Nortel 7430 Deployment Manual

Also see for 7430: User guide

18Below given values are only to be used as a guideline in a situation where no reflections fromsurroundings are present and where there is no interference from other equipment..3.4.4 Impact of Environmental Items on Radio CoverageDifferent weather conditions can have an influence regarding radio coverage. For example, a wetroof or wall can act as a shield. Different seasons of the year can also have an influenceregarding radio coverage. For example, the growth of leaves on trees in the spring that were notpresent when the system was installed in the winter might affect the radio coverage of BaseStations and Repeaters.3.4.5 Metal ConstructionIn situations where there are additional metallic materials within the construction of the building,signal reflection may occur. In the case where reflections occur, signal may be affected evenwhen the handset is very close to the base station. These areas should be documented by thetechnician and the customer. Reflections can often be identified as unstable Q-value in positionswhere the RSSI value is high. In a situation where the Q-value is stable as long as the handsetsis placed in a fixed position (not moving) but fluctuating significant when moved the reason forthis behavior is probably caused by reflections from surroundings.When it is known there is a lot of metal in the site, a thorough survey is necessary. A moreaccurate survey may be better obtained in these circumstances using a Digital Mobility Controllerand a minimum of four base stations to get proper knowledge of the radio signal propagation.NN40110-304 1.1