WO2021102837A1

WO2021102837A1 - Methods, devices, and medium for communication

Info

Publication number: WO2021102837A1
Application number: PCT/CN2019/121717
Authority: WO
Inventors: Lin Liang; Gang Wang
Original assignee: Nec Corporation
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2021-06-03

Abstract

Embodiments of the present disclosure relate to methods, devices, and medium for communication. According to embodiments of the present disclosure, the network device reserves some cell identities for some neighbor network devices and transmits mapping information indicating the cell identities in release information to the terminal device. If the terminal device moves to a neighbor network device, the terminal device determines whether the neighbor network device is in the mapping information. If it is in the mapping information, the terminal device is able to perform the grant free transmission using the reserved cell identity.

Description

METHODS, DEVICES, AND MEDIUM FOR COMMUNICATION

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to methods, devices, and medium for communication.

BACKGROUND

Communication technologies have been developed. The terminal device may be connected with the network device in radio resource control (RRC) connection. There may be different RRC modes. Further, in order to reduce latency, grant free transmission has been proposed.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of grant free transmissions for terminal devices.

In a first aspect, there is provided a method for communication. The method comprises obtaining, at a network device, mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with a terminal device; in accordance with a determination that a connection with the terminal device is to be released, generating release information comprising the mapping information; and transmitting the release information to the terminal device.

In a second aspect, there is provided a method for communication. The method comprises receiving, at a terminal device, release information from a network device, the release information comprising mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with the terminal device; in accordance with a determination that the terminal device is to be connected with a further network device, determining, based on the mapping information, whether the at least one neighbor network device comprises the further network device; and establishing the connection with the further network device for transmission based at least in part on the determination.

In a third aspect, there is provided a network device. The network device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the network device to perform obtaining, at a network device, mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with a terminal device; in accordance with a determination that a connection with the terminal device is to be released, generating release information comprising the mapping information; and transmitting the release information to the terminal device.

In a fourth aspect, there is provided a terminal device. The terminal device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the terminal device to perform receiving, at a terminal device, release information from a network device, the release information comprising mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with the terminal device; in accordance with a determination that the terminal device is to be connected with a further network device, determining, based on the mapping information, whether the at least one neighbor network device comprises the further network device; and establishing the connection with the further network device for transmission based at least in part on the determination.

In a fifth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the first aspect.

In a sixth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the second aspect.

Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some example embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

Fig. 1 is a schematic diagram of a communication environment in which embodiments of the present disclosure can be implemented;

Fig. 2 is a signaling chart illustrating a process according to an embodiment of the present disclosure;

Fig. 3 is a signaling chart illustrating a process according to another embodiment of the present disclosure;

Figs. 4A and 4B illustrate structures of medium access control (MAC) protocol data unit (PDU) according to an embodiment of the present disclosure;

Fig. 5 is a flowchart of an example method in accordance with an embodiment of the present disclosure;

Fig. 6 is a flowchart of an example method in accordance with an embodiment of the present disclosure; and

Fig. 7 is a simplified block diagram of a device that is suitable for implementing 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 limitations as to the scope of the disclosure. The disclosure 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.

As used herein, the term “network device” refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an Evolved NodeB (eNodeB or eNB) , a NodeB in new radio access (gNB) a Remote Radio Unit (RRU) , a radio head (RH) , a remote radio head (RRH) , a low power node such as a femto node, a pico node, a satellite network device, an aircraft network device, and the like. For the purpose of discussion, in the following, some example embodiments will be described with reference to eNB as examples of the network device.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure/network, or image capture devices such as digital cameras, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

In one embodiment, the terminal device may be connected with a first network device and a second network device. One of the first network device and the second network device may be a master node and the other one may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs) . In one embodiment, the first network device may be a first RAT device and the second network device may be a second RAT device. In one embodiment, the first RAT device is eNB and the second RAT device is gNB. Information related with different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In one embodiment, first information may be transmitted to the terminal device from the first network device and second information may be transmitted to the terminal device from the second network device directly or via the first network device. In one embodiment, information related with configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device. Information related with reconfiguration for the terminal device configured by the second network device may be transmitted to the terminal device from the second network device directly or via the first network device.

Communications discussed herein may use conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, 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) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies.

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. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

In conventional technologies, only RRC_CONNECTED terminal device is allowed to initiate grant free transmission. The configuration of grant free is configured by RRC. Further, there may be some requirements for some special terminal devices, for example, industry sensors. The requirements may comprise end-to-end latency (5ms～10ms for Condition monitoring for safety, 50ms～1s for others) . The battery life may be longer than enhanced mobile broadband (eMBB) , which may be up to 1～3 years. The reliability may also be high. It may also need low cost and low complexity. The data rate of the terminal devices may be from several kbps up to several Mbps. Conventional technologies mainly focus on grant free transmission for the terminal devices in RRC_CONNECTED mode.

According to embodiments of the present disclosure, the network device reserves some cell identities for some neighbor network devices and transmits mapping information indicating the cell identities in release information to the terminal device. If the terminal device moves to a neighbor network device, the terminal device determines whether the neighbor network device is in the mapping information. If it is in the mapping information, the terminal device is able to perform the grant free transmission using the reserved cell identity.

Fig. 1 illustrates a schematic diagram of a communication system in which embodiments of the present disclosure can be implemented. The communication system 100, which is a part of a communication network, comprises a terminal device 110-1, a terminal device 110-2, ...., a terminal device 110-N, which can be collectively referred to as “terminal device (s) 110. ” The communication system 100 further comprises a network device 120-1, a network device 120-2, a network device 120-3, ...., a network device 120-M, which can be collectively referred to as “network device (s) 120. ”

In the communication system 100, the terminal device 110 and the network device 120 can communicate data and control information to each other. The number of devices shown in Fig. 1 is given for the purpose of illustration without suggesting any limitations.

Communications in the communication system 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) and the fifth generation (5G) and on 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 Divided Multiple Address (CDMA) , Frequency Divided Multiple Address (FDMA) , Time Divided Multiple Address (TDMA) , Frequency Divided Duplexer (FDD) , Time Divided Duplexer (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Divided Multiple Access (OFDMA) and/or any other technologies currently known or to be developed in the future.

Embodiments of the present disclosure will be described in detail below. Reference is first made to Fig. 2, which shows a signaling chart illustrating interactions between a terminal device and network devices according to some example embodiments of the present disclosure. Only for the purpose of discussion, the process 200 will be described with reference to Fig. 1. The process 200 may involve a terminal device 110, a network device 120-1 and a network device 120-2 in Fig. 1. It should be noted that the network devices 120-1 and 120-2 can be interchangeable.

The network device 120-1 obtains 2005 mapping information. The mapping information indicates one or more cell identities associated with one or more neighbor network devices (for example, the network devices 120-2 and 120-3) . In some embodiments, the network device 120-1 may reserve some cell identifiers for the terminal device 110-1. In an example embodiment, the mapping information may be configured by an operation, admiration and maintenance (OAM) device. In this way, the terminal device is able to perform the grant free transmission using the reserved cell identity.

In some embodiments, the mapping information may be a mapping table. Table 1 below shows an example of the mapping table. It should be noted that the contents in Table 1 are only examples not limitations.

Table 1

Neighbor Network Device	Cell Identity
Network device 120-2	Cell Identity-2
Network device 120-3	Cell Identity-3

Table 2 shows codes for generating the mapping table. It also should be noted that the codes in Table 2 are examples. The mapping table can be generated using any suitable codes.

Table 2

If the network device 120-1 determines to release the connection with the terminal device 110-1, the network device 120-1 generates 2010 the release information which comprises the mapping information. For example, the network device 120-1 may generate the RRC_Release message comprising the mapping information.

The network device 120-1 transmits 2015 the release information to the terminal device 110-1. If the mapping information is not allocated by the current camping network device, but by the last CONNECTED state network device, the cell identities in the mapping information may be conflict. In some embodiments, the cell identities allocated by different network devices for their neighbor network devices may not be overlapped. Alternatively or in addition, the cell identities allocated by different network devices for their neighbor network devices maybe overlapped.

In some embodiments, the network device 120-1 may also transmit 2020 the mapping information to the neighbor network device (for example, the network devices 120-2 and 120-3) . In addition, the network device 120-1may transmit the context of the terminal device 110-1 along with the mapping information. The term “context of the terminal device” or “UE context” refers to a profile of traffic on the terminal device. The context of the terminal device may be a block of information in a network device associated to one active terminal device. The block of information may contain the necessary information required to maintain Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) services towards the active terminal device.

The terminal device 110-1 may move to neighbor cells and connect with other network devices (for example, the network devices 120-2 and 120-3) . Only for the purpose of illustrations, the terminal device 110-1 may move towards to the network device 120-2. The network device 120-2 may broadcast 2025 its system information to the terminal device 110-1. The system information may comprise an index of the network device 120-2.

The terminal device 110-1 determines 2030 whether the one or more neighbor network devices comprise the network device 120-2 based on the mapping information. For example, the terminal device 110-1 may determine whether the index of the network device 120-2 is in the mapping table.

The terminal device 110-1 establishes the connection with the network device 120-2 based on the determination. For examples, if the one or more neighbor network devices comprise the network device 120-2, the terminal device 110-1 does not need to update the mapping information. The terminal device 110-1 may obtain a target cell identity (for example, a C-RNTI or L-RNTI) of the network device 120-2 from the mapping information. The terminal device 110-1 may perform inactive grant free transmission using the target cell identity. In this way, the terminal device is able to perform the grant free transmission using the reserved cell identity.

In other embodiments, the one or more neighbor network devices may not comprise the network device 120-2. In this case, the terminal device 110-1 may not able to perform the grant free transmission directly. The terminal device 110-1 may perform an update for radio access network (RAN) -based notification area. For example, the terminal device 110-1 may report 2025 its location change. The network device 120-2 may transmit the target cell identity to the terminal device 110-1. The terminal device 110-1 may perform the transmission using the received target cell identity.

The network device 120-2 may transmit 2030 further mapping information to the terminal device 110-1. For example, the terminal device 110-1 may have established a RRC connection with the network device 120-2. The network device 120-2 may also determine further mapping information indicating other cell identities associated with other network devices. If the network device 120-2 determines to release the connection with the terminal device 110-1, the network device 120-2 may generate further release information comprising the further mapping information. The network 120-2 may transmit the further release information which comprises the further mapping information.

Fig. 3 shows a signaling chart illustrating interactions between a terminal device and network devices according to some example embodiments of the present disclosure. Only for the purpose of discussion, the process 300 will be described with reference to Fig. 1. The process 300 may involve the terminal device 110-1 and the network device 120-1. It should be noted that the network device can be any suitable network devices.

The terminal device 110-1 may transmit 3010 its type information to the network device 120-1. The type information may indicate that whether the terminal device 110-1 is fixed or nomadic. For example, if the terminal device 110-1 is an industry sensor, the type information may indicate that the terminal device 110-1 is fixed. The terminal device 110-1 may transmit the type information automatically. In other embodiments, the network device 120-1 may transmit 3005 a request for the type information and the terminal device 110-1 may transmit the type information after receiving the request.

The network device 120-1 may determine whether the terminal device 110-1 is fixed or nomadic. In some embodiments, if the terminal device 110-1 is fixed, the network device 120-1 may generate 3015 configuration information for the terminal device 110-1. For example, the configuration information may comprise an indication to deactivate the measurement at the terminal device 110-1. The configuration information may also comprise grant free radio resource allocated to the terminal device 110-1. In other embodiments, the configuration information may comprise the number of blind retransmissions. The network device 120-1 may transmit 3020 the configuration information to the terminal device 110-1. The configuration information may be transmitted in RRC signaling. Alternatively or in addition, the configuration information may be broadcasted in system information.

The network device 120-1 may determine a light radio network temporary identifier (L-RNTI) for the terminal device 110-1 if the terminal device 110-1 is fixed. The network device 120-1 may transmit 3025 the L-RNTI in the release information to the terminal device 110-1. The L-RNTI may be a certain length of identity to indicate the terminal device 110-1 the identity of the serving network device 120-1. The L-RNTI may be any suitable lengths, for example, be 4bits, 8bits, 16bits, 24bits, 32bits, or 40bits.

In an example embodiment, different from the C-RNTI, the terminal device 110-1 may not scramble uplink information with the L-RNTI. The terminal device 110-1 may add 3030 the L-RNTI in a media access control (MAC) protocol data unit (PDU) . In this way, the uplink transmission can be distinguished according to the MAC layer not the physical layer. Referring to Fig. 4A, Fig. 4A shows an example structure of MAC PDU 410 with the L-RNTI. As shown in Fig. 4A, the L-RNTI 400 may comprise 24 bits. Each portion of the L-RNTI (i.e., 400-1, 400-2 and 400-3) may occupy 1 byte. It should be noted that the length of the L-RNTI may be any suitable lengths.

In some embodiments, the terminal device may generate 3035 a MAC header to indicate that the L-RNTI is used. For example, a reserved value may be used to identify the L-RNTT. Table 3 below shows the MAC header. As shown in Table 3, one of the reserved values 33-51 may be used to identify the L-RNTT, for example, 33. The CCCH stands for common control channel. The PHR stands for power headroom report. The BSR stands for buffer status report.

Table 3

Index	LCID values
0	CCCH of size 64 bits
1–32	Identity of the logical channel
33–51	Reserved
52	CCCH of size 48 bits
53	Recommended bit rate query
54	Multiple Entry PHR (four octets C _i)
55	Configured Grant Confirmation
56	Multiple Entry PHR (one octet C _i)
57	Single Entry PHR
58	C-RNTI
59	Short Truncated BSR
60	Long Truncated BSR
61	Short BSR
62	Long BSR
63	Padding

Now with the reference to Fig. 4B, the terminal device 110-1 may generate the header 410 and add the L-RNTI to the MAC PDU 420. It should be noted that the structures shown in Fig. 4B are only examples not limitations. The terminal device 110-1 may transmit 3040 the MAC PDU along with the MAC header to the network device 120-1.

In some embodiments, if the terminal device 110-1 is in RRC_IDLE/RRC_INACTIVE mode, the terminal device 110-1 is not uplink synchronized with the network device 120-1. For example, the network device 120-1may allocate the grant free radio resource with gaps in time and frequency domain for the terminal device 110-1. In other embodiments, the terminal device 110-1 may evaluate timing advance (TA) based on path loss. In a further embodiment, the network device 120-1 may broadcast the accurate global navigation satellite system (GNSS) time in system information, for example SIB 9. If the terminal device 110-1 is equipped with GNSS, the terminal device 120-1 may determine the time difference between SIB9 GNSS time and the GNSS time from satellite. The time difference can be deduced to the TA.

In some embodiments, if the terminal device 110-1 supports a RRC state where small data transmission and grant free transmission is applied, the network device 120-1 may generate further configuration information of light discontinuous reception (LDRX) . The network device 120-1 may transmit the further configuration information in the release information. Alternatively or in addition, the network device 120-1 may transmit the further configuration information in RRC signaling, for example, RRC_Reconfiguration message. The terminal device 110-1 may support an inactive RRC state where small data transmission and grant free transmission is applied. Alternatively, a new RRC state where small data transmission and grant free transmission is applied may be introduced, for example, RRC_Hibernation state. The name of this new RRC state can be any suitable names. This new RRC state applies small data transmission and grant free transmission for new radio light scenarios. In order for the long term DRX cycle applicable to long wake up cycle industry sensors, if the terminal device 110-1 is in the RRC_H state, the terminal device 110-1 may monitor physical downlink control channel (PDCCH) in the LDRX inactive cycle. If the further configuration information is transmitted in the RRC_Reconfiguration message, the terminal device 110-1 may not use the LDRX in RRC-CONNECTED mode but in RRC_IDLE/RRC_INACTIVE mode only. Table 4 below shows examples of LDRX.

Table 4

In some embodiments, if the terminal device 110-1 is in RRC_IDLE/INACTIVE, there is no feedback available. The terminal device 110-1 may perform blind retransmission. For example, the terminal device 110-1 may retransmit the packet for certain times. The number of re-transmissions may configured by the network device 120-1 in the RRC_Release message, or in the RRC_Rconfiguration message when the terminal device 110-1is in RRC_CONNECTED. Alternatively or in addition, the number of retransmissions may be pre-configured.

Fig. 5 shows a flowchart of an example method 500 in accordance with an embodiment of the present disclosure. The method 500 can be implemented at a network device 120-1 as shown in Fig. 1.

At block 510, the network device 120-1 obtains mapping information. The mapping information indicates one or more cell identities associated with one or more neighbor network devices (for example, the network devices 120-2 and 120-3) . In some embodiments, the network device 120-1 may reserve some cell identifiers for the terminal device 110-1. In an example embodiment, the mapping information may be configured by an operation, admiration and maintenance (OAM) device.

At block 520, if the network device 120-1 determines to release the connection with the terminal device 110-1, the network device 120-1 generates the release information which comprises the mapping information. For example, the network device 120-1 may generate the RRC_Release message comprising the mapping information.

At block 530, the network device 120-1 transmits the release information to the terminal device 110-1. If the mapping information is not allocated by the current camping network device, but by the last CONNECTED state network device, the cell identities in the mapping information may be conflict. In some embodiments, the cell identities allocated by different network devices for their neighbor network devices may not be overlapped. Alternatively or in addition, the cell identities allocated by different network devices for their neighbor network devices maybe overlapped.

In some embodiments, the network device 120-1 may also transmit the mapping information to the neighbor network device (for example, the network devices 120-2 and 120-3) . In addition, the network device 120-1may transmit the context of the terminal device 110-1 along with the mapping information.

In some embodiments, the network device 120-1 may receive type information of the terminal device 110-1. The type information may indicate that whether the terminal device 110-1 is fixed or nomadic. The type information can be transmitted automatically. In other embodiments, the network device 120-1 may transmit a request for the type information.

The network device 120-1 may determine whether the terminal device 110-1 is fixed or nomadic. In some embodiments, if the terminal device 110-1 is fixed, the network device 120-1 may generate configuration information for the terminal device 110-1. For example, the configuration information may comprise an indication to deactivate the measurement at the terminal device 110-1. The configuration information may also comprise grant free radio resource allocated to the terminal device 110-1. In other embodiments, the configuration information may comprise the number of blind retransmissions. The network device 120-1 may transmit the configuration information to the terminal device 110-1. The configuration information may be transmitted in RRC signaling. Alternatively or in addition, the configuration information may be broadcasted in system information.

The network device 120-1 may determine a light radio network temporary identifier (L-RNTI) for the terminal device 110-1 if the terminal device 110-1 is fixed. The network device 120-1 may transmit the L-RNTI in the release information to the terminal device 110-1. The L-RNTI may be a certain length of identity to indicate the terminal device 110-1 the identity of the serving network device 120-1. The L-RNTI may be any suitable lengths, for example, be 4bits, 8bits, 16bits, 24bits, 32bits, or 40bits.

In an example embodiment, different from the C-RNTI, the terminal device 110-1 may not scramble uplink information with the L-RNTI. The terminal device 110-1 may add the L-RNTI in a media access control (MAC) protocol data unit (PDU) . In this way, the uplink transmission can be distinguished according to the MAC layer not the physical layer. In some embodiments, the terminal device may generate a MAC header to indicate that the L-RNTI is used. For example, a reserved value may be used to identify the L-RNTT.

In some embodiments, if the terminal device 110-1 is in RRC_IDLE/RRC_INACTIVE mode, the terminal device 110-1 is not uplink synchronized with the network device 120-1. For example, the network device 120-1may allocate the grant free radio resource with gaps in time and frequency domain for the terminal device 110-1. In a further embodiment, the network device 120-1 may broadcast the accurate global position system (GPS) time in system information, for example SIB 9.

In some embodiments, the network device 120-1 may generate further configuration information of light discontinuous reception (LDRX) . The network device 120-1 may transmit the further configuration information in the release information. Alternatively or in addition, the network device 120-1 may transmit the further configuration information in RRC signaling, for example, RRC_Reconfiguration message.

Fig. 6 shows a flowchart of an example method 600 in accordance with an embodiment of the present disclosure. Only for the purpose of illustrations, the method 600 can be implemented at a terminal device 110-1 as shown in Fig. 1.

At block 610, the terminal device 110-1 receives the release information comprising the mapping information from the network device 120-1. The mapping information indicates one or more cell identities associated with one or more neighbor network devices (for example, the network devices 120-2 and 120-3) . In some embodiments, the mapping information may be a mapping table.

At block 620, the terminal device 110-1 determines whether one or more neighbor network devices comprise the network device 120-2 if the terminal device 110-1 determines to connect with the network device 120-2.

At block 630, the terminal device 110-1 establishes the connection with the network device 120-2 based on the determination. For examples, if the one or more neighbor network devices comprise the network device 120-2, the terminal device 110-1 does not need to update the mapping information. The terminal device 110-1 may obtain a target cell identity (for example, a C-RNTI or L-RNTI) of the network device 120-2 from the mapping information. The terminal device 110-1 may perform inactive grant free transmission using the target cell identity.

In other embodiments, the one or more neighbor network devices may not comprise the network device 120-2. In this case, the terminal device 110-1 may not able to perform the grant free transmission directly. The terminal device 110-1 may perform an update for radio access network (RAN) -based notification area. For example, the terminal device 110-1 may report 2025 its location change. The terminal device 110-1 may receive the target cell identity to the network device 120-2. The terminal device 110-1 may perform the transmission using the received target cell identity.

In other embodiments, the terminal device 110-1 may receive further mapping information from the network device 120-2. For example, the terminal device 110-1 may have established a RRC connection with the network device 120-2. The further mapping information may indicate other cell identities associated with other network devices. The terminal device 110-1 may receive further release information comprising the further mapping information.

In some embodiments, the terminal device 110-1 may transmit its type information to the network device 120-1. The type information may indicate that whether the terminal device 110-1 is fixed or nomadic. For example, if the terminal device 110-1 is an industry sensor, the type information may indicate that the terminal device 110-1 is fixed. The terminal device 110-1 may transmit the type information automatically. In other embodiments, the network device 120-1 may transmit 3005 a request for the type information and the terminal device 110-1 may transmit the type information after receiving the request.

In some embodiments, the terminal device 110-1 may receive configuration information from the network device 120-1. For example, the configuration information may comprise an indication to deactivate the measurement at the terminal device 110-1. The configuration information may also comprise grant free radio resource allocated to the terminal device 110-1. In other embodiments, the configuration information may comprise the number of blind retransmissions. The configuration information may be transmitted in RRC signaling. Alternatively or in addition, the configuration information may be broadcasted in system information.

The terminal device 110-1 may add the L-RNTI in a media access control (MAC) protocol data unit (PDU) . In this way, the uplink transmission can be distinguished according to the MAC layer not the physical layer. In some embodiments, the terminal device may generate a MAC header to indicate that the L-RNTI is used. For example, a reserved value may be used to identify the L-RNTT. Table 3 below shows the MAC header.

In some embodiments, if the terminal device 110-1 is in RRC_IDLE/RRC_INACTIVE mode, the terminal device 110-1 is not uplink synchronized with the network device 120-1. In some embodiments, the terminal device 110-1 may evaluate timing advance (TA) based on path loss. In a further embodiment, the network device 120-1 may broadcast the accurate global position system (GPS) time in system information, for example SIB 9. If the terminal device 110-1 is equipped with GPS, the gap between SIB9 GPS time and the GPS time from satellite can be deduced to the TA.

The terminal device 110-1 may receive the further configuration information in the release information. Alternatively or in addition, the further configuration information may be transmitted in RRC signaling, for example, RRCReconfiguration message. The terminal device 110-1 may support a RRC state where small data transmission and grant free transmission is applied. For example, the terminal device 110-1 may support the inactive RRC state where small data transmission and grant free transmission is applied. Alternatively, a new RRC state where small data transmission and grant free transmission is applied may be introduced, for example, RRC_Hibernation state. In order for the long term DRX cycle applicable to long wake up cycle industry sensors, if the terminal device 110-1 is in the RRC_H state, the terminal device 110-1 may monitor physical downlink control channel (PDCCH) in the LDRX inactive cycle. If the further configuration information is transmitted in the RRC_Reconfiguration message, the terminal device 110-1 may not use the LDRX in RRC-CONNECTED mode but in RRC_IDLE/RRC_INACTIVE mode only.

Fig. 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 can be considered as a further example implementation of the terminal device 110, the network device 120, the network device 130, or the transition network device 310 as shown in Fig. 1 and Fig. 3. Accordingly, the device 700 can be implemented at or as at least a part of the terminal device 110, the network device 120, the network device 130, or the transition network device 310.

As shown, the device 700 includes a processor 710, a memory 720 coupled to the processor 710, a suitable transmitter (TX) and receiver (RX) 740 coupled to the processor 710, and a communication interface coupled to the TX/RX 740. The memory 720 stores at least a part of a program 730. The TX/RX 740 is for bidirectional communications. The TX/RX 740 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , or Uu interface for communication between the eNB and a terminal device.

The program 730 is assumed to include program instructions that, when executed by the associated processor 710, enable the device 700 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Fig. 2 and Figs. 4 to 7. The embodiments herein may be implemented by computer software executable by the processor 710 of the device 700, or by hardware, or by a combination of software and hardware. The processor 710 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 710 and memory 720 may form processing means 850 adapted to implement various embodiments of the present disclosure.

The memory 720 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 720 is shown in the device 700, there may be several physically distinct memory modules in the device 700. The processor 710 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 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.

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 representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods 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.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to any of Fig. 2 and Figs. 4 to 7. 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. These program codes 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 codes, 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.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine 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 machine 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. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language 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 method for communication comprising:

obtaining, at a network device, mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with a terminal device;

in accordance with a determination that a connection with the terminal device is to be released, generating release information comprising the mapping information; and

transmitting the release information to the terminal device.
The method of claim 1, further comprising:

transmitting the mapping information to the at least one neighbor network device.
The method of claim 2, further comprising:

transmitting, to the at least one neighbor network device, a context of the terminal device along with the mapping information.
The method of claim 1, wherein obtaining the mapping information comprises:

receiving the mapping information from an operation, admiration and maintenance (OAM) device.
The method of claim 1, further comprising:

receiving, from the terminal device, type information indicating whether the terminal device is fixed or nomadic.
The method of claim 5, further comprising:

in accordance with the type information indicating that the terminal device is fixed, generating configuration information of the terminal device, the configuration information comprising at least one of: an indication to deactivate measurement at the terminal device, a grant free radio resource, or the number of blind retransmissions; and

transmitting the configuration information to the terminal device.
The method of claim 6, wherein transmitting the configuration information comprises:

transmitting the configuration information in radio resource controlling (RRC) signaling; or

broadcasting the configuration information in system information.
The method of claim 5, wherein transmitting the release information to the terminal device comprises:

in accordance with the type information indicating that the terminal device is fixed, determining a light radio network temporary identity for the terminal device; and

transmitting, to the terminal device, the release information comprising the light radio network temporary identity so that the light radio network temporary identity is used by the terminal device without scrambling.
The method of claim 1, further comprising:

in accordance with a determination that the terminal device supports a radio resource control (RRC) state where small data transmission and grant free transmission is applied, generating further configuration information of light discontinuous reception so that a physical downlink control channel is monitored by the terminal device during a light discontinuous reception inactive cycle; and

transmitting the further configuration information of the light discontinuous reception to the terminal device.
The method of claim 9, wherein transmitting the further configuration information comprises:

transmitting, to the terminal device, the further configuration in the release information; or

transmitting, to the terminal device, the further configuration in radio resource control reconfiguration information.
The method of claim 1, further comprising:

in accordance with a determination that the terminal device is asynchronized with the network device, allocating a grant free radio resource with gaps in time and frequency domain for the terminal device; and

transmitting an indication of the grant free radio resource to the terminal device.
The method of claim 1, wherein the at least one cell identity comprises a cell-radio network temporary identifier or a light radio network temporary identifier.
A method for communication comprising:

receiving, at a terminal device, release information from a network device, the release information comprising mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with the terminal device;

in accordance with a determination that the terminal device is to be connected with a further network device, determining, based on the mapping information, whether the at least one neighbor network device comprises the further network device; and

establishing the connection with the further network device for transmission based at least in part on the determination.
The method of claim 13, wherein establishing the connection with the further network device comprises:

in accordance with the determination that the at least one neighbor network device comprises the further network device, determining a target cell identity associated with the further network device from the at least one cell identity based on the mapping information; and

establishing the connection with the further network device using the target cell identity .
The method of claim 13, wherein establishing the connection with the further network device comprises:

in accordance with the determination that the at least one neighbor network device excludes the further network device, performing an update for radio access network (RAN) -based notification area;

receiving a target cell identity from the further network device; and

establishing the connection with the further network device using the target cell identity.
The method of claim 15, further comprising:

receiving, the further network device, further mapping information comprising at least one further cell identity associated with at least one further neighbor network device, the at least one further cell identity to be used by the terminal device to connect with the at least one further neighbor network device.
The method of claim 13, further comprising:

transmitting, to the network device, type information indicating whether the terminal device is fixed or nomadic.
The method of claim 17, further comprising:

in accordance with that the terminal device is fixed, receiving configuration information of the terminal device from the network device, the configuration information comprising at least one of:

an indication to deactivate measurement at the terminal device,

a grant free radio resource, or

the number of blind retransmissions.
The method of claim 18, wherein receiving the configuration information comprises:

receiving the configuration information in radio resource controlling (RRC) signaling; or

receiving the configuration information broadcasted in system information.
The method of claim 13, wherein establishing the connection with the further network device comprises:

in accordance with that the terminal device is fixed, obtaining a light radio network temporary identity from the release information;

adding the light radio network temporary identity in a media access control (MAC) protocol data unit (PDU) ;

generating a MAC header indicating the light radio network temporary identity; and

transmitting the MAC PDU along with the MAC header.
The method of claim 13, further comprising:

receiving, from the network device, further configuration information of light discontinuous reception; and

in accordance with a determination that the terminal device supports a radio resource control (RRC) state where small data transmission and grant free transmission is applied, monitoring a physical downlink control channel during a light discontinuous reception inactive cycle.
The method of claim 21, wherein receiving the further configuration comprises:

receiving the further configuration information in the release information; or

receiving the further configuration in radio resource control reconfiguration information.
The method of claim 13, further comprising:

in accordance with a determination that the terminal device is asynchronized with the network device, evaluating a timing advance based on path loss.
The method of claim 13, further comprising:

in accordance with a determination that the terminal device is asynchronized with the network device, receiving first global navigation satellite system, GNSS, time in system information from the network device;

obtaining second GNSS time from a satellite;

determining a time difference between the first GNSS time in the system information and the second GNSS time from the satellite; and

determining a timing advance based on the time difference.
The method of claim 13, further comprising:

obtaining the number of retransmissions; and

performing blind retransmission based on the number of retransmissions.
A network device, comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the network device to perform:

obtaining mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with a terminal device;

in accordance with a determination that a connection with the terminal device is to be released, generating release information comprising the mapping information; and

transmitting the release information to the terminal device.
The network device of claim 26, wherein the network device is further caused to perform:

transmitting the mapping information to the at least one neighbor network device.
The network device of claim 27, wherein the network device is further caused to perform:

transmitting, to the at least one neighbor network device, a context of the terminal device along with the mapping information.
The network device of claim 26, wherein obtaining the mapping information comprises:

receiving the mapping information from an operation, admiration and maintenance (OAM) device.
The network device of claim 26, wherein the network device is further caused to perform:

receiving, from the terminal device, type information indicating whether the terminal device is fixed or nomadic.
The network device of claim 30, wherein the network device is further caused to perform:

in accordance with the type information indicating that the terminal device is fixed, generating configuration information of the terminal device, the configuration information comprising at least one of: an indication to deactivate measurement at the terminal device, a grant free radio resource, or the number of blind retransmissions; and

transmitting the configuration information to the terminal device.
The network device of claim 31, wherein transmitting the configuration information comprises:

transmitting the configuration information in radio resource controlling (RRC) signaling; or

broadcasting the configuration information in system information.
The network device of claim 30, wherein transmitting the release information to the terminal device comprises:

in accordance with the type information indicating that the terminal device is fixed, determining a light radio network temporary identity for the terminal device; and

transmitting, to the terminal device, the release information comprising the light radio network temporary identity so that the light radio network temporary identity is used by the terminal device without scrambling.
The network device of claim 26, wherein the network device is further caused to perform:

in accordance with a determination that the terminal device supports a radio resource control (RRC) state where small data transmission and grant free transmission is applied, generating further configuration information of light discontinuous reception so that a physical downlink control channel is monitored by the terminal device during a light discontinuous reception inactive cycle; and

transmitting the further configuration information of the light discontinuous reception to the terminal device.
The network device of claim 34, wherein transmitting the further configuration information comprises:

transmitting, to the terminal device, the further configuration in the release information; or

transmitting, to the terminal device, the further configuration in radio resource control reconfiguration information.
The network device of claim 26, wherein the network device is further caused to perform:

in accordance with a determination that the terminal device is asynchronized with the network device, allocating a grant free radio resource with gaps in time and frequency domain for the terminal device; and

transmitting an indication of the grant free radio resource to the terminal device.
The network device of claim 26, wherein the at least one cell identity comprises a cell-radio network temporary identifier or a light radio network temporary identifier.
A terminal device, comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the terminal device to perform:

receiving release information from a network device, the release information comprising mapping information indicating at least one cell identity associated with at least one neighbor network device for use in a connection with the terminal device;

in accordance with a determination that the terminal device is to be connected with a further network device, determining, based on the mapping information, whether the at least one neighbor network device comprises the further network device; and

establishing the connection with the further network device for transmission based at least in part on the determination.
The terminal device of claim 38, wherein establishing the connection with the further network device comprises:

in accordance with the determination that the at least one neighbor network device comprises the further network device, determining a target cell identity associated with the further network device from the at least one cell identity based on the mapping information; and

establishing the connection with the further network device using the target cell identity.
The terminal device of claim 38, wherein establishing the connection with the further network device comprises:

in accordance with the determination that the at least one neighbor network device excludes the further network device, performing an update for radio access network (RAN) -based notification area;

receiving a target cell identity from the further network device; and

establishing the connection with the further network device using the target cell identity.
The terminal device of claim 38, wherein the terminal device is caused to perform:

receiving, the further network device, further mapping information comprising at least one further cell identity associated with at least one further neighbor network device, the at least one further cell identity to be used by the terminal device to connect with the at least one further neighbor network device.
The terminal device of claim 38, wherein the terminal device is caused to perform:

transmitting, to the network device, type information indicating whether the terminal device is fixed or nomadic.
The terminal device of claim 38, wherein the terminal device is caused to perform:

in accordance with that the terminal device is fixed, receiving configuration information of the terminal device from the network device, the configuration information comprising at least one of:

an indication to deactivate measurement at the terminal device,

a grant free radio resource, or

the number of blind retransmissions.
The terminal device of claim 43, wherein receiving the configuration information comprises:

receiving the configuration information in radio resource controlling (RRC) signaling; or

receiving the configuration information broadcasted in system information.
The terminal device of claim 38, wherein establishing the connection with the further network device comprises:

in accordance with that the terminal device is fixed, obtaining a light radio network temporary identity from the release information;

adding the light radio network temporary identity in a media access control (MAC) protocol data unit (PDU) ;

generating a MAC header indicating the light radio network temporary identity; and

transmitting the MAC PDU along with the MAC header.
The terminal device of claim 38, wherein the terminal device is caused to perform:

receiving further configuration information of light discontinuous reception; and

in accordance with a determination that the terminal device supports a radio resource control (RRC) state where small data transmission and grant free transmission is applied,, monitoring a physical downlink control channel during a light discontinuous reception inactive cycle.
The terminal device of claim 46, wherein receiving the further configuration comprises:

receiving the further configuration information in the release information; or

receiving the further configuration in radio resource control reconfiguration information.
The terminal device of claim 38, wherein the terminal device is caused to perform:

in accordance with a determination that the terminal device is asynchronized with the network device, evaluating a timing advance based on path loss.
The terminal device of claim 38, wherein the terminal device is caused to perform:

in accordance with a determination that the terminal device is asynchronized with the network device, receiving first global navigation satellite system, GNSS, time in system information from the network device;

obtaining second GNSS time from a satellite;

determining a time difference between the first GNSS time in the system information and the second GNSS time from the satellite; and

determining a timing advance based on the time difference.
The terminal device of claim 38, wherein the terminal device is caused to perform:

obtaining the number of retransmissions; and

performing blind retransmission based on the number of retransmissions.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 1-12.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 13-25.