Abstract: An optimization process for optimizing inputs data relating to a function of a plurality of input-signals for which it is desired to find output values which give an optimum value of the function. Such output values are found by performing a plurality of cycles to reach a convergence, each of which cycles includes: (a) providing an old current value of each input signal, (b) selecting a test value of one or more input signals; (c) generating the function from the selected test values; and (d) selecting a new current value in dependence upon the relationship between the value of the function for the test value and the value of the function for the old current value. The test values include values close to old current values so as to move the input signal towards a local convergence for the output values.

Abstract: A communications network in which user equipment is provided with a selecting device which communicates with a pricing device in service provider equipment. When communications or other services are required, the selection circuit polls a plurality of service providers, and the pricing circuit of each service provider generates a price signal indicating the level of price for its services. The selection circuit then selects a service provider, based on price (and also other factors such as quality of service).