Method and system for switching coordinator in a personal area network

A method, an apparatus, and a system for switching coordinators in a Personal Area Network (PAN) are provided. The method includes initiating a request for switching at least one device present in a network session to a first priority PAN coordinator, the initiated request including a count of the at least one device, transmitting the initiated request to the first priority PAN coordinator, the initiated request including a requirement for supporting the at least one device of that count, determining whether the first priority PAN coordinator is capable of supporting the at least one device, and switching, when the first priority PAN coordinator is capable of supporting the at least one device, the network session of the at least one device with the first priority PAN coordinator to facilitate establishment of the network session with the first priority PAN coordinator.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a U.S. National Stage application under 35 U.S.C. §371 of an International application filed on Jan. 23, 2013 and assigned application number PCT/KR2013/000542, which claimed the benefit of an Indian patent application filed on Jan. 23, 2012 in the Indian Patent Office and assigned Serial number 284/CHE/2012 and an Indian patent application filed on Jan. 18, 2013 in the Indian Patent Office and assigned Serial number 284/CHE/2012, the entire disclosure of each of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to method, apparatus and system for switching coordinator in a Personal Area Network (PAN). More particularly, the present disclosure relates to method, apparatus and system for switching coordinators based on certain conditions in a Wireless Personal Area Network (WPAN).

BACKGROUND

Wireless Personal Area Networks (WPANs) find application in number of real time situations. For example, WPANs are used in hospitals, transportation and logistics and the like to enable individual devices to interact with each other in a network zone. In such situations, the individual devices are connected to each other within the zone to facilitate certain types of communication, including data, and short message transfer. In order to manage and coordinate communication between the devices, at least one PAN coordinator may be used.

IEEE 802.15.4 standard comprises networking protocols for WPANs, coordinators, and devices that are connected. For example, in a hospital environment, there may be at least one wireless sensory device attached to the body of a patient. The sensory devices are configured to monitor multiple parameters. The sensory devices communicate with the PAN coordinators through wireless means, for example, to report collected parameters. During such situations, if the patient is shifted or relocated within the hospital premises with the attached sensory devices, suitable operations need to be performed to facilitate such a transition with appropriate power consumption. Conventional methods appear to be power consuming during the transition.

SUMMARY

Aspects of the present disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide a method and apparatus for switching coordinator in a Personal Area Network (PAN).

In an aspect of the present disclosure, a method of switching Personal Area Network (PAN) coordinators is provided. The method includes the steps of initiating a request for switching at least one device present in a network session to a first priority PAN coordinator, the request including a count of the at least one device, transmitting the initiated request including a requirement for supporting the at least one device of that count, the initiated request is transmitted to the first priority PAN coordinator, determining whether the first priority PAN coordinator is capable of supporting the at least one device, and switching, when whether the first priority PAN coordinator is capable of supporting the at least one device, the network session of the at least one device with the first priority PAN coordinator to facilitate establishment of the network session with the first priority PAN coordinator.

In another aspect of the present disclosure, an apparatus for switching Personal Area Network (PAN) coordinator in a network with at least one device is provided. The apparatus includes a processor, a memory connected to the processor, configured with at least one program to perform a set of predefined instructions the at least one program executed by the processor, the at least one program including a coordinator switching module configured for initiating a request for switching the at least one device present in a network session to a first priority PAN coordinator, the initiated request including a count of the at least one device at least, transmitting the initiated request including a requirement for supporting the at least one device of that count, the initiated request is transmitted to the first priority PAN coordinator, determining whether the first priority PAN coordinator is capable of supporting the at least one device, and switching, when the first priority PAN coordinator is capable of supporting the at least one device, the network session of the at least one device with the first priority PAN coordinator to facilitate establishment of the network session with the first priority PAN coordinator.

In yet another aspect of the present disclosure, a system is provided. The system includes at least one device at least, and a Personal Area Network (PAN) coordinator configured to manage communication of the at least one device, the PAN coordinator comprises a memory and a processor, the memory includes a coordinator switching module configured to perform the steps of initiating a request for switching the at least one device present in a network session to a first priority PAN coordinator, the initiated request including a count of the at least one device, transmitting the initiated request including a requirement for supporting the at least one device of that count, the initiated request is transmitted to the first priority PAN coordinator, determining whether the first priority PAN coordinator is capable of supporting the at least one device, and switching, when the first priority PAN coordinator is capable of supporting the at least one device, the network session of the at least one device with the first priority PAN coordinator to facilitate establishment of the network session with the first priority PAN coordinator.

DETAILED DESCRIPTION

FIG. 1illustrates a system diagram where at least one device connected to a Personal Area Network (PAN) coordinator according to an embodiment of the present disclosure.

Referring toFIG. 1, a system100includes a first device104a, a second device104b, a third device104c, and a fourth device104d, and a first PAN coordinator102a. The devices104a,104b,104c, and104dare connected to the first PAN coordinator102athrough a Wireless Personal Area Network (WPAN)103according to an embodiment of the present disclosure. The system100may be applicable in number of real time situations. For example, the at least one device104a,104b,104c, and104dmay be sensory devices attached to a body of the patient in a hospital to monitor at least one physical parameter. The PAN coordinator102amay be managing and coordinating communication of the at least one device104a,104b,104c, and104d. Further, in another WPAN103, another PAN coordinator may be present to assist in coordinating the communication of the devices104a,104b,104c, and104dwhen they are out of range of the first PAN coordinator102a.

FIG. 2is a flow diagram of switching PAN coordinators according to the related art.

Referring toFIG. 2, it shall be noted operations occurs between the first PAN coordinator102a, the first device104aand a first priority PAN coordinator102b. The first priority PAN coordinator102bmay be a candidate PAN coordinator102bthat may connect with at least one device within the network and coordinate the communication.

The first PAN coordinator102aand the first device104aare assumed to be in an established network session. The network session is referred in operation202of the flow diagram. In operation204, the device104aindicates the movement to a new location to the first PAN coordinator102a. In an alternative embodiment, the first PAN coordinator102amay determine that location of the first device104ais out of network zone. There may be many reasons for change in location of the first device104a. For example, if the first device104ais attached to body of the patient, when the patient moves, the first device104amoves along with the patient. In operation206, the network session between the first PAN coordinator102aand the first device104ais turned off due to dissociation. In the present example, the dissociation occurred because of the relocation of the first device104a.

In operation208, the first device104amay continually search and locate new PAN coordinators within the network range. The searching and locating of the new PAN coordinators within a network zone is a power consuming activity for the device104a. For example, when the device104alocates the first priority PAN coordinator102bas the new coordinator, in operation210, the first priority PAN coordinator102band the device104aforms an association. Thereafter, in operation212a new network session is established between the second PAN coordinator102band the first device104a. Further, there may be other number of operations involved in re-establishing the network session.

FIG. 3is flow diagram for switching PAN coordinators according to an embodiment of the present disclosure.

Referring toFIG. 3, according to the present embodiment a scheme of events occurring in the system to perform switching of PAN coordinators is provided. In operation302, a network session is established between the existing PAN coordinator and the device104a. In operation304, the device104aindicates the first PAN coordinator102aabout relocation which may take the first device104aout of network zone. On receiving the indication from the device104a, in operation306, the PAN coordinator102atransmits the information of the first priority PAN coordinator102bfor facilitating switching of the PAN coordinator from the first PAN coordinator102ato the first priority PAN coordinator102b. In the same operation306, the PAN coordinator102aand the device104adissociate from each other.

In operation308, the device104aand the first priority PAN coordinator102bform an association and thereafter, in operation310, a network session is established between the device104aand the first priority PAN coordinator102b. During the switching of coordinator, the first coordinator102adetermines whether the first priority PAN coordinator102bis capable of performing network coordination and communication management of the device104aand in case, multiple devices are to be connected to the first priority PAN coordinator102b, then count of the multiple devices is taken into account.

It may be noticed that operation208present inFIG. 2is not performed by the device104ain theFIG. 3. The operation of searching and locating the suitable PAN coordinator is performed by the first PAN coordinator102a. Hence, the power consuming activity is negated according to the present embodiment of the disclosure.

FIG. 4is a flow chart illustrating switching PAN coordinators according to an embodiment of the present disclosure.

Referring toFIG. 4, a method400includes a plurality of operations to perform switching of PAN coordinators. In the operation402, a Mac Layer Management Entity (MLME) coordinator switch request is initiated at the first PAN coordinator102a. The request is intended for switching at least one device connected to an existing PAN coordinator to a new PAN coordinator. The initiation may happen between frame transfers between a Media Access Control (MAC) layer of the PAN coordinator102a(the existing PAN coordinator) and a first network layer. The first network layer may be contributing to any device connected to the PAN coordinator102a. In operation404, the PAN coordinator102amay configure a priority table within to determine potential new PAN coordinators to perform the switch over based on certain criteria. For example, the priority table may include list of PAN coordinators that are candidates for switching in the future, their address and information.

In operation406, the first PAN coordinator102atransmits a switch request including “count of devices” field to the first priority PAN coordinator102b(the new PAN coordinator). The count of devices may refer to the number of devices that are connected to the first PAN coordinator102aand are intended to be switched to the first priority PAN coordinator102b. The count of devices is a requirement for the second PAN coordinator102bfor establishing capability. This operation may ensure the first PAN coordinator102ato prove the capability of replacing the coordination and management activities by the first priority PAN coordinator102bsuccessfully.

In operation408, the first priority PAN coordinator102bprovides or transmits a response for the request raised in the operation406, the response is received at the first PAN coordinator102a. For example, in at least one embodiment, since the communication between the PAN coordinators and the devices connected occur in the MAC layer of the network, the data is shared in the form of frames in accordance with the protocols of Wireless PAN. For example, the response frame from the first priority PAN coordinator102bincludes ‘switch status’ as one of the fields denoting status of switching to the first PAN coordinator102a. In operation410, an acknowledgement frame is transmitted by the first PAN coordinator102ato the first priority PAN coordinator102b. Further, the acknowledgement frame shall be provided by the first PAN coordinator102awithin a threshold time.

On receiving the response from the first priority PAN coordinator102b, the first PAN coordinator102a, in operation412, determines whether the first priority PAN coordinator102bis capable of coordinating and managing the communication of the devices with the count or number of devices, as transmitted in the request. If yes, in operation414, the first PAN coordinator102atransmits a coordinator realignment request frame to the first priority PAN coordinator102b. If no, in operation412, the first PAN coordinator102atransmits a switch request frame to a second priority PAN coordinator in accordance with the priority table and repeats operations406,408,410, and412until it finds the capable PAN coordinator for coordinating and managing the communication of the devices with the count or number of devices transmitted in the request. Thereafter, the first priority PAN coordinator102band the device104bestablish a realigned network session. As denoted in operation416, the method concludes with completion of the switching the PAN coordinator.

FIG. 5Ais a flow diagram illustrating a system to switch PAN coordinators according to an embodiment of the present disclosure.

Referring toFIG. 5A, in operation502, a request for switching at least one device present in a network session with the first PAN coordinator102ais initiated. The request includes a count of the at least one device. The request is initiated by transfer of frames between the network layer and the MAC layer of the first PAN coordinator102a. The first PAN coordinator102amay prioritize the PAN coordinators that present in the network in vicinity. A priority table is created with list of PAN coordinators that are suitable candidates for the coordinator switching. In operation504, at channel1, the first PAN coordinator102transmits a request to switch the at least one device connected to it to the first priority PAN coordinator102b. The request includes a count of number of devices connected to or is in network session with the first PAN coordinator102a. The first priority PAN coordinator102bmay be present at top of the priority table which includes the list of other suitable PAN coordinators. There may multiple factors involved in prioritizing suitable PAN coordinators. Those factors are known to the person skilled in the art and will not be discussed further.

In operation506, the first priority PAN coordinator102bprovides a response to the request. The response more importantly, includes a switch status. On receiving the response from the first priority PAN coordinator102b, the first PAN coordinator102atransmits an acknowledgement frame at508, the acknowledgement frame may be sent within a threshold time after receiving the response. The first PAN coordinator102adetermines the capability of the first priority PAN coordinator102bwhether it may handle and coordinator communication of the at least one device, based on the response.

FIG. 5Bis a flow diagram illustrating a system to switch PAN coordinators according to another embodiment of the present disclosure.

Referring toFIG. 5B, if the first PAN coordinator102adetermines that the first priority PAN coordinator102bis not capable, in operation512, transmits the request for switching to a second priority PAN coordinator102c. While transmitting, the first PAN coordinator102amay select ‘Channel 2’, another channel for communicating with the second priority PAN coordinator102c. Operations512(request for switching),514(reception of coordinator switch response),516(transmission of acknowledgement), and518(determination of capability of the second priority PAN coordinator102c) are similar to the operations504,506,508, and510. Hence, explanation to the mentioned operations is forfeited.

FIG. 5Cis a flow diagram illustrating a system to switch PAN coordinators according to another embodiment of the present disclosure.

Referring toFIG. 5C, the first PAN coordinator102ahas determined that the first priority PAN coordinator102bis capable for handling and coordinating communication of the at least one device connected to the first PAN coordinator102a.

In operation520, a coordinator realignment command frame is transmitted by the first PAN coordinator102ato the device104b. Thereafter, the MAC layer of the first PAN coordinator102atransmits a confirmation of switching of coordinator to the network layer. In operation524, the device104band a capable PAN coordinator establish a switched network session with each other. For example, if the first priority PAN coordinator102bis determined capable of coordinating and managing communication of the number or count of devices connected to the first PAN coordinator102a, then the capable PAN coordinator according to the present embodiment shall be the first priority PAN coordinator102b. For another example, if the first priority PAN coordinator102bis determined to be incapable of supporting the number or count of devices connected to the first PAN coordinator102a, then the capable PAN coordinator according to the present embodiment shall be the second priority PAN coordinator (not illustrated).

FIG. 6illustrates a structure of a coordinator-switch-request frame according to an embodiment of the present disclosure.

Referring toFIG. 6, a coordinator-switch-request frame includes primarily a Message Header (MHR), a command frame identifier, and ‘number of devices’. MHR field of Coordinator Switch Request frame is included in a broadcast transmission from a PAN Coordinator in the Personal Area Network.

In an embodiment, a ‘Destination Addressing Mode’ field shall be included in the request to indicate short addressing, and ‘Source Addressing Mode’ shall be included in the request to indicate extended addressing, when coordinator switch request is broadcasted in a selected channel. Further, during the transmission of request, A ‘Destination PAN Identifier’ field be included which shall contain the PAN identifier that is broadcasted and a ‘Destination Address Field’ be included which shall contain the broadcast short address.

In an embodiment, a ‘Source PAN Identifier’ shall contain the value of MAC identifier of the PAN coordinator that imitates the request. In the same embodiment, ‘Source Address’ contains the value of ‘macExtendedAddress’ of the PAN coordinator that intends to switch.

In one of the various embodiments, the coordinator switch request command may be unicasted to a new PAN coordinator. In such effectuation, the request includes the destination addressing field which is set to include an extended addressing. Further, the destination PAN identifier field includes ‘macPANID’ of the new PAN coordinator and the destination address field includes the ‘macExtendedAddress’ of the new PAN coordinator. Further, in an expansive embodiment, the ‘source PAN identifier field’ includes the value of ‘macPANID’ of the existing PAN coordinator and the ‘source address field’ contains the value of ‘macExtendedAddress’ of the new PAN coordinator that intends to switch.

FIG. 7illustrates a structure of a coordinator switch response frame according to an embodiment of the present disclosure.

Referring toFIG. 7, the present embodiment, the coordinator switch response frame transmitted by a new PAN coordinator intending to switch includes MHR, a command frame identifier, and a ‘switch status’. For example, the command frame identifier value of a command frame identifier may be 0xA0. In an embodiment, the ‘switch status’ may refer to when the new PAN coordinator responds to the unicast coordinator switch request from the existing PAN coordinator with the field of status set to yes, it indicates that it has confirmed its status as the new PAN coordinator. Further, description of fields of MHR is explained in the description ofFIG. 6.

FIG. 8is a block diagram of the first PAN coordinator according to an embodiment of the present disclosure.

Referring toFIG. 8, a first PAN coordinator102aincludes a memory802, a processor804, a bus806, input devices808, output devices810, and a transceiver812, but is not limited thereto. The memory802includes a coordinator switching module814configured to perform switching of PAN coordinators in the network. In an embodiment, the coordinator switching module814includes at least one program and resides in the memory802. The at least one program is executed with the help of processor804. The coordinator switching module814is configured for initiating a request for switching the at least one device present in a network session to a first priority PAN coordinator, the request comprising a count of the at least one device, transmitting the request comprising a requirement for supporting the at least one device of that count, the request is transmitted to the first priority PAN coordinator, determining whether the first priority PAN coordinator is capable of supporting the at least one device, and if yes, switching the network session of the at least one device with the first priority PAN coordinator to facilitate establishment of the network session with the first priority PAN coordinator. Further, the coordinator switching module is configured to perform at least one operation as illustrated inFIGS. 4, 5A, 5B, and 5Cat the end of the first PAN coordinator102a.

Furthermore, the memory800may be volatile memory and non-volatile memory. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions, such as read only memory, random access memory, erasable programmable read only memory, electrically erasable programmable read only memory, hard drive, removable media drive for handling memory cards, Memory Sticks™, and the like.

The processor804, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction word microprocessor, an explicitly parallel instruction computing microprocessor, a graphics processor, a digital signal processor, or any other type of processing circuit. The processor804may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, smart cards, and the like. The transceiver812is for signal reception and transmission with the network. It is provided as an example that the transceiver812is present as a single unit. However, the transceiver812may be present as a separated unit with receiver and transmitter.

FIG. 9is a block diagram of one of the at least one device according to an embodiment of the present disclosure.

Referring toFIG. 9, a second device104bincludes a memory902, a processor904, a bus906, input devices908, output devices910, and a transceiver912, but is not limited thereto. The memory902includes a coordinator switching support module914. The coordinator switching support module914may be configured with at least one program to support switching of PAN coordinators in the network. In an embodiment, the coordinator switching support module914is capable of performing at least one operation occurring at the end of the second device104bin theFIGS. 4, 5A, 5B, and 5C. Other components of the second device104bare known to the persons skilled in the art and will not be explained further. Various embodiments of the present subject matter may be implemented in conjunction with modules, including functions, procedures, data structures, and application programs, for performing tasks, or defining abstract data types or low-level hardware contexts. Machine-readable instructions stored on any of the above-mentioned storage media may be executable by a processor.