HK1237136A1 - Identifying coverage holes using inter-rat handover measurements - Google Patents

Description

Identifying coverage holes using inter-RAT handover measurements

Cross Reference to Related Applications

The priority benefit of U.S. provisional patent application No. 61/676,775, filed on 7/27/2012 and entitled "advanced wireless communication systems and techniques," the contents of which are hereby incorporated by reference in their entirety.

Technical Field

The present disclosure relates generally to wireless communications, and more specifically to systems and techniques for identifying coverage holes in a Radio Access Technology (RAT).

Background

Some RATs, such as evolved universal terrestrial radio access (E-UTRA) technology, may be deployed in densely populated locations in an attempt to alleviate traffic congestion during peak periods. Because these RATs are selectively used in high density sites, any such RAT may have many coverage holes (e.g., in low density sites between high density sites), especially during the initial deployment phase of these RATs. Legacy RATs, such as universal mobile telecommunications system terrestrial radio access (UTRAN) technology or global system for mobile communications enhanced data rates for evolved radio access (GERA) technology, may provide coverage for the underlying areas (in both high and low density sites). In an area with multiple RATs, a User Equipment (UE) utilizing services provided by the RATs may switch between RATs in response to, for example, UE movement and changes in RAT traffic (referred to as inter-RAT handover).

Disclosure of Invention

The present disclosure provides one or more computer-readable media having instructions that, when executed, cause a network managing NM device to: receiving a first report comprising one or more measurements by a first user equipment, UE, in response to an event related to a handover of the first UE between a first radio access technology, RAT, and a second RAT different from the first RAT; receiving a second report including one or more measurements by a second UE in response to an event related to a handover of the second UE between the first RAT and a third RAT different from the first RAT; and identifying a hole in a coverage area of the first RAT based at least in part on the first and second reports.

According to one embodiment, the first RAT is an evolved universal terrestrial radio access (E-UTRA) technology.

According to another embodiment, each of the second and third RATs is a universal mobile telecommunications system terrestrial radio access (UTRA) technology or a global system for mobile communications enhanced data rates for global system for mobile communications (GERA) technology.

According to yet another embodiment, the handover of the first UE between the first RAT and the second RAT is a handover of the first UE between a first evolved universal terrestrial radio access network, E-UTRAN, cell and the second RAT, and the handover of the second UE between the first RAT and the third RAT is a handover of the second UE between a second E-UTRAN cell and the third RAT, the second E-UTRAN cell being different from the first E-UTRAN cell.

According to yet another embodiment, the one or more measurements comprised in the first report comprise one or more of: a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), an identifier of a cell serving the first UE with the first RAT, location information, and a timestamp representing a time of a handover-related event.

According to yet another embodiment, the first and second UEs are common UEs.

According to yet another embodiment, identifying a hole in a coverage area of the first RAT based at least in part on the first and second reports comprises correlating the first and second reports.

According to yet another embodiment, there are further instructions that, when executed, cause the NM device to recommend a corrective action based on the identified hole.

The present disclosure also provides an evolved node B, eNB, associated with a first radio access technology, RAT, the eNB comprising: first transmitter circuitry to transmit a command to a user equipment, UE, in a cell served by the eNB to cause the UE to switch to a second RAT different from the first RAT; receiver circuitry to receive, from the UE in response to the command, one or more measurements made by the UE and representative of conditions near an edge of the cell; and second transmitter circuitry to transmit a report including the one or more measurements to identify a coverage hole in the first RAT to a Domain Management (DM) device or a Network Management (NM) device.

According to one embodiment, the second RAT comprises universal mobile telecommunications system terrestrial radio access (UTRA) technology or global system for mobile communications enhanced data rates for global system for mobile communications (GERA) technology.

According to another embodiment, the one or more measurements are made by the UE in response to receiving the command at the UE.

According to yet another embodiment, the one or more measurements are made by the UE prior to receiving the command at the UE.

According to yet another embodiment, the first transmitter circuit further: transmitting parameters representative of which measurements to be made by the UE to the UE as representative of conditions near the edge of the cell.

According to yet another embodiment, the parameter represents one or more of the following: a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), an identifier of the cell, location information, and a timestamp representing a time of a handover-related event.

According to yet another embodiment, communicating the report including the one or more measurements to the DM device or the NM device includes communicating the report to a centralized coverage and capacity optimization function (CCO) of the NM device.

The present disclosure also provides a User Equipment (UE), comprising: receiver circuitry to receive a command from an evolved node B (eNB) serving the UE to handover the UE to a second Radio Access Technology (RAT) different from a first RAT associated with the first RAT having a coverage hole proximate to the UE; transmitter circuitry to transmit, to the eNB, one or more measurements made by the UE and representative of a condition proximate to the coverage hole in response to receiving the command; and handover circuitry to perform a handover to the second RAT after the one or more measurements are transmitted to the eNB.

According to one embodiment, the second RAT is a universal mobile telecommunications system terrestrial radio access (UTRA) technology or a global system for mobile communications enhanced data rates for global system for mobile communications (GERA) technology.

According to another embodiment, receiving the command to cause the UE to switch to the second RAT occurs when the UE is near an edge of a cell of the first RAT served by the eNB.

According to yet another embodiment, receiving the command to handover the UE to the second RAT occurs when the UE is near an edge of an E-UTRAN cell served by the eNB and no other E-UTRAN cell is sufficiently close to the UE to serve the UE.

According to yet another embodiment, the UE further comprises: measurement circuitry to make the one or more measurements, the one or more measurements including one or more measurements of a set of measurements including a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), an identifier of a cell serving the UE with the first RAT, location information, and a timestamp representing a time of a handover-related event.

Drawings

The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals refer to like structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Fig. 1 illustrates an environment in which two inter-RAT handovers occur near a coverage hole in one RAT, in accordance with various embodiments.

Fig. 2 is a block diagram illustrating an example system of RAT coverage analysis and corrective actions in accordance with various embodiments.

Fig. 3 is a flow diagram of an example inter-RAT handover procedure that may be performed by a Network Management (NM) device, in accordance with various embodiments.

Fig. 4 is a flow diagram of an example inter-RAT handover procedure that may be performed by an evolved node b (enb) in accordance with various embodiments.

Fig. 5 is a flow diagram of an example inter-RAT handover procedure that may be performed by a User Equipment (UE), in accordance with various embodiments.

FIG. 6 is a block diagram of an example computing device for practicing disclosed embodiments, in accordance with various embodiments.

Detailed Description

Embodiments of systems and techniques for identifying coverage holes in a Radio Access Technology (RAT) using inter-RAT handover measurements are described. In some embodiments, a Network Management (NM) apparatus may receive a first report including one or more measurements by a first User Equipment (UE) in response to an event related to a handover of the first user UE between a first Radio Access Technology (RAT) and a second RAT different from the first RAT. The NM apparatus may receive a second report, including one or more measurements made by a second UE, in response to an event related to a handover of the second UE between the first RAT and a third RAT (which is different from the first RAT).

The systems and techniques disclosed herein may enable the detection and characterization of coverage holes that may not otherwise be detectable. For example, when a cell of a source RAT, such as E-UTRAN technology, is covered by one or more cells of other RATs (e.g., UTRAN cells or GERAN cells), a UE that is close to a coverage hole in E-UTRAN may switch to one of the other RATs instead of generating a Radio Link Failure (RLF) report. Because the E-UTRAN does not receive RLF reports, the network management function may not be aware of E-UTRAN coverage holes. According to some of the embodiments disclosed herein, a source RAT (e.g., E-UTRA technology) may identify previously unattended coverage holes by transmitting measurement reports when a handover to another RAT occurs.

Various embodiments of the systems and techniques disclosed herein may be advantageously used in many applications to improve the quality of RAT services. For example, coverage holes identified using inter-RAT handover measurements may be minimized by adjusting one or more service parameters (e.g., shape or size) of existing RAT cells. In another example, the identified coverage holes may be eliminated or reduced by deploying new base stations (e.g., enbs, also known as enhanced node bs and enodebs) in areas of lack of coverage. Such embodiments may be included in Coverage and Capacity Optimization (CCO) operations. The present disclosure is particularly advantageous in self-organizing network (SON) applications, including those where network optimization is focused in one or more NM devices or other apparatuses.

In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments which may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the embodiments is defined by the appended claims and their equivalents.

Various operations may in turn be described as multiple discrete actions or operations in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations may occur out of the order presented. The operations described may be performed in a different order than the described embodiments. Various additional operations may be performed and/or described operations may be omitted in additional embodiments.

For the purposes of this disclosure, the phrases "a and/or B" and "a or B" mean (a), (B), or (a and B). For the purposes of this disclosure, the phrase "A, B and/or C" means (a), (B), (C), (a and B), (a and C), (B and C), or (A, B and C).

The description may use the phrases "in an embodiment" or "in an embodiment," which may each refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," and the like, as used with respect to embodiments of the present disclosure, are synonymous.

As used herein, the term "module" or "circuit" may refer to, be part of, or include the following: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

Referring now to fig. 1, an environment 100 is illustrated in which two inter-RAT handovers occur close to a coverage hole 106 in a first RAT, in accordance with various embodiments. In fig. 1, a first RAT (indicated as RAT 1) may be supported by two base stations 102a and 102 b. Each base station 102a and 102b may provide service in a respective coverage cell 104a and 104 b. In some embodiments, the first RAT may be an E-UTRA technology, and the base stations 102a and 102b may be (or may include) enbs. A second RAT (indicated as RAT 2) may be supported by the base station 108 serving in the coverage cell 110. A third RAT (indicated as RAT 3) may be supported by the base station 112 serving in the coverage cell 114. In some embodiments, the second and third RATs may be different RATs (e.g., UTRA technology and GERA technology). In some embodiments, one or both of the second and third RATs is a different RAT than the first RAT. The coverage cells 104a, 104b, 110, and 114 may overlap in any of a number of combinations.

In some embodiments, the first RAT may have a coverage hole, generally indicated at 106, representing an area of lack of service under the first RAT. The lack of service includes, for example, a failure to achieve a desired level of signal strength or a failure to successfully provide service to the UE device within a certain number of access attempts (e.g., Radio Resource Control (RRC) connection attempts and/or random access attempts). The coverage hole 106 may be the result of a geographic separation of the base stations 102a and 102b, an obstruction (e.g., a building) between the base stations 102a and 102b, or any of a number of other conditions that result in a gap between the coverage cells 104a and 104 b. As the UE travels along line 116 from RAT 1 coverage area 104a to the right, the UE may experience insufficient RAT 1 service as it approaches coverage hole 106. Such a situation is represented in the signal strength graph 122, which illustrates that the strength of the RAT 1 signal at the location 118 (near the coverage hole 106) may be too low to support adequate RAT 1 service. In some embodiments, the UE may switch to RAT2 (supported by base station 108) when the UE is close to the location 118. The inter-RAT handover may occur, for example, when the strength of the RAT2 signal exceeds a relative or absolute threshold above the strength of the RAT 1 signal.

Similarly, as the UE travels left from RAT 1 coverage cell 104b along line 116, the UE may experience insufficient RAT 1 service as it approaches coverage hole 106. The signal strength graph 122 illustrates that the strength of the RAT 1 signal at the location 120 (near the coverage hole 106) may be too low to support adequate RAT 1 service. In some embodiments, the UE may switch to RAT 3 (supported by base station 112) when the UE is close to site 120. The inter-RAT handover may occur, for example, when the strength of the RAT 3 signal exceeds a relative or absolute threshold above the strength of the RAT 1 signal.

In some embodiments, measurements made in response to events related to inter-RAT handovers (e.g., handovers from RAT 1 to RAT2 near location 118 and from RAT 1 to RAT 3 near location 120) may be used to identify coverage holes (e.g., coverage hole 106). For example, a Network Management (NM) apparatus may receive a plurality of reports (e.g., from one or more enbs) including measurements made by a UE in response to an inter-RAT handover event, and may identify a hole (e.g., a location and size of the hole) in a coverage area based at least in part on the reports. Additional embodiments are described herein.

Referring now to fig. 2, a block diagram of an example system 200 for RAT coverage analysis and corrective action is illustrated, in accordance with various embodiments. The system 200 may be configured to support a RAT, such as E-UTRAN. In some embodiments, the RAT supported by the system 200 may be the first RAT (RAT 1) of the environment 100 of fig. 1. Examples of components of system 200 are generally discussed with reference to the 3GPP LTE-a RAT, but system 200 may be used to implement other RATs (such as those discussed herein). The system 200 may be configured to distribute any of a number of services, such as multimedia distribution over HTTP, real-time streaming over RTP, conversational services (e.g., video conferencing), and TV broadcasting. System 200 may include other Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Metropolitan Area Network (WMAN), and/or Wireless Wide Area Network (WWAN) devices such as network interface devices and peripherals (e.g., Network Interface Cards (NICs)), Access Points (APs), redistribution points, endpoints, gateways, bridges, hubs, and the like, to implement a cellular telephone system, a satellite system, a Personal Communication System (PCS), a two-way radio system, a one-way pager system, a two-way pager system, a Personal Computer (PC) system, a Personal Data Assistant (PDA) system, a Personal Computing Accessory (PCA) system, and/or any other suitable communication system. Although embodiments may be described in the context of an LTE-a network, embodiments may also be employed in other networks (e.g., WiMAX networks).

System 200 may include NM device 202. In some embodiments, NM device 202 may monitor components of system 200 and collect performance measurements thereof. Based on analysis of these measurements, NM device 202 may identify potential problems and improvements in the configuration and operation of components of system 200, and may implement changes to system 200. NM apparatus 202 may include a receiver circuit 222, a coverage analysis circuit 224, and a corrective action circuit 226. The receiver circuit 222 may be configured to receive signals from other devices over a wired or wireless connection. For example, the receiver circuitry 222 may be configured to receive signals from or transmit signals to Element Manager (EM) components of an eNB (e.g., any of the enbs 208 and 212), Domain Management (DM) devices 204 (which may provide management functions for a domain or other portion of the system 200), or any other suitably configured apparatus. In some embodiments, NM device 202 may communicate with an eNB via a wired connection. In embodiments where receiver circuit 222 is configured for wireless communication, it may include, for example, one or more directional or omnidirectional antennas (not shown), such as dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas and/or other types of antennas suitable for reception of Radio Frequency (RF) or other wireless communication signals.

In some embodiments, the receiver circuitry 222 may be configured to receive a first report including one or more measurements made by the first UE in response to an event related to handover of the first UE between a first RAT and a second RAT (which is different from the first RAT). The handover-related event may be the issuance of a handover command, the receipt of a handover command, the presence of a handover condition (e.g., sufficiently favorable signal strength provided to the UE by a different RAT), or any other handover-related event. The RATs supported by the system 200 may be the first RAT or the second RAT involved in handover of the first UE.

The first report may include any of a number of measurements made by the first UE, such as one or more of a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), an identifier of a cell serving the first UE with the first RAT, location information (e.g., information about the location of the UE when a handover command is received at the UE), and a timestamp representing the time of an event related to the handover (e.g., a timestamp of the time of the inter-RAT handover).

In some embodiments, the receiver circuitry 222 may be configured to receive a second report including one or more measurements made by the second UE in response to an event related to the second UE switching between the first RAT and a third RAT (which is different from the first RAT). For example, system 200 may support E-UTRA techniques. In some such embodiments, handover of the first UE may occur between the first E-UTRAN cell and the second RAT, and handover of the second UE may occur between the second E-UTRAN cell and the third RAT. In some embodiments, the second E-UTRAN cell may be different from the first E-UTRAN cell. In some embodiments, each of the second and third RATs is a UTRA technology or a GERA technology. In some embodiments, the first UE and the second UE may be a common UE (e.g., a UE that is undergoing multiple inter-RAT handovers).

In some embodiments, one or more of the first and second reports may be transmitted by an eNB (e.g., any of eNB208 and 212) to NM device 202. In some such embodiments, an element manager embedded in or associated with the eNB may transmit one or more of the first and second reports to NM device 202. In some embodiments, one or more reports may be communicated to NM device 202 by Domain Management (DM) device 204 in communication with one or more eNBs (e.g., eNBs 208 and 210, as shown). In some embodiments, the one or more reports may be transmitted to NM device 202 by a Trace Collection Entity (TCE) 206 and/or one or more enbs (e.g., eNB208, as shown) in communication with the DM device (e.g., DM device 204).

NM apparatus 202 as discussed above may include coverage analysis circuitry 224 and corrective action circuitry 226. In some embodiments, coverage analysis circuitry 224 and corrective action circuitry 226 may be included in a centralized Coverage and Capacity Optimization (CCO) function 242 of NM device 202. The coverage analysis circuit 224 may be configured to identify holes in the coverage area of the RATs supported by the system 200 based at least in part on reports associated with the handover events, such as the first and second reports discussed above. For example, in some embodiments, the coverage analysis circuitry 224 may identify holes in the coverage area of the RAT by correlating multiple reports (e.g., first and second reports). Correlating multiple reports may include associating multiple reports with the same user session occurrence or the same geographic region, and so forth.

The corrective action circuit 226 may be configured to recommend a corrective action based on the coverage holes identified by the coverage analysis circuit 224. In some embodiments, the command to implement the corrective action may be communicated to one or more components of the system 200, such as one or more of the eNB208 and 212 or the UE214 and 220. In some embodiments, the coverage analysis circuit 224 and/or the corrective action circuit 226 may include a display or other output configured to provide coverage information or corrective action recommendations to an operator who may then intervene as appropriate.

System 200 may include one or more eNBs, such as eNB208 and 212. Each of the eNBs 208 and 212 may include many components; for ease of illustration, only the components of eNB208 are shown in fig. 2. Enbs other than eNB208 may have similar components. Components of eNB208 (discussed in detail below) may be included in one or more of base stations 102a, 102b, 108, and 112 of fig. 1.

As shown, the eNB208 may include first transmitter circuitry 228. The first transmitter circuit 228 may be configured to transmit the wireless signal to other devices. For example, the first transmitter circuitry 228 may be configured to transmit wireless signals to the UE214 or other suitably configured means for wireless communication. The first transmitter circuitry 228 may include, for example, one or more directional or omnidirectional antennas (not shown), as discussed above. In some embodiments, the first transmitter circuitry 228 may be configured to transmit, via the system 200, a command to a UE (e.g., UE214, as shown) in a cell served by the eNB to switch the UE to a RAT different from the RAT supported by the eNB 208. For example, the RAT supported by the eNB208 may be an E-UTRA technology, and the different RAT may be a UTRA technology or a GERA technology.

eNB208 may include receiver circuitry 230. The receiver circuit 230 may be configured to receive signals from other devices via a wired or wireless connection. For example, receiver circuitry 230 may be configured to receive signals from NM device 202, DM device 204, TCE 206, UE214, or other suitably configured apparatus. If configured to receive wireless signals, receiver circuitry 230 may include, for example, one or more directional or omnidirectional antennas (not shown), as discussed above. In some embodiments, the receiver circuitry 230 of the eNB208 may be configured to receive, from the UE, one or more measurements made by the UE and representative of conditions near an edge of a cell served by the eNB208 in response to the handover command. In some embodiments, the one or more measurements may be made by the UE in response to receiving a command at the UE. In some embodiments, the one or more measurements may be made by the UE prior to receiving the command at the UE.

In some embodiments, the first transmitter circuitry 228 (discussed above) may be configured to transmit parameters to the UE representative of which measurements are to be made by the UE (as representative of conditions near the cell edge). For example, the parameters may represent one or more of RSRP, RSRQ, cell identifiers, location information, and timestamps representing times of handover-related events. In some embodiments, these parameters may be selected by an eNB (e.g., eNB 208), a DM device (e.g., DM device 204), an NM device (e.g., NM device 202), another component of system 200, or a combination of these components.

In some embodiments, the first transmitter circuitry 228 may be configured to transmit a trigger signal to the UE to trigger reporting of measurements from the UE. The trigger signal may be included with or separate from the parameters representing which measurements are to be made by the UE, as discussed above.

eNB208 may include second transmitter circuitry 232. The second transmitter circuit 232 may be configured to transmit signals to other devices via a wired or wireless connection. For example, second transmitter circuit 232 may be configured to transmit signals to NM device 202, DM device 204, TCE 206, or other suitably configured apparatus. If configured to transmit wireless signals, the second transmitter circuitry 228 may include, for example, one or more directional or omnidirectional antennas (not shown), as discussed above. In some embodiments, second transmitter circuitry 232 may be configured to transmit a report including one or more measurements from the UE to a DM device (e.g., DM device 204) or NM device (e.g., NM device 202). The report may be used by the DM device or NM device to identify coverage holes in the RATs supported by the system 200. In some embodiments, the report is communicated to a CCO function of the NM device.

System 200 may include one or more UEs, such as UE214 and 220. One or more of the UEs 214, 220 may comprise any of a number of wireless electronic devices such as, for example, a desktop computer, a laptop computer, a handheld computer, a tablet computer, a cellular telephone, a pager, an audio and/or video player (e.g., an MP3 player or a DVD player), a gaming device, a video camera, a digital camera, a navigation device (e.g., a GPS device), a wireless peripheral (e.g., a printer, a scanner, a headset, a keyboard, a mouse, etc.), a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), and/or other suitable stationary, portable, or mobile electronic devices. In some embodiments, one or more of the UEs 214, 220 may be a mobile wireless device, such as a PDA, cellular telephone, tablet computer, or laptop computer. Each of the UEs 214-220 may include a number of components; for ease of illustration, only the components of the UE214 are shown in fig. 2. UEs other than UE214 may have similar components.

As shown, the UE214 may include receiver circuitry 234. The receiver circuit 234 may be configured to receive wireless signals from other devices. For example, the receiver circuitry 224 may be configured to receive wireless signals from the eNB208 or other suitably configured apparatus for wireless communication. As discussed above, the receiver circuitry 234 may include, for example, one or more directional or omnidirectional antennas (not shown). In some embodiments, the receiver circuitry 234 may be configured to receive a command from an eNB serving the UE (e.g., eNB 208) to cause the UE214 to switch to a RAT different from the RAT supported by the system 200. In some embodiments, the different RAT may be, for example, UTRA technology or GERA technology. In some embodiments, the RATs supported by the system 200 (e.g., E-UTRA technology) may have coverage holes near the UE214 when receiving the command. In some embodiments, the receiver circuitry 234 may receive a command to cause the UE214 to handover to a different RAT when the UE214 is near an edge of a cell served by the eNB. In some embodiments, the receiver circuitry 234 may receive a command to cause the UE214 to handover to a different RAT when the UE214 is near an edge of an E-UTRAN cell served by the eNB and no other E-UTRAN cell is sufficiently close to the UE to serve the UE.

The UE214 may include transmitter circuitry 236. Transmitter circuitry 236 may be configured to transmit wireless signals to other devices. For example, the transmitter circuitry 236 may be configured to transmit wireless signals to the eNB208 or other suitably configured apparatus for wireless communication. As discussed above, transmitter circuitry 236 may include, for example, one or more directional or omnidirectional antennas (not shown). In some embodiments, the transmitter circuitry 236 may be configured to transmit one or more measurements made by the UE214 to the eNB208 or another component of the system 200. These measurements may represent conditions near coverage holes. In some embodiments, transmitter circuitry 236 may transmit the measurements in response to receiving the handover command. In some embodiments, transmitter circuitry 236 may transmit one or more measurements upon detection of a trigger signal. The trigger may be transmitted from an eNB (e.g., eNB 208) or some other component of system 200, or may be transmitted and received within UE 214. The trigger signal may be associated with a handover command (e.g., indicating receipt of the handover command or successful completion of the handover).

The UE214 may include switching circuitry 238. The handover circuitry 238 may be configured to perform handover of the UE214 to a different RAT (or to assist in performing handover of the UE214 to a different RAT). For example, the handover circuitry 238 may be configured to transition the UE214 to a different RAT without interrupting service. The switching circuitry 238 may include, for example, signaling circuitry for sending and receiving request, acknowledgement, error and safety information messages in accordance with various switching protocols. In some embodiments, the handover circuitry 238 may handover after transmitting the one or more measurements (e.g., by the transmitter circuitry 236) to the eNB208 or another component of the system 200.

The UE214 may include measurement circuitry 240. Measurement circuitry 240 may be configured to make one or more measurements discussed above with reference to transmitter circuitry 236. In particular, in some embodiments, the one or more measurements may include RSRP, RSRQ, an identifier of a cell serving the UE with a RAT supported by system 200, location information, and a timestamp representing a time of an event related to the handover (e.g., receipt of a handover command).

Referring now to fig. 3, a flow diagram of an example inter-RAT handover procedure 300 executable by an NM device (e.g., NM device 202 of fig. 2) is illustrated, in accordance with various embodiments. It may be appreciated that although the operations of process 300 (and other processes described herein) are arranged in a particular order and are each illustrated once, in various embodiments, one or more of the operations may be repeated, omitted, or performed out of order. For purposes of illustration, the operations of process 300 may be described as being performed by NM apparatus 202 (FIG. 2), although process 300 may be performed by any suitably configured device.

Process 300 may begin at operation 302, where NM device 202 may receive a first report including one or more measurements made by a first UE (e.g., UE214 of fig. 2) in response to an event related to a handover of the first UE between a first RAT and a second RAT (which is different from the first RAT). In some embodiments, operation 302 may be performed by receiver circuitry 222 (fig. 2). In some embodiments, the first RAT may be an E-UTRA technology. In some embodiments, the one or more measurements included in the first report may include one or more of RSRP, RSRQ, an identifier of a cell serving the first UE with the first RAT, location information, and a timestamp representing a time of the handover-related event.

In operation 304, the NM apparatus 202 may receive a second report, including one or more measurements made by a second UE, in response to an event related to handover of the second UE between the first RAT and a third RAT (which is different from the first RAT). In some embodiments, operation 304 may be performed by receiver circuitry 222 (fig. 2). In some embodiments, the first and second UEs may be common UEs. In some embodiments, each of the second and third RATs may be UTRA technology or GERA technology. In some embodiments, the handover of the first UE between the first RAT and the second RAT (discussed above with reference to operation 302) may be a handover of the first UE between the first E-UTRAN cell and the second RAT, and the handover of the second UE between the first RAT and the third RAT may be a handover of the second UE between the second E-UTRAN cell and the third RAT. The second E-UTRAN cell may be different from the first E-UTRAN cell.

At operation 306, the NM device 202 may identify a hole in the coverage area of the first RAT based at least in part on the first and second reports (received at operations 302 and 304, respectively). In some embodiments, operation 306 may be performed by the coverage analysis circuitry 224 (fig. 2). In some embodiments, operation 306 may include correlating the first and second reports. At operation 308, the NM device 202 may recommend a corrective action based on the identified hole. In some embodiments, operation 308 may be performed by corrective action circuitry 226 (fig. 2). The process 300 may then end.

Referring now to fig. 4, a flow diagram of an example inter-RAT handover procedure 400 that can be performed by an eNB (e.g., eNB208 of fig. 2) in accordance with various embodiments is illustrated. For purposes of illustration, the operations of process 400 may be described as being performed by eNB208 (fig. 2), although process 400 may be performed by any suitably configured apparatus. The eNB208 will also be described as supporting a first RAT (e.g., E-UTRA technology).

The process 400 may begin at operation 402, where the eNB208 may transmit a command to the UE in the cell served by the eNB208 to handover the UE to a second RAT (which is different from the first RAT). In some embodiments, operation 402 may be performed by the first transmitter circuit 228 (fig. 2). In some embodiments, the second RAT is UTRA technology or GERA technology.

At operation 404, the eNB208 may transmit parameters to the UE representative of which measurements are to be made by the UE (as representative of conditions near the cell edge). In some embodiments, operation 404 may be performed by the first transmitter circuit 228 (fig. 2). The parameters may represent, for example, RSRP, RSRQ, an identifier of a cell, location information, and a timestamp representing the time of an event related to handover.

At operation 406, the eNB208 may receive, from the UE, one or more measurements made by the UE and representative of conditions near the cell edge in response to the command of operation 204. In some embodiments, operation 406 may be performed by receiver circuitry 230 (fig. 2). In some embodiments, the one or more measurements may be made by the UE in response to receiving the command (of operation 204) at the UE. In some embodiments, the one or more measurements may be made by the UE prior to receiving the command (of operation 204) at the UE.

At operation 408, the eNB208 may transmit a report including one or more measurements for identifying a coverage hole in the first RAT to the DM device or NM device. In some embodiments, operation 408 may be performed by the second transmitter circuit 222 (fig. 2). In some embodiments, the report transmitted at operation 408 may be transmitted to a CCO function of the NM device.

Referring now to fig. 5, a flow diagram of an example inter-RAT handover procedure 500 that can be performed by a UE (e.g., UE214 of fig. 2) is illustrated, in accordance with various embodiments. For purposes of illustration, the operations of process 500 may be described as being performed by UE214 (fig. 2), although process 500 may be performed by any suitably configured device.

Process 500 may begin at operation 502, where UE214 may receive a command from an eNB (e.g., eNB208 of fig. 2) serving UE214 to cause UE214 to switch to a second RAT different from the first RAT, the eNB being associated with the first RAT having a coverage hole near UE 214. In some embodiments, operation 502 may be performed by receiver circuitry 234 (fig. 2). In some embodiments, the second RAT may be UTRA technology or GERA technology. In some embodiments, receiving the command at operation 502 to cause the UE214 to switch to the second RAT may occur when the UE 514 is near an edge of a cell of the first RAT served by an eNB (e.g., eNB 208). For example, in some embodiments, receiving the command at operation 502 to cause the UE214 to switch to the second RAT may occur when the UE214 is near the edge of an E-UTRAN cell served by the eNB and no other E-UTRAN cell is sufficiently close to the UE214 to serve the UE 214.

At operation 504, the UE214 may make one or more measurements representative of conditions near the coverage hole. In some embodiments, the one or more measurements made at operation 502 may include RSRP, RSRQ, an identifier of a cell serving the UE214 with the first RAT, location information, and/or a timestamp representing a time of the handover-related event. In some embodiments, operation 502 may be performed by measurement circuitry 240 (fig. 2).

In operation 506, the UE214 may transmit one or more measurements made by the UE to the eNB in response to receiving the command of operation 502. In some embodiments, operation 506 may be performed by transmitter circuitry 236 (fig. 2).

At operation 508, the UE214 may perform a handover to the second RAT (per the command of operation 502). In some embodiments, operation 508 may occur after transmitting the one or more measurements to the eNB. In some embodiments, operation 508 may be performed by switching circuitry 238 (fig. 2). Process 500 may then end.

In some embodiments, after the inter-RAT handover of operation 508, UE214 may be configured to record measurements before, during, or after the inter-RAT handover and then transmit these measurements for receipt by NM device 202. The transmission of the measurements may occur after the inter-RAT handover in addition to or instead of prior to the handover (e.g., according to operation 506). In some embodiments, UE214 may transfer the measurements to UTRAN or GERAN after inter-RAT handover, which may forward the measurements to NM device 202. In some embodiments, the UE214 may wait to transmit measurements after the inter-RAT handover until the UE214 is connected to the E-UTRAN, and may then transmit the measurements to the E-UTRAN.

FIG. 6 is a block diagram of an example computing device 600 that may be suitable for use in practicing the various disclosed embodiments. For example, some or all of the components of the computing apparatus 600 may be used in any of NM devices (e.g., NM device 202 of FIG. 2), DM devices (e.g., DM device 204 of FIG. 2), TCEs (e.g., TCE 206 of FIG. 2), eNBs (e.g., eNBs 102a, 102b, 108 and 112 of FIG. 1 and eNB208 and 212 of FIG. 2), or UEs (e.g., UE214 and 220 of FIG. 2). Computing device 600 may include a number of components including one or more processors 604 and at least one communication chip 606. In various embodiments, processor 604 may comprise a processor core. In various embodiments, at least one communication chip 606 may also be physically and electrically coupled to the processor 604. In further implementations, the communication chip 606 may be part of the processor 604. In various embodiments, computing device 600 may include PCB 602. For these embodiments, processor 604 and communication chip 606 may be disposed thereon. In alternative embodiments, the various components may be coupled without employing the PCB 602. The communication chip 606 may be included in any of the receiver and/or transmitter circuits described herein.

The computing device 600 may include other components that may or may not be physically and electrically coupled to the PCB 602 depending on its application. These other components include, but are not limited to, volatile memory (e.g., dynamic random access memory 608, also referred to as DRAM), non-volatile memory (e.g., read only memory 610 (also referred to as "ROM"), one or more hard disk drives, one or more solid state drives, one or more compact disk drives, and/or one or more digital versatile disk drives), flash memory 612, input/output controller 614, digital signal processor(s) (not shown), encryption processor(s) (not shown), graphics processor 616, one or more antennas 618, touch screen display 620, touch screen controller 622, other displays (e.g., liquid crystal display, cathode ray tube display, and electronic ink display, not shown), battery 624, audio codec (not shown), video codec (not shown), Global Positioning System (GPS) device 628, non-volatile memory (e.g., read only memory 610 (also referred to as "ROM"), video codec (not shown), Global Positioning System (GPS) device 628, compass 630, an accelerometer (not shown), a gyroscope (not shown), a speaker 632, a camera 634, and a mass storage device (e.g., a hard drive, a solid state drive, a Compact Disc (CD), a Digital Versatile Disc (DVD)) (not shown)), and the like. In various embodiments, processor 604 may be integrated with other components on the same chip to form a system on a chip (SoC).

In various embodiments, the volatile memory (e.g., DRAM 608), non-volatile memory (e.g., ROM 612), flash memory 612, and mass storage may include programming instructions that, in response to execution by the processor 604, enable the computing device 600 to practice all or selected aspects of the processes described herein. For example, one or more of the memory components, such as volatile memory (e.g., DRAM 608), non-volatile memory (e.g., ROM 610), flash memory 612, and mass storage, may include temporary and/or persistent copies of instructions that, when executed, enable the computing device 600 to operate the control module 636 (which is configured to practice all or selected aspects of the processes described herein). The memory accessible to computing device 600 may include: one or more storage resources that are physically part of a device on which computing device 600 is installed; and/or one or more storage resources that are accessible by, but not necessarily a part of, computing device 600. For example, the storage resources may be accessed by the computing device 600 over a network via the communication chip 606.

The communication chip 606 may enable wired and/or wireless communication for data transfer to and from the computing device 600. The term "wireless" and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, but in some embodiments they may not. Many of the embodiments described herein may be used with WiFi and 3GPP/LTE communication systems. However, the communication chip 606 may implement any of a number of wireless standards or protocols, including, but not limited to, IEEE 702.20, General Packet Radio Service (GPRS), evolution-data optimized (Ev-DO), evolved high speed packet access (HSPA +), evolved high speed downlink packet access (HSDPA +), evolved high speed uplink packet access (HSUPA +), global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Digital Enhanced Cordless Telecommunications (DECT), bluetooth, derivatives thereof, and any other wireless protocol designated as 3G, 4G, 5G, and beyond. The computing device 600 may include a plurality of communication chips 606. For example, a first communication chip 606 may be dedicated to shorter range wireless communications, such as Wi-Fi and Bluetooth, and a second communication chip 606 may be dedicated to longer range wireless communications, such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.

In various implementations, the computing device 600 may be a laptop, a netbook, a notebook, an ultrabook, a smartphone, a computing tablet, a personal digital assistant, an ultra mobile PC, a mobile phone, a desktop computer, a server, a printer, a scanner, a monitor, a set-top box, an entertainment control unit (e.g., a gaming console), a digital camera, a portable music player, or a digital video recorder. In further implementations, the computing device 600 may be any other electronic device that processes data.

Computer-readable media (which includes non-transitory computer-readable media), methods, systems, and apparatus for performing the techniques described above are illustrative examples of embodiments disclosed herein. Additionally, other devices may be configured to perform the various disclosed techniques.

The following paragraphs describe examples of various embodiments. In various embodiments, one or more computer-readable media have instructions that, when executed, cause an NM apparatus to: receiving a first report including one or more measurements by a first UE in response to an event related to a handover of the first UE between a first RAT and a second RAT different from the first RAT; receiving a second report comprising one or more measurements by the second UE in response to an event related to handover of the second UE between the first RAT and a third RAT different from the first RAT; and identifying a hole in the coverage area of the first RAT based at least in part on the first and second reports. In some embodiments, the first RAT is an E-UTRA technology. In some embodiments, each of the second and third RATs is a UTRA technology or a GERA technology. In some embodiments, the handover of the first UE between the first RAT and the second RAT is a handover of the first UE between a first E-UTRAN cell and a second RAT, and the handover of the second UE between the first RAT and a third RAT is a handover of the second UE between a second E-UTRAN cell and a third RAT, the second E-UTRAN cell being different from the first E-UTRAN cell. In some embodiments, the one or more measurements included in the first report include one or more of RSRP, RSRQ, an identifier of a cell serving the first UE with the first RAT, location information, and a timestamp representing a time of the handover-related event. In some embodiments, the first and second UEs are common UEs. In some embodiments, identifying the hole in the coverage area of the first RAT based at least in part on the first and second reports comprises correlating the first and second reports. In some embodiments, one or more computer-readable media further have instructions that, when executed, cause the NM device to recommend a corrective action based on the identified hole. Some embodiments of the NM apparatus include combinations of the foregoing.

In various embodiments, an eNB associated with a first RAT comprises: first transmitter circuitry to transmit a command to a UE in a cell served by an eNB to cause the UE to switch to a second RAT different from the first RAT; receiver circuitry to receive, from the UE in response to the command, one or more measurements made by the UE and representative of a near cell edge condition; and a second transmitter circuit to transmit a report including one or more measurements to identify a coverage hole in the first RAT to the DM device or the NM device. In some embodiments, the second RAT comprises UTRA technology or GERA technology. In some embodiments, the one or more measurements are made by the UE in response to receiving a command at the UE. In some embodiments, the one or more measurements are made by the UE prior to receiving the command at the UE. In some embodiments, the first transmitter circuitry further transmits to the UE a parameter representative of which measurements are to be made by the UE (as representative of a condition near the cell edge). In some embodiments, the parameters represent one or more of RSRP, RSRQ, an identifier of a cell, location information, and a timestamp representing a time of a handover-related event. In some embodiments, communicating the report including the one or more measurements to the DM device or the NM device includes communicating the report to a CCO function of the NM device. Some embodiments of the eNB include a combination of the foregoing.

In various embodiments, the UE comprises: receiver circuitry to receive a command from an eNB serving a UE to handover the UE to a second RAT different from the first RAT, the eNB associated with the first RAT having a coverage hole proximate to the UE; transmitter circuitry to transmit, in response to receiving the command, one or more measurements made by the UE and representative of a condition near a coverage hole to the eNB; and handover circuitry to perform a handover to the second RAT after the one or more measurements are transmitted to the eNB. In some embodiments, the second RAT is UTRA technology or GERA technology. In some embodiments, receiving the command to switch the UE to the second RAT occurs when the UE is near an edge of a cell of the first RAT served by the eNB. In some embodiments, receiving the command to handover the UE to the second RAT occurs when the UE is near an edge of an E-UTRAN cell served by the eNB and no other E-UTRAN cell is sufficiently close to the UE to serve the UE. In some embodiments, the UE further includes measurement circuitry to make one or more measurements including one or more of a group of measurements including RSRP, RSRQ, an identifier of a cell serving the UE with the first RAT, location information, and a timestamp representing a time of the handover-related event. Some embodiments of the UE include a combination of the foregoing.

Although certain embodiments have been illustrated and described herein for purposes of description, a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Accordingly, it is expressly intended that the embodiments described herein be limited only by the claims.

Where the disclosure recites "a" or "a first" element or the equivalent thereof, such disclosure includes one or more such elements, neither requiring nor excluding two or more such elements. Furthermore, ordinal references (e.g., first, second or third) for identified elements are used to distinguish between the elements, and do not indicate or imply a required or limited number of such elements, nor do they indicate a particular position or order of such elements unless otherwise explicitly stated.

Claims (25)

1. A Network Management (NM) apparatus implementing Coverage and Capacity Optimization (CCO) functionality, the apparatus comprising:

means for determining a coverage hole based on obtained measurement data, wherein the measurement data is associated with a coverage area of one or more evolved universal terrestrial radio access network (E-UTRAN) cells providing connectivity to a Long Term Evolution (LTE) network, and the measurement data comprises inter-Radio Access Technology (RAT) measurements, and wherein the coverage hole is an area having insufficient signal strength to provide reliable connectivity to the LTE network; and

means for sending an instruction to alter a service parameter of at least one of the one or more E-UTRAN cells to increase connectivity to the LTE network in the coverage hole.

2. The NM apparatus of claim 1, wherein the coverage hole is between two or more E-UTRAN cells of the one or more E-UTRAN cells.

3. The NM apparatus of claim 1, wherein the coverage hole is partially or completely within a coverage area of one or more other cells provided by a different RAT than E-UTRAN.

4. The NM apparatus of claim 1, wherein the service parameter is one or more of a size of the at least one E-UTRAN cell or a capacity of the at least one E-UTRAN cell.

5. The NM device of claim 1, wherein the measurement data comprises one or more of a Reference Signal Received Power (RSRP) measurement, a Reference Signal Received Quality (RSRQ) measurement, a cell identifier, location information, or a timestamp indicating a time of an inter-RAT handover.

6. The NM apparatus of claim 1, wherein the measurement data comprises one or more measurements collected by one or more User Equipments (UEs).

7. The NM apparatus of claim 6, wherein the inter-RAT measurements are based on measurements made during inter-RAT handover of the one or more UEs from each E-UTRAN cell to other cells provided by a RAT different from E-UTRAN.

8. The NM apparatus of any of claims 1-7, wherein the means for determining the coverage hole comprises:

means for determining a location at which the one or more UEs experience less signal strength than required for connectivity to the LTE network based on the measurement data; and

means for determining that the E-UTRAN coverage hole is an area associated with the determined location.

9. A Network Management (NM) apparatus implementing Coverage and Capacity Optimization (CCO) functionality, the apparatus comprising:

communication circuitry to receive, from one or more evolved node Bs (eNBs), measurement data for one or more evolved Universal terrestrial radio Access network (E-UTRAN) cells provided by the one or more eNBs, wherein each E-UTRAN cell is to provide connectivity to a Long Term Evolution (LTE) network, and wherein the measurement data is based on measurements made during handover from each E-UTRAN cell to other cells provided by a Radio Access Technology (RAT) different from E-UTRAN; and

a processor circuit for identifying an E-UTRAN coverage hole based on the measurement data and determining an E-UTRAN coverage area to adjust based on the E-UTRAN coverage hole, and

wherein the communications circuitry is to communicate instructions to at least one eNB of the set of eNBs to adjust a service parameter of an E-UTRAN cell provided by the at least one eNB to adjust the coverage area.

10. The NM apparatus of claim 9, wherein the NM apparatus

The E-UTRAN coverage hole is between an E-UTRAN cell provided by the at least one eNB and one or more other E-UTRAN cells of the one or more E-UTRAN cells,

the E-UTRAN coverage area is a cell coverage area of an E-UTRAN cell provided by the at least one eNB and

the service parameter is one or more of a size of a coverage area of the E-UTRAN cell provided by the at least one eNB or a capacity of the E-UTRAN cell provided by the at least one eNB.

11. The NM apparatus of claim 9, wherein the measurement data comprises one or more measurements collected by one or more UEs.

12. The NM device of claim 11, wherein the measurement data comprises one or more of a Reference Signal Received Power (RSRP) measurement, a Reference Signal Received Quality (RSRQ) measurement, a cell identifier, location information, or a timestamp indicating a time of an inter-RAT handover.

13. The NM device of claim 11 or 12, wherein to identify the coverage hole, the processor circuit is to:

determining, based on the measurement data, a region in which the one or more UEs experience less signal strength than is required for connectivity to the LTE network; and

determining that the E-UTRAN coverage hole is an area associated with the determined region.

14. The NM apparatus of claim 13, wherein the E-UTRAN coverage hole includes a boundary that includes the determined region.

15. A method to be performed by an evolved node B (eNB), the method comprising:

receiving, by the eNB, measurement data from one or more User Equipments (UEs), wherein the measurement data comprises inter-Radio Access Technology (RAT) measurements;

communicating, by the eNB, the measurement data to a Coverage and Capacity Optimization (CCO) function of a Network Management (NM) device;

receiving, by the eNB from the CCO function, instructions to adjust a service parameter of a cell coverage area based on the measurement data, wherein the adjustment of the service parameter is based on the identified coverage hole indicating a reduction in connectivity to a Long Term Evolution (LTE) network; and

adjusting, by the eNB, the service parameter to provide an increase in connectivity to the LTE network in the coverage hole.

16. The method of claim 15, wherein adjusting the service parameters comprises:

aligning, by the eNB, one or more antennas of the eNB; or

Controlling, by the eNB, power output to the one or more antennas.

17. The method of claim 15, wherein the service parameter is at least one of a size of a coverage area of an evolved universal terrestrial radio access network (E-UTRAN) cell provided by the eNB or a capacity of the E-UTRAN cell.

18. The method of claim 15, wherein the coverage hole is between the eNB and one or more other enbs, and wherein the coverage hole is partially or completely within a coverage area of one or more other cells provided by one or more base stations associated with a RAT different from E-UTRAN.

19. The method of claim 15, wherein the measurement data comprises one or more of a Reference Signal Received Power (RSRP) measurement, a Reference Signal Received Quality (RSRQ) measurement, a cell identifier, location information, or a timestamp indicating a time of an inter-RAT handover.

20. The method of any of claims 15-19, wherein the inter-RAT measurements are based on measurements made during inter-RAT handover of the one or more UEs from an E-UTRAN cell provided by the eNB to other cells provided by a RAT different from E-UTRAN.

21. An apparatus for Coverage and Capacity Optimization (CCO) to be implemented by an evolved node b (enb), the apparatus comprising:

a communication circuit to:

receiving measurement data from one or more User Equipments (UEs), wherein the measurement data comprises inter-Radio Access Technology (RAT) measurements;

communicating the measurement data to a Network Management (NM) function of a NM device; and

receive instructions from the CCO function to adjust service parameters of a cell coverage area based on the measurement data, wherein the adjustment of the service parameters is based on the identified coverage hole indicating a reduction in connectivity to a Long Term Evolution (LTE) network; and

a processor circuit to adjust the service parameter to provide an increase in connectivity to the LTE network in the coverage hole.

22. The apparatus of claim 21, wherein to adjust the service parameter, the processor circuit is to:

control adjustment of one or more antennas of the eNB; or

Controlling power output to the one or more antennas.

23. The apparatus of claim 21, wherein the service parameter is at least one of a size of a coverage area of an evolved universal terrestrial radio access network (E-UTRAN) cell provided by the eNB or a capacity of the E-UTRAN cell, and wherein the coverage hole is between the eNB and one or more other enbs, and wherein the coverage hole is partially or completely within a coverage area of one or more other cells provided by one or more base stations associated with a RAT different from E-UTRAN.

24. The apparatus of any of claims 21-23, wherein the measurement data comprises one or more of a Reference Signal Received Power (RSRP) measurement, a Reference Signal Received Quality (RSRQ) measurement, a cell identifier, location information, or a timestamp indicating a time of an inter-RAT handover.

25. The apparatus of claim 24, wherein the inter-RAT measurements are based on measurements made during an inter-RAT handover of the one or more UEs from an E-UTRAN cell provided by the eNB to other cells provided by a RAT different from E-UTRAN.