# Patent

## Title
Wakeup beacons for mesh networks

## Abstract

This disclosure describes techniques and apparatuses for wakeup beacons for mesh networks, which often permits nodes of a mesh network to save power when operating in a power-save mode. These wakeup beacons can be sent at high transmission rates and/or be small in size, thereby reducing the time a node must be awake to transmit and receive communications.

## Background
RELATED APPLICATION
This application is a continuation of and claims priority to U.S. Utility patent application Ser. No. 13/099,169 filed May 2, 2011, which claims priority to U.S. Provisional Patent Application Ser. No. 61/333,546 filed May 11, 2010, the disclosures of which are incorporated by reference herein in their entirety.


BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A mesh network can be implemented as a wired or wireless communication network of various fixed and/or mobile devices that are commonly referred to as “nodes” of the mesh network. Each of the node devices can communicate data throughout the mesh network, such as throughout a college campus, metropolitan area, or community network. A node device can also function to route data from one node to another within the mesh network.
A wireless mesh network can include various wireless clients and devices implemented for wireless communication utilizing a data packet routing protocol. For example, the Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11s describes mesh networking for wireless communications over a wireless local-area-network (WLAN). A wireless mesh network can also be implemented for data communication with other networks that are communicatively linked to the mesh network, such as with another wireless network, wired network, wide-area-network (WAN), and the like.
In a wireless mesh network, communication links are formed between the various wireless clients and devices that are the nodes of the network. The data packets for wireless communications in the network can be forwarded or routed from a source node (e.g., transmitting device) to a destination node (e.g., receiving device) via intermediate node(s).
In wireless and wired mesh networks, however, node devices often have power constraints, such as those caused by the node operating on battery power (either commonly or in emergency situations) or those imposed by costs or environmental constraints. To save power, conventional node devices may enter a power-save mode. As part of conventional power-save modes, node devices temporarily reduce power and cease communications but periodically power back up to send and receive management beacons. Thus, a node wakes up at a particular time, receives management beacons from neighbor nodes, and transmits its own management beacon to these neighbors. These conventional techniques, however, often fail to save a node device much, if any, power. This is due in part to the size of the management beacons and the speed of reception and transmission of those beacons. This is exacerbated by the structure of many mesh networks, in which a node attempting to save power may have many neighbor nodes. For each neighbor node, the node attempting to save power stays awake to receive a management beacon from each neighbor node.
SUMMARY
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.
A method embodiment is described, which includes determining a wakeup beacon schedule for a node of a mesh network, having the node enter a power-saving state, wherein during the power-saving state, the node has insufficient power to permit communications with one or more peer nodes of the mesh network, exiting, in accordance with the wakeup beacon schedule, the power-saving state and entering a communication state, wherein during the communication state, the node is permitted to communicate with the one or more peer nodes of the mesh network, receiving one or more wakeup beacons from the one or more peer nodes of the mesh network, each of the one or more wakeup beacons indicating whether or not data is waiting to be received by the node, remaining in the communication state if at least one of the one or more wakeup beacons indicates data is waiting to be received by the node, and re-entering the power save mode if not at least one of the one or more wakeup beacons indicates data is waiting to be received by the node.
Another method embodiment is described, which includes receiving, from a transmitting node of a mesh network, data intended for a receiving node currently in a power-save mode, transmitting, in accordance with a previously determined wakeup beacon schedule and by an intermediate node between the transmitting node and the receiving node, a wakeup beacon to the receiving node, the wakeup beacon indicating that the data is available but not including the data within the wakeup beacon, receiving, at the intermediate node and from the receiving node, an indication that the receiving node is able to receive the data or has exited the power-save mode, and responsive to the indication from the receiving node, transmitting the data to the receiving node.
A System-on-Chip embodiment is described that is configured to determine a wakeup beacon schedule for a node of a mesh network, have the node enter a power-saving state, wherein during the power-saving state the node has insufficient power to permit communications with one or more peer nodes of the mesh network, having the node exit the power saving state and enter a communication state in accordance with the wakeup beacon schedule, wherein during the communication state, the node is permitted to communicate with the one or more peer nodes of the mesh network, receive one or more wakeup beacons from the one or more peer nodes of the mesh network, each of the one or more wakeup beacons indicating whether or not data is waiting to be received by the node, maintain the node in the communication state to permit the node to receive the data indicated by the one or more wakeup beacons if at least one of the one or more wakeup beacons indicates data is waiting to be received by the node, and having the node re-enter the power-saving state if not at least one of the one or more wakeup beacons indicates data is waiting to be received by the node.



BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different instances in the description and the figures indicate similar or identical items.
FIG. 1 illustrates an operating environment having wireless-communication-capable devices in accordance with one or more embodiments.
FIG. 2 illustrates an example mesh network, which can be implemented as a wired or wireless communication network in which various node devices can implement wakeup beacons for mesh networks.
FIG. 3 illustrates an example method for using wakeup beacons for mesh networks to save power at nodes operating in a power-save mode from the perspective of the node operating in the power-save mode.
FIG. 4 illustrates an example wakeup beacon schedule having a start time, a wakeup beacon interval, and an offset relative to a management beacon schedule.
FIG. 5 illustrates an example wakeup beacon having fields for category, action, check beacon, timestamp, and traffic information.
FIG. 6 illustrates an example method for using wakeup beacons for mesh networks to save power at nodes operating in a power-save mode, here from the perspective of a node that is transmitting wakeup beacons.
FIG. 7 illustrates part of an example mesh network including a transmit node, intermediate nodes, and a receive node.
FIG. 8 illustrates a System-on-Chip (SoC) environment for implementing embodiments of the techniques described herein.



DETAILED DESCRIPTION
Conventional techniques for saving power at nodes of a mesh network often fail to save significant amounts of power. This disclosure describes techniques and apparatuses for enabling wakeup beacons for mesh networks, which often permits nodes of a mesh network to save additional power. These wakeup beacons can be sent at higher transmission rates and/or can be much smaller than current beacons conventionally sent and received, such as management beacons, thereby reducing the time the node must be awake to transmit and receive communications.
The following discussion describes an operating environment, techniques that may be employed in the operating environment, and a System-on-Chip (SoC) in which components of the operating environment can be embodied. In the discussion below, reference is made to the operating environment by way of example only.
Operating Environment
FIG. 1 illustrates an operating environment 100 having wireless-communication-capable devices 102 (herein “nodes 102”), which are capable of transmitting and receiving wireless communications, such as those of a wireless mesh network. Nodes 102 include a printing device 104, a tablet computing device 106, a set-top box 108, a cellular phone 110, a desktop computing device 112, and a laptop computing device 114, though other devices also or instead may be used.
Each of nodes 102 includes a wireless transmitter 116, a wireless receiver 118, and a manager 120 for managing wakeup beacons. Manager 120 may also handle wireless communications generally, such as those conforming to various communication protocols, e.g., those of the IEEE 802.11 family of protocols. Transmitter 116 and receiver 118 may be separate (shown) or combined (often called a transceiver, not shown) and may be hardware combined with or separate from software or firmware.
Manager 120 may include a set of computer-executable instructions stored on computer-readable storage media 122. When executed by one or more processors 124, node 102 acts according to those instructions. Manager 120 may act independently or in conjunction with various other entities, such as transmitter 116 and receiver 118. Manager 120 may be separate from or integral with other entities of node 102 as well, such as by being firmware integrated into a System-on-Chip (SoC) having or communicating with transmitter 116 and receiver 118.
FIG. 2 illustrates an example environment 200 that includes a mesh network 202, which can be implemented as a wired or wireless communication network in which various node devices can implement wakeup beacons for mesh networks. A mesh node 204 is illustrative of the various nodes that are communicatively linked to form the mesh network 202 with wired and/or wireless communication links. For example, mesh node 204 can be implemented as a wireless communication device having a data communication range depicted at 206. A neighboring mesh node 208 also has a data communication range depicted at 210 that overlaps the communication range of mesh node 204 such that the two nodes are communicatively linked for wireless data communication. Alternatively or in addition, the two neighboring mesh nodes can be communicatively linked via a wired connection.
The various node devices can receive and communicate data throughout the mesh network 202, and any of the node devices can also function as a router or relay to forward data from one node to another within the mesh network. The arrowed communication links, such as communication link 212 that links mesh node 204 with mesh node 208, are merely exemplary to depict the wired and/or wireless communication links and/or routes between the various node devices that are communicatively linked to form the mesh network 202. In general, one or more of the arrowed communication links facilitate two-way data communication, such as from mesh node 204 to mesh node 208 and vice-versa.
The mesh network 202 can also be implemented for data communication with other networks that are communicatively linked to the mesh network, such as with another wireless network, wired network, wide-area-network (WAN) 214, and the like. The mesh network 202 also includes a mesh node 216 that is a root node (also commonly referred to as a “portal”) of the mesh network 202 that connects the network to an external device or other network, such as the WAN 214 (e.g., the Internet or a Public Switched Telephone Network (PSTN)).
In one or more embodiments, mesh network 202 is an example of a mesh network implemented with node devices (e.g., node 102) that wirelessly receive and communicate data utilizing a wireless networking standard. For example, mesh network 202 can be implemented in a wireless LAN (WLAN) communication system in which data packets of the communication data are communicated compliant with the Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11s.
Example Techniques Using Wakeup Beacons for Mesh Networks
The following discussion describes techniques using wakeup beacons for mesh networks. These techniques can be implemented utilizing the previously described environments of FIGS. 1 and/or 2. These techniques include methods illustrated in FIGS. 3 and 6, each of which is shown as a set of operations performed by one or more entities. These methods are not necessarily limited to the orders shown for performing the operations.
FIG. 3 depicts a method 300 for using wakeup beacons for mesh networks to save power at nodes operating in a power-save mode from the perspective of the node operating in the power-save mode. At 302, a wakeup beacon schedule is determined for a node of a mesh network. The wakeup beacon schedule can be determined in various manners, including by manager 120 of FIG. 1 acting on node 102 or node 204, which can negotiate a wakeup beacon schedule with one or more peer nodes of the mesh network (e.g., four peer nodes shown in FIG. 2 for node 204). Manager 120 may provide a wakeup beacon schedule to one or more peer nodes of the mesh network that those nodes accept, or manager 120 may receive and accept the wakeup beacon schedule from peers of the mesh network.
More specifically, manager 120 may transmit a request to peer nodes of the mesh network to establish wakeup beacon broadcasts having the wakeup beacon schedule. Manager 120 then receives, from the peer nodes, responses accepting the request and the wakeup beacon schedule or accepting the request and overriding the requested wakeup beacon schedule with a different wakeup beacon schedule. While not shown in method 300, determining a wakeup beacon schedule may be performed after or commensurate with a node determining that the node and peer nodes are capable of broadcasting and using wakeup beacons. Determining this capability can be performed through sending and receiving, within an extended capability element of a non-wakeup beacon (e.g., a management beacon), an indication of this capability.
This wakeup beacon schedule may include a start time and a wakeup interval, as well as an offset against other scheduled broadcasts, such as non-wakeup beacon broadcasts. FIG. 4 illustrates an example wakeup beacon schedule 402 having a start time 404, a wakeup beacon broadcast interval (wakeup interval) 406, and an offset 408 relative to a management beacon schedule 410. Wakeup beacons 412 are first transmitted and received at start time 404 and then every wakeup interval 406. Management beacons 414 are broadcast (or may be broadcast) every management beacon interval 416 (only the first of each marked for visual brevity). Note that wakeup interval 406 is equal to about two times the management beacon interval 416.
While example wakeup beacon schedule 402 includes wakeup beacons 412 at each of wakeup intervals 406, a node in a power-saving state will not necessarily wake up for every beacon. When a node wakes up at every beacon interval and that interval is short, the node's power-save mode is called a light-sleep mode. In a deep-sleep mode, the node wakes at longer intervals. Some nodes may operate in a light-sleep mode and some in a deep-sleep mode if the mesh network's routing and structure permit this (e.g., a deep-sleep mode for a node at an end of a route), though in some cases all nodes of the mesh network transmit and receive wakeup beacons at a same beacon interval. In some other cases, a wakeup beacon is sent infrequently, and thus transmitting and receiving a wakeup beacon even at every beacon interval is still a deep-sleep mode in that few wakeups are performed.
Continuing with method 300, at 304, a power-saving state of a power-save mode is entered by the node of the mesh network. The power-save mode includes two basic states, the power-saving state and a communication state. The power-saving state is generally a non-communication state, sometimes considered a “sleep” state, which is one in which the device saves power by not communicating with one or more nodes within the mesh network. This power-saving state may involve turning off power to some parts of the node, though this is not necessarily required. The sleep state may also involve a near-complete shutdown of the node device 102, though again this is not required. At the least, however, this power-saving state is one in which node 102 does not communicate with at least one peer node of the mesh network.
Returning to the example wakeup beacon schedule 402 of FIG. 4, manager 120 of node 102 or 204 shuts down power to wireless transmitter 116 and wireless receive 118 at start time 404 and remains in this state for about one or some multiple of wakeup interval 406.
At 306, the power-saving state of the power-save mode is exited by the node of the mesh network in accordance with the wakeup beacon schedule determined at block 302. Thus, at 306, manager 120 has node 102 or 204 exit the power-saving state and enter the communication state. The length of time that node 102 or 204 may remain in the communication state depends on the wakeup beacon schedule, which in turns depends on a transmission rate of the wakeup beacons, a processing time at the node to process the received wakeup beacons, the number of wakeup beacons to be received, and, if the node is transmitting a wakeup beacon, the time associated with the transmission and processing of that transmitted wakeup beacon. In the ongoing example, the time at which the node is out of the power-saving state, and thus in the communication state and permitted to communicate, is shown at awake period 418 of FIG. 4.
By way of example, consider first a size and contents of wakeup beacon 502 shown in FIG. 5. Here wakeup beacon 502 includes five fields, a category field 504, an action field 506, a check beacon field 508, a timestamp 510, and a traffic information map (TIM) element 512. These fields of wakeup beacon 502 can have sizes of 1, 1, 1, 8, and 6-257 octets, respectively, for a total size as little as 35 bytes. In this particular example no offset is included—the offset is instead negotiated previously and is set from a management beacon interval, sometimes referred to as a target beacon transmission time (TBTT).
Timestamp 510 can be used to establish a synchronization between the nodes of the mesh network, such as by all of the nodes sending out their own timestamp and the nodes taking the last-in-time timestamp of those transmitted.
Either or both of check beacon field 508 or TIM element 512 can indicate that information is waiting for the node that is sleeping. In the case of the check beacon field 508, it indicates that a non-wakeup beacon, such as a management frame, has information for the sleeping node. TIM element 512 may include the information itself or indicate, in many cases, that a peer node has information waiting for the node, such as buffered packets of data waiting to be transmitted to the node. Note that this transmission to the node is not necessarily indicative that the node itself is the final destination, as instead it may have data waiting to be received and retransmitted as part of a routing protocol of the mesh network.
Transmission and reception speeds can be at 1 Mbps or higher, such as 6 Mbps or 24 Mbps, to name just a few. At 24 Mbps and 35 bytes in length, each wakeup beacon can take as little as 0.011 microseconds to communicate. Compare this, for example, to current management beacons sent at 1 Mbps and 256 bytes, which take about two milliseconds.
Consider this in the context of mesh network 202 of FIG. 2. Here node 204 has four neighboring peer nodes, node 208 and three others. Thus, four wakeup beacons are received during awake period 418. Here also node 204 transmits one wakeup beacon to these four peer nodes, thus, five wakeup beacons total are communicated. Each of the wakeup beacons takes 0.011 μs to communicate. Each of the received wakeup beacons takes time to process, here assumed to be 0.001 μs. The transmitted wakeup beacon is assumed to take 0.002 μs to process. Thus, the total awake period 418 for this example would be 5×0.011+4×0.001+1×0.002=0.061 μs. Compare this to current management beacons used in some conventional power-save modes, which result in this same 5-node scenario as at least 5×2.0=10.0 ms (excluding processing).
Returning to method 300, at 308 one or more wakeup beacons from one or more peer nodes of the mesh network are received. As noted above, each wakeup beacon, such as wakeup beacon 502, indicates that data is or is not waiting to be received by the node. At 310, whether or not data is waiting for the node is determined. Thus, manager 120 of node 204, for example, may determine, based on reading information in the received wakeup beacons, whether or not data is waiting for node 204, and thus whether or not node 204 should remain awake to receive that data. If data is determined to be waiting, method 300 continues along the “Yes” path to block 312. At block 312, the node maintains the communication state to permit the node to receive data indicated by the one or more wakeup beacons. If data is determined not to be waiting, method 300 continues along the “No” path to block 304 to re-enter the power-saving state of the power-save mode.
Concluding the ongoing example, if manager 120 of node 204 determines, from reading check beacon field 508 and TIM element 512 of wakeup beacon 502, that no data is available, node 204 re-enters the power-saving state. If, on the other hand, manager 120 of node 204 reads check beacon field 508 and TIM element 512 of wakeup beacon 502 and determines that data is waiting for node 204, manager 120 may cause node 204 to stay awake to receive the data. Note that how node 204 acts depends on whether data is in a management or other type of beacon, or is being buffered in a peer node. Node 204 may return to a power-saving state at block 304 at some later time, though this is not required.
FIG. 6 depicts a method 600 for using wakeup beacons for mesh networks to save power at nodes operating in a power-save mode. Method 600 is described from the perspective of a node that is transmitting wakeup beacons, which may or may not also be operating in a power-save mode.
At 602, data intended for a receiving node currently in a power-save mode is received from a transmitting node of a mesh network and by an intermediate node. The intermediate node may be operating normally or, as noted in greater detail above, the intermediate node may be operating in a power-save mode. If operating in a power-save mode, the intermediate node receives an indication that this data is waiting from a transmitting node during a wake period (e.g., during a communication state of the intermediate node's own power-save mode), and then wakes up and receives this data. Note that in such a case the intermediate node may indicate, to the receiving node, that data is waiting prior to receiving the data, so long as the indication received indicates to which downstream node the data is intended.
By way of example, consider FIG. 7, which illustrates part of a mesh network 700 having a transmit node 702, intermediate nodes 704-1, 704-2, 704-3, and 704-4, and receive node 706. Each of these nodes may be examples of node device 102 of FIG. 1 and include manager 120. Here intermediate node 704-4 receives, through wireless communication 708, data from transmit node 702 and intended for receive node 706. Note that the receiving node of method 600 does not have to be the final destination, thus, method 600 may operate with intermediate node 704-2, where the receiving node is then intermediate node 704-3, which then operates to send data on to receive node 706. Likewise, the transmitting node need not be a first source of the data but instead an intermediate from some other node.
At 604, a wakeup beacon is transmitted to the receiving node, the wakeup beacon transmitted according to a previously determined wakeup beacon schedule, by the intermediate node, and indicating whether data is or is not available. This wakeup beacon can indicate that the data is available but does not necessarily include that data. Note that the wakeup beacon schedule is previously determined in one or more manners set forth above. The wakeup beacon can be any one of the wakeup beacons contemplated herein, such as wakeup beacon 502 of FIG. 5.
The data intended for the receiving node can be buffered by manager 120 at intermediate node 704-4, for example, and then this data indicated in the wakeup beacon 502 as part of TIM element 512. The data may instead be included in a management beacon received by intermediate node 704-4. In such a case, intermediate node 704-4 may include a check beacon indicator in check beacon field 508 of the wakeup beacon 502. Intermediate node 704-4 may then transmit this management beacon or, if another node is transmitting the management beacon and receive node 706 is known to be able to receive that management beacon, intermediate node 704-4 may forgo sending the management beacon having the data indicated. Thus, in some cases method 600 is performed by an intermediate node without having to buffer the data intended for the receiving node. Note also that intermediate node 704-4 may forgo transmitting management beacons if its peer neighbors are able to use wakeup beacons. In some cases a node of a mesh network, however, such as 200 or 700, may not be able to send and receive wakeup beacons. In such a case some of the nodes of those mesh networks will then transmit management beacons instead or in additional to wakeup beacons.
At 606, an indication is received, at the intermediate node and from the receiving node, indicating that the receiving node is able to receive the data or has exited the power-save state or mode. Continuing the example, receive node 706 receives the wakeup beacon from intermediate node 704-4 and responds through wireless communication 710 to indicate that receive node 706 is awake and ready to receive data. In some cases, however, 606 is not needed. For data included within a management beacon, for example, manager 120 at intermediate node 704-4 may assume that receive node 706 is awake or will be awake in sufficient time to receive one of multiple management beacons having the data, such as multiple management beacons 414 sent according to management beacon schedule 410, both of FIG. 4.
At 608, the data is transmitted by the intermediate node to the receiving node. As noted, this can be through wireless communication 710, and may be through a management beacon or in other manners, such as those following the 802.11 family of protocols. Concluding the present example, intermediate node 704-4 transmits data to receive node 706.
System-on-Chip
FIG. 8 illustrates a System-on-Chip (SoC) 800, which can implement various embodiments described above. An SoC can be implemented in a fixed or mobile device, such as one or a combination of a media device, computer device, television set-top box, video processing and/or rendering device, appliance device, gaming device, electronic device, vehicle, workstation, WLAN access point or client station, and/or in any other type of device that may communicate wirelessly in a local or personal area network. Examples of some of these are shown in FIG. 1.
SoC 800 can be integrated with electronic circuitry, a microprocessor, memory, input-output (I/O) logic control, communication interfaces and components, other hardware, firmware, and/or software needed to run an entire device. SoC 800 can also include an integrated data bus (not shown) that couples the various components of the SoC for data communication between the components. A device that includes SoC 800 can also be implemented with many combinations of differing components.
In this example, SoC 800 includes various components such as an input-output (I/O) logic control 802 (e.g., to include electronic circuitry) and a microprocessor 804 (e.g., any of a microcontroller or digital signal processor). SoC 800 also includes a memory 806, which can be any type of random access memory (RAM), a low-latency nonvolatile memory (e.g., flash memory), read only memory (ROM), and/or other suitable electronic data storage. SoC 800 can also include various firmware and/or software, such as an operating system 808, which can be computer-executable instructions maintained by memory 806 and executed by microprocessor 804. SoC 800 can also include other various communication interfaces and components, wireless LAN (WLAN) or PAN (WPAN) components, other hardware, firmware, and/or software.
SoC 800 includes wireless transmitter 116, wireless receiver 118, and manager 120. Examples of these various components and/or entities, and their corresponding functionality, are described with reference to the respective components of the environment 100 shown in FIG. 1. Manager 120 in SoC 800, either independently or in combination with other entities, can be implemented as computer-executable instructions maintained by memory 806 and executed by microprocessor 804 to implement various embodiments and/or features described herein, such as acting as transmitter and/or receiver of wakeup beacons, whether in a power-save mode or not. Manager 120 may also be provided integral with other entities of the SoC, such as integrated with one or both of wireless transmitter 116 and wireless receiver 118. Alternatively or additionally, manager 120 and the other components can be implemented as hardware, firmware, fixed logic circuitry, or any combination thereof that is implemented in connection with the I/O logic control 802 and/or other signal processing and control circuits of SoC 800.
Although the subject matter has been described in language specific to structural features and/or methodological operations, the subject matter defined in the appended claims is not necessarily limited to the specific features or operations described above, including orders in which the operations are performed.

## Claims

1. A method comprising:
receiving, from a transmitting node of a mesh network, data intended for a receiving node currently in a power-saving mode;
transmitting, according to a previously determined wakeup beacon schedule and by an intermediate node between the transmitting node and the receiving node, a wakeup beacon to the receiving node, the wakeup beacon indicating that the data is available but not including the data within the wakeup beacon, the previously determined wakeup beacon schedule including a start time and a broadcast interval, the start time offset from non-wakeup beacon broadcasts and the broadcast interval about equal to or about a multiple of a non-wakeup beacon broadcast interval;
receiving, at the intermediate node and from the receiving node, an indication that the receiving node is able to receive the data; and
responsive to the indication from the receiving node, transmitting the data to the receiving node.

2. The method of claim 1, wherein receiving the data is performed by the intermediate node during an awake period following an exit from a power-save state and further comprising re-entering the power-save state after transmitting the data to the receiving node.

3. The method of claim 1, further comprising determining the previously determined wakeup beacon schedule prior to receiving the data.

4. The method of claim 1, wherein the wakeup beacon indicates that the data is waiting to be received by the receiving node, the indication in a check beacon section or traffic information map (TIM) element of the wakeup beacon.

5. The method of claim 1, wherein the wakeup beacon is transmitted at data rates greater than 1 Mbps and is 35 or fewer bytes in size.

6. The method of claim 1, wherein transmitting the wakeup beacon transmits the wakeup beacon at about 6 or 24 Mbps.

7. The method of claim 1, wherein transmitting the data to the receiving node transmits a management beacon.

8. A System-on-Chip (SoC) capable of operating within an intermediate node of a mesh network, the SoC having:
a transceiver; and
a manager, the manager configured to:
receive, at the transceiver of the intermediate node and from a transmitting node of the mesh network, data intended for a receiving node currently in a power-save mode, the transceiver of the intermediate node receiving the data intended for the receiving node during an awake period of the intermediate node and following an exit from a power-saving state of the intermediate node;
transmit, in accordance with a previously determined wakeup beacon schedule and by the intermediate node between the transmitting node and the receiving node, a wakeup beacon to the receiving node and through the transceiver, the wakeup beacon indicating that the data is available but not including the data within the wakeup beacon;
receive, through the transceiver of the intermediate node and from the receiving node, an indication that the receiving node is able to receive the data or has exited the power-save mode; and
transmit, in response to the indication from the receiving node and through the transceiver, the data to the receiving node through a management beacon.

9. The SoC of claim 8, wherein the previously determined wakeup beacon schedule includes a start time offset from non-wakeup beacon broadcasts.

10. The SoC of claim 8, wherein the manager is further configured to cause the intermediate node to re-enter the power-saving state after transmitting the data to the receiving node.

11. The SoC of claim 8, wherein the wakeup beacon further indicates that the data is waiting, the indication in a check beacon field or traffic information map (TIM) element of the wakeup beacon.

12. The SoC of claim 8, wherein the wakeup beacon is 35 or fewer bytes in size and the transceiver is configured to transmit the wakeup beacon at a data rate higher than 1 Mbps.

13. The SoC of claim 8, wherein the wakeup beacon schedule includes a start time and a wakeup beacon broadcast interval, the start time offset from non-wakeup beacon broadcasts and the wakeup beacon broadcast interval about equal to or about a multiple of a non-wakeup beacon broadcast interval.

14. A method comprising:
determining a wakeup beacon schedule for a node of a mesh network, the wakeup beacon schedule including a start time and a wakeup beacon broadcast interval, the start time offset from non-wakeup beacon broadcasts and the wakeup beacon broadcast interval about equal to or about a multiple of a non-wakeup beacon broadcast interval;
having the node enter a power-saving state, the power-saving state in which the node has insufficient power to permit communications with one or more peer nodes of the mesh network;
in accordance with the wakeup beacon schedule, having the node exit the power-saving state and enter into a communication state, the communication state in which the node has sufficient power to communicate with the one or more peer nodes of the mesh network;
receiving, at the node, one or more wakeup beacons from the one or more peer nodes of the mesh network, each of the one or more wakeup beacons indicating whether or not data is waiting to be received by the node;
determining that at least one of the one or more wakeup beacons indicates data is waiting to be received by the node, and:
maintaining the node in the communication state responsive to determining that at least one of the one or more wakeup beacons indicates that data is waiting to be received by the node, the maintaining of the node to permit the node to receive the data indicated by the one or more wakeup beacons; or
having the node re-enter the power-saving state responsive to determining that none of the one or more wakeup beacons indicates data is waiting to be received by the node.

15. The method of claim 14, further comprising transmitting an outgoing wakeup beacon in accordance with the wakeup beacon schedule and intended for the one or more peers nodes of the mesh network, the outgoing wakeup beacon transmitted at a data rate higher than 1 Mbps, being 35 bytes or less in size, and indicating whether or not data is waiting for at least one of the one or more peer nodes.

16. The method of claim 14, wherein the one or more wakeup beacons indicate whether or not data is waiting to be received by the intermediate node in a check beacon field or traffic information map (TIM) element of each of the one or more wakeup beacons.

17. The method of claim 14, wherein the mesh network is a wireless local area network in which communications are made compliant with IEEE standard 802.11s.

18. A method comprising:
receiving, from a transmitting node of a mesh network, data intended for a receiving node currently in a power-save mode;
transmitting, in accordance with a wakeup beacon schedule and by an intermediate node between the transmitting node and the receiving node, a wakeup beacon to the receiving node, the wakeup beacon indicating that the data is available but not including the data within the wakeup beacon, the wakeup beacon schedule including a start time and a wakeup beacon broadcast interval, the start time offset from non-wakeup beacon broadcasts and the wakeup beacon broadcast interval about equal to, or about a multiple of, a non-wakeup beacon broadcast interval;
receiving, at the intermediate node and from the receiving node, an indication that the receiving node is able to receive the data or has exited the power-save mode; and
transmitting, in response to the indication from the receiving node, the data to the receiving node through a management beacon.

19. The method of claim 18, wherein receiving the data is performed by the intermediate node during an awake period following an exit from a power-saving state and further comprising re-entering, at the intermediate node, the power-saving state after transmitting the data to the receiving node.

20. The method of claim 18, wherein the wakeup beacon indicates that the data is waiting, the indication in a check beacon field or traffic information map (TIM) element of the wakeup beacon.