the 3GPP as an important issue in Self-Organizing Networks due to its effectiveness to increase network capacity. In next generation wireless networks, load balancing can be easily implemented by tuning handover (HO) margins, achieving a decrease in call blocking. However, call dropping can be increased as a negative effect of the HO-based load balancing, because users usually are handed over to cells where the radio conditions are worse. In this work, a Fuzzy Logic Controller (FLC) optimized by the fuzzy Q-Learning algorithm is proposed for the load balancing problem, with the aim of decreasing call blocking in congested cells, while at the same time restricting call dropping in neighboring cells according to the network policy. In particular, two different approaches for the FLC optimization are evaluated in this work, highlighting that one of the proposed methods allows to accurately preserve the call quality constraint during the load balancing, while the other can adapt to network variations. Results show that the optimized FLC provides a notable reduction in call blocking while preserving call dropping under the operator constraint.

Abstract: Provisioning of quality of service (QoS) is a key issue in any multi-media system. However, in wireless systems, supporting QoS requirements of different traffic types is a more challenging problem due to the need to simultaneously minimize two performance metrics - the probability of dropping a handover call and the probability of blocking a new call. Since QoS requirements are not as stringent for non-real-time traffic, as opposed to real-time traffic, more calls can be accommodated by releasing some bandwidth from the already admitted non-real-time traffic calls. If the released bandwidth that is used to handle handover calls is larger than the released bandwidth that is used for new calls, then the resulting probability of dropping a handover call is smaller than the probability of blocking a new call. In this paper, we propose an efficient call admission control algorithm that relies on adaptive multi-level bandwidth-allocation scheme for non-realtime calls. The scheme allows reduction of the call dropping probability, along with an increase in the bandwidth utilization. The numerical results show that the proposed scheme is capable of attaining negligible handover call dropping probability without sacrificing bandwidth utilization.

Abstract: The concept “Always Best connected“ (ABC) is one of the main challenges in heterogeneous wireless networks. Based on the functionality of ABC, the users can be always connected to different services anywhere at anytime with multi-interfaces devices. The vertical handover decision is an efficient solution that can used to ensure the ABC paradigm. Thisenhanced vertical handover decision technique paper proposes an enhanced vertical handover decision technique which combines two multi attribute decision making (MADM) methods, the analytic network process (ANP) and the enhanced technique for order preference by similarity to an ideal solution (E-TOPSIS). The ANP method is applied to weigh the criteria and the E-TOPSIS method is used to rank the alternatives. The simulation results show that the proposed technique can effectively reduce the reversal phenomenon and the number of handoffs.

Abstract: Named Data Networking (NDN) is designed for efficient content dissemination. Several researches are carried out for NDN recently, but the user-side mobility problem is not considered sufficiently. To enhance seamless user-side mobility support in the NDN architecture, we propose a Proactive Caching approach for NDN (PCNDN), which is based on the idea that proactively requests and caches the content items that a user does not receive but were requested before a handover process. Thus, once the user reconnects to the network, it can immediately fetch the content items that were transmitted during its disconnection period. Compared with the original NDN, the analytical and simulation results indicate that the proposed approach has lower handover cost, higher delivery ratio and shorter handover latency. Moreover, the proposed approach prevents unnecessary packet losses on the path towards the old location of the user, alleviates negative effects of user-side mobility on real-time services.

Abstract: A method for performing device-to-device (D2D) communication in a wireless communication system is provided. A master user equipment sets a D2D link with a slave user equipment. The master user equipment performs D2D communication with the slave user equipment through the D2D link. The master user equipment receives handover information of the slave user equipment from the slave user equipment. The master user equipment transmits the handover information of the slave user equipment to an evolved NodeB of a handover source cell.

Abstract: An example method is provided in one example embodiment and includes receiving a handover request from a first radio network to handover a user equipment (UE) to a second radio network, wherein the handover request includes an international mobile subscriber identity (IMSI) for a user associated with the UE and a pseudo cell identifier (ID); determining a target channel configuration for the UE using the pseudo cell ID; querying a third radio network using the user IMSI to determine a location of the UE, wherein at least one access point in the third radio network is in communication with the UE; and selecting a particular target access point in the second radio network for handover of the UE based, at least in part, on the location of the UE, the target channel configuration for the UE and a location of the particular target access point.

Abstract: A method for handover in a wireless communication system includes: when a received signal strength difference between a serving beam from a serving base station used for communication by a terminal and a target beam of a neighboring base station is equal to or greater than a first threshold value, and a received signal strength difference between an active beam and the target beam is equal to or greater than a second threshold value, determining a handover to the target beam; and transmitting a message to initiate the handover.

Abstract: Method for unified networking for a device in heterogeneous mobile environments includes maintaining and monitoring active network interfaces, managing the location of the device, managing network access security, enabling disruption tolerance support for applications, enabling service sharing and session mobility, managing system parameters for one or more active application sessions, managing storage functionality in one or more memory devices, and maintaining a mapping for one or more flows corresponding to the one or more active application sessions, maintaining one or more policies, and performing flow control decisions based upon the policies using a policy engine. The method can also include monitoring for network events, evaluating whether to perform a handover based upon policies, and providing seamless secure handovers in a heterogeneous mobile environment. A device, non-transitory computer-readable medium, and a system for unified networking are also provided.

Abstract: A technique is provided for a seamless and transparent handoff from a user's mobile device to the user's stationary terminal of a network address of a remote device for the purpose of establishing a direct communication channel between the stationary terminal and a remote device, where the remote device first contacted the user's mobile device to initiate communications with the user.

Abstract: A node (200-1) of a cellular network detects entry of a vehicle-to-vehicle communication device (100) into a cell of the cellular network. Further, the node (200-1) allocates resources to the vehicle-to-vehicle communication device (100). Then, the node (200-1) sends channel information to the vehicle-to-vehicle communication device (100). This may involve including the channel information into a handover command to the vehicle-to-vehicle communication device (100). The channel information indicates the allocated resources. The vehicle-to-vehicle communication device (100) used the allocated resources for sending of vehicle-to-vehicle communication messages.

Abstract: Knowing a user's next cell allows more efficient resource allocation and enables new location-aware services. To anticipate the cell a user will hand-over to, we introduce a new machine learning based prediction system. Therein, we formulate the prediction as a classification problem based on information that is readily available in cellular networks. Using only Channel State Information (CSI) and handover history, we perform classification by embedding Support Vector Machines (SVMs) into an efficient pre-processing structure. Simulation results from a Manhattan Grid scenario and from a realistic radio map of downtown Frankfurt show that our system provides timely prediction at high accuracy.

Abstract: In a first embodiment, an access network detects whether QoS links for both IMS and non-IMS sessions are allocated to a client device, whereby the non-IMS session is recognized as being associated with a particular application type. An SRVCC feature for the IMS session is disabled if the QoS link for the non-IMS session exists and carries at least a threshold level of traffic. In a second embodiment, a non-IMS session is supported by a first network with QoS and is then handed off to a second network. After the handoff, the second network supports the non-IMS session with an application-specific QoS configuration based on application-identifying information provided from the first network. In a third embodiment, a single or dual-transceiver client device is engaged in a non-IMS session with QoS. A page originating from a CS network is ignored if a do-not-disturb feature is activated for the non-IMS session.

Abstract: Internet access and service utilization has been exploding in mobile devices, through the leverage of WLAN, 3G and now LTE connections It is this explosion as well that is stressing the underlying fabric of the Internet, and motivating new solutions, such as Software Defined Networking (SDN), to build the controlling support and extension capabilities of the Future Internet However, SDN has yet to reach the necessary traction to be deployed, and has been more relayed towards experimentation supporting frameworks and away from wireless environments This paper explores SDN mechanisms and increments them with Media Independent Handover services from the IEEE 80221 standard, coupling them in a single framework for the dynamic optimized support of OpenFlow path establishment and wireless connectivity establishment The framework was implemented over open-source software in a physical testbed, with results showing the benefits that this solution brings in terms of performance and signaling overhead, when compared with more basic approaches

Abstract: Wireless systems have the capability to serve users over broad geographic area without using a costly network infrastructure However, the main drawback of these systems represents the bandwidth restrictions and coverage Deployment of femtocell as the emerging promising wireless access technology becomes one of possible solution how to overcome some of the drawbacks In this paper, we investigate the handover procedure in femtocell network considering, both types of handovers, horizontal and vertical The 3GPP LTE based handover procedure is analysed for three scenarios: hand-in, hand-out and inter-FAP In addition, the reactive handover decision policy, based on the prediction of user movement and the prediction of target-FAP, is proposed as a way to eliminate frequent and unnecessary handovers

Abstract: One of the most challenging topics for next generation wireless networks is vertical handoff concept since several wireless technologies are assumed to cooperate. Plenty of parameters related to user preferences, application requirements, and network conditions, such as; data rate, service cost, network latency, speed of mobile, battery level, interference ratio and etc. must be considered in vertical handoff process along with traditional RSSI information. In this study, a new artificial neural network based handoff decision algorithm is proposed in order to reduce the handoff latency of smart terminal deployed in aforementioned wireless heterogeneous infrastructures. The prominent parameters data rate, monetary cost and RSSI information are taken as inputs of the developed vertical handoff decision system. Performance results of the proposed system are also compared with those of classical Multiple Attribute Decision Making method Simple Additive Weighting, and of some other artificial intelligence based algorithms. According to the results obtained, the proposed neural network based vertical handoff decision algorithm is able to determine whether a handoff is necessary or not properly, and selects the best candidate access network considering the abovementioned parameters. The results also show that, the neural network based algorithm developed significantly reduces the handoff latency while the number of handoffs, which is another vital performance metric, is still reasonable.

Abstract: Technology is discussed for self-optimization approaches within wireless networks to optimize networks for energy efficiency, load capacity, and/or mobility, together with new, supporting channel state measurements and handover techniques. New, Channel State Information-Reference Signals (CSI-RSs) for yet-to-be-configured Cell-IDentifications (Cell-IDs) can be used to determine whether adjacent transmission cells can provide coverage for transmission cells that can be switched off for energy efficiency during formation of a Single Frequency Network (SFN). New approaches are also discussed to facilitate mobility within such a network. The new CSI-RSs and mobility approaches can also be used to split up such a SFN when changing load demands so require. Additionally, such new approaches can be used to create a SFN with a common Cell-ID where high mobility is required, such as near a roadway, and to break it up where high capacity is required, such as during a period of traffic congestion.

Abstract: Technology for performing a handover in a heterogeneous wireless network (HetNet) is disclosed. One method comprises receiving, at an anchor serving cell in the HetNet, channel measurement reports made by a user equipment (UE) for a plurality of cells. A transmission point change request can be sent, based on the channel measurements for the UE, from the anchor serving cell to a target transmission point. The target transmission point is located in one of the plurality of cells. A transmission point change indicator is sent from the anchor cell to the UE to indicate a change in TP with which the UE will communicate via an air interface, while maintaining a connection to the anchor serving cell.

Abstract: In this paper, we propose a mobility-aware call admission control (MA-CAC) algorithm with a handoff queue (HQ) in mobile hotspots, where different admission control policies are employed, depending on the vehicle mobility. Specifically, when a vehicle is static, a handoff priority scheme with guard channels is studied to protect vehicular handoff users because handoff users may get on the vehicle. In addition, an HQ is examined during stopping to further accept handoff users. On the other hand, for a moving vehicle, no guard channels for handoff users are allocated to maximize channel utilization. By means of Markov chains, we evaluate MA-CAC with an HQ in terms of new-call blocking probability (NCBP), handoff-call dropping probability (HCDP), handoff-call waiting time in the HQ, and channel utilization. Analytical and simulation results demonstrate that MA-CAC with an HQ can lower both the HCDP and the NCBP while maintaining high channel utilization.