Abstract: The invention relates to a method of operating a communication network, the network comprising a plurality of stations which are able to transmit data to and receive data from one another so that a message comprising a plurality of data packets is sent from an originating station to a destination station via at least one opportunistically selected intermediate station. The method makes use of probe signals transmitted from each station on a selected probing channel to which other stations respond to indicate their availability as destination or intermediate stations. A Request to Send message is sent, with a Clear to Send message returned by an available station. The station with data to send opportunistically selects an available station and the selected station uses a Packet Acknowledge message to confirm successful reception of the transmitted data packet. An End-to-End Acknowledge message is sent by the originating station, directly or indirectly, to confirm receipt of said data packets.

Abstract: A method of operating a communication network having multiple stations, each able to transmit and receive data, so that the network can transmit a message from an originating station to a destination station via at least one opportunistically selected intermediate station. Stations wishing to transmit data transmit probe signals which are responded to by other stations, thereby to identify available stations. When a station has data to send, it transmits probe signals with Request to Send messages, identifying the data to be sent. When a station receives such data for onward transmission, it transmits its own probe signals with a Request to Send message and including identification information relating to the data. The Request to Send messages are received by other stations in the vicinity, so that they serve as an implied acknowledgement of the receipt of the data by the forwarding station without the need for sending explicit confirmation.

Abstract: The invention relates to a method of operating a communication network, the network comprising a plurality of stations which are able to transmit data to and receive data from one another. The method comprises monitoring, at each station, the transmission path quality between that station and each other station with which that station can communicate. Data corresponding to the monitored path quality is recorded at each station, thereby permitting a transmission power value based on the relevant path quality data to be selected when transmitting data to another station. Thus, the probability of transmitting data to any selected station at an optimum power level is increased. Each station transmits path quality data in its own transmissions as well as local noise/interference data, so that other stations can obtain path quality data for a particular station even if they are out of range of that particular station. The invention extends to communication apparatus which can be used to implement the method.

Abstract: The invention relates to a method of operating a communication network, the network comprising a plurality of stations which are able to transmit data to and receive data from one another. The method comprises defining a first probing channel for the transmission of probe signals to other stations. Other stations which receive the first probe signals from a probing station indicate to the probing station their availability as destination or intermediate stations. A neighbor table comprising details of these other available stations is maintained at each station. Also, second probe signals are sent and received from stations in the neighbor table and a gradient table comprising data related to the cost of communicating with each neighbor station is maintained at each station, thereby to allow each station to select a predetermined number of intermediate stations for onward transmission of data from an originating station to a destination station at minimum cost.

Abstract: The invention provides a method of operating a network which comprises a plurality of stations each able to transmit and receive data so that the network can transmit data directly, or indirectly via one or more intermediate stations, between a requesting station and potential resource providing stations. The method comprises monitoring, at each station, the activity and/or resources of other stations on the network to establish the availability of resources at the other stations, and transmitting, from a requesting station requiring a specified resource, resource request probe signals identifying the specified resource. The resource may be data, connectivity, memory/storage, or another resource. At each station receiving the resource request probe signals, the availability of the specified resource or a portion thereof is determined, and hence whether said station is a potential resource providing station.

Abstract: A packet radio network comprises at least one network operator station and a number of user stations. The user stations transmit message data to one another, either directly or via intermediate stations. When stations are first activated, they transmit key request messages to the network operator station. Other, authenticated stations in the network will not communicate with the new station, but will pass the key request message to the network operator station. The network operator station transmits the necessary keys back to the new station via the other stations to permit the new station to operate. Each user station transmits key probe signals from time to time which advise other stations of its public key.

Abstract: The invention relates to a method of operating a communication network, the network comprising a plurality of stations which are able to transmit data to and receive data from one another. The method comprises monitoring, at each station, the transmission path quality between that station and each other station with which that station can communicate. Data corresponding to the monitored path quality is recorded at each station, thereby permitting a transmission power value based on the relevant path quality data to be selected when transmitting data to another station. Thus, the probability of transmitting data to any selected station at an optimum power level is increased. Each station transmits path quality data in its own transmissions as well as local noise/interference data, so that other stations can obtain path quality data for a particular station even if they are out of range of that particular station. The invention extends to communication apparatus which can be used to implement the method.

Abstract: The invention provides a method of operating a communication network. The network comprises numerous stations, each of which can transmit and receive data in order to transmit messages from originating stations to destination stations opportunistically via intermediate stations. Each station selects one of a number of possible calling channels to transmit probe signals to other stations. The probe signals contain data identifying the station in question and include details of its connectivity to other stations. Other stations receiving the probe signals respond directly or indirectly, thereby indicating both to the probing station and other stations their availability as destination or intermediate stations. The probing station evaluates the direct or indirect responses to identify other stations with which it can communicate optimally.