Intelligent piconet forming

• US 6,901,057 B2
• Filed: 02/27/2001
• Issued: 05/31/2005
• Est. Priority Date: 12/06/1999
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Rune, Johan, Johansson, Per X, Larsson, Tony, Gehrmann, Christian, Sörensen, Johan
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/729,926
• Publication Number:
  US 20010029166A1
• Time in Patent Office: 1,554 Days
• Field of Search: 370/310, 370/338, 370/349, 370352-356, 370/402, 370/401, 370/432, 370/389, 370/390, 370/294, 370/386, 370/393, 370/469, 370/475, 370/465, 375/132, 375/133, 375/134, 455/41.2, 455/464, 455/434, 455/419, 455/418, 455/417
• US Class Current: 370/310
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

When connecting a unit to one or more existing ad hoc wireless networks comprising several units, the units e.g. adapted to communicate according to the Bluetooth specification and the network then being formed according to the same specification to comprise one or more piconets, a unit can discover the units which are the masters in the networks, and then connect as a slave to those masters. Specifically it does not have to use the master-slave switch according to the Bluetooth specification. In the first stage of the unit trying to make a connection it establishes contact with at least one unit in an existing ad hoc network and then additional information on the status, in particular the role of master or slave, of the unit already connected in the network is transferred to the not yet connected unit. This information facilitates the decision of the unconnected unit as to which unit in the network that it should try to correct to. Then, in the actual connecting of the unit to the network, the roles of the unit and of the already connected unit can be chosen by the unit wanting to be connected. In particular, the initially inquiring and paging unit may become a slave unit in a newly formed piconet or in an already existing piconet.

Claims

1. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet, the FHS packet further including information as to at least one of the following;

whether the responding unit is connected to at least one of said at least one piconet, whether the responding unit is a slave in at least one of said at least one piconet, whether the responding unit prefers to be a master or a slave after a subsequent PAGE procedure, number of slaves in at least one of said at least one piconet, the BD_ADD(s) of at least one master unit of said at least one piconet where the responding unit is a slave member, the clock value(s) of at least one master unit of said at least one piconet where the responding unit is a slave member, inter-piconet scheduling parameters at least one unit that is connected to at least two piconets, the battery status of the responding unit, traffic parameters in at least one of the piconets or priority parameters.

24. A computer program product directly loadable into the internal of a digital computer, comprising software code portions for performing the steps of the methods of or the methods performed by any block or device according to claim 1 when the product is run on a computer.

25. A computer program product stored on a computer usable medium, comprising readable program means for causing a computer to control the execution of the steps of the methods performed by any block or device according to claim 1.

2. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the information is encoded using at least one of two undefined bits in the FHS packet.

3. A method according to claim 2, wherein one of said at least two undefined bits encodes whether the responding unit is a master of a piconet.

4. A method according to claim 2, wherein one of said at least two undefined bits encodes whether the responding unit is a slave in at least one piconet.

5. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the information is encoded using the class of device field in the FHS packet.

6. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending and INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the information is encoded using an AM_ADDR field in the FHS packet.

7. A method according to claim 6, wherein the AM_ADDR field is used to encode whether the responding unit, when subsequently paged, will want to connect to the paging unit as a slave or a master.

8. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to a first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the information is encoded using a combination of the undefined bits, a class of device field, and an AM_ADDR field in the FHS packet.

9. A method according to claim 8, wherein the AM_ADDR is used to encode the number of active slave units in the piconet for which responding unit is a master.

10. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the responding unit is a slave in a piconet; and

,

wherein the first unit sends a PAGE to the slave indicating the first unit intent to retrieve the at least one address (BD_ADDR) for the at least one master for the slave and the slave sending a PAGE RESPONSE message containing the requested at least one BD_ADDR.

11. A method according to claim 10, wherein the PAGE RESPONSE includes at least one current clock value of said at least one master units of the responding unit.

12. A method according to claim 10, wherein the PAGE RESPONSE further includes information as to at least one of the following:

whether the responding unit is connected to at least one of said at least one piconet, whether the responding unit is a slave in at least one of said at least one piconet, whether the responding unit prefers to be a master or a slave after a subsequent PAGE procedure, the number of slaves in at least one of said at least one piconet, the BD_ADDR(s) of at least one master unit of said at least one piconet where the responding unit is a slave member, the clock value(s) of at least one master unit of said at least one piconet where the responding unit is a slave member, inter-piconet scheduling parameters of at least one Bluetooth that is connected to at least two piconets, the battery status of responding unit, traffic parameters in at least one of the piconets or priority parameters.

13. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein the step of establishing contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization (FHS) packet, the FHS packet including information of the status of said at least one unit in the at least one piconet;

wherein the INQUIRY message contains a Dedicated Inquiry Access Code which is dedicated to, and will only be responded to, by one of the following;

a unit being a slave unit in one and only one piconet,

a unit being a slave unit in at least one piconet,

a unit being a slave unit in more than one piconet,

a unit being a slave unit in one or more piconets, but a master unit in none,

a unit being a slave unit in one or more piconets and a master unit in one piconet,

a unit being a master unit in one piconet, but a slave unit in none,

a unit that is not connected to any piconet,

a unit with low current traffic load, or

a unit with high current traffic load.

14. A method according to claim 13, wherein the INQUIRY message contains a Dedicated Inquiry Access Code (DIAC) which is only responded to by master units.

15. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein in the establishment of contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronization packet, the INQUIRY message containing Dedicated Inquiry Access Code which is only responded to by units having the role of master.

16. A method for connecting a first unit to an ad hoc network comprising at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network and said at least one unit, in the establishment of contact, sending information to the first unit, the information including an indication of the role of said at least one unit in the ad hoc network;

the first unit thereafter, based on said information, connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein in the establishment of contact, the first unit sends at least one INQUIRY message and said at least one unit responds by sending an INQUIRY RESPONSE message comprising a Frequency Hop Synchronisation packet, the INQUIRY message containing a Dedicated Inquiry Access Code (DIAC) which is dedicated to, and is only be responded to, by one of the following;

a unit being a slave unit in one and only one piconet,

a unit being a slave unit in at least one piconet,

a unit being a slave unit in more than one piconet,

a unit being a slave unit in one or more piconets, but a master unit in none,

a unit being a slave unit in one or more piconets and a master unit in one piconet,

a unit being a master unit in one piconet, but a slave unit in none,

a unit that is not connected to any piconet,

a unit with low current traffic load, or

a unit with high current traffic load.

17. A method according to claim 16, wherein the INQUIRY message contains a Dedicated Inquiry Access Code (DIAC) which is only responded to by master units.

18. A method for connecting a first unit to an ad hoc network comprising at least two units, the at least two units having different roles, the units being adapted to communicate according to the Bluetooth specification, the ad hoc network comprising at least one piconet formed according to the Bluetooth specification, the roles of the units in the ad hoc network comprising master and slave and said at least one unit having the role of master, the method comprising the steps of:

the first unit establishing contact with at least one of the units of the ad hoc network;

the first unit thereafter connecting to said at least one unit, the first unit thereby becoming connected to the ad hoc network;

wherein in the step of connecting, the first unit chooses or determines the roles of itself and of said at least one unit in the ad hoc network formed after the first unit becoming connected;

wherein in the step of connecting, a PAGE message is sent from the first unit to said at least one unit, thereafter a PAGE RESPONSE message is sent from said at least one unit to first unit, and finally a Frequency Hop Synchronization (FHS) packet is sent from the first unit to said at least one unit, the FHS packet including an indication that the first unit has determined to reverse the paging direction from said at least one unit to the first unit.

19. A method according to claim 18, wherein the reversal is performed by terminating the current PAGE procedure and initiating a new PAGE procedure from the master to the first unit.

20. A method according to claim 18, wherein the reversal is performed by the master Bluetooth which receives the request for reversal sending an FHS packet to the first unit with all FHS parameters set as if the sender is the paging unit and the first unit responding with a packet including only the first unit DAC, thereby concluding the reversed page procedure.

21. A method according to claim 18 wherein the paged unit does not accept the reversal of paging direction, and wherein the paged unit responding to the FHS packet with a second FHS packet including the same indication request for reversal of paging direction and the first unit receiving this second FHS packet choosing to either proceed with the PAGE procedure without reversing abandoning the PAGE procedure.

22. A method according to claim 21, wherein if the first unit chooses to proceed with the PAGE procedure it proceeds by restarting the PAGE procedure by sending a new initial PAGE message.

23. A method according to claim 21, wherein if the first unit chooses to proceed with the PAGE procedure it proceeds by sending a third FHS message without an indication of request for reversal of paging direction.

26. A computer program product directly loadable into the internal of a digital computer, comprising software code portions for performing the steps of the methods of or the methods performed by any block or device according to claim 18 when the product is run on a computer.

27. A computer program product stored on a computer usable medium, comprising readable program means for causing a computer to control the execution of the steps of the methods performed by any block or device according to claim 18.