Remote monitoring and thermal management of macro cell site enclosures

Abstract

Outside Plant (OSP) wireless networks use both cabinets and shelters to house macro cellular site carrier communication and support equipment, such as 4G LTE base station radio gear, backhaul, DC power supply, battery storage, etc. Based upon real estate or deployment application restrictions, there will always be a need for some mix of cabinets and shelters. The focus of this paper shall be on both types of enclosures and a new trend in thermal control: the evolution of software network control in macro cell site wireless enclosures, with focus on enclosure remote thermal control. Although micro cell sites can typically be passively cooled or heat exchanger cooled, in contrast, macro cell site enclosures need active cooling elements, and in many cases this requires a microprocessor based controller unit to manage HVAC elements. Thermal equipment consists of HVAC units and perhaps a filtered vent cooling system. For control, a central environmental control unit (ECU) is used. It is the ECU that can be integrated into the remote site management. Since Telecom and Datacom are converging, there has been cross-over in both cooling solutions and network management practices. An example relevant to network connectivity is that data centers have embraced network software control through the introduction and evolution of Data Center Infrastructure Management (DCIM). DCIM systems manage building facility functions, including power and cooling infrastructure, optimizing energy usage and efficiency. The need to remotely monitor, i.e., “see”, and even control cell site enclosure thermal systems is increasing for the following reasons: 1. It lowers site operating costs (OPEX electricity usage) through more efficient thermal and energy management 2. It reduces the number of site visits and helps the technician identify repair materials in advance, eliminating extra truck rolls and repeat visits 3. It enables central software oversight and troubleshooting, relieving pressure due to lowered service tech headcount Traditionally, most enclosure ECUs have been “stand-alone” units, with no communication link to customer internal equipment or outside network (no local or Ethernet network connection). Due to today's converging IT/Telecom network, where network control is moving rapidly toward software management and “Network Function Virtualization,” it is advantageous to have all elements of the enclosure, including the thermal control system, under supervised control. Islanded, “dumb controllers” no longer support today's network needs. As communication providers increasingly embrace and implement a Software Defined Network (SDN), the smart software layer in that system will arguably eventually need to communicate with the ECU controller. Another example is that −48VDC power system controllers were required early on to have network connectivity. Power system status has always been required. Now, nearly all power system controllers are fully modern, equipped with Ethernet network access (and even touchscreens), though carriers may simply use them for alarms. This paper will answer these questions: • Why is network connection of the thermal system control important and what are the benefits? • What cost effective styles of network control and management are possible with enclosure ECUs, with cost being a critical driver • What different techniques and protocols are practical and available in today's equipment environment?