Patent Publication Number: US-9846443-B2

Title: Methods and systems for data interchange between a network-connected thermostat and cloud-based management server

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. application Ser. No. 13/275,307, filed Oct. 17, 2011, and entitled “METHODS AND SYSTEMS FOR DATA INTERCHANGE BETWEEN A NETWORK-CONNECTED THERMOSTAT AND CLOUD-BASED MANAGEMENT SERVER,” which is incorporated by reference herein. 
     The subject matter of this patent specification relates to the subject matter of the following commonly assigned applications: U.S. Ser. No. 12/881,430 filed Sep. 14, 2010; U.S. Ser. No. 12/881,463 filed Sep. 14, 2010; U.S. Ser. No. 61/415,771 filed Nov. 19, 2010; U.S. Ser. No. 61/429,093 filed Dec. 31, 2010; U.S. Ser. No. 12/984,602 filed Jan. 4, 2011; U.S. Ser. No. 12/987,257 filed Jan. 10, 2011; U.S. Ser. No. 13/033,573 filed Feb. 23, 2011; U.S. Ser. No. 29/386,021, filed Feb. 23, 2011; U.S. Ser. No. 13/034,666, U.S. Ser. No. 13/034,674 and U.S. Ser. No. 13/034,678 filed Feb. 24, 2011; U.S. Ser. No. 13/038,191 filed Mar. 1, 2011; U.S. Ser. No. 13/038,206 filed Mar. 1, 2011; U.S. Ser. No. 29/399,609 filed Aug. 16, 2011; U.S. Ser. No. 29/399,614 filed Aug. 16, 2011; U.S. Ser. No. 29/399,617 filed Aug. 16, 2011; U.S. Ser. No. 29/399,618 filed Aug. 16, 2011; U.S. Ser. No. 29/399,621 filed Aug. 16, 2011; U.S. Ser. No. 29/399,623 filed Aug. 16, 2011; U.S. Ser. No. 29/399,625 filed Aug. 16, 2011; U.S. Ser. No. 29/399,627 filed Aug. 16, 2011; U.S. Ser. No. 29/399,630 filed Aug. 16, 2011; U.S. Ser. No. 29/399,632 filed Aug. 16, 2011; U.S. Ser. No. 29/399,633 filed Aug. 16, 2011; U.S. Ser. No. 29/399,636 filed Aug. 16, 2011; U.S. Ser. No. 29/399,637 filed Aug. 16, 2011; U.S. Ser. No. 13/199,108, filed Aug. 17, 2011; U.S. Ser. No. 13/267,871 filed Oct. 6, 2011; U.S. Ser. No. 13/267,877 filed Oct. 6, 2011; U.S. Ser. No. 13/269,501 filed Oct. 7, 2011; U.S. Ser. No. 29/404,096 filed Oct. 14, 2011; U.S. Ser. No. 29/404,097 filed Oct. 14, 2011; U.S. Ser. No. 29/404,098 filed Oct. 14, 2011; U.S. Ser. No. 29/404,099 filed Oct. 14, 2011; U.S. Ser. No. 29/404,101 filed Oct. 14, 2011; U.S. Ser. No. 29/404,103 filed Oct. 14, 2011; U.S. Ser. No. 29/404,104 filed Oct. 14, 2011; and U.S. Ser. No. 29/404,105 filed Oct. 14, 2011. The subject matter of this patent specification further relates to the subject matter of the following commonly assigned applications being filed on the same day as the present U.S. application Ser. No. 13/275,311, entitled, “Methods, Systems, And Related Architectures For Managing Network Connected Thermostats”; U.S. Ser. No. 13/275,307, entitled, “Methods And Systems For Data Interchange Between A Network-Connected Thermostat And A Cloud-Based Management Server”. Each of the above-referenced patent applications is incorporated by reference herein. The above-referenced patent applications are collectively referenced hereinbelow as “the commonly assigned incorporated applications.” 
    
    
     TECHNICAL FIELD 
     This patent specification relates to system monitoring and control, such as the monitoring and control of heating, ventilation, and air conditioning (HVAC) systems. More particularly, this patent specification relates to systems and methods for using a network enabled battery powered thermostat to monitor and control an HVAC system while conserving the use of energy from the battery. 
     BACKGROUND OF THE INVENTION 
     Substantial effort and attention continue toward the development of newer and more sustainable energy supplies. The conservation of energy by increased energy efficiency remains crucial to the world&#39;s energy future. According to an October 2010 report from the U.S. Department of Energy, heating and cooling account for 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Along with improvements in the physical plant associated with home heating and cooling (e.g., improved insulation, higher efficiency furnaces), substantial increases in energy efficiency can be achieved by better control and regulation of home heating and cooling equipment. By activating heating, ventilation, and air conditioning (HVAC) equipment for judiciously selected time intervals and carefully chosen operating levels, substantial energy can be saved while at the same time keeping the living space suitably comfortable for its occupants. 
     It would be beneficial, at both a societal level and on a per-home basis, for a large number of homes to have their existing older thermostats replaced by newer, microprocessor controlled “intelligent” thermostats having more advanced HVAC control capabilities that can save energy while also keeping the occupants comfortable. To do this, these thermostats will need more information from the occupants as well as the environments where the thermostats are located. Preferably, these thermostats will also be capable of connection to computer networks, including both local area networks (or other “private” networks) and wide area networks such as the Internet (or other “public” networks), in order to obtain current and forecasted outside weather data, cooperate in so-called demand-response programs (e.g., automatic conformance with power alerts that may be issued by utility companies during periods of extreme weather), enable users to have remote access and/or control thereof through their network-connected device (e.g., smartphone, tablet computer, PC-based web browser), and other advanced functionalities that may require network connectivity. 
     Among other requirements, the successful implementation of intelligent network-connected thermostats into widespread, practical everyday use in a large number of homes and business requires the deployment of computers, networks, software systems and other network infrastructure capable of providing the necessary provisioning, data management, and support. Data communications methods between the intelligent thermostats and centrally provided management servers (which can also be termed “cloud-based” management servers), needs to be responsive, robust, and scalable. At the same time, however, the hardware and methodologies employed need to be compatible with, and workable in view of, a large installed base of conventional routers and network services that are already in homes and business, such that widespread adoption of the network-connected intelligent thermostats be commercially feasible. 
     One further issue that arises with thermostats relates to the limited external electrical power that is made available to the thermostat in many homes and businesses. As known in the art, for some installations, electronic thermostats can be powered directly from an HVAC system transformer by virtue of a 24 VAC “common” wire (“C-wire”) that runs from the HVAC transformer to the thermostat. When provided, the C-wire has the particular purpose of supplying power for an electronic thermostat. However, many HVAC installations do not have a C-wire provided to the thermostat. For such cases, many electronic thermostats have been designed to extract electrical power by a scheme called “power stealing,” “power sharing” or “power harvesting,” in which power is tapped from the HVAC control wires that lead to the HVAC call relay coils. Such thermostats “steal,” “share” or “harvest” their power during the “OFF” or “inactive” periods of the heating or cooling system by allowing a small amount of current to flow through it into the call relay coil below its response threshold. During the “ON” or “active” periods of the heating or cooling system the thermostat can be designed to draw power by allowing a small voltage drop across itself. The amount of instantaneous electrical power that can safely be supplied by power stealing methods without falsely tripping or un-tripping the HVAC call relays is generally quite limited. These limitations can, in turn, can severely restrict the processing and network communications capabilities that can be provided on a power-stealing thermostat. 
     It would be desirable to provide a microprocessor controlled intelligent thermostat having advanced HVAC control capabilities that can save energy while also keeping the occupants comfortable. It would be further desirable to provide a such a thermostat that is network-capable. It would be even further desirable to provide a cloud-based thermostat management infrastructure to facilitate the provisioning, data management, and support of a large number of such network-connected intelligent thermostats. It would be still further desirable for such intelligent thermostats to be capable of such advanced processing, HVAC control, and networking functionalities while at the same time being capable of being powered by power-stealing, whereby a C-wire or household wall outlet power is not required, so that the thermostat is compatible with a broad array of practical HVAC installations in homes and businesses. It would be even further desirable to provide a network communications architecture, methodology, and protocol for facilitating data communications between the cloud-based management server and such intelligent network-connected thermostat. It would be still further desirable to provide such a thermostat and cloud-based management server in a way that is compatible with a large installed base of conventional routers and network services. Other issues arise as would be apparent to a person skilled in the art in view of the present disclosure. 
     BRIEF SUMMARY OF THE INVENTION 
     The commonly assigned U.S. Ser. No. 13/269,501 and others of the commonly assigned incorporated applications, supra, describe one or more advanced, multi-sensing, microprocessor-controlled intelligent or “learning” thermostats for which one or more of the preferred embodiments is particularly suitable, the thermostat providing a rich combination of processing capabilities, intuitive and visually pleasing user interfaces, and network connectivity, while at the same time not requiring a C-wire (or line power from a household 110V source such as a wall plug) even though the requisite underlying thermostat hardware can require greater instantaneous power than power-stealing can safely provide. The described thermostat achieves these goals at least by virtue of the use of a rechargeable battery (or equivalently capable onboard power storage medium) that will recharge during time intervals in which the hardware power usage is less than what power stealing can safely provide, and that will discharge to provide the needed extra electrical power during time intervals in which the hardware power usage is greater than what power stealing can safely provide. Provided according to one or more embodiments herein are methods, systems and related architectures for facilitating network communications between the thermostat and a cloud-based management server in a manner that promotes reduced power usage and extended service life of the rechargeable battery, while at the same time accomplishing timely data transfer between the thermostat and the cloud-based management for suitable and time-appropriate control of the HVAC system. 
     According to one preferred embodiment, the thermostat includes circuitry for detecting a charge level of the rechargeable battery thereof (“battery level”), a microprocessor having a plurality of different power consumption modes including at least one “sleep” mode (lower-power) and at least one “wake” mode (higher-power), and a wireless communications module such as a Wi-Fi chip. The wireless communications module communicates with an integrated router associated with a local area network (“private network”) that serves the home, business, or other structure (“enclosure”) in which the thermostat is installed. The integrated router includes a network address translation (NAT) functionality and facilitates data connections between devices on the enclosure&#39;s private network and external devices on an outside public network such as the Internet. A cloud-based management server (“cloud server”) having a public address on the Internet is configured and programmed to send data packets to, and receive data packets originating from, the wireless communications module of the thermostat. The wireless communications module is programmed and configured to forward data packets received from the thermostat microprocessor to the integrated router for delivery to the cloud server. The wireless communications module is further programmed and configured to receive data packets from the integrated router that originated at the cloud server, and to selectively forward the received data packets to the microprocessor based on a priority level that has been assigned thereto by the cloud server. For one embodiment, the received data packets have been assigned one of two priority levels, including a standard priority level and a keep-alive priority level. Standard priority packets are forwarded to the microprocessor. Keep-alive priority packets are discarded. If the microprocessor is in a sleep mode, the forwarding of a standard priority packet from the wireless communications chip to the microprocessor causes the microprocessor to enter into a wake mode. During a wake mode, the microprocessor may communicate with the cloud server through the wireless communications module as necessary, opening and closing connections as necessary, with associated packets from the cloud server having standard priority. Included in these communications are ongoing notifications from the thermostat to the cloud server of the current battery level of the thermostat. The cloud server keeps track of the latest battery level received from the thermostat. In the absence of an open connection established for other communications purposes, the microprocessor causes the wireless communication module to send a connection-opening long-polling packet to the cloud server, and keeps the connection open for a long-polling interval that is relatively long, such as 30-60 minutes. In the absence of any required activity, the thermostat microprocessor may subsequently enter a sleep mode during the long-polling interval. During periods of silence from the thermostat, which may correspond to periods of microprocessor sleep, the cloud server may process one or more events that potentially call for a communication to be made to the thermostat (hereinafter “potential communication-triggering events”), for example, remote user commands from a browser or smartphone user interface, external notifications or demand-response requests from utility companies, scheduled programming updates, and so forth. According to a preferred embodiment, the cloud server is configured and programmed to classify each potential communication-triggering event into one of a plurality of thermostatic importance classes, and then to determine whether to instantiate, or not to instantiate, a corresponding standard priority (and therefore microprocessor-waking) communication with the thermostat, wherein this determination is based on (i) the most recent battery level of the thermostat, and (ii) the thermostatic importance class. If the most recent battery level is at high or otherwise non-problematic levels, then standard priority communications are instantiated for all events, whereas if the most recent battery level is at lower or otherwise problematic levels, then standard priority communications are instantiated only for events in high thermostatic importance classes. Finally, the cloud server is configured and programmed to send keep-alive packets to the wireless communications module at predetermined keep-alive intervals, such as every one to five minutes, if there are no standard priority packets to be sent. In one simple example, simple “ACK” packets are sent by the cloud server as keep-alive priority packets, which the wireless communications module is programmed to discard, while all other packets from the cloud server are considered as standard priority packets and forwarded from the wireless communications module to the thermostat microprocessor. It is to be appreciated, however, that “keep-alive priority packet” is not to be construed as limited to TCP “ACK” packets, but rather can refer to any type of message that will pass through the router, get received by the Wi-Fi chip, and be interpreted by the Wi-Fi chip as a message that is not to invoke waking up the microprocessor. In one simple example, an event in which a setpoint temperature change command is received from a user through their smartphone remote control is classified by the cloud server as having a “high” thermostatic importance, and therefore it would trigger a microprocessor-waking standard-priority message to be sent during a long-polling interval, regardless of the battery level, which would wake up the microprocessor and command it to change the setpoint temperature. In contrast, a scheduled periodic software update event would be classified as “low” thermostatic importance by the cloud server, and therefore, if the latest battery level were low or otherwise problematic, the cloud server would not send a corresponding standard priority data communication to the thermostat, thereby allowing a sleeping microprocessor to remain asleep so that the battery would have a better chance of recharging to an acceptable level. Advantageously, at least by virtue of the above described long-polling aspects, the above described battery-conscious power-preserving scheme is compatible with the security firewall functionality built into the integrated router of the private network, since all connections are instantiated from within the private network by virtue of the long-polling functions described above. Advantageously, at the same time, at least by virtue of the above described keep-alive packets, the above described battery-conscious power-preserving scheme is compatible with the network address translation (NAT) table sensitivities of many common routers, which will often shut down NAT table entries in the absence of related traffic before the long polling interval has expired. Advantageously, at the same time, the described scheme is battery-conscious and battery-preserving in that, if the battery is low, a sleeping thermostat microprocessor would not be woken by the cloud server unless there is a thermostatically important event that needs to be taken care of According to other preferred embodiments as described further herein, there may be more than two thermostatic importance classes assigned by the cloud server, more than two different battery levels considered in the cloud server&#39;s decision to send a communications packet, and more than two packet priority levels assigned by the cloud server. According to further preferred embodiments, there can furthermore be different levels of event or packet importance communicated from the wireless communication module to the microprocessor, such as by using different port numbers on transferred packets to represent different levels of importance. 
     Aspects of the present invention provide methods, systems and related architectures for communicating with a network of thermostats powered, in part, by batteries, such as rechargeable batteries. In one aspect of the present invention, a thermostat communication server communicates with a thermostat powered by a battery over a network. Using a public network, such as the Internet, the thermostat provides a battery-level over a communication channel established with the thermostat communication server. The thermostat communication server stores the battery-level in a storage area of the server to determine what data should be sent to the thermostat. Further, the thermostat communication server classifies one or more types of data to be transmitted to the thermostat over the communication channel according to a data priority ranging from a low-priority data type to a high-priority data type. The low-priority data type includes data of lesser importance to the operation of the thermostat communication server and thermostat while the high-priority data type includes data of much higher importance. If the battery-level associated with the battery used by the thermostat is at a low battery-level, the thermostat communication server may only transmit data classified under a high-priority data type over the communication channel to the thermostat. This conserves the power used by the thermostat, allows the battery on the thermostat time to recharge and perform other functions. However, if the battery-level of the thermostat is determined to be at a high-level, the thermostat communication server may transmit a range of data classified from a low-priority type to a high-priority data type over the communication channel to the thermostat. 
     In another aspects of the present invention, the communication channel is established using a public network address registered on the Internet for the thermostat communication server and a public network address provided through a router&#39;s network address translation (NAT) table for the thermostat on a private network. To keep the communication channel available, the thermostat communication server configures a long-poll interval using a network communication protocol, such as TCP over IP, that transmits a keep-alive packet from the thermostat communication server to the thermostat over the communication channel at a maximum time interval not to exceed a NAT time-out period of the router. 
     In yet another aspect of the present invention, the thermostat communication server uses a plurality of communication channels to transmit different data priority types to the thermostat. In one embodiment, the thermostat communication server receives a request from a thermostat to establish the plurality of communication channels between the thermostat communication server and the thermostat. Further, the thermostat communication server classifies one or more types of data to be transmitted to the thermostat according to a data priority ranging from a low-priority data type to a high-priority data type. The thermostat communication server transmits data classified in the low-priority data type to the thermostat over a first network communication channel associated with low-priority data type and transmits data classified in the high-priority data type to the thermostat over a second network communication channel associated with high-priority data type. 
     In another aspect of the invention, the thermostat reserves a first communication channel on the thermostat for receiving data classified as a low-priority data type and reserves a second communication channel on the thermostat for receiving data classified as a high-priority data type. The thermostat processes data received from the thermostat communication server over the first communication channel and the second communication channel and determines whether a battery-level of the battery associated with the thermostat is at or below a low battery-level. When the battery-level is at or below the low battery-level, the thermostat configures itself to discard subsequently received data over the first communication channel classified as a low-priority data type while enabling a processing of subsequently received data over the second communication channel classified as a high-priority data type. If the thermostat determines the battery-level above the low battery-level, the thermostat configures itself to enable a processing of subsequently received data over the first communication channel classified as a low-priority data type and also enable a processing of subsequently received data over the second communication channel classified as a high-priority data type. 
     Another aspect of the invention includes using a proxy reporting thermostat to collect thermostat events from a plurality of thermostats on a network and then store on a central server. The proxy reporting thermostat is part of a thermostat reporting group made up of a plurality of thermostats powered by batteries. In some embodiments, the proxy reporting thermostat is selected from the thermostat reporting group because it has the highest battery-level charge. Each thermostat in the group records its events in a log corresponding to the operation and events occurring on each thermostat. These events recorded by each thermostat are transmitted over a network, gathered together, and stored in a storage area associated with the proxy reporting thermostat. A thermostat identifier included with each event indicates on which thermostat each event occurred. After a period of time or when the storage area becomes full, the proxy reporting thermostat uploads events from the thermostat reporting group to a central server. If a connection is not already established, the proxy reporting thermostat establishes a communication channel with the central server, which is typically on the Internet. Once the events gathered on the storage area associated with the proxy reporting thermostat have been uploaded, the storage area on the proxy reporting thermostat may be cleared to allow for the storage of new events from the group. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an exemplary enclosure using a thermostat implemented in accordance with embodiments of the present invention for controlling one or more environmental conditions; 
         FIG. 2  is a schematic diagram of an HVAC system controlled using a thermostat designed in accordance with embodiments of the present invention; 
         FIGS. 3A-3B  illustrate a forward-facing surface and display of a thermostat designed in accordance with embodiments of the present invention; 
         FIGS. 4A-B  illustrate a user&#39;s hand controlling a thermostat designed in accordance with embodiments of the present invention; 
         FIG. 5  illustrates thermostats and computers on a private network connected to a thermostat management system designed in accordance with embodiments of the present invention; 
         FIGS. 6A-6B  illustrate a thermostat communication server that controls communications using a data priority assigned to the data and a battery-level on a thermostat in accordance with embodiments of the present invention; 
         FIG. 7  illustrates a thermostat communication server portion of the thermostat management system that both conserves energy and promotes high-performance operation of a thermostat in accordance with embodiments of the present invention; 
         FIG. 8A  illustrates a flowchart diagram of the operations that a thermostat communication server uses to communicate with a battery powered thermostat while conserving battery energy and promoting thermostat performance in accordance with embodiments of the present invention; 
         FIG. 8B  is a data flow chart that illustrates the flow of data and events when thermostat communication server transmits data based on a battery-level of a thermostat and data priority type associated with the data in accordance with embodiments of the present invention; 
         FIGS. 9A-9B  illustrates a communication system and schematic of a battery powered thermostat using a plurality of communication channels to receive data classified under different data priority types in accordance with embodiments of the present invention; 
         FIGS. 9C-9D  illustrate flowchart diagrams of operations a thermostat communication server and thermostat use to communicate over a plurality of communication channels accordance with embodiments of the present invention; 
         FIG. 9E  provides an example data flow chart illustrating the flow of data and events using a plurality of communication channels transmitting different data priority types in accordance with embodiments of the present invention; and 
         FIGS. 10A-10B  provide a schematic block diagram and flowchart for a thermostat reporting group with multiple thermostats that gathers events in a common event log in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the various embodiments of the present invention. Those of ordinary skill in the art will realize that these various embodiments of the present invention are illustrative only and are not intended to be limiting in any way. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. 
     In addition, for clarity purposes, not all of the routine features of the embodiments described herein are shown or described. One of ordinary skill in the art would readily appreciate that in the development of any such actual embodiment, numerous embodiment-specific decisions may be required to achieve specific design objectives. These design objectives will vary from one embodiment to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine engineering undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     It is to be appreciated that while one or more embodiments are described further herein in the context of typical HVAC system used in a residential home, such as single-family residential home, the scope of the present teachings is not so limited. More generally, thermostats according to one or more of the preferred embodiments are applicable for a wide variety of enclosures having one or more HVAC systems including, without limitation, duplexes, townhomes, multi-unit apartment buildings, hotels, retail stores, office buildings and industrial buildings. Further, it is to be appreciated that while the terms user, customer, installer, homeowner, occupant, guest, tenant, landlord, repair person, and the like may be used to refer to the person or persons who are interacting with the thermostat or other device or user interface in the context of one or more scenarios described herein, these references are by no means to be considered as limiting the scope of the present teachings with respect to the person or persons who are performing such actions. 
       FIG. 1  is a diagram illustrating an exemplary enclosure using a thermostat  110  implemented in accordance with the present invention for controlling one or more environmental conditions. For example, enclosure  100  illustrates a single-family dwelling type of enclosure using a learning thermostat  110  (also referred to for convenience as “thermostat  110 ”) for the control of heating and cooling provided by an HVAC system  120 . Alternate embodiments of the present invention may be used with other types of enclosures including a duplex, an apartment within an apartment building, a light commercial structure such as an office or retail store, or a structure or enclosure that is a combination of these and other types of enclosures. 
     Some embodiments of thermostat  110  in  FIG. 1  incorporate one or more sensors to gather data from the environment associated with enclosure  100 . Sensors incorporated in thermostat  110  may detect occupancy, temperature, light and other environmental conditions and influence the control and operation of HVAC system  120 . Sensors incorporated within thermostat  110  do not protrude from the surface of the thermostat  110  thereby providing a sleek and elegant design that does not draw attention from the occupants in a house or other enclosure. As a result, thermostat  110  and readily fits with almost any decor while adding to the overall appeal of the interior design. 
     As used herein, a “learning” thermostat refers to a thermostat, or one of plural communicating thermostats in a multi-thermostat network, having an ability to automatically establish and/or modify at least one future setpoint in a heating and/or cooling schedule based on at least one automatically sensed event and/or at least one past or current user input. As used herein, a “primary” thermostat refers to a thermostat that is electrically connected to actuate all or part of an HVAC system, such as by virtue of electrical connection to HVAC control wires (e.g. W, G, Y, etc.) leading to the HVAC system. As used herein, an “auxiliary” thermostat refers to a thermostat that is not electrically connected to actuate an HVAC system, but that otherwise contains at least one sensor and influences or facilitates primary thermostat control of an HVAC system by virtue of data communications with the primary thermostat. In one particularly useful scenario, the thermostat  110  is a primary learning thermostat and is wall-mounted and connected to all of the HVAC control wires, while the remote thermostat  112  is an auxiliary learning thermostat positioned on a nightstand or dresser, the auxiliary learning thermostat being similar in appearance and user-interface features as the primary learning thermostat, the auxiliary learning thermostat further having similar sensing capabilities (e.g., temperature, humidity, motion, ambient light, proximity) as the primary learning thermostat, but the auxiliary learning thermostat not being connected to any of the HVAC wires. Although it is not connected to any HVAC wires, the auxiliary learning thermostat wirelessly communicates with and cooperates with the primary learning thermostat for improved control of the HVAC system, such as by providing additional temperature data at its respective location in the enclosure, providing additional occupancy information, providing an additional user interface for the user, and so forth. 
     It is to be appreciated that while certain embodiments are particularly advantageous where the thermostat  110  is a primary learning thermostat and the remote thermostat  112  is an auxiliary learning thermostat, the scope of the present teachings is not so limited. Thus, for example, while certain initial provisioning methods that automatically pair associate a network-connected thermostat with an online user account are particularly advantageous where the thermostat is a primary learning thermostat, the methods are more generally applicable to scenarios involving primary non-learning thermostats, auxiliary learning thermostats, auxiliary non-learning thermostats, or other types of network-connected thermostats and/or network-connected sensors. By way of further example, while certain graphical user interfaces for remote control of a thermostat may be particularly advantageous where the thermostat is a primary learning thermostat, the methods are more generally applicable to scenarios involving primary non-learning thermostats, auxiliary learning thermostats, auxiliary non-learning thermostats, or other types of network-connected thermostats and/or network-connected sensors. By way of even further example, while certain methods for cooperative, battery-conserving information polling of a thermostat by a remote cloud-based management server may be particularly advantageous where the thermostat is a primary learning thermostat, the methods are more generally applicable to scenarios involving primary non-learning thermostats, auxiliary learning thermostats, auxiliary non-learning thermostats, or other types of network-connected thermostats and/or network-connected sensors. 
     Enclosure  100  further includes a private network accessible both wirelessly and through wired connections and may also be referred to as a Local Area Network or LAN. Network devices on the private network include a computer  124 , thermostat  110  and remote thermostat  112  in accordance with some embodiments of the present invention. In one embodiment, the private network is implemented using an integrated router  122  that provides routing, wireless access point functionality, firewall and multiple wired connection ports for connecting to various wired network devices, such as computer  124 . Each device is assigned a private network address from the integrated router  122  either dynamically through a service like Dynamic Host Configuration Protocol (DHCP) or statically through actions of a network administrator. These private network addresses may be used to allow the devices to communicate with each directly over the LAN. Other embodiments may instead use multiple discrete switches, routers and other devices (not shown) to perform more other networking functions in addition to functions as provided by integrated router  122 . 
     Integrated router  122  further provides network devices access to a public network, such as the Internet, provided enclosure  100  has a connection to the public network generally through a cable-modem, DSL modem and an Internet service provider or provider of other public network service. Public networks like the Internet are sometimes referred to as a Wide-Area Network or WAN. In the case of the Internet, a public address is assigned to a specific device allowing the device to be addressed directly by other devices on the Internet. Because these public addresses on the Internet are in limited supply, devices and computers on the private network often use a router device, like integrated router  122 , to share a single public address through entries in Network Address Translation (NAT) table. The router makes an entry in the NAT table for each communication channel opened between a device on the private network and a device, server, or service on the Internet. A packet sent from a device on the private network initially has a “source” address containing the private network address of the sending device and a “destination” address corresponding to the public network address of the server or service on the Internet. As packets pass from within the private network through the router, the router replaces the “source” address with the public network address of the router and a “source port” that references the entry in the NAT table. The server on the Internet receiving the packet uses the “source” address and “source port” to send packets back to the router on the private network which in turn forwards the packets to the proper device on the private network doing a corresponding lookup on an entry in the NAT table. 
     Entries in the NAT table allow both the computer device  124  and the thermostat  110  to establish individual communication channels with a thermostat management system (not shown) located on a public network such as the Internet. In accordance with some embodiments, a thermostat management account on the thermostat management system enables a computer device  124  in enclosure  100  to remotely access thermostat  110 . The thermostat management system passes information from the computer device  124  over the Internet and back to thermostat  110  provided the thermostat management account is associated with or paired with thermostat  110 . Accordingly, data collected by thermostat  110  also passes from the private network associated with enclosure  100  through integrated router  122  and to the thermostat management system over the public network. Other computer devices not in enclosure  100  such as smartphones, laptops and tablet computers (not shown in  FIG. 1 ) may also control thermostat  110  provided they have access to the public network where the thermostat management system and thermostat management account may be accessed. Further details on accessing the public network, such as the Internet, and remotely accessing a thermostat like thermostat  110  in accordance with embodiments of the present invention is described in further detail later herein. 
     In some embodiments, thermostat  110  may wirelessly communicate with remote thermostat  112  over the private network or through an adhoc network formed directly with remote thermostat  112 . During communication with remote thermostat  112 , thermostat  110  may gather information remotely from the user and from the environment detectable by the remote thermostat  112 . For example, remote thermostat  112  may wirelessly communicate with the thermostat  110  providing user input from the remote location of remote thermostat  112  or may be used to display information to a user, or both. Like thermostat  110 , embodiments of remote thermostat  112  may also include sensors to gather data related to occupancy, temperature, light and other environmental conditions. In an alternate embodiment, remote thermostat  112  may also be located outside of the enclosure  100 . 
       FIG. 2  is a schematic diagram of an HVAC system controlled using a thermostat designed in accordance with embodiments of the present invention. HVAC system  120  provides heating, cooling, ventilation, and/or air handling for an enclosure  100 , such as a single-family home depicted in  FIG. 1 . System  120  depicts a forced air type heating and cooling system, although according to other embodiments, other types of HVAC systems could be used such as radiant heat based systems, heat-pump based systems, and others. 
     In heating, heating coils or elements  242  within air handler  240  provide a source of heat using electricity or gas via line  236 . Cool air is drawn from the enclosure via return air duct  246  through filter  270 , using fan  238  and is heated through heating coils or elements  242 . The heated air flows back into the enclosure at one or more locations via supply air duct system  252  and supply air registers such as register  250 . In cooling, an outside compressor  230  passes a gas such as Freon through a set of heat exchanger coils  244  to cool the gas. The gas then goes through line  232  to the cooling coils  234  in the air handler  240  where it expands, cools and cools the air being circulated via fan  238 . A humidifier  254  may optionally be included in various embodiments that returns moisture to the air before it passes through duct system  252 . Although not shown in  FIG. 2 , alternate embodiments of HVAC system  120  may have other functionality such as venting air to and from the outside, one or more dampers to control airflow within the duct system  252  and an emergency heating unit. Overall operation of HVAC system  120  is selectively actuated by control electronics  212  communicating with thermostat  110  over control wires  248 . 
       FIGS. 3A-3B  illustrate a thermostat designed in accordance with embodiments of the present invention. Inside of thermostat  110  is control circuitry that electrically connects thermostat  110  to an HVAC system, such as HVAC system  120  shown in  FIG. 1  and  FIG. 2 . One or more microprocessors (not shown) inside thermostat  110  are available to perform various computations including a backplate processor in backplate  314  for processing information related to the operation and control of HVAC system  120 . Another head unit processor (not shown) may be used to control the display and user interface portion in the head unit  312  portion of thermostat  110  and the network protocol. A network interface controller or NIC (not shown) is also provided within thermostat  110  enabling wireless communication over a private network such as a LAN and public networks or wide area networks (WANs) such as the Internet. 
     In the embodiment illustrated, thermostat  110  is enclosed by housing  316  with a forward-facing surface including a cover  304  and a grille member  308 . The grille member  308  is designed to complement the sleek, simple, uncluttered and elegant design of thermostat  110  to while facilitating the integration and operation of sensors located within housing  316  of the thermostat. Notably, included in the thermostat according to some preferred embodiments is passive infrared (PIR) occupancy sensors and temperature sensors behind grille member  308 . Additional sensors may also include an ambient light sensor (not shown) and an active proximity sensor (not shown) positioned near the top of the thermostat just behind the cover  304 . Some embodiments of housing  316  include a backplate  314  and a head unit  312 . Housing  316  provides an attractive and durable configuration for one or more integrated sensors used by thermostat  110  and contained therein. 
     A central display area  306  of cover  304  allows information related to the operation of the thermostat to be displayed while an outer area  310  of cover  304  may be made opaque using a paint or smoke finish. For example, central display area  306  may be used to display a current temperature as illustrated in  FIG. 3A  with the numerals, “75” indicating 75 degrees. Central display area  316  may also be used to display wireless networks available within enclosure  100  and present a user-interface for configuring thermostat  110  to select, access and use one of the wireless networks. 
     Embodiments of thermostat  110  are circular in shape and have an outer ring  312  for receiving user input. Side view of thermostat  110  in  FIG. 3B  further highlights this curved spherical shape of cover  304  and grille member  308  gently arcing outward matching the corresponding surface portion of outer ring  302 . In some embodiments, the curvature of cover  304  may tend to magnify information displayed in central display area  306  thus making information easier to read by users. The shape of thermostat  110  not only provides a visually appealing accent when it is mounted on the wall but a natural shape for users to touch and adjust with their hands. Accordingly, the diameter of thermostat  110  may be approximately 80 mm or another diameter that readily fits the hand. In various embodiments, rotating outer ring  302  allows the user to make adjustments, such as selecting a new target temperature. For example, the target temperature may be increased by rotating the outer ring  302  clockwise and decreased by rotating the outer ring  302  counter-clockwise. 
     Operation of the microprocessors, wireless NIC and other electronics are powered by a rechargeable battery (not shown) located within the thermostat  110 . In some embodiments, the battery is recharged directly using 24 VAC power off a “C” wire drawn from the HVAC system or a AC-DC transformer coupled directly into the thermostat  110 . Alternatively, one or more different types of energy harvesting may also be used to recharge the internal battery if these direct methods are not available as described, for example, in U.S. Ser. No. 13/034,678, supra, and U.S. Ser. No. 13/267,871, supra. Embodiments of the present invention communicate and operate the thermostat  110  in a manner that promotes efficient use of the battery while also keeping the thermostat operating at a high level of performance and responsiveness controlling the HVAC system. Some embodiments may use the battery-level charge and the priority or relative importance of a communication to determine when a thermostat management system located on a public network such as the Internet may communicate with the thermostat  110 . Further details on the communication methods and system used in accordance with these embodiments are described in detail later herein. 
       FIGS. 4A-B  illustrate a user&#39;s hand controlling a thermostat designed in accordance with embodiments of the present invention. As illustrated, thermostat  110  is wall-mounted, circular in shape and has a rotatable outer ring  302  for receiving user input. Cover  304  on thermostat  110  includes central display area  306  for providing information and feedback to the user before, during and after operating thermostat  110 . In some embodiments, outer area  310  of cover  304  delineates an area for the user to push or otherwise manipulate thermostat  110  and thus is made opaque with paint or smoke finish. 
     Head unit  312  of thermostat  110  slides on to backplate (not shown) and further includes head unit front  402  and head unit frame  404 . The head unit front  402  includes outer ring  302 , central display area  306  and outer area  310  of cover  304  and grille member  308  designed in accordance with embodiments of the present invention. 
     According to some embodiments, for the combined purposes of inspiring user confidence and further promoting visual and functional elegance, the thermostat  110  is controlled by only two types of user input, the first being a rotation of the outer ring  302  as illustrated in  FIG. 4A  (also referred to as a “rotate ring”), and the second being an inward push on the head unit front  402  until an audible and/or tactile “click” occurs as illustrated in  FIG. 4B . According to some embodiments, the inward push illustrated in  FIG. 4B  only causes the outer ring  302  to move forward, while in other embodiments the entire head unit front  402  moves inwardly together when pushed. In some embodiments, cover  304  and grille member  308  do not rotate with outer ring  302 . 
     According to some embodiments, multiple types of user input may be generated depending on the way a pushing inward of head unit front  402  is effectuated. In some embodiments a single brief push inward of head unit front  402  until the audible and/or tactile click occurs followed by a release (single click) can be interpreted as one type of user input (also referred to as an “inward click”). In other embodiments, pushing the head unit front  402  in and holding with an the inward pressure for an amount of time such as 1-3 seconds can be interpreted as another type of user input (also referred to as a “press and hold”). According to some further embodiments, other types of user input can be effectuated by a user such as double and/or multiple clicks, and pressing and holding for longer and/or shorter periods of time. According to other embodiments, speed-sensitive or acceleration-sensitive rotational inputs may also be implemented to create further types of user inputs (e.g., a very large and fast leftward rotation specifies an “Away” occupancy state, while a very large and fast rightward rotation specifies an “Occupied” occupancy state). 
       FIG. 5  illustrates thermostats and computers on a private network  502  connected to a cloud-based management server  516  designed in accordance with aspects of the present invention. In one embodiment, private network  502  is designed to provide network connectivity primarily within and near an enclosure, such as enclosure  100  in  FIG. 1 , connecting various devices together such a Smartphone  508 , tablet  510 , computer  512 , thermostat  110  and remote thermostat  112 . A router (not shown) in private network  502 , such as integrated router  122  in  FIG. 1 , provides wired and wireless connectivity between these devices using a network protocol such as TCP/IP. Preferably, thermostat  110  and remote thermostat  112  are connected wirelessly to private network  502  as a wired connection in the vicinity of the thermostats may not available and/or it is undesirable to include a wired connection socket on thermostat  110  or remote thermostat  112 . 
     Thermostat access client  514  is a client application designed in accordance with aspects of the present invention to access a cloud-based management server  516  over public network  504 . The term “thermostat management system” can be interchangeably referenced as a “cloud-based management server” for the thermostats, or more simply “cloud server”, in various descriptions hereinabove and hereinbelow. Because thermostat access client  514  is designed to execute on different devices, multiple client applications may be developed using different technologies based on the requirements of the underlying device platform or operating system. For some embodiments, thermostat access client  514  is implemented such that end users operate their Internet-accessible devices (e.g., desktop computers, notebook computers, Internet-enabled mobile devices, cellphones having rendering engines, or the like) that are capable of accessing and interacting with the cloud-based management server  516 . The end user machine or device has a web browser (e.g., Internet Explorer, Firefox, Chrome, Safari) or other rendering engine that, typically, is compatible with AJAX technologies (e.g., XHTML, XML, CSS, DOM, JSON, and the like). AJAX technologies include XHTML (Extensible HTML) and CSS (Cascading Style Sheets) for marking up and styling information, the use of DOM (Document Object Model) accessed with client-side scripting languages, the use of an XMLHttpRequest object (an APlused by a scripting language) to transfer XML and other text data asynchronously to and from a server using HTTP), and use of XML or JSON (Javascript Object Notation, a lightweight data interchange format) as a format to transfer data between the server and the client. In a web environment, an end user accesses the site in the usual manner, i.e., by opening the browser to a URL associated with a service provider domain. The user may authenticate to the site (or some portion thereof) by entry of a username and password. The connection between the end user entity machine and the system may be private (e.g., via SSL). The server side of the system may comprise conventional hosting components, such as IP switches, web servers, application servers, administration servers, databases, and the like. Where AJAX is used on the client side, client side code (an AJAX shim) executes natively in the end user&#39;s web browser or other rendering engine. Typically, this code is served to the client machine when the end user accesses the site, although in the alternative it may be resident on the client machine persistently. Finally, while a web-based application over Internet Protocol (IP) is described, this is not a limitation, as the techniques and exposed user interface technologies may be provided by a standalone application in any runtime application, whether fixed line or mobile. It is to be appreciated that although the TCP/IP protocol is set forth as the network protocol used for communications among the cloud-based management server  516 , the thermostat access client  514 , and other devices for some embodiments, it is set forth by way of example and not by way of limitation, with the use of any other suitable protocol, such as UDP over IP in particular, may be used without departing from the scope of the present teachings. In yet another embodiment, thermostat access client  514  may be a stand-alone application or “app” designed to be downloaded and run on a specific device such Smartphone  508  or table  510  device running the Apple iOS operating system, Google Android operating system or others. 
     It is to be appreciated that the embodiments described herein, while advantageously providing battery-conscious methods for reliable communication of thermostatically related data between the thermostats  110 / 112  and the cloud-based management server  516 , are also advantageously configured to be compatible with a large variety of conventional integrated routers that service a large population of homes and businesses. Thus, by way of example only and not by way of limitation, the router (not shown) that services the private network  502  can be, for example, a D-Link DIR-655 Extreme N Wireless Router, a Netgear WNDR3700 RangeMax Dual Band Wireless USB Gigabit Router, a Buffalo Technology Nfiniti WZR-HP-G300NH Wireless-N Router, an Asus RT-N16 Wireless Router, Cisco Linksys E4200 Dual Band Wireless Router, or a Cisco Linksys E4200 Dual Band Wireless Router. 
     In one embodiment, cloud-based management server  516  illustrated in  FIG. 5  may be accessed over public network  504  by computer devices on private network  502  running thermostat access client  514 . Thermostat access client  514  may also execute or run on a computer device such as tablet  506  directly connected to the public network  504 . Preferably, each thermostat access client  514  has access to a thermostat management account (not illustrated) on cloud-based management server  516  which allows thermostat access client  514  to interact with thermostat  110  or remote thermostat  112  in a variety of different ways. In some embodiments, thermostat access client  514  may be used to access sensor data previously collected from thermostat  110  and remote thermostat  112  then stored on cloud-based management server  516 . In other embodiments, for example, thermostat access client  514  may be used to either remotely control or remotely configure thermostat  110 . Thermostat access client  514  may also gather other information on thermostat  110  or remote thermostat  112  including a battery-level readings, firmware update levels, diagnostic data, or any other data exposed by the thermostats to thermostat access client  514 . 
     Each of the thermostat  110  and remote thermostat  112  also communicate with cloud-based management server  516  through one or several communication channels established through public network  504 . Like other devices on the private network  502 , thermostat  110  and remote thermostat  112  do not have a public network address and therefore cannot communicate directly on the Internet or other public network without the assistance of the router and corresponding entries in NAT table  518 . In the example in  FIG. 5 , thermostat  110  has a private network address of 192.168.1.108 and a private port number of 60720 while remote thermostat  112  has been configured with a private network address of 192.168.1.110 and three different port numbers 60744, 60743, and 60722. In this example, thermostat  110  initiates the establishment of a communication channel with cloud-based management server  516  having a public network address 107.20.224.12 and public port number  443 . Accordingly, the router (not shown) on private network  502  creates an entry in a NAT table  518  identified by NAT PORT 1022 for communications between SOURCE ADDRESS 192.168.1.108 and SOURCE PORT 60720 of thermostat  110  and DESTINATION ADDRESS 107.20.224.12 and DESTINATION PORT 443 of cloud-based management server  516 . 
     In an alternative configuration, thermostats  110  and  112  may be configured with multiple communication channels to cloud-based management server  516  rather than a single connection as depicted with thermostat  110 . As an example, thermostat  112  initiates the establishment of communication channels over three ports 60744, 60743, and 60722, causing the router to make three more entries in the NAT table  518  identified by NAT PORTs 1044, 1921 and 1758. The additional corresponding entries in NAT table  518  identified as NAT PORT 1044, 1921, and 1758 include SOURCE ADDRESS 192.168.1.110 and SOURCE PORTS 60744, 60744, 60722 each associated with DESTINATION ADDRESS 107.20.224.12 and DESTINATION PORT 443 of cloud-based management server  516 . In various embodiments of the present invention, communications between cloud-based management server  516  and other thermostats may take place over a single communication channel as configured on remote thermostat  110  while other embodiments may use multiple communications channels as provided with thermostat  112 . 
     As data is transferred using a protocol such as TCP/IP, the router in private network  502  modifies the addresses in packets of data passing over the communication channels between the private network and a server or device on the public network such as cloud-based management server  516 . In one example, the router may receive a packet from remote thermostat  110  having a SOURCE ADDRESS field of 192.168.1.108 and a SOURCE PORT of 60720 combined with a DEST ADDRESS of 107.20.224.12 and DEST PORT 443 of cloud-based management server  516 . Before placing this packet on the Internet, the router references NAT table  518  and replaces the SOURCE ADDRESS field and SOURCE PORT field values with the public address 76.21.3.203 assigned to the router and the corresponding NAT port 1022 respectively. A resulting modified packet header  520  in  FIG. 5  sent over the public network has the original destination address and destination port but the source address and port are changed to the public address of the router and port number from NAT table  518 . As long as the entries in NAT table  518  are present, thermostats  110  and  112  may communicate over their respective communication channels on the public network  504  to cloud-based management server  516 . 
     During these communications, embodiments of the present invention take into consideration battery-levels of the thermostats and the impact on the performance of the thermostat. If a battery-level on a thermostat is low, further communications with a thermostat may impact the ability of the thermostat to perform essential functions such as controlling the HVAC system or communicating over the network. As illustrated in  FIG. 5 , an enlarged battery image  110 A next to thermostat  110  shows schematically a battery-level of the battery inside of thermostat  110 . The battery image  110 A, in this example, appears about 80% charged thus representing the battery-level inside thermostat  110  to be almost fully charged. In a similar manner, an enlarged battery image  112 A adjacent to remote thermostat  112  appears about 20% charged thus indicating that the battery inside of thermostat  112  has a low battery-level. To accommodate for these different and fluctuating battery-levels, embodiments of the present invention may incorporate one or multiple different strategies in communicating and operating a thermostat. 
     In one embodiment illustrated in  FIG. 6A , cloud-based management server  516  monitors battery-levels on the thermostats and judiciously control the communications according to a priority assigned to the data. In some embodiments, cloud-based management server  516  implements aspects of the present invention however alternate embodiments may distribute functionality from cloud-based management server  516  to one or several servers within the system. In this example, thermostat  110  and thermostat  112  have initiated and established their respective communication channels with cloud-based management server  516  and the router on private network  502  has created NAT table  518  as previously illustrated in  FIG. 5 . To preserve battery-charge, the thermostats  110 / 112  may enter into a low power state while waiting for either (i) a local event that merits wake-up, such as a particular temperature threshold being detected by the temperature sensors, or a detected proximity of a user detected by the proximity sensors, or (ii) a next event or request from cloud-based management server  516  that merits wake-up. 
     Prior to entering into a low power state, each thermostat  110 / 112  sends a connection-opening long-polling packet to the thermostat communication server  620 . When a response is not required for normal operational purposes (i.e., when the cloud-based management server  516  has no instructions or requests to render), cloud-based management server  516  maintains a long-polling communication with thermostats  110 / 112  allowing the communication channels to remain open even though the actual data exchanged may be infrequent or subject to long delays. This not only uses the battery-charge of the thermostats more efficiently but reduces the overhead and delay associated with reestablishing a communication channel for each data transmission. In one embodiment, cloud-based management server  516  maintains the long-polling communication in a manner that preserves the entry in NAT table  518  by sending a keep-alive priority packet at regular keep-alive intervals. In one embodiment, the keep-alive priority packet is consistent with a keep-alive facility built into a TCP/IP protocol stack. If no messages need to otherwise be sent to the thermostats  110 / 112  within the long-polling time interval, the protocol stack sends one or more “keep-alive” packets to the router on private network  502  at respective keep-alive intervals that are less than the long-polling time interval, thereby preserving the entry in NAT table  518 . Preferably, the keep-alive intervals are substantially less than the interval over which many common routers might otherwise flush their NAT table with respect to that particular connection. 
     At a predetermined time interval or upon an event occurrence, thermostats  110  and  112  may wake from a low power state to check on their respective battery-levels and perform other administrative functions. In accordance with some embodiments, the battery-level is transmitted over a wireless connection from each thermostat  110  and  112  through an access point  606  on the private network and then stored for future reference by thermostat communication server  620 . For example, battery image  110 A appears about 80% charged representing the battery-level inside thermostat  110  to be almost fully charged while battery image  112 A appears about 20% charged thus indicating that the battery inside of thermostat  112  is at a low level. One embodiment of cloud-based management server  516  updates this data in a device-battery-charge table  616  that includes a device address, a battery-level, and a keep-alive interval used for the corresponding communication channel. For example, device-battery-charge table  616  provides that device address 76.21.3.203:1022 (corresponding to thermostat  110  by way of NAT table  518 ) has a “high” battery-level and a keep-alive interval set to 5000 time units. In contrast, device addresses 76.21.3.203:1044, 76.21.3.203:1921, and 76.21.3.203:1758 (corresponding to thermostat  112  by way of NAT table  518 ) in device-battery-charge table  616  all have a “low” battery-level and a longer keep-alive interval set to 10000. Some embodiments of cloud-based management server  516  may set the keep-alive interval shorter if the battery-level is high to reduce the chance that an entry in the NAT table  518  will be flushed by the router. If the battery-level is “low”, the keep-alive interval may be set to a maximum long-poll interval that represents a maximum time interval not likely to exceed a NAT time-out period of most router devices. 
     Some embodiments of cloud-based management server  516  may further use device-battery-charge table  616  to help determine when data should be communicated from cloud-based management server  516  to one or more thermostats. To implement, one embodiment further creates a power-priority table  618  that associates low and high battery-levels reported from each thermostat with high thermostatic importance data or low thermostatic importance data. In these embodiments, power-priority table  618  establishes a trade-off between the importance assigned to data being communicated compared with the drain on the current battery charge associated with the thermostat. For example, data communications with data classified as high thermostatic importance data may be filtered and transmitted even when the battery is low since the data is considered of higher importance to the overall operation of cloud-based management server  516  and the thermostat. In one embodiment, a low battery-level may be between 0 and 39% of charge capacity. 
     Data communications classified under a low thermostatic importance may note be transmitted when the battery level is low as indicated in power-priority table  618 . Since the battery is not fully charged, low thermostatic importance data may not be transmitted in accordance with power-priority table  618  to preserve energy on the battery of the thermostat. Accordingly, low and high thermostatic importance data types are transmitted in accordance with some embodiments when the battery-level is detected as high or in a range from 80% to 100% charged. 
     In an alternate embodiment illustrated in  FIG. 6B , power-priority table  618  three battery levels and three levels of thermostatic importance. In the case of a low battery level, data consider to be high thermostatic importance is transmitted while medium and low thermostatic importance data is not sent. When the battery level is at a medium level, data considered of both high and medium thermostatic importance is transmitted. If the battery level is at least at a high level then data considered to be of low, medium and high thermostatic importance is transmitted. Further additional embodiments may also use more than three battery-levels and three data priority level types for the data as well depending on the particular design and implementation requirements. In addition, the percentage charge for low, medium and high battery-levels may include different ranges of charge that do not necessarily include the aforementioned 0-39% charge for a low battery-level, 40% to 79% for a medium battery-level, and 80% to 100% for a high battery-level. 
     In some embodiments, the data communications may be classified in a number of different ways and often will be determined based on the particular implementation requirements of the cloud-based management server  516  and performance requirements for the thermostats. In one implementation, a high-priority data type may include data communications actively requesting a thermostat perform some function. This may include a data communication from cloud-based management server  516  requesting thermostat  110  or  112  to change a temperature setpoint. Another high-priority data type may include a data communication requesting thermostat  110  or  112  to turn on or turn off a cooling function. In contrast, low-priority data types may include certain operations or functions deemed less critical for a thermostat to perform immediately. Downloading a software update from cloud-based management server  516  to a thermostat is one example of a low-priority communication as the software update is not required and likely does not affect the immediate operation of the thermostat. In addition, it may also be preferred to not download a software update when a thermostat has a low battery-level as a partially-completed update may render the thermostat inoperable. 
       FIG. 7  illustrates a cloud-based management server  516  that both conserves energy and promotes high-performance operation of thermostats designed in accordance with embodiments of the present invention. In this embodiment, cloud-based management server  516  includes a processor  704  configured to execute one or more instructions, a memory  702  holding instructions executable on the processor, a network interface controller  706  capable of communication over a network such as the Internet, a storage device  710 , a display adapter and monitor  712  to display information from the server on the monitor, and peripheral drivers &amp; devices  714  that includes keyboards, mice and other interfaces for controlling the server. For example, a CD-ROM/DVD device  716  with media may be attached to peripheral drivers &amp; devices  714  holding various embodiments of the present invention tangibly embodied in a computer program product. 
     In one embodiment, processes in memory  702  may include a battery-level collection process  718  that stores a battery-level associated with the battery used to power a thermostat. As previously described, the battery-level in some embodiments is provided by the thermostat over a communication channel established over a network between the thermostat management system and the thermostat and provides an indication of remaining energy in the battery associated with the thermostat. The battery-level collection process is able to collect these battery-levels over a long period of time as a result of ongoing communications between the thermostat and the cloud-based management server  516 , which includes the long-polling process that keeps the communication channels open between the cloud-based management server  516  and thermostats. In some embodiments, the battery-level data is stored in a device-battery-charge table  616  as illustrated in  FIG. 6  and may be in a local storage area on cloud-based management server  516  or remotely accessed in a database or other remote storage area. 
     Some embodiments may further include a data priority process  720  in memory  702  that classifies and prioritizes one or more types of data to be transmitted to the thermostat over a communication channel. Depending on the implementation, data priority process  720  classifies the data transmission according to a data priority ranging from a low thermostatic importance data type to a high thermostatic importance data type. In some implementations, the low thermostatic importance data is of lesser importance to the operation of the thermostat management system and the thermostat. For example, a low thermostatic importance data type may include a software update as the software update may not be required for the thermostat to operate. In comparison, high thermostatic importance data types may include data of higher importance to the operation of the thermostat management system such as a request to change a setpoint in a thermostat or turn-on heating or cooling in the HVAC system. 
     Further embodiments may also include a power-classification transmission process  722  that transmits data to a thermostat depending on a classification of the data and the battery-level associated with the thermostat. As previously described, the data priority classification ranges from a low thermostatic importance data type to a high thermostatic importance data type depending on the importance of the data to the overall operation of cloud-based management server  516  and the thermostat. Consequently, low thermostatic importance data may not be transmitted when a battery-level is low in order to conserve the battery power remaining on the thermostat. However, the power-classification transmission process  722  may transmit all data classifications when the battery-level associated with a thermostat is fully-charged or “high”. 
     Embodiments of the present invention may also include a long-polling process  724  in memory  702  to facilitate keeping the communication channel open with a thermostat. This long-polling process  724  initially receive receives a request over the network from a thermostat to establish the communication channel between the cloud-based management server  516  located on a public network and the thermostat located on a private network. In some embodiments, cloud-based management server  516  has a public network address registered on the Internet while the thermostat has a shared public network address provided through an entry in a NAT table from a router on a private network, such as NAT table  518  in  FIG. 5 . The long-polling process  724  further configures a network communication protocol, such as TCP/IP, to occasionally transmit a keep-alive packet from the thermostat management system back to the network-attached thermostat over the communication channel. In some implementations, the keep-alive packet sent to the thermostat acknowledges establishment of the communication channel but may not include a payload or data that needs processing. Long-polling process  724  may set the time interval for sending these keep-alive packets at maximum time interval not to exceed a NAT time-out period of a router device. The receipt of the keep-alive packet before the NAT time-out period keeps the entry in the NAT table current and the communication channel from being disconnected. 
       FIG. 8A  illustrates a flowchart diagram of the operations that a thermostat communication server uses to coordinate communications with a battery powered thermostat that both conserves the energy of the battery and promotes performance of the thermostat. The thermostat communication server, such as cloud-based management server  516  in  FIG. 6 , receives a request from a thermostat powered by a battery to establish a communication channel between the thermostat and the thermostat communication server over a network. ( 802 ) When the thermostat initiates the communication channel, a router places an entry in a NAT table, such as NAT table  518  in  FIG. 5 , allowing the thermostat on a private network behind a router to then communicate with thermostat communication server on the Internet, a public network. The entry in the NAT table will not be removed and the communication channel will remain open as long as any gap in communication from the thermostat communication server and the thermostat does not exceed a NAT time-out value associated with router. 
     Next, thermostat communication server classifies one or more types of data to be transmitted to the thermostat over the communication channel according to a thermostatic importance ranging from a low thermostatic importance to a high thermostatic importance classification. ( 804 ) In one implementation, the low thermostatic importance data type includes data of lesser importance to the operation of the overall thermostat management system and thermostat. These may include optional functions to be performed on the thermostat such as software update or other maintenance. Conversely, the high thermostatic importance data type includes data of higher importance to the operation of the thermostat management system and the thermostat and generally includes requests to actively perform an action on the thermostat such as changing a setpoint, turning-on/off heating or cooling or checking ambient temperature in a residence or commercial location where the thermostat is located. 
     Next, thermostat communication server stores a battery-level associated with a thermostat in a storage area accessible by the thermostat communication server. ( 806 ) In some embodiments, each thermostat periodically checks its own battery and provides the battery-level to the thermostat communication server over a communication channel established over the network. Battery-level information for each thermostat may be stored in a device-battery-charge table, such as device-battery-charge table  616  as illustrated in  FIG. 6 . 
     To keep the communication channel open, thermostat communication server may configure a long-poll interval for transmitting a keep-alive packet over the communication channel to the thermostat. ( 808 ) In some embodiments, the thermostat communication server sets the long-poll interval to a maximum value not to exceed a NAT timeout period used by most routers, which is often approximately 100 minutes. 
     If no data passes between thermostat communication server and the thermostat ( 810 —No), a timer value, originally set to the long-poll interval, decreases over time within the communication protocol stack and the process continues. Eventually, if the long-poll interval runs out of time and the communication protocol stack on the thermostat communication server, such as TCP/IP, does not detect communication activity within the long-poll interval, the built-in keep-alive feature sends a packet to keep the NAT entry on the router and communication channel open. ( 812 ) In some embodiments, the thermostat communication server may request to terminate the communication channel when the long-poll interval has elapsed and wait for new communication channel to be established by the thermostat. 
     Alternatively if there is data to be sent, the thermostat communication server checks the most recent battery-level of the thermostat before sending. ( 810 —Yes) One embodiment determines if there is a low battery-level associated with the thermostat ( 814 —Yes) that only data classified as high thermostatic importance data should be transmitted. ( 816 ) This preserves some of the battery charge in the thermostat by not sending low thermostatic importance data. In some embodiments, thermostat communication server have predetermined classifications setup in advance according to a particular configuration requirement. If the data is of higher importance to the operation of the thermostat management system then the data is classified as a high thermostatic importance data type and should be sent even when there is a low battery-level. For example, high thermostatic importance data may include instructions sent to a thermostat actively requesting the thermostat change a temperature setpoint or other setting. 
     When the battery-level associated with the thermostat is not at a low level ( 814 —No), all data classified as low to high thermostatic importance will be transmitted as the battery on the thermostat is considered fully charged. ( 818 ) 
     An example data flow chart in  FIG. 8B  illustrates the flow of data and events when thermostat communication server transmits data based on a battery-level of a thermostat and priority associated with the data. In this example, the thermostat initiates establishment of a communication channel with thermostat communication server causing a router to creates entry in the NAT table. ( 826 ) To save energy, the thermostat enters a low power mode and waits for the next event. ( 828 ). After a period of time, the management server sends a keep-alive packet before the NAT table entry is removed. ( 830 ) In one embodiment, the thermostat wakes from the low power mode and sends a low battery-level to the thermostat communication server indicating the battery-level on the thermostat is nearly discharged ( 832 )—the thermostat then returns to a low power mode to conserve the battery use. ( 834 ) Thermostat communication server associates the low battery-level with the thermostat and stores the results in a storage area. ( 836 ) At this point, a client device, such as tablet  506  running thermostat access client  514  in  FIG. 5 , requests thermostat communication server to change a thermostat setting. ( 838 ) Thermostat communication server classifies request as a high thermostatic importance data type to be transmitted even though the battery on the thermostat is at a low level. ( 840  and  842 ) As a result, the thermostat receives the data transmission and fulfills the request to change the thermostat setting. ( 844 ) Alternate implementations may use more than two battery levels and more than two corresponding thermostatic importance classifications for data such as a three classification system with low, medium, and high thermostatic importance classification data types. 
     In an alternate embodiment, a battery powered thermostat and system illustrated in  FIG. 9A-9B  uses a plurality of communication channels to exchange data classified with different priority in accordance with embodiments of the present invention. Accordingly, in this embodiment the thermostat  112  receives data of different priority from cloud-based management server  516  over corresponding different communication channels and, depending on the battery-level, may either process or discard the data received. Advantageously, the processing associated with this embodiment is distributed partly on cloud-based management server  516  and partly on thermostat  112 . As one distinct advantage, thermostat  112  can determine the battery-level without polling or indirectly gathering data thus resulting in a more accurate processing of data packets received from thermostat communication server  620 . 
     For example, thermostat  112  in  FIG. 9A  has established two wireless communication channels using private network address and port combinations 192.168.1.110:60744 and 192.168.1.110:60743. These private network addresses on thermostat  112  have corresponding entries in NAT table  518  in  FIG. 5  identified with NAT port entries 1044 and 1921. Cloud-based management server  516  in  FIG. 9A  stores corresponding public addresses and port numbers 76.21.3.203:1044 and 76.21.3.203:1921 for thermostat  112  in a priority transmission table  902  and also associates a high and low-priority data type to each address as illustrated. In accordance with some embodiments, cloud-based management server  516  classifies data to be sent to the thermostat as being a low or high-priority data type and then sends over the appropriate communication channel or public address as indicated in priority transmission table  902 . Data passes over public network  504 , private network  502 , and wirelessly from access point  606  illustrated in  FIG. 9A  onto thermostat  112 . 
     Settings within the Wifi module (not shown) of thermostat  112  determine whether to process or discard the data depending on which communication channel the data is received. As a reflection of settings in the Wifi module, a power-priority table  904  identifies that the recent battery-level of thermostat  112  is at a low level, as illustrated by battery image  112 A, and that ports 60744 and 60743 are used to process high and low data types respectively. Because the most recent battery-level was low, power-priority table  904  also indicates in this example that the Wifi module has been configured to ignore or discard low-priority data arriving on ports 60743 and process only high-priority data received over port 60744. Over time, thermostat  112  may update the configuration of the Wifi module to accept or discard packets depending on the battery-level the thermostat  112  detects. If thermostat  112  later determines the battery-level is high, thermostat  112  reconfigures WiFi module to subsequently process both low and high-priority data packets arriving over both ports. In alternate embodiments, Wifi module may also be configured to use greater or fewer ports and process either greater or fewer data priority types. For example, three communication channels may be used to process either high-priority, medium-priority or low-priority data types rather than just either high-priority or low-priority data types. 
     Referring to  FIG. 9B , a schematic block diagram provides an overview of some components inside a thermostat in accordance with embodiments of the present invention. Thermostat  908  is similar to thermostat  112  in  FIG. 9A  except that thermostat  908  also illustrates and highlights selected internal components including a Wifi module  912  and antenna, a head unit processor  914  with associated memory  915 , a backplate processor  916  with associated memory, and sensors  922  (e.g., temperature, humidity, motion, ambient light, proximity). In one embodiment, head unit processor  914  can be a Texas Instruments AM3703 Sitara ARM microprocessor while backplate processor  916 , which may be more specifically referenced to as a “microcontroller”, can be a Texas Instruments MSP430F microcontroller. Further details regarding the physical placement and configuration of the thermostat head unit, backplate, and other physical elements are described in the commonly assigned U.S. Ser. No. 13/199,108, supra. 
     For some embodiments, the backplate processor  916  is a very low-power device that, while having some computational capabilities, is substantially less powerful than the head unit processor  914 . The backplate processor  916  is coupled to, and responsible for polling on a regular basis, most or all of the sensors  922  including the temperature and humidity sensors, motion sensors, ambient light sensors, and proximity sensors. For sensors  922  that may not be located on the backplate hardware itself but rather are located in the head unit, ribbon cables or other electrical connections between the head unit and backplate are provided for this purpose. Notably, there may be other sensors (not shown) for which the head unit processor  914  is responsible, with one example being a ring rotation sensor that senses the user rotation of the outer ring  302  (see  FIGS. 4A-4B , supra). Each of the head unit processor  914  and backplate processor  916  is capable of entering into a “sleep” state, and then “waking up” to perform various tasks. 
     The backplate processor  916 , which in some embodiments will have a low-power sleep state that corresponds simply to a lower clock speed, generally enters into and out of its sleep mode substantially more often than does the more powerful head unit processor  914 . The backplate processor  916  is capable of waking up the head unit processor  914  from its sleep state. For one preferred embodiment directed to optimal battery conservation, the head unit processor  914  is allowed to sleep when its operations are not being called for, while the backplate processor  916  performs polling of the sensors  922  on an ongoing basis, maintaining the sensor results in memory  917 . The backplate processor  916  will wake up the head unit processor  914  in the event that (i) the sensor data indicates that an HVAC operation may be called for, such as if the current temperature goes below a currently active heating setpoint, or (ii) the memory  917  gets full and the sensor data needs to be transferred up to the head unit processor  914  for storage in the memory  915 . The sensor data can then be pushed up to the cloud server (thermostat management server) during a subsequent active communication session between the cloud server and the head unit processor  914 . 
     In the case of Wifi module  912 , one embodiment may be implemented using Murata Wireless Solutions LBWA19XSLZ module, which is based on the Texas Instruments WL1270 chipset supporting the 802.11b/g/n WLAN standard. Embodiments of the present invention configure and program Wifi module  912  to allow thermostat  908  to enter into a low power or “sleep” mode to conserve energy until one or several events occurs. For example, in some embodiments the Wifi module  912  may leave this low power mode when a user physically operates thermostat  908 , as illustrated in  FIGS. 4A and 4B , which in turn may also cause activation of both head-unit processor  914  and backplate processor  916  for controlling functions in head-unit  312  and backplate  314  portions of thermostat  110  depicted in  FIG. 3B . 
     It is also possible for Wifi module  912  to wake from a low power mode at regular intervals in response to a beacon from wireless access point  912 . To conserve energy, Wifi module  912  may briefly leave the low power mode to acknowledge the beacon as dictated by the appropriate wireless standard and then return to a low power mode without activating the processors or other components of thermostat  908  in  FIG. 9B . In an alternative embodiment, Wifi module  912  may also respond to the beacon by awaking briefly and then activating backplate processor  916 , head unit processor  914 , or other portions of thermostat  908  to gather data through sensors  922  and store the results in a data log  926  with a time stamp, event type and corresponding data listed for future reference. In accordance with one embodiment, backplate processor  916  may collect data in data log  926  and store in memory  920  for a period of time or until the log reaches a maximum predetermined size. At that point, the backplate processor  916  may wake head unit processor  914  to coordinate an upload of the data log  926  stored in memory  920  over a public network, such as the Internet, to cloud-based management server  516 . Uploading data log  926  less frequently saves time and energy associated with more frequent transmission of individual records or log entries. 
     In yet another embodiment, WiFi module  912  may selectively filter an incoming data packet to determine if the header is merely an acknowledgement packet (i.e., a keep-alive packet) or contains a payload that needs further processing. If the packet contains only a header and no payload, the WiFi module  912  may be configured to either ignore the packet or send a return acknowledgement to the thermostat management system or other source of the packet received. 
     In further embodiments, WiFi module  912  may be used to establish multiple communication channels between thermostat  112  and cloud-based management server  516  as described and illustrated in  FIG. 9A . As previously described, thermostat  112  uses the multiple communication channels to receive different types of data classified with different levels of priority. In one embodiment, Wifi module  912  may be programmed to use one or more filters and a wake-on-LAN feature to then selectively ignore or discard data arriving over one or more of these communication channels. For example, low-priority data arriving over a port on Wifi module  912  may be discarded by disabling the corresponding wake-on-LAN feature associated with the port. This allows the communication channel to continue to operate yet conserves battery power by discarding or ignoring the low-priority packets. 
     Flowchart diagram in  FIGS. 9C-9D  concern the operations on cloud-based management server  516  and thermostat  112  in accordance with embodiments of the present invention as illustrated in  FIGS. 9A and 9B . In one embodiment, flowchart diagram in  FIG. 9C  provides the operations used by a thermostat communication server to communicate over a plurality of communication channels with a battery powered thermostat. In this embodiment, thermostat communication server, such as cloud-based management server  516  in  FIG. 9A , receives a request from a thermostat powered by a battery to establish a plurality of communication channel between the thermostat and the thermostat communication server over a network. ( 928 ) When the thermostat initiates the communication channel, a router places a plurality of entries in a NAT table, such as NAT table  518  in  FIG. 5 , providing multiple communication channels for the thermostat to communicate with the thermostat communication server on the Internet, a public network. As previously described, these entries in the NAT table will not be removed and the communication channel will remain open as long as any gap in communication from the thermostat communication server and the thermostat does not exceed a NAT time-out value associated with the router. 
     Next, thermostat communication server classifies one or more types of data to be transmitted to the thermostat over the communication channel according to a data priority ranging from a low-priority data type to a high-priority data type. ( 930 ) In one implementation, the low-priority data type includes data of lesser importance to the operation of the overall thermostat management system and thermostat. These may include optional functions to be performed on the thermostat such as software update or other maintenance. Conversely, the high-priority data type includes data of higher importance to the operation of the thermostat management system and the thermostat and generally includes requests to actively perform an action on the thermostat such as changing a setpoint, turning-on/off heating or cooling or checking ambient temperature in a residence or commercial location where the thermostat is located. 
     To keep the communication channel open, thermostat communication server may configure a long-poll interval for transmitting keep-alive packets over the plurality of communication channels to the thermostat. ( 932 ) In some embodiments, the thermostat communication server sets the long-poll interval to a maximum value not to exceed a NAT timeout period used by most routers, which is often approximately 100 minutes. If no data passes between thermostat communication server and the thermostat ( 934 —No), a timer, initially set to the long-poll interval, decreases over time within the communication protocol stack and the process continues. 
     Eventually, if the long-poll interval runs out of time and the communication protocol stack on the thermostat communication server, such as TCP/IP, did not detect communication activity, the built-in keep-alive feature sends packets to keep the NAT entries on the router and the communication channels open. ( 938 ) In some embodiments, the thermostat communication server may request the thermostat to terminate and reestablish the communication channel when the timer associated with the long-poll interval expires to help make sure the communication channel is available and operating properly. 
     Alternatively if there is data to be sent, the thermostat communication server checks the priority of the data and sends over the proper communication channel. Accordingly in one embodiment, if the data is classified as low-priority ( 940 —Yes), thermostat communication server sends the data over a communication channel reserved for low-priority data transmissions. ( 942 ) Alternatively, if the data is classified as high-priority and not low-priority ( 940 —No), thermostat communication server sends the data over a communication channel reserved for high-priority data transmissions. ( 948 ) In this embodiment, thermostat communication server segregates the data on different communication channels but allows the thermostat to determine whether to process or discard the data as it easy easier for the thermostat to obtain battery-level data and make a decisions. 
       FIG. 9D  is a flowchart diagram of the complimentary operations performed on a thermostat to conserve battery energy yet process data at a high level of performance. In this embodiment, a thermostat, such as thermostat  112  in  FIG. 9A , may wake from a low power state to check on battery-levels or possible data packets received over one or several communication channels. ( 950 ) For example, a thermostat may wake from a low power state once every 100 ms to respond to a wireless strobe from an access point  924  and may also check on a battery-level. It is also possible that a wake-on-LAN event wakes the thermostat causing it to leave the low power state and process a data packet received over one or several communication channels reserved for different priority levels of data. 
     In some embodiments, the thermostat may determine that the communication channels with thermostat communication server, such as with thermostat communication server  620 , have not been established. ( 952 —No) Accordingly, one embodiment of the present invention may request and establish two communication channels between the thermostat communication server and the thermostat. ( 954 ) In accordance with some embodiments, the thermostat reserves the first and second communication channels on the thermostat to receive data classified as low and high-priority data types. The thermostat initially configures its Wifi module, such as Wifi module  912  in  FIG. 9B , to receive low and high-priority data packets from each of the several communication channels using a built-in wake-on-LAN feature. ( 956 ) To reduce power consumption, thermostat may then return to a low power state waiting for the next event or receipt of data. ( 958 ) 
     Alternatively, if the communication channels are established, ( 952 —Yes), the thermostat determines if a data packet has been received and requires further processing. ( 960 ) In some embodiments, the Wifi module on the thermostat may inspect the data packet header or payload and determine that the data packet needs no further processing and can be discarded. ( 960 —No) For example, the data packet may be discarded if it is a keep-alive packet meant to preserve the NAT table entries in the router or if the packet otherwise has no payload data associated with it. If the packet is discarded, the thermostat may conserve overall power consumed because other components in the thermostat, such as head unit processor  914  or backplate processor  916 , can remain in a low power state. ( 962 ) 
     If the packet does require further processing, ( 960 —Yes) then the thermostat may activate or power-up other portions of the thermostat to service the data packet received. ( 964 ) In some embodiments, thermostat may activate head unit processor  914  to perform a change of a setpoint or other feature on the thermostat or may activate back plate processor  916  to gather sensor information as requested from thermostat communication server  620 . 
     Once a packet has been processed or discarded, embodiments of the present invention check the current battery-level of the thermostat and adjust the communication channels to either accept or discard subsequent data packets. If the thermostat determines the battery charge is at or below a low battery-level, ( 968 —Yes) the Wifi module is configured to discard subsequent data received over a first communication channel reserved to received low priority data. ( 972 ) As previously described, some embodiments discard packets over a communication channel and port of the Wifi module by turning off a wake-on-LAN feature for the channel. This causes subsequent low priority packets received on the channel to be ignored and discarded. In some implementations, the Wifi module is configured to process packets on the second communication channel using a filter to locate the proper port number and enabling the wake-on-LAN feature for the selected filter. Lastly, if the battery charge is above the low battery-level ( 968 —No) then embodiments of the present invention enable processing of subsequently received packets over the first and second communication channels. ( 978 ) For example, if the battery-level charge is high then embodiments of the present invention are adjusted to process more data and further improve the thermostat&#39;s performance and ability to respond to instructions and requests. After checking the battery-level and adjusting the Wifi module, the thermostat returns to a low power state to conserve energy consumption and await the next event and/or data to be processed. ( 958 ) 
     An example data flow chart in  FIG. 9E  illustrates the flow of data and events using a plurality of communication channels to transmit different priority levels of data. In this example, the thermostat initiates establishment of a plurality of communication channels with thermostat communication server causing a router to creates corresponding entries in a NAT table. ( 960 ) In some embodiments, a first communication channel is reserved for low-priority types of data and a second communication channel is reserved for high-priority types of data. To conserve energy, the thermostat enters a low power mode and waits for the next event. ( 964 ). After a period of time, a long-poll interval expires causing the thermostat communications server to send a keep-alive packet before the NAT table entry is removed. ( 962 ) In one embodiment, the thermostat wakes from the low power mode and sensing a low battery-level and making note of the local condition. In this embodiment, the thermostat does not forward to the thermostat communication server since it is up to the thermostat to determine whether to process the received data packets. Instead, thermostat turns off a wake-on-LAN (WOL) feature for all ports except the port receiving high-priority types of data. ( 970 ) For example, subsequently received packets received on the first communication channel may be discarded since the low-priority data is reserved for the first communication channel. At some later point in time, a client device, such as tablet  506  running thermostat access client  514  in  FIG. 5 , requests that thermostat communication server downloads a software update to the thermostat. ( 972 ) Thermostat communication server classifies request as a low-priority data type and transmits over the first communication channel regardless of the battery-level on the thermostat. ( 974 ) In some embodiments, thermostat communication server segregates different priority data types on different communication channels and lets the thermostat decide whether to discard or process the packets received. Eventually, the thermostat receives the software update request but discards the packets as the battery-level is low and the first communication channel is configured to ignore the low-priority data packets that it may receive. ( 976 ). 
       FIGS. 10A-10B  provide a schematic block diagram and flowchart for creating a thermostat reporting group with multiple thermostats and gathering reporting events in a common event log. In  FIG. 10A , a thermostat reporting group  1002  is formed from several thermostats in a network including thermostat  1004 , thermostat  1006 , thermostat  1008  and thermostat  1010  whereupon each thermostat has a current battery-level as represented by battery images  1004 A, battery image  1006 A, battery image  1008 A and battery image  1010 A respectively. To conserve energy, a proxy reporting thermostat is selected from the thermostat reporting group to receive the event log information from other members of the group and then upload over a network to a central server. In this example, thermostat  1004  is selected as the proxy reporting thermostat since the corresponding battery-level indicated by battery image  1004 A is the highest within the thermostat reporting group. 
     Once selected, thermostat  1004  gathers log data over the network from other thermostats  1006 ,  1008  and  1010  through local transfers  1012 ,  1014 , and  1016  respectively. These local transfers include the log data from each thermostat combined into a common log  1016  identifying a time stamp, event type, device ID and data content for each entry. After a period of time or when memory (not shown) in thermostat  1004  fills up, the common log  1016  is uploaded over a communication channel to a central server such as the cloud-based management server  516 . This approach allows event log information to be gathered using fewer uploads than would be required if each thermostat was required to upload individually. It also allows thermostats having a low battery-level to preserve their battery charge while still allowing such data to be collected and analyzed on a server such as cloud-based management server  516  in  FIG. 5 . 
       FIG. 10B  is a flowchart diagram of the operations associated with gathering reporting events on a proxy reporting thermostat and common event log in accordance with embodiments of the present invention. In one embodiment, a thermostat reporting group is created from a plurality of battery powered thermostats on a network. ( 1016 ) Each battery powered thermostat individually records events in a respective event log corresponding to the one or more operations and events occurring on a thermostat. In some cases, the events may include sensor information provided from humidity sensors, temperature sensors, passive infra-red sensors, ambient light sensors, active proximity sensors or other sensors incorporated into each thermostat. Event logs may also include information describing current or changed settings on a thermostat and the time stamp associated with when these settings were changed. 
     As previously described, embodiments of the present invention select a proxy reporting thermostat to represent the other thermostats. ( 1018 ). In some embodiments, the proxy reporting thermostat is selected based on having the highest battery-level compared with the other battery powered thermostats in the thermostat reporting group. For example, thermostat  1004  in  FIG. 10A  has the highest charged battery in the group and is thus selected as the proxy reporting thermostat. 
     Over time, the proxy reporting thermostat gathers events recorded from each of the thermostats in the thermostat reporting group. ( 1020 ) Proxy reporting thermostat may collect these events from each thermostat in the thermostat reporting group using a wireless ad-hoc connection or a wireless connection made available through a network access point or router. The proxy reporting thermostat generally continues to collect the data from the other thermostats until storage on the proxy reporting thermostat is full or has reached a maximum allocation for such logs. ( 1022 ) For example, a thermostat may have allocated 500 megabytes for storing the log information from multiple thermostats before triggering the upload process. 
     If the storage on the proxy reporting thermostat is full, one embodiment of the proxy reporting thermostat establishes a communication channel to a thermostat management system to store the thermostat events. ( 1024 ) For example, this may be connection over the Internet between the thermostat on a private network and the thermostat management system. Next, one embodiment uploads events gathered on the proxy reporting thermostat over the communication channel to the thermostat management system on behalf of the thermostats in the thermostat reporting group. ( 1026 ) Once the data in the common event log has been successfully uploaded, embodiments of the present invention clear the storage area on the proxy reporting thermostat of the events gathered from the thermostat reporting group. ( 1028 ) This makes way for storage of more events in the event log on the proxy reporting thermostat. 
     While examples and embodiments have been described, they should not serve to limit any aspect of the present invention. Accordingly, various modifications may be made without departing from the spirit and scope of the invention. Indeed, various methods and system for communicating and operating thermostats, HVACSs and other devices have been provided yet the methods and systems are meant to be illustrative and not limiting as to the scope of the overall invention. It is to be appreciated that the term thermostat, as used hereinabove and hereinbelow, can include thermostats having direct control wires to an HVAC system, and can further include thermostats that do not connect directly with the HVAC system, but that sense an ambient temperature at one location in an enclosure and cooperatively communicate by wired or wireless data connections with a separate thermostat unit located elsewhere in the enclosure, wherein the separate thermostat unit does have direct control wires to the HVAC system. Accordingly, the invention is not limited to the above-described embodiments, but instead is defined by the appended claims in light of their full scope of equivalents.