WO2011095687A1

WO2011095687A1 - Methods, apparatuses and computer program products for performing load balancing

Info

Publication number: WO2011095687A1
Application number: PCT/FI2011/050080
Authority: WO
Inventors: Timo NIHTILÄ; Ingo Viering; Szymon Stefanski
Original assignee: Nokia Corporation
Priority date: 2010-02-05
Filing date: 2011-02-01
Publication date: 2011-08-11

Abstract

An apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device may include a processor and memory storing executable computer program code causing the apparatus to at least perform operations including receiving one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The computer program code may further cause the apparatus to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The apparatus includes at least a portion of a first base station. Corresponding methods and computer program products are also provided.

Description

METHODS, APPARATUSES AND COMPUTER PROGRAM PRODUCTS

FOR PERFORMING LOAD BALANCING

TECHNOLOGICAL FIELD

Embodiments of the invention relate generally to communication technology and, more particularly relate to a method, apparatus and computer program product for performing load balancing among base stations in a communication system.

BACKGROUND

The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.

Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. For example, the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term

Evolution (LTE) or 3.9G, is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards.

One advantage of E-UTRAN which continues to be shared with other preceding telecommunication standards is the fact that users are enabled to access a network employing such standards while remaining mobile. Thus, for example, users having mobile terminals equipped to communicate in accordance with such standards may travel vast distances while being connected to and maintaining communication with the network.

In order to maximize the probability of a good connection to the network, a user entity by default may attempt to be connected to a base station (BS) to which it has the strongest signal, e.g., the largest Reference Signal Received Power (RSRP). However, if a large amount of user entities are concentrated to a relatively small area covered by a cellular network, many of the user entities will be connected to the same base station. Connection of too many user entities to a base station may overload the base station. As such, the base station's ability to schedule resources may be minimized or limited. For instance, the base station's ability to schedule resources such as Physical Resource Blocks (PRB) may be minimized and many of the user entities may receive insufficient service. The PRBs may be physical transport carriers (e.g. sub-carriers), or groups thereof, associated with time intervals that the transport carriers may use to transport data.

At the same time the neighbouring base stations of the overloaded base station may be relatively low loaded and in this regard the neighbouring base stations may have plenty of free PRBs. However, the user entities of the overloaded base station may not handover (HO) to the neighbouring base stations since the Reference Signal Received Power received from the neighbouring base stations, by the user entities, may not be high enough.

In this situation it may be beneficial to perform load balancing (LB) between base stations. By performing load balancing some user entities of the overloaded base station may be forced to handover to the neighbouring base stations. The load balancing handover may result in signal quality degradation, but due to the low load, the degradation may be compensated by allocating a larger number of Physical Resource Blocks to the respective user entity.

In this regard, the user entity may receive satisfactory service in a cell that possibly is worse in terms of signal quality, or Signal to Interference and Noise Ratio (SINR), but may be better in terms of available Physical Resource Blocks. However, it may be beneficial to select the user entity to be handed over from a source cell to a neighbouring cell such that the user entity does not consume all the PRBs in the neighbouring cell. Also, selection of an appropriate handover may be beneficial since some of the user entities SINRs with respect to the neighbouring base stations may be very low and thus many more PRBs may be needed to compensate for the low SINRs.

Currently, there may not be suitable mechanisms of determining the impact of the load on another cell (e.g., candidate cell) if a user entity is handed over to the cell by a source cell.

Load balancing may be performed blindly, that is to say without any information about the user entity or the candidate cell that user entity is to be handed over to in order to achieve load balancing. When the load balancing is performed blindly, there may not be any approximations being made that the selected candidate cell is the best possible cell for a load balanced handover. In this regard, the probability of making a wrong decision regarding the cell in which the user entity is to be handed over to may be very high and the performance of the user entity, as well as the performance of other user entities connected to the candidate cell may deteriorate and may be degraded. It is also possible to perform load estimation semi-blindly that is to say by using only the information that is available via RSRP and Reference Signal Received Quality (RSRQ) measurements or values. In this regard, RSRP and RSRQ values may be received by user entities from neighbouring cells and the user entities may report these values to a serving cell. Since the serving cell may know its own RSRP and RSRQ values, the serving cell may determine the differences of the RSRP and RSRQ values between the serving and the candidate cell in order to identify a load for a candidate base station. The values RSRP and RSRQ are downlink measures. As such, currently there may be only downlink information about the neighbouring cells available for load estimation. There may not be any special uplink information available, except a very rough overload indicator, which may be inaccurate.

Since only downlink information may be available by using RSRP and RSRQ values to determine a load estimation of a candidate cell which may result in inaccurate approximations and a high amount of wrong decisions regarding the cell in which the user entity should be handed over to, current load balancing approaches may be unreliable in determining the best cell for handover.

In view of the foregoing drawbacks, it may be beneficial to provide a mechanism for reliably and efficiently determining load estimations among cells in a network and for reliably determining the best cell for a load balanced handover. In this regard, it may be beneficial to provide a mechanism for determining the manner in which resource consumption estimation in an uplink direction may be performed most reliably in order to estimate the future resource consumption of one or more user entities in order to facilitate a load balancing handover to a cell before the handover is executed. BRIEF SUMMARY

A method, apparatus and computer program product are therefore provided that may facilitate communication between base stations in a mobile communication system such as, for example, a Long Term Evolution (LTE) communication system. In particular, the exemplary embodiments may utilize information that may be exchanged between base stations via an interface in order to ensure that the load of a communication system (e.g., a Self Optimizing/Organizing Network (SON) intra-LTE, inter-RAT Network, etc.) is properly balanced.

The exemplary embodiments facilitate the exchange one or more uplink (UL) parameters between base stations of communication systems. The UL parameters may include, but are not limited to, UL pathloss based power control parameter P0, UL pathloss based power control parameter a, and a UL interference level(s). The UL parameters may be sent from neighbor base stations to a respective base station (e.g., base station of a source cell) via a X2 interface or and SI interface. The exemplary embodiments may estimate the average resource consumption of a communication device (e.g., user equipment (UE)) in a target/neighboring cell based at least in part on utilizing at least one of the UL parameters. This estimation may be used by the exemplary embodiments to determine whether the target/neighboring cell has sufficient resources available to service the communication device. In response to determining that the target/neighboring cell has sufficient resources available to service the communication device, the exemplary embodiments may facilitate an efficient and reliable handover of the communication device to the target/neighboring cell. In this regard, the exemplary embodiments may improve load balancing among base stations in a communication system.

Moreover, by performing a careful approximation of the resource consumption of a communication device in a target/neighbouring cell, the exemplary embodiments may minimize unnecessary handover requests, since these handover requests create unnecessary overhead on the base stations of the target cell. The exemplary embodiments may also minimize delay associated with unnecessary handover requests which may possibly delay more appropriate load balancing handover requests received by base stations of the target cell. The unnecessary handover requests may cause a delay since the appropriate handover requests may be initiated only after the first unnecessary handover requests are rejected by a target/neighbouring cell. As such, the exemplary embodiments may minimize negative impacts relating to unnecessary connections between base stations which may decrease the load of the base stations.

In one example embodiment, a method for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The method may include receiving, at a first base station, one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The method may further include determining an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

In another example embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The apparatus may include a processor and a memory including computer program code. The memory and computer program code are configured to, with the processor, cause the apparatus to at least perform operations including receiving one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The computer program code may further cause the apparatus to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The apparatus includes at least a portion of a first base station.

In another example embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The apparatus includes means for receiving, at a first base station, one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The apparatus also includes means for determining an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

In another example embodiment, a computer program product for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The computer program product includes at least one computer- readable storage medium having computer-executable program code instructions stored therein. The computer-executable program code instructions may include program code instructions configured to enable receipt, at a first base station, of one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The program code instructions are also configured to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

In another example embodiment, a method for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The method may include enabling sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level.

In another example embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The apparatus may include a processor and a memory including computer program code. The memory and computer program code are configured to, with the processor, cause the apparatus to at least perform operations including enabling sending of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The apparatus includes at least a portion of a first base station.

In another example embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The apparatus includes means for enabling sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level.

In another example embodiment, a computer program product for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The computer program product includes at least one computer- readable storage medium having computer-executable program code instructions stored therein. The computer-executable program code instructions may include program code instructions configured to enable sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level.

In another example embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a cell for handover of a device is provided. The apparatus may include a processor and a memory including computer program code. The memory and computer program code are configured to, with the processor, cause the apparatus to at least perform operations including receiving one or more uplink parameters from at least one base station. The uplink parameters include at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level. The apparatus includes at least a portion of a first base station.

Embodiments of the invention facilitate an efficient manner in which to perform load balancing estimations before a load balancing handover occurs in order to determine the best cell to handover a mobile device. Such a load balancing handover may be beneficial to minimize a load on an overloaded or constrained base station. In this manner, the exemplary embodiments facilitate efficient utilization of processing capacity and power consumption among devices in a communication network and mobile terminal users may enjoy improved mobile device functionality and services.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is a schematic block diagram of a system according to an exemplary embodiment of the invention;

FIG. 2 is a schematic block diagram of an apparatus according to an exemplary embodiment of the invention;

FIG. 3 is schematic block diagram of a system for exchanging data between base stations via an interface according to an exemplary embodiment of the invention;

FIG. 4 is a schematic diagram showing a system for providing a mechanism for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal according to an exemplary embodiment of the present invention; and

FIGS. 5 & 6 are flowcharts according to exemplary methods for providing a mechanism for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal according to exemplary embodiments of the invention.

DETAILED DESCRIPTION

Some embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like reference numerals refer to like elements throughout. As used herein, the terms "data," "content," "information" and similar terms may be used interchangeably to refer to data capable of being transmitted, received and/or stored in accordance with embodiments of the present invention. Moreover, the term "exemplary", as used herein, is not provided to convey any qualitative assessment, but instead merely to convey an illustration of an example. Thus, use of any such terms should not be taken to limit the spirit and scope of embodiments of the present invention.

Additionally, as used herein, the term 'circuitry' refers to (a) hardware-only circuit implementations (e.g., implementations in analog circuitry and/or digital circuitry); (b) combinations of circuits and computer program product(s) comprising software and/or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions described herein; and (c) circuits, such as, for example, a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation even if the software or firmware is not physically present. This definition of 'circuitry' applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term 'circuitry' also includes an implementation comprising one or more processors and/or portion(s) thereof and accompanying software and/or firmware. As another example, the term 'circuitry' as used herein also includes, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, other network device, and/or other computing device. As referred to herein Physical Resource Blocks may, but need not be, the smallest resource unit that may be assigned to a communication device (e.g., user equipment (UE)) in a communication system such as, for example, a Long Term Evolution system. In this regard, a Physical Resource Block may include, but is not limited to, a frequency chunk of 12 Orthogonal Frequency-Division Multiplexing (OFDM) subcarriers (e.g., 180 kHz) which may be allocated over a timeslot of 1 ms, for example. The timeslot may include 14 OFDM symbols. As such, a PRB may include 168 information symbols (e.g., 12* 14 = 168).

In a system (e.g., 10 MHz LTE system) there may be 50 PRBs which may be allocated to UEs during a time interval (e.g., every ms). The allocation to the UEs may, but need not, be made or assigned arbitrarily. In this regard, each UE may get allocated a certain number of PRBs during a time interval (e.g., 1ms). While the exemplary embodiments may refer to PRBs for purposes of illustration, the exemplary embodiments are not limited to resources such as PRBs and may relate to usage of any suitable communication resources. As such, PRBs may be one exemplary resource among many that are contemplated by the exemplary embodiments of the invention.

FIG. 1 illustrates a generic system diagram in which a device such as a mobile terminal 10 is shown in an exemplary communication environment. As shown in FIG. 1, an embodiment of a system in accordance with an example embodiment of the invention may include a first communication device (e.g., mobile terminal 10) and a second communication device 20 capable of communication with each other via a network 30. In some cases, embodiments of the present invention may further include one or more additional communication devices, one of which is depicted in FIG. 1 as a third

communication device 25. In some embodiments, not all systems that employ

embodiments of the present invention may comprise all the devices illustrated and/or described herein. While several embodiments of the mobile terminal 10 and/or second and third communication devices 20 and 25 may be illustrated and hereinafter described for purposes of example, other types of terminals, such as portable digital assistants (PDAs), pagers, mobile televisions, mobile telephones, gaming devices, laptop computers, cameras, video recorders, audio/video players, radios, global positioning system (GPS) devices, Bluetooth headsets, Universal Serial Bus (USB) devices or any combination of the aforementioned, and other types of voice and text communications systems, can readily employ embodiments of the present invention. Furthermore, devices that are not mobile, such as servers and personal computers may also readily employ embodiments of the present invention.

The network 30 may include a collection of various different nodes (of which the second and third communication devices 20 and 25 may be examples), devices or functions that may be in communication with each other via corresponding wired and/or wireless interfaces. As such, the illustration of FIG. 1 should be understood to be an example of a broad view of certain elements of the system and not an all inclusive or detailed view of the system or the network 30. Although not necessary, in some embodiments, the network 30 may be capable of supporting communication in accordance with any one or more of a number of First-Generation (1G), Second-Generation (2G), 2.5G, Third-Generation (3G), 3.5G, 3.9G, Fourth-Generation (4G) mobile communication protocols, Long Term

Evolution (LTE) or Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Self Optimizing/Organizing Network (SON) intra-LTE, inter-Radio Access Technology (RAT) Network and/or the like. In some embodiments, the network 30 may be a point-to- point (P2P) network.

One or more communication terminals such as the mobile terminal 10 and the second and third communication devices 20 and 25 may be in communication with each other via the network 30 and each may include an antenna or antennas for transmitting signals to and for receiving signals from one or more base sites. The base sites could be, for example one or more base stations (BS) (which in E-UTRAN are referred to as node- Bs) that is a part of one or more cellular or mobile networks or an access point that may be coupled to a data network, such as a Local Area Network (LAN), a Metropolitan Area Network (MAN), and/or a Wide Area Network (WAN), such as the Internet. In turn, other devices such as processing elements (e.g., personal computers, server computers or the like) may be coupled to the mobile terminal 10 and the second and third communication devices 20 and 25 via the network 30. By directly or indirectly connecting the mobile terminal 10 and the second and third communication devices 20 and 25 (and/or other devices) to the network 30, the mobile terminal 10 and the second and third

communication devices 20 and 25 may be enabled to communicate with the other devices or each other. For example, the mobile terminal 10 and the second and third

communication devices 20 and 25 as well as other devices may communicate according to numerous communication protocols including Hypertext Transfer Protocol (HTTP) and/or the like, to thereby carry out various communication or other functions of the mobile terminal 10 and the second and third communication devices 20 and 25, respectively. Furthermore, although not shown in FIG. 1, the mobile terminal 10 and the second and third communication devices 20 and 25 may communicate in accordance with, for example, radio frequency (RF), near field communication (NFC), Bluetooth (BT), Infrared (IR) or any of a number of different wireline or wireless communication techniques, including Local Area Network (LAN), Wireless LAN (WLAN), Worldwide

Interoperability for Microwave Access (WiMAX), Wireless Fidelity (WiFi), Ultra- Wide Band (UWB), Wibree techniques and/or the like. As such, the mobile terminal 10 and the second and third communication devices 20 and 25 may be enabled to communicate with the network 30 and each other by any of numerous different access mechanisms. For example, mobile access mechanisms such as Wideband Code Division Multiple Access (W-CDMA), CDMA2000, Global System for Mobile communications (GSM), General Packet Radio Service (GPRS) and/or the like may be supported as well as wireless access mechanisms such as WLAN, WiMAX, and/or the like and fixed access mechanisms such as Digital Subscriber Line (DSL), cable modems, Ethernet and/or the like.

In example embodiments, the first communication device (e.g., the mobile terminal

10) may be a mobile communication device such as, for example, a wireless telephone or other devices such as a personal digital assistant (PDA), mobile computing device, camera, video recorder, audio/video player, positioning device, game device, television device, radio device, or various other like devices or combinations thereof. The second

communication device 20 and the third communication device 25 may be mobile or fixed communication devices. However, in one example, the second communication device 20 and the third communication device 25 may be servers, remote computers or terminals such as personal computers (PCs) or laptop computers.

In an exemplary embodiment, the network 30 may be an ad hoc or distributed network arranged to be a smart space. Thus, devices may enter and/or leave the network 30 and the devices of the network 30 may be capable of adjusting operations based on the entrance and/or exit of other devices to account for the addition or subtraction of respective devices or nodes and their corresponding capabilities.

In an exemplary embodiment, the mobile terminal as well as the second and third communication devices 20 and 25 may employ an apparatus (e.g., apparatus of FIG. 2) capable of employing some embodiments of the invention.

Referring now to FIG. 2, an apparatus that may benefit from embodiments of the invention is provided. The apparatus 50 may include or otherwise be in communication with a processor 77, a user interface 67, one or more speakers 87, a communication interface 74, a memory device 76 (also referred to herein as memory), and a display 85.

The memory device 76 may include, for example, volatile and/or non-volatile memory. The memory device 76 may be configured to store information, data,

applications, instructions or the like for enabling the apparatus to carry out various functions in accordance with exemplary embodiments of the invention. The memory device 76 could be configured to buffer input data for processing by the processor 77. Additionally or alternatively, the memory device 76 could be configured to store instructions for execution by the processor 77. As yet another alternative, the memory device 76 may be, or may include, one of a plurality of databases that store information and/or media content.

The processor 77 may be embodied in a number of different ways. For example, the processor 77 may be embodied as various processing means such as a processing element, a coprocessor, a controller or various other processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a hardware accelerator, or the like. In an exemplary embodiment, the processor 77 may be configured to execute instructions as well as algorithms stored in the memory device 76 or otherwise accessible to the processor 77. As such, whether configured by hardware or software methods, or by a combination thereof, the processor 77 may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor 77 is embodied as an ASIC, FPGA or the like, the processor 77 may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor 77 is embodied as an executor of software instructions, the instructions may specifically configure the processor 77, which may otherwise be general purpose processing elements or other functionally configurable circuitry if not for the specific configuration provided by the instructions, to perform the algorithms and operations described herein. However, in some cases, the processor 77 may be a processor of a specific device (e.g., a mobile terminal or user equipment (UE)) adapted for employing embodiments of the invention by further configuration of the processor 77 by instructions for performing the algorithms and operations described herein.

In an exemplary embodiment, the processor 77 may be configured to operate a connectivity program, such as a conventional Web browser. The connectivity program may then enable the apparatus 50 to transmit and receive Web content, such as location- based content, according to a Wireless Application Protocol (WAP), for example. The processor 77 may also be in communication with the display 85 and may instruct the display to illustrate any suitable information, data, content or the like.

Meanwhile, the communication interface 74 may be any means such as a device or circuitry embodied in either hardware, software, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device, module or other user(s) 71 in communication with the apparatus 50. In this regard, the communication interface 74 may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network (e.g., network 30). In fixed environments, the communication interface 74 may alternatively or also support wired communication. The communication interface 74 may receive and/or transmit data via one or more

communication channels. Additionally, in some embodiments the communication interface 74 may include a communication modem and/or hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB), Ethernet or other mechanisms.

The user interface 67 may be in communication with the processor 77 to receive an indication of a user input at the user interface 67 and/or to provide an audible, visual, mechanical or other output to the user. As such, the user interface 67 may include, for example, a keyboard, a mouse, pointing device (e.g., stylus, pen, etc.) a joystick, a display, a touch screen, a microphone, a speaker, or other input/output mechanisms. In an exemplary embodiment in which the apparatus is embodied as a server or some other network devices, the user interface 67 may be limited, remotely located, or eliminated.

The processor 77 may comprise user interface circuitry configured to control at least some functions of one or more elements of the user interface. The processor and/or user interface circuitry of the processor may be configured to control one or more functions of one or more elements of the user interface through computer program instructions (e.g., software and/or firmware) stored on a memory accessible to the processor (e.g., volatile memory, non- volatile memory, and/or the like).

Referring now to FIG. 3, a block diagram of a system according to an exemplary embodiment is provided. The system of FIG. 3 may include an E-UTRAN which may include a plurality of base stations 48, 50, 52, 54 and 56 such as for example node-Bs. The node-Bs may be E-UTRAN node-Bs (also referred to herein as eNBs). As shown in FIG. 3, each of the eNBs 48, 50, 52, 54 and 56 may communicate with each other via an eNB to eNB interface such as for example an X2 interface. As referred to herein an X2 interface may be a physical and/or logical interface between eNBs to facilitate communications between the eNBs. Additionally or alternatively, each of the eNBs may communicate with each other via an S 1 interface in which each eNB may send a message to an evolved packet core (EPC) (e.g., EPC 78 of FIG. 4) which may include one or more mobility management entities (MMEs) (not shown) and one or more system architecture evolution (SAE) gateways (not shown). The EPC (also referred to herein as core network) may send the message to a corresponding eNB via an SI interface. The SI interface may be a physical and/or logical interface between eNBs and the EPC. In this regard, the eNBs and the EPC may communicate via the SI interface.

In the exemplary embodiment of FIG. 3, eNB 48 may be an origin eNB which may be currently providing service to user equipment (UE) (e.g., apparatus 50 (e.g., a mobile terminal)) or one or more UEs in a source cell. The eNBs 50, 52, 54 and 56 may be neighboring eNBs operating in respective neighboring cells.

Power control may be dictated by the power per PRB used by a corresponding UE. Generally, a small uplink (UL) pathloss power control parameter P0 value results in a low power per PRB. With a low power per PRB, the number of bits per PRB may be low and thus UEs may need to be allocated more PRBs in compensation. On the other hand, a high P0 value may result in a high power per PRB and as such the number of bits per PRB may be high and thus UEs may need to be allocated less PRBs in compensation. As described above, when a base station such as an eNB is overloaded, the eNBs ability to allocate PRBs so that data can be sent to the UE of user may be inhibited. In this regard, a user may be dissatisfied with his/her service when a serving or origin eNB is overloaded. To overcome this problem and the drawbacks discussed above, the exemplary embodiments may provide an efficient and reliable manner in which to estimate the resource

consumption of each eNB in a network.

In this regard, each of the eNBs (e.g., eNB 48) may estimate the average resource consumption of each UE in a neighboring cell by receiving some information or values from neighboring eNBs (e.g., eNBs 50, 52, 54 and 56). In this regard, according to the exemplary embodiment of FIG. 3 each of the eNBs 48, 50, 52, 54 and 56 may periodically

(e.g., every minute) report or send values or information to each other which may be utilized by respective eNBs to estimate the average resource consumption of each UE in a neighboring cell. The information reported by the neighboring eNBs (e.g., 50, 52, 54 and 56) to a respective eNB (e.g., eNB 48) may include, but is not limited to, an uplink (UL) pathloss based power control parameter P0 (also referred to herein as P0), a received uplink interference level (also referred to herein as interference over Thermal (loT)), a UL pathloss based power control parameter a (also referred to herein as a) and any other suitable information. These values may be exchanged between the eNBs via the X2 interface. Alternatively or additionally, these values or information may be sent by the eNBs to an EPC (e.g., EPC 78 of FIG. 4) and the EPC or the MME may send the values to respective eNBs via an SI interface (See e.g., FIG. 4). As described more fully below, these values may be used by a respective eNB (e.g., an origin eNB (e.g., eNB 48)) to calculate an estimation of resource consumption of one or more UEs currently being serviced by the respective eNB (e.g., an origin eNB (e.g., eNB 48)), which may be a candidate for handover to a neighboring eNB (e.g., eNB 52). In this manner, a respective eNB may utilize these values or information to perform a load balancing determination and based on the load balancing determination, the respective eNB (e.g., eNB 48) may determine a best UE candidate for handover and a best candidate eNB to hand the UE over to, as described more fully below.

It should be pointed out that as referred to herein the UL pathloss based power control parameter P0 may be a parameter composed of the sum of a cell specific nominal component (e.g., Po NOMINAL PUSCHG)) provided from higher layers and a UE specific component (e.g., Po UE PUSCHG))- Additionally, it should be pointed out that as referred to herein the UL pathloss based power control parameter a may be a system parameter or a parameter of a cell that varies from a value of 0 to 1. For instance, a e {0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 } may be a 3-bit cell specific parameter provided by higher layers.

As described above, the UL pathloss based parameters P0 and a may be cell- specific. In general, the UL pathloss based parameters P0 and a may be configured by operation and maintenance by a system or network, for example via network entity (e.g., third communication device 25, e.g., a server). However, the eNBs 48, 50, 52, 54 and 56 may adjust these parameters based on traffic, user positions, etc. For instance, if the traffic is low, the eNBs 48, 50, 52, 54 and 56 may lower the P0 and if traffic is high the eNBs 48, 50, 52, 54 and 56 may raise the P0.

The UL interference level (loT) may be measured by the eNBs and may be a measure of the interference level which a respective eNB may be subject to (e.g., representing intercell interference). The UL interference level may be a single interference level averaged over all resources such as, for example, all PRBs allocated to a system, or a set of interference levels per a resource (e.g., PRB) or resource (e.g., PRB) group, or any other UL interference measure. The UL interference level may be measured as an absolute value, or with respect to thermal noise, for example. The interference level has to be measured, as explained above (e.g. averaging over the interference level on each PRB).

Referring now to FIG. 4, a schematic block diagram of a system for providing a mechanism of performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal according to an exemplary embodiment of the invention is provided. The system includes an E-UTRAN 76 which may include, among other things, a plurality of node-Bs in communication with an evolved packet core (EPC) 78 which may include one or more mobility management entities (MMEs) (not shown) and one or more system architecture evolution (SAE) gateways (not shown). The node-Bs may be E-UTRAN node-Bs (e.g., eNBs such as originating eNB 72 and target eNB 73 and may also be in communication with the UE 70 and other UEs. The E-UTRAN 76 may be in communication with the EPC 78.

The UE 70 may be exemplary of one embodiment of the apparatus 50 (e.g., mobile terminal 10) of FIG. 2. Additionally, the originating eNBs 72 may be exemplary of one embodiment of the eNB 48 and the target eNB 73 may be exemplary of one embodiment of the eNB 52 of FIG. 3. It should be noted that the system of FIG. 4, may be employed in connection with a variety of other devices, both mobile and fixed, and therefore, embodiments of the invention should not be limited to application on devices that are mobile (e.g., a mobile terminal) or the eNBs of FIG. 3.

The eNBs 72 and 73 may provide E-UTRA user plane and control plane (radio resource control (RRC)) protocol terminations for the UE 70. The eNBs 72 and 73 may provide functionality hosting for such functions as radio resource management, radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to UEs in both uplink and downlink, selection of an MME at UE attachment, IP header compression and encryption, scheduling of paging and broadcast information, routing of data, measurement and measurement reporting for configuration mobility, and the like.

The MME may host functions such as distribution of messages to respective node- Bs, security control, idle state mobility control, EPS (Evolved Packet System) bearer control, ciphering and integrity protection of (non access stratum) NAS signaling, and the like. In an exemplary embodiment, the MME of the EPC 78 may receive one or more messages from respective eNBs (e.g., eNB 72) via an SI interface and may send or report the messages to corresponding eNBs (e.g., eNB 73) via the SI interface. In this regard, the MME may exchange messages and data between the eNBs 72, 73 via the SI interface. The messages may include, but are not limited to, data such as an uplink (UL) pathloss power control parameter P0, a received uplink interference level (loT), a UL pathloss based power control parameter a and any other suitable data. The SAE gateway may host functions such as termination and switching of certain packets for paging and support of UE mobility. In an exemplary embodiment, the EPC 78 may provide connection to a network such as the Internet.

As shown in FIG. 4, the eNBs 72 and 73 may each include a memory device 86.

The memory device 86 may include, for example, volatile and/or non-volatile memory. The memory device 86 may be configured to store information, data, applications, instructions or the like for enabling the eNBs 72 and 73 to carry out various functions in accordance with exemplary embodiments of the invention. The memory device 86 could be configured to buffer input data for processing by the load estimation controllers 80 of the eNBs 72 and 73. Additionally or alternatively, the memory device 86 could be configured to store instructions for execution by the load estimation controllers 80 of the eNBs. As yet another alternative, the memory device 86 may be, or may include, one of a plurality of databases that store information and/or media content.

Additionally, as shown in FIG. 4, the eNBs 72 and 73 may each include a load estimation controller 80 configured to execute functions associated with each

corresponding eNB with respect to receiving information from and/or providing information to the UE 70 and/or other eNBs related to, for example, communication format parameters (e.g., transmission format) of the corresponding eNB and/or neighboring eNBs. As such, the load estimation controller 80 may be any means or device embodied in hardware, software or a combination of hardware and software that is configured to perform the functions of the load estimation controller 80 as described herein. In an exemplary embodiment, the load estimation controller 80 of each of the eNBs 72 and 73 may operate under the control of or otherwise be embodied as a processor or a processing element.

The UE 70 may include a processor 82 which may be configured to execute functions with respect to receiving information from and/or providing information to the eNBs 72 and/or 73 related to, for example, RSRP and RSRQ values of the corresponding eNB and/or neighboring eNBs. As such, the processor 82 may be any means or device embodied in hardware, software or a combination of hardware and software that is configured to perform the functions of the processor 82 as described herein. In an exemplary embodiment, the processor 82 may operate under the control of or otherwise be embodied as a processing element (e.g., the processor 77). A processing element such as those described above may be embodied in many ways. For example, the load estimation controllers 80 and/or the processor 82 may be embodied as a processor, a coprocessor, a controller or various other processing means or devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or a FPGA (field- programmable gate array). It should be noted that although FIG. 4 illustrates a load estimation controller as being disposed at each of the eNBs 72 and 73, the load estimation controller 80 could alternatively be disposed at another element of the E-UTRAN 76 or the EPC 78 (e.g., the SAE gateway, the MME, a RAN, etc.) that is accessible to the eNBs 72 and 73.

In an exemplary embodiment, the load estimation controller 80 of each of the eNBs 72 and 73 may be capable of communication with each other (e.g., via an eNB to eNB interface such as an X2 interface) and/or with the processor 82 (either directly or indirectly). Accordingly, the UE 70 may communicate with the load estimation controllers of either or both of the originating eNB 72 and the target eNB 73 in connection with a potential handover of the UE 70 from the originating eNB 72 to the target eNB 73, for example, when the UE 70 moves from a serving area (e.g., cell) associated with the originating eNB 72 to a serving area associated with the target eNB 73. Additionally, or alternatively, the originating eNB 72 may perform a load balancing determination in connection with a potential handover of the UE 70 from the originating eNB 72 to the target eNB 73. Such a determination may be made by the originating eNB 72 when the originating eNB 72 determines that it is overloaded and determines that the target eNB 73 is under loaded or has resources available to provide communications services for the UE 70. Although communications may be described below as occurring between the eNBs 72 and 73 and the UE 70, it should be understood that communications related to load estimations as described herein may be assumed to occur via the load estimation controller 80 of the eNBs and the processor 82, respectively.

It should be noted that the terms "originating" and "target" are merely used herein to refer to roles that any eNB may play at various different times in relation to being a source (e.g., originating) cell initially providing service to a UE or a neighboring or destination or (e.g., target) cell to which service is to be transferred to, for example, the UE moving from the source cell to the neighboring or destination cell or the UE contributing to an overload of the source (e.g., originating) cell. Thus, the terms "originating" and "target" could be applicable to the same eNB at various different times and such terms are not meant to be limiting in any way.

In general terms, some embodiments of the invention may provide that the UE 70 is informed via the originating eNB 72 (e.g., the cell in which the UE 70 is located initially or at least prior to a handover) as to whether the originating eNB 72 will handover the UE 70 to the target eNB 73. The handover of the UE 70 from the originating eNB 72 to the target eNB 73 may be performed in order to balance a load of the originating eNB 72, when the originating eNB 72 is overly constrained or overloaded.

The exemplary embodiments may determine the load in a neighboring/candidate cell, which may be a candidate for handover of one or more UEs. Regarding the manner in which the originating eNB 72 of a source cell (also referred to herein as cell A) may determine the load in a neighboring/candidate cell (also referred to herein as cell B) consider the following example. The target eNB 73 may be part of the neighboring candidate/cell (e.g., cell B) in the example below.

To determine the uplink load estimation, the estimation of UE transmit (Tx) power in the source cell may be calculated first by the load estimation controller 80 of the originating eNB 72. The UE Tx power may correspond to the Tx power of the UE 70 being currently serviced by the source cell (e.g., cell A). The UL pathloss based power control parameters a and P0 may both be cell-specific, as described above. According to the path loss based power control formula of equation (1), UE Tx power in cell A (TxP_A) may be determined by the load estimation controller 80 of originating eNB 72 as follows:

where L_A is the path loss between UE 70 and cell A (e.g., the source cell of originating eNB 72 in which the UE 70 is initially located), POA and A are the UL pathloss based power control parameters P0 and a for cell A, respectively. The originating eNB 72 may know or determine the values of the UL pathloss based power control parameters POA and A since the originating eNB 72 is part of cell A in this example. For example, as described, above P0 and alpha may be configured by operation and maintenance of network entity (e.g., communication device 25

(e.g., a server)). However, the originating eNB 72 may adjust these parameters based on traffic, user positions, etc. The originating eNB 72 may determine the path loss L_A based in part on one or more RSRP measurements which may be reported by the UE 70 to the originating eNB 72. For instance, originating eNB 72 may send one or more reference signals over a downlink to the UE 70. The reference signals may indicate a power in which the originating eNB 72 is transmitting the reference signals. The processor 82 of the UE 70 may measure the received signal strengths of these reference signals to determine the Reference Signal Received Powers (RSRPs) of these reference signals. By calculating the difference between the reference signals and the Reference Signal Received Powers, the processor 82 may determine the path loss L_A of cell A. In this regard, the path loss L_A may denote the loss in power received from the originating eNB 72 as opposed to the actual power in which the originating eNB 72 is transmitting data.

The Tx power in cell B (TXP_B) may be calculated by the load estimation controller

80 of the originating eNB 72 by utilizing the equation (2) as follows:

TxP_B = TxP_A + P0B - P0A + a_B * L_B - a_A * L_A, (2)

where L_B is the path loss between the UE 70 and cell B and P0_B and c¾ are the UL pathloss based power control parameters P0 and a for cell B.

In order to calculate TXP_B the load estimation controller 80 of the originating eNB

72 may utilize a variety of data. For example, information of the UE 70 average Tx power in cell A (TxP_A), which the originating eNB 72 may determine based on equation (1) may be utilized to determine TXP_B. The load estimation controller 80 of originating eNB 72 may also utilize the average Reference Signal Received Power of cell B that may be measured by UE 70 in determining TXP_B. The load estimation controller 80 of the originating eNB 72 may determine the average Reference Signal Received Power of cell B by accessing values of RSRPs for cell B in one or more RSRP reports generated by the UE 70 which may be provided to the originating eNB 72 by the UE 70.

The RSRPs for cell B may be based on one or more RSRPs sent to the UE 70 from target eNB 73. For instance, the target eNB 73 (of cell B in this e.g.) may send one or more reference signals over a downlink and the UE 70 may measure the signal strengths of these reference signals to determine the Reference Signal Received Power (RSRP) of these reference signals. The UE 70 may report the RSRPs to the originating eNB 72 via an uplink and the originating eNB 72 may use the information associated with the RSRPs to determine the average RSRP of cell B (which target eNB 73 is part of in this example) measured by the UE 70.

Additionally, the load estimation controller 80 of originating eNB 72 may utilize the value of the path loss L_A between cell A and the UE 70 determined with respect to equation (1) in determining the transmit power in cell B (TXP_B). The load estimation controller 80 of originating eNB 72 may also utilize the path loss L_B between the UE 70 and cell B in determining TXP_B. The path loss L_B between the UE 70 and cell B may be determined by the originating eNB 72 by using equation (3) as follows:

L_B = TxPceiiB - RSRPB + L_A, (3)

where TxP_ceiiB is the downlink transmit power of the reference signals transmitted by the target eNB 73 of cell B which may be known to the originating eNB 72 of cell A, and RSRP_B is the average RSRPs received by UE 70 from the target eNB 73 of cell B. The originating eNB 73 may determine the path loss L_B based in part on averaging RSRP measurements received by the UE 70 from the target eNB 73 which may be reported by the UE 70 to the originating eNB 72.

As shown in equation (2), the originating eNB 72 may also utilize the UL pathloss based power control parameter P0_B of cell B and the UL pathloss based power control parameter <¾ of cell B in determining TXP_B. In an exemplary embodiment, the UL pathloss based power control parameters P0_B and <¾ may be sent by neighboring cells to other neighboring cells such as, for example, source or originating cells. In this regard, the target eNB 73 of cell B may send the UL pathloss based power control parameter P0_B and the UL pathloss based power control parameter <¾ to the originating eNB 72 of cell A. In an exemplary embodiment, the target eNB 73 of cell B may send the UL pathloss based power control parameter P0_B and the UL pathloss based power control parameter <¾ to the originating eNB 72 of cell A via an interface such as for example an X2 interface. In an alternative exemplary embodiment, the target eNB 73 of cell B may send the UL pathloss based power control parameter P0_B and the UL pathloss based power control parameter <¾ to the EPC 78 via an SI interface and a MME of the EPC 78 may send the UL pathloss based power control parameter P0_B and the UL pathloss based power control parameter <¾, via an S 1 interface, to the originating eNB 72 of cell A.

The target eNB 73 may periodically send or report (e.g., via the X2 interface or via the MME of EPC 78 through the SI interface) the UL pathloss based power control parameter P0_B and the UL pathloss based power control parameter <¾ to the originating eNB 72. However, in alternative exemplary embodiment, the originating eNB 72 of cell A may send a request to the target eNB 73 for the UL pathloss based power control parameters P0_B and <¾ and in response to receipt of the request the target eNB 73 may send the UL pathloss based power control parameters P0_B and <¾ to the originating eNB 72. The request may be sent by the originating eNB 72 to the target eNB 73 via the X2 interface. Alternatively or additionally, the request may be sent by the originating eNB 72 to the EPC 78 via an SI interface and the MME of the EPC 78 may send the request to the target eNB 73 via an SI interface. In response to receipt of the request, the target eNB 73 may send the UL pathloss based power control parameters POB and <¾ to the EPC 78 via an S 1 interface and the MME may send the UL pathloss based power control parameters POB and <¾ to the originating eNB 72 via an S I interface.

Once the originating eNB 72 determines or receives the values for TxP_A, POB, POA, ( B, L_B, (XA and L_A, in the manner described above, the originating eNB 72 may utilize equation (2) to determine the UE Tx power in cell B (TXPB) .

In response to the originating eNB 72 checking that the UE Tx power estimate (e.g., TXPB) in the candidate cell B does not exceed a maximum Tx power, the originating eNB may determine a Signal to Interference and Noise Ratio (SINR). In order to determine the SINR, the originating eNB 72 may determine or estimate the difference between the receive (Rx) powers (ARxP) of cell A and cell B. Additionally, in order to determine the SINR the originating eNB 72 may also determine or estimate the uplink (UL) interferences of the cell A and cell B in order to determine the UL interference difference (ΔΙοΤ) between cell A and cell B.

In order to determine the ARxP, the originating eNB may utilize equation (4) as follows:

ARxP = RxP_B - RxP_A = TxP_B- L_B - ( TxP_A - L_A), (4)

where RXPB is the receive power of a UE (e.g., UE 70) in cell A and RXPA is the receive power of a UE (e.g., UE 70) in cell B. In an exemplary embodiment, the RXPA may be the actual power transmitted by originating eNB 72 in cell A which may be received and measured by the UE 70 and the RXPB may be the actual power transmitted by target eNB 73 in cell B which may be received and measured by the UE 70.

By substituting TxP_B of equation (2), into equation (4), equation (5) is a follows.

ARxP = POB - P0_A + (<x_B - 1) * L_B - (<x_A - 1) * L_A , (5)

Additionally, by substituting L_B from equation (3) into equation (5), equation (6) is as follows

ARxP = POB - P0_A + (a_B - 1) * (RSRP_A - RSRP_B) + (a_B - a_A ) * L_A, (6) As described above, the values of POB, and c¾ may be provided to the originating eNB 72 by the target eNB 73 via an X2 interface or an SI interface via an MME of EPC

78. Since the originating eNB 72 may calculate or determine the parameters or values of equation (6) in the manner described above, the originating eNB 72 may utilize equation (6) to determine ARxP.

In an exemplary embodiment, one or more cells may also report their average UL interference level to their neighbors cells so that the uplink interference difference (ΔΙοΤ) between the cells may be determined. The originating eNB 72 of cell A and the target eNB 73 of cell B may determine their own UL interference levels (also referred to herein as Interference over Thermal). The originating eNB 72 and the target eNB 73 may determine their respective UL interference levels by measuring the interference level that each are subject to (e.g., representing intercell interference). As described above the UL

interference level may be a single interference level averaged over a resource such as, for example, all PRBs, or a set of interference levels per resource (e.g., PRB) or resource (e.g., PRB) group, or any other interference level measurement. The interference level(s) may be determined by the originating and target eNBs 72 and 73 as an absolute value, or with respect to the thermal noise for example, (e.g., interference over thermal IoT).

The originating eNB 72 of cell A is capable of measuring its UL interference level as described above and as such, the originating eNB 72 knows its own UL interference level. The originating eNB 72 of cell A may receive the UL interference level from target eNB 73 of cell B in a manner analogous to the receipt of the UL pathloss based power control parameters P0 and a from target eNB 73. For instance, the target eNB 73 may periodically report or send its UL interference level to the originating eNB 72 via an X2 interface or the target eNB 73 may periodically report or send the UL interference level to the EPC 78 via an SI interface and an MME of the EPC 78 may send the UL interference level of the target eNB 73 to the originating eNB 72.

Additionally or alternatively, the originating eNB 72 may send a request to the target eNB 73 for the UL interference level and in response to receipt of the request, the target eNB 73 may send the UL interference level to the originating eNB 72 via an X2 interface. The originating eNB 72 may also send the request to the EPC 78 via an SI interface and the MME of the EPC 78 may send the request to the target eNB 73. In response to receipt of the request from the MME, the target eNB 73 may send its UL interference level to the EPC 78, via an SI interface, and the MME of the EPC 78 may send the UL interference level of the target eNB 73 to the originating eNB 72.

In response to receipt of the UL interference level from the target eNB 73 of candidate cell B, the originating eNB 72 may utilize this information and its own UL interference level to determine the UL interference level difference ΔΙοΤ (also referred to herein as AIntf) between cell A and cell B. For example, if the originating eNB 72 determined that the UL interference level received by the target eNB 73 was -100 dBm and determined that its own UL interference level was -80 dBm, the originating eNB 72 may determine that the ΔΙοΤ between cells A and B is -20 dB.

By using all the determined and available information, the originating eNB 72 may determine the load estimation in cell B (κ¾) by utilizing equation (7) as follows:

KB = KA - 10^(ARxP- ^ntf)/1°, (7)

where KA is the load of a UE(s) in cell A and κ¾ is the load of a UE(s) in cell B.

In this example, KA may be the load of UE 70 in cell A and κ¾ may be the load of

UE 70 if it is used in cell B (or handed over to cell B). In this regard, κ¾ may be an estimate of the resources that the UE (e.g., UE 70) may be required to use in cell B if it were handed over to cell B. The originating eNB 72 may determine its own load KA, since it knows the number of UEs that it is currently servicing and its available resources (e.g., PRBs). Additionally, the target eNB 73 may provide its actual load in cell B to originating eNB 73 (e.g., via X2 interface or SI interface) and as such the originating eNB may use this information to determine the actual load in cell B.

When the originating eNB 72 uses equation (7) to calculate the load of a UE in cell B, the originating eNB 72 may use the corresponding value to determine whether cell B is a good candidate for handover of the UE(s) (e.g., UE 70). In this regard, when the value of KB is below a predetermined value, the originating eNB 78 may determine that cell B has the capacity to service a UE(s) (e.g., UE 70). In this manner, the originating eNB 72 may perform a load balancing handover and may handover UE 70 from cell A to cell B. As such, the target eNB 73 may provide service to UE 70.

On the other hand, when the originating eNB 72 uses equation (7) to calculate the load of a UE in cell B and determines that the value of κ¾ is above a predetermined value, the originating eNB 78 may determine that cell B does not have the capacity to service a UE(s) (e.g., UE 70). In this regard, the originating eNB 72 may determine that cell B is not a good candidate for handover of the UE(s) (e.g., UE 70). As such, the originating eNB 72 may not handover the UE 70 to cell B.

For purposes of illustration and not of limitation, cell A and cell B may have a resource such as, for example, 50 PRBs in a 10 MHz LTE system for example. The originating eNB 72 may determine its actual overall load and the load of UE 70 in cell A. Also, the originating eNB 72 may know the actual overall or total load of cell B since it may be provided to the originating eNB 72. Consider for example that the originating eNB

72 determines that the UE 70 requires 30 PRBs (e.g., κ¾ = 30) in cell B and that cell B only has 10 PRBs free. In this regard, the originating eNB 72 may determine that cell B is not a good candidate for handover of the UE 70. As such, the originating eNB 72 may not send a request to handover the UE 70 to the target eNB 73, since the originating eNB 72 may determine that cell B would not have sufficient resources to provide service to the UE 70 and handing over the UE 70 to the target eNB 73 may overload cell B (e.g., the

target/candidate cell). In other words, the originating eNB 72 may send a target eNB a handover request when it determines or estimates that both the source cell and the target cell may remain under loaded after the load balancing handover is performed.

On the other hand, consider for example that the originating eNB 72 determines that the UE 70 requires 5 PRBs (e.g., κ_Β = 5) in cell B and that cell B only has 10 PRBs free. In this regard, the originating eNB 72 may determine that cell B is a good candidate for handover of the UE 70. As such, the originating eNB 72 may handover the UE 70 from cell A to cell B so that target eNB 73 may service UE 70.

The value of KA and κ¾ are not limited to a measure of a resource such as PRBs, which is only one example. In general, any particular load metric may serve as a value(s) of KA and κ¾ without departing from the spirit and scope of the invention.

Referring now to FIG. 5, an exemplary method for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal is provided. At operation 500, a base station such as, for example, an eNB (e.g., originating eNB 72) of a source cell (e.g., cell A) may receive one or more uplink parameters from a base station such as for example an eNB (e.g., target eNB 73) or a target/candidate cell (e.g., cell B). The uplink parameters may include at least one of, but are not limited to, UL pathloss based power control parameters P0 and a, as well as UL interference level parameters. The UL uplink parameters may be sent from the target eNB

73 to the originating eNB 72 via an X2 interface. Alternatively, the UL uplink parameters may be sent from the target eNB to the originating eNB 72 via an S 1 interface, in a manner analogous to that described above.

At operation 505, in response to receipt of the uplink parameters from a target eNB

73 of a target cell, the originating eNB 72 may determine the potential resource consumption or potential load of a communication device(s) (e.g., UE 70) in the target cell based in part on one or more of the received uplink parameters. The communication device(s) (e.g., UE 70) may be currently serviced by the originating eNB 72 of the source cell.

At operation 510, based on the determination, by the originating eNB 72, of the potential resource consumption or potential load of the communication device(s) (e.g., UE 70) in the target cell, the originating eNB 72 may determine whether the target cell (e.g., the cell of target eNB 73) is a good candidate for handover of the communication device (e.g., UE 70) that may be currently serviced by the source cell (e.g., the cell of originating eNB 72). The originating eNB 72 may utilize equation (7) in the manner described above to determine the potential resource consumption or potential load of the communication device (e.g., UE 70) in the target cell (e.g., cell B).

When the determination, by the originating eNB 72, reveals that the target cell has sufficient resources (e.g., PRBs) to service the communication device(s) (e.g., UE 70) in the target cell, the originating eNB 72 may handover the communication device(s) (e.g., UE 70) to the target cell so the target eNB 73 may provide communication services to the communication device(s) (e.g., UE 70). On the other hand, when the determination, by the originating eNB 72, reveals that the target cell has insufficient resources (e.g., PRBs) to service the communication device(s) (e.g., UE 70) in the target cell, the originating eNB 72 may determine that the target cell is not a good candidate or the best candidate cell for handover of the communication device(s) (e.g., UE 70).

Referring now to FIG. 6, an exemplary method for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal, according to an exemplary embodiment of the invention. At operation 600, a base station such as, for example, an eNB (e.g., target eNB 73) of a target/candidate cell (e.g., cell B) may send or report one or more uplink parameters to a base stations such as an eNB (e.g., originating eNB 72) of a source cell (e.g., cell A). In this regard, an eNB (e.g., originating eNB 72) of the source cell may determine the potential resource consumption of the target cell or potential load of a communication device(s) (e.g., UE 70) in the target cell. The communication device(s) (e.g., UE 70) may initially or currently be serviced by the eNB (e.g., originating eNB 72) of the source cell. Additionally, the uplink parameters may include, but are not limited to, UL pathloss based power control parameters P0 and a as well as one or more UL interference levels.

The originating eNB 72 of the source cell may determine the potential resource consumption of the target cell or potential load of a communication device(s) (e.g., UE 70) in the target cell based on a calculation of equation (7). The target eNB 73 and the originating eNB may communicate via an X2 interface or a SI interface in a manner analogous to that described above.

At operation 605, the target eNB 73 of the target cell may provide communication service to a communication device(s) (e.g., UE 70) that is handed over to the target cell by the source cell when the determination (by the originating eNB 72) reveals that the target cell has sufficient resources (e.g., PRBs) available to service the communication device(s) (e.g., UE 70).

FIGS. 5 & 6 are flowcharts of a system, method and computer program product according to exemplary embodiments of the invention. It will be understood that each block or step of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by various means, such as hardware, firmware, and/or a computer program product including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, in an example embodiment, the computer program instructions which embody the procedures described above are stored by a memory device(s) (e.g., memory device 76, memory devices 86) and executed by a processor (e.g., processor 77, load estimation controllers 80, processor 82). As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the instructions which execute on the computer or other programmable apparatus cause the functions specified in the flowcharts blocks or steps to be implemented. In some embodiments, the computer program instructions are stored in a computer-readable memory (e.g., memory device 76, memory devices 86) that can direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory (e.g., memory device 76, memory devices 86) produce an article of manufacture including instructions which implement the function specified in the flowcharts blocks or steps. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowcharts blocks or steps.

Accordingly, blocks or steps of the flowcharts support combinations of means for performing the specified functions and combinations of steps for performing the specified functions. It will also be understood that one or more blocks or steps of the flowcharts, and combinations of blocks or steps in the flowcharts, can be implemented by special purpose hardware-based computer systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.

In an exemplary embodiment, an apparatus for performing the methods of FIGS. 5 & 6 above may comprise a processor (e.g., the processor 77, load estimation controllers 80, processor 82) configured to perform some or each of the operations (500 - 510 & 600 - 605) described above. The processor may, for example, be configured to perform the operations (500 - 510 & 600 - 605) by performing hardware implemented logical functions, executing stored instructions, or executing algorithms for performing each of the operations. Alternatively, the apparatus may comprise means for performing each of the operations described above. In this regard, according to an example embodiment, examples of means for performing operations (500 - 510 & 600 - 605) may comprise, for example, the load estimation controllers 80 (e.g., as means for performing any of the operations described above), the processor 82, processor 77 and/or a device or circuit for executing instructions or executing an algorithm for processing information as described above.

In an alternatively exemplary embodiment, the exchange of the UL parameters between eNBs (e.g., eNBs 48, 50, 52, 54, 56, originating eNB 72 and target eNB 73) of the exemplary embodiments may be performed periodically in which a network or network device (e.g., third communication device 25, e.g., a server) may configure a periodicity, for example every minute. As such, the UL parameters may be exchanged between eNBs of the exemplary embodiments periodically (e.g., every minute) as established by the network (e.g., network 30). As described above, the UL parameters exchanged between the eNBs of the exemplary embodiments may include at least one of, but are not limited to, UL related parameters associated with UL pathloss based power control parameters P0 and a as well as one or more UL interference levels.

Additionally or alternatively the exchange of the UL parameters between the eNBs (e.g., eNBs 48, 50, 52, 54, 56, originating eNB 72 and target eNB 73) may be event- triggered. For example, the exchange of the UL parameters between the eNBs may be triggered by a certain event such as, for example, one or more of the UL parameters changing by a value of more than 1 decibel (dB). Additionally or alternatively, the UL parameters may be exchanged between eNBs (e.g., eNBs 48, 50, 52, 54, 56, originating eNB 72 and target eNB 73) of the exemplary embodiments based on polling. As such, an overloaded eNB (e.g., originating eNB 72) may request one or more of the UL parameters from one or more respective eNBs, and then the respective eNB(s) (e.g., target eNB 73) that receives the request may send or report one or more of the UL parameters to the requesting eNB (e.g., originating eNB 72).

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

In one exemplary embodiment, a method for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal is provided. The method may include facilitating receipt, via a first base station, of one or more uplink (UL) parameters from at least one base station. The uplink parameters may include at least one of a UL pathloss based power control parameter P0, a UL pathloss based power control parameter a, or a UL interference level.

The method may further include determining an estimate of resource consumption or an estimated load of at least one candidate device for usage in a target cell based at least in part on utilizing one or more of the UL parameters. The device may be user equipment (UE) that is currently being serviced by a source cell. In one exemplary embodiment, the method facilitates receipt of the one or more UL parameters from the at least one base station via an X2 interface in a Long Term Evolution system. In an alternative exemplary embodiment, method may further include facilitating receipt of the one or more UL parameters from the at least one base station via a SI interface in a Long Term Evolution system.

In another exemplary embodiment, a computer program product for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal is provided. The computer program product includes at least one computer-readable storage medium having computer-executable program code instructions stored therein. The computer-executable program code instructions may include program code instructions for facilitating receipt, via a first base station, of one or more uplink (UL) parameters from at least one base station. The uplink parameters may include at least one of a UL pathloss based power control parameter P0, a UL pathloss based power control parameter a, or a UL interference level.

The computer program product may further include program code instructions for determining an estimate of resource consumption or an estimate of a load of at least one candidate device for usage in a target cell based at least in part on utilizing one or more of the UL parameters. The device may be user equipment (UE) that is currently being serviced by a source cell. In one exemplary embodiment, the computer program product may include program code instructions for facilitating receipt of the one or more UL parameters from the at least one base station via an X2 interface in a Long Term Evolution system. In an alternative exemplary embodiment, the computer program product may include program code instructions for facilitating receipt of the one or more UL parameters from the at least one base station via a SI interface in a Long Term Evolution system.

In another exemplary embodiment, an apparatus for performing load balancing estimations among cells of a network in order to select a best cell for handover of a mobile terminal is provided. The apparatus may include at least one processor and at least one memory storing computer program code configured to, with the at least one processor, cause the apparatus to facilitate receipt of one or more uplink (UL) parameters from at least one base station. The uplink parameters may include at least one of a UL pathloss based power control parameter P0, a UL pathloss based power control parameter a, or a UL interference level.

The memory and the computer program code are further configured to, with the processor, cause the apparatus to determine an estimate of resource consumption or an estimate of a load of at least one candidate device for usage in a target cell based at least in part on utilizing one or more of the UL related parameters. The device may be user equipment (UE) that is currently being serviced by a source cell. In one exemplary embodiment, the memory and the computer program code are further configured to, with the processor, cause the apparatus to facilitate receipt of the UL parameters from the at least one base station via an X2 interface in a Long Term Evolution system. In an alternative exemplary embodiment, the memory and the computer program code are further configured to, with the processor, cause the apparatus to facilitate receipt of the UL parameters by the at least one base station via a SI interface in a Long Term Evolution system. The apparatus may be a first base station.

Claims

THAT WHICH IS CLAIMED:

1. A method comprising:

receiving, at a first base station, one or more uplink parameters from at least one base station, the uplink parameters comprising at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level; and

determining an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

2. The method of claim 1, wherein:

the candidate device is currently connected to the first base station in a source cell; and

the at least one base station is within the target cell.

3. The method of claim 1, wherein receiving the uplink parameters comprises receiving the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the first base station and the at least one base station to facilitate exchange of communications.

4. The method of claim 1, wherein receiving the uplink parameters comprises receiving the uplink parameters via an SI interface in a Long Term Evolution system, the SI interface comprises a physical or logical interface between at least one of the first base station or the at least one base station and a core network to facilitate exchange of communications .

5. The method of claim 1, wherein:

the first uplink pathloss based power control parameter comprises a parameter, denoted as P0, composed of a sum of a cell specific nominal component provided from one or more higher layers and a device specific component;

the second uplink pathloss based power control parameter comprises a parameter, denoted as a, of a cell that comprises a value within a range from 0 to 1; and the uplink interference level comprises an interference level measured by at least one of the first base station or the at least one base station.

6. The method of claim 1, further comprising:

determining that the target cell comprises insufficient resources to provide communications to the candidate device in an instance in which the estimated resource consumption is above a threshold.

7. The method of claim 1, further comprising:

determining that the target cell comprises sufficient resources to provide communications to the candidate device in an instance in which the estimated resource consumption is below the threshold.

8. The method of claim 7, further comprising:

handing over a connection of the candidate device with the first base station of the source cell to the at least one base station of the target cell in response to determining that the estimated resource consumption is below the threshold.

9. The method of claim 1, wherein the estimated resource consumption corresponds to an estimate of a number of Physical Resource Blocks for usage by the candidate device in the target cell in order to determine whether the target cell is a viable cell for handoff of communications from the source cell to the target cell.

10. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:

receive one or more uplink parameters from at least one base station, the uplink parameters comprising at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level; and

determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters, wherein the apparatus comprises at least a portion of a first base station.

11. The apparatus of claim 10, wherein:

the candidate device is currently connected to the apparatus in a source cell; and the at least one base station is within the target cell.

12. The apparatus of claim 10, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to receive the uplink parameters by receiving the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the apparatus and the at least one base station to facilitate exchange of

communications .

13. The apparatus of claim 10, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to receive the uplink parameters by receiving the uplink parameters via an S 1 interface in a Long Term Evolution system, the SI interface comprises a physical or logical interface between at least one of the apparatus or the at least one base station and a core network to facilitate exchange of communications.

14. The apparatus of claim 10, wherein:

the second uplink pathloss based power control parameter comprises a parameter, denoted as a, of a cell that comprises a value within a range from 0 to 1 ; and

the uplink interference level comprises an interference level measured by at least one of the first base station or the at least one base station.

15. The apparatus of claim 10, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to: determine that the target cell comprises insufficient resources to provide services to the candidate device in an instance in which the estimated resource consumption is above a threshold.

16. The apparatus of claim 10, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to:

determine that the target cell comprises sufficient resources to provide

communications to the target device in an instance in which the estimated resource consumption is below the threshold.

17. The apparatus of claim 16, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to:

hand over a connection of the candidate device with the apparatus of the source cell to the at least one base station of the target cell in response to determining that the estimated resource consumption is below the threshold.

18. The apparatus of claim 10, wherein the estimated resource consumption corresponds to an estimate of a number of Physical Resource Blocks for usage by the candidate device in the target cell in order to determine whether the target cell is a viable cell for handoff of communications from the source cell to the target cell.

19. An apparatus comprising:

means for receiving, at a first base station, one or more uplink parameters from at least one base station, the uplink parameters comprising at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level; and

means for determining an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

20. The apparatus of claim 19, wherein: the candidate device is currently connected to the first base station in a source cell; and

the at least one base station is within the target cell.

21. The apparatus of claim 19, wherein the means for receiving the uplink parameters comprises means for receiving the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the first base station and the at least one base station to facilitate exchange of communications .

22. The apparatus of claim 19, wherein the means for receiving the uplink parameters comprises means for receiving the uplink parameters via an S 1 interface in a Long Term Evolution system, the SI interface comprises a physical or logical interface between at least one of the first base station or the at least one base station and a core network to facilitate exchange of communications.

23. A computer program product comprising at least one computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising:

program code instructions configured to enable receipt, at a first base station, of one or more uplink parameters from at least one base station, the uplink parameters comprising at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level; and program code instructions configured to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters.

24. The computer program product of claim 23, wherein:

the at least one base station is within the target cell.

25. The computer program product of claim 23, wherein receipt of the uplink parameters comprises enabling receipt of the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the first base station and the at least one base station to facilitate exchange of communications .

26. The computer program product of claim 23, wherein receipt of the uplink parameters comprises enabling receipt of the uplink parameters via an SI interface in a Long Term Evolution system, the SI interface comprises a physical or logical interface between at least one of the first base station or the at least one base station and a core network to facilitate exchange of communications.

27. A method comprising:

enabling sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters,

wherein the uplink parameters comprise at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level.

28. The method of claim 27, wherein enabling sending of the uplink parameters comprises enabling sending of the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the first base station and the at least one base station to facilitate exchange of communications.

29. The method of claim 27, wherein enabling sending of the uplink parameters comprises enabling sending of the uplink parameters via an S 1 interface in a Long Term Evolution system, the S 1 interface comprises a physical or logical interface between at least one of the first base station or the at least one base station and a core network to facilitate exchange of communications.

30. The method of claim 27, further comprising:

enabling provision of communications to the candidate device in response to a handover of the candidate device from the at least one base station of a source cell to the first base station of the target cell in response to determining that the target cell comprises sufficient resources to provide communications to the candidate device in an instance in which the estimated resource consumption is below a threshold.

31. A apparatus comprising:

at least one processor; and

enable sending of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters,

wherein the uplink parameters comprise at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level, and

wherein the apparatus comprises at least a portion of a first base station.

32. The apparatus of claim 31 , wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to enable sending of the uplink parameters by enabling sending of the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the apparatus and the at least one base station to facilitate exchange of communications.

33. The apparatus of claim 31 , wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to enable sending of the uplink parameters by enabling sending of the uplink parameters via an SI interface in a Long Term Evolution system, the SI interface comprises a physical or logical interface between at least one of the apparatus or the at least one base station and a core network to facilitate exchange of communications.

34. The apparatus of claim 31 , wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to: enable provision of communications to the candidate device in response to a handover of the candidate device from the at least one base station of the source cell to the apparatus of the target cell in response to determining that the target cell comprises sufficient resources to provide communications to the candidate device in an instance in which the estimated resource consumption is below a threshold.

35. An apparatus comprising :

means for enabling sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters,

36. A computer program product comprising at least one computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising:

program code instructions configured to enable sending, at a first base station, of one or more uplink parameters to at least one base station to enable the at least one base station to determine an estimate of resource consumption of at least one candidate device for usage in a target cell based at least in part on evaluation of the received uplink parameters,

37. An apparatus comprising:

at least one processor; and

receive one or more uplink parameters from at least one base station, the uplink parameters comprising at least one of a first uplink pathloss based power control parameter, a second uplink pathloss based power control parameter or at least one uplink interference level,

wherein the apparatus comprises at least a portion of a first base station.

38. The apparatus of claim 37, wherein the at least one memory and the computer program code are further configured to, with the processor, cause the apparatus to receive the uplink parameters by receiving the uplink parameters via an X2 interface in a Long Term Evolution system, the X2 interface comprises a physical or logical interface between the apparatus and the at least one base station to facilitate exchange of

communications .

39. The apparatus of claim 37, wherein: