The 30/20 GHz flight experiment system, phase 2. Volume 2: Experiment system description

A detailed technical description of the 30/20 GHz flight experiment system is presented. The overall communication system is described with performance analyses, communication operations, and experiment plans. Hardware descriptions of the payload are given with the tradeoff studies that led to the final design. The spacecraft bus which carries the payload is discussed and its interface with the launch vehicle system is described. Finally, the hardwares and the operations of the terrestrial segment are presented

Transport in the Trans-Pennine Corridor: Present Conditions and Future Options. Interregional Study Working Paper 3.

This paper reports on a desk study carried out by the Institute for Transport Studies as part of a wider study of opportunities for inter-regional working in the trans-Pennine corridor, considering economic, environmental and transport issues. It draws together available information on transport and movement flows in the trans-Pennine corridor. These patterns of movement are examined from a broad perspective which considers intra-regional, inter- regional and international movements within and across the study area. The report proposes a regional package approach to transport, based on demand management and modal transfer

The economic costs of road traffic congestion

The main cause of road traffic congestion is that the volume of traffic is tooclose to the maximum capacity of a road or network. Congestion in the UK isworse than many, perhaps most, other European countries. More important, itis getting worse, year by year. Current official forecasts imply that congestionwill be substantially worse by the end of this decade, even on the veryfavourable assumption that all current Government projects and policies areimplemented in full, successfully, and to time. This is because road traffic isgrowing faster than road capacity. This is not a temporary problem: it willcontinue to be the case, in the absence of measures to reduce traffic, because itis infeasible to match a road programme to unrestricted trends in traffic growth.The effect, using the current Government method of measuring congestion,and a long established method of valuing it, would be that the widely quotedfigure of an annual cost of £20 billion, would increase to £30 billion by 2010.Under current social and economic frameworks, there are no feasible policiesthat could reduce congestion to zero in practice, or that would be worthwhiledoing in theory. But savings worth £4b-£6b a year could in principle be madeby congestion charging alone, over the whole network, of which (veryapproximately) half might be reflected in the prices of goods, and half insavings in individuals? own time spent travelling. A good proportion of thiscould alternatively be secured by an appropriate package of alternativemeasures: priority lanes and signalling; switching to other modes includingfreight to rail and passenger movements to public transport, walking andcycling; ?soft? policies to encourage reduced travel by car; land-use patternswhich reduce unnecessary travel; and associated measures to prevent benefitsfrom being eroded by induced travel. The combined effects of road chargingand a supportive set of complementary measures represent the best that couldbe reasonably achieved in the short to medium run. This could reducecongestion costs (as distinct from slowing down their increase) by 40%-50%.These broad-brush figures, though based on long-established methods, must betreated with great caution. The ?cost of congestion?, as used for thesecalculations, is based on relationships which in reality are not exact, stable oreven meaningful. The wrong indicator has been used, comparing average realspeeds with average ideal speeds. But in the real world, speeds are differentevery day, and so is the level of congestion. For just-in-time operation, and formuch personal and business travel, variability and reliability are much moreimportant. The really costly effect of congestion is not the slightly increasedaverage time, but the greater than average effect in particular locations andmarkets, and the greatly increased unreliability.During the near future, until road pricing is implemented, increases in roadcongestion can lead to some shift in the balance of attractiveness of rail freight,sufficient for a proportion of the freight market to transfer from road. Thiswould in turn make a small but significant contribution to reducing congestion,especially in some specific important corridors. Even though rail freight isusually a small proportion of all freight, the annual economic saving incongestion cost, to road users generally, from transferring a 5-times a week,200 mile round trip, mostly on congested motorways, from road to rail wouldbe in the order of £40,000 to £80,000, to which should be added thecommercial cost savings made by the freight operator who chooses to do so. Itshould be emphasised that sustaining this would require measures to preventinduced car traffic filling up the relieved road space.An example of the impact of factoring in unreliability is given by approximatecalculations made for journeys such as Glasgow to Newcastle, Cardiff toDover, or London to Manchester. In free-flow theory these could be 3-hourjourneys, but moderate congestion requires adding an hour to the average timeand another hour safety margin to ensure that a tight delivery slot is not missedtoo often. In congestion so severe as to double the average time, the extrasafety margin for unreliability could be as much as 4 hours, which is simply notfeasible in many cases.The ?total cost of congestion? is a large number, but it is practicallymeaningless and by ?devaluing the currency? it distracts attention from moreimportant, achievable, objectives. It would be better not to use it as a target forpolicy. The two key important things to do are:· Strategic action to reduce traffic volume to a level where conditions do notvary too much from day to day. In some circumstances this will slightlyincrease average speed, though not always: in some road conditions areduction of average speed can greatly improve the smoothness of trafficflow. But in both cases, it will greatly increase reliability, this being moreimportant than the change in average speed;· Practical measures to provide good alternatives for freight and passengermovements which reduce the intensity of use of scarce road space incongested conditions. Even where this only applies to a minority ofmovements, significant effects are possible.The Government plans to ?re-launch? the Ten Year Plan for Transport thisSummer or Autumn. It is not reasonable to expect that the re-launch willinclude congestion charging for cars within the decade, so it will need to planfor it as soon as possible after, and a short-term coping strategy of prioritymeasures to protect the most important classes of movement (both passengerand freight) from congestion in the period before charging is implemented

Planning assistance for the 30/20 GHz program, volume 1

Functional requirements for the 30/20 GHz communication system, planning assistance for the 30/20 GHz program, and a review of specified conceptual designs and recommendations are provided

Future benefits and applications of intelligent on-board processing to VSAT services

The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

Softswitch Design and Performance Analysis

The increasing number of subscribers’ demands in telecommunication sector has motivated the operators to provide high quality of service in cost effective way. Moreover, operators need to have an open structure system so that they can move their systems to the next generation network architecture. For this purpose, Softswitch is an appropriate technology because it is a safe and cost efficient solution and though it can migrate from traditional circuit-switching based telephone system to internet protocol packet-switching based networking. Softswitch network divides the logical switch into several parts with different functions such as signaling gateway, media gateway, media server, etc. Standard communication protocols are implemented between those parts. Softswitch is software-based system to make connection between devices, and moreover to control voice calls, data and routes calls through different entities of the networks. Softswitch supports management functions such as provisioning, fault handling and reporting, billing, operational support, etc. Softswitch suitable for all types of traffic and services so it is very demanding in the competitive world of mobile operators. In this thesis, Softswitch has been studied and analyzed in details. Softswitch network consisted of different integrated modules such as transportation, calling and signaling, service application and management. Each module provides different services such as call control, routing, billing and network management. Each module is discussed from functional and service point of views. Softswitch based wireless network architecture as well as variety of service solutions is presented. Different protocol interfaces in softswitch network such as signaling system number 7 are explained. Moreover, bearer calls, independent call control protocol, gateway control protocol, IP bearer control protocol are explained as well. Variety of softswitch network architectures analysis has been done based on their performance and the applicability. Three Softswitch network architectures are proposed which are validated through simulations.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

An Analysis of Next Generation Access Networks Deployment in rural areas

Next generation access networks (NGAN) will support a renewed electronic communication market where main opportunities lie in the provision of ubiquitous broadband connectivity, applications and content. From their deployment it is expected a wealth of innovations. Within this framework, the project reviews the variety of NGAN deployment options available for rural environments, derives a simple method for approximate cost calculations, and then discusses and compares the results obtained. Data for Spain are used for practical calculations, but the model is applicable with minor modifications to most of the rural areas of European countries. The final part of the paper is devoted to review the techno-economic implications of a network deployment in a rural environment as well as the adequacy and possible developments of the regulatory framework involve

Disaggregated Approaches to Freight Analysis: A Feasibility Study.

Forecasting the demand for freight transport is notoriously difficult. Although ever more advanced modelling techniques are becoming available, there is little data available for calibration. Compared to passenger travel, there are many fewer decision makers in freight, especially for the main bulk commodities, so the decisions of a relatively small number of principal players greatly influence the outcome. Moreover, freight comes in various shapes, sizes and physical states, which require different handling methods and suit the various modes (and sub-modes) of transport differently. In the face of these difficulties, present DTp practice is to forecast Britain's freight traffic using a very simple aggregate approach which assumes that tonne kilometres will rise in proportion to GDP. Although this simple model fits historical data quite well, there is a clear danger that this relationship will not hold good in the future. The relationship between tonne kilometres and GDP depends on the mix of products produced, their value to weight ratios, number of times lifted and lengths of haul. In the past, a declining ratio of tonnes to GDP has been offset by increasing lengths of haul. This has come about through a complicated set of changes in product mix, industrial structure and distribution systems. A more disaggregate approach which studies changes in all these factors by industrial sector seems likely to provide a better understanding of the relationship between tonne kilometres and GDP. However, there are also problems with disaggregation. As we disaggregate we get more understanding of what might change in the future, but are less able to project trends forward. This can be seen if we consider the future amounts of coal movements. Theoretically there is clearly scope for better forecasting by allowing for past trends to be overturned by a movement towards gas powered electricity generation and more imports of coal direct to coastal power stations. However, making such a sectoral forecast is extremely difficult, and inaccuracy here may more than offset the theoretical gain referred to earlier. This is because it is usually easier to forecast to a given percentage accuracy an aggregate rather than its components. For example, the percentage error on sales forecasts of Hotpoint washing machines will be greater than that for the sales of all washing machines taken together. This occurs because different makes of washing machines are substitutes for each other, so forecasts for Hotpoint washing machines must take into account uncertainty over Hotpoint's market share as well as uncertainty over the future total sales of washing machines. Nevertheless, a disaggregate investigation of the market could spot trends which were `buried' in the aggregate figures. For example, rapidly declining sales for one manufacturer might indicate their leaving the market, which with less competition would then price up and so reduce the total future sales. We have assumed above that the use of the term disaggregate in the brief refers to disaggregation by industrial sector. An alternative usage of the word disaggregate in this context is when referring to modelling at the level of the individual decision making unit. Disaggregate freight modelling in this sense would involve analysing decisions in order to determine the utility weight attached to different attributes of available transport options. Because data on suitable decisions is not readily available in this country, due to commercial confidentiality, we have recently undertaken research in which we have presented decision makers with hypothetical choices, and obtained the necessary utility weights from their responses. Whilst initial scepticism is understandable, this method has produced results acceptable for use in major projects. ITS itself has provided algorithms (known as Leeds Adaptive Stated Preference) which have been used to derive utility weights for use by British Rail in forecasting cross-channel freight, by DTp in evaluating the reaction of commercial vehicles to toll roads, and by the Dutch Ministry of Transport in modelling freight in the Netherlands. In the light of the above, the following objectives were set for the feasibility study: (1)To determine if a forecasting approach disaggregated by industrial sectors, as under the first definition above, can be used to explain recent trends in freight transport; (2)To test the feasibility of the disaggregated approach for improving the understanding of likely future developments in freight markets, this being informed by current best understanding of the disaggregate decision-making process as under the second definition above

A Review of Rail Research Relevant to the Case for Increased Rail Investment.

The purpose of this paper is to provide a review of rail transport research which has a bearing on the case of increased rail investment. The paper focuses on research which has been conducted on the demand for rail travel, both passenger and freight, rather than the supply side or new technology. The aim is to identify where we believe there to be significant gaps in knowledge and key areas in which further research is required are outlined. The paper deals with the following issues: the investment and funding mechanisms that currently exist for rail; the extent to which changes in the fare and service quality of rail affect the demand for rail travel and also the demand for air and road travel; the environmental and congestion benefits of diverting traffic from road and air to rail; and the links between rail investment and economic development. Where appropriate, the discussion considers inter-urban travel, suburban travel, light rail transit and freight transport separately