Repairs, Upgrades and Checks

The role of Public Safety radio technicians is rapidly changing, and their willingness to learn and attack any technical challenge is paramount. Intimate familiarity with the discrete elements of the radios is being replaced with thorough understanding of the network and system configuration, high-level troubleshooting and radio programming. The ability to perform component level repairs is no longer important, except where legacy equipment is no longer serviced by vendors.

Conversely, with the increase in system complexity, the ability to troubleshoot at network level and diagnose and resolve the source of system failure – antenna system problems, power problems, backbone issues, system configuration errors – is very important. Administrative and computer skills are taken for granted.

Repairs

Virtually all electronic boards are built with surface mount devices, rendering them unserviceable except in highly specialized settings. So the scope of repairs that can be performed in the field is systematically decreasing. Field repairs are typically limited to replacement of antennas, knobs, switches, display boards, speakers, and microphones. For network elements, field repair is now limited to swapping faulty boards or even entire devices. For all other problems, all equipment needs to be returned for factory-based repairs.

Whether to use your own technicians or a third party for repairs is seldom a question of technology, but most often dictated by cost, 24/7 availability or warranty/liability. Whatever the process, responsibility for day-to-day maintenance must be clearly defined.

Upgrading hardware and software

Upgrades are seen as a necessary evil to be avoided by most system administrators. However, every aspect of your P25 system is dependent on software, so it is important that you fully understand the implications of upgrading (or not upgrading).

You need to consider:

• interoperability with your mutual aid partners,
• compatibility with other network components,
• the impact of operating system obsolescence on your upgrade plans,
• the advantages of useful new features and functions.

One-off upgrades are typically more expensive than long term maintenance agreements.

When upgrading software, the best approach is to test it on a dummy system through a local vendor before it is rolled out. It is important to avoid having to roll back – this can have huge implications for your network, and leave communications vulnerable while the issues are resolved. Nevertheless, it is wise to have a rollback plan for worst-case scenarios.

When developing your upgrade roadmap, you can plan to upgrade biennially, but you can budget this annually, to spread the cost and avoid budget peaks.

Occasionally, manufacturers and vendors may offer you the opportunity to evaluate early versions of software. This has advantages and disadvantages, which you need to weigh up carefully.

• You will usually pay considerably less for early pre-release software versions.
• It is likely to have more bugs than later releases.
• You can influence features in product development, so you are likely to end up with software that better suits your needs.

Routine Maintenance

There is a great variety in practice and recommendations for frequency and thoroughness of routine maintenance – from weekly structured checks to a fully reactive approach.

Our recommendation is to schedule thorough maintenance checks, accounting for local geography and weather patterns. Obviously, as your system ages, you will need to schedule maintenance more frequently, but an annual check is the recommended minimum.

Run regular tests and reports on your microwave system. Microwave links will typically have the means to check their operation on site, so your maintenance technician can measure and record parameters such as signal strength, BER or others.

For backhaul networks designed for automatic switchover, you should simulate failure conditions to test switchover functions periodically.

Electronic hardware is becoming ever more reliable. Systems with appropriate environmental (such as temperature and humidity) control can manage with annual checks, but systems working at high capacity or in difficult environments should be checked more often. Maintenance for any base station should include thorough examination of the receiver, transmitter and, above all, antenna system.

Scheduled site maintenance

Site inspections should be scheduled regularly – more often in regions with challenging weather or geography. Inspections should include

• generators, including batteries, propane tank levels,
• fencing,
• cameras,
• security measures,
• on-site spares.

Spring and autumn equipment checks are particularly important in mountain regions. Remote sites need the best equipment you can purchase, to reduce the chance of failure, and to minimize callouts during winter. And while it may seem obvious, make sure that your crews have all necessary spares and tools with them for remote site checks – returning to base to pick up overlooked or forgotten items is costly and inefficient.

One of the most-often overlooked subsystems at the radio sites is back-up power – generators and UPSs. Make sure UPS and DC-bank batteries are maintained to manufacturer recommendations and back-up generators are periodically exercised so they start easily, and have sufficient fuel for extended emergencies.

Subscriber equipment

As digital radios become more reliable and less field-serviceable, routine tune-ups become less common. Instead, radios are tested when they come to the local shop for reprogramming or repair, supplemented by remote monitoring.

However, subscriber equipment is not always as robust as expected. Every radio needs to return to base regularly, especially your portable fleet, which are subject to physical damage as well as malfunction. Give your portables a checkup whenever they are in the shop, and update your records.

It is more difficult to check on your mobile fleet – a wide area system might only see mobiles every seven or ten years. Consider a program of radio maintenance alongside your vehicle maintenance schedule.

Schedule annual checks, in addition to checks performed whenever the radio is in the shop.

Network checklist

• Perform manual switch over monthly to ensure microwave transmitters on hot standby are fully functional.
• Test physical systems regularly
• Save emergency callouts by purchasing suitably robust equipment for mountaintops.
• Check generators and batteries monthly.
• Inspect and replace reels of antenna repair coax at sites during and after weather events.
• Switch active and redundant equipment bi-monthly to ensure both are fully functional.
• Check propane tanks for evaporation.