Patent Application
20160360555
The application pertains to bidirectional mesh networks that provide redundant communications paths. More particularly, the application pertains to such networks which incorporate multiple controllers or controller gateways and multiple communications paths.
Systems are known to protect people and assets within secured areas. Such systems are typically based upon the use of one more wireless detectors that respond to threats within the secured area.
Threats to people and assets may originate from any of number of different sources. For example, a fire may kill or injure occupants who have become trapped by a fire in a home. Similarly, carbon monoxide from a fire may kill people in their sleep.
Alternatively, an unauthorized intruder, such as a burglar, may present a threat to assets within the area. Intruders have also been known to injure or kill people living within the area.
In the case of intruders, detectors, or, sensors may be placed in different areas based upon the respective uses of those areas. For example, if people are present during some portions of a normal day and not at other times, then detectors may be placed along a periphery of the space to provide protection while the space is occupied while additional sensors may be placed within an interior of the space and used when the space is not occupied.
In most cases, threat detectors are connected to a local control panel. In the event of a threat detected via one of the detectors, the control panel may sound a local audible alarm. The control panel may also send a signal to a displaced monitoring station.
While conventional security systems using wireless detectors work well, they are sometimes subject to unexpected failures. For example, fire and security systems that employ mesh networks with single controllers have a single point of failure that could result in lost communications to one or more areas protected by the system. A need exists for better methods and apparatus for diagnosing such systems.
While disclosed embodiments can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles thereof as well as the best mode of practicing same, and is not intended to limit the application or claims to the specific embodiment illustrated.
Systems in accordance herewith provide redundant communications pathways in fire and security systems employing mesh networks. Furthermore, since fire and security systems may use a hybrid combination of wired networks and wireless mesh elements, in another configuration, the wired and wireless portions can be integrated while providing redundant communications paths throughout the system.
In one aspect, each wireless mesh network can contain multiple controllers and a plurality of mesh elements. The mesh elements can include, without limitation, detectors of various types including security related detectors such as glass break detectors, position detectors, motion detectors or door detectors. Other detector types include ambient condition detectors such as fire detectors, gas detectors, thermal detectors, water or humidity detectors.
The controllers may be used to interface the elements of the mesh networks to the wired elements of the system. Each controller determines the parent/child relationships for the mesh elements and communicates with all mesh elements via a bidirectional time slotted, or, frequency allocation method. The time slotted or frequency allocation processes, as would be understood by those of skill are unique to each controller for a given mesh network. As a result, each controller receives communications from all network elements redundantly.
Each controller in a given mesh network will retransmit any communication received from the transmitting mesh elements to all of the mesh elements. In that way, all mesh elements receive all communications redundantly. The system communications are unaffected by the failure of all but one controller.
In the event one of the wireless controllers, such as 14i, does not receive the message wirelessly within the system propagation time, the respective controller sends the message received by wire, such as from path 18i, to the wireless mesh elements with which it is in communication. The system communications are unaffected by the failure of all but the last controller.
In another embodiment 20, illustrated in Fig.2, each wireless mesh network, such as 22, will contain multiple controllers and a number of mesh elements. It will be understood that elements and controllers of a type previously described above have been assigned an identical identification numeral that corresponds to that of
The controllers may be used to interface the mesh network 22 to the wired elements 18-1, -2, -3 and 18-4 of the system 20. Each controller, such as 14a . . . 14d, determines the parent/child relationships for the mesh elements, such as 16i, relative to itself as if it were the master of communications of the mesh network.
As indicated in
When messages are received by the controller, such as 14a . . . 14d, from one or more mesh elements, such as 16i, including the redundant controllers, the controller with highest priority, such as 14a, retransmits the communications to all elements of the mesh network 22, including the redundant controllers. Advantageously with this process, all elements of the mesh network 22 receive all messages from all mesh elements.
Health messages within the mesh network 22 are transmitted periodically. When one or more health messages are missed, not received or responded to, by an element within the mesh, the element will switch to the next highest controller parent/child relationships and time slotted or frequency allocated scheme.
The highest priority controller retransmits messages received to the mesh elements if it has not already done so successfully, and then transmits the message on a wired path if the message has not already been received or transmitted on that path. The lower priority controllers transmit the message on a wired path if the message has not already been received or transmitted on that path. This eliminates circular message paths.
Controllers that receive a message on a wired path, such as 18a . . . 18n, transmit the message on other wired paths if the message has not already been received or transmitted on that wired path. For added redundancy, the lower priority controllers, such as 14b, 14c, 14d, may retransmit messages received on a wired path, such as 18i, wirelessly to the highest priority controller.
The communications of system 20 are unaffected by the failure of all but the last operating controller. It also exhibits reduced radio traffic requirements relative to the embodiment 10 of
In other embodiments, 30, 40 illustrated in
Each controller in a given mesh may retransmit any communication received from the transmitting mesh elements to all the mesh elements. In that way all mesh elements could receive all communications redundantly. A message originating in the mesh is retransmitted to the mesh elements by the controller that first receives it.
Controllers that receive a message transmit the message on wired paths if the message has not already been received or transmitted on that wired path. The system communications are unaffected by the failure of any one controller.
Variations of the embodiments including branches and non-redundant wire segments 58, 68 are also possible as illustrated in
Additional embodiments may include multiple mesh networks 72a,b and 82a,b in various combinations as illustrated in
In summary, the architecture of the network may be integrated into a peer-to-peer network as in the networks illustrated in
Advantageously, the above embodiments can be expected to meet the requirements of National Fire Protection Association (NFPA) Proposed Standard 72 2016 Class Designations A, N, and X. Further, the above embodiments can be incorporated into systems required to meet the SIL requirements as a measure of reliability and/or risk reduction. Examples include:
The architecture of the network may also be integrated into a bus network as in the networks 90, 100 of
In summary, embodiments hereof advantageously avoid single point network failures. Also, such networks can be used as bidirectional transport mediums for messages in larger mixed medium networks.
From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope hereof. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims. Further, logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be add to, or removed from the described embodiments.
