SYSTEM AND METHOD FOR HIGHLY DETERMINISTIC MEDIA ACCESS CONTROL

• US 20170251467A1
• Filed: 02/26/2016
• Published: 08/31/2017
• Est. Priority Date: 02/26/2016
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: DAME, STEPHEN
• Granted Patent: US 10,462,783 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/0028 Variable division signaling therefor H04L5/0092
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0085 when channel conditions change
• CPC Class Codes: H04L 5/0087 when data requirements change
• CPC Class Codes: H04L 5/0089 due to addition or removal of users or terminals
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/38 for collecting sensor information
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/563 of the wireless resources
• CPC Class Codes: H04W 72/566 of the information or information source or recipient
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0858 collision detection

Abstract

A system and method for providing media access control for networked nodes over a plurality of channels. Each channel is divided into a number of time slots per frame of data organized in a channel allocation schedule. The number of time slots is selected for each channel and is greater than or equal to one per second. Each time slot has a slot transfer rate equal to or less than the maximum channel transfer rate. A server receives a request for channel resources that includes a bandwidth requirement. At least one time slot in a channel corresponding to the bandwidth requirement over a frame time is identified and sent to the requesting node.

Claims

1. A method for controlling access to a communication medium by a plurality of network nodes communicating on a plurality of channels on corresponding frequency bands, each channel having a maximum channel transfer rate, the method comprising:

generating a channel allocation schedule where each channel is divided into a channel-assigned number of time slots per frame of data defined by a frame time, each time slot having a slot transfer rate equal to or less than the maximum channel transfer rate;

receiving a request for channel resources from a network node in the plurality of network nodes, the request comprising a bandwidth requirement;

identifying at least one time slot in the frame of a selected channel on the channel allocation schedule, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources; and

sending a channel resource allocation message to the network node identifying the selected channel and the at least one time slot in the frame of the selected channel as allocated to the network node.

2. The method of claim 1 where the step of identifying the at least one time slot further comprises:

identifying in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

matching the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in one frame time.

3. The method of claim 1 where:

the step of generating the channel allocation schedule comprises;

defining a subframe having a subframe time where an integer number of subframes is equal to the frame time, each subframe comprising at least one time slot; and

the step of identifying the at least one time slot further comprises;

identifying in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

matching the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in one subframe time where the data volume and communication periodic rate indicate a requirement for reduced latency.

4. The method of claim 1 where:

the step of generating the channel allocation schedule comprises;

defining a superframe having a superframe time that is an integer multiple of the frame time; and

the step of identifying the at least one time slot further comprises;

identifying in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

matching the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in more than one frame time within one superframe where the data volume and communication periodic rate indicate a tolerance for increased latency.

5. The method of claim 1 where the request for channel resources comprises a request for multichannel redundancy, where the channel on which the request was received is a first channel, the method further comprising:

identifying a second channel and at least one time slot in the frame of the second channel, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources;

where in the step of sending the channel resource allocation message, the channel resource allocation message identifies the first and second channels, and the at least one time slot in each of the first and second channels as allocated to the network node.

6. The method of claim 1 where the step of identifying the at least one time slot in the frame of the channel on which the request was received further comprises:

determining that the time slots in the channel on which the request was received are insufficient to correspond to the requested bandwidth;

identifying a second channel with at least one time slot in the frame of the second channel, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources;

the method further comprising;

sending the channel resource allocation message to the network node identifying the at least one time slot in the frame of the second channel as allocated to the network node.

7. The method of claim 1 where each time slot in the frame includes a gap time and where the method further comprises:

tracking channel usage in the selected channel;

determining an event-driven traffic percentage for the selected channel;

determining a de-rated throughput value to adjust a gap time in the frame of the selected channel;

receiving an event-driven data transmission from the network node; and

receiving the event-driven data from the gap times in the time slots.

8. A server comprising:

a network interface configured to communicate on a communication medium with a plurality of network nodes on a plurality of channels at corresponding frequency bands, each channel having a maximum channel transfer rate;

a media access controller configured to allocate resources to the plurality of network nodes on the plurality of channels using a processor and a non-transitory computer-readable medium storing executable instructions that, when executed by the processor, are operative to;

generate a channel allocation schedule where each channel is divided into a number of time slots per frame of data defined by a frame time, where the number of time slots is selected for each channel and is greater than or equal to one, each time slot having a slot transfer rate equal to or less than the maximum channel transfer rate;

receive a request for channel resources from a network node of the plurality of network nodes, the request comprising a bandwidth requirement;

identify at least one time slot in the frame of a selected channel, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources; and

send a channel resource allocation message to the network node identifying the selected channel and the at least one time slot in the frame of the selected channel as allocated to the network node.

9. The server of claim 8 where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

identify in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

match the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in one frame time.

10. The server of claim 8 where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

in generating the channel allocation schedule, define a subframe having a subframe time where an integer number of subframes is equal to the frame time, each subframe comprising at least one time slot; and

in identifying the at least one time slot;

identify in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

match the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in one subframe time where the data volume and communication periodic rate indicate a requirement for reduced latency.

11. The server of claim 8 where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

in generating the channel allocation schedule;

define a superframe having a superframe time that is an integer multiple of the frame time; and

in identifying the at least one time slot;

identify in the bandwidth requirement a data volume and a communication periodic rate indicating an aggregate data volume communication requirement; and

match the data volume and communication periodic rate with at least one time slot in the channel sufficient to communicate the data volume at the communication periodic rate in more than one frame time within one superframe where the data volume and communication periodic rate indicate a tolerance for increased latency.

12. The server of claim 11 where the request for channel resources comprises a request for multichannel redundancy, where the channel on which the request was received is a first channel, and where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

identify a second channel and at least one time slot in the frame of the second channel, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources;

where in the step of sending the channel resource allocation message, the channel resource allocation message identifies the first and second channels, and the at least one time slot in each of the first and second channels as allocated to the network node.

13. The server of claim 8 where the channel on which the request was received is a first channel, and where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

in identifying the at least one time slot;

determine that the time slots in the channel on which the request was received are insufficient to correspond to the requested bandwidth; and

identify a second channel with at least one time slot in the frame of the second channel, the at least one time slot providing a throughput corresponding to the bandwidth requirement in the request for channel resources; and

send the channel resource allocation message to the network node identifying the at least one time slot in the frame of the second channel as allocated to the network node.

14. The server of claim 8 where each time slot in the frame includes a gap time, and where the non-transitory computer-readable medium stores executable instructions that, when executed by the processor, are operative to:

track channel usage in the selected channel;

determine an event-driven traffic percentage for the selected channel;

determine a de-rated throughput value to adjust a gap time in the frame of the selected channel;

receive an event-driven data transmission from the network node; and

receive the event-driven data from the gap times in the time slots.

15. A method for communicating over a communication medium shared by a plurality of network nodes, the method comprising:

selecting one of a plurality of channels identified by corresponding frequency bands for communicating with a server on the communication medium;

sending a channel request message to the server, the channel request message comprising a bandwidth requirement;

receiving a channel allocation message from the server, the channel allocation message comprising a channel identifier identifying a selected one of the plurality of channels and a time slot identifier identifying at least one time slot in a frame defined by a frame time, the at least one time slot in the frame allocated for communicating on the selected channel;

monitoring the selected channel for the allocated time slot; and

sending data on the communication medium on the selected channel at the allocated time slot.

16. The method of claim 15 where:

the step of selecting the one of the plurality of channels comprises sensing the communication medium on each of the plurality of channels to detect bandwidth usage on each channel and selecting one of the channels having the least bandwidth usage.

17. The method of claim 16 where the step of selecting the one of the plurality of channels comprises:

sensing the communication medium on each of the plurality of channels to detect bandwidth usage on each channel;

selecting a plurality of the channels having the least bandwidth usage;

where the step of sending the channel allocation message to the server comprises including a channel list comprising the selected plurality of channels.

18. The method of claim 15 where:

the step of selecting the plurality of channels includes identifying a primary channel as the channel having the least bandwidth usage, a secondary channel having the second least bandwidth usage, and a tertiary channel having the third least bandwidth usage;

the step of sending the channel allocation message to the server comprises including a channel list comprising a ranked channel list.

19. The method of claim 15 where the step of monitoring the selected channel further comprises:

detecting an error condition in sending the data on the communication medium;

sending an error message to the server;

receiving a second channel resource allocation message; and

communicating on a second channel and at least one time slot identified in the second channel resource allocation message.

20. The method of claim 19 where:

the step of monitoring the selected channel comprises;

sensing the communication medium at the allocated time slot for a collision condition with another data transmission; and

the step of detecting the error condition comprises;

identifying the collision condition as the error condition.