METHOD AND SYSTEM FOR BROADCASTING DATA IN WIRELESS NETWORK

Abstract

A method for communicating data between Bluetooth Low Energy (BLE) devices (200, 202) in a network (100) comprising multiple nodes, the method comprising: broadcasting data from a broadcasting node (200); receiving the data at multiple receiving nodes (202); transmitting an acknowledgement (ACK) packet from each of the receiving nodes (202) to the broadcasting node (200), wherein each receiving node (202) waits for a waiting period before transmitting the ACK packet, and wherein the waiting period is a varying length of time for each receiving node (202).

Claims

1. A method for communicating data between Bluetooth Low Energy (BLE) devices in a network comprising multiple nodes, the method comprising: broadcasting data from a broadcasting node; receiving the data at multiple receiving nodes; transmitting an acknowledgement (ACK) packet from each of the receiving nodes to the broadcasting node, wherein each receiving node waits for a waiting period before transmitting the ACK packet, and wherein the waiting period is a varying length of time for each receiving node.

2. The method of claim 1, wherein the waiting period is a randomly determined length of time.

3. The method of claim 1, wherein the waiting period is determined by information that is unique to the receiving node.

4. The method of claim 3, wherein the information unique to the receiving node is a node ID.

5. The method of claim 3, wherein the information unique to the receiving node is a MAC address.

6. The method of claim 1, wherein the waiting period is determined by the distance the receiving node is from the broadcasting node.

7. The method of claim 1, wherein the waiting period is different for each receiving node.

8. The method of claim 1, wherein the waiting period is determined by information that is non-unique to the receiving node, such as a combination of RF signatures at the receiving node, receiver signal strength, and signal phase.

9. The method of claim 8, wherein the non-unique information is a combination of RF signatures generated at the receiving node.

10. The method of claim 8, wherein the non-unique information is a signal strength at the receiving node.

11. The method of claim 8, wherein the non-unique information is a signal phase at the receiving node.

12. The method of claim 1, wherein the receiving node sends an ACK packet using Code Division Multiple Access (CDMA).

13. A Bluetooth Low Energy network comprising multiple nodes and being an apparatus for communicating data between Bluetooth Low Energy (BLE) devices, the network comprising: a first BLE device configured to broadcast data; and multiple BLE receiving devices configured to receive broadcasted data; wherein the multiple receiving devices are receiving nodes that are configured to transmit an acknowledgement (ACK) packet to the first device upon receipt of broadcasted data, wherein each receiving node is configured to wait for a waiting period before transmitting the ACK packet; and wherein the waiting period is a varying length of time for each receiving node.

14. A Bluetooth Low Energy network configured to operate in accordance with the method of claim 1.

15. A computer programme product containing instructions that, when executed within a Bluetooth Low Energy network comprising multiple nodes, will configure the network to operate in accordance with the method of claim 1.

Description

DRAWING DESCRIPTION

[0043] Certain embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:

[0044] FIG. 1 shows an exemplary BLE network.

[0045] FIG. 2 shows BLE devices as a broadcasting node and a plurality of receiving nodes.

[0046] FIG. 3 is a flowchart illustrating a method for broadcasting data from a broadcasting node to one or more of multiple receiving nodes.

[0047] FIG. 4 shows a schematic view of a pair of BLE devices.

DETAILED DESCRIPTION

[0048] A BLE mesh network may comprise a head node or gateway that transmits data to one or more nodes within the network. The network may comprise any number of nodes. All nodes in the network are considered to be downstream with respect to the head node and, conversely, the head node is upstream of other nodes in the network. The structure of the network may be that data can travel from the head node and through other intermediary nodes before reaching a destination node.

[0049] FIG. 1 shows an example BLE network 100 where the network 100 is depicted as a tree. A head node 102 forms the root of the network 100 and devices in the BLE network form branches in the network. Some BLE devices are not directly connected to the head node 102; instead they are connected via a branch node. This means that any transmissions sent from the head node 102 may have to be communicated through another BLE node before the transmission reaches its destination node.

[0050] A BLE device may be configured to broadcast data to a plurality of other BLE devices. The BLE device that broadcasts data may be termed a broadcaster or a broadcasting node. A BLE device that receives broadcasted data may be termed a receiver or a receiving node.

[0051] FIG. 2 shows a broadcasting node 200 and a plurality of receiving nodes 202. Each node may be able to determine its position in a BLE network relative to other nodes by storing identifying information about its neighbours. Neighbouring nodes may be defined as those that are immediately connected to a node in the network. Identifying information may include hop distance and a unique node ID.

[0052] The broadcasting node 200 is configured to broadcast data to one or more of the plurality of receiving nodes 202. The broadcast data formation should follow the BLE specifications in data transmission. Each receiving node 202 is configured to receive data broadcast from the broadcasting node 200 and to transmit an ACK packet back to the broadcasting node 200. The broadcasting node 200 is configured to receive ACK packets from all of the receiving nodes 202 to which the broadcast data was sent.

[0053] A receiving node 202 may not be directly connected to the broadcasting node 200 in the BLE network. Upon receipt of broadcasted data, the receiving node may transmit its ACK packet via one or more intermediary nodes back to the broadcasting node 200.

[0054] Receiving nodes 202 of the exemplary BLE network are configured to coordinate transmission of ACK packets to the broadcasting node 200. One or more receiving nodes 202 are configured to introduce a time delay before transmission of an ACK packet.

[0055] In one example, the time delay is a random time delay. In this case, receiving nodes 202 are configured to receive data broadcasted from a broadcasting node 200, wait for a random length of time, and transmit an ACK packet to the broadcasting node 200. The longer the random back-off period is, the less likely ACK packet collision will occur.

[0056] In another example, the time delay is determined using a property of the node, such as unique node information. The unique information used includes, but is not limited to, the node ID and the node's MAC address. In this case, receiving nodes 202 are configured to receive data broadcasted from a broadcasting node 200, wait for a length of time that is determined by information unique to each receiving node 202, and transmit an ACK packet to the broadcasting node 200.

[0057] FIG. 3 is a flowchart showing an exemplary method for broadcasting data from a broadcasting node to one or more of multiple receiving nodes. At step 302, a broadcasting node broadcasts data to multiple receiving nodes. At step 304, multiple receiving nodes receive the broadcasted data. At step 306, the receiving nodes wait for a waiting period, where the waiting period for each receiving node may be different. At step 308, the receiving nodes transmit an ACK packet to the broadcasting node.

[0058] At step 306, the length of the waiting period at each receiving node may be a random value or it may be a value that is dependent on information unique to each node.

[0059] FIG. 4 illustrates a pair of BLE devices 400, 410 which may utilise the methods discussed above. The BLE devices 400, 410 might be any suitable known type of device, and they are modified compared to the known devices to operate in accordance with a method as set out above. A first BLE device 400 comprises a processor 402, a memory unit 404, a radio 406, and an antenna 408. Computer program products for performing the methods described herein may be stored as an application in the memory unit 404. The memory unit 404 can be a hard drive, solid state or optical memory source. The processor 402 is configured to access and execute software, applications, and data stored on the memory unit 404.

[0060] The radio 406 is configured to receive and transmit BLE signals via the antenna. The processor 402 is configured to interface with the radio 406 and the application may be configured to control the radio 406 and antenna 408 when executed on the processor 402.

[0061] A second BLE device 410 includes similar hardware an operations to the first BLE device 400. The antenna 408 of the first BLE device 400 is configured to communicate with the antenna 418 of the second BLE device 410.