Hierarchical wireless battery management system

Abstract

In an example, a method includes receiving a first downlink (406A) on a first channel from a wireless master node (302) at a wireless head node (306.1) in a WBMS in a superframe (402A), where the wireless head node (306.1) is a head node of a sub-cluster of one or more wireless devices (308). The method includes transmitting, in the superframe (402A), a second downlink (408) on a second channel from the radio head node (306.1) to each of the one or more wireless devices (308). The method includes receiving, at the radio head node (306.1), an uplink (420) from each of the one or more wireless devices (308) on the second channel in the superframe (402A). The method includes transmitting an aggregated uplink (424) from the wireless head node (306.1) to the wireless master node (302) on the first channel in the superframe (402A), wherein the aggregated uplink (424) includes data from each of the one or more wireless devices (308).

Description

BACKGROUND

[0001] Modern vehicles can include multiple battery cells. Information associated with the cells, such as temperature, voltage, and other indicators of cell state and health, can be monitored for vehicle safety and to ensure proper operation. In conventional wired battery management systems, a rechargeable battery is managed by circuitry for safe and efficient operation of the battery. A wired communication interface can be used to connect a primary microcontroller (primary node or master node) to each battery module (secondary node), and each battery module is linked to the remaining battery modules in a daisy chain. Through the wired communication interface, the primary microcontroller cannot monitor and control all battery modules in parallel without complex wiring. This wiring makes servicing or replacement of individual battery cells more difficult, and importantly, adds weight and bulk to the overall system.

[0002] Wireless connections between battery modules and microcontrollers make management of the battery modules more flexible and easier to service. In a wireless battery management system (WBMS), a microcontroller monitors each battery module and communicates with the battery modules using a wireless communication interface. A primary microcontroller controls all battery modules using a WBMS protocol. The wireless communication interface can suffer from wireless communication channel bandwidth variations, interference, and / or other issues that would impede proper monitoring and management in the WBMS. SUMMARY

[0003] According to at least one example described, a method includes receiving, at a wireless head node in a WBMS, a first downlink from a wireless master node on a first channel in a superframe, where the wireless head node is a head node for a subset cluster of one or more wireless devices. The method also includes transmitting, from the wireless head node, a second downlink to each of the one or more wireless devices in the subset cluster on a second channel in the superframe. The method includes receiving, at the wireless head node, an uplink from each of the one or more wireless devices on the second channel in the superframe. The method also includes transmitting, from the wireless head node, an aggregated uplink to the wireless master node on the first channel in the superframe, where the aggregated uplink includes data from each of the one or more wireless devices in the subset cluster.

[0004] According to at least one example described, a system includes a wireless head node in a WBMS, where the wireless head node is a head node for a subset cluster of one or more wireless devices. The wireless head node is configured to receive, in a superframe, a first downlink from a wireless master node on a first channel. The wireless head node is also configured to transmit, in the superframe, a second downlink to each of the one or more wireless devices in the subset cluster on a second channel. The wireless head node is configured to receive, in the superframe, an uplink from each of the one or more wireless devices on the second channel. The wireless head node is also configured to transmit, in the superframe, an aggregated uplink to the wireless master node on the first channel, where the aggregated uplink includes data from each of the one or more wireless devices in the subset cluster.

[0005] According to at least one example described, a system includes a first wireless head node in a WBMS, where the first wireless head node is a head node for a subset cluster of one or more wireless devices. The first wireless head node is configured to receive, in a superframe, a first downlink from a wireless master node on a first channel. The first wireless head node is also configured to transmit, in the superframe, a second downlink to each of the one or more wireless devices in the subset cluster on a configuration channel. The first wireless head node is configured to wait for a third downlink on the configuration channel to be transmitted by a second wireless head node. The first wireless head node is also configured to receive, in the superframe, an uplink from each of the one or more wireless devices on a second channel. The first wireless head node is configured to transmit, in the superframe, an aggregated uplink to the wireless master node on the first channel, where the aggregated uplink includes data from each of the one or more wireless devices in the subset cluster. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 Perspective view of an example system including a wireless battery management system (WBMS) according to various examples (e.g., a motor vehicle).

[0007] Figure 2A Example WBMS according to various examples.

[0008] Figure 2B Example WBMS according to various examples.

[0009] Figure 3 Block diagram of a hierarchical WBMS according to various examples.

[0010] Figure 4A Block diagram of a superframe structure according to various examples.

[0011] Figure 4B Block diagram of a superframe structure according to various examples.

[0012] Figure 5A superframe structure for network formation according to various examples.

[0013] Figure 6 A data and configuration channel is shown according to various examples.

[0014] Figure 7A An alternative superframe structure according to various examples.

[0015] Figure 7B An alternative superframe structure according to various examples.

[0016] Figure 8A A superframe structure for network formation according to various examples.

[0017] Figure 8B A superframe structure for network formation according to various examples.

[0018] Figure 9A A superframe structure for network formation according to various examples.

[0019] Figure 9B A superframe structure for network formation according to various examples.

[0020] Figure 10A A superframe structure for network formation according to various examples.

[0021] Figure 10B A superframe structure for network formation according to various examples.

[0022] Figure 11A A superframe structure for network formation according to various examples.

[0023] Figure 11B A superframe structure for network formation according to various examples.

[0024] Figure 12A A keep-alive operation according to various examples.

[0025] Figure 12B A keep-alive operation according to various examples.

[0026] Figure 13 A flowchart of a method for hierarchical network operation for WBMS according to various examples.

[0027] The same reference numbers or other reference designators in the drawings and the specification indicate functional and / or structural commonality amongst the elements or figures. DETAILED DESCRIPTION

[0028] Some electronic devices operate using batteries. For example, electric vehicles include multiple battery cells that provide power to those vehicles. Because the battery cells in an electronic device can provide a large amount of power, and further because the power provided by the battery cells can be critical to the operation of the electronic device, the electronic device can include a system to manage the battery cells.

[0029] A battery management system (BMS) can manage the battery cells of an electronic device in various ways. For example, the BMS can monitor the health (e.g., voltage, current, temperature) of the battery cells in the electronic device. Further, the BMS can control various battery cells to manage the amount of power provided by the battery cells and where that power is directed within the electronic device. Generally, the BMS includes multiple components, such as multiple battery modules and a controller to manage the battery modules. Each battery module, in turn, can be coupled to multiple battery cells and include a battery monitor to monitor those battery cells. Thus, the battery cells coupled to the battery modules provide power to the electronic device; the battery monitors in the battery modules monitor the health and operation of the battery cells in the battery modules; and the controller communicates with the battery monitors to ensure that the battery modules and their cells are operating correctly. The controller can also communicate with the battery monitors to control the operation of the battery cells, in order to turn on, turn off, redirect, or otherwise balance the power provided by those battery cells.

[0030] A BMS can incorporate wireless technology to create a wireless battery management system (WBMS). For example, a primary network node contains or is coupled to a controller, and a secondary network node contains a battery module that controls multiple battery cells. The primary and secondary network nodes (e.g., master / controlling node and end node) can communicate wirelessly with each other, such as using radio frequencies. In some protocols, a superframe (SF) is used to facilitate wireless communication between the primary and secondary network nodes. In the SF, the primary network node first broadcasts a downlink communication (or packet) to multiple secondary network nodes. The secondary network nodes individually respond to the primary network node with an uplink communication (or packet) in a serial manner. Additional example details of a WBMS can be found in commonly-assigned U.S. Patent Application No. 17 / 828,895, filed May 31, 2022, entitled “Efficient Unicast Super Frame Communications,” which is incorporated by reference in its entirety.

[0031] In WBMS, latency issues can occur as the number of nodes increases. The primary network node, which communicates directly with a large number of secondary network nodes, receives individual responses from each secondary network node serially, and these responses can take a significant amount of time to transmit to the primary network node. The size of the SF duration increases as the number of nodes increases. Furthermore, in larger networks, some secondary nodes can not be within communication range of the primary node.

[0032] In examples herein, hierarchical WBMS network structures are described that can handle a large number of nodes with low latency and single-hop extension. A primary node, also referred to herein as a wireless master (WM), operates as a master node for the entire network of nodes. Secondary nodes are divided into sub-clusters, with one or more secondary nodes in each sub-cluster. The secondary nodes in each sub-cluster operate as wireless head (WH) nodes and act as master nodes for the sub-cluster to which they belong. The other secondary nodes in each sub-cluster are referred to herein as wireless devices (WDs). In some examples, a dedicated WH node can be used for a sub-cluster rather than selecting one of the WDs as the WH. The WM and the WHs use a master hopping sequence (MHS) to manage the communication channels used by the nodes.

[0033] In the hierarchical systems described herein, the WM communicates with the WHs, and the WHs communicate with the WDs. At least in some examples, the WM and the WDs do not generally communicate directly with each other. The WM is in range to communicate with the WHs, and the WHs are in range to communicate with their respective WDs in their sub-clusters. The sub-clusters can have the same number of WDs, or the sub-clusters can have different numbers of WDs. Multiple SF structures are described herein for managing communications between nodes arranged in the hierarchical system.

[0034] Latency is reduced for WBMS with a large number of nodes with the hierarchical systems and SF structures described herein. Throughput is also increased due to the efficient SF structures. Low network restart counts can be achieved in examples herein, and power consumption can also be reduced. Furthermore, it can be easier to reestablish communication with WDs using the techniques of the present disclosure.

[0035] Figure 1 A perspective view of an example system 98 (e.g., a motor vehicle) including a WBMS 100 according to various examples herein. In some examples, the system 98 is any system that can include a WBMS to supply power to one or more components of the system 98. As shown, the WBMS 100 includes a primary network node 102, a battery controller 104, a plurality of secondary network nodes 106, and a plurality of battery cells 108. The primary network node 102 can be a WM, and the secondary network nodes 106 can be WHs and WDs, with the WDs arranged in sub-clusters and each sub-cluster having a WH to manage its respective WDs. Figure 1WH and WD are depicted as a single stack of secondary network nodes 106, but other figures in this application (e.g., Figure 3 ) depict network architectures that differentiate between WHs and WDs. Although this disclosure primarily describes communication techniques in the context of a wireless system, these techniques can also be applicable to a wired system (e.g., where the connections between nodes 102 and 106 are wired).

[0036] In an example, the primary network node 102 is coupled to the battery controller 104 using a first wired connection 110. In an example, the first wired connection 110 between the primary network node 102 and the battery controller 104 is a Universal Asynchronous Receiver / Transmitter (UART), Inter-Integrated Circuit (I2C), or the like. The WHs in the secondary network nodes 106 are wirelessly coupled to the primary network node 102 (e.g., WM). The WHs and WDs in the secondary network nodes are coupled to the battery cells 108 using a second wired connection 112. Although Figure 1 A single primary network node 102 and a single battery controller 104 are shown, but other example network architectures with multiple primary / primary nodes can be used to implement the techniques of this disclosure. Additional example details of multiple primary nodes in a WBMS can be found in commonly-assigned U.S. Patent Application No. 17 / 823,138, filed August 30, 2022, entitled “Multiple Primary Nodes for Wireless Battery Management System Robustness,” which is incorporated by reference in its entirety.

[0037] In an example, the WBMS 100 provides wireless radio frequency (RF) communication between the primary network node 102 and the WHs of the secondary network nodes 106 and between the WHs and the WDs. In an example, the wireless RF communication uses the unlicensed 2.4 gigahertz (GHz) industrial, scientific, and medical (ISM) band from 2.4 GHz to 2.483 GHz, which is compliant with the Bluetooth Special Interest Group (SIG). In an example, the WBMS 100 uses 2 megabits per second (Mbps) Bluetooth Low Energy (BLE) across the physical layer (PHY). The Open Systems Interconnection (OSI) model includes the PHY as the layer for transmitting raw bits over the physical medium. In this case, the PHY is free space, which the WBMS 100 uses to wirelessly communicate between the primary network node 102 and the WHs of the secondary network nodes 106. In an example, the transmission power of the WBMS 100 is less than or equal to 10 decibel-milliwatts (dBm).

[0038] In an example, wireless RF communication between the master network node 102 and the WHs of the secondary network nodes 106 utilizes frequency hopping and time slot allocation to transmit and receive data across SFs, as does RF communication between the WHs and the respective WDs. An SF, also referred to as a superframe interval, is a time interval containing time and frequency allocations for data exchange between the master network node 102 and the WHs of the secondary network nodes 106 (and between the WHs and the WDs), including interframe spacing between the allocations. Frequency hopping involves transmitting RF signals by rapidly changing the transmission frequency among many distinct frequencies that occupy a frequency spectrum band. In an example, frequency hopping occurs based on a linear shift back register and a master control identification (ID) of the master network node 102. The linear shift back register uses linear bit rotation to indicate a pattern of frequencies on which the master network node 102 and the secondary network nodes 106 will communicate. Time slot allocation is a time slot assigned to one or more of the master network node 102 or the secondary network nodes 106 for transmission to one or more of the secondary network nodes 106 or the master network node 102. Time slot allocation occurs in a half-duplex mode, as both the master network node 102 and the secondary network nodes 106 switch between a transmission mode and a reception mode according to a designated time in a scan / paired frame of exchanged data in a downlink (DL) / uplink (UL) duration.

[0039] In an example, the WBMS 100 uses frequency division multiple access (FDMA) and changes the frequency at which frames are transmitted between the master network node 102 and the respective secondary network nodes 106 (and between the WHs and the WDs) to increase robustness against interference. In an example, the WBMS 100 uses a frequency hopping table, a blacklist of frequencies, and a configuration channel to mitigate interference with other wireless networks. Frequency hopping occurs on a per SF basis, where during an SF, time slot allocations are used for frame exchange. The blacklist suspends use of frequency channels that can be susceptible to interference. The configuration channel can be used for scanning, pairing, and negotiating communication between the master network node 102 and the WHs of the secondary network nodes 106 and between the WHs and the WDs.

[0040] In an example, wireless RF communication between the master network node 102 and the secondary network nodes 106 uses 40 channels, where a subset of the 40 channels (e.g., channels 37, 38, and 39) are used for system configuration and the remaining 37 channels are used for exchanging data. The WHs can also communicate with the WDs using the configuration channel and the data channels. In an example, a single channel can be used as the configuration channel.

[0041] In an example, the WBMS 100 supports periodic and aperiodic data exchange between the secondary network nodes 106 to the primary network node 102 and the WHs and WDs using wireless RF communication. The primary network node 102 and the secondary network nodes 106 use a common data format structure for periodic and aperiodic data exchange. Periodic data exchange occurs based on a repetition interval, while aperiodic data exchange occurs without a repetition interval. The data format is a description of the rules that the data filling the file will follow. Generally, the more detailed the description of the data format, the easier it is to write validation rules on both the transmitting side and the receiving side of the wireless battery management system 100.

[0042] In an example, the primary network node 102 scans the network to obtain a master ID and discover the secondary network nodes 106 or the WHs of the secondary network nodes 106. The primary network node 102 scans the network by transmitting management frames to coordinate media access, wake-up schedules, and clock synchronization within the secondary network nodes 106. The primary network node 102 also uses management frames to learn about the secondary network nodes 106 in the network. Initially, the primary network node 102 performs a passive scan to obtain (or check) master ID values used by other nodes and / or devices. The primary network node 102 then selects a master ID that is different from the master IDs used by other nodes and / or devices.

[0043] In an example, after the primary network node 102 has selected a master ID, the primary network node 102 transmits a scan request frame in every SF period as long as there are secondary network nodes 106 that are not connected to the primary network node 102. In an example, the primary network node 102 is programmed with the total number of secondary network nodes 106 to be connected to the primary network node 102. After all of the secondary network nodes 106 are connected and confirmed, the primary network node 102 will no longer transmit scan requests. The scan request frame contains information about the structure of the SF as well as the frame formatting of the DL and UL slots.

[0044] To scan for secondary network nodes 106, the primary network node 102 enters a scan state. In this state, the primary network node 102 transmits a scan request frame in each SF period. The secondary network nodes 106 reply to the primary network node 102 with a scan response and wait for a pairing request frame from the primary network node 102. After the secondary network nodes 106 receive the pairing request, the secondary network nodes 106 respond in the same SF in the frequency slot assigned by the primary network node 102. In an example, this exchange occurs in the configuration channel. No data exchange occurs in this state. Additional example details of establishing a communication channel can be found in commonly-assigned U.S. Patent Application Publication No. 2022 / 0332213, entitled “Wireless Protocol for Battery Management,” filed April 16, 2021; and U.S. Patent Application Publication No. 2023 / 0051689, entitled “Wireless Battery Management System Setup,” filed August 11, 2021, each of which is incorporated by reference in its entirety.

[0045] In an example, the transmission cycle or SF depends on the number of secondary network nodes 106 and / or battery cells 108 in the network. The primary network node 102 determines the SF interval based on the number of secondary network nodes 106 or the number and size of sub-clusters as described herein. Given the number of secondary network nodes 106 and / or sub-clusters, the primary network node 102 estimates the number of DL slots available for transmitting packets to the secondary network nodes 106.

[0046] The WBMS 100 manages the battery cells 108 using the master network node 102, the battery controller 104, and the secondary network nodes 106. The master network node 102 and the secondary network nodes 106 (e.g., WHs) communicate with each other regarding the status of the battery cells 108. The master network node 102 and the secondary network nodes 106 can communicate with or between each other using various protocol formats. For example, the master network node 102 and the secondary network nodes 106 use a DL protocol format and a UL protocol format, where each of the DL protocol format and the UL protocol format includes a frame control field to communicate battery management information. When a secondary network node 106 is informed of a situation by a battery cell 108, the secondary network node 106 communicates to the master network node 102 (or the respective WH of the sub-cluster) that the situation exists. The master network node 102 receives notification of the situation from the secondary network node 106 (e.g., WH) and alerts the battery controller 104 of the situation. The battery controller 104 determines the correct reaction to the situation and sends instructions to the master network node 102. The master network node 102 transmits the instructions to the secondary network node 106 (e.g., WH). The WH transmits the instructions to the WDs in the sub-cluster. The secondary network node 106 receives the instructions to manage the battery cells 108 in response to the situation. The secondary network node 106 manages the battery cells 108 in response to the situation.

[0047] Figure 2A An example WBMS 200 is illustrated. The WBMS 200 is an example of the wireless battery management system 100 described above. As shown, the WBMS 200 includes the master network node 102, the battery controller 104, a memory 202, a processor 204, a first secondary network node 206, a first plurality of battery cells 208, a second secondary network node 210, and a second plurality of battery cells 212. Additional secondary network nodes 206, 210 can be included, but are not explicitly shown. In one example, the master network node 102 is a WM and the secondary network nodes 206 and 210 are WHs. In another example, the master network node 102 is a WH and the secondary network nodes 206 and 210 are WDs. In this regard, Figure 2A and 2BAn illustration of the communications occurring throughout the multi-tiered network architecture described herein is provided. The master network node 102 includes a memory 202 and a processor 204 configured to execute code 205 stored on the memory 202 to perform one or more of the actions attributed herein to the master network node 102. In an example, a portion of the memory 202 can be non-transitory and a portion of the memory 202 can be transitory. The secondary network nodes 206, 210 can also include a processor and a memory. For example, as shown, the secondary network node 206 includes a processor 262 coupled to a memory 264 storing code 265 that can be executed by the processor 262 to perform one or more of the actions attributed herein to the secondary network node 206.

[0048] The master network node 102, if it is a WM, is coupled to the battery controller 104 using a first wired connection 110 and wirelessly to each of the secondary network nodes 206, 210. The first secondary network node 206 is coupled to the first plurality of battery cells 208 using a third wired connection 214 and wirelessly to the master network node 102. The second secondary network node 210 is coupled to the second plurality of battery cells 212 using a fourth wired connection 216 and wirelessly to the master network node 102. Figure 2A The number of secondary network nodes in the wireless battery management system 200 is not limited; rather, the naming convention indicates that each of the secondary network nodes is coupled to a plurality of battery cells.

[0049] In an example, the master network node 102 is wirelessly coupled to at least eight secondary network nodes 206, 210. In an example, each of the secondary network nodes 206, 210 can be coupled to at least sixteen battery cells using a wired connection. In an example, the wireless battery management system 200 includes one master network node. In other examples, the wireless battery management system 200 includes multiple master network nodes, with each network having its own hierarchical structure.

[0050] The WBMS 200 manages the first plurality of battery cells 208 and the second plurality of battery cells 212 using the primary network node 102, the battery controller 104, the memory 202, the processor 204, the first secondary network node 206, and the second secondary network node 210. Instructions in the memory 202 cause the processor 204 to instruct the primary network node 102 to wirelessly communicate with the first secondary network node 206 and the second secondary network node 210 regarding the status of the first plurality of battery cells 208 and the second plurality of battery cells 212. The primary network node 102 and the secondary network nodes 206, 210 communicate using various protocol formats. For example, the primary network node 102 and the secondary network nodes 206, 210 use a DL protocol format and a UL protocol format, where each of the DL protocol format and the UL protocol format includes a frame control field to communicate battery management information. When the first plurality of battery cells 208 informs the first secondary network node 206 of a condition, the first secondary network node 206 communicates to the primary network node 102 (or to the WH) that the condition exists. The primary network node 102 (or the WH) receives notification of the condition from the first secondary network node 206 and alerts the battery controller 104 (or the WM) of the condition. The battery controller 104 determines the correct response to the condition and sends instructions to the primary network node 102. The primary network node 102 transmits the instructions to the first secondary network node 206 (or to the WH). The first secondary network node 206 receives the instructions to manage the first plurality of battery cells 208 in response to the condition of the first plurality of battery cells 208. The first secondary network node 206 manages the first plurality of battery cells 208 in response to the condition. A similar process can apply to the second secondary network node 210 when a condition exists in the second plurality of battery cells 212. As described herein, through the hierarchical structure, the WM communicates with the WH, and the WH communicates with the respective WDs and then conveys responses from the WDs back to the WM.

[0051] Figure 2B An example WBMS 250 is illustrated. The WBMS 250 is an example of the WBMS 100 described above. As shown, the WBMS 250 includes the first secondary network node 206 (which can be a WD), the first plurality of battery cells 208, a plurality of primary network nodes 252 (which can be a WH), a memory 254, a processor 256, a first wired connection 258, and a plurality of battery controllers 260. The plurality of primary network nodes 252 includes the memory 254 and the processor 256. In an example, a portion of the memory 254 can be non-transitory and a portion of the memory 254 can be transitory. In an example, the memory 254 includes executable code 255 that, when executed by the processor 256, causes the processor 256 to perform the actions ascribed herein to the primary network nodes 252.

[0052] The plurality of master network nodes 252 are coupled to the plurality of battery controllers 260 using the first wired connection 258 and wirelessly coupled to the primary network node 206. The primary network node 206 is coupled to the first plurality of battery cells 208 using the wired connection 214 and wirelessly coupled to the plurality of master network nodes 252. As shown in FIG. 2, the primary network node 206 can include a processor and a memory (e.g., processor 262 and memory 264). Figure 2A As shown in FIG. 2, the primary network node 206 can include a processor and a memory (e.g., processor 262 and memory 264). Figure 2B The number of secondary network nodes in the wireless battery management system 250 is not limited. In an example, each of the plurality of master network nodes 252 is wirelessly coupled to at least eight secondary network nodes. In an example, the primary network node 206 can be coupled to at least sixteen battery cells using the fourth wired connection 216.

[0053] The WBMS 250 manages the first plurality of battery cells 208 using the plurality of master network nodes 252, the plurality of battery controllers 260, the memory 254, the processor 256, and the primary network node 206. Instructions in the memory 254 cause the processor 256 to instruct the plurality of master network nodes 252 to wirelessly communicate with the primary network node 206 regarding the status of the first plurality of battery cells 208. The plurality of master network nodes 252 and the primary network node 206 communicate using various protocol formats. For example, the plurality of master network nodes 252 and the primary network node 206 use a DL protocol format and a UL protocol format, where each of the DL protocol format and the UL protocol format includes a frame control field to communicate battery management information. When the first plurality of battery cells 208 informs the primary network node 206 of a condition, the primary network node 206 communicates to the plurality of master network nodes 252 that the condition exists. The plurality of master network nodes 252 receive notification of the condition from the primary network node 206 and alert the plurality of battery controllers 260 of the condition. The plurality of battery controllers 260 determine the correct reaction to the condition and send instructions to the plurality of master network nodes 252. The plurality of master network nodes 252 transmit the instructions to the primary network node 206. The primary network node 206 receives the instructions to manage the first plurality of battery cells 208 in response to the condition of the first plurality of battery cells 208. The primary network node 206 manages the first plurality of battery cells 208 in response to the condition.

[0054] In an example, the first-time network node 206 communicates with a first master network node of the plurality of master network nodes 252 based on instructions from a master controller (not shown). The first-time network node 206 can transition communications from the first master network node to a second master network node of the plurality of master network nodes 252. The first master network node and the second master network node communicate with each other to coordinate a transfer of active connections of the first-time network node 206 from the first master network node to the second master network node. In an example, the first master network node communicates with the first-time network node 206 and the second master network node monitors a status of the first master network node. The status can indicate whether the first master network node has power and is operating within normal operating conditions. The first master network node provides a clock signal to the second master network node to synchronize communications. The first master network node and the second master network node select different frequencies to communicate with the first-time network node 206. Selecting different frequencies allows the plurality of master network nodes 252 to minimize interference when communicating with the first-time network node 206. For example, if the first master network node is going to lose power, or if the status of the first master network node is going to go out of normal operating conditions, the second master network node can connect to the first-time network node 206 to supplement communications until the first master network node can operate normally again.

[0055] Figure 3 A block diagram of a hierarchical WBMS 300 according to various examples herein. The WBMS 300 includes a WM (Wireless Master) 302, sub-clusters 304, wireless heads (WHs) 306, and wireless devices (WDs) 308. In this example, one WM 302 manages the sub-clusters 304, but other network architectures with two or more WMs can be used to implement the techniques of the present disclosure. The sub-clusters 304 can be referred to collectively as the sub-clusters 304 or individually as a sub-cluster 304. Four sub-clusters 304 are shown in the WBMS 300 (304.1, 304.2, 304.3, and 304.N), but any number of sub-clusters 304 can be present in other examples.

[0056] Each sub-cluster 304 has a WH 306 that manages the sub-cluster 304. In Figure 3 Four WHs 306 (WH1, WH2, WH3, and WHN) are shown in the WBMS 300. The WHs 306 can be referred to collectively as the WHs 306 or individually as a WH 306. Each WH 306 communicates with the WM 302 and with the WDs 308 in its respective sub-cluster 304. Each sub-cluster 304 has one or more WDs 308 that communicate with the WH 306 in the sub-cluster 304. The WDs 308 can be referred to collectively as the WDs 308 or individually as a WD 308.

[0057] In this example, WH1 306.1 manages WDs 308.1-308.6 in sub-cluster 304.1. Six WDs 308 are shown in sub-cluster 304.1 (e.g., WDs 308.1-308.6), but any number of WDs 308 can be present in sub-cluster 304 in other examples. Sub-cluster 304.2 includes WH2 306.2 and WDs 308.7-308.12. Sub-cluster 304.3 includes WH3 306.3 and WDs 308.13-308.18. Sub-cluster 304.N includes WHN 306.N (where N can be any number) and WDs 308.19-308.24. In some examples, in addition to the WH communication functionality described herein, WHs 306 can also operate as WDs 308 and perform the monitoring and management of battery cells 108 that WDs 308 perform. However, in all examples of the present disclosure, WHs 306 do not encompass this monitoring functionality.

[0058] In examples herein, when installed in a WBMS, WM 302 is in communication range of WHs 306, and each WH 306 is in communication range of the respective WDs 308 in its sub-cluster 304. Sub-clusters 304 can have the same number of WDs 308 or different numbers of WDs 308. Six WDs 308 are shown in each sub-cluster 304 in this example, but other numbers can be present in other examples. As described below, WM 302, WHs 306, and WDs 308 can use a master hopping sequence to select channels for communication. Further, as described below, various superframe structures are described below to handle communications within a hierarchical WBMS as described herein.

[0059] Figure 4A and 4B are block diagrams of superframe structures 400A and 400B in accordance with various examples herein. This superframe structure is referred to as a Type 2 structure. Superframe structures 400A and 400B include a master hopping sequence 402 that is used by WM 302 to select a channel for communication. In this example, master hopping sequence 402 is a sequence of 16 channels, but other numbers of channels can be used in other examples. The channels in master hopping sequence 402 are numbered 0-15. In this example, the channels in master hopping sequence 402 are numbered sequentially, but other numbering schemes can be used in other examples. Figure 4A and 4B The uplink (UL) and downlink (DL) for various devices (WM 302, WH1 306.1, WH2 306.2, WD2 308.2, and WD14 308.14) shown on the left side of Figure 4A and 4B The top row of Figure 4A and 4BThe last row of the table shows the UL and DL associated with WD 14 308.14 that are sent by WD 14 308.14 or received by WD 14 308.14.

[0060] The superframe structure 400A includes a first superframe 402A, and the superframe structure 400B includes a second superframe 402B. The superframe structures 400A and 400B include various ULs and DLs 404-454. These ULs and DLs represent communications between devices in an example WBMS (e.g., WBMS 300). Details of each of the ULs and DLs 404-454 are described below.

[0061] The superframe structures 400A and 400B also show the channels that the devices in the WBMS 300 are using for communication. In the first superframe 402A, channels Ml, Al, and Bl are used. In the second superframe 402B, channels M2, A2, and B2 are used. The specific ULs and DLs transmitted on each channel are described below.

[0062] In the WBMS 300, the WM 302 communicates with the WHs 306. The WM 302 can send instructions or requests for battery cell information or battery management information to the WHs 306. The WHs 306 receive the instructions or requests and then send the instructions or requests to each WD 308 managed by the respective WH 306. The WDs 308 collect the information (if needed) and respond to the WH 306 that manages the respective subcluster 304. Each WH 306 can then be configured to aggregate the responses from the WDs 308 in its respective subcluster 304 and transmit the responses to the WM 302. Thus, the WHs 306 can be configured to act as intermediaries between the WM 302 and the WDs 308.

[0063] Figure 4A and 4B An example process using the superframe structures 400A and 400B is shown. In Figure 4A In the first superframe 402A in the table, the WM 302 sends a DL 404 (DL-WM) on channel Ml to each of the WHs 306. In this case, WHl 306.1 receives the DL 406A, and WH2 306.2 receives the DL 406B. The DL 404 can contain instructions for the WHs 306 to query the WDs 308 in their respective subclusters 304 for information (e.g., the status of the battery cells 108). After the WM 302 sends this DL 404, the WM waits for the WHs 306 to receive the responses from the WDs 308 and then provide those responses to the WM 302. This is indicated in the table as "WM not listening" during a portion of the first superframe 402A. Figure 4A

[0064] ​In response to the DL 404, each WH 306 transmits a DL to the WDs 308 in its respective subset cluster 304. In this example, WH1 306.1 transmits a DL 408 (DL WH1) to WD2- WD7 308. The DL 408 is transmitted on channel Al. WH1 306.1 uses channel Al to communicate with its WDs 308 in the first superframe 402A. WH2 306.2 transmits a DL 410 (DL WH2) to WD9- WD14 308. The DL 410 is transmitted on channel Bl. WH2 306.2 uses channel Bl to communicate with its WDs 308 in the first superframe 402A. In this example, each subset cluster 304 uses a different channel for communication between the WHs 306 and WDs 308 in the subset cluster 304.

[0065] Each WD 308 receives the DL (in this example, 408 or 410) from its respective WH 306. Figure 4A Only WD2 308.2 and WD14 308.14 are shown in the example, but the other WDs 308 operate similarly. WD2 308.2 receives the DL 412, and WD14 308.14 receives the DL 414. Each WD 308 responds to its respective WH 306 with a UL. Here, WD2 308.2 sends a UL 416 to WH1 306.1 on channel Al. WD14 308.14 sends a UL 418 to WH2 306.2 on channel Bl. Although Figure 4A The other WDs 308 also send a UL to their respective WHs 306 on the appropriate channel, although not shown in the example.

[0066] After receiving the UL from each WD 308 in its subset cluster, each WH 306 aggregates the information in the ULs from the WDs 308 in its subset cluster and sends a UL to the WM 302. Here, WH1 306.1 sends a UL 424 to the WM 302 on channel Ml. WH2 306.2 sends a UL 426 to the WM 302 on channel Ml. The ULs 424 and 426 are sent on channel Ml at different times as shown, so they do not interfere with each other. The WM 302 receives the ULs 428A-428D from each WH 306 that it manages. At this point, the first superframe 402A is complete and the second superframe 402B begins.

[0067] In the second superframe 402B, the WDs 308 in each subset cluster 304 send a UL to their respective WH 306. In this example, WD2 308.2 sends a UL 430 to WH1 306.1 on channel Al. WD14 308.14 sends a UL 432 to WH2 306.2 on channel Bl. The other WDs 308 also send a UL to their respective WHs 306 on the appropriate channel, although not shown in the example. Figure 4BIn the second superframe 402B, UL and DL transmissions are similar to those described above for the first superframe 402A. In the second superframe 402B, different channels are used than in the first superframe 402A. Channel M2 is used instead of channel Ml. Channel A2 is used instead of channel Al, and channel B2 is used instead of channel Bl.

[0068] In the second superframe 402B, the WM 302 transmits a DL 430 (DL-WM) on channel M2 to each of the WHs 306. In this case, WHl 306.1 receives DL 432A, and WH2 306.2 receives DL 432B. After the WM 302 transmits this DL 430, the WM waits for the WHs 306 to receive responses from the WDs 308 and then provides those responses to the WM 302.

[0069] In response to the DL 430, each WH 306 transmits a DL to the WDs 308 in its respective sub-cluster 304. In this example, WHl 306.1 transmits a DL 434 (DL WHl) to WD2 through WD7 308. The DL 434 is transmitted on channel A2. WH2 306.2 transmits a DL 436 (DL WH2) to WD9 through WD14 308. The DL 436 is transmitted on channel B2.

[0070] Each WD 308 receives a DL (in this example, 434 or 436) from its respective WH 306. WD2 308.2 receives DL 438, and WD14 308.14 receives DL 440. Each WD 308 responds to its respective WH 306 with a UL. Here, WD2 308.2 transmits a UL 442 to WHl 306.1 on channel A2. WD14 308.14 transmits a UL 444 to WH2 306.2 on channel B2.

[0071] After receiving the UL from each WD 308 in its sub-cluster, each WH 306 aggregates the information in the ULs from the WDs 308 in its sub-cluster and transmits a UL to the WM 302. Here, WHl 306.1 transmits a UL 450 to the WM 302 on channel M2. WH2 306.2 transmits a UL 452 to the WM 302 on channel M2. The WM 302 receives the ULs 454A through 454D from each WH 306 that it manages. At this point, the second superframe 402B is complete and another superframe 402 can begin. The next superframe can again hop channels according to the master hopping sequence, and use channels M3, A3, and B3 for communications.

[0072] In the case of the channel hopping sequence described herein, channels A and B can be derived from channel M using a set of offsets. For example, channel A can be derived by calculating M-2, and channel B can be derived by calculating M-4. Any other offset can apply in other examples. Further, in one example, channel A or channel B can be channel M. As Figure 4A and 4B If channel A is also channel M, those channels would not be used at the same time in superframe 402, and thus there would be no interference. Any channel selection can be used as long as the transmissions on the channels do not collide with each other.

[0073] In examples herein, any suitable process can be used for network formation. In one example, WM 302 forms a network using WHs 306 all in a first stage. In a second stage, each WH 306 forms a network with its respective WD 308.

[0074] The network topology can be provided by one of two examples. In a first example, WM 302 knows the network topology before formation. The other nodes are informed of the network topology during the scan phase. The network topology can be enforced by whitelisting selected nodes according to the topology. In this example, only WHs 306 are allowed to pair with WM 302. The paired WHs 306 receive a list of respective WDs 308 that form a subcluster 304 with them. WHs 306 can be configured to whitelist only the received list of WDs 308 of their subcluster 304 to form subcluster 304.

[0075] In a second example, each node is programmed with a cluster ID (clusterID) that should join before network formation. Each WH 306 (and WM 302) is programmed with a cluster ID that will be master (before network formation). WM 302 is programmed with the cluster ID of each WH 306, and each WH 306 is programmed with the cluster ID of the respective WD 308 in its subcluster 304. The cluster ID is advertised in the scan request. If any node receives a scan request, it sends a response only if the cluster ID in the request matches.

[0076] Network formation can be performed in two phases. In phase one, the WM 302 can be configured to perform a passive scan to select its master ID. The WD 308 can be configured to avoid participating in phase one, which can be enforced by being whitelisted at the WM 302. The superframe format used can be type 1 format, which is described below. Scanning and pairing is performed on the WH 306 to pair with the WM 302. In one example, scanning can be performed using the configuration channels. After phase one is complete, the WM 302 switches the network to the master hopping sequence for the data channels. After the WH 306 is paired with the WM 302, phase two begins.

[0077] In phase two, the WM 302 coordinates the WH 306 to form its respective sub-cluster 304 through its own scanning and pairing phase. A dedicated hopping sequence is transmitted by the WM 302 to each paired WH 306 for data exchange within the micro-superframe. The hopping sequence (described below) can be selected from a set of orthogonal hopping sequences or shifted hopping sequences. The superframe type 2 structure can be used throughout network formation and operation. Three options are described below for network formation: options 1, 2, and 3. Option 3 proposes an additional superframe type, type 3. The different options can have different speeds for network formation, with some options being faster than others. However, the faster options can also be more complex than the slower options.

[0078] Figure 5 A type 1 superframe structure 500 for network formation according to various examples herein. In this example, the superframe structure 500 includes two superframes 502A and 502B. Three configuration channels 504A, 504B, and 504C are shown in this example. The superframe structure 500 includes DLs 506 and 512, and ULs 508, 510, 514, and 516.

[0079] In a type 1 superframe, the superframe duration includes 1 DL slot and N UL slots, where N is the number of WHs 306 managed by the WM 302. The type 1 superframe can be suitable for the WH 306 scanning and pairing phase described herein. In superframe 502A, the WM 302 sends a DL scan request 506 on configuration channel 1 504A. The WHs 306 can respond on configuration channel 1 504A in superframe 502A. In this example, WH4 sends a UL 508 scan response to the WM 302. WH2 sends a UL 510 scan response to the WM 302.

[0080] In superframe 502B, WM 302 sends a DL scan request 512 on configuration channel 2 504B. WH 306 can respond on configuration channel 2 504B in superframe 502B. In this example, WH5 sends an UL 514 scan response to WM 302. WH1 sends an UL 516 scan response to WM 302.

[0081] Figure 6 Data and configuration channels 600 are shown in accordance with various examples herein. In some examples, channels 600 can be Bluetooth Low Energy (BLE) frequency channels, where in Figure 6 Example frequencies are shown in Table 1. This example includes three configuration or broadcast channels (602A, 602B, and 602C), which are channels 37, 38, and 39. Channels 604 are data channels, and include channels 0 through 36, for a total of 37 data channels.

[0082] In examples herein, for each subcluster 304, WM 302 communicates a master hopping sequence and a unique offset to calculate channels. The offset for a given subcluster 304 is subtracted from the number of channels, and cycled within [0 to 36]. The offset does not include configuration channels 37, 38, and 39. For example, if the segment of the master hopping sequence is for non-adjacent channels [5, 27, 0, 16], and the offset for the subcluster 304 is 3, then the subcluster will follow channels [2, 24, 34, 13], while the MHS follows channels [5, 27, 0, 16]. The offset should be large enough to minimize adjacent channel interference. WM 302 needs to send only the master hopping sequence and the offset to WH 306 in this example.

[0083] In some examples herein, measurement transient mismatches can occur due to the hierarchical structure. As an example, WM 302 can send instructions to WH 306 to perform measurements, which WH 306 in turn sends to WD 308 in the respective subcluster 304. Thus, WH 306 receives the instructions before WD 308. If the WH performs the measurements before the WD, a measurement transient mismatch will occur, where the measurements of each node are not performed at the same time. Depending on the measurements performed, this mismatch can result in inaccurate data. In examples herein, the instructions can be delayed at WH 306 (e.g., in software) for an appropriate duration, so that the measurements made by WH 306 occur at approximately the same time as the measurements made by WD 308.

[0084] In examples herein, each WH 306 receives data from N WDs 308 and in its own time slot (e.g., in a time slot 606A, 606B, 606C, 606D, 606E, 606F, 606G, 606H, 6061, 606J, 606K, 606L, 606M, 606N, 606P, 606Q, 606R, 606S, 606T, 606U, 606V, 606W, 606X, 606Y, 606Z, 606AA, 606BB, 606CC, 606DD, 606EE, 606FF, 606GG, 606HH, 606II, 606JJ, 606KK, 606LL, 606MM, 606NN, 606OO, 606PP, 606QQ, 606RR, 606SS, 606TT, 606UU, 606VV, 606WW, 606XX, 606YY, 606ZZ, 606AAA, 606BBB, 606CCC, 606DDD, 606EEE, 606FFF, 606GGG, 606HHH, 606III, 606JJJ, 606KKK, 606LLL, 606MMM, 606NNN, 606OOO, 606PPP, 606QQQ, 606RRR, 606SSS, 606TTT, 606UUU, 606VVV, 606WWW, 606XXX, 606YYY, 606ZZZ, 606AAAA, 606BBBB, 606CCCC, 606DDDD, 606EEEE, 606FFFF, 606GGGG, 606HHHH, 606IIII, 606JJJJ, 606KKKK, 606LLLL, 606MMMM, 606NNNN, 606OOOO, 606PPPP, 606QQQQ, 606RRRR, 606SSSS, 606TTTT, 606UUUU, 606VVVV, 606WWWW, 606XXXX, 606YYYY, or 606ZZZZ). Figure 4AThe aggregated data is forwarded to the WM 302 in the UL 424 and 426 slots, which can potentially be longer than other slots. The duration of the aggregated UL slots (e.g., 424 and 426) is less than N times the original UL slot, because the WH 306 does not have to forward the entire frame from the WD 308, but only the payload and identifying information for each WD 308. Thus, this reduces the net overhead for forwarding information from N WDs 308 compared to a single tier network.

[0085] Figure 7A and 7B Alternative superframe structures 700A and 700B according to various examples herein. In this example, the WH 306 receives DL from the WM 302 and then transmits back to the WM 302 before transmitting to the WDs 308 in its respective subset cluster 304. This example has a superframe 702 that is of type 2, but is subdivided into three type 1 superframes (704A, 704B, and 704C). In some examples, the superframes 704A, 704B, and 704C can have different durations. There can be any number of WHs 306 and WDs 308 in examples using the superframe structures 700A and 700B. The superframe structures 700A and 700B can also be used in other examples described herein.

[0086] In this example, during the type 1 superframe 704A in Figure 7A The WM 302 sends a DL 706 on channel Ml to WHl 306.1 and WH2 306.2 during the type 1 superframe 704A in

[0087] In this example, during the type 1 superframe 704A in Figure 7ADuring Type 1 superframe 704B, WH 306 transmits DL to its corresponding WD 308, and WD 308 responds with UL. WM 302 is not listening at this time. In this example, WH1 306.1 sends DL 716 to WD 308 in its sub-cluster 304 on channel A1. WH2 306.2 sends DL 718 to WD 308 in its sub-cluster 304 on channel B1. WD2 308.2 receives DL 720 on channel A1. WD14 308.14 receives DL 722 on channel B1. WD2 308.2 sends UL 724 to WH1 306.1 on channel A1. WD14 308.14 sends UL 726 to WH2 306.2 on channel B1. Other WD 308 ( Figure 7A (Not shown in the image) ULs can also be sent to their respective WH 306s during superframe 704B. In some instances, these aggregated ULs may be longer than the other ULs. WH1 306.1 receives ULs 728A to 728F from its WD 308. WH2 306.2 receives ULs 730A to 730F from its WD308.

[0088] exist Figure 7B During Type 1 superframe 704C, WH 306 aggregates ULs from the corresponding WD 308 and transmits the aggregated ULs to WM 302. First, WM 302 sends DL 732 to WH 306. WH1 306.1 receives DL 734A, and WH2 306.2 receives DL 734B. Each WH 306 aggregates ULs from WD 308 in the corresponding sub-cluster 304 and transmits those aggregated ULs to WM 302. As discussed above, each of WH 306 can be configured to generate aggregated ULs based on ULs received from WD 308 in the corresponding sub-cluster. WH1 306.1 transmits UL 736 to WM 302 on channel M1, and WH2 306.2 transmits UL 738 to WM 302 on channel M1. WM 302 receives UL 740A to 740D on channel M1 in superframe 704C.

[0089] Figure 8A and 8B The examples in this paper are superframe structures 800A and 800B used for network formation. Figure 8A and 8BAn example of network formation option 1 is provided. In option 1, sub-clusters 304 are formed sequentially, with the process coordinated by the WM 302. One sub-cluster 304 is formed (e.g., scanned and paired) at a time. A similar scanning and pairing mechanism is used for each sub-cluster 304 that uses a configuration channel. Each WH 306 can be configured to use its white list received from the WM 302 to admit control WDs 308. Any WH 306 in the network formation phase uses only the configuration channel. After a sub-cluster 304 is formed, the sub-cluster 304 follows its frequency hopping sequence as instructed by the WM 302. The main cluster also follows the master frequency hopping sequence.

[0090] In each type 2 superframe in this example, the corresponding WH 306 reports to the WM 302 the status of its sub-cluster 304 formation. After the WH 306 (e.g., WHN) completes forming its sub-cluster 304, the WM 302 instructs the next WH 306 (e.g., WH(N+1)) to form its cluster starting from the next type 2 superframe. After any sub-cluster 304 is formed, the sub-cluster 304 switches to its frequency hopping sequence derived from the master frequency hopping sequence. The sub-cluster 304 then is in the network operation phase, in which the sub-cluster participates in normal data exchange as described above with respect to, for example, Figure 4A and 4B After network formation of all sub-clusters 304 is completed and confirmed by each WH 306 to the WM 302, all sub-clusters 304 are in normal data exchange operation.

[0091] The superframe structures 800A and 800B show an example of option 1 network formation. The superframe structure 800A includes superframe 802A, and the superframe structure 800B includes superframe 802B, which is a type 2 superframe. In the superframe 802A, WH1 306.1 is in the network formation phase. WH2 306.2 has completed its network formation, and is in the normal data exchange phase. The process begins with the WM 302 sending a DL 804 to each WH 306 in the cluster. In this example, WH1 306.1 receives a DL 806A, and WH2 306.2 receives a DL 806B. The DL 804 contains an indication that WH1 306.1 is in the scanning phase, and WH2 306.2 has completed network formation. Other WHs 306 that have not completed their scanning phase will wait for WH1 306.1 to complete its scanning phase. Other WHs 306 that have completed their scanning phase can participate in normal data exchange operations, such as WH2 306.2 in this example. The DL 804 can also contain acknowledgments of UL frames from all WHs 306.

[0092] WH1 306.1 proceeds with its scan phase. WH1 306.1 transmits a scan request DL 808 on configuration channel 1 to each WD 308 in its respective subcluster 304. As shown, the WDs 308 in this subcluster (e.g., WD2 308.2) receive the scan request in DL 810. The WDs 308 in the subcluster for WH1 306.1 then send individual responses back to WH1 306.1 on configuration channel 1. In superframe 802A, WD3 308 sends an UL 812 to WH1 306.1 and WD5 308 sends an UL 814 to WH1 306.1. ULs 812 and 814 are not sent by WD2 308.2, but are shown on the row of WD2 308.2 for simplicity. WH1 306.1 receives these response ULs 816 and 818, respectively. WH1 306.1 aggregates the responses from its WDs 308 and transmits those responses to WM 302 with an UL 820 on channel M1. UL 820 can note that WH1 306.1 is in the scan phase and include an acknowledgement of the last frame from WM 302.

[0093] While WH1 306.1 is scanning in superframe 802A, WH2 306.2 performs normal data exchange with the WDs 308 in its subcluster. WH2 306.2 transmits a DL 822 on channel B1. In this example, WDs 308.9 through 308.14 are in a subcluster 304 managed by WH2 306.2. For simplicity, only WH14 308.14 is shown here. Each WD 308 in this subcluster 304 receives the DL on channel B1, such as DL 824 received by WD14 308.14. Each WD 308 sends a response to WH2 306.2, such as UL 826 from WD14 308.14. WH2 306.2 receives the ULs 828A through 828F from the WDs 308 in its subcluster 304 on channel B1. WH2 306.2 aggregates the responses and provides an UL 830 to WM 302 on channel M1. UL 830 can indicate that WH2 306.2 has completed its network formation phase and contains aggregated data from the WDs 308 in the respective subcluster 304. UL 830 can also include an acknowledgement of the last frame from WM 302. In this example, ULs 832A through 832D are received at WM 302, but the system can include any number of subclusters 304 and WHs 306. This marks the end of superframe 802A.

[0094] In Figure 8BIn superframe 802B, similar processes occur as discussed above with respect to superframe 802A. In superframe 802B, WH1 306.1 has not completed the scanning and pairing phase, so it continues to scan and pair with unpaired WDs 308 in its subset cluster 304. WH2 306.2 continues normal data exchange with its respective WDs 308.

[0095] WM 302 sends a DL 834 to each WH 306 in the cluster on channel M2. In this example, WH1 306.1 receives a DL 836A and WH2 receives a DL 836B. The DL 834 can be similar to the DL 804 described above.

[0096] WH1 306.1 transmits a scan request DL 838 to each WD 308 in its respective subset cluster 304 on configuration channel 2. As shown, the WDs 308 in this subset cluster (e.g., WD2 308.2) receive the scan request in a DL 840. For those WDs 308 that were not paired with WH1 306.1 in the previous superframe 802, the WDs 308 in the subset cluster for WH1 306.1 then send individual responses back to WH1 306.1 on configuration channel 2. In superframe 802B, WD2 308.2 sends a UL 842 to WH1 306.1 and WD4 308 sends a UL 844 to WH1 306.1. WH1 306.1 receives these response ULs 846 and 848, respectively. WH1 306.1 aggregates the responses from its WDs 308 and transmits those responses to WM 302 with a UL 850 on channel M2. The UL 850 can be similar to the UL 820 described above.

[0097] In superframe 802B, while WH1306.1 is scanning, WH2306.2 performs normal data exchange with the WDs 308 in its subcluster, as it did in superframe 802A. WH2306.2 transmits a DL 852 on channel B2. Each WD 308 in the subcluster 304 managed by WH2306.2 receives the DL on channel B2, such as DL 854 received by WD14308.14. Each WD 308 sends a response to WH2306.2, such as UL 856 from WD14308.14. WH2306.2 receives the UL 858A-858F from the WDs 308 in its subcluster 304 on channel B2. WH2306.2 aggregates the responses and provides a UL 860 to WM302 on channel M2. The UL 860 can be similar to UL 830 described above. In this example, UL 862A-862D are received at WM302, but the system can include any number of subclusters 304 and WHs 306. This marks the end of superframe 802B. Thus, Figure 8A and 8B Option 1 for network formation is described.

[0098] Figure 9A and 9B Superframe structures 900A and 900B for network formation according to various examples herein are shown. Figure 9A and 9B Examples of network formation option 2 are provided. In option 2, groups of subclusters 304 are formed simultaneously rather than one by one as in option 1. In option 2, three subclusters 304 can be formed at a time using three configuration channels. In other examples, more subclusters 304 can be formed at a time if more configuration channels are available.

[0099] Subcluster 304 formation in option 2 is coordinated by WM302. Each WH306 is instructed by WM302 to use one of the configuration channels, and the configuration channels will be rotated in each superframe. Similar scanning and pairing mechanisms as described above in option 1 can be used for each subcluster 304 in the configuration channels. The cluster uses a master hopping sequence as described herein. In each type 2 superframe, the corresponding WH306 reports to WM302 the status of its subcluster 304 formation. After formation of any of the current three subclusters 304, WM302 instructs a new WH306 or a new set of WHs 306 to start network formation. After formation of any subcluster 304, the subcluster 304 switches to its derived hopping sequence derived from the master hopping sequence for normal data exchange. Option 2 can be three times faster than option 1, but uses the same superframe structure and timing.

[0100] The superframe structures 900A and 900B show an example of an option 2 network formation. The superframe structure 900A includes a superframe 902A and the superframe structure 900B includes a superframe 902B, which are type 2 superframes. In the superframe 902A, WH1 306.1, WH2 306.2, and WH4 306.4 are in the network formation phase. WH3 306.3 has completed its network formation and is in the normal data exchange phase. In this example, the WDs 308 are not shown, but the WHs 306 communicate with the WDs 308 in their respective sub-clusters 304 as described above for option 1.

[0101] For option 2, the process begins in the superframe 902A with the WM 302 sending a DL 904 to each WH 306 in the cluster. WH1 306.1 receives a DL 906A, WH2 306.2 receives a DL 906B, WH3 306.3 receives a DL 906C, and WH4 306.4 receives a DL 906D. The DL 904 from the WM 302 contains an indication that WH1 306.1, WH2 306.2, and WH4 306.4 are in the scanning or network formation phase, and WH3 306.3 has completed network formation. The WM 302 allocates selected configuration channels to WH1 306.1, WH2 306.2, and WH4 306.4. WH3 306.3 follows the master frequency hopping sequence. The other WHs 306 that have not formed their networks will not transmit until the WM 302 allocates configuration channels for them.

[0102] Each WH 306 in the network formation phase transmits a scanning request DL to each WD 308 in its respective sub-cluster 304 on its respective configuration channel. WH1 306.1 sends a DL 908 on configuration channel 1, WH2 306.2 sends a DL 910 on configuration channel 2, and WH4 306.4 sends a DL 912 on configuration channel 3. Then, the WDs 308 (not shown) for each WH 306 respond back to their respective WH 306 with a UL for pairing. In this example, WH1 306.1 receives ULs 914A and 914B from its WDs 308, WH2 306.2 receives ULs 914C and 914D from its WDs 308, and WH4 306.4 receives ULs 914E and 914F from its WDs 308. Then, each WH 306 aggregates its received ULs from its WDs 308 and transmits a UL to the WM 302 on channel Ml. Here, WH1 306.1 sends a UL 916, WH2 306.2 sends a UL 918, and WH4 306.4 sends a UL 920.

[0103] During superframe 902A, while WH1 306.1, WH2 306.2, and WH4 306.4 are in the scanning phase, WH3 306.3 performs normal data exchange with its WD 308. WH3 306.3 transmits DL 922 to its WD 308 on channel B1. WD 308 responds to WH3 306.3 on channel B1 with UL 924A to 924F. WH3 306.3 aggregates the responses from WD 308 and transmits UL 926 to WM 302. UL 926 indicates that WH3 306.3 has completed its network formation phase and contains aggregated data from all WD 308s in the WH3 306.3 sub-cluster. WM 302 receives UL 928A to 928D (from one of each WH306 in the cluster) and superframe 902A ends.

[0104] exist Figure 9B In superframe 902B, a process similar to that described above for superframe 902A occurs. In superframe 902B, WH1 306.1, WH2 306.2, and WH4 306.4 have not yet completed the scanning and pairing phase; therefore, those WH 306 continue scanning and pairing with unpaired WD 308 in their respective sub-clusters 304. WH1 306.1, WH2 306.2, and WH4 306.4 can be configured to use different configuration channels in superframe 902B compared to the configuration channel used by each corresponding WH in superframe 902A. WH3 306.3 continues normal data exchange with its corresponding WD 308.

[0105] The process in superframe 902B begins with WM 302 sending DL 930 to each WH 306 in the cluster on channel M2. WH1 306.1 receives DL 932A, WH2 306.2 receives DL 932B, WH3 306.3 receives DL 932C, and WH4 306.4 receives DL 932D. DL 930 can be similar to DL 904 described above.

[0106] Each WH 306 in the network formation phase transmits a scan request DL on its respective configuration channel to each WD 308 in its respective subset cluster 304. WH1 306.1 sends a DL 934 on configuration channel 2, WH2 306.2 sends a DL 936 on configuration channel 3, and WH4 306.4 sends a DL 938 on configuration channel 1. Next, the WDs 308 (not shown) for each WH 306 respond with an UL to their respective WH 306 for pairing. In this example, WH1 306.1 receives ULs 940A and 940B from its WDs 308, WH2 306.2 receives ULs 940C, 940D, and 940E from its WDs 308, and WH4 306.4 receives ULs 940F, 940G, and 940H from its WDs 308. Next, each WH 306 aggregates the ULs it receives from its WDs 308 and transmits an UL to the WM 302 on channel M2. Here, WH1 306.1 sends an UL 942, WH2 306.2 sends an UL 944, and WH4 306.4 sends an UL 946.

[0107] During superframe 902B, while WH1 306.1, WH2 306.2, and WH4 306.4 are in the scan phase, WH3 306.3 performs normal data exchange with its WDs 308 (similar to superframe 902A). WH3 306.3 transmits a DL 948 to its WDs 308 on channel B2. The WDs 308 respond to WH3 306.3 with ULs 950A through 950F on channel B2. WH3 306.3 aggregates the responses from the WDs 308 and transmits an UL 952 to the WM 302. The WM 302 receives ULs 954A through 954D (one from each WH 306 in the cluster) and superframe 902B ends.

[0108] Figure 9A Option 2 in 9B shows that the configuration channels are rotated during each superframe 902 for the WHs 306 in the network formation phase as noted above. Thus, Figure 9A 9B describes Option 2 for network formation.

[0109] Figure 10A and 10B are superframe structures 1000A and 1000B for network formation according to various examples herein. Figure 10A and 10B ​An example of network formation option 3 is provided. Option 3 is more complex than options 1 or 2. In option 3, a new superframe type (type 3) is used until all sub-clusters 304 are formed. Superframe type 3 is similar to type 2, but type 3 has micro-superframes within a longer superframe than type 2. In the case of type 3, all sub-clusters 304 are formed simultaneously with a process coordinated by the WM 302. Each WH 306 is instructed by the WM 302 to use one of the configuration channels of each micro-superframe, and the configuration channels will rotate from superframe to superframe. After network formation is complete, the network switches to superframe type 2 for normal data exchange. The master cluster follows the master hopping sequence. In each type 3 superframe, all WHs 306 report to the WM 302 the status of their sub-cluster 304 formation. After a WH 306 completes formation of its sub-cluster 304, the WH 306 switches its sub-cluster 304 to the correct hopping sequence within the micro-superframe. After all sub-clusters 304 are formed, the WM 302 switches the network to superframe type 2.

[0110] The superframe structures 1000A and 1000B show an example of option 3 network formation. The superframe structures 1000A and 100B include superframes 1002A and 1002B, respectively, which are type 3 superframes. In the superframe 1002A, WH1 306.1, WH2 306.2, WH3 306.3, and WH4 306.4 are in the network formation phase. In this example, the WDs 308 are not shown, but the WHs 306 communicate with the WDs 308 in their respective sub-clusters 304 as described above for options 1 and 2.

[0111] For option 3, the process begins in the superframe 1002A in Figure 10A The DL 1004 from the WM 302 contains an indication that WH1 306.1, WH2 306.2, WH3 306.3, and WH4 306.4 are in the scanning or network formation phase. The WM 302 allocates the selected configuration channels and data channels to WH1 306.1, WH2 306.2, WH3 306.3, and WH4 306.4.

[0112] Each WH 306 in the network formation phase transmits a scan request DL on its respective configuration channel to each WD 308 in its respective subcluster 304. WH1 306.1 sends DL 1008 on configuration channel 1, WH2 306.2 sends DL 1010 on configuration channel 2, and WH3 306.3 sends DL 1012 on configuration channel 3. Because there are four WHs 306 but only three configuration channels, WH4 306.4 must wait in a wait period 1014 for a configuration channel to become available. After the DLS 1008, 1010, and 1012 are sent, a configuration channel is opened, and the WM 302 allocates configuration channel 1 to WH4 306.4. WH4 306.4 then sends DL 1016 to its WDs 308 in its subcluster 304. During the time that the DL 1016 is transmitted, the other WHs 306 wait for the DL 1016 to end. These wait periods are shown as 1018A, 1018B, and 1018C for the first three WHs 306.

[0113] After the scan request DLS are sent to the WDs 308, the WDs 308 respond to their respective WHs 306 in the microsuperframe. For this response, the data channels are used instead of the configuration channels. WH1 306.1 uses channel Al, WH2 306.2 uses channel Bl, WH3 306.3 uses channel Cl, and WH4 306.4 uses channel Dl. WH1 306.1 receives ULs 1020 and 1022, WH2 306.2 receives ULs 1024 and 1026, WH3 306.3 receives ULs 1028 and 1030, and WH4 306.4 receives ULs 1032 and 1034.

[0114] After the ULs have been received by the WHs 306 from the WDs 308, each WH 306 aggregates the responses from its WDs 308 and sends an UL to the WM 302 on channel Ml. WH1 306.1 sends UL 1036, WH2 306.2 sends UL 1038, WH3 306.3 sends UL 1040, and WH4 306.4 sends UL 1042. The WM 302 receives ULs 1044A through 1044D, and the superframe 1002A ends.

[0115] Figure 10B The superframe 1002B operates similarly to the superframe 1002A. In this example, neither of the WHs 306 completed their network formation in the superframe 1002A, so the network formation continues in the superframe 1002B.

[0116] The process begins in superframe 1002B with the WM 302 sending a DL 1046 to each of the WHs 306 in the cluster. WH1 306.1 receives DL 1048A, WH2 306.2 receives DL 1048B, WH3 306.3 receives DL 1048C, and WH4 306.4 receives DL 1048D. The DL 1004 from the WM 302 contains an indication that WH1 306.1, WH2 306.2, WH3 306.3, and WH4 306.4 are in the scanning or network formation phase. The WM 302 assigns selected configuration and data channels to WH1 306.1, WH2 306.2, WH3 306.3, and WH4 306.4.

[0117] Each WH 306 in the network formation phase transmits a scanning request DL to each WD 308 in its respective subset cluster 304 on its respective configuration channel. WH1 306.1 sends DL 1050 on configuration channel 2, WH2 306.2 sends DL 1052 on configuration channel 3, and WH3 306.3 sends DL 1054 on configuration channel 1. WH4 306.4 waits for a configuration channel to become available in wait period 1056. After sending the DLS 1050, 1052, and 1054, the configuration channels are opened, and the WM 302 assigns configuration channel 2 to WH4 306.4. WH4 306.4 then sends DL 1058 to its WDs 308 in its subset cluster 304. During the time that the DL 1058 is being transmitted, the other WHs 306 wait for the DL 1058 to end. These wait periods are shown as 1060A, 1060B, and 1060C for the first three WHs 306.

[0118] After sending the scanning request DL to the WDs 308, the WDs 308 respond to their respective WHs 306 in a micro superframe. For this response, the data channels are used instead of the configuration channels, as they are in superframe 1002A. The data channels are rotated for this superframe 1002B, just as the configuration channels are rotated. WH1 306.1 uses channel A2, WH2 306.2 uses channel B2, WH3 306.3 uses channel C2, and WH4 306.4 uses channel D2. WH1 306.1 receives ULs 1062 and 1064, WH2 306.2 receives ULs 1066 and 1068, WH3 306.3 receives ULs 1070 and 1072, and WH4 306.4 receives ULs 1074 and 1076.

[0119] After the UL has been received by the WHs 306 from the WDs 308, each WH 306 aggregates the responses from its WDs 308 and sends the UL to the WM 302 on channel M2. WH1 306.1 sends UL 1078, WH2 306.2 sends UL 1080, WH3 306.3 sends UL 1082, and WH4 306.4 sends UL 1084. The WM 302 receives ULs 1086A through 1086D, and the superframe 1002B ends.

[0120] If any of the WHs 306 complete forming their subclusters 304, the WHs 306 continue to send DL frames in the assigned configuration channels and receive UL frames in the appropriate frequency hopping sequences. This process continues until all subclusters 304 are formed, and the WM 302 informs all WHs 306 to switch to superframe type 2. In some instances, option 3 is more complex than options 1 or 2, but option 3 can also be faster if there are a large number of subclusters 304.

[0121] Figure 11A and 11B Superframe structures 1100A and 1100B for network formation are shown in accordance with various examples herein, respectively. Figure 11A and 11B is an extended example of network formation option 3, where type 3 superframes are used for network formation, and then the network is switched to type 2 superframes for data exchange.

[0122] Figure 11A The superframe structure 1100A in includes a superframe 1102A, and Figure 11B The superframe structure 1100B in includes a superframe 1102B. The superframe 1102A is a type 3 superframe for network formation. After the superframe 1102A, the network is formed and the WM 302 switches the network to superframe type 2 for superframe 1102B. In this example, the WDs 308 are not shown, but the WHs 306 communicate with the WDs 308 in their respective subclusters 304 as described above for options 1 and 2.

[0123] In the superframe structure 1100A, the superframe 1102A operates similarly to the superframe 1002A discussed above with respect to Figure 10A The process begins in the superframe 1102A with the WM 302 sending a DL 1104 to each WH 306 in the cluster.

[0124] WH1 306.1 receives DL 1106A, WH2 306.2 receives DL 1106B, WH3 306.3 receives DL 1106C and WH4 306.4 receives DL 1106D. The DL 1104 from the WM 302 contains an indication that WH1 306.1, WH2 306.2, WH3 306.3 and WH4 306.4 are in the scanning or network formation phase. The WM 302 allocates selected configuration channels and data channels to WH1 306.1, WH2 306.2, WH3 306.3 and WH4 306.4.

[0125] Each WH 306 in the network formation phase transmits a scanning request DL to each WD 308 in its respective subset cluster 304 on its respective configuration channel. WH1 306.1 sends DL 1108 on configuration channel 1, WH2 306.2 sends DL 1110 on configuration channel 2 and WH3 306.3 sends DL 1112 on configuration channel 3. WH4 306.4 waits for a configuration channel to become available in wait period 1114. After the transmission of DLs 1108, 1110 and 1112, the configuration channels are opened and the WM 302 allocates configuration channel 1 to WH4 306.4. WH4 306.4 then sends DL 1116 to its WDs 308 in its subset cluster 304. The other WHs 306 wait for the end of DL 1116 during the time that DL 1116 is transmitted. These wait periods are shown as 1118A, 1118B and 1118C for the first three WHs 306.

[0126] After sending the scanning request DL to the WDs 308, the WDs 308 respond to their respective WHs 306 in the micro superframe. For this response, the data channels are used instead of the configuration channels. WH1 306.1 uses channel Al, WH2 306.2 uses channel Bl, WH3 306.3 uses channel Cl and WH4 306.4 uses channel Dl. WH1 306.1 receives ULs 1120 and 1122, WH2 306.2 receives ULs 1124 and 1126, WH3 306.3 receives ULs 1128 and 1130 and WH4 306.4 receives ULs 1132 and 1134.

[0127] After the UL has been received by the WHs 306 from the WDs 308, each WH 306 aggregates the responses from its WDs 308 and sends the UL to the WM 302 on channel Ml. WHl 306.1 sends UL 1136, WH2 306.2 sends UL 1138, WH3 306.3 sends UL 1140, and WH4 306.4 sends UL 1142. The WM 302 receives ULs 1144A-D, and the superframe 1002A ends.

[0128] In this example, the network formation is completed after the superframe 1102A. The WHs 306 indicate to the WM 302 that they have completed network formation with the ULs 1136, 1138, 1140, and 1142. Thus, after receiving the ULs 1144A-D, the WM 302 switches to superframe type 2 for superframe 1102B. The superframe 1102B operates similarly to the superframe structure 400A in Figure 4A

[0129] In the superframe 1102B in Figure 11B In the superframe 1102B, the WM 302 sends requests or instructions to the WHs 306, and then the WHs 306 communicate with their respective WDs 308 to collect information and send it back to the WM 302. In this example, the WM 302 sends a DL 1146 to each WH 306 on channel M2. WHl 306.1 receives DL 1148A, WH2 306.2 receives DL 1148B, WH3 306.3 receives DL 1148C, and WH4 306.4 receives DL 1148D. Then, each WH 306 communicates with its WDs 308 (not shown in Figure 11B

[0130] As shown here, the WDs 308 respond to the WHs 306 with ULs. WHl 306.1 receives ULs 1158A-F from its WDs 308 on channel A2, WH2 306.2 receives ULs 1160A-F from its WDs 308 on channel B2, WH3 306.3 receives ULs 1162A-F from its WDs 308 on channel C2, and WH4 306.4 receives ULs 1164A-F from its WDs 308 on channel D2. ​​

[0131] Each WH 306 aggregates responses from WDs 308 and transmits ULs to WM 302 on channel M2. WH1 306.1 transmits UL 1166, WH2 306.2 transmits UL 1168, WH3 306.3 transmits UL 1170, and WH4 306.4 transmits UL 1172. WM 302 receives ULs 1174A-1174D, and superframe 1102B ends. Thus, Figure 11A and 11B It is shown how the superframe type 3 structure can be used for network formation and the superframe type 2 structure can be used for data exchange in WBMS.

[0132] Figure 12A and 12B It is shown how keep-alive operations according to various examples herein. Figure 12A It is shown a superframe structure 1200A including a full type 2 superframe 1202A. Figure 12B It is shown a superframe structure 1200B including a partial type 2 superframe 1202B. Here, WM 302 acts as the master node throughout. As described above, in some examples, only WM 302 is within range of all WHs 306, and thus delegation of the master role is not possible. Based on latency requirements in WBMS, full, partial, and idle superframes can be scheduled. The average power consumption of WM 302 can be reduced because it listens for shorter durations compared to a single-tier network. The average power consumption at WHs 306 can be higher than the average power consumption at WDs 308.

[0133] In superframe 1202A in Figure 12A , it is shown standard data exchange between WH1 306.1, WH2 306.2, and their respective subsets as described above with respect to Figure 4A WM 302 transmits a DL 1204 (DL-WM) on channel M1 to each of the WHs 306. In this case, WH1 306.1 receives DL 1206A, and WH2 306.2 receives DL 1206B. After WM 302 transmits this DL 1204, the WM waits for the WHs 306 to receive responses from WDs 308 and then provides those responses to WM 302.

[0134] In response to the DL 1204, each WH 306 transmits a DL to the WDs 308 in its respective subcluster 304. In this example, WH1 306.1 transmits a DL 1208 (DL WH1) to WD2- WD7 308. The DL 1208 is transmitted on channel Al. WH1 306.1 uses channel Al to communicate with its WDs 308 in the first superframe 1202A. WH2 306.2 transmits a DL 1210 (DL WH2) to WD9- WD14 308. The DL 1210 is transmitted on channel Bl. WH2 306.2 uses channel Bl to communicate with its WDs 308 in the first superframe 1202A. In this example, each subcluster 304 uses a different channel for communication between the WHs 306 and WDs 308 in the subcluster 304.

[0135] Each WD 308 receives the DL (in this example, 1208 or 1210) from its respective WH 306. Figure 12A Only WD2 308.2 and WD14 308.14 are shown in the middle, but the other WDs 308 operate similarly. WD2 308.2 receives the DL 1212, and WD14 308.14 receives the DL 1214. Each WD 308 responds to its respective WH 306 with a UL. Here, WD2 308.2 sends a UL 1216 to WH1 306.1 on channel Al. WD14 308.14 sends a UL 1218 to WH2 306.2 on channel Bl. Although Figure 12A The other WDs 308 also send a UL to their respective WHs 306 on the appropriate channel, although not shown in the middle.

[0136] After receiving the UL from each WD 308 in its subcluster, each WH 306 aggregates the information in the ULs from the WDs 308 in its subcluster and sends a UL to the WM 302. Here, WH1 306.1 sends a UL 1224 to the WM 302 on channel Ml. WH2 306.2 sends a UL 1226 to the WM 302 on channel Ml. The ULs 1224 and 1226 are sent on channel Ml at different times as shown, so they do not interfere with each other. The WM 302 receives the ULs 1228A-1228D from each WH 306 that it manages. At this point, the first superframe 1202A is complete and the second superframe 1202B begins.

[0137] Figure 12BThe superframe 1202B in the middle is a partial type 2 superframe for keep-alive operations. The WM 302 sends a DL 1230 with keep-alive instructions to the WHs 306 on channel M2. The WH1 306.1 receives the DL 1232A and the WH2 306.2 receives the DL 1232B. Then, the WHs 306 send a DL to their respective WDs 308 in their respective data channels. The WH1 306.1 sends a DL 1234 to its WDs 308, including WD2 308.2, and the WH2 306.2 sends a DL 1236 to its WDs 308, including WD1 308.14. The WH1 306.1 communicates with its subset on channel A2 and the WH2 306.2 communicates with its subset on channel B2. The WD2 308.2 receives a DL 1238 from the WH1 306.1 and the WD1 308.14 receives a DL 1240 from the WH2 306.2. In this superframe 1202B, the WDs 308 do not send a response back to the WHs 306 and the WHs 306 do not send a response back to the WM 302. The DL maintains synchronization between the group components while saving power. The UL is not used in the superframe 1202B.

[0138] Examples herein can include procedures for a node rejoin process. If a particular WD 308 in the subset 304 stops communicating while in normal operation, after a timeout, the WH 306 can instruct the WDs 308 in the subset 304 to scan the configuration channel. The WH 306 informs the WM 302 that the WH 306 is entering a pairing phase. Other WHs can continue normal operation. After all WDs 308 in the subset 304 respond to the WH 306, the WH 306 informs the WM 302 and the WM 302 initiates the master hop sequence for the WH 306. In a single tier network, even if only one WD 308 loses connection, all nodes will be required to scan the configuration channel. Here, other subsets 304 can continue operation while another subset 304 performs a rejoin operation.

[0139] If the WH 306 stops communicating with the WM 302, the WM 302 can reinitiate the pairing process for all WHs 306. The WDs 308 will be required to scan the configuration channel to begin the reinitiation.

[0140] Figure 13 A flowchart of a method 1300 for hierarchical network operation for WBMS in accordance with various examples herein. The steps of the method 1300 can be performed in any suitable order. In some examples, the hardware components described above with respect to Figures 1 to 3 The hardware components described above with respect to may perform the method 1300. In some examples, any suitable hardware, software, or digital logic can perform the method 1300.

[0141] Method 1300 begins, at 1310, with a wireless head node (WH 306) receiving, in a superframe, a first downlink on a first channel from a wireless master node (WM 302) in a WBMS, where the wireless head node is a head node for a subcluster 304 of one or more wireless devices 308. One example of the first downlink is Figure 4A DL 406A in superframe 402A in FIG. 4B.

[0142] Method 1300 continues, at 1320, with the wireless head node (WH 306) transmitting, in the superframe, a second downlink on a second channel to each of the one or more wireless devices 308 in the subcluster 304. The second downlink can be Figure 4A DL 408 in FIG. 4B.

[0143] Method 1300 continues, at 1330, with the wireless head node (WH 306) receiving, in the superframe, an uplink on the second channel from each of the one or more wireless devices 308. In one example, the uplink from the wireless devices 308 is Figure 4A UL 420A-F in FIG. 4B.

[0144] Method 1300 continues, at 1340, with the wireless head node (WH 306) transmitting, in the superframe, an aggregated uplink on the first channel from the wireless head node (WH 306) to the wireless master node (WM 302), where the aggregated uplink includes data from each of the one or more wireless devices in the subcluster. In one example, the aggregated uplink is Figure 4A UL 424 in FIG. 4B.

[0145] In examples herein, hierarchical WBMS network structures that can handle a large number of nodes with low latency and single-hop extension are described. A master node (WM 302) operates as a master node for the entire network of nodes. Secondary nodes are divided into subclusters 304, with one or more secondary nodes in each subcluster 304. The secondary nodes in each subcluster operate as a wireless head (WH 306) node and act as a master node for the subcluster 304 that they belong to. The other secondary nodes in each subcluster 304 are WDs 308. In some examples, a dedicated WH 306 node can be used for a subcluster 304 rather than selecting one of the WDs 308 as the WH 306. The WM 302 and the WH 306 can use a master hopping sequence to manage the communication channels used by the nodes.

[0146] In the hierarchical system described herein, the WMs 302 communicate with the WHs 306, and the WHs 306 communicate with the WDs 308. The WMs 302 are in range to communicate with the WHs 306, and the WHs 306 are in range to communicate with their respective WDs 308 in their sub-clusters 304. The sub-clusters 304 can have the same number of WDs 308 or different numbers of WDs 308. A number of superframe structures for managing communications between nodes arranged in a hierarchical system are described herein.

[0147] For a WBMS with a large number of nodes, latency is reduced with the hierarchical system and superframe structures described herein. Throughput is also increased due to the efficient superframe structures. Low network restarts can be achieved in the examples herein, and power consumption can also be reduced.

[0148] In this description, the term "coupled" can encompass a connection, communication, or signal path that enables a functional relationship consistent with this description. For example, if device A generates a signal to control device B to perform an action, then: (a) in a first example, device A is coupled to device B by a direct connection; or (b) in a second example, device A is coupled to device B through intermediate component C, provided that intermediate component C does not alter the functional relationship between device A and device B such that device B is controlled by device A through the control signal generated by device A.

[0149] A device "configured to" perform a task or function can be configured (e.g., programmed and / or hardwired) at a manufacturing or construction facility, by a manufacturer, at a user's site, by the user, or by an additional party. A device configured to perform a task or function can be configured (or reconfigured) to perform the function and / or other additional or alternative functions by firmware and / or software programming of the device, by construction and / or layout of hardware components and interconnections of the device, or combinations thereof.

[0150] In this description, "about," "approximately," or "substantially" preceding a parameter means within + / - 10% of the parameter, unless otherwise stated. Modifications can be made in the described examples, and other examples can be made within the scope of the claims.

Claims

1. A method comprising: In a superframe, a first downlink from a wireless master node on a first channel is received at a wireless head node in a wireless battery management system (WBMS), wherein the wireless head node is the head node of a sub-cluster of one or more wireless devices. In the superframe, a second downlink from the wireless head node on the second channel is transmitted to each of the one or more wireless devices in the sub-cluster. In the superframe, an uplink from each of the one or more wireless devices is received at the wireless head node on the second channel. and In the superframe, an aggregated uplink from the wireless head node is transmitted to the wireless master node on the first channel, wherein the aggregated uplink contains data from each of the one or more wireless devices in the sub-cluster.

2. The method according to claim 1, wherein the superframe is a first superframe, and the method further comprises: In the second superframe, a third downlink on the third channel is received at the wireless head node from the wireless master node; In the second superframe, the fourth downlink from the radio head node on the fourth channel is transmitted to each of the one or more radio devices in the sub-cluster. In the second superframe, an uplink from each of the one or more wireless devices is received at the wireless head node on the fourth channel. and In the second superframe, a second aggregated uplink from the wireless head node is transmitted to the wireless master node on the third channel, wherein the second aggregated uplink contains data from each of the one or more wireless devices in the sub-cluster.

3. The method according to claim 1, wherein the second channel is a configuration channel.

4. The method according to claim 1, wherein the wireless head node is a first wireless head node, the sub-cluster is a first sub-cluster, and the method further includes: In the superframe, the first downlink on the first channel is received at the second wireless head node from the wireless master node, wherein the second wireless head node is the head node of the second sub-cluster. and In the superframe, a third downlink from the second radio head node on the third channel is transmitted to each of the one or more radio devices in the second sub-cluster.

5. The method according to claim 1, wherein the radio head node is a first radio head node, the sub-cluster is a first sub-cluster, the aggregated uplink is a first aggregated uplink, and the method further comprises: In the superframe, a second aggregated uplink from the second wireless head node is transmitted to the wireless master node on the first channel, wherein the second aggregated uplink contains data from each of one or more wireless devices in the second sub-cluster.

6. The method of claim 1, wherein the first channel and the second channel are non-neighboring channels selected by a master control frequency hopping sequence.

7. A system comprising: A wireless head node in a wireless battery management system (WBMS), wherein the wireless head node is the head node of a sub-cluster of one or more wireless devices, and the wireless head node is configured to: Receive the first downlink from the wireless master node on the first channel in the superframe; In the superframe, a second downlink on the second channel is transmitted to each of the one or more wireless devices in the sub-cluster; In the superframe, an uplink from each of the one or more wireless devices is received on the second channel; and In the superframe, an aggregated uplink is transmitted to the wireless master node on the first channel, wherein the aggregated uplink contains data from each of the one or more wireless devices in the sub-cluster.

8. The system of claim 7, wherein the superframe is a first superframe, and the radio head node is further configured to: In the second superframe, a keep-alive downlink on the third channel is received from the wireless master node.

9. The system according to claim 8, wherein the keep-alive downlink is a first keep-alive downlink, and the radio head node is further configured to: In the second superframe, a second keep-alive downlink is transmitted to each of the one or more wireless devices in the sub-cluster.

10. The system of claim 7, wherein the aggregated uplink includes data from the radio head node.

11. The system of claim 7, wherein each of the one or more wireless devices is coupled to at least one battery cell.

12. The system of claim 7, wherein the first downlink includes a request for battery cell information from the one or more wireless devices.

13. The system of claim 12, wherein the wireless head node is configured to delay the measurement of battery cell information of the battery cells coupled to the wireless head node.

14. The system of claim 7, wherein the first downlink and the second downlink are requests for network formation.

15. The system of claim 14, wherein the wireless head node is a first wireless head node, and the first wireless head node is configured to complete the network formation of the sub-cluster before the second wireless head node begins network formation.

16. A system comprising: A first wireless head node in a wireless battery management system (WBMS), wherein the first wireless head node is the head node of a sub-cluster of one or more wireless devices, and the first wireless head node is configured to: Receive the first downlink from the wireless master node on the first channel in the superframe; In the superframe, a second downlink on the configuration channel will be transmitted to each of the one or more wireless devices in the sub-cluster; Waiting for the second wireless head node to transmit the third downlink on the configured channel; In the superframe, an uplink from each of the one or more wireless devices is received on the second channel; and In the superframe, an aggregated uplink is transmitted to the wireless master node on the first channel, wherein the aggregated uplink contains data from each of the one or more wireless devices in the sub-cluster.

17. The system of claim 16, further comprising: The second wireless head node in the WBMS, wherein the second wireless head node is the head node of a second sub-cluster of one or more wireless devices, and the second wireless head node is configured to: The first downlink on the first channel is received from the wireless master node in the superframe; Waiting for the first radio head node to transmit the second downlink on the configured channel; In the superframe, the third downlink on the configured channel is transmitted to each of one or more wireless devices in the second sub-cluster. In the superframe, uplinks from each of the one or more wireless devices in the second sub-cluster are received on the third channel; and In the superframe, a second aggregated uplink is transmitted to the wireless master node on the first channel, wherein the second aggregated uplink contains data from each of the one or more wireless devices in the second sub-cluster.

18. The system of claim 16, wherein the second downlink is a request for network formation of the one or more wireless devices in the sub-cluster.

19. The system of claim 16, wherein each of the one or more wireless devices is coupled to a battery cell.

20. The system of claim 16, wherein the superframe is a first superframe, the configuration channel is a first configuration channel, and the first radio head node is further configured to: In the second superframe, a fourth downlink on the third channel is received from the wireless master node; and In the second superframe, a fifth downlink on the second configuration channel is transmitted to each of the one or more wireless devices in the sub-cluster.

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