Patent Application
20150358959
This disclosure relates generally to telecommunications, and more particularly to femto cell base station management and the like.
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), evolution data optimized (EV-DO), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
To supplement conventional base stations, additional low power base stations can be deployed to provide more robust wireless coverage to mobile devices. For example, low power base stations (commonly referred to as Home Node Bs or Home eNBs, collectively referred to as H(e)NBs, femto nodes, femtocell nodes, pico nodes, micro nodes, etc.) can be deployed for incremental capacity growth, richer user experience, in-building or other specific geographic coverage, and the like. In some configurations, such low power base stations are connected to the Internet via broadband connection (e.g., digital subscriber line (DSL) router, cable or other modem, etc.), which can provide the backhaul link to the mobile operator's network. In this regard, low power base stations are often deployed in homes, offices, etc., without consideration of a current network environment.
In this way, the deployment of small cell base stations (e.g., femto nodes) may provide incremental capacity growth, richer user experience, in-building or other specific geographic coverage, and so on. However, the deployment of small cell base stations may also encroach on the operation of other devices that typically utilize the same space, such as Wireless Local Area Network (WLAN) devices operating in accordance with one of the IEEE 802.11x communication protocols (so-called “Wi-Fi” devices) or other wired or wireless devices sharing the same Internet connection in a user's residence or office building. The unmanaged sharing of common backhaul resources may lead to various throughput and/or data integrity problems for all devices.
For example, backhaul measurements of base stations (e.g., macro cells, femto nodes, or small cells) may vary in time. This may be due to time-varying backhaul load, availability of different backhauls that a cell can select from, and/or the application of different backhaul management schemes (e.g., traffic allocation), etc. The performance of UE mobility and the configuration action of features addressing such performance (e.g. mobility robustness optimization (MRO), frequent handover mitigation, etc.) may depend on backhaul characteristics, for example, backhaul latency or delay.
Thus, there is a desire for a method and an apparatus for managing performance in a wireless network using backhaul measurements.
The present disclosure presents an example method and apparatus for managing performance of a wireless network. For example, the present disclosure presents an example method for managing performance of a wireless network that may include identifying a backhaul condition at a small cell in the wireless network, wherein the backhaul condition is associated with one or more of a backhaul latency measurement, a backhaul error rate, or a backhaul jitter value at the small cell, and triggering an action at the small cell in response to identifying the backhaul condition at the small cell, wherein triggering the action at the small cell includes modifying one or more resource management parameters at the small cell based on the backhaul condition.
Further, the present disclosure provides an apparatus for managing performance of a wireless network that may include means for identifying a backhaul condition at a small cell in the wireless network, wherein the backhaul condition is associated with one or more of a backhaul latency measurement, a backhaul error rate, or a backhaul jitter value at the small cell, and means for triggering an action at the small cell in response to identifying the backhaul condition at the small cell, wherein triggering the action at the small cell includes modifying one or more resource management parameters at the small cell based on the backhaul condition.
Furthermore, the present disclosure provides an apparatus for managing performance of a wireless network that may include a processor coupled to a memory, the processor configured to identify a backhaul condition at a small cell in the wireless network, wherein the backhaul condition is associated with one or more of a backhaul latency measurement, a backhaul error rate, or a backhaul jitter value at the small cell, and trigger an action at the small cell in response to identifying the backhaul condition at the small cell, wherein triggering the action at the small cell includes modifying one or more resource management parameters at the small cell based on the backhaul condition.
The accompanying drawings are presented to aid in the description of various aspects and are provided solely for illustration of the aspects and not limitation thereof.
Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details.
As described further herein, low power base stations, such as femto nodes, can configure radio frequency (RF) parameters based on observations of neighboring access points. In this regard, the low power base stations can, in effect, cause devices to prefer the low power base station or to instead prefer other access points based on the observations. For example, a low power base station can determine capabilities of the neighboring access points based on one or more measured or otherwise received parameters. In addition, the neighboring access points can use broadcast, backhaul, or other (e.g., user device) signals and related parameters to indicate capabilities, which the low power base station can receive and use to adjust RF parameters. In one example, the low power base station can compare its capabilities to those of the low power base station in configuring the RF parameters. Where a neighboring access point has better capabilities than the low power base station, for example, the low power base station can set RF parameters in an attempt to effectively expand a coverage area of the neighboring access point, and thus cause more devices to be served by the neighboring access point rather than the low power base station.
A low power base station, as referenced herein, can include a femto node, a pico node, micro node, home Node B or home evolved Node B (H(e)NB), relay, and/or other low power base stations, and can be referred to herein using one of these terms, though use of these terms is intended to generally encompass low power base stations. In general, a low power base station is referred to as such because it transmits at a relatively low power as compared to a macro base station associated with a wireless wide area network (WWAN). Accordingly, the coverage area of the low power base station is typically substantially smaller than the coverage area of a macro base station.
As used in this application, the terms “component,” “module,” “system” and the like are intended to include a computer-related entity, such as but not limited to hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal.
Furthermore, various aspects are described herein in connection with a terminal, which can be a wired terminal or a wireless terminal. A terminal can also be called a system, device, subscriber unit, subscriber station, mobile station, mobile, mobile device, remote station, remote terminal, access terminal, user terminal, communication device, user agent, user device, or user equipment (UE). A wireless terminal or device may be a cellular telephone, a satellite phone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, a tablet, a computing device, or other processing devices connected to a wireless modem. Various aspects are also described herein in connection with a base station. A base station may be utilized for communicating with wireless terminal(s) and may also be referred to as an access point, a Node B, evolved Node B (eNB), home Node B (HNB) or home evolved Node B (HeNB), collectively referred to as H(e)NB, or some other terminology.
In general, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.
The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, WiFi carrier sense multiple access (CSMA), and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) and other variants of CDMA. Further, cdma2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system may implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). Additionally, cdma2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). Further, such wireless communication systems may additionally include peer-to-peer (e.g., mobile-to-mobile) ad hoc network systems often using unpaired unlicensed spectrums, 802.xx wireless LAN, BLUETOOTH and any other short- or long-range, wireless communication techniques.
Various aspects or features will be presented in terms of systems that may include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems may include additional devices, components, modules, etc., and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches may also be used.
Referring to
As described, the femto nodes 104 and 106 can communicate with the wireless network (not shown) over a broadband connection. In addition, femto nodes 104 and 106 can communicate with one another, and/or with macro node 102, over a backhaul connection. The backhaul connection can be, for example, a connection managed through the core wireless network accessible over the broadband connection at the femto node 104 and/or 106, and/or over a connection through a radio network controller (RNC) that communicates with macro node 102. In one example, upon initialization, one or more of the femto nodes 104 and/or 106 can also communicate with one another to form a grouping (e.g., an ad-hoc network). This allows the femto nodes 104 and/or 106 to communicate to determine parameters related to serving the various devices connected thereto (e.g., resource allocations, interference management, and/or the like). Moreover, femto nodes 104 and 106 can automatically configure themselves to operate in the wireless network (e.g., set transmit power, network identifiers, pilot signal resources, and/or the like based on similar information received over a backhaul connection, over-the-air, or otherwise sensed from surrounding nodes). In this example, the femto nodes 104 and 106 can behave as plug-and-play devices requiring little user interaction to be provisioned on the wireless network.
In one example, femto node 104 can observe capabilities of macro node 102 and/or femto node 106 in determining parameters for providing wireless network access. For example, femto node 104 can determine or adjust transmission power, resource block allocation, utilized frequency spectrum, and/or other RF parameters based on determined capabilities of macro node 102, femto node 106, etc. For example, where capabilities of macro node 102, femto node 106, or other nodes are improved at least a threshold amount over those of femto node 104, femto node 104 can reduce transmission power, resource block allocation, etc., to defer more devices to the other nodes. This can improve coverage for the device. For example, where femto node 104 provides coverage area 110, adjusting RF parameters based on measured capabilities of femto node 106 allows femto node 104 to effectively shrink its coverage area to coverage area 132, which causes device 124 to communicate with femto node 106.
For example, femto node 104 can determine a number of channel elements (CE), backhaul capacity, maximum transmission power, a downlink/uplink load metric, preferred users, access mode, etc. of macro node 102 or femto node 106. This information can be obtained from the macro node 102 or femto node 106 in broadcast channel (BCH) messages, or can be embedded at the physical layer (e.g., in a secondary synchronization channel). In other examples, the macro node 102 and/or femto node 106 can utilize other parameters to indicate the information, such as selecting a physical layer attribute (e.g., primary scrambling code (PSC)). In this example, the attribute can correspond to a subset of attribute values related to low capability or another subset related to high capability. Thus, femto node 106 can select an attribute to indicate the desired capability. In any case, femto node 104 can measure broadcast parameters to determine capabilities of macro node 102 and/or femto node 106 (e.g., using a network listening module (NLM) or otherwise receiving capability parameters measured by a device communicating with femto node 104). In the PSC example above, the femto node 104 can use the mapping to determine the capability information based on the PSC. In another example, macro node 102 and/or femto node 106 can communicate capability information to femto node 104 via a backhaul connection, as described.
Femto node 104 can compare the observed capability information to its own capabilities, in one example, to determine an adjustment of transmission power, resource allocation (e.g., allocation of time and/or frequency blocks), frequency spectrum, etc. For example, where femto node 104 determines femto node 106 has more CEs, femto node 104 can decrease transmission power to reduce its coverage area, which makes reselection or handover of devices communicating with femto node 104 more likely (e.g., to femto node 106 or other nodes). It is to be appreciated that femto node 104 can compare multiple measured or otherwise received capabilities of macro node 102 and/or femto node 106 in determining adjustment of its RF parameters. Moreover, it is to be appreciated that a centralized entity can collect capability information of multiple nodes and accordingly specify RF parameters and/or related adjustments, such as transmission power, resource allocation, frequency spectrum, etc., to the nodes based on capabilities. The nodes can set RF parameters based on the RF parameters or related adjustments received from the centralized entity. Moreover, femto node 104 can similarly adjust mobility parameters based on the measured capabilities.
In one example, femto nodes 104 and 106 can operate in an open or hybrid access mode to offload devices from macro node 102. In this example, allowing the femto nodes to specify communication parameters to define a coverage area based on measured capabilities of other nodes provides a self-configuration ability from which the above scenario can benefit. In this regard, devices offloaded from macro node 102 can be directed to femto nodes that provide the best or at least reasonable communication capabilities for the device. In some examples, however, it is to be appreciated that femto nodes operating in a hybrid access mode can prefer member devices to non-member devices.
In addition, parameters can be updated by certain events, such as addition of femto nodes to the network, removal of femto nodes from the network, etc. For example, femto node 104 can detect a new femto node nearby (e.g., based on parameters received by the NLM) that provides improved capabilities, and can further decrease transmission power, etc., to allow the new femto node to provide access to some devices in the area.
Femto node 202 can include a capability determining component 210 for observing one or more parameters related to capabilities of another access point, and a parameter adjusting component 212 for adjusting one or more RF parameters based in part on the observed capabilities of other access points. Femto node 202 also optionally includes a NLM component 214 for obtaining one or more parameters broadcasted by the access points, and/or a capability specifying component 216 for communicating parameters regarding capabilities of femto node 202 to other access points.
According to an example, femto node 202 can determine RF parameters for communicating in a network given capabilities of femto node 204, macro node 206, or other nodes. This can occur upon initialization of femto node 202 in the wireless network, upon occurrence of one or more detected events—such as addition or removal of an access point in a wireless network, detected load at femto node 202 over a threshold, etc.—based on a timer or command from a core network component, and/or the like. In this example, capability determining component 210 can receive or otherwise determine one or more parameters related to capabilities at femto node 204. This can include capability determining component 210 receiving broadcast parameters from the femto node 204 (e.g., based on decoding signals received there from using NLM component 214), receiving parameters over a backhaul connection thereto, receiving parameters from a device communicating with femto node 202 that can receive and/or measure parameters from femto node 204, etc.
The parameters broadcast by femto node 204 or otherwise determined based on information broadcast by femto node 204 can include a number of CEs, backhaul capacity and cost, maximum transmission power, average downlink/uplink load, preferred users, access mode (open/hybrid/closed), etc. In one example, this information can be broadcast by the femto node 204 (e.g., over a BCH or can be embedded at the physical layer, such as by using the secondary synchronization channel). Thus, NLM component 214, for instance, can receive the BCH, and capability determining component 210 can determine the information based on the parameters (e.g., as indicated or otherwise discerned from the parameters). In other examples, devices communicating with femto node 202 can communicate measurement reports to femto node 202 that include parameters of femto node 204 from which capabilities can be determined. Alternatively, femto node 204 can utilize certain physical layer attributes, such as PSCs, to signal capabilities (e.g., low or high maximum transmission power, low or high resource capacity or utilization, etc.), where the physical layer attributes correspond to a range of attribute values indicative of capability information. In this example, the physical layer attributes are received at femto node 202, and capability determining component 210 compares the physical layer attributes to ranges of attribute values that relate to capability information. Based on the comparison, capability determining component 210 can determine capability information related to femto node 204. In other examples, femto node 204 can communicate the capability information to femto node 202 over a backhaul connection.
In any case, capability determining component 210 can interpret received information to determine capabilities of femto node 204. In a specific example, capability determining component 210 can obtain received pilot strength over total received signal power (Ecp/Io) of femto node 204, and can estimate average downlink load at femto node 204 based thereon (e.g., higher Ecp/Io can indicate lower downlink load, etc.). In this example, femto node 202 can receive the Ecp/Io using NLM component 214 or in measurement reports from a connected device. In another example, capability determining component 210 can estimate the average uplink load at femto node 204 in part by decoding an uplink interference level broadcast by femto node 204 (e.g., higher uplink interference can indicate higher uplink load, etc.). It is to be appreciated that capability determining component 210 can observe additional or alternative parameters, and can compare the parameters to those of femto node 202.
Parameter adjusting component 212 can adjust RF parameters of femto node 202, such as RF parameter 220, based on the comparison of capabilities of femto node 204 to those of femto node 202. For example, once femto node 202 becomes aware of the capabilities of femto node 204 (e.g., and/or macro node 206 or other neighboring nodes), capability determining component 210 can compare the capabilities of the femto node (and/or other access points) with its own capabilities, and parameter adjusting component 212 can adjust RF parameters 220 of femto node 202, such as transmission power, resource allocation, frequency spectrum, etc., to try to maximize the user experience at one or more devices. RF parameter 220 can be used by a transmitter or other component of femto node 202 to communicate in a wireless network.
For example, where one or more neighboring access points, such as femto node 204, have improved capabilities over femto node 202 (e.g., more CEs, better backhaul throughput, lower average load, operation in an open mode where femto node 202 operates in a hybrid mode, etc.), the parameter adjusting component 212 can adjust the RF parameters (e.g., transmission power, number of frequency and/or time resource blocks, frequency spectrum, etc.) to make it more likely for devices to be served by the one or more neighboring access points, such as femto node 204. For example, where parameter adjusting component 212 reduces transmission power, coverage area of the femto node 202 is effectively reduced, thus making it more likely for devices to reselect or handover to a neighboring access point, such as femto node 204.
As another example, femto node 202 can be backhaul limited. For example, this can be due to a constrained broadband internet connection caused by preferring other devices on the network. In other examples, femto node 202 can prefer traffic from member devices, which can cause backhaul limitation for non-member devices. In these examples, capability determining component 210 can determine that other neighboring access points may have backhauls with increased throughput (e.g., based on receiving parameters related to the backhaul throughput, based on determining that the other neighboring access points operate in an open access mode, etc.). In this example, parameter adjusting component 212 can reduce the number of frequency/time blocks or amount of frequency spectrum allocated to femto node 202 so that more resources become available to the neighboring access points with the better backhaul.
In addition, for example, capability specifying component 216 can communicate capability information related to femto node 202 to other access points. For example, capability specifying component 216 can broadcast capabilities in one or more overhead messages. In one example, this can include explicit indication of capabilities, indication using one or more other parameters, such as PSC to indicate information based on comparing the PSC to one or more ranges of PSC values as described, etc. In another example, capability specifying component 216 can communicate the information over a backhaul to one or more access points, such as femto node 204, macro node 206, etc.
Moreover, it is to be appreciated that femto node 202 can be a centralized entity, such as a HNB gateway, HMS, etc., that collects or otherwise determines capability information of various femto nodes as described. In this example, parameter adjusting component 212 can adjust RF parameters for the various femto nodes and communicate the adjusted RF parameters to the femto nodes. The femto nodes can receive the RF parameters and accordingly adjust RF parameters based on those received.
Referring to
Turning to
At 302, capabilities of one or more neighboring access points (e.g., neighboring femto or pico nodes) can be determined based in part on signals received there from. For example, the capabilities can relate to a number of channel elements, a backhaul capacity or cost, a maximum transmission power, an average downlink or uplink load, or an access mode of the one or more neighboring access points as received in a broadcast message from the one or more neighboring access points, and/or the like. Moreover, the determining can comprise receiving information regarding the capabilities over a BCH or backhaul connection, determining the capabilities based on information received over the BCH, inferring capabilities based on mapping one or more received physical layer attributes, such as a PSC, to possible capability parameters, and/or the like.
At 304, the capabilities can be compared to one or more capabilities of the femto node to determine an RF parameter adjustment for the femto node. For example, this can include determining whether the capabilities are better or worse than those determined for the one or more neighboring access points. Where the capabilities are better for the one or more neighboring access points, for example, the RF parameter adjustment can relate to lowering RF parameters to effectively shrink a coverage area of the femto node, such that devices can more often prefer the one or more neighboring access points. Thus, user experience may be improved and better optimized. Where the capabilities of the femto node are better than the neighboring access points, however, the RF parameters can be modified to increase coverage area of the femto node. For example, the RF parameters can relate to a transmission power, resource allocation, frequency spectrum, etc. for the femto node.
At 306, one or more RF parameters can be adjusted based on the comparison, as described. For example, the RF parameter adjustment can be absolute or relative to current values for the one or more RF parameters. The RF parameter can be adjusted at the femto node to effectuate modification of the coverage area.
It will be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding determining capabilities of neighboring access points, determining a corresponding RF parameter adjustment, and/or the like, as described. As used herein, the term to “infer” or “inference” refers generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic—that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources.
With reference to
Further, logical grouping 402 can include an electrical component for adjusting one or more RF parameters based on the comparison. As described, RF parameters may be adjusted to prefer the femto node or the one or more access points by expanding or shrinking a coverage area of the femto node based on comparison of the capabilities, etc. For example, electrical components 404 and 406 can include a capability determining component 210, as described above. In addition, for example, electrical component 408, in an aspect, can include a parameter adjusting component 212, as described above.
Additionally, system 400 can include a memory 410 that retains instructions for executing functions associated with the electrical components 404, 406, and 408. While shown as being external to memory 410, it is to be understood that one or more of the electrical components 404, 406, and 408 can exist within memory 410. In one example, electrical components 404, 406, and 408 can comprise at least one processor, or each electrical component 404, 406, and 408 can be a corresponding module of at least one processor. Moreover, in an additional or alternative example, electrical components 404, 406, and 408 can be a computer program product comprising a computer readable medium, where each electrical component 404, 406, and 408 can be corresponding code.
Referring now to
Base station 502 can communicate with one or more mobile devices such as mobile device 516 and mobile device 522; however, it is to be appreciated that base station 502 can communicate with substantially any number of mobile devices similar to mobile devices 516 and 522. Mobile devices 516 and 522 can be, for example, cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over wireless communication system 500. As depicted, mobile device 516 is in communication with antennas 512 and 514, where antennas 512 and 514 transmit information to mobile device 516 over a forward link 518 and receive information from mobile device 516 over a reverse link 520. Moreover, mobile device 522 is in communication with antennas 504 and 506, where antennas 504 and 506 transmit information to mobile device 522 over a forward link 524 and receive information from mobile device 522 over a reverse link 526. In a frequency division duplex (FDD) system, forward link 518 can utilize a different frequency band than that used by reverse link 520, and forward link 524 can employ a different frequency band than that employed by reverse link 526, for example. Further, in a time division duplex (TDD) system, forward link 518 and reverse link 520 can utilize a common frequency band and forward link 524 and reverse link 526 can utilize a common frequency band.
Each group of antennas and/or the area in which they are designated to communicate can be referred to as a sector of base station 502. For example, antenna groups can be designed to communicate to mobile devices in a sector of the areas covered by base station 502. In communication over forward links 518 and 524, the transmitting antennas of base station 502 can utilize beamforming to improve signal-to-noise ratio of forward links 518 and 524 for mobile devices 516 and 522. Also, while base station 502 utilizes beamforming to transmit to mobile devices 516 and 522 scattered randomly through an associated coverage, mobile devices in neighboring cells can be subject to less interference as compared to a base station transmitting through a single antenna to all its mobile devices. Moreover, mobile devices 516 and 522 can communicate directly with one another using a peer-to-peer or ad hoc technology as described. According to an example, system 500 can be a multiple-input multiple-output (MIMO) communication system.
At base station 610, traffic data for a number of data streams is provided from a data source 612 to a transmit (TX) data processor 614. According to an example, each data stream can be transmitted over a respective antenna. TX data processor 614 formats, codes, and interleaves the traffic data stream based on a particular coding scheme selected for that data stream to provide coded data.
The coded data for each data stream can be multiplexed with pilot data using orthogonal frequency division multiplexing (OFDM) techniques. Additionally or alternatively, the pilot symbols can be frequency division multiplexed (FDM), time division multiplexed (TDM), or code division multiplexed (CDM). The pilot data is typically a known data pattern that is processed in a known manner and can be used at mobile device 650 to estimate channel response. The multiplexed pilot and coded data for each data stream can be modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream can be determined by instructions performed or provided by processor 630.
The modulation symbols for the data streams can be provided to a TX MIMO processor 620, which can further process the modulation symbols (e.g., for OFDM). TX MIMO processor 620 then provides NT modulation symbol streams to NT transmitters (TMTR) 622a through 622t. In various aspects, TX MIMO processor 620 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.
Each transmitter 622 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. Further, NT modulated signals from transmitters 622a through 622t are transmitted from NT antennas 624a through 624t, respectively.
At mobile device 650, the transmitted modulated signals are received by NR antennas 652a through 652r and the received signal from each antenna 652 is provided to a respective receiver (RCVR) 654a through 654r. Each receiver 654 conditions (e.g., filters, amplifies, and downconverts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.
An RX data processor 660 can receive and process the NR received symbol streams from NR receivers 654 based on a particular receiver processing technique to provide NT “detected” symbol streams. RX data processor 660 can demodulate, deinterleave, and decode each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 660 is complementary to that performed by TX MIMO processor 620 and TX data processor 614 at base station 610.
The reverse link message can comprise various types of information regarding the communication link and/or the received data stream. The reverse link message can be processed by a TX data processor 638, which also receives traffic data for a number of data streams from a data source 636, modulated by a modulator 680, conditioned by transmitters 654a through 654r, and transmitted back to base station 610.
At base station 610, the modulated signals from mobile device 650 are received by antennas 624, conditioned by receivers 622, demodulated by a demodulator 640, and processed by a RX data processor 642 to extract the reverse link message transmitted by mobile device 650. Further, processor 630 can process the extracted message to determine which precoding matrix to use for determining the beamforming weights.
Processors 630 and 670 can direct (e.g., control, coordinate, manage, etc.) operation at base station 610 and mobile device 650, respectively. Respective processors 630 and 670 can be associated with memory 632 and 672 that store program codes and data. Processors 630 and 670 can also perform functionalities described herein to support adjusting RF parameters of one or more femto nodes.
Referring again to
A femto node 810 can be deployed on a single frequency or, in the alternative, on multiple frequencies. Depending on the particular configuration, the single frequency or one or more of the multiple frequencies can overlap with one or more frequencies used by a macro cell access node (e.g., node 860). In some aspects, an access terminal 820 can be configured to connect to a preferred femto node (e.g., the home femto node of the access terminal 820) whenever such connectivity is possible. For example, whenever the access terminal 820 is within the user's residence 830, it can communicate with the home femto node 810.
In some aspects, if the access terminal 820 operates within the mobile operator core network 850 but is not residing on its most preferred network (e.g., as defined in a preferred roaming list), the access terminal 820 can continue to search for the most preferred network (e.g., femto node 810) using a Better System Reselection (BSR), which can involve a periodic scanning of available systems to determine whether better systems are currently available, and subsequent efforts to associate with such preferred systems. Using an acquisition table entry (e.g., in a preferred roaming list), in one example, the access terminal 820 can limit the search for specific band and channel. For example, the search for the most preferred system can be repeated periodically. Upon discovery of a preferred femto node, such as femto node 810, the access terminal 820 selects the femto node 810 for camping within its coverage area.
A femto node can be restricted in some aspects. For example, a given femto node can only provide certain services to certain access terminals. In deployments with so-called restricted (or closed) association, a given access terminal can only be served by the macro cell mobile network and a defined set of femto nodes (e.g., the femto nodes 810 that reside within the corresponding user residence 830). In some implementations, a femto node can be restricted to not provide, for at least one access terminal, at least one of: signaling, data access, registration, paging, or service.
In some aspects, a restricted femto node (which can also be referred to as a Closed Subscriber Group H(e)NB) is one that provides service to a restricted provisioned set of access terminals. This set can be temporarily or permanently extended as necessary. In some aspects, a Closed Subscriber Group (CSG) can be defined as the set of access nodes (e.g., femto nodes) that share a common access control list of access terminals. A channel on which all femto nodes (or all restricted femto nodes) in a region operate can be referred to as a femto channel.
Various relationships can thus exist between a given femto node and a given access terminal. For example, from the perspective of an access terminal, an open femto node can refer to a femto node with no restricted association. A restricted femto node can refer to a femto node that is restricted in some manner (e.g., restricted for association and/or registration). A home femto node can refer to a femto node on which the access terminal is authorized to access and operate on. A guest femto node can refer to a femto node on which an access terminal is temporarily authorized to access or operate on. An alien femto node can refer to a femto node on which the access terminal is not authorized to access or operate on, except for perhaps emergency situations (e.g., 911 calls).
From a restricted femto node perspective, a home access terminal can refer to an access terminal that is authorized to access the restricted femto node. A guest access terminal can refer to an access terminal with temporary access to the restricted femto node. An alien access terminal can refer to an access terminal that does not have permission to access the restricted femto node, except for perhaps emergency situations, for example, 911 calls (e.g., an access terminal that does not have the credentials or permission to register with the restricted femto node).
For convenience, the disclosure herein describes various functionality in the context of a femto node. It should be appreciated, however, that a pico node can provide the same or similar functionality as a femto node, but for a larger coverage area. For example, a pico node can be restricted, a home pico node can be defined for a given access terminal, and so on. Accordingly, unless indicated otherwise in its particular context, the term femto node as used herein is generally intended to cover such pico nodes and other low power base stations, as described above.
A wireless multiple-access communication system can simultaneously support communication for multiple wireless access terminals. As mentioned above, each terminal can communicate with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link can be established via a single-in-single-out system, a MIMO system, or some other type of system.
The various illustrative logics, logical blocks, modules, components, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Additionally, at least one processor may comprise one or more modules operable to perform one or more of the steps and/or actions described above. An exemplary storage medium may be coupled to the processor, such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. Further, in some aspects, the processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
In one or more aspects, the functions, methods, or algorithms described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored or transmitted as one or more instructions or code on a computer-readable medium, which may be incorporated into a computer program product. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, substantially any connection may be termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs usually reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
While the foregoing disclosure discusses illustrative aspects and/or aspects, it should be noted that various changes and modifications could be made herein without departing from the scope of the described aspects and/or aspects as defined by the appended claims. Furthermore, although elements of the described aspects and/or aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect may be utilized with all or a portion of any other aspect, unless stated otherwise.
The present disclosure includes a method and an apparatus for managing performance of a wireless network. For example, the present disclosure discusses a femto node (or a small cell) identifying a backhaul condition at the femto node. The backhaul condition may be associated with one or more of a backhaul latency measurement, a backhaul error rate, and a backhaul jitter value at the femto node. For instance, the backhaul condition may be associated with the backhaul latency measurement above a threshold value. Further, the present disclosure discusses triggering an action (e.g., a handover) at the femto node in response to identifying that backhaul latency measurement is above the threshold value. Furthermore, the triggering the action femto node may include modifying one or more resource management parameters at the femto node based on identifying that backhaul latency measurement is above a threshold value.
For example, a home router 1002 is installed in a user residence 1004 and provides access to the Internet 1006 via an Internet service provider (ISP) 1008. The home router 1002 communicates (e.g., transfers user data and/or other signaling information) with ISP 1008 via a modem 1015 over a corresponding backhaul link 1010. In an aspect, for example, the home router 1002 may support various wired and/or wireless devices, such as a home computer 1012, a wireless fidelity (Wi-Fi) enabled TV 1014, etc. In an additional aspect, the home router 1002 may include a wireless access point (AP), for example, a Wi-Fi access point (AP) providing connectivity to such devices. In an additional aspect, for example, the home router 1002 may be integrated with a wireless access point Wi-Fi AP for providing connectivity to such devices.
In an aspect, femto node 1020 is installed in user residence 1004 and serves one or more nearby user equipments (UE) 1022. Femto node 1020 via its connection to home router 1002 and shared backhaul link 1010 provides access to Internet 1006 and core network 1016. As the backhaul link 1010 may be shared between the traffic supported by femto node 1020 (e.g., native traffic) and other traffic generated by other devices (e.g., home computer 1012) that home router 1002 may be serving (e.g., cross traffic), congestion of uplink (UL) traffic, down link (DL) traffic, and/or both may occur with varying degrees of impact on the performance of the femto node and/or other devices sharing the backhaul link 1010.
In an aspect, femto node 1020 may be configured to include a backhaul-aware configuration manager (BACM) 1024 operable to manage performance of femto node 1020. The operation of BACM 1024 may enable femto node 1020 to determine various backhaul measurements, for example, backhaul latency measurements, backhaul error rate, and/or a jitter value and take appropriate actions.
In an aspect, at block 1110, methodology 1100 may include identifying a backhaul condition at a small cell in the wireless network, wherein the backhaul condition is associated with one or more of a backhaul latency measurement, a backhaul error rate, or a backhaul jitter value at the small cell. For example, in an aspect, femto node 1020 and/or BACM 1024 may include a specially programmed processor module, or a processor executing specially programmed code stored in a memory, to identify a backhaul condition at femto node 1020 in the wireless network, wherein the backhaul condition is associated with one or more of a backhaul latency measurement, a backhaul error rate, or a backhaul jitter value at the small cell.
For instance, in an aspect, the backhaul condition may be associated with one or more of a backhaul latency measurement, a backhaul error rate, and/or a jitter value. For example, the backhaul condition associated with backhaul latency measurement may be identified when the backhaul latency measurement is above a threshold value, e.g., backhaul latency measurement threshold value (first threshold value), the backhaul condition associated with backhaul error rate may be identified when the backhaul error rate is above a threshold value, e.g., backhaul error rate threshold value (second threshold value), and/or the backhaul condition associated with jitter value may be identified when the jitter value is above a threshold value, e.g., jitter threshold value (third threshold value). In an additional or optional aspect, any combination of the three backhaul conditions and/or threshold values may be used for identifying the backhaul condition at the femto node. In an aspect, the backhaul condition may be configured at the femto node or dynamically selected at the femto node on a per application basis based on the application.
In an additional or optional aspect, the identifying of the backhaul condition does not have to be performed at the femto node (e.g., femto node 1020). The identifying of the backhaul condition may be performed at an entity that can monitor the backhaul (e.g., backhaul 1010) of femto node 1020 and identify the backhaul condition as described above. That is, there is no need for BACM 1024 to be co-located with femto node 1020, but femto node 1020 has to be aware of the backhaul condition(s) relevant to femto node 1020. For example, in an aspect, the monitoring of backhaul 1010 may be performed at core network 1016.
In an aspect, the backhaul condition may be identified in a passive or an active manner. For example, in an aspect, femto node 1020 and/or BACM 1024 may identify the backhaul condition in a passive manner by computing backhaul latency measurements by monitoring traffic that is already traversing backhaul 1010 of femto node 1020. In an additional aspect, the backhaul condition may be may be identified by computing backhaul latency measurements over longer periods of time (e.g., over several hours) or over shorter periods of time (e.g., over several minutes). For instance, in an example aspect, the backhaul latency measurements may be computed by monitoring the traffic over backhaul 1010 over longer or shorter periods of time depending on the type of application (e.g., VoIP, non-QoS data session, etc.) supported by femto node 1020. In a further additional aspect, the monitoring duration may depend on the type of backhaul 1010 (e.g., fiber, Ethernet, digital subscriber line (DSL), cable, etc.) and/or past performance history of the backhaul (e.g. based on whether the backhaul condition changes frequently). This allows flexibility at the femto node to properly identify the backhaul condition.
In an additional or optional aspect, the backhaul condition may be identified in an active manner. For example, in an aspect, femto node 1020 and/or BACM 1024 may identify the backhaul condition in an active manner by measuring the backhaul latency measurements by pinging another node and computing the backhaul latency (or delay) measurements based on the response time. For instance, in an aspect, the backhaul condition may be identified in an active manner by measuring the backhaul latency measurements by sending a ping message to another node whose delay is known and computing the backhaul latency measurement based on the response time.
In an aspect, the backhaul condition may be identified by computing the backhaul latency measurement between neighboring cells or between a cell and an actual or a virtual reference point. For example, an actual reference point may be a known or a specific host and a virtual reference point may be a hypothetical or an actual host whose latency is assumed or known in relation to other hosts, for which latency is measurable. For instance, in an aspect, femto node 1020 and/or BACM 1024 may identify the backhaul condition by computing the backhaul latency measurements over X2 interfaces between neighboring femto nodes (e.g., femto node 1020 and its neighbor) or a between femto node 1020 and a reference point (e.g., server or a gateway). In an additional aspect, the backhaul condition may be identified by computing round-trip or one-way delays. In an aspect, backhaul latency measurements may be measured from propagation time of existing messages and/or data (e.g., S1, X2, SCTP, TCP, TR-069, HTTP, FTP, etc. messages) taking into consideration end-time processing. For instance, backhaul latency measurements may be measured from time elapsed from message to message or from message to ACK response.
In a further additional aspect, the backhaul latency measurements may be computed using average values, tail or percentile values, and/or a combination of these values. For instance, in an aspect, when packets to multiple network termination points are used in computing the backhaul latency measurements, the backhaul condition may be identified when the backhaul latency measurements are computed while ensuring that the measurements characterize only the femto node rather than the multiple network termination points. In an additional aspect, identifying a backhaul condition using the passive approach may limit observations to traffic from/to network termination points that are known to have similar conditions, e.g., latencies, and/or maintain and use a condition difference table, e.g., a “latency difference” table between a set of network termination points.
In an aspect, at block 1120, methodology 1100 may include triggering an action at the small cell in response to identifying the backhaul condition at the small cell, wherein triggering the action at the small cell includes modifying one or more resource management parameters at the small cell based on the backhaul condition. For example, in an aspect, femto node 1020 and/or BACM 1024 may include a specially programmed processor module, or a processor executing specially programmed code stored in a memory, to trigger an action at femto node 1020 in response to identifying the backhaul condition at the femto node, wherein triggering the action at the femto node includes modifying one or more resource management parameters at the small cell based on the backhaul condition.
For instance, in an aspect, femto node 1020 and/or BACM 1024 may trigger an action that includes modifying one or more resource management parameters at femto node 1020 based on identifying of the backhaul condition. In an example aspect, femto node 1020 and/or BACM 1024 may trigger an action at femto node 1020 to modify (e.g., change, update, revise, etc.) resource management parameters, e.g., radio frequency (RF) thresholds for triggering handovers (e.g., RSRP, RSRQ thresholds), time-to-trigger values, a hysteresis, a filtering coefficient, a mobility target and/or a mobility event.
For example, in an aspect, femto node 1020 and/or BACM 1024 may trigger an action (e.g., a handover) earlier (e.g., earlier than initially configured at femto node 1020) in response to identifying a backhaul condition associated with backhaul latency measurement. For instance, the backhaul condition associated with backhaul latency measurement may be identified when backhaul latency measurement at femto node 1020 is higher than the first threshold value. That is, the backhaul latency measurement is not optimal any more and/or may negatively affect the performance of the wireless network.
In an additional or optional aspect, femto node 1020 may be the serving node of a UE (e.g., UE 1022) and/or information may be received from neighboring nodes (e.g., target nodes) about higher backhaul delay measurements at the target nodes. In such a scenario, femto node 1020 and/or BACM 1024 may trigger an action (e.g., handover) to a neighboring node that has not reported a similar (e.g., higher) backhaul latency measurement or has reported a lower backhaul latency measurement.
In an additional aspect, for example, femto node 1020 and/or BACM 1024 may off-load (e.g., handover) faster moving UEs from nodes with higher backhaul latency measurements to nodes with relatively lower backhaul latency measurements. Such handovers may minimize, reduce, or eliminate scenarios where nodes with higher backhaul latency measurements may drop a UE during a handover. For instance, in an aspect, fast moving UEs may be offloaded to a macro cell which may have better (e.g., lower) backhaul latency measurements as macro cells may be configured with dedicated backhauls that are not shared with other nodes and/or configured with backhauls with higher bandwidth.
In a further additional or optional aspect, if femto node 1020 is supporting UEs with active voice calls or running delay sensitive applications, femto node 1020 and/or BACM 1024 may trigger a handover such UEs to neighboring cells with lower backhaul delay measurements (when compared to femto node 1020). Additionally, the associated threshold values (e.g., backhaul latency measurement threshold value—first threshold value) may be taken into consideration when triggering a handover. For instance, the handover may be triggered if the backhaul latency measurement of the current femto node is higher than the first threshold value.
In an aspect, if femto node 1020 derives one or more resource management parameters by a self organizing network (SON) function (e.g., self-configuration function), the SON function may maintain multiple sets of resource management parameters for optimizing at the femto node 1020, where the multiple sets of resource management parameters apply to distinct ranges of backhaul latency measurements. In an optional aspect, the SON function may discard current parameter values and start configuring new values for the resource management parameters when backhaul latency measurements change. In a further additional or optional aspect, hysteresis and/or time to trigger may be applied before the SON function determines updating or discarding of mobility-related parameters to minimize or avoid modifying resource management parameters for rare or less frequent occurrences.
In an aspect, when the identified backhaul condition includes backhaul latency measurements, femto node 1020 and/or BACM 1024 may exchange backhaul latency measurements with one or more neighboring femto nodes, and may trigger the action based on backhaul latency measurements received from a neighboring femto node. In an additional aspect, triggering the action may include sending a message to a neighboring femto node that includes information on changing a parameters of a user equipment (UE) resource management function at the neighboring femto node.
In an aspect, femto node 1020 and/or BACM 1024 may use the identified backhaul condition (e.g., backhaul latency measurements) to perform resource management between neighboring femto nodes (e.g. TDM, FDM, beamform steering, cell power, RBs, TTIs, sub-frames) which may require stringent criteria for exchange of resource management messages between neighboring nodes. For example, if backhaul latency measurements increase (e.g., higher latency measurement values or above the first threshold value), resource management procedure at femto node 1020 may switch to slow-changing procedures to accommodate the higher latency measurements of the backhaul. In an additional aspect, the frequency of resource management updates may increase and/or resource management message triggered actions may change. For instance, in an aspect, femto node 1020 and/or BACM 1024 may turn down (or reduce) the transmit power of femto node 1020 instead of continuing to perform enhanced coordinated multi-point (eCoMP) communications when backhaul latency measurements increase significantly.
Thus, managing performance in the wireless network using backhaul measurements may be achieved.
Referring to
Additionally, logical grouping 1210 can include an electrical component 1230 for triggering an action at the small in response to identifying the backhaul condition at the small cell, wherein triggering the action at the small cell includes modifying one or more resource management parameters at the small cell based on the backhaul condition. For example, in an aspect, femto node or small cell 1020 and/or BCAM 1024 may trigger an action (e.g., handover) at the femto node in response to identifying the backhaul condition (e.g., backhaul latency measurement above the first threshold value) at femto node 1020, wherein triggering the handover at the femto nodes includes modifying one or more resource management parameters at the femto node. In an aspect, the electrical component 1230 may comprise BACM 1024 and/or an action triggering component 1028 (
Additionally, system 1200 can include a memory 1240 that retains instructions for executing functions associated with the electrical components 1220 and 1230, and stores data used or obtained by the electrical components 1220 and 1230. While shown as being external to memory 1240, it is to be understood that one or more of the electrical components 1220 and 1230 can exist within memory 1240. In one example, electrical components 1220 and 1230 can comprise at least one processor, or each electrical component 1220 and 1230 can be a corresponding module of at least one processor. Moreover, in an additional or alternative example, electrical components 1220 and 1230 can be a computer program product including a computer readable medium (e.g., non-transitory computer readable medium), where each electrical component 1220 and 1230 can be corresponding code.
The present application is a continuation-in-part of U.S. Non-Provisional application Ser. No. 13/779,360 entitled “Method and Apparatus for Determining RF Parameters Based on Neighboring Access Points” filed Feb. 27, 2013, which claims priority to U.S. Provisional Application No. 61/606,212 entitled “Method and Apparatus for Determining RF Parameters Based on Neighboring Access Points” filed Mar. 2, 2012. The present application also claims priority to U.S. Provisional Application No. 62/041,018 entitled “Managing Performance in a Wireless Network Using Backhaul Measurements” filed Aug. 22, 2014. The present application incorporates by reference the aforementioned applications in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61606212 | Mar 2012 | US | |
| 62041018 | Aug 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13779360 | Feb 2013 | US |
| Child | 14829915 | US |
