The Washington State Department of Transportation (WSDOT) is responsible for more than 18,000 lane-miles of roadway, nearly 3,000 vehicular bridges and 524 other structures. As part of that responsibility, they also protect air and water quality; communities; and roadsides.
The headquarters for WSDOT acts a service for the individual regional maintenance areas and traffic operations. Those “internal customers” are the groups to which WSDOT as a whole provides communication.
WSDOT Wireless Data Needs include supporting the design, construction, maintenance and operation of state highways. The department also includes these division or “customers”: Surveying; Mobile LIDAR; Aerial Photography; Machine Control; Roadside Devices; Snow and Ice Removal; AVL Mapping & Data Collection; Incident Response; Remote Structure Monitoring; and Ferries. WSDOT’s North Central Region Smart Snow Plow Project (NCRSSPP) covers the city of Wenatchee and surrounding areas.
NCRSSPP used IPMobileNet
’s (IPMN) IP-based data radio system to enhance communication for WSDOT and the Washington citizens they serve. The NCRSSPP trucks generate consumable usage, status and location information that is intended to be automatically exported from the vehicle to various entities for processing, display and archiving. This information has been traditionally compiled from various sources and reported through verbal, data entry and written methods by the operator. Automated real-time location and reporting of these vehicles will improve efficiency of snow/ice removal by enabling supervisors to make timely, informed decisions as well as returning the operator’s attention back to the road.
The data radio portion of the pilot project demonstrates a real-time data communications solution for the NCRSSPP within a portion of the region utilizing licensed 700MHz spectrum. Export and delivery of this information in real time, over varied terrain of the operational area requires a dependable system of licensed radios developed for this purpose. IPMobileNet Series of Radios IPMobileNet offers the IP Series Mobile Data Radios in both fixed and mobile formats.
The IP Series 32-fixed digital transceivers are intelligent mobile radios designed for the unique requirements of fixed site data applications. Mounted in road signs and other fixed sites, intelligent devices may connect to the serial port or Ethernet port for connectivity through the IPMN mobile data infrastructure back to IPMN’s IP Network Controller (IPNC) and other application servers (CAD, message switch, records servers, etc.) on the network.
These mobile radios utilize a high-performance, four-level Frequency-Shift Keying (FSK) wireless data modem for 32 kbps operation in 25 kHz channels. A mulit-layered approach is taken to maximize signal reliability including data scrambling, data interleaving, Forward Error Correction (FEC), and Viterbi soft-decision error correction algorithms. The result is increased performance improvement over competing products in low signal-to-noise environments. The IP Series 32-D25 and 64-D25 mobile digital transceivers are intelligent mobile radios designed for the requirements of mobile data and voice applications. Mounted in vehicles, intelligent devices may connect to the serial port or Ethernet port for connectivity back to the application servers via the IPNC. The IP Series mobile data radios provide the mobile client link to landbased wired networks. Radios may be programmed to public safety 700 or 800 MHz bands. The dual band 700/800 MHz radio can be programmed for 700 MHz channels together with 800 MHz channels, allowing mobile clients to roam through coverage areas provided by 700 MHz or 800 MHz base stations without a loss of connectivity. This benefits agencies that eventually migrate from 800 MHz spectrum to 700 MHz spectrum without replacing mobile hardware. These mobile radios utilize a high-performance, four-level FSK wireless data modem for 32 kbps operation, and between 4, 8 and 16-level FSK for up to 64 kbps in 25 kHz channels. This modulation scheme is provided by its DSP-based software modem. A multi-layered approach is taken to maximize signal reliability including patented multi-receiver Intelligent Diversity Reception ™, data scrambling, data interleaving, Forward Error Correction (FEC), and Viterbi soft-decision algorithms. The result is up to 20 dB performance improvement over competing products in low signal-to-noise or high multipath interference environments. These unique features assure very high message success rates, even while transferring data in a fast moving vehicle. Smart Snow Plow Project (NCRSSPP)
WSDOT is using the IPMobileNet IPSeries communications equipment for the Smart Snow Plow pilot project. The IP Network Controller (IPNC) is the intelligence that routes the network data to the mobile clients via base stations located at tower sites. The base stations provide coverage (like a cell tower) and the radios provide in-vehicle or fixed (stationary) two-way communications between the end user and people who are gathering information from the field. The current commercial infrastructure within the state provides limited coverage. The IPMN solution allows for an efficient use of existing WSDOT infrastructure to provide greater coverage and capacity within the state. The plan is to build out the network of base station coverage zones and increase the number of users on the network.
John Thomson is one of three electronic design engineers at WSDOT and Tim McDowell is the electronic engineering manager. They work with the Intelligent Transportation System (ITS) communication and wireless technology division of WSDOT. IPMN said the NCRSSPP is still in the build-out stage, so there has not been a full rollout yet.
According to McDowell, one of the things WSDOT addressed when they looked at systems was what does the total DOT need? “We can patchwork something along, or we could actually address the total agency need, and that was part of that process,” he explained.
Thomson said his office title is another name for the radio department in a way. “We have multiple customers within DOT, but we’re very interested in whatever solution we deliver to our customers within DOT, that it’s a public-safety grade system as far as reliability and sustainability.” So for this pilot project, WSDOT wanted to put together a system that would be able to demonstrate that kind of public-safety grade reliability on a daily basis. Once this is demonstrated and documented, WSDOT hopes further consolidation or combining of systems and needs within DOT can proceed from there. “The Smart Snow Plow program gives us a way to address this need and also demonstrate its capabilities,” Thomson related. Benefits
NCRSSPP started out as what McDowell called “resource management” during winter operations. They wanted to automate a lot of the things that were going on in the truck, to prevent any distractions as the driver is removing snow, preventing ice from forming, etc. The management could collect all that data to a central point and they would know what is happening out there on the roadway surface and make decisions to move resources if needed. They’d also be able to answer questions like: ‘Did this section of roadway get treatment?’ without having to go out to the driver and ask him. McDowell said before the IPMN system was in place, the driver actually had to physically enter data into a palm device or go back to the office and fill out a piece of paper. That information was either downloaded or submitted to his supervisor, and he’d have to enter that information into a database. “Now it’s all automated,” he noted.
According to Thomson, this type of system provides the ability to actively manage resources during a storm event and allocate their drivers and equipment to areas that have the greatest needs, while the storm is still going on.
WSDOT’s ‘pro-public, customer needs’ attitude and the fact that they wanted this to be a high-grade system, and they’re concerned about being accountable, made IPMN a logical choice for their IP radio system.
One of the reasons WSDOT looked at IPMN’s technology for this pilot project was its ease of operation. In other words, the operator doesn’t have to do anything, and that was one of the key factors in the selection of this system. The operator can go about his normal business and this product just sits in the background and works. “The operator doesn’t have to push a button, he doesn’t have to mash down on a mic, he doesn’t have to do anything—it just transmits the data when ready,” McDowell stated.
In the state of Washington, WSDOT deals with a varied terrain model. There are a lot of natural canyons as well as urban canyons, open country with desert to alpine conditions. According to McDowell, one of the technologies WSDOT looked at was the ability to use IPMN’s patented diversity reception capability to their advantage in this situation. In addition, the frequency reuse platform IPMN utilizes in their system was a big draw. “That was another thing we thought was really good for this pilot project because we were limited in the number of frequencies we could use in the beginning,” McDowell noted. Scalability was also a factor WSDOT considered when starting this project with IPMN; the ability to go from a really small pilot to a larger roll-out in an easy transition. Thomson said diversity, frequency reuse, and scalability were the three main factors (in that order) for choosing IPMN’s solution.
The Smart Snow Plow project quickly expanded because of the reliability and coverage WSDOT experienced. With the diversity reception technology, WSDOT was able to capture some ITS devices, such as remote weather information stations (RWIS); variable message signs (VMS); and variable speed limit signs. “We’re able to communicate to those individual devices, get information from them, and update them when we’re talking about a roadway sign or a speed limit sign,” McDowell explained. One of the other things WSDOT expanded on was the ability to capture a still photo from a camera. They have a snapshot camera that looks at a specific section of roadway on I-90, takes a snapshot of the road, and sends it every 10 minutes.
The ITS devices WSDOT picks up with IPMN’s radios are all actively used in the process of coordinating response to a storm event, meaning those weather stations will provide updated information. The variable speed limit/variable message signs will be changed to alert the traveling public of a pass closure or a slow-down for snow removal options.
The snapshot camera can tell WSDOT’s traffic management center about a big pile-up or heavy snow. “It gives us the ability to go to places where the only thing that we may have is a signpost and a solar panel or just some power to run a sign, and now we can leverage those to better inform the public and better coordinate our response,” Thomson stated.
The IPMN radios selected in the additional phase of the pilot project expanded from the moving vehicle to include fixed locations. Two fixed locations at Dodson Rd. and Lauderdale (the corner of two highways) had limited coverage with the prior service, which became unavailable as soon as the ground would freeze. Since they’re remote, the commercial services WSDOT was using were intermittent at best during winter operations. “Since we’ve installed the fixed radios, they haven’t had any communication issues,” McDowell noted. WSDOT has been through one and a half winters with the IPMN system of IP radios.
In terms of the ‘real world’ coverage the IPMN system is providing, WSDOT’s modeling software doesn’t have the sophistication to account for the diversity reception capability. They make their service predictions based on coverage modeling, and then they do drive testing. “The diversity receivers tend to easily match or exceed our predictions, it sometimes surprises us with coverage that is well beyond our predictions,” Thomson stated. “We’re seeing that we’re getting better performance through real-time use, than we do from our prediction software,” McDowell continued. The benefit of diversity receivers from IPMN’s solution makes an improvement over how the prediction software sees the performance along the roadway. Transition
Thomson said the transition, as far as installing of the pilot systems from the radio group side, followed the normal engineering and purchasing process. Training-wise, WSDOT’s technicians transitioned to the technology quickly, so that part went smoothly. WSDOT had those technicians working with their mechanics to install the system in the trucks. “Many of our mechanics now use a computer more often than a wrench these days, so the technology was quick for them to pick up,” Thomson said.
The WSDOT team, everyone from snow plow operators to supervisors, likes the IPMN solution. Drivers like it because it’s transparent to them. Supervisors like it because they are getting the data they need for winter operations back quicker. The technicians haven’t experienced any real problems with the equipment, so there hasn’t been any sort of failure rate. On the engineering side, it’s easy for them to engineer it when they know it’s going to perform better than what’s predicted. “We run our prediction software and we take a look at that, and we know it’s going to perform better than this. So it makes it easy for us,” McDowell stated. IPMN has been very responsive with tech support during the implementation process, Thomson said, and that kind of attitude has continued throughout the pilot project. So far, WSDOT has provided much of their own engineering design and installation services, relying on IPMN for telephone and e-mail tech support along with some limited site services. A “partner” relationship has been made and IPMN is prepared to support WSDOT in further deployments. WSDOT’s design philosophy also has some spare devices and a fault tolerant IPNC in the system just in case. Looking Ahead
WSDOT’s intent was to essentially “stretch the wire’; “To give the customer the ability to plug into an Ethernet jack in the vehicle, or at the site, and have that information be connected with the network, and give them that ‘wire-stretcher,’” Thomson said.
It’s too early to tell what the actual cost savings is for the pilot project. “We haven’t been able to do any sort of analysis that’s going to compare the driver’s time to the cost of the equipment and the impact that it has on the state,” McDowell said. If an employee doesn’t have to go back to the office to fill out paperwork, that saves time and money in the long run.
The cost-savings in a publicsafety radio system are two competing interests sometimes because they’re hard to quantify when looking for the reliability and coverage of public safety radio. “What benefit is something that has an extremely high “up-time’? Thomson asked. It can sit there all year, and the one time it needs to work, and it works, it could potentially be paid for. The most complex portion of this system moving forward out of the pilot project is to put the cost of a publicsafety radio system up against a strict cost-savings model. “We can always say, this communication package has a $50/month cost and that’s cheap, but we have no control over reliability. So, if it does fail then it’s useless to us,” Thomson said.
IPMN’s solution has impressed Thomson and McDowell. Thomson elaborated: One of the criteria was to see how can we do an economically responsible pilot project and then be able to leverage that investment and move it up to a statewide program, should it be successful, which we plan for, we anticipate, we work hard to make that happen.” Photos courtesy of WSDOT and IPMobileNet.