Amazon Technologies, Inc.

Alcatel Lucent

Bulin Zhang

Deepak

Ali Masoomzadeh

Mohammad Mamunur Rashid

Baosheng Li

Srikar Rajamani

Sharanya Subramanian

Kavitha Kamarthy

A satellite constellation provides communication between user terminals (UTs) and ground stations that connect to other networks, such as the Internet. Satellites transmit beacon transmissions to particular areas on Earth as particular times. The beacon transmissions include information used by a UT to use a random access channel (RACH) uplink to request communication. Responsive to the request, encryption is established between the satellite and the UT. The satellite may then allocate uplink resources, send data to the UT on a downlink, and so forth. The UT receives additional data about future handovers to other satellites. Based on previously received data the UT may quickly re-establish communication with a satellite after an interruption, such as due to a power outage at the UT. If the previously received data has expired, the UT may again use a beacon transmission.

System for establishing initial communication with satellite system

Technologies directed to scheduling transmissions between a satellite system and customer terminals (CTs) with half-duplex (HD) radios are described. A communication system includes a radio, a modem with a HD controller, a downlink (DL) scheduler, and an uplink (UL) scheduler. The HD controller determines a first set of HD CTs that are eligible DL transmissions for a first radio frame and a second set of HD CTs that are eligible for UL transmissions for a second radio frame. The HD controller determines a throughput value and buffer information about each of the first set and the second set of HD CTs. The HD controller determines a first subset of HD CTs for DL scheduling and a second subset of HD CTs for UL scheduling. The DL scheduler schedules radio resources for a first radio frame and the UL scheduler schedules radio resources for a second radio frame.

Coordinated mac scheduling of half-duplex customer terminals in satellite internet systems

Techniques for improving the efficiency of transmitting data between devices are described. In an example, a first device transmits first data to a second device during a first time interval, whereby the second device is configured to communicate with the first device in a half-duplex mode. During a second time interval, the first device receives second data from the second device. The first device then determines that the second device transmitted the second data during a third time interval that is between the first time and the second time, and during which a reception of the first data by the second device is expected. The first device then retransmits the first data based at least in part on determining that the second device transmitted the second data during the third time interval.

Efficient synchronization of communication involving half-duplex systems

A satellite provides communication between user terminals (UTs) and ground stations that connect to other networks, such as the Internet. Because the satellite is within range of many UTs at any given time, many UTs are in contention to use an uplink to send upstream data to the satellite. Contention for the uplink may be managed by sending grants that allocate a portion of the uplink time and frequency resources to individual UTs. A UT serviced by the satellite uses information based on the grants to determine whether upstream data from a user device connected the UT should be accepted for future transmission promised to deliver specified quality of service to the user device. Acting as a distributed system, each UT may decide to approve upstream data based on one or more factors, such as source address, destination address, header flags, predicted radio availability, and so forth.

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Kirkland, WA, United States of America

Bulin Zhang