Patent Application
20180343578
The present invention relates to the wireless communication systems, and more specifically to a method for improving the UE WLAN measurement reporting in LTE WLAN link aggregation for a wireless communication system and also to a wireless communication system with improved UE WLAN measurement reporting in LTE WLAN link aggregation.
Due to growing traffic demand and increasing importance for unlicensed spectrum, 3GPP has defined network controlled LTE WLAN Aggregation (LWA) in Release 13, supporting both collocated and non-collocated scenarios as defined in 3GPP TS 36.300 v13.3.0.
The introduction of the Xw interface (105) in
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LTE small cell and WLAN AP/AC deployed in the high-density area, such as enterprises, stadiums, convention centers, auditoriums, shopping malls and etc. can be beneficial from LWA and LWIP. As discussed earlier, both LWA and LWIP still need to rely on the LTE licensed spectrum for WLAN measurement reporting. If the threshold value for event W1, W2 and W3 are set too low, this can cause frequent occurrence of Measurement Report message in an LTE network. On the other hand, if the threshold value for event W1. W2 and W3 are set too high, the infrequent occurrence of Measurement Report message in an LTE network hinders the eNB to determine the optimized WLAN AP/AC for LWA and LWIP. In addition, venue owners may also introduce new WLAN AP/AC with different set of WLAN identifier. The measurement performed by the UE is not completely reported to the eNB because the Measurement Report message excludes the non-targeted WLAN identifiers.
US 20150245409 A1 discloses the methods and systems for intelligent aggregation and management of a plurality of network interfaces and connections. The intelligent connection manager may monitor connection and application communication parameters, and can control the distribution of traffics via different connections. The monitor parameters are connection related or IP packet related, such as bandwidth or bitrate, latency, round trip communications time, congestion levels, packet loss rates, signal to noise ratios, maximum transmission unit (MTU) sizes, buffer sizes or fullness, and window sizes. No disclosure relates to the RSSI monitoring on WLAN radio resources.
US 20150043560 A1 discloses the methods and apparatuses for improving measurement reporting involving WLAN for a UE in a wireless communication system. The method includes triggering a transmission of a measurement report involving WLAN due to at least one condition being fulfilled, where the at least one condition includes a first condition related to WLAN load. The improvement disclosed is still based on sending the UE WLAN measurement report using LTE radio resource and no specific disclosures are related to non-targeted WLAN identifiers.
US 20140369329 A1 discloses the techniques of aggregating wireless communications in a femtocell with portion of data transmission via a Long Term Evolution (LTE) interface and another portion of data transmission via a WiFi interface of the wireless router. Although the aggregation policy is based on the channel characteristics of the LTE and WiFi, it fails to disclose the method on how to conduct the measurement to obtain these channel characteristics.
U.S. Pat. No. 9,232,408 B2 discloses the method and devices for providing measurements of WiFi network channels to a cellular radio. A cellular radio transceiver is configured to send the request of WiFi channel measurement to at least one identified user equipments and also to receive the WiFi channel measurement. It emphasizes on using the WiFi transceiver in the user equipments to perform the measurement and depends on the cellular radio to do the reporting.
All the above discussed patents and publications have mainly discussed or disclosed the method related to aggregating traffic utilizing both LTE and WiFi radio resources. The measurement report triggered by the UE on WLAN channel is based on the LTE radio resource due to that the control plane is still anchored by LTE network.
Therefore, there is an imperative need for a method and system for improving the UE WLAN measurement reporting in LTE WLAN link aggregation by reducing the usage of LTE radio resources by the Measurement reporting and including non-targeted identifiers within the proximity of a UE.
The present invention provides a method for improving the UE WLAN measurement reporting for both LWA and LWIP, wherein both LWA and LWIP comprises a eNB, a WLAN AP/AC and a UE. In one embodiment, the method comprises notifying the eNB by the UE for its support of LWA or LWIP and WLAN reporting via LTE radio resource; instructing the UE by the eNB to perform initial WLAN measurement; sending the initial WLAN measurement report to the eNB via LTE radio resource by the UE: instructing the UE by the eNB to be associated to a WLAN AP/AC selected by the eNB; performing post-association WLAN measurement periodically to generate post-association measurement report; determining if a WLAN event is triggered; if No, performing the WLAN measurement periodically; if Yes, the UE sends the post-association WLAN measurement report to the eNB via WLAN radio resource and then performing the WLAN measurement periodically.
In another embodiment of the method, before the step of notifying the eNB by the UE for its support of LWA or LWIP and WLAN reporting via LTE radio resource, further comprising: sending a request by the eNB to a UE for the UE capability using UE Capability Enquiry message; thereby the UE notifies the eNB with the support of LWA and WLAN measurement reporting via LTE radio resource using UE Capability Information message.
In another embodiment of the method, the UE Capability Information message comprises a UE-EUTRA-Capability information element, wherein the support of WLAN measurement reporting via LTE radio resource is indicated by using additional fields in the UE EUTRA Capability information element, known as lwa-wlan-reporting and lwip-wlan-reporting in the LWA-parameters and LWIP parameters respectively.
In another embodiment of the method, the step of instructing the UE by the eNB to associate to a WLAN AP/AC selected by the eNB comprises: sending by the eNB a RRC Connection Reconfiguration message to the UE; replying by the UE with a RRC Connection Reconfiguration Complete message to the eNB; for LWA, the associated WLAN AP/AC notifies the eNB about the UE association using WT Association Confirmation message via Xw interface; for LWIP, the UE notifies its WLAN association status to the eNB using the WLAN Connection Status Report message.
In another embodiment of the method, in the step of determining if a WLAN event is triggered, the event includes: WLAN becomes better than a threshold; all WLAN inside WLAN mobility set become worse than a threshold 1 and a WLAN outside WLAN mobility set become better than a threshold 2; all WLAN inside WLAN mobility set become worse than a threshold.
In another embodiment of the method, the post-association WLAN measurement report includes additional fields that are appeared in pair, known as non-wlan-identifiers and rssiWLAN, in the MeasResultWLAN IE.
In another embodiment of the method, when the UE sends the post-association WLAN measurement report to the eNB via WLAN radio resource, depending upon LWA or LWIP: for LWA, the post-association WLAN measurement report is first sent from the UE to its associated WLAN AP/AC; then the MeasResultWLAN IE is directly encapsulated to the vendor specific element of IEEE 802.11 probe request management frame; and then the associated WLAN AP/AC reroutes the post-association WLAN measurement report to the eNB via Xw interface using WT Status Report message applying additional RSSI IE related to specified BSSID; for LWIP, the post-association WLAN measurement report is directly sent to the eNB via IPSec Tunnel via WLAN radio resource; wherein the post-association WLAN measurement report comprising the MeasResultWLAN IE is sent encapsulating as the LWIPEP SDU.
In another embodiment of the method, the post-association WLAN measurement report includes targeted and non-targeted WLAN identifiers.
The present invention also provides a wireless communication system with improved UE WLAN measurement reporting. In one embodiment, the wireless communication system comprises a Mobility Management Entity (MME) and Serving Gateway (S-GW), an evolved Node B (eNB) being logically connected to the MME/S-GW, a User Equipment (UE), a WLAN AP/AC with Targeted WLAN identifiers, and a WLAN AP/AC with non-Targeted WLAN identifiers; wherein the UE performs WLAN measurement periodically after being associated with one WLAN AP/AC, and sends post-association WLAN measurement report to the eNB via WLAN radio resource.
In another embodiment of the wireless communication system, the UE is embedded with an electronically executable program for performing the following operations: initializing its WLAN transceiver, performing active or passive scanning as instructed by the eNB for WLAN measurement and generates an initial or pre-association measurement report; sending the initial or pre-association WLAN measurement report to the eNB via LTE radio resource; associating to the WLAN AP/AC selected by eNB based on the command from the eNB; performing the scanning periodically to generate post-association WLAN measurement reports; determining if the WLAN event as defined in Table 2 is fulfilled; if No, keeping performing periodic scanning; if Yes, sending the post-association WLAN measurement reports to the eNB via WLAN radio resource.
In another embodiment of the wireless communication system, the electronically executable program further comprises the following operations: determining if there is a command from the eNB to instruct the UE to associate with another newly selected WLAN AP/AC; if No, keeping performing periodic scanning and reporting the measurement via WLAN radio resource; if Yes, associating with the newly selected WLAN AP/AC, and keeping periodic scanning and reporting the measurement via WLAN radio resource.
In another embodiment of the wireless communication system, the eNB is embedded with an electronically executable program for performing the following operations: sending a command to instruct the UE to perform WLAN scanning after being notified by the UE on its support of LWA and LWIP; receiving initial or pre-association WLAN measurement results via LTE radio resource; selecting a WLAN AP/AC for the UE to be associated to, and sends a command to the UE to associate to the selected WLAN AP/AC; deciding whether the UE is LWA-enabled or LWIP-enabled; if the UE is LWA-enabled, awaiting the UE WLAN association status reporting from the WLAN AP/AC; if the UE is LWIP-enable, awaiting the UE WLAN association status reporting from the UE; deciding whether the UE is LWA-enabled or LWIP-enabled; if the UE is LWA-enabled, receiving the WT status report comprising the RSSI of targeted WLAN identifiers and non-targeted WLAN identifiers via WLAN radio resource; if the UE is LWIP-enabled, receiving the UE WLAN measurement report comprising RSSI of targeted and non-targeted WLAN identifiers using IPSec tunnel via WLAN radio resource; performing filtering and sorting algorithm of targeted and non-targeted WLAN identifiers; selecting WLAN AP/AC for traffic aggregation considering non-targeted WLAN identifier and other related WLAN metrics; if the selected WLAN AP/AC for traffic aggregation is a non-targeted WLAN identifier, it will be converted to targeted WLAN identifier.
In another embodiment of the wireless communication system, the filtering and sorting algorithm of targeted and non-targeted WLAN identifiers comprises the following operations: receiving RSSI measurement from non-targeted WLAN identifier; determining if the OUI of the non-targeted WLAN identifier matches the OUI of BSSID for at least one of the targeted WLAN identifiers; if Yes, determining if the RSSI of the non-targeted WLAN identifier is larger than the defined RSSI threshold; if No, filtering out the RSSI measurement for the non-targeted WLAN identifier; if Yes, sorting the RSSI measurement for non-targeted WLAN identifier together with targeted WLAN identifiers.
In another embodiment of the wireless communication system, the RSSI threshold can be based on the average or median of RSSI for targeted WLAN identifiers.
The objectives and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings.
Preferred embodiments according to the present invention will now be described with reference to the Figures, in which like reference numerals denote like elements.
The present invention may be understood more readily by reference to the following detailed description of certain embodiments of the invention.
Throughout this application, where publications are referenced, the disclosures of these publications are hereby incorporated by reference, in their entireties, into this application in order to more fully describe the state of art to which this invention pertains.
The present invention provides a method for improving the UE WLAN measurement reporting for both LWA and LWIP in two ways. One is to enable a UE to transmit the UE WLAN Measurement Report via WLAN radio resource after successfully associated with WLAN AP/AC selected by eNB, reducing the usage of LTE radio resource and enhance the capacity of LTE network. The other is to include in the UE WLAN Measurement Report the non-targeted WLAN identifiers within the proximity of the UE measurement, improving the selection of WLAN AP/AC for LWA and LWIP.
Many abbreviations used in the present application are commonly known; for the sake of brevity, not all of them are provided with their full terms. For example, user equipment (UE); wireless local area network (WLAN); long term evolution (LTE); LTE WLAN Link Aggregation (LWA); LTE WLAN Radio Level Integration with IPSec Tunneling (LWIP); Access point (AP); access controller (AC); evolved Node B (eNB); WLAN Measurement Reporting; Non-targeted WLAN identifiers; Received Signal Strength Indicator (RSSI); Radio Resource Control (RRC) Signaling Message; Generic Routing Encapsulation (GRE); 3rd Generation Partnership Project (3GPP) in Release 13.
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Both RRC connection control and measurement procedures are carried over LTE using Signalling Radio Bearer 1 (SRB 1) with Radio Link Control (RLC) Acknowledgment Mode (AM). The WLAN measurement results as depicted in
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The post-association WLAN measurement report message includes additional fields that are appeared in pair, known as non-wlan-identifiers and rssiWLAN, in the MeasResultWLAN IE as shown in
the WLAN identifiers is in the value of BSSID;
either WLAN band or carrier info is defined.
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As defined in 3GPP TS 36.463.v13.0.0, the WT Status Report message as shown in
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Therefore, the eNB is managed to receive the UE WLAN measurement reporting for targeted and non-targeted WLAN identifiers via WLAN radio resource instead of relying on the LTE radio resource.
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The present invention also provides a wireless communication system with improved UE WLAN measurement reporting. Referring now to
The UE and eNB in the wireless communication system communicate with each other. Referring now to
In the step (1801), the UE initializes its WLAN transceiver;
In the step (1802), the UE performs active or passive scanning as instructed by the eNB for WLAN measurement and generates an initial or pre-association measurement report;
In the step (1803), the UE sends the initial or pre-association WLAN measurement report to the eNB via LTE radio resource;
In the step (1804), the UE associates to the WLAN AP/AC selected by eNB based on the command from the eNB;
In the step (1805), the UE performs the scanning periodically to generate post-association WLAN measurement reports;
In the step (1806), the UE determines if any of the three WLAN events as defined in Table 2 is fulfilled; if No, the UE keeps performing periodic scanning of the step (1805);
In the step (1807), if the determination in the step (1806) is Yes, the UE sends the post-association WLAN measurement reports to the eNB via WLAN radio resource;
In the step (1808), the UE determines if there is a command from the eNB to instruct the UE to associate with another newly selected WLAN AP/AC; if No, go back the step (1805), and the UE keeps continue with periodic scanning and reporting the measurement via WLAN radio resource
In the step (1809), if the determination in the step (1808) is Yes, the UE should associate with the newly selected WLAN AP/AC, and go back the step (1805); and the UE keeps periodic scanning and reporting the measurement via WLAN radio resource.
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In the step (1901), the eNB sends the command to instruct the UE to perform WLAN scanning after being notified by the UE on its support of LWA and LWIP;
In the step (1902), the eNB receives the initial or pre-association WLAN measurement results via LTE radio resource;
In the step (1903), the eNB selects a WLAN AP/AC for the UE to be associated to, and sends a command to the UE to associate to the selected WLAN AP/AC;
In the step (1904), the eNB decides whether the UE is LWA-enabled or LWIP-enabled;
In the step (1905), if the UE is LWA-enabled, the eNB is awaiting the UE WLAN association status reporting from the WLAN AP/AC;
In the step (1906), if the UE is LWIP-enable, the eNB is awaiting the UE WLAN association status reporting from the UE;
In the step (1907), the eNB decides whether the UE is LWA-enabled or LWIP-enabled;
In the step (1908), if the UE is LWA-enabled, the eNB receives the WT status report comprising the RSSI of targeted WLAN identifiers and non-targeted WLAN identifiers via WLAN radio resource;
In the step (1909), if the UE is LWIP-enabled, the eNB receives the UE WLAN measurement report comprising RSSI of targeted and non-targeted WLAN identifiers using IPSec tunnel via WLAN radio resource.
In the step (1910), the eNB performs the filtering and sorting algorithm of targeted and non-targeted WLAN identifiers as described hereinbelow;
In the step (1911), the eNB can then select the optimized WLAN AP/AC for traffic aggregation considering the non-targeted WLAN identifier and other related WLAN metrics; if the selected WLAN AP/AC for traffic aggregation is a non-targeted WLAN identifier, it will be converted to targeted WLAN identifier;
In the step (1912), if the current WLAN AP/AC is still chosen, go back to the step (1907), then the eNB keeps monitoring the WLAN measurement report via WLAN radio resource; if the current WLAN AP/AC is not chosen, go back to the step (1903).
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In the step (2001), the eNB receives RSSI measurement from non-targeted WLAN identifier;
In the step (2002), the filtering is applying only on non-targeted WLAN identifiers; the eNB determines if the OUI of the non-targeted WLAN identifier matches the OUI of BSSID for at least one of the targeted WLAN identifiers;
In the step (2003), if Yes in the step (2002), the eNB determines if the RSSI of the non-targeted WLAN identifier is larger than the defined RSSI threshold; the RSSI threshold can be based on the average or median of RSSI for targeted WLAN identifiers;
In the step (2004), if No in the steps (2002) and (2003), the eNB filters out the RSSI measurement for the non-targeted WLAN identifier;
In the step (2005), if Yes in the step (2003), and after filtering in the step (2004), the eNB sorts the RSSI measurement for non-targeted WLAN identifier together with targeted WLAN identifiers;
The present invention has many unique features. For example, the UE uses header modification and new fields introduced into Measurement Report message (RRC signaling message) and WT Status Report (Xw application message), so that the measurement report can be sent via WLAN radio source, and the new fields are used for XWAP and RRC signaling message for reporting RSSI for non-targeted WLAN identifiers.
The present invention has many advantages; for example:
1. Increase LTE capacity: utilizing WLAN radio resource;
2. Reduce the complexity of protocol implementation in the UE: utilizing active scanning procedure in the UE for WLAN measurement reporting;
3. Better selection of WLAN AP within the proximity of the UE for LWA: enhancing the current state-of-art reporting mechanism to include the non-targeted WLAN identifiers to avoid the best WLAN AP being dropped from consideration.
While the present invention has been described with reference to particular embodiments, it will be understood that the embodiments are illustrative and that the invention scope is not so limited. Alternative embodiments of the present invention will become apparent to those having ordinary skill in the art to which the present invention pertains. Such alternate embodiments are considered to be encompassed within the scope of the present invention. Accordingly, the scope of the present invention is defined by the appended claims and is supported by the foregoing description.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI 2017000768 | May 2017 | MY | national |
