Improved handling of temporarily unreachable zones in wireless communication networks

Abstract

The present disclosure relates to a serving wireless communication node (AP1) in a wireless communication system (1), wherein the serving node (AP1) is adapted to determine that a served user terminal (2) is going to enter a zone (3) which changes between being reachable and unreachable for the serving node (AP1), and to predict data (x m+1 ...x n ) to be transmitted to the user terminal (2) for at least a part of the time the user terminal (2) is in the zone (3) and unreachable for the serving node (AP1). When the zone (3) is reachable, the serving node (AP1) is adapted to transfer the predicted data (x m+1 ...x n ) to a cache node (AP C ) located within the zone (3), so that the cache node (AP C ) can transfer the predicted data (x m+1 ...x n ) to the user terminal (3) when the user terminal (2) is in the zone (3) and unreachable for the serving node (AP1).

Description

Technical Field

[0001] This disclosure relates to maintaining service in a wireless communication network for a user terminal even when the user terminal enters an area that is transitioning between accessible and inaccessible for the service node. Background Technology

[0002] Fifth-generation wireless networks (5G) must provide high-speed data streams to everyone, anywhere, at all times. To meet this demand, large bandwidth is required. Here, it primarily focuses on millimeter-wave-based, potentially massively multi-input multiple-output (MMIMO) links as a key enabler to achieve sufficiently large bandwidth / data rates. Importantly, the existence of very wide bandwidth makes it possible to include wireless backhaul transmissions in the same spectrum as the wireless access. Therefore, in such a setup, there is a sharing of radio resources between the access and backhaul links, meaning that the access and backhaul links compete for the same pool of radio resources.

[0003] For this reason, 3GPP has considered integrated access and backhaul (IAB) network configurations where access points (APs) (e.g., fiber-connected) provide wireless backhaul and access connectivity to other APs and customer premises equipment (CPEs) within their cell area. The access integrated backhaul link can be a single-hop or multi-hop link within the IAB network. In a multi-hop deployment, the IAB network from one AP is relayed along a specific route from AP to AP until that IAB network reaches its destination. Therefore, the IAB network can have a star topology, where multiple APs wirelessly backhaul to fiber-connected APs via direct single-hop connections, or a cascaded configuration, where APs wirelessly connect to fiber-connected APs in a multi-hop manner.

[0004] Today, most mobile services worldwide involve video, and a key aspect of video communication is avoiding disconnections. For example, nobody likes being disconnected while watching their favorite movie in an elevator. In other examples, such as mission-critical video used by first responders in a temporary blind spot outside network coverage, or security surveillance video used by medical staff in a hospital when they lose network connectivity while entering an elevator, service disconnections can lead to loss of life. Therefore, it is desirable to enhance wireless systems to maintain continuous video streaming in temporary blind spots. Consider a temporary blind spot as an area accessible only by an access point (AP) for a limited time, such as an elevator where the AP is accessible when the door is open but not when it is closed. In such places, temporary disconnections can occur, resulting in low quality of service for user terminals.

[0005] Therefore, it is desirable to provide improved data coverage for temporarily inaccessible areas in wireless communication networks. Summary of the Invention

[0006] The purpose of this disclosure is to provide improved data coverage for temporarily inaccessible areas in wireless communication networks.

[0007] This objective is achieved by a serving wireless communication node in a wireless communication system, wherein the serving node is adapted to determine that a served user terminal will enter a zone that varies between reachable and inaccessible for the serving node. The serving node is also adapted to predict data to be transmitted to the user terminal during at least a portion of the time when the user terminal is in that zone and is inaccessible for the serving node.

[0008] When the zone is accessible, the service node is adapted to transmit prediction data to a cache node located within the zone, so that when the user terminal is in the zone and is inaccessible to the service node, the cache node can transmit prediction data to the user terminal.

[0009] This allows user terminals to continue receiving data services even when they are inaccessible from the service node. This provides reliable and uninterrupted data streaming. This means maintaining continuous communication, or at least minimizing disconnection periods, in temporarily inaccessible areas such as elevators. Furthermore, it reduces end-to-end transmission latency for long files. This results in better quality of service and higher end-to-end throughput for user terminals. If the inaccessible area has a very poor signal-to-noise ratio (SNR) and is almost a dead zone, the network will be offloaded because the service node does not need to allocate significant resources to links with very poor SNRs. It also reduces the need for transmissions to multiple service nodes.

[0010] Depending on the context, the service node is adapted to initiate a handover from the service node to the cache node for the user terminal.

[0011] This allows cache nodes to take over from service nodes, ensuring that user terminals can continue to receive data services even when they are inaccessible from the service node.

[0012] In some respects, service nodes are adapted to determine whether to initiate a handover based on location information.

[0013] In this way, the handover is initiated only when the area is close to inaccessible territory.

[0014] According to some aspects, the serving node is adapted to send measurement configurations to the user terminal, which include at least information about which reference signal from the cache node should be measured and on which radio resources the measurement should be performed. This enables the user terminal to send measurement reports to the serving node, which is then adapted to determine whether to initiate a handover based on the measurement reports.

[0015] In this way, a safe and controlled transfer was achieved.

[0016] According to some aspects, the service node is adapted to initiate handover by sending a handover request to the cache node, wherein the handover request includes information related to the user terminal. According to some further aspects, the information related to the user terminal includes at least one of the following: user terminal identifier, processor capability, and number of antenna ports.

[0017] In this way, the identity and capacity of the user terminal are notified to the cache node, enabling reliable and efficient data transmission from the cache node to the user terminal.

[0018] According to some aspects, the service node is adapted to receive handover confirmation from the cache node, send a handover command to the user terminal, and then transmit the prediction data to the cache node.

[0019] Depending on the context, the received handover confirmation includes information related to the cache node.

[0020] According to some sources, the information associated with a cache node includes at least one of the cell identifier and the cache node's RACH (Random Access Channel) configuration.

[0021] In this way, the handover can be performed reliably and efficiently, and the service node has all the necessary information about the cache node.

[0022] According to some aspects, the service node is adapted to notify other nodes of the adapted scheduling, where the adapted scheduling is due to the fact that cache nodes are prioritized when the zone is accessible, the service node performs a handover to the cache node and transmits the prediction data to the cache node.

[0023] This means that other nodes can be adapted to the current situation where cache nodes are prioritized.

[0024] According to some aspects, when the zone becomes accessible to the service node, the service node is adapted to receive information from the cache node about the predicted data that was sent to the user terminal when the user terminal was not accessible to the service node in the zone, and to perform a handover from the cache node to the service node for the user terminal.

[0025] This means notifying the service nodes that are taking over when and where to continue data transmission.

[0026] This objective is achieved through a cache node in a wireless communication system, wherein the cache node is located in a zone that alternates between reachability and inaccessibility with respect to the serving wireless communication node. The cache node is adapted to receive predicted data to be transmitted to the user terminal from the serving node for at least a portion of the time during which the user terminal is inaccessible with respect to the serving node, and to transmit the predicted data to the user terminal when the user terminal is in the zone and is inaccessible with respect to the serving node.

[0027] This allows user terminals to continue receiving data services even when they are inaccessible from the service node. This provides reliable and uninterrupted data streaming. This means maintaining continuous communication, or at least minimizing disconnection periods, in temporary inaccessible areas such as elevators. Furthermore, it reduces end-to-end transmission latency for long files. This results in better quality of service and higher end-to-end throughput for user terminals. If the inaccessible area has a very poor signal-to-noise ratio (SNR) and is almost a dead zone, the network is offloaded because the service node does not need to allocate significant resources to links with very poor SNRs. It also reduces the need for transmissions to multiple service nodes.

[0028] Furthermore, cache nodes are associated with the aforementioned advantages.

[0029] This objective is also achieved through methods and communication systems associated with the aforementioned advantages. Attached Figure Description

[0030] This disclosure will now be described in more detail with reference to the accompanying drawings, in which:

[0031] Figure 1 A schematic view of the wireless communication system according to the first example at a first moment is shown;

[0032] Figure 2 A schematic view of the wireless communication system according to the first example at a second time is shown;

[0033] Figure 3 A view of the wireless communication system according to the first example at a third time is schematically shown;

[0034] Figure 4 A view of the wireless communication system according to the first example at a fourth time is schematically shown;

[0035] Figure 5 A view of the wireless communication system according to the first example at a fifth time is schematically shown;

[0036] Figure 6 A view of the wireless communication system according to the second example at a fifth time is shown schematically;

[0037] Figure 7 A flowchart of the method according to an embodiment is shown; and

[0038] Figure 8 A flowchart of a method according to an embodiment is shown. Detailed Implementation

[0039] The aspects of this disclosure will now be described more fully below with reference to the accompanying drawings. However, the various devices, systems, computer programs, and methods disclosed herein may be implemented in many different forms and should not be construed as limited to the aspects set forth herein. The same reference numerals throughout refer to the same elements.

[0040] The terminology used herein is for describing aspects of this disclosure only and is not intended to limit the invention. 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.

[0041] Network densification leverages wireless backhaul; due to the relatively high installation cost of fiber optic links, relatively small access points (APs) need to be supported by high-speed LOS wireless backhaul links, which incentivizes so-called Integrated Access and Backhaul (IAB) networks.

[0042] Sometimes, an access point (AP) cannot reach a certain area. A temporary dead zone is defined as a zone that alternates between reachable and inaccessible in terms of signals transmitted from the serving node, and thus constitutes an area accessible to the AP only for a limited time period. The aim of such zones is to avoid disconnections or at least shorten the possible disconnection period. Examples of such zones include elevators, vehicle tunnels, trains, and areas with high service demand; this example pertains to elevators.

[0043] Based on the first example, refer to Figure 1 In the IAB network 10 included in the wireless communication system 1, there exists a first serving communication node in the form of a first access point AP1. According to some aspects, the serving node AP1 is connected via, for example... Figure 1 The fiber optic connection 14 or other type of connection shown is used to connect to the core network 13, or alternatively, wirelessly backhauled by another AP connected to the core network 13. The serving node AP1 is adapted to determine that the user terminal 2 being served will enter a zone 3 (here, inside elevator 11) that is transitioning between accessible and inaccessible for the serving node AP1. Such a user terminal 2 can be, for example, a mobile phone on which the user is following a streaming data stream x1, x2...x such as a movie or mission-critical video.m x m+1 ...x n x n+1 ...x N The data streams x1, x2...x are transmitted in streams. m x m+1 ...x n x n+1 ...x N A portion is held in buffer 12 of service node AP1. Figure 1 In the middle, user terminal 2 is approaching elevator 11, which is still closed.

[0044] Service node AP1 is then adapted to predict data x to be sent to user terminal 2 during at least a portion of the time when user terminal 2 is in zone 3 and is inaccessible to service node AP1. m+1 ...x n For certain types of data, this forecasting is mitigated, especially where video communication is of interest because it is pre-recorded and typically consists of long signals, with trending tweets and breaking news serving as seemingly plausible examples. For these reasons, unlike interactive applications such as games and voice calls, video communication can be forecasted and planned. In other words, soon most data traffic will be cacheable, meaning that data signals of interest for the near future can be stored at intermediate nodes to reduce backhaul load and transmission latency.

[0045] When the elevator doors open, zone 3 is reachable for service node AP1. Service node AP1 is then adapted to transmit the predicted data x. m+1 ...x n Transmitted to the cache node AP located in elevator 11 and zone 3 c According to some aspects, the cache node AP c Included in IAB network 10. Service node AP1 can only access cache node AP when the door of elevator 11 is open. c Otherwise, the signaling to the interior of elevator 11 is blocked by the door or because the elevator is moving between different floors.

[0046] In this way, such as Figure 3 As shown, when the elevator door closes, the cache node AP c Able to predict data x m+1 ...x n The data is transmitted to user terminal 3. At that time, user terminal 2 is located in zone 3 and is inaccessible to service node AP1.

[0047] The above can be implemented in many different ways; an example is given below. It should be noted that there are multiple alternatives for the different steps disclosed, and it is not necessary to perform all of them.

[0048] According to some sources, in the first step, when the door of elevator 11 opens, the cache node AP... c It is adapted to establish a wireless connection to the serving node AP1, for example, by performing a random access procedure.

[0049] According to some aspects, in the second step, the service node AP1 is adapted to initiate a request from the service node AP1 to the cache node AP for user terminal 2. c The handover process. Service node AP1 can be adapted to determine whether to initiate a handover based on user terminal location information. This information can be tracked and / or predicted, and a handover can be initiated when it is determined that user terminal 2 is near elevator 11.

[0050] Service node AP1 is adapted to send measurement configuration 4 to user terminal 2. Measurement configuration 4 includes at least information about the measurement to be performed from cache node AP. c The information on which reference signal and on which radio resources the measurement should be performed enables user terminal 2 to send measurement report 5 to serving node AP1, where serving node AP1 is adapted to determine whether to initiate handover based on measurement report 5.

[0051] Based on some aspects, service node AP1 is adapted to provide services to cache node AP. c A handover request 6 is sent to initiate the handover, wherein the handover request 6 includes information related to the user terminal 2, such as at least one of the user terminal identifier, processor capability, and number of antenna ports.

[0052] According to some aspects, in the third step, service node AP1 is adapted from cache node AP c Upon receiving the handover confirmation 7, a handover command 8 is sent to user terminal 2, and then to the cache node AP. c Transmit prediction data x m+1 ...x n .

[0053] Depending on several factors, such as if the cache node AP c If the handover confirmation was not previously known to service node AP1, then the received handover confirmation includes information from cache node AP. c Relevant information. According to some aspects, this information includes the cell identifier and information about the cache node AP. c At least one of the RACH (Random Access Channel) configuration information.

[0054] According to some aspects, the handover command sent to user terminal 2 includes information about the cache node AP. c Based on this information, user terminal 2 can access the high-speed cache node AP. c Without needing to read system information.

[0055] According to some aspects, in the fourth step, user terminal 2 performs random access and connects to the cache node AP. c This completes the handover. Then, as... Figure 4 As shown, the cache node AP c Supply user terminal 2 with its associated buffered prediction data x m+1 ...x n .

[0056] Finally, as Figure 5 As shown, when elevator 11 stops at different floors, the door opens, and user terminal 2 and cache node AP... c Both request access from the service node AP1. Then, upon connection, user terminal 2 receives the remainder of its signal, while the cache node AP... c The buffer is filled with signals from new user terminals and information about associated user terminals.

[0057] Alternative locations, such as Figure 6 As shown, when elevator 11 stops at... Figure 5 When the door opens at different floors as shown, user terminal 2 and cache node AP... c Both request access from another service node AP2 (in this case, the second access point AP2).

[0058] In any case, when local zone 3 becomes accessible to service nodes AP1 and AP2, service nodes AP1 and AP2 are adapted from cache node AP. c Receive the predicted data x that was sent to user terminal 2 when user terminal 2 is unreachable from service nodes AP1 and AP2 in zone 3. m+1 ...x n The information, and performs execution from the cache node AP for user terminal 2. c The handover to service nodes AP1 and AP2.

[0059] According to some aspects, service node AP1 is adapted to notify other nodes of the adapted scheduling, where the adapted scheduling is due to the fact that cache node AP is accessible when the zone is accessible. c Priority is given to service node AP1, which executes the process to cache node AP. c The handover and prediction data x m+1 ...xn Transmitted to cache node AP c .

[0060] According to this disclosure, cache nodes are installed in temporary dead zones, and signaling procedures are adapted to serve user terminals when they move to these dead zones. According to some aspects, in order to maintain service continuity when a user terminal moves to a dead zone such as an elevator, the following signaling should be adapted:

[0061] 1) The cache node AP should be notified to user terminal 2. c The existence of AP, and requesting user terminal 2 to proceed to AP c Measurement / access.

[0062] 2) Cache node AP c It should receive future signals from different user terminals and their associated IDs.

[0063] 3) APs in an IAB network should be based on cache node APs. c The priority of the nodes is used to adapt their scheduling rules, and all other connected nodes are notified accordingly. In this way, the proposed scheme avoids disconnections in temporary blind spots, improves the quality of service for the UE, and reduces end-to-end transmission latency.

[0064] Finally, in light of the above, the following points should also be considered.

[0065] Setup has been provided for the case where there is an AP within elevator 11. However, this is not required. The cache node within elevator 11 can also be considered a UE-type node. This is because high transmit power is not required to deliver cached video content to user terminals within elevator 11, and typically there are not many user terminals waiting to be served within elevator 11. If the cache node is of device / UE type, the main difference from the given setup will be the user terminals and the cache node AP. c The connection setup between them will follow the sidelink connection setup process, and the video delivery within elevator 11 should be updated accordingly, as this will be done by using the sidelink instead of the downlink transmission.

[0066] Although the door is open, there is a certain probability that a user terminal near elevator 11 will not move into elevator 11. In this case, it is not necessary to hand over the user terminal to the cache node AP. c To ensure service continuity even if the service node AP1 cannot detect whether the user terminal will move into elevator 11, a soft handover process can be used for a short period of time, in which the user terminal is connected to both the service node AP1 and the cache node AP. cBoth. Moreover, in this case, the user terminal's internal cache can help ensure continuous streaming.

[0067] Cache node AP c It is not necessary to perform an initial access every time a connection to the serving node AP1 is attempted, because the cell-specific configuration of the serving node AP1 can be quite fixed, and the cache node AP... c It can be configured to know system information about service node AP1 in advance. As a result, cache node AP... c Only a fast random access procedure is needed to establish a connection with the serving node AP1.

[0068] Cache node AP c It is responsible for serving a few user terminals within a relatively short time period. Therefore, it does not require a large buffer and can use a simple method to determine whether the requested signal has already been buffered.

[0069] The four steps described above have been given as examples. However, data transmission processes in different orders can also be considered. For example, in the third step, data is transmitted from service node AP1 to cache node AP... c In the case of sending the user terminal's predicted data of interest, the data can also be sent to the cache node AP in the second step. c .

[0070] When the door is closed, the cache node AP c Not connected to core network 13. Then, due to data and user terminal content information in the cache node AP... c The cache node AP is already available, therefore the cache node AP is available. c It can act as an independent edge node and provide data communication to user terminals within its coverage area (e.g., inside elevator 11).

[0071] This disclosure can be applied to cache node AP c It can be implemented in two ways: either by performing message encryption / decryption, or by performing so-called blind caching on end-to-end encrypted signals. In the cache node AP... c If encryption / decryption is possible, service node AP1 should be a cache node AP. c Provide the required encryption key.

[0072] The above applies to all data types with predictable requests.

[0073] It should be noted that, according to some aspects, the cache node AP cIt is adapted to notify the service node AP1 that it is a special node that is only available for a short period of time and should have a higher priority than other nodes such as other access points.

[0074] This disclosure relates to an intelligent data transmission technology for transmitting data to user terminals in temporary blind spots. The aim is to ensure continuous data transmission to user terminals, or at least to shorten the period of disconnection. For this purpose, intermediate cache nodes are located in the temporary blind spots. Then, when the temporary blind spot becomes accessible, access points directly or indirectly connected to the core network populate the buffers of the cache nodes with portions of signals that may be requested by the user terminal when it moves to the blind spot. Furthermore, signaling and scheduling between different nodes are adapted, and user terminals can perform measurements and / or connect to different nodes based on their location.

[0075] In this way, the QoS experience of user terminals is improved, end-to-end data transmission latency is reduced, and continuous data transmission in temporary dead zones becomes possible. Furthermore, end-to-end transmission latency for long files is reduced. This results in better service quality for the UE and higher end-to-end throughput. If a certain area has a very poor signal-to-noise ratio (SNR) and is almost a dead zone, the proposed scheme will offload the network because APs in the IAB network do not need to allocate a large amount of resources to links with very poor SNR. It also reduces the need for transmission to multiple APs.

[0076] refer to Figure 7 This disclosure relates to a method in a serving wireless communication node AP1 in a wireless communication system 1, wherein the method includes: S100 determining that a user terminal will enter a zone 3 that changes between reachable and inaccessible with respect to the serving node AP1; and S200 predicting data to be transmitted to the user terminal 2 during at least a portion of the time when the user terminal 2 is inaccessible in zone 3. When zone 3 becomes accessible, the predicted data x is transmitted... m+1 ...x n Transmit S400 to the cache node AP located in zone 3 c This allows the cache node AP to... c Able to predict data x m+1 ...x n Transmitted to user terminal 2.

[0077] According to some aspects, the method includes initiating an S300 request for user terminal 2 from service node AP1 to cache node AP1. c The handover process.

[0078] According to some aspects, initiating S300 includes determining whether S310 should initiate a handover based on the user terminal location information.

[0079] According to some aspects, initiating S300 includes sending measurement configuration 4 to user terminal 2, and measurement configuration 4 includes at least information about the measurement to be performed from cache node AP. c The information on which reference signal and on which radio resources the measurement should be performed enables user terminal 2 to send measurement report 5 to serving node AP1, where serving node AP1 is adapted to determine whether to initiate handover based on measurement report 5.

[0080] According to some sources, initiating S300 includes sending a request to the cache node AP. c Send 330 handover request 6, wherein handover request 6 includes information related to user terminal 2.

[0081] According to some aspects, the information related to user terminal 2 includes at least one of user terminal identifier, processor capability, and number of antenna ports.

[0082] According to some sources, initiating S300 includes from the cache node AP c Receive 340 handover confirmation 7, send 350 handover command 8 to user terminal 2, and send 350 handover command 8 to cache node AP. c Transmit 360 prediction data x m+1 ...x n .

[0083] According to some aspects, the received handover confirmation includes information from the cache node AP. c Relevant information.

[0084] According to some aspects, with cache node AP c The relevant information includes the cell identifier and the cache node AP. c At least one of the RACH configurations.

[0085] According to some aspects, the method includes notifying other nodes of the adapted scheduling, wherein the adapted scheduling is due to the fact that the cache node AP is enabled when the zone is accessible. c Priority is given to service node AP1, which executes the process to cache node AP. c The handover and prediction data x m+1 ...x n Transmitted to cache node AP c .

[0086] According to some aspects, when local zone 3 becomes accessible to service nodes AP1 and AP2, the method includes caching nodes AP... cReceive the predicted data x that was sent to user terminal 2 when user terminal 2 is unreachable from service nodes AP1 and AP2 in zone 3. m+1 ...x n Information 9, and execute on user terminal 2 from cache node AP c The handover to service nodes AP1 and AP2.

[0087] refer to Figure 8 This disclosure also relates to a cache node AP in a wireless communication system 1. c The method in which the cache node AP c Located within zone 3, which varies between reachable and inaccessible with respect to the serving wireless communication node AP1, the method includes: receiving from the serving node AP1 predicted data x to be transmitted to the user terminal 2 by T100 during at least a portion of the time during which the user terminal 2 is inaccessible with respect to the serving node AP1. m+1 ...x n ; and when user terminal 2 is located in zone 3 and is inaccessible to service node AP1, the predicted data x will be... m+1 ...x n Transmit T400 to the user terminal.

[0088] According to some aspects, the method includes receiving a T200 handover request 6 from the serving node AP1, wherein the handover request 6 includes information related to the user terminal.

[0089] According to some aspects, the information related to user terminal 2 includes at least one of the following: project identifier, processor capability, and number of antenna ports.

[0090] According to some aspects, the method includes sending a T300 handover confirmation 7 to the serving node AP1 and receiving prediction data x from the serving node AP1. m+1 ...x n .

[0091] According to some aspects, the handover confirmation 7 includes the cache node AP. c Relevant information.

[0092] According to some aspects, with cache node AP c The relevant information includes the cell identifier and the cache node AP. c At least one of the RACH configurations.

[0093] According to some aspects, when zone 3 becomes accessible to serving node AP1, the method includes: sending T500 information to serving node AP1, wherein the information relates to predicted data that was sent to user terminal 2 when user terminal 2 was unreachable from serving node AP1 in zone 3; and performing T600 for user terminal 2 from cache node AP1. c The handover to service node AP1.

[0094] According to some aspects, the method includes notifying the cache node AP1. c It is only available for a limited time period and should be given higher priority than other nodes.

[0095] This disclosure also relates to a wireless communication system 1, including an integrated access and backhaul (IAB) network 10, which in turn includes at least a serving node AP1 as described above and a cache node AP1 as described above. c .

[0096] This disclosure also relates to a cache node AP in a wireless communication system 1. c Among them, the cache node AP c Located within zone 3, which varies between reachable and inaccessible for the serving wireless communication node AP1, the cache node AP... c Adapted to receive predicted data x from serving node AP1 during at least a portion of the time when user terminal 2 is unreachable from serving node AP1. m+1 ...x n And when user terminal 2 is in zone 3 and is inaccessible to service node AP1, the predicted data x will be... m+1 ...x n Transmitted to user terminal 2.

[0097] According to some aspects, cache node AP c It is adapted to receive handover request 6 from service node AP1, wherein handover request 6 includes information related to the user terminal.

[0098] According to some aspects, the information related to user terminal 2 includes at least one of project identifier, processor capability, antenna port, and latency.

[0099] According to some aspects, cache node AP c It is adapted to send a handover confirmation 7 to the service node AP1 and receive prediction data x from the service node AP1. m+1 ...x n .

[0100] According to some aspects, the handover confirmation 7 includes the cache node AP. c Relevant information.

[0101] According to some aspects, with cache node AP c The relevant information includes the cell identifier and the cache node AP. c At least one of the RACH configurations.

[0102] According to some factors, when local zone 3 becomes accessible to service node AP1, cache node AP c Adapted to send information to serving node AP1, wherein the information involves predicted data that was already sent to user terminal 2 when user terminal 2 is unreachable from serving node AP1 in zone 3, and adapted to perform a cache node AP on user terminal 2. c The handover to service node AP1.

[0103] This disclosure is not limited to the foregoing, but can be freely varied within the scope of the appended claims. For example, this disclosure can be targeted at areas requiring enhanced coverage, where cache nodes can be adaptively provided via drones. Enhanced coverage may be needed in densely populated areas (e.g., sporting event venues) or for mission-critical signaling (e.g., military, police, ambulance, and fire department operations). First responders can use mission-critical video for their rescue missions when entering temporary blind spots outside network coverage, or medical personnel in hospitals can use security surveillance video when they lose network connectivity while entering an elevator (where a service outage could lead to loss of life).

Claims

1. A serving node (AP1) in a wireless communication system (1), wherein, The service node (AP1) includes: Processor; and A memory storing a computer program that, when executed by the processor, causes the service node (AP1) to: Determine that the user terminal (2) being served will enter a zone that is accessible and inaccessible for the service node (AP1) (3). The data (x) to be sent to the user terminal (2) is predicted to be sent to the user terminal (2) during at least a portion of the time when the user terminal (2) is in the area (3) and is not accessible to the service node (AP1). m+1 …x n ); When the zone (3) is accessible, an operation is performed on the user terminal (2) to send a request to the cache node (AP) located in the zone (3). c The transfer of ) and the prediction data (x m+1 …x n ) is transmitted to the cache node (AP) c ), such that when the user terminal (2) is in the zone (3) and for the service node (AP1) the user terminal (2) in the zone (3) and the cache node (AP1) c If the service node (AP1) cannot reach the user terminal (2), the cache node (AP1) will take over the cache node (AP1) of the user terminal (2). c ) can convert the predicted data (x) m+1 …x n (2) is transmitted to the user terminal.

2. The service node (AP1) according to claim 1, wherein, When executed by the processor, the computer program also enables the service node (AP1) to determine whether to initiate the handover based on the user terminal location information.

3. The service node (AP1) according to claim 1 or 2, wherein, When executed by the processor, the computer program also causes the service node (AP1) to send a measurement configuration (4) to the user terminal (2), the measurement configuration (4) including at least information about the measurement to be performed from the cache node (AP1). c The computer program provides information on which reference signal and on which radio resources the measurement should be performed, enabling the user terminal (2) to send a measurement report (5) to the serving node (AP1), wherein the computer program, when executed by the processor, also enables the serving node (AP1) to determine whether to initiate the handover based on the measurement report (5).

4. The service node (AP1) according to claim 1 or 2, wherein, When executed by the processor, the computer program also causes the service node (AP1) to send data to the cache node (AP1). c The user terminal (2) sends a handover request (6) to initiate the handover, wherein the handover request (6) includes information related to the user terminal (2).

5. The service node (AP1) according to claim 4, wherein, The information related to the user terminal (2) includes at least one of the following: user terminal identifier, processor capability, and number of antenna ports.

6. The service node (AP1) according to claim 4, wherein, When the computer program is executed by the processor, it also causes the service node (AP1) to retrieve data from the cache node (AP1). c ) Receive handover confirmation (7), send handover command (8) to the user terminal (2), and then send handover command (8) to the cache node (AP) c ) transmit the prediction data (x) m+1 …x n ).

7. The service node (AP1) according to claim 6, wherein, The received handover confirmation includes confirmation with the cache node (AP) c (Related information.) 8. The service node (AP1) according to claim 7, wherein, The high-speed cache node (AP) c The relevant information includes the cache node (AP) c At least one of the cell identifier and random access channel (RACH) configuration.

9. The service node (AP1) according to any one of claims 1-2 and 5-8, wherein, When executed by the processor, the computer program also causes the service node (AP1) to notify other nodes of the adapted scheduling, wherein the adapted scheduling is due to the fact that the cache node (AP1) is accessible when the area is accessible. c Prioritize, and the service node (AP1) performs the execution of sending to the cache node (AP) c The transfer of the predicted data (x) and the transfer of the predicted data (x) m+1 …x n ) is transmitted to the cache node (AP) c ).

10. The service nodes (AP1, AP2) according to any one of claims 1-2 and 5-8, wherein, When the computer program is executed by the processor, it also makes the service nodes (AP1, AP2) accessible from the cache node (AP1, AP2) in the zone (3) for the service nodes (AP1, AP2). c ) Receive the predicted data (x) that has been sent to the user terminal (2) when the user terminal (2) is not reachable from the service nodes (AP1, AP2) in the area (3). m+1 …x n The information is processed by the cache node (AP) and the execution is performed on the user terminal (2). c The handover of services to the service nodes (AP1, AP2).

11. A cache node (AP) in a wireless communication system (1) c ),in, The cache node (AP) c Located within the zone (3) that varies between reachable and inaccessible for the service node (AP1), and includes: Processor; and The memory stores a computer program that, when executed by the processor, causes the cache node (AP) to... c ): When the zone (3) is accessible, the service node (AP1) executes a request to the cache node (AP) for the user terminal (2). c The system takes over the user terminal (2) from the service node (AP1) during the handover of the service node (AP1) and receives the predicted data (x) to be sent to the user terminal (2) during at least a portion of the time when the user terminal (2) is inaccessible to the service node (AP1). m+1 …x n ),as well as When the user terminal (2) is in the zone (3) and for the service node (AP1), the user terminal (2) in the zone (3) and the cache node (AP1) c If the predicted data (x) cannot be reached, then the predicted data (x) will be... m+1 …x n (2) is transmitted to the user terminal.

12. The cache node (AP) according to claim 11 c ),in, The computer program, when executed by the processor, also causes the cache node (AP) to... c The system receives a handover request (6) from the service node (AP1), wherein the handover request (6) includes information related to the user terminal.

13. The cache node (AP) according to claim 12 c ),in, The information related to the user terminal (2) includes at least one of the following: project identifier, processor capability, and number of antenna ports.

14. The cache node (AP) according to claim 12 or 13 c ),in, The computer program, when executed by the processor, also causes the cache node (AP) to... c ) sends a handover confirmation (7) to the service node (AP1) and receives the prediction data (x) from the service node (AP1). m+1 …x n ).

15. The cache node (AP) according to claim 14 c ),in, The handover confirmation (7) includes confirmation with the cache node (AP) c (Related information.) 16. The cache node (AP) according to claim 15 c ),in, The high-speed cache node (AP) c The relevant information includes the cache node (AP) c At least one of the cell identifier and random access channel (RACH) configuration.

17. The cache node (AP) according to any one of claims 11-13 and 15-16 c ),in, The computer program, when executed by the processor, also causes the cache node (AP) to... c When the zone (3) becomes accessible to the service node (AP1), information is sent to the service node (AP1), wherein the information relates to predicted data that was sent to the user terminal (2) when the user terminal (2) was not accessible to the service node (AP1) in the zone (3); and to the user terminal (2) for execution from the cache node (AP1). c The handover of the service node (AP1) to the service node.

18. A method in a serving node (AP1) of a wireless communication system (1), wherein, The method includes: (S100) Determine (S100) that the user terminal is about to enter a zone that is either accessible or inaccessible for the service node (AP1) (3). Predict (S200) the data to be sent to the user terminal (2) during at least a portion of the time when the user terminal (2) is inaccessible in the zone (3); When the zone (3) is accessible, an operation is performed on the user terminal (2) to send a request to the cache node (AP) located in the zone (3). c The transfer of ) and the prediction data (x m+1 …x n The data is transmitted (S400) to the cache node (AP). c ), such that when the user terminal (2) is in the zone (3) and for the service node (AP1) the user terminal (2) in the zone (3) and the cache node (AP1) c If the service node (AP1) cannot reach the user terminal (2), the cache node (AP1) will take over the cache node (AP1) of the user terminal (2). c ) can convert the predicted data (x) m+1 …x n (2) is transmitted to the user terminal.

19. The method according to claim 18, wherein, The initiation (S300) includes determining (S310) whether to initiate the handover process based on the user terminal location information.

20. The method according to claim 18 or 19, wherein, The initiation (S300) includes sending a measurement configuration (4) to the user terminal (2), the measurement configuration (4) including at least information about the measurement to be performed from the cache node (AP). c The user terminal (2) is able to send a measurement report (5) to the serving node (AP1) based on the measurement report (5), which is the reference signal and the radio resources on which the measurement should be performed, so that the user terminal (2) can send the measurement report (5) to the serving node (AP1), wherein the serving node (AP1) is adapted to determine whether to initiate the handover process based on the measurement report (5).

21. The method according to claim 18 or 19, wherein, The initiation (S300) includes sending a request to the cache node (AP). c Send (330) a handover request (6), wherein the handover request (6) includes information related to the user terminal (2).

22. The method according to claim 21, wherein, The information related to the user terminal (2) includes at least one of the following: user terminal identifier, processor capability, and number of antenna ports.

23. The method according to claim 21, wherein, The initiation (S300) includes: From the cache node (AP) c ) Receive (340) Transfer confirmation (7); Send (350) handover command (8) to the user terminal (2); and To the cache node (AP) c Transmit (360) the predicted data (x) m+1 …x n ).

24. The method according to claim 23, wherein, The received handover confirmation includes confirmation with the cache node (AP) c (Related information.) 25. The method according to claim 24, wherein, The high-speed cache node (AP) c The relevant information includes the cache node (AP) c At least one of the cell identifier and random access channel (RACH) configuration.

26. The method according to any one of claims 18-19 and 22-25, wherein, The method includes notifying other nodes of the adapted scheduling, wherein the adapted scheduling is due to the fact that the cache node (AP) is accessible when the zone is accessible. c Prioritize, and the service node (AP1) performs the execution of sending to the cache node (AP) c The transfer of the predicted data (x) and the transfer of the predicted data (x) m+1 …x n ) is transmitted to the cache node (AP) c ).

27. The method according to any one of claims 18-19 and 22-25, wherein, When the zone (3) becomes accessible to the service nodes (AP1, AP2), the method includes accessing the cache node (AP1, AP2) from the cache node (AP1, AP2). c ) Receive the predicted data (x) that has been sent to the user terminal (2) when the user terminal (2) is not reachable from the service nodes (AP1, AP2) in the area (3). m+1 …x n The information (9) is used to execute the data from the cache node (AP) on the user terminal (2). c The handover of services to the service nodes (AP1, AP2).

28. A cache node (AP) in a wireless communication system (1) c The method in ) where, The cache node (AP) c The method is located in the zone (3) that varies between reachable and inaccessible for the service node (AP1), wherein the method includes: When the zone (3) is accessible, the service node (AP1) executes a request to the cache node (AP) for the user terminal (2). c The handover of the user terminal (2) from the service node (AP1) and the receiving (T100) of the predicted data (x) to be sent to the user terminal (2) during at least a portion of the time when the user terminal (2) is inaccessible to the service node (AP1). m+1 …x n );as well as When the user terminal (2) is in the zone (3) and for the service node (AP1), the user terminal (2) in the zone (3) and the cache node (AP1) c If the predicted data (x) cannot be reached, then the predicted data (x) will be... m+1 …x n (T400) is transmitted to the user terminal (2).

29. The method according to claim 28, wherein, The method includes receiving (T200) a handover request (6) from the service node (AP1), wherein the handover request (6) includes information related to the user terminal.

30. The method according to claim 29, wherein, The information related to the user terminal (2) includes at least one of the following: project identifier, processor capability, and number of antenna ports.

31. The method according to claim 29 or 30, wherein, The method includes sending a handover confirmation (7) to the service node (AP1) (T300) and receiving the prediction data (x) from the service node (AP1). m+1 …x n ).

32. The method according to claim 31, wherein, The handover confirmation (7) includes confirmation with the cache node (AP) c (Related information.) 33. The method according to claim 32, wherein, The high-speed cache node (AP) c The relevant information includes the cache node (AP) c At least one of the cell identifier and random access channel (RACH) configuration.

34. The method according to any one of claims 28-30 and 32-33, wherein, When the zone (3) becomes accessible to the service node (AP1), the method includes: Send (T500) information to the service node (AP1), wherein the information relates to predicted data that was sent to the user terminal (2) when the user terminal (2) is not reachable from the service node (AP1) in the area (3); and For the user terminal (2), execute (T600) from the cache node (AP) c The handover of the service node (AP1) to the service node.

35. The method according to any one of claims 28-30 and 32-33, wherein, The method includes notifying the cache node (AP1) of the service node (AP1). c It is only available for a limited time period and should be given higher priority than other nodes.

36. A wireless communication system (1) comprising an integrated access and backhaul (IAB) network (10), said integrated access and backhaul (IAB) network (10) further comprising at least a serving node (AP1) according to any one of claims 1-10 and a cache node (AP1) according to any one of claims 11-17. c ).

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