ZigBee, Thread and BLE co-existence with 2.4 GHz WiFi
A system and method of minimizing interference and retries in an environment where two or more network protocols utilize the same frequency spectrum is disclosed. A lower-power network controller is co-located with a WIFI controller. The lower-power network controller parses incoming packets as they are received and generates a request signal once it is determined that the incoming packet is destined for this device. This maximizes the likelihood that no WIFI traffic will occur while the incoming packet is being received.
1. A system comprising:
a WIFI controller, comprising a request signal used as an input to request exclusive access to a shared medium and a grant signal used as an output indicating that the exclusive access to the shared medium has been granted; and
a lower-power network controller, comprising a network interface in communication with the shared medium, a processing unit and an associated memory element, wherein the lower-power network controller is configured to:
parse a lower-power network packet as it is received from the shared medium;
identify that the lower-power network packet is destined for this controller as it is being received; and
assert the request signal if the lower-power network packet is destined for this controller, wherein the assertion is performed before an entirety of the lower-power network packet has been received.
2. The system of claim 1 , wherein the lower-power network controller is further configured to transmit an acknowledgement packet over the shared medium after the lower-power network packet has been received only if the grant signal is active.
3. The system of claim 1 , wherein the WIFI controller and the lower-power network controller operate in the same frequency spectrum.
4. The system of claim 1 , wherein the WIFI controller further comprises a status signal used as an output to indicate whether the WIFI controller is active.
5. The system of claim 4 , wherein the lower-power network controller is further configured to determine if the WIFI controller is active prior to transmitting an acknowledge packet over the shared medium.
6. The system of claim 4 , wherein the lower-power network controller is further configured to not transmit an acknowledgement packet over the shared medium after the lower-power network packet has been received if the grant signal is not active or the WIFI controller is active.
7. The system of claim 1 , wherein the lower-power network packet comprises a header containing a destination address, and the request signal is asserted by the lower-power network controller after the destination address has been received by the lower-power network controller.
8. A system comprising:
a WIFI controller, comprising a request signal used as an input to request exclusive access to a shared medium and a grant signal used as an output indicating that the exclusive access to the shared medium has been granted; and
a lower-power network controller, comprising a network interface in communication with the shared medium, a processing unit and an associated memory element, wherein the lower-power network controller is configured to:
assert the request signal when the lower-power network controller determines that a lower-power network packet is being received from the shared medium;
parse the lower-power network packet to determine if the lower-power network packet is destined for this controller; and
deassert the request signal if it is determined that the lower-power network packet is not destined for this controller.
9. The system of claim 8 , wherein the lower-power network controller is further configured to transmit an acknowledgement packet over the shared medium after the lower-power network packet has been received only if the grant signal is active.
10. The system of claim 8 , wherein the WIFI controller and the lower-power network controller operate in the same frequency spectrum.
11. The system of claim 8 , wherein the WIFI controller further comprises a status signal used as an output to indicate whether the WIFI controller is active.
12. The system of claim 11 , wherein the lower-power network controller is further configured to determine if the WIFI controller is active prior to transmitting an acknowledge packet over the shared medium.
13. The system of claim 11 , wherein the lower-power network controller is further configured to not transmit an acknowledgement packet over the shared medium after the lower-power network packet has been received if the grant signal is not active or the WIFI controller is active.
14. The system of claim 8 , wherein the lower-power network packet comprises a header containing a destination address, and the request signal is deasserted by the lower-power network controller after receiving the destination address and determining that the lower-power network packet is not destined for this controller.
15. A method of simultaneously operating a WIFI network and a lower-power network over a shared medium, comprising:
determining, using a lower-power network controller, that an incoming packet is being received from the shared medium;
asserting a request signal from the lower-power network controller to a WIFI controller before an entirety of the incoming packet is received from the shared medium; and
transmitting an acknowledgement packet over the shared medium after receiving the incoming packet, using the lower-power network controller, if a destination address of the incoming packet matches an address of the lower-power network controller and the WIFI controller indicates that it is not transmitting a packet.
16. The method of claim 15 , wherein the request signal is asserted by the lower-power network controller after the destination address has been received by the lower-power network controller.
17. The method of claim 15 , wherein the request signal is asserted by the lower-power network controller before the destination address has been received by the lower-power network controller.
18. The method of claim 17 , wherein the request signal is deasserted by the lower-power network controller if the destination address of the incoming packet does not match the address of the lower-power network controller.
19. The method of claim 15 , wherein the lower-power network controller does not transmit the acknowledgement packet over the shared medium if the WIFI controller is receiving a packet.
20. The method of claim 15 , wherein the WIFI controller and the lower-power network controller operate in the same frequency spectrum.