Space Exploration Technologies Corp.

Corning Optical Communications LLC

Spidercloud Wireless, Inc.

Peter J Worters

Yashodhan A Dandekar

Chen Chen

Phillip E Barber

Hithesh Nama

Cong Shen

Brian Dunn

Darshan Purohit

Pavel Chikulaev

David Sacks

Ramakrishna Akella

Khasim Shaheed Shaik Mahammad

Lili Zhang

Jayasuryan V Iyer

Krishna Kamal Sayana

Sergii Ziuzin

Vladimir Skuratovich

Andrei Pushkin

Han-Ting Chiang

Amit Butala

Jaspreet Singh

Martin S McCormick

Tsung-Yi Chen

Oliver Charlesworth

Yashwanth Hemaraj

Colin Campbell

Andrew G Whitlow

Matthew J Monson

Brian Patrick Dunn

Systems, methods, and non-transitory media are provided for low latency handovers. An example method can include receiving, by a user terminal associated with a cell served by a satellite, a schedule of communications between the user terminal and one or more satellites, wherein the one or more satellites comprises the satellite and a different satellite, and wherein the schedule of communications is obtained by the user terminal from the satellite; requesting, based on the schedule, a handover from a beam of the satellite to a different beam of one of the satellite or the different satellite; performing the handover from the beam of the satellite to the different beam of the one of the satellite or the different satellite; and after the handover, transmitting, by the user terminal, one or more packets via the different beam of the one of the satellite or the different satellite.

Low latency schedule-driven handovers

A method of operating an uplink scheduler as part of a medium access control scheduler on a satellite includes selecting, from a plurality of user terminals, a first number of zero-bandwidth request user terminals from the plurality of user terminals, selecting, from the plurality of user terminals, a second number of non-zero-bandwidth request user terminals from the plurality of user terminals, binning the second number of non-zero-bandwidth request user terminals into a plurality of bins based on a respective bandwidth requirement for each non-zero-bandwidth request user terminal and based on a minimum user terminal grant and allocating, according to a grant allocation algorithm, a respective grant of radio resources in an uplink frame to each user terminal of the plurality of user terminals into a respective bin of the plurality of bins in an order associated with increasing bandwidth needs. A downlink scheduler is also disclosed.

System and method of providing a medium access control scheduler

A method for downlink link adaptation includes receiving, from a satellite and at a user terminal, a first data packet data unit according to a first downlink modulation and coding scheme (MCS), computing error vector magnitude data associated with the first data packet data unit, generating, based on one or more of the error vector magnitude data, user terminal signal-to-noise-ratio feedback based on a constant times a previous user terminal signal-to-noise-ratio and a current user terminal signal-to-noise-ratio, and transmitting an uplink packet data unit having a downlink block error rate and the user terminal signal-to-noise-ratio feedback. A satellite runs a link adaptation algorithm based on the user terminal signal-to-noise-ratio feedback and block error rate to generate a second downlink MCS. The method includes receiving at the user terminal a second data packet data unit according to the second downlink MCS for the satellite-to-user-terminal downlink. Uplink link adaptation is also disclosed.

System and method of providing an adaptive modulation and coding scheme

In an embodiment, a user terminal includes a communication module (CM) configured to generate an initial network entry request; an antenna assembly configured to find, in response to the initial network entry request, a satellite based on a search of a sky. The search of the sky includes sequentially changing a beam pointing direction of the antenna assembly. The satellite is assigned to downlink to a geographic cell associated with the user terminal. The user terminal includes a media access control (MAC) layer component configured to generate an uplink radio frame including a random access channel (RACH) request associated with the initial network entry request at a particular portion of the uplink radio frame for the satellite.

Initial network entry to a communications system

Systems, methods, and non-transitory media are provided for synchronization of multi-user uplink transmissions. An example method can include receiving, by a user terminal, a downlink radio frame transmitted by a satellite; determining, by the user terminal, a downlink propagation delay associated with the downlink radio frame and an uplink propagation delay associated with an uplink radio frame from the user terminal to the satellite; based on the downlink propagation delay and the uplink propagation delay, determining, by the user terminal, an uplink transmission delay indicating an amount of time to delay a transmission of the uplink radio frame to the satellite so the uplink radio frame is received at the satellite at a same target time as one or more additional uplink radio frames from one or more additional user terminals; and transmitting, by the user terminal, the uplink radio frame at a time corresponding to the uplink transmission delay.

Synchronization of multi-user uplink transmissions

Systems, methods, and non-transitory media are provided for low latency handovers. An example method can include receiving, by a satellite, a schedule of communications between the satellite and one or more gateways; requesting, based on the schedule, a handover from a link between the satellite and a gateway to a different link between the satellite and the gateway or a different gateway; prior to a completion of the handover, processing packets bicasted over the link between the satellite and the gateway and the different link between the satellite and the gateway or the different gateway; performing the handover from the link between the satellite and the gateway to the different link between the satellite and the gateway or the different gateway; and after the handover, transmitting, by the satellite, one or more packets via the different link between the satellite and the gateway or the different gateway.

Systems, methods, and non-transitory media are provided for timing half-duplex transmissions in a wireless communication system. An example method can include receiving, by a user terminal (UT), a radio frame transmitted by a satellite to a group of UTs; identifying an offset delay defined in the radio frame for scheduling transmissions between the satellite and each UT in the group of UTs, the offset delay providing non-overlapping time intervals for receive, process, and transmit operations at each UT; determining, based on the offset delay and a time when the radio frame was received by the UT, a time for transmitting an uplink radio burst to the satellite, wherein the uplink radio burst transmitted at the time is estimated to arrive at the satellite within a same radio frame interval as uplink radio bursts from other UTs; and transmitting, to the satellite, the uplink radio burst at the time.

Timing half-duplex transmissions

A method for downlink link adaptation includes receiving, from a satellite and at a user terminal, a first data packet data unit according to a first downlink modulation and coding scheme (MCS), computing an error vector magnitude data associated with the first data packet data unit, generating, based on one or more of the error vector magnitude data, user terminal signal-to-noise-ratio feedback based on a constant times a previous user terminal signal-to-noise-ratio and a current user terminal signal-to-noise-ratio, and transmitting an uplink packet data unit having a downlink block error rate and the user terminal signal-to-noise-ratio feedback. A satellite runs a link adaptation algorithm based on the user terminal signal-to-noise-ratio feedback and block error rate to generate a second downlink MCS. The method includes receiving at the user terminal a second data packet data unit according to the second downlink MCS for the user terminal. An uplink link adaptation algorithm is also disclosed.

In an embodiment, a user terminal includes a connection manager component configured to generate an initial network entry request; an antenna assembly communicatively coupled to the connection manager and configured, in response to the initial network entry request, to find a satellite based on a search of a sky, wherein the satellite comprises a satellite assigned to downlink to a geographic cell associated with the user terminal; and a media access control (MAC) layer component communicatively coupled to the connection manager, the MAC layer component configured to generate an uplink radio frame including a random access channel (RACH) request associated with the initial network entry request at a particular portion of the uplink radio frame for the satellite, wherein the particular portion is selected by the MAC layer component from among a plurality of portions of the uplink radio frame.

Systems, methods, and non-transitory media are provided for low latency handovers. An example method can include receiving, by a user terminal associated with a cell served by a satellite, a schedule of communications between the user terminal and one or more satellites; requesting, based on the schedule, a handover from a beam of the satellite to a different beam of one of the satellite or a different satellite; processing packets transmitted over the beam of the satellite and/or the different beam of the one of the satellite or the different satellite; performing the handover from the beam of the satellite to the different beam of the one of the satellite or the different satellite; and after the handover, transmitting, by the user terminal, one or more packets via the different beam of the one of the satellite or the different satellite.

Arrangements disclosed here provide an LTE E-RAN employing a hierarchical architecture with a central controller controlling multiple LTE radio nodes (RNs). The RNs may be clustered within the small cell network. A fractional frequency reuse ('FFR') scheme is provided that dynamically computes the FFR allocations at individual RNs and configures the corresponding schedulers within each RN to improve cell-edge users' experience. Once an FFR pattern has been generated and frequencies allocated, UE throughput can be emulated to predict the resulting bit rates for each UE. Using the prediction, a scheduler emulation may be run to predict the behavior of the system. The results of each cell may then be collected to generate the performance of the entire system, which may in turn be used to generate a new or modified FFR pattern, or new or modified clustering. Optimization of the performance results in an optimized FFR pattern.

Fractional frequency reuse schemes assigned to radio nodes in an LTE network

A method for assigning downlink transmit power levels to radio nodes (RNs) in a small cell radio access network (RAN) includes assigning initial power levels to the RNs. For each cell, first events are counted indicating that UEs receiving a signal from their serving cells with a signal strength below a specified value have entered a coverage hole. For each cell, second events are counted indicating that UEs have re-established a previous connection on one of the cells. For each pair of cells, a coverage hole is identified between them if the number of first events for one cell exceeds a threshold and, a number of second events or re-establishment of a previous connection on the other cell exceeds another threshold. For each identified coverage hole, the downlink transmit power level is increased of at least one RN in the pair of cells between which the coverage hole is identified.

Closed-loop downlink transmit power assignments in a small cell radio access network

Systems and methods are disclosed for managing an aggregated self-organizing network (A-SON). In such, a plurality of small cells is grouped into clusters using available topology information. In one implementation, a subset of clusters is assigned to groups of a first type, such that the clusters within a group of the first type have minimal RF connectivity. For example, scanning or updating of RF parameters may then be coordinated such that adjacent clusters do not scan or update simultaneously but clusters within groups of the first type do have at least partially overlapping scans or updates. Similarly, subsets of clusters may be assigned to first and second groups of a second type, such that the clusters within a first group of the second type have sufficient coverage to provide RF connectivity to clusters within the second group, if the second group encounters a service interruption. Other benefits are also described.

Topology discovery and management and son orchestration

A method of coordinating a plurality of radio access networks (RANs) includes aggregating, with a gateway, communications interfaces between a plurality of RANs and a packet core network through the gateway. A plurality of radio nodes (RNs) in each of the RANs is communicatively coupled to the gateway and to user equipment (UE) devices associated with the RNs in each of the RANs. The gateway also controls and coordinates mobility of the UE devices within and among the RANs.

Growing community of inventors

San Carlos, CA, United States of America

Peter J Worters