METHOD FOR RECONFIGURING A RADIO COMMUNICATIONS INFRASTRUCTURE IN THE EVENT OF RADIO JAMMERING AND CORRESPONDING RADIO COMMUNICATIONS INFRASTRUCTURE

Description

[0001] The present invention relates to radio communication networks in situations of frequency interference.

[0002] When the frequency band on which a communication link is established between a user terminal and a base station of a radio communication network is affected by interference, the quality of communication on this link is degraded. Interference is understood to mean any interference not controlled by the radio communication network. This can lead, in extreme cases, to the interruption of the communication in progress.

[0003] US 2017 / 238226 A1 discloses progressive toggling of communications between user equipment and a base station of a radio communication network. While communications are carried out on a first frequency band, if interference is detected, communications are progressively switched to a second frequency band.

[0004] Document US 6,047,188 A) discloses a radiocommunication infrastructure equipped with a switching device common to several base stations. To avoid instabilities, until a base station has finalized its switch to a new working frequency, the device blocks switchover requests from other base stations.

[0005] Document US 2002 038970 A1 describes the different PDCP, RLC, MAC, PHI blocks of a radio chain. These blocks will be defined below.

[0006] According to the state of the art, protection against interference can be achieved by signal processing techniques implemented at the physical layer, such as "frequency evasion", for example frequency hopping. The frequency of the radio link between the base station and a user equipment UE is changed according to a predefined sequence of frequency hops.

[0007] Furthermore, a mechanism is known, provided for by the 3GPP standard and called dual connectivity - DC ( "dual connectivity" in English), according to which a user equipment, while it has established a first link with a first base station, called master station, simultaneously establishes a second link with a second base station, called secondary station, different from the first base station. This makes it possible to transmit and receive via the master station and / or via the secondary station. For example, if the master station is a 5G station and the secondary station is a 4G station, packets can be routed in 4G via the link with the secondary station and other packets in 5G via the link with the master station, depending on the availability of resources on one of the other paths. This mechanism is for example defined in the 3GPP document TR 37.716 for 5G.

[0008] The aim of the present invention is to solve the problem of protection against interference in an alternative manner, advantageously relying on the dual connectivity mechanism - DC.

[0009] For this purpose, the invention relates to a method for reconfiguring a radiocommunication infrastructure in the event of interference and a radiocommunication infrastructure in accordance with the appended claims.

[0010] The invention and its advantages will be better understood upon reading the following detailed description of a particular embodiment, given solely as a non-limiting example, this description being made with reference to the appended drawings in which: [ Fig 1 ] There figure 1 is a schematic representation of a preferred embodiment of the infrastructure [ Fig 2 ] There figure 2is a block representation of an embodiment of a base station of the infrastructure of the figure 1 ; And, [ Fig 3 ] There figure 3 is a representation of a sequencing of the steps of an embodiment of the method according to the invention implemented by the infrastructure of the figure 1 . Structure

[0011] A preferred embodiment of the radio communication infrastructure is shown in the figure 1 Infrastructure 2 includes: a radio communication network 20; a user terminal 10; an orchestration server 30.

[0012] The radio communication network 20 comprises a plurality of base stations, such as the base stations 21 and 22. It comprises, associated with each base station, a frequency scanner, such as the scanners 25 (associated with the base station 21) and 26 (associated with the base station 22). It also comprises a gateway GW 23 for communication from the network 20 to the orchestration server 30.

[0013] Referring to the figure 2 , a base station, like station 21, includes: a block 100 of packet data convergence protocol - PDCP ("Packet Data Convergence Protocol"); a first radio chain 110, comprising a first radio link control block - RLC ("Radio Link Control") 112, a first media access control block - MAC ("Medium Access Control") 114, a first physical layer access block - PHY ("PHYsical layer") 116 (following a decomposition according to the lower layers of the OSI model), as well as hardware transmission / reception means 118; and, a second radio chain 120, comprising a second RLC block 122, a second MAC block 124, a second PHY block 126, as well as hardware transmission / reception means 128.

[0014] The PDCP block 100 performs the typical functionalities of the PDCP layer according to the 3GPP standard implemented by the radio communication network 20. For example, in the LTE radio protocol stack, the PDCP layer is located above an RLC layer and below an IP layer (for the user plane) and an RRC layer (for the control plane). The PDCP layer is bidirectional, operating in transmission and reception. The main function of the PDCP layer is, in transmission, the compression of the IP packet header by removing redundant headers from one packet to another, and, in reception, by reconstructing the complete headers for the IP layer. The PDCP layer can also perform a security function.

[0015] In the embodiment presented here in detail, the PDCP block is common to both radio chains. Alternatively, each chain could include a PDCP block.

[0016] According to the invention, the PDCP block 100 comprises a switching module 102, capable of switching downlink traffic (control plane and user plane) to the first radio chain 110 or to the second radio chain 120. It should be noted that, in a possible implementation of the dual connectivity mechanism - DC, the PDCP block of the master station comprises such a traffic switching module to transmit the packets either to the radio chain of the master station, or to the radio chain of the secondary station.

[0017] In a nominal operating mode of the infrastructure, the switching module 102 routes the traffic to a main channel, selected from the first and second radio channels, 110, 120, the other channel then being considered as an auxiliary channel.

[0018] When interference is detected, the infrastructure switches to a parasitic operating mode.

[0019] The switching module 102 is then controlled by the reception of an interference notification NP received from the first chain 110 or from the second chain 120 to direct the traffic from the main chain to the auxiliary chain.

[0020] When the interference notification comes from the first channel 110, NP1, the switching module 102 is able to direct the traffic from the first channel 110 used until the instant of receipt of the interference notification as the main radio channel to the second channel 120 used until this instant as the auxiliary radio channel. The second channel 120 is then promoted to the main radio channel, while the first channel 110 is degraded to an auxiliary channel.

[0021] When the interference notification comes from the second channel 120, NP2, the switching module 102 is able to direct the traffic from the second channel 120 used until the instant of receipt of the interference notification as the main radio channel, to the first channel 110 used until this instant as the auxiliary radio channel. The first channel 110 is then promoted to the main radio channel, while the second channel 120 is degraded to an auxiliary channel.

[0022] When redirecting traffic from the main radio chain to the auxiliary radio chain, the switching module 102 is able to transmit an MB switchover notification to the orchestration server 30 indicating a change in the assignment of the main chain role from one chain to the other.

[0023] The first channel 110 is capable of operating on a first frequency band selected from a set of possible frequency bands. The set of possible frequency bands is included in the frequency spectrum of the radiocommunication technology implemented by the network 20. This set depends on the frequency bands owned by the operator of the network 20.

[0024] The first 110 radio channel is frequency reconfigurable.

[0025] For example, reconfiguring the first radio chain 110 to operate in a newly selected first frequency band involves turning off the first chain 110, instantiating the characteristics of the newly selected first frequency band, and turning the first chain 110 back on so that the various blocks thereof operate in the newly selected first frequency band. Alternatively, there are reconfiguration mechanisms that do not require turning off the radio chain, for example based on a selector of the frequency band of the radio chain.

[0026] The first RLC block 112 implements the classic RLC layer functionalities according to the 3GPP standard. The main functions of the RLC layer are segmentation and reassembly of PDCP layer packets to adapt them to the size that can be effectively transmitted over the radio interface. In addition, the RLC layer performs reordering to compensate for out-of-order reception of data by lower layers.

[0027] The first MAC block 114, implements the classic MAC layer functionalities according to the 3GPP standard. In transmission, the MAC layer encapsulates the data frames provided by the RLC layer into frames appropriate to the transmission medium, adds a frame check sequence to identify transmission errors, and transmits the data to the PHY layer. The MAC layer controls when data is sent to the PHY layer to avoid collisions. The MAC layer compensates for collisions by initiating a retransmission of the data. In reception, the MAC layer ensures data integrity by checking the frame check sequences and removing the preamble and padding before transmitting the data to the RLC layer.

[0028] The first PHY block 116 performs the classic functionalities of the PHY layer according to the 3GPP standard. In transmission, the PHY layer defines the means of transmitting a bit stream in the form of a signal which will be transmitted by the first hardware means 118 to a user terminal. It performs an inverse work in reception on the signal received from a user terminal

[0029] According to the invention, the first chain 110, preferably the first MAC block 114, is modified so as to comprise a first interference detection module 115. This first module 115 is capable of detecting interference on the first frequency band used at the current time by the first radio chain 110.

[0030] For example, while a communication link is established between the base station and a user terminal, via the first radio chain 110, a continuous analysis of the radio measurements by the first module 115 (report of the measurements carried out by the user terminal on the downlink then transmitted to the first radio chain of the base station and / or report of the measurements carried out by the first radio chain on the uplink) makes it possible to detect an anomaly characterized for example by a sudden drop in performance. Advantageously, a complementary analysis can be carried out to determine the causes of a detected anomaly in order to confirm that it is indeed a situation of interference and not a technical failure for example of a component of the base station.

[0031] In the event of interference being detected on the first frequency band, the first module 115 is capable of generating a first interference notification, NP1, and transmitting it to the switching module 102.

[0032] The second chain 120 is similar to the first chain 110, except that it is capable of operating on a second frequency band. Like the first frequency band, the second frequency band is selected from the set of possible frequency bands. However, at any time of operation, the second frequency band selected for the second chain 120 is different from the first band selected for the first chain 110, such that, when one frequency band is affected by interference, the other frequency band provides a fallback solution allowing ongoing communication between a mobile terminal and the base station to continue.

[0033] For example, reconfiguring the second radio chain 120 to operate in a newly selected second frequency band includes turning off the second chain 120, instantiating the characteristics of the newly selected second frequency band, and turning on the second radio chain 120 again so that its various blocks operate in the newly selected second frequency band.

[0034] According to the invention, the second chain 120, preferably the second MAC block 124 of the second chain, is modified to include a second interference detection module 125. This second module 125 is capable of detecting interference on the second frequency band used at the current time by the second chain 120. In the event of interference being detected, the second module 125 is capable of generating a second interference notification, NP2, and transmitting it to the switching module 102.

[0035] A frequency scanner, such as the scanner 25 or the scanner 26, is capable of scanning the frequency bands of the frequency spectrum or, at least, all of the possible frequency bands of the frequency spectrum, which are the frequency bands selectable by the first and second radio chains 110 and 120, of the associated base station. A scanner is capable of carrying out measurements of received power per frequency band in the frequency spectrum in order to identify the frequency bands which are, at the instant in question, free or little used in the coverage area of ​​the associated base station. A scanner is capable of transmitting regularly (or upon request from the orchestration server following receipt of a switchover notification) a map of the free frequency bands CL to the orchestration server 30.

[0036] The orchestration system 30 implements a frequency planning module 32, to ensure, following the reception of a NB switchover notification from a base station, the reconfiguration of a interfered radio chain of this base station. The frequency planning module determines the frequency choices to be applied to the interfered radio chain, which is at this moment the auxiliary chain of the base station, so that it is subsequently possible to switch the traffic to this auxiliary chain in the event of interference of the main radio chain.In the preferred embodiment, the module 32 takes into account the measurements carried out by the frequency scanner associated with the base station in question and possibly other criteria, such as for example: the radio constraints on the antennas of the auxiliary radio chain, the quality of experience - QoE ("Quality of Experience") requirements which may require more or less bandwidth, the operating frequency bands of the base stations neighboring the base station in question to avoid interference between neighboring cells, etc. The selection of a new frequency band is transmitted, in a configuration message MC, from the frequency planning module to the base station 21 of which the orchestration server 30 has control, for reconfiguration of the auxiliary radio chain.

[0037] In addition, the orchestration system 30 implements a failover module 34 capable of generating and transmitting a provisioning message MP to the mobile terminal connected to the base station via the main radio chain, in order to provide it with information relating to the auxiliary radio chain, in particular the new frequency configuration dynamically allocated to the auxiliary radio chain.

[0038] Preferably, the communication between the orchestration server 30 and the user terminal 10 is carried out on the standardized interface S14 of the control plane of the link between the base station and the user terminal. The S14 interface is a standardized interface of the 3GPP technology to which the radiocommunication network 20 belongs, which is normally used as a communication interface between the user equipment - UE and the "Access network discovery and selection function" - ANDSF entity. Thus, according to the invention, the S14 interface is used in a manner different from that recommended by the standard.

[0039] The user terminal stores information relating to the auxiliary channel. Thus, in the event of jamming of the main channel requiring it to be stopped and therefore a loss of the current link, the user terminal first seeks to establish a new link with the auxiliary channel. Knowing the radio characteristics of the latter, in particular the operating frequency band of the auxiliary channel, the user terminal does not have to scan the entire spectrum in search of an available frequency band. There is therefore, in uplink communication, an immediate switch of traffic from the interfered main radio channel to the non-interfered auxiliary channel. Functioning

[0040] The method according to the invention will now be described with reference to the figure 3 , which illustrates the sequence of steps implemented by the different entities of infrastructure 2 described previously.

[0041] Phase 201 of method 200 corresponds to a nominal operation of infrastructure 2. For example, the first radio chain 110 is the main radio chain, while the second radio chain 120 is the auxiliary radio chain. The first radio chain 110 is configured to operate in a first frequency band F1, while the second radio chain 120 is configured to operate in a second frequency band F2.

[0042] Thus, at any time, the switching module 102 directs (step 210) the downlink traffic destined for the user terminal - UE 10 towards the first channel 110.

[0043] The communication link between the user terminal 10 and the base station 21 is a first link 212 between the user terminal 10 and the first radio chain 110.

[0044] At any time, the module 115 analyzes (step 214) the quality of the first link 212 in order to detect an interference event of the first frequency band F1.

[0045] In parallel, at step 216, the scanner 25 associated with the base station 21 transmits CL maps indicating the spectrum bands which are free or little used.

[0046] Then, the infrastructure switches from the nominal operating mode to a parasitized operating mode (phase 202), at the moment when the analysis module 115 actually detects (step 218) interference in the first frequency band F1.

[0047] In step 220, the jamming module 115 of the first chain 110 then sends an interference notification NP to the switching module 102.

[0048] In step 222, upon receipt of the NP interference notification, the switching module 102 immediately redirects the downlink traffic to the second radio channel 120 which was until now the auxiliary channel. The second radio channel 120 is then promoted to the main channel while the first radio channel 110, which was until now the main channel, is degraded and becomes the auxiliary channel.

[0049] The first radio channel 110 is preferably switched off so that, in step 224, the first link 212 is interrupted.

[0050] In step 226, the user terminal 10, noting that the first link 212 has disappeared, reads the information relating to the configuration of the second radio channel 120 that it has stored. In particular, the second frequency band F2 on which to establish the second link is indicated, so that the user terminal does not have to scan the entire spectrum in search of a frequency band.

[0051] The user terminal 10 adjusts the operating frequency of its transmission / reception module to operate in the second frequency band F2, so that a second link 228 can be established almost immediately with the second radio chain 212 so as to continue the communication in progress with the base station 21. The communication which was in progress on the first link 212 therefore continues, almost without interruption, on the second link 228.

[0052] In step 222, the switching module 102, after having redirected the traffic by switching from one chain to another, sends (step 230) a switch notification NB to the orchestration server 30.

[0053] In step 232, the orchestration server 30, upon receipt of the NB switchover notification, executes the frequency planning module with the aim of selecting, in the spectrum, a new frequency band F1' allowing a reconfiguration of the first parasitized chain.

[0054] The frequency planning module uses the last CL map transmitted in step 216 by the frequency scanner 25 associated with the base station 21.

[0055] In step 234, the orchestrator service 30 transmits a configuration message MC to the base station 21. This configuration message indicates the new frequency band F1' that the first radio chain 110 must now use.

[0056] In step 236, upon receiving the MC configuration message, the base station 21 configures the first radio channel 110 with the information contained in the MC message.

[0057] Furthermore, in step 238, the provisioning module 34 of the orchestration server 30 sends a provisioning message MP on the interface S14 to the user terminal 10. The information contained in the message MP is stored by the terminal 10. In particular, the new operating frequency band F1' of the first radio chain 110 is stored.

[0058] The reconfiguration phase 202 then ends and the infrastructure returns to a nominal operating mode 201', in which the second radio chain 120 is used as the main chain to support the communication in progress with the user terminal 10, and the first chain is used as the auxiliary chain ready to take over in the event of jamming of the main chain. Variants and advantages

[0059] In the nominal operating mode, all traffic is routed via the main chain. Alternatively, traffic segregation is possible, with only priority traffic being routed via the main chain and non-priority traffic (or traffic associated with lower priority slices) being routed via the auxiliary chain.

[0060] Alternatively, instead of using a frequency scanner, the measurements collected by the various user terminals connected to the base station in question are used to determine the situation of the electromagnetic environment. Indeed, a user terminal has the ability to scan all or part of the spectrum and transmit the measurements taken to the base station.

[0061] Alternatively, the invention applies to the case provided by the dual connectivity mechanism - DC, namely the implementation of two separate base stations, a master station (comprising the first radio chain) and a secondary station (comprising the second radio chain). The present invention can thus constitute an improvement to an architecture implementing the dual connectivity mechanism - DC.

[0062] If in the embodiment presented in detail above, the traffic controller is located at the base station, alternatively, it is remote in the network, for example in the core network as provided for in a possible implementation of the dual connectivity mechanism - DC according to the 3GPP standard.

[0063] In a simplified implementation, instead of an orchestration server, a supervisor ("Scheduler" in English) is used, preferably installed in the base station which it allows to be reconfigured.

[0064] Thus, the invention makes it possible, in a highly disturbed electromagnetic environment, to ensure the continuity of current services.

Claims

1. A method (200) for reconfiguring a radiocommunication infrastructure (2) in case of interference, the radiocommunication infrastructure comprising a user terminal (10) and a radiocommunication network (20), the radiocommunication network comprising a base station (22) comprising a first radio channel (110) for establishing a first communication link with the user terminal in a first frequency band, and a second radio channel (120) for establishing a second communication link with the user terminal in a second frequency band, different from the first frequency band, the radiocommunication network further comprising a routing module (102) capable of directing the traffic of a communication in progress with the user terminal either to the first radio channel or to the second radio channel, comprising the steps of: - while a first link between the user terminal and the first radio channel is established, analyzing (214) a quality of the first link by the base station; - in the event of degradation of the quality of the first link, degradation indicative of interference on the first frequency band, transmitting (220) an interference notification intended for the routing module; upon receipt of the interference notification, - directing (222), by the routing module, the traffic of the communication in progress with the user terminal of the first radio channel toward the second radio channel; and - establishing (226) a second link between the user terminal and the second radio channel of the base station; characterized in that the method comprises the following steps: - transmitting (230), via the routing module, a handover notification to an orchestration server (30) connected to the radiocommunication network; when receiving the handover notification, - selecting (232), via the orchestration server, a new frequency band as first frequency band and ordering (236) reconfiguring of the first radio channel so that it operates in the new selected frequency band; and, - providing (238) the user terminal with information relating to the new frequency band selected for the first radio channel.

2. The method according to claim 1, wherein, the radiocommunication network (20) comprising a base station (21), the base station groups together the first and second radio channels (110, 120).

3. The method according to claim 1 or claim 2, wherein each radio channel among the first and second radio channels (110, 120) comprises a packet data convergence protocol, PDCP, block (100), a radio link control, RLC, block (112, 122), a media access control, MAC, block (114, 124) and a physical layer, PHY, access block (116, 126), the PDCP block possibly being common to the first and second radio channels.

4. The method according to claim 3, wherein the routing module (102) is integrated into the PDCP block (100).

5. The method according to claim 3 or claim 4, wherein the MAC block of each radio channel among the first and second radio channels (110, 120) comprises a module (115, 125) for analyzing the quality of the current link between the radio channel and the user terminal.

6. The method according to any one of claims 1 to 5, wherein the orchestration server (30) takes account of a mapping (CL) of the free frequency bands at the current instant to select a new frequency band when receiving a handover notification.

7. The method according to claim 6, wherein a mapping (CL) is determined by a frequency scanner (25, 26), preferably associated with the first and second radio channels.

8. The method according to any one of claims 1 to 7, wherein the orchestration server (30), to select a new frequency band upon receipt of a handover notification, takes into account additional criteria among the quality of service and a frequency band used at the current time by base stations of the radiocommunication network.

9. A radiocommunication infrastructure (2) comprising a user terminal (10), a radiocommunication network (20), and an orchestration server (30) connected to the radiocommunication network, the radiocommunication network comprising a first radio channel (110) for establishing a first communication link with the user terminal in a first frequency band, and a second radio channel (120) for establishing a communication link with the user terminal in a second frequency band, different from the first frequency band, the radiocommunication network further comprising a routing module (102) capable of directing the traffic of the communication in progress with the user terminal toward a channel among the first and second radio channels, a module (115, 125) for analyzing the quality of the current link with the mobile terminal, the radiocommunication infrastructure being adapted to implement a reconfiguration method (200) in the event of detection of interference according to any one of claims 1 to 8.