System for automated management of spontaneous node migration in a distributed fixed wireless network

FIELD OF THE INVENTION [0002[ The present invention relates to wireless networks for collecting data, and more particularly, to systems and methods for managing the migration of nodes on such networks.

BACKGROUND OF THE INVENTION [00031 The collection of meter data from electrical energy, water, and gas meters has traditionally been performed by human meter-readers. The meter-reader travels to the meter location, which is frequently on the customer’s premises, visually inspects the meter, and records the reading. The meter-reader may be prevented from gaining access to the meter as a result of inclement weather or, where the meter is located within the customer’s premises, due to an absentee customer. This methodology of meter data collection is labor intensive, prone to human error, and often results in stale and inflexible metering data.

[0004] Some meters have been enhanced to include a one-way radio transmitter for transmitting metering data to a receiving device. A person collecting meter data that is equipped with an appropriate radio receiver need only come into proximity with a meter to read the meter data and need not visually inspect the meter. Thus, a meter-reader may walk or drive by a meter location to take a meter reading. While this represents an improvement over visiting and visually inspecting each meter, it still requires human involvement in the process.

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WO 2006/036886 FCT/US2005/034400 [0005] An automated means for collecting meter data involves a fixed wireless network. Devices such as, for example, repeaters and gateways are permanently affixed on rooftops and pole-tops and strategically positioned to receive data from enhanced meters fitted with radio-transmitters. Typically, these transmitters operate in the 902-928 MHz range and employ Frequency Hopping Spread Spectrum (FHSS) technology to spread the transmitted energy over a large portion of the available bandwidth.

[0006] Data is transmitted from the meters to the repeaters and gateways and ultimately communicated to a central location. While fixed wireless networks greatly reduce human involvement in the process of meter reading, such systems require the installation and maintenance of a fixed network of repeaters, gateways, and servers. Identifying an acceptable location for a repeater or server and physically placing the device in the desired location on top of a building or utility pole is a tedious and labor-intensive operation. Furthermore, each meter that is installed in the network needs to be manually configured to communicate with a particular portion of the established network. When a portion of the network fails to operate as intended, human intervention is typically required to test the effected components and reconfigure the network to return it to operation.

10007] Thus, while existing fixed wireless systems have reduced the need for human involvement in the daily collection of meter data, such systems require substantial human investment in planning, installation, and maintenance and are relatively inflexible and difficult to manage. Therefore, there is a need for networks that do not depend on pre-determined communication paths, but instead rapidly adapt to changing wireless communications conditions so as to maintain optimal network connectivity. These networks, where nodes in the network can change communication paths spontaneously based on changing wireless communication performance, have a need for a system to manage the wireless network as nodes migrate among the many communication paths.

SUMMARY OF THE INVENTION [0008] The present invention is directed to methods and systems of managing the migration of wireless nodes amongst repeaters and collectors in a wireless network. According to a first aspect of the invention, there is provided a system for managing a wireless network of meters, the system comprising:

a first collector and a first plurality of meters that communicate wirelessly with said first collector,

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RECEIVED at IPONZ on 17 May 2010 a second collector and a second plurality of meters that communicate wirelessly with said second collector, wherein each of said first plurality of meters has a communication path to the first collector that is either direct or indirect through one or more intermediate meters in said first plurality of meters that serve as repeaters, and wherein each of said second plurality of meters has a communication path to the second collector that is either direct or indirect through one or more intermediate meters in said second plurality of meters that serve as repeaters, the wireless communication paths between each meter and a respective collector defining a layout of the network;

a network management server that determines a network state; and a network management system that maintains a database of said network state;

wherein when said network management server detects that a one of said first plurality of meters is no longer in communication with said first collector but is instead communicating with said second collector and thus has migrated from said first collector to said second collector and has become one of said second plurality of meters, information associated with said meter is retrieved from said network management server and downloaded to said second collector;

wherein said information associated with said meter comprises first collected data collected by said first collector from said meter;

wherein second collector data collected by the second collector from said meter is merged at the second collector with the first collected data; and wherein said first collected data and said second collected data comprise metering information representative of usage of a service or commodity. In this way, the system ensures that each collector has the configuration information for each meter communicating through it.

Throughout this specification, unless the context requires otherwise, the word comprise, and variations such as comprises and comprising, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0009] According to a feature, a current network state database and a historical network state database may be updated to reflect that said meter has migrated from said first collector to said second collector.

[0010] According to another aspect of the invention, there is provided a method of managing meters in a wireless network, wherein the network comprises a first collector and a first plurality of meters that communicate wirelessly with said first collector, and a second collector and a second plurality of meters that communicate wirelessly with said second collector, wherein each of said first plurality of meters has a communication path to the first collector that is either direct or indirect

2a

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RECEIVED at IPONZ on 17 May 2010 through one or more intermediate meters in said first plurality of meters that serve as repeaters, and wherein each of said second plurality of meters has a communication path to the second collector that is either direct or indirect through one or more intermediate meters in said second plurality of meters that serve as repeaters, the wireless communication paths between each meter and a respective collector defining a layout of the network, the method comprising:

detecting that one of said first plurality of meters is no longer in communication with said first collector but is instead communicating with said second collector and thus has migrated from said first collector to said second collector and has become one of said second plurality of meters;

updating a network state;

retrieving information associated with said migrated meter from a global configuration database; and downloading said information to said second collector, wherein said information associated with said meter comprises first collected data collected by said first collector from said meter;

merging, at the second collector, second collector data collected by the second collector from said meter with the first collected data: and wherein said first collected data and said second collected data comprise metering information representative of usage of a service or commodity.

[0011] According to a feature, a current network state database and a historical network state database may be updated to reflect that the meter has migrated from the first collector to the second collector. Also, the meter may be configured in accordance with the information. The information may be removed from the first collector after being downloaded to the second collector.

[0012] According to another aspect of the invention there is provided a method for managing a spontaneous migration of a meter from a first collector to a second collector in a wireless network, wherein the first collector wirelessly communicates with a first plurality of meters, and the second collector communicates with a second plurality of meters, and wherein each of said first plurality of meters has a communication path to the first collector that is either direct or indirect through one or more intermediate meters in said first plurality of meters that serve as repeaters, and wherein each of said second plurality of meters has a communication path to the second collector that is either direct or indirect through one or more intermediate meters in said second plurality of meters that serve as repeaters, the wireless communication paths between each meter and a respective collector defining a layout of the network, the method comprising:

detecting said spontaneous migration of the meter from the first collector to the second collector;

retrieving configuration information and first collected data collected by the first collector from said meter;

2b

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RECEIVED at IPONZ on 17 May 2010 contacting said second collector and downloading said configuration information and said first collected data to said second collector; and merging at said second collector said first collected data with second collected data collected by the second collector from said meter;

wherein said first collected data and said second collected data comprise metering information representative of usage of a service or commodity.

[0013J Additional features and advantages of the invention will be made apparent from the following detailed description of illustrative embodiments that proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] The foregoing summary, as well as the following details description of preferred embodiments, it better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary_

2563146. l.doc

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PCT/US2005/034400 constructions of the invention; however, the invention is not limited to the specific methods and instrumentalities disclosed. In the drawings:

[0015] Fig. 1 is a diagram of a wireless system for collecting data from remote devices;

[0016] Fig. 2 expands upon the diagram of Fig. 1 and illustrates a system in which the present invention is embodied;

[0017] Fig. 3 illustrates an exemplary sequence of events when a meter switches from a first collector to a second collector.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS [0018] Exemplary systems and methods for gathering meter data are described below with reference to Figs. 1-3. It will be appreciated by those of ordinary skill in the art that the description given herein with respect to those figures is for exemplary purposes only and is not intended in any way to limit the scope of potential embodiments.

[0019] Generally, a plurality of meter devices, which operate to track usage of a service or commodity such as, for example, electricity, water, and gas, are operable to wirelessly communicate with each other. A collector is operable to automatically identify and register meters for communication with the collector, When a meter is installed, the meter becomes registered with the collector that can provide a communication path to the meter. The collectors receive and compile metering data from a plurality of meter devices via wireless communications. A communications server communicates with the collectors to retrieve the compiled meter data.

[0020] Fig. 1 provides a diagram of an exemplary metering system 110. System 110 comprises a plurality of meters 114, which are operable to sense and record usage of a service or commodity such as, for example, electricity, water, or gas. Meters 114 may be located at customer premises such as, for example, a home or place of business. Meters 114 comprise an antenna and are operable to transmit data, including service usage data, wirelessly. Meters 114 may be further operable to receive data wirelessly as well. In an illustrative embodiment, meters 114 may be, for example, a electrical meters manufactured by Elster Electricity, LLC.

[0021] System 110 further comprises collectors 116. Collectors 116 are also meters operable to detect and record usage of a service or commodity such as, for example, electricity, water, or gas. Collectors 116 comprise an antenna and are operable to send and receive data wirelessly. In particular, collectors 116 are operable to send data to and receive data from meters 114. In an illustrative embodiment, meters 114 may be, for example, an electrical meter manufactured by Elster Electricity, LLC.

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PCT/US2005/034400 [0022] A collector 116 and the meters 114 for which it is configured to receive meter data define a subnet/LAN 120 of system 110. As used herein, meters 114 and collectors 116 maybe considered as nodes in the subnet 120. For each subnet/LAN 120, data is collected at collector 116 and periodically transmitted to a data collection server 206. The data collection server 206 stores the data for analysis and preparation of bills. The data collection server 206 may be a specially programmed general purpose computing system and may communicate with collectors 116 wirelessly or via a wire line connection such as, for example, a dial-up telephone connection or fixed wire network.

[0023] Generally, collector 116 and meters 114 communicate with and amongst one another using any one of several robust wireless techniques such as, for example, frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS). As illustrated, meters 114a are “first level” meters that communicate with collector 116, whereas meters 114b are higher level meters that communicate with other meters in the network that forward information to the collector 116.

[0024] Referring now to Fig. 2, there is illustrated a system 200 in which the present invention may be embodied. The system 200 includes a network management server 202, a network management system (NMS) 204 and a data collection server 206 that together manage one or more subnets/LANs 120 and their constituent nodes. The NMS 204 tracks changes in network state, such as new nodes registering/unregistering with the system 200, node communication paths changing, etc. This information is collected for each subnet/LAN 120 and are detected and forwarded to the network management server 202 and data collection server 206.

[002SJ In accordance with an aspect of the invention, communication between nodes and the system 200 is accomplished using the LAN ID, however it is preferable for customers to query and communicate with nodes using their own identifier. To this end, a marriage file 208 may be used to correlate a customer serial number, a manufacturer serial number and LAN ID for each node (e.g., meters 114a and collectors 116) in the subnet/LAN 120. A device configuration database 210 stores configuration information regarding the nodes. For example, in the metering system 110, the device configuration database may include data regarding time of use (TOU) switchpoints, etc. for the meters 114a and collectors 116 communicating to the system 200. A data collection requirements database 212 contains information regarding the data to be collected on a per node basis. For example, a user may specify that metering data such as load profile, demand, TOU, etc. is to be collected from particular meter(s) 114a. Reports 214

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PCT/US2005/034400 containing information on the network configuration may be automatically generated or in accordance with a user request.

[0026] The network management system (NMS) 204 maintains a database describing the current state of the global fixed network system (current network state 220) and a database describing the historical state of the system (historical network state 222). The current network state 220 contains data regarding current meter to collector assignments, etc. for each subnet/LAN 120. The historical network state 222 is a database from which the state of the network at a particular point in the past can be reconstructed. The NMS 204 is responsible for, amongst other things, providing reports 214 about the state of the network. The NMS 204 may be accessed via an API 220 that is exposed to a user interface 216 and a Customer Information System (CIS) 218. Other external interfaces may be implemented in accordance with the present invention. In addition, the data collection requirements stored in the database 212 may be set via the user interface 216orCIS218.

[0027] The data collection server 206 collects data from the nodes (e.g., collectors 116) and stores the data in a database 224. The data includes metering information, such as energy consumption and may be used for billing purposes, etc. by a utility provider.

[0028] The network management server 202, network management system 204 and data collection server 206 communicate with the nodes in each subnet/LAN 120 via a communication system 226. The communication system 226 may be a Frequency Hopping Spread Spectrum radio network, a mesh network, a Wi-Fi (802.11) network, a Wi-Max (802.16) network, a land line (POTS) network, etc., or any combination of the above and enables the system 200 to communicate with the metering system 110.

[0029] The present invention provides a system and method for downloading a meter’s collection data from an old collector to a new collector upon determining that the meter changed collectors. The present invention serves to ensure that the new collector is able to provide accurate metering data to the system 200 when requested, as well as properly configure the meter. With reference to Fig. 3, it is shown that the meter 114a has changed its communication path from collector A to collector B (steps 1-2). In the exemplary communication paths, the collectors are intermediary nodes between the meter 114a and the communication system 226. Next, the network management server 202 detects the change in the communication path of meter 114a from LAN A to LAN B (step 3). The network management server 202 then sends network state updates to the network configuration system 204 and the data collection system 206 (step 4). A data collection requirements database 212, may also be updated, if necessary.

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The network management system 204 then updates the current network configuration 220 (step 5) and the historical network configuration 222 (step 6) to reflect the change.

[0030] Prior to the meter 114a changing LANs, it is possible that collector A in LAN A has collected meter data and contains configuration information associated with the meter 114a. This data and configuration information may include historical demand, load profile and event data. If collector A has such data, it is advantageous to make collector B aware of that data in order to accurately collect subsequent data from the meter 114a. Therefore, according to the present invention, to ensure that collector B has all of the data and configuration information associated with meter 114a, the system 200 contacts collector A after detecting the change (step 7) and downloads the meter’s settings and data from collector A. Next, the system 200 communicates the information to collector B (step 8) where the settings and data from collector A are merged with data and configuration information contained in collector B for the meter 114a. The data contained in collector A is removed to free up space on the collector. In this manner, meter data and configuration information is maintained at the appropriate collector. As such, collector B will have all of the historical information for meter 114a and will be able to accurately provide metering data to the system 200 when requested.

[0031] While systems and methods have been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modification and variations may be made without departing from the principles described above and set forth in the following claims. Accordingly, reference should be made to the following claims as describing the scope of disclosed embodiments.

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