Adaptive coding and modulation flow control and traffic shaping systems and methods

Abstract

A process is described to build physical layer frames with a modcode adapted to the signal quality of a destination terminal. Data packets assigned to the same modcode may be sent in the same frame, although packets associated with higher modcodes may be used to complete a frame before switching to the applicable higher modcode for construction of subsequent frames. After an interval, the order of progression is restarted with an out of order packet above a threshold age. Flow control filtering mechanisms and a variable reliability margin may be used to adapt dynamically to the current data traffic conditions.

1 .- 25 . (canceled) 
     
     
         26 . A method of implementing adaptive modulation and coding for a plurality of packets in a network, the method comprising:
 assigning a different modcode to each of a plurality of signal quality ranges, wherein a first range of the plurality of signal quality ranges is associated with a first modcode, a second range of the plurality of signal quality ranges is associated with a second modcode, and a boundary between the first range and the second range substantially defines a transition between the first modcode and the second modcode;   monitoring a latency measurement associated with the network; and   dynamically adjusting, responsive to when the monitored latency measurement crosses a threshold, the boundary to modify a reliability margin for delivery of packets destined for a link in the network with a signal quality within the first or second range.   
     
     
         27 . The method of  claim 26 , wherein the adjusting comprises:
 increasing a minimum signal quality boundary for the second range when a latency measurement decreases across the threshold, to thereby increase the reliability margin for packets associated with the second modcode, wherein the minimum signal quality boundary comprises the boundary.   
     
     
         28 . The method of  claim 26 , wherein the adjusting comprises:
 decreasing a minimum signal quality boundary for the second range when a latency measurement increases across the threshold, to thereby decrease the reliability margin for packets associated with the second modcode, wherein the minimum signal quality boundary comprises the boundary.   
     
     
         29 . The method of  claim 26 , wherein the method is performed by a gateway, and the network comprises a satellite communications network including the gateway. 
     
     
         30 . The method of  claim 29 , further comprising:
 receiving the latency measurement, the latency measurement performed by a device remote from the gateway within the satellite communications network.   
     
     
         31 . The method of  claim 26 , further comprising:
 measuring a delay at a gateway between an arrival timestamp and a transmission timestamp for a plurality of transmitted packets to produce the latency measurement.   
     
     
         32 . The method of  claim 26 , wherein the latency measurement comprises a measurement of traffic load at a gateway. 
     
     
         33 . The method of  claim 26 , wherein the latency measurement comprises a measurement of traffic load in a satellite communications network comprising the network. 
     
     
         34 . The method of  claim 26 , wherein the latency measurement consists of latency statistics received from a plurality of devices comprising the network. 
     
     
         35 . The method of  claim 26 , further comprising:
 transmitting a subset of the plurality of packets according to a defined order of progression; and   interrupting the defined order of progression upon expiration of a timer to transmit an out of order packet of the plurality of packets, the out of order packet exceeding a threshold age.   
     
     
         36 . The method of  claim 35 , further comprising:
 modifying the period of the timer based at least in part on the latency measurement.   
     
     
         37 . The method of  claim 26 , further comprising:
 blocking additional packets when the latency measurement exceeds a second threshold.   
     
     
         38 . The method of  claim 26 , further comprising:
 allowing packets associated with a selected quality of service or class of service while blocking other packets when the latency measurement exceeds a second threshold.   
     
     
         39 . The method of  claim 26 , wherein,
 the adaptive coding and modulation is implemented in accordance with a digital video broadcasting—satellite—second generation specification;   the signal quality comprises at least one of a signal to noise ratio, an estimated signal to noise ratio, a bit error rate, a receive power level, and another communication link quality indicator; and   the reliability margin is greater than zero.   
     
     
         40 . A device for implementing adaptive modulation and coding for a plurality of packets, the device comprising:
 a processor configured to:
 assign a different modcode to each of a plurality of signal quality ranges, wherein a first range of the plurality of signal quality ranges is associated with a first modcode, a second range of the plurality of signal quality ranges is associated with a second modcode, and a boundary between the first range and the second range substantially defines a transition between the first modcode and the second modcode; 
 monitor a latency measurement associated with a network; and 
 dynamically adjust, responsive to when the monitored latency measurement crosses a threshold, the boundary to modify a reliability margin for delivery of packets destined for a link within the first or second range; and 
   a transmitter, communicatively coupled with the processor and configured to:
 transmit a subset of the plurality of packets destined for a link within the first or second range according to an assigned modcode. 
   
     
     
         41 . The device of  claim 40 , wherein the processor is configured to perform the dynamic adjustment by:
 increasing a minimum signal quality boundary for the second range when a latency measurement decreases across the threshold, to thereby increase the reliability margin for the second range, wherein the minimum signal quality boundary comprises the boundary.   
     
     
         42 . The device of  claim 41 , wherein the processor is further configured to perform the dynamic adjustment by:
 decreasing a minimum signal quality boundary for the second range when a latency measurement increases across the threshold, to thereby decrease the reliability margin for the second range, wherein the minimum signal quality boundary comprises the boundary.   
     
     
         43 . The device of  claim 40 , wherein the device is a gateway, and the network comprises a satellite communications network including the gateway. 
     
     
         44 . The device of  claim 40 , wherein the latency measurement is performed remotely from the device. 
     
     
         45 . The device of  claim 40 , wherein the processor is further configured to:
 measure a delay between an arrival timestamp at the device and a transmission timestamp at the device for each of a plurality of received packets to generate the latency measurement.   
     
     
         46 . The device of  claim 40 , wherein the latency measurement comprises a measurement of an amount of data traffic waiting to be transmitted from the device. 
     
     
         47 . The device of  claim 40 , wherein the latency measurement comprises a measurement of data traffic within a satellite communications network. 
     
     
         48 . The device of  claim 40 , wherein the transmitter is further configured to:
 transmit a subset of the plurality of packets according to a defined order of progression; and   interrupt the defined order of progression upon expiration of a timer to transmit an out of order packet of the plurality of packets, the out of order packet exceeding a threshold age.   
     
     
         49 . The device of  claim 48 , wherein the transmitter is further configured to:
 modify the period of the timer based at least in part on the latency measurement.   
     
     
         50 . The device of  claim 40 , wherein the processor is further configured to:
 block additional packets from being processed when the latency measurement exceeds a second threshold.   
     
     
         51 . The device of  claim 40 , wherein the processor is further configured to:
 allow packets associated with a selected quality of service or class of service to be processed, while blocking other packets when the latency measurement exceeds a second threshold.   
     
     
         52 . A device for implementing adaptive modulation and coding for a plurality of packets in a satellite communications network, the method comprising:
 means for assigning a different modcode to each of a plurality of signal quality ranges, wherein a first range of the plurality of signal quality ranges is associated with a first modcode, a second range of the plurality of signal quality ranges is associated with a second modcode, and a boundary between the first range and the second range substantially defines a transition between the first modcode and the second modcode;   means for monitoring a latency measurement associated with the satellite network; and   means for dynamically adjusting, responsive to when the monitored latency measurement crosses a threshold, the boundary to modify a reliability margin for delivery of packets destined for a link with a signal quality within the first or second range.   
     
     
         53 . A satellite communications network for implementing adaptive modulation and coding for a plurality of packets in a satellite communications network, the network comprising:
 a gateway configured to:
 assign a different modcode to each of a plurality of signal quality ranges, wherein a first range of the plurality of signal quality ranges is associated with a first modcode, a second range of the plurality of signal quality ranges is associated with a second modcode, and a boundary between the first range and the second range substantially defines a transition between the first modcode and the second modcode; 
 monitor a latency measurement associated with the satellite network; 
 dynamically adjust, responsive to when the monitored latency measurement crosses a threshold, the boundary to modify a reliability margin for delivery of packets destined for a link within the first or second range; and 
 transmit a subset of the plurality of packets destined for a terminal with a link condition within the first or second range according to the assigned modcode; and 
   the terminal, in communication with the gateway via satellite, and configured to receive the transmitted subset according to the assigned modcode.   
     
     
         54 . The satellite communications network of  claim 53 , wherein the gateway is further configured to:
 receive a signal quality measurement from the terminal via satellite; and   assign the assigned modcode according to signal quality measurement.   
     
     
         55 . The satellite communications network of  claim 53 , wherein the gateway is configured to perform the dynamic adjustment by:
 increasing a minimum signal quality boundary for the second range when a latency measurement decreases across the threshold, to thereby increase the reliability margin for the second range; and   decreasing a minimum signal quality boundary for the second range when a latency measurement increases across the threshold, to thereby decrease the reliability margin for the second range, wherein the minimum signal quality boundary comprises the boundary.