FREQUENCY HOP SEQUENCE DISCOVERY MECHANISM
An apparatus including narrowband receivers and a controller. The narrowband receivers are deployed geographically within a grid, where each of the narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and where each of the plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to an unknown hopping sequence, but a known hop rate. The controller is coupled to the narrowband receivers, and is configured to control the narrowband receivers such that the each of the plurality of AMR meters is identified, and is configured to control the narrowband receivers such that corresponding data from the each of the AMR meters is received on at least one of the plurality of frequency bands.
This application is a continuation of the following U.S. Nonprovisional patent application, which is herein incorporated by reference for all intents and purposes.
The above noted U.S. Nonprovisional patent application claims the benefit of the following U.S. provisional application, which is herein incorporated by reference for all intents and purposes.
This application is related to the following co-pending U.S. Nonprovisional patent applications.
1. Field of the Invention
This invention relates in general to the field of automated resource control, and more particularly to a topology assessment mechanism for deploying and maintaining wireless networks.
2. Description of the Related Art
Since late in the 1800's, electrical power, natural gas, and water providers have been distributing these resources to consumers. And not long after larger distribution grids were deployed by these utilities, the problem of billing based upon consumption arose. Consequently, utilities began to install consumption meters for these resources at their respective points of consumption.
Accordingly, virtually everyone in this country and many countries abroad understand the role of the “meter reader,” for early utility meters provided only a visual indication of how much certain resource had been consumed over a billing period. Thus, in order for a resource provider to determine the amount of that resource which had been consumed over a billing period, it was necessary to dispatch personnel each time a meter reading was required. This typically occurred on a monthly basis.
This manner of obtaining usage data, however, was labor intensive and consequently very costly. In addition, because the act of reading a meter involved interpretation of the meaning of one or more visual indicators (typically analog indicators like the hands on a watch), these readings were subject to inaccuracies due to errors made by the meter readers.
In the past twenty years, developers have begun to address the problems of labor cost and inaccurate readings due to the human element by providing so-called automatic meter reading (AMR) meters, the most prevalent type of which broadcast their current values in a known and encoded low power radio frequency transmission capable of being captured by a corresponding AMR receiver in a moving vehicle. Hence, AMR technologies substantially alleviate the limitations of former meters related to accurate readings and markedly addressed the cost of labor required to read meters.
But in order to deploy AMR products, the resource providers had to completely replace their existing inventory of meters—literally hundreds of millions of meters—at substantial expense, the bulk of which was conveyed either directly or indirectly to consumers.
In the past ten years, developers have responded to demands in the art for so-called “smart meters,” that is, meters that allow for two-way communication between a resource provider and a point of consumption. Two-way communications between a provider and a meter, also known as automated metering infrastructure (AMI) yields several benefits to the provider because with AMI the provider is no longer required to send out personnel to control consumption at an access point. With AMI meters, a utility can turn on and turn off consumption of the resource at the consumption point without sending out service personnel. And what is more attractive from a provider standpoint is that AMI techniques can be employed to perform more complex resource control operations such as demand response control.
The present inventors have observed, however, that to provide for AMI, under present day conditions, requires that the utilities—yet one more time—replace their entire inventory of AMR meters with more capable, and significantly more expensive, AMI meters. In addition, present day approaches that are directed toward providing the two-way communications between the utilities and their fleet of AMI meters all require the development of entirely new communications infrastructures (e.g., Wi-Fi, satellite) or they are bandwidth limited (e.g., cellular).
Consequently, what is required is an apparatus and method for providing AMI capabilities to existing AMR meters without a requirement to entirely replace or significantly modify the existing AMR meters.
In addition, what is required is a mechanism for deploying an AMI grid that minimizes the cost of metering and two-way communications upgrades.
Furthermore, what is needed is a smart grid technique that employs existing AMR meters and moreover leverages already deployed high bandwidth two-way communications infrastructures.
Moreover, what is needed is a cost-effective mechanism for reading existing AMR meter grids.
Further, what is needed is a technique that supports the deployment of wireless devices in a manner that security provisions are tailored according to proximity.
Also, what is needed is a topology assessment mechanism for deploying and maintaining wireless networks.
In addition, what is needed is a technique that allows end-to-end link quality in a wireless network to be easily quantified.
Furthermore, what is needed is a method for discovering a frequency hopping sequence in a system of devices such as AMR meters.
Moreover, what is needed is a large payload fragmentation scheme for use by a network of wireless devices.
Also, what is needed is a mechanism whereby a mesh network of wireless devices may optimally select bands/channels for transmission of messages to other devices in the network.
SUMMARY OF THE INVENTIONThe present invention, among other applications, is directed to solving the above-noted problems and addresses other problems, disadvantages, and limitations of the prior art. The present invention provides a superior technique for receiving and transporting real time resource usage data corresponding to a grid of resource usage devices that employ a frequency hopping algorithm to broadcast usage data. In one embodiment, an apparatus is provided for receiving and transporting real time resource usage data. The apparatus includes a plurality of narrowband receivers and a controller. The plurality of narrowband receivers is deployed geographically within a grid, where each of the plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and where each of the plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to a hopping sequence, and where the hopping sequence is initially unknown to the plurality of narrowband receivers, but a hop rate is known. The controller is coupled to the plurality of narrowband receivers, and is configured to control the plurality of narrowband receivers such that the each of the plurality of AMR meters is identified, where the controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in the list of channels based upon latency of messages having the identical data observed between the channel candidate pairs according to the hop rate.
Another aspect of the present invention contemplates an apparatus for receiving and transporting real time resource usage data. The apparatus has a plurality of narrowband receivers, a controller, and a network operations center (NOC). The plurality of narrowband receivers is deployed geographically within a grid, where each of the plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and where each of the plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to a hopping sequence, and where the hopping sequence is initially unknown to the plurality of narrowband receivers, but a hop rate is known. The controller is coupled to the plurality of narrowband receivers, and is configured to control the plurality of narrowband receivers such that the each of the plurality of AMR meters is identified, and is configured to control the plurality of narrowband receivers such that corresponding data from the each of the AMR meters is received on at least one of the plurality of frequency bands, where the controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in the list of channels based upon latency of messages having the identical data observed between the channel candidate pairs according to the hop rate. The NOC is operatively coupled to the controller via an existing infrastructure, and is configured to receive the real time resource usage data from the controller.
A further aspect of the present invention comprehends a method for receiving and transporting real time resource usage data. The method includes deploying a plurality narrowband receivers within a grid, wherein each of the plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and wherein each of the plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to a hopping sequence, and wherein the frequency hopping sequence is initially unknown to said plurality of narrowband receivers, but a hop rate is known; and controlling the plurality of narrowband receivers such that the each of the plurality of AMR meters is identified, and that corresponding data from the each of the AMR meters is received on at least one of the plurality of frequency bands, wherein the controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in the list of channels based upon latency of messages having the identical data observed between said channel candidate pairs according to the hop rate.
These and other objects, features, and advantages of the present invention will become better understood with regard to the following description, and accompanying drawings where:
Exemplary and illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification, for those skilled in the art will appreciate that in the development of any such actual embodiment, numerous implementation-specific decisions are made to achieve specific goals, such as compliance with system related and/or business related constraints, which vary from one implementation to another. Furthermore, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. Various modifications to the preferred embodiment will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the particular embodiments shown and described herein, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.
The present invention will now be described with reference to the attached figures. Various structures, systems, and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present invention with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present invention. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
In view of the above background discussion on automatic meter reading and associated techniques employed by present day resource providers to obtain meter readings from resource consumers, a discussion of the limitations and disadvantages of these techniques will now be presented with reference to
Turning to
Older meters (not shown) provided some form of visual indication of electrical power consumption, and personnel (i.e., meter readers) were dispatched typically monthly to each building within an electrical power provider's service area (i.e., grid) to manually obtain readings associated therewith. This approach was naturally labor intensive and thus expensive. In addition, because the accuracy of the data obtained depended on human factors, such an approach was subject to error.
Many electrical power providers today utilize automatic meter reading meters 102 that periodically broadcast their respective readings over relatively secure wireless communication links 105. A significant number of AMR meters 102 today employ an encoded receiver transmitter (ERT) technique to broadcast encoded meter readings over the communication links 105. To obtain these readings, the electrical power provider typically dispatches a vehicle 103 that is equipped with an antenna 104 and associated receiver (not shown) that is configured to automatically receive, identify, and store the readings from each of the meters 102. ERT is a low power wideband (i.e., frequency hopping) radio frequency (RF) technique that is widely used for automatic meter reading, but it still requires the dispatch of personnel and equipment in order to gather consumption data from the AMR meters 102. Accordingly, while the accuracy of data obtained through the use of AMR meters 102 is improved over manual approaches, gathering of consumption data is still costly because of the personnel and equipment that are still required to do so. Moreover, AMR meters 102 are one-way communication devices and are thus incapable of serving as a control mechanism responsive to a resource provider's requirements. For example, in order to cut off power to a particular building 101, the provider must dispatch service personnel who manually cut off the power to the particular building 101. Thus, it is impossible for AMR meters 102 to be employed in more sophisticated resource provider programs such as demand response control and the like in any way that does not require the dispatch of personnel.
A number of more recent initiatives are planned to address the one-way and manual limitations of AMR-based grid systems, which include the use of two-way communications provided by so-called “smart meters.” There are a number of different two-way communication technologies that are employed by these smart meters, to include spread spectrum RF, wireless mesh, Wi-Fi, and power line communication (PLC). These smart meters and their associated infrastructures, regardless of their corresponding communication technology, are commonly referred to in the art as automated metering infrastructure (AMI), an example of which will now be discussed with reference to
Turning to
Operationally, the AMI meters 202, 204, are configured to provide for two-way communications within a limited area to provide the resource provider with metering data and to also allow for control of the resource for particular facilities 201. In the wireless mesh example shown, one skilled in the art will appreciate that because wireless transceivers within the AMI meters 202, 204 are low power by design, there is often a requirement to supplement the mesh network by the addition of a repeater 205, which is employed to amplify signals that have been attenuated as a result of propagation distance, propagation path blockage, or interference.
AMI is effective in overcoming the one-way limitations of former AMR systems. As a result, many utilities are currently replacing AMR meters 102 with newer, more capable AMI meters 202, 204. But the present inventors have observed that AMI meters 202, 204 are significantly more expensive than currently deployed AMR meters 102. Stated differently, in order to upgrade a given area within a grid to provide for AMI, it is necessary to completely replace all of the AMR meters 102 in the area with more expensive AMI meters 202, 204. In addition, aggregation points 207 and associated backhaul communications 208 must be deployed to enable two-way communications between the new AMI meters 202, 204 and the resource provider.
Accordingly, the present inventors have observed that resource providers have a tremendous capital investment in AMR meters 102, which comprises a significant portion of the costs associated with distribution, and to replace these AMR meters 102 with newer and more expensive AMI meters 202, 204 requires yet another costly capital outlay. The present inventors have also noted that the burdensome expense of upgrading an existing AMR grid to provide for AMI capabilities is disadvantageous at best because ultimately the consumer will be paying for the cost of these upgrades, either directly (in terms of increased cost of the resource) or indirectly (through demand limitations and consumption caps).
In addition to the above, the present inventors have noted that to provide backhaul communications 208 from the aggregation point 207 to the resource provider, all present day implementations of AMI typically require an entirely new and costly high bandwidth communications infrastructure 208, the cost of which is also passed on to consumers. Lower speed communications infrastructures exist, such as using cellular and satellite communications as the link 208, but these approaches are bandwidth limited and thus restrict the number of AMI functions that can be performed because the amount and frequency of data that can be transmitted over the link 208 is limited.
The present invention overcomes the above noted limitations, and others, by providing apparatus and methods whereby an existing AMR grid is upgraded to provide for AMI capabilities and additional functions through slight modification to the existing AMR meters 102, thereby eliminating the replacement cost of these meters 102. In addition, the present invention utilizes a significant portion of an existing backhaul infrastructure, thereby simplifying communications between a metered area and a resource provider. The present invention will now be discussed with reference to
Now referring to
The master device 310 is coupled to all of the slave devices 311 via a communications link 309. In one embodiment, the communications link 309 comprises a wired variable speed serial data link 309 configured as a star network. In a wireless embodiment, the communications link 309 comprises a wireless mesh network.
One embodiment of the grid system 300 contemplates employment of an existing communications infrastructure 301 that couples the communications link 309 to a network operations center 303. The network operations center (NOC) 303 provides for monitoring and control of the resource to each of the facilities 304 through commands and data transmitted and received over a command link 306 that couples the existing communications infrastructure 301 to a high speed data device 305. The high speed data device 305 is coupled to the master device 310 and the master device 310 provides for monitoring and control of all the slave devices 311 coupled thereto via commands and data transmitted and received over the communications link 309.
One embodiment of the present invention contemplates an existing public telephone network 301, which includes wiring pedestals 302 that provide connectivity of the network 301 to each of the facilities 304. As one skilled in the art will appreciate, a typical existing drop from a pedestal 302 to a facility 304 comprises multiple conductors that are available for connections. According to this embodiment, the conductors may comprise copper or other metal wire, coaxial cable, fiber-optic cable, and any other form of fixed transmission media. Additionally, for specialized installations such as those in extremely dense areas, extremely rural areas, and widely-spaced areas, and for installations that preclude utilizing a wire to provide the short distance local area network, a point-to-point secure wireless bridge is also contemplated as the communication link 309.
Another embodiment of the present invention considers an existing cable infrastructure 301 such as is employed to provide television and Internet connectivity to the structures 304. Accordingly, the pedestals 302 may be deployed above ground on poles or underground.
According to any of the above embodiments, it is noted that the command link 306 couples the local grid to the NOC 303 by utilizing a high speed device 305 that is compatible with the existing infrastructure 301. In the case of a public switched telephone network infrastructure 301, the high speed device 305 comprises a digital subscriber line (DSL) modem 305. In the case of a cable-based infrastructure 301, the high speed device 305 comprises a cable modem 305.
In wired embodiments, the communication link 309 comprises a star network where the coupling point is within an existing pedestal 302 or substantially similar cross connect terminal. In wireless embodiments, the pedestal 302 or substantially similar cross connect terminal is employed solely to provide connectivity of the high speed device 305 to the existing infrastructure 301 via the command link 306. In wireless embodiments, the master interface device 310 may be coupled to the high speed device 305 via a wireless link or a wired link.
In operation, each of the slave interface devices 311 and the master interface device 310 are configured to gather data from their corresponding existing AMR meter 307 via either a wired or wireless interface. The master interface device 310 adaptively configures the data rate of the communications link 309 to enable reliable and efficient transfer of data to/from each of the slave devices 311 according to the propagation lengths that are exhibited by the existing infrastructure 301. As one skilled in the art will appreciate, a residential deployment of telephone or cable connects anywhere from one to greater than ten structures 304 within a single pedestal 302. Thus, the propagation path from the master interface device 310 to individual slave devices 311 may vary by greater than a factor of ten. Advantageously then, the variable speed communication link 309 that is adaptively configured by the master interface device 310 to the slave interface devices 311 within a given grid enables additional slave devices 311 to be added or deleted without a requirement for reprogramming.
Thus, all data that is gathered from the AMR meters 307 within the local grid is transmitted to the master interface device 310 over the communications link 309 and the master interface device 310 transmits this data to the NOC 303 via the high speed device 305 that is coupled to the existing infrastructure 301. One embodiment of the present invention contemplates master and slave interface devices 310-311 that are not only capable of gather billing quality data from the AMR meters 307, but which are also coupled to the resource itself and are capable of sampling consumption of the resource at a sample rate commensurate with the analysis of time-varying loads and signatures. This analysis quality data is also transmitted to the NOC 303 via the high speed device 305.
In addition to billing and analysis data, the present invention also contemplates control of the resource at specified facilities 304 via commands sent from the NOC 303 and received by the master interface device 310. If applicable, these commands are subsequently routed to specified slave devices that are coupled to the specified facilities 304. Accordingly, a resource provider is enabled to inexpensively control consumption of the resource at a given facility 304 via commands generated at the NOC 303. This control can range from simple cut-on and cut-off of the resource to scheduled regulation of the resource, such as might be encountered in an electrical power demand response system. Advantageously, no personnel or equipment need be dispatched to both monitor and control resource consumption and existing AMR meters 307 can be fully utilized.
The present invention enables a private, secure, low cost, high reliability, AMI network solution 300 over existing infrastructure 301 that provides utilities and other resource providers with an accelerated and economical path to deployment of AMI and 2-way communication without the expense of replacement of existing AMR meters 307 with new smart meters 202, and without the risk of less proven communication methods.
The present invention overcomes the deficiencies of present day AMI approaches as noted above, and others limitations related to implementing an AMI network. The present inventors have noted that all present known AMI network solutions require a new infrastructure to be built. Thus, it is a feature of the present invention to use an existing infrastructure 301, which is both ubiquitous and scalable. That is, the existing infrastructure 301 is architected and built to accommodate every dwelling 304 under extreme loads with low latency.
The master interface device 310 according to the present invention is configured to perform the functions and operations disclosed herein. The master interface device 310 comprises logic, circuits, devices, or microcode (i.e., micro instructions or native instructions), or a combination of logic, circuits, devices, or microcode, or equivalent elements that are employed to perform the functions and operations according to the present invention. The elements employed to store perform these functions and operations within the master interface device 310 may be shared with other circuits, microcode, etc., that are employed to perform other functions and operations within master interface device 310. According to the scope of the present application, microcode is a term employed to refer to one or more micro instructions. A micro instruction (also referred to as a native instruction) is an instruction at the level that a unit executes. For example, micro instructions are directly executed by a reduced instruction set computer (RISC) processor. For a complex instruction set computer (CISC) processor such as an x86-compatible microprocessor, x86 instructions are translated into associated micro instructions, and the associated micro instructions are directly executed by a unit or units within the CISC processor.
Likewise, the slave interface device 311 according to the present invention is configured to perform the functions and operations disclosed herein. The slave interface device 311 comprises logic, circuits, devices, or microcode (i.e., micro instructions or native instructions), or a combination of logic, circuits, devices, or microcode, or equivalent elements that are employed to perform the functions and operations according to the present invention. The elements employed to perform these functions and operations within the slave interface device 311 may be shared with other circuits, microcode, etc., that are employed to perform other functions and operations within slave interface device 311.
Now turning to
In all embodiments, the slave interface device 401 includes an AMR interface 404 that couples the slave interface device 401 to the AMRM 412 via AMR link 414. An optional power monitor 405 within the slave interface device 401 is coupled to the resource itself within the AMRM 412 via optional power bus 425. In addition, a home area network interface 403 within the slave interface device 401 is coupled to the HAN 411 via a HAN wireless link 413.
The slave interface device 401 includes a slave controller 402 that is coupled to the HAN interface 403 via bus 416, the AMR interface 404 via bus 417, and the optional power monitor 405 via bus 418. The slave controller 402 is also coupled to a wired communications link 419 that comprises one leg of a wired variable data rate star network as discussed above with reference to
In operation, the AMR interface 404 receives data from the AMRM 412, and from any other AMRM (not shown) within a area of reception for the slave interface device 401. The AMR interface 404 provides this data to the slave controller 402 on bus 417.
The slave controller 402 is configured to communicate with a corresponding master interface device (not shown) over the wired communications link 419 at a data rate prescribed by the master interface device. Accordingly, AMR data from the AMRM 412 and from other AMRMs within the reception area is provided to the master interface device over the wired communications link 419.
Optionally, commands from the master interface device are provided by the slave controller 402 to the power monitor 405 via bus 418 to monitor and/or control the resource that is measured by the AMRM 412. In one embodiment, the power monitor 405 is employed to cut on and cut off the resource as described above with reference to
HAN-related commands provided by the NOC 303 are transmitted by the master interface device over the wired communication link 419 and are communicated to/from the HAN 411 by the HAN interface 403 over the HAN wireless link 413. These commands are used to control and monitor performance of individual devices and appliances within the facility 410.
Now turning to
In all embodiments, the master interface device 501 includes an AMR interface 504 that couples the master interface device 501 to the AMRM 512 via ARM link 514. An optional power monitor 505 within the master interface device 501 is coupled to the resource itself within the AMRM 512 via optional power bus 525. In addition, a home area network interface 503 within the master interface device 501 is coupled to the HAN 511 via a HAN wireless link 513.
The master interface device 501 includes a master controller 502 that is coupled to the HAN interface 503 via bus 516, the AMR interface 504 via bus 517, and the optional power monitor 505 via bus 518. The master controller 502 is also coupled to a wired communications link 519 that comprises one leg of a wired variable data rate star network as discussed above with reference to
In operation, the AMR interface 504 receives data from the AMRM 512, and from any other AMRM (not shown) within an area of reception for the master interface device 501. The AMR interface 504 provides this data to the master controller 502 on bus 517.
The master controller 502 is configured to communicate with corresponding slave interface devices (not shown) over the wired communications link 519 at a data rate prescribed by the master interface device 501. Accordingly, AMR data from the AMRM 412, from other AMRMs within the reception area, and from the corresponding slave interface devices on the wired communication link 519 is provided to the master interface device 501. The master interface device 501 also provides commands to and receives data from the corresponding slave devices on the wired communication link 512 to perform the functions of power monitoring and control and home area network interface discussed above with reference to
Optionally, commands from the NOC 303 are provided by the master controller 502 to the power monitor 505 via bus 518 to monitor and/or control the resource that is measured by the AMRM 512. In one embodiment, the power monitor 505 is employed to cut on and cut off the resource as described above with reference to
HAN-related commands provided by the NOC 303 are examined by the master controller 502 to determine if they are intended for the master interface device 501 or one of the corresponding slave interface devices. If intended for the master interface device 501, then these commands are provided to the HAN interface 503 via bus 516 and are communicated to the HAN 511 via HAN link 513. If intended for a slave device, then these commands are transmitted by the master interface device 501 over the wired communication link 519 and are communicated to/from a HAN within a designated slave interface device.
Now turning to
In all embodiments, the slave interface device 601 includes slave interface 621 that couples the slave interface device 601 to the AMRM 612 via ARM link 614 and to other wireless slave interface devices and a master interface device within the local grid via wireless link 624. In the embodiment shown, communications provided by the slave interface 621 over wireless link 624 take the place of the wired communication link 419 of the embodiment of
An optional power monitor 605 within the slave interface device 601 is coupled to the resource itself within the AMRM 612 via optional power bus 625. In addition, a home area network interface 603 within the slave interface device 601 is coupled to the HAN 611 via a HAN wireless link 613.
The slave interface device 601 includes a slave controller 602 that is coupled to the HAN interface 603 via bus 616, the slave interface 621 via bus 617, and the optional power monitor 605 via bus 618.
In operation, the slave interface 621 receives data from the AMRM 612, and from any other AMRM (not shown) within an area of reception for the slave interface device 601. The slave interface 621 provides this data to the slave controller 602 on bus 617.
The slave controller 602 is configured to communicate with a corresponding master interface device (not shown) over the wireless communications link 624. Accordingly, AMR data from the AMRM 612 and from other AMRMs within the reception area is provided to the master interface device over the wireless communications link 624 via the slave interface 621.
Optionally, commands from the master interface device received by the slave interface 621, provided to the slave controller 602 via bus 617, and are provided by the slave controller 602 to the power monitor 605 via bus 618 to monitor and/or control the resource that is measured by the AMRM 612. In one embodiment, the power monitor 605 is employed to cut on and cut off the resource as described above with reference to
HAN-related commands provided by the NOC 303 are transmitted by the master interface device over the wireless communication link 624 and are communicated to/from the HAN 611 by the HAN interface 603 over the HAN wireless link 613. These commands are used to control and monitor performance of individual devices and appliances within the facility 610.
Turning now to
In all embodiments, the master interface device 701 includes a master interface 721 that couples the master interface device 701 to the AMRM 712 via ARM link 714 and to other wireless slave devices within the local grid via wireless link 724. Embodiments of the wireless link 724 comport with those described for wireless link 624 discussed above with reference to
An optional power monitor 705 within the master interface device 701 is coupled to the resource itself within the AMRM 712 via optional power bus 725. In addition, a home area network interface 703 within the master interface device 701 is coupled to the HAN 711 via a HAN wireless link 713.
The master interface device 701 includes a master controller 702 that is coupled to the HAN interface 703 via bus 716, the master interface 721 via bus 717, and the optional power monitor 705 via bus 718. The master controller 702 is additionally coupled to a high speed device (HSD) interface 720 that is employed to communicate with the NOC 303 over the existing infrastructure 301 via high speed bus 721.
In operation, the master interface 721 receives data from the AMRM 712, and from any other AMRM (not shown) within an area of reception for the master interface device 501. The master interface 721 provides this data to the master controller 702 on bus 717.
The master controller 702 is configured to also direct the master interface 721 to communicate with corresponding slave interface devices (not shown) over the wireless communications link 724. Accordingly, AMR data from the AMRM 712, from other AMRMs within the reception area, and from the corresponding slave interface devices on the wireless communication link 724 is provided to the master interface device 701. The master interface device 701 also provides commands to and receives data from the corresponding slave devices on the wireless communication link 724 to perform the functions of power monitoring and control and home area network interface discussed above with reference to
Optionally, commands from the NOC 303, received over the high speed bus 721, are provided by the master controller 702 to the power monitor 705 via bus 718 to monitor and/or control the resource that is measured by the AMRM 712. In one embodiment, the power monitor 505 is employed to cut on and cut off the resource as described above with reference to
HAN-related commands provided by the NOC 303 are examined by the master controller 702 to determine if they are intended for the master interface device 701 or one of the corresponding slave interface devices. If intended for the master interface device 701, then these commands are provided to the HAN interface 703 via bus 716 and are communicated to the HAN 711 via HAN link 713. If intended for a slave device, then these commands are transmitted by the master interface device 701 over the wireless communication link 724 and are communicated to/from a HAN within a designated slave interface device.
Referring now to
Accordingly, the master interface device 801 additionally includes a master TX/RX 802 that couples the master interface device 801 to the star network. In one embodiment, the master TX/RX 802 is disposed within the master controller 502. Likewise the slave interface devices 803 includes corresponding slave TX/RX 804 that couple the slave interface devices 803 to their respective legs of the star network.
In operation, the master TX/RX 802 performs communication tests with each of the slave interface devices 803 on the star network to determine an optimum data rate at which to operate. A communications protocol according to the present invention includes the capability for the master device 801 to communicate with the slave devices 803 at a prescribed data rate, thus allowing the rate of data transfer to be increased or decreased in order to provide for reliable transmission and reception of data over the various legs 813-817 of the network. In one embodiment, slave TX/RX 804 within each of the slave devices 803 is configured to adjust their respective data rates responsive to direction from the master device 801.
The present inventors have observed that certain resource providers may not be able to move forward in a retrofit of their existing AMR meters to provide the 2-way communications capabilities and other capabilities noted above, yet they may desire to reduce or eliminate fleet costs associated with gather usage data as is shown in
Referring to
The receivers 903 are coupled to a controller 905 and the controller is coupled to a network operations center (NOC) 907 via an existing infrastructure 906 (e.g., DSL, cable, etc.) as is described above with reference to
In operation, the controller 905 configures each of the receivers 903 such that all of the meters 902 in the geographic area are identified and the frequency hopping sequence for each of the meters is determined. Thereafter, the controller 905 configured to configure each of the receivers 903 in terms of channel assignment such that optimal coverage of the AMR meters 902 is achieved to provide for reception of real time usage data. The controller 905 is also configured to transport this real time usage data over the existing infrastructure to the NOC 907 via known mechanisms.
Advantageously, even though the hop sequence of each AMR meter 902 is not initially known, the low cost receivers 903 according to the present invention are initially programmed by the controller 905 to each receive on a different channel. Over time, the channel of each receiver 903 is rotated, such that the total channels for each geographic region are monitored over a sufficiently long interval until all local transmitters 902 have been identified. In one embodiment, the receivers 903 are networked and communicate a time-stamped value of each AMR packet that they receive to the controller 905. The controller 905 is thus enabled to discover local transmitters 902, signal quality, hop sequence, and probable geographic location of each of the transmitters 902. Once the transmitters 902 are mapped with respect to hop sequence, location, and signal quality, the controller 905 then directs the network of receivers 903 to monitor the most efficacious channels providing optimal coverage in order to improve network reliability. Advantageously, the present invention provides significant improvements over a single, centrally located multiband receiver in terms of reduced cost, increased long term signal quality, increased redundancy, providing the capability to identify probable locations of transmitters 902, and eliminating a requirement for any a-priori knowledge of hop sequence.
Turning to
At block 1004, the controller 905 selects a next frequency channel from a pre-programmed list of channels. Flow then proceeds to block 1006.
At block 1006, the controller 905 directs all of the receivers 903 to change reception frequency to the channel selected at block 1004. Flow then proceeds to block 1008.
At block 1008, the receivers 903 receive any AMR packets that are transmitted by the AMR meters 902 on the selected channel and these packets are forwarded to the controller 905. Flow then proceeds to block 1010.
At block 1010, the controller 905 decodes the packets and extracts the meter ID data that was transmitted. The controller 905 creates/updates a meter ID list for the associated receivers 903 that obtained the packets on the selected channel. Flow the proceeds to decision block 1012.
At decision block 1012, an evaluation is made to determine if there are more channels to scan in the channel list. If not, then flow proceeds to block 1014. If so, then flow proceeds to block 1004.
At block 1014, the method completes.
Now referring to
At block 1104, the controller 905 selects a meter ID from the generated meter ID list. Flow then proceeds to block 1106.
At block 1106, receivers 903 that can receive the selected meter ID are selected. Flow then proceeds to block 1108.
At block 1108, each of the selected receivers 903 are configured by the controller 905 to receive AMR packet broadcasts on different frequency channels. Flow then proceeds to block 1110.
At block 1110, the selected receivers 903 receive the AMR packet broadcasts for the selected meter ID on their respective different frequency channels. Flow then proceeds to block 1112.
At block 1112, the controller 905 records a timestamp for each of the AMR packet broadcasts received at block 1110. Flow then proceeds to decision block 1114.
At decision block 1114, an evaluation is made to determine if there are more channels that remain in the channel list. That is, the evaluation is made in the case where there more channels to monitor than there are deployed receivers 903. If not, then flow proceeds to block 1116. If so then flow proceeds to block 1108.
At block 1116, since all channels have been monitored and received packets time stamped, the controller 905 generates a hop sequence for the meter ID selected at block 1104. Flow then proceeds to decision block 1118.
At decision block 1118, an evaluation is made to determine if there are more meters 902 that remain in the meter ID list which have not been mapped for hop sequence. If so, then flow proceeds to block 1104. If not, then flow proceeds to block 1120.
At block 1120, the method completes.
At block 1204, a next receiver 903 is selected from a list of receivers 903 corresponding to the configuration. The list of receivers 903 includes a priority associated with each meter 902 based upon the number of receivers 903 that can receive AMR packet broadcasts therefrom. Flow then proceeds to block 1206.
At block 1206, the controller 905 determines the number of meters 902 that can be read by the selected receiver 903. Flow then proceeds to block 1208.
At block 1208, the hop sequence for each readable meter 902 is determined based upon the results of the method of
At block 1210, a frequency channel that is used by the hop sequence of the largest number of meters 902 that were determined at block 1206 is selected. Flow then proceeds to block 1212.
At block 1212, the controller 905 directs the selected receiver 903 to begin receiving on the selected channel. Flow then proceeds to decision block 1214.
At decision block 1214, an evaluation is made to determine if all receivers 903 in the configuration have been assigned a frequency channel. If not, then flow proceeds to block 1204. If so, then flow proceeds to decision block 1216.
At decision block 1216, an evaluation is made by the controller 905 to determine if there is sufficient coverage from all receivers 903 to address all of the meters 902 in the configuration. If so, then flow proceeds to block 1220. If not, then flow proceeds to block 1218.
At block 1218, the priority of the insufficiently covered receivers 903 is raised and a meter priority list is updated. Flow then proceeds to block 1204.
At block 1220, the method completes.
In view of potential applications of the present invention as discussed above with reference to
Advantageously, by creating a tiered approach to secure communications between devices based upon proximity metrics and/or location information, communication between these devices can be accomplished in a more natural way, just as a computer in a living room has less security access restrictions to users inside a room than for those outside of the room. Not only is the present invention well suited for networks of devices that are portable and mobile, but it is also applicable to networks of devices that require commissioning and configuration in-situ. One embodiment of the present invention comprehends a system for security in a wireless network, where devices within the network utilize geographic location information to dynamically select an appropriate level of security. In this manner, devices that are known to be in closer proximity are configured with reduced security requirements. As the devices in the network become physically separated, the security requirements are appropriately escalated.
Turning now to
Operationally, the controller 1302 configures devices 1301 in the local zone 1304 to implement security provisions as discussed above that are minimal. The controller 1302 configures devices 1301 in the intermediate zone 1305 to implement increased security provisions. And devices 1301 in the remote security zone 1306 are configured by the controller 1302 to implement more security provisions than those devices 1301 in the intermediate zone.
Because the uninstalled device 1303 falls outside the defined security zones, the controller 1302 precludes it from joining the network.
Although only three security zones 1304-1306 are depicted, the present inventors note that such is shown for clarity sake and there present invention contemplates any number of security zones having successively increased levels of security provisions for devices disposed therein.
Now referring to
At decision block 1404, the controller 1302 monitors for requests by uninstalled devices 1303. If there are none, then flow proceeds to decision block 1404. If so, then flow proceeds to decision block 1406.
At decision block 1406, the controller 1302 determines if the uninstalled device 1302 is capable of providing geographic position data (e.g., GPS data). If so, the flow proceeds to decision block 1410. If not, then flow proceeds to block 1408.
At block 1408, the controller determines the relative location of the uninstalled device 1303 by issuing ping messages and evaluating response latencies associated therewith. For example, if ping responses exhibit latencies commensurate with those devices 1301 in the intermediate security zone 1305, then the uninstalled device 1303 is determined by the controller to be in the intermediate security zone 1305 as well. Flow then proceeds to decision block 1410.
At decision block 1410, the controller 1302 determines if the uninstalled device 1303 meets locality criteria for any of the pre-defined security zones 1304-1306. If so, the flow proceeds to block 1416. If not, then flow proceeds to decision block 1412.
At block 1412, the controller 1302 determines if the uninstalled device 1303 possesses a security key for the zone requested by the device 1303. If not, then flow proceeds to block 1414. If so, then flow proceeds to block 1416.
At block 1414, the device 1303 is precluded from joining the network and flow proceeds to block 1418.
At block 1416, the device 1303 is allowed to join the network and flow proceeds to block 1418.
At block 1418, the method completes.
The present inventors have additionally noted that understanding the topology and communication behavior of a mesh network, such as the network discussed with reference to
Consequently, the present inventors have observed that one of the figures of merit affecting the performance of a mesh network installation is the number of hops from a central point to any endpoint. Accordingly, one aspect of the present invention focuses on how a message propagates between routers in the network before arriving at a destination device. A great cost savings occurs in the installation of networks where it is discovered that there are fewer hops than there are routers because the unnecessary routers can be removed and reused.
In order to determine the topology of a given network, most analysis tools clog the network with link status messages between devices and then backhaul diagnostic traffic packets to a collector that can display this information. But it is noted that such an approach is limiting in that the “analysis” traffic introduces an artificial load and type into the network, while also impeding normal operation.
The present invention removes these complexities in measurement by introducing a selectable store-and-forward delay in the operation of each router in a network of devices. By creating a substantial delay in each routed hop in the network, the hops needed to route a message between source and destination can easily be measured. In one embodiment, the store-and-forward delay is orders of magnitude larger than that normally introduced by message propagation and internal routing software. In one embodiment, the routing delays are programmable and provide for the creation of measurable latency in messages sent between a source device and a destination device. This latency is analyzed in order to ascertain the routers that are participating in the message routing, and to understand the topology of a complex network. Because the routing delays are much greater than normal propagation delays, the network according to the present invention is not affected by the introduction of this additional traffic.
This present invention introduces programmable delays inside a router (i.e., any device that routes messages as part of a multi-hop network) in order to delay forwarded (routed) messages. Accordingly, the response latency between a source device and a destination device can be ascertained because it correlates with the sum of delays programmed into the routers that are participating in the message routing.
Now referring to
In operation, once all of the routers 1501 are programmed with associated routing delays, the originating device 1503 transmits a message MSG to the destination device 1504. The message MSG is interpreted by the routers 1501 in the hop chain—in the diagram shown as ROUTER C 1501 and ROUTER D 1501—which each introduce the delay that is programmed into their respective store-forward controllers 1502, and the message MSG is delivered to the destination device 1504. The destination device responds with a link assessment acknowledge message ACK, which returns through the hop chain to the originating device 1503, where the store-forward controllers 1502 in the routers 1501 in the hop chain introduce the programmed delays into the propagation path of the ACK. In one embodiment, the return hop chain for the ACK may be different than the forward hop chain for the message MSG and the delays provided for by the store-forward controllers 1502 are uniquely selected such that it the propagation path and network topology can be clearly discerned from the cumulative round trip propagation time.
The routers 1501 according to the present invention are configured to perform the operations and functions as is described above. The routers 1501 comprise logic, circuits, devices, or microcode (i.e., micro instructions or native instructions), or a combination of logic, circuits, devices, or microcode, or equivalent elements that are employed to perform the operations and functions described above. The elements employed to perform these operations and functions may be shared with other circuits, microcode, etc., that are employed to perform other functions within the routers 1501.
Turning to
At decision block 1604, the router 1501 monitors for incoming messages. If there are none, then flow proceeds to decision block 1604. If an incoming message is detected, then flow proceeds to decision block 1606.
At decision block 1606, the message is parsed to determine if the message is destined for another device. If so, then flow proceeds to decision block 1610. If not, then flow proceeds to decision block 1608.
At decision block 1610, an evaluation is made to determine if the other device is in the instant router's routing table. If not, then flow proceeds to decision block 1604. If so, then flow proceeds to decision block 1614.
At decision block 1614, the router 1501 determines if a link assessment mode is active. If so, then flow proceeds to block 1618. If not, then flow proceeds to block 1620.
At block 1618, since link assessment is active, the router 1501 delays the message by the programmed delay time, and then forwards the message to the next hop towards the destination device 1504. Flow then proceeds to block 1626.
At block 1620, since link assessment is not active, the router 1501 forwards the message to the next hop towards the destination device 1504. Flow then proceeds to block 1626.
At decision block 1608, it is determined if the destination of the message is the instant router 1501. If not, then flow proceeds to decision block 1604. If so, then flow proceeds to block 1612.
At block 1612, the message is received by the instant router and parsed. Flow then proceeds to decision block 1616.
At decision block 1616, it is determined if the message is a link assessment control message. If not, then flow proceeds to block 1622. If so, then flow proceeds to block 1624.
At block 1622, the message is processed. Flow then proceeds to block 1626.
At block 1624, the link assessment state and corresponding link delay are set in the store-forward controller 1502 as directed by the link assessment control message. Flow then proceeds to block 1626.
At block 1626, the method completes.
As one skilled in the art will appreciate, a present day low power wireless network overcomes the power and range limitations of low power devices by allowing the messages to “hop,” that is to be retransmitted by multiple intermediary devices in order to deliver a message to a distant recipient. And most assessments of transmission quality still utilize a signal strength indication for each individual hop, which does not necessarily correlate to the quality of all hops necessary to transport the messages from source to destination. The present inventors have further observed that it is not only desirable to understand the topology and communication behavior of a mesh network, such a the network discussed with reference to
Turning now to
In operation, the originating device 1703 starts a process of testing the end-to-end link quality of the multi-hop network and by sending messages to the destination device 1704, and the display 1705 is employed to indicate an aggregated end-to-end RSSI value. A plurality of ping messages PING and pong messages PONG are sent through the network in order to determine the end-to-end RSSI value. The originating device 1703 sends a ping message PING, and each intermediary device 1701 in the network receives the message, adds RSSI information to a corresponding field R1-R4 of the message PING, and forwards the message PING to the destination device 1704. The destination device 1704 receives the message PING and returns a pong response message PONG. The response PONG is propagated through the network, where each intermediary device 1701 continues to add RSSI information R5-R8. When the pong message PONG is received by the originating device 1703, the RSSI information R1-R8 is examined, a composite end-to-end RSSI value is generated by the originating device 1703, and this composite value is included in a message DISPDATA to the destination device 1704. The composite RSSI value is transmitted to the display 1705 to facilitate installation of the destination device 1705 in a location with adequate end-to-end signal quality. One embodiment of the present invention contemplates single end-to-end RSSI value to indicate end-to-end link quality. Another embodiments consider use of the same mechanism to represent link quality in a different or more complex way, such as by displaying both the number of hops in a network as well as a forward link (i.e., PING) RSSI end-to-end RSSI value and a reverse link (i.e., PONG) end-to-end RSSI value. In one embodiment, individual hop-to-hop RSSI values R1-R8 are indicated as a range of signal strength from 0-255, and the composite RSSI value generated by the originating device 1703 is the average of the hop-to-hop values. An alternative embodiment contemplates generation of the composite RSSI value as a weighted average of the individual hop values, where the weights for each hop are determined based upon system performance and/or cost criteria.
While the low cost mechanism for receiving and transporting real time energy data described above with reference to
Accordingly, the present invention provides for the determination of the specific frequency hopping sequence for a frequency hopping network or device without prior knowledge of the algorithm and/or sequence. The present invention may be employed as part of a network of devices that receive AMR meter broadcasts and forward the real time meter energy readings to a facility, such as a utility or NOC, thus creating a “smart meter” network from pre-existing AMR meters.
Those skilled in the art will appreciate that a hopping sequence may be determined through the use of costly broadband multi-channel radios, by sequentially scanning a list of frequencies, or by employing other brute-force methods. In contrast, the present invention contemplates determining a hop sequence by progressively selecting channel candidates based on latency of messages observed between channels. For instance, in a network where the hop rate is fixed, it follows then that the latency of messages being transmitted across multiple hops should be at a minimum between two channels adjacent to each other in the hopping sequence. Stated differently, two channels are selected, and the latency of messages occurring between the two channels is measured. If the latency measured is that of the fixed hop rate, then those two channels are considered adjacent, with the later message arriving at the latest channel in the list. By progressively monitoring two channels in a list of channels, a sequence list can be built that describes the hopping sequence of the network.
Referring to
At block 1804, a channel is selected from a channel list and the receiver is tuned to the selected channel. Flow then proceeds to decision block 1808.
At decision block 1808, the receiver determines if a message on the selected channel has been received before a timeout corresponding to a predicted hop interval. If so then flow proceeds to block 1812. If not then flow proceeds to block 1810.
At block 1810, the selected channel is marked as an unknown channel and flow proceeds to decision block 1814.
At block 1812, the selected channel is recorded as a used channel and the time of reception of determined in decision block 1808 is recorded. Flow then proceeds to decision block 1814.
At decision block 1814, the receiver performs an evaluation to determine if there are any channels remaining in the channel list that have unknown adjacent channels. If not, then flow proceeds to block 1826. If so, then flow proceeds to block 1816.
At block 1816, the receiver selects another channel from the channel list. Flow then proceeds to block 1820.
At block 1820, the receiver determines if a message on the selected other channel has been received before a timeout corresponding to a predicted hop interval. If so then flow proceeds to decision block 1822. If not then flow proceeds to block 1816.
At decision block 1822, the receiver determines if the latency between the previous two channel transmissions is equal to the expected hop interval. If not then flow proceeds to block 1816. If so, then flow proceeds to block 1824.
At block 1824, the two previous channels are added to a hop list and flow proceeds to block 1806.
At block 1806, a channel with unknown adjacent channels in the hop list is selected and flow proceeds to decision block 1808.
At block 1826, the method completes.
The present inventors have further observed that in many wireless networks it may be necessary to transmit very large payloads to devices within the network, thus resulting in burdensome traffic. Consider one example of a large payload, in the case where, say, a software update must be sent to all of the devices within the network. As one skilled in the art will appreciate, virtually all present day wireless protocols today require fragmentation of a large payload into a series of smaller payloads that can each be transmitted in a single packet. The present inventors have noted, though, for devices that are able to utilize multiple simultaneous bands or channels to receive messages, such as the devices discussed above with reference to
In operation, for transmission, fragmentation logic 1904 in the transmitting device 1901 provides the large payload 1905 to the first transceiver 1902 such that the first transceiver 1902 transmits the fragments 1905.A-1905.B of the payload sequentially starting from a first fragment 1905.A and ending at a last fragment 1905.B. Simultaneously, fragmentation logic 1904 in the transmitting device 1901 provides the large payload 1905 to the second transceiver 1903 such that the second transceiver 1903 transmits the fragments 1905.A-1905.B of the payload sequentially starting from the last fragment 1905.6 and ending at the first fragment 1905.A.
Transmissions are received by the first and second transceivers 1912, 1913 in the receiving device 1911 and the fragmentation logic 1914 in the receiving device 1911 reassembles the large payload 1915 as sequentially increasing segments are received by the first transceiver 1912 and as sequentially decreasing segments are received by the second transceiver 1913. When received segments overlap, the fragmentation logic 1914 considers the large payload 1915 as having been received and may direct the receiving device 1911 to take other actions (such as sending a large payload early termination acknowledgement message) as the host protocol allows.
It is noted that the grid management system described above with reference to
Referring to
Now turning to
At block 2104, the first device access descriptor stores therein to obtain descriptors for the message. Flow then proceeds to block 2106.
At block 2106, the one device accesses the descriptor stores to obtain descriptors at the transceiver and device level. Flow then proceeds to block 2108.
At block 2108, the one device selects a transceiver to send the message to the other device based upon data obtained from the descriptor stores accessed at blocks 2104 and 2106. Flow then proceeds to block 2110.
At block 2110, the one device transmits the message over the selected transceiver. Flow then proceeds to decision block 2112.
At decision block 2112, the one device determines if an acknowledge ACK is received before a timeout for retransmission has expired. If so, then flow proceeds to block 2116. If not, then flow proceeds to decision block 2114.
At decision block 2114, the one device determines if a maximum number of retries has occurred. If so, then flow proceeds to block 2118. If not, the flow proceeds to block 2110.
At block 2118, a next best transceiver is selected for transmission of the message, and flow proceeds to block 2110.
At block 2116, device and transceiver descriptors are updated in the descriptor store within the one device based upon the ACK response. Flow then proceeds to block 2120.
At block 2120, the method completes.
The message descriptors 2201 include a latency requirement field 2202, a message size field 2203, a transceiver energy available field 2204, and an other requirement field.
The transceiver descriptors 2211 include a packet delivery latency field 2212, a payload size field 2213, an energy required per packet field 2214, and an other attribute field 2215.
The device descriptors 2211 each have one or more transceiver attribute descriptors corresponding to a destination device DEVICE 1-DEVICE N. Each of the transceiver attribute descriptors include a transceiver ID field 2222, a delivery reliability field 2223, an energy required per packet field 2224, and an other attribute field 2225.
In operation, by utilizing knowledge about the capabilities and operating characteristics of each medium, stored as a set of descriptors 2201, 2211, 2221, a device according to the present invention may select a transceiver (i.e., frequency band) that provides for optimal interoperation with respect to energy consumption, throughput, and reliability, thus eliminating the problems inherent in single-band networks, where interference from other devices and multipath interference (over a narrow range of frequencies in a band) reduce the reliability of the network.
Portions of the present invention and corresponding detailed description are presented in terms of software, or algorithms and symbolic representations of operations on data bits within a computer memory. These descriptions and representations are the ones by which those of ordinary skill in the art effectively convey the substance of their work to others of ordinary skill in the art. An algorithm, as the term is used here, and as it is used generally, is conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of optical, electrical, or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, or as is apparent from the discussion, terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, a microprocessor, a central processing unit, or similar electronic computing device, that manipulates and transforms data represented as physical, electronic quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Note also that the software implemented aspects of the invention are typically encoded on some form of program storage medium or implemented over some type of transmission medium. The program storage medium may be electronic (e.g., read only memory, flash read only memory, electrically programmable read only memory), random access memory magnetic (e.g., a floppy disk or a hard drive) or optical (e.g., a compact disk read only memory, or “CD ROM”), and may be read only or random access. Similarly, the transmission medium may be metal traces, twisted wire pairs, coaxial cable, optical fiber, or some other suitable transmission medium known to the art. The invention is not limited by these aspects of any given implementation.
The particular embodiments disclosed above are illustrative only, and those skilled in the art will appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention, and that various changes, substitutions and alterations can be made herein without departing from the scope of the invention as set forth by the appended claims.
Claims
1. An apparatus for determining a frequency hopping sequence, the apparatus comprising:
- a plurality of narrowband receivers, deployed geographically within a grid, wherein each of said plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and wherein each of said plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to the frequency hopping sequence, and wherein said frequency hopping sequence is initially unknown to said plurality of narrowband receivers, but a hop rate is known; and
- a controller, coupled to said plurality of narrowband receivers, configured to control said plurality of narrowband receivers such that said each of said plurality of AMR meters is identified, and configured to control said plurality of narrowband receivers such that corresponding data from said each of said AMR meters is received on at least one of said plurality of frequency bands, wherein said controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in said list of channels based upon latency of messages having said identical data observed between said channel candidate pairs according to said hop rate.
2. The apparatus as recited in claim 1, wherein said controller steps said all of said plurality of receivers through all of said plurality of frequency bands to receive identification data from said those of said plurality of AMR meters that that transmit on said all of said plurality of frequency bands.
3. The apparatus as recited in claim 2, wherein, for one of said plurality of AMR meters, said controller directs a set of said plurality of receivers that can receive data from said one of said plurality of AMR meters to receive on different ones of said plurality of frequency bands, and wherein transmissions from said one of said plurality of transmitters are time stamped to generate the frequency hopping sequence.
4. The apparatus as recited in claim 3, wherein said controller determines a corresponding signal quality for each of said all of said plurality of receivers.
5. The apparatus as recited in claim 4 wherein said controller determines a corresponding probable location for said each of said all of said plurality of receivers.
6. The apparatus as recited in claim 5, wherein, for said each of said plurality of receivers, said controller selects the frequency hopping sequence for each of said those of said plurality of AMR meters, and wherein said controller selects channels for said each of said plurality of receivers that are employed by a largest number of said those of said AMR meters to provide optimal coverage.
7. The apparatus as recited in claim 1, further comprising:
- a network operations center (NOC), operatively coupled to said controller via an existing infrastructure, configured to receive the real time resource usage data from said controller.
8. An apparatus for determining a frequency hopping sequence, the apparatus comprising:
- a plurality of narrowband receivers, deployed geographically within a grid, wherein each of said plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and wherein each of said plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to a hopping sequence, and wherein said hopping sequence is initially unknown to said plurality of narrowband receivers, but a hop rate is known;
- a controller, coupled to said plurality of narrowband receivers, configured to control said plurality of narrowband receivers such that said each of said plurality of AMR meters is identified, and configured to control said plurality of narrowband receivers such that corresponding data from said each of said AMR meters is received on at least one of said plurality of frequency bands, wherein said controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in said list of channels based upon latency of messages having said identical data observed between said channel candidate pairs according to said hop rate; and
- a network operations center (NOC), operatively coupled to said controller via an existing infrastructure, configured to receive the real time resource usage data from said controller.
9. The apparatus as recited in claim 8, wherein said controller steps said all of said plurality of receivers through all of said plurality of frequency bands to receive identification data from said those of said plurality of AMR meters that that transmit on said all of said plurality of frequency bands.
10. The apparatus as recited in claim 9, wherein, for one of said plurality of AMR meters, said controller directs a set of said plurality of receivers that can receive data from said one of said plurality of AMR meters to receive on different ones of said plurality of frequency bands, and wherein transmissions from said one of said plurality of transmitters are time stamped to generate the frequency hopping sequence.
11. The apparatus as recited in claim 10, wherein said controller determines a corresponding signal quality for each of said all of said plurality of receivers.
12. The apparatus as recited in claim 11 wherein said controller determines a corresponding probable location for said each of said all of said plurality of receivers.
13. The apparatus as recited in claim 12, wherein, for said each of said plurality of receivers, said controller selects the frequency hopping sequence for each of said those of said plurality of AMR meters, and wherein said controller selects channels for said each of said plurality of receivers that are employed by a largest number of said those of said AMR meters to provide optimal coverage.
14. The apparatus as recited in claim 8, wherein said plurality of frequency bands and said hopping sequence are in accordance with the Encoded Receiver Transmitter (ERT) protocol.
15. A method for determining a frequency hopping sequence, the method comprising:
- deploying a plurality narrowband receivers within a grid, wherein each of the plurality of narrowband receivers is configured to receive transmissions from a least one of a plurality of automated meter reading (AMR) meters, and wherein each of the plurality of AMR meters transmits identical data on each of a plurality of frequency bands that are hopped according to a hopping sequence, and wherein the frequency hopping sequence is initially unknown to said plurality of narrowband receivers, but a hop rate is known; and
- controlling the plurality of narrowband receivers such that the each of the plurality of AMR meters is identified, and that corresponding data from the each of the AMR meters is received on at least one of the plurality of frequency bands, wherein the controller determines the frequency hopping sequence by progressively selecting channel candidate pairs from a list of channels for the frequency hopping sequence, and determines adjacent channel pairs in the list of channels based upon latency of messages having the identical data observed between said channel candidate pairs according to the hop rate.
16. The method as recited in claim 15, wherein the controller steps the all of the plurality of receivers through all of the plurality of frequency bands to receive identification data from the those of the plurality of AMR meters that that transmit on the all of the plurality of frequency bands.
17. The method as recited in claim 16, wherein said controlling further comprises:
- for one of the plurality of AMR meters, directing a set of the plurality of receivers that can receive data from the one of the plurality of AMR meters to receive on different ones of the plurality of frequency bands, and wherein transmissions from the one of the plurality of transmitters are time stamped to generate the frequency hopping sequence.
18. The method as recited in claim 17, wherein said controller determines a corresponding signal quality for each of the all of the plurality of receivers.
19. The method as recited in claim 18, wherein said controller determines a corresponding probable location for the each of the all of the plurality of receivers.
20. The method as recited in claim 19, wherein said controlling further comprises:
- for the each of the plurality of receivers, first selecting the frequency hopping sequence for each of the those of the plurality of AMR meters, and second selecting channels for the each of the plurality of receivers that are employed by a largest number of the those of the AMR meters to provide optimal coverage.
21. The method as recited in claim 15, further comprising:
- transmitting the real time resource usage data to a network operations center (NOC) over an existing infrastructure.
Type: Application
Filed: Jul 2, 2015
Publication Date: Nov 12, 2015
Inventor: RANDY C. WILLIG (Fort Collins, CO)
Application Number: 14/791,149
