A method and apparatus for implementing a network element in a communications network are described. The method includes engaging an implant about an outer surface of a catheter. The optimization determines, for a specified bit error rate, for each possible number of information bits per symbol, the code rate corresponding to the lowest signal-to-noise ratio. Therefore, the driver can surely recognize the reduction of the tire pressure. Alternatively, the segment may be directly arranged on the curved inner surface of a radome. Disposed below both ends of the free layer are bias magnet films 11b.