Abstract: In a packet communication system, wherein nodes are assigned an absolute coordinate-based address and routing decisions are made at each node without the use of directory-based routing, routing decisions made for a particular packet with an ultimate destination are stored at each node so that the next packet sent by that node to that same ultimate destination can be forwarded in accordance with the previous routing decision made for that destination. Routing decisions are stored locally at each node in a routing table. In one embodiment, nodes also store routing information about the source node for a packet so that when a return packet is received for the original source, the relay node will not have to make a routing decision.

Abstract: A microcellular digital packet communication system is provided for digital communication having a plurality of repeating packet-mode fixed-site transceivers each being at a plurality of different sites and each being capable of communicating on mutually-common frequencies, including for example by means of frequency-hopping spread spectrum, wherein a terminal transceiver directly communicates substantially simultaneously with at least a few of the fixed-site transceivers on the mutually-common frequencies and distributes information packets of a single originating message among the fixed-site transceivers, the fixed-site transceivers forwarding the information packets via multiple communication links to a single destination terminal on the mutually-common frequencies at which the message is reassembled. The system enables reliable handoffs and robust connectivity by maintaining multiple simultaneous communication links between terminal transceivers and repeating transceivers.

Abstract: In a wireless packet communication system having a plurality of nodes, each having a transmitter and a receiver, the receiver at each node is assigned a specific frequency hopping band plan on which to receive signals, and the transmitter of any source node desiring to communicate with a target node changes frequency to the frequency of the target node according to the band plan. Thereupon, the source node transmits a poll packet which polls the target node to determine whether the target node is able and willing to accept a specified number of packets, at a specified level of priority. A failure to receive an acknowledgement on the source node's receive channel is a prompt to the source node either to retransmit a polling packet later, to change the polling packet or to redirect the polling packet to another target. In the event the target node returns an acknowledgement, the target node reserves access to itself for the polling station at a determined time for a determined duration.

Abstract: In a wireless LAN packet communication system, for each successfully received packet the strength of the received signal is measured at a target node by monitoring an A/D converted rssi (received signal strength indication) signal. A record of minimum strength among successfully received packets is maintained at the target node. For each succesfully received packet the difference between the signal strength of the packet and the recorded minimum is calculated at the target node and sent over the link to the source node as a quantitative difference indicator. The source node maintains a moving average of difference indicators received over time and adjusts the transmitter power level so as to maintain the moving average at a preselected link margin threshold level. Alternatively, the calculation of a desired source node power level change is performed at the target node and transmitted to the source node.

Abstract: In a mesh communication network, new network nodes acquire information about nearby nodes to which they may communicate through a third-party query whereby an established node with which a new node can communicate is queried to provide a list of nodes in the vicinity of the new nodes with which the new node is likely to be able to communicate. The new node uses this list in attempting to establish communication links and then repeats the third-party query for each node in the list to which it can communicate.

Abstract: In a packet communication system wherein stationary nodes are assigned an absolute coordinate-based address, the addressing of roaming nodes is accomplished by parasitically adopting a coordinate routing scheme used for addressing stationary nodes. Each roaming node selects a parent stationary node with which the roaming node can communicate directly. During the course of network operation, the roaming node may select a new parent node. At the time of reassignment, the coordinates of the new parent node, along with the identity of the roaming node, is recorded at the former parent node. Forwarding of packets to stationary nodes is accomplished according to a known coordinate-based routing scheme. A packet addressed to a destination roaming node is forwarded and directed through the then current stationary parent node. The packet is then forwarded to the destination roaming node.

Abstract: A frequency-hopping packet communication system without a master clock or master control unit is based on use of a receiver's frequency hopping timing and identification to control communication. A frequency-hopping band plan, involving the number of channels and the pseudo-random pattern of frequency change and nominal timing of changes, is universally known to each node in the network. A transmitter acquires synchronization with a target node by use of information previously received from or about a target indicating timing of present idle frequency hop of the target receiver. Each receiving node establishes in each station or node a table of receiver frequency hopping sequence offsets (hop timing offsets) of each other node within its communication range, and each node announces its presence on each frequency in a packet with a hop timing offset indicator. The hop timing offset indicator is a key used to read a table to allow nodes to set themselves in synchronization with one another.

Abstract: A packet network routing method and system based on geographic coordinate identifiers is described. Each node in a network is uniquely identified by absolute geographical coordinates or by a code indicating absolute location in an external coordinate-based reference system (node coordinates), and such absolute geographical coordinates or the equivalent are employed as part of a packet identifier for each packet generated for use in making routing decisions. The node coordinates of a local node and its neighboring nodes and the packet coordinates are used by means at each node through which a packet is routed for determining a desired forwarding route of a data packet. The routing may be prioritized according to preselected criteria, preferably achieving maximum forward progress using the least amount of power. The packet routing protocol according to the invention requires no routing directory or table to perform data routing.

Abstract: A frequency-hopping packet communication system without a master clock or master control unit is based on use of a receiver's frequency hopping timing and identification to control communication. A frequency-hopping band plan, involving the number of channels and the pseudo-random pattern of frequency change and nominal timing of changes, is universally known to each node in the network. Frequency-hopping is implemented by the division of communication slots and the accumulation of slots into epochs, wherein each epoch equals the total number of available slots (number of channels times the number of time frames per channel). A transmitting node tracks the preestablished frequency-hopping pattern for its target receiver based on previously-acquired information. The transmission node identifies a receiver node and a current frequency channel of such receiver node. The transmission node then checks the frequency channel to determine if available (e.g., not in use and within an acceptable noise margin).

Abstract: A packet network routing method and system based on geographic coordinate identifiers is described. Each node in a network is uniquely identified by absolute geographical coordinates or by a code indicating absolute location in an external coordinate-based reference system (node coordinates), and such absolute geographical coordinates or the equivalent are employed as part of a packet identifier for each packet generated for use in making routing decisions. The node coordinates of a local node and its neighboring nodes and the packet coordinates are used by means at each node through which a packet is routed for determining a desired forwarding route of a data packet. The routing may be prioritized according to preselected criteria, preferably achieving maximum forward progress using the least amount of power. The packet routing protocol according to the invention requires no routing directory or table to perform data routing.