Handoff Management Scheme Research Articles

A Cooperative Road Topology-Based Handoff Management Scheme

Selecting the most stable partner on a vehicular ad hoc network (VANET) is a challenging task due to its unique mobility, driver behavior, and networking requirements. Although new partner selection protocols are introduced for mobile ad hoc networks and general mobility, there is a lack of a partner selection protocol that is suitable for VANET. This paper discusses the requirements of such a protocol and presents a handoff protocol that is tailored to VANET requirements. We leverage the use of partner-assisted handoff by introducing a vehicle link expiration time (VLET) metric that is designed to maximize intervehicular connections. The suitability of the proposed protocol is carefully studied and then compared to state-of-the-art protocols. A performance analysis comparing average connection time, connection stability, handoff delay, and success rate is carried out. The simulation results show that the proposed protocol enhances the handoff on VANET and can increase the average connection time among vehicles by 175%. This research advocates the importance of using road topology and traffic information for any future VANET handoff protocols and paves the way for future research on using the introduced VLET in other VANET applications.

Artificial Intelligence-Based Handoff Management for Dense WLANs: A Deep Reinforcement Learning Approach

So far, the handoff management involved in the wireless local area network (WLAN) has mainly fallen into the handoff mechanism and the decision algorithm. The traditional handoff mechanism generates noticeable delays during the handoff process, resulting in discontinuity of service, which is more evident in dense WLANs. Inspired by software-defined networking (SDN), prior works put forward many seamless handoff mechanisms to ensure service continuity. With respect to the handoff decision algorithm, when to trigger handoff and which access point to reconnect to, however, are still tricky problems. In this paper, we first design a self-learning architecture applicable to the SDN-based WLAN frameworks. Along with it, we propose DCRQN, a novel handoff management scheme based on deep reinforcement learning, specifically deep $Q$ -network. The proposed scheme enables the network to learn from actual users’ behaviors and network status from scratch, adapting its learning in time-varying dense WLANs. Due to the temporal correlation property, the handoff decision is modeled as the Markov decision process (MDP). In the modeled MDP, the proposed scheme depends on the real-time network statistics at the time of decisions. Moreover, the convolutional neural network and the recurrent neural network are leveraged to extract fine-grained discriminative features. The numerical results through simulation demonstrate that DCRQN can effectively improve the data rate during the handoff process, outperforming the traditional handoff scheme.

Modelling of routing and spectrum handoff in CR-MANETs

There is an extensive research interest in cognitive radio mobile ad hoc networks (CR-MANETs) to improve the spectrum efficiency by developing innovative design techniques through various layers of the protocol stacks. This paper presents the optimisation of CR-MANETs by exploiting the efficient usage of the available wireless spectrum through a framework for spectrum-aware handoff. In this paper, the concept of integrated handoff management in CR-MANETs is considered. An analytical model for a spectrum handoff scheme is introduced based on spectrum mobility in which secondary users (SUs) will move to another unused spectrum band, giving priority to a Primary User (PU), while satisfying its communication quality of service (QoS). The main contribution is using the Markov chain to model the evolution of the network (node position, node speed, channel quality, etc.) and to propose the combined spectrum handoff and routing. The performance of the network is analyzed based on the Markov chain. The comparison results from both analytical modelling and simulation clearly show an improvement in the performance of the SU network in terms of the route maintenance probability and the SU throughput. It is also proved that not only the PU activity affects the performance of the handoff management scheme but also the channel transmission range and the node mobility have a significant effect on the performance of the management scheme.

A Comparison Study on Selective Traffic Models with Handoff Management Scheme for Wireless Mobile Network Infrastructure

Wireless and Mobile Network Infrastructure services generally examine how different infrastructure providers are positioning themselves to compete in wireless services. These services analyze the opportunities and challenges facing by the infrastructure providers selling to wireless and mobile network operators worldwide. The opportunities and challenges are the review of strategies, market positioning, and future direction in the market for wireless and mobile network infrastructure. The service covers all generations of wireless and mobile network infrastructure: 2G, 2.5G, 3G, and 4G so on global in scope. Majority of the users are mobile while availing these services. Mobility is the most important feature of any wireless and mobile network. Usually, continuous service is achieved by supporting handoff from one cell to another. Poorly designed handoff schemes tend to generate very heavy signaling traffic and, thereby, lead to a dramatic decrease in quality of service. In this paper we make a comparison study on some selective traffic models with priority handoff scheme. The study shows how a handoff procedure has a significant impact on wireless mobile network performance on the basis of two primary criteria - Blocking probability of originating calls and the forced termination probability of ongoing calls. In addition to this the study shows arrival rate of handoff calls, and approximate number of mobile users that get serviced by underlying base station.

Modeling Prioritized Hard Handoff Management Scheme for Wireless Mobile Networks

The channel associated with the current connection serviced by a base station is changed while a call is in progress. Usually, continuous service is achieved by supporting handoff from one cell to another. It is often initiated either by crossing a cell boundary or by deterioration in quality of the signal in the current channel. The existing call is then changed to a new base station . For the traffics which are non stationary at and are away from the servicing base station , the chances of a call to be handed off are increasing. In this paper we propose a scheme S MH 2 to modeling and implementing a traffic el mod with handoff behavior for wireless mobile networks . The simulation model S MH 2 with priority is developed to investigate the performance behavior of hard handoff strategy. Novelty of the proposed model S MH 2 results that it can improve call blocking rate of handoff calls . In addition to this, measurement of blocking probabilities for both g originatin calls and handoff calls is another impressive achievement of the model. Index Terms — Mobile station, traffic model, arrival rate, departure rate, blocking probability, call blocking rate

Handoff management in communication-based train control networks using stream control transmission protocol and IEEE 802.11p WLANs

Communication-based train control (CBTC) network is an automated control network for railways that ensures the safe operation of rail vehicles using data communications. CBTC networks have stringent requirements for communication availability and latency. Wireless local area network (WLAN) is a popular choice in CBTC networks due to the available commercial-off-the-shelf WLAN equipments. However, handoffs in WLANs may result in communication interruption and long latency in WLANs-based CBTC networks. In this article, we propose a handoff management scheme for CBTC networks using stream control transmission protocol (SCTP) and IEEE 802.11p WLANs to provide high communication availability and low latency in CBTC networks. We formulate the handoff decision problem as a stochastic Semi-Markov Decision Process (SMDP) with the objectives of minimizing the handoff latency and maximizing the SCTP throughput. Simulation results are presented to show that the proposed scheme can significantly improve the handoff performance in CBTC networks.

Design and evaluation of a fast MAC layer handoff management scheme for WiFi-based multichannel Vehicular Mesh Networks

Vehicular Mesh Networks (VMNs) are important components of the wireless metropolitan networks. Compared with traditional wireless networks, they are more efficient in terms of deployment, configuration, and maintenance. However, connecting all mesh routers through wireless connection in VMNs results in the network backbone's remarkably lower bandwidth. Multichannel technology, where non-interfering channels are used to enable mesh routers to send and receive packets simultaneously, can be adopted to improve the throughput of VMNs. Due to the limited radio range of mesh routers, mobile clients have to switch among different mesh routers to maintain wireless connections. Therefore, providing smooth roaming in multichannel VMNs has become an important topic in VMN research. In this paper, a novel MAC layer handoff scheme is proposed as a means of minimizing handoff latency for WiFi-based multichannel VMNs to provide smooth communication for real-time applications. By designing a dynamic grouping algorithm for channel selection and allowing mesh routers to switch their channels for probe response messages, our scheme can shorten the waiting time for the detection of available access routers, decrease the loss ratio of data packets during the handoff, and consequently achieve smooth handoff in the MAC layer.

AP-Based Handoff Management Scheme Using Multiple Interfaces in IEEE 802.11 Wireless LANs

We propose an AP-based handoff management scheme in which each AP having multiple interfaces communicates with MSs by turns, prohibiting from using the same channel as neighboring APs at the same time to avoid interference. In the proposed scheme, APs support handoff management to accomplish MS-unaware handoff. Performance evaluation shows that the proposed scheme can not only achieve low handoff delay, but enhance throughput performance.

A cooperative diversity based handoff management scheme

Cooperative diversity has emerged as a promising technique to facilitate fast handoff mechanisms in mobile ad-hoc environments. The key concept behind a prominent cooperative diversity based protocol, namely, Partner-based Hierarchical Mobile IPv6 (PHMIPv6), is to enable mobile nodes anticipate handover events by selecting suitable partners to communicate on their behalves with Mobility Anchor Points (MAPs). In the original design of PHMIPv6, mobile hosts choose partners based on their signal strength. Such a naive selection procedure may lead to scenarios where mobile hosts lose communication with the selected partners before the completion of the handoff operations. In addition, PHMIPv6 overlooks security considerations, which can easily lead to vulnerable mobile hosts and/or partner entities. As a solution to these two shortcomings of PHMIPv6, this paper first proposes an extended version of PHMIPv6 called Connection Stability Aware PHMIPv6 (CSA-PHMIPv6). In CSA-PHMIPv6, mobile hosts select partners with whom communication can last for a sufficiently long time by employing the Link Expiration Time (LET) parameter. To tackle the security issues, the simple yet effective use of two distinct authentication keys is envisioned. Furthermore, to shorten the communication time between mobile hosts and their corresponding partners, a second handoff management approach called Partner Less Dependable PHMIPv6 (PLD-PHMIPv6) is proposed.

Locating mobile nodes using heuristics with fuzzy logic handoff

In wireless and mobile networks ensuring smooth handoff and tracing exact location of destination node and that too without wasting much time and bandwidth of constrained network is much essential. Several related techniques have been proposed in literature. Each has its own advantages/disadvantages. In this paper, we have proposed, first, a fuzzy logic based handoff management scheme that also handles some basic network management activities like call transferring after allotting a suitable wireless or radio link to the incoming node. It also proposes a location management scheme based on simple heuristics technique like time and probability.

Link quality prediction in mesh networks

Wireless self-organizing networks such as mesh networks strive hard to get rid of mobility and radio propagation effects. Links – the basic elements ensuring connectivity in wireless networks – are impacted first from them. But what happens if one could mitigate these effects by forecasting the links’ future states? In this paper, we propose XCoPred (using Cross-Correlation to Predict), a pattern matching based scheme to predict link quality variations. XCoPred does not require the use of any external hardware, it relies simply on Signal to Noise Ratio (SNR) measurements (that can be obtained from any wireless interface) as a quality measure. The nodes monitor and store the links’ SNR values to their neighbors in order to obtain a time series of SNR measurements. When a prediction on the future state of a link is required, the node looks for similar SNR patterns to the current situation in the past (time series) using a cross-correlation function. The matches found are then used as a base for the prediction. Clearly, XCoPred takes advantage of the occurrence and recurrence of patterns observed in SNR measures reflecting the joint effect of human motion and radio propagation. XCoPred focuses only on the scale of links and as such is complementary to mobility prediction schemes, which target prediction at a broader scale. We first prove the occurrence of SNR patterns resulted by the joint effect of human motion and radio propagation. Then we evaluate XCoPred in an indoor mesh network showing, that XCoPred is able to recognize mobility patterns in up to 85% of the cases correctly and the average prediction error on mid-term predictions (i.e., assessing the future link quality more than 1 min ahead) is less than half the error we get using linear prediction. Eventually, we propose and evaluate an enhanced handoff management scheme for 802.11 mesh networks showing the usefulness of XCoPred as a cross-layer input.

Reliable Integrated Architecture for Heterogeneous Mobile and Wireless Networks

The major trend in next-generation or 4G wireless networks (NGWN/4G) is the coexistence of diverse but complementary architectures and wireless access technologies. In this context, an appropriate integration and interworking of existing wireless networks are crucial to allow seamless roaming across those networks. Several integrated architectures have been proposed for 3G cellular networks and wireless local area networks (WLANs) by both third generation wireless initiatives, 3GPP and 3GPP2. However, the proposed architectures have several drawbacks, the most significant being the absence of quality of service (QoS) guarantees, seamless roaming and service continuity. This paper proposes a novel architecture, called Integrated InterSystem Architecture (IISA), which enables the integration and interworking of various wireless networks and hide their heterogeneities from one another. The IISA architecture aims provisioning of guaranteed seamless roaming and service continuity across different access networks. Performance evaluation shows that IISA together with the proposed handoff management scheme provide significant gains than existing interworking architectures and mobility management protocols.

The Research on Handoff Strategy in Beyond 3G Wireless Networks

One of the major challenges for beyond third generation mobile systems is efficient mobility management. This paper proposes a distributed dynamic management scheme of handoff based on B3G networks. This scheme can reduce the cost of update signalling and transmitting packets, and improve the system capability. In this scheme, the dynamic building network approach is adopted to deduce the-update signalling cost. We implement the distributed dynamic management scheme of handoff in a simulation platform and compare its performance with that of general centralized handoff management schemes. Our simulation results indicate that our scheme is capable of reducing the update handoff latency, and enhancing the performance.

Integrating distributed channel allocation and adaptive handoff management for QoS-sensitive cellular networks

Next generation high-speed cellular networks are expected to support multimedia applications, which require QoS provisions. Since frequency spectrum is the most expensive resource in wireless networks, it is a challenge to support QoS using limited frequency spectrum. In the literature, two orthogonal approaches are used to address the bandwidth utilization issue and the QoS provision issue; that is, channel allocation schemes have been proposed to improve bandwidth efficiency, whereas handoff management schemes, based on bandwidth reservation, have been proposed to guarantee a low connection dropping rate. However, little effort has been taken to address both issues together. In this paper, we integrate distributed channel allocation and adaptive handoff management to provide QoS guarantees and efficiently utilize the bandwidth. First, we present a complete distributed distributed channel allocation algorithm and propose techniques to reduce its message complexity and intra-handoff overhead. Second, we integrate the proposed distributed channel allocation algorithm with an adaptive handoff management scheme to provide QoS guarantees and efficiently utilize the bandwidth. Detailed simulation experiments are carried out to evaluate the proposed methodology. Compared to previous schemes, our scheme can significantly reduce the message complexity and intra-handoff overhead. Moreover, the proposed scheme can improve the bandwidth utilization while providing QoS guarantees.

Q-Win --- A New Admission and Handoff Management Scheme for Multimedia LEO Satellite Networks

Low Earth Orbit (LEO) satellite networks are deployed as an enhancement to terrestrial wireless networks in order to provide broadband services to users regardless of their location. In addition to global coverage, these satellite systems support communications with hand-held devices and offer low cost-per-minute access cost, making them promising platform for Personal Communication Services (PCS). LEO satellites are expected to support multimedia traffic and to provide their users with the negotiated Quality of Service (QoS). However, the limited bandwidth of the satellite channel, satellite rotation around the Earth and mobility of end-users makes QoS provisioning and mobility management a challenging task. One important mobility problem is the intra-satellite handoff management. The main contribution of this work is to propose Q-Win, a novel call admission and handoff management scheme for LEO satellite networks. A key ingredient in our scheme is a companion predictive bandwidth allocation strategy that exploits the topology of the network and contributes to maintaining high bandwidth utilization. Our bandwidth allocation scheme is specifically tailored to meet the QoS needs of multimedia connections. The performance of Q-Win is compared to that of two recent schemes proposed in the literature. Simulation results show that our scheme offers low call dropping probability, providing for reliable handoff of on-going calls, good call blocking probability for new call requests, while maintaining bandwidth utilization high.

Synchronization and handoff management schemes for wireless multimedia systems

This paper presents handoff management schemes for synchronization algorithms for wireless multimedia systems. The synchronization and handoff management schemes allow mobile hosts to receive time-dependant multimedia streams without delivery interruption while moving from one cell to another. They also maintain the correct ordering of the media components, through the execution of the wireless multimedia application by a means of timestamped messages passed among mobile hosts, base stations and servers. The timestamp values are used to compute the delay for each multimedia unit for each server. Furthermore, the proposed schemes always search for a quasi-receiver among the base stations with which the mobile hosts can communicate to synchronize multimedia units. We discuss the algorithms and present a set of simulation experiments that evaluate the performance of our schemes, using message complexity and buffer usage at each frame arrival time. Our results indicate that our schemes exhibit no underflow or overflow within the bounded delivery time.

An efficient handoff management scheme for mobile wireless ATM networks

A new handoff management scheme for wireless ATM networks is proposed. In this scheme, all cells are connected to their neighboring cells by permanent virtual circuits (PVCs) and to the access switch (AS) by switched virtual circuits (SVCs) which are only for new calls. Some carefully chosen cells, called rerouting cells, are also connected to the AS by PVCs. In summary, if a mobile roams to an ordinary neighboring cell, its traffic path is simply elongated by a PVC connecting the old and new cells. If a mobile roams to a rerouting cell, its traffic path is rerouted to a PVC between the AS and rerouting cell. By using PVC's for handoff calls, we can guarantee fast and seamless handoff. At the same time, our scheme improves the path efficiency by limiting the maximum number of hops that a path can be extended. Also, allowing path rerouting at a suitable time means the network resources are more efficiently utilized.

An adaptive resource allocation mechanism including fast and reliable handoff in IP-based 3G wireless networks

The aim of the all-IP architecture in third-generation wireless networks is to allow operators to deploy IP technology in delivering third-generation services, that is, an architecture based on packet technologies and IP telephony for simultaneous real-time and non-real-time services. We present a new handoff management scheme that utilizes simultaneous multiple bindings in IP-based 3G wireless networks. The proposed handoff scheme minimizes packet losses and incurs negligible delays during handoff. We also present an adaptive resource allocation scheme that allocates connection resources to incoming calls depending on the network conditions. The resources accumulated by bandwidth degradation for on-going calls are utilized to minimize dropping probability of handoff calls and blocking probability of new calls.

A Fast Handoff Management Scheme in ATM-Based Personal Communication Networks

Future wireless personal communication networks will likely have infrastructures based on asynchronous transfer mode (ATM) networks. It is a challenge to support seamless, fast handoffs in such an environment. We propose a fast handoff management scheme using permanent virtual connections (PVCs) reserved between neighboring base stations (BSs). In the proposed scheme, the handoff can be quickly performed by rerouting the communication path via the PVCs. Handoff calls are distributively controlled only by the corresponding BSs without the involvement of any ATM switches. ATM cell sequence integrity during handoff can be maintained by the BSs. In order to dimension the PVC, we analytically derive the probability of handoff blocking due to the lack of PVCs. We give some numerical examples of PVC dimensioning. The proposed scheme can be utilized in the future IMT-2000 networks accommodating various narrowband services in the range of several kbps to several hundreds kbps.