Terrestrial or non-terrestrial wireless communication systems

Abstract

A wireless communication device comprises: at least a first ground or non-ground base station, the first base station (10, 10', 156) being configured to generate one or more beams (10, 10', 156) for covering at least a first beam coverage area (12); wherein the first base station (10, 10', 156) is configured to broadcast a list of tracking area IDs at least to the first beam coverage area (12), the list of tracking area IDs comprising a first tracking area ID belonging to the first tracking area (12a) and a second tracking area ID belonging to the second tracking area (12b).

Description

Technical Field

[0001] Embodiments of the present invention relate to wireless communication systems, cell network controllers for wireless communication systems, and user equipment. Other embodiments relate to a method for location management and a corresponding computer program. Preferred embodiments relate to a method for location management / tracking area management for non-terrestrial networks. Typically, embodiments of the present invention are applied in conjunction with non-terrestrial networks such as satellite networks or other non-terrestrial networks, such as those based on high-altitude platforms. Background Art

[0002] Location Management (LM) is a function of mobile cellular networks that allows the network to locate a user. Especially when the UE is inactive, this function ensures that the rough location of the UE is known to establish a connection for an incoming call to the UE (paging) when needed.

[0003] Before discussing positioning management, and in particular positioning management methods in the context of GSM or UMTS, the main structures of terrestrial and non-terrestrial networks will be discussed.

[0004] FIG. 8 below is a schematic diagram of an example of a terrestrial wireless network 100 including a core network 102 and a radio access network 104 .

[0005] The radio access network 104 may include a plurality of base stations gNB1 to gNB5, each serving a specific area around the base station schematically represented by a corresponding cell 1061 to 1065. Base stations are provided to serve users within the cell. The term base station BS refers to gNB in ​​5G networks, eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or simply BS in other mobile communication standards. Users may be fixed devices or mobile devices. In addition, mobile or fixed IoT devices connected to the base station or user can access the wireless communication system. Mobile devices or IoT devices may include physical devices, ground vehicles such as robots or cars, aircraft such as manned or unmanned aerial vehicles (UAVs) (the latter also referred to as drones), buildings and other items or devices embedded with electronic devices, software, sensors, actuators, etc., and network connections that enable these devices to collect and exchange data across existing network infrastructure. Figure 8a An exemplary view of only five cells is shown, however, the wireless communication system may include many more such cells. Figure 8aTwo users UE1 and UE2, also referred to as user equipment UE, are shown in cell 1062, served by base station gNB2. Another user UE3 is shown in cell 1064, served by base station gNB4. Arrows 1081, 1082 and 1083 schematically represent uplink / downlink connections for sending data from users UE1, UE2 and UE3 to base stations gNB2, gNB4 or for sending data from base stations gNB2, gNB4 to users UE1, UE2, UE3. In addition, Figure 8a Two IoT devices 1101 and 1102 are shown in a cell 1064, which may be fixed devices or mobile devices. IoT device 1101 accesses the wireless communication system via base station gNB4 to receive and send data, as schematically indicated by arrow 1121. IoT device 1102 accesses the wireless communication system via user UE3, as schematically indicated by arrow 1122. The respective base stations gNB1 to gNB5 may be connected to the core network 102, for example, via an S1 interface, via respective backhaul links 1141 to 1145, which are connected to the core network 102 via the S1 interface. Figure 8a The core network 102 may be connected to one or more external networks. In addition, some or all of the individual base stations gNB1 to gNB5 may be connected to each other, for example, via an S1 or X2 interface or an Xn interface in NR, via corresponding backhaul links 1161 to 1165, which are connected to each other via the S1 or X2 interface or the Xn interface in NR. Figure 8a This is schematically represented by an arrow pointing to the “gNB”. Figure 8a The wireless network or communication system depicted in the figure may consist of a heterogeneous network having two different overlapping networks, a network of macro cells each including a macro base station (e.g., base stations gNB1 to gNB5), and small cell base stations (e.g., femto or pico base stations). Figure 8a The network composition is not shown in the figure.

[0006] For data transmission, a physical resource grid may be used. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, a physical channel may include a physical downlink and uplink shared channel (PDSCH, PUSCH) carrying user-specific data (also referred to as downlink and uplink payload data), a physical broadcast channel (PBCH) carrying, for example, a master information block (MIB) and a system information block (SIB), a physical downlink and uplink control channel (PDCCH, PUCCH) carrying, for example, downlink control information (DCI), etc. For the uplink, the physical channel may also include a physical random access channel (PRACH or RACH) used by the UE to access the network after synchronization and obtaining the MIB and SIB. Physical signals may include reference signals (RS), synchronization signals, etc. The resource grid may include a frame or radio frame having a certain duration (e.g., 10 milliseconds) in the time domain and a given bandwidth in the frequency domain. A frame may have a certain number of subframes with a predetermined length, for example, 2 subframes of 1 millisecond in length. Each subframe may include two slots with 6 or 7 OFDM symbols, depending on the cyclic prefix (CP) length. A frame may also consist of a smaller number of OFDM symbols, for example when utilizing a shortened transmission time interval (sTTI) or a mini-slot / non-slot based frame structure containing only a few OFDM symbols.

[0007] The wireless communication system may be any single tone or multi-carrier system using frequency division multiplexing, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, such as DFT-S-OFDM. Other waveforms such as non-orthogonal waveforms for multiple access may be used, such as filter bank multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), or universal filtering multi-carrier (UFMC). The wireless communication system may operate, for example, according to 4G LTE, 4.5G advanced LTE pro, or 5G NR new radio standards.

[0008] exist Figure 8a In the wireless communication network shown, the radio access network 104 may be a heterogeneous network including a network of primary cells, each of which includes a primary base station, also known as a macro base station. In addition, multiple secondary base stations, also known as small cell base stations, may be provided for each macro cell.

[0009] In addition to the above-mentioned terrestrial wireless networks, there are also non-terrestrial wireless communication networks. Figure 8b 1 is a schematic diagram of an example of a non-terrestrial wireless communication network 150 including a core network 152 and a radio access network 154. Figure 8bThe non-terrestrial wireless network 150 includes a plurality of transceivers 156 (e.g., satellites) and / or airborne transceivers 158 (e.g., unmanned aircraft systems). The corresponding or airborne transceivers 156, 158 may be implemented in corresponding satellite-borne or airborne vehicles, such as the satellites or unmanned aircraft systems described above. The transceivers 156 and 158 are provided to serve one or more users, such as Figure 8b The UE or IoT device 110 shown is provided above or on the ground 160. The UE and IoT device can be the above reference Figure 8a The arrows 1581 to 1584 schematically represent uplink / downlink connections for transmitting data between the user UE 110 and the respective transceivers 156, 158. The transceivers 156, 158 are connected to the core network 152 as schematically represented by arrows 1621, 1622. The non-terrestrial wireless communication network or system described above may be, for example, based on 4G LTE, 4.5G advanced LTE pro or 5G NR new radio standards in accordance with the above reference Figure 8a The ground system operates in a similar manner.

[0010] Data transmitted between the user UE 110 and the transceiver 106, 156, 158 of the above-mentioned communication network may be covered by noise when transmitted through the channels 108, 112, 158, so the data may not be processed correctly or at all at the receiver. For example, when the data to be sent is encoded using a predefined code, the encoded data is generated at the transmitter and forwarded to the receiver through the channel. During transmission, the encoded data may be covered by noise to such an extent that, for example, it is impossible to decode the encoded data due to the noisy channel situation. In order to solve this situation, a retransmission mechanism can be adopted. For example, when the receiver detects that the encoded data cannot be decoded, a retransmission is requested from the transmitter or sender. For example, hybrid automatic repeat request HARQ can be used to request a retransmission from a transmitter such as a UE to correct a decoding failure. At the transmitter, encoding the data includes generating redundancy, which may include redundant bits added to the data to be transmitted. During the first transmission, only a portion of the redundancy can be sent. When a retransmission is requested, the other portion of the redundancy, also referred to as additional or incremental redundancy, can be sent to the receiver. For example, HARQ can use append combining (each retransmission contains the same information - data and parity bits), or incremental redundancy (each retransmission contains different parity bits from the previous one). However, retransmissions cause delays due to the additional round-trip time (RTT), which includes propagation delays on the network and processing delays at the UE and receiver.

[0011] Note that the information in the above section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

[0012] The need for (global) connectivity is increasing dramatically due to the growing number of different services and data demands in an increasingly connected world. This also includes connectivity anywhere, anytime. Even if the number of connected areas worldwide increases dramatically, it is not possible to serve every place on the entire planet (underserved areas, oceans, airplanes, etc.) with fixed / terrestrial cellular networks.

[0013] To support these needs, non-fixed networks also need to support cellular networks. These networks can include, for example, drones, aircraft, high-altitude platforms, low-Earth orbit satellites, medium-Earth orbit satellites. By adding non-fixed base stations to future networks, coverage and reliability can be easily and significantly enhanced, which is necessary for many future services and applications.

[0014] (Connectivity between all of these different types of platforms will be necessary to support Quality of Service (QoS) requirements and ensure sustainability of service, for example in disaster relief situations). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the present invention will now be discussed with reference to the accompanying drawings, in which:

[0016] Figure 1 A schematic diagram for explaining the definition of a specific area for location management is shown;

[0017] Figure 2 A schematic diagram for explaining the concept of conventional location management is shown;

[0018] Figure 3 A schematic diagram showing the concept of list-based location management used according to an embodiment;

[0019] Figure 4 A schematic diagram for discussing a basic embodiment for location management is shown;

[0020] Figure 5a , Figure 5b A schematic diagram of a solution using country regions as exemplary tracking areas is shown, where Figure 5a The first of two exemplary time instances is shown, at Figure 5b A corresponding second time instance is shown in FIG. 1 to illustrate an enhanced embodiment;

[0021] Figure 6 schematically shows a diagram of a solution applied in a terrestrial network according to an embodiment; and

[0022] Figure 7 A schematic block diagram for illustrating a processor for executing a method according to an embodiment of the present invention is shown; and

[0023] Figure 8a , Figure 8b A diagram of terrestrial and non-terrestrial networks is schematically shown. DETAILED DESCRIPTION

[0024] In the following, objects having the same functions are provided with the same reference numerals so that their descriptions are mutually applicable and interchangeable.

[0025] Before discussing embodiments of the present invention, the background of the present invention will be discussed, in particular different approaches for positioning management.Positioning management is used to ensure a coarse position determination of a UE.

[0026] In general, regardless of the specific location management method, LM is based on defining a specific area (AR) within which the UE can move freely without updating the network about its current location. In mobile cellular systems, this area usually corresponds to e.g. Figure 1 The size of the AR can be arbitrarily selected and is subject to the optimization criteria of the network operator. Note that ARs can also overlap. In the 3GPP mobile communication system, AR is called:

[0027] Location Area in GSM

[0028] Routing areas in UMTS

[0029] Registration areas in LTE and NR.

[0030] Below, two popular location management techniques are briefly discussed. For example, one of the two popular LM methods is used in GSM and adapted in UMTS. Conventional location management is a simple method that was first widely used in GSM. Here, different areas that can include multiple cells are called regions (ARs). Note that according to Figure 2 The method is already Figure 1 The area AR discussed in the context of is renamed as the Location Area (LA). Figure 2 The conventional method shown, without loss of generality, these areas are referred to as localization areas (LA).

[0031] Figure 2 Three areas LA1, LA2, LA3 are shown, all of which may include multiple cells C n , as shown in the cell pattern. In different areas, some UEs are marked as examples. For example, UE z is deployed in the cell of LA1, and UE xis shown in another cell within the same location area LA1. Another UE is placed in LA3.

[0032] A unique location area code (LAC) is used to address a location area. In a cellular network, each base station broadcasts the LAC of the LA to which it belongs. The UE obtains the ID of its current LA when it registers with the core network (CN). Figure 2 The UE detects if it has left its LA by comparing the broadcast LAC with the LAC obtained from the network. In this case, the UE requests a location area update, and the CN registers the LA change and subsequently transmits the LAC of the new LA.

[0033] Note that a UE only gets one LAC, so in principle conventional location management assigns the UE to a LA.

[0034] Starting from this conventional location management approach, a list-assisted solution can be used. This was introduced in LTE and extended in NR.

[0035] Figure 3 The list-based location management is shown in FIG. Here, for the list-based location management method, the area AR is renamed as Tracking Area (TA). The background is that in LTE, list-based location management (LM) is used to enhance the effectiveness of location management, where Figure 1 The AR shown is referred to as a Tracking Area (TA) without loss of generality.

[0036] Figure 3 Three tracking areas TA1, TA2 and TA3 are shown, wherein each tracking area TA1 to TA3 is formed by a plurality of cells CN. Two UEs are shown here, UE x is arranged / placed in TA1, and UE y It is arranged in TA3.

[0037] After discussing the architecture, the concept of list-based location management will be discussed.Similar to conventional LM, each tracking area gets a unique identifier - Tracking Area Code (TAC), which is broadcasted by the base station in the tracking area respectively.

[0038] Efficient location management is achieved by additionally introducing a Tracking Area List (TAL) for each UE, which contains a variable number of TACs.

[0039] The TAC of the TAL is selected by the Core Network (CN) taking into account the specific UE context.

[0040] The area specified by the TAL is called a Tracking Area (TR). A TR is a hangover of a location area in conventional location management (ie, within a TR), and the UE does not need to transmit location updates to the CN.

[0041] For example, CN sends a x Allocate TAL x , and to UE y Allocate TAL y , each list contains a different TAC and thus defines a different TR respectively. It can be easily seen that with list-based location management, the TR (area where no UE triggers location update) is now variable and depends on the selection of the TAL entry.

[0042] Similar to regular LM, whenever a UE leaves its assigned TR, it can detect it by comparing the TAL with the broadcast TAC. This event triggers the UE to request a tracking area update. The CN then allocates a new TAL to the UE.

[0043] Note that the information in the above sections is only used to enhance the understanding of the background technology of the present invention, and therefore it may contain information that does not constitute prior art and is known to those of ordinary skill in the art. The methods discussed above are mainly designed for fixed networks. However, in the context of non-fixed networks, the challenges of location management are related to the mobility of service entities such as satellites. Below, the method for providing a solution to the above concept will be discussed.

[0044] Position management in traditional satellite systems relies on the availability of GNSS information. The disadvantage of this approach is that more complexity is required in the user terminal, which is not always possible or desirable. On the other hand, a solution that does not require GNSS information was proposed in [4]. Here, the assumption of time-invariant satellite IDs and a dynamic TA list at the UE form the basis.

[0045] In the presence of high mobility (UE / satellite), current terrestrial SotA location management will incur high signaling workload due to frequent location list updates caused by non-fixed base stations. On the other hand, the SotA LM solution for such lightweight systems requires higher complexity at the user terminal for GNSS capabilities. Therefore, an improved approach is needed.

[0046] The object of the present invention is to provide a concept for location management which is to be applied to non-fixed networks, such as satellite networks.

[0047] This idea is solved by the subject matter of the independent claims.

[0048] An embodiment provides a wireless communication system comprising at least a first terrestrial or non-terrestrial base station. The first (terrestrial / non-terrestrial) base station is configured to generate one or more beams for covering at least a first beam coverage area. The first base station is configured to broadcast a list of tracking area IDs including a first tracking area ID and a second area ID to at least the first beam coverage area. The first tracking area ID belongs to the first tracking area. The second tracking area ID belongs to the second tracking area. Note that according to the example, the corresponding tracking areas (first and second) can be a subset of the first (satellite) beam coverage area.

[0049] Embodiments of the invention are based on the finding that a beam coverage area, which may for example be dynamically arranged to the ground, is subdivided into tracking areas which are (temporarily) covered by one coverage area. Instead of just identifying the entire beam coverage area, a list of tracking area IDs is broadcasted, wherein the list may be updated from time to time, for example when some tracking areas are no longer covered by a coverage area or new tracking areas are covered by the nearest beam. The UE performs tracking by comparing the received tracking area IDs in the list with information about tracking area IDs outside the actual ground area on the ground. This means that it can still track an unrelated tracking area and determine if it is still covered by the first satellite beam coverage area or if the corresponding tracking area ID is now broadcasted by another satellite. Therefore, the principles discussed above for positioning management still apply to non-terrestrial base stations, or base stations with variable beam coverage areas in general. Due to the division of a circular beam coverage area into subsets of beam coverage areas, partially changed beam coverage can be taken into account.

[0050] According to an embodiment, the first base station is configured to broadcast at least a first tracking area ID belonging to the first tracking area, or a list of tracking area IDs, the list including the first tracking area ID belonging to the first tracking area and the second tracking area ID belonging to the second tracking area, to the first beam coverage area only during a limited predetermined first time period. The time period generally depends on the duration for which the base station covers the corresponding tracking area. Due to the method, for example, in the case where the first base station moves relative to the corresponding tracking area, as long as the first beam coverage area covers a certain tracking area, it is enabled to broadcast the corresponding tracking area ID.

[0051] Another embodiment provides a wireless communication system, which includes at least a first ground and / or non-ground base station, which is configured to generate one or more beams for covering at least a first beam coverage area. Here, the first base station is configured to broadcast a first tracking area ID or a list of tracking area IDs belonging to a first tracking area to the first beam coverage area only during a limited predetermined first time period, the list including the first tracking area ID belonging to the first tracking area and the second tracking area ID belonging to the second tracking area. The purpose of this is to enable the corresponding tracking area to be broadcast as long as the first beam coverage area covers a certain tracking area if the first base station moves relative to the tracking area.

[0052] According to an embodiment, the first base station is configured to broadcast another tracking area ID belonging to another tracking area at least to the second beam coverage area during a limited predetermined second time period after the first time period, and / or adapt the list of tracking area IDs within a limited predetermined second time period after the first time period.

[0053] Here, the communication system comprises a core network controller configured to control the first base station for a broadcasted tracking area ID and / or for a list of adapted tracking area IDs.

[0054] According to an embodiment, the instruction for adapting the list of tracking area IDs in advance may be performed by defining valid time window information for each list entry of the list of tracking area IDs. According to an embodiment, the simple list of tracking area IDs for the second time period may include a second tracking area ID belonging to the second tracking area and a third tracking ID belonging to the third tracking area. In this case, the nearest coverage area for the second time period may cover an additional tracking area (here, the third tracking area), but for example no longer covers the first tracking area. Therefore, according to other embodiments, the list of tracking area IDs for the second time period includes the second tracking area ID, but does not include the first tracking area ID. According to other embodiments, the list of tracking area IDs for the second time period includes the third tracking area ID belonging to the third tracking area and the fourth tracking area ID belonging to the fourth tracking area.

[0055] According to other embodiments, the wireless communication system further comprises a user equipment. The user equipment is configured to receive the coverage beam and determine its tracking area by comparing the assigned tracking area ID with the first and second tracking area IDs of the received list.

[0056] User equipment can also be configured to:

[0057] - reporting a single tracking area ID, e.g. the first entry, to the core network controller; and / or

[0058] - Report multiple Tracking Area IDs to the Core Network Controller with or without beam / satellite IDs;

[0059] - Report cross-tracking area IDs from multiple beams / satellites back to the core network controller;

[0060] - Report multiple tracking area IDs in conjunction with time information.

[0061] According to another embodiment, the first base station is a mobile or fixed beam footprint LEO satellite or an earth fixed beam footprint GEO satellite. According to an embodiment, the base station may include single / or multi-beam satellite functionality, or may be a transparent or regenerative satellite. According to other embodiments, the first base station may be a mobile base station, such as a drone or a high altitude platform. According to other embodiments, the wireless communication system is formed by a terrestrial network and / or a non-terrestrial network. Note that the wireless communication system supports heterogeneous networks.

[0062] According to other embodiments, the wireless communication system may include a second base station, which is configured to broadcast a first tracking area ID belonging to the first tracking area, or a list of tracking area IDs including the first tracking area ID belonging to the first tracking area and the second tracking area ID belonging to the second tracking area to at least the first beam coverage area during another limited predetermined time period.

[0063] Note that the first beam coverage area includes at least two tracking areas assigned with fixed tracking area IDs during the above-mentioned first time period, ie temporarily.

[0064] According to other embodiments, the wireless communication system is configured to: if the paging message is dedicated to a user equipment within a first tracking area, route the paging message to one or more beams that are currently broadcasting the first tracking area ID (during its predetermined first time period). Alternatively, if the paging message is dedicated to a user equipment within a second tracking area, it may route the paging message to one or more beams that are currently broadcasting the second tracking area ID (during the predetermined first time period). Here, the UE expects to receive its paging message in a beam with a tracking area ID that is part of its tracking area.

[0065] Another embodiment provides a core network controller for a wireless communication system according to one of the preceding claims, which is configured to control a first base station for a broadcast tracking area ID, a list of broadcast tracking area IDs, a tracking area ID for an adapted broadcast and / or a list of adapted tracking area IDs.

[0066] Note that according to other embodiments, the core network controller may be configured to: if the paging message is dedicated to a user device within a first tracking area, re-page the paging message to one or more base stations selected by currently (e.g., during a predetermined first time period) broadcasting the first tracking area ID using one or more beams, and / or if the paging message is dedicated to a user device within a second tracking area, re-page the paging message to one or more base stations selected for currently broadcasting the second tracking area ID using one or more beams.

[0067] According to several embodiments, a user equipment is provided. The user equipment can be used to communicate with the above communication system and is configured to receive a coverage beam and a list broadcast using the coverage beam. In addition, the user equipment is configured to determine its tracking area by comparing a tracking area ID assigned to the user equipment with a tracking area ID included in the list.

[0068] According to other embodiments, the user equipment receives another coverage beam from another base station, for example during another subsequent time period, and the user equipment can determine its tracking area regardless of which base station the received assigned tracking area ID or the list including the assigned tracking area ID corresponds to.

[0069] Another embodiment provides a method for positioning management. The method includes the following steps: using a first ground or non-ground base station to broadcast a list of tracking area IDs to at least a first beam coverage area, the list including a first tracking area ID belonging to the first tracking area and a second tracking area ID belonging to the second tracking area, the first base station generates one or more beams for covering the first beam coverage area. The purpose of this is to allow the corresponding tracking area to become a subset of the first (nearest) beam coverage area.

[0070] Another embodiment provides another method for positioning management. This includes the following steps: only during a limited predetermined first time period, using a first ground or non-ground base station, at least broadcasting a first tracking area ID belonging to a first tracking area or a list of tracking area IDs, the list including the first tracking area ID belonging to the first tracking area and the second tracking area ID belonging to the second tracking area to a first beam coverage area, and the first base station generates one or more beams for covering the first beam coverage area. The purpose of this is that if the first base station moves relative to the tracking area, as long as the first beam coverage area covers a certain tracking area, the corresponding tracking area ID can be broadcast. Another step refers to: only during a limited predetermined second time period after the first time period, using a second ground or non-ground base station, at least broadcasting the first tracking area ID belonging to the first tracking area, or another list of tracking area IDs, the list including the first tracking area ID belonging to the first tracking area to a second beam coverage area, and the second base station generates one or more beams for covering the second beam coverage area.

[0071] Note that according to other embodiments, the method may further comprise the step of controlling the first base station for the broadcasted tracking area ID and / or for the list of adapted tracking area IDs.

[0072] Note that according to an embodiment, the control is performed by defining a list of tracking area IDs for a first time period and another list of tracking area IDs for a second time period, or adapting the list of tracking area IDs in advance / in the second time period, or defining valid time window information for each list entry in the list of tracking area IDs.

[0073] According to other embodiments, the method may be implemented by a computer program. Therefore, the present embodiment relates to a computer-readable digital storage medium.

[0074] about Figure 4 , methods for tracking management reduced to basic features will be discussed.

[0075] Figure 4 A communication network is shown with a non-terrestrial base station 10, here a satellite, which generates at least one beam 10b1 covering a so-called first beam coverage area. The first beam coverage area 12 comprises two sub-portions 12a and 12b. A third sub-portion 12c is not in the coverage of the beam 10b1. The first sub-portion 12a is also referred to as a first tracking area 12a, while the second sub-portion is referred to as a second tracking area 12b. User equipment 14 is arranged within the first tracking area 12a.

[0076] The user equipment 14 has information about, for example, the so-called first tracking area ID. As long as the user equipment 14 receives this first tracking area ID, it knows that it is still within the same tracking area.

[0077] According to this embodiment, the first tracking area ID is received as part of a list comprising a plurality of tracking area IDs belonging to all tracking areas 12a and 12b covered by beam 10b1 at least during the current time period (the first time period). Thus, the list broadcast by satellite 10 comprises tracking area IDs belonging to the first and second tracking areas 12a / 12b.

[0078] If the first beam coverage area of ​​the satellite changes, for example due to the movement of the satellite (see satellite 10'), it may happen that the second beam coverage area 10b1' no longer covers all previous tracking areas. This situation is shown in the figure, because the beam 10b1' only covers the second tracking area 12b and the third tracking area 12c. Since the transferred coverage area including at least the tracking area ID is updated, the list broadcasted by the satellite 10' only includes the second tracking area ID and the third tracking area ID belonging to the third tracking area 12c.

[0079] Now when looking at the user equipment 14, it no longer receives the expected tracking area ID. However, it may happen that now another satellite or another beam of the satellite 10' covers the first tracking area 12a. This is the exemplary case shown here. According to an embodiment, the satellite 10' broadcasts the list starting from at least the changed first and second beam coverage areas by using the beam 10b2' including the first tracking area ID. From the perspective of the user equipment 14, it can be appreciated that the user equipment still receives the first tracking area ID, so that for this UE, the same tracking mechanism discussed with respect to a strictly terrestrial network can be used. This leads to the following advantages: defining the tracking area (TA) as a non-overlapping area on the ground is still valid and the current paging mechanism can be reused. The background is that, unlike broadcasting a single TAI, the base station / satellite should be able to broadcast a TAI list of covered TAs in order to allow the TA to be a subset of the satellite beam coverage area. The base station / satellite should then adopt a TAI list with respect to its coverage area / beam footprint on the earth. In the case of a transparent satellite, the CN needs to instruct the satellite / NTN gateway in a timely or advance manner to change the TAI list to be broadcast by the satellite. In the case of regenerating satellites, the CN can also directly instruct the satellite in time or in advance. For example, the effective time window information for each TAI list entry can be used to implement instructions for adapting the TAI list broadcast in advance. Other options are not excluded. Other options are given in [4]. The options in [4] are specific to UEs, but can also be applied to satellites, which is proposed by this solution.

[0080] Note that in the presence of high mobility (UE / satellite), current terrestrial SotA location management will incur high signaling volume due to frequent location list updates caused by non-fixed base stations. On the other hand, SotA LM solutions for satellite systems require higher complexity at the user terminal for GNSS capabilities. In the following, we propose a location management solution without GNSS information that relies on the broadcast of multiple time-varying IDs.

[0081] According to an embodiment, a registration area may include one or more tracking areas (see 12a, 12b and 12c). Note that according to an embodiment, a tracking area may be an area smaller than the coverage area of ​​a base station / satellite.

[0082] In the following, different methods are discussed, based on which the user equipment can use the service area information.

[0083] According to an embodiment, the UE reports a single TAI back to the CN (eg, the first entity).

[0084] According to other embodiments, the UE reports multiple TAIs back to the CN with or without beam / satellite IDs.

[0085] According to other embodiments, the UE reports the crossed TAI of multiple beams / satellites back to the CN. This is advantageous because the most accurate position determination can be performed.

[0086] According to other embodiments, the UE reports multiple TAIs in combination with time information. The background is that typically, before the same TAI is broadcast by another satellite or another beam, the TAI is only broadcast by the corresponding satellite during a specific time period.

[0087] about Figure 5a and Figure 5b , the application of the above-mentioned tracking area management for paging non-terrestrial (or terrestrial) networks will be described.

[0088] Figure 5a A map of the area between Switzerland, Germany, Austria (including Liechtenstein) is shown. In this embodiment, these exemplary countries are equivalent to tracking areas. The following four TAIs are defined: TA1: Germany, TA2: Austria, TA3: Switzerland and TA4: Liechtenstein. Note that multiple tracking areas can also be defined in each country. Three satellites 10ro, 10gr and 10bl cover parts of the area as shown by beams 10bro, 10bgr and 10bbl. In Figure 5aIn FIG, satellite 10ro broadcasts three TAIs, namely TAI2, TAI3 and TAI4, because its beam footprint covers TA2, TA3 and TA4. Similarly, satellite 10r broadcasts TAI1 and TAi2, while satellite 10bl broadcasts TAI1, TAI2, TAI3 and TAI4. Figure 5b In the case of a second time point after the time point shown in 5a, for example, the satellite has moved and the coverage areas 10bgr, 10bro and 10bbl have also shifted. The change is represented by a list including tracking area IDs. For example, the list broadcast by 10ro includes only TAI3, the list broadcast by 10gr includes TAI1, TAI2 and TAI3, wherein the list broadcast by satellite 10b1 remains unchanged.

[0089] The above embodiment enables the TAI of the TA belonging to the corresponding country to be received in the position just within the coverage of the corresponding beam 10bgr, 10bro or 10bbl. Note that there is no difference between different positions within the beam 10bgr, 10bro or 10bbl. Figure 6 Another embodiment is shown, which can be determined more accurately. Figure 6 An exemplary arrangement for a terrestrial network is shown, where the cell edges are assigned their own TAI. The embodiment starts from the following assumption: three base stations cover three coverage areas 10bgr, 10bro and 10bbl. These coverage areas 10bro, 10bbl and 10bgr have respective overlaps within which lists / TAIs received from at least two base stations can be received. Due to the different TAIs, this information can be used to define separate TAs, here TA3 and TA4 within the overlap area.

[0090] What all embodiments have in common is that the tracking area based paging mechanism can be reused with minor modifications. The UE does not need GNSS capability for paging. Therefore, this is particularly attractive for low complexity UEs or UEs with high power constraints.

[0091] The concept is applicable to all possible systems with LEO satellites, GEO satellites, mobile or geo-fixed beam footprint, whether they are single-point or multi-spot beam satellites, or transparent or regenerative satellites. It can also be beneficial for mobile base stations, such as drones, high altitude platforms (HAPS), and for terrestrial networks, such as in the case of heterogeneous networks.

[0092] According to other embodiments, instead of broadcasting a TAI based on the satellite coverage area, the satellite may simply broadcast an ID that is unique to the satellite beam. The UE may then report all received IDs back to the CN. The CN may then allocate a registration area for the UE by providing it with the satellite beam IDs and the time windows in which these satellite beams cover the UE. This is described in [4].

[0093] Although some aspects of the described concepts have been described in the context of an apparatus, it is apparent that these aspects also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or item or a feature of a corresponding apparatus.

[0094] The various elements and features of the present invention can be implemented in hardware, software using analog and / or digital circuits, by executing instructions through one or more general or special processors, or as a combination of hardware and software. For example, embodiments of the present invention can be implemented in the environment of a computer system or another processing system. Figure 7 An example of a computer system 600 is shown. The units or modules and steps of the methods performed by the units may be executed on one or more computer systems 600. The computer system 600 includes one or more processors 602, such as a dedicated or general purpose digital signal processor. The processor 602 is connected to a communication infrastructure 604, such as a bus or a network. The computer system 600 includes: a main memory 606, such as a random access memory (RAM); and a secondary memory 608, such as a hard drive and / or a removable storage drive. The secondary memory 608 may allow computer programs or other instructions to be loaded into the computer system 600. The computer system 600 may also include a communication interface 610 to allow software and data to be transmitted between the computer system 600 and external devices. The communication may be in the form of electrical, electromagnetic, optical or other signals that can be processed by the communication interface. The communication may use wires or cables, optical fibers, telephone lines, cellular phone links, RF links and other communication channels 612.

[0095] The terms "computer program medium" and "computer readable medium" are generally used to refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard drive. These computer program products are means for providing software to the computer system 600. The computer program, also known as computer control logic, is stored in the main memory 606 and / or the secondary memory 608. The computer program may also be received via the communication interface 610. The computer program, when executed, enables the computer system 600 to implement the present invention. In particular, the computer program, when executed, enables the processor 602 to implement the process of the present invention, such as any method described herein. Therefore, such a computer program may represent a controller of the computer system 600. In the case of implementing the present disclosure using software, the software may be stored in a computer program product and loaded into the computer system 600 using a removable storage drive, an interface (such as the communication interface 610).

[0096] The implementation in hardware or software can be performed using a digital storage medium, such as cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM or FLASH memory, on which electronically readable control signals are stored, which cooperate (or can cooperate) with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer readable.

[0097] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0098] Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer.The program code may, for example, be stored on a machine readable carrier.

[0099] Other embodiments comprise a computer program stored on a machine readable carrier for performing one of the methods described herein. In other words, an embodiment of the inventive method is therefore a computer program having a program code for performing one of the methods described herein when the computer program runs on a computer.

[0100] Therefore, another embodiment of the method of the present invention is a data carrier (or a digital storage medium or a computer-readable medium) having a computer program recorded thereon, the computer program being used to perform one of the methods described herein. Therefore, another embodiment of the method of the present invention is a data stream or a signal sequence representing a computer program, the computer program being used to perform one of the methods described herein. The data stream or signal sequence can, for example, be configured to be transmitted via a data communication connection (for example, via the Internet). Another embodiment comprises a processing device, for example, a computer or a programmable logic device, the processing device being configured to or adapted to perform one of the methods described herein. Another embodiment comprises a computer having a computer program installed thereon, the computer program being used to perform one of the methods described herein.

[0101] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array can collaborate with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by any hardware device.

[0102] According to an embodiment, a wireless communication system may include a core network or a core network entity and a RAN network such as an AMF, wherein the core network or the core network entity is configured to page a UE in the wireless communication system only via those transmission points indicated in the UE's list.

[0103] According to an embodiment, a wireless communication system comprises:

[0104] - terrestrial network, or

[0105] - non-terrestrial network, or

[0106] - a network or network segment using an airborne vehicle or a satellite-borne vehicle as a terminal, or

[0107] -A combination of these.

[0108] According to an embodiment, the UE includes one or more of the following:

[0109] - a mobile terminal, or

[0110] - Fixed terminal, or

[0111] - Cellular IoT-UE, or

[0112] - Vehicle-mounted UE, or

[0113] -IoT or Narrowband IoT "NB-IoT" devices, or

[0114] - Ground vehicles, or

[0115] - an aircraft, or

[0116] - Drones, or

[0117] - mobile base station, or

[0118] - Roadside Unit, or

[0119] - buildings, or

[0120] - Any other item or device, such as a sensor or actuator, having a network connection that enables the item / device to communicate using a wireless communication network.

[0121] According to an embodiment, the transmission point includes one or more of the following:

[0122] - a macrocell base station, or

[0123] - Small cell base station, or

[0124] - a central unit of a base station, or

[0125] - a distributed unit of a base station, or

[0126] - Roadside Unit, or

[0127] -UE, or

[0128] - Remote Radio Head, or

[0129] -AMF, or

[0130] -SMF, or

[0131] - a core network entity, or

[0132] - such as network slicing in the context of NR or 5G core, or

[0133] - a spaceborne vehicle, such as a satellite or space vehicle at a particular altitude and orbital period or plane, such as low earth orbit (LEO), medium earth orbit (MEO), geosynchronous orbit (GSO), geostationary orbit (GEO) or high earth orbit (HEO), or

[0134] - airborne vehicles, such as unmanned aircraft systems (UAS), such as tethered UAS, lighter-than-air UAS (LTA), heavier-than-air UAS (HTA), and high altitude UAS platforms (HAP), or

[0135] - Any transmission / reception point TRP that enables an item or device to communicate using a wireless communication network, the item or device being provided with a network connection to communicate using a wireless communication network.

[0136] The above embodiments are merely illustrative of the principles of the present invention. It should be understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. Therefore, it is intended that the scope of the present invention be limited only by the scope of the appended patent claims and not by the specific details given by way of the description and explanation of the embodiments herein.

[0137] References and abbreviations

[0138]

Claims

1. A wireless communication system (150), comprising: at least a first mobile transmission point (10, 10', 156), the first mobile transmission point (10, 10', 156) being configured to generate one or more beams (10bl, 10bl', 10b2') for temporarily covering at least a first beam coverage area (12), the first beam coverage area being dynamically arranged as a ground surface and being subdivided into a first tracking area (12a) and a second tracking area (12b); wherein the first mobile transmission point (10, 10', 156) is configured to broadcast a list of tracking area IDs to at least the first beam coverage area (12) only during a limited predetermined first time period, the list of tracking area IDs comprising a first tracking area ID belonging to the first tracking area (12a) and a second tracking area ID belonging to the second tracking area (12b); The list of tracking area IDs is updated from time to time, i.e., when the first beam coverage area (12) no longer covers or serves the first tracking area (12a) and the second tracking area (12b), or when the first beam coverage area (12) covers or serves a third tracking area (12c).

2. The wireless communication system (150) according to claim 1, wherein: The first mobile transmission point (10, 10', 156) is configured to: broadcast another tracking area ID belonging to another tracking area to at least a second beam coverage area (12) during a limited predetermined second time period after the first time period; and / or adapt the list of tracking area IDs within the limited predetermined second time period after the first time period.

3. The wireless communication system (150) according to claim 2, wherein: The communication system (150) comprises a core network controller configured to control the first mobile transmission point (10, 10', 156) for a broadcasted tracking area ID and / or adapting a list of tracking area IDs.

4. The wireless communication system (150) according to claim 2, wherein: The instructions for adapting the list of tracking area IDs in advance are performed by defining validity time window information for each list entry of the list of tracking area IDs.

5. The wireless communication system (150) according to claim 2, wherein: The list of tracking area IDs for the second time period includes a second tracking area ID belonging to the second tracking area (12b) and a third tracking area ID belonging to a third tracking area (12c); or wherein the list of tracking area IDs for the second time period includes the second tracking area ID belonging to the second tracking area (12b) but does not include the first tracking area ID belonging to the first tracking area (12a); or The list of tracking area IDs in the second time period includes a third tracking area ID belonging to a third tracking area and a fourth tracking area ID belonging to a fourth tracking area.

6. The wireless communication system (150) according to claim 1, further comprising: A user equipment is configured to receive the coverage beam and determine a tracking area of ​​the user equipment by comparing the assigned tracking area ID with the first tracking area ID and the second tracking area ID of the received list.

7. The wireless communication system (150) according to claim 6, wherein: The device is configured to: - reporting a single tracking area ID or first entry to the core network controller; and / or - Report multiple Tracking Area IDs to the Core Network Controller with or without beam / satellite IDs; - Report cross-tracking area IDs from multiple beams / satellites back to the core network controller; - Report multiple tracking area IDs in conjunction with time information.

8. The wireless communication system (150) according to claim 1, wherein: The first mobile transmission point (10, 10', 156) is a mobile or earth fixed beam footprint LEO satellite or earth fixed beam footprint GEO satellite, and / or wherein the first mobile transmission point (10, 10', 156) comprises a single-point or multi-point beam satellite or a transparent or regenerative satellite; or The first mobile transmission point (10, 10', 156) is a mobile transmission point (10, 10', 156) or a drone or a high altitude platform HAPS; or Wherein the wireless communication system (150) is formed by a terrestrial network and / or wherein the wireless communication system supports heterogeneous networks.

9. The wireless communication system (150) according to claim 1, wherein: The wireless communication system (150) comprises a second mobile transmission point (10, 10', 156), wherein the second mobile transmission point (10, 10', 156) is configured to broadcast a first tracking area ID belonging to a first tracking area (12a) or a list of tracking area IDs to at least the first beam coverage area (12) during a further limited predetermined time period, wherein the list of tracking area IDs comprises the first tracking area ID belonging to the first tracking area (12a) and the second tracking area ID belonging to the second tracking area (12b).

10. The wireless communication system (150) according to claim 1, wherein: The first beam coverage area (12) comprises at least two tracking areas at least during the first time period, each tracking area being assigned a fixed tracking area ID.

11. The wireless communication system (150) according to claim 1, wherein: If the paging message is dedicated to user equipment within the first tracking area (12a), the wireless communication system (150) routes the paging message to one or more beams (10bl, 10bl', 10b2') currently broadcasting the first tracking area ID; and / or, if the paging message is dedicated to user equipment within the second tracking area (12b), the paging message is routed to one or more beams (10b1, 10bl', 10b2') currently broadcasting the second tracking area ID.

12. The wireless communication system according to claim 1, in, User equipment includes one or more of the following: - a mobile terminal, or - Fixed terminal, or - Cellular IoT-UE, or - Vehicle-mounted UE, or -IoT or Narrowband IoT "NB-IoT" devices, or - Ground vehicles, or - an aircraft, or - Drones, or - mobile base station, or - Roadside Unit, or - buildings, or - a sensor or actuator having a network connection enabling the sensor or actuator to communicate using a wireless communication network, and / or The ground or non-ground mobile transmission point includes one or more of the following: - a macrocell base station, or - Small cell base station, or - a central unit of a base station, or - a distributed unit of a base station, or - Roadside Unit, or -UE, or - Remote Radio Head, or -AMF, or -SMF, or - a core network entity, or - Network slicing in the context of NR or 5G core, or - a satellite or space vehicle or a satellite-borne vehicle at a specific altitude and orbital period or orbital plane, or a low earth orbit LEO, or a medium earth orbit MEO, or a geosynchronous orbit GSO, or a geostationary orbit GEO, or a high earth orbit HEO, or - an airborne vehicle or unmanned aerial system UAS or tethered UAS or lighter-than-air UAS "LTA" or heavier-than-air UAS "HTA" or high altitude UAS platform "HAP", or - A transmission reception point TRP that enables an item or device to communicate using a wireless communication network, the item or device being equipped with a network connection to communicate using the wireless communication network.

13. The wireless communication system according to claim 1, comprising a core network or a core network entity, and a RAN network or an AMF, wherein the core network or the core network entity is configured to page a UE in the wireless communication system only via those transmission points indicated in the list of UEs; and / or in, The wireless communication system comprises: - terrestrial network, or - non-terrestrial network, or - a network or network segment using an airborne vehicle or a satellite-borne vehicle as a terminal, or -A combination of these.

14. A core network controller of the wireless communication system (150) according to claim 1, wherein the core network controller is configured to control the first mobile transmission point (10, 10', 156) for a broadcast tracking area ID, for a list of broadcast tracking area IDs, for an adapted broadcast tracking area ID, and / or for an adapted list of the tracking area IDs.

15. A core network controller of a wireless communication system (150) according to claim 1, wherein the core network controller is configured to: if the paging message is dedicated to user equipment within the first tracking area (12a), route the paging message to one or more mobile transmission points (10, 10', 156) selected for currently broadcasting the first tracking area ID using one or more beams (10bl, 10bl', 10b2'), and / or if the paging message is dedicated to user equipment within the second tracking area (12b), route the paging message to one or more mobile transmission points (10, 10', 156) selected for currently broadcasting the second tracking area ID using one or more beams (10bl, 10bl', 10b2').

16. A user equipment of a wireless communication system (150) according to claim 1, wherein the user equipment is configured to receive a coverage beam and a list broadcast using the coverage beam, and determine a tracking area of ​​the user equipment by comparing a tracking area ID assigned to the user equipment with a tracking area ID included in the list.

17. The user equipment according to claim 16, wherein: The user equipment receives another coverage beam from another mobile transmission point (10, 10', 156) during another subsequent time period, wherein the user equipment is configured to determine the tracking area of ​​the user equipment independently of which mobile transmission point (10, 10', 156) the already received assigned tracking area ID or the list including the assigned tracking area ID corresponds to.

18. A method for location management, the method comprising: Only during a limited predetermined first time period, a list of tracking area IDs is broadcasted to at least a first beam coverage area using a first non-terrestrial mobile transmission point (10, 10', 156), the first mobile transmission point (10, 10', 156) generating one or more beams (10bl, 10bl', 10b2') for temporarily covering a first beam coverage area (12), the first beam coverage area being dynamically arranged as a ground and being subdivided into a first tracking area (12a) and a second tracking area (12b), the list of tracking area IDs comprising a first tracking area ID belonging to the first tracking area (12a) and a second tracking area ID belonging to the second tracking area (12b); and / or only during a limited predetermined second time period after the first time period, broadcasting another list of tracking area IDs to at least a second beam coverage area (12) using a second non-terrestrial mobile transmission point, the another list including first tracking area IDs belonging to the first tracking area (12a), the second mobile transmission point (10, 10', 156) generating one or more beams (10bl, 10bl', 10b2') for temporarily covering the second beam coverage area (12); and The list of tracking area IDs is updated from time to time, i.e., when the first beam coverage area (12) no longer covers or serves the first tracking area (12a) and the second tracking area (12b), or when the first beam coverage area (12) covers or serves a third tracking area (12c).

19. The method for location management according to claim 18, further comprising: The first mobile transmission point (12a) is controlled for a broadcasted tracking area ID and / or for a list of adapted tracking area IDs.

20. The method for location management according to claim 19, wherein: The control is performed by defining a list of tracking area IDs for the first time period and another list of tracking area IDs for the second time period, or adapting the list of tracking area IDs in advance / during the second time period, or defining valid time window information for each list entry of the list of tracking area IDs.

21. A computer-readable digital storage medium having a computer program stored thereon, the computer program having a program code for executing the method according to claim 18 when running on a computer.

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