Patent Publication Number: US-2020288415-A1

Title: Systems and methods for reconnecting a dropped wireless network node

Description:
FIELD 
     The present invention relates generally to systems and methods for wireless network communication. More particularly, the present invention relates to systems and methods for reconnecting a dropped wireless network node to a wireless network. 
     BACKGROUND 
     Security systems are known to detect threats within a secured area, and such threats can include events that represent a risk to human safety or a risk to assets. 
     Security systems typically include one or more security sensors that detect the threats within the secured area. For example, smoke, motion, and/or intrusion sensors can be distributed throughout the secured area in order to detect the threats. However, when the one or more security sensors communicate wirelessly, wireless communication by the one or more security sensors can be interrupted due to interference or poor wireless signal strength. 
     In view of the above, there is a continuing, ongoing need for improved systems and methods. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a system in accordance with disclosed embodiments; 
         FIG. 2  is a flow diagram of a method in accordance with disclosed embodiments; 
         FIG. 3  is a flow diagram of a method in accordance with disclosed embodiments; and 
         FIG. 4  is a flow diagram of a method in accordance with disclosed embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of an embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention. It is not intended to limit the invention to the specific illustrated embodiments. 
     Embodiments disclosed herein can include systems and methods for reconnecting a dropped wireless network node in a wireless network. In some embodiments, the dropped wireless network node can incrementally increase its transmit power until the dropped wireless network node is able to reconnect to a parent node or a neighboring node in the wireless network. As used herein, the term “dropped wireless network node” can be defined as any wireless network node in the wireless network that is not connected to any other wireless network node in the wireless network. 
     In some embodiments, the wireless network can include a mesh network, and each wireless network node within the mesh network can connect to two parent nodes for redundancy. When one wireless network node drops from the wireless network to become a dropped wireless network node, the dropped wireless network node can initially attempt to reconnect to the wireless network after a predetermined period of time by transmitting a reconnection signal at a transmit power level of the dropped wireless network node that is equal to a baseline level (e.g. a rescue mode). However, if the dropped wireless network node is unable to reconnect to the wireless network via the rescue mode, then the dropped wireless network node can enter a special mode in which the dropped wireless network node can attempt to reconnect to the wireless network by periodically transmitting the reconnection signal to the parent nodes while incrementally increasing the transmit power level of the dropped wireless network node to increased levels. 
     In some embodiments, one or both of the parent nodes (or a neighboring node) can also enter the special mode responsive to detecting a child node disconnecting therefrom and/or responsive to a wireless gateway device detecting the child node disconnecting from the wireless network and instructing that one of the parent nodes (or the neighboring node) to enter the special mode. In the special mode, one of the parent nodes (or the neighboring node) can attempt to reconnect to the dropped wireless network node (e.g. the child node) by incrementally increasing the transmit power of that one of the parent nodes (or the neighboring node) to the increased levels. 
       FIG. 1  is a block diagram of a security system  10  in accordance with disclosed embodiments. As seen in  FIG. 1 , the security system  10  can include one or more wireless nodes  12 ,  14 ,  16 ,  18 . In some embodiments, each of the wireless nodes  12 ,  14 ,  16 ,  18  can include security sensors that monitor a secured area  20  for threats, and in some embodiments, each of the wireless nodes  12 ,  14 ,  16 ,  18  can include intrusion, camera, motion, fire, smoke, and gas detectors. Each of the wireless nodes  12 ,  14 ,  16 ,  18  can communicate with a control panel  22  and each other, and the control panel  22  can monitor for activation of the wireless nodes  12 ,  14 ,  16 ,  18 . 
     In some embodiments, the control panel  22  may transmit an alarm message to a central monitoring station  24  upon activation of one of the wireless nodes  12 ,  14 ,  16 ,  18 . The central monitoring station  24  may respond by summoning the appropriate help. For example, if the one of the wireless nodes  12 ,  14 ,  16 ,  18  activated detects a fire, then the central monitoring station  24  may summon a local fire department. Alternatively, if the one of the wireless nodes  12 ,  14 ,  16 ,  18  activated detects an intrusion, then the central monitoring station  24  may summon the police. 
     As seen in  FIG. 1 , the wireless nodes  12 ,  14 ,  16 ,  18  can form a mesh network, and in some embodiments, each of the wireless nodes  12 ,  14 ,  16 ,  18  in the mesh network can have two parent nodes such that each of the wireless nodes  12 ,  14 ,  16 ,  18  can transmit data to both of its parent nodes. For example, in  FIG. 1 , both the wireless node  12  and the wireless node  14  can be the parent nodes of the wireless node  18 . Similarly, both the wireless node  14  and the control panel  22  can be the parent nodes of the wireless node  12 . It is to be understood that the wireless node  16  can also have two parent nodes, but only one of the parent nodes (the wireless node  14 ) is illustrated. 
     Each of the wireless nodes  12 ,  14 ,  16 ,  18  can include control circuitry  32 , which can include a programmable processor  32   a  and executable control software  32   b  as would be understood by one of ordinary skill in the art. The executable control software  32   b  can be stored on a transitory or non-transitory computer readable medium, including, but not limited to local computer memory, RAM, optical storage media, magnetic storage media, and the like. In some embodiments, the control circuitry  32 , the programmable processor  32   a,  and the executable control software  32   b  can execute and control some of the methods disclosed herein. Furthermore, each of the wireless nodes  12 ,  14 ,  16 ,  18  can include a wireless transceiver  34  for communicating with other ones of the wireless nodes  12 ,  14 ,  16 ,  18 . 
       FIG. 2  is a flow diagram of a method  200  in accordance with disclosed embodiments. As seen in  FIG. 2 , the method  200  can include a wireless node (e.g. one of the wireless nodes  12 ,  14 ,  16 ,  18 ) determining whether the wireless node has lost a connection with both of its parent nodes (e.g. whether the wireless node has been dropped from a wireless network), as in  202 . If the wireless node determines that the wireless node has the connection with at least one of its parent nodes as in  202  (e.g. the wireless node is connected to the wireless network), then the method  200  can include the wireless node operating in a normal mode, as in  214 . For example, the normal mode may include the wireless node detecting a fire when the wireless node includes a smoke or fire detector. 
     However, when the wireless node determines that the wireless node has lost the connection with both of its parent nodes as in  202 , the method  200  can include the wireless node entering a rescue mode to facilitate the wireless node reconnecting to one of its parent nodes, as in  204 . In some embodiments, in the rescue mode, the wireless node can wait a predetermined period of time and before attempting to reconnect the wireless node with its parent nodes. Then, the method  200  can include the wireless node determining whether the wireless node was able to reconnect with its parent nodes, as in  206 . If the wireless node determines that the wireless node reconnected to at least one of its parent nodes as in  206 , then method  200  can terminate. 
     However, if the wireless node determines that the wireless node failed to reconnect to both of its parent nodes as in  206 , then the method  200  can include the wireless node entering a special mode (e.g. a sustain fire protection mode), as in  208 . In some embodiments, in the special mode, the wireless node can incrementally increase a transmit power level of signals transmitted from the wireless node. For example, the wireless node can repeatedly increase its transmit power level until a reconnection with the wireless network is established or until a maximum level of the transmit power level is reached. In some embodiments, after reaching the maximum level of the transmit power level, the wireless node can reset its transmit power level to a baseline level. Additionally, in some embodiments, in the special mode, the wireless node can transmit and receive only alarm messages and trouble messages, thereby conserving battery power. 
     After operating in the special mode as in  208 , the method  200  can include the wireless node determining whether the wireless node was able to reconnect to another node (e.g. one of its parent nodes or a neighbor node) in the wireless network, as in  210 . If the wireless node determines that the wireless node failed to reconnect to another node in the wireless network as in  210 , then the method  200  can terminate. 
     However, if the wireless node determines that the wireless node was reconnected to another node in the wireless network as in  210 , then the method  200  can include the wireless node operating normally in the special mode and optimizing its transmit power level, as in  212 . Finally, the method  200  can include the wireless node entering the normal mode, as in  214 . 
       FIG. 3  is a flow diagram of a method  300  in accordance with disclosed embodiments. As seen in  FIG. 3 , the method  300  can include a wireless gateway device (e.g. the control panel  22 ) receiving a trouble message, as in  302 . For example, the wireless gateway device can receive the trouble message responsive to a parent node detecting a disconnection from a child node and determining that the child node has disconnected from a wireless network. 
     Then, the method  300  can include the wireless gateway device instructing the parent node to incrementally increase a transmit power level of signals transmitted from the parent device, as in  304 . For example, the parent node can repeatedly increase its transmit power level until a reconnection with the child node is established or until a maximum level of the transmit power level is reached. After reaching the maximum level of the transmit power level, the gateway device can instruct the parent node to reset its transmit power level to a baseline level. 
     Then, the method  300  can include the wireless gateway device determining whether the parent node was able to reconnect to the child node, as in  306 . If wireless gateway device determines that parent node reconnected to the child node as in  306 , then the method  300  can terminate. 
     However, if the wireless gateway device determines that the parent node failed to reconnect to the child node as in  306 , then the method  300  can include the wireless gateway device identifying a best neighboring node of the child node, as in  308 . For example, in some embodiments, the wireless gateway device can store a list of parent nodes for the child node, a list of neighboring nodes for the child node, and a respective signal strength for each of the parent nodes and each of the neighboring nodes received by the child node during initial registration of the child node. In some embodiments, the best neighboring node of the child node identified as in  308  can have a strongest signal strength of each of the neighboring nodes received by the child node during the initial registration that has not yet attempted to connect to the child node while the child node is disconnected from the wireless network. 
     Then, the method  300  can include the wireless gateway device determining whether the best neighboring node identified as in  308  exists in the wireless network, as in  310 . If the wireless gateway device determines that the best neighboring node fails to exist in the wireless network as in  310 , then the method  300  can terminate or include again identifying the best neighboring node of the child node, as in  308 . 
     However, if the wireless gateway device determines that the best neighboring node exists in the wireless network as in  310 , then the method  300  can include the wireless gateway device instructing the best neighboring node to incrementally increase a transmit power level of signals transmitted from the best neighboring node, as in  312 . For example, the best neighboring node can repeatedly increase its transmit power level until a connection with the child node is established or until the maximum level of the transmit power level is reached. After reaching the maximum level of the transmit power level, the gateway device can instruct the parent node to reset its transmit power level to the baseline level. 
     Then, the method  300  can include the wireless gateway device determining whether best neighboring node was able to connect to the child node, as in  314 . If the wireless gateway device determines that the best neighboring node connected to the child node as in  314 , then the method  300  can terminate. 
     However, if the wireless gateway device determines that the best neighboring node failed to connect to the child node as in  314 , then the method  300  can include the wireless gateway device again identifying the best neighboring node of the child node, as in  308 . In accordance with disclosed embodiments, incrementally increasing a transmit power level as in  208 ,  304 , and  312  can include incrementing the transmit power level in predetermined steps or in a predetermined number of steps. For example, in some embodiments, a first one of the predetermined steps can be a predetermined number of dBs less than a next one of the predetermined steps. Additionally or alternatively, in some embodiments, the predetermined number of steps can include low, medium, and high levels, and the method  200  and the method  300  can include incrementally increasing the transmit power level from a baseline level to the low level, from the low level to the medium level, and from the medium level to the high level (a maximum level) as in  208 ,  304 , and  312 , as necessary until a child node connects to a parent node or a neighboring node in a wireless network. 
     It is to be understood that the method  200  and the method  300  can be executed simultaneously. For example, when a child node is dropped from a wireless network, the child node can execute the method  200  while a wireless gateway device, a parent node of the child node, and/or neighboring nodes of the child node can execute the method  300  in an attempt to reconnect the child node to the wireless network. 
       FIG. 4  is a flow diagram of a method  400  in accordance with disclosed embodiments and illustrates any wireless node (e.g. a child node, a parent node, or a neighboring node) optimizing its transmit power level. As seen in  FIG. 4 , the method  400  can include the wireless node connecting to another node (e.g. the child node connecting to the parent node or the neighboring node), as in  402 , incrementally decreasing its transmit power level, as in  404 , and determining whether the wireless node remains connected to the other node, as in  406 . 
     If the wireless node determines that the wireless node remains connected to the other node as in  406 , then the method  400  can include the wireless node continuing to incrementally decrease its transmit power level, as in  404 . However, if the wireless node determines that the wireless node has disconnected from the other node as in  406 , then the method  400  can include the wireless node increasing its transmit power level by one increment, as in  408 , for example, to the transmit power level at which the wireless node last confirmed a connection to the other node. 
     Although a few embodiments have been described in detail above, other modifications are possible. For example, the steps described above do not require the particular order described or sequential order to achieve desirable results. Other steps may be provided, steps may be eliminated from the described flows, and other components may be added to or removed from the described systems. Other embodiments may be within the scope of the invention. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific system or method described herein is intended or should be inferred. It is, of course, intended to cover all such modifications as fall within the spirit and scope of the invention.