HK1176731A - Method and system for discovery and transparent status reporting for sensor networks - Google Patents

Description

Method and system for discovery and transparent status reporting for sensor networks

Technical Field

The present invention relates generally to network security systems, and more particularly to a method and system for transparently evaluating and reporting the status of wireless nodes in a network security system.

Background

Electronic article surveillance ("EAS") systems are used to protect articles from unauthorized removal from a protected area. Such systems typically operate using sensors secured to the protected item. The sensors are arranged such that the sensors respond to interrogation signals in a predictable manner when activated, thereby allowing an interrogation device (e.g., reader) to determine whether an active sensor is within an interrogation zone. For example, an interrogation zone may be established near an exit of a store such that an item with an activated sensor triggers an alarm when detected by a reader.

The EAS system incorporates a network controller in communication with each sensor in the network. Such communication links between the network controller and the sensors may be wired or wireless. Often, sensors that normally operate within a wired environment may need to be used in a wireless environment. It is desirable to use these sensors without burdensome or costly changes in design or processing. The functions of the sensors and their wireless nodes may be combined into one operating unit. Alternatively, the sensor communicates with a wireless node in the network. The wireless nodes and sensors communicate and manage wireless functions. It would be advantageous to have a network controller learn the status and overall health of the wireless nodes within the network. However, current systems require the sensors themselves to connect to the wireless nodes and determine the relative health and status of each wireless node with which they are in contact and report back to the network controller. When a wireless node is connected to or incorporated within a sensor, the sensor is tasked with monitoring and reporting the health of the wireless node and the functionality of the wireless node to a network controller.

Other wireless networks operate completely independently of the underlying sensor operation and report their status directly to the network controller. This results in two systems, a wired (or wireless) EAS sensor system and a wireless network, resulting in an overall inefficient system from a regulatory perspective. Thus, existing systems either operate inefficiently under two independent systems, or, although operating in coordination, place the evaluation, management, and reporting of the status of the wireless nodes directly on the sensors themselves.

What is needed, therefore, is a system and method for assessing and reporting the health and status of wireless nodes to a network controller without burdening or otherwise altering the design of the sensor devices within the EAS monitoring system.

Disclosure of Invention

The present invention advantageously provides a method and system for providing the health and status of wireless node devices to a network controller in an electronic article surveillance system. This is done by the wireless node devices appending their status information to the sensor device messages that are transmitted to the network controller. The status information of the wireless node device is appended to the message of the sensor device without the sensor knowing it. Thus, the health and status of the wireless node device can be determined without this burden being placed on the sensor device itself.

In one aspect thereof, the present invention provides a method for monitoring wireless node devices in an electronic article surveillance ("EAS") system. The method includes polling at least one sensor device for status information. The at least one sensor device is in communication with at least one wireless node device. The method also includes receiving a response message from the at least one wireless node device, wherein the response message contains sensor status information generated by the at least one sensor device and wireless node status information appended to the sensor status information by the at least one wireless node device. The method also includes extracting status information of the wireless node from a response message, wherein the response message includes a frame transmission.

According to another aspect, the present invention provides a wireless node device for use in an EAS system. The wireless node communicates with at least one sensor device in which the wireless node device has a wireless transmitter. The receiver is arranged for receiving a response message from the at least one sensor device. The processor is in communication with the receiver and the wireless transmitter. The processor is operative to append status information of the wireless node device to a response message received from the at least one sensor device. The processor sends a response message with the attached status information of the wireless node device to the wireless transmitter.

In accordance with yet another aspect, the present invention provides a method for provisioning wireless node device status information from a wireless node device to a network controller in an electronic article surveillance ("EAS") system. Communication with at least one sensor device is established. The status information of the wireless node device is appended to the response message received by the sensor device. A response message with the attached wireless node device's status information is transmitted to the network controller.

Drawings

A more complete understanding of the present invention and the attendant advantages and features thereof will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram of a system constructed in accordance with the principles of the present invention;

FIG. 2 is a block diagram illustrating the relationship between wireless node addresses, sensor device addresses, and network controllers in accordance with the principles of the present invention;

FIG. 3 is a diagram of an exemplary frame structure of a wireless frame transmission incorporating the principles of the present invention;

FIG. 4 is a table of exemplary wireless node addresses and associated sensor device addresses constructed in accordance with the principles of the present invention; and

fig. 5 is a flow chart of an exemplary process performed by a network controller in accordance with the principles of the invention.

Detailed Description

Before describing in detail exemplary embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of apparatus components and processing steps related to implementing a system and method for transparent reporting of status information of wireless node devices in a communication network.

Accordingly, the components of the systems and methods are represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

As used herein, relational terms, such as "first" and "second," "top" and "bottom," and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

One embodiment of the present invention advantageously provides a system and method for transparently assessing and reporting the status and health of wireless network nodes in an EAS monitoring system. The system allows the network controller to obtain status information from the sensor devices without the need for the controller to directly address any wireless nodes within the network and without the need to redesign the sensor or burden it with the extra responsibility of reporting the health of the wireless nodes. The wireless node is located between the network controller and the communication interface of the sensor device. The wireless node appends its status information to a response message transmitted from the sensor device to the network controller in response to the status request. This can be done without changing the structure or design of the sensor device. The network controller extracts the status information of the wireless node from the response message of the sensor device. The network controller constructs a table listing the addresses of each wireless access node and their corresponding sensor device addresses. In this way, the network controller can assess the health of each network node in the network by directing status commands to the address of the node or by processing status information that each wireless node appends to a response message from its corresponding sensor device. The attached wireless node information is thus processed without the knowledge of the sensor, providing a transparent report from the sensor's perspective.

Referring now to the drawings in which like reference designators refer to like elements, there is shown in fig. 1 a schematic diagram of a network topology for an extended star network of an electronic article surveillance ("EAS") communication network 10. The network 10 includes one or more sensor devices 12a-12e (four shown, collectively referred to as "sensor devices 12") and a local device manager ("LDM") or network controller 14. Sensor device 12 may include any type of sensor, such as a temperature sensor or an EAS sensor. System 10 may include a wireless access point 16 for managing network 10 and implementing a poll response protocol method for transmitting information. The wireless access point 16 may be separate from the network controller 14 or incorporated within the network controller 14 as a unit. One or more repeaters (repeaters) 20 are used to extend the range of the wireless access point 16 and facilitate communication of messages between the network controller 14 and the sensor devices 12. Messages routed through the repeater 20 (or range extender) are routed in accordance with methods established for the particular network 10 with the appropriate realm and control. In the case of the basic repeater 20, all messages detected by the repeater 20 are replayed without changing the packet frame (packet frame) of the message in order to extend the range of the network 10. In other cases, the repeater's information is contained within a routing table and the control method is implemented by the repeater 20 to reduce RF transmissions.

Wireless node devices 18a, 18b, and 18c (three shown, collectively referred to as "wireless node devices 18") are also included within the network 10 and are in electronic communication with certain sensor devices 12 and the network controller 14 via the wireless access point 16. It should be noted that network 10 may include any number of wireless access points 16, sensor devices 12, and wireless node devices 18. Each wireless node device 18 may include a power supply, transceiver, microcontroller, external memory, sensors, and analog-to-digital converters, among other hardware and software, to enable the wireless node device 18 to communicate with the sensor device 12, the wireless access point 16, and the network controller 14.

In an EAS system, the sensor device 12 receives a polling request signal from the controller 14. In one embodiment, the sensor device 12 is an electronic transmitter/responder. The sensor device 12 may be a portable or mobile device (e.g., a handheld device) or may be a device within a fixed position/fixed mounting configuration (e.g., a base), depending on the desired application. The sensor devices 12 are responsive to a polling request signal transmitted or communicated from the controller 14. The sensor device 12 (e.g., an EAS system pedestal) may emit radio waves within an interrogation zone to interrogate tags within the interrogation zone, the size of the zone varying with the power output and the frequency used. The sensor device 12 can determine the status of the interrogated tags and communicate corresponding data to the host computer for processing as part of a response to the interrogation request signal.

The sensor devices 12 may communicate with the network controller 14 via a wired network connection or wirelessly. The network controller 14 controls the processing of information and the operation of the wireless access point 16. The network controller 14 manages the network 10 by collecting, evaluating, and processing information related to the health and status of the network 10. In the case of a wireless network, the network controller 14 determines the status and health of the wireless node devices 18 in the network. The present invention provides this information to the network controller 14 in a manner that is transparent to the sensor device 12.

In one embodiment, the sensor devices 12 communicate with the network controller 14 via wireless nodes 18. The sensor devices 12 and the wireless device nodes 18 communicate with each other within the network 10. In one embodiment, wireless node device 18e is embedded or contained within the same housing as sensor device 12 d. In another embodiment, more than one sensor device (e.g., 12a and 12 b) communicates with a single wireless node device 18a, as shown in FIG. 1. The present invention allows the health and status of each wireless node device 18 to be determined and communicated to the network controller 14 without the sensor device 12 being burdened with this task.

The present invention allows the wireless node device 18 to communicate its status to the network controller 14 by appending (e.g., attaching or embedding) its device address and wireless status to a message response from the sensor device 12 with which it is in communication. The appended information is passed to a processing layer outside the medium access and control layer of the wireless access point 16. Because the communications affected are upstream of the controller 14, the sensor devices 12 are unaware that additional status and information is being appended to their message responses. Further, the address of the wireless node device 18 may be associated with an address of more than one sensor device address. This relationship allows the network controller 14 to gather a network topology in which multiple sensor devices 12 may be physically connected to one wireless node device 18 serving a wired network. In this way, the network controller 14 becomes aware of the presence of each wireless node device 18 in the network and knows which sensor device 12 is associated with which wireless node device 18. This allows the network to "self-learn" the topology of the network via the network controller 14.

Referring to fig. 1, a sensor device 12a receives a status request from a network controller 14. The response sent to network controller 14 also includes status information associated with the health and status of wireless node device 18 a. The sensor device 12a and the wireless node device 18a communicate with each other via, for example, a wired RS-485 standard connection. The sensor device 12 receives an inquiry from the network controller 14 about its current status. In response, the sensor device 12 may provide information not only about its relative health status, but also about other sensor data. For example, if the sensor device 12 is a pedestal, the pedestal may report whether an alarm has occurred. If the sensor device 12 is a deactivator, it can report how many deactivations have occurred. Often, the network controller 14 desires to obtain status information from a wireless node device associated with the sensor device 12 a. The wireless node device 18a appends its address and wireless status information to the response message sent by the sensor device 12 a. Similarly, wireless node device 18a can also append its address and wireless status information to the response message sent by sensor device 12 b. In another example, wireless node device 18e is embedded within sensor device 12d and appends its wireless address and status to a response message from sensor device 12d to network controller 14. As described above, in all cases, each sensor device 12 is unaware that additional status and address information is being appended to its message. Messages exchanged between the network controller 14 and the sensor devices 12 can be transmitted directly or via the repeater 20.

Fig. 2 is a schematic diagram showing how network controller 14 and wireless access point 16 receive status information from one or more wireless node devices 18 via the dual addressing method described above. As discussed above, the wireless node device 18 communicates with one or more sensor devices 12. The wireless node device 18 appends information including its current status and health and its wireless node address in the transmission to the sensor device 12. As described above, the address of the wireless node device 18 can be associated with the address of more than one sensor device address. The wireless node devices know the status information transmitted by the sensor device 12 to the network controller 14 by decoding the command field of the message transmitted by the sensor device 12 over the network to the network controller 14. The wireless node device 18 appends its status information and updates other fields in the sensor device's frame transmission as needed. For example, the frame size of the sensor device may need to be increased to accommodate the added information sent within the transmitted frame.

Upon receiving the sensor device's transmission, the network controller 14 builds a table of wireless node device addresses and associated sensor device addresses. This table allows the network controller 14 to directly assess the health of the wireless node by directing status commands to the address of the node or by extracting and processing status information of the wireless node device 18 appended to the response message from the sensor device 12.

Fig. 3 is a schematic diagram of an exemplary frame structure 22 showing fields in an exemplary wireless frame transmission from sensor device 12 to network controller 14. For example, each frame may include a preamble field 24, a Synchronization (SYNC) field 26, a length field 28 indicating the length of the transmission, and a dstddr field 30, the dstddr field 30 representing the destination address, i.e., the address of the wireless access point 16 or network controller 14 to which the frame is being transmitted. As discussed above, the wireless node 18 appends its address to the transmission, represented by the SRCADDR field 32. Fields 34, 36, 38, 40, 42, and 44 contain additional information for the wireless node device 18 whose status information is being sought. Fields 46 and 48 contain information of the sensor device 12 that is sending a response message to the network controller 14.

The frame structure 22 includes fields containing information introduced by the different communication layers. For example, frames 24-30 may be transmitted under a first communication layer (e.g., CC 1101), frames 32-44 under a second communication layer (e.g., SimplicitTI), and frames 46 and 48 under a third communication layer (e.g., SmartNET). The third layer appends the status information of wireless node device 18 to frame 22. The nwkddevstatus field 44 may be a fixed field that is always present within the frame transmission, or it may be dynamic, and the nwkdmd field 40 determines the presence of the nwkddevstatus field 44. Network controller 14 or wireless access point 16 can determine whether the response message of the state device contains a state from wireless node device 18 in a number of ways. For example, a port field in the frame structure 22 may indicate that the port for processing messages includes wireless node device status field processing. Alternatively, field 40 may represent a command indicating when a wireless node's status message is appended to frame 22.

Fig. 4 shows a device state table 50 generated by network controller 14 or wireless access point 16 as it processes state information obtained when wireless node device 18 appends its information to a response message from sensor device 12. The network controller 14 generates and populates a table of wireless node device addresses and associated master sensor device addresses. This table 50 allows the network controller 14 to directly assess the health of the wireless node device 18 by directing status commands to the address of the node. The network controller 14 or wireless access point 16 maintains a table of the health of the nodes that can be associated with routing tables (link paths) for managing the network. The wireless access point table is used to direct the operation of the wireless network node device 18.

The table shown in fig. 4 includes a list of wireless node device addresses 52 and their corresponding sensor device addresses 54. The status of each wireless node device 18 and sensor device 12 is also listed in columns 56 and 58, respectively. To populate the table 50, the network controller 14 polls each sensor device 12 in the network and waits for a response. Each sensor device 12 responds to the network controller 14 with a message that includes its own address and status, as well as the address and status of each wireless node device 18 that is in communication with the polled sensor device 12.

Thus, referring to the network topology illustration in fig. 1 and the table 50 of fig. 4, the addresses of the sensor devices 12a and 12b are assigned sensor device addresses 10 and 20, respectively. Both sensor devices 12a and 12b are associated with a single wireless node device 18a, which wireless node device 18a is assigned a wireless node address (100). Thus, the table in fig. 4 shows that sensor devices with addresses (150) and (250) are associated with a wireless node device with wireless node address (100). As can be seen from the table, the wireless node device 18a associated with the listed wireless node address (100) and the sensor devices 12a and 12b associated with the sensor device addresses (150) and (200) all function properly. On the other hand, the sensor device associated with the sensor device address (450) and the wireless node device associated with the wireless node address (200) are not functioning properly. The network controller 14 uses the table 50 to directly assess the health of any wireless node device 18 in the network by directing the status command to the address of the node or to the address of the sensor device 12 with which the wireless node device 18 is associated.

Fig. 5 is a flowchart showing steps taken by network controller 14 to assess the health and status of wireless node devices 18 within the network. The network controller transmits a status query via the wireless access point 16 to the sensor device 12 in the network from which it wishes to obtain status information (step S60). The network controller 14 receives a response message from the polled sensor device 12 via the wireless access point 16 (step S62). The network controller 14 generates a table 50 listing each responding sensor device 12 in the network, its corresponding device address, and information about its status (i.e., signal strength, noise level, run/no-run status, etc.) (step S64). If, at step S65, the network controller 14 determines that the sensor device' S response includes status information for the wireless node device, the network controller 14 extracts the wireless node device information (step S66) and updates the table 50 to include the status information for the wireless node device including the address of the wireless node device 18 (step S68). In an alternative embodiment, the wireless access point 16 determines that the sensor device's response includes wireless node device status information, extracts the wireless node device information and updates the table 50, which table 50 can either be maintained by the network controller 14 or the wireless access point 16. Thus, either the network controller 14 or the wireless access point 16 can perform these functions and maintain the table 50.

Once the table 50 is created, the network controller 14 can determine which sensor devices 12 have associated wireless node devices 18. By referencing table 50, network controller 14 can determine the health and status of wireless node devices 18 in the network in two ways. If no sensor device 12 is associated with a wireless node device 18, or no response message is received from a polled sensor device 12, the network controller 14 can direct a status request directly to the address of the associated wireless node 18. If there is an address of the sensor device 12 associated with the address of the wireless node device 18, the network controller 14 can direct a status request to the sensor device 12 and receive status information of the attached wireless node device in a transmission frame of a response message from the sensor device 12. Network controller 14 extracts the appended information, determines the status of wireless node device 18, and updates table 50 accordingly. When the wireless node device's message is appended to the sensor device's response message, the sensor device 12 is unaware of the appended information, thereby reducing the processing and storage burden on the sensor device 12.

The present invention provides systems and methods that enable the network controller 14 to communicate with one or more wireless node devices 18 by sending status requests directly to the wireless node devices 18 or by receiving response messages from polled sensor devices 12, wherein the sensor device's response messages include address and status information from the wireless node devices 18 that communicate with the polled sensor devices. Wireless node device 18 appends its status information to the sensor device transmission frame from sensor device 12 and updates other fields in the transmission frame if necessary. Thus, there is no additional processing or storage burden on the sensor device 12 to find status information from the wireless node device. The sensor device 12 simply responds to the network controller 14 now having additional status and address information attached to the frame transmission.

The present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computing system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein.

A typical combination of hardware and software could be a computer system having one or more processing elements and a computer program stored on a storage medium that, when loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Storage media refers to any volatile or non-volatile storage device.

Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) replicated in different material forms.

In addition, unless stated otherwise above, it should be noted that all of the accompanying drawings are not to scale. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.

Claims (20)

1. A method for monitoring wireless node devices in an electronic article surveillance ("EAS") system, the method comprising:

polling at least one sensor device for status information, the at least one sensor device in communication with at least one wireless node device;

receiving a response message from the at least one wireless node device, the response message containing sensor status information generated by the at least one sensor device and wireless node status information appended to the sensor status information by the at least one wireless node device; and

extracting the wireless node status information from the response message, the response message including a frame transmission.

2. The method of claim 1, further comprising: the routing table is populated with wireless node device addresses and sensor device addresses associated with respective wireless node devices.

3. The method of claim 2, wherein the routing table includes a current state of each sensor device and a current state of each associated wireless node device.

4. The method of claim 2, further comprising: evaluating a status of a wireless node device by directing a status command directly to the wireless node device.

5. The method of claim 1, wherein the sensor device and the at least one wireless node device are contained within a same housing.

6. The method of claim 2, wherein the address of the wireless node device is associated with an address of more than one sensor device.

7. The method of claim 1, wherein the response message includes fields containing information introduced by different communication layers of an EAS system.

8. A wireless node device in an electronic article surveillance ("EAS") system, the wireless node device in communication with at least one sensor device, the wireless node device comprising:

a wireless transmitter;

a receiver arranged to receive a response message from the at least one sensor device; and

a processor in communication with the receiver and the wireless transmitter, the processor operative to append wireless node device status information to the response message received from the at least one sensor device,

the processor sends the response message with the appended wireless node device status information to the wireless transmitter.

9. The device of claim 8, wherein the processor determines when a status response message is transmitted by the at least one sensor device.

10. The device of claim 9, wherein the processor determines when a status response message is transmitted by the at least one sensor device by decoding a command field of the response message.

11. The apparatus of claim 8, wherein the response message includes fields containing information introduced by different communication layers of the EAS system.

12. The apparatus of claim 8, wherein the receiver further receives a status query from a network controller.

13. A method for provisioning wireless node device status information from a wireless node device to a network controller in an electronic article surveillance ("EAS") system, the method comprising:

establishing communication with at least one sensor device;

appending wireless node device status information to a response message received from the sensor device; and

transmitting the response message with the appended wireless node device status information to the network controller.

14. The method of claim 13, further comprising: determining when the at least one sensor device transmits the response message.

15. The method of claim 14, wherein determining when the at least one transmitting device transmits the response message comprises: decoding a command field of the response message.

16. The method of claim 13, wherein the response message comprises a sensor device transmission frame, the method further comprising: updating the sensor device transmission frame to accommodate the wireless node device status information.

17. The method of claim 16, wherein updating the sensor device transmission frame comprises: increasing a size of a transmission frame of the sensor device.

18. The method of claim 13, wherein the wireless node device and the at least one sensor device are housed within a single unit.

19. The method of claim 13, wherein the wireless node device status information comprises an address of the wireless node device.

20. The method of claim 19, wherein the address of the wireless node device is associated with an address of more than one sensor device.