Telecom Site Remote Monitoring
The telecommunications industry includes regional operating companies, traditional long distance carriers, wireless carriers, and cable and satellite service providers; they all deliver voice, data, and video services.
Telecommunications companies often house their “last mile” equipment in unmanned sites. Site structures include controlled environment vaults (CEVs), walk-in cabinets, and cell site buildings. For communications companies, “up time” is revenue, and “downtime” is lost revenue. Each structure contains highly sophisticated communications equipment to deliver services rapidly and reliably to customers. Uninterrupted site availability, safety, and therefore uptime is enabled by many supporting systems or devices such as heating, ventilating, and air conditioning (HVAC) systems, generators, DC plant and batteries, occupancy sensors, and environmental sensors.
A best practice for increasing site uptime and improving the safety of the personnel who occasionally have to visit the site is to implement an environmental controller that builds upon a standard set of sensors and relay outputs.
Telecom Site Structures
CEVs are unmanned structures that are installed underground. In addition to communications equipment, CEVs house large banks of constantly charged lead-acid batteries to provide power when a grid power failure occurs, similar to data centers. An environment control system manages dual air conditioners to maintain temperature conditions that are “comfortable” for the equipment during normal unmanned operation, and “comfortable” for the technician when the structure is occupied. The system also manages lights, emergency lights, sump pump, smoke alarms, and door status switches. All abnormal conditions are passed to an alarm handling system for central office notification.
Other structure types include small walk-in cabinets and larger single room buildings. They employ environment control systems similar to those found in CEVs. The primary difference is that the above ground buildings use external, wall-hanging HVAC units that require lead-lag management to ensure equal run time on each air conditioner.
All field structures are connected to head-end computer rooms that are generally located in central office buildings. The subterranean field cabling connections, known as the “back-haul,” enter a cable vault in the basement of the central office. Immediately adjacent to the cable vault, is a power plant with 48 VDC power supplies and rows of battery packs. As with CEVs, many support elements are required to maintain a sustainable environment for personnel.
Gas and Fire Detection
Hazardous gases found in telecom sites include:
- Combustible Gases
- Methane (CH4)
- Hydrogen (H2)
- Hydrogen Sulfide (H2S)
- Carbon Monoxide (CO), leading to Oxygen (O2) Deficiency
CEVs and central office buildings use lead-acid batteries which produce Hydrogen (H2), a combustible gas. The high density of electronic systems increases the risk of fire. Cable vaults are enclosed, poorly ventilated areas with potentially high Carbon Monoxide (CO) and low oxygen content. As all of the structures are connected to a central office over long distances, the underground cables may pass through hostile subterranean soils such as nearby wastewater facilities and landfills. As these sites contains various amounts of decomposed waste, Methane (CH4) or Hydrogen Sulfide (H2S) may leak into the cables and bring the hazard to the cable vault of a central office facility.
Hazardous gas and fire detectors are required to detect and mitigate these hazards within telecom structures.
Automating Telecom Sites
Most telecom site structures require proper cooling to operate efficiently. Thus, a control system that can specifically execute full HVAC control to assure a safe environment for equipment and personnel is necessary. Telecom sites may look to a lead lag controller for air conditioning units. As a structure may have two air conditioning units, a lead lag controller can control the cycle periods in which they operate, with one unit running first (lead) and the other unit following (lag) as the first turns off. Gas monitors may also be connected to HVAC units to act in event of a release of hazardous gas. The control system therefore incorporates gas monitors and takes preventative action, such as increasing ventilation to mitigate the gas risk.
Centralizing all data is important for telecom site owners, for some of the structures are remotely controlled and rarely accessed by personnel. All data from various sensors, devices, and systems can be transferred to one central control system to improve safety, efficiency, and the operation of all telecom sites.