Patent Application
20240205778
The present disclosure generally relates to the field of telecommunication networks, and, more specifically, to method of facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, as well as corresponding nodes and modules.
Relay nodes, for example Integrated Access Backhaul, IAB, nodes, enable flexible and dense deployment of radio cells to increase Quality of Service for User Equipment, UE. Various methods and procedures for IAB nodes are defined in the 3GPP technical report 3GPP TR 38.874.
The IAB node is, for example, a Radio Access Network, RAN, node that support wireless access to UE and wirelessly backhauls the access traffic. The IAB-donor, for example a base station like the gNodeB, is a RAN node which provides the UE interface to the core network of the telecommunication network and wireless backhauling functionality to IAB nodes. IAB nodes may have smaller cells compared to regular base stations. IAB designs are depicted with five architecture reference diagrams. These diagrams vary corresponding to the modification needed on interfaces or additional required functionalities for example to accomplish multi-hop forwarding or anything alike.
In order to obtain OAM functionality for OAM configuration, the IAB node may authenticate with operator's network and establishes IP connectivity. Before initiating the UE's serving phase or further IAB node connections, the IAB node's DU, gNB or UPF are set up with all interfaces to other RAN-nodes and CN. Finally, the IAB node provides service to UE or other IAB nodes.
Topology adaption has the aim of topology modification to assure that an IAB node can provide services for User Equipment, UE, in the case of loss or degradation of current active backhaul path. Topology adaptation is consisting of information collection, topology determination and reconfiguration. In addition, IAB Topology adaptation can be caused by integration or detachment of an IAB node from the topology, backhaul link overload detection, link failure or backhaul link quality deterioration.
In the control plane, the handover preparation and execution phase is performed without core network involvement hence all the messages are exchanged among the base stations. In handover completion phase the release of the resources at the source base station is caused by the target base station. For the user plane handling, in order to avoid data loss during handover in the preparation phase, tunnels can be established among source and target base stations. So that, for execution phase user data can be forwarded.
The location management function, LMF, is arranged to manage the location of a registered UE for coordinating and scheduling of resources. This function evaluates the final location, estimates the velocity and may assess the acquired accuracy. It also obtains location demands for a target UE. In short, the LMF is arranged to determine the outcome of the positioning in geographical coordination.
One of the ongoing challenges in this field relates to the effective deployment of relay stations for supporting in the telecommunication needs of UE in a certain region.
WO 2013/137600 discloses a method for handover of UEs connected to a mobile relay node from a source Donor eNodeB, DeNB, to a target DeNB.
US 2015/334614 discloses a method of handover of a UE between a first base station of a first type and a second base station of a second different type in a cellular network.
US 2013/0225181 discloses a method wherein an access point reduces the service available to lower priority access terminals and/or increase the service available to higher priority access terminals when the usage of one or more resources at the access point exceeds a predetermined threshold.
WO 2014/127795 discloses a method for an inter-Radio access technology handover of a UE from a first network entity to a second network entity.
US2015/0171953 discloses a virtual range extender by selecting a second UE as a relay UE for a first UE.
In a first aspect of the present disclosure, there is presented a method of handing over a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station.
The method comprises the steps of:
The above described aspect may be best explained as follows. Whenever a particular relay node is deployed in a telecommunication network it may cover a particular area. The covered area of the relay node may be comprised by the covered area of the base station it associates with, i.e. the base station on behalf of which it relays traffic to, and from, UE. The covered area of the relay node is thus, typically, much smaller compared to the covered area of the base station.
The above entails that UE that are in range of the relay node may also be in range of the base station. Those UE may, most likely, receive better signals from the relay node compared to the signals received from the base station. The relay node is, after all, most likely closer to those UE compared to the base station.
The inventors have found that it may not be necessary to handover all UE in range of the relay node from the base station to the relay node. The present disclosure focusses on those UE that have a QoS parameter that is below a QoS threshold. The UE that have a Quality of Service that is beneath a given standard, are to be handed over from the base station to the relay station.
The above entails that not all UE in range of the relay station are to be handed over. UE that have a Quality of Service that is acceptable, i.e. above a particular standard, do not need to be handed over. These UE may still be serviced efficiently by the base station itself.
The inventors have found that thus not all UE in the area covered by the relay station are to be handed over to the relay station, as in such a situation, there is a risk that the UE that already have an acceptable QoS will experience a reduced QoS.
It is noted that the relay station is, for example, an Integrated Access Backhaul, IAB, node and the base station is, for example, a gNodeB of a 5G telecommunication network.
The IAB node may be a New Radio, NR, base station which is arranged for terminating the gNodeB-DU functionality towards the UE, access link, and towards gNodeB-CU.
The gNodeB, or the IAB donor, may be a NR base station which is arranged for terminating gNodeB-CU functionality towards the IAB node and N2/Xn interfaces towards the rest of the telecommunication network. The IAB donor may also terminate RRC/PDCP of the MT functionality of the IAB node as well as lower layers in case of single hop.
It is further noted that the QoS parameter may refer to any radio network condition such as throughput, received signal strengths, modulation and coding scheme, latency, etc.
In an example, the method further comprises the steps of:
In an example, the step of determining comprises:
The QoS Status module may be arranged to periodically monitor the QoS of any of the UE and may maintain that particular information. The QoS Status module may thus act as a central node maintaining QoS parameters of UE in the telecommunication network.
In a second aspect of the present disclosure, there is provided a method of facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station, wherein said method comprises the steps of:
It is noted that the advantages and definitions as disclosed with respect to the embodiments of the first aspect of the invention are also applicable to the embodiments of the second aspect of the invention.
The second aspect of the present disclosure is directed to a method performed by a QoS Status module, wherein the QoS Status module is arranged to receive QoS query requests from a relay node, and for transmitting a QoS query acknowledgement back to the relay node. These queries are directed to information whether the QoS parameter of a particular UE is below a QoS threshold.
In an example, the method further comprises the steps of:
The determining step as disclosed above may be conditional on the feature that a likelihood condition is met. The likelihood condition is discussed in more detail with respect to
The above described example is directed to the deployment of a new relay node in the telecommunication network. The inventors have found that the same concept may be utilized for deploying relay nodes in the telecommunication network. That is, a QoS region in which a plurality of UE are located that have a QoS parameter below a QoS threshold may be used for deploying a new relay node. The intention is that those UE are to be handed over to the newly deployed relay node.
In an example, the step of determining said QoS region comprises determining a centroid of said QoS region, and wherein said step of requesting comprises requesting deployment of said relay node at said determined centroid.
The locations of the UE having a QoS parameter below a QoS threshold may be used for determining a centre region of the QoS region. Preferably, the relay node is to be deployed at that centre region for efficiently serving the UE having a QoS parameter below the QoS threshold.
In a further example, the step of determining said QoS region comprises forecasting future QoS parameters and locations of said UE served by said base station based on previous QoS parameters and previous locations of said UE served by said base station.
In another example, the method comprises the steps of:
In a further aspect of the present disclosure, there is provided a relay node for facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station, wherein said relay node comprises:
In an example, the receive equipment is further arranged for receiving, from said UE, a reconfiguration complete message thereby indicating that said UE is handed over from said base station to said relay node, and wherein said transmit equipment is arranged for transmitting to a QoS Status Module a UE status update message thereby indicating that said UE is connected to said relay node.
In a further example, the transmit equipment is further arranged for transmitting a QoS query request to a QoS Status module for querying whether said QoS parameter of said UE is below said QoS threshold, and wherein said receive equipment is arranged for receiving from said QoS Status module a QoS acknowledgement thereby acknowledging that said QoS parameter of said UE is below said QoS threshold
In a further aspect of the present disclosure, there is provided a Quality-of-Service, QoS, status module for facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station, wherein said QoS status module comprises:
In an example, the QoS status module further comprises:
In a further example, the process equipment is further arranged for determining a centroid of said QoS region, and wherein said request equipment is arranged for requesting deployment of said relay node at said determined centroid.
In another example, the process equipment is further arranged for forecasting future QoS parameters and locations of said UE served by said base station based on previous QoS parameters and previous locations of said UE served by said base station.
In another aspect of the present disclosure, there is provided a relay manager module for cooperating with a QoS status modules in accordance with any of the examples provided above, wherein said relay manager module comprises:
In a further aspect, there is provided a computer program product comprising computer readable medium having instructions stored thereon which, when executed by a network function, cause said network function to implement a method in accordance with any of the method examples as provided above.
It is to be understood that a particular network node, for example the base station the relay node, the QSM or the LSM, may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. This is summarized by the wording equipment in the particular embodiments. Moreover, while the components of such a network are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component.
It is further noted that the QSM as well as the LSM may reside in the Radio Access Network, RAN, part of the telecommunication network.
The above mentioned and other features and advantages of the disclosure will be best understood from the following description referring to the attached drawings. In the drawings, like reference numerals denote identical parts of parts performing an identical or comparable function or operation.
Embodiments contemplated by the present disclosure will now be described in more detail with reference to the accompanying drawings. The disclosed subject matter should not be construed as limited to the embodiments set forth herein. Rather, the illustrated embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.
Here, UE with satisfactory and low QoS are represented with dots and crosses, respectively. As seen in
In the current technology, when a new relay node is setup in the region to handle low QoS problems, all UE in the range of the relay node would switch to the relay node, i.e. handed over to the new relay node, because the signal quality received from the new relay node would most likely be higher than that of the base station.
The inventors have found that this might not be the most efficient way forward. Some UE in the coverage 3 of the relay node 5 might be receiving a satisfactory UE already, and their handover to the new relay node 5 might not be necessary. In fact, the handover of these UE to the new relay node might even be undesired. That is, when UE with satisfactory QoS are being handed over to the new relay node besides the ones with low QoS, there might be negligible QoS increase for the UE with low QoS.
After a new IAB node is deployed and activated, all UE in the serving area of the new IAB node might request handover to the new relay node since signal quality from the new relay node will, most likely, be better than the signal quality from the base station. All UE may need to complete all steps of handover such as RRC Reconfiguration, UE Context Transfer, Path Switch, etc. Performing handover for all UE increases handover signaling overhead.
In the existing technology, relay nodes are used to extend the coverage or increase signal strength for UE. However, relay nodes are not aware which UE have lower QoS in advance. When all UE close to the new relay node, regardless of their current QoS, connect to the new relay node, the new relay node's data plane queue might get congested unnecessarily. Thus, in the existing technology, setting up new relay nodes in regions with low QoS might not significantly improve the QoS of the UE with low QoS.
Currently, relay nodes are not aware of the QoS of users in advance. If all UE close to the relay node connect to the new relay node, congestion might occur on the resource limited wireless backhaul of relay nodes. In such a case, some users that already receive high QoS might receive lower QoS if they connect to the new relay node.
The present disclosure is directed to methods and device to solve some problems in existing solutions regarding relay nodes. The QoS Status Module, QSM, may periodically monitor the QoS and location of UE with low QoS and may use a correlator method to detect or predict a low QoS region. Here, QoS may refer to any radio network condition such as throughput, modulation and coding scheme, latency, etc. When a low QoS region is identified, a new relay node may be activated through the IAB Manager Module, IMM, and only UE with low QoS in that region are admitted connecting to the new relay node via, for example, a handover.
In order to detect a low QoS region, the location ranges, based on location accuracy, of a plurality of low QoS UE are correlated with the coverage area of a potential relay node placed at the centroid of low QoS UE. This is, for example, shown in
If the low QoS UE are within the range of relay node with high probability, then a low QoS region is detected. In order to predict a future low QoS region, previous values of the QoS of UE and their location are processed with machine learning methods, such as multi-variate regression, to obtain forecasts on the future QoS and locations of UEs. First, low QOS UE are identified based on predicted QoS values. Then, same procedure is used to identify a low QoS region where location ranges of low QoS UEs are predictions instead. The above is explained in more detail with respect to
A UE 25, 26 is an end-user wireless communication terminal that is able to connect to a base station 4 like the gNodeB (IAB-donor) or the relay node 5 (IAB-node) for data transfer.
Relay node 5 is a Radio Access Network, RAN, node that supports wireless access to UE and wirelessly backhauls the access traffic. In the proposed solution, relay nodes can be activated on-demand by the IMM 24. A relay node can be fixed or a mobile on an Unmanned Aerial Vehicle, UAV.
The IAB-donor, or gNB, is a RAN node which provides UE's interface to the core network of the telecommunication network, and wireless backhauling functionality to IAB-nodes. IMM 24 is a functional node that interacts with IAB-node and QSM 23 for IAB activation, deactivation and management. IMM 24 receives regional IAB activation requests from QSM 23 and activates a suitable relay node or dispatches a UAV relay node to the region.
QSM 23 is a functional node that interacts with gNB and LSM to track the QoS status of the UEs and request location of low QoS UEs from LMF 22. QSM 23 correlates QoS and location of users to identify whether there is a regional low QoS issue. LMF 22 is a location services management function that can reply with the location, having an accuracy level, to the requesting functions.
An example correlator is shown in
Based on the chosen mode of correlator, the observed/forecasted locations and QoS values are used in the subsequent steps 38, 39, 40. In the next step of the correlator, all subsets 38 of low QoS UEs with more than one member may be computed. Then, for each subset, centroid 39 and likelihood of low QoS region is computed. An example scenario with three UE for centroid and likelihood computation is given in
Centroid is computed as the mean value of the locations of UE. Likelihood can be computed, for a given centroid, as the fraction of overlapping areas of location range and relay node range.
In the proactive mode, the location ranges may be forecasted for t+T.
The likelihood may be computed as follows.
p=(AUE1in+AUE2in+AUE3in)/(AUE1tot+AUE2tot+AUE3tot)
A
UEi
tot
=A
UEi
in
+A
UEi
out
Likelihood and centroid may be computed for each subset, and the largest subset with p>1−q, (q<<1), where p denotes the likelihood for a given centroid and q can be predefined by the operator, is identified as being in a low QoS region. For such a subset, likelihood and centroid are denoted with p{circumflex over ( )}* and C{circumflex over ( )}*, respectively. If none of the subsets satisfy the condition, the new relay node may not be activated, and the monitoring may continue.
As the final step, if a low QoS region is identified 40, new relay node activation request 41 is sent to the IMM and UE with low QoS in the range of new relay node are recorded to the Allowed Handover List in the QSM.
Following the activation 52, 53 of a new relay node on a low QoS region, access control for the handover requests to new relay node will be processed. As UE may continuously monitor the radio performance, when a new relay node is activated, any UE in the range of relay node might request handover 54 to the new relay node. Upon receiving a HO request 55, the base station may query the QSM regarding the status of requesting UE. If the UE is recorded as a low QoS UE in the relay node coverage, then the UE will be switched 57m 58 to the new relay node, which is then notified to the QoS Status module 59. Otherwise, the handover request will be rejected 60, and the UE will remain attached to base station.
An example procedure diagram 71 for new IAB node 5 activation is given
Then, QSM may send UE LCS REQUEST message 79 to the LMF with the UE identifier, and the LMF may reply with UE LCS REPLY message 80. The reply may include the location of the UE accompanied with an accuracy. If QSM decides 81 to activate a new IAB node, then it may send an IAB NODE ACTIVATION REQUEST message 82 including the requested IAB location to IMM. Then, IMM may send an IAB NODE ON REQUEST message 83 to an available IAB node on the requested IAB location, and the IAB node may perform IAB Node RRC and Integration setup 84 with the base station 4. IAB node may reply with IAB NODE ON COMPLETE message 85 to notify the IMM regarding the activation status. Finally, IMM may send an IAB NODE ACTIVATION COMPLETE message 86 to the QSM.
An example procedure diagram 91 for UE access control is given in
Based on this message, the IAB node 5 may send HO ACK/NACK 97 to the gNB 4. If HO NACK is sent, meaning the UE 92 is not allowed to handover, the procedure does not proceed further. If HO ACK is sent, RRC RECONFIG message 98 may be sent from the gNB 4 to the UE 92 and the UE switches 99 its cell. Then the UE may send a RRC RECONFIG COMPLETE message 100 to the new IAB and IAB may send a UE LOW QOS ATTACHED message 101 to the QSM for UE status update.
The relay node 5 is arranged for facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station, wherein said relay node comprises:
The Quality-of-Service, QoS, status module 23 is arranged for facilitating the handover of a User Equipment, UE, in a telecommunication network from a base station to a relay node, which relay node is arranged to relay traffic between serving UE and said base station, wherein said QoS status module 23 comprises:
The QoS status module may comprise a processor 123 in conjunction with a memory 124.
The relay manager module is arranged for cooperating with a QoS status module in accordance with any of the claims 13-15, wherein said relay manager module 24 comprises:
The relay manager module 24 may comprise a processor 133 connected to a memory 134.
One of the aspects of the present disclosure is that the functional system block QSM may monitor the QoS and locations of UE via the base station, may identify low QOS region, may request new relay node activation and may respond to queries for low QOS UE access control.
Another aspect of the present disclosure is that the functional system block IMM may continuously monitor relay nodes and may activate a relay node upon request from the QSM.
The Low QoS Region Identification Method running in the QSM, and as explained with respect to
The UE Access Control Method, as explained with respect to, for example,
Other variations to the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed disclosures, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope thereof.
The present disclosure is not limited to the examples as disclosed above, and can be modified and enhanced by those skilled in the art beyond the scope of the present disclosure as disclosed in the appended claims without having to apply inventive skills.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20404002.6 | Mar 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/071475 | 7/30/2020 | WO |
