Enhanced adjacency detection protocol for wireless applications

• US 6,192,053 B1
• Filed: 09/07/1995
• Issued: 02/20/2001
• Est. Priority Date: 09/07/1995
• Status: Expired due to Fees

• Current Assignee: Spry Energy Ltd. (Whitecap Resources, Inc.)
• Original Assignee: Spry Energy Ltd. (Whitecap Resources, Inc.)
• Inventors: Angelico, Dean, Hayes, James Alan
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/526,130
• Time in Patent Office: 1,993 Days
• Field of Search: 370/445, 370/447, 370/448, 370/465, 370/469, 370/910
• US Class Current: 370/448
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 69/325 in the network layer [OSI layer 3], e.g. X.25 H04L69/16 takes precedence
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

An Adjacency Detection Protocol (ADP) whereby a node in a wireless network may collect information about its neighbors. The collected information enables the establishment of link layer connectivity between a node and its neighbors and also is useful for translating network layer addresses into link addresses. The collected information finds further use in preventing medium contention among adjacent nodes and in handling collisions.

Claims

1. In a wireless packet communication network comprising a plurality of nodes, a method for preventing contention over a shared communications medium comprising the steps of:

receiving, at a first node, a packet from a second node including an estimated receiver processing delay of said second node;

thereafter

overhearing, at said first node, a request to send (RTS) packet sent from a third node and addressed to said second node;

thereafter inhibiting transmission from said first node in response to said RTS packet for a time period, wherein said time period represents an estimate of time required at said third node to reply to said RTS packet with a clear-to-send (CTS) packet and is determined in accordance with said estimated receiver processing delay, and

transmitting said CTS packet from said third node to said second node during said time period.

2. In a wireless packet communication network comprising a plurality of nodes, a method for preventing contention over a shared communications medium comprising the steps of:

receiving, at a first node, a packet from a second node including an estimated receiver processing delay of said second node;

thereafter

overhearing, at said first node, a clear to send (CTS) packet sent from a third node and addressed to said second node, said CTS packet including a length of data to be transmitted from said second node to said third node;

thereafter

inhibiting transmission from said first node in response to said CTS packet for a time period, wherein said time period is determined in accordance with said length of data and said estimate receiver processing delay, and

transmitting data from said second node to said third node during said time period.

3. A first node adapted to selectively discontinue transmission in a wireless communication network, said first node comprising:

means for receiving a packet from a second node including an estimated receiver processing delay;

means for overhearing a request to send (RTS) packet sent from a third node and addressed to said second node;

means for inhibiting transmission from said first node in response to said RTS packet for a time period, wherein said time period represents an estimate of time required at said third node to reply to said RTS packet with a clear-to-send packet and is determined in accordance with said estimated receiver processing delay, and

means for transmitting said CTS packet from said third node to said second node during said time period.

4. A first node adapted to selectively discontinue transmission in a wireless communication network, said first node comprising:

means for receiving a packet from a second node including an estimated receiver processing delay of said second node;

means for overhearing a clear to send (CTS) packet sent from a third node and addressed to said second node, said CTS packet including a length of data to be transmitted from said second node to said third node;

means for inhibiting transmission from said first node in response to said CTS packet for a time period, wherein said time period is determined in accordance with said length of data and said estimated receiver processing delay of said second node, and

means for transmitting data from said second node to said third node during said time period.