A. Most prisons are constructed with the guarding towers and observation tower facilitated to guard the inmates. The height of the towers are mostly higher than the buildings of the prison. It will be easier to block the cellular phone signals in the air in case that the antennae height is higher than the highest building. Therefore, to mount the jammer on the observing tower is very easy and more protective. Moreover, the engineering cost can be saved greatly. Installation process can be improved.



B. If there are no prison guarding towers ,or not allowed to be used, we suggest you can choose the perimeter walls. In case that the height of the wall is higher than the highest building, Solution a can be adopted. If the wall is lower than the highest building ,You have to install a fixed holder on the wall. The height of the holders must be 3 to 5 meter higher than the highest building in the prison. The higher it is, the easier it is to install the antennae. The construction cost will be higher than Solution a through such way. If it is a bigger prison, more jammers have to be installed to adopt solution a and Solution b. We propose to mount jammers with omni directional antennae on some buildings in the middle of the prison in order to increase the shielding range and reduce the jammer quantity. Therefore ,the purchasing cost of the jammers can be also saved.



C. If all the guarding tower ,prison building and perimeter wall in prison are not allowed to be adopted, we have to suggest to construct some fixed Cylindrical towers or signal towers. It will be more difficult and more expensive on the engineering cost. The whole construction will be much slower. To some degree, this is our last choice once the other solutions can not be adopted.