Systems employing numerous devices often require or otherwise benefit from the ability for these devices to communicate with one another. While each device may have its own purpose and responsibilities, they may need to transmit information to, and/or receive information from, other devices of the system. Device-to-device communication may be accomplished by wiring the devices together, and communicating via the wires. In more recent times more and more systems are employing wireless communication, which generally makes installation more convenient, and among other things provides greater flexibility and scalability.
A drawback to wireless communication is that information transfer is not confined to a wire, as in a direct wired system. Rather, the information is transmitted over the air, and transmissions from neighboring systems can interfere with system communications. To address this issue, wireless network systems have employed various methods of transmitting radio signals, such as frequency hopping. Frequency hopping generally refers to a modulation technique where the signal carrier is rapidly switched among many frequency channels. Each party to the communication must know the frequency hopping sequence in order to know when it is to transmit at a certain frequency in the sequence. Using the frequency hopping sequence, transmitting devices can properly address targeted devices, and receiving devices can reject information from neighboring devices that are not within their system but within their reception range.
The selection of the ordered list of hopping frequencies, referred to herein as a frequency hopping sequence or frequency hop set, should be selected to minimize interference to and from neighboring systems sharing the same frequency space. However, because a device may be deployed anywhere, it can be problematic to generate a hop set that is unique at the deployed location.
Customarily, a frequency hopping sequence may be based on a value that is programmed into a device at the factory, or entered by an installation technician when the system is being deployed. In either case, to remove the risk of neighboring systems using the frequency hopping sequence, there must be a large enough set of frequency hop sets to accommodate every like system currently or later in existence. This may require additional resources, such as increased local storage, lengthier messages, more complex frequency hopping sequence calculations, etc. Further, multiple devices may share a common frequency hopping sequence so that each communicating device can determine at what time and what frequency other devices are listening for transmitted messages. Each device must be privy to that common frequency hopping sequence. Establishing manners for each of the devices to create the same frequency hopping sequence can be difficult. These difficulties are exacerbated when new or additional devices need to enter the system.
Accordingly, there is a need in the communications industry for a manner of selecting an appropriate frequency hopping sequence for devices regardless of where they may be deployed. The present invention fulfills these and other needs, and offers other advantages over the prior art.