The recent requirement of the Satellite Laser Ranging SLR technique is to reach the accuracy of a millimeter. This requires keeping all the system biases on the sub millimeter level. The Portable Calibration Standard is a global reference for Satellite Laser Ranging systems biases identification and evaluation. It consists of the Pico Event Timer P-PET, meteorological station, epoch and frequency time base, set of reference retroreflectors and the control / data processing software package. The P-PET is compact, stable and easy to re-allocate within days. Its properties are appropriate for calibration standard purposes: the timing resolution is 1.2 psec, 2.5 psec per channel timing jitter, the temporal stability is less than 0.5 psec per hour and below 0.5 psec per Kelvin. The key feature of the timing system is its long term stability: no adjustments and settings are needed. Before we could start the global SLR network calibration, we had to succeed with the calibration missions at several SLR stations in Austria, Germany, Switzerland, United Kingdom, China and Chile. This enabled us to understand the feasibility of using the Pico Event Timer P-PET. Summarizing the results: the ranging precision to ground target is 1-3 millimeters, to satellites is 3-7 millimeters rms, the Calibration Standard demonstrated its capability to identify the SLR system range and time biases at the one-millimeter level. These results might serve as a background to the proposed 6th Framework programme EU Integrated Project EUROLAS CALNet.