Patent Application
20100238990
The present invention relates generally to communication systems and, in particular, to identifying errant channel reporting devices.
In wireless technologies, such as LTE (Long Term Evolution), user equipment (UE) devices report channel quality indicators (CQI) that are used by the network to allocate system resources among the system users. Some UE devices are known to report erroneous CQI. Such reporting can degrade system performance and potentially affect the system's ability to fully service other users. Thus, a need exists, particularly among system operators, for new techniques that enable the identification of errant channel reporting devices.
Specific embodiments of the present invention are disclosed below with reference to
Simplicity and clarity in both illustration and description are sought to effectively enable a person of skill in the art to make, use, and best practice the present invention in view of what is already known in the art. One of skill in the art will appreciate that various modifications and changes may be made to the specific embodiments described below without departing from the spirit and scope of the present invention. Thus, the specification and drawings are to be regarded as illustrative and exemplary rather than restrictive or all-encompassing, and all such modifications to the specific embodiments described below are intended to be included within the scope of the present invention.
To address the need for new techniques that enable the identification of errant channel reporting devices, various embodiments are described. In some embodiments, a network node receives channel quality indicators (CQI) from user equipment (UE) via a connection and determines whether the CQI are erroneous. In response to determining that the CQI are erroneous, the network node records a timestamp and a connection identifier corresponding to the connection between the UE and the network node. In other embodiments, the network node, in response to determining that the CQI are erroneous, records a device hardware identifier for the UE.
Embodiments for other network equipment are also described. In some embodiments, network equipment receives a request for user equipment (UE) to attach. The establishment of a connection for the UE is facilitated and a timestamp, a connection identifier (corresponding to the connection), and a device hardware identifier for the UE are all recorded.
In other embodiments, network equipment receives a request for user equipment (UE) to attach and obtains a device hardware identifier for the UE. The network equipment then sends an indication of the device hardware identifier to the network node.
In the various embodiments, information is recorded and/or obtained and distributed in a manner that enables the identification of errant channel reporting devices within a communication system.
To provide a greater degree of detail in making and using various aspects of the present invention, a description of certain, quite specific, embodiments follows for the sake of example.
Diagram 500 depicts UE 50 attempting to attach to network equipment such as that in an LTE network. UE 50 is able to wirelessly communicate with network nodes such as evolved Node-B (eNB) 60. eNB 60 has network connectivity with network equipment such as Mobility Management Entity (MME) 70, while MME 70 has signaling connectivity with other core network equipment such as Equipment Identity Register (EIR) 80 and Serving Gateway (sGW)/Packet Data Network Gateway (P-GW) 90.
The operator of a system such as that depicted in diagram 500 desires to identify devices that are reporting erroneous channel quality indicators (CQI) which can disrupt the operation of their network. The operator would like the base station (e.g., eNB) to determine which devices are reporting bad CQI (so called “worst offender devices”) and identify them by their IMEI (international mobile equipment identity). The IMEI of a UE is associated with its device hardware rather than a SIM card that may be inserted into the UE. At present, a base station is the only entity that has access to the reported CQI values from its connected devices; however, the base station is not aware of the IMEIs of these connected devices.
Signaling flow diagram 500 depicts an initial attach procedure that takes place in certain embodiments when a UE powers on. The signaling flow is summarized below:
One way to provide the IMEIs of worst offender devices reporting bad CQI values is to generate logging information at the eNB which writes out the E-RAB ID corresponding to the worst offender devices together with a time stamp. The E-RAB ID uniquely identifies the connection of an end user device with the eNB all the way through the serving gateway (sGW) in the core network. The mobility management entity (MME) in the core network is responsible for assigning the E-RAB ID, and the MME is aware of the IMEI from the initial attach procedure (as described above with respect to signaling 4). Therefore, a logging mechanism is also in the MME which writes out the E-RAB ID and the IMEI together with a time stamp each time an EPS bearer is created.
In this way, an operator can compare the eNB and MME logs to determine the IMEI of the worst-offender devices. Note that the time stamp is needed because the E-RAB ID is only a temporary identifier that may be reused. When a user disconnects from the network and then reconnects, it usually gets assigned a new E-RAB ID.
Another more direct way to provide the IMEIs of worst offender devices involves providing the UE IMEIs to the base stations. For example, the IMEI may be provided directly from the MME to the eNB through the S1-MME interface as part of the initial context setup request message. As presently defined in 3GPP TS 36.413, the initial context setup request message does not convey the IMEI to the eNB. Thus, a change to the initial context setup request message is proposed whereby IMEI information for the UE may be indicated to a base station receiving signaling 9 in diagram 500. Specifically, we propose adding the IMEI field to the initial context setup request message. The eNB would then be directly aware of the IMEI and could simply log the IMEI of the worst offender devices for the operator.
Before logging either the E-RAB ID and timestamp or the IMEI for worst offender devices, the base station determines that a device is reporting erroneous CQI values. One way the base station may do this is to compare the MCS (modulation and coding scheme) a device is able to handle to maintain a prescribed error rate (for example a 10% error rate on its first transmission). An internal look up table, for example, could contain a mapping between the reported CQI value and a range of MCS levels that could support the prescribed error rate (the reasons a range is necessary is because it can vary due to different fading channel conditions). Based on the ACK/NACK feedback from the device, the base station can compute the error rate the device is achieving for a particular MCS level for the CQI values that the device is reporting. If it falls substantially outside the range of the internal look up table, the base station can classify this device as a worst offender with erroneous CQI reports and log it for the operator.
Generally speaking, two approaches have been described above. The first approach can be summarized as follows:
The second approach can be summarized as follows:
The detailed and, at times, very specific description above is provided to effectively enable a person of skill in the art to make, use, and best practice the present invention in view of what is already known in the art. In the examples, specific architectures, specific message names, specific message field values, specific messaging formats, and specific messaging sequences are all provided for the purpose of illustrating possible embodiments of the present invention and should not be interpreted as restricting or limiting the scope of the broader inventive concepts.
The present invention can be more broadly understood with reference to
It should be understood that wireless communication systems typically include a plurality of UEs, a plurality of network nodes, and additional network equipment; however,
The network equipment may additionally (or as part of facilitating the connection establishment) send a request for identification of the UE. In response to this request, the network equipment may receive a device hardware identifier from the UE, such as its IMEI (international mobile equipment identity). Having the information that it needs, the network equipment records (103) the connection identifier and the device hardware identifier for the UE along with a current timestamp. It may record this information by any of a variety of known techniques. For example, the information may be written to a log file, sent to another network device for storage/collection, etc.
The network equipment also obtains (302) a device hardware identifier for the UE. To obtain this, the network equipment may send a request for identification of the UE. In response to this request, the network equipment may receive a device hardware identifier from the UE, such as its IMEI (international mobile equipment identity). The network equipment then sends (303) an indication of the device hardware identifier to the network node. It may send a message to the network node that includes the device hardware identifier itself, such as described above with respect to diagram 500, or it may convey the identifier in some less explicit way.
Depending on the embodiment, the network node may have the IMEI of the UE from some prior communication. For example, the network node may receive the device hardware identifier from the UE during some initialization or attachment-related signaling. In other embodiments, the network node may receive the device hardware identifier from network equipment, such that described with respect to diagram 300.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments of the present invention. However, the benefits, advantages, solutions to problems, and any element(s) that may cause or result in such benefits, advantages, or solutions, or cause such benefits, advantages, or solutions to become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims.
As used herein and in the appended claims, the term “comprises,” “comprising,” or any other variation thereof is intended to refer to a non-exclusive inclusion, such that a process, method, article of manufacture, or apparatus that comprises a list of elements does not include only those elements in the list, but may include other elements not expressly listed or inherent to such process, method, article of manufacture, or apparatus. The terms a or an, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. Unless otherwise indicated herein, the use of relational terms, if any, such as first and second, top and bottom, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. Terminology derived from the word “indicating” (e.g., “indicates” and “indication”) is intended to encompass all the various techniques available for communicating or referencing the object/information being indicated. Some, but not all, examples of techniques available for communicating or referencing the object/information being indicated include the conveyance of the object/information being indicated, the conveyance of an identifier of the object/information being indicated, the conveyance of information used to generate the object/information being indicated, the conveyance of some part or portion of the object/information being indicated, the conveyance of some derivation of the object/information being indicated, and the conveyance of some symbol representing the object/information being indicated.
