# Patent

## Title
Controlling wireless device communication with access nodes

## Abstract

When a first loading of a first access node is determined to meet a loading criteria, a handover criteria is decreased for a second access node comprising a coverage area at least a portion of which is within a coverage area of the first access node. A handover is performed of at least one of a plurality of wireless devices from the first access node to the second access node when a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria. Changes are determined in the first loading and in a throughput provided to the at least one of the wireless devices, and the handover criteria for the second access node is adjusted based on the changes in the first loading and the throughput provided to the at least one wireless device.

## Background
TECHNICAL BACKGROUND
Wireless communication networks increasingly comprise a variety of access nodes having different capabilities, including signal transmission power, coverage area, supported frequency bands, number of channels supported, and total number of wireless connections supported, among other things. A coverage area of a larger access node (such as a macro access node) can include second coverage areas of one or more smaller access nodes (such as a micro access node, pico access node, femto access node, and the like). The coverage area of the larger access node can partially or completely overlap with the one or more smaller access node coverage areas.
OVERVIEW
In operation, it is determined that a first loading of a first access node meets a loading criteria, where the first access node is in communication with a plurality of wireless devices in a first coverage area. A handover criteria for a second access node is decreased, where the second access node comprises a second coverage area and least a portion of the second coverage area is within the first coverage area. A handover is performed of at least one of the plurality of wireless devices to the second access node when a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria. Changes are then determined in the first loading and in a throughput provided to the at least one of the plurality of wireless devices, and the handover criteria for the second access node is adjusted based on the change in the first loading and the change in the throughput provided to the at least one of the plurality of wireless devices.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary communication system to control wireless device communication with access nodes.
FIG. 2 illustrates an exemplary method of controlling wireless device communication with access nodes.
FIG. 3 illustrates another exemplary communication system to control wireless device communication with access nodes.
FIG. 4 illustrates another exemplary system to control wireless device communication with access nodes.
FIG. 5 illustrates another exemplary method of controlling wireless device communication with access nodes.
FIG. 6 illustrates an exemplary processing node.



DETAILED DESCRIPTION
FIG. 1 illustrates an exemplary communication system 100 to control wireless device communication with access nodes comprising wireless device 102, access node 104, access node 106, and communication network 108. Examples of wireless device 102 can comprise a cell phone, a smart phone, a computing platform such as a laptop, palmtop, or tablet, a personal digital assistant, or an internet access device, including combinations thereof. Wireless device 102 can communicate with access node 104 over communication link 110, and can communicate with access node 106 over communication link 112. While one wireless device 102 is illustrated in FIG. 1 for conciseness, a greater number of wireless devices can communicate with access node 104 and/or access node 106.
Access nodes 104 and 106 are each a network node capable of providing wireless communications to wireless device 102, and can comprise, for example, a base transceiver station, a radio base station, an eNodeB device, or an enhanced eNodeB device. Access nodes 104 and 106 can be in communication over communication link 114. Access node 104 can communicate with communication network 108 over communication link 116, and access node 106 can communicate with communication network 108 over communication link 118.
Communication network 108 can be a wired and/or wireless communication network, and can comprise processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among various network elements, including combinations thereof, and can include a local area network, a wide area network, and an internetwork (including the Internet). Communication network 108 can be capable of carrying voice information and other data, for example, to support communications by a wireless device such as wireless device 102. Wireless network protocols may comprise code division multiple access (CDMA) 1xRTT, Global System for Mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), High-Speed Packet Access (HSPA), Evolution Data Optimized (EV-DO), EV-DO rev. A, Worldwide Interoperability for Microwave Access (WiMAX), and Third Generation Partnership Project Long Term Evolution (3GPP LTE). Wired network protocols that may be utilized by communication network 108 comprise Ethernet, Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier Sense Multiple Access with Collision Avoidance), Token Ring, Fiber Distributed Data Interface (FDDI), and Asynchronous Transfer Mode (ATM). Communication network 108 may also comprise a wireless network, including base stations, wireless communication nodes, telephony switches, internet routers, network gateways, computer systems, communication links, or some other type of communication equipment, and combinations thereof.
Communication links 110, 112, 114, 116 and 118 can be wired or wireless communication links. Wired communication links can comprise, for example, twisted pair cable, coaxial cable or fiber optic cable, or combinations thereof. Wireless communication links can comprise a radio frequency, microwave, infrared, or other similar signal, and can use a suitable communication protocol, for example, Global System for Mobile telecommunications (GSM), Code Division Multiple Access (CDMA), Worldwide Interoperability for Microwave Access (WiMAX), or Long Term Evolution (LTE), or combinations thereof. Other wireless protocols can also be used.
Other network elements may be present in communication system 100 to facilitate wireless communication but are omitted for clarity, such as base stations, base station controllers, gateways, mobile switching centers, dispatch application processors, and location registers such as a home location register or visitor location register. Furthermore, other network elements may be present to facilitate communication between access node 104, access node 106, and communication network 108 which are omitted for clarity, including additional processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among the various network elements.
In an embodiment, access node 104 can comprise a larger access node, such as a macro access node, and access node 106 can comprise a smaller access node than access node 104, such as a micro access node, a pico access node, a femto access node, and the like. Access node 106 can be deployed such that a coverage area of access node 106 is overlapped partially or completely by a coverage area of access node 104. A smaller access nodes (such as access node 106) may be deployed adjacent to or within a coverage area of a larger access node (such as access node 104) to provide additional wireless communication coverage, for example, in a coverage hole of access node 104, in an area of poor radio frequency coverage by access node 104, and so forth.
Access node 106 may be deployed to provide an access node to which wireless devices may be offloaded from communication with access node 104, for example, when a loading of access node 104 meets a loading criteria. Larger access nodes typically are capable of transmitting signals at a greater signal level or signal power than smaller access nodes. The greater transmit signal level of the larger access node may reduce the effective coverage area of the smaller access node by masking or interfering with a signal from the smaller access node. Accordingly, a wireless device (such as wireless device 102) which is within both a coverage area of access node 104 and a coverage area of access node 106 may not determine that access node 106 is a viable candidate to provide wireless communications to wireless device 102. This can result in inefficient resource utilization of the larger access node and the smaller access node, as well as a degradation of the quality of wireless communications provided to a wireless device which is unable to determine the superior access node.
In operation, it is determined that a first loading of first access node 104 in communication with a plurality of wireless devices (such as wireless device 102) in a first coverage area meets a loading criteria. A handover criteria is decreased for second access node 106, which comprises a second coverage area, at least a portion of which is within the first coverage area of access node 104. A handover is performed of at least one of the plurality of wireless devices from first access node 104 to second access node 106 when a signal level of second access node 106 which is received at the at least one of the plurality of wireless devices meets the decreased handover criteria. When the one or more wireless devices have changed to communicating with access node 106, a change in the first loading and a change in a throughput provided to the at least one of the plurality of wireless devices are determined. Based on the change in the first loading and the change in the throughput provided to the at least one of the plurality of wireless devices, the decreased handover criteria is adjusted for the second access node.
FIG. 2 illustrates an exemplary method of controlling wireless device communication with access nodes. In operation 202, it is determined that a first loading of a first access node in communication with a plurality of wireless devices in a first coverage area meets a loading criteria. The first loading can comprise a utilization or requested utilization of communication link resources of the access node, for example, an amount of data sent to or from the plurality of wireless devices, a number of physical resource blocks or other wireless communication link resource utilized by the plurality of wireless devices, a requested amount of data to be sent to or from the plurality of wireless devices (as may be determined from a buffer status report or similar request for wireless communication link resources), an amount of data buffered for transmission to or from the plurality of wireless devices, and the like, including combinations thereof. The first access node can comprise a first coverage area in which a signal from the first access node can be detected by a wireless device at or above a signal level threshold. For example, referring to FIG. 3, access node 304 can comprise coverage area 304A. Similarly, access node 306 can comprise coverage area 306A, and access node 308 can comprise coverage area 308A. While a single wireless device 302 is illustrated in coverage area 304A, coverage area 304A can comprise a plurality of wireless devices, which can be in communication with access node 304.
Returning to FIG. 2, when it is determined that the first loading of the first access node in communication with the plurality of wireless devices in the first coverage area meets the loading criteria, a handover criteria is decreased for a second access node (operation 204). The second access node can comprise a second coverage area, wherein at least a portion of the second coverage area is within the first coverage area. For example, second access node 306 (FIG. 3) can comprise coverage area 306A, which is substantially overlapped by coverage area 304A. As another example, second access node 308 can comprise coverage area 308A, which is partially overlapped by coverage area 304A. The handover criteria can comprise a signal level of a signal from the second access node, such as a reference signal receive power (RSRP), a received signal strength indication (RSSI), a signal-to-noise ratio (SNR), a carrier to noise ratio (CNR) value, a signal noise and distortion (SINAD), a signal to interference (SII), a signal to noise plus interference (SNIR), a signal to quantization noise ratio (SQNR), and the like. The handover criteria can also comprise a reference signal receive quality (RSRQ), a channel quality indicator (CQI), or another measurement of signal quality. The handover criteria can further comprise combinations of the foregoing. Different second access nodes may comprise different handover criteria. For example, access node 306 may comprise a first handover criteria, and access node 308 may comprise a second handover criteria.
Returning to FIG. 2, the handover criteria for the second access node can be decreased, for example, from a first threshold to a second threshold, to decrease the level of the handover criteria required for a handover to be requested to change the wireless device from communicating with the first access node to communicating with the second access node. When a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria, a handover is performed of at least one of the plurality of wireless devices to the second access node (operation 206). For example, wireless device 302 (FIG. 3) may approach access node 306 to within coverage area 306A. For example, wireless device 302 may detect a signal from access node 306 (such as a pilot signal, a reference signal, and the like) which meets a threshold signal level. The signal level received at wireless device 302 from access node 306 may meet the decreased handover criteria, which can comprise a reduced signal level threshold (i.e., reduced from a previous, higher signal level threshold).
Referring again to FIG. 2, after the handover is performed of the at least one of the plurality of wireless devices to the second access node, the first loading (of the first access node) and a throughput provided to the at least one of the at least one of the plurality of wireless devices can be monitored. A change can be determined in the first loading and in a throughput provided to the at least one of the plurality of wireless devices (operation 208). For example, when one or more wireless devices 302 (FIG. 3) are handed over to the second access node (for example, access node 306), a change in the loading of access node 304, and a change in the throughput provided to wireless device 302 (as between a throughput provided by access node 304 and a throughput provided by access node 306) can be determined.
Returning to FIG. 2, based on the change in the first loading and the change in the throughput provided to the at least one of the plurality of wireless devices, the decreased handover criteria for the second access node can be adjusted (operation 210). For example, when a decrease in the first loading is relatively small, and the throughput provided decreases, the handover criteria can be adjusted to reduce the likelihood of performing additional handovers of wireless devices to the second access node. As another example, when a decrease in the first loading is relatively large, and the throughput provided increases, the handover criteria can be adjusted to increase the likelihood of performing additional handovers of wireless devices to the second access node.
FIG. 4 illustrates another exemplary communication system 400 to control wireless device communication with access nodes comprising wireless device 402, access node 404, access node 406, controller node 408, gateway node 410, and communication network 412. Examples of wireless device 402 can comprise a cell phone, a smart phone, a computing platform such as a laptop, palmtop, or tablet, a personal digital assistant, or an internet access device, including combinations thereof. Wireless device 402 can communicate with access node 404 over communication link 414, and with access node 406 over communication link 416.
Access nodes 404 and 406 are each a network node capable of providing wireless communications to wireless device 402, and can be, for example, a base transceiver station, a radio base station, an eNodeB device, or an enhanced eNodeB device. Access node 304 is in communication with controller node 408 over communication link 420 and with gateway node 410 over communication link 424. Access node 406 is in communication with controller node 408 over communication link 422 and with gateway node 410 over communication link 426. Access nodes 404 and 406 can also communicate with each other over communication link 418. In an embodiment, access nodes 404 and 406 comprise neighboring access nodes of comparable coverage area and/or signal power, for example, two macro eNodeB towers and the like. In an embodiment, access node 406 may comprise a coverage area at least a portion of which is within a coverage area of access node 404, for example, where access node 406 is a smaller access node than access node 404. For example, access node 404 can comprise a macro cell, and access node 406 can comprise a smaller cell such as a micro cell, pico cell, femto cell, and so forth. Other examples are also possible, including combinations of the foregoing.
Controller node 408 can comprise a processor and associated circuitry to execute or direct the execution of computer-readable instructions, and can be configured to control the setup and maintenance of a communication session over communication network 412 for wireless device 402. Controller node 408 can comprise a mobile switching center (MSC), a dispatch call controller (DCC), a mobility management entity (MME), or another similar network node. Controller node 408 can retrieve and execute software from storage, which can include a disk drive, flash drive, memory circuitry, or some other memory device, and which can be local or remotely accessible. The software comprises computer programs, firmware, or some other form of machine-readable instructions, and may include an operating system, utilities, drivers, network interfaces, applications, or some other type of software, including combinations thereof. Controller node 408 can receive instructions and other input at a user interface. Controller node 408 is in communication with communication network 412 over communication link 430, and with gateway node 410 over communication link 428.
Gateway node 410 can comprise a processor and associated circuitry to execute or direct the execution of computer-readable instructions, and can be configured to mediate data communications related to wireless device 402 which is sent between communication network 412 and access node 404 and/or access node 406. Gateway node 410 can retrieve and execute software from storage, which can include a disk drive, flash drive, memory circuitry, or some other memory device, and which can be local or remotely accessible. The software comprises computer programs, firmware, or some other form of machine-readable instructions, and may include an operating system, utilities, drivers, network interfaces, applications, or some other type of software, including combinations thereof. Gateway node 410 can receive instructions and other input at a user interface. Examples of gateway node 410 can include a standalone computing device, a computer system, or a network component, such as an access service network gateway (ASN-GW), a packet data network gateway (P-GW), a serving gateway (S-GW), a mobile switching controller (MSC), a packet data serving node (PDSN), call processing equipment, a home agent, a radio node controller (RNC), a subscriber profile system (SPS), authentication, authorization, and accounting (AAA) equipment, and a network gateway, including combinations thereof. Gateway node 410 is in communication with communication network 412 over communication link 432.
Communication network 412 can be a wired and/or wireless communication network, and can comprise processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among various network elements, including combinations thereof, and can include a local area network, a wide area network, and an internetwork (including the Internet). Communication network 412 can be capable of carrying voice information and other data, for example, to support communications by a wireless device such as wireless device 402. Wireless network protocols may comprise code division multiple access (CDMA) 1xRTT, Global System for Mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), High-Speed Packet Access (HSPA), Evolution Data Optimized (EV-DO), EV-DO rev. A, Worldwide Interoperability for Microwave Access (WiMAX), and Third Generation Partnership Project Long Term Evolution (3GPP LTE). Wired network protocols that may be utilized by communication network 412 comprise Ethernet, Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier Sense Multiple Access with Collision Avoidance), Token Ring, Fiber Distributed Data Interface (FDDI), and Asynchronous Transfer Mode (ATM). Communication network 412 may also comprise a wireless network, including base stations, wireless communication nodes, telephony switches, internet routers, network gateways, computer systems, communication links, or some other type of communication equipment, and combinations thereof.
Communication links 414, 416, 418, 420, 422, 424, 426, 428, 430, and 432 can be wired or wireless communication links. Wired communication links can comprise, for example, twisted pair cable, coaxial cable or fiber optic cable, or combinations thereof. Wireless communication links can comprise a radio frequency, microwave, infrared, or other similar signal, and can use a suitable communication protocol, for example, Global System for Mobile telecommunications (GSM), Code Division Multiple Access (CDMA), Worldwide Interoperability for Microwave Access (WiMAX), or Long Term Evolution (LTE), or combinations thereof. Other wireless protocols can also be used.
Other network elements may be present in communication system 400 to facilitate wireless communication but are omitted for clarity, such as base stations, base station controllers, gateways, mobile switching centers, dispatch application processors, and location registers such as a home location register or visitor location register. Furthermore, other network elements may be present to facilitate communication among access node 404, access node 406, controller node 408, gateway node 410, and communication network 412 which are omitted for clarity, including additional processing nodes, routers, gateways, and physical and/or wireless data links for carrying data among the various network elements.
FIG. 5 illustrates an exemplary method of controlling wireless device communication with access nodes. In operation 502, it is determined that a first loading of a first access node in communication with a plurality of wireless devices in a first coverage area meets a loading criteria. The first loading can comprise a loading of access node 404, such as a utilization or requested utilization of communication link resources of the access node, for example, an amount of data sent to or from the plurality of wireless devices, a number of physical resource blocks or other wireless communication link resource utilized by the plurality of wireless devices, a requested amount of data to be sent to or from the plurality of wireless devices (as may be determined from a buffer status report or similar request for wireless communication link resources), an amount of data buffered for transmission to or from the plurality of wireless devices, and the like, including combinations thereof. The first access node can comprise a first coverage area in which a signal from the first access node can be detected by a wireless device at or above a signal level threshold.
When it is determined that the first loading of the first access node in communication with the plurality of wireless devices in the first coverage area meets the loading criteria, a handover criteria is decreased for a second access node (operation 504). The second access node, such as access node 406, can comprise a second coverage area, wherein at least a portion of the second coverage area is within the first coverage area. The handover criteria can comprise a signal level of a signal from the second access node, such as a reference signal receive power (RSRP), a received signal strength indication (RSSI), a signal-to-noise ratio (SNR), a carrier to noise ratio (CNR) value, a signal noise and distortion (SINAD), a signal to interference (SII), a signal to noise plus interference (SNIR), a signal to quantization noise ratio (SQNR), and the like. The handover criteria can also comprise a reference signal receive quality (RSRQ), a channel quality indicator (CQI), or another measurement of signal quality. The handover criteria can further comprise combinations of the foregoing. In an embodiment, the coverage area of access node 404 may comprise more than one second access node coverage area, and each second access node can comprise a different handover criteria.
The handover criteria for the second access node can be decreased, for example, from a first threshold to a second threshold, to decrease the level of the handover criteria required for a handover to be requested to change the wireless device from communicating with the first access node to communicating with the second access node. When a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria, a handover is performed of at least one of the plurality of wireless devices to the second access node (operation 506). For example, wireless device 402 may approach access node 406 to within coverage area of access node 406, and a signal level received at wireless device 402 from access node 406 may meet the decreased handover criteria, which can comprise a reduced signal level threshold (i.e., reduced from a previous, higher signal level threshold). In an embodiment, the handover of wireless device 402 to access node 406 is performed when the loading of access node 404 meets or exceeds a first threshold, and when a loading of access node 406 meets or is below a second threshold.
After the handover is performed of the at least one of the plurality of wireless devices to the second access node, the first loading (of the first access node) and a throughput provided to the at least one of the at least one of the plurality of wireless devices can be monitored. A change can be determined in the first loading and in a throughput provided to the at least one of the plurality of wireless devices (operation 508). For example, when one or more wireless devices (such as wireless device 402) are handed over to the second access node (for example, access node 306), a change in the loading of access node 404, and a change in the throughput provided to wireless device 402 (as between a throughput provided by access node 404 and a throughput provided by access node 406) can be determined. The change in the throughput for the plurality of wireless device can comprise an average change in throughput, a total change in throughput for all of the handed over wireless devices, and the like.
In addition to determining a change in throughput provided to wireless device 402, additional factors can be evaluated after the handover is performed of the at least one of the plurality of wireless devices to the second access node. A change in a latency of data sent to the at least one of the plurality of wireless devices can also be determined (operation 510). The change in latency can be determined based on a delay of data sent to or received from wireless device 402. For example, data sent to wireless device 402 from access node 404 before the handover is performed may comprise a first delay time, and data sent to wireless device 402 from access node 406 after the handover is performed may comprise a second delay time. A difference between the first delay time and the second delay time can be determined. The difference between the first delay time and the second delay time for the plurality of wireless device can comprise an average difference over the total number of handed-over wireless devices, a total difference for all of the handed-over wireless devices, and the like.
Additionally, a change in a variation of latency of data sent to the at least one of the plurality of wireless devices can be determined (operation 512). The variation of latency of the data can comprise a variation in the periodicity or smoothness of data sent to or received from wireless device 402, such as jitter, burstiness, and the like. For example, data sent to wireless device 402 from access node 404 before the handover is performed may comprise a first variation of latency, and data sent to wireless device 402 from access node 406 after the handover is performed may comprise a second variation of latency. A difference between the first variation of latency and the second variation of latency can be determined. The difference between the first variation of latency and the second variation of latency for the plurality of wireless device can comprise an average difference over the total number of handed-over wireless devices, a total difference for all of the handed-over wireless devices, and the like.
Further, a change in a data loss rate of data sent to the at least one of the plurality of wireless devices can be determined (operation 514). The data loss rate can comprise a measurement over a period of time of data which is sent from an access node to wireless device 402, or which is sent from wireless device 402 to an access node, but which does not arrive. For example, data sent to wireless device 402 from access node 404 before the handover is performed may comprise a first data loss rate, and data sent to wireless device 402 from access node 406 after the handover is performed may comprise a second data loss rate. A difference between the first data loss rate and the second data loss rate can be determined. The difference between the first data loss rate and the second data loss rate for the plurality of wireless device can comprise an average difference over the total number of handed-over wireless devices, a total difference for all of the handed-over wireless devices, and the like.
Moreover, it can be determined that a communication session of the at least one of the plurality of wireless devices is terminated when the handover is performed of at least one of the plurality of wireless devices to the second access node (operation 516). For example, wireless device 402 can be conducting a communication session, such as a voice communication session or a data communication session, through access node 404. Then, when the handover is performed of wireless device 402 from access node 404 to access node 406, the communication session is unintentionally terminated. For example, the voice communication session may be dropped, or the data communication session may be unintentionally discontinued. Termination of a communications session can be caused, among other things, by radio frequency interference, or when a signal level from the second access node is insufficient to support the communication session. In an embodiment, a number of terminations of communication sessions of the at least one of the plurality of wireless devices can be determined when the at least one of the plurality of wireless devices is handed over from access node 404 to access node 406.
In addition, an application requirement can be determined for an application running on each of the at least one of the plurality of wireless devices, and a weighting factor can be determined based on the determined application requirement (operation 518). The application requirement can comprise a minimum data rate, a maximum permitted data delay, a minimum throughput, a maximum error rate, a maximum data loss rate, and the like, of an application running on a wireless device. The application requirement can also be determined based on the application type, such as whether the application is a relatively delay sensitive application (such as a streaming audio application a streaming video application, a voice application, and the like) or a relatively delay insensitive application (such as an email application, a messaging application, a web browsing application, and the like). The application requirement can also be determined based on the application's utilization or requested utilization of communication link resources, for example, an amount of data sent to or from the wireless device, a number of physical resource blocks or other wireless communication link resource utilized by the wireless device, a requested amount of data to be sent to or from the wireless device (as may be determined from a buffer status report or similar request for wireless communication link resources), an amount of data buffered for transmission to or from the wireless device, and the like, including combinations thereof. Further, the application requirement can also be determined based on a traffic class indicator associated with bearer data being sent from the wireless device, such as a quality of service class indicator (QCI) or similar traffic class indicator.
The application requirement can be determined based on information received from the wireless device. The application requirement can also be determined based on deep packet inspection (e.g., at gateway node 410) of information received from wireless device 402. Deep packet inspection generally involves an inspection of packets beyond Open Systems Interconnection (OSI) layer 2 including an inspection of the data portion (also referred to as the payload portion) of a packet (and possibly also the header of a packet). That is deep packet inspection can involve an examination of any of layers 2 through 7 of the OSI model. The data portion of a packet remains distinct from a header portion, even where the packet receives additional header information (such as by packet encapsulation or a similar process). In other words, when a packet is encapsulated, any additional header information does not combine information from the data portion with any header portion.
Based on the determined application requirement, a weighting factor can be determined, and the weighting factor can be applied to the determined change in the throughput provided to the at least one of the plurality of wireless devices (operation 518). For example, a relatively delay sensitive application of a first wireless device may be strongly affected by a decrease in throughput provided to the wireless device by the second access node; accordingly, the weighting factor determined for the first wireless device may be greater. As another example, a relatively delay insensitive application of a second wireless device may be minimally affected by a decrease in throughput provided to the wireless device by the second access node; accordingly, the weighting factor determined for the second wireless device may be smaller.
Further, after the handover is performed of the at least one of the plurality of wireless devices to the second access node, a change in a second loading of the second access node can be determined (operation 520). The second loading can comprise a loading of access node 406, such as a utilization or requested utilization of communication link resources of the access node, for example, an amount of data sent to or from the plurality of wireless devices, a number of physical resource blocks or other wireless communication link resource utilized by the plurality of wireless devices, a requested amount of data to be sent to or from the plurality of wireless devices (as may be determined from a buffer status report or similar request for wireless communication link resources), an amount of data buffered for transmission to or from the plurality of wireless devices, and the like, including combinations thereof.
Then, in operation 522, the decreased handover criteria for the second access node can be adjusted based on some or all of the change in the first loading, and the change in the throughput provided to the at least one of the plurality of wireless devices, the change in a latency of data, the change in the variation of the latency of data, the change in the data loss rate, whether the communication session is terminated with one or more of the plurality of wireless devices, the weighting factor determined based on the application requirements, and the change in the second loading of the second access node.
Next, location characteristics of the second access node are determined (operation 524). Location characteristics can comprise a location of access node 406 relative to access node 404, a distance of access node 406 from access node, an amount of overlap of a coverage area of access node 406 and a coverage area of access node 404, and wireless communication link conditions of access node 406 (such as radio frequency interference, wireless communication link congestion, communication resource utilization, and the like).
Based on the determined location characteristics of the second access node, a handover criteria for a third access node is adjusted (operation 526). The third access node can comprise an access node having substantially similar location characteristics as the location characteristics of the second access node. Thus, the determination of the handover criteria for the second access node, and the adjustment of the handover criteria of the second access node, can be applied to a third access node which is similarly situated as compared to the second access node.
FIG. 6 illustrates an exemplary processing node 600 in a communication system. Processing node 600 comprises communication interface 602, user interface 604, and processing system 606 in communication with communication interface 602 and user interface 604. Processing node 600 can be control wireless device communication with access nodes. Processing system 606 includes storage 608, which can comprise a disk drive, flash drive, memory circuitry, or other memory device. Storage 608 can store software 610 which is used in the operation of the processing node 600. Storage 608 may include a disk drive, flash drive, data storage circuitry, or some other memory apparatus. Software 610 may include computer programs, firmware, or some other form of machine-readable instructions, including an operating system, utilities, drivers, network interfaces, applications, or some other type of software. Processing system 606 may include a microprocessor and other circuitry to retrieve and execute software 610 from storage 608. Processing node 600 may further include other components such as a power management unit, a control interface unit, etc., which are omitted for clarity. Communication interface 602 permits processing node 600 to communicate with other network elements. User interface 604 permits the configuration and control of the operation of processing node 600.
Examples of processing node 600 include controller node 408 and gateway node 410. Processing node 600 can also be an adjunct or component of a network element, such as an element of controller node 408 or gateway node 410. Processing node 600 can also be another network element in a communication system. Further, the functionality of processing node 600 can be distributed over two or more network elements of a communication system.
The exemplary systems and methods described herein can be performed under the control of a processing system executing computer-readable codes embodied on a computer-readable recording medium or communication signals transmitted through a transitory medium. The computer-readable recording medium is any data storage device that can store data readable by a processing system, and includes both volatile and nonvolatile media, removable and non-removable media, and contemplates media readable by a database, a computer, and various other network devices.
Examples of the computer-readable recording medium include, but are not limited to, read-only memory (ROM), random-access memory (RAM), erasable electrically programmable ROM (EEPROM), flash memory or other memory technology, holographic media or other optical disc storage, magnetic storage including magnetic tape and magnetic disk, and solid state storage devices. The computer-readable recording medium can also be distributed over network-coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. The communication signals transmitted through a transitory medium may include, for example, modulated signals transmitted through wired or wireless transmission paths.
The above description and associated figures teach the best mode of the invention. The following claims specify the scope of the invention. Note that some aspects of the best mode may not fall within the scope of the invention as specified by the claims. Those skilled in the art will appreciate that the features described above can be combined in various ways to form multiple variations of the invention, and that various modifications may be made to the configuration and methodology of the exemplary embodiments disclosed herein without departing from the scope of the present teachings. Those skilled in the art also will appreciate that various features disclosed with respect to one exemplary embodiment herein may be used in combination with other exemplary embodiments with appropriate modifications, even if such combinations are not explicitly disclosed herein. As a result, the invention is not limited to the specific embodiments described above, but only by the following claims and their equivalents.

## Claims

1. A method of controlling wireless device communication with access nodes, comprising:
determining that a first loading of a first access node in communication with a plurality of wireless devices in a first coverage area meets a loading criteria;
decreasing a handover criteria for a second access node, wherein the second access node comprises a second coverage area that overlaps at least a portion of the first coverage area;
performing a handover of at least one of the plurality of wireless devices to the second access node when a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria;
determining a change in the first loading and a change in a throughput provided to the at least one of the plurality of wireless devices;
determining a change in a periodicity of data sent to the at least one of the plurality of wireless devices; and
adjusting the decreased handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.

2. The method of claim 1, further comprising:
determining a change in a latency of data sent to the at least one of the plurality of wireless devices; and
adjusting the handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, the change in the periodicity of data sent to the at least one of the plurality of wireless devices, and the change in the latency of data sent to the at least one of the plurality of wireless devices.

3. The method of claim 1, further comprising:
determining a change in a data loss rate of data sent to the at least one of the plurality of wireless devices; and
adjusting the handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, the change in the periodicity of data sent to the at least one of the plurality of wireless devices, and the change in the a change in the data loss rate.

4. The method of claim 1, further comprising:
determining that a communication session of the at least one of the plurality of wireless devices is terminated when the handover is performed of at least one of the plurality of wireless devices to the second access node; and
adjusting the handover criteria for the second access node based on the change in the first loading and whether the communication session is terminated.

5. The method of claim 1, further comprising:
determining an application requirement of an application running on the at least one of the plurality of wireless devices;
determining a weighting factor based on the determined application requirement and applying the weighting factor to the determined change in the throughput provided to the at least one of the plurality of wireless devices; and
adjusting the handover criteria for the second access node based on the change in the first loading, the weighted change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.

6. The method of claim 1, further comprising:
determining location characteristics of the second access node relative to the first access node;
adjusting a handover criteria for a third access node based on the adjusted handover criteria for the second access node when the third access node comprises location characteristics relative to the first access node which are substantially similar to the location characteristics of the second access node.

7. The method of claim 1, further comprising:
determining a change in a second loading of the second access node; and
adjusting the handover criteria for the second access node based on the change in the first loading, the change in the second loading, the change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.

8. The system of claim 1, wherein the processing node is further configured to:
determine a change in a latency of data sent to the at least one of the plurality of wireless devices; and
adjust the handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, the change in the periodicity of data sent to the at least one of the plurality of wireless devices, and the change in the latency of data sent to the at least one of the plurality of wireless devices.

9. A system of controlling wireless device communication with access nodes, comprising:
a processing node, configured to
determine that a first loading of a first access node in communication with a plurality of wireless devices in a first coverage area meets a loading criteria;
decrease a handover criteria for a second access node, wherein the second access node comprises a second coverage area that overlaps at least a portion of the first coverage area;
perform a handover of at least one of the plurality of wireless devices to the second access node when a signal level of the second access node received at the at least one of the plurality of wireless devices meets the decreased handover criteria;
determine a change in the first loading and a change in a throughput provided to the at least one of the plurality of wireless devices;
determine a change in a periodicity of data sent to the at least one of the plurality of wireless devices; and
adjust the decreased handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.

10. The system of claim 9, wherein the processing node is further configured to:
determine a change in a data loss rate of data sent to the at least one of the plurality of wireless devices; and
adjust the handover criteria for the second access node based on the change in the first loading, the change in the throughput provided to the at least one of the plurality of wireless devices, the change in the periodicity of data sent to the at least one of the plurality of wireless devices, and the change in the a change in the data loss rate.

11. The system of claim 9, wherein the processing node is further configured to:
determine that a communication session of the at least one of the plurality of wireless devices is terminated when the handover is performed of at least one of the plurality of wireless devices to the second access node; and
adjust the handover criteria for the second access node based on the change in the first loading and whether the communication session is terminated.

12. The system of claim 9, wherein the processing node is further configured to:
determine an application requirement of an application running on the at least one of the plurality of wireless devices;
determine a weighting factor based on the determined application requirement and applying the weighting factor to the determined change in the throughput provided to the at least one of the plurality of wireless devices; and
adjust the handover criteria for the second access node based on the change in the first loading, the weighted change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.

13. The system of claim 9, wherein the processing node is further configured to:
determine location characteristics of the second access node relative to the first access node;
adjust a handover criteria for a third access node based on the adjusted handover criteria for the second access node when the third access node comprises location characteristics relative to the first access node which are substantially similar to the location characteristics of the second access node.

14. The system of claim 9, wherein the processing node is further configured to:
determine a change in a second loading of the second access node; and
adjusting the handover criteria for the second access node based on the change in the first loading, the change in the second loading, the change in the throughput provided to the at least one of the plurality of wireless devices, and the change in the periodicity of data sent to the at least one of the plurality of wireless devices.