CODE-DIVISION-MULTIPLE-ACCESS (CDMA)-BASED NETWORK CODING FOR MASSIVE MEMORY SERVERS

• US 20160119423A1
• Filed: 10/28/2014
• Published: 04/28/2016
• Est. Priority Date: 10/28/2014
• Status: Active Grant

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: Ma, Xudong
• Granted Patent: US 9,930,114 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Technologies are generally described for code-division-multiple-access (CDMA)-based network-coding for reading data from massive memory servers. According to some examples, data may be modulated by spreading sequences prior to being transmitted from one memory node to another. In addition, the received signals (modulated data) from multiple memory nodes may be combined by a receiver memory node before being forwarded to other memory nodes arranged in a grid of memory nodes. The memory nodes may be assigned communication bandwidths flexibly and rapidly by changing the respective spreading sequences, which may be orthogonal or near-orthogonal for different memory nodes to allow support of random-access burst or dynamic data traffic, and enhancing fault-tolerance.

Claims

1. A method for code-division-multiple-access (CDMA)-based network-coding, the method comprising:

receiving a first signal at a first memory node from a second memory node, the first signal comprising data modulated with a first spreading sequence by the second memory node;

combining the first signal, at the first memory node, with a second signal received at the first memory node from a third memory node to form a combined signal, the second signal comprising data modulated with a second spreading sequence by the third memory node; and

transmitting the combined signal to a fourth memory node that neighbors the first memory node.

2. The method of claim 1, further comprising:

combining the first signal and the second signal, at the first memory node, with a third signal received at the first memory node from a fifth memory node to form the combined signal, the third signal comprising data modulated with a third spreading sequence by the fifth memory node.

3. The method of claim 2, further comprising:

generating a fourth signal at the first memory node by modulating data with a fourth spreading sequence; and

transmitting the fourth signal to the fourth memory node that neighbors the first memory node.

4. The method of claim 3, further comprising:

selecting the fourth spreading sequence based on a communication bandwidth usable for the first memory node, wherein the first, second, and fourth spreading sequences are distinct from each other.

5. The method of claim 4, wherein selecting the fourth spreading sequence comprises one of:

selecting a longer spreading sequence in response to determination that the first memory node is assigned a lower communication rate compared to other memory nodes;

selecting a shorter spreading sequence in response to determination that the first memory node is assigned a higher communication rate compared to other memory nodes;

or

selecting the fourth spreading sequence to be one of an orthogonal or a nearly orthogonal spreading sequence relative to the second spreading sequence and the third spreading sequence.

6. The method of claim 1, further comprising:

transmitting a specific signal to the fourth memory node after one of the second memory node and the third memory node is determined to fail.

7. The method of claim 1, further comprising:

multiplying each received signal with an amplification coefficient at the first memory node.

8. The method of claim 1, wherein combining the first signal and the second signal comprises combining the first signal and the second signal by employing one of an analog summation or a digital summation.

9. A massive memory server configured to employ code-division-multiple-access (CDMA)-based network-coding, the server comprising:

one or more processor modules; and

a plurality of interconnected memory nodes communicatively coupled to the one or more processor modules, wherein each memory node is configured to be controlled by the one or more processor modules to;

modulate data stored at each respective memory node with a respective spreading sequence to generate a signal;

transmit the signal to at least one neighbor memory node;

receive at least two other signals from at least two other neighbor memory nodes;

combine the at least two other signals to form a combined signal; and

transmit the combined signal to the at least one neighbor memory node.

10. The server of claim 9, wherein the plurality of memory nodes are coupled by interconnection networks organized into a grid and each memory node is coupled to neighbor memory nodes through one of a wired connection or an optical connection.

11. The server of claim 9, wherein each memory node is further configured to translate the data into a binary representation prior to modulation.

12. The server of claim 9, wherein each memory node is further configured to employ a random-access, burst memory-access communication protocol.

13. The server of claim 9, wherein each memory node includes one of a flash memory device, a dynamic random access memory (DRAM) device, or a static random access memory (SRAM) device.

14. The server of claim 9, wherein the one or more processor modules are configured to:

select a different spreading sequence for each memory node based on a communication bandwidth assigned to each memory node; and

assign different communication bandwidths dynamically to different memory nodes by change of respective spreading sequences.

15. A system configured to read from massive memory servers through code-division-multiple-access (CDMA)-based network-coding, the system comprising:

one or more massive memory servers, the one or more massive memory servers associated with a network of memory nodes organized into a grid and each memory node is wirelessly or wiredly coupled to neighbor memory nodes,

wherein at least one memory node of the network of memory nodes of the one or more massive memory servers is configured to;

modulate data stored at each respective memory node with a respective spreading sequence to generate a signal;

transmit the signal to at least one neighbor memory node;

receive at least two other signals from at least two other neighbor memory nodes;

combine the at least two other signals to form a combined signal; and

transmit the combined signal to the at least one neighbor memory node.

16. The system of claim 15, wherein the respective spreading sequences for each memory node include one of orthogonal or nearly orthogonal spreading sequences.

17. The system of claim 16, wherein the massive memory servers are configured to enable multiple communication flows to occupy a same transmission line within networks of the plurality of memory nodes without explicit resource allocation through the orthogonal or near-orthogonal spreading sequences.

18. The system of claim 15, wherein the massive memory servers are configured to select:

a longer spreading sequence for memory nodes that are assigned a lower communication rate compared to other memory nodes; and

a shorter spreading sequence for memory nodes that are assigned a higher communication rate compared to other memory nodes.

19. The system of claim 15, wherein the at least one memory node of the one or more massive memory servers is included in a single massive memory server such that the modulate data, transmit the signal, receive at least two other signals, combine the at least two other signals, and transmit the combined signal are performed in the single massive memory server.

20. The system of claim 15, wherein the at least one memory node of the one or more massive memory servers includes a plurality of memory nodes associated with a virtual single massive memory server such that the modulate data, transmit the signal, receive at least two other signals, combine the at least two other signals, and transmit the combined signal are performed in the virtual single massive memory server.

21. The system of claim 15, wherein the at least one memory node of the one or more massive memory servers includes a plurality of memory nodes associated with a plurality of the massive memory servers such that at least some of the modulate data, transmit the signal, receive at least two other signals, combine the at least two other signals, and transmit the combined signal are performed in a distributed manner amongst the plurality of memory nodes associated with the plurality of massive memory servers.