Showing papers on "Handover published in 2017"
TL;DR: In this article, a logical architecture for network-slicing-based 5G systems is introduced, and a scheme for managing mobility between different access networks, as well as a joint power and subchannel allocation scheme in spectrum sharing two-tier systems based on network slicing, where both the co-tier interference and crosstier interference are taken into account.
Abstract: 5G networks are expected to be able to satisfy users' different QoS requirements. Network slicing is a promising technology for 5G networks to provide services tailored for users' specific QoS demands. Driven by the increased massive wireless data traffic from different application scenarios, efficient resource allocation schemes should be exploited to improve the flexibility of network resource allocation and capacity of 5G networks based on network slicing. Due to the diversity of 5G application scenarios, new mobility management schemes are greatly needed to guarantee seamless handover in network-slicing-based 5G systems. In this article, we introduce a logical architecture for network-slicing-based 5G systems, and present a scheme for managing mobility between different access networks, as well as a joint power and subchannel allocation scheme in spectrum-sharing two-tier systems based on network slicing, where both the co-tier interference and cross-tier interference are taken into account. Simulation results demonstrate that the proposed resource allocation scheme can flexibly allocate network resources between different slices in 5G systems. Finally, several open issues and challenges in network-slicing-based 5G networks are discussed, including network reconstruction, network slicing management, and cooperation with other 5G technologies.
585 citations
TL;DR: Experimental results show that the proposed SCH-SpecPSO outperforms 75% more than state of art mobile social networks by optimizing various handover issues.
308 citations
TL;DR: The SpecPSO is proposed for optimizing handovers using supervised machine learning technique for performing dynamic handover by adapting to the environment and make smart decisions compared to the traditional cooperative spectrum sensing (CSS) techniques.
Abstract: Cognitive communication model perform the investigation and surveillance of spectrum in cognitive radio networks abetment in advertent primary users (PUs) and in turn help in allocation of transmission space for secondary users (SUs). In effective performance of regulation of wireless channel handover strategy in cognitive computing systems, new computing models are desired in operating set of tasks to process business model, and interact naturally with humans or machine rather being programmed. Cognitive wireless network are trained via artificial intelligence (AI) and machine learning (ML) algorithms for dynamic processing of spectrum handovers. They assist human experts in making enhanced decisions by penetrating into the complexity of the handovers. This paper focuses on learning and reasoning features of cognitive radio (CR) by analyzing primary user (PU) and secondary user (SU) data communication using home location register (HLR) and visitor location register (VLR) database respectively. The SpecPSO is proposed for optimizing handovers using supervised machine learning technique for performing dynamic handover by adapting to the environment and make smart decisions compared to the traditional cooperative spectrum sensing (CSS) techniques.
287 citations
TL;DR: This paper provides the first comprehensive end-to-end evaluation of handover mechanisms in mmWave cellular systems and reveals significant benefits of the proposed method under several metrics.
Abstract: The millimeter wave (mmWave) bands offer the possibility of orders of magnitude greater throughput for fifth-generation (5G) cellular systems. However, since mmWave signals are highly susceptible to blockage, channel quality on any one mmWave link can be extremely intermittent. This paper implements a novel dual connectivity protocol that enables mobile user equipment devices to maintain physical layer connections to 4G and 5G cells simultaneously. A novel uplink control signaling system combined with a local coordinator enables rapid path switching in the event of failures on any one link. This paper provides the first comprehensive end-to-end evaluation of handover mechanisms in mmWave cellular systems. The simulation framework includes detailed measurement-based channel models to realistically capture spatial dynamics of blocking events, as well as the full details of Medium Access Control, Radio Link Control, and transport protocols. Compared with conventional handover mechanisms, this paper reveals significant benefits of the proposed method under several metrics.
263 citations
12 Oct 2017
TL;DR: A novel service handoff system which seamlessly migrates offloading services to the nearest edge server, while the mobile client is moving, is presented and an important performance problem during Docker container migration is identified.
Abstract: Supporting smooth movement of mobile clients is important when offloading services on an edge computing platform. Interruption-free client mobility demands seamless migration of the offloading service to nearby edge servers. However, fast migration of offloading services across edge servers in a WAN environment poses significant challenges to the handoff service design. In this paper, we present a novel service handoff system which seamlessly migrates offloading services to the nearest edge server, while the mobile client is moving. Service handoff is achieved via container migration. We identify an important performance problem during Docker container migration. Based on our systematic study of container layer management and image stacking, we propose a migration method which leverages the layered storage system to reduce file system synchronization overhead, without dependence on the distributed file system. We implement a prototype system and conduct experiments using real world product applications. Evaluation results reveal that compared to state-of-the-art service handoff systems designed for edge computing platforms, our system reduces the total duration of service handoff time by 80%(56%) with network bandwidth 5Mbps(20Mbps).
157 citations
TL;DR: This work has found that cooperative spectrum sensing among cognitive users to increase the reliability of detection in cognitive radio systems is beneficial.
Abstract: Cognitive radio systems necessitate the incorporation of cooperative spectrum sensing among cognitive users to increase the reliability of detection. We have found that cooperative spectrum sensing...
138 citations
TL;DR: The measurements reveal that LTE can provide coverage for 99 percent of the outdoor and road users, but the LTE-M or NarrowBand-IoT upgrades are required in combination with other measures to allow for additional penetration losses, such as those experienced in underground parking lots.
Abstract: Long Term Evolution, the fourth generation of mobile communication technology, has been commercially deployed for about five years. Even though it is continuously updated through new releases, and with LTE Advanced Pro Release 13 being the latest one, the development of the fifth generation has been initiated. In this article, we measure how current LTE network implementations perform in comparison with the initial LTE requirements. The target is to identify certain key performance indicators that have suboptimal implementations and therefore lend themselves to careful consideration when designing and standardizing next generation wireless technology. Specifically, we analyze user and control plane latency, handover execution time, and coverage, which are critical parameters for connected mobility use cases such as road vehicle safety and efficiency. We study the latency, handover execution time, and coverage of four operational LTE networks based on 19,000 km of drive tests covering a mixture of rural, suburban, and urban environments. The measurements have been collected using commercial radio network scanners and measurement smartphones. Even though LTE has low air interface delays, the measurements reveal that core network delays compromise the overall round-trip time design requirement. LTE's breakbefore- make handover implementation causes a data interruption at each handover of 40 ms at the median level. While this is in compliance with the LTE requirements, and lower values are certainly possible, it is also clear that break-before-make will not be sufficient for connected mobility use cases such as road vehicle safety. Furthermore, the measurements reveal that LTE can provide coverage for 99 percent of the outdoor and road users, but the LTE-M or NarrowBand-IoT upgrades, as of LTE Release 13, are required in combination with other measures to allow for additional penetration losses, such as those experienced in underground parking lots. Based on the observed discrepancies between measured and standardized LTE performance, in terms of latency, handover execution time, and coverage, we conclude the article with a discussion of techniques that need careful consideration for connected mobility in fifth generation mobile communication technology.
107 citations
TL;DR: A velocity-aware HO management scheme for two-tier downlink cellular network to mitigate the HO effect on the foreseen densification throughput gains and the value of BS cooperation along with handover skipping is quantified for different user mobility profiles.
Abstract: While network densification is considered an important solution to cater the ever-increasing capacity demand, its effect on the handover (HO) rate is overlooked. In dense 5G networks, HO delays may neutralize or even negate the gains offered by network densification. Hence, user mobility imposes a nontrivial challenge to harvest capacity gains via network densification. In this paper, we propose a velocity-aware HO management scheme for two-tier downlink cellular network to mitigate the HO effect on the foreseen densification throughput gains. The proposed HO scheme sacrifices the best base station (BS) connectivity, by skipping HO to some BSs along the user trajectory, to maintain longer connection durations and reduce HO rates. Furthermore, the proposed scheme enables cooperative BS service and strongest interference cancellation to compensate for skipping the best connectivity. To this end, we consider different HO skipping scenarios and develop a velocity-aware mathematical model, via stochastic geometry, to quantify the performance of the proposed HO schemes in terms of the coverage probability and user throughput. The results highlight the HO rate problem in dense cellular environments and show the importance of the proposed HO schemes. Finally, the value of BS cooperation along with handover skipping is quantified for different user mobility profiles.
93 citations
TL;DR: This article estimates the neighbor eNB transition probabilities of the mobile node and their available resource probabilities by using a Markov chain formulation and reveals that the proposed strategy reduces the handover delay and failures by 52 and 21 percent compared to the conventional approach.
Abstract: Ultra-densification is a key approach aimed at satisfying high data traffic in next-generation 5G networks. However, the high number of small cell eNB deployments in such ultra-dense networks (UDNs) may result in unnecessary, frequent, and back-and-forth handovers, with additional problems related to increased delay and total failure of the handoff process. Additionally, due to the separation of control and data signaling in 5G technology, the handover operation must be executed in both tiers. In this article, we propose an SDN-based mobility and available resource estimation strategy to solve the handover delay problem. Here, we estimate the neighbor eNB transition probabilities of the mobile node and their available resource probabilities by using a Markov chain formulation. This allows a mathematically elegant framework to select the optimal eNBs and then assign these to mobile nodes virtually, with all connections completed through the use of OpenFlow tables. Finally, we compare the conventional LTE and our proposed handover strategies by analyzing the observed delays according to the densification ratio parameter. Also, we analyze the handover failure ratios of both strategies according to the user number. Results reveal that the proposed strategy reduces the handover delay and failures by 52 and 21 percent compared to the conventional approach.
92 citations
02 May 2017
TL;DR: Results show that pre-alerts caused people to look more at the road before the handover occurred, and to disengage from the secondary task earlier, compared to when there was no pre- alert, which resulted in safer handover situations.
Abstract: Semi-autonomous vehicles occasionally require control to be handed over to the driver in situations where the vehicle is unable to operate safely. Currently, such handover requests require the driver to take control almost instantaneously. We investigate how auditory pre-alerts that occur well before the handover request impact the success of the handover in a dual task scenario. In a study with a driving simulator, drivers perform tasks on their phone while the car is in an autonomous mode. They receive a repeated burst audio pre-alert or an increasing pulse audio pre-alert preceding the standard warning for immediate handover. Results show that pre-alerts caused people to look more at the road before the handover occurred, and to disengage from the secondary task earlier, compared to when there was no pre-alert. This resulted in safer handover situations. Increasing pulse pre-alerts show particular promise due to their communication of urgency. Our detailed analysis informs the design and evaluation of alerts in safety-critical systems with automation.
80 citations
Posted Content•
TL;DR: A logical architecture for network-slicing-based 5G systems is introduced, and a scheme for managing mobility between different access networks, as well as a joint power and subchannel allocation scheme in spectrum-sharing two-tier systems based on network slicing are presented.
Abstract: The fifth-generation (5G) networks are expected to be able to satisfy users' different quality-of-service (QoS) requirements. Network slicing is a promising technology for 5G networks to provide services tailored for users' specific QoS demands. Driven by the increased massive wireless data traffic from different application scenarios, efficient resource allocation schemes should be exploited to improve the flexibility of network resource allocation and capacity of 5G networks based on network slicing. Due to the diversity of 5G application scenarios, new mobility management schemes are greatly needed to guarantee seamless handover in network slicing based 5G systems. In this article, we introduce a logical architecture for network slicing based 5G systems, and present a scheme for managing mobility between different access networks, as well as a joint power and subchannel allocation scheme in spectrum-sharing two-tier systems based on network slicing, where both the co-tier interference and cross-tier interference are taken into account. Simulation results demonstrate that the proposed resource allocation scheme can flexibly allocate network resources between different slices in 5G systems. Finally, several open issues and challenges in network slicing based 5G networks are discussed, including network reconstruction, network slicing management and cooperation with other 5G technologies.
TL;DR: Simulation results show the TBDUOS scheme can effectively reduce the handover failure and call dropping of specific users, especially voice/stream users, high consumption Users, high level users, and the blocking probability is reduced.
Abstract: This paper proposes a telecom big data based user offloading self-optimisation TBDUOS scheme. Its aim is to assist telecom operators to effectively balancing the load distribution with achieving good service performance and customer management in heterogeneous relay cellular systems. To achieve these objectives, in the cell-level offloaded traffic analysis stage, the optimal offloaded traffic is calculated to minimise the total blocking probability. In the user-level offloading stage, the user portrait is drawn and the K-MEANS algorithm is employed to manage the users clustering in the heavily loaded cell, and finally shifting users to assistant cells. Simulation results show the TBDUOS scheme can effectively reduce the handover failure and call dropping of specific users, especially voice/stream users, high consumption users, high level users. The TBDUOS scheme can also reduce the blocking probability.
TL;DR: By introducing SDNC, an intelligent wireless network architecture for NWNs is proposed and virtual RATs design using interface sets is brought up to support diverse services and low handover latency between heterogeneous networks is achieved.
Abstract: With the increase of new devices and applications, the past decade has witnessed exponential growth of traffic volume in communication networks. This triggers much effort for designing NWNs in both academia and industry. To gain natural evolution and meet emerging requirements, it is widely agreed that NWNs shall be multi-tier with overlay coverage and small cell deployment. However, dense deployment of small cells introduces numerous challenges, including inconsistent interfaces, frequent handovers, and extensive backhauling. By decomposing the control plane and data plane, SDN offers a new direction to address the above challenges. In this article, by introducing SDNC, we propose an intelligent wireless network architecture for NWNs. In our architecture, virtual RATs design using interface sets is brought up to support diverse services. Along with our earlier handover approach, low handover latency between heterogeneous networks is achieved. Furthermore, we present SH mechanisms targeted at different failure cases in backhaul connections. With programmability provided by SDN, the aforementioned functions can be deployed as modules in the SDNC. Experimental results validate the efficiency of our proposal.
21 May 2017
TL;DR: Focusing on the latter, the impact of large delays and Doppler shifts on LTE PHY/MAC procedures is discussed and assessed and it will be shown that, while carrier spacings, Random Access, and RN attach procedures do not pose specific issues, HARQ requires substantial modifications.
Abstract: LTE-based satellite systems in LEO constellations are a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to a traditional LTE system. In this paper, two architectures are proposed for a LEO mega-constellation realizing a satellite-enabled LTE system, in which the on-ground LTE entity is either an eNB (Sat-eNB) or a Relay Node (Sat-RN). Focusing on the latter, the impact of large delays and Doppler shifts on LTE PHY/MAC procedures is discussed and assessed. It will be shown that, while carrier spacings, Random Access, and RN attach procedures do not pose specific issues, HARQ requires substantial modifications. Moreover, advanced handover procedures will be also required due to the satellites' movement.
01 Mar 2017
TL;DR: A fundamental approach is proposed for handover modeling by taking into account the effects of both mobility and rotation for a connected user equipment (UE), and novel insights are provided into the handover performance in indoor optical attocell networks using Monte Carlo simulations.
Abstract: Light-fidelity (Li-Fi) is an emerging technology for wireless networking based on visible light communication (VLC). As a licence free, high speed, bidirectional and secure wireless access solution, Li-Fi is a complementary building block for fifth generation (5G) heterogeneous mobile networks. By modulating data on the light intensity emitted by light emitting diode (LED) luminaires which already exist in indoor lighting infrastructure, Li-Fi cellular networks are formed. Such networks are termed optical attocell networks, where the optical attcells are smaller in size than the radio frequency (RF) femtocells. This paper focuses on the problem of handover for downlink in an indoor optical attocell network. A fundamental approach is proposed for handover modeling by taking into account the effects of both mobility and rotation for a connected user equipment (UE). By using a random waypoint (RWP) model for the receiver movement and a geometric model for the receiver orientation, the probability of handover and the handover rate are calculated. Novel insights are provided into the handover performance in indoor optical attocell networks using Monte Carlo simulations.
19 Mar 2017
TL;DR: A time-predicted handover mechanism for vehicles is further developed by leveraging available road information and the enhanced capacity of the MEC server to satisfy the demand for high mobility and reliability.
Abstract: The evolving cellular network with centric-deployed Cloud Centers has greatly improved the mobile user experience. However, the advent of vehicular networks with a wide variety of new services and devices changes the existing cellular network landscape, and the cellular-based vehicular networks are confronted with serious challenge in terms of latency reduction and flexible service delivery. In this paper, we propose to deploy the specific server, called Mobile-Edge Computing (MEC) server, within the Radio Access Network, and allow them to connect with a set of base stations alongside roads, so as to provide flexible vehicle-related service and efficiently control the radio network. Then, the vision of MEC- assisted slicing network and a traffic scheduling policy are presented to promote network customization. As an instance of the MEC-based tailored network service, a time-predicted handover mechanism for vehicles is further developed by leveraging available road information and the enhanced capacity of the MEC server to satisfy the demand for high mobility and reliability.
TL;DR: Following Me Fog is proposed, a framework supporting a new seamless handover timing scheme among different computation access points when computation offloading is in action so that the offloading service is not interrupted, allowing fog computing to provide interruption-resistant services to mobile IoT devices.
Abstract: Equipped with easy-to-access micro computation access points, the fog computing architecture provides low-latency and ubiquitously available computation offloading services to many simple and cheap Internet of Things devices with limited computing and energy resources. One obstacle, however, is how to seamlessly hand over mobile IoT devices among different computation access points when computation offloading is in action so that the offloading service is not interrupted -- especially for time-sensitive applications. In this article, we propose Follow Me Fog (FMF), a framework supporting a new seamless handover timing scheme among different computation access points. Intrinsically, FMF supports a job pre-migration mechanism, which pre-migrates computation jobs when the handover is expected to happen. Such expectations can be indicated by constantly monitoring received signal strengths. Then we present the design and a prototype implementation of FMF. Our evaluation results demonstrate that FMF can achieve a substantial latency reduction (36.5 percent in our experiment). In conclusion, the FMF design clears a core obstacle, allowing fog computing to provide interruption-resistant services to mobile IoT devices.
TL;DR: The results show that the proposed approach is capable of providing secure transmission by resolving the RO problem in PMIPv6 along with the reduction in handover latency, end to end delay and packet loss, and enhancement in throughput and transmission rate even during the handover phase.
Abstract: The communication in the Smart Home Internet of Things (SH-IoT) comprising various electronic devices and sensors is very sensitive and crucial In addition, the key requirements of the SH-IoT include channel security, handover support, mobility management, and consistent data rates Proxy mobile IPv6 (PMIPv6) is considered as one of the core solutions to handle extreme mobility; however, the default PMIPv6 cannot ensure performance enhancement in SH-IoT scenarios, ie, Route Optimization (RO) The existing security protocols for PMIPv6 cannot support secure RO for smart home IoT services, where mobile nodes (MNs) communicate with home IoT devices not belonging to their domain Motivated by this, a secure protocol is proposed, which uses trust between PMIPv6 domain and smart home to ensure security as well as performance over the path between MNs and home IoT devices The proposed protocol includes steps for secure RO and handover management, where mutual authentication, key exchange, perfect forward secrecy, and privacy are supported The correctness of the proposed protocol is formally analyzed using BAN-logic and Automated Validation of Internet Security Protocols and Applications (AVISPA) Furthermore, network simulations are conducted to evaluate the performance efficiency of the proposed protocol The results show that the proposed approach is capable of providing secure transmission by resolving the RO problem in PMIPv6 along with the reduction in handover latency, end to end delay and packet loss, and enhancement in throughput and transmission rate even during the handover phase
28 Jul 2017
TL;DR: Different optimization models for proactive service migration at the Network Edge are investigated, which can exploit prediction of user mobility patterns and aim at respectively minimizing the QoE degradation due to service migration, and the cost of replicas' deployment.
Abstract: Extending cloud infrastructure to the Network Edge represents a breakthrough to support delay-sensitive applications in next 5G cellular systems. In this context, to enable ultrashort response times, fast relocation of service instances between edge nodes is required to cope with user mobility. To face this issue, proactive service replication is considered a promising strategy to reduce the overall migration time and to guarantee the desired Quality of Experience (QoE). On the other hand, the provisioning of replicas over multiple edge nodes increases the resource consumption of constrained edge nodes and the relevant deployment cost. Given the two conflicting objectives, in this paper we investigate different optimization models for proactive service migration at the Network Edge, which can exploit prediction of user mobility patterns. In particular, we define two Integer Linear Problem optimization schemes, which aim at respectively minimizing the QoE degradation due to service migration, and the cost of replicas' deployment. Performance evaluation shows the effectiveness of our proposed solutions.
TL;DR: This paper develops a priority-based channel allocation scheme to assign channels to the mobile stations based on their QoE requirements, and proposes a handoff management technique to overcome the interruptions caused by the handoff.
Abstract: Cognitive radio (CR) is among the promising solutions for overcoming the spectrum scarcity problem in the forthcoming fifth-generation (5G) cellular networks, whereas mobile stations are expected to support multimode operations to maintain connectivity to various radio access points. However, particularly for multimedia services, because of the time-varying channel capacity, the random arrivals of legacy users, and the on-negligible delay caused by spectrum handoff, it is challenging to achieve seamless streaming leading to minimum quality of experience (QoE) degradation. The objective of this paper is to manage spectrum handoff delays by allocating channels based on the user QoE expectations, minimizing the latency, providing seamless multimedia service, and improving QoE. First, to minimize the handoff delays, we use channel usage statistical information to compute the channel quality. Based on this, the cognitive base station maintains a ranking index of the available channels to facilitate the cognitive mobile stations. Second, to enhance channel utilization, we develop a priority-based channel allocation scheme to assign channels to the mobile stations based on their QoE requirements. Third, to minimize handoff delays, we employ the hidden markov model (HMM) to predict the state of the future time slot. However, due to sensing errors, the scheme proactively performs spectrum sensing and reactively acts handoffs. Fourth, we propose a handoff management technique to overcome the interruptions caused by the handoff. In such a way that, when a handoff is predicted, we use scalable video coding to extract the base layer and transmit it during a certain interval time before handoff occurrence to be shown during handoff delays, hence providing seamless service. Our simulation results highlight the performance gain of the proposed framework in terms of channel utilization and received video quality.
TL;DR: This letter employs a family hybrid VLC-Femto system and proposes a VHO algorithm based on decision selection that can compensate for the weakness of classic AHP in comparing the criteria values of different candidates by applying a two- person cooperative game model.
Abstract: Due to the complementary natures of visible light communication (VLC) and radio frequency, a combined application is regarded as a promising approach of supporting both hyperspeed data transmission and reliable signal connectivity. Vertical handover (VHO) is critical for guaranteeing seamless service in such a heterogeneous network. This letter employs a family hybrid VLC-Femto system and proposes a VHO algorithm based on decision selection. Our approach considers multiple attributes, including dynamic network parameters and actual traffic preferences by utilizing analytic hierarchy process (AHP). Additionally, it can compensate for the weakness of classic AHP in comparing the criteria values of different candidates by applying a two-person cooperative game (CG) model. Finally, the rationality degree (RD) of each decision is calculated by combining the results of AHP and CG, and the decision with the higher RD is selected. The simulation results validate the superiority of the proposed AHP-CG VHO algorithm over existing schemes under various circumstances.
TL;DR: A new model for analyzing handover performance in heterogeneous networks (HetNets) as a function of vehicular user velocity, cell size, and mobility management parameters is introduced and it is shown that fading can significantly degrade the hand over performance in HetNet with vehicular users.
Abstract: The handover process is one of the most critical functions in a cellular network and is in charge of maintaining seamless connectivity of user equipments across multiple cells. The handover process is driven by signal measurements from the neighboring base stations (BSs), and it is adversely affected by the time and frequency selectivity of the radio propagation channel. In this paper, we introduce a new model for analyzing handover performance in heterogeneous networks (HetNets) as a function of vehicular user velocity, cell size, and mobility management parameters. In order to investigate the impact of shadowing and fading on handover performance, we extract relevant statistics obtained from a Third-Generation Partnership Project (3GPP)-compliant HetNet simulator, and subsequently, we integrate these statistics into our analytical model to analyze both handover failure and ping-pong probabilities under fluctuating channel conditions. Computer simulations validate the analytical findings, which show that fading can significantly degrade the handover performance in HetNets with vehicular users.
TL;DR: This paper derives the optimal resource-allocation solution, in terms of OFDMA subcarriers and power allocation, using the dual decomposition method, and proposes an efficient algorithm based on the Hungarian method to find a suboptimal but low-complexity solution.
Abstract: A high-speed railway system equipped with moving relay stations placed on the middle of the ceiling of each train wagon is investigated. The users inside the train are served in two hops via orthogonal frequency-division multiple-access (OFDMA) technology. In this paper, we first focus on minimizing the total downlink power consumption of the base station (BS) and the moving relays while respecting specific quality-of-service (QoS) constraints. We first derive the optimal resource-allocation solution, in terms of OFDMA subcarriers and power allocation, using the dual decomposition method. Then, we propose an efficient algorithm based on the Hungarian method to find a suboptimal but low-complexity solution. Moreover, we propose an OFDMA planning solution for high-speed trains by finding the maximal inter-BS distance, given the required user data rates to perform seamless handover. Our simulation results illustrate the performance of the proposed resource-allocation schemes in the case of Third-Generation Partnership Project (3GPP) Long-Term Evolution Advanced (LTE-A) and compare them with previously developed algorithms, as well as with the direct transmission scenario. Our results also highlight the significant planning gain obtained, owing to the use of multiple relays instead of the conventional single-relay scenario.
TL;DR: The results in this article show that the proposed SDNbased handover scenarios perform better than the existing 4G-LTE handover for UAVs.
Abstract: Compared to traditional networking, SDN has better controllability and visibility for network components, which enable better management by using the common controller. In this article, the standard architecture of SDN is enhanced to utilize UAVs as on-demand forwarding switches. The proposed approach can achieve efficient management and fast handovers by decreasing the handover latency, E2E delay, and signaling overheads. The illustrated scenarios will help in understanding the impact of existing handover approaches in the next generation wireless networks, especially the upcoming 5G, which includes small cells, UAVs, UEs, and so on. The simulation study shows that scenarios with both UAVs and small cells perform better than scenarios with only small cells. The results in this article show that the proposed SDNbased handover scenarios perform better than the existing 4G-LTE handover for UAVs.
TL;DR: This letter has utilized semi-Markov model for spatiotemporal mobility prediction coupled with steady state and gain analysis in cellular networks to pave the way for resource reservation prior to actual handover for seamless handover experience and for forecasting user traffic distribution.
Abstract: Mobility prediction, one of the key enablers of proactive self-organizing networks, aims at efficient management of future cellular networks, which are envisaged to be extremely dense and complex due to conglomeration of diverse technologies This paves the way for resource reservation prior to actual handover for seamless handover experience and for forecasting user traffic distribution In this letter, we have utilized semi-Markov model for spatiotemporal mobility prediction coupled with steady state and gain analysis in cellular networks Maximum prediction accuracy of 90% is achieved in the experimental evaluation leveraging on the real network traces generated by smartphone application
Patent•
27 Jul 2017TL;DR: In this article, a handover method for V2V2X communication is presented. But the handover is not considered in this paper, and the handoff method is limited to V2X communications.
Abstract: Provided are methods and apparatuses for controlling the mobility of a user equipment for performing mobile communication network-based Vehicle To Everything (V2X). For example, a handover method may be provided for a user equipment for performing Vehicle To Everything (V2X) communication. The handover method may includes receiving synchronization type information for the V2X communication from a source base station, and configuring a synchronization type, receiving, from the source base station, handover command information including resource configuration information for the V2X communication which is configured by a target base station; and performing the V2X communication until completion of a handover to the target base station by using the resource configuration information.
TL;DR: This paper proposes an analytical model for the cross-tier handover processes in the HetNet using the stochastic geometry and closes-form expressions for the key handover performance metrics are deduced as functions of the base station density, time to trigger and user mobility.
Abstract: Denser deployments of heterogeneous networks (HetNets) lead to more frequent handovers, which results in a decline of user experience as well as heavy signaling overheads to the network. Therefore, the study on handover is of great importance especially in dense HetNets. In this paper, we focus on the analysis of cross-tier handover from the macro cell tier to the small cell tier, which shows the highest handover failure rate in current standards and industry studies. Using the stochastic geometry, we propose an analytical model for the cross-tier handover processes in the HetNet. Based on the derived analytical model, the closed-form expressions for the key handover performance metrics, including the handover rate, handover failure rate, and ping-pong rate, are deduced as functions of the base station density, time to trigger and user mobility. Simulation results verify the accuracy of the proposed analytical model and closed-form theoretical analyses, which provide guidance for the deployments of HetNets and corresponding handover strategies.
TL;DR: This work proposes a core-network efficient radio resource control signaling scheme for active state HO and develops an analytical framework to evaluate its signaling load as a function of network density, user mobility, and session characteristics.
Abstract: Frequent handovers (HOs) in dense small cell deployment scenarios could lead to a dramatic increase in signaling overhead. This suggests a paradigm shift toward a signaling conscious cellular architecture with intelligent mobility management. In this direction, a futuristic radio access network with a logical separation between control and data planes has been proposed in research community. It aims to overcome limitations of the conventional architecture by providing high data rate services under the umbrella of a coverage layer in a dual connection mode. This approach enables signaling efficient HO procedures since the control plane remains unchanged when the users move within the footprint of the same umbrella. Considering this configuration, we propose a core-network efficient radio resource control signaling scheme for active state HO and develop an analytical framework to evaluate its signaling load as a function of network density, user mobility, and session characteristics. In addition, we propose an intelligent HO prediction scheme with advance resource preparation in order to minimize the HO signaling latency. Numerical and simulation results show promising gains in terms of reduction in HO latency and signaling load as compared with conventional approaches.
TL;DR: The control plane structure of LTE/LTE-A is reviewed and a comprehensive discussion of handover procedures such as the phases, techniques, requirements, features, and challenges involved are presented.
Abstract: The increasing demand for mobile communication calls for improvements to network operating services in terms of capacity, coverage, and Quality of Services (QoS). Ensuring QoS is one of the challenges faced by wireless network operators, which include the provision of high mobility speeds, thus the implementation of a seamless and fast handover between network cells is a prominent issue that must be addressed, especially when fulfilling QoS prerequisites. Long Term Evolution (LTE)/LTE-Advance has met these demands of QoS through the use of a new Radio Access Network and distribution of Radio Resource Management including the handover decision technique to evolve NodeB instead of relying on centralized control. In this paper, we review the control plane structure of LTE/LTE-A and present a comprehensive discussion of handover procedures such as the phases, techniques, requirements, features, and challenges involved. According to the overview of the handover decision phase, we surveyed and classified the present handover decision algorithms for a LTE-A system-based technology in regard to the primary handover decision technique. For each class, we describe in detail the fundamental operations and decision parameters using representative algorithms. A summary of input parameters, techniques, and performance evaluation of the handover decision algorithms concludes this work.
TL;DR: The proposed AHA protocol is secure against different kinds of attacks and can meet a variety of security requirements, and has much less computation cost than three latest AHA protocols.
Abstract: With the development of the wireless communication technology and the popularity of mobile devices, the mobile wireless network (MWN) has been widely used in our daily life. Through the access point (AP), users could access the Internet anytime and anywhere using their mobile devices. Therefore, MWNs can bring much convenience to us. Due to the limitation of APs coverage, the seamless handover frequently occurs in practical applications. How to guarantee the users privacy and security and identify the real identity when he/she brings harm to the system becomes very challenging. To achieve such goals, many anonymous handover authentication (AHA) protocols have been proposed in the last several years. However, most of them have high computation costs because mobile nodes need to carry out the bilinear pairing operations or the hash-to-point operations. Besides, most of them cannot satisfy some critical requirements, such as non-traceability and perfect forward secrecy. In this paper, we first outline the security requirements of AHA protocols, and then propose a new AHA protocol to eliminate weaknesses existing in previous AHA protocols. Based on the hardness of two famous mathematical problems, we demonstrate that the proposed AHA protocol is secure against different kinds of attacks and can meet a variety of security requirements. It can be seen from the details of implementations that the proposed AHA protocol also has much less computation cost than three latest AHA protocols.