Characterizing transmission of access nodes within a wireless network

Abstract

Methods, apparatuses and systems for characterizing transmission of access nodes within a wireless mesh network are disclosed. One apparatus includes an access node, wherein the access node is operative to determine a neighbor function based on how many neighboring nodes are affected by signals transmitted from the access node at varying power levels, determine an airtime per link occupied by transmission packets on links to each of the identified neighbor nodes of the neighbor function, determine an airtime metric based on the neighboring nodes and the airtime per link occupied by the transmission packets, calculate combinations of transmission power levels and transmission data rates that jointly minimize an air-time metric, and set a transmission power level and transmission data rate for transmission to a target node based on a path loss between the access node and the target node, and the calculated transmission power levels and data rates.

What is claimed: 
     
         1 . An access node, wherein the access node is operative to:
 determine a neighbor function based on how many neighboring nodes are affected by signals transmitted from the access node at varying power levels;   determine an airtime per link occupied by transmission packets on links to each of the identified neighbor nodes of the neighbor function;   determine an airtime metric based on the neighboring nodes and the airtime per link occupied by the transmission packets;   calculate combinations of transmission power levels and transmission data rates that jointly minimize an air-time metric; and   set a transmission power level and transmission data rate for transmission to a target node based on a path loss between the access node and the target node, and the calculated transmission power levels and data rates.   
     
     
         2 . The access node of  claim 1 , further comprising calculating a transmission power level and transmission data rate for multiple values of expected transmission path loss between the access node and the target node. 
     
     
         3 . The access node of  claim 1 , wherein the air-time per link occupied is determined by a percentage of air-time occupied. 
     
     
         4 . The access node of  claim 1 , wherein determining how many neighboring nodes are affected by a signals from the access node comprises:
 other nodes of the wireless network transmitting a reference signal at predetermined times; and wherein   the node access node is further operative to determine which of the nodes the node can receive the reference signals from, having at least a predetermined minimum power level, and designate these nodes as neighboring nodes.   
     
     
         5 . The access node of  claim 4 , wherein the access node is further operative to estimate a path loss corresponding to each neighboring node. 
     
     
         6 . The access node of  claim 1 , wherein a percentage of airtime per link occupied is estimated based on a transmission packet air-time. 
     
     
         7 . The access node of  claim 1 , wherein a percentage of airtime per link occupied is estimated based on a number of packets transmitted during a period of time. 
     
     
         8 . The access node of  claim 1 , wherein the air-time metric is determined by multiplying a packet transmit time by a number of neighbors that can receive the signal transmitted at the predetermined power level. 
     
     
         9 . The access node of  claim 1 , wherein the air-time metric is determined by multiplying a number of packets transmitted during a period of time by a number of neighbors that can receive the signal transmitted at the predetermined power level. 
     
     
         10 . The access node of  claim 1 , wherein the transmission power and data rate are set for each data packet transmitted. 
     
     
         11 . The access node of  claim 10 , wherein the node periodically checks different calculated transmission power levels and data rates to determine if a different combination provides a better link. 
     
     
         12 . The access node of  claim 10 , wherein the node periodically checks different calculated transmission power levels and data rates to determine if a different combination provides a link that provides a better air-time metric. 
     
     
         13 . The access node of  claim 10 , wherein if an error rate of transmitted data is above a threshold, the access node increases the transmission power level or decreases the transmission data rate according to the calculated transmission power levels and data rates. 
     
     
         14 . The access node of  claim 10 , wherein if an error rate of transmitted data is below a threshold, the access node decreases the transmission power level or increases the transmission data rate according to the calculated transmission power levels and data rates. 
     
     
         15 . An access node, wherein the access node is operative to:
 identify neighboring access nodes of the access node based on path losses of corresponding links between the access node and the neighboring access nodes;   determine a neighbor function based on how many of the identified neighboring access nodes are affected by signals transmitted from the access node at varying power levels;   calculate for a range of transmission path losses between the access node and neighboring access nodes, combinations of transmission power levels and transmission data rates that jointly minimize an air-time metric, wherein the air-time metric is dependent on the neighbor function and an air-time occupied by transmission packets;   set a transmission power level and transmission data rate for transmission to a target node based on a path loss between the access node and the target node, and the calculated transmission power levels and data rates; wherein   the air-time metric is further determined by multiplying a transmit time of a set number of bits by a number of identified neighboring access nodes that can receive the signal transmitted at the predetermined power level.   
     
     
         16 . The access node of  claim 15 , wherein calculating an expected range of transmission path losses between the access node and identified neighboring access nodes, transmission power levels and transmission data rates comprises calculating a transmission power level and transmission data rate for multiple values of expected transmission path loss. 
     
     
         17 . The access node of  claim 15 , wherein the air-time occupied is determined by a percentage of air-time occupied. 
     
     
         18 . The access node of  claim 15 , wherein determining how many neighboring access nodes are affected by a signals from the access node comprises:
 other access nodes of the wireless network transmitting a reference signal at predetermined times;   the access node determining which of the access nodes the access node can receive the reference signals from, having at least a predetermined minimum power level, and designating these access nodes as neighboring access nodes.