This page contains a few illustrated examples of variable hx19 system configurations, with their pros and cons.
The following two images depict a setup where a central computer controls a process using a quadrotor fitted with a hx19v3 transmitter. Stationary receivers are placed on surrounding posts, walls or ceilings, and quadrotor controlled by a central server unloads the packages as they come on the conveyor belt.
quadrotor positioning example
Hx19ms is connected through the USB to the central computer and used to both read the distance from the receivers on the posts to the hx19tx on top of the quadrotor. The hx19tx has a serial output pin that can be used to send commands to the quodrotor at high speeds.
quadcopter positioning example
The pros this system is that it is indefinately expandable in terms of spatial coverage. And the cons: number of objects are limited by the update rate required since only one sonic transmitter can occupy the operating spatial range at a time. 
It is possible to reverse the system since the operation is public or broadcasted, all devices are both public and private, tags (transmitters) and receivers both have private data channel through a simplex serial pin on the device. All hardware communication to and from a hexamite device uses a single simplex pin for bidirectional communications. This minimalist method uses the full features of microcontroller port operations. Normal state of the hx19 port pin is input mode, or high impedance state. Only during data emission the port pin is in low impedance output mode. Hence device to device and multidrop communications are possible, allowing private inter networks using only a signal wire and a return (ground) wire.
In the following the hx19 system is reversed, both Robot Cop and Robot Bug are autonomous, i.e. they know where they are between the triangle transmitter posts. Pros in this case is that indefinate number of objects can be autonomous limited only by the range of the transmitter and thereby the space in which they can move. Cons: spatial expansion becomes harder and requires greater indepth knowledge of the hx19 system. This entails tricks with variable RFID frequencies and sonic firing sequences.
Robot guidance example
In the above Robot Cop does not know where Robot Bug is. By adding a central computer and a hx19ms monitor, both Robot Cop and Robot Bug know each other's position within the spatial boundaries.
Robot guidance example with central control
With the help of the NSA centralised computer monitoring, Robot Cop now knows where Robot Bug is and the Cop can therefore squash the ugly Bug.View the whole system
guided robot application central control