Low data rate broadcast using low earth orbit (LEO) satellites

1. A method comprising:

receiving data packets from an external network;

detecting at least one type of broadcast packet from the received packet data, each type of broadcast packet containing a different broadcast content;

selecting, for each type of broadcast packet detected, a transmit data rate and one or more Walsh codes for achieving the transmit data rate, each Walsh code being selected from a lowest level of a code tree and having a highest spread factor in the code tree;

transmitting the one or more Walsh codes selected for each type of broadcast packet over a broadcast control channel;

compressing the data packets for each type of broadcast packets;

creating, for each type of broadcast packet, at least one RLC block containing the corresponding compressed data packets based, at least in part, on the number of Walsh codes selected; and

transmitting, for each type of broadcast packet, the at least one RLC block from a satellite in a satellite network using the one or more Walsh codes selected for the type of broadcast packet.

2. The method of claim 1 , further comprising simultaneously transmitting the at least one RLC block from at least one additional satellite in the satellite network.

3. The method of claim 1 , further comprising:

monitoring bandwidth usage for the satellite network; and

dynamically increasing or decreasing one or more selected transmit data rates based, at least in part, on the monitored bandwidth usage.

4. The method of claim 1 , wherein the compressed data packets for each type of broadcast packet are segmented into a number of RLC blocks corresponding to the number of Walsh codes selected for the respective type of broadcast packet.

5. The method of claim 4 , wherein:

multiple Walsh codes are selected for a particular type of broadcast packet; and

the number of RLC blocks are sequenced in an order corresponding to an assignment order of each Walsh code for the particular type of broadcast packet.

6. The method of claim 1 , wherein the data packets are compressed using a dictionary based compression methodology.

7. The method of claim 6 , further comprising:

selecting a compression dictionary available to terminals in the satellite network; and

resetting the compression dictionary at predetermined time intervals.

8. The method of claim 1 , further comprising encrypting the at least one RLC block.

9. The method of claim 8 , further comprising:

storing a predefined set encryption keys within terminals of the satellite network;

selecting a particular encryption key from the predefined set of encryption keys for encrypting the at least one RLC block; and

transmitting an index corresponding to the selected encryption key over the broadcast control channel.

10. The method of claim 9 , further comprising:

selecting multiple encryption keys from the predefined set of encryption keys;

transmitting an index corresponding to each of the multiple encryption keys;

creating a new encryption key by applying a key generating algorithm to the multiple encryption keys; and

encrypting the at least one RLC block using the new encryption key.

11. The method of claim 10 , further comprising:

detecting the one of more Walsh codes for each type of broadcast packet from the broadcast control channel;

receiving and decoding the transmitted at least one RLC block using the detected one or more Walsh codes;

decompressing the at least one RLC block into the corresponding at least one type of broadcast packets; and

supplying each type of broadcast packet to one or more broadcast clients.

12. The method of claim 11 , wherein the receiving and decoding further comprises monitoring channels defined by the detected one or more Walsh codes.

13. The method of claim 11 , wherein:

multiple Walsh codes are selected for a particular type of broadcast packet;

the compressed data packets of the particular type of broadcast packet are segmented into multiple RLC blocks; and

decompressing the at least one RLC block further comprises reassembling the multiple RLC blocks based on an assignment order of each Walsh code for the particular type of broadcast packet.

14. The method of claim 1 , wherein multiple broadcast content can be transmitted within each beam of the satellite.

15. A system comprising:

a gateway configured to:

receive data packets from an external network,

detect at least one type of broadcast packet from the received packet data, each type of broadcast packet containing a different broadcast content,

select, for each type of broadcast packet detected, a transmit data rate and one or more Walsh codes for achieving the transmit data rate, each Walsh code being selected from a lowest level of a code tree and having a highest spread factor in the code tree,

transmit the one or more Walsh codes selected for each type of broadcast packet over a broadcast control channel,

compress the data packets for each type of broadcast packets,

create, for each type of broadcast packet, at least one RLC block containing the corresponding compressed data packets based, at least in part, on the number of Walsh codes selected, and

transmit, for each type of broadcast packet, the at least one RLC block, via a satellite in a satellite network, using the one or more Walsh codes selected for the type of broadcast packet; and

one or more terminals configured to:

receive the at least one RLC block for a selected type of broadcast packet from the satellite,

recover broadcast content contained in the selected type of broadcast packets, and

supply the recovered broadcast content to one or more broadcast clients.

16. The system of claim 15 , wherein:

the gateway is further configured to simultaneously transmit the at least one RLC block via at least one additional satellite; and

the one or more terminals are configured to receive the at least one RLC block for a selected type of broadcast packet from either the satellite or the at least one additional satellite.

17. The system of claim 15 , wherein the gateway is further configured to:

monitor bandwidth usage for the satellite network; and

dynamically increase or decrease one or more selected transmit data rates based, at least in part, on the monitored bandwidth usage.

18. The system of claim 15 , wherein the gateway is further configured to segment the compressed data packets for each type of broadcast packet into a number of RLC blocks corresponding to the number of Walsh codes selected for the respective type of broadcast packet.

19. The system of claim 18 , wherein the gateway is further configured to:

select multiple Walsh codes for a particular type of broadcast packet; and

sequence the number of RLC blocks in an order corresponding to an assignment order of each Walsh code for the particular type of broadcast packet.

20. The system of claim 15 , wherein the data packets are compressed using a dictionary based compression methodology.

21. The system of claim 20 , wherein the gateway is further configured to:

select a compression dictionary available to terminals in the satellite network; and

reset the compression dictionary at predetermined time intervals.

22. The system of claim 15 , wherein the gateway is configured to encrypt the at least one RLC block.

23. The system of claim 22 , wherein the gateway is further configured to:

store a predefined set encryption keys within terminals of the satellite network;

select a particular encryption key from the predefined set of encryption keys for encrypting the at least one RLC block; and

transmit an index corresponding to the selected encryption key over the broadcast control channel.

24. The system of claim 23 , wherein the gateway is further configured to:

select multiple encryption keys from the predefined set of encryption keys;

transmit an index corresponding to each of the multiple encryption keys;

create a new encryption key by applying a key generating algorithm to the multiple encryption keys; and

encrypt the at least one RLC block using the new encryption key.

25. The system of claim 24 , wherein the terminal is further configured to:

detect the one of more Walsh codes for each type of broadcast packet from the broadcast control channel;

receive and decode the transmitted at least one RLC block using the detected one or more Walsh codes;

decompress the at least one RLC block into the corresponding at least one type of broadcast packets; and

supply each type of broadcast packet to one or more broadcast clients.

26. The system of claim 25 , wherein the terminal is further configured to monitor channels defined by the detected one or more Walsh codes in order to receive and decode the transmitted at least one RLC block.

27. The system of claim 25 , wherein the terminal is further configured to:

select multiple Walsh codes for a particular type of broadcast packet;

segment compressed data packets of the particular type of broadcast packet into multiple RLC blocks; and

decompress the at least one RLC block by reassembling the multiple RLC blocks based on an assignment order of each Walsh code for the particular type of broadcast packet.

28. The system of claim 15 , wherein multiple broadcast content can be transmitted within each beam of the satellite.

29. The system of claim 15 , wherein the at least one RLC block are encrypted using a symmetric encryption algorithm.

30. The method of claim 1 , wherein the at least one RLC block are encrypted using a symmetric encryption algorithm.