LS of South Africa performed a TETRA planning project for Sasol at their Secunda plant in South Africa. Sasol is a large petroleum manufacturer who uses coal for the source of the petroleum manufacturing process. It is obvious that the accuracy of the design of a network for this environment is critical as it affects many lives and millions of operational cost. LS of SA was responsible for the RF planning tasks which included the microwave link and TETRA planning. The TETRA equipment used for the project was supplied by Rohde & Schwarz and the microwave link equipment was supplied by Nera. A picture of the plant is included below.
The TETRA system was introduced to replace the old analogue two way radio system which was installed some years ago. The new TETRA network was planned to provide secure radio communication at the main plant and between the main plant and the coal mines that provide the coal for the petroleum manufacturing process. The TETRA planning process consisted of the following steps:
- Preparation of a planning guideline which included planning procedures and link budgets for the system.
- Startup meeting to agree on the planning principles and guideline
- Initial planning of the total network
- Installation of a TETRA base station at the main plant
- Measurements of the fieldstrength around the main plant
- Calibration of the Okumura-Hata model by refinement of the 20 X 20 meter clutter class heights and gains as well as the correction of some heights in our 20 X 20 meter data terrain model.
- Detail planning of the total network which included individual coverage, network coverage and best server plots.
- Final measurements of the total network to confirm our planning results.
The project was implemented during 2009 and put into operation. We received excellent feedback on the planning accuracy and for this reason we will now be doing the planning for a second petroleum plant in South Africa during the coming months.