Enhancing capacity of a direct communication link
Capacity enhancement of a direct communication link using a variable redundancy delivery network. An estimated information rate between a source node and a terminal node may be partitioned into a first information rate provided via the direct communication link and a second information rate to be provided via the variable redundancy delivery network. One or more parameters of the variable redundancy delivery network may be calculated to provide the second information rate based on a non-uniform probability density of messages requested by the terminal node. Capacity and reliability of storage media devices in the variable redundancy delivery network may be traded off to provide the second information rate. The variable redundancy delivery network may implement various coding schemes and per-message coding rates that may be determined based on the non-uniform probability distribution of the source message library.
1. A method comprising:
coupling a network gateway device on a mobile platform with a plurality of user communication devices on the mobile platform via respective local communication links;
coupling the network gateway device with a ground station via a direct communication link, the ground station coupled with a network, the network comprising at least one source node for a message library, wherein the direct communication link comprises a satellite communication link between the ground station and the network gateway device;
coupling the network gateway device with a variable redundancy delivery network on the mobile platform;
receiving messages of the message library delivered to the network gateway device from the ground station in response to requests by the plurality of user communication devices;
storing the messages delivered by the direct communication link according to a storage policy for delivery from the variable redundancy delivery network to the plurality of user communication devices, the storage policy determined based at least in part on system variables of the variable redundancy delivery network and a probability density of the messages being requested by the plurality of user communication devices, the storage policy comprising a plurality of redundancy levels associated with a corresponding plurality of ranges of the probability density,
adapting the storage policy based at least in part on a change of one or more of the system variables of the variable redundancy delivery network; and
storing, subsequent to the change of the one or more of the system variables, the messages delivered by the direct communication link according to the adapted storage policy for delivery from the variable redundancy delivery network to the plurality of user communication devices.
2. The method of claim 1 , further comprising:
delivering the messages to the plurality of user communication devices from the variable redundancy delivery network in response to subsequent ones of the requests for the messages.
3. The method of claim 1 , wherein the variable redundancy delivery network comprises a plurality of storage nodes, and wherein the change of one or more of the system variables comprises a failure of a storage node of the plurality of storage nodes.
4. The method of claim 1 , wherein the variable redundancy delivery network comprises one or more storage nodes, and wherein the system variables comprise a storage size of the one or more storage nodes, a type of the one or more storage nodes, or a number of the one or more storage nodes.
5. The method of claim 1 , further comprising:
adapting the storage policy based at least in part on an identified change of the probability density of the messages.
6. The method of claim 1 , wherein the storage policy comprises message replication, parity coding, Reed-Solomon coding, or a combination thereof.
7. The method of claim 1 , wherein the variable redundancy delivery network comprises one or more storage nodes, and wherein the one or more storage nodes of the variable redundancy delivery network are configured in a non-redundant disk array configuration.
8. The method of claim 1 , wherein one of the plurality of redundancy levels comprises not storing the messages.
9. A communication system comprising:
a network gateway device on a mobile platform coupled with a plurality of user communication devices on the mobile platform via respective local communication links;
a direct communication link coupling the network gateway device to a ground station coupled with a network, the network comprising at least one source node for a message library, the direct communication link to deliver messages of the message library to the network gateway device from the ground station in response to requests by the plurality of user communication devices, wherein the direct communication link comprises a satellite communication link between the ground station and the network gateway device; and
a variable redundancy delivery network on the mobile platform and coupled with the network gateway device, the variable redundancy delivery network associated with system variables and configured to:
store the messages delivered by the direct communication link according to a storage policy determined based at least in part on the system variables and a probability density of the messages being requested by the plurality of user communication devices, the storage policy comprising a plurality of redundancy levels associated with a corresponding plurality of ranges of the probability density,
adapt the storage policy based at least in part on a change of one or more of the system variables;
store, subsequent to the change of the one or more of the system variables, the messages delivered by the direct communication link according to the adapted storage policy for delivery from the variable redundancy delivery network to the plurality of user communication devices.
10. The communication system of claim 9 , wherein the variable redundancy delivery network is further configured to:
deliver the messages to the plurality of user communication devices from the variable redundancy delivery network in response to subsequent ones of the requests for the messages.
11. The communication system of claim 9 , wherein the variable redundancy delivery network comprises a plurality of storage nodes, and wherein the change of one or more of the system variables comprises a failure of a storage node of the plurality of storage nodes.
12. The communication system of claim 9 , wherein the variable redundancy delivery network comprises one or more storage nodes, and wherein the system variables comprise a storage size of the one or more storage nodes, a type of the one or more storage nodes, or a number of the one or more storage nodes.
13. The communication system of claim 9 , further comprising:
adapting the storage policy based at least in part on an identified change of the probability density of the messages.
14. The communication system of claim 9 , wherein the storage policy comprises message replication, parity coding, Reed-Solomon coding, or a combination thereof.
15. The communication system of claim 9 , wherein the variable redundancy delivery network comprises one or more storage nodes, and wherein the one or more storage nodes of the variable redundancy delivery network are configured in a non-redundant disk array configuration.
16. The communication system of claim 9 , wherein one of the plurality of redundancy levels comprises not storing the messages.
17. A non-transitory computer readable medium storing code for capacity enhancement of a communications system comprising a network gateway device on a mobile platform coupled with a ground station via a direct communication link and a variable redundancy delivery network on the mobile platform, the direct communication link comprising a satellite communication link between the ground station and the network gateway device, the ground station coupled with a network that comprises at least one source node for a message library, the code comprising instructions executable by a processor for:
coupling the network gateway device with a plurality of user communication devices on the mobile platform via respective local communication links;
receiving messages of the message library delivered to the network gateway device from the ground station in response to requests by the plurality of user communication devices;
storing the messages delivered by the direct communication link according to a storage policy for delivery from the variable redundancy delivery network to the plurality of user communication devices, the storage policy determined based at least in part on system variables of the variable redundancy delivery network and a probability density of the messages being requested by the plurality of user communication devices, the storage policy comprising a plurality of redundancy levels associated with a corresponding plurality of ranges of the probability density,
adapting the storage policy based at least in part on a change of one or more of the system variables of the variable redundancy delivery network; and
storing, subsequent to the change of the one or more of the system variables, the messages delivered by the direct communication link according to the adapted storage policy for delivery from the variable redundancy delivery network to the plurality of user communication devices.
18. The non-transitory computer readable medium of claim 17 , wherein the code further comprises instructions executable by the processor for:
delivering the messages to the plurality of user communication devices from the variable redundancy delivery network in response to subsequent ones of the requests for the messages.