Central coordinator selection, handover, backup and failure recovery

• US 20070013419A1
• Filed: 02/13/2006
• Published: 01/18/2007
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ayyagari, Deepak, Chan, Wai
• Granted Patent: US 7,606,199 B2
• Time in Patent Office: Days
• US Class Current: 327/156
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04L 41/044 comprising hierarchical management structures
• CPC Class Codes: H04L 41/0654 using network fault recovery ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

The embodiments of the present invention provide methods, systems, and devices for improving network management in a centralized network, which typically includes a central coordinator (CCO) that manages and schedules activities within the network. The embodiments of the invention provide a manner of selecting a CCO, including a backup CCO, best suited to manage the network based on a set of rules. Furthermore, the embodiments provide a manner of transferring the current CCO functions to a new CCO, e.g., via message exchanges. Moreover, a process of a backup CCO assuming the function of an unavailable CCO is also described.

Claims

1. A method of network management in a centralized network comprising a first central coordinator (CCO) and a station adapted to transmit beacons comprising network scheduling and resource allocation, the method comprising the steps of:

indicating to the centralized network that a CCO handover is in progress;

transmitting, by the first CCO to the station, a list of stations associated with the centralized network;

receiving, by the first CCO from the station, a message in response to the transmitted list of stations;

initiating a handover countdown timer;

if the handover countdown timer expires, transmitting, by the station, beacons within the centralized network.

2. The method of claim 1, further comprising the step of transmitting, by the first CCO to the station, link information associated with one or more links in the centralized network.

3. The method of claim 2, wherein the link information comprises Quality of Service requirement and channel characteristic associated with each of the one or more links.

4. The method of claim 1, wherein the step of indicating that the CCO handover is in progress is by setting a flag.

5. The method of claim 1, wherein the station is a user-appointed station.

6. A method of improving network management in a centralized network comprising a first central coordinator (CCO), a first backup CCO, and at least one station, the method comprising the steps of:

detecting, by the first backup CCO, first CCO beacons from the first CCO; and

if the first CCO beacons are not detected within a defined period,

transmitting, by the first backup CCO, first backup beacons comprising network scheduling and allocation information, wherein at least one of the first backup beacons is transmitted using a beacon slot previously allocated to the first CCO;

requesting topology information from the at least one station in the centralized network, wherein the topology information comprises at least one of the following;

information related to stations discovered by the at least one station and information related to centralized networks discovered by the at least one station; and

selecting a second backup CCO to replace the first backup CCO.

7. The method of claim 6, wherein the step of selecting the second backup CCO is based on a set of rules of precedence.

8. The method of claim 7, wherein the set of rules of precedence is based on at least one of the following criteria:

whether a CCO is user-appointed;

CCO-capability classification of a CCO;

a count of discovered stations associated with a CCO; and

a count of discovered networks associated with a CCO.

9. The method of claim 8,

wherein

the criterion of whether the CCO is user-appointed is ranked higher than the CCO-capability classification of the CCO;

the CCO-capability classification of the CCO is ranked higher than the count of discovered stations associated with the CCO; and

the count of discovered stations associated with the CCO is ranked higher than the count of discovered networks associated with the CCO;

wherein a greater count value of the count of discovered stations associated with the CCO is ranked higher than a lower count value of the count of discovered stations associated with the CCO; and

wherein a greater count value of the count of discovered networks associated with the CCO is ranked higher than a lower count value of the count of discovered networks associated with the CCO.

10. The method of claim 6, wherein if the first CCO beacons are not detected within a defined period, requesting at least one active link information associated with the at least one station, wherein the at least one active link information comprises quality of service requirement and channel characteristic information.

11. The method of claim 6, wherein at least one of the first backup beacons transmitted by the first backup CCO comprises persistent schedule information previously scheduled by the first CCO.

12. The method of claim 6, wherein if the first CCO beacons are not detected within a defined period, transmitting a timing offset between the first CCO and the first backup CCO.

13. The method of claim 6, wherein if the first CCO beacons are not detected within a defined period, determining by the at least one station a timing offset between the first CCO and the first backup CCO based on time stamp values associated with first CCO beacons and first backup beacons associated with the first backup CCO.

14. A method of selecting a new central coordinator (CCO) within a centralized network comprising a current CCO and at least one station, the method comprising the steps of:

determining one or more stations from the at least one station that are ranked higher than the current CCO based on a topology table associated with the current CCO and a set of rules of precedence, wherein the topology table comprises a list of discovered stations and a list of discovered centralized networks; and

selecting a new CCO with a highest ranking from the determined one or more stations, wherein the selecting step is based on at least one of the following;

if there is only one station from the determined one or more stations with the highest ranking, selecting the only one station to be the new CCO; and

if there are two or more stations from the determined one or more stations with the highest ranking, selecting one of the two or more stations with the highest ranking to be the new CCO.

15. The method of claim 14, wherein the step of selecting the new CCO if there are two or more stations from the determined one or more stations is based on a random selection.

16. The method of claim 14, wherein the set of rules of precedence is based on at least one of the following criteria:

whether a CCO is user-appointed;

CCO-capability classification of a CCO;

a count of discovered stations associated with a CCO; and

a count of discovered networks associated with a CCO.

17. The method of claim 16,

wherein

the criterion of whether the CCO is user-appointed is ranked higher than the CCO-capability classification of the CCO;

the CCO-capability classification of the CCO is ranked higher than the count of discovered stations associated with the CCO; and

the count of discovered stations associated with the CCO is ranked higher than the count of discovered networks associated with the CCO;

wherein a greater count value of the count of discovered stations associated with the CCO is ranked higher than a lower count value of the count of discovered stations associated with the CCO; and

wherein a greater count value of the count of discovered networks associated with the CCO is ranked higher than a lower count value of the count of discovered networks associated with the CCO.

18. A device adapted to be coupled to a centralized network, the device comprising:

a central coordinator (CCO) auto-selection module adapted to;

determine one or more stations associated with the centralized network, wherein the one or more stations are ranked higher than a current CCO; and

select a new CCO with a highest ranking from the determined one or more stations, wherein the selecting step is based on at least one of the following;

if there is only one station from the determined one or more stations with the highest ranking, selecting the only one station to be the new CCO; and

if there are two or more stations from the determined one or more stations with the highest ranking, selecting one of the two or more stations with the highest ranking to be the new CCO; and

a rules of precedence module adapted to;

rank one or more stations associated with the centralized network, based on a topology table associated with the centralized network and a set of rules of precedence, wherein the topology table comprises a list of discovered stations;

wherein the set of rules of precedence is based on at least one of the following criteria;

whether a station is user-appointed;

CCO-capability classification of a station;

a count of discovered stations associated with a station; and

a count of discovered networks associated with a station.

19. The device of claim 18, wherein the topology table further comprises a list of discovered centralized networks.

20. The device of claim 18, further comprising:

a beacon transmission module adapted to;

transmit on a periodic basis a beacon comprising network scheduling and allocation information.

21. The device of claim 18, further comprising:

a central coordinator (CCO) handover module adapted to;

indicate to the centralized network at least one of the following;

that a CCO handover is in progress;

that a CCO handover is not in progress;

transmit a list of stations associated with the centralized network;

transmit information related to one or more links in the centralized network; and

initiate a handover countdown timer.

22. The device of claim 21, wherein

if the handover countdown timer expires, stopping beacon transmission by the device, wherein each beacon comprises network scheduling and allocation information.

23. The device of claim 18, further comprising:

a CCO user-appointed module adapted to;

present a user interface adapted to receive station identification information.

24. A system comprising:

a central coordinator (CCO) adapted to;

transmit beacons, wherein each first beacon comprises network scheduling and allocation information;

auto-select a new CCO from at least one station based on ranking information associated with each of the at least one station, wherein the ranking information is determined based on a CCO topology table and a set of rules of precedence;

accept station identification of a station to function as a new central coordinator;

the backup CCO adapted to;

detect the first beacons transmitted by the CCO;

if the first beacons transmitted by the CCO are not detected within a defined period,

transmit second beacons, each second beacon comprising network scheduling and allocation information, wherein at least one of the second beacons is transmitted using a beacon slot previously allocated to the CCO;

request topology information, wherein the topology information comprises a list of discovered stations and a list of discovered networks;

request link information; and

select a new backup CCO; and

at least one network segment operably connecting the CCO and the backup CCO.

25. A device adapted to be coupled to a centralized network, the device comprising:

an input and output interface adapted to receive and transmit messages within the centralized network; and

a backup and failure recovery module adapted to;

detect first beacons from a CCO; and

if the first beacons are not detected within a defined period,

transmit second beacons, each second beacon comprising network scheduling and allocation information, wherein at least one of the second beacons is transmitted using a beacon slot previously allocated to the CCO;

request topology information from at least one station associated with the centralized network, wherein the topology information comprises information related to a set of stations discovered by the at least one station and information related to centralized networks discovered by the at least one station;

request link information associated with one or more links active within the centralized network; and

select a backup CCO, wherein the backup CCO is adapted to perform CCO operations when currently operating beacons from a currently operating CCO are no longer detected by the second backup CCO.