Patent ID: 12207137

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following, description will be made to example embodiments of the present invention. It is to be understood, however, that the description is given by way of example only, and that the described example embodiments are by no means to be understood as limiting the present invention thereto.

Before describing example embodiments in detail, the problem underlying the present application is described in some more detail.

As mentioned above, RAN3 has enabled Rel-15 signalling allowing per-operator gNB-CU in network sharing scenario where physical layer cell resources are shared between multiple operators. This is documented as follows in TS 38.401 CR #0067r1 (R3-193259):

“One gNB-DU is connected to only one gNB-CU.

NOTE: In case of network sharing with multiple cell ID broadcast, each Cell Identity associated with a subset of PLMNs corresponds to a gNB-DU and the gNB-CU it is connected to, i.e. the corresponding gNB-DUs share the same physical layer cell resources.

NOTE: For resiliency, a gNB-DU may be connected to multiple gNB-CUs by appropriate implementation.”

This new solution implies new scenarios to be supported such as operator addition and operator removal. Some limited description for inter-CU coordination can be found in TS 38.401 CR #0067r1 (R3-193259) annex B.

This description doesn't cover neighbour relation information coordination, and it is also indicated that “Other coordination between gNB-CUs is ensured by appropriate implementation”.

FIG.5shows an CU/DU split architecture, illustrating a scenario with distributed units DU1to DUn denoted by reference signs61,62,63,64and6n, which share the same physical radio resources, and two centralized units CU1and CU2denoted by reference signs51and52.

It is noted that it is broadly assumed that per-PLMN DUs sharing the same radio resources are collocated. In this description we refer to a group of such per-PLMN DUs as a “DU” or “gNB-DU”.

According to some example embodiments, measures are provided by which it is possible that an operator entering a shared network may benefit from already established neighbour relation information (ANR, mobility thresholds) in order to be able to immediately serve its subscribers, and that standardized coordination for this could be considered in future releases.

ANR (Automatic Neighbour Relation) is a function by which a network element such as a gNB can automatically determine which cells are their neighbours. If a newly entered sharing operator has to perform ANR from scratch in an area where the neighbour relations are already well established, its subscribers would unnecessarily experience slower handover execution due to the necessity to perform UE CGI reading, perform TNL discovery and setup new X2 and Xn interfaces each time a “new” neighbour relation is discovered. The newly entered operator may have few users in that area (hence the RAN sharing), so the UE-based ANR process could take time until the full set of neighbour relations is robustly identified. And the same problem is valid for the cell individual offset for MRO; the newly entered operator must use a pre-configured CIO (Cell Individual Offset), without taking benefit from information already available.

The same problem occurs when network topology in that area is updated.

The problem can typically not be solved via OAM, because different operators use different OAMs.

Example embodiments aim to solve this problem.

In the following, a general overview of some example embodiments is described by referring toFIGS.1and2.

FIG.1shows a distributed unit (DU)11as an example for a first apparatus according to the present example embodiment. The DU11may be, together with other distributed units and/or at least one centralized unit (CU) shown inFIG.2, be provided in a gNB or a similar network element. The apparatus may be the distributed unit, or may be a part of the distributed unit, or may be a network element comprising the distributed unit.

The DU11is connectable to at least one user equipment by a radio connection, and being connectable to at least one centralized unit (e.g., CU2shown inFIG.2). The DU11comprises at least one processor111and at least one memory112including computer program code. The at least one processor111, with the at least one memory112and the computer program code, is configured to cause the apparatus to perform: sending to at least one centralized unit sharing information which concern information about sharing of same physical radio resources of the apparatus (as shown, for example, in messages1,3,6and10inFIG.3to be described later).

FIG.2shows a centralized unit (CU)21as an example for a second apparatus according to the present example embodiment. The CU21may be, together with at least one distributed unit (DU) such as shown inFIG.1and other centralized units be provided in a gNB or a similar network element. The apparatus may be the centralized unit, or may be a part of the centralized unit, or may be a network element comprising the centralized unit.

The CU21is connectable to at least one distributed unit (e.g., DU11shown inFIG.2). The CU21comprises at least one processor211and at least one memory212including computer program code. The at least one processor211, with the at least one memory212and the computer program code, is configured to cause the apparatus to perform: receiving, from the at least one distributed unit sharing information which concern information about sharing of same physical resources of the apparatus with more than one centralized unit (as shown, for example, in messages1,3,6and10inFIG.3to be described later).

The DU11may further comprise an I/O unit113, which is capable of transmitting to and receiving from the CU21, and the CU21may further comprise an I/O unit213, which is cable of transmitting to and receiving from the DU11, for example.

Thus, according to example embodiments, information concerning sharing of physical radio resources by a distributed unit is shared between the distributed unit and the centralized unit(s).

For example, the sharing information described above may comprise indicating whether the distributed unit is sharing physical radio resources or not, or may comprise a setup that is being shared with another centralized unit, or may a neighbour relation information, which indicate information concerning neighbour cell relations. For example, the neighbour relation information may be ANR information or the like. Indicating whether the distributed unit is sharing physical radio resources or not may be performed by including an indicator (such as a “Shared Physical Resource Indicator” described later) in the sharing information.

In the following, some example embodiments are described in more detail.

In particular, the following is proposed:

Signaling from collocated DUs to the corresponding possibly separated CUs to indicate sharing of the same physical layer cell resources.

In the presence of sharing of physical layer cell resources, the appropriate signaling and mechanisms to transfer CU related neighbour information to DU over F1 interface are provided, and signaling and mechanisms to update neighbour related information at the DU when this information has changed are provided.

This is described in the following in more detail by referring toFIG.3, which shows an example in which a DU is connected to two CUs, namely CU1and CU2.

A gNB-DU can indicate to a gNB-CU whether it is sharing physical radio resources. This can be done by adding a new information element “Shared Physical Resource Indicator” (which may also referred to as “Shared gNB-DU Indicator”) at F1 SETUP REQUEST message from gNB-DU to gNB-CU (Message1).

A gNB-DU indicates at setup that it is being shared already with other gNB-CU(s).

The Shared Physical Resource Indicator IE can be a binary variable taking value 1 if the gNB-DU is shared and 0 otherwise.

As shown inFIG.3, in process A it is assumed that the DU operates only under CU1. In message1, the DU sends the F1 SETUP REQUEST message, which includes the Shared Physical Resource Indicator. The CU2may then respond with a F1 SETUP RESPONSE message including an ANR Info Subscription Request in message2. That is, the CU2subscribes to ANR information at the DU.

A gNB-DU operating under a gNB-CU in a non-shared mode may become shared when e.g., a new operator joins. The DU in that case may indicate this change of status from non-shared to shared in a gNB-DU CONFIGURATION UPDATE message from gNB-DU to the gNB-CU it is connected.

This is shown inFIG.3in message3. That is, the DU sends a GNB-DU CONFIGURATION UPDATE message to the CU1, which includes the Shared Physical Resource Indicator. The CU1may then respond with an update acknowledgment in a GNB-DU CONF ACK message, which comprises an ANR Info Subscription Request, in message4. That is, similar as in case of message2, the CU1subscribes to ANR information at the DU.

When the CU1has updated ANR information, it sends a GNB-CU ANR INF UPDATE message including ANR information to the DU in message5. The DU forwards this updated ANR information in a GNB-DU ANR INFO UPDATE message to the CU2in message6.

Thus, if the gNB-CU2receives an F1 SETUP REQUEST from the gNB-DU with the indication “Shared Physical Resource Indicator” (message1), the gNB-CU2in the F1 SETUP RESPONSE may request neighbour relation information pertaining to gNB-CU1(messages2-6). Communication of neighbour relation information takes place through the shared DU. It is noted that the ANR information shown inFIG.3is only an example for neighbour relation information.

The request of neighbour relation information in the F1 SETUP RESPONSE is triggered by the DU's change of status from non-shared to shared (message2, message4).

It is now assumed that in process B, the CU2performs a TNL discovery towards neighbour gNBs, and in process C, the CU2detects new neighbour cell relations. Hence, the CU2has updated ANR information. Therefore, the CU2sends a GNB-CU ANR INFO UPDATE message including the ANR information to the DU in message7. The DU forwards the ANR information in a GNB-DU INFO UPDATE message to the CU1in message8.

Likewise, it is assumed that the CU1detects new neighbour cell relations in process D. Then, the CU1sends updated ANR information in a GNB-CU-ANF INFO UPDATE to the DU in message9. The DU forwards the ANR information in a GNB-DU INFO UPDATE message to the CU2in message10.

A gNB-CU can maintain a table of sharing relationships. Namely, gNB-DU IDs that are shared and with which PLMN IDs, which identify the operators, this sharing takes place. When a gNB-CU detects new neighbours, it sends an update message to its gNB-DUs with the updated info.

That is, only new “undiscovered” information needs to be communicated in messages7,9.

When a gNB-DU receives new neighbour relationships from a gNB-CU, it must inform all other gNB-CU(s) with which it is being shared (Messages8,10).

The gNB-DU could alternatively send a gNB-CU ANR information upon request from a gNB-CU.

Hence, according to example embodiments, the following advantages can be achieved:

A newly entered operator can start using the network immediately, and its subscribers will benefit from an already optimized network.

The quality of the neighbour information will not depend on the number of UEs for that operator in the given geographical area.

The above-described example embodiments are only examples and may be modified.

Names of network elements, protocols, and methods are based on current standards. In other versions or other technologies, the names of these network elements and/or protocols and/or methods may be different, as long as they provide a corresponding functionality.

In general, the example embodiments may be implemented by computer software stored in the memory (memory resources, memory circuitry)112,212and executable by the processor (processing resources, processing circuitry)111,211or by hardware, or by a combination of software and/or firmware and hardware.

As used in this application, the term “circuitry” refers to all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of “circuitry” applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term “circuitry” would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term “circuitry” would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

The terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as non-limiting examples.

The memory (memory resources, memory circuitry)112,212may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, and non-transitory computer-readable media. The processor (processing resources, processing circuitry)111,211may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi core processor architecture, as non-limiting examples.

It is to be understood that the above description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.