Method for maximizing throughput for multiple links using directional elements

• US 6,735,178 B1
• Filed: 05/10/2000
• Issued: 05/11/2004
• Est. Priority Date: 05/10/2000
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Ricochet Networks, Inc. (Proxim Wireless Corporation)
• Inventors: Friday, Robert J., Ritter, Michael W., Srivastava, Arty
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): MILLS, DONALD L
• Application Number:
  US09/568,658
• Time in Patent Office: 1,462 Days
• Field of Search: 370/254, 370/238, 370/351, 370/400
• US Class Current: 370/252
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 40/06 based on characteristics of available antennas
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality

Abstract

In an imperfect mesh network or in a star network, the directionality of transmission and reception at each node, as through a directional antenna, is selected to maximize combined or multiple-link end-to-end information throughput. To this end, a maximum throughput metric is provided for separate links through the network between a source node and a collection of end-point nodes to be optimized which is based on 1) measurement of link quality with respect to neighboring nodes and 2) information about link quality and other factors related to propagation delay or “latency” as reported to it by other nodes regarding their neighboring links, and 3) based upon the busy-ness or capacity utilization at each link.

Claims

1. In a multiple node network having a data collection node at a first end and a data transmission node at a second end, a method for selecting the directionality of transmission and reception at one of said nodes to maximize combined information throughput at said data collection end, comprising:

determining a throughput metric for each directional choice based on combined end to end throughput of information for said directional choice; and

selecting directionality according to said throughput metric to maximize end to end throughput between said first end and said second end;

wherein said throughput metric is based on measurement of latency;

wherein said latency is attributable to busy-ness and includes summing simple link throughput times from least busy to busiest with a weighting based on said busy-ness; and

wherein weighted throughput WT is determined as follows;

${\mathrm{WT}}_a=\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\left(1-B_i\right)*{\mathrm{LT}}_{\mathrm{ia}}*\left(\underset{k=1}{\overset{i-1}{\prod <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>B_k\right)\right),$

where;

B_i is the busy-ness measure defined as the ratio of transmission time to the listening time plus the transmission time, for the ith node at the end of each link;

LT_ia is the simple link throughput for the ith node for a particular directionality element a; and

WT_a is the weighted throughput for the directionality element a.

2. In a multiple node network having a data collection node at a first end, a data transmission node at a second end, and multiple wireless nodes at least at one of the first and second ends, the wireless nodes being equivalent but with different throughput metrics, a method for selecting the directionality of wireless transmission and reception at an antenna at one of the wireless nodes, the one wireless node being at or closest to a user, in order to maximize weighted information throughput for end-to-end transmissions, the method comprising:

determining at the one wireless node a throughput metric for each directional choice based on combined end-to-end throughput of information for said directional choice; and

selecting at the one wireless node the directionality according to said throughput metric to maximize end-to-end throughput between said first end and said second end;

wherein weighted throughput WT is determined as follows;

${\mathrm{WT}}_a=\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>\left[\left(1-B_i\right)*{\mathrm{LT}}_{\mathrm{ia}}*\left(\underset{k=1}{\overset{i-1}{\prod <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>B_k\right)\right],$

where;

B_i is the busy-ness measure defined as the ratio of transmission time to the listening time plus the transmission time, for the ith node at the end of each link;

LT_ia is the simple link throughput for the ith node for a particular directionality element a; and

WT_a is the weighted throughput for the directionality element a.

3. The method of claim 2, wherein selecting the directionality of transmission and reception is at the data collection end.