Gorry Fairhurst

Enhanced broadband access as a solution to the social and economic problems of the rural digital divide

This article discusses the danger of a growing digital divide between rural and other areas. It presents broadband as increasingly necessary for the delivery of information, health, education, business, social security, public and leisure services. Access to broadband has become vital for rural communities to participate in a progressively digital economy and to overcome problems of physical and social isolation. Yet rural areas are among those most excluded from fast broadband developments. Although this is partly due to technological/economic barriers in reaching more remote locations, even where technology is available, adoption can still be low in rural areas. This article explores the problems of providing broadband in rural Britain, considers various technological approaches and concludes with key development areas for policy and government.

NEAT: A Platform- and Protocol-Independent Internet Transport API

The sockets API has become the standard way that applications access the transport services offered by the IP stack. This article presents NEAT, a user space library that can provide an alternate transport API. NEAT allows applications to request the service they need using a new design that is agnostic to the specific choice of transport protocol underneath. This not only allows applications to take advantage of common protocol machinery, but also eases introduction of new network mechanisms and transport protocols. The article describes the components of the NEAT library and illustrates the important benefits that can be gained from this new approach. NEAT is a software platform for developing advanced network applications that was designed in accordance with the standardization efforts on transport services in the IETF, but its features exceed the envisioned functionality of a TAPS system.

Evaluation of the impact of packet drops due to AQM over capacity limited paths

For many years Internet routers have been designed and benchmarked in ways that encourage the use of large buffers. When these buffers accumulate a large standing queue, this can lead to high network path latency. Two AQM algorithms: PIE and CoDel, have been recently proposed to reduce buffer latency by avoiding the drawbacks of previous AQM algorithms like RED. This paper explores the performance of these new algorithms in simulated rural broadband networks where capacity is limited. We compared the new algorithms using Adaptive RED as a reference. We observe that to achieve a small queuing delay PIE and CoDel both increase packet loss. We therefore explored this impact on the quality of experience for loss-sensitive unreliable multimedia applications, such as real-time and near-real-time video. The results from simulations show that PIE performs better than CoDel in terms of packet loss rates affecting video quality. We also noted that the performance of ARED is comparable to that of PIE and CoDel in constant capacity links. This suggests that AQM in general is useful for limited capacity network paths.

De-Ossifying the Internet Transport Layer: A Survey and Future Perspectives

It is widely recognized that the Internet transport layer has become ossified, where further evolution has become hard or even impossible. This is a direct consequence of the ubiquitous deployment of middleboxes that hamper the deployment of new transports, aggravated further by the limited flexibility of the application programming interface (API) typically presented to applications. To tackle this problem, a wide range of solutions have been proposed in the literature, each aiming to address a particular aspect. Yet, no single proposal has emerged that is able to enable evolution of the transport layer. In this paper, after an overview of the main issues and reasons for transport-layer ossification, we survey proposed solutions and discuss their potential and limitations. The survey is divided into five parts, each covering a set of point solutions for a different facet of the problem space: 1) designing middlebox-proof transports; 2) signaling for facilitating middlebox traversal; 3) enhancing the API between the applications and the transport layer; 4) discovering and exploiting end-to-end capabilities; and 5) enabling user-space protocol stacks. Based on this analysis, we then identify further development needs toward an overall solution. We argue that the development of a comprehensive transport layer framework, able to facilitate the integration and cooperation of specialized solutions in an application-independent and flexible way, is a necessary step toward making the Internet transport architecture truly evolvable. To this end, we identify the requirements for such a framework and provide insights for its development.

A flexible QoS architecture for DVB-RCS2

SUMMARY n nThis paper presents a QoS, architecture for the Higher Layers Satellite in the second generation Digital Video Broadcasting with Return Channel via Satellite standard. It describes the flexibility offered by integrating link and network functions to support internet protocol-based differentiated QoS. The operation of key mechanisms is outlined and analysed to show how these may be combined to realise differentiated services by defining mappings between per-hop behaviours, to queues in the traffic plane and return channel satellite terminal request classes in the control plane. Simulation is used to show that an appropriate mapping can be used to can tune the offered service to different traffic classes and that an appropriate assignment can significantly improve the satellite bandwidth efficiency and/or the performance/QoS supplied to a traffic class. Copyright

Evaluating Web Traffic Performance over DVB-RCS2

The web has undergone a radical change over time. Changes not only in the volume of data transferred, but also the way content is delivered to the user. Current web server architectures are often highly distributed and adapted for user interaction, with transactions characterised by multiple connections to multiple servers. This paper discusses the implication of this new web on next generation two-way satellite systems. It seeks to answer the question of whether classical resource provisioning remains suitable for this traffic. It first presents a more representative simulation model that captures the key features of modern web traffic. It then uses simulation to evaluate the performance over the second generation of DVB-RCS, assessing the impact on performance for a range of bandwidth on demand methods. This paper may be used to formulate recommendations for how to support web traffic in DVB-RCS2.

Design of the DVB‐RCS2 higher layer satellite architecture

SUMMARY n nThis paper describes the design of the higher layer architecture for the next generation of digital video broadcasting return channel via satellite transmission systems. This is the first open standard that specifies internet protocol (IP)-level functionality. An open IP-based architecture has resulted in a competitive standard that can provide consumer and professional users with a range of IP-based interactive applications. The paper describes key aspects of the architecture and identifies a set of enhancements/adaptations to the IP protocols and techniques to ensure good performance and still efficient use of satellite bandwidth. Copyright

Performance analysis of next generation web access via satellite

Acknowledgements This work was partially funded by the European Unions Horizon 2020 research and innovation programme under grant agreement No. 644334 (NEAT). The views expressed are solely those of the author(s).

Flexible QoS Support in DVB-RCS2

Satellite is considered a vital technology for enabling ubiquitous access to broadband services in many countries. This paper explores provision of IP-based broadband satellite access with Quality of Service (QoS). It analyses a set of example scenarios, based on the recently published DVB-RCS2 standard involving web and voice traffic. It specifically explores the interaction between Bandwidth-on-Demand (BoD) and QoS, showing that this interaction offers the flexibility required for satellite Internet service operators to manage the bandwidth of broadband users in a multi-service access network.