James Irvine

Performance of a statistically multiplexed access mechanism for a TDMA radio interface

The article describes a statistically multiplexed radio access mechanism for third-generation mobile systems, which is an integral part of a resource allocation functional entity. The access mechanism is a key feature of the RACE Mobile R2084 Advanced Time Division Multiple Access (ATDMA) project. It presents an indication of the design parameters adopted for this access mechanism and performance characteristics derived from a comprehensive computer simulation model. It gives particular emphasis to the structure of the resource allocation module and illustrates how the access mechanism is integrated with functionalities which have been incorporated to provide an adaptive radio interface. The access mechanism considered for ATDMA, which allows statistical multiplexing to be implemented on the radio interface is a development of packet reservation multiple access (PRMA) known as PRMA++. >

A design flow for partially reconfigurable hardware

This paper presents a top-down designer-driven design flow for creating hardware that exploits partial run-time reconfiguration. Computer-aided design (CAD) tools are presented, which complement conventional FPGA design environments to enable the specification, simulation (both functional and timing), synthesis, automatic placement and routing, partial configuration generation and control of partially reconfigurable designs. Collectively these tools constitute the dynamic circuit switching CAD framework. A partially reconfigurable Viterbi decoder design is presented to demonstrate the design flow and illustrate possible power consumption reductions and performance improvements through the exploitation of partial reconfiguration.

Nodobo: Mobile Phone as a Software Sensor for Social Network Research

Modern smart phones are now capable of gathering information about a users social interactions. The authors have developed and deployed Nodobo, a suite of social sensor software for Android. Our first study group is a class of senior high school students, each using a Google Nexus One mobile phone running Nodobo, which we use to capture their device usage patterns and social interactions. We provide an overview of the system architecture, describe the trial, and share some initial results.

Dynamic 3G network selection for increasing the competition in the mobile communications market

This paper proposes a market-based framework in which service providers, network operators and users are able to trade communications services. For this purpose, a middleware has been specified in which software agents can supply or purchase QoS contracts. Benefits from the proposal are increased competition in the provision of mobile services, an integrated framework for the management of services and networks in a multi-provider environment and the possibility to develop smarter applications that make an efficient use of the scarce radio spectrum.

Privacy Implications of Wearable Health Devices

With the recent rise in popularity of wearable personal health monitoring devices, a number of concerns regarding user privacy are raised, specifically with regard to how the providers of these devices make use of the data obtained from these devices, and the protections that user data enjoys. With waterproof monitors intended to be worn 24 hours per day, and companion smartphone applications able to offer analysis and sharing of activity data, we investigate and compare the privacy policies of four services, and the extent to which these services protect user privacy, as we find these services do not fall within the scope of existing legislation regarding the privacy of health data. We then present a set of criteria which would preserve user privacy, and avoid the concerns identified within the policies of the services investigated.

Estimation of the performance of link adaptation in mobile radio

The paper is concerned with the performance of a packet based radio access mechanism for the third generation mobile employing link adaptation. The work has been carried out as part of the European RACE R2084 advanced time division multiple access system (ATDMA). Within the project considerable attention has been given to the incorporation of adaptive features for efficient use of radio spectrum.

An Advanced SOM Algorithm Applied to Handover Management Within LTE

A novel approach to handover management for Long-Term Evolution (LTE) femtocells is presented. Within LTE, the use of self-organizing networks (SONs) is included as standard, and handover management is one of its use cases. Base stations can autonomously decide whether handover should take place and assign the values of relevant parameters. Due to the limited range of femtocells, handover requires more delicate attention in an indoor scenario to allow for efficient and seamless handover from indoor femtocells to outdoor macrocells. As a result of the complexity of the indoor radio environment, frequent ping-pong handovers between the femtocell and macrocell layers can occur. A novel approach requiring a small amount of additional processing using neural networks is presented. A modified self-organizing map (SOM) is used to allow a femtocell to learn the locations of the indoor environment from where handover requests have occurred and, based on previous experience, decide whether to permit or prohibit these handovers. Once the regions that coincide with unnecessary handovers have been detected, the algorithm can reduce the total number of handovers that occur by up to 70% while still permitting any necessary handover requests to proceed. By reducing the number of handovers, the overall efficiency of the system will improve as the consequence of a reduction in associated but unnecessary signaling. Using machine learning for this task complies with the plug-and-play functionality required from SONs in LTE systems.

The personnel distributed environment

Beyond 3G continues to dominate discussion within the cellular community. A variety of issues are being actively debated: the requirement for a new air interface, greater interworking with WLANs and other networks, a service-driven approach, and potential for increasing market penetration of network-enabled devices. The Mobile VCE vision for beyond 3G encompasses a world that has embraced a disparate range of networked processing and communications devices. This article presents an architecture for user-centric communication across heterogeneous access networks

Characteristics of WAP traffic

This paper considers the characteristics of Wireless Application Protocol (WAP) traffic. We start by constructing a WAP traffic model by analysing the behaviour of users accessing public WAP sites via a monitoring system. A wide range of different traffic scenarios were considered, but most of these scenarios resolve to one of two basic types. The paper then uses this traffic model to consider the effects of large quantities of WAP traffic on the core network. One traffic characteristic which is of particular interest in network dimensioning is the degree of self-similarity, so the paper looks at the characteristics of aggregated traffic with WAP, Web and packet speech components to estimate its self-similarity. The results indicate that, while WAP traffic alone does not exhibit a significant degree of self-similarity, a combined load from various traffic sources retains almost the same degree of self-similarity as the most self-similar individual source.

System architecture for the MOSTRAIN project (mobile services for high speed trains)

High speed trains are becoming an increasingly common mode of transport, and one of the advantages of this mode of transport is the range of services which can be offered on board. The aim of the ACTS MOSTRAIN project is to further the development of UMTS by addressing the challenges of providing the full range of UMTS services to high speed trains, both for the travelling public, as well as allowing for train control and signalling applications. This paper describes the design requirements and the architecture which is being developed for the system.