Abstract:
A system including an edge router which collects data from a mesh network by receiving on multiple simultaneous frequencies. Using N simultaneous frequencies increases the throughput of a system by up to N-times, reducing the bottleneck that otherwise occurs at the take-out-point of a mesh communications system. Furthermore, nodes in direct communication with the edge router can send each data packet multiple times on multiple frequencies, increasing the probability that the packet is delivered correctly, eliminating the necessity to acknowledge (ACK) each packet. This further enhances system throughput.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to routing data, and more specifically, to routing data using a mesh router. 
         [0002]    Some communication networks, such as smart grid metering networks, (e.g., relating to an electrical power grid) may include mesh networks where each mesh network node may be used in routing the data of neighboring nodes. Different routing techniques may be used. For example, the nodes may route packets through the network using forwarding tables that are stored in the nodes. The forwarding tables generally identify a next-hop node based on the packet&#39;s destination. The next-hop node is generally the same for all packets having the same destination regardless of the packet&#39;s originating node. The forwarding tables are conventionally generated by selecting paths through the network in a hop-by-hop fashion based on next-hops with the lowest cost. Other non-table based routing techniques may also be used. It would be useful to improve on the routing techniques. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below. 
         [0004]    In a first embodiment, a system includes an edge router including a first receiver configured to receive a first frequency. The edge router further includes a a transmitter circuitry configured to transmit a data on a plurality of M frequency hopped channels and a multichannel receiver circuitry configured to receive a plurality of packets on a plurality of L independent frequencies transmitted by a plurality of nodes, wherein the multichannel receiver circuitry is configured to provide for a packet exchange protocol by receiving a packet in the plurality of packets a plurality of times without using an acknowledgement packet (ACK). 
         [0005]    In a second embodiment, a system includes a multi-channel edge router. The multi-channel edge router includes a plurality of receivers configured to use a plurality of frequencies, wherein each of the plurality of receivers is configured to communicate on a different frequency. The system additionally includes a non-transitory machine-readable medium comprising code configured to receive data from a plurality of nodes in direct communication with the multi-channel edge router, broadcast a beacon, synchronize a transmission of data from each of the plurality of nodes based on the beacon, and receive data from each of the plurality of nodes to the multi-channel edge router approximately simultaneously a plurality of times redundantly so that the use of an acknowledgement packet (ACK) is not required for reliable packet transfer from a node to the edge router. 
         [0006]    In a third embodiment, a method includes selecting a second radio frequency at random and discovering a second node disposed on the wireless mesh network, wherein the second node is not in direct communication with the multi-channel edge router. The method further includes assigning a second frequency hopping pattern to the second node based on the second radio frequency and communicating data between the second node and the multi-channel edge router by using the intermediate node, wherein the intermediate node is in direct communication with the multi-channel edge router and with the second node, and wherein the second node is configured to use the second frequency hopping pattern to communicate with the intermediate node. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
           [0008]      FIG. 1  is a schematic diagram illustrating an embodiment of a multichannel wireless mesh network; 
           [0009]      FIG. 2  is a node density diagram illustrating an embodiment of a node density for the multichannel wireless mesh network of  FIG. 1 ; 
           [0010]      FIG. 3  is a block diagram illustrating an embodiment of a multichannel wireless edge router disposed in the multichannel wireless mesh network of  FIG. 1 ; 
           [0011]      FIG. 4  is a flowchart of an embodiment of a process useful in routing data between level  0  and level  1  of the multichannel wireless mesh network of  FIG. 1 ; and 
           [0012]      FIG. 5  is a flowchart of an embodiment of a process useful in routing data between level  1  and levels  2  through k of the multichannel wireless mesh network of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
         [0014]    When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
         [0015]    Certain communication networks, such as a mesh networks, may include multiple nodes intermeshed or communicatively coupled to other nodes. These networks may be used in a variety of applications, such as electrical power grids having utility meters (e.g. smart meters) at various locations (e.g. businesses, residences, etc.) throughout the grid. In a smart grid network example, a network node may include an advanced metering infrastructure (AMI) smart meter communicatively connected to one or more neighborhood meters. These meters monitor and/or control the flow of a utility (e.g. electricity, water, or gas) into the location (e.g., building). The intercommunication between nodes is referred to as a mesh network. Mesh networks enable enhanced communication reliability due to the multiple paths that may be present between nodes. Should one path fail, a second path may be used to communicate with the node. Certain mesh networks may use the Institute for Electrical and Electronics Engineers (IEEE) 802.15.4 specification for enabling mesh network communications. Other specifications or standards may also be used, such as ZigBee, Optimized Link State Routing Protocol (OLSR), Babel, Ad hoc On-Demand Vector Routing (AODV), and/or Destination-Sequenced Distance Vector Routing (DSDV). 
         [0016]    In certain mesh networks, the nodes may be functionally organized in a tree structure, with a root or edge node communicatively coupled with varying levels of branch nodes. The edge node may then facilitate communications between branch nodes and other systems, such as internet-based systems. Because the edge node may be communicatively coupled to a plurality of branch nodes, the edge node may become a communicative bottleneck. For example, in traditional systems, such as those following the IEEE 802.15.4 standard, the edge node may only communicate through a single channel. The embodiments described herein include routing systems, methods, and computer instructions stored in a non-transient computer readable medium useful for enabling multichannel communications at the edge node of a mesh network. The multichannel communications may minimize or eliminate the edge node as a communications bottleneck. Indeed, the use of the systems, methods, and computer instructions described herein, may enable a substantial increase in communications throughput between the edge node and branch nodes, thus increasing the node density (e.g., total number of branch nodes) communicating via the edge node. This increased throughput may be particularly beneficial for various applications, such as utility meters (e.g., smart meters) distributed throughout a utility grid (e.g., electrical power grid). 
         [0017]    Each node may use a different frequency hopping pattern suitable for sending and receiving data packets. The edge node may use hardware and/or software techniques, as described in more detail below, to implement a multichannel edge router suitable for using all the available frequencies to communicate with branch nodes. Unique frequency hopping patterns may further enable the use of all available frequencies. By employing all available frequencies, including non-standard frequencies (e.g., unlicensed frequencies not licensed by the Federal Communications Commission [FCC]), the systems and methods described herein may support a higher density of nodes per geographic area. In a smart grid example, the systems and methods may increase the data capacity from remote nodes to the edge router ten to hundred times the data capacity of a single channel edge router. The edge router is configured to broadcast a beacon used to synchronize a transmission of data from each of the plurality of nodes based on the beacon. Further, the edge router is configured to receive data from each of the plurality of nodes approximately simultaneously. Each node transmits on a nearly uncorrelated frequency hopping pattern over the available frequency channels. Multiple nodes can simultaneously transmit using the using the uncorrelated hopping pattern with a known probability of collision per packet. Transmitting the packet on multiple frequencies removes the need for acknowledging (ACK) each packet; rather resend the message using a set of N uncorrelated frequencies from the set of available frequencies. If any one of the N transmissions is received the message is received correctly. The probability of error P can be arbitrarily reduced to P N . 
         [0018]    With the foregoing in mind,  FIG. 1  is a block diagram illustrating an embodiment of a multichannel wireless mesh network  10 . A legend  12  is also depicted, suitable for identifying various branch nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24 . The nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may include almost any device that operates as a wireless router, including an (advance metering infrastructure) AMI smart meter (e.g., an electricity, gas, or water meter of a utility grid), a personal digital assistant (PDA), a laptop or portable computer, a tablet, a cell phone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, or other device that may receive and/or transmit information wirelessly. In the depicted embodiment, nodes  14  are disposed at a first level or layer of the network  10 , nodes  16  are disposed at a second level, nodes  18  are disposed at a third level, nodes  20  are disposed at a fourth level, nodes  22  are disposed at a fifth level, and nodes  24  are disposed at a sixth level of the network  10 . Accordingly, the legend  12  includes icons  15 ,  17 ,  19 ,  21 ,  23 , and  25 , used to identify the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24 , respectively. It is to be noted that, in other embodiments, more or less network  10  levels may be used. Also depicted is a section  26  of the network  10  that includes n−2 additional branches, similar to branches  28  and  30 , which may include additional nodes at various levels. In a smart grid example, the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may include AMI smart meters suitable for measuring and providing information to the smart grid (e.g., a utility grid such as a electrical power grid, a water grid, or a gas grid). For example, the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may include electric smart meters, water meters, gas meters, and the like, used to meter or consumption of utilities. 
         [0019]    Each of the node nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may automatically form an ad hoc mesh network when the node is introduced into the network  10 . For example, each of the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may communicate with neighboring nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  by using a mesh network protocol, such as the Routing Protocol for Low power and lossy Networks (RPL) protocol or standards, and self-configure as a communicating member of the network  10 . For example, ad hoc discovery, handshaking, and so forth, may be used during self-configuration. As mentioned above, other protocols or standards may be used alternative or additional to RPL, including the IEEE 802.15.4 standard, ZigBee, OLSR, Babel, AODV, DSDV, and so on. By automatically forming a mesh network, the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  and nodes found in section  26  of the multichannel wireless mesh network  10  may provide for a robust, scalable network. For example, redundancy may be provided by including multiple wireless communication paths. Should a node become inoperative, other neighboring nodes (e.g., nodes within wireless signal reach) may be used to send and receive data through the network  10 . Such capabilities allow the network  10  to minimize infrastructure components, as the nodes themselves provide for most of the infrastructure used by the network  10 . Indeed, cabling and switches are minimized or eliminated. Additionally, because the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  may provide for techniques suitable for ad hoc discovery and handshaking with neighboring nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24 , the setup time and cost for the network  10  may be minimized. 
         [0020]    In the illustrated embodiment, the multichannel wireless mesh network  10  includes an edge router  32  directly connected with the nodes  14  in layer  1 , and indirectly connected with the nodes  16 ,  18 ,  20 ,  22 , and  24  in the remaining layers (e.g., layers  2 ,  3 ,  4 ,  5 , and  6 ). It is to be noted that, while the depicted network  10  includes one edge router  32 , multiple edge routers  32  may be used. In the presently contemplated embodiment, the edge router  32  may directly communicate with each node in level  1 , while the remainder levels (e.g., levels  2 ,  3 ,  4 ,  5 , and  6 ) of nodes may communicate with each other. Eventually, data from levels  2 ,  3 ,  4 ,  5 , and  6  may make its way up to the edge router  32 . Additionally, the edge router  32  may be communicatively coupled to other systems  34 . The other systems  34  may include intranet and/or internet systems, such as a utility provider (e.g., electricity, water, gas provider) that may collect or meter utility usage data, outage data, and the like, by using the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24 . The utility provider may then use the data to bill customers, to analyze usage patterns, to react to utility outages, and so on. 
         [0021]    In one example, the other systems  34  may communicate with the edge router  32  and nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  by using internet protocol version 6 (IPv6) standard and data packets using the Internet Engineering Task Force (IETF) Request for Comments (RFC) 4944. Indeed, IPv6 data packets may be sent through the network system  10 , such as IETF RFC 4944 data packets. 
         [0022]    The IETF RFC 4944 data packets may be particularly constructed to be used in conjunction with the IEEE 802.15.4 standard. Other communication standards may be used by the other systems  34 , including but not limited to the internet protocol version 4 (IPv4). By providing for a link between the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24 , and the other systems  34 , the edge router  32  may increase the number of nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  communicating with the other systems  34 , and may do so in a more efficient and cost-effective manner. Accordingly, unsolicited meter reads (e.g., query of data from any node  14 ,  16 ,  18 ,  20 ,  22 , and  24  from the utility provider) may be sent using IPv6. 
         [0023]      FIG. 2  illustrates an embodiment of a node density diagram  36  depicting a set of concentric rings representing the relative area each layer of the nodes  14 ,  16 ,  18 ,  20 ,  22 , and  24  of the mesh will occupy. Each ring has the same thickness equal to the average range of peer to peer connection. As mentioned above, nodes  14  disposed in layer  1  would be communicatively coupled directly to the multichannel edge router  32 . Accordingly, layer  1  is depicted as the center of the diagram  36 . The nodes  16  at layer  2  may connect with the edge router  32  through layer  1 . Accordingly, layer  2  is depicted as surrounding layer  1 . In a similar manner, the nodes  18  at layer  3  connect with the edge router  32  through layer  2 , the nodes  20  at layer  4  connect with the edge router  32  through layer  3 , the nodes  24  at layer  6  connect with the edge router  32  through layer  4 , the nodes  22  at layer  5  connect with the edge router  32  through layer  5 , and so on. Accordingly, incremental layers are shown as surrounding the previous layer. The edge router  32  would then be disposed at layer  0 . 
         [0024]    Given that nodes are uniformly distributed over an area, layer  1  is defined to have n nodes, the ratio of nodes at level  1  connecting to the edge router is 1:n. As depicted, Layer  2  has 3x the area of layer  2  and thus assuming uniformly distributed nodes has 3n nodes, layer  3  has 5x the area of layer  1  thus has 5n nodes, layer  4  has 7x the area of layer  1  and thus has 7n nodes, layer  5  has 9x the area of layer  1  and thus has 9n nodes, and layer  6  has 11x the area of layer  1  and thus has 11n nodes. Accordingly, the density ratio for each layer  2 ,  3 ,  4 ,  5 , and  6  is of 3:1, 5:3, 7:5, 9:7, and 11:9, respectively. Indeed, the multicast techniques described herein define a node density of (2*k+1):(2*(k−1)+1) for a layer k and k+1. Thus, (2*(k−1)+1) nodes may be directly connected to a next layer having at least 2*(k−1) nodes. In examples where the nodes represent AMI smart meters, Table 1 below shows per square mile density values for the nodes. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Node Density Per Square Mile (DPSM) 
               
             
          
           
               
                   
                 Urban Density 
                 Suburban Density 
                 Rural Density 
               
               
                   
                   
               
             
          
           
               
                 Node DPSM 
                 1000 
                 250 
                 50 
               
               
                 Nodes in layer 1 = n 
                 1000 
                 250 
                 50 
               
               
                 Nodes in layer 2 
                 3000 
                 750 
                 150 
               
               
                 Nodes in layer 3 
                 5000 
                 1250 
                 250 
               
               
                 Nodes in layer 4 
                 7000 
                 1750 
                 350 
               
               
                 Nodes in layer 5 
                 9000 
                 2250 
                 450 
               
               
                 Nodes in layer 6 
                 11000 
                 2750 
                 550 
               
               
                   
               
             
          
         
       
     
         [0025]    As depicted in Table 1, if layer  1  is assumed to have an area of 1 square mile then number of nodes in layer  1  would be equal to 1000 in urban areas, 250 in suburban areas and 50 in rural areas. Using the ratio of nodes in each layer previous defined the nodes in each layer are as defined in Table 1 In this example, the ratio of nodes in all layers greater than layer  1  have a ratio of 3:1 or smaller, but in layer  1  to the edge router the ratio of nodes connecting to the edger outer takeout point is n:1 or 1000:1 for metro, 250:1 for suburban and 50:1 for rural. Because these ratios are much bigger than the 3:1 or smaller ratios of the higher layers the channel access scheme and capacity of the system is limited by the layer  1  to edge router capacity and channel access method. Such node density may be enabled as described in more detail below with respect to  FIG. 3 . 
         [0026]      FIG. 3  is a block diagram depicting an embodiment of the multichannel wireless mesh network  10 , including the edge router  32  disposed on layer  0 , the nodes  14  disposed on layer  1 , the nodes  16  disposed on layer  2 , and nodes  38  disposed on layer k. The network  10  is also communicatively connected to other systems  34  (e.g., electric, gas, water utilities) through the edge router  32 . As depicted, the edge router  32  includes M fixed frequencies or frequency hopping patterns  40 ,  42 ,  44 ,  46 , and  48 . That is, the edge router  32  may be a multichannel edge router  32  suitable for using multiple channels M of communication, each channel communicating on a different frequency or set of frequencies  40 ,  42 ,  44 ,  46 , and  48 . The frequency ranges for frequencies  40 ,  42 ,  44 ,  46 , and  48  may include any frequency range suitable for communicating with the nodes in the bottom layers  0 - k.  For example, any frequency ranges used by the IEEE 802.15,4, IEEE 802.11 a/b/g/x, IEEE 802.11s. Indeed, any radio frequency may be used. 
         [0027]    The edge router  32  includes a set of radio receivers  50 ,  52 ,  54 ,  56 , and  58 , suitable for receiving the frequencies  40 ,  42 ,  44 ,  46 , and  48 , respectively. In one embodiment, the receivers  50 ,  52 ,  54 ,  56 , and  58  are implemented in hardware. In another embodiment, the receivers  50 ,  52 ,  54 ,  56 , and  58  are implemented in software (e.g., software-defined radio). In this software embodiment, certain components, such as mixers, filters, amplifiers, modulators/demodulators, and/or detectors, are implemented by using non-transient computer instructions stored in a machine-readable medium executable by a computing device. In yet another embodiment, the receivers  50 ,  52 ,  54 ,  56 , and  58  may include hardware receivers, software receivers, or a combination thereof. 
         [0028]    The use of multiple receivers may significantly increase the ability of nodes  14 ,  16 ,  18 ,  20 ,  22 ,  24 , and  38  to communicate and route packets in the network  10 . In a single-channel mesh network, any one edge node&#39;s transmission on a particular communication channel creates a bottleneck and may potentially interfere with other node&#39;s communicating on that channel, depending on the distance between nodes in the single-channel network. This may result in increased collisions, increased dropped packets, and increased packet retransmissions throughout the entire network. By using multichannel communications, such as through the frequencies  40 ,  42 ,  44 ,  46 , and  48 , the edge router  32  effectively provides for the functionality of multiple edge routers  32 . Indeed, each receiver  50 ,  52 ,  54 ,  56 , and  58  may functionally provide the virtual equivalent of a traditional edge node. Additionally, certain processes, described in more detail below with respect to  FIGS. 4 and 5 , may be used to enable substantially higher throughput through the multichannel wireless mesh network  10 . 
         [0029]      FIG. 4  is a flow chart depicting an embodiment of the edge router&#39;s process  60  suitable for transmitting or receiving data between the edge router  32  disposed in layer  0  and the nodes  14  disposed in layer  1  of the wireless mesh network  10 . The process  60  may be implemented as non-transient, executable instructions stored in a machine-readable medium, such as memory, a computing device, a controller, etc. In the depicted example, the edge router  32  transmits a beacon on one of M frequencies (e.g.,  40 ,  42 ,  44 ,  46 , and  48 ) for the purpose of synchronization (block  62 ); then transmits data packets (block  64 ) to nodes  14  disposed in layer  1  of the network  10 . Then, in block  66  receives data packets from nodes  14  disposed in layer  1  of the network  10 ; and in block  68  removes any duplicate packets. Then the process  60  selects the next frequency in the hop patterns for transmit and receive and repeats back to block  62 . The process  60  also repeats by node  14  returning to block  76  to receive the next Edge Router  32  beacon. 
         [0030]    Each node in the system has a random frequency hopping pattern with respect to receiving data from other nodes in the network, as shown in  FIG. 4 , where each node hops on M independent center frequency channels. There is a limit to the uniqueness given number of pattern is limited by the M number of available frequency channels. Each node discovers and synchronizes with nodes at the lowest layer it can reliably connect. Because each node in the system is using a different random hopping pattern the system spans the entire frequency set using up to M times the bandwidth of a node connection pair when sending data packets from layer N to lower layers of the mesh. 
         [0031]    In the layer  1  to edge router connection in a prior art implementation all layer  1  nodes must transmit on a single frequency of the edge router receiver frequency set the edge router is using at that instance. To acquire the edge router receiver frequency hopping pater the process  60  requires an unsynchronized node  14  on layer  1  to select a random frequency from a known set M (block  64 ) for nodes  14  to use to discover the network timing and configuration. In one embodiment, the process  60  may use a set of multiple M receivers each with its own individual frequency of the set of M frequencies (e.g., 2 to 1,000 frequencies), such as the frequencies  40 ,  42 ,  44 ,  46 , and  48  associated with the receivers  50 ,  52 ,  54 ,  56 , or  58 . In this embodiment, different frequency sequences  40 ,  42 ,  44 ,  46 , or  48  may be assigned to each node  14  that is disposed in layer  1 . The system can support up to a factorial equation of nodes  14  without the need to limit the duty cycle that a particular node can transmit. The system can support a larger number of nodes at layer  1  to edge router by limiting the duty cycle a particular node can transmit. The number of nodes grow proportional to the duty cycle reduction 
         [0032]    The edge router  32  may then multicast or broadcast a beacon (block  66 ). The broadcasted beacon (block  66 ) may be received by all nodes  14  in layer  1  and used to synchronize the nodes  14  for subsequent transmission of data packets. In one example, the broadcast beacon (block  66 ) may be used as part of a channel access standard, such as time division multiple access (TDMA) incorporated in the IEEE 802.15.4 standard. The broadcast beacon (block  66 ) and associated TDMA protocols may then be used to synchronize (block  68 ) node  14  communications. For example, all nodes  14  may simultaneously (or near simultaneously) transmit data packets (block  70 ) that may then be received by the edge router  32 . In this manner, all available frequencies  40 ,  42 ,  44 ,  46 , and  48  may be used. 
         [0033]    In one embodiment, the transmitted data packets (block  70 ) may not be acknowledged. Indeed, rather than send an acknowledge (ACK) data packet (and associated communications), the edge router  32  may save time and transmitive energy by not acknowledging the transmitted data packets (block  70 ). Instead, each node may hop frequencies (block  72 ) and retransmit the data packet, thus substantially minimizing or eliminating dropped data packets. Each data packet may be transmitted 2, 3, 4, 5, 6, M times, or more, where M is the total number of frequencies  40 ,  42 ,  44 ,  46 , and  48  available. The frequency hop (block  72 ) may be sequential and cyclical. For example, for a node  14  that is assigned the frequency  40 , the node  14  may then hop to frequency  42 , then to frequency  44 , then to frequency  46 , then to frequency  48 , and so on. When the last frequency is reached (e.g., frequency M), then the cycle may restart, with the next hop using the first frequency (e.g., frequency  40 ). 
         [0034]    As depicted, after hopping frequencies (block  72 ), the nodes  14  may then iterate to block  70  to retransmit the data packet or to transmit a new data packet (block  70 ). Also as depicted, after hopping frequencies (block  72 ), the process may iterate to the broadcasting of the beacon (block  66 ), to enable the synchronization (block  68 ) of new nodes  14  that may have recently joined the network  10 . By enabling the use of multiple frequencies  40 ,  42 ,  44 ,  46 , and  48 , including unlicensed frequencies, and by eliminating the use of ACK packets and associated communications, the process  60  may maximize frequency use while minimizing error-correction time and energy. Additionally, routing from levels  1  up to and including level k may also use all available frequencies, as described in more detail below with respect to  FIG. 5 . 
         [0035]      FIG. 5  depicts an embodiment of a process  72  suitable for transmitting or receiving data between the nodes  14  disposed in layer  1  and the edge router  32  and nodes  16 ,  18 ,  20 ,  22 ,  24 , and  38  disposed in layers  2 ,  3 ,  4 ,  5 , and k of the wireless mesh network  10 . As mentioned above, the multichannel wireless mesh network  10  using the multichannel edge router  32  enables a higher throughput of data when compared to a single channel network. The techniques disclosed herein provide for improved data throughput and reliability and may use various mesh implementations for mesh connectivity between layers  1 ,  2 ,  3 ,  4 ,  5 , and k. The process  70  may be implemented as non-transient machine-readable instructions executable in a computing device. 
         [0036]    In the depicted embodiment, the nodes  14  in layer  1  synchronize with the beacon to obtain TDMA timing and frequency hopping synchronization (block  74 ) used for communications. Once synchronized, each node  14  may begin receiving beacons (block  76 ) and packets from the edge router (block  78 ). In block  80  each of the nodes  14  transmits packets to the edge router or layer  2  devices. In block  82  the next hop is selected in the frequency hop pattern for the transmitter and receiver. Using this TDMA and frequency hopping process packets from node  14  are repeatedly sent to the edge router  1  to i times in separate TDMA slots using a different frequency in each slot. A process, such as a CRC32 error correction process, can be used at the edge router to determine successful packet transfer. Only one of the i packets needs to be received for successful packet transfer. Using multiple transmissions creates frequency and time diversity, greatly increasing the probability that a packet is transferred successfully, and eliminating the need to ACK packets. 
         [0037]    For mesh connectivity between nodes  16 ,  18 ,  20 ,  22 ,  24 , and  38  the network may use a variety of mesh implementations for connectivity between layers  1 , 2 , 3 , 4 , 5 , and k, such as Ad hoc On-Demand Distance Vector (AODV), Better Approach to Mobile Ad hoc Networking (BATMAN), Babel, Dynamic Nix-Vector Routing (DSDV), Dynamic Source Routing (DSR), Hazy-Sighted Link State (HSLS), Hybrid Wireless Mesh Protocol (HWMP), Zone Routing Protocol (ZRP), and so on. By using the multichannel edge router for connectivity to layer  1  bandwidth of the network is significantly increased and latency is reduced, improving nodes&#39;  16 ,  18 ,  20 ,  22 ,  24 , and  38  communication performance with the edge router. Because each node  16 ,  18 ,  20 ,  22 ,  24 , and  38  in the network  10  may be using a unique hopping pattern, the network  10  may span the entire frequency band simultaneously, including unlicensed frequencies, using up to M times the bandwidth of a node connection pair when moving data packets from layer n to nodes to on layer  1  of the network  10 . Additionally, the communication between the nodes  16 ,  18 ,  20 ,  22 ,  24 , and  38  in layers  2  through N may not use ACK packets. For example, the nodes  16 ,  18 ,  20 ,  22 ,  24 , and  38  may retransmit data 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, thus eliminating the use of ACK packets to provide acknowledgments of receipt or sending of data. 
         [0038]    Technical effects of the invention include a wireless mesh network of nodes disposed in multiple layers, with the nodes on layer  1  directly connected to a multichannel edge router. The nodes on layer  1  may communicate with the edge router by hopping through multiple frequencies M simultaneously. Additionally or alternatively, the communications between the nodes on layer  1  and the edge router may eliminate the use of acknowledgement (ACK) packets, thus improving network throughput. In one embodiment, the ACK packets may be eliminated by transmitting data multiple times, thus providing for multiple copies of data packets. 
         [0039]    Technical effects additionally include multichannel communications of the nodes in layers  2  through layer N using random frequency selection and TDMA-based hopping. By using randomness in the selection of the frequency, each node may include a unique hopping pattern. Accordingly, the use of multiple frequencies may be substantially improved. 
         [0040]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.