Space Exploration Technologies Corp.

Khasim Shaheed Shaik Mahammad

Yashodhan A Dandekar

Ramakrishna Akella

Peter J Worters

Chen Chen

Phillip E Barber

Jayasuryan V Iyer

Jeffrey A Gardner

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

Systems, methods, and techniques are provided for a radio link control (RLC) sublayer. An example satellite or user terminal can include a divisional of layer 2 of the OSI protocol layer structure. An example method includes providing a RLC sublayer on top of a MAC sublayer and adaptively switching, via the RLC sublayer and based on external data, between an unacknowledged mode and an acknowledged mode for the electronic communications. If the RLC sublayer is operating in the unacknowledged mode, the RLC sublayer provides one or more of (1) fragmentation and reassembly of service data units; (2) a use of RLC headers; and/or (3) no delivery guarantees. If the RLC sublayer is operating in the acknowledged mode, the RLC sublayer provides reliability in a sequence delivery service and one or more of (1) fragmentation and reassembly of service data units; and/or (2) the use of RLC headers.

System and method of providing a radio link control sublayer

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.

Growing community of inventors

Milpitas, CA, United States of America

Khasim Shaheed Shaik Mahammad