Power, signal and data connectors are being installed outdoors at an ever increasing rate in telecom applications, such as those associated with wireless broadband technologies WiMAX and LTE. Long-term outdoor exposure places significant demands on the connectors and cable assemblies selected. Easy to install, highly reliable, and maintenance free connectors are required in these applications.
Various environmental rating standards come into play when specifying outdoor communications connectors, such as those published by ANSI, TIA, IEC, IEEE, Telcordia, etc. Many of these organizations reference IEC 60529 environmental protection for outdoor connectors – specifically IP65 and IP67 for water and dust protection. What does that mean in terms of the protection provided, and how are connectors tested to make sure they really provide that level of protection? Designers need the answers to these and related questions to get the right connectors for outdoor communications equipment, or even indoor equipment that faces severe conditions.
A shift in system design is taking place that drastically changes the connectivity in base station architectures. Older architectures use heavy coax cable between base stations and amplifiers, and between the amplifiers and passive antennas. Figure 1 shows the major technical changes in the architectures of cellular sites. The left part of the figure depicts a standard configuration for a 3G cell. It includes the base station with amplifier, the roof reinforcement due to its size and weight, the coax feeder cable to connect the tower mounted amplifier (TMA), a coax jumper to the antenna and the antenna with remote electrical tilt (RET). There is usually one high power cable for power supply.