It has become more important for railway owners and operators to be able to monitor and locate assets, including railcars, locomotives and trains on a real time basis. 
From a safety point of view, it is important to monitor various operational parameters of railcars, for example, bearing temperature, in real time, to be able to predict and stop impending failures, which could result in severe consequences, such as derailment.  It is also important to be able to raise alerts of such conditions, and to communicate these operational parameters relating to alerts to an on-board operator or a remote railroad operations center, such that action to mitigate any unsafe conditions can be taken in a timely manner. 
From an operational point of view, it is important for railway operators to determine whether a railcar is in a train consist outside of a rail yard, in a train consist in a rail yard, or if a railcar is in a loaded or unloaded condition.  The significance of knowing the status of railcars, allows an operator to determine if railcars are being utilized or idle at any given point in time and makes it easier to manage rail yard operations. 
As current industry practice, the management of train consists and train yards in railroad operations relies on reading, at fixed points in the rail network, passive radio frequency identification (RFID) tags which are affixed to each railcar.  While this method has provided railroad operators with significant increases in performance, it lacks the benefits of a dynamic wireless network capable of transmitting information and data, such as location and condition or performance data when not in range of an RFID reader.  Further, the current system does not provide a mechanism to communicate operational alerts to the locomotive which allows the alerts to be actioned in a timely manner. 
Given the demanding and harsh environments in which railroad trains operate, any monitoring system must be rugged, reliable and able to operate for long periods with little or no maintenance.  In addition, to be cost effective, it should not add significant cost to install, maintain or operate the system.  Because there are more than 1.5 million freight railcars in North America alone, a system of monitoring all railcars in use is highly desirable and, as such, the system needs to be scalable to handle a very large number of potential devices. 
It is therefore desirable to provide a monitoring system that can be used while a train is operational, to monitor various operational parameters of the railcars and to communicate alert conditions to an on-board operator or off-train, and which also can be used when trains and/or railcars are in a rail yard to ease the management of assembling and de-assembling train consists.