Tokens and policy descriptors are used for dynamic on demand session management in a distributed and scalable architecture for on demand sessions and resource management. The phase selector can include two matched transistor circuits. The fuel nozzle disposed close to an igniter is provided with a local fuel injection port through which fuel is jetted out from a predetermined position in an air passage in the main fuel injection nozzle to create a combustible fuel mixture zone in the vicinity of the igniter at least while the igniter is in an ignition operation. If the device determines that such a tone has been generatedreceived, a call corresponding to the tone is processed. The Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data.