Chapter 6. Maintenance & Warranties


A basic truth of nature is that all things change. Until this point, the Telecommunication Handbook for Transportation Professionals has looked at the planning and development of the communication system. Chapter 6 will discuss maintenance of telecommunication systems and look at issues that should be addressed by the operator of a system. The chapter provides information on the reasons for maintenance, technician qualifications, explanation of warranties, and typical cost of maintenance agreements.

Note: This chapter provides a focus on telecommunications equipment. The reader is referred to FHWA Handbook: "Guidelines for Transportation Management Systems Maintenance Concepts and Plans" for more information about the development of equipment maintenance programs. See:

Communication systems are made of physical things that wear out (or change) over time. It is difficult to see the change, because there are very few moving parts. However, the components (transistors, capacitors, microprocessors, etc.) that make up devices that are part of a communication system do change, and lose their performance tolerances. When enough components operate at less than specification, the overall system (or device) will not perform as required. Operationally speaking, there is not a huge difference between a freeway system and a communication network. Both wear out from use and require maintenance and revitalization.

Communication networks should be treated as any other element of a modern transportation system. DOTs need to provide an adequate budget for maintenance, and training for personnel to become familiar with the elements of the communication equipment. The DOT technicians don't have to be capable of repairing the communications equipment. They simply have to be able to determine when the communication hardware is not functioning, and in many cases replace the device with a spare.

Most manufacturers provide a detailed manual of installation, testing and maintenance recommendations. Many provide on-site and factory depot service plans. The use of these plans may be a critical part of your overall maintenance program.

This chapter will:

Systems maintenance and upgrade is crucial to efficient operations. All communication equipment does eventually wear out, or reach the end of useful operational life. The communication system is the glue that unites the elements of a traffic signal, FMS, or ITS system, keep it operating with an efficient maintenance and upgrade program.

Why Create a Maintenance Budget?

Fifty years ago, communication equipment needed constant attention. The "state-of-the-art" used components that were highly sensitive to environmental variables (heat, cold, moisture, dust, etc.). Communication systems required significant adjustments by operations and maintenance personnel. All equipment was manufactured with external controls that were used to adjust the device back to specified parameters. Current equipment is less affected by its environment, and most manufacturers have eliminated the external adjustment controls.

The use of fixed value components minimizes the need for adjustments. Communication devices either perform as specified, or must be replaced. Manufacturers have created "board level" systems with all necessary components placed on a single card.

Some manufacturers will make significant claims about the reliability of their products. Many will claim MTBFs (mean-time-between-failures) that make it seem as though failures occur once in a million years. But, nothing lasts forever.

Most communication system component hardware is constructed on a single printed circuit board that can easily be replaced by a qualified technician. The components are so small that they can't be repaired, or replaced. Simply replacing the board with the failing component saves time and money.

Don't confuse the "feature option" switches, or option setting software for maintenance controls. The feature setting switches and software are only provided to allow users to optimize a device for a specific operational requirement.

Communication hardware normally fails either during, or just after, installation. These failures are the direct result of manufacturing "birth defects" – that is, the manufacturing testing process fails to identify a manufacturing error, or substandard component. However, the leading cause of near term failures is the result of improper installation or operation. Hardware manufacturers have standard component testing procedures to help assure that virtually all equipment leaving the production facility meets specifications (more on this subject later in the chapter).

Installation failures are caused when technicians fail to familiarize themselves with the manufacturer's recommendations. Many technicians will try to use shortcuts to reduce the installation time, or because they have installed similar equipment and believe that there are no differences between devices manufactured by different companies. Another common error is to assume that there won't be differences between old and new versions of the same device.

On a long term basis, most failures are the result of electronic component aging (through constant heating and cooling components will fail to meet original specifications). Systems will either fail, or develop substandard functional characteristics.

Don't forget that equipment also fails because of lightning strikes, electrical power surges, and connection of electrical power to a communications port.

Most communications equipment is built with internal monitoring capabilities. Diagnostics are displayed in one of two general ways: external display on the equipment, or via diagnostics terminal (or as a program on a PC). Most modems have L.E.D. indicator lamps to show that the device is functioning in a proper manner. A multiplexer or router will provide diagnostics via directly connected terminal, or through a device setup and management program on a PC.

photograph of a basic fiber optic modem used for traffic signal control systems, with lights for T1, R1, T2, and R2 and a window showing ring status

Figure 6-1: Photograph of a Fiber Optic Modem – Courtesy GDI Communications, LLC

Keeping track of all communication devices is part of any maintenance program. A simple equipment list table is best. The following is an example:

Table 6-1: Example Communication Device Inventory List
Item I.D. Serial # Date Installed Warranty Term Device Location
empty cell empty cell empty cell empty cell empty cell

An individual should be assigned to keep track of all equipment, and maintain relationships with manufacturers, installation companies, and system integrators. This person should have experience (or training) for completing simple repair and installation of communications equipment. If there is not enough equipment to require a full-time staff maintenance specialist, the agency should consider part-time personnel, or an outsource contractor. A field verification inventory should be conducted at least once per year. Whenever a new system is installed, an information table should be completed and added to the database.

If communication systems are very reliable and don't require constant attention, why budget for maintenance?

Creating the Maintenance Budget

Creating a budget to provide for maintenance requires that several factors be considered:

One of the first items to consider when creating a maintenance budget is "who" will do the maintenance work, and what type of services will they be required to provide? This is in some way a "chicken or the egg" question. If full maintenance services are provided (testing, using diagnostic equipment, and full repairs), you will need highly qualified and trained technicians. If maintenance is viewed as a matter of blowing the dust out of the cabinet, and making a call to an outsourced repair and maintenance service, a semi-skilled individual with minimal experience and training will suffice.

Most DOTs have been using some type of communications system to support traffic management and department operations for many years. A few have created an internal staff function to support maintenance and upgrade functions, others outsource the required services. Following is a suggested maintenance technician experience level table:

Table 6-2: Technician Experience Classification
Level Yrs Experience Type of Experience Amount of Training
Entry 0–2 years PC Skills, Technical Ability

Vocational education from an accredited High School, or Technical School.

Mid 2–6 years Military Experience with communication systems, or, Above + Working Knowledge of the Communication equipment in the system + Ability to replace module boards. Military Training, or above + Communication Theory Courses + Manufacturer Equipment Courses
High 6–10 years Above + Additional Knowledge of communication systems + provide presentations at professional meetings + ability to trouble-shoot, and resolve system problems. Above + advanced communication theory courses
Senior 10+ years Above + participation in communication standards efforts + review of technical papers Above + additional technical training as required + extensive reading of technical books on communication process and theory.

These levels of experience should be applied to both department personnel and/or outsourced personnel responsible for the maintenance of telecommunication equipment. These levels are directly related to experience with telecommunication and other technology based systems, not general work experience. An individual with 10 years of experience as a project manager would not be considered as having the qualifications to be a maintenance technician for telecommunication equipment. There are a number of good High School Vocational education programs, and Technical School programs that provide individuals with the proper knowledge and skills for an entry level maintenance technician position. The U.S. military provides well grounded maintenance technician training and experience for at least a mid-level position.

The type of equipment will often help determine the experience level of personnel required to support a maintenance function. If everything is leased from a communication carrier, entry level personnel can be used. Their primary job description will be to manage the services supplied by the communication carrier, and call for support when necessary.

The components of a $4 million maintenance budget would include:

  • Personnel
  • Maintenance Shop Facilities
  • Test Equipment
  • Spare parts inventory & consumable repair supplies
  • Tools
  • Technician Training
  • Service Vehicles
  • Etc.

A system comprised of a large number of communication devices with a mix of new (less than 2 years old) and legacy (more than 5 years old) equipment will require support from more experienced personnel. With this type of system, the maintenance personnel will need to know when to call in outside support to effect repairs.

If the system consists of a few CCTV cameras, several changeable message signs and traffic flow detectors, with required communication equipment, it's probably best to arrange for outsourced services. Consider that special tools and test equipment may be needed to help troubleshoot communication problems, with highly compensated experienced maintenance technicians.

A communication equipment maintenance contract will typically cost between 10 and 20 percent (per year) of the original equipment cost. If the total system cost was $300,000, maintenance will average no more than $15,000 per year – significantly less than the cost of hiring a qualified individual.

A system with several thousand devices spread over a large area that cost $20,000,000 to deploy will require a significant investment in maintenance and upgrade services. Outsourcing the needed services will most likely cost $4,000,000 per year (using the 10% to 20% rule). The cost of hiring five qualified personnel and supporting them with necessary tools, transportation, spare parts and training might be about $2,000,000 per year. Make certain that at least one of the technicians has a significant background for maintaining telecommunication systems.

Basic traffic signal systems use modems and wireline transmission media. Technicians will only have to be able to do general troubleshooting and item replacement. Traffic signal repair personnel can be trained to this level of repair.

A simple single function system (traffic signal control) will require personnel with fewer skill sets. Training will be limited to knowledge of upgrades to cover new equipment. Systems will have minimum complexity. Complex systems supporting multiple types of communications equipment and systems will require a larger staff with more skill sets and continuous training for changes in systems and upgrades.

One important aspect of the budget development process is completion of a risk assessment. This should have been done for the overall system design during consideration of redundancy, and will have a direct impact on the maintenance budget. The communication system is, in most respects, the least failure prone element of an overall system, but potentially has a high risk of being disrupted by outside forces.

The risk assessment is not done to create the maintenance budget. Elements of the assessment will provide an indication of how much money will be required to accomplish repairs in the event of a problem. In this case, risk does not refer to intentional disruption – although, that certainly is a factor – but the potential for power failures, "Backhoe Fade" (cable cuts from construction), lightning strikes, HVAC failures, etc. The risk assessment should consider the following:

Knowing which elements of your communication system can be out of service and awaiting repairs will help provide effective management of resources. The cost to effect repairs during a holiday period will always be more than repairs completed during normal business hours. Even during holiday periods there are portions of the system that can be out of service without effecting operations.

Communication devices will require some type of upgrade during their life cycle. Most communication equipment will operate for 10, or more, years without a problem. Equipment manufacturers will offer firmware updates, and occasionally revise the physical design of the equipment. Very often, these updates are not critical to existing operations and systems. However, you should budget for occasional updates, especially if the manufacturer offers a major firmware update.

The firmware updates are normally free (some vendors do charge), but the end-user is required to cover the cost of installation. Installation of most firmware is usually only a matter of uploading the update via the system manager program and can be accomplished by the operation staff. Occasionally the operation is more complex and will require the services of a qualified technician for a few days. Legacy systems may require significant replacements of components to accomplish the update. Consider the overall cost of updating older equipment and compare with replacement by new equipment.

Upgrades to existing equipment, due to addition of new sections, can be accomplished via a budget provided by the contractor adding the new section – however, there may be unforeseen consequences as a result of the additions which were not considered as part of the new section budget. Consider availability of older equipment. The contractor may not be able to purchase exact duplicates of equipment used in older sections of highway. Make certain that the contractor gets new price estimates for the desired equipment. Older equipment becomes difficult to find and may cost more than the original.

Warranties, Extended Warranties, & Service Plans

This section takes a look at various aspects of product warranties and their relationship to maintenance programs. There is a tendency to assume that a warranty will take the place of a maintenance program. Often, as consumers, we have become accustomed to relying on product warranties to help protect us against failure of a product. These warranties are very specific about the coverage, the rights of the company, and the rights of the consumer. "Note: The author suggests that you read a complete product warranty for any consumer electronics item you may have recently purchased. All of the examples considered for publication here had an express prohibition of reproducing without written permission". All warranties reviewed had one thing in common – the very last sentence: "Specifications and availability subject to change without notice".

This last sentence is important, because manufacturers do change specifications on a regular basis. A key reason for changes is product updates. Products are updated based on feature demands from customers, or product problems discovered during warranty repairs. Standards also cause changes in product specifications. Often, manufacturers will release a product using a preliminary standard, and make changes when a standard is finalized.

Consumer based telecommunication products have a life cycle of 18 to 24 months with new variants being released every 4 months. Wireless handsets are a good example. Commercial products have a longer life cycle, usually based on market demand. If the demand is strong, a manufacturer will keep producing a product for 5 to 10 years. However, that doesn't keep the product from changing. Manufacturers do make changes for the reasons stated above.

Some telecommunication products are manufactured to serve both consumer and commercial demand. Wireless routers based on the 802.11 series of standards are an example. Their life cycle and new product introduction cycle follow the consumer market. If you are using these types of products in your system (most likely within a TMC) be prepared to have several different versions, and possibly units from different manufacturers.


Following are a few key facts about warranties:

Warranties for commercial products are essentially the same as consumer products with one general exception. Consumer product warranties tend to be very short term – 30 days to one year. Commercial product warranties tend to be offered for longer periods – 90 days to 5 years.

Some manufacturers will provide full replacement, while others will only provide parts and require payment for labor charges. Most commercial product warranty periods start on date of manufacture, others on date of shipment, and others on the date of installation. There are no government or industry standards for warranties. The terms of the warranty are set by the manufacturer. Commercial law and court decisions help to mold the wording of warranty terms.

Extended Warranties

Many manufacturers offer factory service and repair programs. For a small one-time fee (paid in advance) products can be returned to the factory (or authorized repair center) for "out-of-warranty" service. Instead of providing the standard warranty, the manufacturer offers an extension (typically one to three years) beyond the basic time period. Coverage is the same as the basic warranty. Damages due to abuse, or lightning strikes, or power surges, floods, fire, etc., are not covered. Factory service can provide overall savings for a maintenance program when used for "commodity" type products. Commodity products are low cost and mass produced. These would include modems used for traffic signal controllers, or fiber optic modems used in FMS, or handheld 2-way radios used by roadway maintenance personnel. The products can be easily replaced with spares by a technician with minimal experience and returned to the factory for repair. Extended warranty programs help reduce the maintenance cost associated with component degradation and failure. Under the warranty, the factory will replace components that no longer meet specification, and upgrade the product to the latest version. Extended warranties do not provide for on-site service and trouble shooting of external system problems affecting the warranted device.

The following is a typical hardware warranty from a manufacturer of modems/fiber optic modems used in traffic signal and freeway management systems:

XXX Communications, LLC

XXX Communications LLC

Traffic Electronics Manufacturer Specializing in Communications

Limited Warranty

XXX Communications LLC (XXX) warrants to the Buyer that all XXX goods (equipment and component parts) when sold are free from defects in materials and workmanship under normal use and service for a period of one year from the date of shipment, as evidenced by XXX's or its agent's packing list or transportation receipt. XXX's obligation under this warranty shall be limited to the repair or replacement of goods, at XXX's option, which XXX's examination shall disclose to its satisfaction to be defective. In no event shall XXX's liability for any breach of warranty exceed the net selling price of the defective goods. No person, including any dealer, agent or representative of XXX, is authorized to assume for XXX any other liability on its behalf.

XXX has no obligation or responsibility for goods which have been repaired or altered by other than XXX's employees.

This warranty is the only warranty made by seller and is expressly in lieu of all other warranties express or implied, and warranties of merchantability and fitness for any particular purpose are specifically excluded.

Warranty Claim Procedures

Defective goods must be returned, transportation charges prepaid, to XXX for correction. XXX will pay return transportation charges for warranty repair. Upon redelivery of goods corrected under this warranty, the repaired or replaced portions shall be subject to this warranty for a period of 90 days or until expiration of the original warranty, whichever is later. All claims of failed or defective goods must be in writing and received by XXX within the specified warranty period. XXX will provide Buyer a return authorization number as authority to return the goods and for use in monitoring repair status.

Repair or replacement of defective goods will be at XXX's discretion and for the Buyer's account when the cause of failure is determined by XXX's examination to be misuse, mishandling or abnormal conditions of operation. In such event a firm price quotation for correction of the goods may be submitted to the buyer. No repair or replacement work will be initiated prior to receipt of the buyers written authorization to proceed and approval of price, except as may be necessary to complete XXX's examination of the goods. If returned goods are determined not to be defective or if the Buyer elects not to authorize correction at its expense of goods not covered by this warranty, XXX may charge a reasonable amount for such evaluation. Any amounts due XXX under these conditions will be subject to the same payment terms as the original sale. The Buyer will not recover from XXX by offset, deduction or otherwise, the price of any goods returned to XXX under this warranty.

Note that there are statements which limit the liability of the manufacturer, and the fact that the warranty starts on the date of shipment. There is no agreement under the standard warranty with respect to acceptance of a system or other testing.

Relationship of Warranties to System Specifications

There is nothing in the terminology of a warranty that makes the manufacturer responsible for the functioning of their products in a system. Manufacturers of hardware generally do not take responsibility for system construction and system integration. Because they do not have total control over the situations in which their products are used, manufacturers will only take responsibility for the quality of their manufacturing process and the components used.

A number of specifications for freeway management and traffic signal systems will require that a system be installed, optimized and pass acceptance testing before a warranty period starts. This is contrary to the statements in manufacturer warranties. Many products are delivered three to six months before installation. Some manufacturers will take this into account and extend the warranty start date, if requested in advance. However, the terms of the warranty do not change.

Most systems are installed by a general contractor (GC) or systems integrator. The GC is ultimately responsible for meeting the D.O.T. specifications. If the end objective is to hold the general contractor responsible for the system until it passes final acceptance testing, then state this in the specifications. Don't confuse manufacturer warranty terms with contractual purchasing terms. Often, the general contractor asks a manufacturer if their product meets specification, but fails to ask if the manufacturer will agree to the purchase terms. The end result is that the general contractor does not account for the testing and acceptance period in their bid pricing. Ultimately, a low bid price translates into system optimization delays while the GC and the equipment vendors work to resolve contractual issues.

Service Plans

A "do-it-yourself" systems maintenance and service policy doesn't always make sense when you're trying to manage time, people and budget. Maintenance service plans help to off-load some of the cost of keeping a communication system running. Advantages of a service plan are:

Service plans (or maintenance agreements) are a fixed fee contract with a hardware vendor, system integrator, or maintenance services company for the routine maintenance and repair of hardware and systems. Contracts are typically based on the following elements:

The largest factor in determining the fees for a service contract is the total number and types of devices. Service companies have statistics that indicate how often a product, or type of product, will need routine maintenance and general repairs. They use this as a baseline to determine pricing. Generally, the greater the number of devices, the lower the unit cost. One device may require two service incidents per year plus two routine maintenance calls per year, but 10 devices may still only require two service incidents per year, plus routine maintenance. A service incident can be defined as the requirement for an actual repair due to failure. Therefore, a service company may charge $500 per year to maintain a single device, and $1,000 to service 10 devices. The cost of the service incidents is spread over 10 units.

Variety of devices (modems, video CODECS, CCTV cameras, etc.) and manufacturers will affect the total fees because of a need to maintain spare parts and devices, and technicians with different skill sets. A large system spread over an entire state will require more resources than the same system deployed in a small area.

Maintenance contracts can be limited to a few services, such as emergency repairs only. Or, they may include a whole suite of services including a requirement to replace devices that have been in the field for more than 3 years. The more services required, the greater the cost of the contract.

There are some things that most service plans do not cover. They won't cover repairs required because of acts of vandalism, faulty electrical service, power surges, damage due to "acts-of-god", outages of telecommunication lines, or faulty installation. However, you can make stipulations in a contract and pay extra to provide coverage because of those problems.

Before starting a service contract make certain that your system is fully functional and that all problems created by faulty installation have been corrected. Don't expect the service contractor to make up for the short-comings of a poor installation, or faulty design.

To learn if a maintenance/service contract is a good option for your operation, complete a full equipment inventory, and ask qualified vendors to submit an estimate for their services using an RFI process. Don't be concerned about vendor qualifications at this point. The objective is to determine potential costs and the number of vendors interested in providing services. If you determine that a service/maintenance contract will help save money, or improve your overall operation, then use a formal bid process. Apply the technician qualifications listed at the beginning of this chapter. Also request a list of current clients and complete a user satisfaction survey (contact existing clients) before selecting a vendor. Don't forget to refer to the FHWA Handbook "Guidelines for Transportation Management Systems Maintenance Concepts and Plans" for more information.


All communication systems require some form of maintenance. Current design and manufacturing techniques have eliminated a lot of the requirement to constantly check that equipment is running to specification. Most current communication hardware and systems, once properly installed and optimized, will run trouble-free for life. However, that does not eliminate the need for checking the system at least once every three to six months. The technicians can check for loose connections or moisture and dust, or other problems which may affect system performance. The technician can also verify equipment inventory. A good maintenance program will help to assure relatively trouble free system performance, and ultimately lower overall cost of operations.

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