Patent Description:
The present invention, in some embodiments thereof, relates to framing scheduling methods and devices, and more specifically, but not exclusively, to synchronized framing scheduling methods for tree mesh networks.

A wireless mesh network (WMN) is a communications network comprising a plurality of wireless routing nodes which may operate in a peer-to-peer fashion to establish communication paths with one another for the purposes of providing network access to wireless clients or mobile stations organized in a mesh topology.

Wireless mesh networks may be deployed using different wireless technologies including, for example, <NUM>, <NUM>, <NUM>, and 3GPP (cellular technologies), and need not be restricted to any specific technology or protocol.

Some wireless mesh networks are hierarchical in nature with the routing nodes that bridge wireless traffic onto a wired network at the top of the hierarchy. The wireless mesh routing nodes can be one, two, or multiple radio systems including, for example, omnidirectional and/or directional antennas, and systems that provide backhaul traffic over the same mesh hierarchy but over multiple channels. In single radio systems, the radio unit is used to act as an access point to its clients and as a backhaul to a parent routing node.

As the number of routing nodes in WMN increases, certain problems emerge because the routing nodes essentially share the same frequency resources, and therefore compete for access to the transmission medium, resulting in radio interference. To avoid such radio interference among the routing nodes, each routing node in the WMN may generally employ a packet collision avoidance mechanism as part of the wireless communications protocol, such as the <NUM> protocol. Accordingly, a typical way of initiating communication between routing nodes begins with the transmission of a "Request-to-send" (RTS) packet by an initiating routing node. This packet is typically received by all routing nodes within the transmission range of the packet sender (i.e., initiating routing node) and is operating on the same channel, as the initiating routing node. The RTS packet notifies these routing nodes that the initiating routing node intends to transmit a flow of packets to a specified target routing node. After receiving an RTS packet, the target routing node responds by transmitting a "Clear-to-Send" (CTS) packet that notifies the initiating routing node that the target routing node is ready to receive the data stream. The CTS packet also serves to notify other routing nodes within a range that the transmission medium has been reserved such that they refrain from transmissions that might interfere with the transmission between the initiating and target routing nodes. Accordingly, since other routing nodes within range of the initiating and target routing nodes are forced to remain idle during data stream transmission, system throughput can be drastically impaired as the number of routing nodes and clients increase. Further, IEEE <NUM> or other collision avoidance mechanisms may not ensure that each routing node receives a fair share of access to the transmission medium.

Additionally, this solution is wasteful, specifically in cases where there are multiple routing nodes.

Intra-Node Interference may also be caused in current Tree Mess Topologies. For example, as shown in <FIG>, the Intra-Node Interference related to Relay Nodes is caused when Station Nodes (STA) and Access Point (AP) functions transmit and receive signals that overlap in time.

To address these problems, WMN routing nodes can employ channel assignment schemes and mechanisms to reduce or eliminate interference between adjacent routing nodes. The limited number of non-overlapping operating channels in a given band, however, does present certain limitations for channel re-use when the number and/or density of routing nodes increases. Directional antennas have also been deployed to reduce or control interference across routing nodes. Without some coordination mechanism, however, interference between routing nodes, as well as fair access to the transmission medium, remains a significant factor.

Present multi-hierarchical and relay wireless communication solutions are used to extend the wireless coverage for various technologies such as cellular relays, WiFi mesh/MANET (Mobile Adhoc NETwork), WiMAX self-backhauling, 3GPP IAB (Integrated Access & Backhaul) and the like. However, these solutions use two or more modem radios and frequency channels with large guard band between them for mesh and relay functionalities. Other known solutions, including systems and devices using single-radio modems experience reduction in performance and high overhead.

In light of the above, improved synchronized framing scheduling methods systems and devices for tree mesh networks that overcome at least some of the above-mentioned deficiencies of the prior scheduling methods and systems would be beneficial. Ideally, such scheduling methods and systems should enable simultaneous switching between downlink and uplink transmission, massive communication, latency, fast roaming, and overhead reduction.

Document <CIT> discloses procedures for distributed interference measurement and management for mesh networks with directional transmission and reception wherein each node in the mesh network may obtain a refined interference neighbour list and form its respective refined interference measurement cluster.

Document <CIT> discloses a method for limiting the amount of interference between OBSSs where the timing between different groups may be coordinated between overlapping BSSs and the coordination may be centralized or distributed.

There are provided methods and devices for scheduling downlink (DL) and uplink (UL) channels in a Tree Mesh network comprising two or more Clusters in a synchronized wireless network such as a synchronized hierarchical Tree Mesh network.

The methods in accordance with some embodiments, comprise allocating and/or mapping Framing Slots within Multi-Frames (such as the Multi-Frames shown in <FIG>) for multiple associated Node Groups within a tree-mesh cluster. Specifically, the method comprises scheduling plurality Framing Slots in one or more Multi-Frames in the synchronized hierarchical Tree Mesh network.

As shown in <FIG> and <FIG>, in accordance with embodiments, a Root AP <NUM> is responsible for synchronizing the Nodes (such as nodes <NUM> and <NUM>) within cluster <NUM> for a Multi-Frame <NUM>. The synchronization method includes scheduling a plurality Framing Slots in one or more Multi-Frames in the hierarchical Tree Mesh network in a way that the Nodes (e.g. Nodes in all hierarchies) will be synchronized in time one with the others at the beginning of the Multi-Frame and Framing Slot numbering within the Multi-Frame.

In operation, the Root AP <NUM> divides the Clusters of Relay Nodes into at least two Groups of Relay Nodes and assigns/allocates to a portion of directly associated/connected Nodes (e.g. Hierarchy <NUM> Relay Nodes and STAs) to the different Node Groups. Additionally, the Root AP <NUM> assigns/allocates Framing Slot within a Multi- Frame to the directly associated Nodes per Node Group.

In accordance with embodiments, the Cluster of Relay Nodes is divided into a number of Groups where each Group has specific allocation of Framing Slot portion within the one or more Multi-Frames. Therefore, each specific Relay Nodes' Group is respectively related to Framing Slots and/or to a portion of Framing Slots within the Multi-Frame.

In accordance with some embodiments, the tree mesh cluster <NUM> shown in <FIG> and related Multi-Frame <NUM> are divided into three groups, for example, as follows:.

Groupe one: comprises Framing Slots which are used for communication between the Root AP and all directly associated Nodes (e.g. Hierarchy <NUM>). During these Framing Slots the Hierarchy <NUM> Relay Nodes cannot communicate with the next hierarchy associated Nodes (Hierarchy <NUM>), but Hierarchy <NUM> Relay Nodes may communicate with Hierarchy <NUM> associated Nodes. In such a way, during this portion of Framing Slots the communication is possible for even Hierarchy Levels between the Relay Nodes and associated Nodes (for instance Hierarchy Levels of <NUM>, <NUM>, <NUM>, <NUM>,.

Group two: comprises Framing Slots which are used for one of the Node Groups. The Relay Nodes in this Node Group, which are connected directly to the Root AP (in Hierarchy Level <NUM>) and communicate with the associated Nodes in Hierarchy Level <NUM>. In such a way, during this group on Framing Slots, communication is possible for odd Hierarchy Levels between the Relay Nodes and associated Nodes (for instance Hierarchy Levels of <NUM>, <NUM>, <NUM>, <NUM>,.

Group three: comprises Framing Slots which may be used for additional Node Groups similarly. During these Framing Slots group, the Root AP does not communicate with appropriate Hierarchy Level <NUM> Nodes within the relevant associated Relay Nodes of the Node Group.

In some embodiments, Node STAs (which are not Relays) connected to the Root AP may communicate during the Framing Slots (e.g. all Framing Slots) in the Multi-Frame and should not be part of any Node Group.

<FIG> shows, a method for resource allocation scheduling serving Tree-Mesh topology <NUM> based on Framing Slot <NUM> Time Division, in accordance with embodiments. The method comprises dividing Framing Slot <NUM>, for example, in time domain for multiple subgroups. In the example shown in <FIG> the Framing Slot <NUM> is divided to two subgroup divisions subgroup <NUM> and subgroup <NUM>, however, embodiments according to the present invention are not limited to any specific number of subgroups and Framing Slot <NUM> may be divided to multiple subgroups.

In accordance with embodiments, the DL and UL direction in Framing Slot <NUM> includes multiple transmission time-zones. Each time-zone can be used for one of the Node Groups (e.g. Node Group <NUM> or Node Group <NUM>) or by Root AP to serve some or all associated STAs. Specifically, <FIG> shows an example where the first time-zone within the Framing Slot used for DL and UL transmissions is allocated for AP to serve all associated STAs and the other time-zone is used for one of Node Groups.

In accordance with some embodiments, each Multi-Frame of a plurality of Multi-Frames comprises at least one Maintenance Framing Slot. Maintenance Framing Slot main goals include distributing information per Tree-Mesh Cluster (e.g. broadcasting announcement).

In accordance with some embodiments, Beacon message can be used for <NUM> networks.

In accordance with some embodiments, the Root AP which is used as a Cluster Master is configured and enabled to distribute or broadcast the Announcement Message (e.g. <NUM> Beacon). Additionally, the Announcement Message should be listened by the Nodes (e.g. all Nodes) within Tree-Mesh Cluster.

In accordance with some embodiments, to improve the broadcast signal propagation, Relay Nodes may also broadcast the same Beacon Message (on behalf of Root AP) which is completely synchronized with the Root AP within the Maintenance Framing Slot, and as such enabling signal diversity within the cluster.

In accordance with embodiments, the broadcasted Beacon Message includes information for the Tree-Cluster management, such as:.

<FIG> shows LTE and 5GNR general Relay architecture, in accordance with embodiments. LTE/5GNR Relay Node has similar architecture as <NUM> networks. Moreover, LTE / <NUM> Relay functions similar to IAB (Integrated Access-Backhaul) node as defined by 3GPP.

In accordance with embodiments, there are provided methods and systems for avoiding intra-node interference and therefore preventing cases where signal transmission of one radio interferes with signal reception of another radio. Accordingly, the Relay Grouping methods and systems as provided by the present invention avoid such self-interference.

<FIG> shows Tree Mesh Cluster Scheduling and grouping based on LTE/5GNR Multi-Frame structure, in accordance with embodiments.

In an embodiment, the Root eNB divides the Tree Mesh Relays, for example, into two Relay Node Groups. For example, a group of elements which are not part of any Relay Node and a Group including UEs.

In accordance with embodiments, there are provided methods, systems and devices which define the mechanism where the LTE DL or UL slots are used for different Node Relay Groups. Specifically, as shown in <FIG> the scheduling and mechanism may include allocating the resources in the Framing Slot as follows:.

In some cases, such Relay Node Groups allocation may be repeated or changed per each Multi-Frame level, where each Multi-Frame comprises n LTE/5GNR frames and a related number of slots (e.g. for LTE case if Multi-Frame has <NUM> frames, it has <NUM> slots).

In some cases, the allocation mapping may be on slot resolution (for example for each slot <NUM>,<NUM>. n in a single frame as shown in <FIG>) or on frame resolution (for example for each Frame as defined in LTE/<NUM> (or equivalate to Framing Slot as defined in the present invention). Such allocation mapping is pre-configured in the system or broadcasted in the control message periodically as shown in <FIG>. Such broadcast control message delivers equivalent information to the Beacon message as explained in the <NUM> part of this invention.

In accordance with embodiments, as explained hereinabove with respect to <NUM> network configuration of the present invention, also LTE & 5GNR tree-mesh management may include update procedures and such messages are delivered as additional information using for example LTE & 5GNR existing MAC control channels (e.g. extension to 3GPP defined RLC or RRC) or as completely new messaging structure using PDSCH and PUSCH channels.

In accordance with embodiments of the present invention there is provided a method for scheduling a plurality Framing Slots in one or more Multi-Frames in a synchronized hierarchical Tree Mesh network, wherein said synchronized hierarchical Tree Mesh network comprising: one or more Clusters, each Cluster of said one or more Clusters comprises: a Single Root Access Point (AP) used as a master of the Cluster; a plurality of Relay Nodes, which are associated directly to the Single Root AP or associated via other Relay Nodes of the plurality of Relay Nodes within the Cluster; one or more Station Nodes (STAs), which are associated directly to the Single Root AP or associated via other Relay Nodes of the plurality of Relay Nodes within the Cluster; and wherein said one or more Multi-Frames comprise said plurality of Framing Slots, wherein each Framing Slot of said plurality of Framing Slots comprises downlink (DL) and uplink (UL) transmissions, said method comprising the steps of: dividing said one or more Clusters to at least two groups of Relay Nodes; allocating, respectively, Framing Slots in said Multi-Frame per each Group of Relay Nodes of said at least two groups of Relay Nodes, so each Group of Relay Nodes is respectively related to one or more allocated Framing Slots within the Multi-Frame.

In an embodiment, the method comprises allocating Framing Slots to three or more groups of Framing Slots.

In an embodiment, the method comprises dividing said one or more Clusters to a first Group of Relay Nodes, a second Group of Relay Nodes and a Group of STA Only Nodes, wherein said Groups of STA Only Nodes comprise STA Only Nodes directly associated to the Root AP; allocating Framing Slots of said one or more Multi-Frames to three groups, wherein: a First Group of Framing Slots comprises: allocated Framing Slots for associated Node Relays from the first Group of Relay Nodes; a Second Group of Framing Slots comprises: allocated Framing Slots for associated Node Relays from the second Group of Relay Nodes; a Third Group of Framing Slots comprises: allocated Framing Slots for Groups of STA Only Nodes.

In an embodiment, the step of allocating the first group of framing slots comprises allocating the first group of Framing Slots for communication of EVEN hierarchies (hierarchies <NUM>, <NUM>,. 2n) of the first Group of Relay Nodes of the said hierarchical Tree Mesh and serving communication of the ODD hierarchies (e.g. <NUM>, <NUM>,. 2n+<NUM>) of the second Group of Relay Nodes of the hierarchical Tree Mesh; and wherein the step of allocating the second group of Framing Slots comprises allocating the second group for communication of EVEN hierarchies (hierarchies <NUM>, <NUM>,. 2n) of the second Group of Relay Nodes of the said hierarchical Tree Mesh and for communication of the ODD hierarchies (hierarchies <NUM>, <NUM>,. 2n+<NUM>) of the first Group of Relay Nodes of the said hierarchical Tree Mesh; and the step of allocating the third group of the Framing Slots comprises allocating the third group for communication of STA Nodes only directly associated to the Root AP.

In an embodiment, the STA Nodes only associated directly to the Root AP are allocated by all three groups of Framing Slots.

In an embodiment, one of the Framing slots of the plurality of Framing Slot is allocated as a Maintenance Framing Slot.

In an embodiment, the plurality of Relay Nodes have single-radio architecture or dual-radio architecture which use the same or adjacent RF channels.

In an embodiment, each Framing Slot of said one or more Multi-Frames is divided to multiple time periods for said DL and UL transmissions where each time period of said multiple time periods within the Framing Slot is used by said at least two Groups of Relay Nodes communicating in EVEN or ODD Hierarchy Levels.

In an embodiment, the method comprising: announcing by the Root AP the Tree Mesh scheduling profile, once any tree mesh topology change caused by new node entry or existing node leaving the cluster the scheduling profile comprises Relay Node distribution between the Node Groups and time resource allocation per each Node Group of Framing Slots or the Framing Slot DL and UL allocation per each Node Group.

In an embodiment, the method comprises: updating a Hierarchy Level of any new STA Node or roaming Node, connected to the Cluster and existing Node disconnected from the Cluster.

In an embodiment, the Hierarchy Level update procedure is initiated as Broadcast Announcement Procedure or as Unicast Procedure.

In an embodiment, the Broadcast Announcement Procedure comprises: executing by the New/Roaming STA Node an Association Procedure; updating the Root AP by a serving Relay Node with an Update Message, which is sent through the serving Relay Nodes within the Cluster; Relay Nodes and Root AP updating their list of Relay IDs and their Hierarchy Level; distributing the next Broadcast Message by Root AP or by Relay APs within the Cluster with updated Relay List Nodes said list comprises Hierarchy Level and Node Group per each Relay Node within the Cluster.

In an embodiment, the Unicast Announcement Procedure comprises: executing by the New/Roaming STA Node an Association Procedure; transmitting Cluster Hierarchy Level update information about the specific Hierarchy Level and Node Group is sent as unicast in one or more Response Messages during the Association Procedure, wherein the Hierarchy Level information delivery is relevant for Node STA new network entry process as well as roaming process between APs within the cluster or between the clusters.

In an embodiment, the Broadcast Control information is sent by the Root AP for the Nodes within the Cluster and wherein the Broadcast information delivers the Nodes with the Node Group mapping of the Framing Slots per one or more Multi-Frames.

In accordance with a second embodiment of the present invention there is provided a Root Access Point (AP) for scheduling a plurality Framing Slots in one or more Multi-Frames in a synchronized hierarchical Tree Mesh network, wherein said hierarchical Tree Mesh network comprises: one or more Clusters, wherein each Cluster of said one or more Clusters comprises:.

In an embodiment, the processor comprises instructions to allocate Framing Slots to three or more groups.

In an embodiment, the processor comprises instructions to: divide said one or more Clusters to a first Group of Relay Nodes a second Group of Relay Nodes and a Groups of STA Only Node allocate said plurality of Framing Slots to three groups, wherein: a First Group of Framing Slots comprises: allocated Framing Slots for associated Node Relays from the first Node Group;
a Second Group of Framing Slots comprises: allocated Framing Slots for associated Node Relays from second Node Group; a Third Group of Framing Slots comprises: allocated Framing Slots for STA Only Nodes directly associated with the Root AP.

In an embodiment, the processor comprises instructions to divide each Framing Slot of said one or more Multi-Frames to multiple time periods for said DL and UL transmissions where each time period of said multiple time periods within the Framing Slot is used by said at least two Groups of Relay Nodes communicating in EVEN or ODD Hierarchy Levels.

In an embodiment, the single Root Access Point (AP) is used as a master of the Cluster.

A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of embodiments of the present disclosure are utilized, and the accompanying drawings.

In the following description, various aspects of the invention will be described. For the purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art that there are other embodiments of the invention that differ in details without affecting the essential nature thereof. Therefore, the invention is not limited by that which is illustrated in the figure and described in the specification, but only as indicated in the accompanying claims, with the proper scope determined only by the broadest interpretation of said claims.

As used herein, like characters refer to like elements.

Prior to the detailed description of the invention being set forth, it may be helpful to set forth definitions of certain terms that will be used hereinafter. Specifically, some of these definitions are presented to align <NUM>. 11ax terminologies presented in this invention with LTE & <NUM> terminology:.

As used herein, the term "Framing Slot" encompasses a slot comprising a fixed time period for the AP and directly connected STAs exchange datagrams between them in DL (Downlink) and UL (Uplink) directions (as shown for example in <FIG>). A Framing Slot may use various PTMP (point-to-multipoint) communication synchronized methods as supported in wireless industry including and not limited to TDD (Time Division Duplexing), FDD (Frequency Division Duplexing), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access). In LTE&5GNR a Framing Slot encompasses a subset of Sub-Frames which comprise OFDMA DL and UL transmissions.

As used herein, the term 'Multi Frame' encompasses subframes, such as Framing Slots, that are grouped or linked together to perform specific functions. The sub-frames may be LTE/5GNR sub-frames of Framing Slots. A Multi-Frame structure of LTE/5GNR may include n*frames (n=<NUM>,<NUM>,<NUM>,<NUM>,. Meaning; if n=<NUM> so LTE/5GNR Multi-Frame is <NUM>*<NUM>=<NUM> sub-frames.

As used herein the term 'Other Relay Nodes' encompasses any Relay Node in the Cluster which is not the Node itself.

As used herein, the term 'AP' (Access Point <NUM> master) encompasses eNB and gNB for LTE and 5GNR respectively.

As used herein, the term 'Root AP' encompasses the main gateway wireless node connecting the wireless STAs to the transport network.

As used herein, the term 'Relay Node' encompasses a node which enables multi-hop connectivity between different hierarchies of the network. Hierarchy level is defined as the number of hops from the Root AP. Relay Node supports AP and STA functionalities.

As used herein, the term STA encompasses a common wireless device connected to one of the APs (e.g. Root or Relay), such as <NUM> STA or LTE/5GNR UE (User Equipment).

As used herein, the term 'Resource Unit (RU)' in <NUM>. 11ax is equivalent to 'Resource Block' (RB) term in LTE/5GNR for OFDMA PHY structure to communicate with multiple STAs/UEs.

The present invention, in some embodiments thereof, relates to framing scheduling methods, and specifically to synchronized framing scheduling methods for tree mesh networks.

In accordance with embodiments, the synchronized framing scheduling methods, systems and devices comprise using a Multi-Frame which comprises a plurality of Framing Slots in WMN.

The methods, systems and devices in accordance with embodiments comprise scheduling a plurality Framing Slots in one or more Multi-Frames in a Tree Mesh network such as a synchronized hierarchical Tree Mesh network, wherein the synchronized hierarchical Tree Mesh network comprises: one or more Clusters, each Cluster of the one or more Clusters comprises: a Single Root Access Point (AP) used as a master of the Cluster; a plurality of Relay Nodes, which are associated directly to the Root AP or associated via other Relay Nodes of the plurality of Relay Nodes within the Cluster; one or more Station Nodes (STAs), which are associated directly to the Root AP or associated via other Relay Nodes plurality of Relay Nodes within the Cluster; and wherein the one or more Multi-Frames comprise the plurality of Framing Slots, wherein each Framing Slot comprises downlink (DL) and uplink (UL) transmissions, the method comprising the steps of: dividing the one or more Clusters to at least two Groups of Relay Nodes; and allocating, respectively, Framing Slots in said Multi-Frame per each Group of Relay Nodes of the at least two Groups of Relay Nodes, so each Group of Relay Nodes is respectively related to one or more allocated Framing Slots within the Multi-Frame.

In WMN a Single-Radio Relay Node can't function simultaneously (while for example AP and STA may function simultaneously). Therefore, in accordance with embodiments, the Relay Node supports dynamic switching between AP and STA modes, per internal logic.

Advantageously, the systems, devices and methods in accordance with embodiments are configured and enabled to provide throughput, latency, and mobility events control in multi-hierarchical tree-mesh wireless networks for high-quality communication using for example a single-radio modem.

<FIG> shows a plurality of synchronized Multi-Frames <NUM> (e.g. Multi-Frame i, Multi-Frame i+<NUM>) and a Multi-Frame structure <NUM> as may be used in accordance with embodiments. A detailed description of Multi-Frame structure <NUM> and other types of scheduling methods that may be used in accordance with embodiments are illustrated in <CIT> entitled SYNCHRONIZED FRAMING SCHEDULER METHODS AND SYSTEMS FOR OFDMA BASED WIRELESS SYSTEMS, which is incorporated herein by reference in its entirety.

It is stressed that other types of schedulers and/or scheduling methods and systems may be used.

Specifically, in a wireless synchronized system, a Multi-Frame includes a constant number of consequent Framing Slots. The Framing Slots within the Multi-Frame are numbered (e.g. from <NUM> to <NUM> as shown in <FIG>). For each Multi-Frame the Framing Slot sequent numbering is restarted from the beginning of the Multi-Frame. Framing Slot duration and the number of Framing Slots per each Multi-Frame defines the fixed time period of the Multi-Frame.

In accordance with embodiments, each Node within the network is synchronized in timing for the transmission at the beginning of the Multi-Frame and as such each Node may compute the same Framing Slot sequent number in each Multi-Frame simultaneously. The number of Framing Slots and Framing Slot duration may vary between different Multi-Frames, which accordingly defines Multi-Frame structure profile. Such Multi-Frame structure profile may be announced, for example, at the beginning of the Multi-Frame by for example a Root AP within a Maintenance Framing Slot (as shown in <FIG>).

In the example shown in <FIG>, each Multi-Frame (e.g. Multi-Frame i, Multi-Frame i+<NUM>) comprises <NUM> Framing Slots (#<NUM> to #<NUM>).

It is stressed that the present invention is applicable for any number of Framing Slots per Multi-Frame.

In the synchronized Multi-Frames <NUM>, the Multi-Frames are cascaded continuously one after the other (e.g. i, i+<NUM>). Additionally, each Multi-Frame has at least one Maintenance Framing Slot and Regular Framing Slots (Regular Framing Slot are defined as 'not a Maintenance Framing Slot').

In accordance with embodiments, the Maintenance Framing Slot is used for broadcasting the maintenance information by the Root AP within the cluster and may be used for other purposes such as Beamforming training and calibration as specified for example in <NUM>.

As shown in <FIG>, each Regular Framing Slot such as Framing Slot #<NUM> in Multi-Frame i+<NUM> comprises DL <NUM> and UL <NUM> transmissions periods between AP and associated STAs. The communication between AP and STAs may be PTMP (point-to-multipoint); OFDMA, TDM. It is stressed that other types of PTMP communications may be used.

<FIG> shows an example of a wireless tree-mesh topology <NUM>, in accordance with embodiments. The tree-mesh <NUM> is a hierarchical multi-hop communication network. As explained above, the tree-mesh topology uses three main wireless node functions:.

In accordance with embodiments, the method for scheduling plurality of Framing Slots in one or more Multi-Frames relates to a Synchronized Hierarchical Tree Mesh network.

Specifically, in a Synchronized Hierarchical Tree Mesh Networks one of the Wireless Nodes is used as Root AP/BS. Root AP/BS is used as themaster clock for the other Wireless Nodes within the Tree Mesh network topology. Hence, all Wireless Nodes simultaneously start and end Framing Slot transmissions and uses the same sequence counting of Framing Slots within the Multi-Frame. Other Wireless Nodes are used as Wireless Relay Nodes or STAs. Additionally, other Wireless Nodes connected to the Root AP/BS or to one of the Relay Nodes within the Mesh network and as such it creates an Hierarchical Tree Mesh Topology as shown in <FIG>.

<FIG> shows a TDD (Time Division Duplex) Communication frame <NUM>, in accordance with embodiments. As shown, Nodes A and B communication includes using the synchronized TDD Frame structure <NUM>. Each TDD Frame includes time periods for DL (downlink) and for UL (uplink) transmissions.

<FIG>, <FIG> show a Wireless Relay Node physical and functional architecture, such as Single-Radio architecture and avoidance of self-interference, in accordance with the prior art.

<FIG> is a block diagram of a device <NUM> such as AP/Relay Node/STAs in accordance with the prior art.

In <FIG>, device <NUM> may include a memory <NUM>, one or more processors such as processor <NUM> and one or more Radio Frequency (RF) units such as RF unit <NUM>.

In some cases, the RF unit <NUM> may be connected to the processor <NUM> and may transmit/receive one or more radio signals via one or more RF antennas. The RF unit <NUM> may transmit the signals by up-converting data received from the processor <NUM> to a transmission/reception band.

In some cases, the RF unit <NUM> may include one or more transmitters for applying RF signals and one or more receivers for receiving RF signals.

In some cases, the RF unit <NUM> may include one or more transceivers configured and enabled to transmit and receive RF signals (wireless signals).

The processor <NUM> may implement the physical layer and/or the MAC layer according, for example, to the IEEE <NUM>/LTE system with being connected to the RF unit <NUM>. The processor <NUM> may be constructed to perform the operation according to the various embodiments of the present invention and according to the drawings and description. In addition, the module or methods for implementing the operation of the device <NUM> according to the various embodiments of the present invention described herein above and below may be stored in the memory <NUM> and executed by the processor <NUM>. In some cases, device <NUM> may be the root AP or any element illustrated in the mesh network of <FIG>.

In accordance with embodiments, the processor is configured and enabled to control the transceiver and/or the one or more transmitters and receivers.

In some cases, the memory <NUM> may be connected to the processor <NUM>, and stores various types of information for execution by the processor <NUM>. In some cases, memory <NUM> may be included interior of the processor <NUM> or installed exterior of the processor <NUM>, and may be connected with the processor <NUM> by a well-known means.

In addition, device <NUM> may include a single antenna or a multiple antenna.

The detailed construction of the device <NUM> of <FIG> may be implemented such that the description of the various embodiments of the present invention is independently applied or two or more embodiments are simultaneously applied.

<FIG> shows a specific example of Architecture Block Diagram <NUM> comprising Networking (Network Processor <NUM>), Modem <NUM> and RF Front End Modules <NUM> with multiple Tx/Rx ports for MIMO and Beamforming support for antennas <NUM>, in accordance with the prior art.

Networking block <NUM> supports Layer2 and Layer3 datagrams (or packet) switching functionalities between the Modem block <NUM> and LAN/WAN port/s <NUM> (used for connecting to backhaul/backbone or various external devices).

In accordance with embodiments, Modem block <NUM> supports Wireless MAC and PHY functions, and RF Front-End block <NUM> supports A/D & D/A and Tx / Rx analog chains with access to the antenna ports. The antenna <NUM> can be OMNI or multiple directional antennas for <NUM>° coverage. The antenna's <NUM> architecture is a typical single-radio block diagram as commonly used by <NUM> wireless devices.

<FIG> shows a Logic Block Diagram <NUM>, in accordance with the prior art. The Relay Node function as STA and AP. Relay STA function is associated to the higher hierarchy AP, while Relay AP function serves the next hop STA (one or more). Both AP and STA may use the same RF Channel (e.g. f1) or closed RF Channels (e.g. adjacent) in case of dual radio architecture as shown in <FIG>. Specifically, <FIG> shows the conceptual Relay Node topology, which includes communication of the Relay Node with it's parent AP on one side and connecting the child STA on other side. As shown in <FIG> although on both sides the Relay Node uses the same frequency channel f1, the present invention and embodiments allow using any adjacent and not frequency channels. Hence, using same frequency channel f1 demonstrates the problem of self-interference (or Intra-Node interference) as presented in <FIG> and the present invention solves with other problems.

<FIG> shows an example of AP and STA functionality <NUM> in time domain, in accordance with the prior art. Specifically, <FIG> shows an example of AP and STA radios within the Relay Node, which transmit and receive signals in different time periods to avoid Intra-Node interference affect as shown in <FIG>.

<FIG> illustrates an example of Tree-Mesh Network <NUM> comprising two Clusters <NUM> and <NUM>, in accordance with embodiments. Each Tree-Mesh Cluster comprises:.

As shown in <FIG> the Relay Node may use OMNI directional antennas or multi-antenna MIMO modem (e.g. <NUM>, <NUM> ports). OMNI directional antenna is less efficient for multi-hierarchical mesh topologies, which results in less-controlled interference between the nodes within the Cluster and between the Cluster. Therefore, Relay Nodes with multi-antenna MIMO modem, which supports antenna switching (or beamforming capability) to the desired direction may minimize the interference effect vs. OMNI directional antenna option.

In accordance with embodiments, multi-hierarchical tree topology is used for delivering data traffic between cascading nodes (also called "Relay Node"). The multi-hierarchical tree comprises one or more clusters wherein each cluster comprises a Root Access Point (AP) which is connected to a transport Point of Presence (POP) (e.g. using fiber) in both directions as shown for example in detail with respect to <FIG>. Each Relay Node comprises STA (Station) which may be connected to the AP of higher hierarchy and an AP which connects the next-hierarchy STAs.

In accordance with embodiments, each cluster comprises a Root AP which is in communication to the backbone network, STAs and Relay Nodes. Each STA can be used as Relay Node within the cluster. The network may comprise single or multiple clusters, while STAs and Relay Nodes may switch between the clusters in case of roaming. Therefore, the network, in accordance with embodiments, may support static or mobile Relay Nodes.

In accordance with embodiments, TDD (Time Division Duplex) radio links methods shown for example in detail with respect to <FIG> are used for transmitting the data, since in TDD communication the radio may transmit or receive a signal on the same radio channel not simultaneously.

Additionally, in accordance with some embodiments the methods, systems and devices, include using single-radio Relay Nodes, meaning AP and STA functionalities are running on a single radio-modem entity (as shown for example in detail with respect to <FIG>).

The systems devices and methods, according to some embodiments, may be based on various standards for wireless local-area networks, typically the IEEE <NUM> standard for wireless local-area networks as the common functions for most <NUM> based radios allows flexible switching between AP and STA modes. As such, AP and STA in the same Relay Node may use the same frequency channel (as shown for example in <FIG>). It is stressed, however, that the systems, devices and methods may be configured for different frequency channels as well.

The systems and methods in accordance with embodiments include the following advantages:.

Reference is now made to <FIG> which shows methods systems and devices <NUM> for scheduling a plurality of Framing Slots in one or more Multi-Frames, such as Multi-Frame <NUM>, in a Tree Mesh Cluster <NUM> of a Tree-Mesh Network such as a synchronized Tree-Mesh Network <NUM>, in accordance with embodiments. <FIG> shows a block mapping of the Framing Slots in the Multi-Frame shown in <FIG>, in accordance with embodiments.

Specifically, the methods systems and devices comprise scheduling downlink (DL) and uplink (UL) channels in the Tree Mesh network <NUM>, and more specifically for allocating/mapping Framing Slots within the one or more Multi-Frames for multiple associated Node Groups within the Tree-Mesh Cluster <NUM>, in accordance with embodiments.

The Tree-Mesh Network <NUM> may be for example the Tree-Mesh Network shown in <FIG>.

In the example shown in <FIG>, the Tree-Mesh Network <NUM> comprises a single cluster <NUM> which comprises a plurality of Relay Nodes, such as Relay Nodes <NUM><NUM> and <NUM>, creating multi-hierarchical tree-mesh topology (as shown in <FIG>). The Tree-Mesh Network <NUM> further comprises one or more STAs (such as STA <NUM> and <NUM>). The Relay Nodes in the hierarchy level <NUM> and the STAs are in direct communication with a root AP <NUM>.

In accordance with embodiments, the Root AP <NUM> is responsible for synchronizing the Relay Nodes within the cluster <NUM> for the Multi-Frame <NUM> in a way that all Nodes (e.g. Relay Nodes and STA only Nodes) in the hierarchies (e.g. all hierarchies) will be synchronized on the beginning of each Multi-Frame of the one or Multi-Frames and Framing Slot numbering within each Multi-Frame (e.g. Multi-Frame <NUM>).

In operation, the Root AP <NUM> assigns/allocates a portion of directly associated Nodes (e.g. Relay Nodes in Hierarchy level <NUM>) to different Node Groups such as Node group <NUM> or Node group <NUM>. Additionally, the Root AP <NUM> instructs the directly associated Nodes of the Node Group Framing Slot allocation within the Multi- Frame <NUM>.

For example, the tree mesh cluster <NUM> and related Multi-Frame <NUM> shown in Error! Reference source not found. A are divided, for example by the Root AP <NUM> into groups as follows:.

In accordance with embodiments, the Root AP <NUM> is configured and enabled to manage/schedule different Framing Slots Within the Multi-Frame <NUM>, as follows:.

In some embodiments, Node STAs (which are not Relays) connected to the Root AP may communicate during all Framing Slots and should not be part of any Node Group.

It is stressed that the scheduling methods structure in accordance with embodiments are not limited to the specific example shown in <FIG> and may support any number of Node Groups and any number or structure of Nodes per Node Groups and Framing Slots allocation.

Reference is now made to <FIG> which show systems methods and devices <NUM> for Tree Mesh Cluster <NUM> scheduling in a Tree-Mesh Network <NUM>, based on Framing Slot Time Division such as Time Division of Framing Slot <NUM>, in accordance with embodiments. Specifically, the method includes allocating DL and UL transmission periods which are divided into time blocks (e.g. two DL Blocks- <NUM>,<NUM> and two UL blocks <NUM>,<NUM>).

Hence, while <FIG> shows methods and systems for scheduling/allocating resources based on separately allocating resources for each Framing Slot in a Multi Frame, <FIG> shows methods for scheduling/allocating resources based on separately allocating resources in a Framing Slot.

In accordance with embodiments, the DL and UL direction in Framing Slot <NUM> includes multiple transmission time-zones. Each time-zone can be used for one of the Node Groups or by Root AP to serve some or all associated STAs. Specifically, <FIG> shows an example where the first time-zone within the Framing Slot <NUM> used for DL and UL transmissions is allocated for AP <NUM> to serve all associated STAs and the other time-zone is used for one of the Node Groups.

For example, the diagonal lined marked DL blocks (block <NUM>) and UL blocks (block <NUM>) are used by Root AP for allocating radio resources for associated Node Relays from Node Group <NUM> (e.g. Rely Nodes <NUM> or <NUM>). Accordingly, for example, simultaneously:.

The square marked DL (block <NUM>) and UL block (block <NUM>) are used by Root AP to allocate radio resources for associated Node Relays from Node Group <NUM> (e.g. Relay Node <NUM>). Accordingly, for example, simultaneously:.

In some cases, the scheduling/allocating resources methods may be based on separately allocating resources for each Framing Slot and in a Framing Slot (e.g. combing the scheduling methods illustrated in <FIG> and <FIG>).

In accordance with further embodiments, there are provided methods for updating the Root AP with a new Node which wishes to join the Cluster. The new Node may function as STA only or Relay Node with attached Nodes behind.

In accordance with further embodiments, there are provided methods systems and devices for updating the Root AP on a roaming Node that wishes to join the Cluster, for example, as a result of roaming from other Cluster(s) or within the Cluster. The method includes updating the hierarchy and new association of existing Nodes within the cluster. Specifically, it includes updating the new AP (e.g. Root or Relay), that the existing Node changed its association within the Cluster (resulted from the roaming event).

<FIG> further illustrates hierarchy Level Update procedures <NUM> for updating for example Root AP with the new Node, in accordance with embodiments.

In operation, a New Node, which is Node STA, may decide to connect to one of the Relay Node AP or Root AP after completing the scanning process. Once the New Node is connected, the Serving AP (Relay or Root) updates the New Node on the Hierarchy Level and accordingly the New Node is updated with its own ID and capabilities (e.g. STA only or Relay Node).

In case the Roaming Node is a Relay Node with Nodes behind (behind meaning that Relay Node has its own Childs / STA connected as a result of the roaming, in cases of new entry process, it is not possible to have any connected devices behind the New STA/Relay), then the Roaming Node updates all connected Relay Nodes IDs and their new Hierarchy Level. The update messages are propagated over the Relay Nodes in the Tree-Mesh Cluster toward the Root AP. In accordance with embodiments, the Roaming Relay Node updates all Nodes behind it, e.g. the New Relay Node updates its associated STAs (and Relays) with a new Hierarchy Level, as it changed the location within the Cluster or roamed from other Cluster with their new Hierarchy Levels within the Cluster and accordingly all nodes are synchronized to the Multi-Frame and get the Cluster broadcast information through the broadcast announcement (e.g. Beacon) in the Maintenance Framing Slot. In other words, as the whole network is synchronized according to the Multi-Frame timing, the Nodes behind the New Relay are updated with their new Hierarchy and other essential information from the Broadcast message sent during Maintenance Framing Slot.

In other words, as the network is synchronized according to the Multi-Frame timing, the Nodes behind the New Relay are updated with their new Hierarchy and other essential information from the Broadcast message sent during Maintenance Framing Slot.

At the end of the updating process, the Root AP and all Nodes of the Cluster are aware of the changes resulting from the New Node entry.

In accordance with embodiments, in cases where a Node is disconnected from the Cluster, the Serving Node AP (Relay or Root), to which the Node was connected, should propagate the change toward Root AP. Accordingly Root AP updates the Tree Mesh Cluster. This procedure is mostly relevant for Relay Nodes, but the present invention is not limited to any Node within the cluster.

In accordance with embodiments, the Cluster has common identification (ID), meaning that the Nodes (e.g. all Node)s within the Cluster have the same ID.

In some cases, for <NUM> networks, service set identifier (SSID) can be used as a common cluster ID. SSID can be shared also with multiple Clusters within the same network.

In some cases, a unique ID may be used per each Cluster as well.

In some cases, each Node AP (Root or Relay) includes also its own ID. For <NUM> networks Basic Service Set Identifier (BSSID) can be used as unique ID per each Node AP.

In accordance with embodiments the procedures of updating the Root AP and the Cluster with the new Node/ Roaming Node and disconnected Node may use the Hierarchy Level distribution procedure.

<FIG> shows hierarchy level updating method <NUM>, in accordance with embodiments. Method <NUM> comprises updating Each Node connected to the specific Cluster with the Hierarchy Level. Hierarchy Level update is required so any new Relay STA will get the right scheduling allocation per Node Group. The update procedure may be done by different methods as follows:.

<FIG> shows an LTE Framing Structure <NUM>, which may be used by the present invention methods and systems as shown for example in <FIG> or <FIG> for Tree Mesh Cluster Scheduling in a Tree-Mesh Network, in accordance with embodiments.

The LTE Framing Structure <NUM> comprises a Multi-Frame <NUM>, which may comprise for example <NUM> sub-frames and accordingly <NUM> slots. Within the Multi-Frame <NUM> each sub-frame is numbered. It is stressed that any numbering method may be used and accordingly any number of sub-frames per Multi-Frame may be used.

In accordance with embodiments, each slot has multiple RBs (Resource Blocks as defined in 3GPP) and each RB or set of RBs and multiple slots can be allocated per UE enabling very flexible OFDMA UE allocation.

For TDD communication each Sub-Frame or slot can be used for DL or UL transmission. As LTE and <NUM> NR has different DL and UL profiles, where <NUM> NR is much more flexible, still the present invention may be utilized for any profile flexibility.

The number of DL and UL sub-frames or slots or symbols per frame (e.g. <NUM> msec) defines the relation between DL and UL, which is equivalent for TDD DL:UL split ratio. In a fully synchronized network, all eNBs and UEs use the same TDD split and the same DL and UL transmission slots to minimize interference within the radio network.

In LTE/<NUM> wireless systems typically two different modems are used for gNB and UE sides. However, the present invention is relevant for LTE/<NUM> since even with two radios self-interference cancellation is required when using the same RF channel or closed RF channels (e.g. adjacent).

As shown in <FIG>, LTE/<NUM> NR Relay architecture <NUM> includes a UE model which is connected to higher hierarchy eNB and eNB module, which serves the next hierarchy UEs. MAC and Network Processor Module is used to coordinate between UE and eNB module. In addition, MAC and Network Processor Module is responsible for forwarding the packets, enabling protocol control functions of MAC and high layers as defined by 3GPP. An example for 3GPP Relay Node is IAB (Integrated Access-Backhaul) units, which includes UE and eNB function within the same network location. Such IAB enables link extension using chain configuration.

Advantageously, the present invention enables IAB units to establish flexible tree-mesh topologies using a single channel or limited number of overlapping channels and avoiding Intra-Node Interference effect.

<FIG> shows an example of a tree-mesh Relay Node Groups mapping <NUM> of DL and UL slots using LTE Multi-Frame structure <NUM> to enable different Relay Nodes in Tree Mesh Cluster <NUM> to communicate with each other for different Hierarchical Levels and avoiding intra-node interference, in accordance with embodiments. While <FIG> shows an example of <NUM> synchronized framing approach <FIG> shows a similar concept using LTE structure, both in accordance with embodiments.

As shown in <FIG> the Multi-Frame <NUM> includes using one of the slots such as the first Slot 1251to send information about the Node Group mapping structure per one or more Multi-Frames. The slot, which holds the broadcast information may be used for regular DL transmission (e.g. where regular DL transmission means 'no maintenance' but rather regular data packet to the associated UEs / Relay). It is considered, that Broadcast information is not big enough and therefore remained resources can be used for regular communication similarly "white slots") as well in other RBs (if available) to all Hierarchy <NUM> nodes / UEs. Broadcast information can be avoided per Multi-Frame if no change Relay Node Group allocations in the following Multi-Frame.

It is stressed that while <FIG> shows an example using two Node Groups any number of Node Groups may be used such as three, four and more.

It is stressed that the description in the present invention refers to a Multi-Frame using <NUM> Framing Slots with 2msec per Framing Slot such as in <NUM>. However, the invention is not limited to the specific number and Framing slot duration within the Framing Slot or specific wireless standard and system. In addition, the invention description refers to <NUM> OFDMA-based technology, but not limited to OFDMA provided frequency and time domain wireless resource allocation flexibility between AP and associated STAs, which is very efficient for PTMP (Point-To-Multi-Point) communication topologies. This invention has the advantage of using OFDMA, but also may use other wireless methods; e.g. OFDM/TDMA in case it is structured as Multi-Frame (as shown in <FIG>).

This invention is relevant also for other synchronized framed schedulers as used in WiMAX, LTE,5GNR and other future synchronized PTMP communication methods (e.g. future 3GPP Releases). This text explains how the grouping approach as described in this invention can be applied on TDD LTE and 5GNR implementations. Certainly, this invention also can be relevant for any future wireless technologies if synchronized frames structure is used.

As shown in <FIG> the LTE & 5GNR PHY structure consists of <NUM> sub-frame, while <NUM> sub-frames formats 10msec frame. Such frame in LTE & <NUM> is used for periodic PHY procedures as defined by 3GPP. Each frame consists of multiple slots, while a number of slots depends on the numerology as defined in 5GNR. As per <FIG>, the example in the detailed description refers to LTE PHY structure case. LTE includes only one numerology of two slots per sub-frame of 1msec and each slot has <NUM> OFDM symbols in time (NOTE: 5GNR has some differences in terminologies and number of symbols, but for this invention the approach of grouping is similar). The OFDMA structure of LTE & <NUM> is based on Resource Blocks (RBs), where each RB can be allocated per UE (User Equipment - equivalent to STA in <NUM>). Each RB is constructed from <NUM> subcarriers and <NUM> symbols (slot in LTE). If referring to LTE TDD structure some sub-frames may be used for DL transmission and others for UL, in 5GNR DL and UL transmissions can be done per symbol basis (based on 3GPP profile).

A detailed description of other type of schedulers and scheduling methods that may be used in accordance with embodiments are illustrated in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>. Specifically, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> show examples of Framing Slot and Multi-Frame Synchronized structure for <NUM> OFDMA as illustrated by the current applicant <CIT>, entitled "SYNCHRONIZED FRAMING SCHEDULER METHODS AND SYSTEMS FOR OFDMA BASED WIRELESS SYSTEMS" (attorney docket no. CM001/USP) which is incorporated herein by reference in its entirety and which may be used as a reference for <NUM> system Tree Mesh scheduling in accordance with the present invention and embodiments.

<FIG> shows a Framing Slot structure and scheduling method and system <NUM> for OFDMA based wireless systems such as IEEE <NUM> standard, in accordance with embodiments.

As shown in <FIG>, each network may comprise an access point (AP) and a plurality of stations (e.g. STAs A1, A2. An) in <NUM> OFDMA wireless communication system.

In accordance with embodiments, the AP synchronizes the plurality of STAs within each network using one or more synchronization signals over the air (e.g. using Timestamps) delivered between the AP and the STAs.

The method includes allocating one or more Framing Slots, such as Framing Slot <NUM> and Framing Slot <NUM>. Each Framing Slot (e.g. Framing Slot i, Framing Slot i+<NUM>. ), comprises a fixed time duration (e.g. <NUM> msec).

In some cases, the Framing Slot's time duration may vary per traffic characteristics (e.g. latency, throughput, etc.).

In accordance with embodiments, each Framing Slot such as Framing Slot <NUM> comprises DL and UL transmission periods <NUM> and <NUM>. Per each Framing Slot, the AP (e.g. AP A) may transmit datagrams (e.g. Data STA1, Data STA A2, Data STA3) to multiple STAs (e.g. A1, A2, A3) using for example one or more Data Units such as Data Units <NUM> (e.g. HE MU-PPDU <NUM> frame) in the DL direction.

The Framing Slot structure, further defines, in accordance with embodiments, a piggyback mechanism, where part of RUs is used for Trigger Frame <NUM> for UL RU allocation and part of RUs is used for Block Ack messages <NUM> for previous Framing Slots for non-allocated STAs (e.g. STA <NUM> and <NUM>).

As shown in <FIG>, each Framing Slot is numbered <NUM>, <NUM>,. i, i+<NUM> and Guard Time intervals <NUM> are included between each DL and UL transmission to compensate on the two-way signal propagation time over the air between AP and associated STAs.

In accordance with embodiments, the defined allocations, such as Framing Slot <NUM>, include a number of time slots in which each time slot is scheduled as follows:.

In accordance with embodiments, the DL and UL transmission periods <NUM> and <NUM> included in the Framing Slot may have different time durations and the duration ratio between them defines TDD split. Advantageously, by using different DL and UL durations the network system may provide DL and UL or symmetric oriented services. In other words, the synchronized scheduling method and system in accordance with embodiments provide managed DL and UL with continuous behavior, hence, bursts (such as Data Units <NUM> and <NUM>) are transmitted continually one burst following the previous burst, while prior <NUM> schedulers provide opportunistic (e.g. not managed and not continuous) DL and UL scheduling transmissions opportunities.

Specifically, the framing structure as described in accordance with embodiments includes one or more DL transmission bursts such as DL Data Unit <NUM> (e.g. HE MU-PPDU) during the fixed-time DL period <NUM> and UL transmission bursts such as UL Data Unit <NUM> (e.g. HE TB PPDU) during fixed-time UL period <NUM>.

In the DL transmission period <NUM>, the first burst is transmitted by AP at the beginning of each Framing Slot. If more than one DL burst is transmitted during the DL period (as illustrated for example in <FIG>) the following DL bursts are transmitted with a time offset from the beginning of the Framing Slot as per AP scheduling decision. The total time for all DL bursts transmissions will not exceed the fixed-time DL period <NUM>.

In the UL transmission period <NUM>, the STAs transmit to the AP a first burst (Data Unit <NUM> such as HE TB PPDU) at the beginning of the UL period within the Framing Slot <NUM>. If more than one UL burst is transmitted by another set of STAs within the UL period of the Framing Slot (as illustrated in <FIG>), these bursts should be transmitted with time-offset from the beginning of the UL period as indicated by AP to the STAs during the DL period. The total time for all UL bursts transmissions will not exceed the fixed-time UL period.

In accordance with embodiments, within the continuous synchronized behavior of the scheduling, the fixed-time Framing Slots are transmitted constantly, while AP and STAs are completely synchronized one with the other on the same transmission timings, transmission durations and numbering sequence of the Framing Slots.

More specifically, as illustrated in <FIG> a set of functionalities per each Framing Slot are defined as follows, in accordance with embodiments:.

UL Random access - Each Framing Slot may enable UL Random access for other STAs also using the Trigger Frame. Such capability is enabled using UORA (Uplink OFDMA Random Access) mechanism according to <NUM>. As shown in <FIG> the time duration of the DL and UL bursts transmissions are fixed time periods comprising fixed time guard between the Framing Slots in each Framing Slot.

In accordance with embodiments, the Framing Slots are transmitted constantly one after another creating continuous synchronized communication between AP and STAs. Each Framing Slot is numbered with a time stamp, and AP and STAs are updated on each Framing Slot timing and sequence number.

A Group of Framing Slots generates a Multi-Frame as explained hereinafter with respect to <FIG>.

In accordance with embodiments, each Framing Slot may support one or more Data Units (e.g. PPDU frames) per each DL transmission and each UL transmission. While <FIG> shows an example of a single Data Unit (e.g. PPDU frame) per DL transmission and UL transmission (for explanation simplicity), <FIG> shows an example including two Data Units in DL and two Data Units in UL per Framing Slot. The number and duration of Data Units in DL and UL slots can vary as long as the total time duration of data units is not exceeding the DL and UL time duration as set by TDD split in the system.

Specifically, as shown in <FIG>, the systems and methods in accordance with embodiments may define scheduling methods and systems configured and enabled for transmitting/receiving multiple Data Units (such as <NUM>. 11ax HE MU-PPDU) per Framing Slot in each DL and UL directions.

For example, a number of Framing Slots, such as Framing Slot <NUM> and Framing Slot <NUM> having a fixed time duration may be allocated. Each Framing Slot such as Framing Slot <NUM> includes a DL transmission period <NUM> and UL transmission period <NUM>. In accordance with embodiments, the DL transmission period <NUM> and UL transmission period <NUM> comprise respectively one or more DL Data Unit bursts and one or more UL Data Unit bursts such as DL Data Unit bursts <NUM> and <NUM> (e.g. HE MU PPDU) and UL Data unit bursts <NUM> and <NUM> (e.g. HE TB PPDU).

In accordance with embodiments, each Data Unit Burst may have a different time length based on the AP scheduling decision, but the total time length of all transmission bursts cannot exceed the fixed DL period time. Additionally, in accordance with embodiments, different Data Units may allocate RU to a different set of Data Units, and/or the same STAs may belong to a different set of STAs. For example, STA1 may be in the first Data Unit <NUM> and also in the second Data Unit <NUM>.

In accordance with embodiments, in operation AP, such AP A, transmits one or more DL Data Unit bursts (Data Units <NUM> and <NUM>) to one or more STAs (STA1, STA2, STA3 , TA4 and STA5) during DL transmission period <NUM>. Each DL Data Unit burst comprises:.

Accordingly, STAs, which are communicating with AP (Such AP A) and which received UL transmission instructions in Trigger Frame during the DL transmission period send UL Data Unit Bursts <NUM> and <NUM> (such as <NUM>. 11ax HE TB-PPDU ) during the UL transmission period (e.g. UL transmission period <NUM>) as allocated in accordance with embodiments, as follows:.

It is noted that though <FIG> presents example of two Data Units (e.g. two PPDUs) per Framing Slot, the systems, devices and methods, in accordance with embodiments, may include any combination of Data Units per Framing Slot. The Data Units time duration can vary, but is limited to the DL and UL periods, which are fixed in the synchronized network.

Multi-Frame structure as defined in accordance to embodiments, includes multiple Framing Slots. Examples of Multi Frames are illustrated in <FIG>.

In accordance with another embodiment, there is provided a Multi-Frame for OFDMA based wireless systems such as IEEE <NUM> standard for wireless local-area networks. The Multi-Frame comprises multiple Framing Slots, for example, a predefined group of Framing Slots.

According to some embodiments, the Multi-Frame comprises consequent Framing Slots, where AP and STAs are synchronized, respectively, one with the others by having common (e.g. same) timing to identify the beginning and end of the Multi-frame. Additionally, AP and STAs are both synchronized one with the others with shared Framing Slot ordering and numbering within the Multi-Frame.

In accordance with embodiments, in the wireless local-area networks one or more Multi-Frames may be transmitted continuously one after the other.

In some cases, one, some, or all Framing Slots of the Multi-Frame may be the Framing Slot <NUM> shown in <FIG> or Framing Slot <NUM> shown in <FIG>.

In accordance with embodiments, the numbering of Framing Slots is circulated per Multi-Frame size.

<FIG> shows, in accordance with embodiments, a plurality of Multi-Frames <NUM>(e.g. Multi Frame i, Multi Frame i +<NUM>) and Multi Frame structure, in accordance with embodiments.

Each Multi-Frame may comprise for example <NUM> Framing Slots. It is stressed that the Multi-Frame structure may include any number of Framing Slots, for example, more or less than <NUM> Framing Slots.

According to one embodiment, one or more of the Framing Slots of each Multi-Frame may be used as Maintenance Framing Slot such as Framing Slot <NUM> and <NUM>' (slot numbered '<NUM>'). Preferably, the Maintenance Framing Slot time duration is equivalent to each of the other fixed Frame Slots (slots '<NUM>'- '<NUM>') time duration in the Multi-Frame. In the example shown in <FIG> the time duration of the Maintenance Framing Slot <NUM> and other Framing Slots is the same.

In the example shown in <FIG>, the Maintenance Framing Slot <NUM> is numbered '<NUM>' and located at the beginning of Multi-Frame <NUM>.

In accordance with some embodiments, the Multi-Frame <NUM> total time duration and number of Framing Slots may vary between different Multi-Frames, hence, the time duration of a Multi-Frame is determined according to the number of Framing Slots in the Mult-Frame.

In some cases, the Multi-Frame duration can be broadcasted by AP to all STAs by the Maintenance Framing Slot <NUM> in a Multi-Frame for the following Multi-Frames to synchronize Framing Slot sequence (e.g. numbering) between AP and STAs.

<FIG> shows a Maintenance Framing Slot <NUM> (in Synchronous Mode) comprising Long BF Training and <FIG> shows a Maintenance Framing Slot (Synchronous Mode) <NUM> w/o BF Training. The Maintenance Framing Slot <NUM> may comprise, in accordance with embodiments, a Beacon message <NUM> for broadcasting specific network information as described hereinbelow and optionally also Beamforming Training procedure. When no Beamforming training procedure exists, the Maintenance Slot <NUM> includes DL and UL PPDU following the Beacon message.

In <FIG> the numbering in the Maintenance Framing Slot <NUM> relates to the typical OFDM symbols numbers needed to transmit DL broadcast message (e.g. Beacon message) and Beamforming training messages sequence.

The Multi-Frame structure, in accordance with embodiments, supports the following capabilities:.

Maintenance Framing Slot is used, in accordance with embodiments, by the AP/BST for the Framing Slot scheduling profile announcement and other <NUM> broadcasting information (such as SSID (Service Set Identifier) broadcasting in according to <NUM>). Such announcements can be broadcasted using for example <NUM> Beacon message.

The Framing Slot scheduling profile information includes (but not limited to), in accordance with embodiments:.

According to one embodiment, the Maintenance Framing Slot structure as shown in Figure 14B may be divided to transmission bursts (based on the typical OFDM symbols numbering) as follows:.

According to one embodiment, the Maintenance Framing Slot structure as shown in Figure 14C may be divided to transmission bursts (based on the typical OFDM symbols numbering) as follows:.

In accordance with some embodiments, the structure of the Maintenance Framing Slot is mandatory however the number of symbols per each OFDM burst can vary.

According to another embodiments, the methods, devices and systems in accordance with embodiments may use a Semi-Synchronous Multi-Frame structure which is a subset of the fully synchronous Framing Scheduler. The Semi-Synchronous Multi-Frame structure may be applicable for small networks (limited number of APs per network), where DL and UL transmission synchronization is not essential for inter-cell interference avoidance. Such deployment does not require a synchronization source (like as GPS or IEEE <NUM>). Another advantage of the Semi-Synchronous Multi-Frame structure is R&D implementation simplicity, where most of standard <NUM>. 11ax procedures can be used as is.

This approach enables using CSMA/CA combined with the Multi-Frame structure as illustrated hereinabove with respect to <FIG> and <FIG>. The Semi-Synchronous Multi-Frame structure is suitable for example for unlicensed bands, where regulation requires LBT.

<FIG> shows a plurality of Multi-Frames <NUM> and a Multi-Frame structure <NUM> for non-synchronized network, in accordance with embodiments. The Multi-Frame structure <NUM> includes Maintenance Framing Slot <NUM>, which don't have a fixed time i.e. Maintenance Framing Slot <NUM> may have different time durations than the other fixed time/regular Framing Slots (slots '<NUM>'-'<NUM>') and therefore must be transmitted before the regular Framing Slots are performed. Since this structure is not network synchronized it may include CSMA/CA timers (e.g. DIFS and Backoff) prior to any Multi-Frame. This Multi-Frame structure enables using NAV mechanism as defined in <NUM> using MU RTS/CTS messages and TXOP field.

The Maintenance Framing Slot <NUM> includes:.

The Semi-synchronized scheduler according to embodiments has the following functionalities which are not part of a synchronized scheduling methods and systems:.

<FIG> shows an example of a Framing Slot <NUM>, which can be used for Semi-Synchronous Multi-Frame procedure, for OFDMA based wireless systems such as IEEE <NUM> standard, in accordance with embodiments. The Framing Slot <NUM> may reuse the procedures as defined in <NUM>.

The Framing Slot <NUM> for semi-synchronized scheduler comprises, in accordance with embodiments, DL and UL procedures- DL procedure <NUM> includes Data Unit <NUM> (e.g. HE MU-PPDU) signaled by AP toward STAs and in response an acknowledgment message Data unit <NUM> (ACK/Block Ack in HE TB PPDU) from STAs toward AP. UL procedure <NUM> includes Trigger Frame <NUM> sent by AP toward STAs in order to instruct and synchronize regarding simultaneous UL transmission from STAs. Following Trigger Frame <NUM>, the STAs send Data Units <NUM> (e.g. HE TB-PPDU) toward AP. At the end of the Framing Slot <NUM>, AP responds with an acknowledgment (Block ACK) toward STAs. Each duration of DL and UL procedures can vary in time, however, in accordance with embodiments, the combined DL and UL procedures within the Framing Slot are fixed in time (e.g. <NUM> msec) and predefined.

In some cases, the semi-synchronous Framing Slot <NUM> may include using piggyback approach for Trigger Frame and acknowledgment information as defined for Synchronized Framing Slot as shown in <FIG> and <FIG>, however, between each <NUM> PPDU the system should keep SIFS <NUM> timers and consider the SIFS periods as part of the semi-synchronized Framing Slot total duration.

It is stressed that the present invention refers to any OFDMA based systems and networks such as <NUM> standard releases for example <NUM>.

It is stressed that all procedures and grouping approaches as described with respect to the present invention are relevant and applicable for LTE and 5GNR PHY structures.

In further embodiments, the processing unit may be a digital processing device including one or more hardware central processing units (CPU) that carry out the device's functions. In still further embodiments, the digital processing device further comprises an operating system configured to perform executable instructions. In some embodiments, the digital processing device is optionally connected to a computer network. In further embodiments, the digital processing device is optionally connected to the Internet such that it accesses the World Wide Web. In still further embodiments, the digital processing device is optionally connected to a cloud computing infrastructure. In other embodiments, the digital processing device is optionally connected to an intranet. In other embodiments, the digital processing device is optionally connected to a data storage device.

Those of skill in the art will recognize that many smartphones are suitable for use in the system described herein. Those of skill in the art will also recognize that select televisions with optional computer network connectivity are suitable for use in the system described herein. Suitable tablet computers include those with booklet, slate, and convertible configurations, known to those of skill in the art.

In some embodiments, the digital processing device includes an operating system configured to perform executable instructions. The operating system is, for example, software, including programs and data, which manages the device's hardware and provides services for execution of applications.

In some embodiments, the digital processing device includes an input device to receive information from a user. In some embodiments, the input device is a keyboard. In some embodiments, the input device is a pointing device including, by way of non-limiting examples, a mouse, trackball, track pad, joystick, game controller, or stylus. In some embodiments, the input device is a touch screen or a multi-touch screen. In other embodiments, the input device is a microphone to capture voice or other sound input. In other embodiments, the input device is a video camera to capture motion or visual input. In still further embodiments, the input device is a combination of devices such as those disclosed herein.

The functionality of the computer readable instructions may be combined or distributed as desired in various environments. In some embodiments, a computer program comprises one sequence of instructions. In some embodiments, a computer program comprises a plurality of sequences of instructions. In some embodiments, a computer program is provided from one location. In other embodiments, a computer program is provided from a plurality of locations. In various embodiments, a computer program includes one or more software modules. In various embodiments, a computer program includes, in part or in whole, one or more web applications, one or more mobile applications, one or more standalone applications, one or more web browser plug-ins, extensions, add-ins, or add-ons, or combinations thereof. In some embodiments, a computer program includes a mobile application provided to a mobile digital processing device. In some embodiments, the mobile application is provided to a mobile digital processing device at the time it is manufactured. In other embodiments, the mobile application is provided to a mobile digital processing device via the computer network described herein.

In some embodiments, the system disclosed herein includes software, server, and/or database modules, or use of the same. In view of the disclosure provided herein, software modules are created by techniques known to those of skill in the art using machines, software, and languages known to the art. The software modules disclosed herein are implemented in a multitude of ways. In various embodiments, a software module comprises a file, a section of code, a programming object, a programming structure, or combinations thereof. In further various embodiments, a software module comprises a plurality of files, a plurality of sections of code, a plurality of programming objects, a plurality of programming structures, or combinations thereof. In various embodiments, the one or more software modules comprise, by way of non-limiting examples, a web application, a mobile application, and a standalone application. In some embodiments, software modules are in one computer program or application. In other embodiments, software modules are in more than one computer program or application. In some embodiments, software modules are hosted on one machine. In other embodiments, software modules are hosted on more than one machine. In further embodiments, software modules are hosted on cloud computing platforms. In some embodiments, software modules are hosted on one or more machines in one location. In other embodiments, software modules are hosted on one or more machines in more than one location.

In the above description, an embodiment is an example or implementation of the inventions. The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

Reference in the specification to "some embodiments", "an embodiment", "one embodiment" or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the inventions.

It is to be understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, figures and examples.

It is to be understood that the details set forth herein do not construe a limitation to an application of the invention.

Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

It is to be understood that the terms "including", "comprising", "consisting" and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

It is to be understood that where the claims or specification refer to "a" or "an" element, such reference is not be construed that there is only one of that element. It is to be understood that where the specification states that a component, feature, structure, or characteristic "may", "might", "can" or "could" be included, that particular component, feature, structure, or characteristic is not required to be included. Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described. Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

The descriptions, examples, methods and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only. Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined. The present invention may be implemented in the testing or practice with methods and materials equivalent or similar to those described herein.

Claim 1:
A method for scheduling a plurality Framing Slots in one or more Time Division Multiple Access, TDMA Multi-Frames in a synchronized hierarchical Tree Mesh Orthogonal Frequency Division Multiple Access, OFDMA network, wherein said synchronized hierarchical Tree Mesh network comprising:
one or more Clusters in said synchronized hierarchical Tree Mesh network, each Cluster of said one or more Clusters comprises:
an OFDMA-based Single Root Access Point, AP used as a master of the Cluster;
a plurality of OFDMA Relay Nodes, which are associated directly to the Single Root AP or associated via other Relay Nodes of the plurality of Relay Nodes within the Cluster;
one or more OFDMA Station Nodes, STAs, which are associated directly to the Single Root AP or associated via other Relay Nodes of the plurality of Relay Nodes within the Cluster; and
wherein said one or more TDMA Multi-Frames comprise said plurality of Framing Slots, wherein each Framing Slot of said plurality of Framing Slots comprises downlink, DL and uplink, UL transmissions,
characterized in that said method comprises the steps of:
dividing said one or more Clusters to at least two Groups of Relay Nodes to avoid Intra-Node Interference of said Relay Nodes;
allocating, respectively, Framing Slots in said Multi-Frame per each Group of Relay Nodes of said at least two Groups of Relay Nodes, so each Group of Relay Nodes is respectively related to one or more allocated Framing Slots within the Multi-Frame.