British Telecommunications Public Limited Company

British Telecommunications Corporation

Ian W Marshall

Christopher M Roadknight

Michael J O'Mahony

Martin John Yates

Julian Richard Hill

Mark Bagley

Jane E Tateson

Patrick B Farley

Patrick Brian Farley

Philip D Constantine

Mark B Tweddle

A routing protocol scatters a stream of packets along a number of parallel paths, the packets being treated independently. The next hop for each packet is chosen probabilistically by comparing the 'resistance' of available options. The resistance of a given hop depends upon the time the packet would spend in an output buffer from the current node, the time the packet would spend in the input buffer of the next hop node, the transfer time between the nodes and the number of hops that the packet would take from the current node to the ultimate destination of the packet using the shortest path. This routing protocol is more efficient that shortest path first routing under simulation.

Packet routing

An emergent network is autonomous at the service level. Network nodes have policies that enable them to process different types of service requests, with the processing earning the nodes 'rewards'. Successful nodes can pass some or all of their policies to other nodes using the evolutionary biology of bacteria as a model.

Communications network

Layered communications network with adaptively distributed nodal policies

A services provision system provides information services over one or more communications networks and has a software infrastructure divided into domains. Each domain has an intelligent software agent and this community of agents sits in a computing environment represented in each domain by a DPE kernel. The community of agents co-operates to provide service and service management functionality to user. At least one of the agents is reconfigurable to change the functionality the system makes available. Reconfigurability is based on the use of a plurality of reusable software modules, the agent reconfiguring by selecting a new combination of modules. The software modules themselves incorporate rules, or policies, which determine process steps offered by the modules at run-time. These policies are external to the modules and may be loaded at run-time, allowing dynamic modification to functionality of the system. The system as a whole offers functionality associated with using services, providing them and managing them and the reconfigurability allows it to offer the different types of functionality in an efficient way. It also allows access control to functionality at different levels with particularly good security against fraudulent use.

Reconfigurable service provision via a communication network

A method of obtaining positional information about individual wireless devices a&#x2013;a, r&#x2013;rwithin a wireless ad-hoc network including a plurality of position determining devices r&#x2013;rwhich include means for estimating the distance between themselves and other similar devices which are within range. The method includes the steps of: calculating the hypothetical distance between a respective node's estimated position and the estimated position of each of its neighbouring devices whose broadcast estimated position has been received and whose distance from the respective node has been measured comparing the calculated hypothetical distance with the measured distance; modifying the respective node's estimated position so as to reduce an error function dependent upon the difference between the hypothetical and measured distances and periodically resetting the respective node's estimated location to a new position in a manner which does not seek to reduce the error function within a single iteration so as to avoid the location from getting stuck in a local minimum value of the error function.

Method and apparatus for locating devices

An emergent network that is autonomous at the service level. Network nodes have policies that enable them to process different types of service requests, with the processing earning the nodes 'rewards'. Successful nodes can pass some or all of their policies to other nodes using the evolutionary biology of bacteria as a model.

A services provision system provides information services over one or more communications networks and has a software infrastructure divided into domains. Each domain has an intelligent software agent and this community of agents sits in a computing environment represented in each domain by a DPE kernel. The community of agents co-operates to provide service and service management functionality to a user. At least one of the agents is reconfigurable to change the functionality the system makes available. Reconfigurability is based on the use of a plurality of reusable software modules, the agent reconfiguring by selecting a new combination of modules. The software modules themselves incorporate rules, or policies, which determine process steps offered by the modules at run-time. These policies are external to the modules and may be loaded at run-time, allowing dynamic modification to functionality of the system. The system as a whole offers functionality associated with using services, providing them and managing them and the reconfigurability allows it to offer the different types of functionality in an efficient way. It also allows access control to functionality at different levels with particularly good security against fraudulent use.

Optical processing in asynchronous transfer mode network

A laser amplifier operable such that at the commencement of each output pulse the carrier level has recovered from depletion by the previous pulse. Under these conditions output power commensurate with a much higher carrier density than is usually available is possible. The mode of operation is especially useful as a way of providing high power pulses, for example for use in optical time domain reflectometry. Using a travelling wave amplifier in conjunction with return to zero format data pulses is also disclosed.

Optical amplifier

High gain semiconductor laser amplifier package

Laser amplifier

An optical amplifier having a saturable absorption region is operated below the lasing threshold for the device. Non-linear effects and bistability are observable at temperatures above room temperature. A selected input wavelength .lambda..sub.i within the gain spectrum of the device is amplified and an output at the same wavelength .lambda..sub.i is produced. This is in contrast to the normal operation at threshold, where there is a wavelength shift to the lasing wavelength and, depending on the laser used for the naturable absorption device, the output may be multimode for a monomode input. Best gain is achieved by tuning the input wavelength to a peak of a Fabry-Perot mode in the gain spectrum for the amplifier. The amplifier may be used as wavelength controlled optical switch, when operated bistably, or as a regenerative amplifier when operated in the non-linear region without hysteresis effects.

Growing community of inventors

Woodbridge, United Kingdom

Ian W Marshall