Network device and method of operation of a device in a network

1 . A method for operating a parent device in a ZigBee network, the method comprising:

monitoring a network for a potential network attack;

in response to detecting a potential network attack, changing an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation the parent device is configured to accept unsecured rejoin requests;

in the second mode of operation the parent device is configured to not accept unsecured rejoin requests during a first time interval and to accept unsecured rejoin requests during a second time interval; and

in response to not detecting a potential network attack, changing an operating mode from the second mode of operation to the first mode of operation.

2 . A method for operating a parent device in a ZigBee network, the method comprising:

monitoring a network for a potential network attack;

in response to detecting a potential network attack, changing an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation the parent device is configured to accept unsecured rejoin requests;

in the second mode of operation the parent device is configured to not accept unsecured rejoin requests during a first time interval and to accept unsecured rejoin requests during a second time interval, wherein the second time interval is a rejoin time interval; and

in response to detecting a potential network attack broadcasting a signal including the rejoin time interval.

3 . A method for operating a parent device in a ZigBee network, the method comprising:

monitoring a network for a potential network attack;

in response to detecting a potential network attack, changing an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation the parent device is configured to accept unsecured rejoin requests; and

in the second mode of operation the parent device is configured to not accept unsecured rejoin requests during a first time interval and to accept unsecured rejoin requests during a second time interval, wherein the second time interval is a rejoin time interval, wherein the rejoin time interval is randomly generated.

4 . The method of claim 1 , wherein monitoring the network for a potential network attack comprises monitoring a rate of unsecured rejoin requests.

5 . The method of claim 4 , further comprising: detecting a potential network attack if the rate of unsecured rejoin requests is greater than or equal to a rejoin request rate threshold value.

6 . A method for operating a parent device in a ZigBee network, the method comprising:

monitoring a network for a potential network attack;

in response to detecting a potential network attack, changing an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation the parent device is configured to accept unsecured rejoin requests;

in the second mode of operation the parent device is configured to not accept unsecured rejoin requests during a first time interval and to accept unsecured rejoin requests during a second time interval, wherein the second time interval is a rejoin time interval; and

wherein monitoring the network for a potential network attack comprises monitoring a rate of fill of a neighbor table.

7 . The method of claim 6 further comprising: detecting a potential network attack if the rate of fill of the neighbor table is greater than or equal to a rate of fill threshold value.

8 . A method for operating a parent device in a ZigBee network, the method comprising:

monitoring a network for a potential network attack;

in response to detecting a potential network attack, changing an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation the parent device is configured to accept unsecured rejoin requests;

in the second mode of operation the parent device is configured to not accept unsecured rejoin requests during a first time interval and to accept unsecured rejoin requests during a second time interval, wherein the second time interval is a rejoin time interval;

in the first mode of operation, transmitting a private network parameter to a child device joining the network; and

in the second mode of operation, transmitting a publicly disclosable parameter comprising a network key protected by the private network parameter.

9 . A parent device for a ZigBee network, the parent device comprising:

a processor;

a memory coupled to the processor; and

a transceiver coupled to the processor; wherein the processor is configured to:

monitor a network for a potential network attack;

in response to detecting a potential network attack, change an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation accept unsecured rejoin requests;

in the second mode of operation not accept unsecured rejoin requests during a first time interval, and accept unsecured rejoin requests during a second time interval, and

in response to not detecting a potential network attack, change the operating mode from the second mode of operation to the first mode of operation.

10 . A parent device for a ZigBee network, the parent device comprising:

a processor;

a memory coupled to the processor; and

a transceiver coupled to the processor; wherein the processor is configured to:

monitor a network for a potential network attack;

in response to detecting a potential network attack, change an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation accept unsecured rejoin requests; and

in the second mode of operation not accept unsecured rejoin requests during a first time interval, and accept unsecured rejoin requests during a second time interval;

wherein the parent device is further configured to:

in the first mode of operation, transmit a private network parameter to a child device joining the network; and

in the second mode of operation, transmit a publicly disclosable parameter comprising a network key protected by the private network parameter.

11 . A ZigBee network comprising the parent device of claim 10 and a child device.

12 . The ZigBee network of claim 11 wherein the parent device is one of a ZigBee Coordinator and ZigBee Router and the child device is one of a ZigBee Router and ZigBee End Device.

13 . A parent device for a ZigBee network, the parent device comprising:

a processor;

a memory coupled to the processor; and

a transceiver coupled to the processor; wherein the processor is configured to:

monitor a network for a potential network attack;

in response to detecting a potential network attack, change an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation accept unsecured rejoin requests; and

in the second mode of operation not accept unsecured rejoin requests during a first time interval, and accept unsecured rejoin requests during a second time interval, wherein the second time interval is a rejoin time interval.

14 . The parent device of claim 13 , further configured to: in response to detecting a potential network attack broadcasting a signal including the rejoin time interval.

15 . A ZigBee network comprising the parent device of claim 13 and a child device.

16 . The ZigBee network of claim 15 wherein the parent device is one of a ZigBee Coordinator and ZigBee Router and the child device is one of a ZigBee Router and ZigBee End Device.

17 . A parent device for a ZigBee network, the parent device comprising:

a processor;

a memory coupled to the processor; and

a transceiver coupled to the processor; wherein the processor is configured to:

monitor a network for a potential network attack;

in response to detecting a potential network attack, change an operating mode from a first mode of operation to a second mode of operation;

in the first mode of operation accept unsecured rejoin requests; and

in the second mode of operation not accept unsecured rejoin requests during a first time interval, and accept unsecured rejoin requests during a second time interval;

wherein the memory comprises a neighbor table and wherein the processor is further configured to monitor the network for a potential network attack by monitoring a rate of fill of the neighbor table.

18 . A ZigBee network comprising the parent device of claim 9 and a child device.

19 . The ZigBee network of claim 18 wherein the parent device is one of a ZigBee Coordinator and ZigBee Router and the child device is one of a ZigBee Router and ZigBee End Device.

20 . A ZigBee network comprising the parent device of claim 17 and a child device.

21 . The ZigBee network of claim 20 wherein the parent device is one of a ZigBee Coordinator and ZigBee Router and the child device is one of a ZigBee Router and ZigBee End Device.