1.PDA system monitoring objects are huge in number, complicates in types, and strong dispersion in regions.
2.Harsh working conditions.
3.The number of station-side equipment is huge, which greatly increases the complexity of the construction of communication systems.
4.To obtain the controlling power and working power is difficult.
5.Power distribution automation is based on completion of distribution network wiring and a transformation of the equipment. But the transformation of power distribution network needs to invest a lot of manpower, material and capitals.