US 8,300,551 B2Granted

Ascertaining presence in wireless networks

AssigneeGoogle Inc.

InventorsLamonte Peter Koop, Edward Allen Payne

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Abstract

One of many aspects of the invention relates to an ad hoc network in which inbound messages are communicated from an originating node to a gateway node via a plurality of intermediate nodes. In this respect, a method performed by an intermediate node in communicating the inbound message to the gateway node includes: maintaining a routing table; and using the routing table, selecting a node for use as the next hop by determining whether a maximum number of allowable hops for an inbound message is exceeded by using such node, and comparing a preference of using such node to preferences of using other known nodes by which the maximum number of allowable hops would not be exceeded. Another aspect includes sending a “leave” message when an intermediate node leaves the ad hoc network, whereby the intermediate node is removed from similar routing tables maintained by other intermediate nodes.

Claims13

Dependent claims

In an ad hoc network in which inbound messages are communicated from an originating node to a gateway node via a plurality of intermediate nodes, a method performed by an intermediate node in communicating an inbound message to a gateway node, comprising the steps of:

(a) maintaining, at a first node of the plurality of intermediate nodes, a routing table including a set of known intermediate nodes for use as a next hop towards a gateway node, the routing table comprising, for each known intermediate node, fields including,
(i) a next hop address, representing a unique address of the respective intermediate node,
(ii) a next hop hopcount, representing a hop count to a gateway node, and
(iii) a next hop qualifier, representing a preference for using the respective known intermediate node as a next hop towards a gateway node relative to other nodes that may be used as a next hop towards a gateway node;
(b) receiving, at the first node, an inbound message for communication to a gateway node;
(c) selecting, at the first node, a node for use as the next hop towards a gateway node for communicating the inbound message to a gateway node by,
(i) determining, for two or more known intermediate nodes maintained in the routing table, whether a sum of the next hop hopcount maintained in the routing table for the respective known intermediate node and a current hopcount of the inbound message exceeds a maximum number of allowable hops for the inbound message,
(ii) comparing next hop qualifiers maintained in the routing table for two or more known intermediate nodes for which the maximum number of allowable hops for an inbound message is not exceeded;
(d) communicating, by the first node, the inbound message to the node identified by the next hop address for which the next hop qualifier is determined to be preferred based on said comparison;
(e) receiving, at the first node, an acknowledgment from the known intermediate node the inbound message was communicated to, the acknowledgment containing indicators of a general traffic load of the known intermediate node the inbound message was communicated to;
(f) updating, at the first node based at least partially on the indicators of a general traffic load contained in the received acknowledgment, the next hop qualifier maintained in the routing table for the known intermediate node the acknowledgment was received from.

8 more elements

In an ad hoc network in which inbound messages are communicated from an originating node to a gateway node via a plurality of intermediate nodes, a method performed by an intermediate node in communicating the inbound message to the gateway node, comprising the steps of:

(a) maintaining a routing table including a set of one or more rows, wherein each row of the set comprises fields including,
(i) a next hop address, representing a unique address of a node,
(ii) a next hop hopcount, representing a hop count to the gateway, and
(iii) a next hop qualifier, representing a preference to using a node as a next hop towards a gateway node relative to other nodes that may be used as a next hop towards a gateway node,
all fields of the row pertaining to a known intermediate node for use as a next hop towards the gateway node;
(b) selecting a node for use as the next hop towards the gateway node for communicating the inbound message to the gateway node by,
(i) determining whether a sum of the next hop hopcount from a row and a current hopcount of the inbound message exceeds a maximum number of allowable hops for an inbound message, and
(ii) comparing a next hop qualifier of a row to a next hop qualifier of another row, wherein, for both rows, the maximum number of allowable hops for an inbound message is not exceeded;
and
(c) communicating the inbound message to the node identified by the next hop address for which the next hop qualifier is determined to be preferred based on said comparison;
(d) wherein the ad hoc network comprises a class-based network;
and
(e) wherein the routing table is a first routing table associated with a first class, and
(f) wherein the method further includes maintaining a second routing table including a set of one or more rows, wherein each row of the set comprises fields including,
(i) a next hop address, representing a unique address of a node,
(ii) a next hop hopcount, representing a hop count to the gateway, and
(iii) a next hop qualifier, representing a preference to using a node as a next hop towards a gateway node relative to other nodes that may be used as a next hop towards a gateway node,
all fields of the row pertaining to a known intermediate node for use as a next hop towards the gateway node;
(g) wherein the second routing table is associated with a second class.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/696,044Filed 28 Jan 2010 · us provisional application
Priority: 28 Jan 2009
Published: US 2010/0238940 A123 Sep 2010
Granted: 30 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04W 40/246
Connectivity information management, e.g. connectivity discovery or connectivity update: connectivity information discovery
H04L 45/122
Shortest path evaluation: by minimising distances, e.g. by selecting a route with minimum of number of hops
H04L 45/124
Shortest path evaluation: using a combination of metrics
H04L 45/20
Routing or path finding of packets in data switching networks: hop count for routing purposes, e.g. TTL