EP4677896A1

EP4677896A1 - Connectivity loss detection and reassociation

Info

Publication number: EP4677896A1
Application number: EP23926658.8A
Authority: EP
Inventors: Muhammad Majid BUTT; Yonggang Wang; Ahlem KHLASS; Navin Hathiramani
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2023-03-10
Filing date: 2023-03-10
Publication date: 2026-01-14
Also published as: CN120883652A; WO2024187298A1

Abstract

Example embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage medium for connectivity loss detection and reassociation. In a method, a device broadcasts a query message to a set of terminal devices associated with the device and then monitors for a query response for the query message, from the set of terminal devices. The device transmits, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.

Description

CONNECTIVITY LOSS DETECTION AND REASSOCIATION

FIELDS
Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to devices, methods, apparatuses and computer readable storage medium for connectivity loss detection and reassociation.

BACKGROUND

With an energy harvesting technology, a device, in particular a passive device, may harvest an energy present in an ambient environment. This may allow the device to use the harvested energy and operate in a passive mode. Ambient internet of thing (IoT) is a type of energy harvesting enabled communication services and has been widely used in various vertical industries. A tag is a typical example of Ambient (also called Passive IoT (PIoT) ) devices and may have limited capabilities. The tag may be connected or associated with the network through a reader. Tags and/or readers may not always be statically located at one position. Due to reader and/or tag mobility, the tags may lose their connectivity with the network.
SUMMARY
In a first aspect of the present disclosure, there is provided a device. The device comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the device at least to perform: broadcasting a query message to a set of terminal devices associated with the device; monitoring for a query response for the query message, from the set of terminal devices; and transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
In a second aspect of the present disclosure, there is provided a network device. The device comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to perform: receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost; broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports; receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and associating the set of terminal devices and the third set of devices.
In a third aspect of the present disclosure, there is provided a terminal device. The device comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to perform: receiving, from a device, a query message comprising a request for a query response; and transmitting, to the device, a query response including an identification of the terminal device.
In a fourth aspect of the present disclosure, there is provided a method. The method comprises: broadcasting a query message to a set of terminal devices associated with the device; monitoring for a query response for the query message, from the set of terminal devices; and transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
In a fifth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost; broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports; receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and associating the set of terminal devices and the third set of devices.
In a sixth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a device, a query message comprising a request for a query response; and transmitting, to the device, a query response including an identification of the terminal device.
In a seventh aspect of the present disclosure, there is provided an apparatus. The apparatus comprises: means for broadcasting a query message to a set of terminal devices associated with the device; means for monitoring for a query response for the query message, from the set of terminal devices; and means for transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
In an eighth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises: means for receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost; means for broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports; means for receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and means for associating the set of terminal devices and the third set of devices.
In a ninth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises: means for receiving, from a device, a query message comprising a request for a query response; and means for transmitting, to the device, a query response including an identification of the terminal device.
In a tenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing a device to perform at least the method according to the fourth, fifth or sixth aspect.
It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:
FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;
FIG. 2 illustrates a high-level signaling diagram of a process for connectivity loss detection according to some example embodiments of the present disclosure;
FIG. 3 illustrates a flowchart of an example method for connection loss detection in accordance with some example embodiments of the present disclosure;
FIG. 4 illustrates an example process of a reassociation check with configured parameters according to some example embodiments of the present disclosure;
FIG. 5 illustrates a flowchart of an example method for reassociation of a terminal device in accordance with some example embodiments of the present disclosure;
FIG. 6 illustrates a flowchart of an example method for connection loss detection in accordance with some example embodiments of the present disclosure;
FIG. 7 illustrates a signaling diagram of a reassociation process according to some example embodiments of the present disclosure;
FIG. 8 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and
FIG. 9 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.
Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.
In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.
References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
It shall be understood that although the terms “first, ” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.
As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.
As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.
As used in this application, the term “circuitry” may refer to one or more or all of the following:
(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and
(b) combinations of hardware circuits and software, such as (as applicable) :
(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and
(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and
(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.
This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.
As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.
As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , an New Radio (NR) NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.
The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.
In some example embodiments, the terminal device may comprise an Ambient/passive IoT device such as a tag. The Passive IoT device may harvest energy from both the third Generation Partnership Project (3GPP) and non-3GPP devices. For example, the passive IoT device may be illuminated by energy signals and backscatter information to a device (such as a reader) capable of receiving and processing a signal backscattered by a passive IoT such as a tag.
A device (such as a passive IoT device) , powered by energy harvesting, may also be referred to as an energy harvesting device, may use an energy harvested from radio waves or any other form of energy that may be harvested in its (particular) deployment scenario. If an energy is harvested from radio waves, an output power of an energy harvester may be from several micro-watt to tens of micro-watt. If a solar panel is used for energy harvesting from solar and/or light, the output power of the energy harvester may be less than 1 milli-watt due to a small size of the solar panel.
Some energy harvesting devices may possess an active transmission circuitry. After harvesting the energy, such an energy harvesting device may use this active circuit for transmission, similar to a conventional transmitter. Some other energy harvesting devices, also referred to a passive device , may not possess an active transmission circuitry and backscatter a signal in a passive mode.
The Passive IoT services have been widely used in various vertical industries including logistics, manufacture, transportation, energy industry, and/or the like. Enabling passive IoT devices in both public and private networks may benefit the 5G or even 6G ecosystem. Passive IoT may be applied in the following scenarios: 1) a scenario where a device operates under extreme environmental conditions such as a high pressure, an extremely high or low temperature, a humid environment, vibration, and/or the like; 2) a scenario where ultra-low complexity (or cost) , a very small terminal size (or form) factor (for example, thickness of mm) , a maintenance-free and longer life cycle and/or the like are required; 3) other scenarios where a device driven by a battery is not applicable. Therefore, it may be required to support passive IoT using either a battery-less device or a device with a limited energy storage capability (for example, using a capacitor) .
For Passive IoT, radio frequency identification (RFID) solutions together with the backscattering technology may be used, also called backscattering RFID solutions. An objective of passive IoT is to use 3GPP technologies to enhance coverage for the backscattering RFID solutions as well as introducing new solutions with advanced features such as harvesting an energy from a dedicated source or an ambient energy source and spending the energy efficiently for IoT-type of data transmissions. Some relevant use cases, traffic scenarios and key performance indicators (KPIs) may be defined in 3GPP. The considered devices cover both the battery-less type of devices or devices with limited energy storage capabilities, and the energy may be provided via radio wave harvesting, light, motion, and/or the like.
For passive IoT or ambient energy enabled IoT with energy harvesting capabilities, low rate and low complexity may be targeted, and both battery-less devices and devices with small batteries may need to be supported. Moreover, both active and passive IoT devices may need to be supported. Radio Access Network (RAN) design targets may be based on the identified deployment scenarios and their characteristics for the relevant use cases, which may include power consumption, complexity, coverage, data rates, and positioning accuracy, for example.
In some scenarios, tags and/or readers may not be always statically located at one position. Due to reader and/or tag mobility, the tags may lose their connectivity with a network. As “make before break” functionality may not be required for such low-end devices which may support use cases such as warehouse inventory management, there may be no need to allocate resources in advance and develop mechanisms to maintain connectivity and service continuity, as for legacy New Radio (NR) devices.
Thus, there may be some tag association challenges. For example, it may be difficult for a tag to be aware of a lost connection with the originally associated reader. Meanwhile, it may be difficult for a reader to know that the tag is out of its coverage and when a reassociation or reattachment process needs to be started.
Example embodiments of the present disclosure propose a scheme for connectivity loss detection and reassociation for a terminal device. This scheme relies on a query and response process between a terminal device (such as a tag) and its attached device (such as a reader) . With this scheme, a device, which may be connected to a set of terminal devices and capable of illuminate or excite signals to the set of terminal devices, broadcast a query message to the set of terminal devices. The device detects a query response for the query message, from the set of terminal devices. If the device determines at least one terminal device in the set of terminal devices is missing or lost, the device transmits, to a network device such as a gNB, a report that a connection with the at least one terminal device is lost. Accordingly, the network device may reestablish connectivity of the missing terminal device with the network through the same or different device.
As discussed above, a passive IoT device such as a tag is a low complexity device, typically with no active circuit. The majority of the low-end use cases may not require continuous tag-mobility management, and a procedure similar to “make before break” may not be required. If a tag is already associated with a network (NW) through a particular reader but loses its connectivity, the proposed scheme may provide an effective and efficient solution of connectivity loss detection for tags with limited capabilities and be applied in the low-end use case.
FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a network device 110 serves a coverage area 115. Examples of the network device 110 may comprise a base station in a cellular network, and the coverage area 115 may be a cell served by the base station. Alternatively, the network device 110 may operate as an access point or other network devices.
A plurality of terminal devices 120_1, …, 120_K, …, 120_M (individually or collectively referred to as a terminal device 120) are located in the coverage area 115, where K and M represent positive integers and K < M. In an example, the terminal devices 120 may be capable of harvesting ambient energy from different energy sources, such as mechanical vibrations, electromagnetic sources, light, acoustic, airflow, heat, temperature variations, and/or the like, and converting the ambient energy into usable electrical energy. For example, terminal devices 120 may harvest energy from an electromagnetic energy source 125 which may be either a 3GPP or non-3GPP ambient energy source.
Examples of the terminal devices 120 may comprise a device with a limited capability such as a tag or a RFID tag or a wireless device (for example, a sensor) with a tag. The terminal device 120 may be provided with a transceiver (or a receiver and a transmitter) to receive and transmit (or backscatter) a signal and with or without a power source (for example, in the form of a battery) . Alternatively, or in addition, the terminal devices 120 may operate as a slightly smarter device with a microprocessor which may have the capability of performing some limited processing after receiving a signal and/or prior to transmitting a signal. The terminal devices 120 may operate as other more intelligent wireless devices such as a smarter IoT device. For the purpose of discussion, some example embodiments will be discussed by taking tags as an example of the terminal devices 120.
The communication environment 100 may further include devices 130_1, 130_2, …, 130_N (individually or collectively referred to as a device 130) which provide corresponding coverage areas 135_1, …, 135_N (individually or collectively referred to as a coverage area 135) , where N represents a positive integer. The devices 130 may communicate with both the network device 110 and the terminal devices 120 within their coverage areas 135. For example, the device 130_1 may serve the coverage area 135_1 and be associated with the terminal devices 120_1, 120_2, …, 120_K within its served coverage area 135_1.
Examples of the devices 130 may comprise a reader or a RFID reader which may receive a signal transmitted (or backscattered) by the associated terminal device 120. The device 130 may be provided in a monostatic or bistatic configuration. In the monostatic configuration, the device 130 (for example, a reader) may both illuminate and receive signals. In the bistatic configuration, the device 130 may include two distributed units or modules (for example, an illuminator/excitor and a reader) , one for signal illumination and the other for signal reception. Thus, a terminal device 120 may be connected or associated with the network through a particular device 130 such as a reader (in the monostatic configuration) or a pair of an illuminator and a reader pair (in the bistatic configuration) . Although some example embodiments are discussed in a monostatic scenario, these embodiments are also applicable to a bistatic scenario.
The devices 130 may operate as other wireless devices for the signal illumination and reception, which may include a terminal device such as a UE and a network device such as a base station. For the purpose of discussion, some example embodiments will be discussed by taking readers as an example of the devices 130.
It is to be understood that the numbers of devices are shown in FIG. 1 only for the purpose of illustration without suggesting any limitations. The communication environment 100 may include any suitable numbers of network devices 110, terminal devices 120 and associated (or attached) devices 130. Any suitable number of terminal devices 120 and the associated devices 130 may be located in the coverage area 115 of the network device 110, and any suitable number of terminal devices 120 may be located in a coverage area 135 of a device 130.
Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , the sixth generation (6G) , and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) , RFID, and/or any other technologies currently known or to be developed in the future.
In the environment 100, the terminal device 120_1 may be originally associated with (or connected or attached to) the device 130_1 which may maintain a list of terminal devices 120_1, 120_2, …, 120_K associated with or connected to it. The connectivity may be maintained for a configured time T. If a terminal device 120_1, 120_2, …, 120_K does not transmit any data during this time T, connectivity information may be terminated. In this case, association procedures may be performed between the terminal devices 120_1, 120_2, …, 120_K and the device 130_1. However, during this time T, connectivity between the terminal devices 120_1, 120_2, …, 120_K and the device 130_1 may need to be maintained such that the terminal devices 120_1, 120_2, …, 120_K may be able to communicate whenever they have data to transmit.
In some scenarios, the terminal devices 120 and/or the device 130 may not be statically located at one position. Due to the mobility of the terminal devices 120 and/or the device 130, the terminal devices 120 may lose their connectivity with the network. For example, as shown in FIG. 1, the terminal device 120_1 is moving out of the coverage area 135_1 of the device 130_1 and towards the coverage area 135_2 of the device 130_2. Thus, the terminal device 120_1 may lose a connection with the network. As the terminal device 120_1 may be limited in its capabilities, the network (for example, the network device 110) and the associated device 130_1 may be primed with connectivity loss detection.
In some example embodiments, a lost connection with the terminal device 120_1 may be determined or detected based on a query message and a query response between the device 130_1 and the terminal device 120_1. If a connection with the terminal device 120_1 is determined or identified to be missing or lost, the device 130_1 transmits a report to the network device 110. Then, the network device 110 initiates a reassociation process of the lost terminal device 120_1.
FIG. 2 shows a high-level signaling diagram of a process 200 for connectivity loss detection according to some example embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to FIG. 1.
As shown in FIG. 2, the device 130_1 may broadcast (205) a query message to a set of terminal devices 120_1, 120_2, …, 120_K associated with the device 130_1. Depending on the specific implementations, the device 130_1 may be associated with any number of terminal devices. The set of associated terminal devices may comprise one or more terminal devices. The set of terminal devices 120_1, 120_2, …, 120_K may receive (210) the query message, which may allow a terminal device 120_1, 120_2, …, 120_K to confirm its presence by responding to the query message.
The device 130_1 may determine (215) whether a query response for the query message is received from the set of terminal devices 120_1, 120_2, …, 120_K. If the device 130_1 receives this response from a terminal device 120_1, 120_2, …, 120_K, the device 130_1 may verify that the terminal device 120_1, 120_2, …, 120_K is still in its connectivity range and is able to communicate whenever it has data to transmit. In this example, the device 130_1 does not receive a response from the terminal device 120_1 due to the mobility of the terminal device 120_1 towards the device 130_2. Then, the device 130_1 may declare that the terminal device 120_1 is lost and report it to the network. Such querying may be repeated for a number of times before declaration of a lost terminal device.
As shown in FIG. 2, the device 130_1 may transmit (220) to the network device 110 a report of a lost connection e.g., that at least one terminal device (for example, including the terminal device 120_1) in the set of terminal devices 120_1, 120_2, …, 120_K is lost. After the network device 110 receives (225) the report from the device 130_1 and such reports from other devices 130 (not shown) , the network device 110 may make a list of lost terminal devices and start a search for these lost terminal devices. With identifications (IDs) of the lost terminal devices, an association procedure for the lost terminal devices 120 may be simplified.
In the process 200, as shown in FIG. 2, the network device 110 may broadcast (230) , through a set of devices (for example, including the device 130_2) , a search message including a list of IDs of the lost terminal devices based on a set of reports received from a set of devices 130_1, 130_2, …, 130_N. The search message may be broadcast by the network device 110 through all available devices.
As the terminal device 120_1 has lost the connection due to mobility towards the device 130_2, the terminal device 120_1 may receive (235) the search message through the device 130_2. Then, the terminal device 120_1 may transmit (240) to the device 130_2 an acknowledgement (ACK) message (or response) including the ID of the terminal device 120_1. In an example, if the terminal device 120_1 finds its ID or determines its ID in the list of IDs of lost terminal devices, the terminal device 120_1 may backscatter its ID to the corresponding device 130_2.
After the device 130_2 receives (245) the acknowledgement message from the terminal device 120_1, the device130_2 may transmit (250) to the network device 110 a report that includes at least one ID of at least one lost terminal device 120 (for example, including the ID of the terminal device 120_1) from which the acknowledgement message is received. After the network device 110 receives (255) the report from the device 130_2 and such reports from other devices 130 (not shown) , the network device 110 associates (260) a set of lost terminal devices and a set of corresponding devices.
In this way, it may not be required for continuous mobility tracking for the terminal devices 120 and for the capability of the terminal device 120 to measure a Reference Signals Received Power (RSRP) on a forward (or downlink) channel from the device 130 to the terminal device 120. The continuous connectivity between the terminal devices 120 and the NW such as the network device 110 may be accomplished by using a query message broadcast by the device 130 which may allow the terminal device 120 to confirm its connectivity by simply responding to the message. Such loss detection may be more feasible and efficient. Moreover, the proposed association mechanism may simply reestablish connectivity with low complexity as compared to a legacy NR process for mobility management.
Some example implementations for the connectivity loss detection and reassociation will be discussed below with reference to FIGS. 3 to 7.
FIG. 3 shows a flowchart of an example method 300 for detecting a lost connection of the terminal device 120 in accordance with some example embodiments of the present disclosure. The method 300 may be implemented at the device 130. For the purpose of discussion, the method 300 will be described from the perspective of the device 130 with reference to in FIG. 1.
At block 310, the device 130 (such as the device 130_1) broadcasts a query message to a set of terminal devices 120 associated with the device 130, such as the terminal devices 120_1, 120_2, …, 120_K. The association between the terminal devices 120 and the device 130 may be established in advance by using any suitable association approaches.
The query message may be broadcast by the device 130 periodically. For example, the device 130 may broadcast the query message every query time interval to all the associate terminal devices 120. The query time interval may be configured by the network device 110 based on any suitable rules or criteria. In some example embodiments, the device 130 may receive a first configuration for a query time interval for broadcasting the query message. The first configuration may be implemented in any suitable form. For example, a parameter query_interval may be used to indicate the configured query time interval.
Alternatively, or in addition, the query message may be triggered by an event. For example, the device 130 may broadcast the query message in response to receiving no signal from the set of terminal devices 120 during the query time interval. If a terminal device 120 is transmitting data, a query message may be not required, and data transmission may be considered a default query response. In some example embodiments, the device 130 may broadcast the query message every query time interval to the terminal devices 120 which do not send any data. As an example, the broadcast query message may include a first list of IDs of the set of terminal devices 120 (also called groupID) which may be associated with the device 130 and have not transmitted anything for a preconfigured time.
In some example embodiments, the query message may comprise a request for a query response e.g., an indication that the query response is needed. Such an indication may be implemented in any suitable form. For example, the query message may contain a field forceResponse that may help the terminal device 120 to determine whether a response is needed even if it has no data to transmit.
At block 320, the device 130 monitors for a query response for the query message, from the set of terminal devices 120. If the device 130 receives this response which may include an ID of the terminal device 120, the device 130 may verify that the terminal device 120 is still in its coverage range. If no query response is received from the at least one terminal device 120 such as the terminal device 120_1, the device 130 such as the device 130_1 may repeatedly broadcast the query message to the at least one terminal device 120, for example, with the query time interval.
The device 130 may determine whether the at least one terminal device 120 has lost the connection with the device 130, based on a threshold number of query messages, which may be the maximum number of query messages that the device 130 sends before declaring that a terminal device 120 is lost. For example, if no query response is received from the at least one terminal device 120 for the threshold number of query messages, the device 130 may determine or declare that the at least one terminal device 120 has lost the connection.
The threshold number of query messages may be configured by the network. For example, the device 130 may receive from the network device, a second configuration for the threshold number of query messages for determining the lost connection with the terminal device 120. The second configuration may be a part of the first configuration for the query time interval or independent from the first configuration. As an example, the second configuration may be implemented in a form of a parameter max_query used to indicate the maximum number of query messages or in any other forms.
In some example embodiments, the loss determination may be based on a counter which may be associated with a lost terminal device 120. For example, the device 130 may determine whether a query response is received from a terminal device of the set of terminal devices 120. If it is determined that no query response is received from the terminal device 120, the device 130 may increment a value of a counter associated with the terminal device 120. If the value of the counter equates, reaches, meets, exceeds, or otherwise satisfies the threshold number of query messages, the device 130 may determine that the terminal device 120 has lost the connection with the device 130. If a query response is received from the terminal device, the device 130 may reset the counter.
The counter may be indicated by a parameter missing_counter, for example. In the case that the threshold number of query messages is indicated by the parameter max_query, if the device 130 does not receive a response from the terminal device 120, it may increment a counter missing_counter; and if for max_query attempts for the query messages, the device 130 does not receive any response from the terminal device 120, it may declare a lost terminal device120 and report it to the network device 110. If the device 130 receives a message from the terminal device 120 in any of the attempts, the counter missing_counter may be reset.
At block 330, the device 130 transmits, to the network device 110, a report that a connection with at least one terminal device in the set of terminal devices 120 is lost e.g., that the at least one terminal device is lost. The report may include a second list of IDs of the at least one lost terminal device 120.
The reporting may be done when a criterion is met, for example, when receiving no query response for a certain time. In an example, the report may be transmitted periodically, for example, based on a (pre-) configuration from the network device 110 if at least one terminal device 120 is declared lost. In another example, the reporting may be done autonomously by the device 130, based on some rules. For example, the report may be triggered by an event, for example, that the number of lost terminal devices reaches a threshold number that may be configured by the network device 110.
Upon receiving such reports from one or more devices 130, the network device 110 may make a list of lost terminal devices and start a search for the terminal devices. Detailed implementations at the network device 110 will be discussed in the following paragraph with reference to FIG. 5.
In some example embodiments, the device 130 (such as the device 130_2) may receive, from the network device 110, a search message including a third list of IDs of lost terminal devices (for example, including the terminal device 120_1) . Then, the device 130 may broadcast the search message. For example, the device 130 may immediately send the search message with a field forceResponse to indicate that the response is needed, and a field missinggroupID to indicate the lost terminal devices 120 to be searched. As a result, the lost terminal device 120 may find its ID in the missinggroupID list and send its ID to the device 130, which will be detailed in the following paragraph with reference to FIG. 6.
In some example embodiments, the device 130 such as the device 130_2 may receive at least one acknowledgement (ACK) message from at least one terminal device 120 such as the terminal device 120_1. The at least one acknowledgement message may include at least one ID of the at least one terminal device 120. If the device 130 determines that the at least one identification of the at least one terminal device 120 is included in the third list of IDs of lost terminal devices, the device 130 may transmit, to the network device 110, a report that includes the at least one ID of the at least one lost terminal device 120. This report may be transmitted either instantly upon reception of an ACK message from a terminal device 130, or after collecting such ACK information from a plurality of terminal devices.
In some example embodiments, after the device 130 receives the search message from the network device 110, which includes the third list of IDs of lost terminal devices, the search message may be broadcast by the device 130 in combination with a query message including the first list of identifications of terminal devices 120 associated with the device 130. In this example, if the device 130 determines that the at least one ID of the at least one terminal device 120 is excluded from both the first list of IDs of the associated terminal devices and the third list of IDs of lost terminal devices, the device 130 may transmit, to the network device 110, a report including the at least one ID of the at least one lost terminal device.
By way of example, in the case that the device 130 combines the search message with the query message, if the device 130 receives the backscattered signal including the ID of the lost terminal device, the device 130 may report it to the network device. If the received ID is included in its groupID list, the device 130 may takes no further action as the response from the terminal device 120 is a response to the groupID field. If the received ID is not included in both the groupID and LostgroupID lists, the device 130 may detect this ID as a new ID and reports to the network device 110.
FIG. 4 shows an example process 400 of a reassociation check at the device 130 with the parameters configured by the network device 110 according to some example embodiments of the present disclosure. In this example, a gNB may act as the network device 110, a tag may act as the terminal device 120, and a reader may act as the device 130.
As shown in FIG. 4, at 402, Max_query and query_interval parameters are configured by the gNB at the readers. The value of the Max_query parameter shows how many unsuccessful consecutive query attempts which the reader makes before declaring a tag lost. A lower number may result in an unnecessary reattachment procedure while a higher number may delay data transmission of a tag if it has lost the connection with the device such as a reader. Thus, there is a tradeoff between the unnecessary reattachment and the transmission delay. Similar tradeoff may be involved for the parameter query_interval (or Query Interval) . A shorter interval may result in a lot of unnecessary attempts to force tag responses, while tags are low complexity and low mobility devices. A larger value, on the other hand, may result in a tag losing a connection with the device for a longer time.
The reader may use these parameters to decide frequency of polling query messages and number of unsuccessful messages it need to send before declaring a lost tag. To implement this, a counter missing_counter may be used. As shown in FIG. 4, at 404, the missing_counter may be reset to zero, for example, whenever a tag responds with its ID. At 406, a query with the forceResponse field may be broadcast. At 408, it may be determined whether a response with tag ID received. If yes, at 410, it is determined that the tag is associated, and then no further action may be required and the device may wait for the next query_interval.
If a reader does not receive any query response for its forceResponse message, then at 412, the missing_counter may be incremented. At 414, it may be determined whether missing_counter = Max_query. If no, then at 416, the reader may wait for the next query_interval for a next round of polling query messages. When the counter reaches max_query, at 418, it may be determined that the tag is not associated and reassociation is needed. In this case, the reader may declare a lost tag and reports it to the network device or the gNB. Then, the gNB may initiate a reassociation procedure for the lost tag.
Example implementations at the network device 110 will be discussed below with reference to FIG. 5.
FIG. 5 shows a flowchart of an example method 500 for reassociation between the terminal device 120 and the device 130 in accordance with some example embodiments of the present disclosure. The method 500 may be implemented at the network device 110. For the purpose of discussion, the method 500 will be described from the perspective of the network device 110 with reference to in FIG. 1.
At block 510, the network device 110 receives, from a first set of devices 130 (for example, including the device 130_2) , a set of reports that terminal devices 120 (for example, including the terminal device 120_1) associated with the first set of devices 130 are lost. The reports may be transmitted by the individual devices 130 periodically or based on an event trigger, as discussed above. A report of the set of reports received from a device of the first set of devices 130 may include the second list of IDs of at least one lost terminal device 120.
In some example embodiment, the network device 110 may transmit, to a device of the first set of devices 130, a first configuration for a query time interval to cause the device 130 to query an associated terminal device 120 with the query time interval. In some example embodiment, the network device 110 may transmit, to a device of the first set of devices 130, a second configuration for a threshold number of query messages such that the device 130 may use the threshold number of query messages for determining a lost connection with a terminal device 130.
At block 520, the network device 110 broadcasts, through a second set of devices 130, a search message including the third list of IDs of the lost terminal devices 120 based on the set of reports. In an example, the network device 110 may determine the third list of IDs of lost terminal devices 120 based on the received reports for the lost terminal devices 120. As the network device 110 knows the IDs of the lost terminal devices 120, the network device 110 may use them to simplify the association procedure.
The second set of devices 130 may be different or overlapping with the first set of devices 130 which reports the lost terminal devices 120. In an example, the second set of devices may be determined based on the third list of IDs of the lost terminal devices.
Instead of a “blank” message to search a lost tag in a larger area, a hierarchical broadcast may be used to search lost terminal devices 120. The network device 110 may be aware of locations of the devices 130. Thus, the network device 110 may first try to search terminal devices 120 in neighborhood of a device 120 and then try to extend its search area. If the network device 110 is not able to find a lost terminal device 120 by using available devices 130 in its area, the network device 110 may forward this information on the lost terminal device 120 to another network device (for example, in a core network) . The network device 110 may rely on advanced procedures already employed by the core network to determine which search area may be used.
At block 530, the network device 110 receives, from a third set of devices 130, a report including a set of IDs of a set of terminal devices 120. The third set of devices 130 may be a subset of the second set of devices 130 through which the search message is broadcast.
At block 540, the network device 110 associates the set of terminal devices 120 (for example, including the terminal device 120_1) and the third set of devices 130 (for example, including the device 130_2) . For example, the network device 110 may combine the reports from the third set of devices 130 and use a refinement step to update the associations of the involved terminal devices 120. This refinement may be needed when multiple devices 130 report the same terminal devices. Then, the network device 110 may perform the association of the terminal devices 120 and the device 130 based on any predetermined criterion such as load balancing.
In some example embodiment, the network device 110 may store an association between the set of terminal devices 120 and the third set of devices 130. Thus, the association between the terminal devices 120 and the devices 130 may be updated. In some example embodiment, the network device 110 may transmit, to the third set of devices 130, an indication of the association between the set of terminal devices 120 and the third set of devices 130. In this way, the respective devices 130 may be informed of the updated association. Alternatively, or in addition, the terminal device 120 may be informed that it is associated with the device.
Since the lost terminal device is already known, the reassociation procedure can be simplified. Such reassociation may avoid repeating an association procedure which may include identifying the presence of the terminal devices 120 first and then associate them with the suitable devices 120. This reassociation procedure may have low complexity with minimized signalling overhead.
The proposed loss detection and reassociation scheme for a terminal device 120 needs simple query-response operations of the terminal devices 120 and the attached devices 130, which may be applied in the low-end use cases. Example implementations at the terminal device 120 will be discussed below with reference to FIG. 6.
FIG. 6 shows a flowchart of an example method 600 at the terminal device 120 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the terminal device 120 with reference to in FIG. 1.
At block 610, the terminal device 120 receives, from a device 130, a query message requesting a query response, e.g., comprising an indication that a query response is needed. At block 620, the terminal device 120 transmits, to the device 130, a query response including an ID of the terminal device 120. The terminal device 120 may respond to the equerry message broadcast by the device 130 by employing a contention-based scheme to avoid collisions.
In some example embodiments, the query message comprises a first list of identifications of terminal devices 120 associated with the device 130. In this example, if the terminal device 120 finds or determines the ID of the terminal device 120 in the first list of IDs, the terminal device 120 may transmit, to the device 130, the query response including the identification of the terminal device 120.
In some example embodiments, the terminal device 120 such as the terminal device 120_1 may move out of the coverage area 135 (such as the coverage area 135_1) of the device 130 such as the device 130_1 and lose a connection with the device 130. In an example, the terminal device 120 may receive, from a device 130 such as the device 130_2, a search message including a third list of IDs of lost terminal devices. If the lost terminal device 120 finds or determines its ID in the third list of IDs, the terminal device 120 may transmit, to the device 120, an acknowledgement message including the ID of the terminal device 120. For example, the terminal device 120 may try to search the third list of IDs of lost terminal devices. If the terminal device 120 finds its ID, it may backscatter its ID to the corresponding device 130.
In some example embodiments, the search message may be combined by the device 130 with the query message that includes a first list of IDs of terminal devices associated with the device 130. In this example, the terminal device 120 may try to search both the first list of IDs of associated terminal devices and the third list of IDs of lost terminal devices. If the terminal device 120 finds its ID in any of the lists, it may send its ID to the device 130.
All operations and features related to the network device 110 and the terminal device 120 as described above with reference to FIGS. 1 to 4 are likewise applicable to the methods 500 and 600 and have similar effects. For the purpose of simplification, the details will be omitted.
FIG. 7 shows a signaling diagram of a reassociation process 700 according to some example embodiments of the present disclosure. For the purpose of discussion, the process 700 will be described with reference to FIG. 1. In this example, a tag 702, labelled as Tag1, may act as the terminal device 120, an attached device 704, labelled as attached reader, may act as one of the devices 130 which is associated or connected with the tag 702. Devices 706 and 708, labelled as Reader1 and Reader 2 respectively, may act as another two of the devices 130. A gNB 710 may act as the network device 110.
As shown in FIG. 7, at 712, the attached reader 704 and the readers 706 and 708 perform Tag-Reader association, and max_query and query_interval may be configured. The tag-reader association may be established by using any suitable procedures and criteria. At 714, the attached reader 704 may broadcast an illumination signal with groupID and forceResponse. The groupID represents a list of tag IDs associated with the attached reader 704 and have not transmitted anything for a preconfigured time. The forceResponse may help the tag 702 to determine if a response is needed even if it has no data to transmit.
At 716, the tag 702 may search for its ID in groupID. At 718, the tag 702 may backscatter a signal with a unique identification (UID) of the tag 702. Then, at 720, the reader 704 may continue the query attempts based on query_interval. At 724, the reader 704 does not receive a response from the tag 702. At 726, the reader 704 may report to the gNB 710 an event of the lost tag (s) with UID_list which may indicate a lost tag list.
At 728, the gNB 710 may decide which readers or exciters need broadcast based on all UID_list received from the readers 704, 706, and 708. At 730, the gNB 710 may send a polling request with missinggroupID and forceResponse to the involved readers 706 and 708. The missinggroupID may indicate a lost tag list for reassociation. At 732, the readers 706 and 708 may broadcast an illumination signal with groupID, missinggroupID and forceResponse.
At 734, the tag 702 may search for its ID in missinggroupID. At 736, the tag 702 may backscatter a signal with UID. In this example, the reader 708 receives the backscattered signal. At 738, the reader 708 may report the information of the received tag with UID. At 740, the gNB 710 may update the information in the records with reader ID and UID. At 742, the gNB 710 may confirm the update with UID with the reader 708. At 744, the reader 708 may perform attachment confirmation with the tag 702.
In some example embodiments, the apparatus capable of performing any of the method 300 (for example, the device 130 in FIG. 1) may comprise means for performing the respective operations of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the device 130 in FIG. 1.
In some example embodiments, the apparatus comprises means for broadcasting a query message to a set of terminal devices associated with the device; means for monitoring for a query response for the query message, from the set of terminal devices; and means for transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
In some example embodiments, the apparatus comprises means for receiving, from the network device, a first configuration for a query time interval for broadcasting the query message.
In some example embodiments, the query message comprises an indication that the query response is needed.
In some example embodiments, the apparatus comprises: means for based on a determination that no query response is received from the at least one terminal device for a threshold number of query messages, determining that the at least one terminal device has lost a connection with the device; and means for based on a determination that the at least one terminal device has lost the connection, transmitting the report that the connection with the at least one terminal device in the set of terminal devices is lost.
In some example embodiments, the apparatus comprises: means for receiving, from the network device, a second configuration for the threshold number of query messages for determining the lost connection with the terminal device.
In some example embodiments, the apparatus comprises: means for determining whether a query response is received from a terminal device of the set of terminal devices; means for based on a determination that no query response is received from the terminal device, incrementing a value of a counter associated with the terminal device; and means for in response to the value of the counter satisfying the threshold number of query messages, determining that the terminal device has lost the connection with the device.
In some example embodiments, the apparatus comprises: means for based on a determination that a query response is received from the terminal device, resetting the counter.
In some example embodiments, the query response includes an identification of the terminal device.
In some example embodiments, the apparatus comprises: means for broadcasting the query message in response to receiving no signal from the set of terminal devices during the query time interval.
In some example embodiments, the query message includes a first list of identifications of the set of terminal devices.
In some example embodiments, the query message is broadcast periodically or triggered by an event.
In some example embodiments, the report includes a second list of identifications of the at least one lost terminal device.
In some example embodiments, the report is transmitted to the network device periodically or triggered by an event.
In some example embodiments, the apparatus comprises: means for in response to the number of lost terminal devices reaching a threshold number, transmitting, to the network device, the report that the terminal devices are lost.
In some example embodiments, the apparatus comprises: means for receiving, from the network device, a search message including a third list of identifications of lost terminal devices; and means for broadcasting the search message.
In some example embodiments, the apparatus comprises: means for receiving at least one acknowledgement message from at least one terminal device, at least one acknowledgement message including at least one identification of the at least one terminal device; and means for based on a determination that the at least one identification of the at least one terminal device is included in the third list of identifications of lost terminal devices, transmitting, to the network device, a report that includes the at least one identification of the at least one lost terminal device.
In some example embodiments, the apparatus comprises: means for based on a determination that the at least one identification of the at least one terminal device is excluded from both the first list of identifications of the associated terminal devices and the third list of identifications of lost terminal devices, transmitting, to the network device, an indication of the at least one identification of the at least one lost terminal device.
In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 300 or the device 130. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.
In some example embodiments, an apparatus capable of performing any of the method 500 (for example, the network device 110 in FIG. 1) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the network device 110 in FIG. 1.
In some example embodiments, the apparatus comprises: means for receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost; means for broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports; means for receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and means for associating the set of terminal devices and the third set of devices.
In some example embodiments, the second set of devices is determined based on the third list of identifications of the lost terminal devices.
In some example embodiments, the apparatus comprises: means for transmitting, to a device of the first set of devices, a first configuration for a query -time interval to cause the device to query an associated terminal device with the query time interval.
In some example embodiments, the apparatus comprises: means for transmitting, to a device of the first set of devices, a second configuration for a threshold number of query messages for determining a lost connection with a terminal device.
In some example embodiments, a report of the set of reports received from a device of the first set of devices includes a second list of identifications of at least one lost terminal device.
In some example embodiments, the set of reports is received periodically or triggered by an event.
In some example embodiments, the apparatus comprises: means for storing an association between the set of terminal devices and the third set of devices.
In some example embodiments, the apparatus comprises: means for transmitting, to the third set of devices, an indication of the association between the set of terminal devices and the third set of devices.
In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 500 or the network device 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.
In some example embodiments, an apparatus capable of performing any of the method 600 (for example, the terminal device 120 in FIG. 1) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the terminal device 120 in FIG. 1.
In some example embodiments, the apparatus comprises: means for receiving, from a device, a query message comprising a request for a query response; and means for transmitting, to the device, a query response including an identification of the terminal device.
In some example embodiments, the apparatus comprises: means for in response to determining the identification of the terminal device in the first list of identifications of the associated terminal devices, transmitting, to the device, the query response including the identification of the terminal device.
In some example embodiments, the apparatus comprises: means for receiving, from a device, a search message including a third list of identifications of lost terminal devices; and means for in response to determining the identification of the terminal device in the third list of identifications of lost terminal devices, transmitting, to the device, an acknowledgement message including the identification of the terminal device.
In some example embodiments, the search message is combined with the query message including a first list of identifications of terminal devices associated with the device.
In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 600 or the terminal device 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.
FIG. 8 is a simplified block diagram of a device 800 that is suitable for implementing example embodiments of the present disclosure. The device 800 may be provided to implement a communication device, for example, the device 130, the network device 110 or the terminal device 120 as shown in FIG. 1. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor 810, and one or more communication modules 840 coupled to the processor 810.
The communication module 840 is for bidirectional communications. The communication module 840 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 840 may include at least one antenna.
The processor 810 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.
The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 824, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 822 and other volatile memories that will not last in the power-down duration.
A computer program 830 includes computer executable instructions that are executed by the associated processor 810. The instructions of the program 830 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 830 may be stored in the memory, e.g., the ROM 824. The processor 810 may perform any suitable actions and processing by loading the program 830 into the RAM 822.
The example embodiments of the present disclosure may be implemented by means of the program 830 so that the device 800 may perform any process of the disclosure as discussed with reference to FIG. 1 to FIG. 7. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.
In some example embodiments, the program 830 may be tangibly contained in a computer readable medium which may be included in the device 800 (such as in the memory 820) or other storage devices that are accessible by the device 800. The device 800 may load the program 830 from the computer readable medium to the RAM 822 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .
FIG. 9 shows an example of the computer readable medium 900 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 900 has the program 830 stored thereon.
Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.
Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.
The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.
Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the device at least to perform:

broadcasting a query message to a set of terminal devices associated with the device;

monitor for a query response for the query message, from the set of terminal devices; and

transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
The device of claim 1, wherein the at least one memory and the at least one processor further cause the device to perform:

receiving, from the network device, a first configuration for a query time interval for broadcasting the query message.
The device of any of claims 1-2, wherein the query message comprises an indication that the query response is needed.
The device of any of claims 1-3, wherein the at least one memory and the at least one processor cause the device to perform:

based on a determination that no query response is received from the at least one terminal device for a threshold number of query messages, determining that the at least one terminal device has lost connection with the device; and

based on a determination that the at least one terminal device has lost the connection, transmitting the report that the connection with the at least one terminal device in the set of terminal devices is lost.
The device of claim 4, wherein the at least one memory and the at least one processor further cause the device to perform:

receiving, from the network device, a second configuration for the threshold number of query messages for determining the lost connection with the terminal device.
The device of any of claims 4-5, wherein the at least one memory and the at least one processor cause the device to perform:

determining whether a query response is received from a terminal device of the set of terminal devices;

based on a determination that no query response is received from the terminal device, incrementing a value of a counter associated with the terminal device; and

in response to the value of the counter satisfying the threshold number of query messages, determining that the terminal device has lost the connection with the device.
The device of claim 6, wherein the at least one memory and the at least one processor cause the device to perform:

based on a determination that a query response is received from the terminal device, resetting the counter.
The device of claim 7, wherein the query response includes an identification of the terminal device.
The device of any of claims 1-8, wherein the at least one memory and the at least one processor cause the device to perform:

broadcasting the query message in response to receiving no signal from the set of terminal devices during the query time interval.
The device of any of claims 1-9, wherein the query message includes a first list of identifications of the set of terminal devices.
The device of any of claims 1-10, wherein the query message is broadcast periodically or triggered by an event.
The device of any of claims 1-11, wherein the report includes a second list of identifications of the at least one lost terminal device.
The device of any of claims 1-12, wherein the report is transmitted to the network device periodically or triggered by an event.
The device of claim 13, wherein the at least one memory and the at least one processor cause the device to perform:

in response to the number of lost terminal devices reaching a threshold number, transmitting, to the network device, the report that the terminal devices are lost.
The device of any of claims 1-14, wherein the at least one memory and the at least one processor further cause the device to perform:

receiving, from the network device, a search message including a third list of identifications of lost terminal devices; and

broadcasting the search message.
The device of claim 15, wherein the at least one memory and the at least one processor further cause the device to perform:

receiving at least one acknowledgement message from at least one terminal device, at least one acknowledgement message including at least one identification of the at least one terminal device; and

based on a determination that the at least one identification of the at least one terminal device is included in the third list of identifications of lost terminal devices, transmitting, to the network device, a report that includes the at least one identification of the at least one lost terminal device.
The device of claim 16, wherein the search message is broadcast in combination with a query message including a first list of identifications of terminal devices associated with the device, and wherein the at least one memory and the at least one processor further cause the device to perform:

based on a determination that the at least one identification of the at least one terminal device is excluded from both the first list of identifications of the associated terminal devices and the third list of identifications of lost terminal devices, transmitting, to the network device, a report including the at least one identification of the at least one lost terminal device.
A network device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to perform:

receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost;

broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports;

receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and

associating the set of terminal devices and the third set of devices.
The network device of claim 18, wherein the second set of devices is determined based on the third list of identifications of the lost terminal devices.
The network device of any of claims 18-19, wherein the at least one memory and the at least one processor further cause the network device to perform:

transmitting, to a device of the first set of devices, a first configuration for a query time interval to cause the device to query an associated terminal device with the query time interval.
The network device of any of claims 18-20, wherein the at least one memory and the at least one processor further cause the network device to perform:

transmitting, to a device of the first set of devices, a second configuration for a threshold number of query messages for determining a lost connection with a terminal device.
The network device of any of claims 18-21, wherein a report of the set of reports received from a device of the first set of devices includes a second list of identifications of at least one lost terminal device.
The network device of any of claims 18-22, wherein the set of reports is received periodically or triggered by an event.
The network device of any of claims 18-23, wherein the at least one memory and the at least one processor further cause the network device to perform:

storing an association between the set of terminal devices and the third set of devices.
The network device of claim 24, wherein the at least one memory and the at least one processor further cause the network device to perform:

transmitting, to the third set of devices, an indication of the association between the set of terminal devices and the third set of devices.
A terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to perform:

receiving, from a device, a query message comprising a request for a query response; and

transmitting, to the device, a query response including an identification of the terminal device.
The terminal device of claim 26, wherein the query message comprises a first list of identifications of terminal devices associated with the device, and wherein the at least one memory and the at least one processor cause the terminal device to perform:

in response to determining the identification of the terminal device in the first list of identifications of the associated terminal devices, transmitting, to the device, the query response including the identification of the terminal device.
The terminal device of any of claims 26-27, wherein the at least one memory and the at least one processor further cause the terminal device to perform:

receiving, from a device, a search message including a third list of identifications of lost terminal devices; and

in response to determining the identification of the terminal device in the third list of identifications of lost terminal devices, transmitting, to the device, an acknowledgement message including the identification of the terminal device.
The terminal device of claim 28, wherein the search message is combined with the query message including a first list of identifications of terminal devices associated with the device.
A method comprising:

broadcasting a query message to a set of terminal devices associated with a device;

monitoring for a query response for the query message, from the set of terminal devices; and

transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
A method comprising:

receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost;

broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports;

receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and

associating the set of terminal devices and the third set of devices.
A method comprising:

receiving, from a device, a query message comprising an indication that a request for a query response; and

transmitting, to the device, a query response including an identification of the terminal device.
An apparatus comprising:

means for broadcasting a query message to a set of terminal devices associated with the device;

means for monitoring for a query response for the query message, from the set of terminal devices; and

means for transmitting, to a network device, a report that a connection with at least one terminal device in the set of terminal devices is lost.
An apparatus comprising:

means for receiving, from a first set of devices, a set of reports that terminal devices associated with the first set of devices are lost;

means for broadcasting, through a second set of devices, a search message including a third list of identifications of the lost terminal devices based on the set of reports;

means for receiving, from a third set of devices, a report including a set of identifications of a set of terminal devices; and

means for associating the set of terminal devices and the third set of devices.
An apparatus comprising:

means for receiving, from a device, a query message comprising a request for a query response; and

means for transmitting, to the device, a query response including an identification of the terminal device.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of any of claims 30-32.