Lambros Lambrinos

Smart parking solutions for urban areas

Finding a parking place in a busy city centre is often a frustrating task for many drivers; time and fuel are wasted in the quest for a vacant spot and traffic in the area increases due to the slow moving vehicles circling around. In this paper, we present the results of a survey on the needs of drivers from parking infrastructures from a smart services perspective. As smart parking systems are becoming a necessity in todays urban areas, we discuss the latest trends in parking availability monitoring, parking reservation and dynamic pricing schemes. We also examine how these schemes can be integrated forming technologically advanced parking infrastructures whose aim is to benefit both the drivers and the parking operators alike.

Applying adaptive QoS-aware medium access control in priority-based vehicular ad hoc networks

This paper proposes a novel, adaptive medium access control mechanism for vehicular ad hoc networks. A simple, effective, and efficient nonlinear control law is built, based on fuzzy logic control principles, which can be easily adopted in different network environments (e.g. vehicle-to-vehicle (V2V) communication and vehicle-to-infrastructure (V2I) communication). We demonstrate, via simulative evaluation, that the proposed fuzzy control methodology offers inherent robustness with effective control of the system under dense and dynamic conditions, without the need to (re)tune any parameters. The proposed approach offers distinct differentiation among differently prioritized traffic types, thus providing adequate Quality of Service (QoS) in terms of throughput performance, in contrast with the IEEE 802.11p MAC protocol we compared against.

Creating a maritime wireless mesh infrastructure for real-time applications

Advances in computing and networking technologies have revolutionised the way people communicate using interactive real-time applications such as instant messaging and audio and videoconferencing. This category of applications is nowadays readily available to users in terrestrial areas with high speed Internet connectivity. The aim of this work is to investigate the provision of IP-based network connectivity onboard sailing vessels in order to support real-time communication applications. More precisely, instead of the expensive and high-latency satellite communications solutions widely deployed in the maritime industry, we propose the use of long-range wireless networking technologies for creating a vessel-to-shore mesh network that can be used to form an infrastructure for the provision of telephony services based on Voice-over-IP (VoIP).

Improving Service Quality for Parking Lot Users Using Intelligent Parking Reservation Policies

Various smart parking solutions have recently become available. They typically utilize specific technological components in their operations including RFID and various other sensors. The information gathered using such means can be processed to provide useful indicators (e.g. parking occupancy) which can be exploited by both the operators as well as the drivers. In this paper, we propose an intelligent parking reservation management architecture which is based on an optimization strategy that exploits interval scheduling principles. The aim is to improve service quality for the drivers while increasing parking lot utilization.

Optimising file delivery in a maritime environment through inter-vessel connectivity predictions

It is well known that the Internet infrastructure is experiencing an ever growing demand for large file/data transfers. To date, Delay Tolerant Networking (DTN) seems as the only economically viable over-the-sea communications paradigm to support bulk data transfers between seagoing vessels and the fixed Internet. In this work, we construct an architectural prototype of this DTN overlay to connect sailing vessels to the fixed Internet infrastructure. The proposed architecture integrates elements of the existing vessel Automatic Identification System (AIS) to fetch and manipulate mobility and trip related data of every vessel that could come into close contact (at any future instance in time) with a destination node and therefore assist in message forwarding. Considering both current and future contact opportunities all within the same optimization strategy allows for the maximization of routing performance. Ultimately, it is shown that the proposed architecture allows for computationally efficient routing solutions to be generated with variable optimization objectives. As an initial assessment of the performance of the routing functions of this architecture we illustrate the optimal minimum delay routing paths that deliver messages from an arbitrary infrastructure node to a target destination mobile host.

Integrating Voice over IP Services in IPv4 and IPv6 Networks

The transition from the current IPv4 network protocol structure to the next generation IPv6 network has always been deemed as a lengthy process. As the deployment of IPv6 infrastructures evolves, interaction with the existing IPv4 networks is unavoidable. This interaction may occur at the network level (simple data pass-through) or at the application level (between IPv6 and IPv4 endpoints). In this paper we concentrate on application level interoperability and select an increasingly popular application: Voice Over IP (VoIP). The use of VoIP technologies is becoming more widespread as end-users and network providers recognise the potential benefits that the usage of the application provides. It is important to provide an environment where IPv4 and IPv6 networks and applications / devices can interoperate in the context of VoIP. This environment is based on an architecture that integrates all the components together (whether they support IPv4 or IPv6 or both) thereby providing ubiquitous access to IP telephony services based on the SIP signaling protocol. We present our experiences from realising the proposed architecture.

DisAssist: An internet of things and mobile communications platform for disabled parking space management

People with disabilities face many issues when it comes to parking in urban areas which include the limited availability of spaces allocated for their use and the unauthorised usage of such spaces. This paper presents DisAssist which is a system designed and developed based on the principles brought forward by the Internet of Things and Smart Cities initiatives; it integrates sensors and smart phones along with wireless and mobile communications to provide for better utilisation and management of parking spaces allocated for use by people with disabilities. Through the use of DisAssist, people with disabilities may obtain real-time availability of parking slots in an area of interest, reserve a slot and authenticate themselves when parking assisting the authorities with usage monitoring for law enforcement as well as capacity planning purposes. Entitlement verification is possible through a multitude of ways enabling users to embrace technology at the level and format they wish.

Improving quality of experience in wireless VoIP through novel call scheduling

In the last few years we have experienced a dramatic increase in the use of IP networks for voice applications (VoIP) over wireless networks due to increased bandwidth availability and enhanced device capabilities. Since demand often exceeds available capacity, Call Admission Control mechanisms are in place to prevent the uncontrolled usage of bandwidth. Through the use of an intermediary gateway, VoIP calls are in many cases terminated to a normal landline or cellphone; the capacity of such a gateway is also a finite resource since the number of users can vary significantly as many are mobile. In this article we propose an enhanced scheme that aims to manage access to the lines available so that they are used in a fair manner and utilized to the highest degree possible. This management is facilitated by enhancing a proxy implementation with a number of call scheduling policies. The ability to satisfy pending call requests as soon as lines become available, results in increased user service satisfaction. Moreover, it increases line utilization which is crucial from an economic viewpoint. The ultimate goal is to improve Quality of Experience which is deemed as highly important especially considering that wireless network users experience opportunistic and intermittent connectivity.

Demystifying low-power wide-area communications for city IoT applications

Low Power Wide Area (LPWA) communication technologies have the potential to provide a step change in the enablement of cost-effective and energy efficient Internet of Things (IoT) applications. With an increase in the number of offerings available the real performance of these emerging technologies remain unclear. That is, each technology comes with its own advantages and limitations; yet there is a lack of comparative studies that examine their trade-offs based on empirical evidence. This poses a major challenge to IoT solution architects and developers in selecting an appropriate technology for an envisioned IoT application in a given deployment context. In this paper, we look beyond data sheets and white papers of LPWA communication technologies and provide insights into the performance of three emerging LPWA solutions based on real world experiments with different traffic loads and in different urban deployment contexts. Under the context of this study, specialized hardware was created to incorporate the different technologies and provide scientific quantitative and qualitative information related to data rates, success rates, transmission mode energy and power consumption, and communication ranges. The results of experimentation highlight the practicalities of placing LPWA technologies in real spaces and provide guidelines to IoT solution developers in terms of LPWA technology selection. Overall aim is to facilitate the design of new LPWA technologies and adaptive communication strategies that inform future IoT platforms.

An Adaptive Live Media Streaming Architecture

Multimedia streaming is a well established application in today’s Internet and broadcasts of live events are increasingly popular. It is often the case that network conditions change during a live broadcast and this can potentially lead to Quality of Service issues at the receiving clients. This paper proposes a multimedia streaming architecture that can adapt to changing network conditions. For scalability purposes and to reduce network load, jitter and packet loss, stream relays form an integral part of this architecture as they forward media data to nearby clients. During operation, and in a manner transparent to the user, clients may be dynamically assigned to different stream relays, this results in server load balancing and in maintaining high Quality of Service for the end-users.