Remote - M2M Special Issue 2013 - (Page 6)

Feature Article Intelligent Power Distribution for M2M Communications Ben Stump, Chief Technology Officer Westell Power, it is needed for virtually all machine-to-machine (M2M) communications, and with the growing complexity of IT infrastructure, it has become less manageable. With the increasing power costs and demand for power, effectively and efficiently managing power from multiple sources has become essential. Power management and distribution among devices and multiple tenants at distributed sites is always a challenge and varies from site to site. Often, facilities managers, service providers and tower operators rely on limited information to identify power-related problems at the site and equipment level. As wireless networks continue to grow rapidly (especially in high traffic and rural areas) and data centers need to manage more equipment, understanding and managing power distribution between and within equipment is imperative. Monitoring network equipment and environmental conditions while remotely managing and controlling the distribution of power at cell/tower sites, central offices and data centers has also gained importance. For decades, when a communications network became unavailable, the source of the issue was usually unknown until a technician visited the site. After diagnosis, hopefully the right tools were available to fix the problem, which was often power related, without additional site visits. More recently, power management has grown in popularity to more cost effectively monitor, manage and control power-related M2M communications. Intelligent power distribution management, a critical aspect to an overall power management solution, provides an integrated view into the performance, consumption and health of each circuit in the network. An automated process provides key performance indicators (KPIs), alarms and other data collected from equipment and transmits the information for remote monitoring. Power Monitoring and Distribution Intelligent power distribution management provides the ability to remotely monitor power distribution to all downstream equipment (radios, Ethernet backhaul or broadband devices, etc.). When downstream equipment malfunctions, such as when a circuit locks up, an intelligent solution sends an alarm to the designated personnel identifying the issue and locating the problem circuit. The intelligent power distribution equipment can then be accessed remotely to conduct a power cycle or reset the circuit, bringing the equipment and ultimately the network back online quickly. To supply real-time monitoring, feedback, and most importantly, remotely controlling the M2M communications, an intelligent power distribution (fuse) panel is often networked between the rectifier and downstream equipment to monitor the power usage and health of the power being distributed. Thresholds can be set for each load line (circuit), and the intelligent fuse panel monitors the supply voltage and current draw to each circuit and identifies issues if thresholds are exceeded. A 48 volt power supply must supply voltage within the acceptable operating range of the network elements (sensors, generator controllers, heating, ventilation, and air conditioning units, distributed antenna system controllers, etc.). If the voltage fluctuates outside the defined range (identified by red in Figure 1), the distribution panel sends an alarm to the relevant personnel and logs the data. This archived data can then be reviewed to identify if there is a recurring trend where voltage consistently falls outside of the predefined threshold or if it was an isolated occurrence (such as a lightning storm). A trend of poor voltage (over- or under-voltage) could mean equipment failure or malfunctions in control equipment. Similarly, if the current load being drawn by downstream equipment is more or less than expected, an alarm is sent and the data is logged. Current fluctuations could result from an issue with the downstream equipment or issues within the power lines to the equipment. For example, assume a fan tray used to cool equipment in an outdoor cabinet typically consumes four amps. An alarm showing the fan tray is only drawing three amps may 6 indicate one of the fans within the fan tray has failed, exposing equipment to elevated temperatures. Receiving an early indication that the cooling system is not working properly helps avoid catastrophic failures due to exposure of long term elevated temperatures. Keeping M2M communications equipment and designated systems functioning when commercial power is lost and battery backup is utilized is important. Most cell sites process both voice and data traffic, however, when batteries are being utilized, it may be necessary to have some circuits identified as “critical” for obtaining power while others can be shut down until AC power is restored (load shedding). An intelligent power distribution panel is notified (usually by a rectifier) when battery backup is being used, and only the circuits that have been identified as critical will receive battery power. Figure 1. Real-time status is available via a mobile phone for each It is common that emergency services (such circuit in the network. as 911 in the US) and voice lines are marked as critical. This increases battery life, which is important when the AC power loss is for an indefinite amount of time. When the primary power source at a site is unavailable, it is also important for an intelligent power distribution solution to successfully manage power from multiple sources. For example, if commercial power is the primary source and it becomes unavailable, the solution will intelligently switch to a backup power source (generators, batteries or alternative power sources such as solar, wind, hydrogen fuel cells, bio-fuel, etc.). If batteries are the backup power source, the solution will discharge the batteries until voltage levels reach an appropriate end-of-discharge limit. At this time, the generator will start and continue to run until the batteries have been fully recharged, and then power will switch back to running on batteries. At any time that commercial power becomes available, the power distribution solution will switch back to commercial power, minimizing fuel consumption on the generator, extending the useful life of batteries, and maximizing site availability. Intelligent power distribution can also be used to identify how much power each circuit is using. Power metering provides the actual power consumption and health per circuit. For tower providers that may have multiple tenants at a cell site, power metering enables each tenant to be charged based on actual power consumption. This information can also be used to determine sizing requirements for future site builds. Additionally, if commercial power and generator power are both consumed, the data will be provided to enable billing at different rates. Tenant power metering provides insight into load balancing to reduce failures and can identify individual phase issues to minimize network downtime. An intelligent distribution panel monitors power distribution and generates alarms as issues arise. Reports are automatically created on a daily, weekly, monthly, or any predefined time period and accessible on demand or sent at a defined time via email, text message or SNMP. Alarms are available via email and text message. Alarm status for all monitored circuits in the network can be viewed using the web graphical user interface (Figure 2), and each alarm can be addressed individually. Environmental Monitoring Equipment is often affected by the environmental conditions both inside and outside of a cabinet, and maintaining the equipment requires strict monitoring of the temperature and humidity surrounding the equipment. Intelligent power monitoring tracks the environmental conditions and generates an alarm when conditions exceed a predefined threshold. Reports are available to view trending over time for both temperature and humidity readings. These reports are automated or created manually and sent via

Table of Contents for the Digital Edition of Remote - M2M Special Issue 2013

Towards Right-Sizing Security for M2M Solutions: A Practical Approach
Intelligent Power Distribution for M2M Communications
Optimizing Remote Monitoring in the Cloud
Exponential M2M Market Growth Calls for Innovative RF and Antenna Solutions
Benefits of Using Wireless Networks to Automate FAA-Mandated Obstruction Light Monitoring Requirements
Energy Management Systems For Green Buildings
M2M Products and Services
Industry News

Remote - M2M Special Issue 2013