Handoff Delay Research Articles

Proactive Caching for Mobile Video Streaming in Millimeter Wave 5G Networks

Mobile video streaming is fundamental to advanced applications in the fifth generation (5G) networks. Millimeter wave (mmWave) communication represents a leading 5G technology, which provides rich bandwidth and, therefore, great potentials for high-quality mobile video streaming. However, mobile video streaming in mmWave 5G networks faces fundamental challenges due to mmWave antenna directivity and high user mobility. As such, users typically have short connection durations and frequent handoffs, making video streaming suffer from long handoff delays and connection latency. In this paper, we tackle the issues by developing a caching-based mmWave framework, which precaches video contents at the base station for handoff users and thus significantly reduces the connection and retrieval delays. As a result, high-mobility users with frequent handoffs can enjoy continuous high-quality video streaming. Specifically, we model the proposed system as a cache management problem and attain optimal video streaming quality by using Markov decision process to dynamically allocate proper cache memory space of each base station to mobile users. A cell-by-cell decomposition method is proposed to solve the dynamic programming problem with significantly reduced computational complexity. Using extensive simulations, we demonstrate that the proposed solution can effectively maintain high-quality mobile video streaming for high-mobility 5G users moving among mmWave small cells with directional antenna.

DMP-IOT: A distributed movement prediction scheme for IOT health-care applications

Mobility prediction in IP-based WSNs makes it possible to predict the next movement direction of mobile sensor nodes, which results in less power consumption and delay during handoff. The previous direction detection approaches need specific hardware facilities and impose considerable overhead during handoff. The advantage of DMP-IOT is distributing the learning model data around static sensors of the proposed tree, after the training phase. DMP-IOT includes a recovery mechanism that avoids disconnection of the mobile sensor node(s) to the network in case of a false prediction. The simulation results show about 25% improvement of DMP-IOT in saving power consumption and reducing handoff delay and packet loss, compared to movement direction approaches in similar works. The accuracy of the proposed movement prediction scheme is 83%, in average, which is validated by t−Student statistical test. Comparing the second-order Hidden Markov Model (HMM) with ANN reveals the superiority of the second-order HMM model in our application.

A Numerical Framework for the Analysis of Handoff Delay Component in Proxy NEMO Environment

Network Mobility Basic Support Protocol (NEMO-BSP), the existing IETF standard for mobile network support, signifies an important portion for future heterogeneous wireless access networks. The reason is to provide continuous Internet connectivity during movement of Mobile Router (MR) in NEMO. This paper conducted a quantitative analysis on the handoff delay component of NEMO-BSP as well as its existing enhancements, i.e., Fast NEMO (F-NEMO) handoffs, and an Extension of F-NEMO (EF-NEMO), using the numerical framework. The mathematical scenario includes two access routers, one local home agent and up to 20 MRs that interrelate by two different wireless access networks are mainly WiFi and WiMAX. The analysis offers quantitative outcomes of the performance enhancements achieved via the proposed improvements concerning handoff delay gain, packet loss, and packet loss ratio. The numerical results assist in understanding the influence of link switching delay, mobility rate, and radius on the handoff delay gain, packet loss, and packet loss ratio. The results of this analysis will also be aided to pick an appropriate mobility management scheme for Proxy NEMO environment.

User-oriented seamless service handoff in the ubiquitous computing environment

Purpose User-oriented seamless service handoff is prosperous in the ubiquitous computing environment. This paper aims to present an open architecture for the user-oriented seamless service handoff across heterogeneous platforms. The migration of service environment is the key to implement the user-oriented service handoff. A distributed service handoff scheme based on the binary sensor network and context-aware middleware has been proposed. Design/methodology/approach To validate this scheme, a test-bed has been constructed in the lab environment. Findings The experimental results show that the proposed scheme can reduce the service handoff delay compared to the centralized scheme. Originality/value The experimental results show that the scheme can reduce the delay of service handoff compared to the traditional centralized scheme.

Extended Vertical Handoff Decision in Next Generation Wireless Networks

In the vision of 4G wireless communications, it is requisite to provide seamless mobility support across heterogeneous access networks. The benefit of heterogeneous network is that, devices can connect to different wireless networks without interruption of service while the network is being switched. The problem in heterogeneous environments is that transition between diverse types of access technologies can lead to reduced performance, mainly due to incompatibility problems. Seamless mobility can be achieved by enabling mobile terminals to conduct seamless handovers across diverse access networks, that is, seamlessly transfer and continue their ongoing sessions from one access network to another. One major challenge in cellular/WLAN internetworking is how to take advantage of the wide coverage and almost universal roaming support of cellular networks and the high data rates of WLAN. Many issues should be carefully addressed to achieve seamless interworking, such as mobility management, resource allocation, call admission control, security and billing. The vertical handoff requirements are potential of the network, network cost, handoff latency, network conditions, power consumption and user's preference. These must be considered during vertical handoff. In this research paper a new vertical handoff decision based on ARM & AI Techniques is designed. A refined, intelligent Associative Rule Mining (ARM) and Artificial Intelligence (AI) based technique is used to execute the vertical handoff intelligent mechanism in fourth generation wireless networks to produce an effective service which reduces the handoff delay and complexity.

A framework for optimal cost media streaming in three-tier wireless networks

Heterogeneous networking is envisioned as a key solution for accommodating the traffic surge resulting from resource demanding applications such as video streaming. In this paper, the diversity in cost, coverage, and resource availability in heterogeneous systems is exploited to minimize the streaming session cost in three-tier integrated systems. A sub-optimal streaming decision engine is developed to overcome the complexity of the original problem whose solution contradicts with both the limited processing capabilities of end-user equipment and short handoff delay requirements. Our results show that the developed framework achieves significant monetary cost savings in comparison to typical greedy streaming behavior. Additionally, our solution can be easily tuned to compromise the tradeoff between monetary, signaling and quality cost components.

A Real-time Spectrum Handoff Algorithm for VoIP based Cognitive Radio Networks: Design and Performance Analysis

Secondary Users (SUs) in a Cognitive Radio Network (CRN) face unpredictable interruptions in transmission due to the random arrival of Primary Users (PUs), leading to spectrum handoff or dropping instances. An efficient spectrum handoff algorithm, thus, becomes one of the indispensable components in CRN, especially for real-time communication like Voice over IP (VoIP). In this regard, this paper investigates the effects of spectrum handoff on the Quality of Service (QoS) for VoIP traffic in CRN, and proposes a real-time spectrum handoff algorithm in two phases. The first phase (VAST-VoIP based Adaptive Sensing and Transmission) adaptively varies the channel sensing and transmission durations to perform intelligent dropping decisions. The second phase (ProReact-Proactive and Reactive Handoff) deploys efficient channel selection mechanisms during spectrum handoff for resuming communication. Extensive performance analysis in analytical and simulation models confirms a decrease in spectrum handoff delay for VoIP SUs by more than 40% and 60%, compared to existing proactive and reactive algorithms, respectively and ensures a minimum 10% reduction in call-dropping probability with respect to the previous works in this domain. The effective SU transmission duration is also maximized under the proposed algorithm, thereby making it suitable for successful VoIP communication.

HMMCCN: a hierarchical mobility management scheme for content-centric networking

Content-centric networking CCN has emerged as a promising paradigm in current internet. Owing to the interest-driven, we concern more about the content itself rather than the place it located, and therefore, CCN supports subscriber mobility natively, however, it remains a major challenge in publisher mobility. In this paper, we propose a hierarchical mobility management scheme for CCN HMMCCN which contains an overlay mapping structure to store the old-to-new name binding relationship and perform the mobility management for mobile devices. This allows for efficient simultaneous mobility and supports seamless handoff for interactive communication. The main goals of this paper are: a to propose a mobility scheme suitable for all mobile nodes in CCN, both the publishers and subscribers; b to describe the hierarchical mobility management procedure during intra-domain and inter-domain handoff; c to establish an analytical model and formulate the location update signalling cost, handoff delay; d to calculate k

HMMCCN: a hierarchical mobility management scheme for content-centric networking

Content-centric networking (CCN) has emerged as a promising paradigm in current internet. Owing to the interest-driven, we concern more about the content itself rather than the place it located, and therefore, CCN supports subscriber mobility natively, however, it remains a major challenge in publisher mobility. In this paper, we propose a hierarchical mobility management scheme for CCN (HMMCCN) which contains an overlay mapping structure to store the old-to-new name binding relationship and perform the mobility management for mobile devices. This allows for efficient simultaneous mobility and supports seamless handoff for interactive communication. The main goals of this paper are: a) to propose a mobility scheme suitable for all mobile nodes in CCN, both the publishers and subscribers; b) to describe the hierarchical mobility management procedure during intra-domain and inter-domain handoff; c) to establish an analytical model and formulate the location update signalling cost, handoff delay; d) to calculate kopt in the content router (CR) for decreasing the total overhead during handoff.

Joint Routing and Admission Control in Wireless Mesh Network

Wireless Mesh Network is a promising technology with many challenges yet to be addressed. Novel and efficient algorithms need to be developed for routing and admission control with the objective to increase the acceptance ratio of new calls without affecting the Quality of Service (QoS) of the existing calls and to maintain the QoS level provided for the mobile calls. In this paper, a novel Markov Decision-based Admission Control and Routing (MDACR) algorithm is proposed. The MDACR algorithm finds a near optimal solution using the value iteration method. To increase the admission rate for both types of calls, a multi-homing admission and routing algorithm for handoff and new calls is proposed. This algorithm associates the user with two different access points which is beneficial in a highly congested network and proposes a new routing metric to assure seamless handoff in the network. Our proposed algorithm outperforms other algorithms in the literature in terms of handoff delay, blocking probability, and number of hard handoff.

An Improved SIP Protocol in Heterogeneous Mobile Network for Efficient Communication

Disaster response and recovery requires timely interaction and coordination of disaster responders in order to save people lives and property. Public safety land mobile radio networks provide only limited support of low speed data services, which is not efficient for the emergency communication. The Land Mobile Radio accesses the radio resources of cellular network for getting a wide variety of benefits such as new multimedia services, increased data rates. SIP based handoff solutions is still not good enough in the interworking public safety LMR and cellular network for emergency communication because SIP has been used “Break-before-make” mechanism. This paper describes proposed approach and its prototype implementation. The proposed approach, Seamless Session Initiation Protocol (S-SIP) with Optimal Radio Resource Utilization framework is proposed to ensure reduction of handoff delay, increase the radio resource utilization for service availability and service continuity. The “Make-before-break” mechanism is used in Seamless SIP scheme. As a result, it is found that the proposed schemes performed better than existing schemes sometimes that is double.

Traffic‐Adaptive Proactive Spectrum Handoff Strategy for Graded Secondary Users in Cognitive Radio Networks

In order to meet different delay requirements of various communication services in Cognitive radio (CR) networks, Secondary users (SUs) are divided into two classes according to the priority of accessing to spectrum in this paper. Based on the proactive spectrum handoff scheme, the Preemptive resume priority (PRP) M/G/1 queueing is used to characterize multiple spectrum handoffs under two different spectrum handoff strategies. The traffic-adaptive spectrum handoff strategy is proposed for graded SUs so as to minimize the average cumulative handoff delay. Simulation results not only verify that our theoretical analysis is valid, but also show that the strategy we proposed can reduce the average cumulative handoff delay evidently. The effect of service rate on the proposed spectrum switching point and the admissible access region are provided.

Implementing PMIPv6 Protocol Based on Extended Service Set for IEEE 802.11 Infrastructure WLAN

With the popularity of IEEE 802.11 based wireless fidelity (Wi-Fi) portable devices, it becomes increasingly significant to support the mobile users carrying Wi-Fi devices to access the Internet of Things (IoT) so that the communications between the mobile users and the smart objects deployed in the IoT stay uninterrupted when the mobile users are in movement. A scheme using Extended Service Set- (ESS-) based architecture is presented to implement the proxy mobile IPv6 protocol, that is, PMIPv6, for IEEE 802.11 infrastructure Wireless Local Area Networks (WLANs). The key signaling packets together with their time sequences for the mobility management in the proposed scheme are proposed. Moreover, the handoff delay in the proposed scheme is derived, through which the performance of the proposed scheme is analyzed. Numerical analysis indicates that the proposed scheme considerably outperforms the existing scheme that uses the Basic Service Set (BSS) based architecture in terms of handoff delay in the case when the delay between Mobile Access Gateway (MAG) and local mobile anchor (LMA) is relatively large.

Efficient Vertical Handoff Algorithm for Mission-Critical Management

In the Global scenario, a variety of wireless access networks are available. Heterogeneous Wireless Networks is an integration of two different networks (Cellular and WLAN). When connections need to migrate between heterogeneous networks, vertical handoff is required to provide the best performance and better QoS. With reference to the performance of VHO, there is an acute need to develop algorithm for Mission Critical Management and thus improving network performance. During disaster management operations, there is a possibility of a failure in network connectivity of the corresponding MN. So there is an inefficient system, where lot of casualties are to be reported while there is loss of communication. Due to the above reason, the MN initiates the handoff triggering to the neighboring network. In this work, a VHO decision algorithm is proposed based on the markov model. The proposed M-OPTG algorithm is selecting a network based on the load, battery life time of the MN and call dropping rate. The M-OPTG enables a wireless access network to balance the overall load among all attachment points, which improves battery life time of MN, reduces call drop probability, reducing the handoff delay and thus improving the system throughput. This algorithm gives better result when compared to traditional RSS method and OPTG.

Group-Based Predictive Handoff for SIP Sessions in Vehicular M2M Network Mobility Management

When a group of machine type communication (MTC) ‘smart mobile devices’ in vehicular area network move together as a single unit, the network requires to resolve how to manage the group-based location transition and handoff for all group members with efficient signaling exchange and congestion mitigation. As an attractive solution, the Session Initiation Protocol (SIP) based Network Mobility (SIP-NEMO) has attracted much interests among the industry and academia. However, SIP-NEMO is vulnerable to the simultaneous handoff problem and weak in supporting seamless services, because of the direct binding updates between both mobile SIP nodes, as well as a potentially large number of mobile devices. In this paper, we investigate a novel group-based SIP sessions mobility management scheme for the MTC devices that are onboard traveling among long term evolution base stations. Firstly, some novel basic attributes of the SIP protocol are defined and the corresponding key SIP session procedures, including session setup, location registration and location update, are optimized. Then, we propose a predictive resource reservation algorithm for group-based handoff to achieve seamless services. Furthermore, we develop an analytical model to study the performance from the aspect of the average handoff delay. The simulation results indicate that the network congestion caused by the simultaneous handoff of a group of MTC devices onboard could be reduced effectively.

Quantifying picker blocking in a bucket brigade order picking system

Bucket brigade is a linear order-picking process with one loading station and one unloading station. Here we model and quantify picker blocking in bucket brigade order picking systems (OPSs). A bucket brigade improves throughput and reduces variability in OPSs. However, each order picking trip fills different orders and creates workload variation per order. We show that bucket brigade order picking experiences picker blocking when there is a workload imbalance per pick face. We derive a closed-form solution to quantify the level of blocking for two extreme walk speed cases. Additional simulation comparisons validate the picker blocking model which includes backward walk and hand-off delays. We identify the relationship between picker blocking in bucket brigade OPSs and picker blocking in a circular-aisle abstraction of OPSs in which backward walk and hand-off delays as well as forward walk speed are considered. Our analytical model and simulations show that aggregating orders into batches smoothes the workload variation by pooling the randomness of picks in each order and that slowest-to-fastest picker sequencing modulates picker blocking between two pickers, i.e., the interaction between neighboring pickers.

Implementation and Performance Analysis of Mobile Handoff Process on OpenFlow-based Wi-Fi Network

Research in communication networks has its limits due to the problems of supply frequency and equipment. To overcome this problem, open source can be the solution to build a helpful test bed for research or academic purposes. Open source networks can be developed using a Software Defined Network (SDN) which has been continuously developed due an enormous number of installed base equipment and protocols that are inflexible, predefined, and fixed since SDN offers a flexible, dynamic, and programmable functionality of network systems. By using OpenFlow as its protocol, we can program the network flow in a flow table on different switches and routers. This research approches an OpenFlow-based Wi-Fi environment using an OpenFlow-based Access Point (OFAP) and an OpenFlow controller. Each OFAP is deployed in two different rooms and several experiments were performed to evaluate handoff delay. The result of these experiments shows that an OpenFlow-based network delivers a more stable process than a traditional network because of the installed flows that are given to each packet. However, the discovered value needs to be examined further due to a better mechanism for installed flows. The handoff delay between OFAPs is 24% faster than the handoff delay between a traditional AP with an average of 79.9 miliseconds. By using this system, we believe it could deliver a high performance network and an increased reliability for real-time traffic over WLAN, by reducing the handoff delay compared to a classical Wi-Fi environment.

A Pre-Scanning Fast Handoff Scheme for VoIP in WLANs

IEEE 802.11 wireless local area networks (WLAN) have been widely deployed, and many applications are implemented on WLAN. As one of the interesting wireless services, wireless voice over internet protocol (VoIP) can provide low-cost real-time voice service to mobile users. But the IEEE 802.11 wireless network cannot satisfy the QoS of VoIP. The delay during handoff process can last up to 1 second. Applications with delay restraint like VoIP will drop the call when the delay is more than 50 ms. Therefore this paper analyzed the delay made by the handoff process, and proposed a pre-scanning fast handoff scheme. This fast handoff scheme is based on selective scanning and caching. It can predict the next AP for STAs and use pre-scanning before the handoff is triggered. Simulations on OPNET show this proposed scheme can reduce the average handoff delay to 23.45 ms and avoid some unnecessary handoffs. The pre-scanning fast handoff scheme is feasible and economical according to its performance in the handoff process.

Channel Availability Analysis of Spectrum Handoff in Cognitive Radio Networks

In this letter, steady-state analyses of spectrum handoff delay and channel availability are presented when spectrum handoff is used in a cognitive radio network. The effects of spectrum sensing time, data transmission time, and state transition rates of primary user signals are studied. Numerical results show that executing spectrum handoff results in higher channel availability than not executing spectrum handoff. However, this benefit of spectrum handoff decreases as the data transmission time or the state transition rates of primary user signals increase.

이동 클라우딩 환경에서 LBS 지원 핸드오프 기법

본 논문에서는 이동 클라우딩 환경에서 LBS(Location Based Services)를 지원하는 핸드오프 기법을 제안한다. 이동 클라우딩 컴퓨팅은 핸드오프 지연과 함께 재인증 지연이 발생한다. 단말이 새로운 AP에 도착하면 클라우드 서버로부터 다시 인증을 받는 절차가 필요하다. 하지만 위치정보를 이동 단말의 재인증에 사용하면 인증에 따른 지연시간을 감축시킬 수 있다. 이를 위해 제안하는 기법은 위성신호를 받지 못하는 실내에서 사용할 수 없는 GPS기반 기술을 보완할 수 있는 WiFi 기반의 위치정보 서버에 AP의 위치정보를 구축하고 핸드오프 수행 시에 위치정보를 수집하도록 하였다. 또한 핸드오프 시에 위치정보 요청을 분리하여 처리하도록 하여 핸드오프지연 시간의 증가 없이 LBS 처리를 가능하도록 하였다. 성능 분석은 핸드오프 지연시간과 위치정보 처리시간과 이에 따라 발생하는 데이터의 양을 기존의 클라우드 환경에서의 핸드오프 기법과 비교 분석하였다. 제안한 기법은 핸드오프 시에 위치정보 서버를 통해 위치정보를 수신하도록 하여 LBS 처리에 따른 지연시간이 낮았으며 핸드오프 수행시간이 증가하지 않는 것을 확인하였다. In this paper, we propose a handoff method supporting LBS (Location Based Services) Information in mobile clouding environment. In mobile clouding computing, handoff delay and re-authentication is occurred. A mobile node needs re-authentication procedure from cloud server whenever it arrives new AP. But Using of location information of node enables to reduce delay time due to re-authentication. To reduce re-authentication delay time, proposed method stores location information of APs on WiFi based location server to complement. GPS-based technology which can't receive satellite signal in indoor and then node collects location information of AP at handoff time. And also enables to process LBS without increasing handoff delay by splitting the process of handoff from process of requesting location information. For analysis of proposed method, We analyze handoff delay and location information process time and have compared previous handoff method in cloud environment. We confirmed that proposed method shows lower delay time without increasing LBS process time than previous method because node receives location information from location information server when handoff is occurred.