Mobile satellite beam capacity compensation

Abstract

The described technology relates to improved methods, systems, devices, and apparatuses for supporting mobile satellite beam capacity compensation. Communication services may be provided to a mobile terminal via respective beamformed spot beams that track the mobile terminal's movement. A beam manager may perform resource element allocation for the beam. The beam manager may compensate for link impairments associated with resource elements associated with the beam by modifying one or more characteristics associated with the resource elements. The beam manager may determine the presence of link impairments associated with the resource elements and, based thereon, allocate more power to the associated beam and / or assign the beam to additional resource elements. The beam manager may determine the presence or absence of link impairments and compensate for them during repeated time periods.

Description

[Technical Field]

[0001] The following relates generally to communications involving mobile satellite beam capacity compensation. [Background technology]

[0002] Communication devices may communicate with each other using wired connections, wireless (e.g., radio frequency (RF)) connections, or both. Wireless communication between devices may be performed using a radio spectrum designated for a service provider, a radio technology, or both. In some examples, the amount of information that can be communicated over a wireless communication network is based on the amount of radio spectrum designated for the service provider and the amount of frequency reuse in the area in which the service is provided. Satellite communications may use beamforming to establish beams to increase frequency reuse. However, providing high levels of frequency reuse in satellite communication systems using beamforming presents challenges. Summary of the Invention

[0003] The described technology relates to improved methods, systems, devices, and apparatuses that support mobile satellite beam capacity compensation. For example, communication services may be provided to a mobile terminal via respective beamformed spot beams that track the mobile terminal's movement. A beam manager may perform resource element allocation for the beam. The beam manager may compensate for link impairments associated with resource elements associated with the mobile terminal by modifying one or more characteristics associated with the resource elements. The beam manager may determine the presence of link impairments associated with the resource elements and allocate more power to the associated beams and / or assign beams to additional resource elements based thereon. The beam manager may determine the presence or absence of link impairments and compensate for them during repeated time periods. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 illustrates an example satellite communication system that supports mobile satellite beam capacity compensation, according to examples described herein. [Figure 2A] FIG. 2A illustrates example resources and resource elements for a satellite communications system supporting mobile satellite beam capacity compensation, according to examples described herein. [Figure 2B] FIG. 2B illustrates example resources and resource elements for a satellite communications system supporting mobile satellite beam capacity compensation, according to examples described herein. [Figure 3] FIG. 3 illustrates an example satellite communication system supporting mobile satellite beam capacity compensation according to examples disclosed herein. [Figure 4A] FIG. 4A illustrates various examples illustrating possible link impairments and mitigation strategies to support mobile satellite beam capacity compensation, according to examples disclosed herein. [Figure 4B] FIG. 4B illustrates various examples illustrating possible link impairments and mitigation strategies to support mobile satellite beam capacity compensation, according to examples disclosed herein. [Figure 5A] FIG. 5A illustrates a timing diagram of an exemplary mitigation strategy to support mobile satellite beam capacity compensation, according to examples disclosed herein. [Figure 5B] FIG. 5B illustrates a timing diagram of an exemplary mitigation strategy to support mobile satellite beam capacity compensation, according to examples disclosed herein. [Figure 6] FIG. 6 illustrates a block diagram of a beam manager supporting mobile satellite beam capacity compensation according to examples disclosed herein. [Figure 7] FIG. 7 illustrates a block diagram of a beam compensation manager supporting mobile satellite beam capacity compensation according to examples disclosed herein. [Figure 8] FIG. 8 illustrates a flowchart illustrating a method for supporting mobile satellite beam capacity compensation according to examples disclosed herein. [Figure 9] FIG. 9 illustrates a flowchart illustrating a method for supporting mobile satellite beam capacity compensation according to examples disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0005] Link failures associated with mobile terminals occur periodically and can cause performance degradation and disruption to end users due to packet loss or delay, or changes in beam congestion levels or capacity. In some satellite communication systems, a lower coding rate is implemented when a link failure occurs. This increases redundancy and can reduce the number of interruptions that might otherwise occur. However, redundancy reduces the overall communication speed of the terminal, resulting in performance degradation and inefficiency for the user.

[0006] Techniques are described for compensating (with little or no performance degradation) for link failures associated with resource elements associated with beamformed spot beams to which a moving mobile terminal is assigned. The techniques may enable communication services to be provided to the mobile terminal via each beamformed spot beam that tracks the mobile terminal's movement. A beam manager may compensate for the link failure. In some cases, the beam manager may change one or more characteristics associated with resource elements associated with the spot beam to compensate for the link failure. In some cases, the beam manager may associate additional resource elements with the beam to compensate for link failures associated with mobile terminals assigned to the beam. In some cases, the beam manager may assign additional power to the beam to compensate for the link failure. In some cases, the mobile terminal may switch to a different coverage area with more capacity to compensate for the link failure. The capacity of the beam may be improved by using additional resource elements or additional power, or by switching to a different coverage area. This may allow the beam to handle the link failure while providing users with at least the same level of capacity (e.g., communication speed) as the beam provided before the link failure, thereby reducing or preventing performance degradation during the link failure.

[0007] In some cases, resource element allocation and / or power allocation may be performed by determining when a link failure associated with the mobile terminal exists, determining to increase the power and / or the number of resource elements to associate with a beam associated with the mobile terminal, and based thereon, allocating more power to the beam and / or allocating the spot beam to additional resource elements. In some cases, the presence or absence of a link failure may be determined during repeated time periods.

[0008] The description herein generally refers to a link failure as being "associated" with a resource element. Alternatively, the link failure may be considered to be "associated" with a beamformed spot beam with which the resource element is associated, or with a mobile terminal assigned to the beamformed spot beam. Thus, when a link failure is said to be associated with a resource element herein, the link failure may also be considered to be associated with the beamformed spot beam and / or the mobile terminal associated with the resource element. Similarly, the resource element, the beamformed spot beam, and the mobile terminal may be considered to be associated with the link failure.

[0009] Descriptions herein may refer to resource elements being assigned to beamformed spot beams or beamformed spot beams being assigned to resource elements. As used herein, these terms may be considered interchangeable. That is, resource elements being assigned to beamformed spot beams may be considered the same as beamformed spot beams being assigned to resource elements. Similarly, assigning resource elements to beamformed spot beams may be used interchangeably with assigning beamformed spot beams to resource elements.

[0010] Aspects of the present disclosure are first described in the context of a satellite communication system. Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, block diagrams, and flowcharts related to mobile satellite beam capacity compensation.

[0011] 1 illustrates an example satellite communications system 100 that supports mobile satellite beam capacity compensation according to examples described herein. The satellite communications system 100 may include a terrestrial network 135 and a satellite network 101, which are configured to track and provide communications services to one or more mobile terminals 120.

[0012] The terrestrial network 135 may include a collection of earth stations 170 having access nodes 140 configured to communicate with the satellite network 101 via feeder links 132 (e.g., one or more satellite beams). The access nodes 140 may be coupled to access node transceivers 145. The access node transceivers 145 are configured to process signals to be received from and transmitted through corresponding access node(s) 140. The access node transceivers 145 may also be configured to connect to and function with a network 125 (e.g., the Internet). This may be done, for example, through a network device 130 (e.g., a network operations center, a satellite and gateway terminal command center, or other central processing center or device), which may provide an interface for communicating with the network 125.

[0013] The terrestrial network may also include a beam manager 175. The beam manager 175 is for controlling tracking of mobile terminals as communication services are provided to the mobile terminals via beamformed spot beams, adjusting resource elements used by the beams, and compensating for link impairments of the mobile terminals, as described herein. To perform the control, adjustment, and compensation, the beam manager 175 may obtain information (e.g., associated with the satellite network 101 and the terminals 120) from the satellite network 101 (e.g., via the feeder links 132 and the access nodes 140) and, in response, may send commands (e.g., to the satellite network 101 and / or the terminals 120) (e.g., via the access nodes and the feeder links).

[0014] In some examples, the beam manager 175 may be a single device. Alternatively, the beam manager 175 may be distributed throughout the system, for example, across two or more elements of the satellite network and / or the terrestrial network. For example, the beam manager 175 may be incorporated into one or more devices of the terrestrial network (e.g., network device 130 or access node transceiver 145), or one or more devices of the satellite network (e.g., within a single satellite 105 or distributed among multiple satellites), or a combination of devices in the terrestrial and satellite networks. In some examples, a first portion of the beam manager 175 may be located in the terrestrial network 135 and a second portion may be located in the satellite network 101.

[0015] In some examples, the beam manager 175 may determine when a link failure associated with a mobile terminal exists, determine to increase the power and / or number of resource elements to associate with a beam associated with the mobile terminal to compensate for the link failure, and then increase the power and / or number of resource elements associated with the beam. In some examples, the beam manager may determine when a link failure exists by determining the presence or absence of a link failure during repeated time periods.

[0016] Terminal 120 may include various devices configured to communicate signals with satellite network 101. While terminal 120 is illustrated on an aircraft, terminal 120 may include a fixed terminal (e.g., a ground-based stationary terminal), or a mobile terminal mounted on a moving platform (e.g., a watercraft, aircraft, ground-based vehicle, etc.), or a combination of fixed and mobile terminals. Terminal 120 may communicate data and information with access node 140 via satellite network 101. The data and information may be communicated to a destination device (e.g., network device 130) or some other device or distributed server associated with network 125.

[0017] Various physical layer transmission modulation and coding techniques may be used by access nodes 140, and terminals 120, and components (eg, satellites) of satellite network 101 for communication of signals.

[0018] The satellite network 101 may include one or more satellites 105 (e.g., a single satellite 105 or a network of satellites) deployed in space orbit (e.g., low Earth orbit, medium Earth orbit, geosynchronous orbit, geostationary orbit, etc.). Each satellite 105 included in the satellite network 101 may include one or more antennas (e.g., a single antenna or an antenna array). In some examples, one or more satellites 105 with multiple antennas may each include one or more antenna panels including an array of evenly distributed antennas (which may also be referred to as antenna elements). In some examples, a satellite may include an antenna array including antennas unevenly distributed over a wide area. The ground network 135 may also include an access node 140 with multiple antenna array elements.

[0019] The terminal 120 may include an antenna assembly, which may also include various hardware for mounting the antenna. The antenna assembly may also include circuitry and / or a processor for converting between radio frequency (RF) satellite communication signals and satellite terminal communication signals transmitted between the antenna and the satellite terminal receiver (e.g., performing frequency conversion, modulation / demodulation, multiplexing / demultiplexing, filtering, forwarding, etc.). In the case of a mobile terminal, the antenna assembly may be mounted on the exterior of the mobile platform (e.g., the exterior of the fuselage of an aircraft). Additionally or alternatively, the terminal 120 may include a transceiver. The transceiver may be mounted inside or outside the mobile platform and may include circuitry and / or a processor for performing various RF signal operations (e.g., receiving, performing frequency conversion, modulation / demodulation, multiplexing / demultiplexing, etc.).

[0020] The satellite network 101 may have a large aperture size that can be widened by the antenna array or multiple satellites of the satellite network 101. The beam manager 175 may support beamforming techniques within the satellite communication system coverage area 155 using one or more satellites to enhance utilization of resources used for communication. The beam manager 175 may use beamforming (including the use of multiple-input multiple-output (MIMO) techniques) to take advantage of multipath signal propagation and improve spectral efficiency by transmitting and receiving multiple signals via different spatial layers on the same frequency resource. The beam manager 175 may transmit multiple signals by a transmitting device (e.g., satellite 105) via a set of antennas according to a set of weighting coefficients. Similarly, multiple signals may be received by a receiving device (e.g., satellite terminal 120) via a set of antennas according to a set of weighting coefficients. Each of the multiple signals may be associated with a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords).

[0021] In some examples, some or all of the antenna elements on the satellite 105, the terrestrial network 135, and / or the terminal 120 may be arranged as an array of constituent receive and / or transmit feed elements that cooperate to enable various examples of on-board beamforming (OBBF), terrestrial beamforming (GBBF), end-to-end beamforming, or other types of beamforming. In a GBBF implementation, there may be multiple transmit or receive antennas on the terrestrial network access node(s).

[0022] The beam manager 175 may determine weighting factors to apply to the set of antennas. For example, when forming N spatial layers, the beam manager 175 may utilize an (MxN) MIMO matrix, where M may represent the number of antennas in the set of antennas. In some examples, M may be equal to N. The beam manager 175 may determine the MIMO matrix based on the channel matrix and may use the MIMO matrix to separate different spatial layers of the channel. In some examples, the beam manager 175 may select weighting factors to emphasize signals transmitted using different spatial layers while reducing interference of signals transmitted on other spatial layers. Thus, processing signals received at each antenna of the set of antennas (e.g., signals received at the set of antennas) using the MIMO matrix may result in multiple signals being output, each of the multiple signals may correspond to one of the spatial layers. In some examples, the weighting factors used for MIMO communication may be referred to as beam coefficients or beamforming coefficients, and the multiple spatial layers may be referred to as beams or spot beams.

[0023] The beam manager 175 may determine elements of the MIMO matrix to use to form the spatial layers of the channel based on the channel sounding probe. The channel sounding probe may include a reference signal periodically transmitted between the satellite network 101 and a device (e.g., terminal 120) coupled to the satellite network. For example, the channel sounding probe may be periodically transmitted from the terminal 120 to the satellite 105, or from the satellite to the terminal, or both, and may include a sequence known to the transmitter and receiver (e.g., based on a terminal identifier or other parameter known to the transmitter and receiver). A receiving device (e.g., terminal or satellite) may use the received channel sounding probe to evaluate the connection (e.g., to determine signal strength, interference, etc.) by correlating the received channel sounding probe with a signal expected for the channel sounding probe and make a decision based thereon. The periodicity of the signal may allow the receiving device to know when to receive the signal.

[0024] The beam manager 175 may use beamforming techniques to shape or direct communication beams along spatial paths between one or more satellites and the mobile terminals 120 within a geographic region. The beam manager 175 may form communication beams by determining weighting coefficients for the antenna elements of the antenna array that will combine signals transmitted from or received at the antenna elements so that signals propagating in certain directions relative to the antenna array are subject to constructive interference, while other signals are subject to destructive interference. Thus, beamforming may be used to transmit signals with focused energy in the direction of the communication beam and to receive signals that arrive in the direction of the communication beam with increased signal power (compared to without beamforming). The beam manager 175 may use the weighting coefficients to apply amplitude offsets, phase offsets, or both to signals carried through the antennas.

[0025] In some examples, the beam manager 175 may apply weighting coefficients to the antennas to form multiple beams, each associated with a different direction, and may use the multiple beams to simultaneously communicate multiple signals having the same frequency to different user terminals. This may be referred to as multi-user MIMO. The weighting coefficients used for beamforming may be referred to as beam coefficients, and the multiple signals may be referred to as beam signals. The resulting beam may be referred to herein as a beamformed spot beam, spot beam, or beam.

[0026] The beam manager 175 may calculate the amplitude and phase of each weighting coefficient taking into account the geometry and location of the antenna array and reflector and the desired beam location. However, such an approach may be impractical due to inaccuracies (e.g., satellite location, array orientation, geometry, atmospheric scintillation effects, etc.). Instead, the beam manager 175 may calculate the weighting coefficients using continuous or periodic measurements of MIMO propagation channel characteristics (e.g., pairwise channels from each system antenna element to each terminal antenna element) and adjust the weighting coefficients based on changing channel characteristics. The measured MIMO channel characteristics may include pairwise gain and phase responses and noise levels, sometimes referred to as MIMO channel state information (CSI). Once the MIMO CSI is available, the beam manager 175 may derive the weighting coefficients by solving a series of equations or applying a series of adaptive formulas. Various beamformer computation and adaptation techniques may be used (e.g., least mean squares (MMSE) beamformer, zero forcing beamformer, MIMO sphere decoder, etc.).

[0027] The measured MIMO CSI may involve the association of at least one terminal for each beam. The situation may differ in the forward link direction (from the satellite to the terminal) versus the return link direction (from the terminal to the satellite). In the return link, each terminal may transmit a channel probing signal that may be orthogonal to the probing signals of other terminals. The satellite may determine which channel probing signal was transmitted from each terminal and process the signal to estimate the channel parameters of the channel corresponding to that terminal. In this way, the MIMO CSI on the return link may be calculated locally at the satellite for the terminal transmitting the channel probing signal. In contrast, on the forward link, the satellite may transmit channel probing signals. Different antenna elements may transmit signals that are orthogonal to each other. Each terminal tasked with calculating the MIMO CSI may do so by processing the probing signals corresponding to each transmitting antenna element. Furthermore, each such terminal may transmit the MIMO CSI back to the satellite using a return link control channel.

[0028] The spot beams thus generated may be tailored to the MIMO CSI provided by the user terminals, with each beam illuminating the direction of each such terminal. Each beam has a finite coverage area 160 (e.g., a diameter of several kilometers) and may therefore illuminate additional terminals that may be in the vicinity of the CSI-generating terminal. These additional terminals may not provide CSI because this may unnecessarily increase CSI reporting channel overhead. The terminal used to provide MIMO CSI for each beam may be considered a reference terminal for that beam. The reference terminal may be a mobile terminal. In some examples, the coverage area 160 of a beam may be determined based on the wavelength of the carrier and the diameter of the aperture. The coverage area 160 may correspond, for example, to a footprint where the power level of the beam exceeds a threshold or where the power level drops off away from the center of the beam by less than a threshold amount (e.g., 3 decibels (dB) or 6 dB). In some examples, the coverage area 160 may be based on the beamwidth of the beam.

[0029] In some examples, one or more aircraft-based terminals 120 may be sufficiently distant from each other and from other aircraft that beam manager 175 may use a separate beam for each of the one or more terminals. In some examples, two or more of terminals 120 may be in close proximity (e.g., at an airport) such that beam manager 175 may illuminate the terminals with the same beam. In the former case, each terminal on the aircraft may be a reference terminal for that beam, and in the latter case, one of the multiple terminals on the aircraft may serve as a reference terminal for the beam.

[0030] As the mobile terminal 120 moves through the airspace, the MIMO CSI changes and the beam direction may change. The beam manager 175 may adjust the beam direction based on the changed MIMO CSI so that the reference terminal may remain at or near the center of the beam. Thus, as the reference terminal moves, the beam may track its movement, as described further herein.

[0031] The beam manager 175 may associate the beamformed spot beam with a set of resources of the satellite communication system 100. The set of resources may include, for example, frequency resources, time resources, and polarization resources. For example, a predetermined frequency range for the satellite communication system 100 may include frequency resources or channels, and a predetermined time may include different recurring time slots. For example, the beam manager 175 may use a frequency channel to carry a signal (e.g., a modulated signal carried in the beamformed spot beam) on one of the recurring time slots. By doing so, the beamformed spot beams may spatially overlap without interference if they are associated with different frequency / time resource combinations. Additionally, the beam manager 175 may use multiple polarizations so that two beamformed spot beams may spatially overlap without interference if they are associated with different polarizations.

[0032] In this manner, beamformed spot beams may spatially overlap without interference if they are associated with different combinations of resources (e.g., different frequency channel / time slot / polarization combinations). The different combinations may be known as resource elements, which together form a set of resource elements that the beam manager 175 may use to communicate signals via the beam. The beam manager 175 may control the association of beams with resource elements, as described herein, and may determine when to assign a beam to one or more of the resource elements. The beam manager 175 may also control the amount of power to allocate to each beam and when to adjust the power for each beam, as described herein.

[0033] The beam manager 175 may adjust the individual coverage areas or footprints of the beamformed spot beams (e.g., by adjusting weighting coefficients) to track (e.g., move with) the respective mobile terminals. As described herein, when the beamformed spot beams track the mobile terminals, the beam manager 175 may compensate for link failures by modifying one or more characteristics associated with the resource elements associated with the spot beams. For example, if a link failure associated with the mobile terminal occurs, the beam manager 175 may allocate the spot beam associated with the mobile terminal to additional resource elements or allocate more power to the spot beam. Alternatively, the beam manager 175 may switch the mobile terminal to a different coverage area. Modifying one or more characteristics may improve the beam's capacity, allowing the beam to handle the link failure while providing users with at least the same level of capacity (e.g., communication speed) as the beam provided before the link failure. This may compensate for (e.g., reduce or prevent) performance degradation and communication interruptions that may occur during a link failure, and may enable communication services associated with the mobile terminal to continue at a high level despite the link failure as the mobile terminal moves through the coverage area of ​​the satellite communication system.

[0034] 2A illustrates example resources 200 for a satellite communications system supporting mobile satellite beam capacity compensation, according to examples described herein. Resources 200 may correspond to a frequency division of the satellite communications system. For example, frequency range 205 (e.g., a frequency band) may include a set of different frequency resources or frequency channels 210 (e.g., frequency channel 210-a, frequency channel 210-b, frequency channel 210-c, frequency channel 210-d) that carry signals between the satellite network and terminals. Resources 200 may correspond to frequency channels 210 in frequency range 205.

[0035] Each frequency channel 210 carries a signal associated with a single terminal (e.g., at a time). For example, each frequency channel 210 may carry a single modulated signal. Information (e.g., data, control information) may be modulated onto the modulated signal using various single-carrier or multi-carrier modulation techniques (e.g., orthogonal frequency division multiplexing (OFDM), direct sequence spread spectrum (DSSS), linear pre-coded OFDM (LP-OFDM)). A beamformed spot beam may be associated with one or more frequency channels 210 (e.g., by the beam manager 175) to provide communication to and track mobile terminals, as described herein.

[0036] 2A, resources 200 may correspond to frequency channels 210. That is, each frequency channel 210 may be a separate resource 200. In some examples, separate resources may also be resource elements due to the lack of other types of resources. Thus, in this example, the number of available resource elements may correspond to the number N of frequency channels.

[0037] 2B illustrates an example resource element 250 for a satellite communications system supporting mobile satellite beam capacity compensation, according to examples described herein. In this example, frequency channels 210 may again be used to carry signals associated with terminals. Additionally, frequency channels 210 may be time multiplexed. That is, each frequency channel 210 may be configured to carry signals to terminals in time slots that repeat after a certain period of time. For example, time period 215 may be divided into a set of sub-periods or time slots t, each having a length 225 (e.g., time slot t1, time slot t2, time slot t3, time slot t4, time slot t5, time slot t6, time slot t7, time slot t8, time slot t9, time slot t10, time slot t11, time slot t12, time slot t13, time slot t14, time slot t15, time slot t16, time slot t17, time slot t18, time slot t19, time slot t20, time slot t21, time slot t22, time slot t23, time slot t24, time slot t25, time slot t26, time slot t27, time slot t28, time slot t29, time slot t30, time slot t31, time slot t32, time slot t33, time slot t34, time slot t35, time slot t36, time slot t37, time slot t38, time slot t39, time slot t40, time slot t41, time slot t42, time slot t43, time slot t44, time slot t45, time slot t46, time slot t47, time slot t48, time slot t49, time slot t50, time slot t51, time slot t52, time slot t53, time slot t54, time m) Each frequency channel 210 may carry a signal to a different terminal during each time slot t, or in some cases, multiple time slots within time period 215 may be assigned to the same terminal. For example, each frequency channel 210 may carry a single modulated signal during each time slot t. Information (e.g., data, control information) may be modulated onto the modulated signal using various single-carrier or multi-carrier modulation techniques (e.g., OFDM, DSSS, LP-OFDM) as described herein to provide communications to and track mobile terminals (e.g., by the beam manager 175).

[0038] Once the time period 215 ends, the process may be repeated such that each frequency channel 210 may further carry signals associated with different terminals within the resource period. As a result, the beam manager 175 may use the frequency channel 210 to communicate with the terminal during one time slot t per time period 215. In some examples, the beam manager 175 may assign a terminal to multiple time slots per time period, such that communication with the terminal may occur over multiple time slots per time period for the frequency channel 210.

[0039] In the example of Figure 2B, resource elements 250 may correspond to a combination of frequency channel 210 and time slot t in time period 215. That is, each unique combination of frequency channel 210 and time slot t may be a separate resource element 250. Thus, in this example, the number of available resource elements may correspond to the number of frequency channels times the number of time slots (or N x m). Thus, this example may provide more resource elements than the example of Figure 2A.

[0040] In addition to being multiplexed in time or frequency, different polarizations may be used to define the resource elements to be assigned to the beamformed spot beam. For example, a set of resource elements may include a first subset of resource elements associated with a first polarization and a second subset of resource elements associated with a second, orthogonal polarization. The first and second polarizations may be orthogonal and may be linear or circular (e.g., right-hand circular polarization (RHCP) or left-hand circular polarization (LHCP)). Thus, the set of resource elements available to the beam manager 175 for assignment to the beamformed spot beam may be defined according to frequency resources (e.g., frequency channels), time resources (e.g., subperiods of a resource period), or polarization resources.

[0041] In some examples, resource element types may be combined. For example, in the same system, one or more frequency channels may be divided into time slots (e.g., as in FIG. 2B), while one or more other frequency channels may be used as separate resource elements without division (e.g., as in FIG. 2A). Other combinations are possible.

[0042] FIG. 3 illustrates an example satellite communications system 300 supporting mobile satellite beam capacity compensation according to examples disclosed herein. The satellite communications system 300 may be an example of the satellite communications system 100 described with reference to FIG. 1 or an embodiment thereof. The satellite communications system 300 may include a satellite network 101 having one or more satellites 105. The one or more satellites 105 are configured to generate beamformed spot beams 150 (e.g., beam 150-a) for communicating with a set of terminals 120 (e.g., terminals 120-a, 120-b, 120-c, 120-d) within a coverage area 155 of the satellite communications system, as directed by a beam manager 175. The beamformed spot beams may be referred to herein as spot beams or beams.

[0043] Terminals 120 may be considered mobile terminals 120 because they may be located on movable platforms or vehicles (e.g., automobiles, ships, or aircraft). In some examples, each vehicle may include a single mobile terminal. In other examples, one or more vehicles may each include two or more mobile terminals. At least some of the mobile terminals 120 may be multi-user mobile terminals, and thus, satellite communications system 300 may provide communication services to multiple user devices (e.g., smartphones, laptops, tablets) connected via mobile terminals 120.

[0044] In some examples, the satellite communication system 300 may provide communication services to a mobile terminal 120 via a set of movable beamformed spot beams 150. The set of movable beamformed spot beams 150 is controlled by a beam manager 175 to track the mobile terminal as it moves. For clarity, only a single movable beamformed spot beam 150-a associated with a single mobile terminal 120-a is shown in FIG. 3. Although not shown in FIG. 3, the movable beamformed spot beam 150 may also be associated with one or more of the other mobile terminals 120.

[0045] In some examples, the beam manager 175 may associate each beamformed spot beam 150 with a different mobile terminal 120. Each mobile terminal 120 associated with its spot beam may also be considered a reference terminal. Each spot beam 150 may have a respective coverage area 160 (e.g., coverage areas 160-a, 160-b, 160-c, 160-d). A coverage area may correspond, for example, to a footprint where the power level of the beam exceeds a threshold or where the drop in power level away from the center of the beam is less than a threshold amount (e.g., 3 dB or 6 dB).

[0046] In some examples, a beamformed spot beam associated with a reference terminal may be formed (e.g., controlled by beam manager 175) to include the terminal's physical location within the beamformed spot beam's coverage area. For example, as shown in FIG. 3, mobile terminal 120-a (acting as the reference terminal) may be physically located within coverage area 160-a of beamformed spot beam 150-a, and mobile terminals 120-b, 120-c, and 120-d may be physically located within coverage areas 160-b, 160-c, and 160-d of respective beamformed spot beams (not shown). Satellite communications system 300 may provide communications services to mobile terminal 120-a (e.g., via beam manager 175) via beamformed spot beam 150-a.

[0047] In some examples, the beam manager 175 may cause the beamformed spot beam to track a moving mobile terminal while communication services are provided to the terminal via the beam. For example, as the mobile terminal 120-a physically moves from location A to location B (indicated by arrow 325), the beamformed spot beam 150-a may “move” to track the mobile terminal (indicated by arrow 330). In some examples, to “move” the beamformed spot beam, the beam manager 175 may change and apply beamforming coefficients associated with the beamformed spot beam to the signal associated with the beamformed spot beam. This may change the directionality of the beamformed spot beam (e.g., “move” the beam), resulting in a change (e.g., “move”) in the coverage area of ​​the beamformed spot beam.

[0048] To follow or track a mobile terminal, beamforming coefficients may be changed by beam manager 175 such that the coverage area of ​​the beamformed spot beam may move to reflect the movement of the mobile terminal (e.g., move with the mobile terminal). Beam manager 175 may continually adjust the coverage area (e.g., by periodically changing beamforming coefficients to provide continuous coverage) to continue to accommodate the moving physical location of the moving mobile terminal, thereby tracking the mobile terminal. For example, beam manager 175 may move coverage area 160-a of beamformed spot beam 150-a (e.g., from coverage area 160-a1 to coverage area 160-a2) to encompass the physical location of mobile terminal 120-a as mobile terminal 120-a moves from location A to location B. This may allow communication services associated with the mobile terminal to be provided via the same beamformed spot beam as the mobile terminal moves through the coverage area of ​​the satellite communication system. For example, the beam manager 175 may provide continuous communication service to the mobile terminal 120-a via the beamformed spot beam 150-a without handoff when the mobile terminal moves between location A and location B.

[0049] In some examples, the beam manager 175 may stop changing the beamforming coefficients associated with a mobile terminal while the mobile terminal is stationary because the coverage area of ​​the beamformed spot beam may already correspond to the physical location of the stationary terminal. In other examples, the beam manager 175 may change the beamforming coefficients even when the mobile terminal is stationary. For example, in some systems, there may be a set of beamforming coefficients that can generate all of the beams from all of the beam signals. In such cases, the beam manager 175 may change the beamforming coefficients used for all terminals even if only one terminal moves.

[0050] In some examples, to track the mobile terminal, the beam manager 175 may adjust the coverage area of ​​the spot beam (e.g., move the spot beam) based on measurements of signals communicated with the mobile terminal. In some examples, the terminal may regularly and periodically return channel state information to the satellite network, and the beam manager 175 may process this channel state information to calculate appropriate beamforming coefficients so that the beam energy for the beam signal associated with the aircraft is focused on that aircraft. As the aircraft moves, the channel state information may change, and in turn, the beam weighting coefficients calculated by the beam manager 175 may change. Through this beamformer adaptation process, the beam center may be continuously positioned at the same location as the aircraft (following the aircraft).

[0051] Instead, the beam manager 175 may use an initial estimate of where to move the beam based on the mobile terminal's most recent speed and heading. In some examples, the beam manager 175 may move the spot beam so that the mobile terminal remains centered within the coverage area as the mobile terminal moves. This may allow the SNR of the mobile terminal to remain high, and may also increase the overall communication speed and spectral efficiency associated with the mobile terminal.

[0052] In some examples, the beam manager 175 may determine the location of the mobile terminal based on information received from the mobile terminal (e.g., location coordinates (e.g., determined via a positioning system such as GPS), speed, direction, or other information associated with the mobile terminal). In some examples, the beam manager 175 may determine the location of the mobile terminal based on information external to the mobile terminal (e.g., based on radar or other signals).

[0053] In some examples, the satellite communication system may provide communication services to one or more mobile terminals via beamformed spot beams associated with the terminals. For example, in FIG. 3, the beam manager 175 may establish beamformed spot beams 150 (e.g., beamformed spot beams 150-a, 150-b, 150-c, and 150-d) for each of the mobile terminals 120-a, 120-b, 120-c, and 120-d to provide communication services to the terminals and track the mobile terminals as they move within the coverage area 155 of the satellite communication system.

[0054] In some examples, the beam manager 175 may use initial channel state information to determine the locations of the mobile terminals. The beam manager 175 may determine the initial channel state information based on measurements (e.g., signal strength) of initial signals communicated with (e.g., transmitted to and received from) the mobile terminals. The initial channel state information may be based on a first location (e.g., location A for mobile terminal 120-a) of each of the mobile terminals within the coverage area 155. In some examples, the initial signals may include each initial channel sounding probe communicated with the mobile terminal.

[0055] In some examples, to generate beamformed spot beams, the beam manager 175 may apply beamforming coefficients to convert between beam signals associated with each of the beamformed spot beams and component signals associated with multiple antenna elements of the satellite communications system. For example, to generate spot beams for transmitting information to a mobile terminal, the beam manager 175 may apply beamforming coefficients to the beam signals (including the information) to obtain component signals that can be applied to the antenna elements, and to generate spot beams for receiving information from a mobile terminal, the beam manager 175 may apply beamforming coefficients to component signals received from the mobile terminal at the antenna elements to obtain beam signals including the information. The beam manager may also determine power levels to assign to the spot beams. Generally, beams with higher power levels may have greater capabilities (e.g., data rates).

[0056] The multiple antenna elements may be located on one or more of the satellites 105 or may be located on components of a terrestrial network (not shown) of the satellite communications system 300 (e.g., access node 140 of terrestrial network 135 as shown in FIG. 1 ). The beam manager 175 may use the beamforming coefficients to form a beamformed spot beam 150 between the satellite 105 and the coverage area 160. The beam manager 175 may base the beamforming coefficients on initial channel state information such that the coverage area 160 of the beam 150 may encompass a first location (e.g., location A) of each of the associated terminals 120.

[0057] The beamformed spot beam 150 may be a forward link beamformed spot beam (e.g., for transmitting information to a mobile terminal) and / or a return link beamformed spot beam (e.g., for receiving information from a mobile terminal). For example, the beamforming coefficients may include multiple sets of forward link beamforming coefficients and multiple sets of return link beamforming coefficients.

[0058] Beam manager 175 may apply the first set of forward link beamforming coefficients to the set of forward link beam signals at a first time to generate a first set of forward link component signals for transmission to one or more mobile terminals via the antenna elements at the first time. Transmitting the first set of forward link component signals to the mobile terminals via the antenna elements may form forward link beamformed spot beams (each corresponding to one of the mobile terminals for the first time).

[0059] Beam manager 175 may apply the second set of forward link beamforming coefficients to the set of forward link beam signals at the second time to generate a second set of forward link component signals for transmission to the mobile terminal via the antenna elements at the second time. By transmitting the second set of forward link component signals to the mobile terminal via the antenna elements, forward link beamformed spot beams (each corresponding to a mobile terminal for the second time) may be formed. One or more of the forward link beamformed spot beams at the second time may have moved from the corresponding forward link beamformed spot beam at the first time to track movement of the corresponding mobile terminal.

[0060] On the return link, the beam manager 175 may apply a first set of return link beamforming coefficients at a first time to the return link component signals received from the mobile terminals via the antenna elements at a first time. By applying the first set of return link beamforming coefficients, return link beamformed sport beams (each corresponding to one of the mobile terminals for the first time) may be formed.

[0061] The beam manager 175 may apply a second set of return link beamforming coefficients at a second time to the return link component signals received from the mobile terminal via the plurality of antenna elements at a second time. Applying the second set of return link beamforming coefficients may form return link beamformed spot beams for the second time. One or more of the return link beamformed spot beams at the second time may have moved from the corresponding return link beamformed spot beam at the first time to track movement of the corresponding mobile terminal.

[0062] In some examples, the beam manager 175 may use the subsequent channel state information to determine the subsequent location of the mobile terminal. The beam manager 175 may determine the subsequent channel state information based on measurements (e.g., signal strength) of subsequent signals communicated with the mobile terminal. The subsequent channel state information may be based on a second location (e.g., location B relative to mobile terminal 120-a) of each of the mobile terminals within the coverage area 155. The difference between the initial channel state information and the subsequent channel state information may be based on movement of the mobile terminal to the respective second location.

[0063] In some examples, the subsequent signal may include each subsequent channel sounding probe communicated with the mobile terminal. The modifications made to the beamforming coefficients may be based on each subsequent channel sounding probe. In some examples, each initial and subsequent channel sounding probe may be communicated with the mobile terminal at a first periodicity, and the beamforming coefficients may be updated at a second periodicity based thereon.

[0064] In some examples, the beam manager 175 may modify the beamforming coefficients and apply them to convert between the beam signals and component signals associated with multiple antenna elements of the satellite network. The modified beamforming coefficients may be based on subsequent channel state information so that a new coverage area of ​​the beam (e.g., coverage area 160-a2) may encompass a second location (e.g., location B) of each of the mobile terminals.

[0065] The determination of the mobile terminal's subsequent location and the modification of the beamforming coefficients based thereon may be repeated as frequently and for as long as desired by the beam manager 175. In this manner, the multiple beamformed spot beams 150 may track the movement of the reference terminal 120 throughout the coverage area 155 of the satellite communication system while communication services are provided to the terminal.

[0066] In some examples, the beamforming coefficients (e.g., initial beamforming coefficients and modified beamforming coefficients) may include sets of beamforming coefficients. Each set of beamforming coefficients may correspond to a different time period for the set of beamformed spot beams. In some examples, the beamforming coefficients may be modified based on a characteristic, attribute, or condition that satisfies (e.g., meets, exceeds, and / or falls below) a threshold. For example, the beam manager 175 may modify and apply the beamforming coefficients based on the received signal quality (e.g., measured at the mobile terminal or the satellite communication system) falling below a threshold (e.g., due to a link impairment associated with the mobile terminal). For example, the beamforming coefficients may be modified such that the power for the beams may be increased. This may allow the signal quality associated with the mobile terminal to remain high, which may result in higher overall communication speeds and efficiency associated with the mobile terminal. In some examples, the beam manager 175 may determine the received signal quality based on subsequent channel state information.

[0067] In some examples, two or more beams may use different resource elements to provide communication services to each mobile terminal. For example, the beam manager 175 may cause each beam to use different resource elements (e.g., different combinations of frequency channels, time slots, and polarizations) to provide communication to each mobile terminal while tracking the mobile terminal. By using different resource elements, interference between beams may be reduced or eliminated even when mobile terminals may be close to each other.

[0068] In some examples, two or more beams may use the same resource elements to provide communication services to each mobile terminal. For example, the beam manager 175 may cause two or more beams to use the same combination of frequency channel, time slot, and polarization to provide communication to each mobile terminal while tracking the mobile terminal. This may be desirable when the mobile terminals are far enough apart so that the respective beams do not interfere with each other. Using the same resource elements increases frequency reuse because more beams may be used with a particular set of resources.

[0069] 4A and 4B illustrate various examples 410 (e.g., examples 410-a through 410-f) illustrating possible link impairments and mitigation strategies supporting mobile satellite beam capacity compensation, according to examples disclosed herein. In each example 410, each mobile terminal 120 is assigned to its own beam 150. Furthermore, for each example 410 affected by a link impairment (examples 410-b, 410-c, 410-d, and 410-f), the example is shown after mitigation has been performed to compensate for the link impairment, as described herein. That is, the example is shown after the beam manager 175 has performed compensation to ameliorate the interference.

[0070] For ease of explanation, for all of the mobile terminals 120 in example 410, the spot beams associated with the mobile terminals each use a single resource element at a power equal to 1 to provide communication to the respective mobile terminal if the mobile terminals were not faulty. Thus, for example, 410-a and 410-e (corresponding to examples where no link failures associated with the corresponding mobile terminals 120-a and 120-e were detected) are shown with the number of resource elements and the power both equal to 1. Furthermore, if multiple coverage areas are available, each spot beam is assigned to a first coverage area.

[0071] Some link failures may be static. For purposes of this application, a static link failure refers to a link failure that may be known in advance without receiving current failure information from a mobile terminal or an associated spot beam. Examples 410-b, 410-c, and 410-d in FIG. 4A illustrate examples of static link failures.

[0072] An example of a static link failure may include a failure resulting from a type of mobile terminal. Example 410-d corresponds to this type of link failure. In some examples, the type of mobile terminal may be based on characteristics of an antenna corresponding to the mobile terminal. In some examples, the type of mobile terminal may be based on performance of a receiver corresponding to the mobile terminal.

[0073] In some examples, the type of mobile terminal may be based on different capabilities for the terminal's equipment (e.g., antennas, high-power amplifiers, and / or low-noise amplifiers). In some examples, the type of mobile terminal may be based on information from previous communication sessions. For example, the type of mobile terminal may be based on channel performance indicators (e.g., those described herein) associated with the mobile terminal and determined from one or more previous communication sessions. In another example, the type of mobile terminal may be based on past satellite calibration measurements associated with the mobile terminal or an associated spot beam and / or satellite performance.

[0074] Another example of a static link failure may include a failure resulting from a mobile terminal being a disadvantaged mobile terminal. Example 410-b corresponds to this type of link failure. A disadvantaged mobile terminal may be a mobile terminal known to have a slow speed associated with transmitting and / or receiving signals via an associated spot beam. This may be because the mobile terminal has a smaller antenna, a worse noise figure, or problems with the antenna or any other part of the communication link, resulting in a link failure, than other mobile terminals. There may be overlap between disadvantaged terminals and types of terminals. That is, a disadvantaged terminal may also be considered a particular type of terminal.

[0075] The beam manager 175 may determine the presence of many types of static link impairments based on known information associated with the mobile terminal. For example, the beam manager 175 may determine the presence of an impairment associated with a mobile terminal based on the mobile terminal being disadvantaged or of a known particular type.

[0076] Another example of a static link failure may include a failure resulting from the location of the mobile terminal. Example 410-c corresponds to this type of link failure. This qualifies as a static link failure because the location of the mobile terminal can be determined without receiving failure information from the mobile terminal. In one example, the failure may occur as a result of the mobile terminal approaching the edge of the coverage area of ​​a satellite communications system (e.g., a high scan angle for a phased array antenna). In another example, a reflector associated with the mobile terminal may be associated with a phased array, and the failure may occur as a result of the mobile terminal approaching the edge of the coverage region corresponding to the reflector. Other examples of static link failure may also be found.

[0077] The beam manager 175 may determine the presence of these types of static link failures based on the location of the mobile terminal. For example, the beam manager 175 may determine the presence of a failure associated with the mobile terminal based on the mobile terminal approaching the edge of a coverage area of ​​a satellite communications system or the edge of a coverage region associated with the mobile terminal.

[0078] In some examples, to determine the presence of a link failure based on the mobile terminal approaching an edge of the coverage area of ​​the satellite communications system or an edge of a coverage region associated with the mobile terminal, the beam manager 175 may determine that the mobile terminal is within a threshold distance of the edge of the coverage area of ​​the satellite communications system or an edge of a coverage region associated with the mobile terminal. In some examples, the threshold distance may be based on a scan angle of one or more spot beams from the center of the coverage area of ​​the satellite communications system or the center of the coverage region associated with the mobile terminal.

[0079] Some link failures may be dynamic. For purposes of this application, a dynamic link failure refers to a link failure that is not known in advance. Failure information is received from a mobile terminal or an associated spot beam and used to determine when a link failure exists. Example 410-f in Figure 4B illustrates an example of a dynamic link failure.

[0080] An example of a dynamic link failure may include a failure resulting from rain attenuation. Example 410-f corresponds to this type of link failure. Rain attenuation may refer to a failure caused by rain (or other weather phenomena) between a mobile terminal and its associated spot beam. Other examples of dynamic link failure may also be found.

[0081] The beam manager 175 may determine the presence of a dynamic link failure based on failure information received from the mobile terminal or the associated spot beam. For example, the beam manager 175 may determine the presence of a dynamic link failure associated with the mobile terminal based on one or more channel performance indicators associated with the mobile terminal. In some examples, the channel performance indicators may include one or more of a channel gain, a receiver gain, a noise level, an interference level (e.g., a signal-to-interference-and-noise ratio (SINR)), etc. associated with the mobile terminal.

[0082] In some examples, the beam manager 175 may receive a channel performance indicator and determine the presence of a failure if the channel performance indicator meets a threshold. For example, as shown in FIG. 4B, the beam manager 175 may receive a channel performance indicator (e.g., SINR) associated with one or more mobile terminals (e.g., mobile terminals 120-e, 120-f) and compare the channel performance indicator with a threshold (e.g., threshold SINR). To initiate this, the beam manager 175 may cause the mobile terminals to transmit their respective channel performance indicators to the beam manager 175. The beam manager 175 may determine the presence of a link failure if the channel performance indicator associated with the mobile terminal meets the threshold. For example, in the example of FIG. 4B, the beam manager 175 may receive a high SINR from the mobile terminal 120-e associated with the beamformed spot beam 150-e and a low SINR from the mobile terminal 120-f associated with the beamformed sport beam 150-f. If the threshold SINR is between the low SINR and the high SINR, the beam manager 175 may determine that a link failure associated with mobile terminal 120-f exists and that a link failure associated with mobile terminal 120-e does not exist.

[0083] Action may be taken to mitigate or compensate for the link impairment. For example, upon determining the existence of a link impairment associated with one or more mobile terminals, the beam manager 175 may modify the characteristics associated with the resource elements associated with the mobile terminals.

[0084] In some examples, mitigating or compensating for a link impairment may include assigning additional resource elements to the beamformed spot beam. For example, the beam manager 175 may assign additional resource elements (e.g., additional unique combinations of time slots, frequency channels, and polarizations) to a beam associated with a mobile terminal associated with the link impairment. Example 410-b illustrates an example in which the beam manager 175 assigns a second resource element to the spot beam 150-b to compensate for a link impairment associated with the mobile terminal 120-b.

[0085] In some examples, mitigating or compensating for a link impairment may include increasing the power allocated to a resource element by increasing the power for a beamformed spot beam. For example, the beam manager 175 may increase the power for a beam associated with a mobile terminal having a link impairment. Example 410-c illustrates an example in which the beam manager 175 has increased the power for spot beam 150-c to compensate for a link impairment associated with mobile terminal 120-c. In some examples, the beam manager 175 may increase the power by sending a signal to the mobile terminal indicating an adjustment to be made to the transmit power associated with the mobile terminal. The power of the beam may be adjusted accordingly using beamforming coefficients and / or by adjusting the transmit power from one or more antenna elements.

[0086] In some examples, mitigating or compensating for a link failure may include switching a mobile terminal to a different coverage area. For example, a satellite network may include multiple antenna arrays (e.g., multiple phased array antennas on one or more satellites). In some examples, each of the multiple antenna arrays may be a phased array-fed reflector. The beam manager 175 may switch a mobile terminal associated with a link failure from a coverage area currently associated with the mobile terminal to one of other coverage areas having more favorable characteristics for the mobile terminal. For example, the beam manager 175 may switch the mobile terminal from a reflector having a coverage area where the mobile terminal is near the edge of the coverage area to a different reflector having an overlapping coverage area where the mobile terminal may not be near the edge of the coverage area. Example 410-d illustrates an example in which the beam manager 175 has switched a beamformed spot beam 150-d associated with mobile terminal 120-d to a different coverage area to compensate for a link failure associated with mobile terminal 120-d.

[0087] In some examples, two or more steps may be performed in conjunction with each other to compensate for a link failure. For example, the amount of resource elements and the power associated with the beam may be used in conjunction with each other. Example 410-f illustrates an example in which beam manager 175 allocates a second resource element to spot beam 150-f and increases the power for spot beam 150-f to compensate for a link failure associated with mobile terminal 120-f.

[0088] 5A and 5B illustrate timing diagrams 500 and 550 of example mitigation strategies for supporting mobile satellite beam capacity compensation, according to examples disclosed herein. Using the mitigation strategies, link impairments associated with a mobile terminal (e.g., mobile terminal 120 of FIGS. 4A and 4B) may be compensated for using a beam manager (e.g., beam manager 175) via an associated spot beam (e.g., spot beam 150 of FIGS. 4A and 4B).

[0089] Timing diagrams 500 and 550 may be comprised of multiple time periods 510 (e.g., time periods 510-a through 510-g). For example, a first time period 510-a may extend from time t1 to time t2, a first time period 510-b may extend from time t2 to time t3, etc. In some examples, the time periods 510 are equal in duration. During each time period 510, communication services may be provided to the mobile terminal via the associated spot beam as the spot beam tracks the mobile terminal's movement as controlled by the beam manager. Communication services may be provided to the mobile terminal by the spot beam using respective resource elements at respective power levels during each time period.

[0090] Timing diagram 500 corresponds to an example mitigation strategy associated with a dynamic link failure. At time t1, a beam may use a single resource element at a normal beam power level (e.g., equal to power 1 in FIGS. 4A and 4B) to provide communication services to a mobile terminal.

[0091] During each time period 510, as represented by window 515 in time period 510-a, the mobile terminal may transmit impairment information (e.g., a channel performance indicator) to the beam manager via the spot beam. During a second window 520 of the time period, the spot beam may use the impairment information to determine whether an impairment associated with the mobile terminal exists (e.g., by comparing the channel performance indicator to a threshold). This transmission and comparison may be repeated during each time period 510.

[0092] During each time period 510, if the beam manager determines that a fault exists (e.g., by determining that a performance metric meets a threshold), the beam manager may compensate for the fault by allocating more power to the spot beam, allocating the spot beam to additional resource elements, or both.

[0093] For example, during time period 510-b, the beam manager may determine that a link failure exists by determining that a performance metric received from the mobile terminal during time period 510-b meets a threshold. To compensate for the link failure, the beam manager may allocate more power to the beam and / or allocate additional resource elements to the beam starting at the beginning of the next time period 510-c. During subsequent time periods (e.g., time periods 510-c and 510-d), if the beam manager determines that the link failure still exists, the beam manager may cause the beam to maintain use of the increased power and / or additional resource elements.

[0094] If, during a subsequent time period (e.g., time period 510-e), the beam manager determines that the link impairment no longer exists (e.g., by determining that the performance indicator no longer meets the threshold), the beam manager may cause the beam to no longer use increased power and / or additional resource elements (e.g., from the next time period 510-f).

[0095] Timing diagram 550 corresponds to an example mitigation strategy associated with a static link failure. Timing diagram 550 is similar to timing diagram 500, except for some differences. Similar to the mitigation strategy of timing diagram 500, the beam manager may determine whether a failure exists during each time period 510, as represented by window 520. However, because the failure is a static failure, the beam manager may determine the presence or absence of a failure without using failure information transmitted by the mobile terminal. For example, the beam manager may determine the presence or absence of a static failure associated with the mobile terminal by using the mobile terminal's location, which the beam manager may already know from determining beam coefficients for steering beams to track the mobile terminal.

[0096] Similar to the mitigation strategy of timing diagram 500, if the beam manager determines during a time period (e.g., time period 510-b) that a failure exists (e.g., by determining that the mobile terminal is within a threshold distance to the edge of the coverage area of ​​the satellite communications system or the edge of a coverage region associated with the mobile terminal), the beam manager may compensate for the failure by allocating more power to the spot beam and / or additional resource elements to the spot beam starting from the beginning of the next time period (e.g., time period 510-c). Also similar to the mitigation strategy of timing diagram 500, if the beam manager determines during a subsequent time period (e.g., time period 510-e) that a link failure no longer exists (e.g., by determining that the mobile terminal is no longer within a threshold distance to the edge of the coverage area or coverage region), the beam manager may cause the beam to no longer use increased power and / or additional resource elements (e.g., starting from the next time period 510-f).

[0097] 6 shows a block diagram 600 of a beam manager 605 supporting mobile satellite beam capacity compensation according to examples disclosed herein. The beam manager 605 may be an example of the beam manager 175 of FIG. 1. The beam manager 605 may include a bus 625, a beam compensation manager 670, a memory 630, code 635, a processor 640, a beamformer 645, and a beam signal processor 650, and may be configured to control beam tracking for a mobile terminal (e.g., mobile terminal 120) and resource allocation and interference avoidance for a beamformed spot beam (e.g., beamformed spot beam 150) via the antenna array 610.

[0098] The beam manager 605 may be located within the terrestrial network (e.g., terrestrial network 135 of FIG. 1 ) or the satellite network (e.g., satellite network 101 of FIG. 1 ) of the satellite communications system. Alternatively, the beam manager 605 may be split between the terrestrial network and the satellite network. In one example (e.g., corresponding to a GBBF configuration), all of the components of the beam manager 605 may be located within the terrestrial network. In another example (e.g., corresponding to an OBBF configuration), the beamformer 645 may be located within the satellite network (e.g., within one or more of the satellites), with the remainder of the components of the beam manager 605 located within either the terrestrial network or the satellite network, respectively. In some examples, a distributed implementation may be used. For example, one or more components of the beam manager 605, or portions thereof, may reside on different servers (e.g., hosted in the cloud). In some examples, the beam manager 605 may be located in a single entity.

[0099] The antenna array 610 may be an example of an antenna of the satellite network 101 of FIG. 1 and may include antenna elements 615. In some examples, one or more of the antenna elements 615 may be or may include antenna panels. The spacing between the antenna elements 615 may be evenly distributed across the aperture of the antenna array 610, or the spacing of the antenna elements 615 may vary across the antenna array 610. In some examples, a first antenna array 610 may be included in the ground segment and a second antenna array 610 (e.g., one or more antenna arrays coupled to each other using transponders) may be included in the space segment.

[0100] The bus 625 may represent an interface through which signals may be exchanged between components of the beam manager 605 and a location (e.g., a central location) that may be used to distribute signals to the signal processing components of the beam manager 605 (e.g., beam compensation manager 670, beam signal processor 650, beamformer 645). The bus 625 may include one or more wired interfaces. Additionally or alternatively, the bus 625 may be a wireless interface used to wirelessly communicate signaling between the signal processing components, for example, according to a communication protocol. The beamformer 645 may be coupled to the antenna elements 615 via one or more wired or wireless interfaces.

[0101] The memory 630 may include volatile memory (e.g., random access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM)). Other types of memory may be possible. The memory 630 may store computer-readable and computer-executable code 635. The code may include instructions that, when executed by the processor 640, cause the beam manager 605 to perform various functions described herein. The code 635 may be stored in a non-transitory computer-readable medium (e.g., system memory or another type of memory). In some cases, the code 635 may not be directly executable by the processor 640, but may cause a computer to perform the functions described herein (e.g., when compiled and executed). In some cases, the memory 630 may include, among other things, a basic I / O system (BIOS), which may control basic hardware or software operations (e.g., interactions with peripheral components or devices).

[0102] The processor 640 may include an intelligent hardware device (e.g., a general-purpose processor), a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a programmable logic device (PLD), discrete gate or transistor logic components, discrete hardware components, or any combination thereof. The processor 640 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 630) to cause the beam manager 605 to perform various functions (e.g., functions or tasks that support mobile satellite beam resource allocation). For example, the processor 640 and memory 630 may be configured to perform various functions described herein.

[0103] The beam signal processor 650 may be configured to process (e.g., demodulate, decode) the received beam signals 654 received from the beamformer 645. The beam signal processor 650 may decode data symbols included in the received beam signals 654 to obtain received beam data signals 664. The information (e.g., packets) in the received beam data signals 664 may be passed to a destination device (e.g., via network(s) 125). The beam signal processor 650 may also be configured to process (e.g., encode, modulate) the transmit beam data signals 662 to obtain and transmit the transmit beam signals 652 to the beamformer 645. The transmit beam data signals 662 may include information (e.g., packets) received (e.g., via network(s) 125) for transmission to the terminal 120.

[0104] The beam compensation manager 670 may be configured to determine the presence or absence of link impairments associated with mobile terminals tracked by each spot beam, determine changes to power levels and resource elements for the spot beams based on the presence or absence of link impairments, and direct the implementation of those changes. The beam compensation manager 670 may include the terminal tracker 620 and an impairment compensator 675.

[0105] The terminal tracker 620 may be configured to determine information for the beamformer 645 to use in forming beamformed spot beams (e.g., beamformed spot beams 150 of FIG. 1 ) using the antenna elements 615. To determine the information for forming the beamformed spot beams, the terminal tracker 620 may identify a set of terminals (e.g., mobile terminals 120 of FIG. 1 ) to assign as reference terminals and may determine spatial information associated with the reference terminals. The terminal tracker 620 may determine a set of beamforming coefficients (e.g., phase shifts, amplitude components) that the beamformer 645 may use to generate beamformed spot beams having individual coverage areas directed to the spatial information associated with the reference terminals.

[0106] The terminal tracker 620 may determine beamforming coefficients to separate signals transmitted via the beamformed spot beams from one another (e.g., for each beamformed spot beam, by emphasizing the signal transmitted within the beamformed spot beam and canceling interference from signals transmitted within other beamformed spot beams). The beamforming coefficients may be included in an MxN matrix. The value of M may indicate the number of antennas, and the value of N may indicate the number of spatial layers. The value of N may be less than or equal to the value of M.

[0107] In some examples, the beamforming coefficients may be determined at one or more satellites 105. In some examples, the beamforming coefficients may be received by one or more satellites from one or more ground stations (e.g., network devices 130 or other stations of the terrestrial network 135) after the terminal tracker 620 determines the beamforming coefficients.

[0108] The impairment compensator 675 may be configured to perform beam resource allocation (including adjusting the resource elements used by the beams). For example, the impairment compensator 675 may determine one or more frequency ranges or channels (e.g., frequency channel 210 in FIG. 2B), one or more time periods and / or time slots (e.g., time period 215, time slot t in FIG. 2B), and / or polarity for the allocation of each beamformed spot beam. The impairment compensator 675 may be configured to assign the number of resource elements to the beam based on link impairments associated with the mobile terminal associated with the beam. To assign the beams to the determined resource elements, the impairment compensator 675 may include various components (e.g., a frequency converter, a scheduler, and a polarization component).

[0109] The impairment compensator 675 may be further configured to allocate power to the beams. For example, the impairment compensator may allocate power to the beams based on link impairments associated with mobile terminals associated with the beams.

[0110] In some examples, to transmit the beamformed spot beam via the antenna element 615, the impairment compensator 675 may determine a frequency range or channel, a time slot, and a power level for applying a set of transmit beam signals 652 associated with the beamformed spot beam. The beamformer 645 may apply a set of transmit beamforming coefficients to the set of transmit beam signals 652 based on the frequency range or channel and the power level to obtain component signals 656 for transmission via the antenna element 615.

[0111] In some examples, to receive the beamformed spot beam via the antenna element 615, the terminal tracker 620 may determine a set of receive beamforming coefficients based on the frequency range or channel and power level determined by the impairment compensator 675 to obtain a set of component signals 656. The frequency range or channel and time slot may be applied to the component signals 656 by the impairment compensator 675 or the beamformer 645 to obtain a set of receive beam signals 654 associated with the beamformed spot beam.

[0112] In some examples, the terminal tracker 620, the impairment compensator 675, the beamformer 645, the beam signal processor 650, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a DSP, an ASIC, an FPGA or other PLD, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting means for performing the functions described in this disclosure. In some examples, a processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by the processor executing instructions stored in the memory).

[0113] Additionally or alternatively, the terminal tracker 620, the impairment compensator 675, the beamformer 645, the beam signal processor 650, or various combinations or components thereof may be implemented in code 635 executed by the processor 640 (e.g., as communications management software or firmware). When implemented in code 635 executed by the processor 640, the functions of the terminal tracker 620, the impairment compensator 675, the beamformer 645, the beam signal processor 650, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof, or other programmable logic device (e.g., configured as or otherwise supporting a means for performing the functions described in this disclosure).

[0114] FIG. 7 shows a block diagram 700 of a beam compensation manager 720 supporting mobile satellite beam capacity compensation according to examples disclosed herein. The beam compensation manager 720 may be an example of an aspect of the beam compensation manager 670 as described with reference to FIG. 6. The beam compensation manager 720 (or various components thereof) may be an example of a means for performing various aspects of the mobile satellite beam capacity compensation described herein. For example, the beam compensation manager 720 may include a communications manager 725, an allocation director 730, a beamforming manager 735, an impairment determiner 740, a terminal subset determiner 745, a resource element subset determiner 750, an impairment compensation manager 755, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

[0115] The communications manager 725 may be configured as or otherwise support a means for providing communication services to a plurality of mobile terminals using a set of resource elements via a set of beamformed spot beams of a satellite communications system, as described herein. Each mobile terminal may be assigned to a beamformed spot beam. In some examples, the communications manager 725 may include one or more of the other components of the beam compensation manager 720. In some examples, the communications manager 725 may include an allocation director 730, a beamforming manager 735, an impairment determiner 740, a terminal subset determiner 745, a resource element subset determiner 750, and an impairment compensation manager 755.

[0116] Allocation director 730 may be configured as or otherwise support a means for assigning mobile terminals to beamformed spot beams and assigning beamformed spot beams to resource elements, as described herein. In some examples, allocation director 730 may be configured as or otherwise support a means for assigning resource elements to beamformed spot beams and / or assigning beamformed spot beams to mobile terminals. In some examples, allocation director 730 may be configured as or otherwise support a means for assigning beamformed spot beams to which mobile terminals of a subset of the mobile terminals are assigned to additional resource elements. In some examples, allocation director 730 may be configured as or otherwise support a means for de-assigning beamformed spot beams from additional resource elements.

[0117] The beamforming manager 735 may be configured or otherwise support a means for adjusting the coverage area of ​​each of the beamformed spot beams to track the movement of each of a plurality of mobile terminals within the coverage area of ​​the satellite communications system, as described herein. The adjustment may be performed over multiple time periods. In some examples, the beamforming manager 735 may be configured or otherwise support a means for increasing the power allocated to a resource element by increasing power to a beamformed spot beam associated with the resource element.

[0118] The fault determiner 740 may be configured as or otherwise support a means for determining the presence of a link failure associated with one or more mobile terminals, as described herein. The determination may be performed over one or more time periods. In some examples, the fault determiner 740 may be configured as or otherwise support a means for determining that one or more of the link failures no longer exist. In some examples, the fault determiner 740 may be configured as or otherwise support a means for receiving feedback from the mobile terminal. The feedback may include a channel performance indicator. In some examples, the fault determiner 740 may be configured as or otherwise support a means for determining that a channel performance indicator of the mobile terminal meets a threshold. In some examples, the fault determiner 740 may be configured as or otherwise support a means for determining that the mobile terminal is within a threshold distance of an edge of a coverage area of ​​the satellite communication system or an edge of a coverage region associated with the mobile terminal. In some examples, the fault determiner 740 may be configured as or otherwise support a means for determining the presence of a link fault based at least in part on a determination that the mobile terminal is within a threshold distance of an edge of a coverage area of ​​the satellite communications system or an edge of a coverage region associated with the mobile terminal.

[0119] The terminal subset determiner 745 may be configured as or otherwise support a means for determining a subset of mobile terminals associated with a link failure, as described herein. The determination may be performed for each time period in which the presence of a link failure is determined.

[0120] The resource element subset determiner 750 may be configured as or otherwise support a means for determining a subset of resource elements associated with a link failure, as described herein. The determination may be performed for each time period in which the presence of a link failure is determined.

[0121] The fault compensation manager 755 may be configured as or otherwise support a means for compensating for a link failure, as described herein. Compensation may include modifying characteristics associated with a subset of resource elements. Compensation may be performed for each time period for which the presence of a link failure is determined. In some examples, the fault compensation manager 755 may be configured as or otherwise support a means for switching a mobile terminal to a different coverage area. In some examples, the fault compensation manager 755 may be configured as or otherwise support a means for instructing the allocation director 730 to allocate beamformed spot beams to additional resource elements. In some examples, the fault compensation manager 755 may be configured as or otherwise support a means for instructing the beamforming manager 735 to increase power to a beamformed spot beam associated with the mobile terminal.

[0122] In some examples, aspects of one or more components of beam compensation manager 670 or 720 may be found in other components of the beam compensation manager or even outside of the beam compensation manager. For example, processor 640 and memory 630 may be used in performing one or more functions associated with components of beam compensation manager 720.

[0123] FIG. 8 illustrates a flowchart illustrating a method 800 for supporting mobile satellite beam capacity compensation, according to examples disclosed herein. The operations of method 800 may be performed by a satellite communications system or components thereof as described herein. For example, the operations of method 800 may be performed by a beam manager as described with reference to FIGS. 1-7. In some examples, a processor may execute a set of instructions to control functional elements of the beam manager to perform the described functions. Additionally or alternatively, the beam manager may use dedicated hardware to perform aspects of the described functions.

[0124] At 805, the method may include providing communication services to a plurality of mobile terminals via a set of beamformed spot beams of a satellite communication system using the set of resource elements. The operations of 805 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 805 may be performed by communications manager 725 as described with reference to FIG. 7. In some examples, providing communication services may include operations of 810, 815, 820, 825, 830, and 835.

[0125] At 810, the method may include assigning each mobile terminal of a plurality of mobile terminals to a beamformed spot beam of the set of beamformed spot beams, the beamformed spot beam being associated with a resource element of the set of resource elements. The operations of 810 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 810 may be performed by allocation director 730 as described with reference to FIG. 7.

[0126] At 815, the method may include adjusting the coverage area of ​​each of the set of beamformed spot beams over multiple time periods to track movement of each of the multiple mobile terminals within the coverage area of ​​the satellite communications system. The operations of 815 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 815 may be performed by the beamforming manager 735 as described with reference to FIG. 7.

[0127] At 820, the method may include determining, for one or more time periods of the plurality of time periods, the presence of one or more link failures for a subset of the set of resource elements associated with a subset of the set of beamformed spot beams to which the subset of the plurality of mobile terminals is assigned. The operations of 820 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 820 may be performed by the failure determiner 740 as described with reference to FIG. 7.

[0128] At 825, the method may include, for each of one or more time periods in which the presence of a link failure is determined, compensating for one or more link failures associated with the subset of resource elements for the one or more time periods. The operations of 825 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 825 may be performed by a failure compensation manager 755 as described with reference to FIG. 7.

[0129] FIG. 9 illustrates a flowchart illustrating a method 900 for supporting mobile satellite beam capacity compensation, according to examples disclosed herein. The operations of the method 900 may be performed by a beam manager or components thereof as described herein. For example, the operations of the method 900 may be performed by a beam manager as described with reference to FIGS. 1-7. In some examples, a processor may execute a set of instructions to control functional elements of the beam manager to perform the described functions. Additionally or alternatively, the beam manager may use dedicated hardware to perform aspects of the described functions.

[0130] At 905, the method may include providing communication services to a mobile terminal using a set of resource elements via a beamformed spot beam of a satellite communication system. The operations of 905 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 905 may be performed by communications manager 725 as described with reference to FIG. 7. In some examples, providing the communication services may include operations of 910, 915, 920, and 925.

[0131] At 910, the method may include assigning the mobile terminal to a beamformed spot beam associated with a resource element of the set of resource elements. The operations of 910 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 910 may be performed by the allocation director 730 as described with reference to FIG.

[0132] At 915, the method may include adjusting the coverage area of ​​the beamformed spot beam to track movement of the mobile terminal within the coverage area of ​​the satellite communications system. The operations of 915 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 915 may be performed by the beamforming manager 735 as described with reference to FIG.

[0133] At 920, the method may include determining, during a first time period, a presence of a link failure associated with the resource element. The operations of 920 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 920 may be performed by the failure determiner 740 as described with reference to FIG.

[0134] At 925, the method may include compensating for link failures associated with the resource element for a second time period. The operations of 925 may be performed in accordance with examples disclosed herein. In some examples, aspects of the operations of 925 may be performed by a failure compensation manager 755 as described with reference to FIG.

[0135] In some examples, an apparatus as described herein may perform the method(s) (e.g., method 800 and / or method 900). The apparatus may include features, circuits, logic, means, or instructions (e.g., a non-transitory computer-readable medium storing instructions executable by a processor) for performing the method(s), or any combination thereof.

[0136] It should be noted that these methods describe example implementations, and that the operations and steps may be rearranged or otherwise modified so that other implementations are possible. In some examples, aspects from two or more of the methods may be combined. For example, each aspect of the method may include steps or aspects of other methods, or other steps or techniques described herein.

[0137] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout this specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0138] The various example blocks and modules described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, an 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 alternatively, 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, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration).

[0139] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions may be stored or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. The features that implement the functions may also be physically located in various locations, e.g., may be distributed so that parts of the functions are implemented in different physical locations.

[0140] Computer-readable media includes both non-transitory computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CDROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer or processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (e.g., infrared, radio, and microwave), the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (e.g., infrared, radio, and microwave) are included in the definition of medium. Disk and disc, as used herein, include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs; disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0141] As used herein, including the claims, "or" used in a list of items (e.g., a list of items prefaced by phrases such as "at least one" or "one or more") indicates an inclusive list, such as, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be construed similarly to the phrase "based at least in part on."

[0142] In the accompanying figures, similar components or features may have the same reference label. Furthermore, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes among the similar components. When only a first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of a second reference label, or any other subsequent reference label.

[0143] The description set forth herein in connection with the accompanying drawings describes exemplary configurations and does not represent every example that may be implemented or fall within the scope of the claims. As used herein, the term "exemplary" means "serving as an example, instance, or illustration," and does not mean "preferred" or "advantageous over other examples." The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, these technologies may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0144] The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A method comprising: providing communication services to a plurality of mobile terminals (120) using a set of resource elements via a set of beamformed spot beams (150) of a satellite communication system (100), wherein providing the communication services includes: assigning each mobile terminal (120) of the plurality of mobile terminals to a beamformed spot beam (150) of the set of beamformed spot beams, the beamformed spot beam being associated with a resource element of the set of resource elements; adjusting the coverage area (160) of each of the set of beamformed spot beams (150) over a plurality of time periods (510) to track movement of each of the plurality of mobile terminals (120) within a coverage area (155) of the satellite communications system (100); determining, for one or more time periods (510) of the plurality of time periods, the presence of one or more link failures for a subset of the set of resource elements associated with a subset of the set of beamformed spot beams (150) to which a subset of the plurality of mobile terminals (120) is assigned; and for each of the one or more time periods (510) during which the presence of the link failure is determined, compensating for the one or more link failures associated with the subset of resource elements for the one or more time periods.

2. 2. The method of claim 1, wherein compensating for the one or more link failures comprises modifying characteristics associated with the subset of resource elements for the one or more time periods.

3. Compensating for the one or more link failures includes:

3. The method of claim 1, comprising increasing power allocated to resource elements of the subset of resource elements by increasing power to beamformed spot beams associated with the resource elements for the one or more time periods.

4. Compensating for the one or more link failures includes: The method of any one of claims 1 to 3, comprising allocating beamformed spot beams (150) of a subset of the beamformed spot beams to additional resource elements.

5. The coverage area (155) of the satellite communication system (100) includes a plurality of coverage regions having different characteristics, and compensating for the one or more link impairments comprises: The method of any one of claims 1 to 4, comprising switching mobile terminals (120) of said subset of mobile terminals to a different coverage area.

6. The method of any one of claims 1 to 5, wherein the one or more link failures include one or more of a static link failure or a dynamic link failure.

7. The method of any one of claims 1 to 6, wherein the one or more link failures include failures due to disadvantaged mobile terminals.

8. The method of any one of claims 1 to 7, wherein the one or more link impairments include rain attenuation.

9. Determining the presence of one or more link failures includes: receiving a channel performance indicator associated with a mobile terminal (120) of the plurality of mobile terminals; determining that the channel performance indicator associated with the mobile terminal (120) meets a threshold; The method of any one of claims 1 to 8, comprising: determining, based at least in part on the determination that the channel performance indicator associated with the mobile terminal (120) satisfies the threshold, that there is a link failure associated with the resource element associated with the beamformed spot beam (150) to which the mobile terminal (120) is assigned.

10. 10. The method of claim 9, wherein the channel performance indicators include one or more of a channel gain, a receiver gain, an interference level, or a noise level associated with the mobile terminal (120).

11. 10. The method of claim 9, wherein the channel performance indicator comprises a signal-to-interference-noise ratio (SINR) associated with the mobile terminal (120).

12. Determining the presence of one or more link failures includes: determining that a mobile terminal (120) of the plurality of mobile terminals is within a threshold distance of an edge of the coverage area (155) of the satellite communications system (100); The method of any one of claims 1 to 11, comprising determining, based at least in part on the determination that the mobile terminal (120) is within the threshold distance of the edge of the coverage area (155) of the satellite communication system (100), that there is a link failure associated with the resource element associated with the beamformed spot beam (150) to which the mobile terminal (120) is assigned.

13. 13. The method of claim 12, wherein the threshold distance is based at least in part on a scan angle of one or more beamformed spot beams (150) of the set of beamformed spot beams from a center of the coverage area (155) of the satellite communication system (100).

14. The method of any one of claims 1 to 13, wherein determining the presence of one or more link failures is based at least in part on channel performance indicators of the plurality of mobile terminals (120).

15. The method of any one of claims 1 to 14, wherein determining the presence of one or more link failures is based at least in part on a type of mobile terminal (120) of the plurality of mobile terminals.

16. 16. The method of claim 15, wherein the type of the mobile terminal is based at least in part on characteristics of each antenna associated with the mobile terminal.

17. 16. The method of claim 15, wherein the type of the mobile terminal (120) is based at least in part on the capabilities of a receiver corresponding to the mobile terminal.

18. Assigning each mobile terminal to a beamformed spot beam includes assigning a first mobile terminal (120) to a first beamformed spot beam (150) associated with a first resource element; adjusting the coverage area of ​​each of the set of beamformed spot beams to track movement of the respective mobile terminals includes adjusting the coverage area of ​​the first beamformed spot beam to track movement of the first mobile terminal; Determining the presence of one or more link failures includes determining the presence of a first link failure associated with the first resource element during a first time period (510); 18. The method of claim 1, wherein compensating for the one or more link failures comprises compensating for the first link failure associated with the first resource element for a first time period (510).

19. Compensating for the first link failure includes:

20. The method of claim 18, comprising modifying a characteristic of the first resource element.

20. Providing the communication service further comprises: determining that the first link failure no longer exists for a third time period (510); and resetting the characteristic of the first resource element for a fourth time period (510).

21. Compensating for the first link failure includes:

21. The method of claim 18, comprising increasing power allocated to the first resource element by increasing power to the first beamformed spot beam (150).

22. Compensating for the first link failure includes: The method of any one of claims 18 to 21, comprising allocating the first beamformed spot beam (150) to additional resource elements of the set of resource elements.

23. Providing the communication service further comprises: determining that the first link failure no longer exists for a third time period (510); and de-allocating the first beamformed spot beam from the additional resource elements for a fourth time period.

24. The coverage area (155) of the satellite communication system (100) includes a plurality of coverage regions having different characteristics, and compensating for the first link impairment comprises: The method of any one of claims 18 to 23, comprising switching the first mobile terminal (120) to a different coverage area.

25. The method of any one of claims 18 to 24, wherein the first link failure comprises a static link failure or a dynamic link failure.

26. The method of any one of claims 18 to 25, wherein the first link failure comprises a failure due to the first mobile terminal (120) being a disadvantaged mobile terminal.

27. The method of any one of claims 18 to 25, wherein the first link impairment comprises rain attenuation.

28. Determining the presence of the first link failure includes: The method of any one of claims 18 to 27, comprising determining that a channel performance indicator of the first mobile terminal (120) satisfies a threshold.

29. Providing the communication service further comprises:

30. The method of claim 28, comprising receiving feedback from the first mobile terminal (120) for the first time period (510), the feedback including the channel performance indicator.

30. Providing the communication service further comprises: determining, for a third time period (510), that the first link failure no longer exists, wherein determining that the first link failure no longer exists comprises:

30. The method of any one of claims 28 or 29, comprising determining that the channel performance indicator of the first mobile terminal (120) does not meet the threshold.

31. 31. The method of claim 18, wherein determining the link failure is based at least in part on the adjustment of the coverage area (160) of the first beamformed spot beam (150).

32. The method of any one of claims 18 to 31, wherein determining the presence of the first link impairment is based at least in part on terminal and satellite calibration measurements of the first mobile terminal (120).

33. Determining the presence of the first link failure includes: determining that the first mobile terminal (120) is within a threshold distance of an edge of the coverage area (155) of the satellite communications system (100); and determining that the first link failure exists based at least in part on the determination that the first mobile terminal (120) is within the threshold distance of the edge of the coverage area (155) of the satellite communications system (100).

34. 34. The method of claim 33, wherein the threshold distance is based at least in part on a scan angle of the first beamformed spot beam (150) from a center of the coverage area (155) of the satellite communication system (100).

35. 1. An apparatus comprising: a beam manager (175) associated with the memory device, the beam manager (175) providing the apparatus with: The satellite communication system (100) is configured to provide a communication service to a plurality of mobile terminals (120) using a set of resource elements via a set of beamformed spot beams (150), and providing the communication service includes: assigning each mobile terminal (120) of the plurality of mobile terminals to a beamformed spot beam (150) of the set of beamformed spot beams, the beamformed spot beam being associated with a resource element of the set of resource elements; adjusting the coverage area (160) of each of the set of beamformed spot beams (150) over a plurality of time periods (510) to track movement of each of the plurality of mobile terminals (120) within a coverage area (155) of the satellite communications system (100); determining, for one or more time periods (510) of the plurality of time periods, the presence of one or more link failures for a subset of the set of resource elements associated with a subset of the set of beamformed spot beams (150) to which a subset of the plurality of mobile terminals (120) is assigned; and for each of the one or more time periods (510) during which the presence of the link failure is determined, compensating for the one or more link failures associated with the subset of resource elements for the one or more time periods (510).

36. Compensating for the one or more link failures includes:

36. The apparatus of claim 35, configured to cause characteristics associated with the subset of resource elements to change for the one or more time periods (510).

37. Compensating for the one or more link failures includes:

37. The apparatus of claim 35, configured to increase power allocated to resource elements of the subset of resource elements by increasing power to beamformed spot beams associated with the resource elements for the one or more time periods.

38. Compensating for the one or more link failures includes: The apparatus of any one of claims 35 to 37, configured to cause beamformed spot beams (150) of a subset of the beamformed spot beams to be allocated to additional resource elements.

39. The coverage area (155) of the satellite communication system (100) includes a plurality of coverage regions having different characteristics, and compensating for the one or more link impairments further comprises the apparatus: An apparatus according to any one of claims 35 to 38, configured to cause mobile terminals (120) of said subset of mobile terminals to switch to different coverage areas.

40. The apparatus of any one of claims 35 to 39, wherein the one or more link failures include one or more of a static link failure or a dynamic link failure.

41. The apparatus of any one of claims 35 to 40, wherein the one or more link failures include failures due to disadvantaged mobile terminals.

42. The apparatus of any one of claims 35 to 41, wherein the one or more link impairments include rain attenuation.

43. Determining the presence of one or more link failures may include: receiving a channel performance indicator associated with a mobile terminal (120) of the plurality of mobile terminals; determining that the channel performance indicator associated with the mobile terminal (120) meets a threshold; and determining, based at least in part on the determination that the channel performance indicator associated with the mobile terminal (120) satisfies the threshold, that there is a link failure associated with the resource element associated with the beamformed spot beam (150) to which the mobile terminal (120) is assigned.

44. 44. The apparatus of claim 43, wherein the channel performance indicators include one or more of a channel gain, a receiver gain, an interference level, or a noise level associated with the mobile terminal (120).

45. 44. The apparatus of claim 43, wherein the channel performance indicator comprises a signal-to-interference-noise ratio (SINR) associated with the mobile terminal (120).

46. Determining the presence of one or more link failures may include: determining that a mobile terminal (120) of the plurality of mobile terminals is within a threshold distance of an edge of the coverage area (155) of the satellite communications system (100); The apparatus of any one of claims 35 to 45, configured to: determine, based at least in part on the determination that the mobile terminal (120) is within the threshold distance of the edge of the coverage area (155) of the satellite communication system (100), that there is a link failure associated with the resource element associated with the beamformed spot beam (150) to which the mobile terminal (120) is assigned.

47. 47. The apparatus of claim 46, wherein the threshold distance is based at least in part on a scan angle of one or more beamformed spot beams (150) of the set of beamformed spot beams from a center of the coverage area (155) of the satellite communication system (100).

48. The apparatus of any one of claims 35 to 47, wherein determining the presence of one or more link failures is based at least in part on channel performance indicators of the plurality of mobile terminals (120).

49. The apparatus of any one of claims 35 to 48, wherein determining the presence of one or more link failures is based at least in part on a type of mobile terminal (120) of the plurality of mobile terminals.

50. 50. The apparatus of claim 49, wherein the type of the mobile terminal is based at least in part on characteristics of each antenna associated with the mobile terminal (120).

51. 50. The apparatus of claim 49, wherein the type of the mobile terminal is based at least in part on capabilities of a receiver corresponding to the mobile terminal (120).

52. Assigning each mobile terminal to a beamformed spot beam is configured to cause the apparatus to assign a first mobile terminal (120) to a first beamformed spot beam (150) associated with a first resource element; adjusting the coverage area of ​​each of the set of beamformed spot beams to track the movement of the respective mobile terminal is configured to cause the device to adjust the coverage area of ​​the first beamformed spot beam to track the movement of the first mobile terminal; Determining the presence of one or more link failures is configured to cause the apparatus to determine the presence of a first link failure associated with the first resource element during a first time period (510); 52. The apparatus of claim 35, wherein compensating for the one or more link failures is configured to cause the apparatus to compensate for the first link failure associated with the first resource element for a first time period (510).

53. Compensating for the first link failure may include causing the apparatus to:

53. The apparatus of claim 52 configured to cause a characteristic of the first resource element to be changed.

54. Providing the communication service further comprises: determining that the first link failure no longer exists during a third time period (510); and resetting the characteristic of the first resource element for a fourth time period (510).

55. Compensating for the first link failure may include causing the apparatus to:

55. The apparatus of claim 52, configured to increase power allocated to the first resource element by increasing power to the first beamformed spot beam (150).

56. Compensating for the first link failure may include causing the apparatus to: The apparatus of any one of claims 52 to 55, configured to cause the first beamformed spot beam (150) to be allocated to additional resource elements of the set of resource elements.

57. Providing the communication service further comprises: determining that the first link failure no longer exists during a third time period (510); and, for a fourth time period (510), deallocating the first beamformed spot beam (150) from the additional resource elements.

58. The coverage area (155) of the satellite communication system (100) includes a plurality of coverage regions having different characteristics, and compensating for the first link impairment comprises the device: An apparatus according to any one of claims 52 to 57, configured to cause the first mobile terminal (120) to switch to a different coverage area.

59. The apparatus of any one of claims 52 to 58, wherein the first link failure comprises a static link failure or a dynamic link failure.

60. The apparatus of any one of claims 52 to 59, wherein the first link failure comprises a failure based on the first mobile terminal (120) being a disadvantaged mobile terminal.

61. 60. The apparatus of any one of claims 52 to 59, wherein the first link impairment comprises rain attenuation.

62. Determining the presence of the first link failure may include: An apparatus according to any one of claims 52 to 61, configured to cause a determination that a channel performance indicator of the first mobile terminal (120) satisfies a threshold.

63. Providing the communication service further comprises:

63. The apparatus of claim 62, configured to receive feedback from the first mobile terminal (120) during the first time period (510), the feedback including the channel performance indicator.

64. Providing the communication service further comprises: and determining that the first link failure no longer exists during a third time period (510), wherein determining that the first link failure no longer exists includes causing the device to:

64. An apparatus according to any one of claims 62 or 63, configured to cause a determination that the channel performance indicator of the first mobile terminal (120) does not satisfy the threshold.

65. 65. The apparatus of claim 52, wherein determining the link failure is based at least in part on the adjustment of the coverage area (160) of the first beamformed spot beam (150).

66. The apparatus of any one of claims 52 to 65, wherein determining the presence of the first link impairment is based at least in part on terminal and satellite calibration measurements of the first mobile terminal (120).

67. Determining the presence of the first link failure may include: determining that the first mobile terminal (120) is within a threshold distance of an edge of the coverage area (155) of the satellite communications system (100); and determining that the first link failure exists based at least in part on the determination that the first mobile terminal (120) is within the threshold distance of the edge of the coverage area (155) of the satellite communications system (100).

68. 68. The apparatus of claim 67, wherein the threshold distance is based at least in part on a scan angle of the first beamformed spot beam (150) from a center of the coverage area (155) of the satellite communication system (100).

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