Experimental analysis of connectivity management in mobile operating systems

We are immerse in a world that becomes more and more mobile every day, with ubiquitous connectivity and increasing demand for mobile services. Current mobile terminals support several access technologies, enabling users to gain connectivity in a plethora of scenarios and favoring their mobility. However, the management of network connectivity using multiple interfaces is still starting to be deployed. The lack of smart connectivity management in multi interface devices forces applications to be explicitly aware of the variations in the connectivity state (changes in active interface, simultaneous access from several interfaces, etc.). In this paper, we analyze the present state of the connection management and handover capabilities in the three major mobile operating systems (OSes): Android, iOS and Windows. To this aim, we conduct a thorough experimental study on the connectivity management of each operating system, including several versions of the OS on different mobile terminals, analyzing the differences and similarities between them. Moreover, in order to assess how mobility is handled and how this can affect the final user, we perform an exhaustive experimental analysis on application behavior in intra- and inter-technology handover. Based on this experience, we identify open issues in the smartphone connectivity management policies and implementations, highlighting easy to deploy yet unimplemented improvements, as well as potential integration of mobility protocols.This work has been partially supported by the European Community through the CROWD project, FP7-ICT-318115.Publicad

On secure communication in integrated internet and heterogeneous multi-hop wireless networks.

Integration of the Internet with a Cellular Network, WMAN, WLAN, and MANET presents an exceptional promise by having co-existence of conventional WWANs/WMANs/WLANs with wireless ad hoc networks to provide ubiquitous communication. We call such integrated networks providing internet accessibility for mobile users as heterogeneous multi-hop wireless networks where the Internet and wireless infrastructure such as WLAN access points (APs) and base stations (BSs) constitute the backbone for various emerging wireless networks (e.g., multi-hop WLAN and ad hoc networks. Earlier approaches for the Internet connectivity either provide only unidirectional connectivity for ad hoc hosts or cause high overhead as well as delay for providing full bi-directional connections. In this dissertation, a new protocol is proposed for integrated Internet and ad hoc networks for supporting bi-directional global connectivity for ad hoc hosts. In order to provide efficient mobility management for mobile users in an integrated network, a mobility management protocol called multi-hop cellular IP (MCIP) has been proposed to provide a micro-mobility management framework for heterogeneous multi-hop network. The micro-mobility is achieved by differentiating the local domain from the global domain. At the same time, the MCIP protocol extends Mobile IP protocol for providing macro-mobility support between local domains either for single hop MSs or multi-hop MSs. In the MCIP protocol, new location and mobility management approaches are developed for tracking mobile stations, paging, and handoff management. This dissertation also provides a security protocol for integrated Internet and MANET to establish distributed trust relationships amongst mobile infrastructures. This protocol protects communication between two mobile stations against the attacks either from the Internet side or from wireless side. Moreover, a secure macro/micro-mobility protocol (SM3P) have been introduced and evaluated for preventing mobility-related attacks either for single-hop MSs or multi-hop MSs. In the proposed SM3P, mobile IP security has been extended for supporting macro-mobility across local domains through the process of multi-hop registration and authentication. In a local domain, a certificate-based authentication achieves the effective routing and micro-mobility protection from a range of potential security threats

Intra-domain mobility management

Mobility supporting protocols are designed to provide connectivity of mobile nodes from any point of attachment to the Internet. Fast handoff, low signaling overhead and packet loss are the key factors to be addressed in designing a mobility management protocol. This work proposes Intra Domain Mobility Management (IDMM) protocol, based on micro-mobility concept. The protocol implements an efficient tracking mechanism for locating the mobile nodes and ensures that their movements remain transparent to communicating nodes. The protocol is designed with the hierarchical tree topology in mind that allows for low cost solution and efficient management. The optimized routing enables fast delivery of packets to the mobile node in the micro-mobility domain. IDMM is implemented using Network Simulator (ns2) tools. Packet loss, throughput, delay in the network and traffic overhead due to location management are studied. The comparison with major mobility protocols such as Mobile IP and Cellular IP is done to demonstrate the performance of IDMM under high frequency of roaming

Analytic Evaluation and Experimental Validation of a Network-Based IPv6 Distributed Mobility Management Solution

Mobile Internet traffic is growing steeply, mainly due to the deployment of new broadband wireless technologies and the ever increasing connectivity demand coming from new services being available to mobile users. Current mobile network architectures rely on centralized mobility protocols which intrinsically pose enormous burdens on the central anchors, both in terms of connectivity needs and user mobility management. In order to face these issues, a new paradigm, called Distributed Mobility Management, is being explored, based on flattening the network architecture by deploying multiple mobility anchors at the edge of the network. In this article we conduct an analytic and experimental evaluation of a network-based IP distributed mobility management solution that leverages Proxy Mobile IPv6 protocol operations. We develop an analytic model of the signaling and packet delivery costs, as well as the handover latency of both Proxy Mobile IPv6 and our distributed solution. We have also implemented a Linux-based prototype of our proposal, which has been used to experimentally assess the handover latency in a real IEEE 802.11 scenario. Finally, we use the results obtained from the analytic and experimental performance to evaluate the benefits that could be achieved by deploying a distributed mobility management solution.The research leading to these results has received funding from the European Community's Seventh Framework Program FP7/2007-2013 under grant agreement 317941-project iJOIN. The European Union and its agencies are not liable or otherwise responsible for the contents of this document; its content reflects the view of its authors only. The research of Antonio de la Oliva has also been partially funded from the Spanish Government, MICINN, under research Grant TIN2010-20136-C03Publicad

The design of a Bayesian Network for mobility management in Wireless Sensor Networks

Mobility in Wireless Sensor Networks (WSNs) is achieved by attaching sensors to mobile objects such as animals (Juang et al. 2002), people (Campbell et al. 2008), and robots (Dantu et al. 2005). Currently, the research about WSN management is mainly focused on energy management functions to control how sensors should use their power; fault management functions to solve sensor problems; quality of services (QoS) management functions to quantify and control the performance; and mobility management functions to detect the sensor movement so that the network wireless connectivity is always maintained (Wang et al. 2010; Ruiz et al. 2003). However, the sensor mobility has not only an impact on the network connectivity, but also on the network spatial coverage. In mobile WSNs, the extension of the spatial coverage is often changing, and as a result, the region of interest might be inaccurately sensed by the mobile sensors. Therefore, the representation of a movement context is important to avoid making interpretations and decisions outside of the situation in which the WSN is capturing information; and make possible to decide where, when and how the sensing is performed in order to obtain the most suitable spatial coverage of a region of interest. This paper proposes a Bayesian network (BN) approach for making explicit the structural and parametric components of a movement context using WSN metadata. The aim is to infer mobility management requirements when a spatial coverage is incorrectly covering a Region of Interest (ROI), regardless the network connectivity. The BN approach provides several advantages regarding to the probabilistic representation of a movement context, the inference of mobility management requirements based on such a context, and the dynamic updating of the movement context every time new metadata are retrieved from the WSN. Previous research works in WSNs have used a similar approach focusing on energy management (Elnahrawy and Nath 2004) and prediction of sensor movement directions (Coles et al. 2009). The main contribution of our work is the analysis of how well a ROI is being covered by mobile sensors, and what are the requirements to improve that coverage given a movement context. A controlled experiment was carried out and the results show that, when the ROI is not being sufficiently covered by a WSN, the BN can probabilistically infer different mobility management requirements, based on a given movement context. Two movement contexts have been used to illustrate this approach. They are related to whether the sensing is being carried out in an emergency situation or not

MDP-based Vehicular Network Connectivity Model for VCC Management

Vehicular Cloud computing is a new paradigm in which vehicles collaboratively exchange data and resources to support services and problem-solving in urban environments. Characteristically, such Clouds undergo severe challenging conditions from the high mobility of vehicles, and by essence, they are rather dynamic and complex. Many works have explored the assembling and management of Vehicular Clouds with designs that heavily focus on mobility. However, a mobility-based strategy relies on vehicles' geographical position, and its feasibility has been questioned in some recent works. Therefore, we present a more relaxed Vehicular Cloud management scheme that relies on connectivity. This work models uncertainty and considers every possible chance a vehicle may be available through accessible communication means, such as vehicle-to-everything (V2X) communications and the vehicle being in the range of road-side units (RSUs) for data transmissions. We propose an markov-decisision process (MDP) model to track vehicles' connection status and estimate their reliability for data transmissions. Also, from analyses, we observed that higher vehicle connectivity presents a trace of repeated connection patterns. We reinforce the connectivity status by validating it through an availability model to distinguish the vehicles which support high availability regardless of their positioning. The availability model thus determines the suitability of the MDP model in a given environment

Assessment of habitat quality and landscape connectivity for forest-dependent cracids in the Sierra Madre del Sur Mesoamerican biological corridor, Mexico

Assessing landscape connectivity allows us to identify critical areas that impede or facilitate the movement of organisms and their genes and to plan their conservation and management. In this article, we assessed landscape connectivity and ecological condition of the habitat patches of a highly biodiverse region in Chiapas, Mexico. We employed data of three cracid species with different characteristics in habitat use and mobility. The habitat map of each species was derived from a spatial intersection of the models of potential distribution and a high-resolution map of current land cover and land use. The ecological condition of vegetation types was evaluated using 75 field plots. Structure of landscape was estimated by fragmentation metrics, while functional connectivity was assessed using spatially explicit graph analysis. The extent of suitable habitat for Oreophasis derbianus, Penelopina nigra, and Penelope purpurascens correspond to 25%, 46%, and 55% of the study area (5,185.6 km2), respectively. Although the pine-oak forests were the most fragmented vegetation type, habitats of the three species were well connected, and only 4% to 9% of the fragments located on the periphery of the corridor had low connectivity. Landscape connectivity depends mainly on land uses with an intermediate and lower ecological condition (secondary forests and coffee agroforestry systems). Therefore, we suggest that in addition to promoting the improvement in connectivity in fragmented forests, conservation efforts should be aimed at preventing the conversion of mature forests into agricultural uses and maintaining agroforestry systems

Multi-Service Group Key Management for High Speed Wireless Mobile Multicast Networks

YesRecently there is a high demand from the Internet Service Providers to transmit multimedia services over high speed wireless networks. These networks are characterized by high mobility receivers which perform frequent handoffs across homogenous and heterogeneous access networks while maintaining seamless connectivity to the multimedia services. In order to ensure secure delivery of multimedia services to legitimate group members, the conventional cluster based group key management (GKM) schemes for securing group communication over wireless mobile multicast networks have been proposed. However, they lack efficiency in rekeying the group key in the presence of high mobility users which concurrently subscribe to multiple multicast services that co-exist in the same network. This paper proposes an efficient multi-service group key management scheme (SMGKM) suitable for high mobility users which perform frequent handoffs while participating seamlessly in multiple multicast services. The users are expected to drop subscriptions after multiple cluster visits hence inducing huge key management overhead due to rekeying the previously visited cluster keys. The already proposed multi-service SMGKM system with completely decentralised authentication and key management functions is adopted to meet the demands for high mobility environment with the same level of security. Through comparisons with existing GKM schemes and simulations, SMGKM shows resource economy in terms of reduced communication and less storage overheads in a high speed environment with multiple visits