In a wireless network, for example, an LTE network, the context information relating to a mobile terminal UE is transmitted to a plurality of network nodes eNB 2, 3 and 4 from a source network node, eNB 1. The transmitter then filters the shifted signal to filter out the non-centered sideband, and then adds the tone signal to form a composite signal. An access path monitor is provided for obtaining status information related to the access paths in accordance with the monitoring procedure. A spring is provided on a member formed in one body with the valve seat portion, for positioning the valve to the valve seat portion, wherein clearance volume of the discharge port is reduced, so as to improve the performances thereof. The end of the communication message can be reliably delimited by sending the first symbol containing only bits from a next cell of information at a lower symbol rate and including an extra bit in that symbol. Another embodiment includes an adjustable length shunt stub connected on the transmission media, a variable phase shifter connected between the DUT port and the adjustable length shunt stub, a probe arranged for movement in a direction transverse to the direction of signal propagation.