Transportation hubs, such as airports, use a variety of methods to track passengers in queues. For example, an airport may include an identifier (e.g., bar code or radio-frequency identification (RFID)) on passengers' boarding passes in order to estimate the moving speed of a boarding queue by scanning the identifier at the entry and the exit points of the queue. However, all passengers may not possess an identifier that can be tracked.
In some systems, the movement of passengers at transportation hubs may be tracked using their cellular devices. For example, transmissions from these devices to a local computer network via infrared (IR) or radio frequencies (RF) signals may include an identifier of a cellular device and/or a passenger that can be tracked though a queue. However, passengers may not possess a cellular device that can transmit such an identifier.