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Embodiments relate generally to method, system and apparatus for multi-standard communications between multiple wireless sensor nodes for wireless sensor networks. More specifically, disclosed are system and apparatus that enable wireless communications between devices using different wireless transmission protocols.
In the world of ubiquitous computing, wireless sensor networks (WSNs) are becoming more important as more devices are connected to each other and the Internet. In the so-called “Internet of Things” (IoT), many devices are equipped with sensors, actuators, transceivers that need to communicate with each other. For example, in home automation, devices can make decisions based on information receive from other wirelessly connected devices without the involvement of the network owner. For instance, the coffee maker can make coffee when the motion sensor detects movement near the kitchen in the morning, or the hallway lights turn on. To enable such home automation, the devices need to exchange data wirelessly, e.g. in a two-way communication.
One of the major hurdles is that there is no unified wireless transmission standard or protocol that enables devices and applications to exchange data easily. The existing contenders (e.g. Zigbee, Z-Wave, etc.) all have their advantages and disadvantages. As a result, device manufacturers equip their products (e.g. lamps and appliances) with sensors and a selected wireless radio based on the selected wireless transmission standard. In addition, the consumers who purchase off-the-shelf products can obtain devices that employ different radio frequencies based on different wireless transmission standards.
A current solution to solve this multi-standard hurdle is to use a hub that is equipped with multiple radios transceivers to cover any possible standards that may be used in the market. The hub can communicate with all the devices, which means that all the devices are connected through the hub. For example, the hub can include multiple radio transceivers each designed to communicate in one of the popular wireless transmission standards (e.g. Zigbee, Z-Wave, Bluetooth Low Energy, 802.11ah, and ANT+). Problems of this solution include numerous and complex hardware and software need to be installed in the hub based on each of the transmission standards. The resulting hub is expensive and bulky, which limit the numbers of hubs can be deployed.
Another major hurdle is the distance limit of a single hub to connect to more distantly located devices. The more distant devices consume more energy to reach a single hub or intermediate device, which result in less battery life for the distant devices. Furthermore, each wireless transmission standard has a transmission limit in distance or areas.
Thus, there is a need to provide a multi-standard wireless sensor network via a cost-effective, efficient and compact wireless intermediate device that can communicate with devices based on different wireless transmission standards. Furthermore, such an intermediate device can also communicate with multiple intermediate devices to form a flexible and expandable mesh network to cover a large communication space.
Various embodiments or examples (“examples”) of the technology are disclosed in the following detailed description and the accompanying drawings:
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure.
Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the above-described inventive techniques are not limited to the details provided. There are many alternative ways of implementing the above-described techniques. The disclosed examples are illustrative and not restrictive.
Various embodiments relate to a multi-standard intermediate device for communicating with multiple devices based on different wireless transmission standards. The multi-standard intermediate device can be used in a broad filed of applications including home automation, heath care, emergency response and intelligent shopping.
Various embodiments also be used to create a clustered mesh network that aggregates separate networks into one mesh network. A wireless mesh network is a communication network including radio nodes organized in a mesh topology. Mesh infrastructure can transmit data over large distances by splitting the distance into multiple hops between the intermediate nodes or devices. Intermediate devices can enhance the signal and route data between different intermediate devices by making forwarding decisions based on the forwarding tables or other network information.
In some embodiments, the multi-standard intermediate device can include a receiver radio frequency (RF) front end chip based on a concurrent multi-standard reception (CMS). The CMS can enable the chip to concurrently receive all radio transmissions in different radio frequency ranges/bands when each transmission occupies a different part of the band and all the transmissions are not overlapping partially through digital signal processing (DSP). The CMS can also enable the chip to concurrently receive a sub-1 GHz radio transmission and a 2.4-2.5 GHz radio transmission via a sub-1 GHz antenna and a 2.4-2.5 GHz antenna, respectively. In some embodiments, the multi-standard intermediate device can demodulate all transmissions based on different transmission standards via multiple demodulators each for a specific transmission standard. Accordingly, the CMS can eliminate the need of multiple wireless radios.
In some embodiments, the multi-standard intermediate device can include a digital signal processor (DSP) for conditioning the received data. The DSP can include multiple digital process modules each corresponding to a specific transmission standard (e.g. Zigbee, Z-Wave, etc.) for conditioning the digital data. For any radio signals received in one of the two radio frequency bands (800M-1 GHz and 2.4-2.5 GHz), the DSP can determine a corresponding digital process module corresponding to the received radio signals based on a specific radio frequency range. For example, a Z-wave radio signals at 908 MHz is associated with a Z-wave digital process module. Through this approach, the multi-standard intermediate device can receive an entire radio band (e.g. a sub-1 G radio band or a 2.4 G radio band) and separate each individual radio transmission in the multi-module DSP. Thus, the multi-standard intermediate device can concurrently process multiple radio transmissions each sitting in a different carrier frequency without multiple radio receivers.
In addition, the DSP can include a plurality of demodulators each corresponding to a specific transmission standard for demodulating the signals. (e.g. Z-wave demodulator).
In some embodiments, the DSP can also provide digital hopping in the radio frequencies to remove the need for frequency hopping phase lock loops (PLLs) for some transmission standards.
In some embodiment, the multi-standard intermediate device can include a transmitter radio frequency (RF) end chip that can be used to re-transmit the received signals. In some embodiment, the re-transmission can enhance the received signals and make them travel a further distance.
In some embodiments, the multi-standard intermediate device can enable devices based on different transmission standards to communicate with each other (e.g. exchange data). For example, for a Z-wave device to communicate with a Zigbee device, the multi-standard intermediate device can receive Z-wave radio signals and convert them to Zigbee radio signals.
In addition, several different types of MACs can be used in the multi-standard intermediate device. For example, the multi-standard intermediate device can employ multiple medium access controls (MAC) for handling communications based on multiple transmission standards. The multi-standard intermediate device can further include a multi-standard MAC coordinator that can centralize and coordinate the communications between the multiple MACs. Furthermore, the multi-standard intermediate device can include an inter-device MAC to manage the communications between different multi-standard intermediate devices, e.g. packet routing.
In addition, in some embodiments, several multi-standard intermediate devices can communicate with each other to form a flexible and expandable mesh network that can cover a larger geographical area as well as connect more devices. In some embodiments, the multi-standard intermediate device can repeat the received data to enable the data to cover a further distance. In addition, in a multi-center mesh network, devices can connect to a closer multi-standard intermediate device to conserve energy for data transmission.
In some embodiments, a multi-standard intermediate device can be an internet gateway that provides internet access to multiple radio nodes as well as other multi-standard intermediate devices. In addition, the multi-standard intermediate device can provide internet access for the multiple intermediate-device mesh network.
Furthermore, in some embodiments, a multi-standard intermediate device can connect to a control device such as an electronic device (e.g. a smart phone, a tablet or a computer) to enable a centralized control with or without the network owner's interference. Such a control device can run applications to manage the multi-standard intermediate device as well as the wireless network. For example, the control device can analyze the collected data from the radio notes and issue commands to the radio nodes based on these data. (e.g. enable the coffee machine to brew coffee when the motion sensor senses movement in the kitchen). In some embodiments, the multi-standard intermediate device can function as the control device. Yet in some embodiments, the control function can be distributed in each of the radio nodes. Thus, each of the radio nodes can be autonomous and intelligent.
Different sensor nodes (e.g. 114, 116, 118, 120 and 122) can be used in multi-center mesh network 100. Examples of sensor nodes include smart thermometers, cameras, humidity meters, GPS sensors, gyroscopes, etc. Sensor nodes can monitor environmental conditions such as temperature, humidity, sound and location. Each of these sensor nodes is equipped with a radio transceiver based on a selected transmission standard, a microcontroller and an energy source (e.g. battery).
In some embodiment, a sensor node can conduct a two-way communication with another sensor node, an intermediate multi-standard device, or a control device/base station. The two-way communication enables the sensor node to make intelligent and autonomous decisions based on the collected data.
According to some embodiments, two groups of transmission standards are generally available for wireless network communication, wherein each of the transmission standards has its advantages and disadvantages that are known in the art. The first group uses the industrial, scientific and medical (ISM) radio bands from 2.4 to 2.485 GH; the second group uses the UHF band ranging from 755 MHz to 1 GHz or the sub-1 G band. Examples of the first group (2.4 G band) include Zigbee, Bluetooth (BL), and Bluetooth Low Energy (BLTE). Examples of the second group (sub-1 G band) include Z-wave, EnOcean, 802.11ah, and Insteon. In addition, other industrial transmission protocols can be implemented in the multi-stand intermediate device, such as TCP/IP based protocols.
Particularly, Zigbee is a major transmission standard that has certain advantageous characteristics. For example, Zigbee offers a range of up to 10 m with 16 channels when each channel has 2 MHz Bandwidth and they are 5 MHz apart. One channel is used for each communication path with Direct Sequence Spread Spectrum. For each Wi-Fi channel, there are four overlapping ZigBee channels. ZigBee allows dynamic channel selection, a scan function steps through a list of supported channels in search of beacon, receiver energy detection, link quality indication. A feature called frequency agility is specified in the ZigBee standard to improve the robustness of ZigBee networks. According to this function, if interference is detected and reported in the current channel, a ZigBee network may move to a clear channel. The frequency agility function enables easier usage of these extra channels. For example, when a network is first formed the node seeks a channel with the least noise or traffic. If overtime extra traffic appears or noise becomes present, the host application scans for a better channel and moves the whole network to the new channel, thus allowing the network to adapt overtime to changing RF environments.
In some embodiments, multi-standard intermediate device 108 can use the specific Zigbee characteristics to enable concurrent signal processing. For example, multi-standard intermediate device 108 can implement new protocols that allow multiple Zigbee devices to use different unoccupied Zigbee channels at the same time. Multi-standard intermediate device 108 can receive and demodulate these non-overlapping channels. Thus, the devices that use non-overlapping channels do not need to wait for their turn to use the medium when the intermediate device's Zigbee radio is engaged with another device. This feature can lead to lower transmitter active time, faster channel access, and ultimately less power consumption.
As shown in
Different wireless sensor network topologies can be applied in multi-center mesh network 100. Examples of the wireless sensor network topologies include a single hop topology and a multi-hop topology (flat or cluster). In a single hop architecture, all sensor nodes can communicate with the base station or control station directly, which makes it difficult for a network that needs to cover a large area (as the base station is inaccessible). In a multi-hop cluster architecture, as shown in
Furthermore, each of the multi-standard intermediate devices 102, 104, 106 and 108 can communicate with each other through a selected wireless transmission protocols. In some embodiments, such communications between the devices can repeat the signals and send it to a further distance, thus creating a mesh network that covers a larger area. In some embodiments, such communications can route the data provided by sensor nodes to a cluster head for centralized data collection and management.
In some embodiments, the two digitalization pathways can individually and concurrently receive and process radio signals when the two radio carrier frequency ranges do not overlap with each other.
In some embodiments, digital process module 302 can condition a received digital radio signals. For example, digital process module 302 can include a digital mixer 304, a decimation filter 306, and a channel select filter 308 to separate each individual signal channel from others. After being processed at the digital process module, the digitally separated and conditioned signal channel is delivered to the corresponding demodulator for demodulation.
As shown in
Accordingly, the device can include a plurality of standard specific medium access control (MAC) for each commonly used standard. Each stand specific MAC can manage the data generated by each of the standard specific demodulator and can. For example, the device can include a Zware MAC, a BL/BLTE MAC, a 802.11ah MAC, an ANT MAC, an EnOcean MAC. Furthermore, the device can include a Zigbee MAC or multiple Zigbee MACs, or a Multi-Zigbee MAC coordinator. Furthermore, each standard specific MAC can communicate with the Multi-standard MAC coordinator as described herein.
Furthermore, the multi-standard intermediate device can include an inter-device MAC that coordinates the communication between multiple devices.
In some embodiments, RF front end 502 can digitalize the received analog signals for further processing in DSP. As shown in
In some embodiments, since multiple Zigbee channels can be received at the same time, multi-standard intermediate system 500 can employ a multi-Zigbee MAC coordinator 504 that uses this feature to reduce channel access time and energy consumption.
According to some examples, computing platform 700 performs specific operations by processor 704 executing one or more sequences of one or more instructions stored in system memory 706, and computing platform 700 can be implemented in a client-server arrangement, peer-to-peer arrangement, or as any mobile computing device, including smart phones and the like. Such instructions or data may be read into system memory 706 from another computer readable medium, such as storage device 708. In some examples, hard-wired circuitry may be used in place of or in combination with software instructions for implementation. Instructions may be embedded in software or firmware. The term “computer readable medium” refers to any tangible medium that participates in providing instructions to processor 704 for execution. Such a medium may take many forms, including but not limited to, non-volatile media and volatile media. Non-volatile media includes, for example, optical or magnetic disks and the like. Volatile media includes dynamic memory, such as system memory 706.
Common forms of computer readable media includes, for example, floppy disk, flexible disk, hard disk, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EPROM, FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read. Instructions may further be transmitted or received using a transmission medium. The term “transmission medium” may include any tangible or intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible medium to facilitate communication of such instructions. Transmission media includes coaxial cables, copper wire, and fiber optics, including wires that comprise bus 702 for transmitting a computer data signal.
In some examples, execution of the sequences of instructions may be performed by computing platform 700. According to some examples, computing platform 700 can be coupled by communication link 721 (e.g., a wired network, such as LAN, PSTN, or any wireless network) to any other processor to perform the sequence of instructions in coordination with (or asynchronous to) one another. Computing platform 700 may transmit and receive messages, data, and instructions, including program code (e.g., application code) through communication link 721 and communication interface 713. Received program code may be executed by processor 704 as it is received, and/or stored in memory 706 or other non-volatile storage for later execution.
In the example shown, system memory 706 can include various modules that include executable instructions to implement functionalities described herein. In the example shown, system memory 706 includes a digital signal processor 710, which can be configured to provide one or more functions described herein.
Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the above-described inventive techniques are not limited to the details provided. There are many alternative ways of implementing the approaches for various approaches for embodiments described herein and the disclosed examples are illustrative and not restrictive.
Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the above-described inventive techniques are not limited to the details provided. There are many alternative ways of implementing the approaches for various approaches for embodiments described herein and the disclosed examples are illustrative and not restrictive.
This application claims priority to U.S. provisional application 61,977,016, filed Apr. 8, 2014, and entitled “METHODS, SERVICES, SYSTEMS, AND ARCHITECTURES FOR HARMONY, A SMART MESH HUB FOR INTERNET OF THINGS”, the disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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61977016 | Apr 2014 | US |