Managed Transmission of Wireless DAT Messages

Patent metadata

Field	Value
Publication number	US-2020396769-A1
Application number	US-202016875419-A
Country	US
Kind code	A1
Filing date	May 15, 2020
Priority date	Jun 13, 2019
Publication date	Dec 17, 2020
Grant date	—

Abstract

Disclosed herein are systems and methods for enhancing wireless message throughput at high traffic density and high interference rates, by use of a managed message transmission protocol in which the base station instructs each node to transmit or retransmit a DAT message. For example, the base station may determine which node has experienced the most delays and may grant that node permission to transmit immediately, while instructing other nodes to wait their turn. Protocols can provide, under control of the base station, prompt mitigation and message completion after messages are corrupted by interference. The average delays, collision rate, and failure rate may be substantially reduced while the success rate and uniformity of access may be substantially improved. The managed transmission protocols can be incorporated in current and planned systems by software updates at low cost, while retaining the ability to receive and process messages from legacy nodes transparently, according to some embodiments.

First claim

1 . A local area network (LAN) comprising:
a plurality of nodes, each node configured to transmit an RTS message requesting permission to: transmit a DAT message that contains data, receive a CTS message granting permission to transmit the DAT message, transmit the DAT message responsive to the CTS message, and receive an ACK message indicating that the DAT message was received; and a base station, configured to: receive the RTS message, transmit the CTS message responsive to the RTS message, receive the DAT message, and transmit the ACK message responsive to the DAT message; wherein: the base station is further configured to: select a selected node of the plurality of nodes, and transmit a CTS message to the selected node.

2 . The LAN of claim 1 , wherein the selected node is at least one of:
a node having a largest number of backoff delays after receiving an ACK message; a node having a largest amount of time in backoff delays after receiving an ACK message; a node with the earliest unfulfilled RTS message; a node having a highest quality of service (QoS); a node having a highest priority; a node having a shortest DAT message to send; a node having a fewest number of fragments to send; a node indicating that the associated DAT message is an emergency message, or combinations thereof.

3 . The LAN of claim 1 , wherein the base station is configured to:
count how many times the base station has sent a CTS message to each node; upon transmitting an ACK message to each respective node, reset the count for that node to zero; and select a node that has the largest count.

4 . The LAN of claim 1 , wherein the base station is configured to prepare, in non-transient memory, an array or a table of values, each value corresponding to one of the nodes respectively, and to increment a selected value in the array or table upon transmitting the CTS message to the selected node corresponding to the selected value, and to reset the selected value to zero upon transmitting an ACK message to the selected node.

5 . The LAN of claim 1 , wherein the base station is configured to transmit the CTS message to the selected node responsive to detection of a triggering event , wherein the triggering event is in the list comprising:
an RTS message or an ending of the RTS message; a CTS message or an ending of the CTS message; a DAT message or an ending of the DAT message; an ACK message or an ending of the ACK message; a beacon message or an ending of the beacon message; a wireless message or an ending of the wireless message; an interference or an ending of the interference; or combinations thereof.

6 . The LAN of claim 5 , wherein the base station is configured to transmit the CTS message to the selected node at a particular time following the triggering event, wherein the particular time is in the list:
one or two slots, a slot being a predetermined time unit specified by the base station; one or two SIFS, a SIFS being a predetermined time unit specified by the base station; less than one DIFS, a DIFS being a predetermined time unit which a node is required to delay before transmitting an RTS message; or one PIFS, a PIFS being a predetermined time unit larger than a SIFS and shorter than a DIFS.

7 . The LAN of claim 1 , wherein:
a specific node, of the plurality of nodes, has an integer number of fragments to send; the specific node is configured to indicate, in an RTS message, the integer number of fragments; the base station is configured to indicate, in a CTS message, a particular fragment, of the integer number of fragments; and the specific node is configured to transmit, responsive to the CTS message, the particular fragment.

8 . The LAN of claim 7 , wherein the base station is configured to determine whether the particular fragment has been received within a predetermined interval, and upon determining that the particular fragment was not received, to retransmit the CTS message to the specific node.

9 . The LAN of claim 1 , wherein the base station is configured to determine whether a particular DAT message, transmitted by the selected node, is corrupted;
to transmit, upon determining that the particular DAT message is not corrupted, an ACK message addressed to the selected node; to transmit, upon determining that the particular DAT message is corrupted, a CTS message addressed to the selected node; upon determining that the particular DAT message is not corrupted and that interference is present after the DAT message, to transmit nothing until the interference ends, and then to transmit the ACK message to the selected node; and upon determining that the particular DAT message is corrupted and that interference continues after the DAT message, to transmit nothing until the interference ends, and then to retransmit the CTS message to the selected node.

10 . The LAN of claim 1 , wherein the base station is configured to determine whether the selected node has transmitted a DAT message within a predetermined time following transmission of the CTS message, and upon determining that the selected node has not transmitted the DAT message within the predetermined time, to retransmit the CTS message.

11 . A non-transitory computer-readable medium, operating on a base station in a local area network (LAN), the base station in signal communication with a plurality of nodes, each node configured to: transmit an RTS message requesting permission to transmit a DAT message that contains data, receive a CTS message granting permission to transmit the DAT message, transmit the DAT message responsive to the CTS message, and receive an ACK message indicating that the DAT message was received, the medium containing instructions for causing a processor in the base station to perform a method comprising:
selecting a particular node of the plurality of nodes according to a criterion; and transmitting a CTS message to the particular node; wherein the criterion is that the particular node has the largest number of accumulated backoff delays or the largest amount of accumulated backoff time or the largest amount of chronological time waiting to transmit a DAT message of the nodes in the LAN.

12 . The medium of claim 11 , wherein the method further comprises:
preparing, in non-transient memory, an array or table of values associated with each of the nodes, respectively; decoding an RTS message, thereby determining a delay value included in the RTS message and a Transmitter Address included in the RTS message; recording, in the array or table, the delay value associated with the Transmitter Address so determined; determining a most-delayed value in the array or table, the most-delayed value being larger than any other value in the array or table; selecting a most-delayed node that is associated with the most-delayed value; and transmitting the CTS message to the most-delayed node.

13 . The medium of claim 11 , wherein the method further comprises:
preparing, in non-transient memory, an array or table of values associated with each of the nodes, respectively; upon receiving an RTS message from a transmitting node, incrementing the value associated with the transmitting node; upon receiving a DAT message from the transmitting node, setting the value associated with the transmitting node to zero; determining a most-delayed value in the array or table, the most-delayed value being larger than any other value in the array or table; selecting a most-delayed node that is associated with the most-delayed value; and transmitting the CTS message to the most-delayed node.

14 . The medium of claim 11 , where

Assignees

• Newman David E
• Massengill R Kemp

Inventors

• Newman David E
• Massengill R Kemp

Classifications

• H04W72/541

  using the level of interference · CPC title

• H04W74/0816 Primary

  with collision avoidance · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04W88/08

  Access point devices · CPC title

• H04W92/20

  between access points · CPC title