create a mesh network, where devices can communicate with each other in addition to the central hub. Advantages to a mesh network include greater range and compatibility, and a stronger network. Z-Wave LR devices operate on a star network topology that features the hub at a central point and then establishes a direct connection to each device, rather than sending signals from node to node until the intended destination is met, as in a mesh network. The key difference between a star network and a mesh network is the direct hub-to-device connection. Both Z-Wave LR and traditional Z-Wave nodes can coexist within the same network. The simplest network is a single controllable device and a primary controller. Devices can communicate to one another by using intermediate nodes to actively route around and circumvent household obstacles or radio dead spots that might occur in the multipath environment of a house. A message from node A to node C can be successfully delivered even if the two nodes are not within range, providing that a third node B can communicate with nodes A and C. If the preferred route is unavailable, the message originator will attempt other routes until a path is found to the C node. Therefore, a Z-Wave network can span much farther than the radio range of a single unit; however, with several of these hops a slight delay may be introduced between the control command and the desired result. Additional devices can be added at any time, as can secondary controllers, including traditional hand-held controllers, key-fob controllers, wall-switch controllers and PC applications designed for management and control of a Z-Wave network. A Z-Wave network can consist of up to 232 devices, or up to 4,000 nodes on a single smart-home network with Z-Wave LR. Both allow the option of bridging networks if more devices are required. A device must be "included" to the Z-Wave network before it can be controlled via Z-Wave. This process (also known as "pairing" and "adding") is usually achieved by pressing a sequence of buttons on the controller and on the device being added to the network. This sequence only needs to be performed once, after which the device is always recognized by the controller. Devices can be removed from the Z-Wave network by a similar process. The controller learns the signal strength between the devices during the inclusion process and will utilize this