26/03/2010 by David Slade.

24 March 2010

 Louise Jackman and Kelvin Annable report on the findings of research into the use of water mist systems in large open-plan office spaces.

In the UK water mist systems are increasingly being considered and used for the fire protection of buildings, including commercial premises and as an alternative to sprinkler systems. However, the impact of design variables in the application of such systems is often not well understood.

Water mist systems employ a spray of fine water droplets that can suppress a fire by cooling, wetting and displacing oxygen (by droplet conversion to steam). In a small compartment, such as a prison cell (3m by 4m and 3m high) with a closed door, water mist has been shown to be very effective, both at suppressing the fire and improving tenable conditions [1]. However, in larger spaces water mist may not be as effective, as small water droplets are not contained in the vicinity of the burning fuel and air/fire dynamics can deflect droplets away from combustion gases. Hence, water mist system designs for larger spaces will often require greater water delivery rates and closer nozzle spacings.

For a water mist system to be accepted for use in a building, it is necessary to undertake a full review of a particular system in the context that it will be used [2]. One key part of this review is a requirement to demonstrate the system’s effectiveness against fire performance tests that are appropriate to the real life application, because each water mist system is a bespoke system. Currently, there are only a very limited number of fire performance tests for different end use applications in the draft British Standard for commercial and industrial water mist systems [3].

BRE Global has recently completed a three year experimental research programme to investigate the parameters that influence the performance of a water mist system. This work was commissioned by the BRE Trust and was supported by industry partners. The aim of the work was to investigate water mist system design parameters, investigate building/room parameters that influence suppression effectiveness, and develop a fire performance test that could be applied to large open office areas.

BRE Trust experimental research programme
BRE Global conducted 48 fire tests, with low pressure and high pressure water mist systems. The commercial systems were provided by industry partners.

To assess the performance of water mist systems, three stages of experimental work were completed:

• Parameter testing with crib fire tests;
• Development of a full scale fire test protocol for open plan office spaces;
• Testing with the full scale fire test protocol for open plan office spaces.

Tests were carried out under an open ceiling, i.e. a freestanding ceiling supported on columns, but with no walls at the edge of the ceiling. Several compartment tests were also conducted.

Parameter testing with crib fire tests
A series of wood crib fire tests in open conditions was conducted, where the fire source was a single wood crib. The wood crib was developed for the project, so that the fire had the potential for progressive horizontal spread. The fire size was relatively small (approximately 500kW), operating an automatic water mist nozzle with a quick response glass bulb rated at 68°C at approximately three minutes under a 2.8m open ceiling.

The crib was ignited at one end and allowed to burn freely until the fire had spread to involve approximately half the crib. A low pressure water mist system (a single operating nozzle) was activated and water was discharged for a 10 minute period. Any remaining fire was manually extinguished at the end of the 10 minutes. During the tests the flames were observed, the temperatures were measured and at the end of the test the damage was assessed. The arrangements assessed included the following ‘water mist system design parameters’: nozzle type; nozzle spacing; and water flowrate; and the following ‘building/room design parameters’: obstructions; ventilation; and compartmentation.

Findings from parameter tests
The findings from the parameter tests with wood crib fires included:
• Wetting of the wood crib fuel load was demonstrated to be an effective means of either reducing fire spread or preventing any further fire spread, depending on the ‘wetting’ flux density.
• Suppression was observed when the crib fire was exposed within the water mist spray envelope. Test results demonstrated that it is critical to install water mist nozzles at spacings that deliver sufficient water over the area of the fire. At small increases in nozzle spacing it has been shown in the open scenarios in this project that fire suppression may not be achieved.
• A reduction in the water flow rate of the tested water mist system resulted in reduced fire suppression effectiveness.
• With the crib fully shielded from the water discharge, only minimal fire control was demonstrated.
• With the crib fire partially shielded, the water mist system was effective at preventing spread to exposed fuel protected by a high water flux discharge density. A level of fire control was also demonstrated within the part-shielded portion of the fire.
• Ventilation, in open conditions, had a highly significant influence on the water distribution pattern of the mist discharge. A significant amount of the water mist droplets could be seen being ‘blown’ away from the fire. The water coverage flux density at the fire location was much reduced. The suppression outcome was dependent on the ventilation rate and location. Ventilation affects both the fire and the water mist system. With ventilation across a floor, the development of the crib fire was affected. Initially, the flaming struggled to become established but then spread quickly. The performance of the water mist system was detrimentally affected by the ventilation. The fire was not effectively suppressed, particularly in comparison to testing in ‘still air’ conditions, and fire continued to spread along the crib.
• Within a compartment, water mist performed well in a fully sealed enclosure, but its performance was reduced with ventilation, such as an open door with or without mechanical room ventilation.

In summary, installation parameters, e.g. nozzle spacings, were found to be critical in achieving effective fire suppression. Building parameters, e.g. fuel shielding, ceiling height, ventilation and compartmentation were all found to potentially have a highly significant influence on the effectiveness of the tested water mist systems. Hence, it is important that for proving and acceptance testing, a fire test protocol accurately addresses the potential impact of these parameters.

Development of a full scale fire test protocol for open plan office spaces
Prior to developing a fire test protocol, an assessment was made of typical open office areas. Information was gathered and reviewed from an office survey, office fire load surveys, office fire test data and standard test fires. In the development of the draft British Standard [3] the UK committee did not adopt the European office fire performance tests [4], preferring to wait for the outcome of this BRE Trust project.

BRE Global sought to develop an office test fire that met the following criteria:

• A ‘stylised’ scenario that represents a typical office fire, in terms of the fire load distribution, fire growth rate and heat release rate.
• A scenario that challenges a water mist system, by including a shielded fire source and an open ceiling.
• A readily repeatable scenario.
• An ignition scenario with the potential to spread both within the initially ignited fuel and to other fuels in the vicinity, so that a reliable progression of fire spread within the fire load is achieved.
• A fuel arrangement that was not susceptible to collapse (in the early stages of the fire).
• A fuel arrangement that allows a clear means for determining pass/fail criteria in terms of limiting the fire spread and the extent of fire damage, by means of temperature and assessment.
• Fuel and materials that can be closely specified easily sourced and repeatedly obtained.
• A scenario that is simple and relatively cost effective.

The BRE Global developed arrangement consisted of two combustible 12mm thick plywood walls at right angles to each other and two 22mm thick chipboard tables. The tables were positioned with a 10mm gap to the walls. Additional fuel loading consisted of two cribs of wood and polypropylene. These cribs were beneath the table. All of the wood-based products used in these tests were non fire-retardant treated. An arrangement of cardboard box files (four of which are filled with paper) and polyurethane foam sheets were placed on the table.

The ‘corner’ wood crib was ignited at the end closest to the corner of the wall arrangement. The fire was allowed to develop freely, involving the first crib, plywood wall and table. The gap between the chipboard table and the plywood walls allows flames to penetrate easily and involve the ‘target’ box files and foam sheets above. For the development work and to establish the repeatability of test, the fuel arrangement was located below the BRE Global calorimeter hood which allowed for the measurement of heat release from the test fire. Additional thermocouples were located above the wood cribs, folders and foam sheets and at a height of 2.5m. You can see pictures of the test below:

Shortly after ignition		Flames spreading above table
Fully involved		Post test

The heat release from the fire is shown below:

Gas phase temperatures during the test are shown below:

Testing with the full scale fire test protocol for open plan office spaces
A series of tests was undertaken to assess the performance of industry provided water mist systems (both low and high pressure) and a sprinkler system against the BRE Global developed office fire test protocol. The test work was used to develop criteria for the determination of effective fire suppression.
Tests included:
• Sprinkler system – an array of four sprinkler heads on a 3m by 3.5m spacing at a 5mm/min coverage (to aid the development of criteria for effective fire suppression);
• Low pressure water mist system – an array of four nozzles with water supply pressure of approximately 12 bar, on a 2.5m by 2.5m spacing with water supply pressure of approximately 12 bar and nominal coverage of 5mm/min; and on a 3m by 3m spacing and nominal coverage of 3.5mm/min;
• High pressure water mist system – an array of four nozzles with water supply pressure of approximately 100 bar, with both a 3m by 3m spacing and 4m by 4m spacing, and nominal coverage of 1.6 and 2.8mm/min respectively.

The fuel arrangement for the described tests was located centrally within the array of four nozzles. A 6m by 6m open ceiling was used for the installation of the water mist systems. The floor to ceiling height for all tests was 5 m. Nozzles were sealed and the suppression systems automatically activated on operation of heat sensitive elements; at approximately 5 minutes in normal operation.

Success criteria
The criteria determined for a successful test was as follows:
• The water mist system, operating without manual intervention, shall successfully suppress the test fire.
• The temperature, measured 75mm below the centre of the ceiling, after operation of the water mist system, shall not exceed 80^oC for a period longer than two minutes for the entire 30 minute duration of system operation.
• There shall be evidence of unburnt foam and box files remaining after the completion of the test.
• Fire damage to the plywood shall not extend to the ends of the walls.

Findings with the full scale fire test protocol for open plan office spaces
All the systems, as a minimum, demonstrated temperature reduction at ceiling level and reduced fire damage, compared with the unsuppressed fire test. However, not all arrangements demonstrated effective fire suppression meeting the criteria for a successful test:
• The sprinkler and low pressure water mist system (at 2.5m by 2.5m spacing) were successful.
• The low pressure water mist system (3m by 3m spacing) was not successful.
• The high pressure water mist system (installed with various arrangements) was not successful.

Conclusion
Fire performance tests are necessary to demonstrate the effectiveness of a particular water mist system for specific end use applications. In this work, the primary focus was on open plan office areas.

BRE Global has developed a fire test protocol that can be employed for testing the effectiveness of water mist systems in this scenario. This stylised office fire test will be submitted to the relevant British Standards committee for their consideration to include as a new Part containing a fire test protocol for open plan office areas in draft British Standard DD 8489 [3].

Overall, the full scale test results were of concern. Most water mist system arrangements were not able to provide expected levels of fire protection for the tested scenario (open plan office areas with a high ceiling). Or, in terms of the design of the tested systems, the spacing between nozzles was too great and the quantity of water discharged too low, to provide effective fire suppression.

Critical for the successful operation of a water mist system are the system design details, in particular, nozzle type, nozzle spacing, water flowrate and building/room design details, in particular, obstructions, ventilation, ceiling height, compartmentation and openings.

The general findings from this work are likely to be equally valid to other types of application and occupancy types. It is therefore advisable to always carry out fire performance tests to support the use of water mist systems in different applications.

Acknowledgements
This study was conducted as part of a BRE Trust project. The authors would like to thank the following for their contribution to the work, BRE Global colleagues, Tyco Fire and Integrated Solutions (TFIS), Ultra Suppression Systems Ltd, and Royal and Sun Alliance (RSA) Insurance Group.

References
1. K Annable and P Reading, IWMA Conference 2008 Proceedings, Fire safety in prison cells - effectiveness of water mist suppression systems, www.iwma.net
2. CLG Guide 2006, C Williams and L Jackman, An independent guide on water mist systems for residential buildings, CI 71/5/24 (BD2502), BRE, http://www.bre.co.uk/filelibrary/rpts/water/Water_Mist_Guide_v2.pdf
3. British Standard Draft for Development 8489 Part 1 to Part 7 – Commercial and industrial water mist systems (committee draft only).
4. ‘Fixed firefighting systems – Watermist systems – Design and installation’, European Committee for Standardization, CEN Technical Specification, CEN/TS 14972: 20

Posted in Fire performance test, Royal and Sun Alliance (RSA) Insurance Group, BRE, water mist system | No Comments »

26/03/2010 by David Slade.

Accurate people counting gives you powerful intelligence for strategic planning.

People counting technology has transformed the way business decisions are made. It’s the only practical way to get a clear picture of occupancy, pedestrian flows and retail traffic. And it can make customer behaviour transparent, revealing exactly how visitors respond in their movements around a site.

People counting systems you can…

• Immediately evaluate and adapt marketing activities according to retail traffic.
• Improve customer service and reduce staff costs by matching staff levels to varying occupancy.
• Make best use of low occupancy periods, for example with maintenance activities.
• Assess sales conversion rates and see how new product lines or services affect footfall.
• Identify high performing stores and pinpoint the reasons for their success

A footfall dashboard puts you in control of the data…

• See total and average footfall to date and for any given period.
• Compare different periods over a number of years with graphs and statistics.
• Automatically highlight key dates such as bank holidays.
• Create a journal to evaluate and compare your own special events and marketing activities.
• Upload sales data to see sales conversion rates.
• Analyse data against number of staff working.
• View and compare parameters such as occupancy, footfall or dwell time.

Posted in Footfall - people counting | No Comments »

26/03/2010 by David Slade.

HomePNA is the leading standard and technology used for transferring Internet Protocol (IP) content across existing coax cables and phone wires. The main goal of HomePNA is to deliver rich media content such as HDTV streams, VoIP and broadband data without having to install new CAT-5 wiring.HomePNA is the marketing name for the ITU-T G.9954 standard - the only open global standard on the market today for “no-new-wires” networking. HomePNA is designed to run over coax and phone lines. While phone line was the original purpose of HomePNA, over a million homes now have HomePNA running over their coax wiring. In fact, HomePNA connects enough coax wiring to circumnavigate the globe.

HomePNA Delivers More for Less

HomePNA is the leading Home Entertainment Networking technology for a reason - it delivers more content for less money and hassles. HomePNA is optimized for existing coax and phone lines - making it easy for service providers to quickly and economically deploy IPTV Solutions and other services. A typical service provider can deploy IPTV using HomePNA at roughly half the install cost and time as that of deploying IPTV with Cat-5.

HomePNA is capable of delivering a total payload of over 200 Mbit/s. This is more than enough for the delivery of current rich multimedia content distribution and it provides ample headroom for the high bandwidth based applications of the future.

HomePNA is optimized for the real world. It coexists well with broadband and narrowband services (xDSL, TV, telephone) on the same wire and delivers prioritized and parameterized QoS for better quality of experience results.

HomePNA Networks are Easy to Install

The concept behind HomePNA is pretty straightforward. Simply connect the first HomePNA enabled device to any available phone jack or coax/TV outlet and the other HomePNA device to another phone jack or coax/TV outlet and you are good to go. Using HomePNA, every phone jack and every coax/TV outlet becomes a connectivity point which enables the extention of the network to every room in the house.

HomePNA Runs the Applications You Want to Deliver

HomePNA is perfect for a broad range of home entertainment, MDU and broadband access solutions.

• Home Entertainment Networks
• IPTV Solutions
• Triple Play Services
• Whole Home DVR
• Over the Top Applications
• MDU and Hospitality
• IPTV Solutions for MDU
• Broadband Access

HomePNA Fits Your Environment

The secret to any great technology is it works well within its environment. This is true with HomePNA. CopperGate’s HomePNA chipsets quickly and easily fit within your environment:

• Works on either coax or phone. With HomePNA, installers can decide on site which media is best for that specific installation. Only HomePNA provides this level of flexibility.
• Supports any Ethernet based service in the home. Whether it is IPTV, VoIP, Internet surfing, Whole Home DVR, it doesn’t matter. Anything that is IP based can be supported by HomePNA. That is why HomePNA has such a broad ecosystem of devices and partners.
• Coexists well with Cable TV, ADSL and VDSL. HomePNA has been optimized to work in bands that coexist with either ADSL or VDSL on the same wire. A simple DSL filter is all that is needed. In addition, HomePNA can work over the same coax infrastructure with analog or digital cable TV (no low frequency band return channel) and HomePNA is perfect for delivering IPTV and cable TV over the same coax line for applications.
• Tunable to the environment. HomePNA has the flexibility to operate over different frequency bands such as 12-28 Mhz, 12-44 Mhz, 36-52 Mhz or 36-68 Mhz. This provides flexibility in finding the optimal frequency for your environment and makes it easier to fit your regulatory requirements.

HomePNA is Popular

Many service providers are deploying HomePNA around the world. Four out of the top five North American Telcos deploying IPTV have selected HomePNA as their Home Entertainment Networks solution. You should, too. HomePNA is installed by dozens of service providers worldwide and more are joining every day. Already over 1,000,000 homes are running HomePNA today.

HomePNA Performs Great

HomePNA delivers the performance that service providers want. HomePNA is:

• Stable. Once a system has been installed and the network has been qualified, there are virtually no truck rolls with HomePNA and the performance level is maintained as long as the equipment is connected and operational.
• Robust. The HomePNA technology can mitigate both narrow band interferers such as Ham radio transmissions as well as broadband noise sources typical to unshielded phone lines or coaxial MDU environments.
• Great Reach. HomePNA can reach over 750 feet over phone lines before any degration in bandwidth. HomePNA can maintain connectivity all the way past 1,500 feet - over 500 yards.
• Excellent Attenuation Response. CopperGate’s HomePNA chips deliver maximum throughput without any degradation for attenuations up to 40 dB, and continue to work up to roughly 70 dB.
• Parameterized and Prioritized QoS. HomePNA supports both parameterized and prioritized quality of service (QoS) and guarantees the delivery of high priority packets in the presence of best effort data streams.
• Multiple End-Points. HomePNA can add end points without performance degradations. The number of end points does not affect the total system bandwidth of the network. For example, HomePNA can support up to 62 end points in MDU and Hospitality applications.
• Rate Negotiation. HomePNA provides the best performance for each line condition using a sophisticated peer-to-peer rate negotiation process.
• Remote Management. HomePNA enables TR-069 based remote and local monitoring of the network to check for quality, network speed, network load, the noise floor, and other key parameters that describe the overall system behavior.

Posted in ITU-T G.9954, HomePNA, IP (Internet Protocol) | 2 Comments »

26/03/2010 by David Slade.

The future of Home Entertainment Networks is here today.

It’s called IPTV. It is one of the most promising new opportunities for carriers. A recent In-Stat report projects that telco TV subscribers will grow to 71.6 million worldwide by 2012.

Imagine a home entertainment system that offers viewers the freedom to pause a television show in one room and resume watching it in another. That’s possible with IPTV distribution. Viewers can fast forward, rewind, and record while accessing global channels, personal media channels, electronic program guides, and more. It delivers television-on-demand with multiple picture-in-picture features as well as cutting-edge functions enabling viewers to record their favorite shows from wherever they are in the world.

This is great news for telcos. IPTV deployments are proven to stop landline subscriber erosion, increase ARPU, reduce churn and improve broadband purchases. IPTV is also protecting telcos from competitive threats of Triple Play Services coming from the cable industry.

Understanding the Home Entertainment Network

The secret to successful IPTV deployments is to best understand the network inside the home. While access technology is important, the bigger challenge is to have enough bandwidth inside the home entertainment network to deliver the performance and robustness required for pay-TV services.

The Home Entertainment Network is different from the traditional home network in several ways. First, it is essentially a real-time network. There is very little tolerance for network latency. Unlike data networks where the customers can tolerate jitter and other network delay problems, the customer’s expectations for pay-TV services require a much higher robustness.

Second, Home Entertainment Networks are bandwidth intensive. Delivering multiple HDTV streams, Whole Home DVR, and other services all add up in terms of bandwidth. Typically, the throughput requirements for Home Entertainment Networks are 5-10x bigger than those of traditional home data networks.

WiFi and CAT-5 Are Not the Solution

While a widely deployed networking technology such as Ethernet or 802.11 WiFi might seem the obvious choice, they don’t meet the requirements of carriers. They lack the home coverage, cost and/or performance requirements needed to deliver Home Entertainment Networks. WiFi isn’t a viable alternative because it doesn’t have the bandwidth or robustness to deliver the performance required for HDTV streams. Plus, coverage inside the home can be spotty and unreliable.

CAT-5 is also considered a possible technology. However, CAT-5 is not widely available throughout most homes and is very time consuming and expensive to install.

The best approach is to find existing wires in the house that can meet the bandwidth requirements of Home Entertainment Networks. The most reliable approach uses coax, powerline or twisted pair.

HomePNA - the most popular Home Entertainment Network Solution for Carriers

When telcos want to get into IPTV and triple play, the technology they turn to most is HomePNA, the ITU-T based standard G.9954. Four out of the top five largest carriers in North America deploying IPTV have selected HomePNA. In a recent report, HomePNA 3.1 was ranked the most widely deployed IPTV solution amongst service providers worldwide.

What makes HomePNA so relevant to carriers?
It provides all the performance and business attributes telcos want: great performance, compatibility with existing infrastructure and an attractive business model.Telcos that have deployed HomePNA have received higher fixed line retention, higher ARPU, and greater customer satisfaction. To date, the addition of CopperGate-enabled IPTV has generated more than $1 billion in new revenues for service providers.

HomePNA 3.1 delivers high bandwidth IP traffic over existing coax and phone wires. The latest HomePNA solutions deliver more than 200 Mbit/s of continuous throughput - enough to meet all the needs of service providers for the foreseeable future. HomePNA solutions provide enhanced features such as guaranteed quality of service (QoS) and remote management and diagnostics capabilities that were developed specifically to allow telcos to provide reliable cutting-edge television service while minimizing operation expenditures.

HomePNA also works well with telco infrastructure. It coexists with ADSL, VDSL and related technologies. This makes it easy for service providers to quickly and economically deploy IPTV inside the home.
HomePlug AV - The Powerline Solution for Triple-Play Home Entertainment Networking

For service providers and consumers, HomePlug AV 1.1 based solutions provide a cost effective, high performance solution for the most demanding whole-home entertainment networking for triple-play home services - video, audio, data, and voice applications - over existing AC power lines.

For homes without existing coax wiring infrastructure, the powerline provides a cost effective, high performance solution for whole home distribution of video, phone and broadband services. With PHY performance of up to 200 Mbps, HomePlug AV is an excellent choice for consumer home entertainment products where power lines are the distribution media.

G.hn - The Next Generation in IPTV Home Networking

CopperGate welcomes the recent adoption of G.hn, the next generation home networking standard, ratified by members of the International Telecommunications Union in December 2008. This new standard will make IPTV even more popular and cost-effective, thus paving the way for increasingly innovative features and applications throughout the broadband home.

Posted in quality of service (QoS), G.hn, Home Entertainment Network, powerline, IPTV, HomNet | No Comments »

26/03/2010 by David Slade.

Automatic vehicle location (AVL) is a computer-based system used for tracking vehicles, primarily transit buses but also fleets of trucks (see freight) and automobiles. For transit, the actual real-time position of each vehicle is determined and relayed to a control center. Actual position determination and relay techniquesvary, depending on the needs of the transit system and the technologies employed. Typically, vehicle position information is stored on the vehicle for a specific time, which can be as short as a fewseconds or as long as several minutes. Position information can be relayed to the control center in raw form or processed on-board the vehicle before its transmission. Transit agencies often incorporate AVL with other operational functions such as computer-aided dispatch, mobile data terminals and emergency alarms. Increasingly, transit agencies are also using AVL for services that directly benefit riders such as:-

• Real-time passenger information
• Automatic passenger counters
• Automated fare payment systems

Other components that may be integrated with AVL systems include:-

• Automatic stop announcements
• Automated destination signs
• Vehicle component monitoring
• Traffic signal priority

Benefits of AVLAVL systems can help transit agencies increase fleet utilization and reduce fuel, labor and capital costs. Key benefits of AVL include improved schedule adherence and timed transfers, more accessible passenger information, increased availability of data for transit management and planning, and the efficiency/productivity improvements in transit services. A 2003 survey of transit agencies using AVL, conducted by the Transit Cooperative Research Program (TCRP), found that, while many transit agencies deployed AVL systems for the purpose of increasing operational efficiency, an additional benefit was improved customer service due to the ability of AVL systems to provide customers with real-time predictions of bus arrivals. Thus, transit agencies are increasingly integrating real-time information systems into their existing AVL systems. Respondents of the survey indicated that the area of greatest improvement with AVL was improved customer service, while increased customer satisfaction was the second greatest benefit.

Furthermore, due to supplemental technology such as automatic passenger counters, transit agencies are better able to analyze transit service performance in real time and historically, to gather information needed for system planning, and to locate vehicles for emergency repairs. The 2003 survey also reported that transit agencies implementing AVL can expect ridership and revenue to increase and that a modal shift toward public transportation may result.

Benefits of AVL include:

• Operations
  • Transit firm productivity gains: increased passenger trips, capital savings (potential reductions in fleet size due to better utilization of vehicles), lower annual maintenance costs and generally a lower vehicle cost per mile.
  • Improved schedule adherence, accuracy in schedule adherence monitoring and transfer coordination.
  • Increased transit ridership.
  • Labor savings: reduced need for additional road supervisors and manual data entry.
  • Improved ability of dispatchers to control bus operations as well as better monitoring of driver performance.
  • Effective tracking of off-route buses as well as paratransit vehicles and drivers.
• Communications
  • Improved communications between supervisors, dispatchers, and operators
  • Reduced voice radio traffic and loss of radio calls
• Passenger Information
  • Provides capability to inform passengers of predicted bus arrival times enhancing the quality of transit service and allowing travelers to make better travel decisions.
  • Reduces customer complaints and the need to add customer information operators.
  • Improves image of agency.
• Scheduling and Planning
  • Provides more complete and accurate data for scheduling and planning.
  • Allows for potential reduction in schedule preparation time and staff.
  • Aids in effective bus stop placement (when combined with a G.I.S. database and automatic passenger counters).
• Safety and Security:
  • Enhances driver and traveler security (particularly when coupled with silent alarm technology) by allowing quick location of vehicles and faster security response.
  • Enhances driver and traveler safety: accurate and quick location information allows for faster response to accidents.
  • Provides better operational response during detours caused by accidents, roadway closings or bad weather.

Vehicle Location Technologies

AVL systems use one of four types of navigation technology, or may combine two of these technologies to compensate for inevitable shortcomings of any one technology. The four principal technologies employed for AVL systems are:

* Global Positioning System (GPS Satellite Location)
* Signpost and odometer
* Radio navigation/location
* Dead-reckoning

Global Positioning System
GPS is the newest of these and is by far the most popular choice for transit agencies implementing new AVL systems today. GPS employs the signals transmitted from a network of satellites orbiting the earth. These signals are picked up by a receiver onboard the bus. The satellite system covers almost all of North America, eliminating the need to place transmitters/receivers along any route. The existence of the satellite system means that the main cost for the agencies result from purchase of the GPS receivers and equipment to transmit to dispatch. The accuracy and reasonable cost of GPS make it the most appealing option, though it too has some problems. Foliage, tall buildings, and tunnels can block the satellite signal, and at times satellite signals do not reach specific locations. Some agencies use dead reckoning in conjunction with GPS to fill in such gaps.

Link to story on how GPS works: http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=102387

Satellite Technology in Europe
Until recently, Europe has depended on information derived from GPS satellites and from the Russian GLONAS satellite systems, combing satellite technology other, older systems. Without a true alternative to GPS, however, certain areas of Europe, particularly in northern Europe, were not well covered by satellite technology. However, major changes are underway in Europe. A system called EGNOS began a test phase in early 2005. This system comprises a network of more than 40 European ground stations that record, correct and improve data coming from the US global positioning system (GPS). The modified signals are communicated to users via geostationary satellites. More significantly, Europe is developing its own satellite technology, known as Global Navigation Satellite System (GNSS), or Galileo. Galileo is based on 30 satellite constellations supported by ground stations. Galileo is currently being built by the European Union (EU) and European Space Agency (ESA) With the addition of these 30 satellites, positions will be determined far more accurately for most places on Earth, even in cities where buildings obscure signals from satellites low on the horizon.

Galileo is intended to provide more precise measurements than available through GPS or GLONASS (Galileo will be accurate down to the metre range) including the height (altitude) above sea level, and better positioning services at high latitudes. The political aim is to provide an independent positioning system upon which European nations can rely even in times of war or political disagreement, since Russia or the USA could disable use of their national systems by others (through encryption).

Like the US GPS, use of basic (low-accuracy) Galileo services will be free and open to everyone. However, the high-accuracy capabilities will be restricted to military use and paying commercial users.

Dead-Reckoning
Some transit agencies use dead reckoning systems in combination with GPS. Dead reckoning systems, among the oldest navigation technologies, determine vehicle position by measuring distance traveled from a known location and direction of travel. Dead reckoning sensors can measure distance and direction from a fixed point (under the most basic setup, an odometer and compass could be used to calculate position from a specific stop on a route). Typically, these systems act as a backup to another AVL system. This relatively inexpensive system is self-contained on the bus. Dead reckoning, however, has a number of drawbacks. Uneven surfaces and hills can compromise the positioning information. Should the vehicle leave a fixed route, its location will no longer be known since there will be no waypoints off the fixed route. Also, accuracy degrades with distance traveled, and regular recalibration is required (tire circumference changes with wear).

Signpost/Odometer Systems
The signpost/odometer system was the most common navigation technology until the advent of GPS. In this system, a receiver is mounted on the bus, while transmitters are placed along the bus’ route. Utility poles and signposts are most commonly used as mounting locations for these transmitters. The bus picks up a low-powered signal from these transmitters as it passes by and the mileage is noted. When the bus reports its location, the distance from the last pole is used to locate the vehicle’s position on a route. The system can be run in reverse, with the transmitter on the bus and multiple receivers mounted along the route. However, should the bus need to leave the route, there will be no information about the bus, so most agencies prefer to have a receiver on the bus. This older technology has some drawbacks. Creation of new routes requires the placement of new transmitters, and the system is maintenance intensive due to the relatively high number of transmitters and receivers involved.

Radio Navigation/Location
Radio navigation systems also tend to be combined with other systems. Radio location systems use a low-frequency signal to cover the system, and the buses are located as they receive the signal. Loran-C (Long Range Aid to Navigation) is the most common type of land-based radio location. Despite the simplicity of the system, it is subject to some major drawbacks. Overhead power lines or power substations can cause signal interference, and signal reception is typically very poor in canyons.
Integrating AVL with Other Systems

Buses equipped with AVL offer many possibilities for transit interface with highway and traffic organizations or transportation management centers. Opportunities include: providing transit buses with traffic signal priority; obtaining traffic congestion data at the dispatch center to allow rerouting of buses or informing customers of delay; incorporating transit information in traveler information systems; developing multi-application electronic payment systems; using buses to automatically communicate traffic speed; and reporting of roadway incidents by transit vehicle operators.

Traffic signal priority on arterials and at freeway on-ramps can substantially improve the schedule adherence of transit vehicles and reduce run times. This effort requires cooperation between transit and highway departments because traffic signals are normally the responsibility of highway departments, and giving transit vehicles priority affects other vehicle movements.

Transit information should be an important element of any regional traveler information system. Adding real-time transit information to available highway information can be helpful to travelers in making mode choice decisions and would be expected to increase transit ridership.

Electronic fare payment may be one of the more appealing adjuncts to an AVL system for potential riders because of the convenience it offers the user. The greatest benefits of electronic payment systems would result from the inclusion of multiple transit agencies and integration with other activities, such as toll collection, and payment for parking and retail purchases.

AVL-equipped buses can be used as probes for determining travel speeds on freeways and arterial roadways—a valuable information resource for a transportation management center, especially one with limited traffic detection or observation capabilities, particularly on arterials. Bus operators can also be useful in reporting incidents they see during their trips. Using the known location of the bus at the time of an incident report, the response of arterial, freeway, and incident management systems and emergency services can be more quickly provided. Paratransit dispatchers would be able to more efficiently route their vehicles if they have real-time information on freeway and arterial speeds and incidents.

Data Transmission to Dispatch

The two most common methods of transmitting bus location data to dispatch are through polling and exception reporting via wireless communications.Many agencies use a combination.

Under polling, the computer at dispatch operations polls each bus, in turn, asking for its location. This method requires the bus to be able to read or calculate its position. The bus location is then transmitted by radio to the dispatch center. Once all the buses have been polled, the computer starts again with the first bus and repeats the cycle. The amount of time it takes to complete a cycle will increase as the number of buses to be polled increases. However, because the computer can poll different buses simultaneously over different radio channels, the time to complete a polling cycle depends on the number of radio channels that are utilized.

In exception reporting, each bus reports its location to dispatch at only a few specified locations or where the bus is running off-schedule beyond selected tolerances. Exception reporting makes more efficient use of available radio channels.

Data Use at Dispatch

Training employees is a key to maximizing the use of an AVL system. When coupled with mapping software, AVL information can be analyzed to anticipate and address bus failures, monitor schedules and direct emergency response They can also trigger location-specific announcements, either visual or auditory, to comply with the Americans with Disabilities Act (ADA).
Implementation and Operational Challenges

Early adopters of AVL systems experienced many technical and institutional problems. The biggest challenge for agencies implementing AVL today is the potentially lengthy procurement and installation period (particulalry software development and integration of technical components). For this reason, agencies procuring an AVL system may want to use an existing design, with customization capabilities. Such an approach would substantially limit potential risks and problems. Other implementation and operational challenges to consider are:

Implementation:
o Institutional relationships may be difficult.
o Development of new software or extensive customization of existing software can result in deployment difficulties.
o Considerable effort may be required to establish an accurate geographic information system database.
o Systems should be consistent with the National ITS Architecture.
Operations:
o New technical expertise is usually required at the transit agency.
o Some existing staff may be reluctant to learn the new technology.
o The schedule adherence function design requires careful thought.
o A global positioning system signal reception problem may occur in certain areas.
o The huge volume of data that an AVL system can record may overwhelm existing agency analysis capability.

Posted in Galileo, global positioning system (GPS), Global Navigation Satellite System (GNSS), Automatic vehicle location (AVL) | 2 Comments »

26/03/2010 by David Slade.

One way to increase public revenue from public parking spaces is by improving the way parking meters gather data. Improved parking meters have evolved that increase car park revenue as well as efficiency in service and operations. It provides parking meters with the capacity to provide real-time information. This information consist primarily of the status of parking spaces (it indicates which expired metered spaces have parked vehicles.) The technology consists of sensors located at meters that report on their condition (i.e. whether it is working or if it is expired). This information is processed by a microprocessor and then sent via an internal wireless modem to the server. This server then processes the information from all the parking meters and sends it to the public institution in charge of them. This system also provides verification of parking permits. For example, disabled people with special license plates can be automatically approved for parking in designated places.

Posted in Advance parking meters | No Comments »

26/03/2010 by David Slade.

One of the major problems of cash-based parking payment systems has been the time spent in queues waiting to obtain a ticket or to pay a cashier. Queues can cause congestion in areas within and outside of parking facilities. Electronic payment can eliminate the need to stop when getting a ticket or paying. For a description of electronic payment and its different technologies. Advanced fare payment systems are also used in advanced parking, and one of the most widely used technology is Radio Frequency Identification (RFID).The use of RFID or Transponders is surging throughout the world because they permit fast and easy access to parking facilities. RFID is a wireless process that recognizes an object by detecting and reading a unique radio-signal. The signal conveys information regarding the user; when it is within five feet of the entrance, the transponder emits a signal that the main computer then verifies. This system permits hands-free, nonstop parking access. People need not loose time searching for money or cards when paying.

One emerging parking payment technology falls under the rubric of m-commerce, which refers to the wireless payment of services (or products) like parking. An m-commerce parking lot allows drivers to use their mobile phones to wirelessly “deposit” money towards time in a parking space and remain updated via SMS messaging on the time remaining. Drivers usually have to register their license plate and credit card number in order to use the wireless metering. These virtual parking systems exist in various stages of development around the world but have made the most progress in Asia and Europe.

Posted in m-commerce, Radio Frequency Identification (RFID), Car Park System, SMS | No Comments »

26/03/2010 by David Slade.

Advanced Parking Systems obtain information about available parking spaces, process it and then present it to drivers by means of variable message signs (VMS). APS is used in two ways: to guide drivers in congested areas to the nearest parking facility with empty parking spaces and to guide drivers within parking facilities to empty spaces. Although the former function is more common, guidance systems within parking lots are becoming more common. This growing number of guidance systems addresses drivers’ need for more information about the position and number of the spaces that are actually available within a parking structure. These systems reduce time and fuel otherwise wasted while searching for empty spaces and helps the car park operate more efficiently.

The need for APS is most prominent in highly dense areas, where the search for parking facilities congests and interrupts traffic flows.

PARKING GUIDANCE SYSTEMS

Basics of Parking Guidance Systems

Parking Guidance and Information (PGI) systems, or Car Park Guidance Systems systems are based primarily on the use of message signs to give drivers information regarding parking availability. The systems combine traffic monitoring, communication, processing and variable-message sign technologies to provide the service. PGI systems are designed to aid the in the search for vacant parking spaces by directing drivers to car parks where occupancy levels are low.

The availability of parking spaces in each facility is obtained from sensors that count the number of cars entering and exiting or, in other cases, by comparing the tickets issued at machines or cash registers to the capacity of the facility. This information is sent to a central or main computer that processes it, determining the locations of available parking. Availability is generally expressed in terms of “full” or “empty,” but in some cases the actual number of spaces is given.

A problem with showing actual numbers is that when the number is small, drivers tend not to enter because they think that all of the spaces will be taken by cars already in the facility. This would not actually happen because the availability takes into account cars that have already entered the facility. The systems include VMS that show parking availability and nearest parking facilities. In some cases static signs guide drivers to the facilities. Other means of providing availability information are via roadside radio terminals, where small static VMS show the frequency at which it is being broadcast; by phone, where automated answering machines can give information on congestion and parking availability; via the Internet, where one of the main services is to provide information and parking reservations; and via in-vehicle navigation systems.

Example software used to control PGI systems

A Parking Guidance and Information system has four essential elements:

• Vehicle monitoring
• Communication
• Instation control system
• Variable Message Signs (VMS) or Changeable Message Signs (CMS)

Monitoring equipment must be installed at parking areas to establish the flow into and out of the car parks in order to calculate the number of available spaces. Vehicles entering and exiting car parks are often monitored through activation of existing barrier equipment, infrared, radar detector or by underground inductive loop. Real-time vehicle counts within car parks are held on count-stations or out-stations made up of firmware apable of handling the count data.

Car park count data are transmitted back to a central location or in-station, and processed through PGI software on a standard PC. PGI software is often capable of producing occupancy statistic and flow rates for traffic analysis. Variable-message signs are located at suitable decision points on the network present the information, so that a driver’s journey time to a vacant space is minimised. VMS generally show the number of vacant spaces or information such as “Spaces”, “Full” and “Closed”. Car parks are often grouped into zones to reduce the information that has to be presented on a single sign.

Communication systems between out-station and in-station, and then in-station to VMS also required. Systems can be hard-wired, however, for city wide projects wireless communication including GPRS may be suitable.

Integrated systems allow the user to exchange information between applications more easily avoiding duplication and potentially reducing communication costs. The UTMC Specifications offer a means of achieving integration efficiently, while allowing the adoption of the latest technological developments.

Multi-storey car park application of a PGI system

Multi-storey car parks

As well as city-wide applications, PGI systems can also be used for internal multi-story car park applications with entrance signs and level-by level signs.

Protective parking schemes

Parking Guidance and Information Systems have been used within protective parking schemes. These schemes are designed to minimise disruption and discourage visitors driving to major events in residential areas. Under such schemes, only eligible residents, their visitors and local businesses would be able to hold Event Day Permits, allowing them to park in the roads in the Event Day Zone when major sporting or music events are held. One such scheme is now employed by Brent Council at Wembley Stadium. This means any visitors driving to events at Wembley Stadium without a pre-booked parking space, will not be able to park in the surrounding streets. A Parking Information System consisting of VMS and a control in-station is used to inform residents and visitors alike of the Event Days when parking restrictions apply.

Benefits of APS/PGS

• Reduction in time spent searching for parking. The efficiency and accessibility benefits from reduced searching can also result in some reductions in accidents due to reduced driver frustration
• Reduced pollution. Changes in pollutant emissions due to PGI are most closely related to changes in overall travel time, for example, annual pollutant emissions are reported to have been reduced due to a PGI system in Munich, Germany.
• Reduction in congestion due to fewer cars driving around searching for spaces.
• Elimination of queues entering parking facilities because drivers will not go to a facility where there is no available space.
• Reduction in illegally parked vehicles.
• Better distribution of flow and parking demand through the area.
• APS systems result in higher revenues and profitability for the parking facilities.

Posted in Parking Guidance and Information (PGI) systems, Changeable Message Signs (CMS), variable message signs (VMS), Advance Carparking Systems (APS), Car Park System, Intelligent Car Park System | No Comments »

26/03/2010 by David Slade.

Carlo Gavazzi Dupline(R) Car Park System
Carlo Gavazzi has introduced an innovative new system to reduce the stress and time taken to find a vacant space in covered car parks at supermarkets, shopping centres, town centres and office buildings. This intelligent system is a cost-effective solution for providing an easy and environmentally friendly car parking experience.

The Dupline(R) Car Park Guidance System from Carlo Gavazzi is a reliable and easy to install solution that offers car park owners the chance to provide their customers with a more efficient service. As drivers are guided to find the nearest available parking space quicker thereby reducing the volume of toxic fumes and pollution, the amount of ventilation required and operating costs are also lowered.

The system is easily installed using a 3-wire Dupline(R) bus and is simple to configure. A ceiling mounted ultrasonic sensor is installed in each parking space to detect if a vehicle is present. This transmits the availability of spaces to displays situated around the area with built in LEDs to indicate how many spaces there are. A green arrow shows the location and quickest route to the next available parking space.

Dedicated handicapped parking spaces are shown using a blue LED and a red cross indicates that there are no spaces free within that section.

Posted in Car Park System, Intelligent Car Park System | No Comments »

26/03/2010 by David Slade.

A report by AMA Research estimates that the UK market for lighting was worth around £1.4 billion at manufacturers selling prices in 2009. Being a mature market, it mostly relies on replacement purchases which, generally, results in moderate growth or decline in line with the economy. However, the recession saw a market decline of 10% in 2009, and is forecast to fall a further 4% in 2010.

This will result in the lighting market struggling somewhat in the short term, but trading conditions in the longer term still remain positive.

In 2009, the lighting market was dominated by sales of luminaires, which accounted for 67% of the market, with lamps accounting for a further 26% and lighting controls the remaining 7%, although in the long term it is expected that lighting controls will gain share.

Growing sectors in the lighting market include LEDs, which represent a growing threat to more traditional products. Product development in LEDs will continue to offer this sector greater differentiation and it is expected that this will result in an increased market share in the medium to long-term.

Energy efficiency also continues to grow in importance, driven by legislative changes and increasing fuel bills. The government remains committed to promoting the use of energy efficient products, promoting use within public sector projects and through the introduction of energy conservation and monitoring legislation. Indeed, AMA has undertaken a more detailed study into the energy efficient lighting products market which has remained bouyant as a result of legislation, public information campaigns, and a high level of subsidisation (particularly in the domestic sector) which has largely offset the general economic decline and slowdown in housebuilding and construction activity.

The market for energy efficient lighting comprises lamps or bulbs, luminaires and lighting controls, and in 2009 it accounted for 36%, in value terms, of the greater UK lighting market, up from just 21% in 2005.

Some of the most notable trends in the sector include energy efficient lamps being designed to fit most standard luminaires, and growth in the luminaires and controls sector is therefore increasingly mirroring growth in the lamps sector – a trend likely to become even more noticeable as technology advances even further.

The value of the UK energy efficient lighting market is expected to reach £969 million in 2014, and the rate of growth – which slowed down slightly in 2009 – is expected to remain buoyant.
Given the projected decline in the use of non-energy efficient lighting solutions, largely as a result of legislation, AMA Research expects that the share of energy efficient lighting in the overall UK lighting market – 36% in 2009 – will reach 63% by 2014.

Copies of AMA Research’s “Energy Efficient Lighting Products Market – UK 2010-2014” and “Lighting Market - UK 2010-2014” reports are available from www.amaresearch.co.uk

Posted in Lighting, Construction workload | No Comments »