Method and apparatus for contention management in a radio-based packet network

Abstract

In a mesh communication network, a poll request protocol (PRP) is provided in which a special packet is broadcast by the congested node when it is ready to provide services. The controlling node (usually the more congested node) broadcasts a packet to request poll signals from nodes desiring resources of the controlling node. The contending nodes then have equal chances to request the services of the controlling node by sending poll signals. The controlling node can then arbitrate the requests, determine the most fair and efficient use of its resources, and broadcast a scheduling packet to inform the contending nodes when to inform the contending nodes of controlling node scheduling. The contending nodes then send their packets to the controlling node without lost packets caused by congestion collisions. The controlling node can then send data to the contending nodes also without lost packets.

1 . In a mesh network having a plurality of communication nodes, wherein one or more nodes may be either a contending node when sending data for transmission within the mesh network or a controlling node for receiving data for transmission within the mesh network, a method for accessing a controlling node, comprising: 
 accessing the controlling node in a non-PRP mode where multiple nodes are not contending for access to the controlling node; and    accessing the controlling node in a PRP mode where multiple nodes are contending for access to the controlling node, the PRP mode comprising: 
 withholding, at a contending node, requests for access to a controlling node until receipt, at the contending node, of a poll request packet broadcast from the controlling node, the poll request packet containing information indicating availability of a communication slot;  
 broadcasting from the controlling node to a plurality of contending nodes the poll request packet when the controlling node is ready to provide services;  
 directing from the contending node a poll packet to request access to the controlling node; and  
 broadcasting from the controlling node to all of the plurality of contending nodes a control packet containing rules information for each contending node requesting access to follow in order to send data to the controlling node.  
   
   
   
       2 . The method according to  claim 1 , wherein the control packet has rules information from the controlling node that directs the requesting nodes when to send and receive data; and wherein the method further comprises: 
 causing each individual requesting node to transmit local data in turn to the controlling node.    
   
   
       3 . The method of  claim 2 , further including: 
 scheduling each individual requesting node which receives rules information from the controlling node; thereafter    receiving at each individual requesting node acknowledgments from the controlling node, the acknowledgments being for corresponding individually transmitted data packets from the requesting node; and thereafter    transmitting from each individual requesting node further acknowledgments to receipt of data if data has been previously transmitted to it by the controlling node.    
   
   
       4 . The method according to  claim 3 , further comprising: 
 purging data packets from a transmitting node upon receipt of acknowledgment of successful reception of said data packets.    
   
   
       5 . In a mesh network having a plurality of communications nodes, wherein one or more modes may be either a contending node or a controlling node, an apparatus for requesting access to a congested controlling node, comprising: 
 means for accessing the controlling node in a non-PRP mode where multiple nodes are not contending for access to the controlling node; and    means for accessing the controlling node in a PRP mode where multiple nodes are contending for access to the controlling node, the means for accessing in a PRP mode comprising: 
 means for withholding, at a requesting node, requests for access to said congested node while awaiting receipt, at said requesting node, of a poll request packet containing a first datum of information indicating availability of a communication slot;  
 broadcasting means for broadcasting from said congested node said poll request packet when said congested node is ready to provide services; and thereafter  
 means at said requesting node for directing from said requesting node a poll packet to request access to the congested node; and  
 means operative to broadcast a control packet from the congested node to all the requesting nodes having rules information that directs the requesting nodes when to send and receive data packets.  
   
   
   
       6 . The apparatus according to  claim 5 , further comprising: 
 means to cause thereafter each individual requesting node to transmit its data packets in turn to the controlling node.    
   
   
       7 . The apparatus according to  claim 6 , further including: 
 means at said controlling node for scheduling transmitting times for each individual requesting node which receives rules information from the controlling node;    means for receiving at each individual requesting node acknowledgments of corresponding individually transmitted data packets from the requesting node; and    means for transmitting from each individual requesting node further acknowledgments to receipt of data if data has been previously transmitted to it by the controlling node.    
   
   
       8 . The apparatus according to  claim 7 , further comprising: 
 means for purging data packets from a transmitting node upon receipt of acknowledgment of successful reception of said data packets.