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We present an experimental evaluation of energy usage and performance in a wireless LAN cell based on a test bed using the 5 GHz ISM band for 802.11a and 802.11n. We have taken an application-level approach, by varying the packet size and transmission rate at the protocol level and evaluating energy usage across a range of application transmission rates using both large and small packet sizes. We have observed that both the application's transmission rate and the packet size have an impact on energy efficiency for transmission in our test bed. We also included in our experiments evaluation of the energy efficiency of emulations of YouTube and Skype flows, and a comparison with Ethernet transmissions. Informationstechnologie und Informationsmanagement

We present vNurse, a system based on a smartphone platform that permits comprehensive, secure and modular patient remote monitoring outside a clinical environment, e.g. in the home. Using both virtualisation of the phone OS and virtual mobile networks of sensors with full Internet Protocol (IP) connectivity, we enable real-time remote sensor readings of patient Wireless Body Area Networks (WBANs) to be stored, processed and forwarded securely to healthcare practitioners based at clinical sites, while patients are remote or mobile.

Motivated by our ongoing work exploring an alternative Internet architecture, we wish to make use of naming services in order to support functionality such as: host and network mobility; application and/or virtual machine migration; and various forms of traffic control (e.g. multi-homing). Currently, the Domain Name System (DNS) is used to resolve names to DNS records, with relatively large time-to-live (TTL) values (several thousands of seconds) for caching the results. To support new agile services and systems, cached results may need to have much lower TTL values, so that cached DNS values do not become stale as system changes occur, e.g. changes to end-system location information to support new methods of mobility. However, current conventions for DNS configuration normally use conservatively high TTL values. We have conducted an empirical study of a live DNS deployment where we have reduced to zero the TTL values of records for the entire School of Computer Science at the University of St Andrews. Our results show that the increase in DNS load is much lower than might be expected, following a highly non-linear decrease with respect to the TTL value of the DNS records.

One of the operational goals of a middleware platform is to provide a mechanism of distributing computation requests in a way that hides from the programmer the complexity of the underlying systems platform. This means that distribution mechanisms used to harness a set of computer and network resources should not expose to the programmer the detailed systems aspects which are unrelated to their application. Ideally, the programmer should be left to concentrate on the functionality of his/her application without having to be concerned with how the distribution is achieved or how the resources are used. However, this is not true today: programmers need to be aware of details of the middleware in use and are constrained by it in the design of their application, e.g. API constraints. We present a proof-of-concept demonstration of a middleware platform that imposes absolutely no constraints on the programmer apart form those used in the programming language itself. We demonstrate the efficacy of our approach with a prototype implementation in Java, running on a cluster of 20 nodes with a performance comparison with XML-RPC and Java-RMI.

Wireless mobile devices are becoming increasingly prevalent in society. As a result, aggregation of network connectivity through the use of mobile networks is becoming increasingly relevant to service providers as well as for mobile users. The current approach being pursued within the IETF Mobile Extensions for IPv6 (MEXT) WG, is based on the Network Mobility (NEMO) architecture. NEMO uses IP-in-IP tunnelling for providing mobile network capability on an existing IPv6 network. This approach can result in non-optimal routing between source and destination nodes. Other proposals such as OptiNets extend NEMO and try to address issues such as sub-optimal routing. There are alternative approaches also being proposed, such as the Identifier Locator Network Protocol (ILNPv6), which is based on the use of naming, to enable a flexible and integrated mobile network capability based on IPv6.We have conducted a comparative analysis of the cost of providing optimal routing, in terms of packet and bandwidth overhead, based on an emulation, using data from the London Circle Line metropolitan railway as a scenario. Our analysis shows that these different approaches to mobility offer significantly different performance trade-offs in routing for mobile networks, depending on the constraints of the network scenario.

We aim to merge the benefits of network mobility and virtualisation to provide a simple, mobile and secure method for providing mobile network (as opposed to mobile host) platforms. We demonstrate our approach by showing the use of a mobile network of sensors and wide area connectivity for maintaining and managing a Wireless Body Area Networks (WBAN) for healthcare. WBANs are a mature field of research, where the challenges and applications have been explored for quite some time. One of the most promising applications for WBANs is healthcare. Wireless sensors are used to monitor patient health statistics and activity. With the ubiquity of wireless mobile personal devices (such as smart phones), their increased CPU and power capability, the feasibility of using them to build mobile network platforms is increasingly possible. In this paper we describe our novel approach, which is to utilise, through virtualisation, an individual's smartphone not only as a mobile router that manages his personal mobile network, but also as a platform to host his WBAN.

One of the aims of cloud-based services is to offer cost savings through elastic service provision. This elasticity refers to use of resources by the customer and the provision of resources by the provider. An increasingly important resource to consider is energy (or power). As cloud services are intended to be ‘always on’ the energy costs of cloud service provision is already significant, and will continue to rise as global energy prices continue to rise and more users make use of cloud services. While providers can invest in energy-efficient hardware, how can we make users (customers) energy-aware, and incentives users towards energy-efficient use of cloud systems? Clearly, being able to measure actual energy usage will allow the provision of suitable feedback to users, as well as enable new energy-aware systems metrics that allow systems management policies to become responsive to energy usage. We list the requirements and described a prototype for such an energy measurement system.

New transport protocols continue to appear as alternatives to the Transmission Control Protocol (TCP). Many of these are designed to address TCP’s inefficiency in operating over paths with a high bandwidth-delay product (BDP). To test these new protocols, especially comparatively, and to understand their interactions, extensions to the ns2 simulator allow real code from the linux kernel to be used within the ns2 simulations. However, how does the performance of such configurations compare to test-bed experiments of the same configuration? Although, anecdotally, there are often comments within the research community about such issues, there are no studies that quantify the differences for a specific protocol suite. Using a simple testbed, we assess four different transport protocols in a comparative study to examine how well ns2 matches reality. Our tests are all conducted at 100Mb/s over a wide range of delay and router buffer conditions: end-to-end delays from 25ms to 400ms, with end-to-end path buffering of 20% to 100% of the BDP. We find that in our simple configuration, there are significant differences in performance between ns2 and the testbed.

After nearly14 years since the first version of IPv6 was defined by the Internet Engineering Task Force (IETF), there is still just a minimal amount of native IPv6 deployment in today's Internet. Clearly, the evolution of IPv6 since its initial roots as the Simple Internet Protocol has turned the next generation IP effort into one lacking any significant "must have" features. This paper revisits the subject of a next generation IP and presents a new design that builds upon previous and on-going research in proposing a strawman design that we term IPv10.0. Our objective is to present a starting point for discussion of a new IP version that is extensible, introduces new architectural features, and prompts new innovative capabilities.

Interest continues to grow in alternative transport protocols to the Transmission Control Protocol (TCP). These alternatives include protocols designed to give greater efficiency in high-speed, high-delay environments (so-called high-speed TCP variants), and protocols that provide congestion control without reliability. For the former category, along with the deployed base of ‘vanilla’ TCP – TCP NewReno – the TCP variants BIC and CUBIC are widely used within Linux: for the latter category, the Datagram Congestion Control Protocol (DCCP) is currently on the IETF Standards Track. It is clear that future traffic patterns will consist of a mix of flows from these protocols (and others). So, it is important for users and network operators to be aware of the impact that these protocols may have on users. We show the measurement of fairness in throughput performance of DCCP Congestion Control ID 2 (CCID2) relative to TCP NewReno, and variants Binary Increase Congestion control (BIC), CUBIC and Compound, all in “out-of-the box” configurations. We use a testbed and endto- end measurements to assess overall throughput, and also to assess fairness – how well these protocols might respond to each other when operating over the same end-to-end network path. We find that, in our testbed, DCCP CCID2 shows good fairness with NewReno, while BIC, CUBIC and Compound show unfairness above round-trip times of 25ms.

This chapter offers a survey of the emerging field of private peer-to-peer networks, which can be defined as internet overlays in which the resources and infrastructure are provided by the users, and which new users may only join by personal invitation. The last few years have seen rapid developments in this field. We describe deployed systems, classify them architecturally, and identify some technical and social tradeoffs in the design of private peer-to-peer networks.

In Mobile Ad hoc Networks (MANETs), timers have been used widely to maintain routing (state) information. The use of fixed-interval timers is simple to implement but, in practise, may be difficult to configure in dynamic operational environments, and so may give reduced performance in the presence of frequent topology changes. This paper proposes a self-tuning timer approach within a simple control system for MANET routing protocols with the aim of allowing dynamic, autonomic, re-calibration of routing update frequencies. A novel dynamic timer algorithm is presented to automatically tune routing performance by adapting timer intervals to network conditions. Our simulation results have shown that, compared to the default fixed timer approach, the proposed algorithm could effectively improve routing throughput without manual configuration.

Mobile Networks are increasingly important in land-, sea-and air-based military scenarios. The interest in supporting network mobility for Internet Protocol (IP) networks has led to the Network Mobility (NEMO) protocol extensions being proposed for IP within the IETF. These extensions are based on the work already completed on host mobility for Mobile IP (MIP). The current work is based on the use of software agents: a Home Agent (HA) intercepts packets destined for the addresses in the mobile network and uses an IP-in-IP tunnel to send the packets to the Mobile Router (MR) located at a Care of Address (CoA), which terminates the tunnel. As the mobile network moves to new IP networks, the MR updates the HA with its new CoA. While this tunnelling approach represents a sound engineering solution for backwards compatibility, and is the only one that has been pursued within the IETF, it has seen little deployment, either in support of mobile hosts or mobile networks. We make the case for an alternative approach based on secure naming. We make a comparison in operation with the current tunnelling-based approach, both in architecture and by analysis of protocol operation. Our initial analyses indicate that a naming-based approach shows promise as a viable alternative to a tunnelling-based approach, and could offer other architectural benefits.

Site multi-homing is an important capability in modern military networks. Resilience of a site is greatly enhanced when it has multiple upstream connections to the Global Information Grid, including the global Internet. Similarly, the ability to provide traffic engineering for a site can be important in reducing delays and packet loss over low-bandwidth and/or high-delay uplinks. Current approaches to site multi-homing and site traffic engineering (a) require assistance from a trusted network service provider; (b) inject significant additional routing information into the global Internet routing system. This approach reduces flexibility, does not scale and is a widespread concern today. The proposed Identifier-Locator Network Protocol (ILNP) offers backward compatible extensions for IPv6 to enable a site to (a) use multiple routing prefixes concurrently, without needing to advertise these more-specific site prefixes upstream to the site's service providers; (b) enables edge-site controlled traffic engineering and localised addressing, without breaking end-to-end connectivity. This feature combination provides both multi-homing and traffic engineering capabilities without any adverse impact on the routing system and does not require anything more than unicast routing capability in the provider network. ILNP enables concurrent multi-path transmission for a flow, without requiring multicast routing, to increase flow resilience to path interruptions. This technique has a secondary security benefit of reducing the risk of an adversary successfully blocking an ILNP flow via a Denial-of-Service attack on any single path or single link.

Using data of passenger numbers and train schedules from the London Underground metropolitan railway system, we compare a Tunnelling-based to a Naming-based approach for supporting mobile networks. We show that, in terms of packet overhead, a naming based approach may have similar performance overhead to a tunnelling approach, and so may offer a viable alternative, whilst also offering other benefits.

We propose a cross-layer routing protocol for a Code Division Multiple Access (CDMA) Multihop Cellular Network (MCN). In designing the routing protocol for MCN, multiple constraints are imposed on intermediate relay node selection and end-to-end path selection. The constraints on relay nodes include willingness for cooperation, sufficient neighbourhood connectivity and the level of interference offered on the path. Path constraints include end-to-end throughput and end-to-end delay. A facile incentive mechanism is presented to motivate the cooperation between nodes in call forwarding. In addition, we present a route resilience scheme in the event of dynamic call dropping. In particular, a fast neighbour detection scheme for route resilience is proposed. Instead of using periodic HELLO messages as in traditional ad-hoc routing, the proposed neighbour detection scheme adopts an explicit handshake mechanism to reduce neighbour detection latency. We conclude the paper by demonstrating the superior performance of the proposed routing protocol compared with the other well known routing algorithms.

Next generation network architectures will benefit from the many years of practical experience that have been gained in designing, using and operating network protocols. Over time, the networking community has gradually improved its understanding of networked systems in terms of architecture, design, engineering and testing. However, as protocols and networked systems become more complex, it is our contention that it will be necessary for programming techniques to evolve similarly so that they better support the design, implementation and testing of both the functional and the non-functional requirements for the network protocols that will be used.We therefore envisage new levels of programming language support that permit: (a) the design and implementation of new protocols with provably correct construction; (b) inline testing; and (c) the expression of protocol behaviour within the design. Based on our ongoing work with both network protocols and programming language design, we believe that exploiting the capabilities of recent work in Domain Specific Languages (DSLs) will allow us to meet such requirements, allowing straightforward and ``correct-by-construction'' design and implementation of next generation network protocols.

Keeping router buffering low helps minimise delay (as well as keeping router costs low), whilst increasing buffering minimises loss. This is a trade-off for which there is no single `correct' solution. In order to maintain effective throughput for TCP, whilst minimising router buffer requirements, current results suggest that different amounts of buffering are needed depending on the position in the network (e.g., edge or core), and on the relative capacity of ingress and egress links to a router. However, today we have several different variants of TCP in use, and each is designed to have different behaviour especially on paths with high bandwidth-delay product (BDP) values. We use a testbed to investigate the effects of different amounts of `on-path' buffering (OPB) on the performance of four TCP variants - TCP NewReno, BIC, CUBIC, and Compound TCP - over various end-to-end round-trip-times (RTTs). Specifically, we consider how the variants respond when competing for bandwidth on a bottleneck link. We find that overall performance depends on both the RTT and the OPB provision, and that the observed behaviour is not consistent across the range of RTT and OPB values.

This paper describes two approaches to manipulating JPEG2000 frames with programmable and active networks. The first approach is the use of transcoding and the second is intelligent dropping. These two approaches where considered, in particular, for possible deployment with space based platforms; specifically, communication satellites which are not only IP enabled but may host active components. Each approach offers different possibilities and may be suitable for solving overlapping but different problems.

Military communications currently require secure end-to-end, resilient connectivity via multi-homed connections, and need to support both mobile hosts and mobile networks. Today, such functions are possible to some degree, but the functions are not harmonised. Standards that support these functions were designed independently and implemented in isolation. So, achieving converged capabilities for optimal communications in forward operating areas is a technical challenge, and results in a complex network landscape which is likely to be difficult to operate and manage, and brittle under failure conditions. From our ongoing work, we present a new naming approach and use this to formulate a proposal to provide the following capability harmoniously: (a) multi-homed connectivity for traffic engineering and resilience; (b) true end-to-end network-layer security with high compatibility with the HAIPE architecture; (c) support for mobile hosts and mobile networks. Our approach is backwards compatible with IPv6 network equipment (existing IPv6 backbones can be used), and is also incrementally deployable.

Mobile, delay-tolerant, ad hoc and pocket-switched networks may form an important part of future ubiquitous computing environments. Understanding how to efficiently and effectively route information through such networks is an important research challenge, and much recent work has looked at detecting communities and cliques to determine forwarding paths. Such detected communities, however, may miss important aspects. For instance, a user may have strong social ties to another user that they seldom encounter; a detected social network may omit this tie and so produce sub-optimal forwarding paths. Moreover, the delay in detecting communities may slow the bootstrapping of a new delay-tolerant network. This paper explores the use of self-reported social networks for routing in mobile networks in comparison with detected social networks discovered through encounters. Using encounter records from a group of participants carrying sensor motes, we generate detected social networks from these records. We use these networks for routing, and compare these to the social networks which the users have self-reported on a popular social networking website. Using techniques from social network analysis, we find that the two social networks are different. These differences, however, do not lead to a significant impact on delivery ratio, while the self-reported social network leads to a significantly lower cost.

Many new transport protocols are being defined, including, for example, variants of the Transmission Control Protocol (TCP), to better match the requirements of new applications. A key issue in the evaluation of protocol flows, in terms of their performance, is how fair they are to other flows. Specifically, it is important to understand how a mix of existing and/or new protocols will interact with each other when using the same network resources. Such observations help to inform protocol design, and allow an assessment of potential impacts on users. We present a simple, yet effective, methodology for examining a specific case of inter-flow fairness based solely on measurements of flow performance. As well as using an existing fairness metric, we propose a new metric which provides a richer information summary for the evaluation of fairness.

An Identifier/Locator addressing scheme can enable a new approach to mobile hosts and mobile networks. Identifier and Locator information is stored in Domain Name System (DNS) Resource Records. In our on-going work using the Identifier-Locator Network Protocol (ILNP), the DNS would be updated with new Locator values as hosts and/or networks move; new sessions would obtain the correct Locator(s) for a mobile host and/or mobile network from the DNS, in much the same way as currently happens for IP address resolution. However, this use of the DNS is not currently required for IP mobility. We examine the potential impact on DNS from using a naming approach to mobility.

There is a growing interest in the use of variants of the Transmission Control Protocol (TCP) in high-speed networks. ns-2 has implementations of many of these high-speed TCP variants, as does Linux. ns-2, through an extension, permits the incorporation of Linux TCP code within ns-2 simulations. As these TCP variants become more widely used, users are concerned about how these different variants of TCP might interact in a real network environment -- how fair are these protocol variants to each other (in their use of the available capacity) when sharing the same network. Typically, the answer to this question might be sought through simulation and/or by use of an experimental testbed. So, we compare with TCP NewReno the fairness of the congestion control algorithms for 5 high-speed TCP variants -- BIC, Cubic, Scalable, High-Speed and Hamilton -- on both ns-2 and on an experimental testbed running Linux. In both cases, we use the same TCP code from Linux. We observe some differences between the behaviour of these TCP variants when comparing the testbed results to the results from ns-2, but also note that there is generally good agreement.

In mobile ad hoc networks (MANETs), timers have been widely used to maintain routing (state) information. The use of fixed-interval timers is simple to implement but, in practise, may be difficult to configure in dynamic operational environments, and so may give reduced performance in the presence of frequent topology changes. This paper proposes a self-tuning timer approach within a simple control system for MANET routing protocols with the aim of allowing dynamic, autonomic, re-calibration of routing update frequencies. A novel dynamic timer algorithm is presented to automatically tune routing performance by adapting timer intervals to network conditions. Our simulation results have shown that, compared to the default fixed timer approach, the proposed algorithm could effectively improve routing throughput without manual configuration.

This paper investigates the route dynamics of shortest-path first (SPF) routing in mobile ad hoc networks (MANETs). In particular, we find, from a statistical analysis of route duration and route change interval, that route dynamics may require complex modelling. Our analysis considers various mobility models, node velocities and node densities of the MANET network. Our findings show that, in a MANET with moderate or high rate of mobility, the route duration could be approximated by an exponential distribution with approximate parameters, while the route duration of specific lengths could not. Our findings suggest that minimum hop-count routing in MANETs may be inappropriate and that further investigation is required in order to develop models that let us understand MANET route dynamics.

Many researchers have used game theory to study the problem of encouraging cooperation in peer-to-peer and mobile ad hocnetworks, where resources are provided collectively by the users. Previous work has modelled the problem as either a multi-player social dilemma or a network of two-player prisoner's dilemmas, but neither of these approaches captures a crucial aspect of the problem, namely scarcity: when resources are limited, players must not only consider how to establish and sustain cooperation with each opponent, but how to allocate resources among their opponents in order to maximise the total cooperation received. This paper presents a new game theoretic model of cooperation under scarcity, the sharer's dilemma, and a simple expected utility strategythat is shown to perform well against a wide range of opponents. The expected utility strategy can easily be applied to file sharing networks to create an incentive for users to contribute resources.

We present experimental results evaluating fairness of several proposals to change the TCP congestion control algorithm, in support of operation on high bandwidth-delay- product (BDP) network paths. We examine and compare the fairness of New Reno TCP BIC, cubic, hamilton-TCP, highspeed-TCP and Scalable-TCP. We focus on four different views of fairness: TCP-friendliness RTT-fairness, intra- and inter-protocol fairness.

The high volume of packets and packet rates of traffic on some router links makes it exceedingly difficult for routers to examine every packet in order to keep detailed statistics about the traffic which is traversing the router. Sampling is commonly applied on routers in order to limit the load incurred by the collection of information that the router has to undertake when evaluating flow information for monitoring purposes. The sampling process in nearly all cases is a deterministic process of choosing 1 in every N packets on a per-interface basis, and then forming the flow statistics based on the collected sampled statistics. Even though this sampling may not be significant for some statistics, such as packet rate, others can be severely distorted. However, it is important to consider the sampling techniques and their relative accuracy when applied to different traffic patterns. In this paper, we assess the performance of the sampling process as used in NetFlow in detail, and we discuss some techniques for the compensation of loss of monitoring detail.

Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being separate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Meanwhile, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have postulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a separate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.

As Mobile IP is deployed, so the requirements for its deployment evolve, reflecting the actual use of IP networks today. This includes the ability to use Mobile IP with IPsec, NATs and multi-homed networks. Furthermore, new requirements arise as people start to use IP in scenarios where the whole network is mobile (e.g. military networks), and where edge-networks may not be IP-enabled (e.g. sensor networks), but there is a requirement to interoperate across an IP network. In all these cases, rather than engineering retro-fits, creating an increasingly complex network landscape with possible unforeseen feature interactions and dependencies, we would prefer an integrated architectural solution. We present, from our ongoing work, a solution that would seem to meet all these needs, through a modified use of naming and addressing. Our proposal is incrementally deployable and existing core network routers & routing protocols need not change.

We describe a method for enabling dependable forwarding of messages in untrusted networks. Nodes perform only relatively lightweight operations per message, and only the originator and destination need to trust each other. Whereas existing protocols for dependable communication rely on establishing a verifiable identity for every node, our protocol can operate in networks with unknown or varying membership and with no limits on the creation of new identities. Our protocol supports the maintenance of unlinkability: relays cannot tell whether a given originator and destination are communicating. The destination of each message generates an unforgeable acknowledgement (U-ACK) that allows relays and the originator to verify that the message was delivered unmodified to the destination, but relays do not need to share keys with the originator or destination, or to know their identities. Similarly, the endpoints do not need to know the identities of the relays. U-ACKs can be seen as a building block for dependable communication systems; they enable nodes to measure the level of service provided by their neighbours and optionally to adjust the level of service they provide in return, creating an incentive for nodes to forward messages. Our work is ongoing.

In wireless mission-critical systems, systems may be resource-constrained including limited bandwidth, so minimising protocol overhead, whilst maintaining performance, is important. Proactive MANET routing protocols tend to provide smaller route discovery latency than on-demand protocols because they maintain route information to all the nodes in the network at all time. However, such protocols may impose excessive soft-state routing control overhead which is generated by disseminating periodic update messages. In order to mitigate the side effects of the soft-state control over-heads, we propose two adaptive proactive routing algorithms, namely DT_MIAD and DT_ODPU. By tuning the value of refresh intervals dynamically and automatically, refresh updates are triggered based on traffic conditions and node mobility. We show through simulations that the proposed adaptive routing algorithms can outperform a traditional proactive routing protocol (OLSR).

This paper presents a fast neighbour detection scheme for a proactive MANET routing protocol. Instead of using periodic HELLO messages, the proposed scheme adopts explicit handshake mechanism to reduce the latency in neighbour detection. In particular, two route handshake options are presented, namely the Broadcast based handshake (BHS) algorithm and Unicast based handshake (UHS) algorithm. Our simulation results show that the proposed scheme improves routing performance, especially in networks with moderate or high mobility. In low-density networks, the unicast option improves the routing throughput significantly without introducing extra control overhead.

At present, military communications within battlefields are very restricted, both by policy and due to technology limitations. In Southwest Asia today, there are needlessly long and complex communications paths, often involving multiple relays and use of constrained-bandwidth MILSATCOM back-haul outside the theatre, when nearby forces could communicate directly via existing interoperable radios. This is a current problem for NATO and Coalition forces. The current Internet Protocol suite lacks core support for mobility, scalable support for multi-homed nodes, and does not provide the capabilities needed for optimal communications in forward operating areas. We propose a coalition-based, multi-homed approach lever-aging both local-area and wide-area connectivity, improving both the flexibility and robustness of communication, without conflicting with the security policy of sensitive communication. The Coalition Peering Domain (CPD), is a distributed, self-configuring architecture that supports the secure, collaborative networking relationships needed to provide this flexibility and robustness. The CPD facilitates the inter-connection of cooperating, but administratively separate, network segments. The CPD exploits multi-homed and multi-path communication to better-utilise all available connectivity. The Identifier-Locator Network Protocol (ILNP) provides native support for improved scalability in multi-homing and mobility, while easing use of network layer security and allowing inter-operation across different administrative domains. Our approach is compatible with current work in Mobile Ad-Hoc Networking (MANET). ILNP has excellent compatibility with IPv6: existing IPv6 backbone networks do not require any modification to carry ILNP traffic natively. There are practical, realistic and deployable engineering solutions to realise the CPD and ILNP within the framework of IPv6.

Mobile devices available today provide users the ability to communicate using a number of different wireless network interfaces. However, these devices do not yet fully exploit the potential for multi-homed and multi-path communication allowing them to better utilise all the connectivity that is available to them. We present here the coalition peering domain (CPD), an architecture that supports collaborative networking relationships between mobile devices. This improves the speed and robustness of communication through more flexible use of all available connectivity

This paper examines four scalability hypotheses of interest for mobile meshes via the following questions: 'Do meshes self-generate capacity as new nodes join?' 'Are meshes more spectrally efficient?' 'Do directional antennas confer significant benefits for hand-held below 3.5 GHz?' 'No' is the answer because these hypotheses, whilst having a theoretical basis, can be shown to rely on inappropriate real world assumptions. However the following hypothesis is found to be true: 'Meshes may improve spectrum utilization'. Importantly however, there remain properties of meshes which make them uniquely attractive, such as coverage extension. However this raises a further question over the ability of mobile mesh architecture to provide a guaranteed quality of service. Finally, the wider aspects of commercial innovation are considered